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The most widely used process for hydrogen production is steam methane reforming. It can be carried out using a membrane reactor in which simultaneous hydrogen production and purification occur. Mathematical modeling of these reactors plays a key role in the selection of the design and operating parameters that yield high performance for the reactor. This review study discusses, synthesizes, and compares different mathematical modeling studies on the packed bed membrane reactors for hydrogen production from methane found in the literature. Different approaches used in these modeling studies for the hydrogen permeation steps, reaction kinetic expressions, phases involved (pseudo-homogeneous and heterogeneous), and spatial dimensions (one, two, and three dimensional) are given.

The reversible dissociation/carbonation of metal carbonates, performed in fluidized bed reactors, is one of the most promising technological solution for thermochemical energy storage (TCES) in concentrating solar power plants (CSP). In this framework, the SrCO3/SrO system is receiving increasing interest due to its high energy density (4 GJ/m3) and working temperatures (up to 1200 ?C). As the more investigated CaCO3/CaO couple, also SrO undergoes a dramatic drop of reactivity over multiple carbonation/calcina- tion cycles due to sintering. Even though the potentiality of this system has already been proved by thermo-gravimetric analyses, its actual reaction performances in a fluidized bed are strongly dependent on the gas-solid contact efficiency and heat/mass transfer between the gaseous and solid phase. In this work, the cyclic carbonation/calcination of the SrO/SrCO3 system for TCES-CSP has been investigated by thermo-gravimetric analysis and, for the first time, in a lab-scale fluidized bed rig, thus providing useful applicative insights. A new Al2O3-stabilized composite has been synthesized, i.e. Al2O3 has been added to SrO/SrCO3 system as both sintering inhibitor and flow conditioner. In particular, composite materials with different Al2O3/SrO composition have been synthesized to investigate the ef- fect of the inhibitor amount on both the fluidizability and energy storage performances.

Intention of this work is to investigate the opportunity and feasibility of energy efficient networking in Home and Building automation protocols. Wired HBAS have traditionally devoted a relatively little attention to this point, especially if compared to wireless networks. This paper will try to address the issue by evaluating the introduction of power state switching in a real scenario and proposing the concept of functional and spatial adjacency among packets.

Il volume contiene gli abstract dei lavori accettati per i contributi orali e i poster presentati a HYPOTHESIS XII

Castor (Ricinus communis L.) is an oilseed species, which in southern Italy is cultivated as annual during the spring-summer period under irrigation, but in most temperate areas such as those of eastern coast of Sicily, it could be grown as semiperennial with no irrigation, by the adoption of autumnal sowings. A field experiment was conducted in southeastern Sicily with the aim of assessing plant surviving, seed yield and oil quality of four castor genotypes originating from different geographical areas (two Sicilian, one Tunisian and one Brazilian). The favorable climatic conditions allowed the plant to survive during the fall-winter period. Seed yield reached 3.45 t ha-1 on average of the two years and seed oil content ranged from 45% (Tunisian cultivar) to 48% ('Local RG 2' Sicilian genotype). Oil yield reflected the variation in seed yield. Genetic diversity for fatty acid composition and saponification number, iodine value and cetane number was evidenced. When ricinoleic acid is not taken into account, the oil of all genotypes satisfied the E.U. standards for biodiesel. The ricinoleic acid was the lowest (79%) in the Sicilian 'Local RG 2' and the highest (89%) in the Tunisian one, revealing a greater suitability of oil of the first genotype for biodiesel. In turn, the oil of Tunisian genotype could be exploited in other bio-based industrial sectors. The study also demonstrated that in the southeastern coast of Sicily autumnal sowings might be advantageous for castor grown as semi-perennial crop, mainly since they allow saving irrigation water.

