426 research outputs found
Exploring antecedents of innovations for small- and medium-sized enterprises' environmental sustainability: An interpretative framework
The need to pursue sustainable development has become a central topic in Western countries due to citizens' greater sensitivity to improving environmental and social conditions. Companies can reach this objective more easily through green innovations, which are now considered a strategic opportunity that simultaneously allows for adherence to sustainable development criteria and the pursuit of competitive advantages. Scholars have identified the determinants that encourage companies to adopt green innovations, but the outcomes of their investigations thus far have often been ambiguous and contradictory. Our paper proposes an interpretative framework for addressing such inconsistencies. Using the partial least squares structural equation modelling (PLS-SEM) methodology, we validate this framework on a sample of small- and medium-sized enterprises (SMEs) and show that SMEs' choices are influenced by cultural elements and stimulated by the prospect of obtaining economic advantages over competitors. SMEs also pay close attention to stakeholder solicitations, while public administration does not affect their eco-innovating choices. The results have policy implications for executives and insiders
Vacuum energy of a massive scalar field in the presence of a semi-transparent cylinder
We compute the ground state energy of a massive scalar field in the
background of a cylindrical shell whose potential is given by a delta function.
The zero point energy is expressed in terms of the Jost function of the related
scattering problem, the renormalization is performed with the help of the heat
kernel expansion. The energy is found to be negative for attractive and for
repulsive backgrounds as well.Comment: 17 pages, 5 figure
Local and Global Casimir Energies for a Semitransparent Cylindrical Shell
The local Casimir energy density and the global Casimir energy for a massless
scalar field associated with a -function potential in a 3+1
dimensional circular cylindrical geometry are considered. The global energy is
examined for both weak and strong coupling, the latter being the well-studied
Dirichlet cylinder case. For weak-coupling,through ,
the total energy is shown to vanish by both analytic and numerical arguments,
based both on Green's-function and zeta-function techniques. Divergences
occurring in the calculation are shown to be absorbable by renormalization of
physical parameters of the model. The global energy may be obtained by
integrating the local energy density only when the latter is supplemented by an
energy term residing precisely on the surface of the cylinder. The latter is
identified as the integrated local energy density of the cylindrical shell when
the latter is physically expanded to have finite thickness. Inside and outside
the delta-function shell, the local energy density diverges as the surface of
the shell is approached; the divergence is weakest when the conformal stress
tensor is used to define the energy density. A real global divergence first
occurs in , as anticipated, but the proof is supplied
here for the first time; this divergence is entirely associated with the
surface energy, and does {\em not} reflect divergences in the local energy
density as the surface is approached.Comment: 28 pages, REVTeX, no figures. Appendix added on perturbative
divergence
3D CAMERAS ACQUISITIONS FOR THE DOCUMENTATION OF CULTURAL HERITAGE
Abstract. Photography has always been considered as a valid tool to acquire information about reality. Nowadays, its versatility, together with the development of new techniques and technologies, allows to use it in different fields of application. Particularly, in the digitization of built heritage, photography not only enables to understand and document historical and architectural artifacts but also to acquire morphological and geometrical data about them with automated digital photogrammetry. Nowadays, photogrammetry enables many tools to give virtual casts of reality by showing it in the way of point cloud. Although they can have metric reliability and visual quality, traditional instruments &ndash; such as monoscopic cameras &ndash; involve a careful planning of the campaign phase and a long acquisition and processing time. On the contrary, the most recent ones, based on the integration of different sensors and cameras, try to reduce the gap between time and results. The latter include some systems of indoor mapping who, thanks to 360&deg; acquisitions and SLAM technology, reconstruct the original scene in real time in great detail and with a photorealistic rendering. This study is aimed at reporting a research evaluating metric reliability and the level of survey detail with a Matterport Pro2 3D motorized rotating camera, equipped with SLAM technology, whose results have been compared with point clouds obtained by image-based and range-based processes.</p
Casimir effect in a wormhole spacetime
We consider the Casimir effect for quantized massive scalar field with
non-conformal coupling in a spacetime of wormhole whose throat is rounded
by a spherical shell. In the framework of zeta-regularization approach we
calculate a zero point energy of scalar field. We found that depending on
values of coupling , a mass of field , and/or the throat's radius
the Casimir force may be both attractive and repulsive, and even equals to
zero.Comment: 2 figures, 10 pages, added 2 reference
Cancer management during COVID-19 pandemic: is immune checkpoint inhibitors-based immunotherapy harmful or beneficial?
The coronavirus disease 2019 (COVID-19) is currently representing a global health threat especially for fragile individuals, such as cancer patients. It was demonstrated that cancer patients have an increased risk of developing a worse symptomatology upon severe acute respiratory syndrome associated coronavirus-2 (SARS-CoV-2) infection, often leading to hospitalization and intensive care. The consequences of this pandemic for oncology are really heavy, as the entire healthcare system got reorganized. Both oncologists and cancer patients are experiencing rescheduling of treatments and disruptions of appointments with a concurrent surge of fear and stress. In this review all the up-to-date findings, concerning the association between COVID-19 and cancer, are reported. A remaining very debated question regards the use of an innovative class of anti-cancer molecules, the immune checkpoint inhibitors (ICIs), given their modulating effects on the immune system. For that reason, administration of ICIs to cancer patients represents a question mark during this pandemic, as its correlation with COVID-19-associated risks is still under investigation. Based on the mechanisms of action of ICIs and the current evidence, we suggest that ICIs not only can be safely administered to cancer patients, but they might even be beneficial in COVID-19-positive cancer patients, by exerting an immune-stimulating action
Heat Kernel Expansion for Semitransparent Boundaries
We study the heat kernel for an operator of Laplace type with a
-function potential concentrated on a closed surface. We derive the
general form of the small asymptotics and calculate explicitly several
first heat kernel coefficients.Comment: 16 page
Effect of sunlight exposure on anthocyanin and non-anthocyanin phenolic levels in pomegranate juices by high resolution mass spectrometry approach
Quali-quantitative analyses of anthocyanins and non-anthocyanin phenolic compounds performed with the use of liquid chromatography coupled with high resolution mass spectrometry, were evaluated in juice of pomegranate fruits (âDente di Cavalloâ), in relation to different light exposures (North, South, West and East). A total of 16 compounds were identified, including phenolic acids, flavonoids, hydrolysable tannins, and anthocyanins, known for their health-promoting effects. Striking differences were observed about the total phenolic content, which was high in juices from fruits with east- and north-facing position, while it was lower in juices facing south. The greatest contents of total flavonoids and anthocyanins were recorded in fruit juices with southern exposure; however, there are no great differences in the content in phenolic acids. Tannins were mainly synthesized in fruit juices with West exposure. The results showed that the position within the tree had no significant effects on color juice, however, it significantly (p < 0.05) affected data on fruit weight, soluble sugars and juice yield. Remarkable synergies existed among polyphenols and phytochemicals in pomegranate juice, but collecting fruits with different solar exposure could enhance different health benefits, i.e., the juices with higher polyphenols content could have more anticancer effect or those with higher tannins content could have more antimicrobial effect
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