Search results for "bulk"
showing 10 items of 286 documents
Could sonic delivery of bulk-fill resins improve the bond strength and cure depth in extended size class I cavities?
2020
Background The implementation of restorative procedures that guarantee success and optimize clinical time is the target of investigations in Restorative Dentistry. This study aimed to analyze the influence of sonic insertion of bulk-fill (BF) and conventional (C) resin composites on the microtensile bond-strength (µ-TBS) and cure depth (CD) of large and deep class I restorations. Material and Methods Fifty-six healthy human premolars were selected and occlusal cavities (4 x 4 x 3 mm; factor C = 5) were prepared. TC - Tetric N-Ceram (BF), SF - SonicFill (BF), and Z350 - Filtek Z350 XT (C) composite resins were used to restore the cavities, using sonic (S) and non-sonic (NS) insertion techniq…
Nitrogen Hydrate Cage Occupancy and Bulk Modulus Inferred from Density Functional Theory-Derived Cell Parameters
2021
International audience; Gas clathrate hydrate solid materials, ubiquitous in nature as found either on the ocean floor, permafrost on the Earth, or in extraterrestrial planets and comets, are also technologically relevant, for example, in energy storage or carbon dioxide sequestration. Nitrogen hydrate, in particular, is of great interest as a promoter of the kinetics of the methane replacement reaction by carbon dioxide in natural gas hydrates. This hydrate may also appear in the chemistry of planets wherever nitrogen constitutes the majority of the atmosphere. A fine understanding of the stability of this hydrate under various thermodynamic conditions is thus of utmost importance to asses…
Comparative study of illite clay and illite-based geopolymer products
2011
Quaternary (Q-clay) clayey deposits are one of the dominating parts of mineral raw materials of the sedimentary cover at present area of Latvia. These clays can be characterised by illite content up to 75-80 %. Two ways for use of illite clays were studied: conventional and geopolymers method. Purpose of the second mentioned method was showing the influence of alkali (KOH) on the transformation of Q-clay/illite structure. Obtained products were investigated by IR–spectroscopy, DTA and XRD, pore size distribution was determined as well. Some ceramic properties and compressive strength were determined and compared. IR-spectrum showed the effect of alkali on the transformation of Q-clay/illite…
Jet-vortex spray freeze drying for the production of inhalable lyophilisate powders
2016
Abstract Spray-freeze-dried powders were suggested for nasal, epidermal (needle-free injection) or pulmonary application of proteins, peptides or nucleic acids. In spray-freeze-drying processes an aqueous solution is atomized into a refrigerant medium and subsequently dried by sublimation. Droplet-stream generators produce a fast stream of monodisperse droplets, where droplets are subject to collisions and therefore the initial monodispersity is lost and droplets increase in diameter, which reduces their suitability for pulmonary application. In jet-vortex-freezing, a droplet-stream is injected into a vortex of cold process gas to prevent droplet collisions. Both the injection position of t…
Sequential and site-specific on-surface synthesis on a bulk insulator
2013
cited By 15; International audience; The bottom-up construction of functional devices from molecular building blocks offers great potential in tailoring materials properties and functionality with utmost control. An important step toward exploiting bottom-up construction for real-life applications is the creation of covalently bonded structures that provide sufficient stability as well as superior charge transport properties over reversibly linked self-assembled structures. On-surface synthesis has emerged as a promising strategy for fabricating stable, covalently bound molecular structure on surfaces. So far, a majority of the structures created by this method have been obtained from a rat…
The effect of different insertion techniques on the depth of cure and vickers surface micro-hardness of two bulk-fill resin composite materials
2016
BACKGROUND The aim of this study was to evaluate the Vickers surface micro-hardness and the depth of cure of two bulk-fill resin composites and one incremental-fill resin composite. MATERIAL AND METHODS Two Bulk-fill dental resin composites (X-tra Fil, Voco; Sonic-FillTM 2, Kerr Corporation) and an incremental-fill dental resin composite (Filtek™ Z250 XT, 3M ESPE) were used. Sixty cylindrical specimens of 4 mm thickness were prepared using split Teflon moulds. Specimens were divided into six groups (n=10) according to the type of the material used and according to the insertion technique applied (bulk or incremental). Prepared specimens were stored dry in complete darkness at 37°C for 24 ho…
High pressure in-situ X-ray diffraction study on Zn-doped magnetite nanoparticles
2018
We have performed high pressure synchrotron X-ray powder diffraction experiments on two different samples of Zn-doped magnetite nanoparticles (formula Fe(3-x)ZnxO4; x = 0.2, 0.5). The structural behavior of then a noparticles was studied up to 13.5 GPa for x = 0.2, and up to 17.4 GPa for x = 0.5. We have found that both systems remain in the cubic spinel structure as expected for this range of applied pressures. The analysis of the unit cell volume vs. pressure results in bulk modulus values lower than in both end-members, magnetite (Fe3O4) and zinc ferrite (ZnFe2O4), suggesting that chemical disorder may favor compressibility, which is expected to improve the increase of the Neel temperatu…
Substrate templating upon self-assembly of hydrogen-bonded molecular networks on an insulating surface.
2012
M olecular self-assembly on insulating surfaces, despite being highly relvant to many applications, generally suffers from the weak molecule–surface interactions present on dielectric surfaces, especially when benchmarked against metallic substrates. Therefore, to fully exploit the potential of molecular self-assembly, increasing the infl uence of the substrate constitutes an essential prerequisite. Upon deposition of terephthalic acid and trimesic acid onto the natural cleavage plane of calcite, extended hydrogen-bonded networks are formed, which wet the substrate. The observed structural complexity matches the variety realized on metal surfaces. A detailed analysis of the molecular struct…
Modeling of ITER TF cooling system through 2D thermal analyses and enthalpy balance
2017
Abstract The winding pack of the ITER Toroidal Field (TF) coils is composed of 134 turns of Nb3Sn Cable in Conduit Conductor (CICCs) wound in 7 double pancakes and cooled by supercritical helium (He) at cryogenic temperature. The cooling of the Stainless Steel (SS) case supporting the winding pack is guaranteed by He circulation in 74 parallel channels. A 2D approach to compute the temperature distribution in the ITER TF winding pack is here proposed. The TF is divided in 32 poloidal segments, for each segment the corresponding 2D model is built and a thermal analysis is performed applying the corresponding nuclear heating computed with MCNP code considering the latest design updates, such …
Bond strength of dental nanocomposites repaired with a bulkfill composite
2017
Background The aim of this study was to analyze the bond strength of aged resin based nanocomposites repaired with the same and bulk fill composites. Material and Methods Seventy-two disc shaped resin composites consisted of three different nanocomposite resins (Filtek Ultimate/FU, Herculite XRV Ultra/HXRV, and Reflectys/R) were produced. After storing the samples for 8 weeks in distilled water, each material was combined with the same material or the bulk-fill composite resin system (Filtek Ultimate+Filtek Ultimate/Group-1; Filtek Ultimate+Tetric BF/Group-2; Herculite XRV+Herculite XRV/Group-3; Herculite XRV+Tetric BF/ Group-4; Reflectys+Reflectys/Group 5; Reflectys+Tetric BF/Group-6), for…