Search results for "strength"
showing 10 items of 2415 documents
Multifunctionality: Epistemic diversity and concept oriented research clusters
2008
International audience; This paper provides a mapping of the different uses of the word multifunctionality. To explore the diversity of meanings and interpretations, a comparative analysis was conducted through five national case studies in France, the Netherlands, Poland, Spain and Switzerland. The analysis conducted at national level makes it possible to identify eight Concept Oriented Research Clusters (CORCs), based on a relative homogeneity in the research practices, in the research questions addressed, in the concepts used or discussed by scientists to lead their work and in the scientific disciplines, the stream of thought or possibly the epistemic community researchers belong to. Th…
NEUROPLASTIC AND BEHAVIORAL CHANGES FOLLOWING PRISM ADAPTATION
2022
Prismatic or Prism adaptation (PA) is a particular visuomotor procedure that through the deviation of visual field and a motor task influences brain activity (Redding & Wallace, 2006). Initially developed 1998, when Rossetti et al. study showed an improvement of neglected hemispace exploring emineglected stroke patients, the number of studies focused on PA was greatly increased. The PA effects were investigated in healthy subjects as well as in patients in different tasks targeting different cognitive functions. A large number of applications of PA procedure was developed in the different studies but the majority of the procedures includes a movement task during the wearing of lenses that d…
Hydrolysis of Monomethyl-, Dimethyl-, and Trimethyltin(IV) Cations in Fairly Concentrated Aqueous Solutions at I = 1 mol L-1 (NaNO3) and T = 298.15 K…
2011
The hydrolysis of methyltin(IV) cations at fairly high concentrations was investigated to evaluate the formation of polynuclear species in aqueous solution. The hydrolysis of monomethyltin(IV), dimethyltin(IV), and trimethyltin(IV) was studied by potentiometry at T = 298.15 K and at I = 1 mol L-1 in NaNO3 aqueous solutions. The results obtained gave evidence for the formation of the following polynuclear species, in addition to the mononuclear species already reported, which were also considered in the models proposed for the three systems investigated: [(CH3)Sn(OH)3]0, [(CH3)Sn(OH)4]-, [((CH3)Sn)2(OH)4]2+, [((CH3)Sn)2(OH)5]+, [((CH3)Sn)2(OH)7]-, [((CH3)Sn)3(OH)5]4+, [((CH3)Sn)3(OH)7]2þ, [(…
Electric strength, space charge and surface discharge characterization of nanostructured epoxy-silicate insulating materials
2005
A set of surface discharge ageing procedures, space charge observations and dielectric strength measurements has been implemented on a type of insulating nanofilled epoxy-resin (nanostructured by compatibilised synthetic layered silicates) and on its non-filled base resin. Promising improvements in the electrical behaviour of the nanofilled epoxy, particularly as concerns surface discharge endurance, were detected. Regarding space charge, it was found that its accumulation rate as a function of ageing time is lower for the nanostructured resin. Finally, the nanofilled material evidenced a highly homogeneous behaviour of the dielectric strength data distribution.
Particle surface engineering effect on the mechanical, optical and photoluminescent properties of ZnO/vinyl-ester resin nanocomposites
2007
Zinc oxide (ZnO) nanoparticles functionalized with a bi-functional coupling agent methacryloxypropyl-trimethoxysilane (MPS) were used to fabricate a vinyl-ester resin polymeric nanocomposite, which shows an improved interfacial interaction between the particle and matrix. As a result, in comparison to the unmodified particle-filled nanocomposites, the functionalized particle-filled composites possessed higher resistance to thermal degradation, and demonstrated improved UV shielding and enhanced photoluminescent properties. The more uniform particle dispersion, passivation of the particle surface with MPS and increased oxygen vacancies were justified to contribute to the increased thermal st…
Morphology, flexural, and thermal properties of sepiolite modified epoxy resins with different curing agents
2006
A bisphenol A-based epoxy resin was modified with 5 wt% organically modified sepiolite (Pangel B40) and thermally cured using two different curing agents: an aliphatic diamine (Jeffamine D230, D230) and a cycloaliphatic diamine (3DCM). The morphology of the cured materials was established by scanning and transmission electron microscopy analysis. The thermal stability, thermo-mechanical properties, and flexural behaviour of the sepiolite-modified matrices were evaluated and compared with the corresponding neat matrix. The initial thermal decomposition temperature did not change with the addition of sepiolite. The flexural modulus of the epoxy matrix slightly increases by the incorporation o…
Mechanical properties and water vapor permeability of starch/montmorillonite nanocomposites
2009
Results of an investigation into an unmodified-montmorillonite (MMT)-filled nanocomposite based on plasticized starch are reported. Data on the influence of MMT content on the tensile mechanical properties of the material are presented. Particular attention is given to the water vapor permeability of the nanocomposite. It is found that the resistance to water permeation of plasticized starch can be improved considerably by introducing a rather small amount of the filler into it. Data on the influence of MMT content on the coefficients of moisture diffusion, solubility, and permeability are reported. Also, a simple method for determining the effect of irregularly oriented platelike filler pa…
Starch Based Biodegradable Nanocomposites: Structure and Properties
2009
Plasticized starch (PS)/montmorillonite clay (MMT) nanocomposites were prepared by casting technique. Structural features, stress-strain characteristics and sorption properties were investigated. Upon introduction of rather small amounts of MMT, the PS parameters of the mechanical and barrier properties considerably improve. Tensile strength and elastic modulus of the materials examined decrease with increased moisture content, but the effect of reinforcement of PS with MMT nanoparticles remain intact.
Nonporous, Strong, Stretchable, and Transparent Electrospun Aromatic Polyurea Nanocomposites as Potential Anticorrosion Coating Films
2021
This study, for the first time, focused on the fabrication of nonporous polyurea thin films (~200 microns) using the electrospinning method as a novel approach for coating applications. Multi-walled carbon nanotubes (MWCNTs) and hydrophilic-fumed nanosilica (HFNS) were added separately into electrospun polyurea films as nano-reinforcing fillers for the enhancement of properties. Neat polyurea films demonstrated a tensile strength of 14 MPa with an elongation of 360%. At a loading of 0.2% of MWCNTs, the highest tensile strength of 21 MPa and elongation of 402% were obtained, while the water contact angle remained almost unchanged (89°). Surface morphology analysis indicated that the producti…
Fracture strength of endodontically treated lateral incisors restored with new zirconia reinforced rice husk nanohybrid composite
2020
Background This study aimed to compare the fracture strength, fracture pattern and type of fracture of endodontically treated maxillary lateral incisors restored with new zirconia reinforced rice husk nanohybrid composite. Material and Methods Eighty mature permanent maxillary lateral incisors from patients age range of 30-60 years with single canal were selected and randomly divided into: Group 1 – RCT + nanofilled composite (Filtek), Group 2 – RCT + microhybrid composite (Zmack), Group 3 – RCT + new nanohybrid composite (Zr-Hybrid) and Group 4 - Intact teeth (control). Standardized mesio-palatal-distal cavity was prepared, and endodontic treatment was carried out using crown-down techniqu…