Search results for " Stab"
showing 10 items of 1773 documents
Coupling tyrosol, quercetin or ferulic acid and electron beam irradiation to cross-link chitosan–gelatin films: A structure–function approach
2015
International audience; Marine industry by-products, chitosan and fish gelatin, entrapping natural antioxidants (ferulic acid, quercetin and tyrosol) were used to prepare edible active films by casting. The films were composed of chitosan and fish gelatin (1:1 w:w) and incorporating antioxidants (∼50 mg/g). After solvent evaporation (drying), the films were irradiated at 60 kGy by electron beam. This treatment aims at investigating the coupled effect of irradiation with the presence of active compound on the structure and functional properties of the films. Electron Spin Resonance (ESR) unravelled free radical formation during irradiation in films containing ferulic acid or tyrosol which fa…
Koherentu procesu lāzeru spektroskopijas pētījumi sārmu metālu atomos un molekulās
2014
Promocijas darbs veltīts Zēmana koherenču atomu un molekulu elektroniskajos pamatstāvokļos veidošanas un sabrukšanas teorētiskajai un eksperimentālajai izpētei ar nelineārās spektroskopijas metodēm. Pirmkārt, tiek ziņots polarizācijas modulācijas pētījums, ierosinot D1 pārejas ar Cs tvaikiem pildītā šūnā. Otrkārt, izstrādāta spektroskopijas metode magnētiskā lauka stipruma divdimensiju sadalījuma kartēšanai, izmantojot fluorescences sadalījuma reģistrēšanu. Treškārt, veikts nelineāro magneto-optisko rezonanšu pētījums K2 molekulas pamatstāvoklī ar lielām leņķiskā momenta kvantu skaitļa J~100 vērtībām. Lai uzlabotu diožu lāzera ilgtermiņa frekvences stabilitāti, izstrādāta frekvences divmodu…
Reconstruction of human subsistence and husbandry strategies from the Iberian Early Neolithic: A stable isotope approach
2018
Objectives The Early Neolithic involved an important social and economic shift that can be tested not only with the material culture, but also through biomolecular approaches. The Iberian Peninsula presents few Early Neolithic sites where fauna and humans can be analyzed together from an isotopic perspective. Here we present an isotopic study on the site of Cueva de Chaves as an example for understanding the dietary and economical changes that took place during Early Neolithic in Iberia. Material and methods Here we apply carbon and nitrogen stable isotope analysis to bone collagen from 4 humans and 64 faunal samples from 14 different species. The large dataset belongs to the same unique ch…
Distributed $n$-player approachability and consensus in coalitional games
2015
We study a distributed allocation process where, at each time, every player: i) proposes a new bid based on the average utilities produced up to that time, ii) adjusts such allocations based on the inputs received from its neighbors, and iii) generates and allocates new utilities. The average allocations evolve according to a doubly (over time and space) averaging algorithm. We study conditions under which the average allocations reach consensus to any point within a predefined target set even in the presence of adversarial disturbances. Motivations arise in the context of coalitional games with transferable utilities (TU) where the target set is any set of allocations that makes the grand …
Light hydrocarbons as a proxy to identify the origin of the gas manifestations in Greece
2017
The geologic emissions of greenhouse gases (CO2 and CH4) have an important natural contribution in the global carbon budget. Tectonics, through faults in geothermal and oil producing areas, play a significant role in the release of C-gases in many non-volcanic regions of the Earth. Methane, the most abundant organic compound in Earth’s atmosphere, has a potential global warming that is 28 times higher than that of CO2 on a 100-year time horizon. In this study, δ13C-CH4, δ2H-CH4 and light hydrocarbon (alkane: CH4, C2H6, C3H8, C3H6, i-C4H10, n-C4H10; alkene C3H6, iC4H8; and aromatic C6H6) gas concentration data of 119 gas samples (103 unpublished data and 16 literature data) from volcanic-hyd…
Mineralogy of the soils altered by fumarolic activity at Nisyros volcano, Greece
2017
Nisyros is the easternmost island of the South Aegean Active Volcanic arc in Greece. It is an active stratovolcano known for its intense hydrothermal activity. In this study we present the results of the mineralogical analyses of 20 soil samples collected in the caldera area. Samples were analysed through X-ray diffraction and the results allow us to divide them in two groups: Lakki Plain and Stefanos Crater. In their majority the soils of Lakki Plain have a main mineralogical assemblage that consists of quartz, feldspar and gismondine (Ca2Al4Si4O16·9H2O). Gismondine as well as stellerite (CaAl2Si7O18·7H2O), which is appearing in some samples, derive from hydrothermal alteration, whilst wol…
Supramolecular Hydro- and Ionogels: A Study of Their Properties and Antibacterial Activity.
2017
Diimidazolium-based organic salts, bearing peptides or amino acids as anions have been synthesised and tested for their gelling ability in biocompatible solvents. These low molecular weight salts were successfully used as gelators in phosphate buffered saline (PBS) solution and ionic liquids. Then, the properties of the obtained soft materials were analysed in terms of melting temperature and gel strength as accounted for by rheological investigations. The gel-phase formation was studied by using UV/Vis and resonance light scattering measurements, whereas the morphology of the soft materials was analysed by using polarised optical microscopy and scanning electron microscopy. To get informat…
Video display terminal use and dry eye: preventive measures and future perspectives
2022
Background: Dry eye disease (DED) is a common cause of ocular pain and discomfort. Dry eye disease (DED) stems from a loss-of-tear film homeostasis and is frequently seen in video display terminal (VDT) users. Video display terminal (VDT) use reduces blink rates and increases incomplete blinks, leading to tear film instability and ocular inflammation, promoting DED. Purpose: To assess and evaluate the methods for preventing VDT-associated DED and ocular discomfort. Methods: Studies were found using PubMed and Embase with the search terms: (digital visual terminal* OR computer use OR screen use OR smartphone OR display OR visual display terminal* OR computer vision syndrome OR tablet OR phon…
Some Considerations on 3-D and 2-D Numerical Models for the Assessment of the Stability of Underground Caves
2014
The application of numerical modeling to the analysis of the stability of both natural and man-made underground caves is rapidly increasing due to the availability of powerful numerical codes, that can account for either continuum or discontinuum behavior of the rock masses. Numerical methods allow to overcome traditional methods for cave stability analysis that assume too simplified geometrical, geological and geomechanical conditions. Further, they are also able to assess the potential failure mechanisms of underground systems. On the other hand, the application of numerical methods requires availability of a detailed geo-structural survey of the cave, as well as a proper geomechanical ch…
Characterisation and origin of hydrothermal waters at São Miguel (Azores) inferred by chemical and isotopic composition
2017
Abstract This study focuses on the characterisation and origin of hydrothermal waters discharging from three main active volcanoes (Furnas, Fogo and Sete Cidades) at Sao Miguel, where 33 water with temperatures ranging between 13 and 97 °C, and 5 precipitate samples were collected. The developed conceptual model for this active hydrothermal system reveals that all waters can be classified by Na-HCO 3 , Na-Cl and Na-SO 4 types and are of meteoric origin. This is confirmed by the stable hydrogen and oxygen isotope data that are positioned close to the local meteoric water line (− 4.1‰ ≤ δ 18 O H2O ≤ 5.2‰; − 17.6‰ ≤ δD H2O ≤ 20.4‰), except for the Na-Cl type water at Ferraria (Sete Cidades a…