Search results for "Composite"

Assessing the sustainability of small wastewater treatment systems: A composite indicator approach

2014

The assessment of the sustainability of wastewater treatment (WWT) systems has gained interest in recent years. However, most previous studies have focused on environmental and/or economic dimensions ignoring social aspects. Moreover, they tend to be based on sets of indicators rather than providing a holistic assessment. To overcome this limitation, this paper proposes an innovative methodology to assess the sustainability of WWT systems based on the development of a composite indicator embracing economic, environmental and social issues. Subsequently, the global sustainability of seven WWT technologies for secondary treatment in small communities is compared. The joint application of the …

Selective and Sensitive Chromogenic Detection of Cyanide and HCN in Solution and in Gas Phase

2013

Two triphenylmethane based chemodosimeters for selective and chromogenic sensing of cyanide anions in aqueous environments and of hydrogen cyanide in gas phase were prepared and studied.

Isoelectronic series of twofold coordinated Si, Ge, and Sn atoms in glassy SiO2: a luminescence study

1992

Abstract Luminescence centers causing optical absorption bands in the 5 eV region in oxygen-deficient pure (‘Si-doped’), as well as in Ge- and Sn-doped glassy SiO2 were studied. The spectral and particularly kinetic data show that in all cases luminescence centers with closely similar properties exist which constitute an isoelectronic series. They are attributed to defects, formed by electrically neutral twofold coordinated Si, Ge, and Sn atoms (T20 centers) in glassy SiO2. Twofold coordinated Si causes the characteristic ‘B2’ optical absorption band at 5.03 eV. Upon reaction with atomic hydrogen, T20 centers convert to the well known ‘H(I)’, ‘H(II)’ and ‘H(III)’ ESR-active defects. The alt…

Solution-Processed Ni-Based Nanocomposite Electrocatalysts: An Approach to Highly Efficient Electrochemical Water Splitting

2021

In this study, we report an up-scalable and low-cost solution-processed method to in situ synthesize an earth-abundant non-stoichiometric NiOx-based electrocatalytic film for water oxidation. The catalytic activity was found to be inversely proportional to the baking temperature, which varied from 50 to 500 °C. We found the formation of a hybrid nanocomposite thin film of NiOx nanocrystals (<2 nm size) inside an acetate-based organic matrix at low temperatures (<200 °C). The defective and short-range structural order of the NiOx-based nanocomposite electrocatalysts, compatible with lattice stress, low electrical conductivity, and high density of catalytically active surface species, and hig…

Dynamic composition of services : application to designing and developping information systems in a distributed environment

2010

The service oriented computing paradigm plays an increasingly important role in structuring complex systems. Application design and development approaches are witnessing a shift from traditional models towards a more dynamic service oriented model promoting reuse and adaptability. In this thesis, we study an approach for application design and development based on services’ composition. We propose DyCoSe, an environment for sharing services. It consists of an enterprise ecosystem wherein members, organized in communities, share a global agreement describing traditional business functionalities and common non-functional properties. DyCoSe relies on a three level architecture for service base…

Influence of the Substituent on Selective Photocatalytic Oxidation of Aromatic Compounds in Aqueous TiO2 Suspensions.

2006

Experimental results are reported showing that the photocatalytic oxidation of aromatic compounds containing an electron-donor group (EDG) gives rise mainly to ortho- and para-monohydroxy derivatives while in the presence of an electron-withdrawing group (EWG) all the monohydroxy derivatives are obtained.

Reuse and recycling in construction: novel photocatalytic nano-mortars from valorised industrial wastes

2021

Production of novel eco-composite nano-mortars for architectural finishing, designed to combat environmental pollution affecting building shells, is reported. Specimens consist of a natural hydraulic lime mortar matrix doped with various kinds of nanophotocatalysts, produced from valorized industrial wastes: TiO2-hexaferrite from Fe3O2, and Ti(SO4)2-hydroxyapatite from Atlantic codfish bones. Samples were characterized and their photocatalytic activity was evaluated. Analysis showed that industrial wastes may be usefully reused to produce a new generation of sustainable, cheap and multifunctional novel building materials.

Influence of Nylon 6,6 nanofiber mats on cure behavior and properties of CFR epoxy resin

2014

In this work Nylon 6,6 nanofibrous mats produced by electrospinning were used as interlayers in carbon fiber reinforced laminates. A high crossilinked epoxy resin was chosen as matrix. The effects of polymeric mats on cure behavior, thermal and delamination properties of the composite laminates were investigated.

Preparation and photocatalytic activity of ZnO-SnO2, ZnO-ZnWO4 and SnO2-ZnO-ZnWO4 nanocomposites

2014

Printable Thermo- and Photo-stable Poly(D,L-lactide)/Carbon Nanodots Nanocomposites via Heterophase Melt-Extrusion Transesterification

2022

We propose for the first time an one-pot synthesis of carbon nanodots-poly(D,L-lactide) (CDs-PLA) nanocomposites, obtained by a simple reactive melt-extrusion process involving polar surface groups of multicolor CDs and ester bonds of PLA chains. Apart from providing an excellent method to produce polyester-coated CDs, our protocol allows obtaining perfect PLA@CDs blends giving rise to homogeneous extruded PLA@CDs filaments (ePLA@CDs) suitable for 3D printing applications (e.g., additive manufacturing for biomaterials and biodegradable encoded polymer ink technology). We demonstrate that ePLA@CDs filaments can be used to build a huge range of fluorescent objects with increasing architectura…