Influence of the Synthesis pH on the Properties and Activity of Sol-Gel TiO 2

The activity of titania photocatalysts is highly dependent on the synthesis procedure. This work reports a study of the correlation between the photocatalytic activity and the physicochemical and photoelectrochemical properties of sol-gel TiO2 powders and electrodes synthesized using different pH values and temperatures. The activity of the materials has been evaluated using the decolorization of Reactive Orange 16 (RO16) as model reaction. In contrast with the large number of studies reporting the influence of the temperature, our results point out that preparation pH has even more influence on the crystalline phases and the photocatalytic activity of TiO2 powders and photocurrents of the electrodes. However, the effects on the activity and the photocurrents recorded after immobilization on a conducting support do not vary accordingly. Consequently, our results indicate that the measurement of the photocurrent in an electrolyte media is not a good indicator of the photocatalytic activity of the unsupported system

Theoretical physics takes root in America : John Archibald Wheeler as student and mentor

John Archibald Wheeler (09 July 1911- ) is a familiar name to physicists and historians of physics alike. Among his many contributions to the corpus of knowledge, in 1939 John Wheeler and Niels Bohr co-authored the first paper on the generalized mechanism of nuclear fission. Beyond that seminal work, Wheeler was a key player in the production of the 'Fat Man' plutonium weapon in the Manhattan project, and later, in the development of the Hydrogen Bomb. Wheeler introduced the scattering matrix (or S-matrix) to account for all possible final quantum states of collisions between nucleons. After turning his attention to general relativity, Wheeler and his students made a number of significant contributions to cosmology and cosmology. In fact, John Wheeler coined the term "black hole," and developed the concepts of a "Planck Length," a Planck-time," "quantum foam," and "wormholes" in space-time. Outside the physics community however, considerably less is known about John Wheeler as a mentor of physicists. Mentoring is important because, while there can be no progress in physics without contributions to the corpus of knowledge, these contributions are, by their very nature additive. In contrast, the contributions of skilled mentors such as John Archibald Wheeler are multiplicative through a number of intellectual generations. Until quite recently, studies of mentoring in science were limited to 'laboratory' and/or 'field' disciplines such as chemistry and the life sciences. Clearly, mentoring styles are highly individualized. Nonetheless, a comprehensive census of elite mentors can offer considerable insight into the practice of mentoring in theoretical physics. This examination of the mentoring style and outcomes of John Archibald Wheeler traces his work as an apprentice under mentors Karl Herzfeld, Gregory Breit, and Niels Bohr, through Wheeler's career as a mentor in his own right at Princeton University during the years 1938-1977

Atmospheric transport of organochlorines in the North Atlantic gyre

Chlorinated pesticides and polychlorinated biphenyls (PCB) circulating over the North Atlantic were measured during 1977-78 at Barbados and during the 1977 summer at the southern tip of Newfoundland. Total organochlorines were collected using a glass fiber filter backed up by a polyurethane foam trap, and were analyzed by electron capture gas chromatography on packed and glass capillary columns...

An Interprofessional Consensus of Core Competencies for Prelicensure Education in Pain Management: Curriculum Application for Physical Therapy

Core competencies in pain management for prelicensure health professional education were recently established. These competencies represent the expectation of minimal capabilities for graduating health care students for pain management and include 4 domains: multidimensional nature of pain, pain assessment and measurement, management of pain, and context of pain (Appendix 1). The purpose of this article is to advocate for and identify how core competencies for pain can be applied to the professional (entry-level) physical therapist curriculum. By ensuring that core competencies in pain management are embedded within the foundation of physical therapist education, physical therapists will have the core knowledge necessary for offering best care for patients, and the profession of physical therapy will continue to stand with all health professions engaged in comprehensive pain management

