906 resultados para Emerson, Ralph Waldo


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Phthalocyanine compounds have been widely investigated as candidate materials for technological applications, which is mainly due to their thermal stability and possibility of processing in the form of thin films. In most applications, the controlled growth of thin films with high crystalline quality is essential. In this study, zinc phthalocyanine (ZnPc) thin films were prepared by evaporation on glass and Au-coated glass substrates with subsequent annealing at different temperatures in ambient atmosphere. The morphological and structural features of 80 nm thick zinc phthalocyanine films were investigated, evidencing an alpha -> beta phase transformation after annealing the films at 200 A degrees C, as indicated by UV-Vis spectroscopy and FTIR analyses. A better uniformity of the annealed films was also evidenced via AFM analysis, which may be of importance for applications where film homogeneity and excellent optical quality are required.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Given an algorithm A for solving some mathematical problem based on the iterative solution of simpler subproblems, an outer trust-region (OTR) modification of A is the result of adding a trust-region constraint to each subproblem. The trust-region size is adaptively updated according to the behavior of crucial variables. The new subproblems should not be more complex than the original ones, and the convergence properties of the OTR algorithm should be the same as those of Algorithm A. In the present work, the OTR approach is exploited in connection with the ""greediness phenomenon"" of nonlinear programming. Convergence results for an OTR version of an augmented Lagrangian method for nonconvex constrained optimization are proved, and numerical experiments are presented.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper describes the preparation and characterization of a solid polymer electrolyte based on amylopectin-rich starch plasticized with glycerol. The samples were characterized through ionic conductivity (sigma) measurements, scanning electron microscopy, thermal analysis, and spectroscopy in the UV-Vis-NIR region. The results showed that the highest sigma (1.1 x 10(-4) Scm(-1) at 30 degrees C) was obtained for the sample with n = [O]/[Li] = 6.5 ratio. In addition, the samples plasticized with 30-35 wt.% of glycerol presented high ionic conductivity, transparency and conduction stability. The ionic conductivity measurements as a function of lithium salt contents showed a maximum for n=6.5. The ionic conductivity as a function of time for amylopectin-rich starch plasticized with 30 wt.% of glycerol and containing [O]/[Li] = 10 showed conduction stability over 6 months (sigma similar to 3.01 x 10(-5) S cm(-1)). (C) 2010 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Carpentry students from the New York Trade School at work during a class. Black and white photograph.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Literacy is an invaluable asset to have, and has allowed for communication, documentation and the spreading of ideas since the beginning of the written language. With technological advancements, and new possibilities to communicate, it is important to question the degree to which people’s abilities to utilise these new methods have developed in relation to these emerging technologies. The purpose of this bachelor’s thesis is to analyse the state of students’ at Dalarna University mulitimodal literacy, as well as their experience of multimodality in their education. This has led to the two main research questions: What is the state of the students at Dalarna University multimodal literacy? And: How have the students at Dalarna University experienced multimodality in education? The paper is based on a mixed-method study that incorporates both a quantitative and qualitative aspect to it. The main thrust of the research paper is, however, based on a quantitative study that was conducted online and emailed to students via their program coordinators. The scope of the research is in audio-visual modes, i.e. audio, video and images, while textual literacy is presumed and serves as an inspiration to the study. The purpose of the study is to analyse the state of the students’ multimodal literacy and their experience of multimodality in education. The study revealed that the students at Dalarna University have most skill in image editing, while not being very literate in audio or video editing. The students seem to have had mediocre experience creating meaning through multimodality both in private use and in their respective educational institutions. The study also reveals that students prefer learning by means of video (rather than text or audio), yet are not able to create meaning (communicate) through it.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Evelyn Mae Levine was born April 11, 1907 and died on February 6, 1957. She was one of the children born to William and Sarah Levine. The scrapbook includes photographs, family memories, negative copies of grade sheets from Coburn Classical Instituteand Emerson College.