(Non-)specificity across languages: constancy, variation, v-variation

Indefinites are known to give rise to different scopal (specific vs non-specific) and epistemic (known vs unknown) uses. Farkas & Brasoveanu (2020) explained these specificity distinctions in terms of stability vs. variability in value assignments of the variable introduced by the indefinite. Typological research (Haspelmath 1997) showed that indefinites have different functional distributions with respect to these uses. In this work, we present a formal framework where Farkas & Brasoveanu (2020)’s ideas are rigorously formalized. We develop a two-sorted team semantics which integrates both scope and epistemic effects. We apply the framework to explain typological variety of indefinites, their restricted distribution and licensing conditions, and some diachronic developments of indefinite forms

EMI filter design for matrix converters in airspace applications

Advanced power electronics systems are increasingly being used for AC motor drives, due to their numerous advantages in terms of performance and flexibility; however, due to their switching behaviour, they introduce significant harmonic content. To reduce any interaction with other appliances suitable EMI filters need to be designed and implemented. The focus of this thesis is on the characterization of a matrix converter induction motor drive for aerospace application from the point of view of EMI interference and on the design and implementation of suitable filtering systems. Concerns about Electro Magnetic Interferences are particularly justified in the light of the fact that high reliability is sought after in such applications. The main interest in this work lies in the electromagnetic regulations defining the allowable conducted emissions in the frequencies between 150 kHz and 30 MHz. The first goal achieved by this work is to characterize the EMI signature of a matrix converter induction motor drive using common and differential mode measurements of the converter and motor impedances separately. Based only on these measurements the project aims to synthesize accurate HF models for the Induction Motor and the Matrix Converter in common and differential mode, without the need of deep level studies that may involve long Finite Elements (FE) simulations of the physical system characteristics. This thesis proposes two general novel HF models for Matrix Converters and Induction Motors that could also be applied in any other application or operating condition. These models are automatically tuned and optimized by a suitably developed Genetic Algorithm (GA) routine capable to match those models with real experimental measurements. This thesis reports the methodologies used for both input and output filter design, together with description and analysis of some issues encountered during the process

EMI filter design for matrix converters in airspace applications

Advanced power electronics systems are increasingly being used for AC motor drives, due to their numerous advantages in terms of performance and flexibility; however, due to their switching behaviour, they introduce significant harmonic content. To reduce any interaction with other appliances suitable EMI filters need to be designed and implemented. The focus of this thesis is on the characterization of a matrix converter induction motor drive for aerospace application from the point of view of EMI interference and on the design and implementation of suitable filtering systems. Concerns about Electro Magnetic Interferences are particularly justified in the light of the fact that high reliability is sought after in such applications. The main interest in this work lies in the electromagnetic regulations defining the allowable conducted emissions in the frequencies between 150 kHz and 30 MHz. The first goal achieved by this work is to characterize the EMI signature of a matrix converter induction motor drive using common and differential mode measurements of the converter and motor impedances separately. Based only on these measurements the project aims to synthesize accurate HF models for the Induction Motor and the Matrix Converter in common and differential mode, without the need of deep level studies that may involve long Finite Elements (FE) simulations of the physical system characteristics. This thesis proposes two general novel HF models for Matrix Converters and Induction Motors that could also be applied in any other application or operating condition. These models are automatically tuned and optimized by a suitably developed Genetic Algorithm (GA) routine capable to match those models with real experimental measurements. This thesis reports the methodologies used for both input and output filter design, together with description and analysis of some issues encountered during the process

Design and initial testing of a high speed 45 kW switched reluctance drive for aerospace application

This paper presents innovative research towards the development of a 45 kW high speed switched reluctance drive as an alternative starter-generator for future aero-engines. To perform such a function the machine had to be designed with a very wide constant power-speed range. During engine-start/motoring mode, a peak torque demand of 54 Nm at 8 krpm was met, whilst in generating mode, 19.2-32 krpm, the machine was designed to deliver a constant power of 45 kW. The key enabling feature of the design lies in the novel rotor structure developed so as to allow for such a wide speed range. The results presented, are those measured during the initial testing phase and validate the system design and performance in the low-speed region with the machine operated in starting-mode. The measured machine power density is at 9.8 kW/ltr, whilst the global system efficiency is at 82%

Grid Parameter estimation using Model Predictive Direct Power Control

This paper presents a novel Finite Control Set Model Predictive Control (FS-MPC) approach for grid-connected converters. The control performance of such converters may get largely affected by variations in the supply impedance, especially for systems with low Short Circuit Ratio (SCR) values. A novel idea for estimating the supply impedance variation, and hence the grid voltage, using an algorithm embedded in the MPC is presented in this paper. The estimation approach is based on the difference in grid voltage magnitudes at two consecutive sampling instants, calculated on the basis of supply currents and converter voltages directly within the MPC algorithm, achieving a fast estimation and integration between the controller and the impedance estimator. The proposed method has been verified, using simulation and experiments, on a 3-phase 2-level converter

