2,805 research outputs found

    Study of bonding between glass and plastic in glass-reinforced plastics - Extended work Quarterly progress report, 1 Jan. - 31 Mar. 1967

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    Procedures for fluorination and alkylation of glass fabric for subsequent use in production of laminate

    Assessing the Relationships between Interdigital Geometry Quality and Inkjet Printing Parameters

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    Drop on demand (DoD) inkjet printing is a high precision, non-contact, and maskless additive manufacturing technique employed in producing high-precision micrometer-scaled geometries allowing free design manufacturing for flexible devices and printed electronics. A lot of studies exist regarding the ink droplet delivery from the nozzle to the substrate and the jet fluid dynamics, but the literature lacks systematic approaches dealing with the relationship between process parameters and geometrical outcome. This study investigates the influence of the main printing parameters (namely, the spacing between subsequent drops deposited on the substrate, the printing speed, and the nozzle temperature) on the accuracy of a representative geometry consisting of two interdigitated comb-shape electrodes. The study objective was achieved thanks to a proper experimental campaign developed according to Design of Experiments (DoE) methodology. The printing process performance was evaluated by suitable geometrical quantities extracted from the acquired images of the printed samples using a MATLAB algorithm. A drop spacing of 140 µm and 170 µm on the two main directions of the printing plane, with a nozzle temperature of 35◦C, resulted as the most appropriate parameter combination for printing the target geometry. No significant influence of the printing speed on the process outcomes was found, thus choosing the highest speed value within the investigated range can increase productivity

    New experimental limit on the Pauli Exclusion Principle violation by electrons

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    The Pauli Exclusion Principle (PEP) is one of the basic principles of modern physics and, even if there are no compelling reasons to doubt its validity, it is still debated today because an intuitive, elementary explanation is still missing, and because of its unique stand among the basic symmetries of physics. The present paper reports a new limit on the probability that PEP is violated by electrons, in a search for a shifted Kα_\alpha line in copper: the presence of this line in the soft X-ray copper fluorescence would signal a transition to a ground state already occupied by 2 electrons. The obtained value, 1/2β24.5×1028{1/2} \beta^{2} \leq 4.5\times 10^{-28}, improves the existing limit by almost two orders of magnitude.Comment: submitted to Phys. Lett.

    VIP: An Experiment to Search for a Violation of the Pauli Exclusion Principle

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    The Pauli Exclusion Principle is a basic principle of Quantum Mechanics, and its validity has never been seriously challenged. However, given its fundamental standing, it is very important to check it as thoroughly as possible. Here we describe the VIP (VIolation of the Pauli exclusion principle) experiment, an improved version of the Ramberg and Snow experiment (E. Ramberg and G. Snow, {\it Phys. Lett. B} {\bf 238}, 438 (1990)); VIP has just completed the installation at the Gran Sasso underground laboratory, and aims to test the Pauli Exclusion Principle for electrons with unprecedented accuracy, down to β2/210301031\beta^2/2 \approx 10^{-30} - 10^{-31}. We report preliminary experimental results and briefly discuss some of the implications of a possible violation.Comment: Plenary talk presented by E. Milotti at Meson 2006, Cracow, 9-13 June 200

    New experimental limit on Pauli Exclusion Principle violation by electrons (the VIP experiment)

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    The Pauli Exclusion Principle is one of the basic principles of modern physics and is at the very basis of our understanding of matter: thus it is fundamental importance to test the limits of its validity. Here we present the VIP (Violation of the Pauli Exclusion Principle) experiment, where we search for anomalous X-rays emitted by copper atoms in a conductor: any detection of these anomalous X-rays would mark a Pauli-forbidden transition. ] VIP is currently taking data at the Gran Sasso underground laboratories, and its scientific goal is to improve by at least four orders of magnitude the previous limit on the probability of Pauli violating transitions, bringing it into the 10**-29 - 10**-30 region. First experimental results, together with future plans, are presented.Comment: To appear in proceedings of the XLVI International Winter Meeting on Nuclear Physics, Bormio, Italy, January 20-26, 200

    Testing the Pauli Exclusion Principle for Electrons

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    One of the fundamental rules of nature and a pillar in the foundation of quantum theory and thus of modern physics is represented by the Pauli Exclusion Principle. We know that this principle is extremely well fulfilled due to many observations. Numerous experiments were performed to search for tiny violation of this rule in various systems. The experiment VIP at the Gran Sasso underground laboratory is searching for possible small violations of the Pauli Exclusion Principle for electrons leading to forbidden X-ray transitions in copper atoms. VIP is aiming at a test of the Pauli Exclusion Principle for electrons with high accuracy, down to the level of 1029^{-29} - 1030^{-30}, thus improving the previous limit by 3-4 orders of magnitude. The experimental method, results obtained so far and new developments within VIP2 (follow-up experiment at Gran Sasso, in preparation) to further increase the precision by 2 orders of magnitude will be presented.Comment: Proceedings DISCRETE 2012-Third Symposium on Prospects in the Physics of Discrete Symmetries, Lisbon, December 3-7, 201

    Beyond quantum mechanics? Hunting the 'impossible' atoms (Pauli Exclusion Principle violation and spontaneous collapse of the wave function at test)

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    The development of mathematically complete and consistent models solving the so-called "measurement problem", strongly renewed the interest of the scientific community for the foundations of quantum mechanics, among these the Dynamical Reduction Models posses the unique characteristic to be experimentally testable. In the first part of the paper an upper limit on the reduction rate parameter of such models will be obtained, based on the analysis of the X-ray spectrum emitted by an isolated slab of germanium and measured by the IGEX experiment. The second part of the paper is devoted to present the results of the VIP (Violation of the Pauli exclusion principle) experiment and to describe its recent upgrade. The VIP experiment established a limit on the probability that the Pauli Exclusion Principle (PEP) is violated by electrons, using the very clean method of searching for PEP forbidden atomic transitions in copper

    High sensitivity tests of the Pauli Exclusion Principle with VIP2

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    The Pauli Exclusion Principle is one of the most fundamental rules of nature and represents a pillar of modern physics. According to many observations the Pauli Exclusion Principle must be extremely well fulfilled. Nevertheless, numerous experimental investigations were performed to search for a small violation of this principle. The VIP experiment at the Gran Sasso underground laboratory searched for Pauli-forbidden X-ray transitions in copper atoms using the Ramberg-Snow method and obtained the best limit so far. The follow-up experiment VIP2 is designed to reach even higher sensitivity. It aims to improve the limit by VIP by orders of magnitude. The experimental method, comparison of different PEP tests based on different assumptions and the developments for VIP2 are presented.Comment: 6 pages, 3 figures, Proceedings DISCRETE2014 Conferenc
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