context-based chemistry studies: Topics by Science.gov

Sample records for context-based chemistry studies

A Thematic Review of Studies into the Effectiveness of Context-Based Chemistry Curricula

ERIC Educational Resources Information Center

Ultay, Neslihan; Calik, Muammer

2012-01-01

Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords "context-based", "contextual learning" and "chemistry…
A Thematic Review of Studies into the Effectiveness of Context-Based Chemistry Curricula

NASA Astrophysics Data System (ADS)

Ültay, Neslihan; Çalık, Muammer

2012-12-01

Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords `context-based', `contextual learning' and `chemistry education' in well-known databases (i.e. Academic Search Complete, Education Research Complete, ERIC, Springer LINK Contemporary). Further, in case the computer search by key words may have missed a rather substantial part of the important literature in the area, the authors also conducted a hand search of the related journals. To present a detailed thematic review of context-based chemistry studies, a matrix was used to summarize the findings by focusing on insights derived from the related studies. The matrix incorporates the following themes: needs, aims, methodologies, general knowledge claims, and implications for teaching and learning, implications for curriculum development and suggestions for future research. The general knowledge claims investigated in this paper were: (a) positive effects of the context-based chemistry studies; (b) caveats, both are examined in terms of students' attitudes and students' understanding/cognition. Implications were investigated for practice in context- based chemistry studies, for future research in context- based chemistry studies, and for curriculum developers in context- based chemistry studies. Teachers of context-based courses claimed that the application of the context-based learning approach in chemistry education improved students' motivation and interest in the subject. This seems to have generated an increase in the number of the students who wish to continue chemistry education at higher levels. However, despite the fact that the majority of the studies have reported advantages of context-based chemistry studies, some of them have also referred to pitfalls, i.e. dominant structure of out-of-school learning, tough nature of some chemistry topics, and teacher anxiety of lower-ability students.
Students' Perceptions of Teaching in Context-based and Traditional Chemistry Classrooms: Comparing content, learning activities, and interpersonal perspectives

NASA Astrophysics Data System (ADS)

Overman, Michelle; Vermunt, Jan D.; Meijer, Paulien C.; Bulte, Astrid M. W.; Brekelmans, Mieke

2014-07-01

Context-based curriculum reforms in chemistry education are thought to bring greater diversity to the ways in which chemistry teachers organize their teaching. First and foremost, students are expected to perceive this diversity. However, empirical research on how students perceive their teacher's teaching in context-based chemistry classrooms, and whether this teaching differs from traditional chemistry lessons, is scarce. This study aims to develop our understanding of what teaching looks like, according to students, in context-based chemistry classrooms compared with traditional chemistry classrooms. As such, it might also provide a better understanding of whether teachers implement and attain the intentions of curriculum developers. To study teacher behaviour we used three theoretical perspectives deemed to be important for student learning: a content perspective, a learning activities perspective, and an interpersonal perspective. Data were collected from 480 students in 24 secondary chemistry classes in the Netherlands. Our findings suggest that, according to the students, the changes in teaching in context-based chemistry classrooms imply a lessening of the emphasis on fundamental chemistry and the use of a teacher-centred approach, compared with traditional chemistry classrooms. However, teachers in context-based chemistry classrooms seem not to display more 'context-based' teaching behaviour, such as emphasizing the relation between chemistry, technology, and society and using a student-centred approach. Furthermore, students in context-based chemistry classrooms perceive their teachers as having less interpersonal control and showing less affiliation than teachers in traditional chemistry classrooms. Our findings should be interpreted in the context of former and daily experiences of both teachers and students. As only chemistry is reformed in the schools in which context-based chemistry is implemented, it is challenging for both students and teachers to deal with these reforms.
Making Connections: Learning and Teaching Chemistry in Context

ERIC Educational Resources Information Center

King, Donna; Bellocchi, Alberto; Ritchie, Stephen M.

2008-01-01

Even though several studies have reported positive attitudinal outcomes from context-based chemistry programs, methodological obstacles have prevented researchers from comparing satisfactorily the chemistry-learning outcomes between students who experience a context-based program with those who experience a content-driven program. In this…
Beyond "Inert" Ideas to Teaching General Chemistry from Rich Contexts: Visualizing the Chemistry of Climate Change (VC3)

ERIC Educational Resources Information Center

Mahaffy, Peter G.; Holme, Thomas A.; Martin-Visscher, Leah; Martin, Brian E.; Versprille, Ashley; Kirchhoff, Mary; McKenzie, Lallie; Town, Marcy

2017-01-01

As one approach to moving beyond transmitting "inert" ideas to chemistry students, we use the term "teaching from rich contexts" to describe implementations of case studies or context-based learning based on systems thinking that provide deep and rich opportunities for learning crosscutting concepts through contexts. This…
Impact of STS (Context-Based Type of Teaching) in Comparison with a Textbook Approach on Attitudes and Achievement in Community College Chemistry Classrooms

ERIC Educational Resources Information Center

Perkins, Gita

2011-01-01

The purpose of this study was to analyze the impact of a context-based teaching approach (STS) versus a more traditional textbook approach on the attitudes and achievement of community college chemistry students. In studying attitudes toward chemistry within this study, I used a 30-item Likert scale in order to study the importance of chemistry in…
New Perspectives on Context-Based Chemistry Education: Using a Dialectical Sociocultural Approach to View Teaching and Learning

ERIC Educational Resources Information Center

King, Donna

2012-01-01

Context-based chemistry education aims to improve student interest and motivation in chemistry by connecting canonical chemistry concepts with real-world contexts. Implementation of context-based chemistry programmes began 20 years ago in an attempt to make the learning of chemistry meaningful for students. This paper reviews such programmes…
The Use of "Contexts" as a Challenge for the Chemistry Curriculum: Its Successes and the Need for Further Development and Understanding

ERIC Educational Resources Information Center

Pilot, Albert; Bulte, Astrid M. W.

2006-01-01

In this paper we reflect on the experiences and results of the development and implementation of context-based chemistry education. This development is discussed with respect to five challenges defined for chemistry curricula (Gilbert, 2006). Five context-based approaches were selected that will provide the data for this study (Bennett & Lubben,…
Students' Understanding of Acids/Bases in Organic Chemistry Contexts

ERIC Educational Resources Information Center

Cartrette, David P.; Mayo, Provi M.

2011-01-01

Understanding key foundational principles is vital to learning chemistry across different contexts. One such foundational principle is the acid/base behavior of molecules. In the general chemistry sequence, the Bronsted-Lowry theory is stressed, because it lends itself well to studying equilibrium and kinetics. However, the Lewis theory of…
Exploring a Framework for Professional Development in Curriculum Innovation: Empowering Teachers for Designing Context-Based Chemistry Education

NASA Astrophysics Data System (ADS)

Stolk, Machiel J.; de Jong, Onno; Bulte, Astrid M. W.; Pilot, Albert

2011-05-01

Involving teachers in early stages of context-based curriculum innovations requires a professional development programme that actively engages teachers in the design of new context-based units. This study considers the implementation of a teacher professional development framework aiming to investigate processes of professional development. The framework is based on Galperin's theory of the internalisation of actions and it is operationalised into a professional development programme to empower chemistry teachers for designing new context-based units. The programme consists of the teaching of an educative context-based unit, followed by the designing of an outline of a new context-based unit. Six experienced chemistry teachers participated in the instructional meetings and practical teaching in their respective classrooms. Data were obtained from meetings, classroom discussions, and observations. The findings indicated that teachers became only partially empowered for designing a new context-based chemistry unit. Moreover, the process of professional development leading to teachers' empowerment was not carried out as intended. It is concluded that the elaboration of the framework needs improvement. The implications for a new programme are discussed.
Construction of Context-Based Module: How OLED can be used as a Context in High School Chemistry Instruction

NASA Astrophysics Data System (ADS)

Anugrah, I. R.; Mudzakir, A.; Sumarna, O.

2017-09-01

Teaching materials used in Indonesia generally just emphasize remembering skill so that the students’ science literacy is low. Innovation is needed to transform traditional teaching materials so that it can stimulate students’ science literacy, one of which is by context-based approach. This study focused on the construction of context-based module for high school using Organic Light-Emitting Diode (OLED) topics. OLED was chosen because it is an up-to-date topic and relevant to real life. This study used Model of Educational Reconstruction (MER) to reconstruct science content structure about OLED through combining scientist’s perspectives with student’s preconceptions and national curriculum. Literature review of OLED includes its definition, components, characteristics and working principle. Student’s preconceptions about OLED are obtained through interviews. The result shows that student’s preconceptions have not been fully similar with the scientist’s perspective. One of the reasons is that some of the related Chemistry concepts are too complicated. Through curriculum analysis, Chemistry about OLED that are appropriate for high school are Bohr’s atomic theory, redox and organic chemistry including polymers and aromatics. The OLED context and its Chemistry concept were developed into context-based module by adapting science literacy-based learning. This module is expected to increase students’ science literacy performance.
Identifying Relevant Acid-Base Topics in the Context of a Prenursing Chemistry Course to Better Align Health-Related Instruction and Assessment

ERIC Educational Resources Information Center

Brown, Corina E.; Henry, Melissa L. M.; Hyslop, Richard M.

2018-01-01

This study explores the acid-base topic in the context of a chemistry course taken as a prerequisite for a baccalaureate nursing program. Core findings were derived from semistructured interviews with experts in the areas of chemistry and nursing, and a multiple university survey of experts' opinions. The acid-base topic was reviewed and evaluated…
Textbook Questions in Context-Based and Traditional Chemistry Curricula Analysed from a Content Perspective and a Learning Activities Perspective

ERIC Educational Resources Information Center

Overman, Michelle; Vermunt, Jan D.; Meijer, Paulien C.; Bulte, Astrid M. W.; Brekelmans, Mieke

2013-01-01

In this study, questions in context-based and traditional chemistry textbooks were analysed from two perspectives that are at the heart of chemistry curricula reforms: a content perspective and a learning activities perspective. To analyse these textbook questions, we developed an instrument for each perspective. In total, 971 textbook questions…
Students' Perceptions of Teaching in Context-Based and Traditional Chemistry Classrooms: Comparing Content, Learning Activities, and Interpersonal Perspectives

ERIC Educational Resources Information Center

Overman, Michelle; Vermunt, Jan D.; Meijer, Paulien C.; Bulte, Astrid M. W.; Brekelmans, Mieke

2014-01-01

Context-based curriculum reforms in chemistry education are thought to bring greater diversity to the ways in which chemistry teachers organize their teaching. First and foremost, students are expected to perceive this diversity. However, empirical research on how students perceive their teacher's teaching in context-based chemistry classrooms,…
A context based approach using Green Chemistry/Bio-remediation principles to enhance interest and learning of organic chemistry in a high school AP chemistry classroom

NASA Astrophysics Data System (ADS)

Miller, Tricia

The ability of our planet to sustain life and heal itself is not as predictable as it used to be. Our need for educated future scientists who know what our planet needs, and can passionately apply that knowledge to find solutions should be at the heart of science education today. This study of learning organic chemistry through the lens of the environmental problem "What should be done with our food scraps?" explores student interest, and mastery of certain concepts in organic chemistry. This Green Chemistry/ Bio-remediation context-based teaching approach utilizes the Nature MillRTM, which is an indoor food waste composting machine, to learn about organic chemistry, and how this relates to landfill reduction possibilities, and resource production. During this unit students collected food waste from their cafeteria, and used the Nature MillRTM to convert food waste into compost. The use of these hands on activities, and group discussions in a context-based environment enhanced their interest in organic chemistry, and paper chromatography. According to a one-tailed paired T-test, the result show that this context-based approach is a significant way to increase both student interest and mastery of the content.
Evaluating a Professional Development Framework to Empower Chemistry Teachers to Design Context-Based Education

ERIC Educational Resources Information Center

Stolk, Machiel Johan; Bulte, Astrid; De Jong, Onno; Pilot, Albert

2012-01-01

Even experienced chemistry teachers require professional development when they are encouraged to become actively engaged in the design of new context-based education. This study briefly describes the development of a framework consisting of goals, learning phases, strategies and instructional functions, and how the framework was translated into a…
Progressive Transitions in Chemistry Teachers' Understanding of Nature of Science Based on Historical Controversies

ERIC Educational Resources Information Center

Niaz, Mansoor

2009-01-01

The objective of this study is to facilitate progressive transitions in chemistry teachers understanding of nature of science in the context of historical controversies. Selected controversies referred to episodes that form part of the chemistry curriculum both at secondary and university freshman level. The study is based on 17 in-service…
Contextualized Chemistry Education: The American experience

NASA Astrophysics Data System (ADS)

Schwartz, A. Truman

2006-07-01

This paper is a survey of context-based chemistry education in the United States. It begins with a very brief overview of twentieth-century chemistry texts and teaching methods, followed by a short description of a pioneering secondary school text. The major emphasis is on post-secondary instruction and the central case study is provided by Chemistry in Context, a university text intended for students who are not specializing in science. The paper is more concerned with strategies for curriculum reform than with educational research, and the emphasis is more pragmatic than theoretical. A chronological sequence is used to trace the creation of Chemistry in Context. This developmental account is overlaid with the curricular representations of Goodlad and Van den Akker. The Ideal Curriculum was the goal, but the Formal Curriculum was created and revised as a consequence of iteration involving perceptions of the users, the implementation of the curriculum, the experience of students and teachers, and formal and informal assessment of what was attained. The paper also includes descriptions of other, more recent, context-based college chemistry curricula. It concludes with a list of problems and unanswered questions relating to this pedagogical approach.
A Research on the Generative Learning Model Supported by Context-Based Learning

ERIC Educational Resources Information Center

Ulusoy, Fatma Merve; Onen, Aysem Seda

2014-01-01

This study is based on the generative learning model which involves context-based learning. Using the generative learning model, we taught the topic of Halogens. This topic is covered in the grade 10 chemistry curriculum using activities which are designed in accordance with the generative learning model supported by context-based learning. The…
Stimulating Students' Intrinsic Motivation for Learning Chemistry through the Use of Context-Based Learning Modules

ERIC Educational Resources Information Center

Vaino, Katrin; Holbrook, Jack; Rannikmae, Miia

2012-01-01

This paper introduces a research project in which five chemistry teachers, working in cooperation with university researchers, implemented a new teaching approach using context-based modules specially designed to stimulate the intrinsic motivation of students. The intention was to induce change in chemistry teachers' teaching approach from more…

Analysing task design and students' responses to context-based problems through different analytical frameworks

NASA Astrophysics Data System (ADS)