Ante-Autobiography and the Archive of Childhood

This essay examines the concept of children’s autobiography via several autobiographical extracts written by the author as a child. Although only a small proportion of people will compose and publish a full-length autobiography, almost everyone will, inadvertently, produce an archive of the self, made from public records and private documents. Here, such works are seen as providing access to writing both about and by children. The essay explores the ethics and poetics of children’s writing via the key debates in life writing; in particular, the dynamic relationship between adults and children, both as distinct stages of life and dual parts of one autobiographical identity. The term “ante-autobiography” is coined to refer to these texts which come before or instead of a full-length narrative. They are not read as less than or inadequate versions of autobiography, but rather as transgressive and challenging to chronological notions of the genre

The Detail Behind Web-Scale: Selecting and Configuring Web-Scale Discovery Tools to Meet Music Information Retrieval Needs.

Web-scale discovery tools are rapidly gaining popularity as a purported "one-stop search" for discovering library information. Music, particularly printed music and recordings, presents unique information retrieval needs. This article identifies, explores, and makes recommendations regarding key music-related aspects to consider when selecting and implementing a discovery tool, considering scope, metadata, and interface

Uncertainties and recommendations

An assessment of the impacts of changes in climate and UV-B radiation on Arctic terrestrial ecosystems, made within the Arctic Climate Impacts Assessment (ACIA), highlighted the profound implications of projected warming in particular for future ecosystem services, biodiversity and feedbacks to climate. However, although our current understanding of ecological processes and changes driven by climate and UV-B is strong in some geographical areas and in some disciplines, it is weak in others. Even though recently the strength of our predictions has increased dramatically with increased research effort in the Arctic and the introduction of new technologies, our current understanding is still constrained by various uncertainties. The assessment is based on a range of approaches that each have uncertainties, and on data sets that are often far from complete. Uncertainties arise from methodologies and conceptual frameworks, from unpredictable surprises, from lack of validation of models, and from the use of particular scenarios, rather than predictions, of future greenhouse gas emissions and climates. Recommendations to reduce the uncertainties are wide-ranging and relate to all disciplines within the assessment. However, a repeated theme is the critical importance of achieving an adequate spatial and long-term coverage of experiments, observations and monitoring of environmental changes and their impacts throughout the sparsely populated and remote region that is the Arctic

Effects of changes in climate on landscape and regional processes, and feedbacks to the climate system

Biological and physical processes in the Arctic system operate at various temporal and spatial scales to impact large-scale feedbacks and interactions with the earth system. There are four main potential feedback mechanisms between the impacts of climate change on the Arctic and the global climate system: albedo, greenhouse gas emissions or uptake by ecosystems, greenhouse gas emissions from methane hydrates, and increased freshwater fluxes that could affect the thermohaline circulation. All these feedbacks are controlled to some extent by changes in ecosystem distribution and character and particularly by large-scale movement of vegetation zones. Indications from a few, full annual measurements of CO2 fluxes are that currently the source areas exceed sink areas in geographical distribution. The little available information on CH4 sources indicates that emissions at the landscape level are of great importance for the total greenhouse balance of the circumpolar North. Energy and water balances of Arctic landscapes are also important feedback mechanisms in a changing climate. Increasing density and spatial expansion of vegetation will cause a lowering of the albedo and more energy to be absorbed on the ground. This effect is likely to exceed the negative feedback of increased C sequestration in greater primary productivity resulting from the displacements of areas of polar desert by tundra, and areas of tundra by forest. The degradation of permafrost has complex consequences for trace gas dynamics. In areas of discontinuous permafrost, warming, will lead to a complete loss of the permafrost. Depending on local hydrological conditions this may in turn lead to a wetting or drying of the environment with subsequent implications for greenhouse gas fluxes. Overall, the complex interactions between processes contributing to feedbacks, variability over time and space in these processes, and insufficient data have generated considerable uncertainties in estimating the net effects of climate change on terrestrial feedbacks to the climate system. This uncertainty applies to magnitude, and even direction of some of the feedbacks