Nanofriction behavior of cluster-assembled carbon films

We have characterized the frictional properties of nanostructured (ns) carbon films grown by Supersonic Cluster Beam Deposition (SCBD) via an Atomic Force-Friction Force Microscope (AFM-FFM). The experimental data are discussed on the basis of a modified Amonton's law for friction, stating a linear dependence of friction on load plus an adhesive offset accounting for a finite friction force in the limit of null total applied load. Molecular Dynamics simulations of the interaction of the AFM tip with the nanostructured carbon confirm the validity of the friction model used for this system. Experimental results show that the friction coefficient is not influenced by the nanostructure of the films nor by the relative humidity. On the other hand the adhesion coefficient depends on these parameters.Comment: 22 pages, 6 figures, RevTex

A fixed combination of probiotics and herbal extracts attenuates intestinal barrier dysfunction from inflammatory stress in an in vitro model using Caco-2 cells.

Background: Inflammatory Bowel Diseases (IBD), are considered a growing global disease, with about ten million people being affected worldwide. Maintenance of intestinal barrier integrity is crucial for preventing IBD onset and exacerbations. Some recent patents regarding oily formulations containing probiotics (WO2010122107A1 and WO2010103374A9) and the use of probiotics for gastrointestinal complaints (US20110110905A1 and US9057112B2) exist, or are pending application. Objective: In this work, we studied the effect of a fixed combination of registered Lactobacillus reuteri and Lactobacillus acidophilus strains and herbal extracts in an in vitro inflammation experimental model. Methods: Caco-2 cell monolayer was exposed to INF-\u3b3+TNF-\u3b1 or to LPS; Trans Epithelial Electrical Resistance (TEER) and paracellular permeability were investigated. ZO-1 and occludin Tight Junctions (TJs) were also investigated by mean of immunofluorescence. Results: Pre-treatment with the fixed combination of probiotics and herbal extracts prevented the inflammation-induced TEER decrease, paracellular permeability increase and TJs translocation. Conclusions: In summary, the fixed combination of probiotics and herbal extracts investigated in this research was found to be an interesting candidate for targeting the re-establishment of intestinal barrier function in IBD conditions

Laboratory-scale anaerobic sequencing batch reactor for treatment of stillage from fruit distillation

This work describes batch anaerobic digestion tests carried out on stillages, the residue of the distillation process on fruit, in order to contribute to the setting of design parameters for a planned plant. The experimental apparatus was characterized by 3 reactors, each with a useful volume of 5 L. The different phases of the work carried out were: determining the basic components of the Chemical Oxygen Demand (COD) of the stillages; determining the specific production of biogas; and estimating the rapidly biodegradable COD contained in the stillages. In particular, the main goal of the anaerobic digestion tests on stillages was to measure the parameters of Specific Gas Production (SGP) and Gas Production Rate (GPR) in reactors in which stillages were being digested using ASBR (Anaerobic Sequencing Batch Reactor) technology. Runs were developed with increasing concentrations of the feed. The optimal loads for obtaining the maximum SGP and GPR values were 8\u20139 gCOD L-1 and 0.9 gCOD g-1VS

Assessment Of Environmental Impact From Renewable And Non-renewable Energy Sources

The scientific studies show that the greatest amount of CO2 emissions, in the European Union, results from the production of electricity and heat (for example, the production of coal-based energy in the EU Member States generates an amount of approximately one billion tons of CO2 emissions, that is about 1/4 of total CO2 emissions in the EU). The waste sector is a significant contributor to greenhouse gas (GHG) emissions accountable for approximately one twentieth of the global greenhouse budget. This contribution consists of CH4 emission from waste anaerobic decomposition and CO2 from thermal treatments. This study presents some district heating preliminary considerations through thermo-chemical conversion of renewable and non-renewable sources. Three locations are virtually analyzed, two counties from Romania and one from Italy. A comparison is made between using different potential types of fuel: wood, coal, MSW, residual municipal solid waste (RMSW), bio-dried waste (BD) and solid-recovered fuel (SRF). The lower heating values (LHVs) of the two types of studied lignite (coal from Romania and Italy) are higher in comparison with the LHV of MSW, similar to the ones of RMSW and BD waste, but lower to the ones of SRF and wood, with some exceptions. Data suitable for preliminary global environmental balances and local impact considerations from atmospheric emissions were carried out for the quantity of primary fuel as presented. Results demonstrate that, even from the preliminary considerations, the environmental performances of district heating are strongly affected by the choice of the fuel.This paper work has been partially funded by Erasmus+ under financial agreement 2014-1-RO01-KA203-002986

Tamanho mínimo de amostra de plantas e frutos do algodoeiro para monitoramento das populações de Anthonomus grandis Boh. (Coleoptera: Curculionidae).

