335 research outputs found
Modelli previsionali di dispersione delle emissioni da traffico in ambito urbano
Nel corso dei secoli l'aumento della mobilità è stato comunemente associato al miglioramento della qualità della vita. Per contro, l’emissione di composti in atmosfera da parte dei veicoli a motore comporta la generazione di una pressione negativa sull’ambiente. La stima della dispersione delle emissioni da traffico veicolare risulta complessa in riferimento alle diverse caratteristiche delle aree colpite e dei veicoli utilizzati ma è comunemente perseguita con modelli di calcolo di ampia diffusione. L’impiego di modelli di dispersione in atmosfera risulta di grande utilità per la determinazione delle pressioni sull’ambiente, tuttavia la complessità del fenomeno e le numerose interazioni possibili richiedono una continua innovazione. Il lavoro introduce i più utilizzati strumenti di modellazione della dispersione delle emissioni in atmosfera da traffico veicolare e delle pressioni ambientali ad essi connesse
Transport properties in bilayer Quantum Hall systems in the presence of a topological defect
Following a suggestion given in Phys. Lett. B 571(2003) 621, we show how a
bilayer Quantum Hall system at fillings nu =1/p+1 can exhibit a point-like
topological defect in its edge state structure. Indeed our CFT theory for such
a system, the Twisted Model (TM), gives rise in a natural way to such a feature
in the twisted sector. Our results are in agreement with recent experimental
findings (Phys. Rev. B 72 (2005) 041305) which evidence the presence of a
topological defect in the transport properties of the bilayer system.Comment: 10 pages, 4 figures; talk given by A. Naddeo at "X Training Course in
the Physics of Correlated Electron Systems and High-Tc Superconductors,
Vietri sul Mare (SA),Italy, 3-14 October 200
Environmental odour management by artificial neural network – A review
Unwanted odour emissions are considered air pollutants that may cause detrimental impacts to the environment as well as an indicator of unhealthy air to the affected individuals resulting in annoyance and health related issues. These pollutants are challenging to handle due to their invisibility to the naked eye and can only be felt by the human olfactory stimuli. A strategy to address this issue is by introducing an intelligent processing system to odour monitoring instrument such as artificial neural network to achieve a robust result. In this paper, a review on the application of artificial neural network for the management of environmental odours is presented. The principal factors in developing an optimum artificial neural network were identified as elements, structure and learning algorithms. The management of environmental odour has been distinguished into four aspects such as measurement, characterization, control and treatment and continuous monitoring. For each aspect, the performance of the neural network is critically evaluated emphasizing the strengths and weaknesses. This work aims to address the scarcity of information by addressing the gaps from existing studies in terms of the selection of the most suitable configuration, the benefits and consequences. Adopting this technique could provide a new avenue in the management of environmental odours through the use of a powerful mathematical computing tool for a more efficient and reliable outcome. Keywords: Electronic nose, Environmental pollution, Human health, Odour emission, Public concer
Ultrasonic processes for the advanced remediation of contaminated sediments.
