4,390 research outputs found
Editorial: new challenges In theory and practice of corporate governance
The aim of international conference “New Challenges in Corporate Governance: Theory And Practice” is to move the field closer to a global theory by advancing our understanding of corporate governance, which combines insights from the literature on firm governance bundles with insights from the national governance systems literature, investigating new perspectives and challenges for corporate governance and outlining possible scenarios of its development
Groups with Decomposable Set of Quasinormal Subgroups
A subgroup H of a group G is said to be quasinormal if HX =
XH for all subgroups X of G. In this article groups are characterized for
which the partially ordered set of quasinormal subgroups is decomposable
Verso una “sostenibilità programmata”: valutazioni LCA e LCC per la progettazione di coperture piane
Le sempre più chiare e pressanti indicazioni normative spingono i progettisti verso scelte più consapevoli sia in termini di sostenibilità , sia nei riguardi degli aspetti economici, che prendano però in considerazione tutte le fasi del ciclo di vita.
Attraverso una valutazione comparativa effettuata con l’ausilio delle note metodologie di Life Cycle Assessment e Life Cycle Costing, è possibile individuare, fra le diverse tipologie di componenti e di sistemi costruttivi, quelli che presentino un minor impatto sull’ambiente e che siano maggiormente sostenibili anche dal punto di vista economico, grazie a più appropriate strategie manutentive.
Anche l’analisi condotta con riguardo ad una semplice copertura piana da adeguare termicamente presenta spunti di interesse e di approfondimento a questa problematica rispetto alla quale troppo spesso si operano scelte non adeguate
Phenomenological interpolation of the inclusive J/psi cross section to proton-proton collisions at 2.76 TeV and 5.5 TeV
We present a study of the inclusive J/psi cross section at 2.76 TeV and 5.5
TeV. The energy dependence of the cross section, rapidity and transverse
momentum distributions are evaluated phenomenologically. Their knowledge is
crucial as a reference for the interpretation of A-A and p-A J/psi results at
the LHC. Our approach is the following: first, we estimate the energy evolution
of the pt-integrated J/psi cross section at mid-rapidity; then, we evaluate the
rapidity dependence; finally, we study the transverse momentum distribution
trend. Whenever possible, both theory driven (based on pQCD predictions) and
functional form (data driven fits) calculations are discussed. Our predictions
are compared with the recently obtained results by the ALICE collaboration in
pp collisions at 2.76 TeV.Comment: 23 pages, 19 figures, updated text+figures, added comparison to ALICE
measurements at 2.76Te
Speed and entropy of an interacting continuous time quantum walk
We present some dynamic and entropic considerations about the evolution of a
continuous time quantum walk implementing the clock of an autonomous machine.
On a simple model, we study in quite explicit terms the Lindblad evolution of
the clocked subsystem, relating the evolution of its entropy to the spreading
of the wave packet of the clock. We explore possible ways of reducing the
generation of entropy in the clocked subsystem, as it amounts to a deficit in
the probability of finding the target state of the computation. We are thus
lead to examine the benefits of abandoning some classical prejudice about how a
clocking mechanism should operate.Comment: 25 pages, 14 figure
Groups with many abelian subgroups
AbstractIt is known that a (generalized) soluble group whose proper subgroups are abelian is either abelian or finite, and finite minimal non-abelian groups are classified. Here we describe the structure of groups in which every subgroup of infinite index is abelian
Spatial distribution of phase singularities in optical random vector waves
We acknowledge funding from ERC Advanced, Investigator Grant (no. 240438-CONSTANS). ADF acknowledges support from EPSRC (EP/L017008/1).Phase singularities are dislocations widely studied in optical fields as well as in other areas of physics. With experiment and theory we show that the vectorial nature of light affects the spatial distribution of phase singularities in random light fields. While in scalar random waves phase singularities exhibit spatial distributions reminiscent of particles in isotropic liquids, in vector fields their distribution for the different vector components becomes anisotropic due to the direct relation between propagation and field direction. By incorporating this relation in the theory for scalar fields by Berry and Dennis, we quantitatively describe our experiments.PostprintPeer reviewe
Pericranial and scalp rotation flaps for occipitocervical hardware exposure with CSF leak in rheumatoid arthritis patient: A case report and review of the literature
Background: There are several etiologies of craniocervical junction instability (CCJI); trauma, rheumatoid arthritis (RA), infections, tumors, congenital deformity, and degenerative processes. These conditions often require surgery and craniocervical fixation. In rare cases, breakdown of such CCJI fusions (i.e., due to cerebrospinal fluid [CSF] leaks, infection, and wound necrosis) may warrant the utilization of occipital periosteal rescue flaps and scalp rotation flaps to achieve adequate closure. Case Description: A 33-year-old female with RA, cranial settling, and high cervical cord compression underwent an occipitocervical instrumented C0-C3/C4 fusion. Two months later, revision surgery was required due to articular screws pull out, CSF leakage, and infection. At the second surgery, the patient required screws removal, the application of laminar clamps, and sealing the leak with fibrin glue. However, the CSF leak persisted, and the skin edges necrosed leaving the hardware exposed. The third surgery was performed in conjunction with a plastic surgeon. It included operative debridement and covering the instrumentation with a pericranial flap. The resulting cutaneous defect was then additionally reconstructed with a scalp rotation flap. Postoperatively, the patient adequately recovered without sequelae. Conclusion: A 33-year-old female undergoing an occipitocervical fusion developed a postoperative persistent CSF leak, infection, and wound necrosis. This complication warranted the assistance of plastic surgery to attain closure. This required an occipital periosteal rescue flap with an added scalp rotation flap
Microfibers: Environmental Problems and Textile Solutions
Microplastics have become a topic of considerable concern and intensive study over the past decade. They have been found everywhere in the oceans, including the deepest trenches and remotest parts of the Arctic. They are ingested by many animals and some are incorporated into tissues. There is considerable effort in studying what effects they have on marine life. It has become clear that when water samples are collected in ways that prevent most long thin particles from escaping through pores of a net, the most abundant type of microplastics found in water and sediments are microfibers (fibers with dimensions less than 5 mm). The major source of these pollutants is synthetic textiles, such as polyester or polyamides, which shed microfibers during their entire life cycle. Microfibers are released during textile manufacturing, everyday activities (e.g., washing, drying, wearing) and final disposal. The complexity of microfiber release mechanisms and of the factors involved make the identification and application of ways to reduce the inputs of microfibers very challenging. A comprehensive approach is strongly needed, taking into account solutions at a number of levels, such as re-engineering textiles to minimize shedding, applying washing machine filters, developing advanced wastewater treatment plants and improving the management of textile wastes. To harmonize and make mandatory the solutions identified, a variety of potential government policies and regulations is also needed.</jats:p
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