Search results for "RIZ"
showing 10 items of 9613 documents
How the Combination of Bio-based Polymers and Ionic Liquids in Gel Phases Works for the Desulfurization of Fuels
Ionic Liquids as Homogeneous Catalysts for Glycerol Oligomerization
2022
Ionic liquids (ILs) were used for the first time as catalysts for the glycerin condensation reaction. A series of imidazolium and ammonium ionic liquids differing in the length of the alkyl substituent (C2, C12, and C14) and the type of anion (Br−, CH3COO−, and NaHPO4−) were synthesized using a typical two-step method. The structure of the obtained ILs was confirmed by nuclear magnetic resonance 13C NMR, and their base power was determined on the basis of the Hammett function. The oligomerization of glycerin with the participation of the obtained ionic liquids and, for comparison, in the presence of a homogeneous basic catalyst Na2CO3, was carried out for 3 h at 180 °C, under a pressure of …
Nośnikowy katalizator wanadocenowy z udziałem cieczy jonowych w polimeryzacji etylenu
2018
W pracy zsyntezowano szereg układów SILP z katalizatorem wanadocenowym – Cp2VCl2 poprzez immobilizację cieczy jonowych na różne rodzaje krzemionek, różniących się powierzchnią właściwą i wielkością porów, które modyfikowano wybranym związkiem glinoorganicznym – AlEtCl2 lub AlEt2Cl. Zsyntezowane układy analizowano metodami: FTIR, analiza elementarna, BET, AAS i SEM. Każdy z otrzymanych układów SILP był aktywny w polimeryzacji etylenu, niezależnie od ilości i rodzaju zastosowanego aktywatora (AlEtCl2 lub AlEt2Cl). Najwyższą aktywność w polimeryzacji etylenu osiągnięto wobec układu SILP z udziałem krzemionki o bardzo regularnej morfologii, gdzie do utworzenia etylochloroglinianowych anionów pi…
Bio-based chitosan and cellulose ionic liquid gels: polymeric soft materials for the desulfurization of fuel
2022
Desulfurization of fuel that avoids the introduction in the atmosphere of toxic sulfur volatile compounds, usually formed during combustion, is a viable strategy to reduce pollution. To find new efficient and eco-sustainable adsorbent materials, bio-based polymers such as chitosan (CS), cellulose (CE) and cellulose acetate (CEOAc) were dissolved in ionic liquids (ILs) to form ionic liquid gels (ILGs). Gelling and swelling ability, porosity, morphology, rheology and mechanical response were studied as a function of the polymer and ionic liquid (IL) used. The best performing gels were tested for fuel desulfurization using a fuel mimicking solution of thiophene (T), benzothiophene (BT) and dib…
Commento Artt. 2502 e 2502 bis
2015
The Photocycle of Bacteriophytochrome Is Initiated by Counterclockwise Chromophore Isomerization.
2022
Photoactivation of bacteriophytochrome involves a cis–trans photoisomerization of a biliverdin chromophore, but neither the precise sequence of events nor the direction of the isomerization is known. Here, we used nonadiabatic molecular dynamics simulations on the photosensory protein dimer to resolve the isomerization mechanism in atomic detail. In our simulations the photoisomerization of the D ring occurs in the counterclockwise direction. On a subpicosecond time scale, the photoexcited chromophore adopts a short-lived intermediate with a highly twisted configuration stabilized by an extended hydrogen-bonding network. Within tens of picoseconds, these hydrogen bonds break, allowing the c…
Experimental Confirmation of a Topological Isomer of the Ubiquitous Au25(SR)18 Cluster in the Gas Phase
2021
High-resolution electrospray ionization ion mobility mass spectrometry has revealed a gas-phase isomer of the ubiquitous, extremely well-studied Au25(SR)18 cluster both in anionic and cationic form. The relative abundance of the isomeric structures can be controlled by in-source activation. The measured collision cross section of the new isomer agrees extremely well with a recent theoretical prediction (Matus, M. F.; et al. Chem. Commun. 2020, 56, 8087) corresponding to a Au25(SR)18– isomer that is energetically close and topologically connected to the known ground-state structure via a simple rotation of the gold core without breaking any Au–S bonds. The results imply that the structural d…
Raman spectroscopy of glycolic acid complexes with N2
2019
High overtone excitation induced conformational isomerization of glycolic acid – nitrogen complex in an argon matrix was investigated by Raman spectroscopy. The interaction between glycolic acid and nitrogen change the green light (532 nm) induced isomerization processes compared to non-complexed glycolic acid. The 180° rotation around of the Csingle bondC bond and stabilization of carboxyl Odouble bondCsingle bondOsingle bondH dihedral angle to trans position were the main conformational changes observed in the complex of the lowest energy conformer and nitrogen. Interestingly, only one stable light-induced conformational product was observed, which isomerises back to the lowest energy con…
2.3.4. Il processo di alienazione: Palazzo Barlotta di San Giuseppe e Palazzo Miano
2010
Il processo di alienazione del patrimonio costruito messo in atto dalle pubbliche amministrazioni impossibilitate a far fronte a costi di gestione e manutenzione dei beni in loro possesso ha posto la necessità di indirizzare e controllare i processi di trasformazione cui inevitabilmente i beni alienati saranno sottoposti. Ciò ha imposto che le pubbliche amministrazioni si dotino di nuove procedure e strumenti attraverso cui esercitare l’azione di indirizzo e di controllo sugli interventi previsti in modo da garantire funzioni compatibili e la permanenza dei valori espressi dai beni stessi. Nel contributo si riporta l’iter di alienazione seguito per alcuni immobili di proprietà comunale inse…
Jauktā mācīšanās skolēnu iesaistīšanai angļu valodas stundās 7.klasē
2017
Mūsdienu tehnoloģijas strauji mainās un attīstās, bet izglītības sistēmā un mācīšanas metodēs tik pamanāmas izmaiņas nenotiek. Jauktā mācīšanās apvieno tradicionālo frontālo mācīšanu un datorizēto mācīšanos. Diplomdarba autors izpēta jauktās mācīšanās jēdzienu, analizē dažādus jauktās mācīšanās modeļus un padziļināti koncentrējas uz metodēm, lai iesaistītu skolēnus mācību stundās. Izvēlētā pētījuma metode ir situācijas analīze. Tā izvēlēta, lai izpētītu skolēnu un skolotājas viedokli par jaukto mācīšanos, analizētu divas jauktās mācīšanās stundas un piedāvātu konkrētus pielāgojumus šīs metodes lietošanai Tukuma pamatskolai.