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Caracterização sazonal do pólen apícola quanto à origem botânica, aspectos físico-químicos e elementos traços como bioindicadora de poluição ambiental; Seasonal characterization of apiary pollen as for its origin, physical chemistry and trace elements as environmental pollution bioindicators

Silveira, Talita Antonia da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 07/03/2012 PT
Relevância na Pesquisa
66.09%
As características produtivas e reprodutivas de colônias de abelhas são influenciadas pelo clima e a disponibilidade de alimento na região em que são criadas ou mantidas, assim, o armazenamento de mel e pólen, a postura da rainha e a ocupação dos favos estão sujeitos às variações sazonais. O presente estudo foi desenvolvido no apiário do Departamento de Entomologia e Acarologia, no campus Luiz de Queiróz, ESALQ/USP, no município de Piracicaba, em área contendo plantas frutíferas, ornamentais e fragmento de mata nativa. O objetivo foi verificar quais e a qualidade ambiental dos recursos políniferos usados pelas abelhas A. mellifera durante as quatro estações do ano (2010-2011) 5 colmeias de Apis mellifera L., durante 7 dias consecutivos. Em cada uma das estações verificaram-se os tipos polínicos presentes nas massas de pólen (bolotas), as características físicoquímicas (lipídeos, fibras e proteína) e os metais (Zn 2+; Cu 2+; Pb 2+ ; Cd 2+). Para preparação das amostras para palinologia adotou-se o método da acetólise (ERDTMAN, 1952); para a determinação de metais foi utilizada a técnica de Voltametria de Redissolução Anódica de Pulso Diferencial (DPASV); para proteína foi utilizado o Método de Bradford...

Uma proposta pedagógica para o uso da modelagem computacional no curso de licenciatura em química do cefet campos; A pedagogical for the use of computational modeling in the chemistry education course at cefet-campos

Costa, Rodrigo Garret da; Passerino, Liliana Maria
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
POR
Relevância na Pesquisa
56.01%
Relata-se a experiência no uso de um ambiente de simulação e modelagem computacional no ensino de Físico-Química. A pesquisa foi realizada com alunos do curso de Licenciatura em Química do Cefet Campos, RJ, e teve como objetivos: examinar a contribuição do uso do software Modellus no processo de ensino-aprendizagem; promover um ambiente colaborativo e cooperativo entre os estudantes; verificar as modificações na Zona de Desenvolvimento Proximal dos alunos proporcionadas por interações sociais nesse ambiente computacional. Os resultados obtidos nos testes indicaram uma melhora significativa na compreensão dos conceitos e das representações relativas aos modelos estudados, principalmente entre os alunos que obtiveram baixo rendimento no teste inicial.; This study presents an experiment on the use of a simulation and modelling computer environment in the teaching of Physical Chemistry. The research was conducted with students attending the Chemistry Teaching program at Cefet Campos aiming at: examining the contribution of using Modellus in the teaching and learning process, promoting a cooperative and collaborative learning environment among students, and observe changes in the student’s Zone of Proximal Development promoted by social and cognitive interactions in that computational environment. The results obtained in the tests indicate a significant improvement in the understanding of the concepts and representations of the models investigated in the research...

Físico-química experimental : uma proposta para abordar equilíbrio de fases em sistemas ternários; Experimental physical chemistry : a proposal to address phase equilibria in three-component systems

Reiznautt, Quelen Bulow; Girelli, Bruna; Santa Catharina, Vinícius Millán; Samios, Dimitrios; Garcia, Irene Teresinha Santos
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
POR
Relevância na Pesquisa
66.01%
On undergraduate courses, practical classes represent periods in which students can verify the concepts presented in theoretical classes. Conversely, the teaching internship in graduate programs allows these students to incorporate pedagogical practices into their experience, predominantly involving observation and reproduction of methods adopted by supervisors. We propose internship teaching as a period for reflection on our pedagogical practice and present a methodology for an experimental physical chemistry classroom. The students can interact with the experiment and instructor, furthering the study of ternary systems while developing their skills for investigative work.

