Search results for " organic"

Trapping and Reactivity of a Molecular Aluminium Oxide Ion

2019

Aluminium oxides constitute an important class of inorganic compound that are widely exploited in the chemical industry as catalysts and catalyst supports. Due to the tendency for such systems to aggregate via Al‐O‐Al bridges, the synthesis of well‐defined, soluble, molecular models for these materials is challenging. Here we show that reactions of the potassium aluminyl complex K 2 [( NON )Al] 2 ( NON = 4,5‐bis(2,6‐diiso‐propylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethylxanthene) with CO 2 , PhNCO and N 2 O all proceed via a common aluminium oxide intermediate. This highly reactive species can be trapped by coordination of a THF molecule as the anionic oxide complex [( NON )AlO(THF)] ‐ , which …

Low‐Valent Germanylidene Anions: Efficient Single‐Site Nucleophiles for Activation of Small Molecules

2021

Abstract Rare mononuclear and helical chain low‐valent germanylidene anions supported by cyclic (alkyl)(amino)carbene and hypermetallyl ligands were synthesised by stepwise reduction from corresponding germylene precursors via stable and isolable germanium radicals. The electronic structures of the anions can be described with ylidene and ylidone resonance forms with the Ge−C π‐electrons capable of binding even weak electrophiles. The germanylidene anions reacted with CO2 to give μ‐CO2‐κC:κO complexes, a rare coordination mode for low‐valent germanium and inaccessible for the related neutral germylones. These results implicate low‐valent germanylidene anions as efficient single‐site nucleop…

Labile nitrogen, carbon, and phosphorus pools and nitrogen mineralization and immobilization rates at low temperatures in seasonally snow-covered soi…

2006

Surface mineral horizons from four ecosystems sampled in the northwestern Italian Alps were incubated at −3 and +3°C to simulate subnivial and early thaw period temperatures for a seasonally snow-covered area. The soil profiles at these sites represent extreme examples of management, grazed meadow (site M) and extensive grazing beneath larch (site L) or naturally disturbed by avalanche and colonized by alder (site A) and the expected forest climax vegetation beneath fir (site F). Changes in labile pools of nitrogen (N) and phosphorus (P) were active at all sites at both temperatures during 14 days of laboratory incubation. Ammonium was the dominant inorganic form of total dissolved N (TDN),…

SULLA NATURA GIURIDICA DEL RAPPORTO TRA AMMINISTRATORE E SOCIETÀ PER AZIONI

2017

Il presente lavoro analizza la recente pronuncia della Suprema Corte a Sezioni Unite (Cass., 20.01.2017, n. 1545, S.U.) sulla natura del rapporto intercorrente tra amministratore e società di capitali, in cui la Cassazione abbandona la tesi della parasubordinazione per abbracciare quella dell'immedesimazione organica di tipo societario.

Soil carbon in Mediterranean ecosystems and related management problems

2011

Elaborazione e validazione di modelli dell’impatto antropico e dei cambiamenti climatici sulle qualità dei suoli in Sicilia, con particolare attenzio…

Il declino della sostanza organica e l’erosione idrica sono due fattori di rischio di degrado del suolo fra i più diffusi in Sicilia. In che misura è possibile contrastarli modificando le attività antropiche ed in particolare quelle in ambito agricolo? Lo scopo della presente ricerca di dottorato è stato quello di mettere a punto dei modelli che permettessero di spiegare le relazioni esistenti fra le azioni dell’uomo in ambito agricolo con la sostanza organica e con l’erosione idrica nei suoli siciliani, tenendo conto anche del clima. Le due indagini sono state svolte separatamente, in parallelo, in aree agricole della Sicilia occidentale per la sostanza organica, sull’intero territorio sic…

Afforestation and reforestation: the Sicilian case study

2014

In some regions of the world such as the Northern Hemisphere, the abandonment of agricultural land is one of the most widespread forms of land use change. In general, abandonment is followed by colonization by herbaceous and woody plants. Since the 1950s, wide areas of Southern Italy have been afforested for soil conservation improvement. In order to quantify the effects of agricultural abandonment and artificial afforestation on soil organic carbon (SOC), a dataset of 48 Sicilian sites has been analyzed. Because of their high environmental variability, these sites can be considered as representative of Southern Italy and in general of the Mediterranean basin. Soil samples were taken throug…

Improving local soil carbon inventories, IPCC coefficients tuning for vineyard improved management in semi-arid environment

2013

Comparing soil inventory with modelling : Carbon balance in central European forest soils varies among forest types

2018

Forest soils represent a large carbon pool and already small changes in this pool may have an important effect on the global carbon cycle. To predict the future development of the soil organic carbon (SOC) pool, well-validated models are needed. We applied the litter and soil carbon model Yasso15 to 1838 plots of the German national forest soil inventory (NFSI) for the period between 1985 and 2014 to enables a direct comparison to the NFSI measurements. In addition, to provide data for the German Greenhouse Gas Inventory, we simulated the development of SOC with Yasso15 applying a climate projection based on the RCP8.5 scenario. The initial model-calculated SOC stocks were adjusted to the m…

Evaluation of Soil Organic Carbon Storage of Atillo in the Ecuadorian Andean Wetlands

2022

Identifying the SOC levels and revealing the potential of SOC storage of ecosystems difficult to sample and study are necessary contributions to the understanding of the global reserves of SOC. Wetlands store large amounts of SOC within their soils. They have an important role in water regulation and have great biological and floristic diversity. Therefore, this study aimed to assess the SOC stock in Atillo micro-watershed in the Ecuadorian Andean wetlands at two soil depths (0–30 cm and 30–60 cm below ground) and to assess the importance of the ecosystem and its conservation in favor of reducing emissions due to degradation processes. For that, we sampled the study zone with 10…