Search results for "element"

Key challenges of new and small virtual team

2007

The purpose of this thesis is to study the factors must be noticed when building a new and small virtual team. These virtual teams are groups of people who work together without the boundaries of time or space using technology (Lipnack & Stamps 2000, 18). The main goal is to study in detail some of the common challenges faced when working with the small virtual teams, especially in the early stages of team development. With this study and the results of it, the reader is aware of the challenges of virtual teams and the differences and similarities between traditional and virtual teams. In addition the reader knows also some factors that must be noticed when a new small virtual team is suppo…

Addition of Ethylene or Hydrogen to a Main-Group Metal Cluster under Mild Conditions

2015

Reaction of the tin cluster Sn8(Arinline image)4 (Arinline image=C6H2-2,6-(C6H3-2,4,6-Me3)2) with excess ethylene or dihydrogen at 25 °C/1 atmosphere yielded two new clusters that incorporated ethylene or hydrogen. The reaction with ethylene yielded Sn4(Arinline image)4(C2H2)5 that contained five ethylene moieties bridging four aryl substituted tin atoms and one tin–tin bond. Reaction with H2 produced a cyclic tin species of formula (Sn(H)Arinline image)4, which could also be synthesized by the reaction of {(Arinline image)Sn(μ-Cl)}2 with DIBAL-H. These reactions represent the first instances of direct reactions of isolable main-group clusters with ethylene or hydrogen under mild conditions…

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…

THE IMPACT OF VOLCANIC EMISSIONS ON ETNA’S SNOW COVER

2011

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),…

Soil carbon in Mediterranean ecosystems and related management problems

2011

Solai in legno e gesso

2010

Terzo di una sequenza di tre articoli con i primi esiti di uno studio condotto al fine di sviluppare ipotesi progettuali per una particolare tipologia di solaio con struttura in legno lamellare, casseri di alleggerimento in conglomerato di gesso e aggregati, nonché finiture prevalentemente in gesso e in materiali a basso costo. Si presentano gli esiti progettuali: dal sistema nel suo complesso allo studio dei dettagli più minuti e delle modalità di posa in opera. L’ambito produttivo a cui si riferisce il sistema è soprattutto quello dell’intervento sull’esistente: esso presenta problematiche tecniche specifiche cui il sistema potrebbe far fronte e predilige la scelta di operare nell’ambito …

Use of peat-based sorbents for removal of arsenic compounds

2013

Abstract It is important to apply sorbent materials for purification of water from arsenic contamination due to serious arsenic pollution worldwide. We have developed new sorbents based on natural materials that provide a cheap and environmentally friendly alternative. For the first time, peat modified with iron compounds and iron humates were tested for sorption of arsenic compounds. The highest sorption capacity was found in peat modified with iron compounds. We have found that sorption of different arsenic speciation forms was strongly dependent on solution pH, reaction time and temperature. Calculations of the sorption process using thermodynamic parameters indicate the spontaneity of s…

Numerical simulation of fluid-structure interaction between acoustic and elastic waves

2011

Pd2Au36(SR)(24) cluster: structure studies

2015

The location of the Pd atoms in Pd2Au36(SC2H4Ph)(24), is studied both experimentally and theoretically. X-ray photoelectron spectroscopy (XPS) indicates oxidized Pd atoms. Palladium K-edge extended X-ray absorption fine-structure (EXAFS) data clearly show Pd-S bonds, which is supported by far infrared spectroscopy and by comparing theoretical EXAFS spectra in R space and circular dichroism spectra of the staple, surface and core doped structures with experimental spectra.