Comparative in vivo study of commercially pure Ti implants with surfaces modified by laser with and without silicate deposition: Biomechanical and scanning electron microscopy analysis

Souza, Francisley A.; Queiroz, Thallita P.; Guastaldi, Antônio C.; Garcia-Júnior, Idelmo R.; Magro-Filho, Osvaldo; Nishioka, Renato S.; Sisti, Karin E.; Sonoda, Celso K.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 76-84
ENG
Relevância na Pesquisa
46.01%
The purpose of this study was to evaluate commercially pure titanium implant surfaces modified by laser beam (LS) and LS associated with sodium silicate (SS) deposition, and compare them with machined surface (MS) and dual acid-etching surfaces (AS) modified. Topographic characterization was performed by scanning electron microscopy-X-ray energy dispersive spectroscopy (SEM-EDX), and by mean roughness measurement before surgery. Thirty rabbits received 60 implants in their right and left tibias. One implant of each surface in each tibia. The implants were removed by reverse torque for vivo biomechanical analysis at 30, 60, and 90 days postoperative. In addition, the surface of the implants removed at 30 days postoperative was analyzed by SEM-EDX. The topographic characterization showed differences between the analyzed surfaces, and the mean roughness values of LS and SS were statistically higher than AS and MS. At 30 days, values removal torque LS and SS groups showed a statistically significant difference (p < 0.05) when compared with MS and AS. At 60 days, groups LS and SS showed statistically significant difference (p < 0.05) when compared with MS. At 90 days, only group SS presented statistically higher (p < 0.05) in comparison with MS. The authors can conclude that physical chemistry properties and topographical of LS and SS implants increases bone-implant interaction and provides higher degree of osseointegration when compared with MS and AS. © 2012 Wiley Periodicals...

Uso de artigos científicos em uma disciplina de Físico-Química

Santos,Gelson Ribeiro dos; Sá,Luciana Passos; Queiroz,Salete Linhares
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2006 PT
Relevância na Pesquisa
46.09%
This paper describes the use of primary chemistry literature in a fifth-semester physical chemistry course for undergraduate chemistry students. The main goal is to expose students to the primary literature of physical chemistry, demonstrating how they can benefit from using it. The assignment addresses issues in chemical education such as scientific writing, relating lecture material to the real world, and conducting literature searches. The student evaluation of this assignment, consisting of two surveys and one focus group, showed its usefulness. The details of the evaluation instruments and their results are provided. Out of 45 students enrolled in the course, 30 (67%) students completed the assignment.

Enhancing Interdisciplinary, Mathematics, and Physical Science in an Undergraduate Life Science Program through Physical Chemistry

Pursell, David P.
Fonte: American Society for Cell Biology Publicador: American Society for Cell Biology
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
Relevância na Pesquisa
46.16%
BIO2010 advocates enhancing the interdisciplinary, mathematics, and physical science components of the undergraduate biology curriculum. The Department of Chemistry and Life Science at West Point responded by developing a required physical chemistry course tailored to the interests of life science majors. To overcome student resistance to physical chemistry, students were enabled as long-term stakeholders who would shape the syllabus by selecting life science topics of interest to them. The initial 2 yr of assessment indicates that students have a positive view of the course, feel they have succeeded in achieving course outcome goals, and that the course is relevant to their professional future. Instructor assessment of student outcome goal achievement via performance on exams and labs is comparable to that of students in traditional physical chemistry courses. Perhaps more noteworthy, both student and instructor assessment indicate positive trends from year 1 to year 2, presumably due to the student stakeholder effect.

Introduction to Chemistry and Applications in Nature of Mass Independent Isotope Effects Special Feature

Thiemens, Mark H.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.01%
Stable isotope ratio variations are regulated by physical and chemical laws. These rules depend on a relation with mass differences between isotopes. New classes of isotope variation effects that deviate from mass dependent laws, termed mass independent isotope effects, were discovered in 1983 and have a wide range of applications in basic chemistry and nature. In this special edition, new applications of these effects to physical chemistry, solar system origin models, terrestrial atmospheric and biogenic evolution, polar paleo climatology, snowball earth geology, and present day atmospheric sciences are presented.

