Supporting the learning of deaf students in higher education: a case study at Sheffield Hallam University

This article is an examination of the issues surrounding support for the learning of deaf students in higher education (HE). There are an increasing number of deaf students attending HE institutes, and as such provision of support mechanisms for these students is not only necessary but essential. Deaf students are similar to their hearing peers, in that they will approach their learning and require differing levels of support dependant upon the individual. They will, however, require a different kind of support, which can be technical or human resource based. This article examines the issues that surround supporting deaf students in HE with use of a case study of provision at Sheffield Hallam University (SHU), during the academic year 1994-95. It is evident that by considering the needs of deaf students and making changes to our teaching practices that all students can benefit

Determination of Ideal Broth Formulations Needed to Prepare Hydrous Aluminum Oxide Microspheres via the Internal Gelation Process

A simple test-tube methodology was used to determine optimum process parameters for preparing hydrous aluminum oxide microspheres by the internal gelation process. Broth formulations of aluminum, hexamethylenetetramine, and urea were found that can be used to prepare hydrous aluminum oxide gel spheres in the temperature range of 60-90 C. A few gel-forming runs were made in which microspheres were prepared with some of these formulations in order to equate the test-tube gelation times with actual gelation times. These preparations confirmed that the test-tube methodology is reliable for determining the ideal broths

A database and tool for boundary conditions for regional air quality modeling: description and evaluation

Transported air pollutants receive increasing attention as regulations tighten and global concentrations increase. The need to represent international transport in regional air quality assessments requires improved representation of boundary concentrations. Currently available observations are too sparse vertically to provide boundary information, particularly for ozone precursors, but global simulations can be used to generate spatially and temporally varying lateral boundary conditions (LBC). This study presents a public database of global simulations designed and evaluated for use as LBC for air quality models (AQMs). The database covers the contiguous United States (CONUS) for the years 2001–2010 and contains hourly varying concentrations of ozone, aerosols, and their precursors. The database is complemented by a tool for configuring the global results as inputs to regional scale models (e.g., Community Multiscale Air Quality or Comprehensive Air quality Model with extensions). This study also presents an example application based on the CONUS domain, which is evaluated against satellite retrieved ozone and carbon monoxide vertical profiles. The results show performance is largely within uncertainty estimates for ozone from the Ozone Monitoring Instrument and carbon monoxide from the Measurements Of Pollution In The Troposphere (MOPITT), but there were some notable biases compared with Tropospheric Emission Spectrometer (TES) ozone. Compared with TES, our ozone predictions are high-biased in the upper troposphere, particularly in the south during January. This publication documents the global simulation database, the tool for conversion to LBC, and the evaluation of concentrations on the boundaries. This documentation is intended to support applications that require representation of long-range transport of air pollutants

Searching for highly obscured AGN in the XMM-Newton serendipitous source catalog

The majority of active galactic nuclei (AGN) are obscured by large amounts of absorbing material that makes them invisible at many wavelengths. X-rays, given their penetrating power, provide the most secure way for finding these AGN. The XMM-Newton serendipitous source catalog is the largest catalog of X-ray sources ever produced; it contains about half a million detections. These sources are mostly AGN. We have derived X-ray spectral fits for very many 3XMM-DR4 sources ($\gtrsim$ 114 000 observations, corresponding to $\sim$ 77 000 unique sources), which contain more than 50 source photons per detector. Here, we use a subsample of $\simeq$ 1000 AGN in the footprint of the SDSS area (covering 120 deg$^2$) with available spectroscopic redshifts. We searched for highly obscured AGN by applying an automated selection technique based on X-ray spectral analysis that is capable of efficiently selecting AGN. The selection is based on the presence of either a) flat rest-frame spectra; b) flat observed spectra; c) an absorption turnover, indicative of a high rest-frame column density; or d) an Fe K$\alpha$ line with an equivalent width > 500 eV. We found 81 highly obscured candidate sources. Subsequent detailed manual spectral fits revealed that 28 of them are heavily absorbed by column densities higher than 10$^{23}$ cm$^{-2}$. Of these 28 AGN, 15 are candidate Compton-thick AGN on the basis of either a high column density, consistent within the 90% confidence level with N$_{\rm H}$ $>$10$^{24}$ cm$^{-2}$, or a large equivalent width (>500 eV) of the Fe K$\alpha$ line. Another six are associated with near-Compton-thick AGN with column densities of $\sim$ 5$\times$10$^{23}$ cm$^{-2}$. A combination of selection criteria a) and c) for low-quality spectra, and a) and d) for medium- to high-quality spectra, pinpoint highly absorbed AGN with an efficiency of 80%.Comment: 18 pages, 10 figures, accepted for publication in A&

Unequal relationships in high and low power distance societies: a comparative study of tutor - student role relations in Britain and China

This study investigated people's conceptions of an unequal role relationship in two different types of society: a high power distance society and a low power distance society. The study focuses on the role relationship of tutor and student. British and Chinese tutors and postgraduate students completed a questionnaire that probed their conceptions of degrees of power differential and social distance/closeness in this role relationship. ANOVA results yielded a significant nationality effect for both aspects. Chinese respondents judged the relationship to be closer and to have a greater power differential than did British respondents. Written comments on the questionnaire and interviews with 9 Chinese academics who had experienced both British and Chinese academic environments supported the statistical findings and indicated that there are fundamental ideological differences associated with the differing conceptions. The results are discussed in relation to Western and Asian concepts of leadership and differing perspectives on the compatibility/incompatibility of power and distance/closeness

Fossil extraction bans and carbon taxes: Assessing their interplay through multiple models

