Search results for "composite"
showing 10 items of 4584 documents
Effect of perspiration on skin temperature measurements by infrared thermography and contact thermometry during aerobic cycling
2015
[EN] The aim of the present study was to compare infrared thermography and thermal contact sensors for measuring skin temperature during cycling in a moderate environment. Fourteen cyclists performed a 45-mM cycling test at 50% of peak power output. Skin temperatures were simultaneously recorded by infrared thermography and thermal contact sensors before and immediately after cycling activity as well as after 10 min cooling-down, representing different skin wetness and blood perfusion states. Additionally, surface temperature during well controlled dry and wet heat exchange (avoiding thermoregulatory responses) using a hot plate system was assessed by infrared thermography and thermal conta…
Size Distribution, Mechanical and Electrical Properties of CuO Nanowires Grown by Modified Thermal Oxidation Methods
2020
Size distribution, Young&rsquo
Volume change characteristics of fine-grained soils due to sequential thermo-mechanical stresses
2019
Know-how of volume change characteristics, VCC, of the fine-grained soils, exposed to thermal stresses, is essential for design of various thermo-active structures. These stresses are known to induce excess pore-water pressure, Δu θ , in the saturated state of such soils, which in turn affects their compression and shear strength characteristics. In this context, through several experimental studies, the effect of thermo-mechanical stress-path, the over-consolidation ratio (OCR) and degree of saturation on VCC (viz., thermally induced volumetric strain, ε vθ , compression and re-compression indices, c c and c r ) of the fine-grained soils has been demonstrated by earlier researchers. Howeve…
Architectural technologies for life environment: Spent coffee ground reuse in lime-based mortars. A preliminary assessment for innovative green therm…
2022
Spent coffee ground, the residue obtained from the brewing process, is the primary unavoidable (inedible) waste from the coffee consumption. As coffee production and beverage consumption are increasing worldwide, a more sustainable waste management is required since the usual disposal in landfill is a liability to both humans and the environment. This paper is aimed at showing a possible alternative reuse of coffee ground wastes in novel green building materials intended for thermo-plastering applications in construction, in a circular economy context. Coffee waste was used in various percentages (up to 17.5%) to assess the engineering performance of the produced bio-composite mortars. The …
Evaluation of wood-polyethylene composites biodegradability caused by filamentous fungi
2017
Abstract This study describes the impact of filamentous fungi on wood-polymer composites (WPCs) containing various types of fillers (coniferous, deciduous, cellulose) in the amount of 30 wt.% to 50 wt.%. The selection of fungal strain of filamentous fungi was performed prior to the study on the impact of the wood type on the progress of WPCs biodegradability. The changes associated with various water absorption of the examined WPCs, were observed using scanning electron microscopy (SEM). The impact of fungal mycelium, which had affected the changes in WPCs material, was examined using thermogravimetric analysis (TG). The results showed, that the growth of mycelium on WPCs, influenced mainly…
Rapid synthesis of tin (IV) oxide nanoparticles by microwave induced thermohydrolysis
2008
Abstract Tin oxide nanopowders, with an average size of 5 nm, were prepared by microwave flash synthesis. Flash synthesis was performed in aqueous solutions of tin tetrachloride and hydrochloric acid using a microwave autoclave (RAMO system) specially designed by the authors. Energy dispersive X-ray analysis (EDX), X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, nitrogen adsorption isotherm analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM), were used to characterize these nanoparticles. Compared with conventional synthesis, nanopow…
PMMA-titania nanocomposites: Properties and thermal degradation behavior
2012
Titania nanoparticles were prepared using a solegel method and calcination at 200 and 600 � C in order to obtain anatase and rutile phases, respectively. The obtained powders were used to prepare PMMAe titania nanocomposites by a melt compounding method. The effect of the crystalline phase and the amount of titania, in the range 1e5 wt.%, on the morphology, mechanical properties and thermal degradation kinetics of PMMA was investigated by means of X-ray diffractometry (XRD), transmission electron microscopy (TEM), 13 C cross-polarization magic-angle spinning nuclear magnetic resonance spectroscopy ( 13 C{ 1 H}CP-MAS NMR), including the measurement of proton spinelattice relaxation time in t…
Bentonite-ionic liquid composites for Congo red removal from aqueous solutions
2021
Abstract Clay-organic composites have attracted great interest due to their ability to remove various contaminants from wastewater. The surfactants are the most commonly used organic compounds for clay modification. However, cationic surfactants are toxic and can be environmentally hazardous. Ionic liquids are a new promising alternative to the cationic surfactants due to lesser toxicity and appropriate thermal stability. The research aim is to prepare an environmentally friendly new class of clay sorbents modified with ionic liquids for potential applications in wastewater treatment from the textile industry. Imidazolium-based ionic liquids with different lengths of alkyl chains were inter…
Preparation and characterization of gels with garnet structure: A3B2C3O12, using ‘non-classical’ solvents
1992
Abstract Synthesis and characterization of some crystalline garnets by sol-gel techniques is described. The effects of emthanol, dimethyl sulfoxide (DMSO), CH2Cl2 and toluene solvents on gelation of TEOS are considered. Multicomponent gel formation in systems with stoichiometries 3CaO·Cr2O3·3SiO2 and 3CaO·Al2O2 was studied using DMSO, a polar solvent, and toluene, an apolar solvent. The dried gel was thermally treated and the powder was characterized by X-ray diffraction, differential thermal analysis/thermogravimetric analysis and scanning electron microscopy.
Structure and performance properties of environmentally-friendly biocomposites based on poly(ɛ-caprolactone) modified with copper slag and shale dril…
2018
The potential application of two types of industrial wastes, drill cuttings (DC) and copper slag (CS), as silica-rich modifiers of poly(ɛ-caprolactone) (PCL) was investigated. Chemical structure and physical properties of DC and CS fillers were characterized using X-ray diffractometer, X-ray fluorescence spectroscopy, particle size and density measurements. PCL/DC and PCL/CS composites with a variable content of filler (5 to 50 parts by weight) were prepared by melt compounding in an internal mixer. It was observed that lower particle size of DC filler enhanced processing of biocomposites comparing to CS filler. Smaller particles of DC filler and thus the higher specific surface area, enabl…