Search results for " transition"
showing 10 items of 2751 documents
GÉOCARREFOUR KEY WORDS Local level development planning, night-time, light pollution, branding, energy transition
2015
La pollution lumineuse est progressivement devenue un enjeu environnemental. Elle produit ainsi de nouveaux périmètres pour l’action publique, dans un contexte de transition énergétique incitant à modifier les pratiques d’éclairage public pour protéger la « nuit noire ». Pour les territoires de faible densité, cette vision renouvelée de la nuit constitue une « aubaine » en termes de développement territorial. Des processus différenciés de protection, de labellisation et de mise en tourisme des « ressources environnementales nocturnes » émergent, devenant ainsi un levier de la transition énergétique. For several decades, the negative impacts of artificial light on environmental mechanisms ha…
RISCALDAMENTO GLOBALE E CITTÀ L’incremento della vegetazione e la progettazione urbana, tra non finito e paesaggio urbano
2023
Il contributo mette a fuoco l’interazione fra la progettazione urbana e le strategie per il contenimento del riscaldamento globale costruendo un ragionamento che partendo dall’eredità del Movimento Moderno, include gli esiti delle ricerche più recenti. Da tale base di partenza scientifica emerge come protagonista la tesi fondata sull’aumento della vegetazione in ambito urbano, come strumento indispensabile alla mitigazione delle temperature. Tale proposta trova, nel corso dell’approfondimento, una verifica sperimentale attraverso alcune concrete esperienze di progettazione che coniugano l’obiettivo ambientale avendo cura, al contempo, della qualità degli spazi dell’abitare. I progetti dimos…
Riflessioni e traiettorie di ricerca interdisciplinari sulla transizione ecologica
2023
Il volume 13 di AGATHÓN segue il precedente sulla Innovability©® | Transizione Digitale e raccoglie saggi e ricerche su Innovability©® | Transizione Ecologica, consapevole della sua incalzante attualità, ma anche del portato che la proposta di una doppia chiave di interpretazione suggerisce. I contributi del volume ci consegnano riflessioni e traiettorie di ricerca basate sulla necessità di una natura multiscalare degli interventi, che garantisca effetti indotti a un contesto ambientale più ampio di quello di riferimento, e di team che affrontino le criticità con un approccio collaborativo inter e transdisciplinare olistico e sistemico, in una sorta di speciazione delle discipline che ne mo…
Russia’s economy in the global crisis: An assessment of the Medvedev era
2011
This article analyses the state of the Russian economy during Dmitri Medvedev’s term of office (March 2008 to the present). The author begins by examining the country’s situation before the new president officially took up his post, after which the article goes on to describe the reforms the government subsequently attempted to bring in. These reforms were determined by the outbreak of a severe economic crisis that commenced in 2008 and which highlighted the structural problems ailing Russia’s economy. These problems, which the author describes in detail, may turn into very grave obstacles to the country’s sustained, long-term growth. Finally, the author describes the essential economic sec…
Optical investigation of spin-crossover in cobalt(II) bis-terpy complexes
2007
Abstract The spin transition of the [Co(terpy) 2 ] 2+ complex (terpy = 2,2′:6′,2″-terpyridine) is analysed based on experimental data from optical spectroscopy and magnetic susceptibility measurements. The single crystal absorption spectrum of [Co(terpy) 2 ](ClO 4 ) 2 shows an asymmetric absorption band at 14 400 cm −1 with an intensity typical for a spin-allowed d–d transition and a temperature behaviour typical for a thermal spin transition. The single crystal absorption spectra of suggest that in this compound, the complex is essentially in the high-spin state at all temperatures. However, the increase in intensity observed in the region of the low-spin MLCT transition with increasing te…
High-spin → low-spin relaxation in the two-step spincrossover compound [Fe(pic)3]Cl2EtOH (pic = 2-picolylamine)
1998
Abstract The spin-crossover compound [Fe(pic) 3 ]Cl 2 EtOH (pic = 2-picolylamine) shows an unusual two-step spin transition. This is thought to be caused by specific nearest-neighbour interactions and short-range correlations and requires a theoretical treatment of the elastic interactions between the spin-changing molecules beyond the mean-field approximation. Such short-range correlations also influence the high-spin → low-spin relaxation following the light-induced population of the high-spin state at cryogenic temperatures, leading to characteristic deviations from the predictions of a mean-field treatment. These deviations are directly observable by comparison of the full and unperturb…
The [Fe(etz)6](BF4)2 Spin-Crossover System—Part One: High-Spin ⇌ Low-Spin Transition in Two Lattice Sites
1996
The [Fe(etz),](BF,), spin-cross-over system (etz = 1-ethyl-1 H-tetrazole) crystallizes in space group P1, with the following lattice constants at 298 K: a 10.419(3), b=15.709(1), c = 18.890(2) A = = 71.223(9), =77.986(10), and = 84.62(1)° V = 2862.0(9) A3 and Z = 3. Two nonequivalent lattice sites, one without (site A) and one with (site B) inversion symmetry, are observed. The population of the two sites nA:nB is 2:l. Iron(II) on site A undergoes a thermal low-spin (LS) high-spin (HS) transition with T1/2I, = 105 K. whereas that on site B remains in the high-spin state down to cryogenic temperatures. Application of external pressure of up to 1200 bar between 200 and 60 K does not cause for…
A new 3-D polymeric spin transition compound: [tris(1,4-bis(tetrazol-1-yl)butane-N1,N 1′)iron(II)] bis(perchlorate)
2001
A series of novel polymeric compounds of formula [M(btzb)3][ClO4]2 (Mll = Fe, Ni or Cu) with btzb = 1,4-bis-(tetrazol-1-yl)butane have been prepared and their physical properties investigated. The btzb ligand has been prepared and its crystal structure determined, together with a tentative crystal structure of the 3-D compound [Fe(btzb)3][ClO4]2. The model of the latter shows two symmetry-related, interpenetrating Fe-btzb networks in which the iron(II) ions approach each other as close as 8.3 and 9.1 A. This supramolecular catenane undergoes a sharp thermal spin transition around 160 K with hysteresis (20 K) along with a pronounced thermochromic effect. The spin crossover behaviour has been…
Low-lying electromagnetic transition strengths in 180 Pt
2018
Lifetime measurements have been performed using the 98 Mo ( 86 Kr , 4 n ) 180 Pt reaction at a beam energy of 380 MeV, and the recoil distance Doppler-shift method. In a second experiment the 168 Yb ( 16 O , 4 n ) 180 Pt reaction at a beam energy of 88 MeV using the Ge-gated γ − γ fast timing technique was used to determine lifetimes. Lifetimes of the four lowest yrast states of 180 Pt have been determined. The experimental data are compared to calculations within the framework of the interacting boson model and the general collective model. Both models predict a deformed ground state and are consistent with all the remaining experimental results. peerReviewed
β-decay rates of 115,117Rh into 115,117Pd isotopes in the microscopic interacting boson-fermion model
2020
The structure of odd-A 115,117Rh and 115,117Pd isotopes is studied by means of the neutron-proton interacting boson-fermion model (IBFM-2). JP=12+ quantum number assignment for the 115,117Pd ground states is critically discussed and the predicted energy levels are compared to the existing experimental data. The resulting nuclear wave functions are used to compute the β-decay ft values of the transitions from 115,117Rh to 115,117Pd in the microscopic IBFM-2 and the results compared with the data. peerReviewed