Broman, Karolina; Bernholt, Sascha; Parchmann, Ilka

2015-05-01

Background:Context-based learning approaches are used to enhance students' interest in, and knowledge about, science. According to different empirical studies, students' interest is improved by applying these more non-conventional approaches, while effects on learning outcomes are less coherent. Hence, further insights are needed into the structure of context-based problems in comparison to traditional problems, and into students' problem-solving strategies. Therefore, a suitable framework is necessary, both for the analysis of tasks and strategies. Purpose:The aim of this paper is to explore traditional and context-based tasks as well as students' responses to exemplary tasks to identify a suitable framework for future design and analyses of context-based problems. The paper discusses different established frameworks and applies the Higher-Order Cognitive Skills/Lower-Order Cognitive Skills (HOCS/LOCS) taxonomy and the Model of Hierarchical Complexity in Chemistry (MHC-C) to analyse traditional tasks and students' responses. Sample:Upper secondary students (n=236) at the Natural Science Programme, i.e. possible future scientists, are investigated to explore learning outcomes when they solve chemistry tasks, both more conventional as well as context-based chemistry problems. Design and methods:A typical chemistry examination test has been analysed, first the test items in themselves (n=36), and thereafter 236 students' responses to one representative context-based problem. Content analysis using HOCS/LOCS and MHC-C frameworks has been applied to analyse both quantitative and qualitative data, allowing us to describe different problem-solving strategies. Results:The empirical results show that both frameworks are suitable to identify students' strategies, mainly focusing on recall of memorized facts when solving chemistry test items. Almost all test items were also assessing lower order thinking. The combination of frameworks with the chemistry syllabus has been found successful to analyse both the test items as well as students' responses in a systematic way. The framework can therefore be applied in the design of new tasks, the analysis and assessment of students' responses, and as a tool for teachers to scaffold students in their problem-solving process. Conclusions:This paper gives implications for practice and for future research to both develop new context-based problems in a structured way, as well as providing analytical tools for investigating students' higher order thinking in their responses to these tasks.
Effects of Storylines Embedded within the Context-Based Approach on Pre-Service Primary School Teachers' Conceptions of Matter and Its States

ERIC Educational Resources Information Center

Demircioglu, Hülya; Ayas, Alipasa; Demircioglu, Gökhan; Özmen, Haluk

2015-01-01

In this study, the effect of the context-based approach on pre-service primary school teachers' understanding of matter and its states and their attitude towards chemistry was investigated. Using a simple experimental design, the study was conducted with 35 pre-service primary school teachers who were exposed to context-based material with…
Comprehensive understanding of mole concept subject matter according to the tetrahedral chemistry education (empirical study on the first-year chemistry students of Technische Universität Dresden)

NASA Astrophysics Data System (ADS)

Prabowo, D. W.; Mulyani, S.; van Pée, K.-H.; Indriyanti, N. Y.

2018-05-01

This research aims to apprehend: (1) the shape of tetrahedral chemistry education which is called the future of chemistry education, (2) comprehensive understanding of chemistry first-year students of Technische Universität Dresden according to the chemistry education’s tetrahedral shape on mole concept subject matter. This research used quantitative and qualitative; paper and pencil test and interview. The former was conducted in the form of test containing objective test instrument. The results of this study are (1) learning based on tetrahedral shape of chemistry education put the chemical substance (macroscopic), symbolic representation (symbol), and its process (molecular) in the context of human beings (human element) by integrating content and context, without emphasis on one thing and weaken another, (2) first-year chemistry students of Technische Universität Dresden have comprehensively understood the mole concept associated with the context of everyday life, whereby students are able to find out macroscopic information from statements that are contextual to human life and then by using symbols and formulas are able to comprehend the molecular components as well as to interpret and analyse problems effectively.
The Effect of Context-Based Chemical Equilibrium on Grade 11 Students' Learning, Motivation and Constructivist Learning Environment

ERIC Educational Resources Information Center

ilhan, Nail; Yildirim, Ali; Yilmaz, Sibel Sadi

2016-01-01

In recent years, many countries have adopted a context-based approach for designing science curricula for education at all levels. The aim of this study was to determine the effectiveness of a Context-Based Chemistry Course (CBCC) as compared with traditional/existing instruction, on 11th grade students' learning about chemical equilibrium,…
Inquiry-Based Chemistry Education in a High-Context Culture: A Qatari Case Study

ERIC Educational Resources Information Center

Qureshi, Sheila; Vishnumolakala, Venkat Rao; Southam, Daniel C.; Treagust, David F.

2017-01-01

This research took place within the context of ongoing educational reforms to promote inquiry-based science instruction and a desire to draw evidence to inform adoptions of western pedagogical practices in a high-context culture like Qatar. We report on the outcomes from Process Oriented Guided Inquiry Learning (POGIL) in a foundation chemistry…
Investigating Prospective Teachers' Ability to Write Context-Based Problems

ERIC Educational Resources Information Center

Ültay, Neslihan; Donmez Usta, Necla

2016-01-01

Purpose: The purpose of this study is to investigate the prospective teachers' ability to write context-based problems about the concepts in radioactivity unit. Methodology: The study is carried out in a university in Turkey with 21 prospective teachers in physics, chemistry and biology in 2014-2015 fall terms. In the study, data are collected…
A Comparison of Different Teaching Designs of "Acids and Bases" Subject

ERIC Educational Resources Information Center

Ültay, Neslihan; Çalik, Muammer

2016-01-01

Inability to link the acid-base concepts with daily life phenomena (as contexts) highlights the need for further research on the context-based acid-base chemistry. In this vein, the aim of this study is to investigate the effects of different teaching designs (REACT strategy, 5Es learning model and traditional (existing) instruction) relevant with…
Development and Assessment of Green, Research-Based Instructional Materials for the General Chemistry Laboratory

ERIC Educational Resources Information Center

Cacciatore, Kristen L.

2010-01-01

This research entails integrating two novel approaches for enriching student learning in chemistry into the context of the general chemistry laboratory. The first is a pedagogical approach based on research in cognitive science and the second is the green chemistry philosophy. Research has shown that inquiry-based approaches are effective in…
General Chemistry Students' Conceptual Understanding and Language Fluency: Acid-Base Neutralization and Conductometry

ERIC Educational Resources Information Center

Nyachwaya, James M.

2016-01-01

The objective of this study was to examine college general chemistry students' conceptual understanding and language fluency in the context of the topic of acids and bases. 115 students worked in groups of 2-4 to complete an activity on conductometry, where they were given a scenario in which a titration of sodium hydroxide solution and dilute…
Academic Success in Context-Based Chemistry: Demonstrating Fluid Transitions between Concepts and Context

ERIC Educational Resources Information Center

King, Donna Therese; Ritchie, Stephen M.

2013-01-01

Curriculum developers and researchers have promoted context-based programmes to arrest waning student interest and participation in the enabling sciences at high school and university. Context-based programmes aim for student connections between scientific discourse and real-world contexts to elevate curricular relevance without diminishing…
Teaching High School Chemistry in the Context of Pharmacology Helps Both Teachers and Students Learn

ERIC Educational Resources Information Center

Schwartz-Bloom, Rochelle D.; Halpin, Myra J.; Reiter, Jerome P.

2011-01-01

Few studies demonstrate the impact of teaching chemistry embedded in a context that has relevance to high school students. We build upon our prior work showing that pharmacology topics (i.e., drugs), which are inherently interesting to high school students, provide a useful context for teaching chemistry and biology. In those studies, teachers…
Ionic Liquids as a Basis Context for Developing High school Chemistry Teaching Materials

NASA Astrophysics Data System (ADS)

Hernani; Mudzakir, A.; Sumarna, O.

2017-02-01

This research aims to produce a map of connectedness highschool chemical content with the context of the modern chemical materials applications based on ionic liquids. The research method is content analysis of journal articles related to the ionic liquid materials and the textbooks of high school chemistry and textbooks of general chemistry at the university. The instrument used is the development format of basic text that connect and combine content and context. The results showed the connectedness between: (1) the context lubricants ionic liquid with the content of ionic bonding, covalent bonding, metal bonding, interaction between the particles of matter, the elements of main group, the elements of transition group, and the classification of macromolecules; (2) the context of fuel cell electrolite with the content of ionic bonding, covalent bonding, metal bonding, interaction between the particles of matter, Volta cell, and electrolysis cell; (3) the contect of nanocellulose with the content of ionic bonding, covalent bonding, metal bonding, interaction between the particles of matter, colloid, carbon compound, and the classification of macromolecules; and (4) the context of artificial muscle system with the content of ionic bond, covalent bond, metal bonding, interaction between the particles of matter, hydrocarbons, electrolytes and non-electrolytes, and the classification of macromolecules. Based on the result of this content analysis, the context of ionic liquid is predicted can be utilized for the enrichment of high school chemistry and has the potential to become teaching material’s context of high school chemistry in the future.
Development and Assessment of a Chemistry-Based Computer Video Game as a Learning Tool

ERIC Educational Resources Information Center

Martinez-Hernandez, Kermin Joel

2010-01-01

The chemistry-based computer video game is a multidisciplinary collaboration between chemistry and computer graphics and technology fields developed to explore the use of video games as a possible learning tool. This innovative approach aims to integrate elements of commercial video game and authentic chemistry context environments into a learning…
Instructional Misconceptions in Acid-Base Equilibria: An Analysis from a History and Philosophy of Science Perspective

ERIC Educational Resources Information Center

Kousathana, Margarita; Demerouti, Margarita; Tsaparlis, Georgios

2005-01-01

The implications of history and philosophy of chemistry are explored in the context of chemical models. Models and modeling provide the context through which epistemological aspects of chemistry can be promoted. In this work, the development of ideas and models about acids and bases (with emphasis on the Arrhenius, the Bronsted-Lowry, and the…
An approach to teaching general chemistry II that highlights the interdisciplinary nature of science.

PubMed

Sumter, Takita Felder; Owens, Patrick M

2011-01-01

The need for a revised curriculum within the life sciences has been well-established. One strategy to improve student preparation in the life sciences is to redesign introductory courses like biology, chemistry, and physics so that they better reflect their disciplinary interdependence. We describe a medically relevant, context-based approach to teaching second semester general chemistry that demonstrates the interdisciplinary nature of biology and chemistry. Our innovative method provides a model in which disciplinary barriers are diminished early in the undergraduate science curriculum. The course is divided into three principle educational modules: 1) Fundamentals of General Chemistry, 2) Medical Approaches to Inflammation, and 3) Neuroscience as a connector of chemistry, biology, and psychology. We accurately anticipated that this modified approach to teaching general chemistry would enhance student interest in chemistry and bridge the perceived gaps between biology and chemistry. The course serves as a template for context-based, interdisciplinary teaching that lays the foundation needed to train 21st century scientists. Copyright © 2010 Wiley Periodicals, Inc.
An Approach to Teaching General Chemistry II that Highlights the Interdisciplinary Nature of Science*,†

PubMed Central

Sumter, Takita Felder; Owens, Patrick M.

2012-01-01

The need for a revised curriculum within the life sciences has been well-established. One strategy to improve student preparation in the life sciences is to redesign introductory courses like biology, chemistry, and physics so that they better reflect their disciplinary interdependence. We describe a medically relevant, context-based approach to teaching second semester general chemistry that demonstrates the interdisciplinary nature of biology and chemistry. Our innovative method provides a model in which disciplinary barriers are diminished early in the undergraduate science curriculum. The course is divided into three principle educational modules: 1) Fundamentals of General Chemistry, 2) Medical Approaches to Inflammation, and 3) Neuroscience as a connector of chemistry, biology, and psychology. We accurately anticipated that this modified approach to teaching general chemistry would enhance student interest in chemistry and bridge the perceived gaps between biology and chemistry. The course serves as a template for context-based, interdisciplinary teaching that lays the foundation needed to train 21st century scientists. PMID:21445902
Teaching Analytical Chemistry to Pharmacy Students: A Combined, Iterative Approach

ERIC Educational Resources Information Center

Masania, Jinit; Grootveld, Martin; Wilson, Philippe B.

2018-01-01

Analytical chemistry has often been a difficult subject to teach in a classroom or lecture-based context. Numerous strategies for overcoming the inherently practical-based difficulties have been suggested, each with differing pedagogical theories. Here, we present a combined approach to tackling the problem of teaching analytical chemistry, with…
Visualizing the Chemistry of Climate Change (VC3Chem): Online resources for teaching and learning chemistry through the rich context of climate science

NASA Astrophysics Data System (ADS)

McKenzie, L.; Versprille, A.; Towns, M.; Mahaffy, P.; Martin, B.; Kirchhoff, M.

2013-12-01

Global climate change is one of the most pressing environmental challenges facing humanity. Many of the important underlying concepts require mental models that are built on a fundamental understanding of chemistry, yet connections to climate science and global climate change are largely missing from undergraduate chemistry courses for science majors. In Visualizing the Chemistry of Climate Change (VC3Chem), we have developed and piloted a set of online modules that addresses this gap by teaching core chemistry concepts through the rich context of climate science. These interactive web-based digital learning experiences enable students to learn about isotopes and their relevance in determining historical temperature records, IR absorption by greenhouse gases, and acid/base chemistry and the impacts on changing ocean pH. The efficacy of these tools and this approach has been assessed through measuring changes in students' understanding about both climate change and core chemistry concepts.
Some Aspects of Science Education in European Context

ERIC Educational Resources Information Center

Naumescu, Adrienne Kozan; Pasca, Roxana-Diana

2008-01-01

Some up-to-date problems in science education in European context are treated in this paper. The characteristics of science education across Europe are presented. Science teachers' general competencies are underlined. An example of problem-solving as teaching method in chemistry is studied in knowledge based society. Transforming teacher practice…
Using the Curriculum Emphasis Concept to Investigate Teachers' Curricular Beliefs in the Context of Educational Reform

ERIC Educational Resources Information Center

van Driel, Jan H.; Bulte, Astrid M. W.; Verloop, Nico

2008-01-01

This paper reports a study on teachers' domain-specific beliefs about the chemistry curriculum for upper-secondary education in The Netherlands. Teachers' beliefs were investigated using a questionnaire focused on the goals of the chemistry curriculum. The design of the questionnaire was based on three curriculum emphases: "fundamental…

An Application of Context- and Problem-Based Learning (C-PBL) into Teaching Thermodynamics

NASA Astrophysics Data System (ADS)

Baran, Mukadder; Sozbilir, Mustafa

2017-05-01

This study aims to investigate the applicability of context- and problem-based learning (C-PBL) into teaching thermodynamics and to examine its influence on the students' achievements in chemistry, retention of knowledge, students' attitudes, motivation and interest towards chemistry. The embedded mixed method design was utilized with a group of 13 chemistry students in a 2-year program of "Medical Laboratory and Techniques" at a state university in an underdeveloped city at the southeastern region of Turkey. The research data were collected via questionnaires regarding the students' attitudes, motivation and interest in chemistry, an achievement test on "thermodynamics" and interviews utilized to find out the applicability of C-PBL into thermodynamics. The findings demonstrated that C-PBL led a statistically significant increase in the students' achievement in thermodynamics and their interest in chemistry, while no statistically significant difference was observed in the students' attitudes and motivation towards chemistry before and after the intervention. The interviews revealed that C-PBL developed not only the students' communication skills but also their skills in using time effectively, making presentations, reporting research results and using technology. It was also found to increase their self-confidence together with the positive attitudes towards C-PBL and being able to associate chemistry with daily life. In light of these findings, it could be stated that it will be beneficial to increase the use of C-PBL in teaching chemistry.
Improving the Interest of High-School Students toward Chemistry by Crime Scene Investigation

ERIC Educational Resources Information Center

Basso, A.; Chiorri, C.; Bracco, F.; Carnasciali, M. M.; Alloisio, M.; Grotti, M.

