Search results for "SITES"
showing 10 items of 2851 documents
PyCellBase
2019
Python package for easy retrieval of biological data from heterogeneous sources.
Fast-growing willow (Salix viminalis) as a filler in polyethylene composites
2018
Abstract The study investigated the possibility of using wood flour obtained from fast-growing willow chips (Salix viminalis) as an alternative for standard hard- and softwood flours used in the production of wood polymer composites (WPCs). The composites contained willow flour and polyethylene matrix (OPCs) were prepared, characterized and compared with other WPCs which had been filled with hard- or softwood flours. Moreover, the structural and functional properties were investigated and discussed. Greater hemicellulose contents and lower lignin contents in OPCs resulted in better impact strength values of those materials. Which is interesting, the chemical composition of OPCs was found si…
PBAT Based Composites Reinforced with Microcrystalline Cellulose Obtained from Softwood Almond Shells
2021
This study explores the processability, mechanical, and thermal properties of biocompostable composites based on poly (butylene adipate-co-terephthalate) (PBAT) as polymer matrix and microcrystalline cellulose (MCC) derived from softwood almond (Prunus dulcis) shells (as-MCC) as filler at two different weight concentration, i.e., 10 wt% and 20 wt%. The materials were processed by melt mixing and a commercial MCC (c-MCC) was used as filler comparison. The fibrillar shape of as-MCC particles was found to change the rheological behavior of PBAT, particularly at the highest concentration. The melt mixing processing allowed obtaining a uniform dispersion of both kinds of fillers, slightly reduci…
Synthesis and optical characterization of Er-doped bismuth titanate nanoparticles grown by sol-gel hydrothermal method
2017
Abstract The Er 3+ -doped bismuth titanate (Bi 4 Ti 3 O 12 , BIT) nanoparticles were synthesized by a combined sol–gel and hydrothermal method under a partial oxygen pressure of 30 bar. The composition and morphology were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman scattering. They showed pure and homogeneous spherical BIT nanoparticles with a size below the 30 nm. The incorporation of Er ions showed a strong decrease in the lattice parameters, as well as averaged particle size. The photoluminescence up-conversion (excitation wavelength =1480 nm) showed an enhancement of the infrared emission (980 nm) as Er concentration increased, achieving a maxi…
State selective electron injection in non-aggregated titanium phthalocyanine sensitised nanocrystalline TiO2 films
2004
We describe a novel titanium phthalocyanine that shows no aggregation when anchored to nanocrystalline TiO2 films through its axial carboxylated ligand without the use of co-adsorbents; state selective electron injection into the TiO2 is demonstrated, resulting in efficient photocurrent generation in dye sensitised photoelectrochemical solar cells. Palomares Gil, Emilio J, epagil@alumni.uv.es
The effects of solar radiation in archaeological sites
2013
Ruined walls, paving and decorative elements of archaeological sites are mainly composed of materials with chemical, physical and biological degradation problems that are primarily due to environmental factors. The conservation of archaeological finds requires a protection against these factors. Solar radiation may constitute one of those causes of deterioration. In recent decades the use of glass to cover archaeological sites has been more and more widespread (Fig. 1). The purpose of those glass covers is to reconcile the need of the display capabilities with the preservation of the remains. In general, a protective cover structure determines new conditions that must be carefully controlle…
Solunto: dalla conoscenza alla conservazione
2016
Per l’antica città di Solunto (Santa Flavia-Palermo), solo alla fine del XVIII sec., inizia un processo di analisi finalizzato alla sua conservazione, mediante tutela e restauro, che prosegue fino ai nostri giorni. Pertanto il mio saggio vuole essere un contributo per conoscere e meglio conservare questo patrimonio rappresentato da materiali e strutture, attraverso continue cure, al fine di assicurare vita alla vita delle testimonianze, per la nostra generazione, ma soprattutto per quelle che ci seguiranno. To the ancient city of Solunto (Santa Flavia-Palermo), only in the late Eighteenth century, begins a process of analysis aimed at its preservation, through protection and restoration, wh…
Halogen bonding drives the self-assembly of piperazine cyclophanes into tubular structures.
2009
Halogen bonding with 1,4-diiodotetrafluorobenzene leads to the self-assembly of piperazine cyclophanes into well-defined tubular structures with solvent inclusion.
Effect of UD carbon on the specific mechanical properties of glass mat composites for marine applications
2009
In this work the influence of a uniaxial carbon fabric layer on the mechanical performances of a glass mat/epoxy composite used for marine applications has been studied. All the structures have been made, at room temperature, by vacuum bagging technique. Tension and flexural tests have been carried out in order to evaluate the specific mechanical properties of the composite and to compare these with those of the marine aluminium alloy 6016-T4. The glass composites have higher specific strength but lower specific modulus than aluminium alloy. To increase the specific modulus of the composites, each layer of glass mat has been replaced with a layer of uniaxial carbon fabric. In addition, a s…
Strength and Damage of Elementary Flax Fibers Extracted from Tow and Long Line Flax
2009
Flax fibers possess high specific strength and stiffness, and thus are competitive in terms of mechanical properties with traditional reinforcing fibers used in polymer-matrix composite materials. For environmental and economical benefit, it would be preferable to apply nontextile grade fibers in composites provided their mechanical characteristics are acceptable. Elementary fibers have been extracted from long line flax, used as high-quality raw material for textile industry, and flax tow, and their strength distribution and damage level determined. It is shown that the elementary flax fibers coming from short flax fiber are not inferior to those of textile-quality flax in terms of streng…