Adsorption/Desorption Equilibria and Kinetics at Reconstructible Surfaces

A general kinetic theory, which takes explicit account of the phenomena occurring at reconstructible surfaces while adsorption or desorption proceed, is proposed. The theory contains a few free parameters which specify the adsorption and desorption rate constants, and the reconstruction and irreversibility degrees of the process

Fractal Nanotechnology

Self-similar patterns are frequently observed in Nature. Their reproduction is possible on a length scale 102–105 nm with lithographic methods, but seems impossible on the nanometer length scale. It is shown that this goal may be achieved via a multiplicative variant of the multi-spacer patterning technology, in this way permitting the controlled preparation of fractal surfaces

Development of a Torsiometer for On-board Application☆

Abstract Modern combustion control strategies require accurate combustion control to meet the requirements for pollutant emissions reduction. Optimal combustion control can be achieved through a closed-loop control based on indicated quantities, such as engine torque and center of combustion, which can be directly calculated through a proper processing of in-cylinder pressure trace. However, on-board installation of in-cylinder pressure sensors is uncommon, mainly because it causes a significant increase in the cost of the whole engine management system. In order to overcome the problems related to the on-board installation of cylinder pressure sensors, this work presents a remote combustion sensing methodology based on the simultaneous processing of two crankshaft speed signals. To maximize the signal-to-noise ratio, each speed measurement has been performed at opposed ends of the crankshaft, i.e. in correspondence of flywheel and distribution wheel. Since an engine speed sensor, usually faced to the flywheel, is already present on-board for other control purposes, the presented approach requires that an additional speed sensor is installed. Proper processing of the signals coming from the installed speed sensors allows extracting information about crankshaft's torsional behavior. Then, the calculated instantaneous crankshaft torsion can be used to real-time estimate both torque delivered by the engine and combustion phasing within the cycle. The presented methodology has been developed and validated using a light-duty L4 Common-Rail Diesel engine mounted in a test cell at University of Bologna. However, the discussed approach is general, and can be applied to engines with a different number of cylinders, both CI and SI

Optimal Supervisory Control of Hybrid Vehicles

Hybrid vehicles (HV), comprising a conventional ICE-based powertrain and a secondary energy source, to be converted into mechanical power as well, represent a well-established alternative to substantially reduce both fuel consumption and tailpipe emissions of passenger cars. Several HV architectures are either being studied or already available on market, e.g. Mechanical, Electric, Hydraulic and Pneumatic Hybrid Vehicles. Among the others, Electric (HEV) and Mechanical (HSF-HV) parallel Hybrid configurations are examined throughout this Thesis. To fully exploit the HVs potential, an optimal choice of the hybrid components to be installed must be properly designed, while an effective Supervisory Control must be adopted to coordinate the way the different power sources are managed and how they interact. Real-time controllers can be derived starting from the obtained optimal benchmark results. However, the application of these powerful instruments require a simplified and yet reliable and accurate model of the hybrid vehicle system. This can be a complex task, especially when the complexity of the system grows, i.e. a HSF-HV system assessed in this Thesis. The first task of the following dissertation is to establish the optimal modeling approach for an innovative and promising mechanical hybrid vehicle architecture. It will be shown how the chosen modeling paradigm can affect the goodness and the amount of computational effort of the solution, using an optimization technique based on Dynamic Programming. The second goal concerns the control of pollutant emissions in a parallel Diesel-HEV. The emissions level obtained under real world driving conditions is substantially higher than the usual result obtained in a homologation cycle. For this reason, an on-line control strategy capable of guaranteeing the respect of the desired emissions level, while minimizing fuel consumption and avoiding excessive battery depletion is the target of the corresponding section of the Thesis

Medical devices nomenclature systems: a scoping review

Inventory is a fundamental process throughout the life cycle of medical devices. The maintenance program for each piece of equipment must comply with current regulations that are constantly evolving. The need to set up an evidence based management of the inventory of thousands of medical devices hosted in the Careggi University Hospital (AOUC), in Florence (Italy), has suggested to conceive a method to group medical devices in sub-classes, in order to monitor their performances and maintenance. The starting point to reach this goal is to establish a suitable nomenclature, a complex system of rules, codes, and definitions employed by healthcare systems and organizations to identify sets of medical devices. This paper describes the literature search performed on both Ovid and Scopus databases, that made it possible to identify several classifications and nomenclatures for medical devices. On the basis of this search, only a few works fulfil the requirement of classifying medical devices for management purposes (e.g., inventories, database, and supply chains). The analysis has shown that it is possible to reduce the number of classes into macro groups when applying the Italian National Classification of Medical Devices (CND). Although the CND nomenclature shows inconsistencies for complex groups it is an effective and successful choice, in terms of efficiency and optimization, also considering that it is the basis for the European Medical Device Nomenclature (EMDN)

Atomic structural details of a protein grafted onto gold nanoparticles

Abstract The development of a methodology for the structural characterization at atomic detail of proteins conjugated to nanoparticles would be a breakthrough in nanotechnology. Solution and solid-state NMR spectroscopies are currently used to investigate molecules and peptides grafted onto nanoparticles, but the strategies used so far fall short in the application to proteins, which represent a thrilling development in theranostics. We here demonstrate the feasibility of highly-resolved multidimensional heteronuclear spectra of a large protein assembly conjugated to PEGylated gold nanoparticles. The spectra have been obtained by direct proton detection under fast MAS and allow for both a fast fingerprinting for the assessment of the preservation of the native fold and for resonance assignment. We thus demonstrate that the structural characterization and the application of the structure-based methodologies to proteins bound to gold nanoparticles is feasible and potentially extensible to other hybrid protein-nanomaterials

Thermodynamic Assessment on the Integration of Thermo-Electric Modules in a Wood Fireplace

The growing demand for electricity produced from renewable sources and the development of new technologies for the combustion of biomass, arose a growing interest on the possible coupling of thermoelectric modules with stove-fireplaces. The current thermoelectric generators have a solid structure, do not produce noise, do not require maintenance and can be used for the recovery of waste heat or excess, at the same time they hold a very low conversion efficiency and they need an adequate cooling system. Nevertheless, they still hold a cost, which is still too high to make them attractive. Nonetheless, if the modules are applied to a heat source which otherwise would be wasted, the attractiveness of the solution certainly rises. In this study, a thermodynamic analysis of a stove-fireplace is presented, considering both combustion process and the flame – walls heat transfer of the. A design solution for a concentrator device to funnel the wasted heat from the fireplace to the thermo-electric modules is also presented

Phase Transitions and Adsorption Isotherm in Multilayer Adsorbates with Lateral Interactions

We analyze here a model for an adsorbate system composed of many layers by extending a theoretical approach used to describe pattern formation on a monolayer of adsorbates with lateral interactions. The approach shows, in addition to a first order phase transition in the first layer, a transition in the second layer together with evidence of a "cascade" of transitions if more layers are included. The transition profiles, showing a staircase structure, corroborate this picture. The adsorption isotherm that came out of this approach is in qualitative agreement with numerical and experimental results.Comment: Submited to Physica A, LaTex, 22 pgs, 6 figure