Search results for " NIR"

Nanomateriales basados en lantánidos: caracterización y visualización

2022

Las nanopartículas upconversion (UCNP) comenzaron a desarrollarse a inicios del presente siglo, generando una gran expectación e interés por sus propiedades fotofísicas particulares. Las UCNP son nanomateriales capaces de producir el fenómeno upconversion (UC) mediante el cual fotones de baja energía (de la región del infrarrojo cercano, NIR) se transforman en fotones de alta energía (en la región del UV-vis). Los principales actores del fenómeno son los iones lantánidos que se encuentran como dopantes de una matriz nanométrica transparente. Por tanto, en las UCNP, a diferencia de las nanopartículas (NP) semiconductoras, el confinamiento nanométrico no es el responsable de las propiedades ó…

Near infrared reflectance spectroscopy (NIRS) characterization of European sea bass (Dicentrarchus labrax) from different rearing systems

2009

The present study aimed to predict by NIRS the proximate chemical composition and some carcass traits of sea bass coming from 11 farms with different rearing systems (extensive, intensive in land-based basins, sea cages) and located in northern (Friuli, Veneto), central (Tuscany) and southern (Puglia and Sicily) Italy. NIRS analysis of freeze dried sea bass fillets gave fairly good predictions of slaughter weight and fillet yield (R2cv=0.48-0.55), while results for carcass yield were poor. NIRS analysis was highly predictive for the condition factor (R2cv=0.790, SECV=0.09) and for water, ether extract and gross energy showing high correlations (R2cv>0.90) with NIR spectral infor- mation and…

Denitrifying microbial communities along a boreal stream with varying land-use

2019

Streams have an important role in regulating nitrogen (N) transportation from terrestrial ecosystems to downstream waters. Here, we examined how catchment land-use affects potential denitrification rates and the function and composition of denitrifier communities in boreal stream sediments, using stable isotope incubations and qPCR and 454-pyrosequencing targeted on nirS, nirK and nosZ genes. Although land-use influenced the water chemistry as higher nitrite + nitrate (NO x − ) concentration at the agriculture-affected sampling point, sediment organic matter content was found to be the key factor in regulating potential denitrification rates. However, the abundance as well as the diversity …

Investigations of methyl lactate in the presence of reverse micelles by vibrational spectroscopy and circular dichroism

2012

Abstract The FT-IR and vibrational circular dichroism (VCD) spectra of ( S )- and -( R )-methyl lactate have been recorded for neat samples and at various concentrations in CCl 4 and DMSO solutions. These spectra are used to analyse the FT-IR and VCD spectra of methyl lactates in presence of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in CCl 4 , where the surfactant molecules are known to form reverse micelles. Some tendency of methyl lactate to interact with AOT micellar aggregates is observed, but not as well defined as previously observed for dimethyl tartrate in analogous circumstances. Besides, near infrared (NIR) absorption and VCD data have been obtained for most of the above system…

A Polish professional real estate intermediary's ethics after the deregulation of the profession

2016

Effect of Heat on the Adsorption Properties of Silica Gel

2012

Published version of an article in the journal: International Journal of Engineering and Technology. Also available from the publisher at: http://www.ijetch.org/papers/416-T886.pdf Open access. Adsorption properties of silica gel have been attributed to the surface hydroxyl groups of silica gel. Some hydroxyl groups are free standing and called free silanol groups. Some are hydrogen bonded to neighbouring silanol groups. Christy has shown that a high silanol number and a balanced concentration proportionality between these two different types of hydroxyl groups is necessary for effective adsorption of water molecules. Thermal treatment of silica gel samples alters the proportions of these g…