5.61 Physical Chemistry, Fall 2004; Physical Chemistry

Griffin, Robert Guy; Nelson, Keith A.
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
EN-US
Relevância na Pesquisa
56.09%
Introductory quantum chemistry; particles and waves; wave mechanics; atomic structure and the Periodic Table; valence and molecular orbital theory; molecular structure; and photochemistry. From the course home page: Course Description This course presents an introduction to quantum mechanics. It begins with an examination of the historical development of quantum theory, properties of particles and waves, wave mechanics and applications to simple systems -- the particle in a box, the harmonic oscillator, the rigid rotor and the hydrogen atom. The lectures continue with a discussion of atomic structure and the Periodic Table. The final lectures cover applications to chemical bonding including valence bond and molecular orbital theory, molecular structure, spectroscopy.

5.62 Physical Chemistry II, Spring 2004; Physical Chemistry II

Nelson, Keith A.; Steinfeld, Jeffrey I.
Fonte: MIT - Massachusetts Institute of Technology Publicador: MIT - Massachusetts Institute of Technology
EN-US
Relevância na Pesquisa
46.12%
Elementary statistical mechanics; transport properties; kinetic theory; solid state; reaction rate theory; and chemical reaction dynamics.

APCELL: The Australian Physical Chemistry Enhanced Laboratory Learning Project

Barrie, Simon Christopher; Buntine, Mark Anthony; Jamie, Ian M.; Kable, Scott Henderson
Fonte: The Royal Australian Chemical Institute Publicador: The Royal Australian Chemical Institute
Tipo: Artigo de Revista Científica
Publicado em //2001 EN
Relevância na Pesquisa
46.01%
The Australian Physical Chemistry Enhanced Laboratory Learning project was established to address the problem of falling student enrolments and continuations in Australian physical chemistry courses. The Project has pooled the resources of over 30 Australian universities (and several New Zealand affiliates) to establish a protocol for developing and assuring the quality of laboratory teaching experiments. Using a ‘research-led teaching’ approach an “Educational Template” was developed which ensures that contributions to the project are strongly learner focussed. In this paper we introduce the APCELL project, describe some of the approaches that have been employed in developing the project, outline important progress achieved to date, and discuss the interaction between APCELL and This Journal.; http://www.acell.org/ACELL-Document-Library.cfm?obj_id=87; © ACELL & Associates

Graphene chemistry: Synthesis and modulation

Sun, Zhengzong
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Thesis; Text Formato: 232 p.; application/pdf
ENG
Relevância na Pesquisa
46.01%
This thesis investigates the chemistry of graphene from its basic synthesis to further modulation of its structure, geometry and surface chemical functional groups. A series of wet chemistry and dry chemistry experiments were performed. The wet chemistry includes the diazonium salt functionalization, graphene oxidation and reduction, nanotube unzipping chemistry, graphite intercalation and exfoliation. The dry chemistry includes chemical vapor deposition and solid carbon source synthesis of graphene, the control of domain size and stacking order, graphene hydrogenation and lithographically patterned graphene superlattices. With all these chemical approaches, graphene's electrical and optical properties, solubility in organic solvents, crystallography, and chemical reactivity were carefully investigated and discussed. In addition to the fundamental chemistry of graphene, the bio- and environmental impact of this new material was also taken into consideration and investigated.

Educational analysis of the first year chemistry experiment 'Thermodynamics Think-In': an ACELL experiment

Read, Justin Robert; Kable, Scott Henderson
Fonte: Royal Society of Chemistry Publicador: Royal Society of Chemistry
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
Relevância na Pesquisa
55.98%
This paper describes an educational analysis of a First Year University chemistry practical called ‘Thermodynamics Think-In’. The analysis follows the formalism of the Advancing Chemistry by Enhancing Learning in the Laboratory (ACELL) project, which includes a statement of education objectives, and an analysis of the student learning experience. The practical consists of a suite of ten well-known, short experiments on the general theme of ‘thermodynamics in chemical change’. Pairs of students undertake a specified and graded set of five of these experiments. All experiments require careful observation by both students, followed by discussion between them until a common, mutually-agreed explanation for their observations can be formulated. The pair then discusses their explanation with a demonstrator, who may challenge it, point out flaws, or provide new information. Student surveys were conducted using the ACELL Student Learning Experience instrument. Analysis of the data shows that students enjoy working on the practical, and report it to be a beneficial learning experience that effectively develops their understanding of thermodynamic principles. The practical also fosters significant interest, and through a process of collaboration and cooperation aids the students in further developing their generic thinking skills.; http://www.acell.org/ACELL-Document-Library.cfm?obj_id=87; Justin R. Read and Scott H. Kable; © The Royal Society of Chemistry

