12,371 research outputs found
Combined membrane process for dealcoholization of wines: Osmotic distillation and reverse osmosis
The demand of beverages with low or zero alcohol content is fast growing over the last years for health benefits of drinkers and more restrictive policies in alcohol consumption. Membrane processes are nowadays the most commonly used. They have undoubtedly led to improvements in quality, particularly for the low processing temperatures, but determined volatile compounds loss which in many instances resulted in unsatisfactory sensory quality. This study evaluates the combination of two membrane processes for the production of lower alcohol wines: osmotic distillation (OD) and reverse osmosis (RO). It aims for retain the flavour, preserve the good taste of wine with low alcohol content. A red wine (13.2 %v/v) was reduced in alcohol strength of about -5, -6, -8 %v/v through a RO and OD combined process: the initial wine was firstly treated through RO and was subsequently processed through OD to obtain partial dealcoholized wines. Such wines were then compared with those obtained through OD technique. Low alcohol wines were analysed for chemico-physical parameters and volatile composition. The results showed a better retention of the main chemical properties and volatile compounds in wines with low alcohol content obtained through the combined OD and RO process than those through single OD
Stable non-BPS states in string theory: a pedagogical review
We present a pedagogical review of the stable non-BPS states in string theory
which have recently attracted some attention in the literature. In particular,
following the analysis of A. Sen, we discuss in detail the case of the stable
non-BPS D-particle of Type I theory whose existence is predicted (and required)
by the heterotic/Type I duality. We show that this D-particle originates from
an unstable bound state formed by a D1/anti-D1 pair of Type IIB in which the
tachyon field acquires a solitonic kink configuration. The mechanism of tachyon
condensation is discussed first at a qualitative level and then with an exact
conformal field theory analysis.Comment: 58 pages, 1 figure; minor correction
Study of the general mechanism of stress corrosion of aluminum alloys and development of techniques for its detection Quarterly report, 1 Dec. 1967 - 29 Feb. 1968
Stress corrosion of aluminum alloys and techniques for its detectio
Drying kinetics and physico-chemical quality of mango slices
Mango (Mangifera indica L.) is an important tropical fruit consumed worldwide and grown in Italy only in Sicily, where the areas of the Tyrrhenian coast have proved to be suitable to produce valuable fruits. Mango fruit has a pleasant aroma and taste, which are important qualities for consumer’s sensorial acceptance. However, they are highly perishable, prone to progressive undesired changes if stored untreated, resulting in around 25% postharvest losses, which is further increased during storage and transportation. An alternative for reducing the above-mentioned undesired changes is the dehydration of the cut fruit, which reduce the fruit water activity, thereby avoiding the deteriorative process and extending the shelf-life. This study investigates the effect of dehydration at different temperatures (50, 60 and 70°C) on drying kinetics and volatile compounds of two cultivars (Keitt and Osteen) of mango fruits cultivated in Sicily. Significant losses of volatile constituents of fresh mango occurred at higher temperature, especially for the Osteen cultivar. A diffusion model including the effect of shrinkage is also proposed, which may be used to describe drying behaviour of fruits and to define the optimal drying conditions.. Experimental data of the moisture ratio during drying were well predicted by the model
Negative symptoms as key features of depression among cannabis users: a preliminary report.
OBJECTIVE:
Cannabis use is frequent among depressed patients and may lead to the so-called "amotivational syndrome", which combines symptoms of affective flattening and loss of emotional reactivity (i.e. the so-called "negative" symptomatology). The aim of this study was to investigate the negative symptomatology in depressed patients with concomitant cannabis use disorders (CUDs) in comparison with depressed patients without CUDs.
PATIENTS AND METHODS:
Fifty-one patients with a diagnosis of Major Depressive Disorder (MDD) and concomitant CUD and fifty-one MDD patients were enrolled in the study. The 21-Item Hamilton Depression Rating Scale (HDRS) and the negative symptoms subscales of the Positive and Negative Syndrome Scale (PANSS) were used to assess depressive and negative symptomatology.
RESULTS:
Patients with cannabis use disorders presented significantly more severe negative symptoms in comparison with patients without cannabis use (15.18 ± 2.25 vs 13.75 ± 2.44; t100 = 3.25 p = 0.002).
