170 research outputs found
Estimating the circularity performance of an emerging industrial symbiosis network: The case of recycled plastic fibers in reinforced concrete
In recent times, the construction industry has been handling circular economy strategies in order to face the most important challenges in the sector, namely the lack of raw materials and the environmental impacts derived from all the processes linked to the entire supply chain. The industrial symbiosis approach represents an effective strategy to improve the circularity of the construction industry. This study analyses the circularity performance of an emerging industrial symbiosis network derived from the production of a cement mortar reinforced with recycled synthetic fibers coming from artificial turf carpets. From the collection of artificial turf carpets at the end-of-life stage it is possible to recover several materials, leading to potential unusual interactions between industries belonging to different sectors. A suitable indicator, retrieved from the literature, the Industrial Symbiosis Indicator (ISI), has been used to estimate the level of industrial symbiosis associated with increasing materials recirculation inside the network. Four scenariosâranging from perfect linearity to perfect circularityârepresenting growing circularity were tested. Findings demonstrate that the development of an effective industrial symbiosis network can contribute to improving the circular approach within the construction sector, reducing environmental and economic pressures
Kob-Andersen model: a non-standard mechanism for the glassy transition
We present new results reflecting the analogies between the Kob-Andersen
model and other glassy systems. Studying the stability of the blocked
configurations above and below the transition we also give arguments that
supports their relevance for the glassy behaviour of the model.
However we find, surprisingly, that the organization of the phase space of
the system is different from the well known organization of other mean-field
spin glasses and structural glasses.Comment: New reference added and one update
Persistent itching associated to silodosin in an elderly patient: Implications for drug-drug interactions and pharmacogenetics
Itching is a complaint affecting especially the elderly, in whom comorbidities and polypharmacy increase the risk of adverse drug reactions. We reported the case of an 83-year-old man with a generalized itching lasting more than 3 years underwent to our attention during his enrollment in a clinical study at University Hospital of Salerno, Italy where he was planned for a thromboendoarteriectomy because of left internal carotid artery stenosis. His medical history included arterial hypertension, ischemic heart disease, chronic cerebrovasculopathy, dyslipidaemia and prostatic hyperplasia. His therapy was olmesartan medoxomil 10 mg/die, nebivolol 5 mg x 1/2/die, acetylsalicylic acid 100 mg/die, omeprazole 20 mg/die, atorvastatin 20 mg/die, supplements contain ing EPA and DHA, vitamins K2, B6, B12 and folic acid (vit B9) and silodosin 8 mg/die. The patientâs demographic clinic, laboratory data and a pharmacological anamnesis were collected. Screening of two ABCB1 polymorphisms associated to a decrease of P-glycoprotein (P-gp) activity was performed by realtime PCR. An iatrogenic cause of the itching was suspected and the Naranjo algorithm was applied, revealing possible association between such an adverse reaction and all used drugs. Because the patient reported the beginning of the itching in concomitance with the aspirin assumption, this agent was discontinued but without improvement. Then, because silodosin-atorvastatin interaction may increase the silodosin plasma concentration, this drug was switched to doxazosin and the itching disappeared. This clinical case stresses the potential misleading based on the patientsâ beliefs and the importance to consider all the patientsâ available information to ascertain the cause of adverse drug reactions
Spin-Glass Model for Inverse Freezing
We analyze the Blume-Emery-Griffiths model with disordered magnetic
interaction displaying the inverse freezing phenomenon. The behaviour of this
spin-1 model in crystal field is studied throughout the phase diagram and the
transition and spinodal lines for the model are computed using the Full Replica
Symmetry Breaking Ansatz that always yelds a thermodynamically stable phase. We
compare the results both with the quenched disordered model with Ising spins on
lattice gas - where no reentrance takes place - and with the model with
generalized spin variables recently introduced by Schupper and Shnerb [Phys.
Rev. Lett. 93, 037202 (2004)]. The simplest version of all these models, known
as Ghatak-Sherrington model, turns out to hold all the general features
characterizing an inverse transition to an amorphous phase, including the right
thermodynamic behavior.Comment: 6 pages, 4 figures, to appear in the Proceeding for the X
International Workshop on Disordered Systems (2006), Molveno, Ital
Diazoxide maintains human myocyte volume homeostasis during stress
BACKGROUND: Exposure to hypothermic hyperkalemic cardioplegia, hyposmotic stress, or metabolic inhibition results in significant animal myocyte swelling (6% to10%) and subsequent reduced contractility (10% to 20%). Both are eliminated by the adenosine triphosphate-sensitive potassium channel opener diazoxide (DZX). The relationship between swelling and reduced contractility suggests that the structural change may represent one mechanism of postoperative myocardial stunning. This study evaluated human myocyte volume during stress to investigate if similar phenomena exist in human myocytes. METHODS AND RESULTS: Human atrial myocytes isolated from tissue obtained during cardiac surgery were perfused with Tyrode's physiological solution (20 minutes, 37°C), test solution (20 minutes), and Tyrode's (37°C, 20 minutes). Test solutions (n=6 to 12 myocytes each) included Tyrode's (37°C or 9°C), Tyrode's+DZX (9°C), hyperkalemic cardioplegia (9°C)±DZX, cardioplegia+DZX+HMR 1098 (sarcolemmal adenosine triphosphate-sensitive potassium channel inhibitor, 9°C), cardioplegia+DZX+5-hydroxydeconoate (mitochondrial adenosine triphosphate-sensitive potassium channel inhibitor, 9°C), mild hyposmotic solution±DZX, metabolic inhibition±DZX, and metabolic inhibition+DZX+5-hydroxydeconoate. Myocyte volume was recorded every 5 minutes. Exposure to hypothermic hyperkalemic cardioplegia, hyposmotic stress, or metabolic inhibition resulted in significant human myocyte swelling (8%, 7%, and 6%, respectively; all P<0.05 vs control). In all groups, the swelling was eliminated or lessened by DZX. The addition of channel inhibitors did not significantly alter results. CONCLUSIONS: DZX maintains human myocyte volume homeostasis during stress via an unknown mechanism. DZX may prove to be clinically useful following the elucidation of its specific mechanism of action. (J Am Heart Assoc. 2012;1:jah3-e000778 doi: 10.1161/JAHA.112.000778.