2018-01-01

Improving the interest of high-school students towards chemistry (and science in general) is one of the goals of the Italian Ministry of Education. To this aim, we designed a context-based activity that actively involved students in six different laboratory experiences interconnected by a case study of the murder of Miss Scarlet, from the famous…
The Effects of the Design and Development of a Chemistry Curriculum Reform on Teachers' Professional Growth: A Case Study

ERIC Educational Resources Information Center

Coenders, Fer; Terlouw, Cees; Dijkstra, Sanne; Pieters, Jules

2010-01-01

A curriculum innovation requires new learning material for students and a preparation program for teachers, in which teacher learning is a key ingredient. In this paper we describe how three experienced teachers, involved in the development and subsequent classroom enactment of student learning material for context-based chemistry education,…
The Development of a Visual-Perceptual Chemistry Specific (VPCS) Assessment Tool

ERIC Educational Resources Information Center

Oliver-Hoyo, Maria; Sloan, Caroline

2014-01-01

The development of the Visual-Perceptual Chemistry Specific (VPCS) assessment tool is based on items that align to eight visual-perceptual skills considered as needed by chemistry students. This tool includes a comprehensive range of visual operations and presents items within a chemistry context without requiring content knowledge to solve…
Teaching Thinking Skills in Context-Based Learning: Teachers' Challenges and Assessment Knowledge

NASA Astrophysics Data System (ADS)

Avargil, Shirly; Herscovitz, Orit; Dori, Yehudit Judy

2012-04-01

For an educational reform to succeed, teachers need to adjust their perceptions to the reform's new curricula and strategies and cope with new content, as well as new teaching and assessment strategies. Developing students' scientific literacy through context-based chemistry and higher order thinking skills was the framework for establishing a new chemistry curriculum for Israeli high school students. As part of this endeavor, we developed the Taste of Chemistry module, which focuses on context-based chemistry, chemical understanding, and higher order thinking skills. Our research objectives were (a) to identify the challenges and difficulties chemistry teachers faced, as well as the advantages they found, while teaching and assessing the Taste of Chemistry module; and (b) to investigate how they coped with teaching and assessing thinking skills that include analyzing data from graphs and tables, transferring between multiple representations and, transferring between chemistry understanding levels. Research participants included eight teachers who taught the module. Research tools included interviews, classroom observations, teachers-designed students' assignments, and developers-designed students' assignments. We documented different challenges teachers had faced while teaching the module and found that the teachers developed different ways of coping with these challenges. Developing teachers' assessment knowledge (AK) was found to be the highest stage in teachers' professional growth, building on teachers' content knowledge (CK), pedagogy knowledge (PK), and pedagogical-content knowledge (PCK). We propose the use of assignments designed by teachers as an instrument for determining their professional growth.
Impact of STS (Context-Based Type of Teaching) in Comparison With a Textbook Approach on Attitudes and Achievement in Community College Chemistry Classrooms

NASA Astrophysics Data System (ADS)

Perkins, Gita

The purpose of this study was to analyze the impact of a context-based teaching approach (STS) versus a more traditional textbook approach on the attitudes and achievement of community college chemistry students. In studying attitudes toward chemistry within this study, I used a 30-item Likert scale in order to study the importance of chemistry in students' lives, the importance of chemistry, the difficulty of chemistry, interest in chemistry, and the usefulness of chemistry for their future career. Though the STS approach students had higher attitude post scores, there was no significant difference between the STS and textbook students' attitude post scores. It was noted that females had higher postattitude scores in the STS group, while males had higher postattitude scores in the textbook group. With regard to postachievement, I noted that males had higher scores in both groups. A correlation existed between postattitude and postachievement in the STS classroom. In summary, while an association between attitude and achievement was found in the STS classroom, teaching approach or sex was not found to influence attitudes, while sex was also not found to influence achievement. These results, overall, suggest that attitudes are not expected to change on the basis of either teaching approach or gender, and that techniques other than changing the teaching approach would need to be used in order to improve the attitudes of students. Qualitative analysis of an online discussion activity on Energy revealed that STS students were able to apply aspects of chemistry in decision making related to socioscientific issues. Additional analysis of interview and written responses provided insight regarding attitudes toward chemistry, with respect to topics of applicability of chemistry to life, difficulties with chemistry, teaching approach for chemistry, and the intent for enrolling in additional chemistry courses. In addition, the surveys of female students brought out subcategories with regard to emotional and professional characteristics of a good teacher, under the category of characteristics of teaching approach. With respect to the category of course experience, subcategories of useful knowledge to solve real-life problems and knowledge for future career were revealed. The differences between the control group females and STS group females with respect to these characteristics was striking and threw insight into how teacher behavior and teaching approach shape student attitudes to chemistry in case of female students.
Science or Pseudoscience: Does Science Education Demarcate? The Case of Chemistry and Alchemy in Teaching.

ERIC Educational Resources Information Center

Erduran, Sibel

Themes from history and philosophy of chemistry have traditionally been absent in chemistry education. This paper targets the problem of demarcationism within the context of chemistry and alchemy. In so doing, it argues that demarcationism can be an appropriate base for bringing the historical and philosophical aspects of the discipline of…
The Impact of Active and Context-Based Learning in Introductory Chemistry Courses: An Early Evaluation of the Modular Approach

NASA Astrophysics Data System (ADS)

Gutwill-Wise, Joshua P.

2001-05-01

This study evaluates new materials, "modules", for teaching introductory chemistry courses. The modules, under development by faculty from two NSF-funded consortia, employ real-world contexts and an interactive class format to foster conceptual understanding, scientific thinking, and improved attitudes toward science. The evaluation studies were conducted at two institutions, a small college and a large university. The experimental design at each school compared students in a course section taught with modules to those in a section that used a textbook and lecture format. At both schools, students in the modular section outperformed the control group on conceptual problems in chemistry and on scientific thinking problems. Modular section students at the large university also outperformed their peers on the first midterm exam in the subsequent organic chemistry course. Regarding attitudes, the modular section students were more positive about chemistry and the course than their peers in the control section at the small college. However, at the large school, the opposite attitudinal pattern was found. An analysis of informal focus group data provides insight into the negative attitudes in the modular section of the large course. Possible remedies for the issues raised are discussed.
The Efficacy of Problem-Based Learning in an Instrumental Analyse Laboratory

ERIC Educational Resources Information Center

Seyhan, Hatice Güngör

2016-01-01

In the context of the study, an instrumental analysis laboratory course offering Problem-Based Learning (PBL) was designed as an alternative to traditional laboratory practices. The study was conducted with a total of 36 volunteer, prospective chemistry teachers consisting of fourth year undergraduates and graduates. While PBL activities were…
I. Cognitive and Instructional Factors Relating to Students' Development of Personal Models of Chemical Systems in the General Chemistry Laboratory II. Solvation in Supercritical Carbon Dioxide/Ethanol Mixtures Studied by Molecular Dynamics Simulation

ERIC Educational Resources Information Center

Anthony, Seth

2014-01-01

Part I: Students' participation in inquiry-based chemistry laboratory curricula, and, in particular, engagement with key thinking processes in conjunction with these experiences, is linked with success at the difficult task of "transfer"--applying their knowledge in new contexts to solve unfamiliar types of problems. We investigate…
Pre-Service Chemistry Teachers' Competencies in the Laboratory: A Cross-Grade Study in Solution Preparation

ERIC Educational Resources Information Center

Karatas, F. O.

2016-01-01

One of the prerequisites for chemistry teacher candidates is to demonstrate certain laboratory skills. This article aims to determine and discuss the competencies of pre-service chemistry teachers in a chemistry laboratory context working with solution chemistry content. The participants in this study consisted of a group of pre-service chemistry…
Effects of `Environmental Chemistry' Elective Course Via Technology-Embedded Scientific Inquiry Model on Some Variables

NASA Astrophysics Data System (ADS)

Çalik, Muammer; Özsevgeç, Tuncay; Ebenezer, Jazlin; Artun, Hüseyin; Küçük, Zeynel

2014-06-01

The purpose of this study is to examine the effects of `environmental chemistry' elective course via Technology-Embedded Scientific Inquiry (TESI) model on senior science student teachers' (SSSTs) conceptions of environmental chemistry concepts/issues, attitudes toward chemistry, and technological pedagogical content knowledge (TPACK) levels. Within one group pre-test-post-test design, the study was conducted with 117 SSSTs (68 females and 49 males—aged 21-23 years) enrolled in an `environmental chemistry' elective course in the spring semester of 2011-2012 academic-years. Instruments for data collection comprised of Environmental Chemistry Conceptual Understanding Questionnaire, TPACK survey, and Chemistry Attitudes and Experiences Questionnaire. Significant increases in the SSSTs' conceptions of environmental chemistry concepts/issues, attitudes toward chemistry, and TPACK levels are attributed to the SSSTs learning how to use the innovative technologies in the contexts of the `environmental chemistry' elective course and teaching practicum. The study implies that the TESI model may serve a useful purpose in experimental science courses that use the innovative technologies. However, to generalize feasibility of the TESI model, it should be evaluated with SSSTs in diverse learning contexts.
Transforming Undergraduate Students into Junior Researchers: Oxidation-Reduction Sequence as a Problem-Based Case Study

ERIC Educational Resources Information Center

Saloranta, Tiina; Lo¨nnqvist, Jan-Erik; Eklund, Patrik C.

2016-01-01

In our upper-level undergraduate laboratory course in organic chemistry we focus on a research-oriented task in a context-based and problem-based learning approach. The course starts with a preliminary training period where the students learn how to safely and independently perform synthesis and purification procedures and to operate the most…
Classroom Action Research on Formative Assessment in a Context-Based Chemistry Course

ERIC Educational Resources Information Center

Vogelzang, Johannes; Admiraal, Wilfried F.

2017-01-01

Context-based science courses stimulate students to reconstruct the information presented by connecting to their prior knowledge and experiences. However, students need support. Formative assessments inform both teacher and students about students' knowledge deficiencies and misconceptions and how students can be supported. Research on formative…
Quantitative Analysis of Science and Chemistry Textbooks for Indicators of Reform: A complementary perspective

NASA Astrophysics Data System (ADS)

Kahveci, Ajda

2010-07-01

In this study, multiple thematically based and quantitative analysis procedures were utilized to explore the effectiveness of Turkish chemistry and science textbooks in terms of their reflection of reform. The themes gender equity, questioning level, science vocabulary load, and readability level provided the conceptual framework for the analyses. An unobtrusive research method, content analysis, was used by coding the manifest content and counting the frequency of words, photographs, drawings, and questions by cognitive level. The context was an undergraduate chemistry teacher preparation program at a large public university in a metropolitan area in northwestern Turkey. Forty preservice chemistry teachers were guided to analyze 10 middle school science and 10 high school chemistry textbooks. Overall, the textbooks included unfair gender representations, a considerably higher number of input and processing than output level questions, and high load of science terminology. The textbooks failed to provide sufficient empirical evidence to be considered as gender equitable and inquiry-based. The quantitative approach employed for evaluation contrasts with a more interpretive approach, and has the potential in depicting textbook profiles in a more reliable way, complementing the commonly employed qualitative procedures. Implications suggest that further work in this line is needed on calibrating the analysis procedures with science textbooks used in different international settings. The procedures could be modified and improved to meet specific evaluation needs. In the Turkish context, next step research may concern the analysis of science textbooks being rewritten for the reform-based curricula to make cross-comparisons and evaluate a possible progression.
Characterizing Teaching Assistants' Knowledge and Beliefs Following Professional Development Activities within an Inquiry-Based General Chemistry Context

ERIC Educational Resources Information Center

Wheeler, Lindsay B.; Maeng, Jennifer L.; Whitworth, Brooke A.

2017-01-01

The purpose of this investigation was to explore changes in undergraduate and graduate teaching assistants' (TAs') content knowledge and beliefs about teaching within the context of an inquiry-based laboratory course. TAs received professional development (PD), which was informed by the TA training literature base and was designed for TAs…
Teachers and Students' Conceptions of Computer-Based Models in the Context of High School Chemistry: Elicitations at the Pre-Intervention Stage

ERIC Educational Resources Information Center

Waight, Noemi; Gillmeister, Kristina

2014-01-01

This study examined teachers' and students' initial conceptions of computer-based models--Flash and NetLogo models--and documented how teachers and students reconciled notions of multiple representations featuring macroscopic, submicroscopic and symbolic representations prior to actual intervention in eight high school chemistry…
Students' Science Attitudes, Beliefs, and Context: Associations with Science and Chemistry Aspirations

ERIC Educational Resources Information Center

Mujtaba, Tamjid; Sheldrake, Richard; Reiss, Michael J.; Simon, Shirley

2018-01-01

There is a widespread concern that relatively few students, especially those from disadvantaged backgrounds, continue to study chemistry and other science subjects after compulsory education. Yet it remains unclear how different aspects of students' background and home context, their own attitudes and beliefs, and their experiences of particular…
Teaching High School Chemistry in the Context of Pharmacology Helps Both Teachers and Students Learn

PubMed Central

Schwartz-Bloom, Rochelle D.; Halpin, Myra J.; Reiter, Jerome P.

2014-01-01

Few studies demonstrate the impact of teaching chemistry embedded in a context that has relevance to high school students. We build upon our prior work showing that pharmacology topics (i.e., drugs), which are inherently interesting to high school students, provide a useful context for teaching chemistry and biology. In those studies, teachers were provided professional development for the Pharmacology Education Partnership (PEP) in an onsite venue (either five-day or one-day workshop). Given financial difficulties to travel, teachers have asked for alternatives for professional development. Thus, we developed the same PEP training workshop using a distance learning (DL) (two-way live video) approach. In this way, 121 chemistry and biology teachers participated in the DL workshops to learn how to incorporate the PEP modules into their teaching. They field-tested the modules over the year in high school chemistry and biology classes. Teacher knowledge of chemistry and biology increased significantly after the workshop and was maintained for at least a year. Their students (N = 2309) demonstrated a significant increase in knowledge of chemistry and biology concepts, with higher scores as the number of modules used increased. The increase in both teacher and student knowledge in these subjects was similar to that found previously when teachers were provided with onsite professional development. PMID:24882881
Now for the Science Bit: Implementing Community-Based Learning in Chemistry

ERIC Educational Resources Information Center

McDonnell, Claire; Ennis, Patricia; Shoemaker, Leslie

2011-01-01

Purpose: The purpose of this paper is to contribute to the understanding of student learning from community engagement by critically assessing the implementation of this pedagogical approach in the context of teaching and learning chemistry and also evaluating the role of personal development in student-community engagement.…

Using a Thematic Laboratory-Centered Curriculum to Teach General Chemistry

ERIC Educational Resources Information Center

Hopkins, Todd A.; Samide, Michael

2013-01-01

This article describes an approach to general chemistry that involves teaching chemical concepts in the context of two thematic laboratory modules: environmental remediation and the fate of pharmaceuticals in the environment. These modules were designed based on active-learning pedagogies and involve multiple-week projects that dictate what…
You Said "Neutral", but What Do You Mean?

