Energy Independence and Research for Economic, Social and Environmental Sustainability

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Approaching sustainable development through energy management, the case of Fongo Tongo, Cameroon

This work is aimed at defining a possible solution for sustainable energy development in the Menoua Department, West Cameroon. The purpose of the cooperation between ALA Milano Onlus and the Biomass Energy Efficiency Laboratory of the University of Modena and Reggio Emilia was to analyze the case study in order to propose a solution for energy production capable of meeting the needs of the Cameroonian society while also heading towards a sustainable development. Primary researches suggested that the most viable solution was to integrate the corn food processing with the gasification of the cobs. The thermo-conversion process was modeled with a black-box approach; the results of the model were further compared with the energy required for corn processing, therefore demonstrating the sustainability and virtuosity of the chosen solution. A commercial 20 kW$$_el$$el gasifier was selected for supplying electrical power to three central buildings: the city hall, the Chaufferie and the school. This solution is a security measure assuring continue power supply to these vital buildings. Furthermore, it will bind the relation between the rural and the city areas through the energy exchange process

Spent Coffee Grounds in the Production of Lightweight Clay Ceramic Aggregates in View of Urban and Agricultural Sustainable Development

This paper presents an innovative application for spent coffee grounds (SCGs) used as filler for the formulation of lightweight clay ceramic aggregates (LWA). LWA can be used for urban and agricultural purposes as a sustainable solution. Spent coffee grounds were tested as a pore forming agent partially acting as a replacement for red clay in material formulation before firing. Substitutions of 10, 15, and 20 wt.% of red clay were tested. The properties of lightweight aggregates with 15 wt.% of SCGs were improved using a specifically tailored fertilizer glass due to its low pH and conductivity within the soil tolerance range. Packaging glassy sand, cattle-bone flour ash, and potassium carbonate were mixed and melted in order to obtain this glass, which when added to the clayey batch functionalized the aggregates by phosphorus and potassium nutrients. The results (in particular, porosity and bulk density) show that the lightweight aggregates obtained have interesting properties for possible uses both in urban (e.g., green roofs as a drainage layer) and agricultural purposes. Moreover, pH and conductivity are in line with the Italian Standard regarding soil amendment (D.lgs. 75/2010). In addition, several leaching tests were performed in a solution containing 2 vol.% citric acid (C6H8O7) to evaluate the release capacity not only of nutrients (P and K)mbut also to check the presence and release of heavy metals, such as lead (Pb), that may come from the glassy precursor. The results obtained showed that nutrients are effciently released in 21 days (P = 87.73% and K = 25.74% of released percentage) and Pb release is under the standard threshold of 30 ppm

Combined Effects of LED Lights and chicken manure on Neochloris oleoabundans Growth

In this study a photobioreactor prototype is presented for the culture growth of microalgae model organism Neochloris oleoabundans by using chicken manure waste as feedstock along with the optimum combination of led light wavelengths and light intensity. Particularly interesting results are observed on the strains fed by chicken manure medium under the proper combination of red and blue LED light illumination, the microalgal growth resulted comparable with the strains fed by the costly commercial microalgal growth medium (BG 11 medium). Cell concentration, optical density, growth rate, cell size, total lipid and photosynthetic pigment content have been monitored during a time-course experiment. The data suggest that there are difficulties due to white light diffusion into the dark chicken medium, which leads to a generally lower intensity scattered along all wavelengths; blue or combined red and blue lights resulted in a higher irradiation density, affecting microalgae cell growth

Evaporazione a gocce. Parte II: analisi teorica e numerica

Nel presente articolo viene presentata la seconda parte di un lavoro sviluppato in forma sperimentale, teorica e numerica sul fenomeno dell'evaporazione a gocce. La parte sperimentale della ricerca è stata esposta in precedenza, e qui si descrive l'approccio teorico, costituito da un modello matematico basato su un metodo di calcolo agli elementi di contorno (Boundary Element Method) accoppiato con metodo integrale ai volumi di controllo (Control Volume Method). Viene inoltre descritto il codice di calcolo in cui il modello matematico è stato implementato, e i risultati della simulazione numerica vengono confrontati con i dati sperimentali ottenuti in precedenza. Si osserva come la simulazione numerica permetta di calcolare con grande precisione i tempi di evaporazione di singole gocce d'acqua che evaporano su superfici calde di conducibilità termica estrememente diversa tra loro. Inoltre si riscontra come i risultati teorico-numerici siano in eccellente accordo con i dati sperimentali anche per ciò che riguarda la determinazione della distribuzione di temperatura sulla superficie solida raffreddata durante il transitorio di evaporazione

Droplet Cooling: Theory, Experiments and Models.

