23,223 research outputs found
Shaking off the cloak of ‘certainty’ and embracing ethical dilemmas in baby rooms research
For a decade, we (the authors) have been actively engaged in funded research about Early Childhood Education and Care (ECEC) for babies and toddlers. In all cases, our work was approved by a Research Ethics Committee (REC). This scrutiny process provides an important mechanism for encouraging researchers to consider carefully the impact of their intentions and for protecting research participants from harm. But it can be simplistic in its requirements, its application and its conceptualisations of research relationships, procedures and outcomes.
This article is not concerned with the shortcomings of RECs; instead, we consider some of the situated and relational ethical considerations that we encountered and which, in our experience, rarely surface in applications for ethical approval. We acknowledge that the very act of researching can do harm or lead to unintended consequences. Through our work, we became aware that research can produce results that may be unpalatable to the researchers and / or the participants.
We have used Tronto’s (2013) five elements of an Ethic of Care to frame our post hoc reflections about researching the principles and practice of early childhood education and care (ECEC) for babies from birth to two in England. We employ the term, ‘palimpsest’ to convey our understanding of the ways in which multiple scripts, including research narratives, are layered upon those working with babies and young children. For example, the imposition of a national curriculum ‘script’ has the potential to usurp pre-existing professional beliefs, knowledge, understanding, identity and autonomy
Thermocouple installation
A thermocouple assembly which includes a plug having a pair of small diameter holes near one end thereof which are spaced a small distance apart to leave a thin quantity of plug material between the holes is presented. There are a pair of thermocouple wires extending through the different holes and with the outer ends of the wires joined to the thin quantity of plug material which lies between the holes to form a thermocouple junction
Seeking Froebel's mother songs in daycare for babies
In 2013, we undertook a small exploratory study that involved baby room practitioners who work in full daycare settings in southeast England caring for babies from 3 weeks to around 18 months of age. We had received funding from The Froebel Trust to examine whether Froebel’s principles for early childhood education and care and the particular emphasis he placed on singing with babies and young children resonated with contemporary practices in settings that did not express any affiliation to Froebelian ideas. We adopted an interpretative approach, used predominantly narrative methods for data collection (including practitioners’ reflections on filmed observations of their practice) and applied thematic methods for qualitative data analysis. Our enquiry was framed and guided by findings from our previous research into the processes and practice of baby rooms (Goouch and Powell 2013) and a rapid review of literature about the benefits of singing to/with babies and Froebel’s writings on the subject. Our initial conceptual framework was underpinned by four propositions, which guided our research questions and design for the study. Although this pilot left us with many questions requiring further exploration, we were reasonably confident that our four propositions had been affirmed by our enquiries. Namely, that singing can facilitate intimacy; supports language development; can be a means to improve relationships with families; and enhances the wellbeing of practitioners during their working day. But we also discovered that singing is not overtly promoted in policy nor are its multiple facets and benefits necessarily recognised in practice. Consequently, although the practitioners involved frequently demonstrated that they broadly concurred with Froebel’s ideas about the value of singing, they did so only when it was drawn to their attention. Also they were largely unaware of Froebel’s principles and any resonance was coincidental. But they were fascinated by the enquiry, keen to learn about research on singing and Froebel’s beliefs, enthusiastic in their engagement in the project and replete with suggestions about how they could explore singing as a tool for connecting with babies’ parents and home lives
Determination of ASPS performance for large payloads in the shuttle orbiter disturbance environment
A high fidelity simulation of the annular suspension and pointing system (ASPS), its payload, and the shuttle orbiter was used to define the worst case orientations of the ASPS and its payload for the various vehicle disturbances, and to determine the performance capability of the ASPS under these conditions. The most demanding and largest proposed payload, the Solar Optical Telescope was selected for study. It was found that, in all cases, the ASPS more than satisfied the payload's requirements. It is concluded that, to satisfy facility class payload requirements, the ASPS or a shuttle orbiter free-drift mode (control system off) should be utilized
Phase field theory of interfaces and crystal nucleation in a eutectic system of fcc structure: I. Transitions in the one-phase liquid region