DISCUSSION:
A deeper knowledge of the "negative" psychopathological profile of MDD patients who use cannabis may lead to novel etiopathogenetic models of MDD and to more appropriate treatment approaches
Decay Modes of Intersecting Fluxbranes
Just as the single fluxbrane is quantum mechanically unstable to the
nucleation of a locally charged spherical brane, so intersecting fluxbranes are
unstable to various decay modes. Each individual element of the intersection
can decay via the nucleation of a spherical brane, but uncharged spheres can
also be nucleated in the region of intersection. For special values of the
fluxes, however, intersecting fluxbranes are supersymmetric, and so are
expected to be stable. We explicitly consider the instanton describing the
decay modes of the two--element intersection (an F5-brane in the string theory
context), and show that in dimensions greater than four the action for the
decay mode of the supersymmetric intersection diverges. This observation allows
us to show that stable intersecting fluxbranes should also exist in type 0A
string theory.Comment: 19 pages, 6 figures. References adde
Flavor from M5-branes
We study various aspects of the defect conformal field theory that arises
when placing a single M5-brane probe in AdS_4 x S^7. We derive the full set of
fluctuation modes and dimensions of the corresponding dual operators. We argue
that the latter does not depend on the presence of a non-trivial magnetic flux
on the M5-brane world-volume. Finally we give a mass to the hypermultiplet
living on the defect, and compute the resulting mesonic spectrum.Comment: 19 page
Deterministic single-photon source from a single ion
We realize a deterministic single-photon source from one and the same calcium
ion interacting with a high-finesse optical cavity. Photons are created in the
cavity with efficiency (88 +- 17)%, a tenfold improvement over previous
cavity-ion sources. Results of the second-order correlation function are
presented, demonstrating a high suppression of two-photon events limited only
by background counts. The cavity photon pulse shape is obtained, with good
agreement between experiment and simulation. Moreover, theoretical analysis of
the temporal evolution of the atomic populations provides relevant information
about the dynamics of the process and opens the way to future investigations of
a coherent atom-photon interface
Surgical treatment of sporadic vestibular schwannoma in a series of 1006 patients. Trattamento chirurgico degli schwannomi vestibolari: risultati su una serie di 1006 pazienti
La gestione dello schwannoma vestibolare (SV) sporadico si è gradualmente evoluta negli ultimi decenni. Lo scopo di questo studio è di
analizzare l’evoluzione negli esiti chirurgici dell’exeresi di queste lesioni, realizzata da un team neurotologico tra il 1990 e il 2006, attraverso differenti approcci. È stata eseguita una revisione retrospettica monocentrica dei dati clinici di 1006 pazienti. Al fine di valutare
eventuali modifiche e progressi, il periodo di 17 anni è stato diviso in tre periodi, ciascuno comprendente rispettivamente 268 SV (1990-
1996), 299 SV (1997-2001), e 439 SV (2002-2006). Il follow-up medio è stato di 5,9 ± 2,4 anni. Complessivamente l’asportazione totale è
stata ottenuta nel 99,4% dei casi. Il tasso di mortalità è stato dello 0,3%, la meningite e la perdita di liquido cefalo rachidiano (LCR) sono
stati osservati nel 1,2% e il 9% dei casi, rispettivamente. La frequenza della perdita di LCR è diminuita dal 11,6% al 7,1% tra il primo e
dell’ultimo periodo (p < 0,01) e la revisione chirurgica dal 3,4% al 0,9% (p < 0,05). Il nervo facciale è stato anatomicamente conservato
nel 97,7% dei casi. Ad un anno, una buona funzione del nervo facciale è stata osservata nel 85,1% dei pazienti (I e II grado HouseBrackmann), con una variazione tra il primo e l’ultimo periodo che andava dal 78,4% al 87,6% (p < 0,05). Ad un anno post-operatorio la
conservazione dell’udito è stata ottenuta nel 61,6% dei pazienti, passando dal 50,9% del primo periodo, al 69,0% del periodo piú recente
(p < 0,05) (classe A + B + C dalla classificazione AAO-HNS). L’udito utile (classe A + B) è stato conservato nel 33,5% dei casi complessivamente, con percentuali comprese tra il 21,8% e 42% nel primo e nell’ultimo periodo rispettivamente (p < 0,01). Gli esiti chirurgici
dell’asportazion dello schwannoma vestibolare sporadico sono migliorati negli anni per quanto riguarda i risultati funzionali del nervo
facciale, la conservazione dell’udito, le perdite di liquido cefalorachidiano, principalmente grazie all’esperienza del team neurotologico. I
risultati funzionali dopo la rimozione microchirurgica completa SV di grandi dimensioni dipendono dall’ esperienza maturata sulle lesioni
di piccole dimensioniThe management of sporadic vestibular schwannoma (VS) has evolved in the last decades. The aim of this study was to analyse the evolution in surgical outcomes of VSs operated by a neurotological team between 1990 and 2006 by different approaches. A monocentric retrospective review of medical charts of 1006 patients was performed. In order to assess eventual changes and progress, the 17-years period was divided in three periods, each one comprehending 268 VS (1990-1996), 299 VS (1997-2001), and 439 VS (2002-2006). Mean follow-up was 5.9 ± 2.4 years. Overall, complete VS removal was achieved in 99.4% of cases. Mortality rate was 0.3%, meningitis and CSF leaks were observed in 1.2 % and 9 % of the cases, respectively. CSF leakage decreased from 11.6% to 7.1% between the first and last period (p < 0.01) as well as revision surgery from 3.4 % to 0.9 % (p < 0.05). Facial nerve was anatomically preserved in 97.7% of cases. At one year, a good facial nerve function was observed in 85.1% of patients (grade I and II of House-Brackmann grading scale), which ranged between the first and last period from 78.4% to 87.6% (p <0.05). At one year, hearing preservation was obtained in 61.6% of patients, which increased from the first period to the last one from 50.9% to 69.0% (p < 0.05) (class A+B+C from the AAO-HNS classification). Useful hearing (class A+B) was observed in 33.5% of cases overall, with 21.8% and 42% in the first and last period, respectively (p < 0.01). Surgical outcomes of sporadic vestibular schwannoma have improved concerning facial nerve function outcomes, hearing preservation and cerebrospinal fluid (CSF) leaks, mainly due to the neuro-otological team's experience. Functional results after complete microsurgical removal of large VS depend on experience gained on small VS removal
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