Search results for "carbon"
showing 10 items of 6057 documents
Pyrolytic formation of polycyclic aromatic hydrocarbons from sesquiterpenes
2012
Author's version of an article in the journal: Food Chemistry. Also available from the publisher at: http://dx.doi.org/10.1016/j.foodchem.2012.06.033 The products of the pyrolysis of four sesquiterpenes, β-caryophyllene, α-cedrene, longifolene and valencene, have been examined. Pyrolysis was carried out at 300, 400 and 500 °C, the products determined by GC–MS and then examined for similarities and differences using multivariate data analysis. Analysis showed that longifolene was most resistant and caryophyllene least resistant to pyrolysis with cedrene and valencene occupying intermediate positions. While the compounds were largely unchanged at 300 °C, polycyclic aromatic hydrocarbons (PAHs…
Amorphous silicon nanotubes
2017
In the following, the attention will be focused on the silicon nanotube (SiNTs) that is a highly desired form of silicon for its fundamental role in the miniaturization trend of the electronic devices. After a description of the properties and applications of SiNTs and their fabrication methods, the attention will be focused on chemical vapour deposition (CVD) template synthesis that is the most usual synthetic method for this material. Then, galvanic template synthesis will be described as a general method for the fabrication of different metals and oxides nanostructures, therefore the use of this technique for synthesizing SiNTs will be detailed. Characterization methods will be also desc…
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…
Osservazioni fitosociologiche su aspetti di vegetazione a Prunus mahaleb subsp. cupaniana (Rosaceae) dei Monti Madonie (Sicilia)
2010
Zinc Adsorption by Activated Carbon Prepared from Lignocellulosic Waste Biomass
2019
Sawdust was used as a precursor for the production of biomass-based activated carbon. Carbonization and activation are single-stage processes, and steam was used as a physical activation agent at 800 °
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 …
Extraordinary Performance of Carbon‐Coated Anatase TiO 2 as Sodium‐Ion Anode
2015
The synthesis of in situ polymer‐functionalized anatase TiO2 particles using an anchoring block copolymer with hydroxamate as coordinating species is reported, which yields nanoparticles (≈11 nm) in multigram scale. Thermal annealing converts the polymer brushes into a uniform and homogeneous carbon coating as proven by high resolution transmission electron microscopy and Raman spectroscopy. The strong impact of particle size as well as carbon coating on the electrochemical performance of anatase TiO2 is demonstrated. Downsizing the particles leads to higher reversible uptake/release of sodium cations per formula unit TiO2 (e.g., 0.72 eq. Na+ (11 nm) vs only 0.56 eq. Na+ (40 nm)) while the …
Influence of Calcium Carbonate Nanoparticles on the Soil Burial Degradation of Polybutyleneadipate-Co-Butylenetherephthalate Films.
2022
A polybutyleneadipate-co-butylenetherephthalate (PBAT) sample, commercially known as Ecoflex®, was processed via melt extrusion with CaCO3 nanoparticles coated with a hydrophobic coating. Blown films of PBAT and two composites with nanofiller (2% and 5%wt) were prepared and degradation tests in soil at 30 °C up to 180 days were carried out with weight loss measurements. Furthermore, biodegradation test according to ISO 14851 was carried out at 30 °C. The effect of CaCO3 on soil burial degradation was assessed by surface wettability and SEM. ATR-FTIR and XPS analyses highlighted chemical modifications induced by soil degradation. CaCO3 nanoparticles decreased surface wettability …
An analysis of carbon storage protected areas with relation to agroforestry management and biodiversity
2008
This work investigated the role of land cover and land use change (LUC) as a soil ability to store carbon and reduce carbon dioxide emission in a Mediterranean area. Using a paired site approach we estimated the effect of land cover change on the carbon stock from 1972 to 2008 in a natural reserve (Grotta di S. Ninfa) in the West of Sicily. Fifteen paired sites representative of five land use change were selected. We studied the effect of land use on soil organic carbon (SOC) content in bulk soil and 2000-1000 µm, 1000-500 µm, 500-250 µm, 250-63 µm, 63-25 µm and <25 µm size fractions. Furthermore, laboratory incubation of the soil samples was conducted to measure carbon dioxide evolution in…