ERIC Educational Resources Information Center

Jasien, Paul G.

2010-01-01

Using the term "neutral" as an example, this discussion examines difficulties that chemistry students face when trying to contextualize chemical terminology. Interview responses of 20 undergraduate students (majors in either chemistry or biology) indicate that some of students' context-based interpretations of "neutral" are shared, although up to…
Process-Oriented Guided Inquiry Learning (POGIL) as a Culturally Relevant Pedagogy (CRP) in Qatar: a Perspective from Grade 10 Chemistry Classes

NASA Astrophysics Data System (ADS)

Treagust, David F.; Qureshi, Sheila S.; Vishnumolakala, Venkat Rao; Ojeil, Joseph; Mocerino, Mauro; Southam, Daniel C.

2018-04-01

Educational reforms in Qatar have seen the implementation of inquiry-based learning and other student-centred pedagogies. However, there have been few efforts to investigate how these adopted western pedagogies are aligned with the high context culture of Qatar. The study presented in this article highlights the implementation of a student-centred intervention called Process-Oriented Guided Inquiry Learning (POGIL) in selected independent Arabic government schools in Qatar. The study followed a theoretical framework composed of culturally relevant pedagogical practice and social constructivism in teaching and learning. A mixed method research design involving experimental and comparison groups was utilised. Carefully structured learning materials when implemented systematically in a POGIL intervention helped Grade 10 science students improve their perceptions of chemistry learning measured from pre- and post-tests as measured by the What Is Happening In this Class (WIHIC) questionnaire and school-administered achievement test. The study further provided school-based mentoring and professional development opportunities for teachers in the region. Significantly, POGIL was found to be adaptable in the Arabic context.
Teaching Thinking Skills in Context-Based Learning: Teachers' Challenges and Assessment Knowledge

ERIC Educational Resources Information Center

Avargil, Shirly; Herscovitz, Orit; Dori, Yehudit Judy

2012-01-01

For an educational reform to succeed, teachers need to adjust their perceptions to the reform's new curricula and strategies and cope with new content, as well as new teaching and assessment strategies. Developing students' scientific literacy through context-based chemistry and higher order thinking skills was the framework for establishing a new…
Development and Evaluation of a Chemistry-Specific Version of the Academic Motivation Scale (AMS-Chemistry)

ERIC Educational Resources Information Center

Liu, Yujuan; Ferrell, Brent; Barbera, Jack; Lewis, Jennifer E.

2017-01-01

Fundamentally concerned with motivation, self-determination theory (SDT) represents a framework of several mini-theories to explore how social context interacts with people's motivational types categorized by degree of regulation internalization. This paper aims to modify an existing theory-based instrument (Academic Motivation Scale, or AMS) and…
Investigating Students' Success in Solving and Attitudes towards Context-Rich Open-Ended Problems in Chemistry

ERIC Educational Resources Information Center

Overton, Tina L.; Potter, Nicholas M.

2011-01-01

Much research has been carried out on how students solve algorithmic and structured problems in chemistry. This study is concerned with how students solve open-ended, ill-defined problems in chemistry. Over 200 undergraduate chemistry students solved a number of open-ended problem in groups and individually. The three cognitive variables of…
Explaining Secondary School Students' Attitudes towards Chemistry in Chile

ERIC Educational Resources Information Center

Montes, L. H.; Ferreira, R. A.; Rodríguez, C.

2018-01-01

Research into attitudes towards chemistry in Latin America and indeed towards science in general is very limited. The present study aimed to adapt and validate a shortened version of Bauer's Attitude toward the Subject of Chemistry Inventory version 2 (ASCIv2) for use in a Latin American context. It also explored attitudes towards chemistry of…
Developing and Implementing Inquiry-Based, Water Quality Laboratory Experiments for High School Students to Explore Real Environmental Issues Using Analytical Chemistry

ERIC Educational Resources Information Center

Mandler, Daphna; Blonder, Ron; Yayon, Malka; Mamlok-Naaman, Rachel; Hofstein, Avi

2014-01-01

This paper describes the rationale and the implementation of five laboratory experiments; four of them, intended for high-school students, are inquiry-based activities that explore the quality of water. The context of water provides students with an opportunity to study the importance of analytical methods and how they influence our everyday…
Turkish Chemistry Teachers' Views about an Implementation of the Active Learning Approaches in Their Lessons

ERIC Educational Resources Information Center

Karamustafaoglu, Sevilay; Costu, Bayram; Ayas, Alipasa

2006-01-01

Active learning is advocated as a better way of teaching for several decades in science education. The purpose of this study was to determine chemistry teachers' thinking and views about student-centered activities applicable in chemistry teaching and learning in the study context. A case study approach was used in this research. At the beginning,…
Effect of Scientific Argumentation on the Development of Scientific Process Skills in the Context of Teaching Chemistry

ERIC Educational Resources Information Center

Gultepe, Nejla; Kilic, Ziya

2015-01-01

This study was conducted in order to determine the differences in integrated scientific process skills (designing experiments, forming data tables, drawing graphs, graph interpretation, determining the variables and hypothesizing, changing and controlling variables) of students (n = 17) who were taught with an approach based on scientific…
Classroom Implementation of Context-Based Chemistry Education by Teachers: The Relation between Experiences of Teachers and the Design of Materials

ERIC Educational Resources Information Center

Vos, Martin Anton Jozef; Taconis, Ruurd; Jochems, Wim M. G.; Pilot, Albert

2011-01-01

Worldwide, a tendency is visible in which upper secondary science curricula are innovated in the direction of context-based education. Crucial to these innovations is the way teachers interact with newly developed teaching materials and implement them in classroom practice. The focus of our research is to identify characteristics of the…
Internationalisation of the Chemistry Curriculum: Two Problem-Based Learning Activities for Undergraduate Chemists

ERIC Educational Resources Information Center

Overton, Tina L.; Bradley, John S.

2010-01-01

In this paper we describe the development and evaluation of two activities for delivery in first year B.Sc. and M.Chem. degree courses, in which we introduced an international context representing either a linguistic or a cultural modification to the previously developed case studies. The case studies focus on an industrial and an environmental…
Integrating Model-Based Learning and Animations for Enhancing Students' Understanding of Proteins Structure and Function

ERIC Educational Resources Information Center

Barak, Miri; Hussein-Farraj, Rania

2013-01-01

This paper describes a study conducted in the context of chemistry education reforms in Israel. The study examined a new biochemistry learning unit that was developed to promote in-depth understanding of 3D structures and functions of proteins and nucleic acids. Our goal was to examine whether, and to what extent teaching and learning via…
Students' Application of Chemical Concepts When Solving Chemistry Problems in Different Contexts

ERIC Educational Resources Information Center

Broman, Karolina; Parchmann, Ilka

2014-01-01

Context-based learning approaches have been implemented in school science over the last 40 years as a way to enhance students' interest in, as well as learning outcomes from, science. Contexts are used to connect science with the students' lives and to provide a frame in which concepts can be learned and applied on a…
An Approach to Teaching General Chemistry II that Highlights the Interdisciplinary Nature of Science

ERIC Educational Resources Information Center

Sumter, Takita Felder; Owens, Patrick M.

2011-01-01

The need for a revised curriculum within the life sciences has been well-established. One strategy to improve student preparation in the life sciences is to redesign introductory courses like biology, chemistry, and physics so that they better reflect their disciplinary interdependence. We describe a medically relevant, context-based approach to…
Teaching Assistants' Perceptions of a Training to Support an Inquiry-Based General Chemistry Laboratory Course

ERIC Educational Resources Information Center

Wheeler, Lindsay B.; Maeng, Jennifer L.; Whitworth, Brooke A.

2015-01-01

The purpose of this qualitative investigation was to better understand teaching assistants' (TAs') perceptions of training in a guided inquiry undergraduate general chemistry laboratory context. The training was developed using existing TA training literature and informed by situated learning theory. TAs engaged in training prior to teaching (~25…
Increasing Interactivity and Authenticity of Chemistry Instruction through Data Acquisition Systems and Other Technologies

ERIC Educational Resources Information Center

Milner-Bolotin, Marina

2012-01-01

Interactivity and inquiry-based learning science are effective ways of helping students overcome their perception of chemistry as an alien and abstract topic and instead approach the subject as a creative way of understanding ideas and applying mastered concepts to new contexts. Data acquisition systems are an extremely useful form of educational…
Creating a Context for Chemistry

NASA Astrophysics Data System (ADS)

Truman Schwartz, A.

Until relatively recently, the teaching of chemistry at the college and university level in the United States has been quite traditional and oriented primarily toward the preparation of chemists. Students not concentrating in the sciences have often been poorly served by existing courses. Chemistry in Context: Applying Chemistry to Society, a textbook for nonscience majors developed under the sponsorship of the American Chemical Society, is an effort to address the needs and interests of this audience. The book introduces the phenomena and principles of chemistry within the context of socially significant issues such as global warming, ozone depletion, alternate energy sources, nutrition, and genetic engineering. The chemistry is presented as needed to inform an understanding of the central topics, and the text features student-centered activities designed to promote critical thinking and risk-benefit analysis as well as an understanding of chemical principles. This paper summarizes the origin, development, content, pedagogy, evaluation, and influence of Chemistry in Context and considers its potential implications for other disciplines and the instruction of science majors.
Chemistry in Context: Analysis of Thematic Chemistry Videos Available Online

ERIC Educational Resources Information Center

Christensson, Camilla; Sjöström, Jesper

2014-01-01

United Nations declared 2011 to be the International Year of Chemistry. The Swedish Chemical Society chose twelve themes, one for each month, to highlight the connection of chemistry with everyday life. Examples of themes were fashion, climate change, love, sports, communication, health issues, and food. From the themes various context-based…
Perfectly Reasonable in a Practical World: Understanding Chemistry Teacher Responses to a Change Proposal

NASA Astrophysics Data System (ADS)

Westbroek, Hanna; Janssen, Fred; Doyle, Walter

2017-12-01

Curriculum ideals often get compromised as a curriculum moves through its various levels of representation. Across the different science reforms, this process of slippage is clearly present. Research shows that teacher subject matter knowledge, PCK, beliefs and context factors all influence implementation. Professional development arrangements focus on fixing deficiencies in teachers' knowledge, beliefs or work context. This approach has not solved the problem of slippage, as we still do not understand what mechanisms operate when teachers make decisions about change proposals. In this study, we unpacked the decision mechanisms of three highly qualified chemistry teachers who subsequently adapted an innovative context-based chemistry unit. In spite of a state of the art professional development arrangement and the teachers being highly qualified, slippage occurred. The teachers' goal systems were used to interpret their reasoning. A goal system is a context-dependent, within-person mental construct that consists of a hierarchy of a person's goals and means in pursuit of a task. We showed that all three teachers adopted or redesigned elements of the change proposals to meet their core goals, i.e., goals that had multiple connections with other goals. This indicated that the adaptations teachers made were perfectly reasonable ways to serve their professional goals. For change to happen, we contend that one should begin with ways to connect teachers' core goals with the lesson or unit goal demands of a proposed innovation. Change emerges from the adaptions teachers make in the service of their core goals.

Time-dependent interstellar chemistry

NASA Technical Reports Server (NTRS)

Glassgold, A. E.

1985-01-01

Some current problems in interstellar chemistry are considered in the context of time-dependent calculations. The limitations of steady-state models of interstellar gas-phase chemistry are discussed, and attempts to chemically date interstellar clouds are reviewed. The importance of studying the physical and chemical properties of interstellar dust is emphasized. Finally, the results of a series of studies of collapsing clouds are described.
Students' Understanding of Mathematical Expressions in Physical Chemistry Contexts: An Analysis Using Sherin's Symbolic Forms

ERIC Educational Resources Information Center

Becker, Nicole; Towns, Marcy

2012-01-01

Undergraduate physical chemistry courses require students to be proficient in calculus in order to develop an understanding of thermodynamics concepts. Here we present the findings of a study that examines student understanding of mathematical expressions, including partial derivative expressions, in two undergraduate physical chemistry courses.…
Holistic Metrics for Assessment of the Greenness of Chemical Reactions in the Context of Chemical Education

ERIC Educational Resources Information Center

Ribeiro, M. Gabriela T. C.; Machado, Adelio A. S. C.

2013-01-01

Two new semiquantitative green chemistry metrics, the green circle and the green matrix, have been developed for quick assessment of the greenness of a chemical reaction or process, even without performing the experiment from a protocol if enough detail is provided in it. The evaluation is based on the 12 principles of green chemistry. The…
Cooperative and Context-Based Learning on Eletrochemical Cells in Lower Secondary Chemistry: A Project of Participatory Action Research

ERIC Educational Resources Information Center

Markic, Silvija; Eilks, Ingo

2006-01-01

This paper discusses a project of Participatory Action Research (PAR) on lower secondary chemistry education. In this ongoing project, practicing teachers and university researchers in chemical education jointly carry out projects for developing and evaluating new lesson plans. The focus of the PAR group is to develop teaching/learning activities…
Development and assessment of a chemistry-based computer video game as a learning tool

NASA Astrophysics Data System (ADS)

Martinez-Hernandez, Kermin Joel

The chemistry-based computer video game is a multidisciplinary collaboration between chemistry and computer graphics and technology fields developed to explore the use of video games as a possible learning tool. This innovative approach aims to integrate elements of commercial video game and authentic chemistry context environments into a learning experience through gameplay. The project consists of three areas: development, assessment, and implementation. However, the foci of this study were the development and assessment of the computer video game including possible learning outcomes and game design elements. A chemistry-based game using a mixed genre of a single player first-person game embedded with action-adventure and puzzle components was developed to determine if students' level of understanding of chemistry concepts change after gameplay intervention. Three phases have been completed to assess students' understanding of chemistry concepts prior and after gameplay intervention. Two main assessment instruments (pre/post open-ended content survey and individual semi-structured interviews) were used to assess student understanding of concepts. In addition, game design elements were evaluated for future development phases. Preliminary analyses of the interview data suggest that students were able to understand most of the chemistry challenges presented in the game and the game served as a review for previously learned concepts as well as a way to apply such previous knowledge. To guarantee a better understanding of the chemistry concepts, additions such as debriefing and feedback about the content presented in the game seem to be needed. The use of visuals in the game to represent chemical processes, game genre, and game idea appear to be the game design elements that students like the most about the current computer video game.
Exploring the Progression in Preservice Chemistry Teachers' Pedagogical Content Knowledge Representations: The Case of "Behavior of Gases"

ERIC Educational Resources Information Center

Adadan, Emine; Oner, Diler

2014-01-01

This multiple case study investigated how two preservice chemistry teachers' pedagogical content knowledge (PCK) representations of behavior of gases progressed in the context of a semester-long chemistry teaching methods course. The change in the participants' PCK components was interpreted with respect to the theoretical PCK learning…
General Chemistry Students' Goals for Chemistry Laboratory Coursework

ERIC Educational Resources Information Center

DeKorver, Brittland K.; Towns, Marcy H.

