519 research outputs found
ZnO/ionic liquid catalyzed biodiesel production from renewable and waste lipids as feedstocks
A new protocol for biodiesel production is proposed, based on a binary ZnO/TBAI (TBAI = tetrabutylammonium iodide) catalytic system. Zinc oxide acts as a heterogeneous, bifunctional Lewis acid/base catalyst, while TBAI plays the role of phase transfer agent. Being composed by the bulk form powders, the whole catalyst system proved to be easy to use, without requiring nano-structuration or tedious and costly preparation or pre-activation procedures. In addition, due to the amphoteric properties of ZnO, the catalyst can simultaneously promote transesterification and esterification processes, thus becoming applicable to common vegetable oils (e.g., soybean, jatropha, linseed, etc.) and animal fats (lard and fish oil), but also to waste lipids such as cooking oils (WCOs), highly acidic lipids from oil industry processing, and lipid fractions of municipal sewage sludge. Reusability of the catalyst system together with kinetic (Ea) and thermodynamic parameters of activation (∆G‡ and ∆H‡) are also studied for transesterification reaction
Lotta agli sprechi alimentari in Puglia: misure di garanzia del “diritto al cibo” mediante buone pratiche di eco-sostenibilità ed economia circolare
Lo spreco alimentare rappresenta una vera e propria emergenza mondiale. Tale fenomeno assume una rilevanza non solo sul piano economico e sociale, ma anche su quello sanitario e ambientale. Nell’ottica, invece, dell’economia circolare gli sprechi e le perdite alimentari possono essere reimpiegati in altri processi come “materia prima seconda”, riducendo così il consumo di risorse e materie prime, gli impatti e i costi legati allo smaltimento dei rifiuti, la dipendenza dalle importazioni. Su questo sfondo si colloca l’interessante esperienza pugliese che ha coniugato la lotta allo spreco alimentare con interventi di innovazione sociale, puntando su iniziative di partenariato pubblico-privato che vedono coinvolto il livello di governo comunale insieme agli Enti del Terzo settore. Si tratta di esperienze di collaborazione tra settore pubblico, privato e no-profit idonee a trasformarsi in una forma più matura di sussidiarietà orizzontale che, nel valorizzare anche i doveri di solidarietà attraverso il contributo di tutti gli attori sociali - dal mondo delle imprese fino ai singoli cittadini - possono aiutare a definire ed implementare efficaci politiche urbane di tutela del ‘diritto al cibo’ e all’ambiente salubre nonché buone pratiche di economia circolare
Il contributo delle cc.dd. “aree interne” alla transizione energetica
Il contributo delle cc.dd. “aree interne” alla transizione energetica
Le “aree interne”, in quanto territori marginalizzati rispetto all’offerta di un livello adeguato di servizi di cittadinanza, sono protagoniste di una specifica strategia di valorizzazione della gestione sostenibile del territorio (la c.d. SNAI). Anche il PNRR dedica ampio spazio alla SNAI riconoscendo e promuovendo l’intersezione dello “sguardo nazionale” con lo “sguardo locale” nella formulazione della strategia di sviluppo economico e di coesione sociale del Paese (politiche place-based, ovvero “rivolte ai luoghi”). Peraltro, ripensare i servizi offerti ai cittadini in un’ottica di ribilanciamento territoriale implica la necessità di ricorrere a nuove soluzioni di governance, capaci di coinvolgere volta per volta i diversi attori, i presidi territoriali e gli Enti locali competenti nelle specifiche materie di riferimento. In proposito, merita una particolare attenzione lo sviluppo della filiera dell’energia rinnovabile. Con riguardo a quest’ultimo ambito, deve segnalarsi la recentissima esperienza pugliese dell’Area interna dei Monti Dauni che, attraverso il coinvolgimento di cittadini, imprese e numerose altre realtà del territorio (tra le quali merita menzione il GAL Meridaunia) si propone, non senza difficoltà, di produrre, consumare e scambiare energia in un’ottica di transizione energetica, economia circolare, oil free zone e avvio di una vera e propria CER (Comunità energetica rinnovabile). Fondate sulla cittadinanza attiva e sulla partecipazione di diversi attori sociali, e orientate alla produzione di fonti rinnovabili, le comunità energetiche possono rappresentare importanti acceleratori di una transizione ecologica/energetica sostenibile e, se attivate in territori marginalizzati come le aree interne del Paese, contribuire a valorizzare le culture locali e territoriali
Consistent Posttest Calculations for LOCA Scenarios in LOBI Integral Facility
Integral test facilities (ITFs) are one of the main tools for the validation of best estimate thermalhydraulic system codes. The experimental data are also of great value when compared to the experiment-scaled conditions in a full NPP. The LOBI was a single plus a triple-loop (simulated by one loop) test facility electrically heated to simulate a 1300 MWe PWR. The scaling factor was 712 for the core power, volume, and mass flow. Primary and secondary sides contained all main active elements. Tests were performed for the characterization of phenomenologies relevant to large and small break LOCAs and special transients in PWRs. The paper presents the results of three posttest calculations of LOBI experiments. The selected experiments are BL-30, BL-44, and A1-84. They are LOCA scenarios of different break sizes and with different availability of safety injection components. The goal of the analysis is to improve the knowledge of the phenomena occurred in the facility in order to use it in further studies related to qualifying nodalizations of actual plants or to establish accuracy data bases for uncertainty methodologies. An example of procedure of implementing changes in a common nodalization valid for simulating tests occurred in a specific ITF is presented along with its confirmation based on posttests results
