1,721,043 research outputs found
Progettazione e ottimizzazione di un prototipo di torre di reazione con preseparatore semiciclonico
No full textThermal stress analysis of PCM containers for temperature smoothing of waste gas
No full textThis article develops an analytical and numerical approach to evaluate thermal stress in a phase change material (PCM) system, used for temperature smoothing of waste gas of Electric Arc Furnace, in which the PCM is encapsulated in a cylindrical steel container. Thermal analysis shows that temperature distribution in the PCM system can be considered as uniform at any time instant according to the lumped capacitance method; the thermal behaviour of PCM system is thus simulated as a sequence of steady state analyses. Mechanical analysis adopts an axialsymmetric plane analytical model to compare elastic thermal stress distribution for different stainless steels and to identify AISI 316 as the most suitable material for the PCM container. A simple two-bars model and a stress index are also used to allow a physical understanding and a satisfactory interpretation of the PCM system response. Mechanical analysis shows that thermal stresses exceed the yield point of both stainless steels used in the container. A finite element elastic-plastic model is then developed to estimate the extension of the plastic zone. Finally, an alternative PCM system geometry based on concentric pipes is designed to keep the maximum stresses in the PCM container below the yielding point. A sensitivity analysis shows that the most relevant design parameters of the alternative geometry are the diameter of inner pipe and thickness of the external pipe
Copper(I), Silver(I), and Gold(I) Complexes with the Hybrid Ligand 1-(Diphenylphosphino)-2-(2-pyridyl)ethane (ppye). Variable-temperature NMR Investigations and the Crystal Structure of Au(ppye-P)2 PF6
No full textCopper(I), silver(I) and gold(I) complexes with the ligand 1-(diphenyphosphino)-2-(2-pyridyl)ethane (ppye) of general formula M(ppye)(2)PF6 have been prepared and characterized by means of IR and multinuclear (H-1,C-13 and np) NMR spectroscopy The copper(I) and silver(I) complexes are bis(chelate) with a tetrahedral geometry around the metal atom. On the contrary, the gold(I) derivative exhibits a digonal structure with monodentate P-bound ppye ligands co-ordinated to the metal centre. The complex [Au(ppye-P)(2)]PF6 has been characterized in the solid state by X-ray diffraction analysis. Crystal data: triclinic, space group P ($) over bar 1, a=9.972(1), b=10.299(2), c=10.521(2) Angstrom, alpha=69.90(2), beta=66.03(1), gamma=78.51(1)degrees, Z=1, R=0.039. The gold atom. which lies on a symmetry centre, is linearly co-ordinated by the P atoms of ppye (P-Au-P, 180 degrees). Variable-temperature NMR studies show that the [M(ppye-P,N)(2)](+) species rearrange in solution by inversion at the tetrahedral metal centre. Furthermore. all three ppye derivatives undergo ligand-exchange processes. The reactions of the cations [M(ppye-P,N)(2)](+) and [Au(ppye-P)(2)](+) with ppye have been investigated
Impatto energetico-ambientale della logistica globale di approvvigionamento per un'azienda industriale
No full textPerché consumare cibo vegano? Una scelta etica e spirituale, non salutistica
No full textToday, the consume of vegan food has become a must. Extant literature has since long studied this phenomenon from different perspectives, evidencing the main role of ethical and spiritual motives, while social and health reasons kept scholars’ attention only recently. However, drivers of vegan consumption were often investigating in a disjointed
way and mixing vegetarians with vegans. Given this acknowledgment, in order to get a comprehensive and focused understanding of the phenomenon and, in this way, contributing to the studies on consumer behavior, this work explores the impact and intensity of the determinants of the intention to buy vegan food through the mediating role of consumer attitude towards this food option.
The study was performed via a survey accomplished through administering a structured questionnaire to a sample of vegan people caught on social networks dedicated to veganism and then applying structural equation modeling (Sem) to the data collected. Findings confirm the crucial role of all the drivers investigated in developing a positive behavioral intention to buy vegan food through the mediating role of attitude towards vegan food products, while attention to health does not proved to exert any significant effect. Scientific and managerial implications are developed.Today, the consume of vegan food has become a must. Extant literature has since long studied this phenomenon from different perspectives, evidencing the main role of ethical and spiritual motives, while social and health reasons kept scholars’ attention only recently. However, drivers of vegan consumption were often investigating in a disjointed way and mixing vegetarians with vegans. Given this acknowledgment, in order to get a comprehensive and focused understanding of the phenomenon and, in this way, contributing to the studies on consumer behavior, this work explores the impact and intensity of the determinants of the intention to buy vegan food through the mediating role of consumer attitude towards this food option. The study was performed via a survey accomplished through administering a structured questionnaire to a sample of vegan people caught on social networks dedicated to veganism and then applying structural equation modeling (Sem) to the data collected. Findings confirm the crucial role of all the drivers investigated in developing a positive behavioral intention to buy vegan food through the mediating role of attitude towards vegan food products, while attention to health does not proved to exert any significant effect. Scientific and managerial implications are developed
Incorporating Environmental and Economic Objectives in the Design of Distributed Generation and District Heating Plants Through Externalities: Dealing with Uncertainty
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Analisi dell’opportunità tecnico-economica di impianti integrati per la termovalorizzazione dei rifiuti industriali e la floricoltura in serra
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