Living thought and living things On Roberto Esposito’s "Il pensiero vivente"

The essay discusses Roberto Esposito’s claim that Italian thought and the Italian tradition offer philosophy a way out of the dire situation it has fallen into as a consequence of the linguistic turn it took at the beginning of the 20th century. According to Esposito, Italian thought is animated by a genealogical vocation generating political, historical, and life paradigms that may revive philosophy’s universal ambitions against its current linguistic relativism. The essay discusses this claim in light of the tension between ontology and history that Esposito himself raises. It concludes that the opportunities opened up by Italy’s “genealogical vocation” should be supplemented by a philosophy of history that is currently lacking from Esposito’s account

Living thought and living things On Roberto Esposito’s "Il pensiero vivente"

The essay discusses Roberto Esposito’s claim that Italian thought and the Italian tradition offer philosophy a way out of the dire situation it has fallen into as a consequence of the linguistic turn it took at the beginning of the 20th century. According to Esposito, Italian thought is animated by a genealogical vocation generating political, historical, and life paradigms that may revive philosophy’s universal ambitions against its current linguistic relativism. The essay discusses this claim in light of the tension between ontology and history that Esposito himself raises. It concludes that the opportunities opened up by Italy’s “genealogical vocation” should be supplemented by a philosophy of history that is currently lacking from Esposito’s account

Interferometric cavity ring-down technique for ultra-high Q-factor microresonators

Microresonators (MRs) are key components in integrated optics. As a result, the estimation of their energy storage capacity as measured by the quality factor (Q) is crucial. However, in MR with high/ultra-high Q, the surface-wall roughness dominates the intrinsic Q and generates a coupling between counter-propagating modes. This splits the usual sharp single resonance and makes difficult the use of classical methods to assess Q. Here, we theoretically show that an interferometric excitation can be exploited in a Cavity Ring-Down (CRD) method to measure the ultimate Q of a MR. In fact, under suitable conditions, the resonant doublet merges into a single Lorentzian and the time dynamics of the MR assumes the usual behavior of a single-mode resonator unaffected by backscattering. This allows obtaining a typical exponential decay in the charging and discharging time of the MR, and thus, estimating its ultimate Q by measuring the photon lifetime.Comment: 5 pages and 2 figure

Field-Induced Nonlinearities in Silicon Waveguides Embedded in Lateral p-n Junctions

Silicon waveguides embedded in lateral p-n junctions show field-induced optical nonlinearities. By properly polarizing the junction, these can be used to achieve electro-optic modulation through the Direct Current Kerr effect. In addition, these enable second-order nonlinear processes such as the electric-field-induced second harmonic generation (EFISHG). In this work, we study in detail electro-optic effects in integrated silicon microresonators and demonstrate experimentally a field-induced resonance wavelength shift. This process is due to both the DC Kerr effect and the plasma-dispersion effect. By means of finite element method simulations, these effects are properly modeled and their contributions are accurately disentangled. The strength of the equivalent second-order nonlinear coefficient that would have provided the same electro-optic effect is about 16 pm/V. This result is comparable with that of materials possessing an intrinsic second order nonlinearity, and is one order of magnitude stronger than the most recent measurements of strain-induced Pockels effect in silicon

A detailed mineralogical, petrographic, and geochemical study of the highly reduced chondrite, Acfer 370

Among the many ungrouped meteorites, Acfer 370, NWA 7135, and El Médano 301—probably along with the chondritic inclusion in Cumberland Falls and ALHA 78113—represent a homogeneous grouplet of strongly reduced forsterite‐rich chondrites characterized by common textural, chemical, mineralogical, and isotopic features. All of these meteorites are much more reduced than OCs, with a low iron content in olivine and low‐Ca pyroxene. In particular, Acfer 370 is a type 4 chondrite that has olivine and low‐Ca pyroxene compositional ranges of Fa 5.2–5.8 and Fs 9.4–33.4, respectively. The dominant phase is low‐Ca pyroxene (36.3 vol%), followed by Fe‐Ni metal (16.3 vol%) and olivine (15.5 vol%); nevertheless, considering the Fe‐oxyhydroxide (due to terrestrial weathering), the original metal content was around 29.6 vol%. Finally, the mean oxygen isotopic composition Δ17O = +0.68‰ along with the occurrence of a silica phase, troilite, Ni‐rich phosphides, chromite, and oldhamite confirms that these ungrouped meteorites have been affected by strong reduction and are different from any other group recognized so far

Stochastic approach to hydraulic barrier design: an example in northeastern Italy

