Microscopic Features of Adhesive Bonds for Non-Destructive Measurements

Inelastic electron tunneling spectroscopy, or lETS, provides an extremely sensitive method for monitoring the chemical and physical state of a molecular substance adsorbed onto an oxide surface. Inelastic tunneling data directly reflect the molecular vibrational frequencies of the first monolayer of adsorbed molecules and changes in the vibrational spectrum can be correlated with changes in the chemical state of the molecule/oxide interface. We have carried out lETS experiments on the components of the commercial adhesive, Hercules 3501. This epoxy system consists ·of two molecular components; diamino diphenyl sulfone (DPS) and tetraglycidycl 4,4\u27 diamino diphenyl methane (DPM). lETS spectra of the individual components and of the epoxy mixture adsorbed on aluminum oxide have been obtained and the vibrational modes and frequencies assigned by comparison with computer calculations and existing infrared optical spectra. Some evidence for an aging effect has been observed for the adsorbed DPS. This effect appears as a dramatic change in the low frequency vibrational modes and may be associated with the formation of hydrogen bonds or the polymerization of the DPS. Further studies of this effect are in progress. The effects of water permeation may be studied using D2O as a tracer. The vibrational modes of D20 are easily distinguished from those of water which may be present as a contaminant. If the exchange reaciton D2O + HCR → DHO + DCR occurs, it would be easily detected in the lETS spectrum. Initial experiments performed by simply immersing the tunnel junction into liquid D2O for several hours were unsuccessful because severe corrosion of the tunnel junction resulted. Experiments employing aluminum/aluminum oxide/adhesive/gold thin film junction for the study of H2O permeation are in progress. Further studies are planned to monitor the effects of heat treatment on the adhesive components and mixture

On the resonance and shelf/open-ocean coupling of the global diurnal tides

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/123032/1/jpo_2013_diurnaltideresonance.pd

Combining cosmological datasets: hyperparameters and Bayesian evidence

A method is presented for performing joint analyses of cosmological datasets, in which the weight assigned to each dataset is determined directly by it own statistical properties. The weights are considered in a Bayesian context as a set of hyperparameters, which are then marginalised over in order to recover the posterior distribution as a function only of the cosmological parameters of interest. In the case of a Gaussian likelihood function, this marginalisation may be performed analytically. Calculation of the Bayesian evidence for the data, with and without the introduction of hyperparameters, enables a direct determination of whether the data warrant the introduction of weights into the analysis; this generalises the standard likelihood ratio approach to model comparison. The method is illustrated by application to the classic toy problem of fitting a straight line to a set of data. A cosmological illustration of the technique is also presented, in which the latest measurements of the cosmic microwave background power spectrum are used to infer constraints on cosmological parameters.Comment: 12 pages, 6 figures, submitted to MNRA

The r'-band luminosity function of Abell1367: a comparison with Coma

We made a large (approximately 1degr x 1degr) r'-band imaging survey of the central regions of the two nearby clusters of galaxies, Abell1367 and Coma. The data, presented as a catalog, are used to construct the r'-band luminosity function (LF) of galaxies in these two clusters, by subtracting the Yasuda et al. (2001) galaxy counts from our cluster counts. Our Coma luminosity function is consistent with previous determinations, i.e. providing a faint end slope alpha = -1.47_-0.09^+0.08, significantly steeper than the one we find for Abell1367 (alpha = -1.07_-0.16^+0.20). The counts in Abell1367 show a relative minimum at r' ~ 19, followed by a steep increase faintward. The difference between the two clusters appears significant, given the consistency of the experimental conditions in the two clusters. Whereas for Coma we find a significant increase of the slope of the LF outwards, no such effect is found for Abell1367.Comment: 12 pages, 8 figures, accepted for publication in A&

Multiaperture UBVRIzJHKUBVRIzJHK Photometry of Galaxies in the Coma Cluster

We present a set of $UBVRIzJHK_s$ photometry for 745 $J+H$ band selected objects in a $22.5' \times 29.2'$ region centered on the core of the Coma cluster. This includes 516 galaxies and is at least 80% complete to H=16, with a spectroscopically complete sample of 111 cluster members (nearly all with morphological classification) for $H < 14.5$. For each object we present total \cite{kron80} magnitudes and aperture photometry. As an example, we use these data to derive color-magnitude relations for Coma early-type galaxies, measure the intrinsic scatter of these relations and its dependence on galaxy mass, and address the issue of color gradients. We find that the color gradients are mild and that the intrinsic scatter about the color-magnitude relation is small ($\sim 0.05$ mag in $U-V$ and less than $\sim 0.03$ in $B-R$, $V-I$ or $J-K$). There is no evidence that the intrinsic scatter varies with galaxy luminosity, suggesting that the cluster red sequence is established at early epochs over a range of $\sim 100$ in stellar mass.Comment: 41 pages, 5 figures, 18 data tables attached to source files or available on request from R. De propris. Accepted for publication in Astrophysical Journal Supplement Serie

An Evaluation of the Return to Practice Programme (Nursing) at City University of London (2017-2018)

In response to concerns over a predicted chronic nursing shortage recent focus has been placed on Return to Practice (RTP) programmes, which aim to increase the nursing workforce by enabling former nurses to return to the profession. In order to encourage former nurses to return to practice, it is important to understand the motivations, expectations and experiences of current returnees by evaluating RTP programmes. Aims: To evaluate the RTP programme by exploring the views and experiences of returnees to nursing, and of the nursing staff who support them. Methods: This was a mixed methods study: an electronic survey of all students currently or recently on the RTP programme at City, University of London; and interviews with a range of stakeholders, including returnees, mentors and senior managers, at North East London Foundation Trust (NELFT). Descriptive statistics were used to summarise quantitative responses to the survey and Framework method was employed to analyse qualitative data. Results: Seventy-four responses to the survey were received; eight interviews were carried out with returnees, and five with NELFT staff. Overall, data suggests that the programme has been very successful: most views were positive, many were very positive. Though returnees found the course fairly challenging, they also found it largely fit for purpose. There were many useful suggestions about how to improve and promote the programme. There were also some reservations about the organisation of placements and of mentorship arrangements, the latter largely due to the difficulty of arranging for time for returnees and their mentors to work together. Recommendations: RTP programmes should be continued and if possible expanded. Wider advertising, ideally involving successful RTP returnees, should be used to attract more recruits, and funding for returnees should be maintained or increased. Higher Education Institutions (HEIs) should offer support to enable RTP nurses to return to study and to achieve their academic objectives as smoothly as possible. This may include responding to the individual learning needs of RTP nurses and allowing flexibility for students who need longer for private study. National Health Service (NHS) Trusts/Boards should ensure that Human Resource (HR) departments are willing and able to deal quickly with arrangements for employed RTP students. Processes for arranging placements should include realistic timetables for Disclosure and Barring Service (DBS) checks to be carried out. NHS providers should consider the suggestion that returnees can arrange their own placements if they wish. NHS providers should make even greater efforts to ensure that front-line staff understand the position of RTP nursing students, what they can expect from them and what their responsibilities to them are. Recent RTP graduates should be encouraged and enabled to support future RTP students. As champions of the programme, they should support the Trust in clarifying to existing staff what RTP students need and can be permitted to do