The Effect of Ultraviolet Light on the Color of Unbleached Pulps: Literature Survey

A literature survey was prepared which covered the published information on the effects of ultraviolet light on the color of unbleached pulps. Experiments were conducted with eight types of unbleached pulp which were converted into optical test pads under varying pH conditions, using sulphuric acid and caustic soda as well as alum and sodium aluminate for adjustment of the hydrogen ion concentration. The optical test pads were exposed to ultraviolet irradiation. Thereafter, reflectance measurements were taken, covering the range of visible light. From the limited number of experiments which were conducted we can conclude that: 1. Unbleached coniferous kraft, unbleached hardwood, sulphite, and unbleached hardwood soda pulps brightened when exposed to ultraviolet light. 2. Unbleached hardwood H.S.S.C. (70% yield), unbleached hardwood N.S.S.C. (78% yield), unbleached coniferous sulphite, unbleached hardwood cold soda, and unbleached hardwood chemi-groundwood pulps yellowed when exposed to ultraviolet light. 3. Adjusting the pH four with sulphuric acid increased the reflectance of most pulps while adjusting the pH to ten with sodium hydroxide decreased the reflectance of the pulps. This was observed before irradiation with ultraviolet light. 4. When papermakers\u27 alum was used to adjust the pH of the sheets to four, the reflectance values before irradiation decreased slightly in most cases. There was a larger drop in the reflectance value when the pH of the pulp is adjusted to the pH ten with sodium aluminate. 5. Both means of adjusting the pH to ten, namely sodium hydroxide and sodium aluminate, decreased the initial brightness of the pulp. However, there was little correlation between the effects of the two compounds used to adjust the pulp pH to four, namely sulphuric acid and papermakers\u27 alum. 6. Experimental results showed that none of the compounds used in pH control stabilized consistently the color of unbleached pulp exposed to ultraviolet irradiation

A distributional model of semantic context effects in lexical processinga

One of the most robust findings of experimental psycholinguistics is that the context in which a word is presented influences the effort involved in processing that word. We present a novel model of contextual facilitation based on word co-occurrence prob ability distributions, and empirically validate the model through simulation of three representative types of context manipulation: single word priming, multiple-priming and contextual constraint. In our simulations the effects of semantic context are mod eled using general-purpose techniques and representations from multivariate statistics, augmented with simple assumptions reflecting the inherently incremental nature of speech understanding. The contribution of our study is to show that special-purpose m echanisms are not necessary in order to capture the general pattern of the experimental results, and that a range of semantic context effects can be subsumed under the same principled account.›

Interventions for neurocognitive dysfunction

Purpose of review: To evaluate current barriers to HIV cure strategies and interventions for neurocognitive dysfunction with a particular focus on recent advancements over the last three years. Recent findings: Optimal anti-retroviral therapy (ART) poses challenges to minimise neurotoxicity, whilst ensuring blood brain barrier penetration and minimising the risk of cerebrovascular disease. CSF biomarkers, BCL11B and neurofilament light chain may be implicated with a neuroinflammatory cascade leading to cognitive impairment. Diagnostic imaging with diffusion tensor imaging as well as resting-state fMRI show promise in future diagnosis and monitoring of HAND. Summary: The introduction of ART has resulted in a dramatic decline in HIV-associated dementia. Despite this reduction, milder forms of HIV-associated neurocognitive disorder (HAND) are still prevalent and are clinically significant. The central nervous system (CNS) has been recognised as a probable reservoir and sanctuary for HIV, representing a significant barrier to management interventions

Researching the role of the PhD in developing an academic career: does it make a difference?

This single paper builds on the arguments developed through the think piece by Bak (2013) in that it will report on research that explored academics’ experiences of the role of the PhD in developing their academic careers. Bak (2013) questions the ‘conventional way of approaching the PhD´ in South Africa (p.1) and proposes reconsideration of how doctoral education is conceptualised, delivered and valued. The current study, undertaken in Australia and the UK, commenced from the premise that it is commonly assumed that the PhD prepares people for academic careers, yet little is known about how academics are influenced and developed through doctoral study. Early findings demonstrate that the PhD has not been particularly effective in preparing academics for independent research and teaching and that changes in doctoral education are neede

Staff-student Partnership in Practice in Higher Education : The Impact on Learning and Teaching

© 2012 The Authors. Published with open access by Elsevier Ltd.This staff-student collaborative project involved six small project teams each composed of staff and undergraduate students studying within the University of Hertfordshire, UK. Each project team engaged in a mini-project designed to research an aspect of learning and teaching to develop learning and teaching and to enhance students’ employability skills. The ‘student researchers’ from the small project teams were also members of a larger coaching group that met with the project lead and other experienced colleagues and undertook joint enquiry. Students used reflective logs as one means of recording data on their developing employability skills and their learning from the project. Evaluation activities included documentation of all coaching group workshops and collecting quantitative and qualitative data for each learning and teaching research project. The usefulness of this data was evaluated by staff members in relation to its impact on their module planning. The main implication of this approach is that staff-student partnership in learning and teaching has a significant impact on learning and teaching development and enhancement, learning to learn, raising the profile of research into learning and teaching, and employability skills and attributes. The student researchers came to a much deeper understanding of learning and teaching, and became much more aware of their responsibility for their own learning and committed to enhancing the learning of others. Members of staff noted that working with students had been ‘extremely inspirational’- seeing students work with other students and what they could achieve that could not be achieved by members of staff

Enabling rural broadband via TV "white space"

The use of multiple frequency bands within a wireless network allows the advantages of each band to be exploited. In this paper we discuss how HopScotch, a rural wireless broadband access test bed running in the Scottish Highlands and Islands, uses both 5 GHz and ultra high frequency "white space" bands to offer large data rates and expansive coverage whilst reducing the number of base stations or required transmission power. This reduction in energy consumption allows HopScotch to provide a low-cost and green solution for rural broadband delivery

Positioning ourselves for research and teaching: a cross-country analysis of academic formation

This paper presents early findings emerging from an international collaborative research project that addresses the key question of the nature of academic work, how academics make decisions regarding teaching and research and how they develop their academic identities. Drawing on survey data and pilot interviews administered in Australian and English Universities, the paper considers emerging evidence in relation to factors that contribute to success in research as well as contextual factors that discourage it. The paper begins to illuminate how academics in different countries, university contexts and with different career orientations, interpret and position themselves in relation to those contexts and how structural and agential factors may influence the formation of academic identity. The findings emerging from this research will provide new in-depth understandings about how institutions might most effectively support, develop and encourage world-class teaching, and the capacity for high quality research

"WindFi" - a renewable powered base station for rural broadband

The HopScotch rural wireless broadband access test bed uses a network of low power base stations, powered by renewable energy sources to provide a low-cost rural broadband solution. In this paper we discuss the low power design aspects of the HopScotch base station and the impact on the required generation potential of renewable sources, battery bank sizing and the use of tracking PV arrays

Qualitatively Different Conceptions of Research: Implications for Adult Education Research

This paper reports on an investigation into academics’ qualitatively different ideas about what research is and about what they are doing when they carry it out. It presents an overview of the literature, outlines the findings of the study and then discusses the implications for adult education research