7,648 research outputs found
Log-sine evaluations of Mahler measures, II
We continue the analysis of higher and multiple Mahler measures using
log-sine integrals as started in "Log-sine evaluations of Mahler measures" and
"Special values of generalized log-sine integrals" by two of the authors. This
motivates a detailed study of various multiple polylogarithms and worked
examples are given. Our techniques enable the reduction of several multiple
Mahler measures, and supply an easy proof of two conjectures by Boyd.Comment: 35 page
TTA school-based research consortium initiative, the evaluation, final report
This is the final report of the evaluation of th School-Based Research Consortium Initiative which ran in England from 1998 to 2001. The initiative was sponsored via a public/private partnership between the Teacher Training Agency (TTA), a UK Government agency, and the Centre for British Teachers (CfBT), a private not-for-profit company. The aim of the initiative was to create local infrastructures of support and action for teachers to engage âin and withâ research. Those infrastructures were made up of consortia, consisting in each case of a small number of schools together with a university department of education and at least one local education authority (LEA). Over the three years that it ran, the initiative spawned a considerable range and volume of research activities, including peer observation of teaching, peer review of videos of teaching, interview-based study, surveys measuring such things as rewards and sanctions in the classroom. In addition to well-developed teacher-university collaborations and some joint work with local education authorities, there were many examples of teacher-teacher collaboration (some of it between different schools), and also times when teachers and pupils worked together to devise, carry out or interpret research activity. In practice, the initiative created an environment in which it was possible to develop new research relationships across a range of partners, rather than merely transfer the locus of research to schools. Three aspects of teacher experience of the initiative are important to highlight. The first was the overwhelming testimony of teachers that the value of the initiative for them was the rediscovery of their professional confidence in a climate of low trust accountability, characterised by constant monitoring, target setting and bureaucratic demands. The second was the growth of familiarity with research practices that teachers gained through working collaboratively with their peers, with pupils, and with colleagues from the university. The third was how the process of research itself was necessarily situated in teachersâ own practices
Tissue compatibility of poly(hydroxypropylglutamate)-prazosin conjugates
Biocompatibility of an injectable biodegradable drug delivery system for prazosin was investigated in Sprague-Dawley rats by histological studies after subcutaneous injection ofpoly(hydroxypropyl glutamate)-prazosin (PHPG-prazosin) conjugate particles. The studies showed that (1) the acute inflammatory response to this injectable biodegradable polymeric prodrug system was mild and of only short duration, (2) the chronic inflammation was minimal to zero, (3) the fibrous capsule could be seen starting from 7 days and became more prominent at longer time periods, (4) a collagen network was formed into the injection site after 21 days, (5) the macrophages and foreign giant cells reacted to the globules of conjugate particles, and (6) no adverse reactions were identified. Focal inflammation and the formation of the fibrous capsule around the injection site were the significant histological findings in the histopathological studies. Therefore, it is concluded that the biodegradable injectable PHPG-prazosin carbamate polymeric prodrug system is tissue biocompatible
Generating functions of Legendre polynomials: A tribute to Fred Brafman
AbstractIn 1951, Brafman derived several âunusualâ generating functions of classical orthogonal polynomials, in particular, of Legendre polynomials Pn(x). His result was a consequence of Baileyâs identity for a special case of Appellâs hypergeometric function of the fourth type. In this paper, we present a generalisation of Baileyâs identity and its implication to generating functions of Legendre polynomials of the form ân=0âunPn(x)zn, where un is an ApĂ©ry-like sequence, that is, a sequence satisfying (n+1)2un+1=(an2+an+b)unâcn2unâ1, where nâ„0 and uâ1=0, u0=1. Using both Brafmanâs generating functions and our results, we also give generating functions for rarefied Legendre polynomials and construct a new family of identities for 1/Ï
Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells
This letter reports effective passivation of crystalline silicon (c-Si) surfaces by thermal atomic layer deposited tantalum oxide (Ta2O5) underneath plasma enhanced chemical vapour deposited silicon nitride (SiNx). Cross-sectional transmission electron microscopy imaging shows an approximately 2 nm thick interfacial layer between Ta2O5 and c-Si. Surface recombination velocities as low as 5.0 cm/s and 3.2 cm/s are attained on p-type 0.8 Ω·cm and n-type 1.0 Ω·cm c-Si wafers, respectively. Recombination current densities of 25 fA/cm2 and 68 fA/cm2 are measured on 150 Ω/sq boron-diffused p+ and 120 Ω/sq phosphorus-diffused n+ c-Si, respectively. Capacitance-voltage measurements reveal a negative fixed insulator charge density of -1.8 à 1012cm-2 for the Ta2O5 film and -1.0 à 1012cm-2 for the Ta2O5/SiNx stack. The Ta2O5/SiNx stack is demonstrated to be an excellent candidate for surface passivation of high efficiency silicon solar cells
Statistics of nonlinear internal waves during the Shallow Water 2006 Experiment
Author Posting. © American Meteorological Society, 2016. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 33 (2016): 839-846, doi:10.1175/JTECH-D-15-0221.1.During the Shallow Water Acoustic Experiment 2006 (SW06) conducted on the New Jersey continental shelf in the summer of 2006, detailed measurements of the ocean environment were made along a fixed reference track that was parallel to the continental shelf. The time-varying environment induced by nonlinear internal waves (NLIWs) was recorded by an array of moored thermistor chains and by X-band radars from the attending research vessels. Using a mapping technique, the three-dimensional (3D) temperature field for over a month of NLIW events is reconstructed and analyzed to provide a statistical summary of important NLIW parameters, such as the NLIW propagation speed, direction, and amplitude. The results in this paper can be used as a database for studying the NLIW generation, propagation, and fidelity of nonlinear internal wave models.This research was supported by the Office of Naval Research Ocean Acoustics Program (322OA) through Grants N00014-10-1-0396 and N00014-11-1-0701.2016-10-1
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