Analysis of the Technical Feasibility of Sustainable Concrete Production Using Waste Foundry Sand as a Fine Aggregate.

Waste foundation sand (WFS) is one of the most abundant residues in the foundation industry. Currently, its annual production is estimated to be three million tons. This material has properties that make it an attractive candidate for implantation as an alternative constituent to a natural fine aggregate in concrete applications.

Using Thermomechanical Properties to Reassess Particles' Dispersion in Nanostructured Polymers: Size vs. Content.

Nanoparticle-filled polymers (i.e., nanocomposites) can exhibit characteristics unattainable by the unfilled polymer, making them attractive to engineer structural composites.

Influence of Pre-Milling of CrC-25 NiCr Spray Powder on the Fatigue Life of HVOF-Sprayed Coating on ASTM A516 Steel Substrate.

The aim of the present investigation is to evaluate the influence of the powder size of CrC-25NiCr spraying powder on the fatigue behavior of HVOF-sprayed coating on the ASTM A516 steel substrate. Conventional commercial CrC-25NiCr spraying powder was previously treated through high-energy milling. The crystallite sizes of milled powders were measured by X-ray diffraction and transmission electronic microscopy.

Characterization and in vivo toxicological evaluation of multi-walled carbon nanotubes: a low-dose repeated intratracheal administration study.

This study characterized and investigated the toxicity of two multi-walled carbon nanotubes (MWCNT) NM-401 and NM-403 at 60 and 180 µg after four repeated intratracheal instillations; follow-up times were 3, 7, 30, and 90 days after the last instillation. NM-401 was needle-like, long, and thick, while NM-403 was entangled, short, and thin. Both MWCNT types induced transient pulmonary and systemic alterations in renal function and oxidative lipid damage markers in recent times.

Effect of Feldspar Substitution by Basalt on Pyroplastic Behaviour of Porcelain Tile Composition.

This work aims to evaluate the effects of feldspar substitution by basalt on porcelain tile composition with respect to its porosity, flexural strength, and pyroplastic deformation. Three ceramic formulations with different amounts of feldspar substituted with basalt, 50% (C1), 75% (C2), and 100% (C3), were evaluated at three different temperatures, 1200, 1220, and 1240 °C. Specifically, the effect of replacing feldspar with basalt on the pyroplastic deformation of ceramic bodies was analysed using optical fleximetry.

In-Plane Shear Strength of Single-Lap Co-Cured Joints of Self-Reinforced Polyethylene Composites.

The present study introduces the analysis of single-lap co-cured joints of thermoplastic self-reinforced composites made with reprocessed low-density polyethylene (LDPE) and reinforced by ultra-high-molecular-weight polyethylene (UHMWPE) fibers, along with a micromechanical analysis of its constituents. A set of optimal processing conditions for manufacturing these joints by hot-press is proposed through a design of experiment using the response surface method to maximize their in-plane shear strength by carrying tensile tests on co-cured tapes. Optimal processing conditions were found at 1 bar, 115 °C, and 300 s, yielding joints with 6.

True Strength of Ceramic Fiber Bundles: Experiments and Simulations.

A study on the strength of ceramic fiber bundles based on experimental and computational procedures is presented. Tests were performed on single filaments and bundles composed of two fibers with different nominal fiber counts. A method based on fiber rupture signals was developed to estimate the amount of filament rupture during the test.

Floating treatment wetlands integrated with microbial fuel cell for the treatment of urban wastewaters and bioenergy generation.

The objective of the present study was to develop a combined system composed of anaerobic biofilter (AF) and floating treatment wetlands (FTW) coupled with microbial fuel cells (MFC) in the buoyant support for treating wastewater from a university campus and generate bioelectricity. The raw wastewater was pumped to a 1450 L tank, operated in batch flow and filled with plastic conduits. The second treatment stage was composed of a 1000 L FTW box with a 200 L plastic drum inside (acting as settler in the entrance) and vegetated with mixed ornamental plants species floating in a polyurethane support fed once a week with 700 L of wastewater.

Exploring Needle-Like Zinc Oxide Nanostructures for Improving Dental Resin Sealers: Design and Evaluation of Antibacterial, Physical and Chemical Properties.

This study aimed to evaluate the effect of needle-like zinc oxide nanostructures (ZnO-NN) on the physical, chemical, and antibacterial properties of experimental methacrylate-based dental sealers. ZnO-NN was synthesized and characterized. ZnO-NN was added to a co-monomer blend at 20, 30, and 40 wt.

Cerium Dioxide Particles to Tune Radiopacity of Dental Adhesives: Microstructural and Physico-Chemical Evaluation.

The insufficient radiopacity of dental adhesives applied under composite restorations makes the radiographic diagnosis of recurrent caries challenging. Consequently, the misdiagnosis may lead to unnecessary replacement of restorations. The aims of this study were to formulate experimental dental adhesives containing cerium dioxide (CeO) and investigate the effects of different loadings of CeO on their radiopacity and degree of conversion for the first time.

Novel core-shell nanocomposites based on TiO -covered magnetic Co O for biomedical applications.

Magnetic Co O nanoparticles (NPs) have great potential for applications in biomedicine, as contrast enhancement agents for magnetic resonance imaging, or for drug delivery. Although these NPs are so attractive, their potential toxicity raises serious questions about decreasing cellular viability. In this context, Co O NPs were prepared via sol-gel method and encapsulated with a layer of TiO , a biocompatible oxide, and subjected to structural, magnetic and toxicity characterization.

Effect of nanostructured zirconium dioxide incorporation in an experimental adhesive resin.

