2,062 research outputs found

    A solvent-extraction module for cyclotron production of high-purity technetium-99m

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    The design and fabrication of a fully-automated, remotely controlled module for the extraction and purification of technetium-99m (Tc-99m), produced by proton bombardment of enriched Mo-100 molybdenum metallic targets in a low-energy medical cyclotron, is here described. After dissolution of the irradiated solid target in hydrogen peroxide, Tc-99m was obtained under the chemical form of 99mTcO4-, in high radionuclidic and radiochemical purity, by solvent extraction with methyl ethyl ketone (MEK). The extraction process was accomplished inside a glass column-shaped vial especially designed to allow for an easy automation of the whole procedure. Recovery yields were always >90% of the loaded activity. The final pertechnetate saline solution Na99mTcO4, purified using the automated module here described, is within the Pharmacopoeia quality control parameters and is therefore a valid alternative to generator-produced 99mTc. The resulting automated module is cost-effective and easily replicable for in-house production of high-purity Tc-99m by cyclotrons

    Conceptual evidence collection and analysis methodology for Android devices

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    Android devices continue to grow in popularity and capability meaning the need for a forensically sound evidence collection methodology for these devices also increases. This chapter proposes a methodology for evidence collection and analysis for Android devices that is, as far as practical, device agnostic. Android devices may contain a significant amount of evidential data that could be essential to a forensic practitioner in their investigations. However, the retrieval of this data requires that the practitioner understand and utilize techniques to analyze information collected from the device. The major contribution of this research is an in-depth evidence collection and analysis methodology for forensic practitioners.Comment: in Cloud Security Ecosystem (Syngress, an Imprint of Elsevier), 201

    KAJIAN PENGARUH JUMLAH DAN LEBAR PERKUATAN GEOTEKSTIL TERHADAP DAYA DUKUNG TANAH GAMBUT

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    Peat soils have a high compressibily and low bearing capacity. These unfavorable characteristics can cause differential settlement and the construction failure, so that the appropriate improvement methods are required to solve the problems. Peat soil improvement methods that commonly used are mechanical and chemical improvement methods. In this research, the peat soil reinforced with geotextile was conducted in order to find the influence of the reinforcement in increasing the bearing capacity. Reinforcement was applied to the construction model with variation in the number of reinforcement which were N=1, N=2, N=3, and reinforcement width which were 2B, 3B and 4B (B is foundation width in scale). The results show that the insertion of geotextile sheets in peat soil can increase the bearing capacity of the soil foundation. The increasing of the bearing capacity is proportional to the increasing of the number and width of the geotextile. Variation in reinforcement width is given more influence in increasing the ultimate bearing capacity (q) compare to variation in the number of reinforcement. Compare to the modeled construction without reinforcement, the maximum bearing capacity increase as much as 232.3 % and BCR as of 3.32 with reinforcement width of 4B and N=3.Key words: peat, reinforcement, bearing capacit

    Spontaneous and stimulated emission tuning characteristics of a Josephson junction in a microcavity

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    We have investigated theoretically the tuning characteristics of a Josephson junction within a microcavity for one-photon spontaneous emission and for one-photon and two-photon stimulated emission. For spontaneous emission, we have established the linear relationship between the magnetic induction and the voltage needed to tune the system to emit at resonant frequencies. For stimulated emission, we have found an oscillatory dependence of the emission rate on the initial Cooper pair phase difference and the phase of the applied field. Under specific conditions, we have also calculated the values of the applied radiation amplitude for the first few emission maxima of the system and for the first five junction-cavity resonances for each process. Since the emission of photons can be controlled, it may be possible to use such a system to produce photons on demand. Such sources will have applications in the fields of quantum cryptography, communications and computation

    Nanolayers for early diagnostics of proteins involved in degenerative amyloidosis