2015-01-01

Little research exists on college students' learning goals in chemistry, let alone specifically pertaining to laboratory coursework. Because students' learning goals are linked to achievement and dependent on context, research on students' goals in the laboratory context may lead to better understanding about the efficacy of lab curricula. This…
There Is Another Choice: An Exploration of Integrating Formative Assessment in a Chinese High School Chemistry Classroom through Collaborative Action Research

ERIC Educational Resources Information Center

Yin, Xinying; Buck, Gayle A.

2015-01-01

This study explored integrating formative assessment to a Chinese high school chemistry classroom, where the extremely high-stakes testing and Confucian-heritage culture constituted a particular context, through a collaborative action research. One researcher worked with a high school chemistry teacher in China to integrate formative assessment…
Questioning Behavior of Students in the Inquiry Chemistry Laboratory: Differences between Sectors and Genders in the Israeli Context

ERIC Educational Resources Information Center

Blonder, Ron; Rap, Shelley; Mamlok-Naaman, Rachel; Hofstein, Avi

2015-01-01

The present research is part of a longitude research study regarding the questioning behavior of students in the inquiry chemistry laboratory in Israel. We found that students who were involved in learning chemistry by the inquiry method ask more and higher-level questions. However, throughout the years, we have observed that differences between…
Opera and Poison: A Secret and Enjoyable Approach to Teaching and Learning Chemistry

ERIC Educational Resources Information Center

Andre, Joao Paulo

2013-01-01

The storyline of operas, with historical or fictional characters, often include potions and poisons. This has prompted a study of the chemistry behind some operatic plots. The results were originally presented as a lecture given at the University of Minho in Portugal, within the context of the International Year of Chemistry. The same lecture was…
Plumbing the depths of batholiths

USGS Publications Warehouse

Zen, E.-A.

1989-01-01

Knowledge of the pressure of consolidation of a pluton and the pressure-time history of magmatic evolution should allow better understanding of the tectonic and thermal history of the crust. Available methods to estimate pressures of plutons are mainly for those of consolidation. These are either extrinsic, based on geological context, or intrinsic, based on mineral texture, mineral assemblage, fluid inclusions, mineral inclusions, apparent cooling rates, and mineral chemistry. The methods of lattice-dimension matching of mineral inclusions and of detailed chemistry for zoned minerals could lead to pressure-time reconstructions. Future barometers based on mineral chemistry should use atomic species that have low diffusion coefficients and whose values are not sensitive to computational schemes and cumulative analytical errors. Aluminum and silicon in coexisting hornblende, biotite, pyroxene, plagioclase, or garnet are reasonable candidate phases for barometry. -from Author
High School Students' Engagement in Planning Investigations: Findings from a Longitudinal Study in Spain

ERIC Educational Resources Information Center

Crujeiras-Pérez, B.; Jiménez-Aleixandre, M. P.

2017-01-01

This paper examines the process of high school students' planning investigations in the chemistry laboratory across two consecutive academic years in terms of their actions and their progress. The context is a set of five inquiry-based laboratory tasks in which participants (9th and 10th graders, 14-15 and 15-16 years of age) are required to plan…
The Analysis of a Murder, a Case Study

ERIC Educational Resources Information Center

Dinan, Frank J.; Szczepankiewicz, Steven H.; Carnaham, Melinda; Colvin, Michael T.

2007-01-01

The analysis of a Murder case study can be used in general chemistry or nonscience major chemistry courses to teach data handling and analysis in a non-laboratory context. This case study will help students to respond more enthusiastically and with more interest to a set of material placed before them related to a real case rather than…
Argumentative Discourse in a High School Chemistry Classroom

ERIC Educational Resources Information Center

Abi-El-Mona, Issam; Abd-El-Khalick, Fouad

2006-01-01

This study aimed to identify the types of arguments promoted in various contexts common to a high school chemistry classroom, including lecture-discussion and laboratory activities. The study was guided by the following research question: What types of argument structures and schemes, if any, are promoted and engaged by students within various…
Exploring the Everyday Context of Chemical Elements: Discovering the Elements of Car Components

ERIC Educational Resources Information Center

Franco-Mariscal, Antonio Joaquín

2015-01-01

This paper presents a project about the chemical elements made by 15-year-old Spanish high school students of Chemistry. It focuses on context-based teaching combined with the advantages of creating a large mural which subsequently is exposed in the school. The project consisted of researching the chemical elements in the different materials that…
Developing 21st century skills in chemistry classrooms: Opportunities and challenges of STEAM integration

NASA Astrophysics Data System (ADS)

Hadinugrahaningsih, Tritiyatma; Rahmawati, Yuli; Ridwan, Achmad

2017-08-01

The paper portrays the first year of two-year study in integration Science, Technology, Engineering, Art, and Mathematics (STEAM) in chemistry learning. The research focused on developing 21st-century skills of chemistry students in secondary schools. The 21st-century skills as a set of abilities that students need to develop in facing the future challenge which involves learning, literacy, and life skills. The study was conducted in two secondary schools both public and private school in topics of hydrocarbon, petroleum, solubility, and acid base in year 10 and 11. The qualitative methodology was applied to explore the students' learning experiences and understanding the research context. Data was collected through observation, interview, reflective journal, and 21st-century rubric. The STEAM approach was integrated through modification of project-based learning model. The students had opportunities to develop their own projects by integrating chemistry and STEAM principles to their project. The results show that students have developed their critical and creative thinking, problem-solving skills, collaboration and argumentation skills, leadership and responsibility, information and literacy skills. The researchers faced the challenges of integrating STEAM within the chemistry curricula, empowering students, and managing the teaching and time resources. Students have started to challenge their critical and creative thinking within the existing learning environments. Integrating STEAM into chemistry learning has developed students' 21st-century skills in those three areas. Teachers also learned to develop their competencies for being facilitators and agents of change, in addition to skills development in dealing with students' differences.
Citrus Quality Control: An NMR/MRI Problem-Based Experiment

ERIC Educational Resources Information Center

Erhart, Sarah E.; McCarrick, Robert M.; Lorigan, Gary A.; Yezierski, Ellen J.

2016-01-01

An experiment seated in an industrial context can provide an engaging framework and unique learning opportunity for an upper-division physical chemistry laboratory. An experiment that teaches NMR/MRI through a problem-based quality control of citrus products was developed. In this experiment, using a problem-based learning (PBL) approach, students…
Dragonfly: In Situ Exploration of Titan's Organic Chemistry and Habitability

NASA Astrophysics Data System (ADS)

Turtle, E. P.; Barnes, J. W.; Trainer, M. G.; Lorenz, R. D.

2017-12-01

Titan's abundant complex carbon-rich chemistry, interior ocean, and past presence of liquid water on the surface make it an ideal destination to study prebiotic chemical processes and document the habitability of an extraterrestrial environment. Titan exploration is a high science priority due to the level of organic synthesis that it supports. Moreover, opportunities for organics to have interacted with liquid water at the surface (e.g., in impact melt sheets) increase the potential for chemical processes to progress further, providing an unparalleled opportunity to investigate prebiotic chemistry, as well as to search for signatures of potential water-based or even hydrocarbon-based life. The diversity of Titan's surface materials and environments drives the scientific need to be able to sample a variety of locations, thus mobility is key for in situ measurements. Titan's atmosphere is 4 times denser than Earth's reducing the wing/rotor area required to generate a given amount of lift, and the low gravity reduces the required magnitude of lift, making heavier-than-air mobility highly efficient. Dragonfly is a rotorcraft lander mission proposed to NASA's New Frontiers Program to take advantage of Titan's unique natural laboratory to understand how far chemistry can progress in environments that provide key ingredients for life. Measuring the compositions of materials in different environments will reveal how far organic chemistry has progressed. Surface material can be sampled into a mass spectrometer to identify the chemical components available and processes at work to produce biologically relevant compounds. Bulk elemental surface composition can be determined by a neutron-activated gamma-ray spectrometer. Meteorology measurements can characterize Titan's atmosphere and diurnal and spatial variations therein. Geologic features can be characterized via remote-sensing observations, which also provide context for samples. Seismic sensing can probe subsurface structure and activity. In addition to surface investigations, Dragonfly can perform measurements during flight, including atmospheric profiles and aerial observations of surface geology, which also provide sampling context and scouting for landing sites.
Chemistry Vocabulary Attainment among Higher Secondary Students

ERIC Educational Resources Information Center

Gafoor, K. Abdul; Greeshma, K.

2014-01-01

In the context of growing empirical evidence to lack of clear understanding of the language of the science content, undesirable student outcomes including difficulty in learning science and a lack of interest with their science content area, and chemistry being particularly loaded with specialized terminology of its own, this study analyzed the…
Thinking about online sources: Exploring students' epistemic cognition in internet-based chemistry learning

NASA Astrophysics Data System (ADS)

Dai, Ting

This dissertation investigated the relation between epistemic cognition---epistemic aims and source beliefs---and learning outcome in an Internet--based research context. Based on a framework of epistemic cognition (Chinn, Buckland, & Samarapungavan, 2011), a context--specific epistemic aims and source beliefs questionnaire (CEASBQ) was developed and administered to 354 students from college--level introductory chemistry courses. A series of multitrait--multimethod model comparisons provided evidence for construct convergent and discriminant validity for three epistemic aims--- true beliefs, justified beliefs, explanatory connection, which were all distinguished from, yet correlated with, mastery goals. Students' epistemic aims were specific to the chemistry topics in research. Multidimensional scaling results indicated that students' source evaluation was based on two dimensions--- professional expertise and first--hand knowledge, suggesting a multidimensional structure of source beliefs. Most importantly, online learning outcome was found to be significantly associated with two epistemic aims---justified beliefs and explanatory connection: The more students sought justifications in the online research, the lower they tended to score on the learning outcome measure, whereas the more students sought explanatory connections between information, the higher they scored on the outcome measure. There was a significant but small positive association between source beliefs and learning outcome. The influences of epistemic aims and source beliefs on learning outcome were found to be above and beyond the effects of a number of covariates, including prior knowledge and perceived ability with online sources.

Students' Energy Understanding Across Biology, Chemistry, and Physics Contexts

NASA Astrophysics Data System (ADS)

Opitz, S. T.; Neumann, K.; Bernholt, S.; Harms, U.

2017-07-01

Energy is considered both as a disciplinary core idea and as a concept cutting across science disciplines. Most previous approaches studied progressing energy understanding in specific disciplinary contexts, while disregarding the relation of understanding across them. Hence, this study provides a systematic analysis of cross-disciplinary energy learning. On the basis of a cross-sectional study with n = 742 students from grades 6, 8, and 10, we analyze students' progression in understanding energy across biology, chemistry, and physics contexts. The study is guided by three hypothetical scenarios that describe how the connection between energy understanding in the three disciplinary contexts changes across grade levels. These scenarios are compared using confirmatory factor analysis (CFA). The results suggest that, from grade 6 to grade 10, energy understanding in the three disciplinary contexts is highly interrelated, thus indicating a parallel progression of energy understanding in the three disciplinary contexts. In our study, students from grade 6 onwards appeared to have few problems to apply one energy understanding across the three disciplinary contexts. These findings were unexpected, as previous research concluded that students likely face difficulties in connecting energy learning across disciplinary boundaries. Potential reasons for these results and the characteristics of the observed cross-disciplinary energy understanding are discussed in the light of earlier findings and implications for future research, and the teaching of energy as a core idea and a crosscutting concept are addressed.
Teaching Applied Chemistry in a Pollution Control Context.

ERIC Educational Resources Information Center

Sell, Nancy J.

1982-01-01

Discusses rationale behind and content of a course (Industrial Pollution Control Techniques) combining knowledge from fields of industrial chemistry and chemical engineering and utilizing this knowledge in the context of understanding pollution problems and potential methods of pollution control. (Author/SK)
Exploring Zimbabwean Advanced Level Chemistry Students' Approaches to Investigations from a Learning Perspective

ERIC Educational Resources Information Center

Chirikure, Tamirirofa; Hobden, Paul; Hobden, Sally

2018-01-01

In this paper we report on the findings of a study on Advanced Level Chemistry students' approaches to investigations from a learning perspective in the Zimbabwean educational context. Students' approaches to investigations are inextricably linked to the quality of learning and performances in these practical activities. An explanatory…
The Development of Dalton's Atomic Theory as a Case Study in the History of Science: Reflections for Educators in Chemistry

NASA Astrophysics Data System (ADS)

Viana, Hélio Elael Bonini; Porto, Paulo Alves

2010-01-01

The inclusion of the history of science in science curricula—and specially, in the curricula of science teachers—is a trend that has been followed in several countries. The reasons advanced for the study of the history of science are manifold. This paper presents a case study in the history of chemistry, on the early developments of John Dalton’s atomic theory. Based on the case study, several questions that are worth discussing in educational contexts are pointed out. It is argued that the kind of history of science that was made in the first decades of the twentieth century (encyclopaedic, continuist, essentially anachronistic) is not appropriate for the development of the competences that are expected from the students of sciences in the present. Science teaching for current days will benefit from the approach that may be termed the “new historiography of science”.
Carbohydrate CuAAC click chemistry for therapy and diagnosis.

PubMed

He, Xiao-Peng; Zeng, Ya-Li; Zang, Yi; Li, Jia; Field, Robert A; Chen, Guo-Rong

2016-06-24

Carbohydrates are important as signaling molecules and for cellular recognition events, therefore offering scope for the development of carbohydrate-mimetic diagnostics and drug candidates. As a consequence, the construction of carbohydrate-based bioactive compounds and sensors has become an active research area. While the advent of click chemistry has greatly accelerated the progress of medicinal chemistry and chemical biology, recent literature has seen an extensive use of such approaches to construct functionally diverse carbohydrate derivatives. Here we summarize some of the progress, covering the period 2010 to mid-2015, in Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition CuAAC "click chemistry" of carbohydrate derivatives, in the context of potential therapeutic and diagnostic tool development. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Potential Role of Inorganic Confined Environments in Prebiotic Phosphorylation.

