186,776 research outputs found
Synthesis and characterisation of some novel sodalite phases
No full textAluminate sodalites of general composition M8[A102]12.X2, where M = Ca2+, Sr2+, Cd2+; and X = SO42-, SeO32-, WO42-, MoO42-, CrO42-, have been prepared by a solid state sintering method at 1000-1200 oC. The sulphate and selenite bearing sodalites have been reduced to 100% H2 at 600-800 oC to yield a new range of S2- and Se2- bearing sodalites. Sodalites crystallising in the simple cubic space group 143m were structurally characterised by Rietveld refinement of powder X-ray or time-of-flight neutron diffraction data. The aluminate framework is capable of incorporating this variety of different sized metals and anions by a partial collapse of the framework. This is achieved by cooperative rotations of the A104 tetrahedra and by changing the A1-O-A1 angle and deformation of the A104 tetrahedra. For sodalites containing XOn2-, the anions were found to have their oxygens disordered over twelve one-third occupied sites.Vibrational spectra of the sodalities showed smooth transitions of the frequencies of the framework modes as a function of both cell parameter and A1-O-A1 angle. The observed bands were related to the complex vibrational modes giving rise to them. Modes associated with the anions were found to be very similar in frequency to the free ions. 27A1 MAS NMR spectroscopy showed a linear relationship between the isotropic chemical shift and the A1-O-A1 angle. The extent of A104 tetrahedral distortion as measured by structure refinement is directly related to the quadrupolar coupling constant. Optical spectroscopy of the S2- bearing sodalites showed that each M4X cluster is electronically isolated by the framework and undergoes a charge transfer process.Alumino-silicate sodalites, of general composition M8[A1SiO4]6.X2, were synthesised by hydrothermal methods with the incorporation of NaC104 and NaMnO4. These sodium sodalites were ion exchanged with Li+, K+ and Ag+. Structural characterisation of these materials was performed in the space group P43n by Rietveld refinement of powder X-ray or time-of-flight neutron diffraction data. The framework was shown to be able to incorporate metals of different sizes by a partial collapse of the framework facilitated by cooperative rotations of the ordered A104 and SiO4 tetrahedra accompanied by a decrease in the A1-O-Si angle. The XO4- anions were found to be disordered over a twelve fold site and to possess a large amount of vibrational freedom in the expanded K+ bearing sodalites.</p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Barriers to successful implementation of care in home haemodialysis (BASIC-HHD):1. Study design, methods and rationale: BMC Nephrology
No full textBackground: Ten years on from the National Institute of Health and Clinical Excellence' technology appraisal guideline on haemodialysis in 2002; the clinical community is yet to rise to the challenge of providing home haemodialysis (HHD) to 10-15% of the dialysis cohort. The renal registry report, suggests underutilization of a treatment type that has had a lot of research interest and several publications worldwide on its apparent benefit for both physical and mental health of patients. An understanding of the drivers to introducing and sustaining the modality, from organizational, economic, clinical and patient perspectives is fundamental to realizing the full benefits of the therapy with the potential to provide evidence base for effective care models. Through the BASIC-HHD study, we seek to understand the clinical, patient and carer related psychosocial, economic and organisational determinants of successful uptake and maintenance of home haemodialysis and thereby, engage all major stakeholders in the process. Design and methods. We have adopted an integrated mixed methodology (convergent, parallel design) for this study. The study arms include a. patient; b. organization; c. carer and d. economic evaluation. The three patient study cohorts (n = 500) include pre-dialysis patients (200), hospital haemodialysis (200) and home haemodialysis patients (100) from geographically distinct NHS sites, across the country and with variable prevalence of home haemodialysis. The pre-dialysis patients will also be prospectively followed up for a period of 12 months from study entry to understand their journey to renal replacement therapy and subsequently, before and after studies will be carried out for a select few who do commence dialysis in the study period. The process will entail quantitative methods and ethnographic interviews of all groups in the study. Data collection will involve clinical and biomarkers, psychosocial quantitative assessments and neuropsychometric tests in patients. Organizational attitudes and dialysis unit practices will be studied together with perceptions of healthcare providers on provision of home HD. Economic evaluation of home and hospital haemodialysis practices will also be undertaken and we will apply scenario (what. if) analysis using system dynamics modeling to investigate the impact of different policy choices and financial models on dialysis technology adoption, care pathways and costs. Less attention is often given to the patient's carers who provide informal support, often of a complex nature to patients afflicted by chronic ailments such as end stage kidney disease. Engaging the carers is fundamental to realizing the full benefits of a complex, home-based intervention and a qualitative study of the carers will be undertaken to elicit their fears, concerns and perception of home HD before and after patient's commencement of the treatment. The data sets will be analysed independently and the findings will be mixed at the stage of interpretation to form a coherent message that will be informing practice in the future. Discussion. The BASIC-HHD study is designed to assemble pivotal information on dialysis modality choice and uptake, investigating users, care-givers and care delivery processes and study their variation in a multi-layered analytical approach within a single health care system. The study results would define modality specific service and patient pathway redesign. Study Registration. This study has been reviewed and approved by the Greater Manchester West Health Research Authority National Research Ethics Service (NRES) The study is on the NIHR (CLRN) portfolio. © 2013 Jayanti et al.; licensee BioMed Central Ltd
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Edward P. Wimberly, ITC, July 2011
No full textThis video is a conversation with Dr. Edward P. Wimberly. Dr. Wimberly talks about his book, "No Shame in Wesley's Gospel: A Twenty-First Century Pastoral Gospel". Brad Ost, AUC Woodruff Library, is the interviewer
Author Rights and Scholarly Publishing
Full text linkOriginally posted at
http://blog.library.gsu.edu/2014/10/24/author-rights-and-scholarly-publishing/</p
The Lakesman Terrane: the Lower Palaeozoic record of the deep marine Lakesman Basin, a volcanic arc and foreland basin
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