Given concerns about the ambition and effectiveness of current climate policies, a case has been made for the combination of demand side policies such as carbon pricing with supply side bans on fossil fuel extraction. However, little is known about their interplay in the context of climate stabilization strategies. Here, we present a multi-model assessment quantifying the effectiveness of supply side policies and their interactions with demand-side ones. We explore a variety of fossil fuel bans with four integrated assessment models and find that international supply side policies reduce carbon emissions but not at sufficient levels to stabilize temperature increase to well below 2°C. When combined with demand side policies, supply side policies reduce the required carbon price, dampen reliance on CO2 removal technologies, and increase investment in renewable energy. The results indicate the opportunity to integrate fossil fuel bans alongside price-based policies when exploring pathways to reach ambitious mitigation targets

Minimal size of a barchan dune

Barchans are dunes of high mobility which have a crescent shape and propagate under conditions of unidirectional wind. However, sand dunes only appear above a critical size, which scales with the saturation distance of the sand flux [P. Hersen, S. Douady, and B. Andreotti, Phys. Rev. Lett. {\bf{89,}} 264301 (2002); B. Andreotti, P. Claudin, and S. Douady, Eur. Phys. J. B {\bf{28,}} 321 (2002); G. Sauermann, K. Kroy, and H. J. Herrmann, Phys. Rev. E {\bf{64,}} 31305 (2001)]. It has been suggested by P. Hersen, S. Douady, and B. Andreotti, Phys. Rev. Lett. {\bf{89,}} 264301 (2002) that this flux fetch distance is itself constant. Indeed, this could not explain the proto size of barchan dunes, which often occur in coastal areas of high litoral drift, and the scale of dunes on Mars. In the present work, we show from three dimensional calculations of sand transport that the size and the shape of the minimal barchan dune depend on the wind friction speed and the sand flux on the area between dunes in a field. Our results explain the common appearance of barchans a few tens of centimeter high which are observed along coasts. Furthermore, we find that the rate at which grains enter saltation on Mars is one order of magnitude higher than on Earth, and is relevant to correctly obtain the minimal dune size on Mars.Comment: 11 pages, 10 figure

Secondary organic aerosol (SOA) formation from reaction of isoprene with nitrate radicals (NO_3)

Secondary organic aerosol (SOA) formation from the reaction of isoprene with nitrate radicals (NO3) is investigated in the Caltech indoor chambers. Experiments are performed in the dark and under dry conditions (RH<10%) using N2O5 as a source of NO3 radicals. For an initial isoprene concentration of 18.4 to 101.6 ppb, the SOA yield (defined as the ratio of the mass of organic aerosol formed to the mass of parent hydrocarbon reacted) ranges from 4.3% to 23.8%. By examining the time evolutions of gas-phase intermediate products and aerosol volume in real time, we are able to constrain the chemistry that leads to the formation of low-volatility products. Although the formation of ROOR from the reaction of two peroxy radicals (RO2) has generally been considered as a minor channel, based on the gas-phase and aerosol-phase data it appears that RO2+RO2 reaction (self reaction or cross-reaction) in the gas phase yielding ROOR products is a dominant SOA formation pathway. A wide array of organic nitrates and peroxides are identified in the aerosol formed and mechanisms for SOA formation are proposed. Using a uniform SOA yield of 10% (corresponding to Mo≅10 μg m−3), it is estimated that ~2 to 3 Tg yr−1 of SOA results from isoprene + NO3. The extent to which the results from this study can be applied to conditions in the atmosphere depends on the fate of peroxy radicals (i.e. the relative importance of RO2+RO2 versus RO2+NO3 reactions) in the nighttime troposphere

Projected effect of 2000-2050 changes in climate and emissions on aerosol levels in China and associated transboundary transport

We investigate projected 2000–2050 changes in concentrations of aerosols in China and the associated transboundary aerosol transport by using the chemical transport model GEOS-Chem driven by the Goddard Institute for Space Studies (GISS) general circulation model (GCM) 3 at 4° × 5° resolution. Future changes in climate and emissions projected by the IPCC A1B scenario are imposed separately and together through sensitivity simulations. Accounting for sulfate, nitrate, ammonium, black carbon (BC), and organic carbon (OC) aerosols, concentrations of individual aerosol species change by −1.5 to +0.8 μg m^(−3), and PM_(2.5) levels are projected to change by about 10–20% in eastern China as a result of 2000–2050 change in climate alone. With future changes in anthropogenic emissions alone, concentrations of sulfate, BC, and OC are simulated to decrease because of assumed reductions in emissions, and those of nitrate are predicted to increase because of higher NO_x emissions combined with decreases in sulfate. The net result is a predicted reduction of seasonal mean PM_(2.5) concentrations in eastern China by 1–8 μg m^(−3) (or 10–40%) over 2000–2050. It is noted that current emission inventories for BC and OC over China are judged to be inadequate at present. Transboundary fluxes of different aerosol species show different sensitivities to future changes in climate and emissions. The annual outflow of PM_(2.5) from eastern China to the western Pacific is estimated to change by −7.0%, −0.7%, and −9.0% over 2000–2050 owing to climate change alone, changes in emissions alone, and changes in both climate and emissions, respectively. The fluxes of nitrate and ammonium aerosols from Europe and Central Asia into western China increase over 2000–2050 in response to projected changes in emissions, leading to a 10.5% increase in annual inflow of PM_(2.5) to western China with future changes in both emissions and climate. Fluxes of BC and OC from South Asia to China in spring contribute a large fraction of the annual inflow of PM_(2.5). The annual inflow of PM_(2.5) from South Asia and Southeast Asia to China is estimated to change by −8%, +281%, and +227% over 2000–2050 owing to climate change alone, changes in emissions alone, and changes in both climate and emissions, respectively. While the 4° × 5° spatial resolution is a limitation of the present study, the direction of predicted changes in aerosol levels and transboundary fluxes still provides valuable insight into future air quality