Model Predictive Control for shunt active filters with fixed switching frequency

This paper presents a modification to the classical Model Predictive Control algorithm, named Modulated Model Predictive Control, and its application to active power filters. The proposed control is able to retain all the advantages of a Finite Control Set Model Predictive Control whilst improving the generated waveforms harmonic spectrum. In fact a modulation algorithm, based on the cost function ratio for different output vectors, is inherently included in the MPC. The cost function-based modulator is introduced and its effectiveness on reducing the current ripple is demonstrated. The presented solution provides an effective and straightforward single loop controller, maintaining an excellent dynamic performance despite the modulated output and it is self-synchronizing with the grid. This promising method is applied to the control of a Shunt Active Filter for harmonic content reduction through a reactive power compensation methodology. Significant results obtained by experimental testing are reported and commented, showing that MPC is a viable control solution for active filtering systems

A milk and ochre paint mixture used 49,000 years ago at Sibudu, South Africa

Gas chromatography/mass spectrometry, proteomic and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS) analyses of residue on a stone flake from a 49,000 year-old layer of Sibudu (South Africa) indicate a mixture of ochre and casein from milk, likely obtained by killing a lactating wild bovid. Ochre powder production and use are documented in Middle Stone Age South African sites but until now there has been no evidence of the use of milk as a binder. Our analyses show that this ochre-based mixture was neither a hafting adhesive nor a residue left after treating animal skins, but a liquid mixture consisting of a powdered pigment mixed with milk; in other words, a paint medium that could have been applied to a surface or to human skin. The significance of our finds also lies in the fact that it establishes the antiquity of the use of milk as a binder well before the introduction of domestic cattle in South Africa in the first millennium AD

A Decidable Characterization of a Graphical Pi-calculus with Iterators

This paper presents the Pi-graphs, a visual paradigm for the modelling and verification of mobile systems. The language is a graphical variant of the Pi-calculus with iterators to express non-terminating behaviors. The operational semantics of Pi-graphs use ground notions of labelled transition and bisimulation, which means standard verification techniques can be applied. We show that bisimilarity is decidable for the proposed semantics, a result obtained thanks to an original notion of causal clock as well as the automatic garbage collection of unused names.Comment: In Proceedings INFINITY 2010, arXiv:1010.611

Novel application of liquid chromatography/mass spectrometry for the characterization of drying oils in art: Elucidation on the composition of original paint materials used by Edvard Munch (1863-1944)

Modern oil paints, introduced at the beginning of the 20th century, differ from those classically used in antiquity in their chemical and compositional features. The main ingredients were still traditional drying oils, often used in mixtures with less expensive oils and added with several classes of additives. Consequently, detailed lipid profiling, together with the study of lipid degradation processes, is essential for the knowledge and the conservation of paint materials used in modern and contemporary art.A multi-analytical approach based on mass spectrometry was used for the study of original paint materials from Munch's atelier, owned by the Munch Museum in Oslo. The results obtained in the analysis of paint tubes were compared with those obtained by characterizing a paint sample collected from one of the artist's sketches for the decoration of the Festival Hall of the University of Oslo (1909-1916).Py-GC/MS was used as screening method to evaluate the presence of lipid, proteic or polysaccaridic materials. GC/MS after hydrolysis and derivatization allowed us to determine the fatty acid profile of the paint tubes, and to evaluate the molecular changes associated to curing and ageing. The determination of the fatty acid profile is not conclusive for the characterization of complex mixtures of lipid materials, thus the characterization of the triglyceride profiles was performed using an analytical procedure based on HPLC-ESI-Q-ToF.This paper describes the first application of HPLC-ESI-Q-ToF for the acquisition of the triglyceride profile in a modern paint sample, showing the potentialities of liquid chromatography in the field of lipid characterization in modern paint materials. Moreover, our results highlighted that the application of this approach can contribute to address dating, authenticity and conservation issues relative to modern and contemporary artworks

IL-27, but not IL-35, inhibits neuroinflammation through modulating GM-CSF expression

IL-27 and IL-35 are heterodimeric cytokines, members of the IL-12 family and considered to have immunomodulatory properties. Their role during neuroinflammation had been investigated using mutant mice devoid of either one of their subunits or lacking components of their receptors, yielding conflicting results. We sought to understand the therapeutic potential of IL-27 and IL-35 delivered by gene therapy in neuroinflammation. We constructed lentiviral vectors expressing IL-27 and IL-35 from a single polypeptide chain, and we validated in vitro their biological activity. We injected IL-27 and IL-35-expressing lentiviral vectors into the cerebrospinal fluid (CSF) of mice affected by experimental neuroinflammation (EAE), and performed clinical, neuropathological and immunological analyses. Both cytokines interfere with neuroinflammation, but only IL-27 significantly modulates disease development, both clinically and neuropathologically. IL-27 protects from autoimmune inflammation by inhibiting granulocyte macrophages colony-stimulating factor (GM-CSF) expression in CD4+ T cells and by inducing program death-ligand 1 (PD-L1) expression in both CNS-resident and CNS-infiltrating myeloid cells. We demonstrate here that IL-27 holds therapeutic potential during neuroinflammation and that IL-27 inhibits GM-CSF and induces pd-l1 mRNA in vivo