The aim of this work was the calibration and validation of mathematical models based on a quantitative structure–activity relationship approach to discriminate sweet, tasteless and bitter molecules. ...The sweet-tasteless and the sweet-bitter datasets included 566 and 508 compounds, respectively. A total of 3763 conformation-independent Dragon molecular descriptors were calculated and subsequently reduced through both unsupervised reduction and supervised selection coupled with the
k
-nearest neighbors classification technique. A model based on nine descriptors was retained as the optimal one for sweet and tasteless molecules, while a model based on four descriptors was calibrated for the sweetness-bitterness dataset. Models were properly validated through cross-validation and external test sets. The applicability domain of models was investigated, and the interpretation of the role of the molecular descriptors in classifying sweet and non-sweet tastes was evaluated. The classification and the performance of the models presented in this paper are simple but accurate. They are based on a relatively small number of descriptors and a straightforward classification approach. The results presented here indicate that the proposed models can be used to accurately select new compounds as potential sweetener candidates.
The Piemonte mountains surrounding the city of Torino comprise a wide variety of rocks, characterized by a multitude of minerals, structures and colors. The Alps, because of their long and complex ...history, have produced a wide variety of ornamental stone used in the town, over the centuries, for both esthetic and structural reasons. TOURinSTONES is an application for mobile phones that allows geotourists to walk in the center of Torino, where the visitor can find Alpine rocks used in palaces and historical monuments as witnesses and tangible symbols of the city. The application consists of 26 historical sites of interest in each of which ornamental stones of historical and scientific interest can be observed in detail. The sites are grouped in four thematic itineraries through which the user can discover the city from the cultural and architectural point of view. By a numbered list of the stones used in all the described monuments, the user can access specific data on each rock including quarry location, petrographic description and utilization in Torino. The mobile application can be downloaded free from the App Store or Google Play respectively for Apple and Android devices.
In the literature, several vulnerability/resilience indicators and indexes are based and assessed by taking into account and combining different dimensions. Housing vulnerability is one of these ...dimensions and is strictly related to the buildings’ physical features and to the socio-economic condition of their occupants. This research aims to study housing vulnerability in relation to the real estate market by identifying possible indicators and spatially analyzing their influence on property prices. Assuming the city of Turin and its territorial segmentation as a case study, spatial analyses were performed to take into account the presence of spatial dependence and to identify the variables that significantly influence the process of property price determination. The results of this study highlighted the fact that two housing vulnerability indicators, representative of fragile buildings’ physical features, were spatially correlated with property prices and had a significant and negative influence on them. In addition, their comparison with two social vulnerability indicators demonstrated that the presence of economical buildings and council houses was spatially correlated with the presence of people with a low education level. The results of the spatial regression model also confirmed that one of the social vulnerability indicators had the highest and most negative explanatory power in the property price determination process.
The electronic structure of the neutral vacancy in diamond is investigated by using a periodic approach (supercells containing 32, 64 and 128 atoms have been considered), the Hartree–Fock (HF), pure ...DFT (LDA, PBE), global (B3LYP and PBE0) and range-separated (HSE06) “hybrid” functionals, and a local basis set as implemented in the CRYSTAL14 code. LDA and GGA provide metallic solutions for the three possible spin states (characterized by
S
z
=
0
,
1
,
2
), whereas hybrids and HF, thanks to the “exact” exchange, which plays such a crucial role in the present case, provide well-localized defect states in the band gap of the insulating system. As a consequence of the metallic solution, for the
S
z
=
0
and 1 states, the spin polarization tends to disappear when pure DFT is used, while with HF and hybrids the uncoupled electrons remain strongly localized on the first nearest neighbors, as documented by the spin density maps. The relative stability between the three spin states is
0
<
1
<
2
for HF and hybrids, with a small difference between the first two (about 5
mE
h
in the case of hybrids and HF) and a much larger difference between
S
z
=
1
and 2 (about 50
mE
h
for hybrids, 28 for HF). As regards PBE and LDA results, the stability order between
S
z
=
0
and 1 is reversed, and
S
z
=
2
is less stable than
S
z
=
0
by only 8–10
mE
h
. The defect crystalline orbitals are classified by symmetry and identified in the band structure with respect to the valence and conducting electrons. The formation energy of the vacancy, evaluated with six different functionals, is close to 7 eV for three of them (7.00 HSE06, 7.05 LDA, 7.11 PBE0), slightly smaller in B3LYP (6.74) and PBE (6.56). Cluster calculations (
C
35
H
36
and
C
455
H
196
) are also performed in comparison with the supercell results and for obtaining, with the smaller one, a coupled-cluster estimate of the energy differences between the three spin states that turn out to be close to the ones obtained with hybrids.
