Search results for "DF"

Metadata-Oriented Language Model in Translingual Retrieval of Digital Data

2015

Translingual retrieval relies on processing a source language to retrieve digital document content in a target language. From the perspective of successful browsing digital catalogues, probability of retrieving the full text document in a language other than the query language is close to zero owning to the fact that it is not only the library collection, but especially a problem of matching the index terms with the query keywords which are assumed to be their translation equivalents. In addition, hardly any digital library system is incorporated with a translation component. As a result, such a matching is rather coincidental. Our approach to the translingual document retrieval problem is …

The role of the transportation phase for a green management of municipal solid waste

2017

Municipal solid waste management (MSWM) constitutes a high challenging issue to cope with to move towards sustainability of the urban policies. Despite new standards call for recycling and reusing materials contained in the city waste, several municipalities still use extensive landfills. Other than the environmental pressure exerted by these plants, the waste transportation from the recovery points of towns to landfills needs consideration to correctly assess the whole burden of the waste management. In this paper, the Ecological Footprint indicator is applied to the MSWM of the town of Palermo (Sicily). Results show that the effects produced by the involved transportation vehicles, both i…

Biogas from municipal solid waste landfills: A simplified mathematical model

2018

AbstractMunicipal solid waste (MSW) landfills now represent one of the most important issues related to the waste management cycle. Knowledge of biogas production is a key aspect for the proper exploitation of this energy source, even in the post-closure period. In the present study, a simple mathematical model was proposed for the simulation of biogas production. The model is based on first-order biodegradation kinetics and also takes into account the temperature variation in time and depth as well as landfill settlement. The model was applied to an operating landfill located in Sicily, in Italy, and the first results obtained are promising. Indeed, the results showed a good fit between me…

Modeling of perched leachate zone formation in municipal solid waste landfills.

2010

The paper presents a 1D mathematical model for the simulation of the percolation fluxes throughout a landfill for municipal solid waste (MSW). Specifically, the model was based on mass balance equations, that enable simulation of the formation of perched leachate zones in a landfill for MSW. The model considers the landfill divided in several layers evaluating the inflow to and outflow from each layer as well as the continuous moisture distribution. The infiltration flow was evaluated by means of the Darcy’s law for an unsaturated porous medium, while the moisture distribution evaluation has been carried out on the basis of the theory of the vertically distributed unsaturated flow. The solu…

On the way to ‘zero waste’ management: Recovery potential of elements, including rare earth elements, from fine fraction of waste

2018

Abstract Existing schemes of solid waste handling have been improved implementing advanced systems for recovery and reuse of various materials. Nowadays, the ‘zero waste’ concept is becoming more topical through the reduction of disposed waste. Recovery of metals, nutrients and other materials that can be returned to the material cycles still remain as a challenge for future. Landfill mining (LFM) is one of the approaches that can deal with former dumpsites, and derived materials may become important for circular economy within the concept ‘beyond the zero waste’. Perspectives of material recovery can include recycling of critical industrial metals, including rare earth elements (REEs). The…

Hydrogen activation on N‐doped carbon networks

2014

Aromaticity and planarity of zinc phthalocyanine (ZnPc) characterized by splitting of NICS(1) index

2018

The planarity of zinc phthalocyanine (ZnPc) in the gas phase and water, with solute-solvent interactions modeled by polarized continuum model (PCM), has been characterized with new indexes of aromaticity. The aromaticity of individual ring subunits of ZnPc molecule was studied on the basis of nucleus independent chemical shift index (NICS) above and below the molecular plane. Density functional theory (DFT) with selected Pople-type basis sets was used to study the local aromaticity. The calculated NICS(1) and NICS(-1) indexes of aromaticity for a non-planar ZnPc molecule in the polar environment are significantly different.

Method and basis set dependence of the NICS indexes of aromaticity for benzene

2018

The role of theory level in prediction of benzene magnetic indexes of aromaticity is analysed and compared with calculated nuclear magnetic shieldings of 3 He used as NMR probe. Three closely related nucleus-independent chemical shift (NICS) based indexes were calculated for benzene at SCF-HF, MP2, and DFT levels of theory and the impact of basis set on these quantities was studied. The changes of benzene NICS(0), NICS(1), and NICS(1)zz parameters calculated using SCF-HF, MP2 and several density functionals were within 1 to 3 ppm. Similar deviations between magnetic indexes of aromaticity were observed for values calculated with selected basis sets. Only very small effect of polar solvent o…

Ag44(SeR)30: A Hollow Cage Silver Cluster with Selenolate Protection.

2015

Selenolate protected, stable and atomically precise, hollow silver cluster was synthesized using solid state as well as solution state routes. The optical absorption spectrum shows multiple and sharp features similar to the thiolated Ag44 cluster, Ag44(SR)30 whose experimental structure was reported recently. High-resolution electrospray ionization mass spectrometry (HRESI MS) shows well-defined molecular ion features with two, three, and four ions with isotopic resolution, due to Ag44(SePh) 30. Additional characterization with diverse tools confirmed the composition. The closed-shell 18 electron superatom electronic structure, analogous to Ag44(SR)30 stabilizes the dodecahedral cage with a…

A continuum damage model for functionalized graphene membranes based on atomistic simulations

2017

A continuum model for GO membranes is developed in this study. The model is built representing the membrane as a two-dimensional, heterogeneous, two-phase continuum and the constitutive behavior of each phase (graphitic or oxidized) is built based on DFTB simulations of representative patches. A hyper-elastic continuum model is employed for the graphene areas, while a continuum damage model is more adequate for representing the behavior of oxidized regions. A finite element implementation for GO membranes subjected to degradation and failure is then implemented and, to avoid localization instabilities and spurious mesh sensitivity, a simple crack band model is adopted. The developed impleme…