339 research outputs found

    Preliminary investigation on thermal behavior of vehicles in different climate conditions

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    The objective of this paper is to provide an initial estimate, albeit rough, about the possible energy savings that can be achieved by reducing the use of the air condition system in cars. A simplified numerical model of the car has been created to predict the cabin temperature in different climatic conditions. In order to reduce the thermal load and so the temperature inside the cabin several different types of glazing have been considered, characterized by different absorbance coefficients and solar factors. Furthermore, two types of coatings with different absorbance coefficients were examined for the envelope. The paper describe

    Surface plasmon enhanced absorption and suppressed transmission in periodic arrays of graphene ribbons

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    Resonance diffraction in the periodic array of graphene micro-ribbons is theoretically studied following a recent experiment [L. Ju et al, Nature Nanotech. 6, 630 (2011)]. Systematic studies over a wide range of parameters are presented. It is shown that a much richer resonant picture would be observable for higher relaxation times of charge carriers: more resonances appear and transmission can be totally suppressed. The comparison with the absorption cross-section of a single ribbon shows that the resonant features of the periodic array are associated with leaky plasmonic modes. The longest-wavelength resonance provides the highest visibility of the transmission dip and has the strongest spectral shift and broadening with respect to the single-ribbon resonance, due to collective effects.Comment: 5 pages, 3 figure

    Pilot Study of a New Mandibular Advancement Device

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    This study was conducted to determine the efficacy of a customized mandibular advancement device (MAD) in the treatment of obstructive sleep apnea (OSA). Eight patients (M = 3; F = 5; mean age = 56.3 ± 9.4) with a diagnosis of OSA confirmed by polysomnography (PSG) were re-cruited on the basis of the following inclusion criteria: apnea-hypopnea index (AHI) > 5, age between 18 and 75 years, body mass index (BMI) < 25, and PSG data available at baseline (T0). All were treated with the new NOA® MAD by OrthoApnea (NOA® ) for at least 3 months; PSG with NOA in situ was performed after 3 months of treatment (T1). The following parameters were calculated at T0 and T1: AHI, supine AHI, oxygen desaturation index (ODI), percentage of recording time spent with oxygen saturation <90% (SpO2 < 90%), and mean oxygen desaturation (MeanSpO2%). Data were submitted for statistical analysis. The baseline values were AHI = 21.33 ± 14.79, supine AHI = 35.64 ± 12.80, ODI = 17.51 ± 13.5, SpO2 < 90% = 7.82 ± 17.08, and MeanSpO2% = 93.45 ± 1.86. Four patients had mild OSA (5 > AHI < 15), one moderate OSA (15 > AHI < 30), and three severe OSA (AHI > 30). After treatment with NOA®, statistically significant improvements in AHI (8.6 ± 4.21) and supine AHI (11.21 ± 7.26) were recorded. OrthoApnea NOA® could be an effective alternative in the treatment of OSA: the device improved the PSG parameters assessed

    Selection of new markers for animal by-products characterization by classical microscopy

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    The aim of this study was to identify possible markers to distinguish differences between land animals by using the microscopic method in association with computer image analysis. For this purpose bone fragments from poultry and mammals were obtained and analysed by microscopic method. Through a digital camera and an image analysis software 85 bone lacunae images have been processed and elaborated in order to obtain for each lacuna a monochrome mask on which several measurements were performed. Data were analysed by ANOVA and LDA. Results obtained in the present study indicated that of 32 descriptors processed by image analysis software, only 12 were significantly (P<0.001) different between mammalian and poultry. However, when morphometric measurements were analysed by LDA, 86% of lacunae were correctly classified into the animal class of origin (i.e. mammalian as mammalian and poultry as poultry). By contrast 14% of lacunae were incorrectly classified. In conclusion, data here presented indicate that some of descriptors used by image analysis appears promising not only for a reliable distinction between the different origins of animal meal at the level of vertebrate classes, but also for further characterisation and identification of processed animal proteins in animal feeds

    Superradiance mediated by Graphene Surface Plasmons

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    We demonstrate that the interaction between two emitters can be controlled by means of the efficient excitation of surface plasmon modes in graphene. We consider graphene surface plasmons supported by either two-dimensional graphene sheets or one-dimensional graphene ribbons, showing in both cases that the coupling between the emitters can be strongly enhanced or suppressed. The super- and subradiant regimes are investigated in the reflection and transmission configurations. Importantly, the length scale of the coupling between emitters, which in vacuum is fixed by the free space wavelength, is now determined by the wavelength of the graphene surface plasmons that can be extremely short and be tuned at will via a gate voltage

