3,065 research outputs found
Domain wall pinning and potential landscapes created by constrictions and protrusions in ferromagnetic nanowires
The potential experienced by transverse domain walls (TDWs) in the vicinity
of asymmetric constrictions or protrusions in thin Permalloy nanowires is
probed using spatially resolved magneto-optical Kerr effect measurements. Both
types of traps are found to act as pinning centers for DWs. The strength of
pinning is found to depend on the trap type as well as on the chirality of the
incoming DW; both types of traps are seen to act either as potential wells or
potential barriers, also depending on the chirality of the DW. Micromagnetic
simulations have been performed that are in good qualitative agreement with the
experimental results.Comment: 6 pages, 7 figure
Sharing learning outcomes in chemistry teaching at HE level: Beneficial or detrimental?
The sharing of explicit learning objectives and/or learning outcomes is considered to be good practice in schools, with OFSTED observation criteria indicating that this is a pre-requisite to a good or outstanding lesson1. Such practice does not appear to be widespread in chemistry teaching at HE level. Whilst a statement of aims/objectives/outcomes can normally be found in the documentation accompanying any given unit of teaching, these are typically in a less student-friendly format than those used in school, or are too vague to be useful. At the same time, many lecturers do communicate aims at the start of a lecture, but there may be scope for doing this in a more effective way. The extent to which students are exposed to „learning outcomes‟ varies greatly from institution to institution, discipline to discipline and from teacher to teacher, and as such it is difficult to discern the best approach.This article presents some background on developments at pre-university level that have influenced practice in this area, and outlines the findings of a research project carried out in the School of Chemistry at the University of Southampton. The project probed the views of staff and students regarding the usefulness of learning outcomes. Several different approaches to sharing learning outcomes with first year students were trialled and evaluated during the course of the 2010-11 academic year. This work is part of an on-going initiative which aims to identify effective methods to support students in becoming independent learners when making the transition to university, and to improve retention rates
Why There Cannot be Any Such Thing as “Time Travel"
Extending work of Wittgenstein, Lakoff and Johnson I suggest that it is the (spatial) metaphors we rely on in order to conceptualise time that provide an illusory space for time-travel-talk. For example, in the “Moving Time” spatialisation of time, “objects” move past the agent from the future to the past. The objects all move in the same direction – this is mapped to time always moving in the same direction. But then it is easy to imagine suspending this rule, and asking why the objects should not start moving in the opposite direction. This is one way of generating the idea of time-travel “back” into the past. Time-travel-talk essentially involves the unaware projection of fragments of our time-talk – taken from powerful conceptual metaphors – onto the nature of reality itself. Understanding this dissolves away the charm and attractions of such talk
Discovery of a large and bright bow shock nebula associated with low mass X-ray binary SAX J1712.6-3739
In a multiwavelength program dedicated to identifying optical counterparts of
faint persistent X-ray sources in the Galactic Bulge, we find an accurate X-ray
position of SAX J1712.6-3739 through Chandra observations, and discover its
faint optical counterpart using our data from EFOSC2 on the ESO 3.6m telescope.
We find this source to be a highly extincted neutron star LMXB with blue
optical colours. We serendipitously discover a relatively bright and large bow
shock shaped nebula in our deep narrowband H alpha imaging, most likely
associated with the X-ray binary. A nebula like this has never been observed
before in association with a LMXB, and as such provides a unique laboratory to
study the energetics of accretion and jets. We put forward different models to
explain the possible ways the LMXB may form this nebulosity, and outline how
they can be confirmed observationally.Comment: Accepted for publication in MNRAS-Letters; 5 pages, 4 figures, 2
tables. Quality of figure 2 downgraded because of arXiv file size limit
Diabetes and Technology for Increased Activity (DaTA) Study: Results of a remote monitoring intervention for prevention of metabolic syndrome
Objective: An increasingly aged, overweight, and sedentary population has resulted in elevated risk of cardiovascular disease (CVD). The escalating incidence of diabetes and other chronic illnesses, deficits in health care budgets, and physician shortages, especially in rural communities, have prompted investigations of feasible solutions. The Diabetes and Technology for Increased Activity (DaTA) study was designed to test the effectiveness of a lifestyle intervention driven by self-monitoring of blood glucose (BG), blood pressure (BP), physical activity (PA), and weight to positively impact CVD risk factors in a medically underserviced rural population with a high incidence of metabolic syndrome (MS). Research Design and Methods: Conducted in a community-based research setting, this single-center open feasibility study used smart phones to transmit BP, BG, pedometer, weight, heart rate, and activity measurements to a database. Technology allowed participants to interface with the clinical team and self-monitor their personal health indicators. Results: Twenty-four participants aged 30 to 71 years completed the 8-week intervention. Participants had significant improvement in clinic (p = .046) and self-monitored diastolic BP (p = .001), body mass index (p = .002), and total cholesterol (p = .009), and steps per day. Daily PA increased as well as participants\u27 interest in and willingness to make lifestyle changes that impact health outcomes. Conclusions: The DaTA study demonstrated that self-monitoring of the risk factors for MS and increased PA improved the participant\u27s CVD risk profile. Considering the 8-week time period of this intervention, results are encouraging. This lifestyle intervention, which uses education and technology as tools, confirms the utility of remote health monitoring. © Diabetes Technology Society
The breaking of quantum double symmetries by defect condensation
In this paper, we study the phenomenon of Hopf or more specifically quantum
double symmetry breaking. We devise a criterion for this type of symmetry
breaking which is more general than the one existing in the literature, and
therefore extends the number of possible breaking patterns that can be
described consistently. We start by recalling why the extended symmetry notion
of quantum double algebras is an optimal tool when analyzing a wide variety of
two dimensional physical systems including quantum fluids, crystals and liquid
crystals. The power of this approach stems from the fact that one may
characterize both ordinary and topological modes as representations of a single
(generally non-Abelian) Hopf symmetry. In principle a full classification of
defect mediated as well as ordinary symmetry breaking patterns and subsequent
confinement phenomena can be given. The formalism applies equally well to
systems exhibiting global, local, internal and/or external (i.e. spatial)
symmetries. The subtle differences in interpretation for the various situations
are pointed out. We show that the Hopf symmetry breaking formalism reproduces
the known results for ordinary (electric) condensates, and we derive formulae
for defect (magnetic) condensates which also involve the phenomenon of symmetry
restoration. These results are applied in two papers which will be published in
parallel.Comment: 65 pages, 7 figures, correction in table 3, updated reference
Logical realism and the metaphysics of logic
‘Logical Realism’ is taken to mean many different things. I argue that if reality has a privileged structure, then a view I call metaphysical logical realism is true. The view says that, first, there is ‘One True Logic’; second, that the One True Logic is made true by the mind‐and‐language‐independent world; and third, that the mind‐and‐language‐independent world makes it the case that the One True Logic is better than any other logic at capturing the structure of reality. Along the way, I discuss a few alternatives, and clarify two distinct kinds of metaphysical logical realism.Accepted manuscrip
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