Search results for " organic"

Dynamics of soil organic matter pools after agricultural abandonment

2014

Changes of land use from croplands to natural vegetation usually increase Carbon (C) stocks in soil. However, the contribution of old and new C to various pools still is not clearly analyzed.We measured the 13C signature of soil organic carbon (SOC) pools after vegetation change from vineyard (C3) to grassland (C4) under Mediterranean climate to assess the changes of old and new C in total SOC, microbial biomass (MB), dissolved organic C (DOC), and CO2 efflux from soil. Development of the perennial grass Hyparrhenia hirta (C4) on vineyard abandoned for 15 or 35 years ago increased C stocks for 13% and 16%, respectively (in the upper 15 cm). This increase was linked to the incorporation of n…

Supramolecular aggregation of bis-imidazolium functionalised perylene bisimides

Ionic self assembly in the design of fluorinated ionic liquid crystals (ILCs)

2011

Ionic liquid crystals are a class of compounds containing anions and cations, that combine the properties of liquid crystals and ionic liquids[1]. In the conventional design of ionic liquid crystalline compounds, an ionic core is connected with mesogenic groups via chemical covalent bonding . Alternatively, in ionic compounds, strong electrostatic interactions between cation and anion can be used to build up liquid crystalline order at supramolecular level. This general approach, called ionic self-assembly (ISA), allows one to create ionic phases and mesophases with highly organized supramolecular order [2]. In this context, a new series of fluorinated ionic liquids (ILs) and ionic liquid c…

Entrapment of a linear water pentamer into a uranyl-salophen dimer in the solid state

2019

In the solid state, uranyl-salophen complex 1, decorated with bipyridyl sidearms, self-assembles from moist acetonitrile into dimeric species displaying a confined water pentamer, as observed by X-...

Low cost, efficient hybrid solar cells

2017

Actualmente, existen diversas estrategias para producir energía limpia mediante fuentes renovables, pero es la explotación directa de la energía del Sol la que se presenta como una solución ideal, siendo la mayor fuente de energía verde en la Tierra. La potencia de la energía solar que llega a la Tierra cada año es del orden de 86000 TW (Terawatt, 1012 Watt). Esto representa 4800 veces la demanda energética anual del mundo, estimada en 18 TW. Además, todos los depósitos de energía fósil reconocidos (petróleo, carbón y gas) contienen todos juntos tan sólo una cantidad de energía equivalente a la recibida del Sol durante 56 días. Esta situación muestra claramente la necesidad de aprovechar es…

Nature in vendita. Il packaging dei prodotti biologici

2012

Questo contributo indaga il funzionamento semiotico del packaging dei prodotti del mercato biologico. Tanti prodotti, tante marche, tanti pack che hanno in comune la naturalità come fi lo conduttore, una massa eteroclita che dice e ri-dice sempre lo stesso concetto di fondo. Ma come lo mette in forma? Quali sostanze specifi che vengono prodotte a livello del contenuto? E quali soggettività vengono delineate dal punto di vista narrativo ed enunciativo? Quali tipi di consumatori? Qui mi concentrerò su alcuni packaging alimentari, come confezioni per pasta, biscotti e altri prodotti di uso comune, prendendo in considerazione alcune delle marche più diffuse nei negozi specializzati bio.

Cytotoxic Effect of Eudesmanolides Isolated from Flowers of Tanacetum vulgare ssp. siculum

2012

WOS: 000306752700042

Study of the Stability of Citrate Capped AgNPs in Several Environmental Water Matrices by Asymmetrical Flow Field Flow Fractionation

2021

Asymmetrical flow field-flow fractionation (AF4) coupled to UV-Vis and dynamic light scattering (DLS) detectors in series, was tested for stability studies of dispersions of citrate-capped silver nanoparticles (AgNPs) in several water matrices. The main goal is to provide knowledge to understand their possible behavior in the environment for short times since mixturing (up to 180 min). Ultrapure (UPW), bottled (BW1, BW2), tap (TW), transitional (TrW) and sea water (SW) matrices were assayed. Observations were compatible with the aggregation of AgNPs, a change in the plasmon band and a size growth with time were done. Fractograms showed different evolution fingerprints in the function of the…

Synthesis and characterization of Zwitterionic Zn(II) and Cu(II) coordination compounds with ring-substituted 2,2′-biimidazole derivatives

2016

Zwitterionic coordination compounds with strongly asymmetrical charge distribution were synthesized and characterized. Ring-substituted biimidazoles were used as the primary ligands for Zn and Cu compounds. Formation of Zwitterionic coordination compound was found to be strongly dependent on the pH of the reaction medium as well as on the ring and nitrogen substituents of the ligand. Reaction of the Df-R2biim (Df-R2biim = 2,2′-bi-1R-imidazole-5,5′-dicarboxaldehyde, R = Me, Et or Pr) with ZnCl2 in neutral conditions led to binuclear compounds [Zn2Cl4(Df-R2biim)2] with two bridging ligands (1a–c). Reaction with CuCl2·2H2O gave neutral mononuclear compound [CuCl2(Df-Me2biim)] (1d) with chelati…

Carbon Monoxide Activation by a Molecular Aluminium Imide: C−O Bond Cleavage and C−C Bond Formation

2020

Anionic molecular imide complexes of aluminium are accessible via a rational synthetic approach involving the reactions of organo azides with a potassium aluminyl reagent. In the case of K 2 [( NON )Al(NDipp)] 2 ( NON = 4,5‐bis(2,6‐di iso propylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethyl‐xanthene; Dipp = 2,6‐di iso propylphenyl) structural characterization by X‐ray crystallography reveals a short Al‐N distance, which is thought to be due primarily to the low coordinate nature of the nitrogen centre. The Al‐N unit is highly polar, and capable of the activation of relatively inert chemical bonds, such as those found in dihydrogen and carbon monoxide. In the case of CO, uptake of two molecules of …