Extension and application of a sequential estimator

Improved sequential estimation technique for nonlinear time varying system

Passivity-based harmonic control through series/parallel damping of an H-bridge rectifier

Nowadays the H-bridge is one of the preferred solutions to connect DC loads or distributed sources to the single-phase grid. The control aims are: sinusoidal grid current with unity power factor and optimal DC voltage regulation capability. These objectives should be satisfied, regardless the conditions of the grid, the DC load/source and the converter nonlinearities. In this paper a passivity-based approach is thoroughly investigated proposing a damping-based solution for the error dynamics. Practical experiments with a real converter validate the analysis.

User-based evaluation of academic digital libraries : case studies, Social Science Information Gateway, Art, Design Architecture & Media Gateway and the Electronic Journals Service of the University of Patras, Greece

The purpose of this study was to evaluate the use of academic digital libraries from a user-oriented approach. For this purpose, end-users were invited to describe how they perceive and make use of academic digital libraries. The study was focused on Subject Based Information Gateways (SBIGs) and Electronic Journals Services. Specifically, two gateways were examined: the Social Science Information Gateway (SOSIG) and the Art, Design, Architecture and Media (ADAM) gateway, and an electronic journals service: the Electronic Journals Service of the Library and Information Service (LIS), the University of Patras, Greece. The target group was the academic community: academic staff, research staff and students (undergraduate and postgraduate). The research methods used were online questionnaires, face-to-face interviews and transaction logs analysis (TLA). Concerning the perception of academic digital libraries, users were invited: to provide the advantages and/ or disadvantages of electronic information over print, to compare the electronic and print version of a piece of information, to evaluate services or features as very important, important, or not important and to specify factors that would discourage them from accessing a digital library. Regarding the use of academic digital libraries, users were asked to specify: how frequently they use digital libraries, what reasons they use digital libraries for, what place they gain access from, what their preferred method of searching for information is, what their preferred method of storing and reading electronic information is, whether they use the support services provided, what types of information they want to be provided with and what the role of communication in a digital library is. The study concluded that end-users seem to appreciate the implementation of academic digital libraries. However, there are still some disadvantages that might prevent them from accessing them. A typical user would access them from their office or home for a variety of reasons, such as: for writing up a term paper/project or a thesis/dissertation, writing up a paper for publication, e. g. journal article or conference/workshop paper, keeping up with progress in the relevant subject area, supporting a lecture or for personal reasons. Concerning their search behaviour, they would adopt a relatively unsophisticated, simplistic approach to searching and limited use of Boolean operators or other commands. Notwithstanding their low search abilities, they would be reluctant to consult the online help function that could support their searches. Sometimes, they prefer to ask a person rather than attempt to use the online help. When they have identified information and want to read it, they print it out. But, when they want to store information for the future, they either print it out, or save it on disk. This information might differ in its formats, including electronic journals, reports and papers, digitised books, scholarly mailing lists and archives and educational software. Finally, some users would appreciate the opportunity to communicate with information scientists, authors, or other users who share the same interests with them. Some others emphasized the importance of the communication between users and digital library systems

A model of maxilla resection to test new hybrid implants:macroporous titanium and tissue engineering elements

Maxillary bone loss in commonly found in humans, due to bone ageing, tooth loos, periodontal disease and, more severely, to trauma, radiotherapy and tumor resection. Masillofacial reconstructive surgery is a still unmet clinical demand, available therapies include grafting of autologous or heterologous bone tissue and/or the implantation of metallic plates, buy these treatments are still unable to resume form and function. The emrgence of 3D-printing technology applied to metal alloys now allows the manufacturing of customized, patient-tailored prosthetic implants. However, poor bone quiality at the implant site due to ageing or disease still hamper proper osseointegration. By combining Electron Beam Melting metal sintering and tissue engineering, we are developing hybrid maxillofacial implants, wher a metal framework of Ti6Al4V alloy confers both and appropiaate shape and mechanical stabilty, while stem cells and osteogenic molecules stimulate bone growth into the metal framework, thus pormoting osseointegration. We hereby present the in vitro work driving to the development of our hybrid maxillofacial prostheses, as well as the setting up of an in vivo model of complete maxilla full resection, created in order to test the prostheses in a preclinical studyUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Acute myocardial infarction with occlusion of all three main epicardial coronary arteries: When Mother Nature takes care more than physicians