Emergency building, devoted to give rapid and effective housing solutions to catastrophic and unexpected events, relies on the basic principles of construction rapidity and reversibility as well as the use of alternative energy sources. The growing need for environmental impact reduction in the building sector represents for temporary housing - especially under emergency conditions - a priority requisite, since, after given time lapses, areas occupied with emergency settlements will have to be recovered to their original use. In this case, the buildings' service life does not correspond to the life cycle of their materials and components; as a consequence, design activities will have to assure the dismantability and reusability of structures for further service cycles, making the whole process reversible: from construction to 'zero waste' de-construction. This paper aims at defining design criteria for low-impact emergency dwellings, assessing at the same time their applicability to corrugated steel pipes, obtained by assembling galvanized curved sheets - commonly used for underpasses and conduits - for which different use possibilities have been investigated. In this view, the research program has led to the definition of modular dwelling solutions. Then, technical feasibility studies have been carried out in collaboration with the industrial sector, taking advantage of consolidated production lines for innovative use purposes. Along the different research stages, a methodology has been defined for the assessment of the fundamental sustainability criteria through different simulation procedures; among these, the evaluation of the life-cycle environmental impacts with SimaPRO software and the 3D modelling for the maximization of the construction/environment integration - also in relation to the use of PV modules - have produced interesting results.

M.J.M. acknowledges funding from FCT through the grant SFRH/BPD/115566/2016. ALTALUZ (Reference PTDC/CTM-ENE/5125/2014). The optical properties of localized surface plasmon resonances (LSPR) sustained by self-assembled silver nanoparticles are of great interest for enhancing light trapping in thin film photovoltaics. First, we report on a systematic investigation of the structural and the optical properties of silver nanostructures fabricated by a solid-state dewetting process on various substrates. Our study allows to identify fabrication conditions in which circular, uniformly spaced nanoparticles are obtainable. The optimized NPs are then integrated into plasmonic back reflector (PBR) structures. Second, we demonstrate a novel procedure, involving a combination of opto-electronic spectroscopic techniques, allowing for the quantification of useful and parasitic absorption in thin photovoltaic absorber deposited on top of the PBR. We achieve a significant broadband useful absorption enhancement of 90% for 0.9 µm thick μc-Si:H film and demonstrate that optical losses due to plasmonic scattering are insignificant below 730 nm. Finally, we present a successful implementation of a plasmonic light trapping scheme in a thin film a-Si:H solar cell. The quantum efficiency spectra of the devices show a pronounced broadband enhancement resulting in remarkably high short circuit current densities (Jsc). preprint published

Decentralized detection in a network of wireless sensor nodes involves the fusion of information about a phenomenon of interest (PoI) from geographically dispersed nodes. In this paper, we investigate the problem of binary decentralized detection in a dense and randomly deployed wireless sensor network (WSN), whereby the communication channels between the nodes and the fusion center are bandwidth-constrained. We consider a scenario in which sensor observations, conditioned on the alternate hypothesis, are independent but not identically distributed across the sensor nodes.We compare two different fusion architectures, namely, the parallel fusion architecture (PFA) and the cooperative fusion architecture (CFA), for such bandwidthconstrained WSNs, where each sensor node is restricted to send a 1-bit information to the fusion center. For each architecture, we derive expression for the probability of decision error at the fusion center. We propose a consensus flooding protocol for CFA and analyze its average energy consumption. We analyze the effects of PoI intensity, realistic link models, consensus flooding protocol, and network connectivity on the system reliability and average energy consumption for both fusion architectures. We demonstrate that a trade-off exists among spatial diversity gain, average energy consumption, delivery ratio of the consensus flooding protocol, network connectivity, node density, and PoI intensity in CFA. We then provide insight into the design of cooperative WSNs.

Analysis of interdependencies in Electric Power Systems (EPS) has been recognized as a crucial and challenging issue to improve their trustworthiness. The recent liberalization process in energy markets has promoted the entry of a variety of operators in the electricity industry. The resulting new organization contributed to increase in complexity, heterogeneity and interconnection. This paper proposes a framework for analyzing EPS organized as a set of interconnected regions, both from the point of view of the electric power grid and of the cyber control infrastructure. The emphasis is on interdependencies and in assessing their impact on indicators representative of the QoS perceived by users. Taking a reference power grid as test case, the effects of failures on selected measures are shown, both in case the grid is partitioned in a number of regions and in case of a single region, to illustrate the behavior of different grid and control configurations.