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    FK-506 binding protein (FKBP12) is a protein of the family of immunophilins, involved in many neurodegenerative diseases such as Alzheimer’s syndrome where FKBP12 is known to be over-expressed in early stages of the disease. We designed and built Langmuir-Blodgett nanostructures incorporating ligands with high affinity for FKBP12: Tacrolimus (FK506) and Rifaximin as candidate nanosensors to detect low FKBP12 concentration in the initial phase of the amyloidosis. The binding process of the different ligands has been studied by means of photophysical measurements investigating the fluorescence quenching of the tryptophan residue in the binding pocket of FKBP12 by addition of the ligand in solution. Immobilization of the ligands was achieved adopting biomimetic strategy: phospholipid Langmuir-Blodgett films are proposed as nanoscaffolds for ligand inclusion. Several phospholipid nanoarchitectures differing in lipid composition, fluidity, number of layers and method of production (incubation versus co-spreading) were screened. The results have shown that both FK506 and Rifaximin ligands penetrate the lipid matrix either as monomers or as aggregates depending on their initial concentration. More importantly, the experiments demonstrated that the ligands in the LB scaffolds efficiently quench FKBP12 fluorescence in solution as a consequence of ligand binding to the protein

    Psychoanalysis and hermeneutics

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    An overview of the relationship between psychoanalysis and hermeneutics. We would like to open this introduction by confessing an initial ambition that we now see with a more critical eye. The idea that initially prompted the construction of this issue of Critical Hermeneutics was to rethink in a systematic way the relationship between these two disciplines that have constantly but ambivalently attracted each other, perhaps since the birth of the younger one: psychoanalysis. However, we realised that the goal of a systematic review of the relationship between hermeneutics and psychoanalysis is not yet feasible. There are too many directions that can be given to reflection. The works that have arrived – and which we will briefly present in the next paragraph – testify precisely to this polyphony of voices, sometimes dissonant, but fertile and innovative. Indeed, by moving in so many different directions – from clinic to art, from historiography to phenomenology, from ethics to textual analysis – the resulting picture contributes to broadening perspectives, but also suggests the epoché of any possible claim to synthesis. However, it is still appropriate to ask what are the fundamental assumptions that legitimise and make necessary, today more than yesterday, the dialogue between hermeneutics and psychoanalysis. This reminds us of what Hans Georg Gadamer (2003) said at a psychiatry conference about their relationship with hermeneutics: although both disciplines are dedicated to understanding, it is not so much this that distinguishes them, but the common interest in what escapes understanding itself. First of all, psychoanalysis can be included entirely in the field of hermeneutics, since language and the construction of meaning are strictly linked to the affective/emotional transformations they aim to activate. As Ricoeur (1988) states, analytic treatment is possible because affectivity is not foreign to language and consists in bringing into language what has been excluded from it. ..

    Quasar Accretion Disk Sizes from Continuum Reverberation Mapping in the DES Standard-star Fields

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    Measurements of the physical properties of accretion disks in active galactic nuclei are important for better understanding the growth and evolution of supermassive black holes. We present the accretion disk sizes of 22 quasars from continuum reverberation mapping with data from the Dark Energy Survey (DES) standard-star fields and the supernova C fields. We construct continuum light curves with the griz photometry that span five seasons of DES observations. These data sample the time variability of the quasars with a cadence as short as 1 day, which corresponds to a rest-frame cadence that is a factor of a few higher than most previous work. We derive time lags between bands with both JAVELIN and the interpolated cross-correlation function method and fit for accretion disk sizes using the JAVELIN thin-disk model. These new measurements include disks around black holes with masses as small as ∼107 M o˙, which have equivalent sizes at 2500 Å as small as ∼0.1 lt-day in the rest frame. We find that most objects have accretion disk sizes consistent with the prediction of the standard thin-disk model when we take disk variability into account. We have also simulated the expected yield of accretion disk measurements under various observational scenarios for the Large Synoptic Survey Telescope Deep Drilling Fields. We find that the number of disk measurements would increase significantly if the default cadence is changed from 3 days to 2 days or 1 day. © 2020. The American Astronomical Society. All rights reserved
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