Giuseppe Castaldi, Vincenzo Galdi, Andrea Alù and Nader Engheta
The work is aimed at studying the electromagnetic interaction between a homogeneous, isotropic single-negative (SNG) slab and an inhomogeneous, anisotropic double-positive (DPS…
Abstract
Purpose
The work is aimed at studying the electromagnetic interaction between a homogeneous, isotropic single-negative (SNG) slab and an inhomogeneous, anisotropic double-positive (DPS) slab.
Design/methodology/approach
The approach is based on the transformation optics framework, which allows systematic design and modelling of anisotropic, inhomogeneous metamaterials with inherent field-manipulation capabilities.
Findings
The paper finds that a transformation-optics-based DPS slab can compensate the inherent opaqueness to the electromagnetic radiation of a SNG slab. Here, “compensation” means that the resulting bi-layer may give rise to zero-reflection for a normally-incident plane wave at a given frequency. Such phenomenon is inherently accompanied by (de)funneling effects for collimated-beam illumination, and it turns out to be quite robust to material losses as well as geometrical and constitutive-parameter truncation.
Originality/value
The results provide further evidence and insight in how SNG-like responses may be emulated (within narrow parametric ranges) by suitably-engineered spatial inhomogeneity and anisotropy in DPS media. Moreover, they also show that resonant transmission phenomena through SNG materials may be engineered via the powerful framework of transformation optics.
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Mirko Barbuto, Andrea Alù, Filiberto Bilotti, Alessandro Toscano and Lucio Vegni
– The purpose of this paper is to present an analytical expression for the characteristic impedance of a microstrip line in presence of a dielectric cover.
Abstract
Purpose
The purpose of this paper is to present an analytical expression for the characteristic impedance of a microstrip line in presence of a dielectric cover.
Design/methodology/approach
Assuming a quasi-TEM propagation mode, a rigorous conformal mapping based on the Schwarz-Christoffel transformation is employed to derive the equivalent capacitance model, which can then be applied to derive a closed analytical expression for the effective permittivity and the characteristic impedance of the line.
Findings
Such a formulation is not limited to the case of a single cover layer, but an arbitrary number of electric overlays can be considered as well. Comparisons with published numerical results and full-wave simulations in the case of a single cover layer have been also performed to test the validity of the proposed approach.
Originality/value
The new analytical formula for the characteristic impedance of a microstrip line with a single dielectric cover shows better performances compared to the one of closed formulas already presented in the literature.
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After a long slide, organized labor is back waving some high‐flying numbers—and demanding a higher profile in the lives of workers and management. Here's a look at what this means…
Abstract
After a long slide, organized labor is back waving some high‐flying numbers—and demanding a higher profile in the lives of workers and management. Here's a look at what this means for corporate strategists, especially those determined to dodge the old game of “us versus them.”
Opeyemi Femi-Oladunni, Pablo Ruiz-Palomino and Israel Roberto Pérez Jiménez
This study aims to identify how Spanish consumers’ extrinsic preferences for food have evolved by examining the extant literature on food preferences in Spain, focusing on…
Abstract
Purpose
This study aims to identify how Spanish consumers’ extrinsic preferences for food have evolved by examining the extant literature on food preferences in Spain, focusing on food-related attributes and food-related values.
Design/methodology/approach
This study is based on a synthetic review of the extant academic literature on Spanish consumer preferences for food-related attributes and food-related values from the mid-20th to the 21st century. This study uses key economic and social milestones that are most likely to influence food value chain actors to show how consumer preferences have evolved over the study period.
Findings
Spanish consumer food attribute preferences expanded as the food sector of the nation continued to grow, and value preferences showed a similar pattern from the mid-20th to the 21st century. The drivers of these preferences were trust, lifestyle, education (campaigns), sociodemographic factors and purchasing power.
Originality/value
Evaluating the extant literature’s contribution to consumer preferences for food-related attributes and values is important because it can aid in understanding the hierarchy and variety of consumers’ food preferences as well as the factors that drive these preferences. To the best of the authors’ knowledge, this study is the first to explore how Spanish consumer preferences evolved between the mid-20th and 21st centuries.
