https://www.ucl.ac.uk/~ucaptt0/toxicology-nanoparticles%202011.pdf

Toxicology and clinical potential of nanoparticles.

Understanding the relationships between the physicochemical properties of engineered nanomaterials and their toxicity is critical for environmental and health risk analysis. However, this task is confounded by material diversity, heterogeneity of published data and limited sampling within individual studies. Here, we present an approach for analysing and extracting pertinent knowledge from published studies focusing on the cellular toxicity of cadmium-containing semiconductor quantum dots. From 307 publications, we obtain 1,741 cell viability-related data samples, each with 24 qualitative and quantitative attributes describing the material properties and experimental conditions. Using random forest regression models to analyse the data, we show that toxicity is closely correlated with quantum dot surface properties (including shell, ligand and surface modifications), diameter, assay type and exposure time. Our approach of integrating quantitative and categorical data provides a roadmap for interrogating the wide-ranging toxicity data in the literature and suggests that meta-analysis can help develop methods for predicting the toxicity of engineered nanomaterials. Literature data mining and knowledge extraction (known as meta-analysis) can be used to derive the relationships between toxicological outcome and the physicochemical properties of cadmium-containing quantum dots.

Meta-analysis of cellular toxicity for cadmium-containing quantum dots

In recent years, nanoparticles (NPs) have increasingly found practical applications in technology, research, and medicine. The small particle size coupled with their unique chemical and physical properties is thought to underline their exploitable biomedical activities. Its form may be latex body, polymer, ceramic particle, metal particles, and the carbon particles. Due to their small size and physical resemblance to physiological molecules such as proteins, NPs possess the capacity to revolutionise medical imaging, diagnostics, therapeutics, as well as carry out functional biological processes. But these features may also underline their toxicity. Indeed, a detailed assessment of the factors that influence the biocompatibility and toxicity of NPs is crucial for the safe and sustainable development of the emerging NPs. Due to the unique structure, size, and shape, much effort has been dedicated to analyzing biomedical applications of nanotubes. This paper focuses on the current understanding of the biocompatibility and toxicity of NPs with an emphasis on nanotubes.

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Biocompatibility and toxicity of nanoparticles and nanotubes

Extensive worldwide validation and climate sensitivity analysis of direct irradiance predictions from 1-min global irradiance

A prior requirement to the design of any solar-based conversion systems is the knowledge of optimum orientation and tilt surface at which peak solar energy can be collected. In many parts of the world, however, the solar radiation data for the surfaces of interest are not always available. This paper presents a numerical approach to calculate the solar radiation on sloped planes by integrating the measured sky radiance distributions. The annual total solar yield at different sloped surfaces
facing various orientations and monthly solar radiations at the optimal tilt surface and three vertical planes facing east, south, and west were determined. The energy outputs and efficiencies were simulated using a computer package. The environmental benefits in terms of greenhouse gases reductions and cost implications were also considered. The findings provide technical information for engineers to design and evaluate photovoltaic (PV) systems which could contribute to the environmental, energy, and economic aspects.

/pdf/determining-the-optimum-tilt-angle-and-orientation-for-solar-492mp0a1s6.pdf

Determining the Optimum Tilt Angle and Orientation for Solar Energy Collection Based on Measured Solar Radiance Data

The aim of this study was to assess the effects of a series of different surface coated quantum dots (QDs) (organic, carboxylated [COOH] and amino [NH₂] polytethylene glycol [PEG]) on J774.A1 macrophage cell viability and to further determine which part of the QDs cause such toxicity. Cytotoxic examination (MTT assay and LDH release) showed organic QDs to induce significant cytotoxicity up to 48 h, even at a low particle concentration (20 nM), whilst both COOH and NH₂ (PEG) QDs caused reduced cell viability and cell membrane permeability after 24 and 48 h exposure at 80 nM. Subsequent analysis of the elements that constitute the QD core, core/shell and (organic QD) surface coating showed that the surface coating drives QD toxicity. Elemental analysis (ICP-AES) after 48 h, however, also observed a release of Cd from organic QDs. In conclusion, both the specific surface coating and core material can have a significant impact on QD toxicity.

Quantum dot cytotoxicity in vitro: an investigation into the cytotoxic effects of a series of different surface chemistries and their core/shell materials.

The effects of surfactants on the dynamics and characteristics of plain and composite electroless nickel plating (ENP) are highlighted and discussed herein. An outline of the rudiments of surfactants and some underlying selection criteria is presented at the outset, before emphasis is laid on the salient benefits of introducing such external agents during the plating process. Evidence suggests that their influence on key coating characteristics such as the rate of deposition, structure, corrosion resistance, and the degree of second-phase particle incorporation into the nickel matrix is significant, and depending on the nature and concentration of surfactant employed, can be of immense value to the system.

On the Influence of Surfactant Incorporation during Electroless Nickel Plating

The influence of a surfactant on the composition of nickel – yttria stabilised zirconia (YSZ) cermet coatings, applied by electroless nickel plating technique was examined. The amphiphilic characteristics of anionic surfactant sodium dodecyl sulphate (SDS), was relied upon for enhanced dispersion of YSZ particles co-deposited for use as anodes in solid oxide fuel cell technology and potential heat absorbing layers in thermal barrier coatings. Optical microscopy was employed to study the correlation between the plating thickness, level of ceramic loading and SDS concentration while the effect of the surfactant and fineness of YSZ particles on the as-deposited coating’s ceramic to metal ratio, was analysed using energy dispersive X-ray analysis (EDXA) characterisation technique.

/pdf/effect-of-sodium-dodecyl-sulphate-on-the-composition-of-3dbylzpn7n.pdf

Effect of Sodium Dodecyl Sulphate on the Composition of Electroless Nickel—Yttria Stabilized Zirconia Coatings

The paper discusses optimising work on a method of processing ceramic / metal composite coatings for various applications and is based on preliminary work on processing anodes for solid oxide fuel cells (SOFCs). The composite coating is manufactured by the electroless co-deposition of nickel and yttria stabilised zirconia (YSZ) simultaneously on to a ceramic substrate. The effect on coating characteristics of substrate surface treatments and electroless nickel bath parameters such as pH and agitation methods are also investigated. Characterisation of the resulting deposit by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA) is also discussed. Keywords—Electroless deposition; nickel; YSZ; composite

Manufacture of Electroless Nickel/YSZ Composite Coatings

This article provides an overview of energy loads associated with the application of powder coated aluminium profiles on the exterior wooden surface of double glazed windows. The entire powder coating process has been analysed to measure its energy and environmental contribution towards window cladding. Materials involved in aluminium clad windows have been analysed for their energy impacts. The energy embodied in a standard double glazed 1.2 m × 1.2 m aluminium clad window has been calculated, and is quantified as 1459 MJ, 1967 MJ, and 5.96 GJ respectively for argon, krypton and xenon infill gases. The energy consumed in powder coating the window cladding has been estimated to be 27 MJ and the total embodied energy of adding aluminium cladding to the window has been evaluated as 724 MJ.

Alan Davidson

Papers

Quantum dot cytotoxicity in vitro: an investigation into the cytotoxic effects of a series of different surface chemistries and their core/shell materials.

On the Influence of Surfactant Incorporation during Electroless Nickel Plating

Effect of Sodium Dodecyl Sulphate on the Composition of Electroless Nickel—Yttria Stabilized Zirconia Coatings

Manufacture of Electroless Nickel/YSZ Composite Coatings

Embodied energy analysis of aluminium-clad windows