Double-arterial coronary stent thrombosis in acute myocardial infarction (AMI) is an infrequent but severe complication, especially when the third main coronary artery is chronically occluded. The conus artery (CA) can serve as a major source of collateral when the left anterior descendent coronary artery (LAD) becomes obstructed. We report a case of a 48-year-old man presenting with AMI due to a very late double-arterial stent thrombosis (ST) following drug-eluting stent implantation and a chronic occlusion of LAD collateralized by a large anomalous CA, which provided for the entire vascularization of the coronary tree. © 2010 Springer

Evidence for immunomodulation and apoptotic processes induced by cationic polystyrene nanoparticles in the hemocytes of the marine bivalve Mytilus

none8sìPolymeric nanoparticles can reach the marine environment from different sources as weathering of plastic debris and nanowaste. Nevertheless, few data are available on their fate and impact on marine biota. Polystyrene nanoparticles (PS NPs) can be considered as a model for studying the effects of nanoplastics in marine organisms: recent data on amino-modified PS NPs (PS-NH2) toxicity in sea urchin embryos underlined that marine invertebrates can be biological targets of nanoplastics. Cationic PS NPs have been shown to be toxic to mammalian cells, where they can induce apoptotic processes; however, no information is available on their effects and mechanisms of action in the cells of marine organisms. In this work, the effects of 50 nm PS-NH2 were investigated in the hemocytes of the marine bivalve Mytilus galloprovincialis. Hemocytes were exposed to different concentrations (1, 5, 50 μg/ml) of PS-NH2 suspension in ASW. Clear signs of cytoxicity were evident only at the highest concentrations (50 μg/ml). On the other hand, a dose dependent decrease in phagocytic activity and increase in lysozyme activity were observed. PS-NH2 NPs also stimulated increase in extracellular ROS (reactive oxygen species) and NO (nitric oxide) production, with maximal effects at lower concentrations. Moreover, at the highest concentration tested, PS-NH2 NPs induced apoptotic process, as evaluated by Flow cytometry (Annexin V binding and mitochondrial parameters). The results demonstrate that in marine invertebrates the immune function can represent a significant target for PS-NPs. Moreover, in Mytilus hemocytes, PS-NH2 NPs can act through mechanisms similar to those observed in mammalian cells. Further research is necessary on specific mechanisms of toxicity and cellular uptake of nanoplastics in order to assess their impact on marine biota.openCanesi, L; Ciacci, Caterina; Bergami, E; Monopoli, M. P; Dawson, K. A; Papa, Stefano; Canonico, Barbara; Corsi, I.Canesi, L; Ciacci, Caterina; Bergami, E; Monopoli, M. P; Dawson, K. A; Papa, Stefano; Canonico, Barbara; Corsi, I

Multifunctional halloysite and hectorite catalysts for effective transformation of biomass to biodiesel

Halloysite surface was modified with tetrabutylammonium iodide, and then the obtained nanomaterial was used as support for ZnO nanoparticles. After characterization, the nanomaterial was used as a catalyst for fatty acid methyl esters (FAMEs) production. The recyclability of the nanomaterial was also investigated, and the optimization of reaction conditions by the design of experiments approach was performed as well. In addition, the synthesized nanomaterial was tested as a catalyst for FAME production from a series of waste lipids affording biodiesel in moderate to good yields (35–95%), depending on the matrix. To fully exploit the feasibility of clay minerals as catalysts in biodiesel formation, a screening of different clays and clay minerals with different morphologies and compositions, such as sepiolite, palygorskite, bentonite, and hectorite was also performed in the esterification of FFAs (a mixture of 1:1 palmitic and stearic acids). Finally, hectorite, chosen as a model of 2:1 clay minerals, was covalently modified, and tested as a catalyst in the esterification of FFAs