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Zinc oxide (ZnO) mat-based conductometric devices were fabricated using a thermal oxidation technique. A metallic zinc layer was deposited on the alumina transducer and then oxidized in a controlled atmosphere, in order to obtain ZnO nanostructures. Two different batches of sensors have been prepared, and their sensing performances have been evaluated towards oxidizing and reducing gases. Functional measurements showed very good sensing performances towards ethanol and acetone at 500 ° C, and NO2 at 200 ° C, indirectly confirming the n-type behaviour of the material. The influence of the humidity on the response has been explored. In practical conditions the interference of humidity is very small, and could be neglected in many applications. Simultaneous measurements on different devices from the same batch confirm the high reproducibility of the response within the batch. [ABSTRACT FROM AUTHOR]

Abstract: CuO nanowires (NWs) were grown by thermal oxidation of metallic Cu thin layer deposited by sputtering on different substrates. Optimal growth parameters were found, studying the influence of the oxidizing temperature and the atmosphere during the oxidation process. A strong relation between oxidation parameters and morphology has been detected. The preliminary response of this sensing material, using nanowire's mat-based device, to various oxidizing and reducing target gases has been evaluated, in order to corroborate the functional properties of the CuO NWs as potential sensing material under certain conditions and to confirm the p-type conductometric response of the material. [Copyright &y& Elsevier]

Measurement uncertainty in experiments is receiving increasing interest among practitioners both for quantitative and qualitative evaluations. Applications may be found, for example, to compare experiments run in different laboratories, to certify the precision of gauges used in the masurement process or to measure uncertainty in a classification process, i.e. when objects are qualitatively evaluated by appraisers. In this paper, after having briefly presented how to measure uncertainty using gauge repeatability and reproducibility studies, we focus on a problem quite relevant for practitioners: how to deal with the presence of correlation among 'replications'. This issue is common to many food/agriculture experiments. By a modification of a nested mixed effect design, we describe the impact of dependencies among replications on measurement capability. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Al-doped Nickel oxide (Al:NiO) nanostructured thin films, prepared by RF sputtering technique, were tested for NO 2 gas detection. The films were deposited on alumina substrates with thicknesses ranging between 52 nm and 167 nm, while the at.% of Al was varied from 5.0% to 6.7%. The effect of the thickness on the morphological, structural and optical properties was investigated. Moreover, the sensing characteristics were examined and optimized with respect to film thickness and operating temperature (200 °C and 300 °C), at NO 2 concentrations ranging from 200 ppb to 2500 ppb and in presence of a constant relative humidity (RH) of 40%. An ultimate response of 271% towards a NO 2 concentration of 200 ppb at 200 °C was obtained, concluding that Al:NiO can be potentially used as a sensing material for this specific gas. • Highly transparent Al-doped NiO films were grown by rf-sputtering technique at RT followed by post-deposition annealing. • Al atoms were introduced in the NiO structure and increase significantly the conductivity. • Al-doped NiO films appeared to have high response of 271% in 200 ppb NO 2 , at an operation temperature of 200 °C. [ABSTRACT FROM AUTHOR]

This work presents a new porous material (SUNSPACE) designed for air particulate matter (PM) capture. It was developed in answer to the European Commission request of an innovative, affordable, and sustainable solution, based on design-driven material, to reduce the concentration of air particulate matter in urban areas. SUNSPACE material was developed from by-products and low-cost materials, such as silica fume and sodium alginate. Its capability to catch ultrafine PM was evaluated by different ad-hoc tests, considering diesel exhaust fumes and incense smoke PM. Despite the fact that procedures and materials can be designed for remediation, the high impact on the environment, for example in terms of natural resources consumption and emissions, are not usually considered. Instead, we believe that the technologies must be always evaluated in terms of material embodied energy (EE) and carbon footprint (CF). We define our approach to solve environment problems by a sustainable methodology “Azure Chemistry”. For the SUNSPACE synthesis, the multi-criteria decision analysis was performed to select the best sustainable solution. The emissions and the energies involved in the synthesis of SUNSPACE material were evaluated with the Azure Chemistry approach, showing that this could be the best available technology to face the problem of capturing the PM in urban area. [ABSTRACT FROM AUTHOR]

We present a comparative study of gas sensing properties of p-type CuO nanowires, characterized by Kelvin Probe (KP) surface workfunction gas sensing and formal conductometric (chemoresistive) gas sensing schemes, with main emphasis on the detection performance of low concentrations of butanol. P-type CuO nanowires were prepared by thermal oxidation of Cu thin film in a controlled environment at oxidation temperatures of 300 °C and 400 °C. Structural characterizations of grown nanomaterials were carried out by X-ray diffraction, micro-Raman spectrophotometry and scanning electron microscopy (SEM). Butanol sensing responses recorded from both methods were compared and further analyzed to calculate approximate values of electron affinity variations. [ABSTRACT FROM AUTHOR]