61 research outputs found
Efficient energy harvesting for microbial fuel cell dedicated to wireless sensor network
No full textMicrobial Fuel Cell (MFC) is novel technology for harvesting a fully sustainable zero emissions bioenergy that, by means of dedicated electronic circuits, suitably can be used for the proper functioning of a single Wireless Sensor Network (WSN) node. MFC is a bioreactor that transforms energy stored in chemical bonds of organic compounds into electrical energy. Low-power electronic devices allow now the design of electronic systems characterized by very low energy consumption. Accordingly, this allows the use of power sources based on energy harvesting techniques that involve clean renewable sources as MFC The first section of the paper introduces technological characteristics of the cell. The second one briefly examines the gap between electrical supplying of the cell and the energy requirements of WSN nodes. The design requires the usage of a step-up DC/DC converter, so the last part of the paper deals with the problems that occur when you want realize a system including a single MFC reactor for powering a single WSN nod
Integration of Ground Penetrating Radar with Global Position System and Inertial Measurement Unit for archaeological application
No full textIn the last years, Ground Penetrating Radar (GPR) technology has been used extensively in different fields of heritage investigation. The use of other technics that integrate GPR technology as Global Positioning System (GPS) together with Inertial Measurement Unit (IMU) can effectively improve the precision of buried object location, by means of an efficient control of route and attitude of the GPR. This article aims at investigate on some technics oriented to the issues solution, as those that are consequence of used specific detection methods, e.g. GPR pulled by a terrestrial vehicle or carried by an aerial platform. Moreover, we present a basic structure of our low cost design, which integrates functionalities of GPS and IMU dedicated to GPR’s use
Development of embedded and user-side software for interactive setup of a frequency-modulated continuous wave ground penetrating radar dedicated to educational purposes
No full textThis paper describes the software and firmware programs for interactive control of a frequency-modulated continuous-wave ground-penetrating radar (GPR). The presented radar system is being developed at Sapienza University of Rome in the framework of the project carried out by European Cooperation in Science and Technology (COST) Action TU1208. The research is focused on developing an affordable GPR and introducing it into the educational process. At the current stage of the project a GPR prototype was implemented from off-the-shelf components, it combines cheapness with fine operating characteristics and allows studying different signal modulation patterns. The developed software for the GPR prototype proper functioning was written in Python, it provides graphical user interface allowing simple and convenient user interaction with the system. Moreover, a complementing firmware program was developed to realize control functionalities such as selecting frequency range, period and waveform of the transmitted signal
Improved remediation processes through cost-effective estimation of soil properties from surface measurements
No full textA wide range of technologies is presently available for the remediation of contaminated soils. The optimal selection depends on a number of soil characteristics. However, if the depth of the contaminated layer is considerable, the direct measurement of these properties can be costly and sometimes outright infeasible. In this paper, a method originally developed for the early detection of leaks in landfill liners has been properly modified to accommodate the estimation of soil characteristics. In particular, while the soil properties were considered known parameters in the previous model, they are now present as non-linear parameters and their estimation constitutes the main goal of the article. The resulting algorithm consists in the optimization of a suitable objective function with respect to both linear and non-linear variables and makes it possible to estimate soil characteristics from surface measurements. In particular, it is shown that partitioning linear and non-linear variables into two different sets and regularizing the inverse problems resulting from the discretization of the Richardsâ problem with unknown boundary conditions provides a robust numerical procedure. As an example, the method has been applied to the estimation of soil porosity, demonstrating its robustness and reliability potential. Including an inexpensive estimation procedure for proper soil parameters in the preliminary analysis can greatly improve the performances of remediation technologies whose convenience depends critically on the parameters selected case by case
Wireless Sensor Network Powered by a Terrestrial Microbial Fuel Cell as a Sustainable Land Monitoring Energy System
No full textThis work aims at investigating the possibility of a wireless sensor network powered by an energy harvesting technology, such as a microbial fuel cell (MFC). An MFC is a bioreactor that transforms energy stored in chemical bonds of organic compounds into electrical energy. This process takes place through catalytic reactions of microorganisms under anaerobic conditions. An anode chamber together with a cathode chamber composes a conventional MFC reactor. The protons generated in the anode chamber are then transferred into the cathode chamber through a proton exchange membrane (PEM). A possible option is to use the soil itself as the membrane. In this case, we are referring to, more properly, a terrestrial microbial fuel cell (TMFC). This research examines the sustainability of a wireless sensor network powered by TMFC for land monitoring and precision agriculture. Acting on several factors, such as pH, temperature, humidity and type of soil used, we obtained minimum performance requirements in terms of the output power of the TMFC. In order to identify some of the different network node configurations and to compare the resulting performance, we investigated the energy consumption of the core components of a node, e.g., the transceiver and microcontroller, looking for the best performance
Design and realisation of a cheap GPR for educational purposes
No full textThe paper aims at explaining how to design and realize a frequencymodulated continuous-wave (FCMW) GPR, with detailled informa,on for the step by step construc,on phases, schemes, soGware codes, and all the necessary documenta,on to independently build a GPR prototype
Heavy metals removal and recovery from hazardous leather sludge
No full textThe tanning industry is one of the oldest industries in the world and is known for the production of a wide variety
of toxic waste (aqueous and solid) containing chromium salts and other heavy metals. Solid waste is produced
during the conversion of putrescible collagen fibres into finished non-putrescible leather products. In this
process, the use of a variety of chemicals during the fleshing or trimming phases, results in different hazardous
waste, such as wet blue leather, crust leather, chrome shaving, finished leather off-cuts, and unusable chrome
spilt.