Dois modelos estatísticos foram desenvolvidos visando determinar o tamanho mínimo de amostra para monitoramento de populações do bicudo do algodoeiro, Anthonomus grandis Boh. (Coleoptera: Curculionidae). A amostra consistiu no número mínimo de plantas e/ou frutos do algodoeiro avaliados para se detectar as densidades populacionais do inseto próximas ao limiar econômico, considerando-se ainda a área da cultura a ser monitorada

Aeraulic behaviour of a biotrickling filter pilot plant: experiments and simulations

Trickling bed biofilters (or biotrickling filters, BTFs) are biological systems for polluted air treatment. Hydrodynamics of BTFs, and reactors in general, is of paramount importance for obtaining good performances. In fact, a non-uniform distribution of the pollutant into the bed brings to dead zones or bypass which reduce the bed working volume and, therefore, cause low removal efficiencies. The paper presents the preliminary results obtained regarding the aeraulic behavior of a BTF pilot plant with seashells as packing material. Experimental results of bed void fraction and pressure drop at several flow rates were used to obtain Ergun equation coefficients for dry bed. A numerical simulation of the reactor flow field carried out with a commercial CFD (Computational Fluid Dynamics) code, validated by the means of velocity measurements made with a Hot Wire Anemometer (HWA) completed the analysis of the reactor hydrodynamics

Potentials of the waste-to-energy sector for an unconventional district heating system

In spite of being a process that exploits a renewable source of energy, the combustion of wood-based biomass contributes to deteriorate outdoor and indoor air quality. Critical situations for human exposure may occur in mountainous areas, where wood-based biomass is usually abundant and the complex morphology may favour the stagnation of air pollutants in valleys. Replacing wood/pellet stoves with centralised systems would reduce the impact, but the construction of district heating systems may not be convenient in areas with low density of houses. A possible solution could rely on direct electrical heating (DEH) systems, preferably fed by thermochemical processes that help achieve environmental goals for the local community, like the reduction of waste landfilling and the valorisation of the energy content of waste. This paper aims at presenting a comparison between the impacts expected by household wood/pellet stoves and by a modern waste-to-energy (WtE) plant, in terms of emissions of air pollutants into the atmosphere, when replacing wood stoves with a DEH system fed by the electric energy generated by the WtE plant. The comparison shows that the replacement of household stoves with an equivalent DEH system would be beneficial in terms of impacts on the local air quality. Such an approach could be considered to reduce the health impacts from biomass burning in critical areas like the Alpine region

Poultry manure gasification and its energy yield

The disposal of poultry manure is one of the main problems of the poultry sector. The results of some tests developed in a gasification pilot plant are presented in this paper. The aim was to preliminarily analyze the energy generation from poultry manure treated by gasification. The level of energy yields and the quantification of the produced syngas are also reported. The good results suggests an possible application at full scale

PCDD/F Emissions From Virgin And Treated Wood Combustion

Energy from biomass is becoming increasingly important as fossil fuel reserves diminish. The utilization of biomass is already prevalent in the domestic heating sector, but produces significant amounts of pollutants that are detrimental to human health. Dioxins, formed in any combustion process where carbon, oxygen and, chlorine are present, are a subject of major interest due to their carcinogenicity. Much research has been carried out to study emissions from hazardous and municipal waste incinerators. Dioxin emission from wood combustion plants are also of interest, especially those due to combustion of treated, varnished or PVC-coated wood, which can produce high polychlorinated dibenzofurans (PCDD/F) emissions. This study compares the PCDD/F emissions produced by burning treated wood and virgin wood to verify if the differences are significant. Six different wood samples were analysed (three of treated wood and three of virgin wood) and a two-step wood gasification boiler was used. The analysis has been conducted both on off gas and on ashes. The measured PCDD/F concentrations are to be considered particularly limited and the treated wood use does not cause a general worsening in the PCDD/F emission. Thus, the wood treatment – subject of study – is not dangerous for PCDD/F. Finally, the experimental results indicated that during the thermal treatment, the formation mechanism of PCDD/F is the de novo synthesis