The published version of this Article can be accessed from the link below - Copyright @ 2007 American Institute of PhysicsThe phase field theory (PFT) has been applied to predict equilibrium interfacial properties and nucleation barrier in the binary eutectic system Ag-Cu using double well and interpolation functions deduced from a Ginzburg-Landau expansion that considers fcc (face centered cubic) crystal symmetries. The temperature and composition dependent free energies of the liquid and solid phases are taken from CALculation of PHAse Diagrams-type calculations. The model parameters of PFT are fixed so as to recover an interface thickness of approximately 1 nm from molecular dynamics simulations and the interfacial free energies from the experimental dihedral angles available for the pure components. A nontrivial temperature and composition dependence for the equilibrium interfacial free energy is observed. Mapping the possible nucleation pathways, we find that the Ag and Cu rich critical fluctuations compete against each other in the neighborhood of the eutectic composition. The Tolman length is positive and shows a maximum as a function of undercooling. The PFT predictions for the critical undercooling are found to be consistent with experimental results. These results support the view that heterogeneous nucleation took place in the undercooling experiments available at present. We also present calculations using the classical droplet model classical nucleation theory (CNT) and a phenomenological diffuse interface theory (DIT). While the predictions of the CNT with a purely entropic interfacial free energy underestimate the critical undercooling, the DIT results appear to be in a reasonable agreement with the PFT predictions.This work has been supported by the Hungarian Academy of Sciences under Contract No. OTKA-K-62588 and by the ESA PECS Contract Nos. 98005, 98021, and 98043
Quench dynamics across quantum critical points
We study the quantum dynamics of a number of model systems as their coupling
constants are changed rapidly across a quantum critical point. The primary
motivation is provided by the recent experiments of Greiner et al. (Nature 415,
39 (2002)) who studied the response of a Mott insulator of ultracold atoms in
an optical lattice to a strong potential gradient. In a previous work
(cond-mat/0205169), it had been argued that the resonant response observed at a
critical potential gradient could be understood by proximity to an Ising
quantum critical point describing the onset of density wave order. Here we
obtain numerical results on the evolution of the density wave order as the
potential gradient is scanned across the quantum critical point. This is
supplemented by studies of the integrable quantum Ising spin chain in a
transverse field, where we obtain exact results for the evolution of the Ising
order correlations under a time-dependent transverse field. We also study the
evolution of transverse superfluid order in the three dimensional case. In all
cases, the order parameter is best enhanced in the vicinity of the quantum
critical point.Comment: 10 pages, 6 figure
Effects of asymmetry on the dynamic stability of aircraft
The oblique wing concept for transonic aircraft was proposed to reduce drag. The dynamic stability of the aircraft was investigated by analytically determining the stability derivatives at angles of skew ranging from 0 and 45 deg and using these stability derivatives in a linear analysis of the coupled aircraft behavior. The stability derivatives were obtained using a lifting line aerodynamic theory and found to give reasonable agreement with derivatives developed in a previous study for the same aircraft. In the dynamic analysis, no instability or large changes occurred in the root locations for skew angles varying from 0 to 45 deg with the exception of roll convergence. The damping in roll, however, decreased by an order of magnitude. Rolling was a prominent feature of all the oscillatory mode shapes at high skew angles
Asymptotically optimal Bayesian sequential change detection and identification rules
Cataloged from PDF version of article.We study the joint problem of sequential change detection and multiple hypothesis
testing. Suppose that the common distribution of a sequence of i.i.d. random variables
changes suddenly at some unobservable time to one of finitely many distinct alternatives,
and one needs to both detect and identify the change at the earliest possible time. We propose
computationally efficient sequential decision rules that are asymptotically either Bayesoptimal
or optimal in a Bayesian fixed-error-probability formulation, as the unit detection
delay cost or the misdiagnosis and false alarm probabilities go to zero, respectively. Numerical
examples are provided to verify the asymptotic optimality and the speed of convergence
A layered SAW device based on ZnO/LiTaO3 for liquid media sensing applications
Surface Acoustic Wave (SAW) sensors comprising a zinc oxide guiding layer deposited on a 36°-YX lithium tantalate substrate were developed. They were found to have greater mass sensitivity than other LiTaO3 based SAW sensors, such as the -SiO2/LiTaO3 configuration. In this paper, the fabrication of the ZnO/LiTaO3 sensor is described and micro-characterisation of the deposited films is presented. Sensitivity of these devices to surface mass and dielectric perturbations is then presented, followed by an analysis of temperature stability
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Crystal design approaches for the synthesis of paracetamol co-crystals
Crystal engineering principles were used to design three new co-crystals of paracetamol. A variety of potential cocrystal formers were initially identified from a search of the Cambridge Structural Database for molecules with complementary hydrogen-bond forming functionalities. Subsequent screening by powder X-ray diffraction of the products of the reaction of this library of molecules with paracetamol led to the discovery of new binary crystalline phases of paracetamol with trans-1,4- diaminocyclohexane (1); trans-1,4-di(4-pyridyl)ethylene (2); and 1,2-bis(4-pyridyl)ethane (3). The co-crystals were characterized by IR spectroscopy, differential scanning calorimetry, and 1H NMR spectroscopy. Single crystal X-ray structure analysis reveals that in all three co-crystals the co-crystal formers (CCF) are hydrogen bonded to the paracetamol molecules through O−H···N interactions. In co-crystals (1) and (2) the CCFs are interleaved between the chains of paracetamol molecules, while in co-crystal (3) there is an additional N−H···N hydrogen bond between the two components. A hierarchy of hydrogen bond formation is observed in which the best donor in the system, the phenolic O−H group of paracetamol, is preferentially
hydrogen bonded to the best acceptor, the basic nitrogen atom of the co-crystal former. The geometric aspects of the hydrogen bonds in co-crystals 1−3 are discussed in terms of their electrostatic and charge-transfer components
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