Il Pooling-score (P-score): Variabilit\ue0 inter- e intra-individuale nella valutazione endoscopica della gravit\ue0 della disfagia
This study evaluated the intra- and inter-rater reliability of the Pooling score (P-score) in clinical endoscopic evaluation of severity of swal- lowing disorder, considering excess residue in the pharynx and larynx. The score (minimum 4 - maximum 11) is obtained by the sum of the scores given to the site of the bolus, the amount and ability to control residue/bolus pooling, the latter assessed on the basis of cough, raclage, number of dry voluntary or re ex swallowing acts ( 5). Four judges evaluated 30 short lms of pharyngeal transit of 10 solid (1/4 of a cracker), 11 creamy (1 tablespoon of jam) and 9 liquid (1 tablespoon of 5 cc of water coloured with methlyene blue, 1 ml in 100 ml) boluses in 23 subjects (10 M/13 F, age from 31 to 76 yrs, mean age 58.56\ub111.76 years) with different pathologies. The lms were randomly distributed on two CDs, which differed in terms of the sequence of the lms, and were given to judges (after an explanatory ses- sion) at time 0, 24 hours later (time 1) and after 7 days (time 2). The inter- and intra-rater reliability of the P-score was calculated using the intra-class correlation coef cient (ICC; 3,k). The possibility that consistency of boluses could affect the scoring of the lms was considered. The ICC for site, amount, management and the P-score total was found to be, respectively, 0.999, 0.997, 1.00 and 0.999. Clinical evaluation of a criterion of severity of a swallowing disorder remains a crucial point in the management of patients with pathologies that predispose to complications. The P-score, derived from static and dynamic parameters, yielded a very high correlation among the scores attributed by the four judges during observations carried out at different times. Bolus consistencies did not affect the outcome of the test: the analysis of variance, performed to verify if the scores attributed by the four judges to the parameters selected, might be in uenced by the different consistencies of the boluses, was not signi cant. These initial data validate the clinical use of the P-score in the management of patients with deglutition disorders by a multidisciplinary team
Valorization of cigarette butts for synthesis of levulinic acid as top value-added chemicals
Unprecedented in the literature, levulinic acid (LA), one of the top value-added intermediates of chemical industry, is obtained from cigarette butts as cellulose feedstock by means of a one-pot hydrothermal process carried out at 200 °C for 2 h and catalysed by phosphoric acid. The protocol avoids the use of more aggressive and toxic H2SO4 and HCl, that are generally employed on several cellulose sources (e.g. sludge paper), thus minimizing corrosion phenomena of plants. Neither chemical pre-treatment of butts nor specific purification procedure of LA are required. Notably, by simply modifying acid catalyst (e.g. using CH3COOH), another top value-added fine chemical such as 5-hydroxymethylfuraldehyde (HMF) is obtained, thus widening the scope of the method. Being cigarette filters a waste available in quantities of megatonnes per year, they represent an unlimited at no cost source of cellulose, thus enabling the up-scale to an industrial level of LA production
Concerning synthesis of new biobased polycarbonates with curcumin in replacement of bisphenol a and recycled diphenyl carbonate as example of circular economy
Curcumin (CM) is a natural polyphenol well-known for its antioxidant and pharmaceutical properties, that can represent a renewable alternative to bisphenol A (BPA) for the synthesis of biobased polycarbonates (PC). In the presented strategy, preparation of the CM-based PC was coupled with chemical recycling of the fossil-based BPA polycarbonate (BPA-PC) conducting a two-steps trans-polymerization that replaces BPA monomer with CM or its tetrahydrogenated colorless product (THCM). In the first step of synthetic strategy, depolymerization of commercial BPA-PC was carried out with phenol as nucleophile, according to our previous procedure based on zinc derivatives and ionic liquids as catalysts, thus producing quantitatively diphenyl carbonate (DPC) e BPA. In the second step, DPC underwent a melt transesterification with CM or THCM monomers affording the corresponding bio-based polycarbonates, CM-PC and THCM-PC, respectively. THCM was prepared by reducing natural bis-phenol with cyclohexene as a hydrogen donor and characterized by 1H-NMR and MS techniques. Polymerization reactions were monitored by infrared spectroscopy and average molecular weights and dispersity of the two biobased polymers THCM-PC and CM-PC were determined by means of gel permeation chromatography (GPC). Optical properties of the prepared polymers were also measured
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