This work is aimed at presenting a comprehensive review of the cooling effect that liquid droplets induce on hot solid surfaces. In particular, the review addresses theoretical results, experimental studies and modeling approaches, highlighting fundamental results from early studies as well as important contributions from recent research approaches. The characteristics of sessile and impinging droplets are presented, and the governing parameters of both cases of droplet cooling are pointed out. Although a very large number of significant works is shown to be available, this study emphasizes the need to unify the experimental research and the modeling efforts in order to provide better predictive correlations.A final part of this paper focuses on recent experimental results obtained by the non-intrusive method of infrared thermography, which appears to be very promising in terms of useful information for modeling efforts and improvements of cooling efficiency

Evaporazione a gocce. Parte I: analisi sperimentale

Nel presente lavoro sono esposti gli sviluppi ed i risultati di una ricerca condotta in forma sperimentale, teorica e numerica sul fenomeno dell' evaporazione a gocce. Tale ricerca, svolta in collaborazione con il Dipartimento di Ingegneria Meccanica dell' Università del Maryland (U.S.A.), ha coperto un arco di tempo di circa sei anni, ed alcune sue parti sono tuttora in corso. Pertanto, la presentazione del lavoro compiuto e dei risultati ottenuti è stata suddivisa in tre parti, che coincidono in larga parte con le tre fasi cronologiche della ricerca. Nella prima parte (relazionata nel presente articolo) sono descritti i metodi, gli apparati ed i risultati della fase sperimentale. Nella seconda parte verranno presentate le metodologie di approccio teorico ed il codice di calcolo con cui è stata effettuata la simulazione numerica dei fenomeni analizzati. Nella terza parte, infine, verranno presentati gli sviluppi della ricerca relativi all'estensione delle analisi dai sistemi a goccia singola a quelli multigocce (spray)

Full scale experiments on water-mist fire-suppression systems in High-Hazard Storages (HHS) \u2013 A temperature-based comparison between sole water and water/additive flow

Water-mist systems have gained wide popularity over the last twenty years as an innovative technology in fire protection. Moreover, insertion of additives in the flow is typically applied to provide additional improvements in terms of suppression effectiveness and temperature control. The present work consists of an experimental approach in a real-scale facility, which has been aimed at challenging water mist against severe fire scenarios. The sole water flow is compared to water endowed with a commercial additive, the F-500 by Hazard Control Technologies Inc. As the fire setting, a high-rise storage has been explored: this real scenario is commonly recognized as severely hazardous even by technical standards, because of both its nominal fire load and the designed physical domain. The thermal transient within the test chamber during the fire development has been measured as the main quantitative parameter: K-type thermocouples have been employed to the purpose over a set of remarkable locations. Moreover, the fire evolution has been evaluated through a post-fire estimation of the damages. Despite the large amount of released smoke and smoldering materials, water mist is shown to be efficient in fire control, if endowed with the chosen additive, while the sole water flow does not appear suitable for such hazardous conditions

Fuel cell systems and traditional technologies. Part I: Experimental CHP approach

One of the most innovative solutions concerning CHP for residential and industrial applications consists in using fuel cell devices. The importance of this technology is connected to the possibility of having a nearly complete energetic independence. A comparison between traditional systems for energy generation and co-generative fuel cell systems is needed to properly evaluate whether fuel cells could be a reasonable alternative to conventional systems.The present work describes the project of an experimental setup which is focused on testing the high temperature Solid Oxide FuelCells (SOFC) concept as a promising innovative system. The problem of planning facilities based on fuel cell devices is faced, and the still-to-be-solved question of thermal storage is addressed. The core of the work consists of a theoretical calculation and comparison of fuel consumption for both the fuel cell and traditional systems