4,064 research outputs found
The ground state of a spin-1/2 neutral particle with anomalous magnetic moment in a Aharonov-Casher configuration
We determine the (bound) ground state of a spin 1/2 chargless particle with
anomalous magnetic moment in certain Aharonov-Casher configurations. We recast
the description of the system in a supersymmetric form. Then the basic physical
requirements for unbroken supersymmetry are established. We comment on the
possibility of neutron trapping in these systems
Principles and perspectives of radiographic imaging with muons
Radiographic imaging with muons, also called Muography, is based on the measurement of the absorption of muons, generated by the interaction of cosmic rays with the earth’s atmosphere, in matter. Muons are elementary particles with high penetrating power, a characteristic that makes them capable of crossing bodies of dimensions of the order of hundreds of meters. The interior of bodies the size of a pyramid or a volcano can be seen directly with the use of this technique, which can rely on highly segmented muon trackers. Since the muon flux is distributed in energy over a wide spectrum that depends on the direction of incidence, the main difference with radiography made with X-rays is in the source. The source of muons is not tunable, neither in energy nor in direction; to improve the signal-to-noise ratio, muography requires large instrumentation, long time data acquisition and high background rejection capacity. Here, we present the principles of the Muography, illustrating how radiographic images can be obtained, starting from the measurement of the attenuation of the muon flux through an object. It will then be discussed how recent technologies regarding artificial intelligence can give an impulse to this methodology in order to improve its results
Unbroken supersymmetry in the Aharonov-Casher effect
We consider the problem of the bound states of a spin 1/2 chargless particle
in a given Aharonov-Casher configuration. To this end we recast the description
of the system in a supersymmetric form. Then the basic physical requirements
for unbroken supersymmetry are established. We comment on the possibility of
neutron confinement in this system
Occupational Therapy Assistant Students’ Perceptions of using Standardized Patient Encounters as a Replacement for Traditional Level I Fieldwork
Standardized patient encounters are being utilized more often in occupational therapy education as a replacement for traditional fieldwork. While there is a growing body of research to support the use of this model in developing student skillsets and confidence, there remains limited information on the topic, and no studies which look at its use with occupational therapy assistant students. Twenty-four occupational therapy assistant students participated in standardized patient encounters which served as a replacement for traditional Level I fieldwork. All students completed an anonymous supplementary course evaluation regarding their experiences. A secondary analysis of the data looked at their perceptions of a standardized patient encounter model for fieldwork and how it did or did not prepare them for future Level II clinicals. Quantitative and qualitative data exposed aspects of these experiences which students found to be most and least effective. Overall, data showed moderate support for use of standardized patient encounters to support student confidence and skills in anticipation of Level II fieldwork. The student perception of these types of experiences is influenced by environmental (e.g., structure) and personal (e.g., student personality) factors. Success requires adequate preparation of all involved parties. Use of standardized patient encounters should be researched further to determine its impact on fieldwork performance evaluation scores and future employment
A new cylindrical borehole detector for radiographic imaging with muons
Muon radiography is a methodology which enables measuring the mass distribution within large objects. It exploits the abundant flux of cosmic muons and uses detectors with different technologies depending on the application. As the sensitive surface and geometric acceptance are two fundamental parameters for increasing the collection of muons, the optimization of the detectors is very significant. Here we show a potentially innovative detector of size and shape suitable to be inserted inside a borehole, that optimizes the sensitive area and maximizes the angular acceptance thanks to its cylindrical geometry obtained using plastic arc-shaped scintillators. Good spatial resolution is obtained with a reasonable number of channels. The dimensions of the detector make it ideal for use in 25 cm diameter wells. Detailed simulations based on Monte Carlo methods show great cavity detection capability. The detector has been tested in the laboratory, achieving overall excellent performance
Muon Radiography Investigations in Boreholes with a Newly Designed Cylindrical Detector
Muons are constantly produced in cosmic-rays and reach the Earth surface with a flux of about 160 particles per second per square meter. The abundance of muons with respect to other cosmic particles and their capability to cross dense materials with low absorption rate allow them to be exploited for large scale geological or human-made object imaging. Muon radiography is based on similar principles as X-ray radiography, measuring the surviving rate of muons escaping the target and relating it to the mass distribution inside the object. In the course of decades, after the first application in 1955, the methodology has been applied in several different fields. Muography allows us to measure the internal density distribution of the investigated object, or to simply highlight the presence of void regions by observing any excess of muons. Most of these applications require the detector to be installed below the rock being probed. In case that possible installation sites are not easily accessible by people, common instrumentation cannot be installed. A novel borehole cylindrical detector for muon radiography has been recently developed to deal with these conditions. It has been realized with a cylindrical geometry to fit typical borehole dimensions. Its design maximizes the geometrical acceptance, minimizing the dead spaces by the use of arc-shaped scintillators. The details of the construction and preliminary results of the first usage are described in this paper. © 2022 by the authors
Faculty-Led Virtual Level 1 Community Fieldwork during the COVID-19 Pandemic
Fieldwork is an integral portion of occupational therapy education that ensures students have the opportunity to develop basic competencies in real world practice settings. The national shortage of fieldwork placements, particularly in the area of mental health, in combination with the COVID-19 pandemic, have led to the adoption of increasingly innovative fieldwork models. This retrospective, qualitative study investigates occupational therapy assistant students’ experiences of completing a faculty-led (i.e. where faculty served as the primary fieldwork educator) and virtual (i.e., where services were offered in a virtual environment) Level I fieldwork with a community-based peer led behavioral health agency. Twenty-three students completed a confidential survey describing their experiences in Fall 2020. A secondary analysis of students’ responses was performed using principles of thematic analysis, which yielded results centered on four themes: knowledge, skills, attitudes, and structure. Subcategories highlighted growth across multiple areas including knowledge of occupational therapy’s role in mental health, interpersonal skills, and use of technology and other resources. Students’ preconceived notions of individuals with mental illness were challenged and many reported increased confidence in their abilities to work with these individuals. Both positive and constructive feedback were provided regarding the overall virtual fieldwork experience. The faculty-led virtual fieldwork model was viable in supporting occupational therapy assistant students’ skills to engage people with mental health and substance use challenges in a community setting. The potential use of this model is discussed in light of the anticipated increase of behavioral health problems for many across the lifespan post-COVID-19 pandemic
A Fast Digital Integrator for Magnetic Field Measurements at CERN
A self-calibrating digital instrument for flux measurements on magnets for accelerators used in basic research on subnuclear particles is proposed. The instrument acquires voltage arising from rotating coils transducers with a theoretical resolution of 10 ppt and a maximum sampling frequency of 800 kS/s. Then, samples are integrated on-line and suitably processed in order to improve time resolution and flux accuracy. This allows the limits of state-of-the-art digital fluximeters, related mainly to newgeneration rotating coils, with trigger rate of 20 kHz and coils speed of 10 rps, to be overcome. The instrument has been prototyped at Magnetic Measurement and Testing (MTM) Group of European Laboratory for Nuclear Research (CERN), under a framework of cooperation with the University of Sannio. Details on hardware and firmware conception, as well as on experimental results of the instrument principle validation, and of the preliminary metrological characterization of the prototype, are provided
Ultrasound in the diagnosis of calcium pyrophosphate dihydrate deposition disease. A systematic literature review and a meta-analysis
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