485 research outputs found
Introduction
Introduction to the special issue of Cosmos and History, 'The Italian Difference: Between Nihilism and Biopolitics'. This volume brings together essays by different generations of Italian thinkers which address, whether in affirmative, problematizing or genealogical registers, the entanglement of philosophical speculation and political proposition within recent Italian thought. Nihilism and biopolitics, two concepts that have played a very prominent role within contemporary Italian thought, serve as the thematic foci around which the collection orbits, as it seeks to define the historical and geographical particularity of these notions as well their continuing impact on an international debate. The volume also covers the debate around âweak thought' (pensiero debole), the feminist thinking of sexual difference, the re-emergence of political anthropology and the question of communism. The contributors provide contrasting narratives of the development of post-war Italian thought and delineate paths out of the theoretical and political impasses of the presentâagainst what Negri, in the text from which the volume takes its name, calls âthe Italian desert'. The Italian Difference features texts by Antonio Negri, Pier Aldo Rovatti, Gianni Vattimo, Roberto Esposito, Matteo Mandarini, Luisa Muraro, Mario Tronti, Alberto Toscano, Paolo Virno and Lorenzo Chiesa
DEFINITION OF THE FLEXIBLE AIRCRAFT LONGITUDINAL MODEL FOR A PRELIMINARY CONTROL DESIGN
Developing control system of high aspect ratio aircraft can be challenging due to flexibility involved
in the control loop design. A model based approach can be straightforward to tune the control system
parameters and, to this aim, a reliable aircraft flexible model is necessary. This paper aims to present
the approach followed to design the longitudinal control strategy considering the aircraft simulator in
the loop. The elastic modes are calculated from the lumped mass geometrical model and an
aerodynamic properties from a reference aircraft. The approach and the model validation have been
done in partnership with Leonardo Aircraft, as a thesis topic. Beginning with verification of the trim
conditions, the flexible dynamic modes are compared to the rigid ones in order to highlight the
relevant changes in the aircraft modes. A preliminary design of the longitudinal control strategy is
herein proposed to achieve the dynamic response objectives
Nitrogen-Doped Zinc Oxide for Photo-Driven Molecular Hydrogen Production
Due to its thermal stability, conductivity, high exciton binding energy and high electron mobility, zinc oxide is one of the most studied semiconductors in the field of photocatalysis. However, the wide bandgap requires the use of UV photons to harness its potential. A convenient way to appease such a limitation is the doping of the lattice with foreign atoms which, in turn, introduce localized states (defects) within the bandgap. Such localized states make the material optically active in the visible range and reduce the energy required to initiate photo-driven charge separation events. In this work, we employed a green synthetic procedure to achieve a high level of doping and have demonstrated how the thermal treatment during synthesis is crucial to select specific the microscopic (molecular) nature of the defect and, ultimately, the type of chemistry (reduction versus oxidation) that the material is able to perform. We found that low-temperature treatments produce material with higher efficiency in the water photosplitting reaction. This constitutes a further step in the establishment of N-doped ZnO as a photocatalyst for artificial photosynthesis
In vitro antibacterial activity of different pulp capping materials
Background: Direct pulp capping involves the application of a dental material to seal communications between the
exposed pulp and the oral cavity (mechanical and carious pulp exposures) in an attempt to act as a barrier, protect
the dental pulp complex and preserve its vitality. The aim of this study was to evaluate and compare, by the agar
disc diffusion test, the antimicrobial activity of six different pulp-capping materials: Dycal (Dentsply), Calcicur
(Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), Biodentine (Septodont).
Material and Methods:
Streptococcus salivarius
,
Streptococcus sanguis
and
Streptococcus mutans
strains were
selected to evaluate the antimicrobial activity by the agar disc diffusion test of different pulp capping materials.
Paper disks were impregnated whit each pulp capping materials and placed onto culture agar-plates pre-adsorbed
with bacterial cells and further incubated for 24 h at 37°C. The growth inhibition zones around each pulp capping
materials were recorded and compared for each bacterial strain.
Results: For the investigation of the antibacterial properties the ANOVA showed the presence of significant differences among the various materials. Tukey test showed that MTA-based materials induced lower growth inhibition
zones.