Volatile organic compounds, groundwater contamination, multi-layered aquifer syste

BOLD Features to Detect Texture-less Objects

Object detection in images withstanding significant clut-ter and occlusion is still a challenging task whenever the object surface is characterized by poor informative content. We propose to tackle this problem by a compact and dis-tinctive representation of groups of neighboring line seg-ments aggregated over limited spatial supports and invari-ant to rotation, translation and scale changes. Peculiarly, our proposal allows for leveraging on the inherent strengths of descriptor-based approaches, i.e. robustness to occlu-sion and clutter and scalability with respect to the size of the model library, also when dealing with scarcely textured objects. 1

Triple-Cut Computer-Aided Design-Computer-Aided Modeling: More Oncologic Safety Added to Precise Mandible Modeling

PURPOSE: Computer-aided design-computer-aided modeling (CAD-CAM) has become standard in mandibular reconstruction because it offers better outcomes. Occasionally, the reconstructive plans need to be changed intraoperatively and the custom-made prefabricated devices may become inadequate. We present an efficient adjunct to the standard CAD-CAM technique that resolves this problem. MATERIALS AND METHODS: Customized surgical devices with our "triple-cut" concept were used in 5 patients for mandibular reconstruction with free fibula flap (4 after mandibular resection for squamous cell carcinoma and 1 after mandibular osteoradionecrosis). In all patients the mandibular and fibular cutting guides were provided with 3 different cutting levels per side. RESULTS: Three different cutting levels on the mandible permitted an accurate resection based on the intraoperative needs. The corresponding 3 "cutting levels" on the fibula created perfectly matching segments of vascularized bone. Good contact of bony segments was obtained in all patients. CONCLUSIONS: The prefabricated triple-cut cutting guides make changing the dimensions of bony resection, while still using the prefabricated CAD-CAM reconstructive plate, possible

The INSEAN E779a Propeller Test Case: a Database For CFD Validation

In the last few years, remarkable improvements in numerical modeling of viscous flows around marine propellers have been obtained. In particular, Reynolds Averaged Navier-Stokes (RANS) equation solvers start to be widely used to analyze viscosity effects on propulsors at model-scale Reynolds number, in the case of uniform inflow and non-cavitating conditions. The development of such advanced computational tools is required, especially in modern propeller design, where for reducing propeller-induced hull vibrations, efficiency decay and noise generation due to cavitation, there is a continuous trend towards an increased complexity of the blade geometry, primarily due to the low aspect ratio and to the skew of marine propellers, which cause strong three-dimensional effects. This complexity requires a better knowledge of the wake characteristics in terms of the mean field and turbulent quantities. Therefore, there is a rising interest on detailed data of the velocity flow field around the blades and in the wake, supporting the flow modeling and the validation of the computational tools. Starting since 1997 at INSEAN started a project aimed to obtain high quality data for CFD validation. Measurements of velocity fields, radiated pressure fields cavitation patterns were performed. The chosen propeller was the INSEAN E779a, propeller which was already investigated in the 80\u27s by adopting phase sampling LDV technique

Spotting local environments in self-assembled monolayer-protected gold nanoparticles

Organic-inorganic (O-I) nanomaterials are versatile platforms for an incredible high number of applications, ranging from heterogeneous catalysis, molecular sensing, cell targeting, imaging, cancer diagnosis and therapy, just to name a few. Much of their potential stems from the unique control of organic environments around inorganic sites within a single O-I nanomaterial, which allows for new properties inaccessible using purely organic or inorganic materials. Structural and mechanistic characterization plays a key role in understanding and rationally designing such hybrid nanoconstructs. Here, we introduce a general methodology to identify and classify local (supra)molecular environments in an archetypal class of O-I nanomaterials, i.e. self-assembled monolayer-protected gold nanoparticles (SAM-AuNPs). By using an atomistic machine-learning guided workflow based on the Smooth Overlap of Atomic Positions (SOAP) descriptor, we analyze a collection of chemically different SAM-AuNPs, and detect and compare local environments in a way that is agnostic and automated, i.e. with no need of a-priori information and minimal user intervention. In addition, the computational results coupled with experimental electron spin resonance measurements prove that is possible to have more than one local environment inside SAMs, being thickness of the organic shell and solvation primary factors in determining number and nature of multiple co-existing environments. These indications are extended to complex mixed hydrophilic-hydrophobic SAMs. This work demonstrates that it is possible to spot out and compare local molecular environments in SAM-AuNPs exploiting atomistic machine-learning approaches, establishes ground rules to control them, and holds the potential for rational design of O-I nanomaterials instructed from data