Search results for "Absorption of water"
showing 10 items of 60 documents
Synergistic effect of fiber content and length on mechanical and water absorption behaviors of Phoenix sp. fiber-reinforced epoxy composites
2016
Phoenix sp. fiber-reinforced epoxy composites have been manufactured using compression molding technique. The effect of reinforcement volume content (0%, 10%, 20%, 30%, 40%, and 50%) and size (300 µm particles, 10 mm, 20 mm, and 30 mm fibers) on quasi-static and dynamic mechanical properties was investigated. Moreover, the water absorption properties of composites were analyzed at different environmental conditions (10℃, 30℃, and 60℃). For each reinforcement size, composites loaded with 40% in volume show highest tensile and flexural properties. Furthermore, composites with 300 µm particles present the best impact properties and the lowest water absorption, regardless of the environmental …
Conifer Needles as Thermoplastic Composite Fillers: Structure and Properties
2016
This study describes the properties of thermoplastic polymer composites based on polyethylene (of low and high density) and ethylene-propylene copolymers using various types of conifer needles (pine, spruce, fir, and cedar) as fillers. For the needles, thermogravimetric analysis (TGA) and TGA/Fourier transform infrared spectroscopy (TGA/FTIR) were performed to investigate their structures and thermal resistance, as required for the composite processing methods. Moreover, structural differences were studied for the analyzed fillers and composite materials (FTIR). The results were compared with the values obtained for composites with conifer wood flour. Composites with conifer needles (pine) …
Physico-chemical properties and sensory profile of durum wheat Dittaino PDO (Protected Designation of Origin) bread and quality of re-milled semolina…
2018
To help future quality checks, we characterized the physico-chemical and sensory properties of Dittaino bread, a sourdough-based durum wheat bread recently awarded with Protected Designation of Origin mark, along with the quality features of re-milled semolina used for its production. Semolina was checked for Falling Number (533–644 s), protein content (12.0–12.3 g/100 g d.m.), gluten content (9.7–10.5 g/100 g d.m.), yellow index (18.0–21.0), water absorption (59.3–62.3 g/100 g), farinograph dough stability (171–327 s), softening index (46–66 B.U.), alveograph W (193 × 10−4–223 × 10−4 J) and P/L (2.2–2.7). Accordingly, bread crumb was yellow, moderately hard (16.4–27.1 N) and chewy (88.2–10…
Retrieval of canopy water content of different crop types with two new hyperspectral indices: Water Absorption Area Index and Depth Water Index
2018
Crop canopy water content (CWC) is an essential indicator of the crop’s physiological state. While a diverse range of vegetation indices have earlier been developed for the remote estimation of CWC, most of them are defined for specific crop types and areas, making them less universally applicable. We propose two new water content indices applicable to a wide variety of crop types, allowing to derive CWC maps at a large spatial scale. These indices were developed based on PROSAIL simulations and then optimized with an experimental dataset (SPARC03; Barrax, Spain). This dataset consists of water content and other biophysical variables for five common crop types (lucerne, corn, potato, sugar …
An Introduction to Soil and Water Infiltration
2016
This chapter provides a short presentation of general characteristics of the soil. Basic concepts concerning soil water content and potential and flow of water in the porous medium are then reported since these concepts are diffusely used throughout this book. The infiltration process is finally illustrated considering different modeling approaches. In particular, development of analytical infiltration models is described with reference to one-dimensional gravity-free water absorption, one-dimensional gravity driven infiltration, one-dimensional gravity and capillary driven infiltration and, finally, three-dimensional gravity and capillary driven infiltration.
Synthesis of polymeric derivatives of isoniazid: characterization and in vitro release from a water-soluble adduct with polysuccinimide.
1989
Coupling of isoniazid with polysuccinimide afforded a water-insoluble polymeric pro-drug; by reaction with ethanolamine it was chemically transformed in a water-soluble adduct. The in vitro release of isoniazid from the drug-polymer adduct was studied by using an artificial stomach wall lipid membrane. The transfer rate constant from simulated gastric juice to simulated plasma was defined and compared with that of an equivalent dose of pure drug.
X-ray CT imaging as a scientific tool to study the capillary water absorption in sedimentary rocks used in cultural heritages
2009
This paper proposes the X-Ray CT imaging as appropriate tool for investigating the capillary water absorption in sedimentary rocks. This technique, in fact, provides information useful for deeping the knowledge about of the porosity and the kinetics of the water capillary absorption in porous materials. The possibility to improve in non invasive manner, the understanding of this phenomenon, constitutes a fundamental aspect to take actions in the restoration and conservation of lapideous artifact and monuments from cultural heritages. The investigated sedimentary rocks come from different Sicilian quarries and were used for the building of the Greek temples in the archaeological areas of Agr…
The effects of water absorption and salt fog exposure on agglomerated cork compressive response
2022
The replacement of synthetic foams with agglomerated cork in sandwich composites can meet the increasing environmental concerns. Its peculiar morphology and chemical composition lead to outstanding dimensional recovery that endorsed a broad investigation of its compressive behavior. The knowledge of neat material response is fundamental to obtain a reliable design dataset, but it is necessary to consider all the environmental factors (water, moisture and sunlight) that significantly modify material mechanical properties. In view of this, the present work investigates the effect of distilled and seawater absorption and salt fog exposure on the compressive behavior of two agglomerated corks w…
Investigation of water sorption and aluminum releases from high viscosity and resin modified glass ionomer.
2019
Background High viscosity glass ionomer cement (HVGIC) and resin-modified glass ionomer cement (RMGIC) have recently been clinically preferred thanks to their numerous advantages. However, initial moisture contamination has a negative effect on the mechanical and physical properties of these cements. The aim of this study was in vitro of HVGICs and RMGICs, with and without surface protection, on water sorption, solubility and release of aluminum. Material and Methods In this study, as HVGICs; Equia Forte, IonoStar Plus, Riva Self Cure; as RMCIS, Ionolux and Riva Light Cure; and as control, Z250 universal composite was used. Equia coat, Voco varnish and Riva coat were chosen as surface prote…
Absorption kinetics and swelling stresses in hydrothermally aged epoxies investigated by photoelastic image analysis
2015
Abstract The present work proposes an experimental optical methodology able to measure the transient swelling stresses induced by the water uptake ageing of polymers. In particular, the work describes the implementation of a Photoelastic technique to quantify internal stresses arising during the hydrothermal ageing of cast epoxy samples. The material investigated is a model DGEBA/DDS epoxy system. Curing and post-curing cycles have been optimised in order to obtain a fully cured, high T g , and completely stress free initial condition. Rectangular beam samples were then left in a hydrothermal bath at 90 °C, and regularly monitored by gravimetric and photoelastic analyses. The quantitative e…