Structural characterization of carbon nanotubes via the vibrational density of states

The electrical and chemical properties of carbon nanotubes vary significantly with different chirality and diameter, making the experimental determination of these structural properties important. Here, we show that the vibrational density of states (VDOS) contains information on the structure of carbon nanotubes, particularly at low frequencies. We show that the diameter and chirality of the nanotubes can be determined from the characteristic low frequency $L$ and $L'$ modes in the VDOS. For zigzag nanotubes, the $L$ peak splits into two peaks giving rise to another low energy $L"$ peak. The significant changes in the frequencies and relative intensities of these peaks open up a route to distinguish among structurally different nanotubes. A close study of different orientations of Stone-Wales defects with varying defect density reveals that different structural defects also leave distinct fingerprints in the VDOS, particularly in the $L$ and $L'$ modes. With our results, more structural information can be obtained from experiments which can directly measure the VDOS, such as inelastic electron and inelastic neutron spectroscopy.Comment: 5 Figures, Accepted for publication in Carbo

When the workshop is working: The role of artists in collaborative research with young people and communities

Purpose: This paper comes from workshop activities and structured reflection by a group of artists and researchers who have been using artistic practice within research projects aimed at enabling researchers to collaborate with communities. The paper aims to discuss these issues. Design/methodology/approach: Three out of four in the group have a practicing creative background and their own studio/workshop space. Findings: Artists are often employed – whether in schools or research projects – to run workshops; to bring a distinctive set of skills that enable learning or collaboration to take place. In this paper the authors reflect on the different meanings and connotations of “workshop” – as noun (as a place where certain types of activity happen, a bounded space) and a verb (to work something through; to make something together). From there the authors will then draw out the different principles of what artistic practice can offer towards creating a collaborative space for new knowledge to emerge. Research limitations/implications: Key ideas include different repertories of structuring to enable different forms of social interaction; the role of materal/ality and body in shifting what can be recognised as knowing; and the skills of “thinking on your feet”, being responsive and improvising. Originality/value: The authors will conclude by reflecting on aspects to consider when developing workshops as part of collaborative research projects

Towards Promotion of Community rewards to Volunteer Community Health Workers? Lessons from Experiences of Village Health Teams in Luwero, Uganda

In the debate regarding volunteer Community Health Workers (CHWs) some argue that lack of remuneration is exploitation while others caution that any promise to pay volunteers will decrease the volunteer spirit. In this paper we discuss the possibility of community rewards for CHWs. Ethnographic fieldwork that lasted 18 months utilised methods including participant observation, FGDs, in-depth interviews and key informant interviews to gain insight into the dynamic relationship between volunteer CHWs known as Village Health Teams (VHTs) and the community. Contextual transcription was done and data was thematically analysed. Findings show that community members are willing to reward volunteer CHWs with cash, material and symbolic rewards in appreciation for their help. Factors crucial for this gesture included: care and recognition of the VHTs’ work by medical staff, fulfilment of the promises made to the community by government and exemplary behaviour by CHWs. Therefore, effort should be made to facilitate volunteer CHWs to be seen as helpful to their communities. Especially, there needs to be a smooth operation at the intersection between the VHTs, local government and medical structures. Community rewards could be a more sustainable way of motivating CHWs while a solution to health personnel shortage is sought

'Chardonel' Grape

'Chardonel' resulted from the cross, 'SeyvaT x 'Chardonnay,' made in 1953. Fruit were first observed in 1958, and the original vine was propagated in 1960 under the number NY 45010. In later testing, it was re-named GW 9 (Geneva White 9) for ease of identification in cooperatively run yield trials. The vine was initially described as vigorous and productive with large clusters

Spin-Glass State in CuGa2O4\rm CuGa_2O_4

Magnetic susceptibility, magnetization, specific heat and positive muon spin relaxation (\musr) measurements have been used to characterize the magnetic ground-state of the spinel compound $\rm CuGa_2O_4$. We observe a spin-glass transition of the S=1/2 $\rm Cu^{2+}$ spins below $\rm T_f=2.5K$ characterized by a cusp in the susceptibility curve which suppressed when a magnetic field is applied. We show that the magnetization of $\rm CuGa_2O_4$ depends on the magnetic histo Well below $\rm T_f$, the muon signal resembles the dynamical Kubo-Toyabe expression reflecting that the spin freezing process in $\rm CuGa_2O_4$ results Gaussian distribution of the magnetic moments. By means of Monte-Carlo simulati we obtain the relevant exchange integrals between the $\rm Cu^{2+}$ spins in this compound.Comment: 6 pages, 16 figure

VIS: the visible imager for Euclid

Euclid-VIS is a large format visible imager for the ESA Euclid space mission in their Cosmic Vision program, scheduled for launch in 2019. Together with the near infrared imaging within the NISP instrument it forms the basis of the weak lensing measurements of Euclid. VIS will image in a single r+i+z band from 550-900 nm over a field of view of ~0.5 deg2. By combining 4 exposures with a total of 2240 sec, VIS will reach to V=24.5 (10{\sigma}) for sources with extent ~0.3 arcsec. The image sampling is 0.1 arcsec. VIS will provide deep imaging with a tightly controlled and stable point spread function (PSF) over a wide survey area of 15000 deg2 to measure the cosmic shear from nearly 1.5 billion galaxies to high levels of accuracy, from which the cosmological parameters will be measured. In addition, VIS will also provide a legacy imaging dataset with an unprecedented combination of spatial resolution, depth and area covering most of the extra-Galactic sky. Here we will present the results of the study carried out by the Euclid Consortium during the Euclid Definition phase.Comment: 10 pages, 6 figure

Net neutrality discourses: comparing advocacy and regulatory arguments in the United States and the United Kingdom

Telecommunications policy issues rarely make news, much less mobilize thousands of people. Yet this has been occurring in the United States around efforts to introduce "Net neutrality" regulation. A similar grassroots mobilization has not developed in the United Kingdom or elsewhere in Europe. We develop a comparative analysis of U.S. and UK Net neutrality debates with an eye toward identifying the arguments for and against regulation, how those arguments differ between the countries, and what the implications of those differences are for the Internet. Drawing on mass media, advocacy, and regulatory discourses, we find that local regulatory precedents as well as cultural factors contribute to both agenda setting and framing of Net neutrality. The differences between national discourses provide a way to understand both the structural differences between regulatory cultures and the substantive differences between policy interpretations, both of which must be reconciled for the Internet to continue to thrive as a global medium

Net neutrality discourses: comparing advocacy and regulatory arguments in the United States and the United Kingdom

Telecommunications policy issues rarely make news, much less mobilize thousands of people. Yet this has been occurring in the United States around efforts to introduce "Net neutrality" regulation. A similar grassroots mobilization has not developed in the United Kingdom or elsewhere in Europe. We develop a comparative analysis of U.S. and UK Net neutrality debates with an eye toward identifying the arguments for and against regulation, how those arguments differ between the countries, and what the implications of those differences are for the Internet. Drawing on mass media, advocacy, and regulatory discourses, we find that local regulatory precedents as well as cultural factors contribute to both agenda setting and framing of Net neutrality. The differences between national discourses provide a way to understand both the structural differences between regulatory cultures and the substantive differences between policy interpretations, both of which must be reconciled for the Internet to continue to thrive as a global medium