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Jose María Roncero Heras, Manuel Alvarez-Ortí, Arturo Pardo-Giménez, Adrián Rabadán, José Emilio Pardo and Alicia Roncero
Almond oil is a gourmet product with functional food characteristics owing to its high almond oil content and high nutritional quality. One of the primary constraints on its…
Abstract
Purpose
Almond oil is a gourmet product with functional food characteristics owing to its high almond oil content and high nutritional quality. One of the primary constraints on its production is the lack of information regarding oil extraction from an industrial perspective, including by-products generation.
Design/methodology/approach
The performance, quality and composition characteristics were analyzed, both from the physical-chemical and organoleptic point of view, of the almond oils obtained through two pressure systems: screw press (SP) and hydraulic press (HP). To ensure the success of almond oil production at a commercial scale, in this work, an economic study of the costs of the process was carried out as a complementary part of optimizing the production of virgin almond oil.
Findings
Physicochemical analysis showed little difference, just in total sterols (HP 2069, SP 2153) and some quality indexes (K232: HP 1.63, SP 2.13; peroxide index: HP 1.74, SP 0.95), in contrast to sensory analysis. Consumer judges valued roasted almond oil extracted using a HP the best. The production cost of the oil extracted with the SP was €23.05/l. With the HP it was €25.13/l, owing to the lower oil yield in the extraction. The most expensive treatment was for the HP with toasted almonds (€27.76/l), owing to the greater need for processing.
Originality/value
Production costs derived from the method used have received little attention. This paper presents data that allow for the transference between academic and industrial ambit and their economic viability.
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The purpose of this paper is to offer a framework for the analysis and evaluation of city brands equity that is firmly anchored to the interdisciplinary characteristics of the…
Abstract
Purpose
The purpose of this paper is to offer a framework for the analysis and evaluation of city brands equity that is firmly anchored to the interdisciplinary characteristics of the city branding research domain.
Design/methodology/approach
The study builds upon a database of 217 articles dealing with the phenomena of city branding retrieved from Lucarelli and Berg.
Findings
City brands are understood by different scholars as being characterized by both intangible and tangible elements, properly researched adopting a mixture of different methods and endowing certain type of outcomes that concern both the more directly related image and identity of the city as well, to a larger extent, the socio‐political and economical aspects.
Research limitations/implications
The study is based only on published English articles in the last 20 years.
Originality/value
The present paper suggests a framework that is based on the individualization of diverse city brand elements and the relations those have with the reported impact and the methodologies applied to reach this purpose. The framework can be used for both analyzing city brand equity research and practices. The paper contributes to the emerging field of city branding by offering a city brand equity framework that goes beyond the previous attempt in its interdisciplinary breath.
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Andrea Lucarelli and Per Olof Berg
The aim of the paper is to carry out a contemporary and concise “state‐of‐the‐art” review of the city branding research domain, in particular how scholars have approached this…
Abstract
Purpose
The aim of the paper is to carry out a contemporary and concise “state‐of‐the‐art” review of the city branding research domain, in particular how scholars have approached this field of study, what aspects of city branding have been studied, what cities have been chosen, and how the studies are designed.
Design/methodology/approach
Through an iterative search in multiple literature databases, 217 qualified research studies on city branding were identified and retrieved. Those studies were examined, analyzed and categorized according to six categories: bibliographical data, methodologies used, empirical foundation, conceptual frameworks, branding elements, and reported outcomes of branding efforts.
Findings
City branding is emerging as an internationally recognized research domain characterized by a high degree of multi‐disciplinary, rapid proliferation in and between disciplines, and a somewhat fragmented theoretical foundation. On the basis of research interests, three perspectives were identified (producing, consuming, and criticizing city branding) emerging across academic disciplines
Research limitations/implications
The study is based on research articles in English, published in academic journals, which limits the international and professional scope of the study. Another limitation is the selected time period, which does not include studies prior to 1988 or later than 2009.
Originality/value
As a state‐of‐the‐art review, the main contribution of this paper is a contemporary and comprehensive overview of the field as such. A methodological contribution is the attempt to run a multi‐variate analysis of the branding elements in relation to the output and performance data reported in the studies. Another contribution is the identification of three cross‐disciplinary research perspectives in the field today.