Search results for "absorptio"

Mushrooms as biomonitors of heavy metals contamination in forest areas

2018

The aim of the research was to assess the level of contamination with heavy metals (manganese, iron, nickel, copper, zinc, cadmium and lead) in two forest areas selected in different places in Poland: the first one in the Swietokrzyskie Province (forests of the Staporkow Forest Division) and the second one in the Opolskie Province (forests of the Kup Forest Division). The degree of contamination of these forest areas with analytes was found using edible large-fruited mushrooms naturally occurring there - the research was carried out using passive biomonitoring method. Heavy metals in mushrooms (separately in stems and hats) as well as in soil samples were determined by atomic absorption spe…

Effect of air-absorbed oxygen and moisture on the chemical stability of photoexcitedMg,ZnandEuphthalocyanines in dimethylformamide

2006

Absorption of oxygen and moisture from air by MPc-DMF systems was studied and related to the molecular stability demonstrated by phthalocyanine complexes (unsubstituted MPc's : MgPc , ZnPc and EuPc2; Pc = phthalocyanine ligand, C32H16N8) subjected to UV irradiation. A lower stability of air-exposed dimethylformamide solutions is observed and is due to a specific affinity for molecular oxygen revealed by the Pc macrocycle. SEM results proved oxygen molecules fixed to the phthalocyanine solids by forces strong enough to sustain desorption under vacuum. Absorption curves determined for MPc-DMF systems also indicate oxygen accommodated by the phthalocyanine moiety. This explains the predominant…

Recent advances in ground-based ultraviolet remote sensing of volcanic SO2 fluxes

2011

Measurements of volcanic SO2 emission rates have been the mainstay of remote-sensing volcanic gas geochemistry for almost four decades, and they have contributed significantly to our understanding of volcanic systems and their impact upon the atmosphere. The last ten years have brought step-change improvements in the instrumentation applied to these observations, which began with the application of miniature ultraviolet spectrometers that were deployed in scanning and traverse configurations, with differential optical absorption spectroscopy evaluation routines. This study catalogs the more recent empirical developments, including: ultraviolet cameras; wide-angle field-of-view differential …

Structural analysis, phase stability and electrochemical characterization of Nb doped BaCe0.9Y0.1O3−x electrolyte for IT-SOFCs

2012

Abstract To improve the chemical stability of high temperature proton conductors based on barium cerate, electrolyte powders doped with different amounts of niobium were synthesized by the citrate–nitrate auto-combustion method. Pure single phases of BaCe 0.9− x Nb x Y 0.1 O 3− x (BCYN, 0.03 ≤  x  ≤ 0.12) were obtained by thermal treatment at 1000 °C. Sintering at 1450 °C for 10 h produced dense pellets. X-ray absorption spectroscopy allowed to define the dopant ion insertion site and the co-dopant valency. Treatments in pure CO 2 atmosphere at 700 °C for 3 h and subsequent XRD analysis were carried out to probe the chemical stability of the produced electrolytes. The influence of the prese…

Spectroscopic Properties of Holmium-Aluminum- Germanium Co-doped Silica Fiber

2020

We report the basic spectroscopic properties of a home-made holmium-aluminum-germanium co-doped silica fiber, designed for laser applications. We present the ground-state and excitedstate absorption spectra of the fiber along with the upconversion emission spectrum under laser action, which served for making an energy levels’ diagram of Ho3+ ion. We discuss the ways to assess the kinetics of Ho3+ 2-μm fluorescence, focusing on measuring fluorescence lifetime from 5I7 level and nonradiative decay time from 5I6 level. The simple analytical formulae, applicable for fitting of the fluorescence decay curve, are derived, which can be useful for precise modeling of holmiumdoped fiber lasers. PID20…

Efficacy of oral pancreatic enzyme therapy for the treatment of fat malabsorption in HIV-infected patients

2001

Cladding-Pumped Er/Yb-Co-Doped Fiber Amplifier for Multi-Channel Operation

2022

The Institute of Solid State Physics, University of Latvia, as a Center of Excellence, has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2. We express our gratitude to rer. nat. Nicoletta Haarlammert from Fraunhofer Institute for Applied Optics and Precision Engineering IOF for the refractive index measurements of ytterbium/erbium-co-doped fibers. This work is supported by the European Regional Development Fund project No. 1.1.1.1/18/A/068.

The Assessment of Heavy Metal Contamination of the Cultivated Soils in the Odra River Floodplain

2021

Abstract The aim of the study was to assess the contamination of selected heavy metals in cultivated soils of the Odra river floodplain. The heavy metals Mn, Fe, Cu, Zn, Ni, Cd and Pb were determined in soil samples collected in the autumn of 2020 - after the vegetation period of plants from designated measurement points. Concentrations of the analytes were measured using an atomic absorption spectrometer (F-ASA). A comparison was made between concentrations of heavy metals in soil samples collected from areas flooded in 1997 and from areas flooded as a result of rainfall, snowmelt and winter floods. The results of the studies were compared with the data for soils taken from non-flooded are…

Développement de l'acceptabilité des aliments solides. A partir de quel âge les morceaux sont-ils acceptés par l'enfant sain ?

2019

Les aliments solides sont proposés aux nourrissons vers 4-6 mois, lorsque leurs besoins nutritionnels ne peuvent plus être uniquement assurés par le lait. Ces aliments (fruits, légumes, produits céréaliers…) sont généralement proposés sous forme de purée ou de bouillie. Au fil des mois, les purées sont ensuite remplacées par des textures de plus en plus consistantes et dures, permettant à l'enfant d'apprendre progressivement à manger les aliments de la table familiale. Cet apprentissage est dépendant du développement des capacités masticatoires de l'enfant, particulièrement dynamique dans la petite enfance. En effet, pour accepter un aliment, l'enfant doit être capable de le manger. Si, à l…

The Effect of Some Commercial Fibers on Dough Rheology

2011

Bread is largely consumed and could be used as a carrier for different nutrients. Fibers play an important role in human nutrition but the bread are depleted in this nutrient. For fibers, supplementation could be used different sources. The fibers needed to be tested before their use in breadmaking. This work investigates how some commercial fibers (Exafine, Apple AF12, Potato KF 200, Oat HF 200 and Wheat WF400) influence the rheology of dough at 10 and 15 % addition. All fibers increased the water absorption and development time because of competition for water between fibers and flour component. Product Apple AF12 deteriorates the dough rheology by dough stability reduction and increases …