Sediments play a fundamental role in the aquatic environment, so that the presence of contaminants poses severe concern for the possible negative effects on both environmental and human health. Sediment remediation is thus necessary to reduce pollutant concentrations and several techniques have been studied so far. A novel approach for sediment remediation is the use of Advanced Oxidation Processes, which include ultrasound (US). This paper focuses on the study of the ultrasonic effects for the simultaneous reduction of both organic and inorganic contaminants from sediments. To this end, the US technology was investigated as a stand-alone treatment as well as in combination with an electro-kinetic (EK) process, known to be effective in the removal of heavy metals from soil and sediments. The US remediation resulted in higher organic compound degradation, with an average 88% removal, but promising desorption yields (47-84%) were achieved for heavy metals as well. The combined EK/US process was found to be particularly effective for lead. Experimental outcomes highlighted the potential of the ultrasonic technology for the remediation of contaminated sediments and addressed some considerations for the possible scale-up
Efficient and Sustainable Treatment of Tannery Wastewater by a Sequential Electrocoagulation-UV Photolytic Process
Tannery wastewater contains large amounts of pollutants that, if directly
discharged into ecosystems, can generate an environmental hazard. The present
investigation has focused the attention to the remediation of wastewater
originated from tanned leather in Tunisia. The analysis revealed wastewater
with a high level of chemical oxygen demand (COD) of 7376 mgO2/L. The
performance in reduction of COD, via electrocoagulation (EC) or UV photolysis
or, finally, operating electrocoagulation and photolysis in sequence was
examined. The effect of voltage and reaction time on COD reduction, as well as
the phytotoxicity were determined. Treated effluents were analysed by UV
spectroscopy, extracting the organic components with solvents differing in
polarity. A sequential EC and UV treatment of the tannery wastewater has been
proven effective in the reduction of COD. These treatments combined afforded
94.1 % of COD reduction, whereas the single EC and UV treatments afforded
respectively 85.7 and 55.9 %. The final COD value of 428.7 mg/L was found
largely below the limit of 1000 mg/L for admission of wastewater in public
sewerage network. Germination tests of Hordeum Vulgare seeds indicated reduced
toxicity for the remediated water. Energy consumptions of 33.33 kWh/m3 and
314.28 kWh/m3 were determined for the EC process and for the same followed by
UV treatment. Both those technologies are yet available and ready for scale-up
Electrical conductivity of carbon nanofiber reinforced resins: potentiality of Tunneling Atomic Force Microscopy (TUNA) technique
Epoxy nanocomposites able to meet pressing industrial requirements in the
field of structural material have been developed and characterized. Tunneling
Atomic Force Microscopy (TUNA), which is able to detect ultra-low currents
ranging from 80 fA to 120 pA, was used to correlate the local topography with
electrical properties of tetraglycidyl methylene dianiline (TGMDA) epoxy
nanocomposites at low concentration of carbon nanofibers (CNFs) ranging from
0.05% up to 2% by wt. The results show the unique capability of TUNA technique
in identifying conductive pathways in CNF/resins even without modifying the
morphology with usual treatments employed to create electrical contacts to the
ground
Cost-effective removal of COD in the pre-treatment of wastewater from the paper industry
The present paper reveals results of research for cost-effective removal of chemical oxygen demand (COD) contained in industrial paper mill effluent. Not only process efficiency but also wastewater treatment costs are discussed. Different pre-treatment processes are applied aiming to investigate the COD removal before discharge to the municipal sewage network. The objective of this paper is to find the optimal operating conditions for the coagulation process. The effects of key operational parameters, including the type of coagulant, initial pH, temperature and coagulant dose, on COD percentage removal were investigated. The laboratory experiments confirmed the high efficiency of chemically enhanced mechanical treatment towards COD. The data obtained show that even low dose of chemicals provides sufficient COD reduction. The initial pH of the wastewater had a significant impact on the COD removal. Under the optimal operational conditions (pH = 7.5, T = 18 °C) the treatment of wastewater from paper industries by coagulation has led to a reduction of 70% COD for wastewater discharged. In terms of the investigated paper industry wastewater, polyaluminium chloride appears to be most suitable for treatment of high COD concentration. However, in an economic evaluation of requirements for wastewater treatment, operating costs and associated saving were such that PAX was more favourable.Fil: Boguniewicz Zablocka, Joanna. Opole University Of Technology; PoloniaFil: Klosok Bazan, Iwona. Opole University Of Technology; PoloniaFil: Naddeo, Vincenzo. Universita di Salerno; ItaliaFil: Mozejko, Clara Alexandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Avanzados en Ingeniería y Tecnología. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Estudios Avanzados en Ingeniería y Tecnología; Argentin
Editorial: Environmental technologies for the sustainable development of the water and energy sectors.
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