This work aimed to study the influence of seven hybrid functionals (B3LYP, B1WC, B3PW, PBE0, PBESOL0, SOGGAXC, and WC1LYP) and selected basis sets in the CRYSTAL software library on the calculated ...structural, electronic, mechanical, and vibrational properties of BaSnO
3
under the framework of periodic density functional theory. Based on the results showing the best approximation of the experimental band gap energy and lattice parameter, the PBE0 functional and the Baranek basis set were used to optimize the outer valence shell functions, α
sp
and α
d
, in order to improve the quality of calculated properties. An analysis was done to determine the density of states, band structure, elastic constants, and infrared (IR) active modes. The results were compared with other reported quantum mechanical calculations and available experimental data.
The City of Turin launched in 2015 a series of Space Analysis and recalculation of the area managed to public green space. The job was to select all the areolas that made up the garden / green area. ...Once the selection phase has been completed, the shapefile has been saved in a dedicated folder and coded one for each district garden, to perform the estimative metric calculation that quantifies the actual turf surface of the Garden itself and assigns its maintenance cost based on the type of processing. From 2017 a pilot project has been activated on the District 2 of the City of Turin that directly uses the attribute tables of QGIS for the importation of metadata on the WebMap.
The City of Turin launched in 2015 a series of Space Analysis and recalculation of the area managed to public green space. The job was to select all the areolas that made up the garden / green area. ...Once the selection phase has been completed, the shapefile has been saved in a dedicated folder and coded one for each district garden, to perform the estimative metric calculation that quantifies the actual turf surface of the Garden itself and assigns its maintenance cost based on the type of processing. From 2017 a pilot project has been activated on the District 2 of the City of Turin that directly uses the attribute tables of QGIS for the importation of metadata on the WebMap.
The charge transport properties of two fused-ring thienoacenes, (a) the
syn
-isomer of dibenzo-thieno-dithiophene (DBTDT), packing in the solid state with a π–π stacking arrangement and also known as ...bis-benzo-thieno-thiophene (BBTT) and (b) C6-DBTDT, an alkylated derivative, packing in the more conventional herring-bone arrangement, are investigated computationally in the framework of the non-adiabatic hopping mechanism. Charge transfer rate constants are computed within the Marcus–Levich–Jortner formalism including a single effective mode treated quantum mechanically and are injected in a kinetic Monte Carlo scheme to propagate the charge carrier in the crystal. Charge mobilities are computed at room temperature with and without the influence of an electric field and are shown to compare very well with the measured mobilities in single-crystal devices. Both systems show an almost 1D charge transport with C6-DBTDT displaying about a ten times larger mobility value, in agreement with experiment. It is shown that the role of the HOMO-1 orbital is not relevant for BBTT, while it might contribute to a more marked 2D charge transport character for C6-DBTDT.
A theoretical study of the mechanism of intramolecular proton transfer reactions in formamide and thioformamide is presented; the focus is on the characterization of the role of water in the ...reactions. The reaction mechanisms was analyzed with the help of energy profiles in the frame of the reaction force analysis and using the reaction electronic flux to characterize the electronic activity that takes place along the reaction. Bader’s quantum theory of atoms in molecules is used to confirm the reaction mechanism and help elucidate the specific role of water. Results at the DFT/B3LYP 6-311G** level of theory show that water catalyzes the proton transfer reaction lowering the activation energy by a factor of two. The reaction force analysis allowed the characterization of activation energies, indicating that in all four reactions, it is mostly due to structural reordering.
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