PubMed

Dass, Avinash Vicholous; Jaber, Maguy; Brack, André; Foucher, Frédéric; Kee, Terence P; Georgelin, Thomas; Westall, Frances

2018-03-05

A concise outlook on the potential role of confinement in phosphorylation and phosphate condensation pertaining to prebiotic chemistry is presented. Inorganic confinement is a relatively uncharted domain in studies concerning prebiotic chemistry, and even more so in terms of experimentation. However, molecular crowding within confined dimensions is central to the functioning of contemporary biology. There are numerous advantages to confined environments and an attempt to highlight this fact, within this article, has been undertaken, keeping in context the limitations of aqueous phase chemistry in phosphorylation and, to a certain extent, traditional approaches in prebiotic chemistry.
Potential Role of Inorganic Confined Environments in Prebiotic Phosphorylation

PubMed Central

Jaber, Maguy; Brack, André; Foucher, Frédéric; Kee, Terence P.; Westall, Frances

2018-01-01

A concise outlook on the potential role of confinement in phosphorylation and phosphate condensation pertaining to prebiotic chemistry is presented. Inorganic confinement is a relatively uncharted domain in studies concerning prebiotic chemistry, and even more so in terms of experimentation. However, molecular crowding within confined dimensions is central to the functioning of contemporary biology. There are numerous advantages to confined environments and an attempt to highlight this fact, within this article, has been undertaken, keeping in context the limitations of aqueous phase chemistry in phosphorylation and, to a certain extent, traditional approaches in prebiotic chemistry. PMID:29510574
Thinking Processes Associated with Undergraduate Chemistry Students' Success at Applying a Molecular-Level Model in a New Context

ERIC Educational Resources Information Center

Teichert, Melonie A.; Tien, Lydia T.; Dysleski, Lisa; Rickey, Dawn

2017-01-01

This study investigated relationships between the thinking processes that 28 undergraduate chemistry students engaged in during guided discovery and their subsequent success at reasoning through a transfer problem during an end-of-semester interview. During a guided-discovery laboratory module, students were prompted to use words, pictures, and…
Evolution of Instrumentation for the Study of Gas-Phase Ion/Ion Chemistry via Mass Spectrometry

PubMed Central

Xia, Yu; McLuckey, Scott A.

2008-01-01

The scope of gas phase ion/ion chemistry accessible to mass spectrometry is largely defined by the available tools. Due to the development of novel instrumentation, a wide range of reaction phenomenologies have been noted, many of which have been studied extensively and exploited for analytical applications. This perspective presents the development of mass spectrometry-based instrumentation for the study of the gas phase ion/ion chemistry in which at least one of the reactants is multiply-charged. The instrument evolution is presented within the context of three essential elements required for any ion/ion reaction study: the ionization source(s), the reaction vessel or environment, and the mass analyzer. Ionization source arrangements have included source combinations that allow for reactions between multiply charged ions of one polarity and singly charged ions of opposite polarity, arrangements that enable the study of reactions of multiply charged ions of opposite polarity, and most recently, arrangements that allow for ion formation from more than two ion sources. Gas phase ion/ion reaction studies have been performed at near atmospheric pressure in flow reactor designs and within electrodynamic ion traps operated in the mTorr range. With ion trap as a reaction vessel, ionization and reaction processes can be independently optimized and ion/ion reactions can be implemented within the context of MSn experiments. Spatial separation of the reaction vessel from the mass analyzer allows for the use of any form of mass analysis in conjunction with ion/ion reactions. Time-of-flight mass analysis, for example, has provided significant improvements in mass analysis figures of merit relative to mass filters and ion traps. PMID:18083527
Design and Assessment of an Assignment-Based Curriculum to Teach Scientific Writing and Scientific Peer Review

ERIC Educational Resources Information Center

Glaser, Rainer E.

2014-01-01

A writing-intensive, upper-level undergraduate course which integrates content, context, collaboration, and communication in a unique fashion, is described. The topic of the seminar is "Scientific Writing in Chemistry" and an assignment-based curriculum was developed to instruct students on best practices in all aspects of science…
Chemistry Graduate Teaching Assistants' Experiences in Academic Laboratories and Development of a Teaching Self-image

NASA Astrophysics Data System (ADS)

Gatlin, Todd Adam

Graduate teaching assistants (GTAs) play a prominent role in chemistry laboratory instruction at research based universities. They teach almost all undergraduate chemistry laboratory courses. However, their role in laboratory instruction has often been overlooked in educational research. Interest in chemistry GTAs has been placed on training and their perceived expectations, but less attention has been paid to their experiences or their potential benefits from teaching. This work was designed to investigate GTAs' experiences in and benefits from laboratory instructional environments. This dissertation includes three related studies on GTAs' experiences teaching in general chemistry laboratories. Qualitative methods were used for each study. First, phenomenological analysis was used to explore GTAs' experiences in an expository laboratory program. Post-teaching interviews were the primary data source. GTAs experiences were described in three dimensions: doing, knowing, and transferring. Gains available to GTAs revolved around general teaching skills. However, no gains specifically related to scientific development were found in this laboratory format. Case-study methods were used to explore and illustrate ways GTAs develop a GTA self-image---the way they see themselves as instructors. Two general chemistry laboratory programs that represent two very different instructional frameworks were chosen for the context of this study. The first program used a cooperative project-based approach. The second program used weekly, verification-type activities. End of the semester interviews were collected and served as the primary data source. A follow-up case study of a new cohort of GTAs in the cooperative problem-based laboratory was undertaken to investigate changes in GTAs' self-images over the course of one semester. Pre-semester and post-semester interviews served as the primary data source. Findings suggest that GTAs' construction of their self-image is shaped through the interaction of 1) prior experiences, 2) training, 3) beliefs about the nature of knowledge, 4) beliefs about the nature of laboratory work, and 5) involvement in the laboratory setting. Further GTAs' self-images are malleable and susceptible to change through their laboratory teaching experiences. Overall, this dissertation contributes to chemistry education by providing a model useful for exploring GTAs' development of a self-image in laboratory teaching. This work may assist laboratory instructors and coordinators in reconsidering, when applicable, GTA training and support. This work also holds considerable implications for how teaching experiences are conceptualized as part of the chemistry graduate education experience. Findings suggest that appropriate teaching experiences may contribute towards better preparing graduate students for their journey in becoming scientists.
Content-related interactions and methods of reasoning within self-initiated organic chemistry study groups

NASA Astrophysics Data System (ADS)

Christian, Karen Jeanne

2011-12-01

Students often use study groups to prepare for class or exams; yet to date, we know very little about how these groups actually function. This study looked at the ways in which undergraduate organic chemistry students prepared for exams through self-initiated study groups. We sought to characterize the methods of social regulation, levels of content processing, and types of reasoning processes used by students within their groups. Our analysis showed that groups engaged in predominantly three types of interactions when discussing chemistry content: co-construction, teaching, and tutoring. Although each group engaged in each of these types of interactions at some point, their prevalence varied between groups and group members. Our analysis suggests that the types of interactions that were most common depended on the relative content knowledge of the group members as well as on the difficulty of the tasks in which they were engaged. Additionally, we were interested in characterizing the reasoning methods used by students within their study groups. We found that students used a combination of three content-relevant methods of reasoning: model-based reasoning, case-based reasoning, or rule-based reasoning, in conjunction with one chemically-irrelevant method of reasoning: symbol-based reasoning. The most common way for groups to reason was to use rules, whereas the least common way was for students to work from a model. In general, student reasoning correlated strongly to the subject matter to which students were paying attention, and was only weakly related to student interactions. Overall, results from this study may help instructors to construct appropriate tasks to guide what and how students study outside of the classroom. We found that students had a decidedly strategic approach in their study groups, relying heavily on material provided by their instructors, and using the reasoning strategies that resulted in the lowest levels of content processing. We suggest that instructors create more opportunities for students to explore model-based reasoning, and to create opportunities for students to be able to co-construct in a collaborative manner within the context of their organic chemistry course.
Fostering Analogical Transfer: The Multiple Components Approach to Algebra Word Problem Solving in a Chemistry Context

ERIC Educational Resources Information Center

Ngu, Bing Hiong; Yeung, Alexander Seeshing

2012-01-01

Holyoak and Koh (1987) and Holyoak (1984) propose four critical tasks for analogical transfer to occur in problem solving. A study was conducted to test this hypothesis by comparing a multiple components (MC) approach against worked examples (WE) in helping students to solve algebra word problems in chemistry classes. The MC approach incorporated…
Challenging Gifted Learners: General Principles for Science Educators; and Exemplification in the Context of Teaching Chemistry

ERIC Educational Resources Information Center

Taber, Keith S.

2010-01-01

There is concern in some counties about the number of able young people entering degree level study and careers in physical science, including chemistry. Too few of the most talented young people are selecting "STEM" subjects to ensure the future supply of scientists, engineers and related professionals. The present paper sets out general…
Improving the Effectiveness of Organic Chemistry Experiments through Multimedia Teaching Materials for Junior High School Students

ERIC Educational Resources Information Center

Lou, Shi-Jer; Lin, Hui-Chen; Shih, Ru-Chu; Tseng, Kuo-Hung

2012-01-01

The purpose of the study aimed to explore the effects of three different forms of the multimedia teaching materials on the achievements and attitudes of junior high school students in a chemistry laboratory context. The three forms of the multimedia teaching materials, static pictures, video, and animation, were employed to teach chemistry…
Joseph Priestley across Theology, Education, and Chemistry: An Interdisciplinary Case Study in Epistemology with a Focus on the Science Education Context

ERIC Educational Resources Information Center

de Berg, Kevin C.

2011-01-01

This paper discusses the findings of a search for the intellectual tools used by Joseph Priestley (1733-1804) in his chemistry, education, and theology documents. Priestley's enquiring democratic view of knowledge was applicable in all three areas and constitutes a significant part of his lifework. Current epistemological issues in science…
A Compilation of Postgraduate Theses Written in Turkey on Computer Assisted Instruction in Chemistry Education

ERIC Educational Resources Information Center

Bozdogan, Aykut Emre; Demirbas, Murat

2014-01-01

The purpose of the study conducted is to present in-depth information about the postgraduate theses written within the context of Computer Assisted Instruction in Chemistry Education in Turkey. The theses collected in National Thesis Centre of Turkish Council of Higher Education were examined. As a result of an examination, it was found that about…
There is another choice: an exploration of integrating formative assessment in a Chinese high school chemistry classroom through collaborative action research

NASA Astrophysics Data System (ADS)

Yin, Xinying; Buck, Gayle A.

2015-09-01

This study explored integrating formative assessment to a Chinese high school chemistry classroom, where the extremely high-stakes testing and Confucian-heritage culture constituted a particular context, through a collaborative action research. One researcher worked with a high school chemistry teacher in China to integrate formative assessment into his teaching with 54 students in one of his classes. Data resources included transcripts from planning sessions, lesson plans, teacher interviews, classroom observations, student work, student interviews and surveys. The findings of this study revealed that as the teacher allowed his original views about students' learning and assessment tasks to be challenged by the students' learning, his teaching practice and understandings of formative assessment were transformed. Students' learning experience was also examined in the formative assessment process. The potentials and challenges of integrating formative assessment in the Chinese high school science classroom are discussed. This study indicated that formative assessment is promising to implement in Chinese high school science classrooms to enhance students' learning and meet the imperative needs for high-stakes exam preparation as well; and writing formative assessment tasks are favorable in this particular socio-cultural context. Further, this study suggested that facilitating in-service science teachers to integrate formative assessment through collaborative action research is a powerful professional development on improving teaching and learning under the highly constraint context.
Teachers and Students' Conceptions of Computer-Based Models in the Context of High School Chemistry: Elicitations at the Pre-intervention Stage

NASA Astrophysics Data System (ADS)

Waight, Noemi; Gillmeister, Kristina

2014-04-01

This study examined teachers' and students' initial conceptions of computer-based models—Flash and NetLogo models—and documented how teachers and students reconciled notions of multiple representations featuring macroscopic, submicroscopic and symbolic representations prior to actual intervention in eight high school chemistry classrooms. Individual in-depth interviews were conducted with 32 students and 6 teachers. Findings revealed an interplay of complex factors that functioned as opportunities and obstacles in the implementation of technologies in science classrooms. Students revealed preferences for the Flash models as opposed to the open-ended NetLogo models. Altogether, due to lack of content and modeling background knowledge, students experienced difficulties articulating coherent and blended understandings of multiple representations. Concurrently, while the aesthetic and interactive features of the models were of great value, they did not sustain students' initial curiosity and opportunities to improve understandings about chemistry phenomena. Most teachers recognized direct alignment of the Flash model with their existing curriculum; however, the benefits were relegated to existing procedural and passive classroom practices. The findings have implications for pedagogical approaches that address the implementation of computer-based models, function of models, models as multiple representations and the role of background knowledge and cognitive load, and the role of teacher vision and classroom practices.
Recent advances in gossypol derivatives and analogs: a chemistry and biology view.

PubMed

Lu, Yuzhi; Li, Jun; Dong, Chun-E; Huang, Jian; Zhou, Hai-Bing; Wang, Wei

2017-07-01

Gossypol as a natural occurring polyphenol has been studied in a wide range of therapeutic contexts for a long time. The chemical modifications on gossypol were limited due to the unique chemical properties of polyphenols. The design and synthesis of gossypol derivatives and the exploration of their biological activities are the interest of the synthetic chemists, medicinal chemists and pharmacologists. Thus, the progress of diverse gossypol derivatives and analogs' synthesis, biological activities, mechanism elucidation and drug discovery based on gossypol scaffold is summarized.

