1,182 research outputs found
Sustainable landfilling: hybrid bioreactors and final storage quality
No full textModern landfilling constitutes an unavoidable final step in solid waste management. It aims to close the “Material Cycle” bringing elements back to the non-mobile state they were in before their extraction. At the same time, the application of Sustainability Principle to landfills prescribes to guarantee environmental protection and health safety, ensuring that the disposed waste will be chemically and biochemically stable within a reasonable amount of time. A “Sustainable Landfill” must combine these two fundamental purposes, balancing the efforts to obtain a “sustainable closure of material loop”.
The enhancement of biochemical processes in a landfill, with the purpose of reaching faster environmentally safe conditions and terminate the post closure care, is one of the main debated topics in waste management scientific literature. The general aim of the PhD project was giving a contribution to this debate through the lab-scale testing of systems able to simulate landfills behaviour and the analysis of the long-term expectable chemical status of waste undergone to sustainable landfilling.
The first part of the work is an overview on the basic biochemical processes in landfills and on the laboratory-scale landfill simulation tests. The approach used by the PhD student is mainly experimental, starting from the design and the management of several laboratory-scale landfill simulation tests. The elaboration of the obtained data was useful for evaluating the performances of the tested bioreactor concepts as well as for comparing the results to other scientific data derived from a thorough bibliographic research. The original work produced by the student can be subdivided in three different arguments.
The Semi-aerobic, Anaerobic, Aerated (S.An.A. ®) hybrid bioreactor is an innovative landfill concept, lab-scale run with promising results concerning the enhancement of methane production and the reduction of the long-term emissions.
The effects of the recirculation of reverse osmosis leachate concentrate inside the landfill have been analysed to check if the potential accumulation of contaminants in waste body can turn this practice unsustainable.
The Final Storage Quality (FSQ) procedure, for endorsing the landfill Post Closure Care termination, was tested on an over-stabilized waste of which total emissions and chemical speciation of main elements were calculated.Il moderno sistema di deposito finale dei rifiuti in discarica costituisce un passaggio inevitabile nella gestione dei rifiuti solidi. Il suo scopo è chiudere il “ciclo della materia” riportando gli elementi allo stato di immobilità in cui erano prima di essere estratti. Contemporaneamente, l’applicazione del principio di sostenibilità alle discariche prescrive di garantire la salvaguardia ambientale e della salute, assicurando che il rifiuto smaltito diventi chimicamente e bio-chimicamente stabile entro un tempo “ragionevole”. Una “Discarica Sostenibile” deve combinare questi due principi, bilanciando i contributi per ottenere una “chiusura sostenibile del ciclo della materia”.
Il potenziamento dei processi biochimici in discarica, con lo scopo di raggiungere più velocemente condizioni che garantiscano la salvaguardia ambientale e terminare la fase di post-chiusura, è uno degli argomenti più dibattuti nella letteratura scientifica inerente alla gestione dei rifiuti. Lo scopo generale del progetto di dottorato è stato contribuire a questo dibattito, mediante lo svolgimento di test in scala di laboratorio utili a simulare l’andamento dei processi in discarica e analizzando lo stato biochimico finale dei rifiuti trattati.
La prima parte del lavoro consiste in una panoramica sui processi biochimici in discarica e sulla metodica dei test biochimici in scala di laboratorio. L’approccio usato dallo studente in questa tesi è principalmente sperimentale, basato sulla progettazione, l’esecuzione e la rielaborazione dei dati di svariate simulazioni di discarica in laboratorio. La discussione dei risultati ottenuti è stata propedeutica alla valutazione delle performance dei modelli concettuali testati così come al confronto con altri risultati ottenuti grazie a una approfondita ricerca bibliografica. Il lavoro originale svolto dallo studente può essere diviso in tre progetti principali.
Il reattore ibrido Semi-aerobico, Anaerobico, Aerato (S.An.A ®) è una concetto innovativo testato in scala di laboratorio con promettenti risultati per quanto concerne la stimolazione della produzione di metano e la riduzione delle emissioni di lungo termine.
Gli effetti del ricircolo del concentrato di percolato da osmosi inversa all’interno del corpo rifiuti di una discarica sono stati analizzati per verificare se possano esistere potenziali accumuli di contaminanti che rendano insostenibile tale pratica.
La procedura di Final Storage Quality (FSQ) per determinare la chiusura della fase di aftercare di una discarica è stata testata su un rifiuto sovra-stabilizzato di sui sono state calcolate emissioni totali e la speciazione chimica degli elementi principali
POWER OPTIMIZATION OF DIGITAL IP MACROCELLS FOR EMBEDDED CONTROL SYSTEMS
No full textThis paper addresses the problem of power optimization of Intellectual Property (IP) digital macrocells in embedded control systems. With reference to the case study of an 8051-compliant microcontroller, first the IP cell is analyzed to highlight the main building blocks contributing to power consumption; then Register Transfer Level (RTL) techniques such as state encoding, clock gating and operand isolation are applied to reduce dynamic power consumption. As final result, when implementing the original and the modified IP in submicron CMOS standard-cells technology, a considerable decrease of power consumption, up to 40%, is achieved at the expenses of limited area and timing overheads. Our custom clock gating is also compared to the automatic clock gating insertion performed by commercial CAD tools, proving its higher power optimization efficiency. The proposed approach preserves the IP high-reusability and technology independence, as it only consists of modifications to the VHDL source code. Being technology and CAD independent, these architecture-level optimizations can be combined with other low-power techniques proposed in literature at different design levels
Power optimization of an 8051-compliant IP microcontroller
No full textSeveral IP cells are available in the market to implement 8051-compliant microcontroller in embedded systems. Yet they frequently lack features that have become a key point in such systems, like power optimization. This paper aims at lowering the power consumption of an 8051 IP core while keeping unaltered performances, through Register Transfer Level techniques such as clustered clock gating, operand isolation and state encoding. This approach preserves the IP high-reusability and technology independence, as it only consists of modifications to the source VHDL code. A total power reduction of about 40% is achieved, with limited area overhead
Strategies for the multivariate representation of micro-environmental design space. Considerations on parallel coordinates plot
No full textThis paper reports the results of experiences with the use of parallel coordinates plots for the analysis of multi-objective, multivariate problems for architectural design at the micro-environmental scale, as possible through the support of thermal and lighting simulation analyses.
