Search results for "Water content"
showing 10 items of 380 documents
Unravelling textural heterogeneity in obsidian:shear-induced outgassing in the Rocche Rosse flow
2016
Obsidian flow emplacement is a complex and understudied aspect of silicic volcanism. Of particular importance is the question of how highly viscous magma can lose sufficient gas in order to erupt effusively as a lava flow. Using an array of methods we study the extreme textural heterogeneity of the Rocche Rosse obsidian flow in Lipari, a 2. km long, 100. m thick, ~. 800. year old lava flow, with respect to outgassing and emplacement mechanisms. 2D and 3D vesicle analyses and density measurements are used to classify the lava into four textural types: 'glassy' obsidian (<. 15% vesicles), 'pumiceous' lava (>. 40% vesicles), high aspect ratio, 'shear banded' lava (20-40% vesicles) and lo…
Effects of water on gas chromatographic column efficiency measurements applied to on-column injections of volatile aroma compounds
2002
International audience
Biodeterioration of cardboard-based liquid containers collected for fibre reuse.
1999
Liquid packaging board (LPB) collected in Germany is processed in Finland as recycled fibre and as plastic reject for incineration. The chemical, biological and physical changes occurring in recycled LPB bales were monitored during storage of six and 18 months. The moisture content in the core of the bales ranged from 7% to 53%, and pH values varied from 6.0 to 8.5. The average amount of mesophilic bacteria per container was 1.5 x 10(7) - 5 x 10(8), which means that recycled LPB pulp cannot be recommended for sanitary use. The concentration of CO2 inside the bale is an indicator of the activity of aerobic microorganisms and might be suitable for identifying deteriorated bales and removing t…
Effect of Aspect ratio and water contamination on the electric properties of nanostructured insulating materials
2010
Organically-modified nanofiller clays can have significantly different aspect ratios as well as accumulate a relatively large amount of water in the composite bulk due to the contribution of the filler itself and the interaction between filler and polymer matrix. This paper investigates the effect of water absorption in a nanostructured thermoplastic polymer, namely ethylene-vinyl-acetate (EVA), on electrical property modifications considering the contribution of aspect ratio. The change of electrical properties (particularly space charge accumulation, electric strength, bulk conductivity and permittivity/losses) is studied as a function of water content absorbed by nanofillers having diffe…
Pectin biopolymer mechanics and microstructure associated with polysaccharide phase transitions.
2019
Polysaccharide polymers like pectin can demonstrate striking and reversible changes in their physical properties depending upon relatively small changes in water content. Recent interest in using pectin polysaccharides as mesothelial sealants suggests that water content, rather than nonphysiologic changes in temperature, may be a practical approach to optimize the physical properties of the pectin biopolymers. Here, we used humidified environments to manipulate the water content of dispersed solution of pectins with a high degree of methyl esterification (high-methoxyl pectin; HMP). The gel phase transition was identified by a nonlinear increase in compression resistance at a water content …
A portable NMR sensor to measure dynamic changes in the amount of water in living stems or fruit and its potential to measure sap flow.
2014
Nuclear magnetic resonance (NMR) and NMR imaging (magnetic resonance imaging) offer the possibility to quantitatively and non-invasively measure the presence and movement of water. Unfortunately, traditional NMR hardware is expensive, poorly suited for plants, and because of its bulk and complexity, not suitable for use in the field. But does it need to be? We here explore how novel, small-scale portable NMR devices can be used as a flow sensor to directly measure xylem sap flow in a poplar tree (Populus nigra L.), or in a dendrometer-like fashion to measure dynamic changes in the absolute water content of fruit or stems. For the latter purpose we monitored the diurnal pattern of growth, ex…
A Radiation Fog Model with a Detailed Treatment of the Interaction between Radiative Transfer and Fog Microphysics
1990
Abstract A one-dimensional radiation fog model is presented which includes a detailed description of the interaction between atmospheric radiative transfer and the microphysical structure of the fog. Aerosol particles and activated cloud droplets are treated using a two-dimensional joint size distribution whereby the activation process of aerosols is explicitly modeled. For this purpose a new positive definite semi-Lagrangian advection scheme is developed that produces only small numerical diffusion and is numerically very efficient. For the radiative calculations, time dependent attenuation parameters are determined from the actual particle size distributions. The diffusional growth of the…
Model Analysis of Hydrometeor Scattering Effects on Free Space Near-Infrared Links
2012
A promising technology for peer-to-peer connections and urban area networks is represented by wireless communications through free space using optical carrier (Free Space Optics, FSO). This technology ensures high data rates, with relatively low error rates, low power consumption and inherent security. Nevertheless FSO links are quite sensitive to atmospheric condition. Fog droplets, but also raindrops and snowflakes, may introduce severe path attenuation which drastically reduces the channel availability. A parametric model to simulate droplets scattering effects over the FSO link in terms of extinction coefficient, albedo factor and asymmetry coefficient as function of the particle water …
Influence of water, temperature and sucrose on dynamics in glassy starch-based products studied by low field 1H NMR
2009
Abstract In this study, the influence of both water content and temperature on the mobility of glassy starch-based matrices (starch alone or mixed with sucrose at the ratio 0% to 20% db) were studied using time domain 1 H NMR. The 2nd moment M 2 , and transversal relaxation time T 2 ∗ were used to study the molecular mobility of the rigid and mobile fraction of the NMR signal, respectively. The molecular mobility of the protons constituting the samples increased with water content (up to 13% wb) at all temperatures. For a given water content, both rigid and mobile protons exhibited a lower mobility in the presence of sucrose. When mobility characteristic parameters, M 2 second moment values…
The Storage of Dried Apricots: The Effect of Packaging and Temperature on the Changes of Texture and Moisture
2012
During storage, the packaging material was crucial in the product's moisture variation. The aim of this work was to study the changes of both the moisture content and the texture of dried apricots packaged in two types of containers, namely glass and polypropylene trays, which were thermosealed with two different films and stored at a constant temperature (5, 15, 25 and 35C). The moisture content and texture of the product were analyzed periodically over a period of 12 months. In addition, a differential scanning calorimetry of the product was carried out for a better understanding of the relationship between these parameters. In samples packaged in films, the maximum force value increased …