Conclusions: MTA-based products show a discrete antibacterial activity varying from calcium hydroxide-based
materials which present an higher antibacterial activity
Effect of different protective agents on enamel erosion : an in vitro investigation
The purpose of this in vitrostudy was to compare the effect of different protective agents on enamel erosion by measuring mean percentage weight loss. Extracted teeth were sectioned into uniform slabs and enamel specimens were randomly distributed to different groups. Initial weight of all enamel specimens was registered. The protective agents used in this study were Tooth Mousse, MI Paste Plus, Remin Pro and Remin Pro Forte. A control group was treated just with tap water. All the specimens were immersed in Coca-Cola for a total of 8 min at room temperature, dried and weighed. Enamel dissolution caused by acidic soft drink was analyzed: specimens were weighed after each immersion period and mean percent weight loss was calculated. Weight loss data were subjected to Analysis of Variance (One-way ANOVA) followed by Bonferroni?s post hoc tests. All the groups showed a statistically significant loss of weight (p<0.01) during the testing periods, increased after 8 days (~55%) and 12 days (~70%) of exposure. Specimens treated with protective agents showed significantly lower % of weight loss especially with Remin Pro or Remin Pro Forte. Soft drinks can cause enamel erosion, but protective agents tested may enhance enamel resistance against erosion
Development of a Biomolecular Assay for Post-mortem Diagnosis of Taenia saginata Cysticercosis
Reconstructing force profiles with an amplitude-modulation AFM in tapping mode
Here we demonstrate how to reconstruct force profiles with an amplitude-modulation AFM operated in in standard tapping mode. Our example is based on the Cypher scanning probe microscope from Asylum Research. The method is based on Sader and Katanâs algorithm, but we have implemented an experimental set-up that allows for robust reconstruction. We discuss the details here
The Mendeleev-Meyer force project
Here we present the MendeleevâMeyer Force Project which aims at tabulating all materials and substances in a fashion similar to the periodic table. The goal is to group and tabulate substances using nanoscale force footprints rather than atomic number or electronic configuration as in the periodic table. The process is divided into: (1) acquiring nanoscale force data from materials, (2) parameterizing the raw data into standardized input features to generate a library, (3) feeding the standardized library into an algorithm to generate, enhance or exploit a model to identify a material or property. We propose producing databases mimicking the Materials Genome Initiative, the Medical Literature Analysis and Retrieval System Online (MEDLARS) or the PRoteomics IDEntifications database (PRIDE) and making these searchable online via search engines mimicking Pubmed or the PRIDE web interface. A prototype exploiting deep learning algorithms, i.e. multilayer neural networks, is presented.Award-winningPostprint (author's final draft
Color stability of CAD/CAM Zirconia ceramics following exposure to acidic and staining drinks
The aim of this in vitro study was to evaluate the color stability of CAD/CAM Zirconia ceramics following exposure to acidic drink (Coca Cola) and after exposure to staining solution (coffee). All the samples were immersed in different staining solutions over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. Shapiro Wilk test and Kruskal-Wallis ANOVA were applied to assess significant differences among restorative materials. Paired t-test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. One week immersion in acidic drink did not cause a perceivable discoloration for all restorative materials (?E < 3.3). Subsequent immersion in coffee affected color stability of all Zirconia samples, even if Kruskal-Wallis ANOVA found significant differences among the various restorative materials. The ?Es of CAD/CAM Zirconia ceramics after immersion in coffee varied among the products, but color integrity is not affected by contact with acidic drinks
RepresentaçÔes de crianças do Ensino Fundamental acerca do conceito de cĂ©u a partir do MĂ©todo ClĂnico-CrĂtico
Este trabalho apresenta os resultados de uma pesquisa realizada com o objetivo de conhecer as representaçÔes das crianças acerca do conceito de cĂ©u. Utilizou-se o MĂ©todo ClĂnico-CrĂtico na realização da coleta e anĂĄlise das representaçÔes. A amostra constitui-se de crianças de sete a doze anos, estudantes do Ensino Fundamental em escolas pĂșblicas e particulares. A anĂĄlise apontou para a existĂȘncia de trĂȘs grandes categorias de representaçÔes, sĂŁo elas: Crença religiosa; CĂ©u como abĂłbada e CĂ©u diferente de espaço sideral. A partir dessa pesquisa Ă© possĂvel aprofundarmos as questĂ”es didĂĄticas implicadas no trabalho com as ideias dos alunos no ensino de conteĂșdos de astronomia no Ensino Fundamental
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