Parametric analyses applied at the micro-urban level may produce a wealth of information which is difficult to exploit for what both design and decision-taking are concerned. One reason for this is the sheer difficulty of producing convincing visual representations of the complex relations between the most relevant variables in play.
Pragmatic strategies for the use of parallel coordinate plots have been experimented by the author to produce pictorially eloquent representations blending quantitative and quantitative information. This was mainly done through three strategies:
- texturing, allowing for an increase of understandability of large data domains;
- layering, through the superimposition of suitably treated representations of distinct objective functions;
- filtering, through the application of threshold levels to objective functions
Myeloid cells in the tumor microenvironment: role of adenosine
No full textAdenosine, deriving from ATP released by dying cancer cells and then degradated in the tumor
environment by CD39/CD73 enzyme axis, is linked to the generation of an immunosuppressed
niche favoring the onset of neoplasia. The effects of adenosine are mediated by four adenosine
receptors, named A1, A2A, A2B and A3, that are widely expressed on several immune cell
populations. A critical role of this nucleoside is emerging in the modulation of myeloid cell subsets
accumulation and functions into tumor microenvironment, providing new insights that might be
useful for the development of novel therapeutic approaches aimed to undermine the immune
privileged sites where cancer cells grow and proliferat
Voiceless Victims in Sin tetas no hay paraíso
No full textIn his article Voiceless Victims in Sin tetas no hay paraíso Henry James Morello discusses Gustavo Bolívar\u27s Sin tetas no hay paraiso. The novel is, in Bolívar\u27s words, his way of bringing attention to the problem of young women in Colombia using prostitution in order to pay for plastic surgery a very specific problem facing the youth of Colombia. However, at what price is the success of the novel? Or, rather, who is compromised as a result of this cultural phenomenon? The author may have intended to write a novel that called attention to the problems facing Colombian society, the result, however, is very different. The outcome of the novel and its subsequent telenovela incarnations is nothing short of the reification and commodification of the people of Pereira, Colombia. In examining Bolivar\u27s choice of genre and narrative voice, Morello argues that Bolivar\u27s claim to bring attention to a terrible situation breaks down
sj-pdf-1-vet-10.1177_03009858241244853 – Supplemental material for Hypoxia-associated markers in the prognosis of oral canine melanoma
No full textSupplemental material, sj-pdf-1-vet-10.1177_03009858241244853 for Hypoxia-associated markers in the prognosis of oral canine melanoma by Cecilia Gola, Lorella Maniscalco, Selina Iussich, Emanuela Morello, Matteo Olimpo, Eugenio Martignani, Paolo Accornero, Davide Giacobino, Eugenio Mazzone, Paola Modesto, Katia Varello, Luca Aresu and Raffaella De Maria in Veterinary Pathology</p
Bioreactors landfills: comparison and kinetics of the different systems
No full textThe need for more sustainable landfilling has increased interest in bioreactor landfills as a suitable tool for optimising degradation processes. Bioreactors can be categorised as follows: anaerobic, aerobic, semi aerobic and hybrid. The choice of a specific bioreactor can be strongly influenced by the desired treatment objectives (i.e., energy recovery, increased rate of waste stabilisation, washing) as well as by the specific site conditions (e.g., waste characteristics, climate and social/economic situation, regulations). However, the increased rate of waste stabilisation should be the primary driving principle in the bioreactor landfill design (Cossu, 2010). Full-scale bioreactor landfills are still uncommon and one of the reasons is the perception that the effectiveness of this technology is not well demonstrated. This paper aims to contribute to filling this knowledge gap by analysing and comparing the lab scale applications of different types of bioreactors available in the literature and providing a survey of the different methods by considering their respective advantages and disadvantages. Qualitative analysis of the main types of bioreactor landfills is provided according to a few selected characteristics (i.e. energy recovery, biochemical kinetics, technological complexity, costs). Considering landfill sustainability, the discussion is primarily focused on the quantification of the stabilisation capability of the different bioreactors which is calculated in terms of COD and ammonia removal kinetics. The results demonstrate that the optimisation of COD removal kinetics is the highest in aerated bioreactors, while ammonia removal kinetics is maximum in hybrid bioreactors (i.e., 6 and 10 times higher, respectively, compared to the anaerobic bioreactors)
Storage potential and residual emissions from fresh and stabilized waste samples from a landfill simulation experiment
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