Research for the advancement of green chemistry practice: Studies in atmospheric and educational chemistry

NASA Astrophysics Data System (ADS)

Cullipher, Steven Gene

Green chemistry is a philosophy of chemistry that emphasizes a decreasing dependence on limited non-renewable resources and an increasing focus on preventing pollution byproducts of the chemical industry. In short, it is the discipline of chemistry practiced through the lens of environmental stewardship. In an effort to advance the practice of green chemistry, three studies will be described that have ramifications for the practice. The first study examines the atmospheric oxidation of a hydrofluorinated ether, a third-generation CFC replacement compound with primarily unknown atmospheric degradation products. Determination of these products has the potential to impact decisions on refrigerant usage in the future. The second study examines chemistry students' development of understanding benefits-costs-risks analysis when presented with two real-world scenarios: refrigerant choice and fuel choice. By studying how benefits-costs-risks thinking develops, curricular materials and instructional approaches can be designed to better foster the development of an ability that is both necessary for green chemists and important in daily decision-making for non-chemists. The final study uses eye tracking technology to examine students' abilities to interpret molecular properties from structural information in the context of global warming. Such abilities are fundamental if chemists are to appropriately assess risks and hazards of chemistry practice.
Effects of Context on Students' Molecular-Level Ideas

ERIC Educational Resources Information Center

Teichert, Melonie A.; Tien, Lydia T.; Anthony, Seth; Rickey, Dawn

2008-01-01

In the studies reported here, we investigate the effects of context on students' molecular-level ideas regarding aqueous solutions. During one-on-one interviews, 19 general chemistry students recruited from a two-year community college and a research university in the United States were asked to describe their molecular-level ideas about various…
The Characterization of Cognitive Processes Involved in Chemical Kinetics Using a Blended Processing Framework

ERIC Educational Resources Information Center

Bain, Kinsey; Rodriguez, Jon-Marc G.; Moon, Alena; Towns, Marcy H.

2018-01-01

Chemical kinetics is a highly quantitative content area that involves the use of multiple mathematical representations to model processes and is a context that is under-investigated in the literature. This qualitative study explored undergraduate student integration of chemistry and mathematics during problem solving in the context of chemical…
Assessing Student Knowledge of Chemistry and Climate Science Concepts Associated with Climate Change: Resources to Inform Teaching and Learning

ERIC Educational Resources Information Center

Versprille, Ashley; Zabih, Adam; Holme, Thomas A.; McKenzie, Lallie; Mahaffy, Peter; Martin, Brian; Towns, Marcy

2017-01-01

Climate change is one of the most critical problems facing citizens today. Chemistry faculty are presented with the problem of making general chemistry content simultaneously relevant and interesting. Using climate science to teach chemistry allows faculty to help students learn chemistry content in a rich context. Concepts related to…
Towards Eco-reflexive Science Education. A Critical Reflection About Educational Implications of Green Chemistry

NASA Astrophysics Data System (ADS)

Sjöström, Jesper; Eilks, Ingo; Zuin, Vânia G.

2016-05-01

The modern world can be described as a globalized risk society. It is characterized by increasing complexity, unpredictable consequences of techno-scientific innovations and production, and its environmental consequences. Therefore, chemistry, just like many other knowledge areas, is in an ongoing process of environmentalization. For example, green chemistry has emerged as a new chemical metadiscipline and movement. The philosophy of green chemistry was originally based on a suggestion of twelve principles for environment-friendly chemistry research and production. The present article problematizes limitations in green chemistry when it comes to education. It argues that the philosophy of green chemistry in the context of education needs to be extended with socio-critical perspectives to form educated professionals and citizens who are able to understand the complexity of the world, to make value-based decisions, and to become able to engage more thoroughly in democratic decision-making on sustainability issues. Different versions of sustainability-oriented science/chemistry education are discussed to sharpen a focus on the most complex type, which is Bildung-oriented, focusing emancipation and leading to eco-reflexive education. The term eco- reflexive is used for a problematizing stance towards the modern risk society, an understanding of the complexity of life and society and their interactions, and a responsibility for individual and collective actions towards socio-ecojustice and global sustainability. The philosophical foundation and characteristics of eco-reflexive science education are sketched on in the article.
Constructing a Coherent Problem Model to Facilitate Algebra Problem Solving in a Chemistry Context

ERIC Educational Resources Information Center

Ngu, Bing Hiong; Yeung, Alexander Seeshing; Phan, Huy P.

2015-01-01

An experiment using a sample of 11th graders compared text editing and worked examples approaches in learning to solve dilution and molarity algebra word problems in a chemistry context. Text editing requires students to assess the structure of a word problem by specifying whether the problem text contains sufficient, missing, or irrelevant…
Using Familiar Contexts to Ease the Transition between A-Level and First-Year Degree-Level Chemistry

ERIC Educational Resources Information Center

Turner, John J.

2013-01-01

This article endeavours to define how an understanding of the context of chemical principles and processes investigated at A-level (post-16) and earlier can be continued and contribute to easing the tensions and uncertainties encountered by chemistry and chemical engineering students on entry to university. The importance of using chemistry…
Chemistry and Chemical Education through Text and Image: Analysis of Twentieth Century Textbooks Used in Brazilian Context

ERIC Educational Resources Information Center

Souza, Karina Ap F. D.; Porto, Paulo Alves

2012-01-01

Assuming that textbooks give literary expression to cultural and ideological values of a nation or group, we propose the analysis of chemistry textbooks used in Brazilian universities throughout the twentieth century. We analyzed iconographic and textual aspects of 31 textbooks which had significant diffusion in the context of Brazilian…
The James Webb Space Telescope: Inspiration and Context for Physics and Chemistry Teaching

ERIC Educational Resources Information Center

Hillier, Dan; Johnston, Tania; Davies, John

2012-01-01

This article describes the design, delivery, evaluation and impact of a CPD course for physics and chemistry teachers. A key aim of the course was to use the context of the James Webb Space Telescope project to inspire teachers and lead to enriched teaching of STEM subjects. (Contains 1 box and 3 figures.)
Selection of Authentic Modelling Practices as Contexts for Chemistry Education

ERIC Educational Resources Information Center

Prins, Gjalt T.; Bulte, Astrid M. W.; van Driel, Jan H.; Pilot, Albert

2008-01-01

In science education, students should come to understand the nature and significance of models. In the case of chemistry education it is argued that the present use of models is often not meaningful from the students' perspective. A strategy to overcome this problem is to use an authentic chemical modelling practice as a context for a curriculum…
Writing-to-Learn in High-School Chemistry: The Effects of Using The Science Writing Heuristic to Increase Scientific Literacy

ERIC Educational Resources Information Center

Nurnberg, Denae

2017-01-01

Writing-to-Learn in High-School Chemistry: The Effects of Using the Science Writing Heuristic to Increase Scientific Literacy The purpose of this study was to investigate the effectiveness of using the Science Writing Heuristic (SWH) as an instructional tool to improve academic achievement and writing in the context of scientific literacy. This…
Predicting Student Success on the Texas Chemistry STAAR Test: A Logistic Regression Analysis

ERIC Educational Resources Information Center

Johnson, William L.; Johnson, Annabel M.; Johnson, Jared

2012-01-01

Background: The context is the new Texas STAAR end-of-course testing program. Purpose: The authors developed a logistic regression model to predict who would pass-or-fail the new Texas chemistry STAAR end-of-course exam. Setting: Robert E. Lee High School (5A) with an enrollment of 2700 students, Tyler, Texas. Date of the study was the 2011-2012…
Student Conceptions of Ionic Bonding: Patterns of thinking across three European contexts

NASA Astrophysics Data System (ADS)

Taber, Keith S.; Tsaparlis, Georgios; Nakiboğlu, Canan

2012-12-01

Previous research has reported that students commonly develop alternative conceptions in the core topic of chemical bonding. Research in England has reported that students there commonly demonstrate an alternative 'molecular' conceptual framework for thinking about ionic bonding: in terms of the formation of molecule-like ions pairs through electron transfer, which are internally bonded, but not bonded to other ions. The present study reports the use of translated versions of a diagnostic instrument to elicit the conceptions of bonding in NaCl (commonly used as the teaching example of an ionic compound) from two samples of students setting out on university courses in Greece and Turkey. The study reports that students in these two contexts displayed high levels of support for statements based upon the alternative conceptual framework identified in the English context. Students commonly develop similar alternative conceptions of ionic bonding in these three different educational contexts. The study also found some quite large differences in the specific response patterns across these three contexts, some of which could reflect specific features of the different curriculum contexts. The study reinforces the cross-national nature of the challenge of effectively teaching the abstract models of chemistry at the submicroscopic level. It also provides intriguing suggestions that a close study of the interactions between specific curriculum contexts and specific patterns in students' thinking offers much potential for identifying particular aspects of subject pedagogy that either support or impede the learning of accepted scientific models.
Identifying relationships between baseflow geochemistry and land use with synoptic sampling and R-Mode factor analysis

USGS Publications Warehouse

Wayland, Karen G.; Long, David T.; Hyndman, David W.; Pijanowski, Bryan C.; Woodhams, Sarah M.; Haak, Sheridan K.

2003-01-01

The relationship between land use and stream chemistry is often explored through synoptic sampling rivers at baseflow condition. However, base flow chemistry is likely to vary temporally and spatially with land use. The purpose of our study is to examine the usefulness of the synoptic sampling approach for identifying the relationship between complex land use configurations and stream water quality. This study compares biogeochemical data from three synoptic sampling events representing the temporal variability of baseflow chemistry and land use using R-mode factor analysis. Separate R-mode factor analyses of the data from individual sampling events yielded only two consistent factors. Agricultural activity was associated with elevated levels of Ca2+, Mg2+, alkalinity, and frequently K+, SO42-, and NO3-. Urban areas were associated with higher concentrations of Na+, K+, and Cl-. Other retained factors were not consistent among sampling events, and some factors were difficult to interpret in the context of biogeochemical sources and processes. When all data were combined, further associations were revealed such as an inverse relationship between the proportion of wetlands and stream nitrate concentrations. We also found that barren lands were associated with elevated sulfate levels. This research suggests that an individual sampling event is unlikely to characterize adequately the complex processes controlling interactions between land uses and stream chemistry. Combining data collected over two years during three synoptic sampling events appears to enhance our ability to understand processes linking stream chemistry and land use.
Zero-Order Chemical Kinetics as a Context to Investigate Student Understanding of Catalysts and Half-Life

ERIC Educational Resources Information Center

Bain, Kinsey; Rodriguez, Jon-Marc G.; Towns, Marcy H.

2018-01-01

Zero-order systems provide an interesting opportunity for students to think about the underlying mechanism behind the physical phenomena being modeled. The work reported here is part of a larger study that seeks to characterize how students integrate chemistry and mathematics in the context of chemical kinetics. Thirty-six general chemistry…
High to Low Tide: The High School-University Transition

ERIC Educational Resources Information Center

Stone, David C.

2010-01-01

In this paper I summarize some key findings from a three-year study of the high school-university transition for students attending a large arts and science faculty, within the context of their first university chemistry course. I then discuss these results within the broader context of research on success in higher education. Final conclusions…
Using the Socioscientific Context of Climate Change to Teach Chemical Content and the Nature of Science

ERIC Educational Resources Information Center

Flener-Lovitt, Charity

2014-01-01

A thematic course called "Climate Change: Chemistry and Controversy" was developed for upper-level non-STEM students. This course used the socioscientific context of climate change to teach chemical principles and the nature of science. Students used principles of agnotology (direct study of misinformation) to debunk climate change…
WATER FORMATION IN THE UPPER ATMOSPHERE OF THE EARLY EARTH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fleury, Benjamin; Carrasco, Nathalie; Marcq, Emmanuel

2015-07-10

The water concentration and distribution in the early Earth's atmosphere are important parameters that contribute to the chemistry and the radiative budget of the atmosphere. If the atmosphere above the troposphere is generally considered as dry, photochemistry is known to be responsible for the production of numerous minor species. Here we used an experimental setup to study the production of water in conditions simulating the chemistry above the troposphere of the early Earth with an atmospheric composition based on three major molecules: N{sub 2}, CO{sub 2}, and H{sub 2}. The formation of gaseous products was monitored using infrared spectroscopy. Watermore » was found as the major product, with approximately 10% of the gas products detected. This important water formation is discussed in the context of the early Earth.« less
Crisis, change and creativity in science and technology: chemistry in the aftermath of twentieth-century global wars.

PubMed

Johnson, Jeffrey Allan

2011-07-01

This paper presents the organising ideas behind the symposium "Chemistry in the Aftermath of World Wars," held at the 23rd International Congress of History of Science and Technology, Budapest, 2009, whose theme was "Ideas and Instruments in Social Context." After first recounting the origins of the notion of "crisis" as a decisive turning point in general history as well as in the history of science, the paper presents war and its aftermath as a form of crisis that may affect science and technology, including chemistry, in a variety of contexts and leading to a variety of types of change. The twentieth-century world wars were exemplary forms of crisis, whose aftermaths shaped the contexts for decisive changes in modern chemistry, which continue to offer challenging opportunities for historical research. In discussing these, the paper cites selected current literature and briefly describes how the individual papers of the symposium, including the three papers published in this volume, approached these challenges.
First-Year Chemistry in the Context of the Periodic Table.

ERIC Educational Resources Information Center

Woodgate, Sheila D.

1995-01-01

Describes the methods that have been developed to blend descriptive chemistry and principles in a first-year chemistry course. The key is active teaching of the subject using the periodic table as a template. Inorganic chemistry is taught using a group approach: developing trends that help teaching and learning become obvious if all elements of…

Students' science attitudes, beliefs, and context: associations with science and chemistry aspirations

NASA Astrophysics Data System (ADS)

Mujtaba, Tamjid; Sheldrake, Richard; Reiss, Michael J.; Simon, Shirley

2018-04-01

There is a widespread concern that relatively few students, especially those from disadvantaged backgrounds, continue to study chemistry and other science subjects after compulsory education. Yet it remains unclear how different aspects of students' background and home context, their own attitudes and beliefs, and their experiences of particular teaching approaches in school might limit or facilitate their studying aspirations; concurrently, less research has specifically focused on and surveyed disadvantaged students. In order to gain more insight, 4780 students were surveyed, covering those in Year 7 (age 11-12 years) and in Year 8 (age 12-13) from schools in England with high proportions of those from disadvantaged backgrounds. Predictive modelling highlighted that the students' aspirations to study non-compulsory science in the future, and to study the particular subject of chemistry, were strongly associated with their extrinsic motivation towards science (their perceived utility of science, considered as a means to gain particular careers or skills), their intrinsic interest in science, and their engagement in extra-curricular activities. Additionally, their self-concept beliefs (their confidence in their own abilities in science), some teaching approaches, and encouragement from teachers and family alongside family science capital had smaller but still relevant associations.
Comparing Two Tests of Formal Reasoning in a College Chemistry Context

ERIC Educational Resources Information Center

Jiang, Bo; Xu, Xiaoying; Garcia, Alicia; Lewis, Jennifer E.

2010-01-01

The Test of Logical Thinking (TOLT) and the Group Assessment of Logical Thinking (GALT) are two of the instruments most widely used by science educators and researchers to measure students' formal reasoning abilities. Based on Piaget's cognitive development theory, formal thinking ability has been shown to be essential for student achievement in…
Bringing in the Bard: Shakespearean Plays as Context for Instrumental Analysis Projects

ERIC Educational Resources Information Center

Kloepper, Kathryn D.