Universal Magnetic Fluctuations with a Field Induced Length Scale
We calculate the probability density function for the order parameter
fluctuations in the low temperature phase of the 2D-XY model of magnetism near
the line of critical points. A finite correlation length, \xi, is introduced
with a small magnetic field, h, and an accurate expression for \xi(h) is
developed by treating non-linear contributions to the field energy using a
Hartree approximation. We find analytically a series of universal non-Gaussian
distributions with a finite size scaling form and present a Gumbel-like
function that gives the PDF to an excellent approximation. We propose the
Gumbel exponent, a(h), as an indirect measure of the length scale of
correlations in a wide range of complex systems.Comment: 7 pages, 4 figures, 1 table. To appear in Phys. Rev.
Dynamics of the frustrated Ising lattice gas
The dynamical properties of a three dimensional model glass, the frustrated
Ising lattice gas (FILG) are studied by Monte Carlo simulations. We present
results of compression experiments, where the chemical potential is either
slowly or abruptly changed, as well as simulations at constant density. One
time quantities like density and two time ones like correlations, responses and
mean square displacements are measured, and the departure from equilibrium
clearly characterized. The aging scenario, particularly in the case of density
autocorrelations is reminiscent of spin glass phenomenology with violations of
the Fluctuation-dissipation theorem, typical of systems with one replica
symmetry breaking. The FILG, as a valid on-lattice model of structural glasses
can be described with tools developed in spin glass theory and, being a finite
dimensional model, can open the way for a systematic study of activated
processes in glasses.Comment: to appear in Phys. Rev. E, november (2000
How glasses explore configuration space
We review a statistical picture of the glassy state derived from the analysis
of the off-equilibrium fluctuation-dissipation relations. We define an
ultra-long time limit where ``one time quantities'' are close to equilibrium
while response and correlation can still display aging.
In this limit it is possible to relate the fluctuation-response relation to
static breaking of ergodicity. The resulting picture suggests that even far
from that limit, the fluctuation-dissipation ratio relates to the rate of
growth of the configurational entropy with free-energy density.Comment: To appear in the proceedings of the "3rd workshop on non-equilibrium
phenomena in supercooled fluids, glasses and amorphous materials" Pisa 22-27
September 200
Metastable states in glassy systems
Truly stable metastable states are an artifact of the mean-field
approximation or the zero temperature limit. If such appealing concepts in
glass theory as configurational entropy are to have a meaning beyond these
approximations, one needs to cast them in a form involving states with finite
lifetimes.
Starting from elementary examples and using results of Gaveau and Schulman,
we propose a simple expression for the configurational entropy and revisit the
question of taking flat averages over metastable states. The construction is
applicable to finite dimensional systems, and we explicitly show that for
simple mean-field glass models it recovers, justifies and generalises the known
results. The calculation emphasises the appearance of new dynamical order
parameters.Comment: 4 fig., 20 pages, revtex; added references and minor change
Synergistic use of Lagrangian dispersion and radiative transfer modelling with satellite and surface remote sensing measurements for the investigation of volcanic plumes: the Mount Etna eruption of 25â27 October 2013
Abstract. In this paper we combine SO2 and ash plume dispersion modelling with satellite and surface remote sensing observations to study the regional influence of a relatively weak volcanic eruption from Mount Etna on the optical and micro-physical properties of Mediterranean aerosols. We analyse the Mount Etna eruption episode of 25â27 October 2013. The evolution of the plume along the trajectory is investigated by means of the FLEXible PARTicle Lagrangian dispersion (FLEXPART) model. The satellite data set includes true colour images, retrieved values of volcanic SO2 and ash, estimates of SO2 and ash emission rates derived from MODIS (MODerate resolution Imaging Spectroradiometer) observations and estimates of cloud top pressure from SEVIRI (Spinning Enhanced Visible and InfraRed Imager). Surface remote sensing measurements of aerosol and SO2 made at the ENEA Station for Climate Observations (35.52°âŻN, 12.63°âŻE; 50âŻmâŻa.s.l.) on the island of Lampedusa are used in the analysis. The combination of these different data sets suggests that SO2 and ash, despite the initial injection at about 7.0âŻkm altitude, reached altitudes around 10â12âŻkm and influenced the column average aerosol particle size distribution at a distance of more than 350âŻkm downwind. This study indicates that even a relatively weak volcanic eruption may produce an observable effect on the aerosol properties at the regional scale. The impact of secondary sulfate particles on the aerosol size distribution at Lampedusa is discussed and estimates of the clear-sky direct aerosol radiative forcing are derived. Daily shortwave radiative forcing efficiencies, i.e. radiative forcing per unit AOD (aerosol optical depth), are calculated with the LibRadtran model. They are estimated between â39 and â48âŻWâŻmâ2âŻAODâ1 at the top of the atmosphere and between â66 and â49âŻWâŻmâ2âŻAODâ1 at the surface, with the variability in the estimates mainly depending on the aerosol single scattering albedo. These results suggest that sulfate particles played a large role in the transported plume composition and radiative forcing, while the contribution by ash particles was small in the volcanic plume arriving at Lampedusa during this event
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