7,637 research outputs found
Synthesis and application of zeolite and glass fiber supported zero valent iron nanoparticles as membrane component for removal nitrate and Cr (+6) ions
In the present paper the synthesis and characterization of zeolite and glass fiber supported zero valent iron
nanoparticles (Ze-ZVI, GF-ZVI NPs) are reported.ZVI, Ze-ZVI and GF-ZVI NPs size, composition and
morphology were characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM),
Energy Dispersive Spectroscopy (EDS). Synthesized nanostructures were tested as reducing agents of nitrate
and hexavalent Chromium. Batch experiments were carried for revealing of efficacy of prepared nanomaterials
(ZE-ZVI NPs and GF-ZVI NPs). Nitrate removal efficiency (at initial concentration 50 mg/mL) was rapidly
increased from 26% to 76% for GF-ZVI NPs at 60-240 min time interval for and from 34% to 90% for ZE-ZVI
NPs at the same time interval.Also was studied the efficacy of prepared nanostructures ZE-ZVI and ZE-ZVI
NPs as membrane component with 5% of ZVI NPS weight contentfor the removal of nitrate from water
solution that made 85% for ZE-ZVI NPs and 76% for GF-ZVI NPs, respectively. The results of this study
indicate that the application of GF-ZVI and ZE-ZVI NPs as membrane component is advantageous because it
allows to prevent the additional pollution of treated solution caused by unreacted ZVI NPs
Changes in carbonyl compounds in Chardonnay and Cabernet Sauvignon wines as a consequence of malolactic fermentation
To study changes in carbonyl compounds in Chardonnay and Cabernet Sauvignon wines as a consequence of malolactic fermentation (MLF), wines were fermented by inoculation of commercial strains of Oenococcus oeni, and compared with unfermented (control) wines. Carbonyl compounds were determined by GC/MS analysis on the basis of their O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine derivatives after sample preparation on an ion exchange column to remove pyruvic acid. With MLF, marked changes were revealed, particularly with regard to diacetyl, acetoin and aliphatic saturated aldehydes; the presence of unsaturated aldehydes was also revealed. A significant increase in glycoladehyde was observed, which is presumed to be part of a reduction system with glyoxal. Higher acetoin/diacetyl ratios were found in Chardonnay and higher glycolaldehyde/glyoxal ratios in Cabernet Sauvignon.
Design, realization and test of C-band accelerating structures for the SPARC_LAB linac energy upgrade
Investigating and modelling the effects of information accuracy on travellers' compliance with ATIS approach
Public reporting on individual hospitals’ quality: the risk of misinformation
Obiettivo: benché con sempre maggiore frequenza i mass media riportino informazioni sulla qualità dei servizi, spesso con
l’esplicito intento di individuare i «migliori», la comunicazione di questi temi avviene attraverso modalitĂ che o sono troppo semplicistiche nel loro sforzo di confrontare le performance cliniche dei singoli centri, o ricorrono a indicatori di qualitĂ
inadeguati. In tale senso, queste informazioni possono facilmente portare a interpretazioni errate. Questo lavoro considera due esempi concreti per evidenziare il problema.
Metodi: sono stati utilizzati due casi recenti di comunicazione
attraverso i mass media delle performance cliniche di centri cardiochirurgici: i risultati dello studio BPAC «Esiti a breve termine di interventi di by-pass coronarico nelle cardiochirurgie
italiane», coordinato dall’ISS, e la pubblicazione sulla rivista
Panorama di quelle che erano definite come le migliori cardiochirurgie italiane sulla base di un indice di reputazione.
Risultati: il primo dei casi citati evidenzia i problemi della rappresentazione delle performance con semplici league tables. Con
un metodo basato su Markov Chain Monte Carlo si evince che
il ricorso alle classifiche, pur basate su un corretto indicatore di
esito, è un esercizio potenzialmente fuorviante. Nel secondo caso, si dimostra l’inaffidabilità di un indice reputazionale utilizzato come indicatore della qualità dei servizi.
Conclusione: le modalità con cui si comunica al pubblico la qualità dei servizi sono ancora largamente inadeguate e quindi potenzialmente fuorvianti nell’indirizzare le scelte dei cittadini
Experimental assessment on exploiting low carbon ethanol fuel in a light-duty dual-fuel compression ignition engine
Compression ignition (CI) engines are widely used in modern society, but they are also recognized as a significative source of harmful and human hazard emissions such as particulate matter (PM) and nitrogen oxides (NOx). Moreover, the combustion of fossil fuels is related to the growing amount of greenhouse gas (GHG) emissions, such as carbon dioxide (CO2). Stringent emission regulatory programs, the transition to cleaner and more advanced powertrains and the use of lower carbon fuels are driving forces for the improvement of diesel engines in terms of overall efficiency and engine-out emissions. Ethanol, a light alcohol and lower carbon fuel, is a promising alternative fuel applicable in the dual-fuel (DF) combustion mode to mitigate CO2 and also engine-out PM emissions. In this context, this work aims to assess the maximum fuel substitution ratio (FSR) and the impact on CO2 and PM emissions of different nozzle holes number injectors, 7 and 9, in the DF operating mode. The analysis was conducted within engine working constraints and considered the influence on maximum FSR of calibration parameters, such as combustion phasing, rail pressure, injection pattern and exhaust gas recirculation (EGR). The experimental tests were carried out on a single-cylinder light-duty CI engine with ethanol introduced via port fuel injection (PFI) and direct injection of diesel in two operating points, 1500 and 2000 rpm and at 5 and 8 bar of brake mean effective pressure (BMEP), respectively. Noise and the coefficient of variation in indicated mean effective pressure (COVIMEP) limits have been chosen as practical constraints. In particular, the experimental analysis assesses for each parameter or their combination the highest ethanol fraction that can be injected. To discriminate the effect on ethanol fraction and the combustion process of each parameter, a one-at-a-time-factor approach was used. The results show that, in both operating points, the EGR reduces the maximum ethanol fraction injectable; nevertheless, the ethanol addition leads to outstanding improvement in terms of engine-out PM. The adoption of a 9 hole diesel injector, for lower load, allows reaching a higher fraction of ethanol in all test conditions with an improvement in combustion noise, on average 3 dBA, while near-zero PM emissions and a reduction can be noticed, on the average of 1 g/kWh, and CO2 compared with the fewer nozzle holes case. Increasing the load insensitivity to different holes number was observed
I resti scheletrici della grotta di S. Teodoro presso il Museo Gemmellaro di Palermo: il nuovo restauro conservativo di ST2
The work describes the restoration of the cranium ST2 of the Epipalaeolithic site of S. Teodoro, Sicily. This restoration has been conducted in accordance to modern criteria of conservation limiting the integrative and reconstructive interpretation to the minimum. After the restauration ST2 has been morphologically described and measured. The fortuitous recovery of a left incus bone allowed
its morphological and metrical description
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