Produzione e caratterizzazione di acqua attivata mediante plasmi freddi atmosferici per applicazioni in agricoltura

This thesis is concerned with the production and characterization of PAW and its application to promote seeds germination. Two low temperature plasma devices operating at atmospheric pressure will be compared: an RF capacitively coupled source, COST Reference Microplasma Jet and another jet based on a DBD configuration, thus named DBD jet. After plasma treatments, variations of physicochemical properties induced in PAW, such as dissolved oxygen content, electrical conductivity, pH and concentrations of the main reactive species, were measured. Finally, the effects of the resulting solutions in enhancing germination were investigated, through the use of these liquids for the imbibition of two varieties of radish seeds (Raphanus sativus var. Sativus), chosen as model seeds

Optical trapping and critical Casimir forces

Critical Casimir forces emerge between objects, such as colloidal particles, whenever their surfaces spatially confine the fluctuations of the order parameter of a critical liquid used as a solvent. These forces act at short but microscopically large distances between these objects, reaching often hundreds of nanometers. Keeping colloids at such distances is a major experimental challenge, which can be addressed by the means of optical tweezers. Here, we review how optical tweezers have been successfully used to quantitatively study critical Casimir forces acting on particles in suspensions. As we will see, the use of optical tweezers to experimentally study critical Casimir forces can play a crucial role in developing nano-technologies, representing an innovative way to realize self-assembled devices at the nano- and microscale.Comment: 18 pages, 11 figure

Energy recovery and efficiency improvement for an activated sludge, agro-food WWTP upgrade

Abstract Wastewater treatment's primary purpose is to protect surface water quality, aquatic life, beneficial and recreational uses of waterways, and primarily comply with local water emission standards. Lately, additional requirements were added for these facilities, concerning minimization of a series of sidestream environmental impacts (i.e., odours, generated waste by-products, etc.), air emissions, including CO2, methane and nitrogen greenhouse gases (GHGs), and mitigation of various other likely impacts resulting from energy and chemical use in treatment processes. This paper describes a case study in Northern Europe, where critical analysis of an industrial wastewater treatment plant's present conditions, during an evaluation of upgrade possibilities to improve regulatory compliance, led to a sustainable intervention proposal. According to the formulated proposal, process improvement, energy recovery, and overall savings and GHG emissions reduction could be simultaneously achieved with a series of relatively simple interventions

Análisis de las características del periodismo económico en el tratamiento informativo del suplemento de economía y negocios Emprendedores (2009)

RESUMEN En la actualidad, los temas de economía, finanzas y negocios han dejado de ser exclusivos de los especialistas en el sector para interesar al público en general. Por eso, los medios especializados en economía de la prensa escrita deben tener un tratamiento informativo, independientemente de su estilo, acorde con las características del periodismo económico: cuanto más claro, didáctico y utilitario sea, tendrán una mejor comunicación con su público. La presente investigación aporta información específica sobre la presencia de las características del periodismo económico en el estilo del tratamiento informativo de las publicaciones especializadas en economía, a partir del caso del suplemento de economía y negocios Emprendedores del diario La Industria de Trujillo, Perú.ABSTRACT Nowadays, economics, finance and business are no longer exclusive to specialists in this subjects but it’s in the general public’s interest. For this reason, the specialized media in the written press must have an informative treatment, regardless of their style, according to the characteristics of business journalism: the clearer, didactic and utilitarian, they will have a better communication with their public. The present research focuses on providing specific information about the characteristics of business journalism in the style of informative treatment of specialized publications in economics, studying the case of Emprendedores, the business supplement of La Industria, newspaper from Trujillo, Peru

In situ groundwater remediation with bioelectrochemical systems: A critical review and future perspectives