In the present study, we deal with the treatment of these hazardous leather sludge and the recovery of heavy
metals contained in them. The leather sludge was pyrolyzed in a torch plasma reactor at a temperature of 1,400-
1,500 °C producing an inert solid residue. However, the high temperatures involved induce the volatilization of
some metals, which condense to form hazardous dusts (21.8% Zn, 0.70% Cr, 4,080 ppm Pb and 123 ppm Cd)
that have to be properly dealt with. Numerous leaching tests have been conducted to maximize the amount of
the individual components solubilized from the powder. Then, different treatment strategies have been combined
for the recovery of the main metals: precipitation for Pb and Zn, and adsorption on chitosan for Cd
Sustainable Removal of Nitrates from Wastewater Using Membrane Bioreactors
No full textThe presence of nitrogen compounds in surface and groundwater is a serious concern. The treatment
technologies currently used, based mainly on membrane and ion exchange processes, are expensive, complex
and above all not very selective. On the other hand, biological processes are very efficient and selective towards
nitrate, but the phases following denitrification, in which the treated water is separated from the biomass
(potentially harmful to public health), are still very expensive.
In this work, an original solution is proposed that combines biological treatment with the use of membranes to
keep the water to be treated separate from bacterial cultures, thus limiting or eliminating the subsequent
disinfection stages. As a result, efficiencies of up to 98% are achieved depending on operating conditions, while
keeping costs low
Antimicrobial activity of catechol functionalized-chitosan versus Staphylococcus epidermidis
No full textProtein mussel-inspired adhesive polymers, characterized by the presence of catechol groups, possess superior muco-adhesive properties and have great potentiality in wound healing. Suitable materials for wound dressing should properly combine muco-adhesiveness and antimicrobial activity. In this work, catechol-functionalized chitosan was obtained by reaction with hydrocaffeic acid (HCAF), in order to investigate how catechol introduction at different content could affect the intrinsic antimicrobial activity of the polymer itself. Unexpectedly, an enhancement of chitosan antimicrobial activity was observed after catechol functionalization, with a fourfold reduction in the polymer minimum inhibitory concentration versus Staphylococcus epidermidis. Additionally, a commercial wound dressing coated with one of the synthesized CS-HCAF derivatives showed a significant reduction in the adhesion of S. epidermidis compared to the uncoated dressing (3-log reduction). The CS-HCAF derivatives also showed an interesting antioxidant property (EC50 ranging from 20 to 60 μg/mL), which further confirms the potentiality of these materials as wound dressings
Nanofiber applications in microbial fuel cells for enhanced energy generation: a mini review
No full textMicrobial fuel cells (MFCs) represent simple devices that harness the metabolic activities of microorganisms to produce electrical energy from diverse sources such as organic waste and sustainable biomass. Because of their unique advantage to generate sustainable energy, through the employment of biodegradable and repurposed waste materials, the development of MFCs has garnered considerable interest. Critical elements are typically the electrodes and separator. This mini-review article presents a critical assessment of nanofiber technology used as electrodes and separators in MFCs to enhance energy generation. In particular, the review highlights the application of nanofiber webs in each part of MFCs including anodes, cathodes, and membranes and their influence on energy generation. The role of nanofiber technology in this regard is then analysed in detail, focusing on improved electron transfer rate, enhanced biofilm formation, and enhanced durability and stability. In addition, the challenges and opportunities associated with integrating nanofibers into MFCs are discussed, along with suggestions for future research in this field. Significant developments in MFCs over the past decade have led to a several-fold increase in achievable power density, yet further improvements in performance and the exploration of cost-effective materials remain promising areas for further advancement. This review demonstrates the great promise of nanofiber-based electrodes and separators in future applications of MFCs
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