30 research outputs found
Mining Big Data for Tourist Hot Spots: Geographical Patterns of Online Footprints
Understanding the complex, and often unequal, spatiality of tourist
demand in urban contexts requires other methodologies, among which the information base available online and in social networks has gained prominence. Innovation
supported by Information and Communication Technologies in terms of data access
and data exchange has emerged as a complementary supporting tool for the more traditional data collection techniques currently in use, particularly, in urban destinations
where there is the need to more (near)real-time monitoring. The capacity to collect
and analise massive amounts of data on individual and group behaviour is leading to
new data-rich research approaches. This chapter addresses the potential for discovering geographical insights regarding tourists’ spatial patterns within a destination,
based on the analysis of geotagged data available from two social networks.
·info:eu-repo/semantics/publishedVersio
Diagnosing When Evidence of Bias Is Problematic: Methodological Cookbooks and the Unfortunate Complexities of Reality
T1954 Pre-Endoscopic Proton Pump Inhibitors in Non-Variceal Upper Gastrointestinal Bleeding; Continuous Infusion vs. Bolus
Group VI Metal Carbonyl Complexes of Bis((diphenylphosphino)methyl)diphenylborate and an Assessment of Their Utility for Template Ligand Syntheses
Zerovalent
group VI metal chemistry of anionic bis((diphenylphosphino)methyl)diphenylborate
(Ph<sub>2</sub>BP<sub>2</sub>) offers some surprises in comparison
to the chemistry of analogous complexes of neutral bidentate phosphines.
The enhanced donor ability of Ph<sub>2</sub>BP<sub>2</sub> relative
to related bis-PPh<sub>2</sub> ligands is confirmed by IR spectral
analysis of [ASN][M(CO)<sub>4</sub>(Ph<sub>2</sub>BP<sub>2</sub>)]
(ASN = 5-azoniaspiro[4.4]nonane; M = Cr, Mo, W). The mononitriles
[ASN][<i>fac</i>-M(CO)<sub>3</sub>(RCN)(Ph<sub>2</sub>BP<sub>2</sub>)] (M = Cr, R = Me; M = Mo, R = Et; M = W, R = Et) are useful
reagents for the introduction of sulfur dioxide and isocyanides to
the π-basic M(CO)<sub>3</sub>(Ph<sub>2</sub>BP<sub>2</sub>)
fragment. While the fundamental coordination chemistry of this anionic
fragment mostly mirrors that of its conventional neutral cousins,
the electronic impact of Ph<sub>2</sub>BP<sub>2</sub> leads to divergent
reactivity in some cases. For example, the sulfur dioxide complexes
[ASN][<i>mer</i>-M(CO)<sub>3</sub>(SO<sub>2</sub>)(Ph<sub>2</sub>BP<sub>2</sub>)] (M = Mo, W) are unreactive toward CH<sub>2</sub>N<sub>2</sub>, dramatically different from the case for <i>mer</i>-M(CO)<sub>3</sub>(SO<sub>2</sub>)(L<sub>2</sub>) (L<sub>2</sub> = dppm, dppe, dppp). The spectral data of [ASN][Mo(CO)<sub>3</sub>(CNC<sub>6</sub>H<sub>4</sub>(2-NH<sub>2</sub>))(Ph<sub>2</sub>BP<sub>2</sub>)] and [ASN][Mo(CO)<sub>3</sub>(CNCH<sub>2</sub>CH<sub>2</sub>NH<sub>2</sub>)(Ph<sub>2</sub>BP<sub>2</sub>)], salts containing
the first anions of 2-aminophenyl isocyanide and 2-aminoethyl isocyanide,
respectively, indicate that the anionic M(CO)<sub>3</sub>(Ph<sub>2</sub>BP<sub>2</sub>) fragment may be more useful than neutral M(CO)<sub>3</sub>(dppe) for the π-back-bonding induced stabilization
of ligands prepared via template syntheses