Groundwater contamination is an ever-growing environmental issue that has attracted much and undiminished attention for the past half century. Groundwater contamination may originate from both anthropogenic (e.g., hydrocarbons) and natural compounds (e.g., nitrate and arsenic); to tackle the removal of these contaminants, different technologies have been developed and implemented. Recently, bioelectrochemical systems (BES) have emerged as a potential treatment for groundwater contamination, with reported in situ applications that showed promising results. Nitrate and hydrocarbons (toluene, phenanthrene, benzene, BTEX and light PAHs) have been successfully removed, due to the interaction of microbial metabolism with poised electrodes, in addition to physical migration due to the electric field generated in a BES. The selection of proper BESs relies on several factors and problems, such as the complexity of groundwater and subsoil environment, scale-up issues, and energy requirements that need to be accounted for. Modeling efforts could help predict case scenarios and select a proper design and approach, while BES-based biosensing could help monitoring remediation processes. In this review, we critically analyze in situ BES applications for groundwater remediation, focusing in particular on different proposed setups, and we identify and discuss the existing research gaps in the field. Keywords: Bioelectrochemical systems, In situ treatment, Groundwater remediation, Bioelectroremediation, Denitrification, Microbial electrochemical technologie

Industrial wastewater treatment with a bioelectrochemical process: assessment of depuration efficiency and energy production

Abstract Development of renewable energy sources, efficient industrial processes, energy/chemicals recovery from wastes are research issues that are quite contemporary. Bioelectrochemical processes represent an eco-innovative technology for energy and resources recovery from both domestic and industrial wastewaters. The current study was conducted to: (i) assess bioelectrochemical treatability of industrial (dairy) wastewater by microbial fuel cells (MFCs); (ii) determine the effects of the applied organic loading rate (OLR) on MFC performance; (iii) identify factors responsible for reactor energy recovery losses (i.e. overpotentials). For this purpose, an MFC was built and continuously operated for 72 days, during which the anodic chamber was fed with dairy wastewater and the cathodic chamber with an aerated mineral solution. The study demonstrated that industrial effluents from agrifood facilities can be treated by bioelectrochemical systems (BESs) with >85% (average) organic matter removal, recovering power at an observed maximum density of 27 W m−3. Outcomes were better than in previous (shorter) analogous experiences, and demonstrate that this type of process could be successfully used for dairy wastewater with several advantages

Controlling the dynamics of colloidal particles by critical Casimir forces

Critical Casimir forces can play an important role for applications in nano-science and nano-technology, owing to their piconewton strength, nanometric action range, fine tunability as a function of temperature, and exquisite dependence on the surface properties of the involved objects. Here, we investigate the effects of critical Casimir forces on the free dynamics of a pair of colloidal particles dispersed in the bulk of a near-critical binary liquid solvent, using blinking optical tweezers. In particular, we measure the time evolution of the distance between the two colloids to determine their relative diffusion and drift velocity. Furthermore, we show how critical Casimir forces change the dynamic properties of this two-colloid system by studying the temperature dependence of the distribution of the so-called first-passage time, i. e., of the time necessary for the particles to reach for the first time a certain separation, starting from an initially assigned one. These data are in good agreement with theoretical results obtained from Monte Carlo simulations and Langevin dynamics

Ligand signature in the membrane dynamics of single TrkA receptor molecules

The neurotrophin receptor TrkA (also known as NTRK1) is known to be crucially involved in several physio-pathological processes. However, a clear description of the early steps of ligand-induced TrkA responses at the cell plasma membrane is missing. We have exploited single particle tracking and TIRF microscopy to study TrkA membrane lateral mobility and changes of oligomerization state upon binding of diverse TrkA agonists (NGF, NGF R100E HSANV mutant, proNGF and NT-3). We show that, in the absence of ligands, most of the TrkA receptors are fast moving monomers characterized by an average diffusion coefficient of 0.47 μm^2/second; about 20% of TrkA molecules move at least an order of magnitude slower and around 4% are almost immobile within regions of about 0.6 mm diameter. Ligand binding results in increased slow and/or immobile populations over the fast one, slowing down of non-immobile trajectories and reduction of confinement areas, observations that are consistent with the formation of receptor dimeric and oligomeric states. We demonstrate that the extent of TrkA lateral mobility modification is strictly ligand dependent and that each ligand promotes distinct trajectory patterns of TrkA receptors at the cell membrane (ligand ‘fingerprinting’ effect). This ligand signature of receptor dynamics results from a differential combination of receptor-binding affinity, intracellular effectors recruited in the signalling platforms and formation of signalling and/or recycling endosome precursors. Thus, our data uncover a close correlation between the initial receptor membrane dynamics triggered upon binding and the specific biological outcomes induced by different ligands for the same receptor