1,721,310 research outputs found
A three-phase single sheet tester with digital control of flux loci based on the contraction mapping principle
No full textOPTIMIZED CONFIGURATIONS FOR MICRO-PHOTOGRAMMETRIC SURVEYING ADAPTABLE TO MACRO OPTICS AND DIGITAL MICROSCOPE
No full textThe configuration of new survey approaches for digitizing tiny artefacts is gradually emerging in favour of the related results sharing innew modalities such as 3D printing and or Cultural Heritage open-access datasets. Unfortunately, due to the still high cost of theinstrumentations and the time required for specialized operators training, both the digital documentation of small artefacts and thedissemination of 3D data are still a long way from becoming truly mainstream practices.Alternative solutions, often at low cost, could be considered, involving the use of passive sensors for image-based modelling processes,relying on a widespread technology that is now within everyone’s reach. Therefore, we intend to meet the demand for the three-dimensional representation of small objects with complex surfaces and sub-millimetre morphological characteristics by designingseveral custom accessories that optimize the photogrammetric workflow while maintaining very high metric rigour.In this current work, the authors will focus on researching the most suitable acquisition method and hardware setup to achieve a digitaltwin of a complex and detailed cuneiform tablet replica using the now widely available on the market digital portable microscopes, ableto achieve high magnification. The results were compared with a reference dataset from an active sensor acquisition for the necessaryprocedure validations
Quale politica fiscale regionale? Analisi del federalismo italiano attraverso un modello CGE
No full textFrom the Gaulard-Gibbs secondary generator to present-day transformers: evolution of magnetic core materials through a century
No full textA comprehensive approach to broadband characterization of soft ferrites
Full text linkWe present and discuss methods, setups, and results concerning the characterization of Mn-Zn and Ni-Zn ferrites in the frequency range DC-1 GHz, by which we bring to light the physical mechanisms responsible for the observed frequency behavior of magnetic losses W and permeability mu and provide thorough assessment of the broadband response of the material. A comprehensive array of polarization J(p) and frequency f values is investigated. A fluxmetric approach is applied up to a few MHz, which is substituted by a transmission line method at higher frequencies, up to 1 GHz. The fluxmetric measurements are made at defined J(p) value, typically from a few mT to some hundred mT. The waveguide characterization, centered on the use of a network analyzer, is instead made under defined exciting power. But a full experimental W(J(p), f) matrix up to 1 GHz and J(p) values typically belonging to the Rayleigh region is in any case retrieved, thanks to the linear response of the material at high-frequencies. Disaccommodation measurements are the route followed in these experiments to separate the rotations from the domain wall process at all frequencies. Whatever the magnetization mode, the role of eddy currents in Mn-Zn ferrite losses is put in evidence by means of resistivity measurements and ensuing multiscale numerical modeling, the loss experiments being made on progressively thinned ring samples. It is concluded that an eddy current free W(J(p), f) behavior can always be obtained, which can be decomposed into domain wall and rotation related contributions. The latter can be calculated assuming a suitable distribution of the effective internal anisotropy fields and its introduction in the Landau-Lifshitz-Gilbert derivation of the rotational susceptibility
The economics of politics: patronage and political selection in Italy
Full text linkThis article investigates patronage in the Second Italian Republic by considering patronage a fundamental device able to guarantee a party presence in the governance of public bodies. The study sheds light on a particular area of party patronage, namely political appointments concerning legislators; it analyzes the factors which could determine whether a member of Parliament will be appointed to a state-owned enterprise’s board of directors after a legislature, seeking to gain a better understanding of how political actors exploit this opportunity. Direct political connections can be conceptualized as instruments to control and reward politicians and/or strategies to enhance political control over the bureaucracy. The empirical investigation suggests that legislators’ efforts in Parliament play a role in the likelihood of patronage appointments. Education does not seem to significantly increase the probability of receiving a nomination for a seat on public firms’ boards, moreover our result casts doubt on the merits or competencies of the appointed politicians
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