Objectives: The aim of this study was to evaluate the influence of nanostructured zirconium dioxide incorporation in an experimental adhesive resin.

Methods: ZrO particles were characterized by X-ray diffraction (XRD), micro-Raman spectroscopy and Brunauer-Emmett-Teller (B.E.

Influence of Different Defects in Vertically Aligned Carbon Nanotubes on TiO2 Nanoparticle Formation through Atomic Layer Deposition.

The chemical inertness of carbon nanotubes (CNT) requires some degree of "defect engineering" for controlled deposition of metal oxides through atomic layer deposition (ALD). The type, quantity, and distribution of such defects rules the deposition rate and defines the growth behavior. In this work, we employed ALD to grow titanium oxide (TiO2) on vertically aligned carbon nanotubes (VACNT).

Adsorption of Direct Blue 53 dye from aqueous solutions by multi-walled carbon nanotubes and activated carbon.

Multi-walled carbon nanotubes (MWCNT) and powder activated carbon (PAC) were used as adsorbents for adsorption of Direct Blue 53 dye (DB-53) from aqueous solutions. The adsorbents were characterised using Raman spectroscopy, N2 adsorption/desorption isotherms, and scanning and transmission electron microscopy. The effects of initial pH, contact time and temperature on adsorption capacity of the adsorbents were investigated.

The addition of nanostructured hydroxyapatite to an experimental adhesive resin.

Objectives: Was produced nanostructured hydroxyapatite (HAnano) and evaluated the influence of its incorporation in an adhesive resin.

Methods: HAnano was produced by a flame-based process and was characterized by scanning electron microscopy. The surface area, particle size, micro-Raman and cytotoxicity were evaluated.

Adsorption of Reactive Blue 4 dye from water solutions by carbon nanotubes: experiment and theory.

Multi-walled and single-walled carbon nanotubes were used as nanoadsorbents for the successful removal of Reactive Blue 4 textile dye from aqueous solutions. The adsorbents were characterised by infrared and Raman spectroscopy, N(2) adsorption/desorption isotherms and scanning and transmission electron microscopy. The effects of pH, shaking time and temperature on adsorption capacity were studied.

Niobium pentoxide as a novel filler for dental adhesive resin.

Objectives: The purpose of this study was to develop an adhesive resin with incorporation of niobium pentoxide and evaluate its properties.

Methods: Niobium pentoxide was characterised by X-ray diffraction, surface area, particle size, micro-Raman, scanning electron microscopy and the effectiveness of silanisation process by Fourier Transform Infrared (FTIR). An experimental adhesive resin was formulated with 0, 5, 10 and 20wt% Nb(2)O(5).

Adsorption of Reactive Red M-2BE dye from water solutions by multi-walled carbon nanotubes and activated carbon.

Multi-walled carbon nanotubes and powdered activated carbon were used as adsorbents for the successful removal of Reactive Red M-2BE textile dye from aqueous solutions. The adsorbents were characterised by infrared spectroscopy, N(2) adsorption/desorption isotherms and scanning electron microscopy. The effects of pH, shaking time and temperature on adsorption capacity were studied.

Application of titania fibers obtained by electrospinning in photocatalytic degradation of methyl orange.

Composite fibers of polyvinylpirrolidone and titanium propoxide were prepared using the electrospinning technique. Titanium oxide fibers were obtained on heat treatment of this composite. These fibers were characterized by means of specific surface area, thermal analysis, X-ray diffraction and electronic microscopy processes.

Analysis of primary tooth dentin after indirect pulp capping.

Purpose: The purpose of this study was to evaluate the characteristics of primary molar dentin after indirect pulp capping (ICP) by of color, consistency and microhardness analyses.

Methods: The study design consisted of 3 groups: a test group of 13 primary molars that had been submitted to ICP with either calcium hydroxide or resin-modified glass ionomer cement; a positive control group of 15 sound molars; and a negative control group of 15 molars with deep acute carious lesions. The test group teeth had their restorations and pulp-capping materials removed and their cavity depth measured (mean depth=3-4 mm).

Injectability evaluation of tricalcium phosphate bone cement.

Calcium phosphate cements are biomaterials made from a mixture of calcium phosphate powder in aqueous solutions that forms a paste that reacts at the body temperature and hardens as a result of precipitation reactions. These cements are commonly used in dentistry and orthopedic bone filling surgeries, which require extremely invasive procedures. The challenge consists in formulating an injectable paste by additives incorporation.

Sinterability study of ceramic bodies made from a mixture of mineral coal bottom ash and soda-lime glass cullet.

The aim of this study was to investigate the sinterability to improve the technical properties of ceramic bodies made from coal bottom ash and soda-lime glass cullet. Different mixtures of bottom ash and glass cullet were formulated. The amount of bottom ash was 100, 70, 50 and 30 wt.

Electrostatic painting residues as an alternative raw material for red clay industry.

In this study, the viability of using electrostatic painting residues--paint sludge--as a raw material to the red clay industry was investigated. Red clay-based ceramic masses containing electrostatic paint residues were formulated during the study. The clays were obtained from the Rio do Rastro deposit, in Gravataí, and were of the standard formulation used in industry.

Recycling of iron foundry sand and glass waste as raw material for production of whiteware.

The purpose of this study was to evaluate the production feasibility of triaxial whiteware using sand from cast iron moulds as a raw material instead of silica, and recycled glass in place of feldspar. Formulations were prepared using sand, glass waste, and white-firing clay such that only 50% of the composition was virgin material (clay). The ceramic bodies were formed by pressing and fired at different temperatures (between 1100 and 1300 degrees C).