Extracting physical chemistry from mechanics: a new approach to investigate DNA interactions with drugs and proteins in single molecule experiments

Rocha, M. S.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 17/04/2015
Relevância na Pesquisa
46.09%
In this review we focus on the idea of establishing connections between the mechanical properties of DNAligand complexes and the physical chemistry of DNA-ligand interactions. This type of connection is interesting because it opens the possibility of performing a robust characterization of such interactions by using only one experimental technique: single molecule stretching. Furthermore, it also opens new possibilities in comparing results obtained by very different approaches, in special when comparing single molecule techniques to ensemble-averaging techniques. We start the manuscript reviewing important concepts of the DNA mechanics, from the basic mechanical properties to the Worm-Like Chain model. Next we review the basic concepts of the physical chemistry of DNA-ligand interactions, revisiting the most important models used to analyze the binding data and discussing their binding isotherms. Then, we discuss the basic features of the single molecule techniques most used to stretch the DNA-ligand complexes and to obtain force x extension data, from which the mechanical properties of the complexes can be determined. We also discuss the characteristics of the main types of interactions that can occur between DNA and ligands, from covalent binding to simple electrostatic driven interactions. Finally...

Building Bridges Between the Physical and Biological Sciences

Ninham, Barry; Bostrom, Mathias Anders
Fonte: C M B Association Publicador: C M B Association
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
56.04%
This paper attempts to identify major conceptual issues that have inhibited the application of physical chemistry to problems in the biological sciences. We will trace out where theories went wrong, how to repair the present foundations, and discuss current progress toward building a better dialogue.

Food Physical Chemistry and Biophysical Chemistry

I.C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Relevância na Pesquisa
56.17%
Food Physical Chemistry is considered to be a branch of Food Chemistry^1,2^ concerned with the study of both physical and chemical interactions in foods in terms of physical and chemical principles applied to food systems, as well as the applications of physical/chemical techniques and instrumentation for the study of foods^3,4,5,6^. This field encompasses the "physiochemical principles of the reactions and conversions that occur during the manufacture, handling, and storage of foods"^7^. Two rapidly growing, related areas are Food Biotechnology and Food Biophysical Chemistry.

Food Physical Chemistry and Biophysical Chemistry (v2)

I. C. Baianu
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Manuscript
Relevância na Pesquisa
56.17%
Food Physical Chemistry is considered to be a branch of Food Chemistry^1,2^ concerned with the study of both physical and chemical interactions in foods in terms of physical and chemical principles applied to food systems, as well as the applications of physical/chemical techniques and instrumentation for the study of foods^3,4,5,6^. This field encompasses the "physiochemical principles of the reactions and conversions that occur during the manufacture, handling, and storage of foods"^7^. Two rapidly growing, related areas are Food Biotechnology and Food Biophysical Chemistry.

AVALIAÇÃO MICROBIOLÓGICA E FÍSICO-QUÍMICA DE DOCE DE LEITE E REQUEIJÃO PRODUZIDOS COM LEITE DE BUFÁLA NA ILHA DO MARAJÓ- PA

