Multimodal Dependent Type Theory

We introduce MTT, a dependent type theory which supports multiple modalities. MTT is parametrized by a mode theory which specifies a collection of modes, modalities, and transformations between them. We show that different choices of mode theory allow us to use the same type theory to compute and reason in many modal situations, including guarded recursion, axiomatic cohesion, and parametric quantification. We reproduce examples from prior work in guarded recursion and axiomatic cohesion, thereby demonstrating that MTT constitutes a simple and usable syntax whose instantiations intuitively correspond to previous handcrafted modal type theories. In some cases, instantiating MTT to a particular situation unearths a previously unknown type theory that improves upon prior systems. Finally, we investigate the metatheory of MTT. We prove the consistency of MTT and establish canonicity through an extension of recent type-theoretic gluing techniques. These results hold irrespective of the choice of mode theory, and thus apply to a wide variety of modal situations

Experimental thermographic investigation for dry finish turning of SAF 2507 steel

The Oil&Gas Industry widely uses Super-Duplex Stainless Steels (S-DSS) since their combination of high mechanical characteristics and corrosion resistance. Among them, the SAF 2507 is one of the renowned. The challenges associated with the machining of these steels are directly related to the high temperature that influences the tool-life and the quality of the finished products. This phenomenon is induced by the low thermal conductivity which leads to a high concentration of heat. In order to properly understand their thermal behavior, the distribution of the temperature varying the cutting parameters should be investigated. During dry finish turning, the evolution of the temperature can be captured through a thermographic test campaign, for instance following a L18 - 2 · 37-5 fractional factorial design with no replications. The data acquired can be deeply studied with a statistical methodology framework, the relationship between the response of the experiment and the machining parameters can be established, and a surrogate model for predicting the temperature can be built and validated. The results show that, for the SAF 2507 steel, the cutting temperature for dry finishing turning is mostly influenced by the deep of cut, the feed rate and slightly by the cutting speed

Application of Shape Memory Alloys in Historical Constructions

A device prototype, based on the superelastic properties of Shape Memory Alloys (SMAs), is proposed to enhance the thermal and seismic behavior of steel tie-rods. First, the thermal behavior of steel tie-rods with and without SMAs is presented based on the results of extensive experimental tests in thermal room. Next, the seismic performances of the proposed SMA system are discussed based on the results of a series of shaking table tests on a 1:4-scale timber roof truss model. In this article, the functioning principles of the proposed SMA-based device prototype are illustrated and the main aspects related to its implementation in practice are discussed in detail. Finally, a recent example of application of the proposed technology to a historic single-aisle church, realized in the 13th century in Brindisi (southern Italy), and equipped with inadequate and deteriorated steel tied rods, is shown

Developing Solutions Based on Shape Memory Alloys for Historical Constructions

The superelastic properties of Shape Memory Alloys (SMAs) can be used to improve the thermal and seismic behavior of steel tie-rods, which are often used in historical constructions. In this paper, a device prototype based on SMAs is presented, whose performances have been assessed through extensive experimental tests in thermal chamber and shaking table tests on reduced-scale testing models. The functioning principles of the device and the main steps for its implementation are first illustrated. The experimental behavior of the device is then examined. Finally, a recent example of application of the proposed technology to a historic single-aisle church, realized in the 13th century in Brindisi (southern Italy), and equipped with inadequate and deteriorated steel tied rods, is shown

Optical spectroscopy and excited states dynamics of CaMoO4:Pr3+

International audienceThe luminescence properties of CaMoO4:Pr3+ have been investigated in different experimental conditions in order to obtain information on the excitation and de-excitation pathways of this system. The structure of the emission spectrum depends on different factors: excitation conditions, doping level, temperature, etc. In addition, measurements carried out on single crystals and on micro- or nano-crystalline powders obtained by solid state reaction and sol-gel method have revealed that the morphology of the sample, and then the concentration of the lattice defects, strongly influences the excitation mechanism. These effects have been analysed in the light of available models and a general scheme accounting for the experimental observations has been propose

Experimental studies by combined NDT of capillary rise monitoring in masonry specimens

In the case of Cultural Heritage a destructive or partly destructive investigation approach is rightly hindered by high protection measures. Nevertheless, for preservation purposes it is fundamental to deepen the knowledge about the various types of historic structures and their health state of conservation as well as on evolution of material decay due to environmental factors. The role of non destructive techniques (NDT) for assessment purposes becomes fundamental in these cases but their use is still not sufficiently widespread nor the technique\u2019s limits or possibilities are completely explored. Radar and infrared thermography are nondestructive investigation techniques becoming more frequently employed in diagnostics. This paper describes an integrated experimental approach based on infrared thermography and radar for the assessment of masonry structures. At a laboratory scale, the focus was placed onto their evaluation capacity to detect construction details and the beginning of material changes/deterioration and evolution with particular regard to moisture and brine capillary transport

Masonry circular columns confined with glass and basalt fibers

The mechanical behaviour of masonry columns having a circular cross section, confined with glass and basalt FRP systems was studied in this paper. An extended experimental investigation is presented in order to show the results of axial compression tests on circular masonry columns built with natural calcareous blocks that may be commonly found in Italy and all over Europe in historical buildings. Totally twenty masonry columns were built, instrumented and tested. Different fibres were used including glass and basalt (sheets and grids), different strengthening schemes were applied for confinement of the columns, including complete jacketing and discontinuous FRP strips, different bonding agents were employed including epoxy resin and polymer/cement-based mortar. In four GFRP-confined columns the strengthening action was activated by the presence of Shape Memory Alloys (SMA) filaments immersed in the FRP system. This novel technique is also presented in the paper