Semi-transparent Boundary Conditions in the Worldline Formalism

The interaction of a quantum field with a background containing a Dirac delta function with support on a surface of codimension 1 represents a particular kind of matching conditions on that surface for the field. In this article we show that the worldline formalism can be applied to this model. We obtain the asymptotic expansion of the heat-kernel corresponding to a scalar field on $\mathbb{R}^{d+1}$ in the presence of an arbitrary regular potential and subject to this kind of matching conditions on a flat surface. We also consider two such surfaces and compute their Casimir attraction due to the vacuum fluctuations of a massive scalar field weakly coupled to the corresponding Dirac deltas.Comment: 12 page

Boundaries in the Moyal plane

We study the oscillations of a scalar field on a noncommutative disc implementing the boundary as the limit case of an interaction with an appropriately chosen confining background. The space of quantum fluctuations of the field is finite dimensional and displays the rotational and parity symmetry of the disc. We perform a numerical evaluation of the (finite) Casimir energy and obtain similar results as for the fuzzy sphere and torus.Comment: 19 pages, 6 figures. Replaced by published versio

Worldline approach to noncommutative field theory

The study of the heat-trace expansion in noncommutative field theory has shown the existence of Moyal nonlocal Seeley-DeWitt coefficients which are related to the UV/IR mixing and manifest, in some cases, the non-renormalizability of the theory. We show that these models can be studied in a worldline approach implemented in phase space and arrive to a master formula for the $n$-point contribution to the heat-trace expansion. This formulation could be useful in understanding some open problems in this area, as the heat-trace expansion for the noncommutative torus or the introduction of renormalizing terms in the action, as well as for generalizations to other nonlocal operators.Comment: 19 pages, version

An Experimental Evaluation of Resistive Defects and Different Testing Solutions in Low-Power Back-Biased SRAM Cells

This paper compares different types of resistive defects that may occur inside low-power SRAM cells, focusing on their impact on device operation. Notwithstanding the continuous evolution of SRAM device integration, manufacturing processes continue to be very sensitive to production faults, giving rise to defects that can be modeled as resistances, especially for devices designed to work in low-power modes. This work analyzes this type of resistive defect that may impair the device functionalities in subtle ways, depending on the defect characteristics and values that may not be directly or easily detectable by traditional test methods. We analyze each defect in terms of the possible effects inside the SRAM cell, its impact on power consumption, and provide guidelines for selecting the best test methods

Dual-readout Calorimetry

The RD52 Project at CERN is a pure instrumentation experiment whose goal is to understand the fundamental limitations to hadronic energy resolution, and other aspects of energy measurement, in high energy calorimeters. We have found that dual-readout calorimetry provides heretofore unprecedented information event-by-event for energy resolution, linearity of response, ease and robustness of calibration, fidelity of data, and particle identification, including energy lost to binding energy in nuclear break-up. We believe that hadronic energy resolutions of {\sigma}/E $\approx$ 1 - 2% are within reach for dual-readout calorimeters, enabling for the first time comparable measurement preci- sions on electrons, photons, muons, and quarks (jets). We briefly describe our current progress and near-term future plans. Complete information on all aspects of our work is available at the RD52 website http://highenergy.phys.ttu.edu/dream/.Comment: 10 pages, 10 figures, Snowmass White pape

Hydrolytic Degradation of 3D-Printed Poly (Lactic Acid) Structures

Hydrolytic degradation of commercially available 3D printing filament, i.e. poly (lactic acid) with broad molecular weight distribution was induced by incubating 3D-printed parts in deionized water at 3 temperatures. Small changes in orthogonal dimensions occurred due to relaxation of printing stresses, but no mass or volume loss were detected over the time-frame of the experiments. Molecular weight decreased while polydispersity remained constant. The most sensitive measure of degradation was found to be nondestructive, small-amplitude oscillatory tensile measurements. A rapid decay of tensile storage modulus was found with an exponential decay time constant of about an hour. This work demonstrates that practical monitoring of commercially available PLA degradation can be achieve with linear viscoelastic measurements of modulus

Hadron detection with a dual-readout fiber calorimeter

In this paper, we describe measurements of the response functions of a fiber-based dual- readout calorimeter for pions, protons and multiparticle "jets" with energies in the range from 10 to 180 GeV. The calorimeter uses lead as absorber material and has a total mass of 1350 kg. It is complemented by leakage counters made of scintillating plastic, with a total mass of 500 kg. The effects of these leakage counters on the calorimeter performance are studied as well. In a separate section, we investigate and compare different methods to measure the energy resolution of a calorimeter. Using only the signals provided by the calorimeter, we demonstrate that our dual-readout calorimeter, calibrated with electrons, is able to reconstruct the energy of proton and pion beam particles to within a few percent at all energies. The fractional widths of the signal distributions for these particles (sigma/E) scale with the beam energy as 30%/sqrt(E), without any additional contributing terms

Utility of magnetic resonance imaging in the follow-up of children affected by acute osteomyelitis

Acute osteomyelitis is characterized, especially in children, by high morbidity due to extension of the infectious process or its chronicization. No guidelines exist for the post-discharge follow-up of children affected by acute osteomyelitis, especially regarding the utility of magnetic resonance imaging (MRI). To investigate if MRI is useful in the follow-up of AO pediatric patients. We reviewed medical records and MRI studies of children admitted to our Pediatric Department for acute osteomyelitis from 2008 to 2015. All children who had a follow-up MRI performed at least 10 days after diagnosis were included in the study. We analyzed if MRI follow-up prompted a change in patients\u2019 treatment. A total of 28 MRI studies were performed in 27 children (13 males and 14 females). Infection involved the appendicular skeleton in 64.3% of patients. Five (18%) of these studies prompted a change in patients\u2019 treatment. The only statistically significant indication for change in the therapeutic approach was MRI performed for persistence or worsening of the disease (p=0.0058). Change in bone signal at MRI, and time interval (more or less than 28 days) between MRI at diagnosis and at follow-up were not significantly associated with change in the patients\u2019 treatment (p=0.40; p=0.40, respectively). Routine MRI follow-up is not useful in children affected by acute osteomyelitis who adequately respond to antibiotic treatment. It can be useful, in adjunct to clinical evaluation, in non-responders patients. Clinical monitoring remains the mainstay in the follow-up of these patients