SOUSA, CONSUELO L.; NEVES, ELISA CRISTINA A.; CARNEIRO, CÉSAR AUGUSTO A.; DE FARIAS, JOVANA B.; PEIXOTO, MARIA REGINA S.
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 09/12/2005 POR
Relevância na Pesquisa
46.09%
Avaliou-se a qualidade microbiológica e físico-química de doces de leite e requeijões produzidos, na Ilha do Marajó – PA (Brasil), com leite de búfala. Não foi detectada a presença de Salmonellas e Staph ylococcus aureus nas amostras dos produtos analisados e os resultados obtidos para contagem de bactérias mesófilas e bolores e leveduras para o doce de leite demonstraram boas condições higiênicosanitárias do produto. Porém, 28,60% das amostras de requeijão apresentaram condições higiênico-sanitárias insatisfatórias, sendo 14,26% consideradas impróprias para o consumo humano. Na caracterização físico-química, 83,34% das amostras de doce de leite apresentaram teores de gordura superiores ao padrão (6,0 a 9,0%) e uma amostra mostrou-se acima do limite permitido (máx. 30%) para umidade. Verificou-se que 100% das amostras de requeijão apresentaram teores de proteínas (mín. 5%) e umidade (máx. 60%) de acordo com os padrões e apenas 14,86% enquadraram-se no padrão para gordura no extrato seco total (45 a 54,9%). Esses resultados sugerem que o requeijão de leite de búfala pode estar sendo produzido a partir de matérias-primas de qualidade microbiológica inadequada ou o produto está sendo contaminado durante a produção...

The Contributions of James Moir to Physical Chemistry

Loyson,P.
Fonte: South African Journal of Chemistry Publicador: South African Journal of Chemistry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
Relevância na Pesquisa
76.16%
James Moir was a pioneering chemist in the early 1900s who played a leading role in various chemical societies in South Africa. Although he was mainly an organic chemist, he was a very good all-round chemist, whose analytical and organic activities have already been covered in this j ournal. This article examines his research in physical chemistry, covering the spectral analysis of the ruby and emerald gemstones, a detailed analysis of part of the Fraunhofer lines of the solar spectrum, and an examination of the spectra of cobalt compounds, the permanganate ion, and uranium compounds. Finally, as part of his inorganic and analytical investigations, he also delved into the physical chemistry aspects of solution chemistry, particularly the hydrolysis of the cyanide ion.

Students' conceptions about the sub-microscopic approach to explanations in chemistry throughout their BSc degree course

Serobatse,Boingotlo M; Selvaratnam,Mailoo; Drummond,Helen P.
Fonte: South African Journal of Chemistry Publicador: South African Journal of Chemistry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
Relevância na Pesquisa
46.06%
The main objective of this study was to test chemistry students' competence, throughout the entire BSc course at North-West University (Mafikeng Campus), in the use of the important and widely applicable strategy of explaining the facts, principles and laws of chemistry in terms of the properties of the constituent sub-microscopic particles. Seventeen questions were used for systematically testing all basic aspects of chemistry. The aspects tested included the following: the types of particles present and their properties in various types of matter (e.g. metals, non-metals, ionic compounds, covalent compounds, mixtures, gases, liquids, solids, solutions); the changes in the nature, arrangement and properties of the particles during both physical and chemical changes; the explanation of physical and chemical properties of substances in terms of the properties of the constituent particles. Student performance was consistently bad and it did not improve as they progressed from year to year in their BSc course. More than half of them (average performance in all questions) had difficulty in answering the questions. Analysis of students' answers suggested that most students' difficulties were due to their not identifying clearly the problem that had to be solved and their not using the relevant principles and reasoning to solve the problems. Instead...

The first publication of the New Chemistry in America in Mercurio Peruano (1792) by Joseph Coquette

Bifano,Claudio; Whittembury,Guillermo
Fonte: ASOCIACIÓN INTERCIENCIA Publicador: ASOCIACIÓN INTERCIENCIA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2007 EN
Relevância na Pesquisa
46.08%
Joseph Coquette, first director of the non-university scholarly learning center, Lima’s Mining Tribunal in Peru, published (1792) a text on chemistry in the Peruvian journal Mercurio Peruano: "Principles of Physical Chemistry ….", which was the first text published in America on the new chemistry, as it appeared five years before Lavoisier’s book of 1789 was printed in Spanish in Mexico, in 1797. It was complemented by "About the need to perfect and reform the Nomenclature in Chemistry…." in 1793. In addition he published "Didactic dissertation on Mining…..", also in 1792. The present essay examines in extenso "Principles of Physical Chemistry ….", and comments on the others. Some scholars and institutions of advanced learning in the New Continent are also mentioned. Mercurio Peruano is looked upon in more detail, after Alexander von Humboldt deemed it so important that he donated the 12 volume collection to the Berlin Library of King Frederick William III.