    Feed particle size evaluation: conventional approach versus digital holography based image analysis

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    The aim of this study was to evaluate the application of image analysis approach based on digital holography in defining particle size in comparison with the sieve shaker method (sieving method) as reference method. For this purpose ground corn meal was analyzed by a sieve shaker Retsch VS 1000 and by image analysis approach based on digital holography. Particle size from digital holography were compared with results obtained by screen (sieving) analysis for each of size classes by a cumulative distribution plot. Comparison between particle size values obtained by sieving method and image analysis indicated that values were comparable in term of particle size information, introducing a potential application for digital holography and image analysis in feed industry

    Transcriptional regulation of lipid metabolism and inflammation in transition dairy goats by fish oil and stearate

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    To better understand the interaction between saturated or unsaturated fatty acids and its effect on expression of genes involved in subcutaneous adipose tissue metabolism, 23 second parity alpine dairy goats were enrolled in the experiment and fed either a non fat-supplemented basal diet (C; n=8), the basal diet supplemented with stearic acid (ST; n=7) or the basal diet supplemented with fish oil (FO; n=8). 30g/head/d supplemental fatty acids during the dry period and 50g/head/d during lactation were delivered starting one week before parturition up to 21 days in milk. Subcutaneous adipose tissue samples were harvested at day -7, 7 and 21 relative to kidding and mRNA levels of genes involved in inflammation were measured via qPCR. Data were analyzed using the MIXED procedure of SAS. No significant effects for treatment were observed, however eight genes were significant for time. HP and SAA3 expression peaked at day 7 postpartum, to then return at prepartum level around 21 d relative to kidding, while IL8, IL10, and IL18 expression constantly increased along the transition period. Vice versa, expression of IL1\u3b2, IL6R, and RXRA decreased in response to kidding, with a subsequent increase at day 21. The obtained results led us to hypothesize that goats face a postponed lipomobilization after kidding, probably related to their reduced production. The next step will involve the analysis of miRNA related to immune cell infiltration, adipocyte inflammation and lipolysis and positive regulation of adipogenesis to better understand the complex network of lipid metabolism in periparturient goats

    The role of antioxidants in the interplay between oxidative stress and senescence

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    Cellular senescence is an irreversible state of cell cycle arrest occurring in response to stressful stimuli, such as telomere attrition, DNA damage, reactive oxygen species, and oncogenic proteins. Although beneficial and protective in several physiological processes, an excessive senescent cell burden has been involved in various pathological conditions including aging, tissue dysfunction and chronic diseases. Oxidative stress (OS) can drive senescence due to a loss of balance between pro-oxidant stimuli and antioxidant defences. Therefore, the identification and characterization of antioxidant compounds capable of preventing or counteracting the senescent phenotype is of major interest. However, despite the considerable number of studies, a comprehensive overview of the main antioxidant molecules capable of counteracting OS-induced senescence is still lacking. Here, besides a brief description of the molecular mechanisms implicated in OS-mediated aging, we review and discuss the role of enzymes, mitochondria-targeting compounds, vitamins, carotenoids, organosulfur compounds, nitrogen non-protein molecules, minerals, flavonoids, and non-flavonoids as antioxidant compounds with an anti-aging potential, therefore offering insights into innovative lifespan-extending approaches

    Olfactometric techniques in feed analysis: preliminary calibration of DON in durum wheat

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    Approcci olfattometrici nell\u2019analisi dei mangimi: calibrazione preliminare per il rilievo di DON nel grano duro. Le analisi olfattometriche, attraverso l\u2019uso del naso elettronico, trovano sempre pi\uf9 spazio nella valutazione della qualit\ue0 e sicurezza in campo alimentare. I principali vantaggi di tale approccio risiedono nella sua flessibilit\ue0 di impiego. Una volta messi a punto adeguati protocolli d\u2019analisi e modelli statistici di tipo multivariato, infatti, il naso elettronico si pu\uf2 rivelare uno strumento adatto alle realt\ue0 di campo in quanto caratterizzato da rapidit\ue0 e basso costo d\u2019esercizio. Lo scopo di questo lavoro \ue8 stato quello di verificare, a livello preliminare, l\u2019efficienza del naso elettronico nel riconoscere la presenza di micotossina deossinivalenolo (DON) in 10 campioni di grano duro (Triticum durum) di diversa provenienza geografica. I risultati hanno dimostrato che il protocollo applicato consente di riconoscere la presenza di DON nonch\ue9 di discriminare i diversi campioni in funzione del loro livello di contaminazione
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