1,176 research outputs found

    Is demagnetization an efficient optimization method?

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    Demagnetization, commonly employed to study ferromagnets, has been proposed as the basis for an optimization tool, a method to find the ground state of a disordered system. Here we present a detailed comparison between the ground state and the demagnetized state in the random field Ising model, combing exact results in d=1d=1 and numerical solutions in d=3d=3. We show that there are important differences between the two states that persist in the thermodynamic limit and thus conclude that AC demagnetization is not an efficient optimization method.Comment: 2 pages, 1 figur

    Removal of metallic elements from real wastewater using zebra mussel bio-filtration process

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    The metallic element pollution is a serious environmental problem but still unsolved since these contaminants are released mainly by human activity, reaching all the environmental compartments. Traditional wastewater treatment plants are very efficient in removing metallic elements only when their concentration is in the order of mg/L, but are not able to remove them until \u3bcg/L, as it would be needed to cope with the water quality standards in low flow receptors. Therefore, the aim of our study was to evaluate the potential removal of some recalcitrant metallic elements to the classical treatments, by the natural process of bio-filtration performed by the invasive zebra mussel (Dreissena polymorpha). For this purpose we built a pilot-plant at the Milano-Nosedo wastewater treatment plant, where we placed about 40,000 D. polymorpha specimens appointed to the wastewater bio-filtration. The metallic element removal due to zebra mussel activity was evaluated in the treated wastewater with a plasma optical emission spectrometry (ICP-OES). Data obtained in these experiments showed an encouraging metallic element removal due to D. polymorpha activity; in particular, the total abatement (100%) of Cr after one day of bio-filtration exposure is remarkable. Therefore, this study encourages further research related with the use of bivalves as a new tool for the wastewater depuration process; in this regard, the contaminated mollusks used in the bio-filtration could be incinerated or stored in special landfills, as is also the case of traditional sewage sludge

    Life Products of Stars

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    We attempt to document complete energetic transactions of stars in their life. We calculate photon and neutrino energies that are produced from stars in their each phase of evolution from 1 to 8 M_sun, using the state-of-the-art stellar evolution code, tracing the evolution continuously from pre-main sequence gravitational contraction to white dwarfs. We also catalogue gravitational and thermal energies and helium, and heavier elements that are stored in stars and those ejected into interstellar space in each evolutionary phase.Comment: 26 pages, including 8 figures and 3 tables. Submitted to ApJ

    The effects of reiterated cell photo-stimulation with an azobenzene

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    Optical stimulation of living cells is an innovative and success- ful tool, having a significant impact on neuroscience. A recently synthesized am- phiphilic azobenzene, named Ziapin2, has been developed exploiting a non-covalent approach for targeting the membrane and achieving cell photostimulation. Here, we investigate, using both experimental data and mathematical modelling, the effect of repetitive light stimulation on the cell response. We discuss some possible explana- tions for the drop in the stimulation efficiency in reiterated stimulation processes

    Prevalence of comorbidities according to predominant phenotype and severity of chronic obstructive pulmonary disease

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    BACKGROUND: In addition to lung involvement, several other diseases and syndromes coexist in patients with chronic obstructive pulmonary disease (COPD). Our purpose was to investigate the prevalence of idiopathic arterial hypertension (IAH), ischemic heart disease, heart failure, peripheral vascular disease (PVD), diabetes, osteoporosis, and anxious depressive syndrome in a clinical setting of COPD outpatients whose phenotypes (predominant airway disease and predominant emphysema) and severity (mild and severe diseases) were determined by clinical and functional parameters. METHODS: A total of 412 outpatients with COPD were assigned either a predominant airway disease or a predominant emphysema phenotype of mild or severe degree according to predictive models based on pulmonary functions (forced expiratory volume in 1 second/vital capacity; total lung capacity %; functional residual capacity %; and diffusing capacity of lung for carbon monoxide %) and sputum characteristics. Comorbidities were assessed by objective medical records. RESULTS: Eighty-four percent of patients suffered from at least one comorbidity and 75% from at least one cardiovascular comorbidity, with IAH and PVD being the most prevalent ones (62% and 28%, respectively). IAH prevailed significantly in predominant airway disease, osteoporosis prevailed significantly in predominant emphysema, and ischemic heart disease and PVD prevailed in mild COPD. All cardiovascular comorbidities prevailed significantly in predominant airway phenotype of COPD and mild COPD severity. CONCLUSION: Specific comorbidities prevail in different phenotypes of COPD; this fact may be relevant to identify patients at risk for specific, phenotype-related comorbidities. The highest prevalence of comorbidities in patients with mild disease indicates that these patients should be investigated for coexisting diseases or syndromes even in the less severe, pauci-symptomatic stages of COPD. The simple method employed to phenotype and score COPD allows these results to be translated easily into daily clinical practice

    How do we comprehend linguistic and visual narratives? A study in children with typical development

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    The present study investigated the comprehension of narrative with reference to global coherence, i.e., the global representation of story meaning and connectedness, across two different expressive modalities: stories conveyed through written language and stories conveyed through sequences of images. Two cognitive abilities possibly underpinning such comprehension were assessed: Central Coherence (CC) and Theory of Mind (ToM). Two groups of children with typical development aged between 8.00 and 10.11 years were included in the study: 40 participants received the narrative comprehension task in the linguistic modality; 40 participants were administered the narrative comprehension task in the visual condition. Analyses revealed that a change in the expressive code used to convey narratives did not entail a change in the overall comprehension performance: children of the two groups performed similarly on the narrative task. As for the cognitive abilities, CC and ToM scores were positively correlated with narrative comprehension score only in the visual narrative comprehension task, and not in the linguistic one. Moreover, a regression analysis showed that, along with age, CC significantly predicted the visual narrative comprehension score. The implications of these results are discussed.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    Mean Curvature Flow on Ricci Solitons

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    We study monotonic quantities in the context of combined geometric flows. In particular, focusing on Ricci solitons as the ambient space, we consider solutions of the heat type equation integrated over embedded submanifolds evolving by mean curvature flow and we study their monotonicity properties. This is part of an ongoing project with Magni and Mantegazzawhich will treat the case of non-solitonic backgrounds \cite{a_14}.Comment: 19 page
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