2015-01-01

Scenes from the works of William Shakespeare were incorporated into individual and group projects for an upper-level chemistry class, instrumental analysis. Students read excerpts from different plays and then viewed a corresponding video clip from a stage or movie production. Guided-research assignments were developed based on these scenes. These…
Design of a Food Chemistry-Themed Course for Nonscience Majors

ERIC Educational Resources Information Center

Bell, Patrice

2014-01-01

The physical science curriculum design at Georgia Gwinnett College requires a theme-based course (lecture and group work, and laboratory) for nonscience majors. Increased student engagement is anticipated when science topics are taught in the context of a topic of which students can select during course registration. This paper presents the course…
Analysis of the effect of specific vocabulary instruction on high school chemistry students' knowledge and understanding

NASA Astrophysics Data System (ADS)

Labrosse, Peggy

The purpose of this study was to analyze the effects of specific vocabulary instruction on high school chemistry students' knowledge and understanding. Students might be able to formally recite a definition for a term without actually having understood the meaning of the term and its connection to other terms or to related concepts. Researchers (Cassels & Johnstone, 1983; Gabel, 1999; Johnstone, 1991) have been studying the difficulty students have in learning science, particularly chemistry. Gabel (1999) suggests that, "while research into misconceptions (also known as alternative conceptions) and problem-solving has dominated the field for the past 25 years, we are no closer to a solution that would improve the teaching and learning of chemistry" (P. 549). Gabel (1999) relates the difficulty in learning chemistry to use of language. She refers to student difficulty both with words that have more than one meaning in English and with words that are used to mean one idea in chemistry and another idea in every day language. The Frayer Model, a research-based teaching strategy, is a graphic organizer which students use to create meaningful definitions for terms in context (Frayer, Frederick, & Klausmeier, 1969). It was used as the treatment---the specific vocabulary instruction---in this research study. The researcher collected and analyzed data to answer three research questions that focused on the effect of using the Frayer model (a graphic organizer) on high school students' knowledge and understanding of academic language used in chemistry. The research took place in a New England high school. Four intact chemistry classes provided the student participants; two classes were assigned to the treatment group (TG) and two classes were assigned to the control group (CG). The TG received vocabulary instruction on 14 chosen terms using the Frayer Model. The CG received traditional vocabulary instruction with no special attention to the 14 terms selected for this study. The vocabulary knowledge was examined by means of multiple-choice pre- and post-tests which were administered to all student participants. The choices included a scientific synonym, an everyday synonym, and a synonym based on a common misconception related to the term. Student understanding of the chemistry content was examined using chemistry content understanding pre- and post-tests comprised of four probes based on the National Science Education Standards (National Research Council, 1996) and linked to common student misconceptions which were administered to all student participants. Vocabulary knowledge effect scores were compared between the TG and CG using a t-test. Only a slight gain in vocabulary knowledge mean effect scores was found in the TG compared to the CG; however, it was not statistically significant. Chemistry content understanding effect scores were compared between the TG and CG using Chi-square analysis. The results of the chemistry content understanding effect scores in the TG compared to the CG showed that the student participants in the CG did significantly better. Chemistry content understanding effect scores and vocabulary knowledge effect scores were compared using a t-test. Chapter V provides explanations for the results which do not corroborate those found by other researchers. The researcher contends that the use of the Frayer model for specific terms in content across the curriculum is worth further study.
Green Goggles: Designing and Teaching a General Chemistry Course to Nonmajors Using a Green Chemistry Approach

ERIC Educational Resources Information Center

Prescott, Sarah

2013-01-01

A novel course using green chemistry as the context to teach general chemistry fundamentals was designed, implemented and is described here. The course design included an active learning approach, with major course graded components including a weekly blog entry, exams, and a semester project that was disseminated by wiki and a public symposium.…
Using a Deliberation of Energy Policy as an Educational Tool in a Nonmajors Chemistry Course

ERIC Educational Resources Information Center

Drury, Sara A. Mehltretter; Stucker, Kyle; Douglas, Anthony; Rush, Ryan A.; Novak, Walter R. P.; Wysocki, Laura M.

2016-01-01

A central goal of nonmajors chemistry courses is to instill within students the sense that chemistry does not occur in a vacuum but rather permeates everyday life. To encourage students to consider chemistry within the broader context of society and public policy, a week-long module in a survey course for nonmajors was designed to connect…
Upon Further Review: A Commodity Chemist on Green Chemistry

NASA Astrophysics Data System (ADS)

Carroll, William F.

2016-09-01

Green chemistry is most often thought of in the context of specialty or pharmaceutical chemicals where many synthetic chemistry approaches are in play. However, principles similar to those of green chemistry and engineering were employed over the years in reducing cost and increasing volume of chemicals that became commodities. This paper considers some of those principles, their impact, and some perspectives on the potential and limits associated with green chemistry for commodity chemicals.
High-School Chemistry Teaching through Environmentally Oriented Curricula

ERIC Educational Resources Information Center

Mandler, Daphna; Mamlok-Naaman, Rachel; Blonder, Ron; Yayon, Malka; Hofstein, Avi

2012-01-01

Discussions held in the chemical education community have generated a variety of reports and recommendations for reforming the chemistry curriculum. The recommendations refer to teaching chemistry in the context of real-world issues. This has been suggested as a way to enhance students' motivation. It is suggested that real-world problems…
The Chemistry of Perfume: A Laboratory Course for Nonscience Majors

ERIC Educational Resources Information Center

Logan, Jennifer L.; Rumbaugh, Craig E.

2012-01-01

"The Chemistry of Perfume" is a lab-only course for nonscience majors. Students learn fundamental concepts of chemistry through the context of fragrance, a pervasive aspect of daily life. The course consists of laboratories pertaining to five units: introduction, extraction, synthesis, characterization, and application. The introduction unit…
Through the looking glass of a chemistry video game: Evaluating the effects of different MLEs presenting identical content material

NASA Astrophysics Data System (ADS)

Hillman, Dustin S.

The primary goal of this study is to evaluate the effects of different media-based learning environments (MLEs) that present identical chemistry content material. This is done with four different MLEs that utilize some or all components of a chemistry-based media-based prototype video game. Examination of general chemistry student volunteers purposefully randomized to one of four different MLEs did not provide evidence that the higher the level of interactivity resulted in a more effective MLE for the chemistry content. Data suggested that the cognitive load to play the chemistry-based video game may impaired the chemistry content being presented and recalled by the students while the students watching the movie of the chemistry-based video game were able to recall the chemistry content more efficiently. Further studies in this area need to address the overall cognitive load of the different MLEs to potentially better determine what the most effective MLE may be for this chemistry content.
Effects of the 5E Instructional Model Incorporated with Multiple Levels of Representations on Thai Students with Different Levels of Cognitive Development

ERIC Educational Resources Information Center

Wichaidit, Patcharee Rompayom; Wichaidit, Sittichai

2016-01-01

Learning chemistry may be difficult for students for several reasons, such as the abstract nature of many chemistry concepts and the fact that students may view chemistry as irrelevant to their everyday lives. Teaching chemistry in familiar contexts and the use of multiple representations are seen as effective approaches for enhancing students'…
Science Teachers' Understanding and Practice of Inquiry-Based Instruction in Uganda

NASA Astrophysics Data System (ADS)

Ssempala, Fredrick

High school students in Uganda perform poorly in science subjects despite the Ugandan government's efforts to train science teachers and build modern science laboratories in many public high schools. The poor performance of students in science subjects has been largely blamed on the inability by many science teachers to teach science through Inquiry-Based Instruction (IBI) to motivate the students to learn science. However, there have been no empirical studies done to establish the factors that influence science teachers' understanding and practice of IBI in Uganda. Most of the published research on IBI has been conducted in developed countries, where the prevailing contexts are very different from the contexts in developing countries such as Uganda. Additionally, few studies have explored how professional development (PD) training workshops on inquiry and nature of science (NOS) affect chemistry teachers' understanding and practice of IBI. My purpose in this multi-case exploratory qualitative study was to explore the effect of a PD workshop on inquiry and NOS on chemistry teachers' understanding and practice of IBI in Kampala city public schools in Uganda. I also explored the relationship between chemistry teachers' NOS understanding and the nature of IBI implemented in their classrooms and the internal and external factors that influence teachers' understanding and practice of IBI. I used a purposive sampling procedure to identify two schools of similar standards from which I selected eight willing chemistry teachers (four from each school) to participate in the study. Half of the teachers (those from School A) attended the PD workshop on inquiry and NOS for six days, while the control group (those from School B) did not. I collected qualitative data through semi-structured interviews, classroom observation, and document analysis. I analyzed these data by structural, conceptual and theoretical coding approach. I established that all the participating chemistry teachers had insufficient understanding of IBI at the beginning of the study. However, teachers from School A improved their understanding and practice of IBI after attending the PD workshop. I also found that the participating chemistry teachers' NOS epistemological views were, to some extent, related to the nature of IBI implemented in their classroom. The main internal factors the participating teachers perceived to influence their understanding and practice of IBI were their attitudes and teaching experience, whereas the external factors were lack of motivation, lack of necessary instructional materials, mode of assessment, class size, the nature of pre-service and in-service training, support from peer teachers and limited time in relation to many lessons and much content to cover Based on the above findings, I conclude that the current science teacher training in Uganda may not be improving science teachers' understanding and practice of IBI, and most of the factors are beyond their control (external). Hence, there is an urgent need for teacher educators and policymakers in Uganda to address the internal and external factors influencing science teachers' understanding and practice of IBI to improve the teaching and learning of science subjects. Additionally, more quantitative and qualitative studies should be done among teachers of different disciplines to establish how the above factors and others affect teachers' understanding and practice of IBI in developing countries like Uganda.
Towards the ophthalmology patentome: a comprehensive patent database of ocular drugs and biomarkers.

PubMed

Mucke, Hermann A M; Mucke, Eva; Mucke, Peter M

2013-01-01

We are currently building a database of all patent documents that contain substantial information related to pharmacology, drug delivery, tissue technology, and molecular diagnostics in ophthalmology. The goal is to establish a 'patentome', a body of cleaned and annotated data where all text-based, chemistry and pharmacology information can be accessed and mined in its context. We provide metrics on patent convention treaty documents, which demonstrate that ocular-related patenting has shown stronger growth than general patent cooperation treaty patenting during the past 25 years, and, while the majority of applications of this type have always provided substantial biological data, both data support and objections by patent examiners have been increasing since 2006-2007. Separately, we present a case study of chemistry information extraction from patents published during the 1950s and 1970s, which reveal compounds with corneal anesthesia potential that were never published in the peer-reviewed literature.
Infrared spectroscopy of organics of planetological interest at low temperatures

NASA Technical Reports Server (NTRS)

Khanna, R. K.

1994-01-01

In the context of prebiotic chemistry in space, some of the outer planetary objects display H, C, N and O rich chemistry similar to the one in the biosphere of Earth. Of particular interest are Saturn's moon, Titan; Neptune's moon, Triton; and Pluto where extreme cold conditions prevail. Identifications of chemical species on these objects (surfaces and atmospheres) is essential to a better understanding of the radiation induced chemical reactions occuring thereon. There have been several ground based observations of these planetary objects in the infrared windows from 1 to 2.5 micrometers. Voyager also provided spectra in the thermal infrared (6 to 50 micrometers) region. Interpretation of these data require laboratory infrared spectra of relevant species under the temperature conditions appropriate to these objects. The results of some of these studies carried out in our laboratory and elsewhere and their impact on the analyses of the observed data will be summarized.
Scale-dependent effects of land cover on water physico-chemistry and diatom-based metrics in a major river system, the Adour-Garonne basin (South Western France).

PubMed

Tudesque, Loïc; Tisseuil, Clément; Lek, Sovan

2014-01-01

The scale dependence of ecological phenomena remains a central issue in ecology. Particularly in aquatic ecology, the consideration of the accurate spatial scale in assessing the effects of landscape factors on stream condition is critical. In this context, our study aimed at assessing the relationships between multi-spatial scale land cover patterns and a variety of water quality and diatom metrics measured at the stream reach level. This investigation was conducted in a major European river system, the Adour-Garonne river basin, characterized by a wide range of ecological conditions. Redundancy analysis (RDA) and variance partitioning techniques were used to disentangle the different relationships between land cover, water-chemistry and diatom metrics. Our results revealed a top-down "cascade effect" indirectly linking diatom metrics to land cover patterns through water physico-chemistry, which occurred at the largest spatial scales. In general, the strength of the relationships between land cover, physico-chemistry, and diatoms was shown to increase with the spatial scale, from the local to the basin scale, emphasizing the importance of continuous processes of accumulation throughout the river gradient. Unexpectedly, we established that the influence of land cover on the diatom metric was of primary importance both at the basin and local scale, as a result of discontinuous but not necessarily antagonist processes. The most detailed spatial grain of the Corine land cover classification appeared as the most relevant spatial grain to relate land cover to water chemistry and diatoms. Our findings provide suitable information to improve the implementation of effective diatom-based monitoring programs, especially within the scope of the European Water Framework Directive. © 2013 Elsevier B.V. All rights reserved.
Explicit argumentation instruction to facilitate conceptual understanding and argumentation skills

NASA Astrophysics Data System (ADS)

Seda Cetin, Pinar

2014-01-01

Background: Argumentation is accepted by many science educators as a major component of science education. Many studies have investigated students' conceptual understanding and their engagement in argumentative activities. However, studies conducted in the subject of chemistry are very rare. Purpose: The present study aimed to investigate the effects of argumentation-based chemistry lessons on pre-service science teachers' understanding of reaction rate concepts, their quality of argumentation, and their consideration of specific reaction rate concepts in constructing an argument. Moreover, students' perceptions of argumentation lessons were explored. Sample: There were 116 participants (21 male and 95 female), who were pre-service first-grade science teachers from a public university. The participants were recruited from the two intact classes of a General Chemistry II course, both of which were taught by the same instructor. Design and methods: In the present study, non-equivalent control group design was used as a part of quasi-experimental design. The experimental group was taught using explicit argumentation activities, and the control group was instructed using traditional instruction. The data were collected using a reaction rate concept test, a pre-service teachers' survey, and the participants' perceptions of the argumentation lessons questionnaire. For the data analysis, the Wilcoxon Signed Rank Test, the Mann-Whitney U-test and qualitative techniques were used. Results: The results of the study indicated that an argumentation-based intervention caused significantly better acquisition of scientific reaction rate-related concepts and positively impacted the structure and complexity of pre-service teachers' argumentation. Moreover, the majority of the participants reported positive feelings toward argumentation activities. Conclusions: As students are encouraged to state and support their view in the chemistry classroom when studying reaction rate, it was observed that their understanding increased in terms of both the context and the quality of the argumentation that they produced. In light of the findings, it is suggested that argumentation activities should be developed to promote students' science content knowledge and argumentation skills.
Influence of subject matter discipline and science content knowledge on National Board Certified science teachers' conceptions, enactment, and goals for inquiry

NASA Astrophysics Data System (ADS)

Breslyn, Wayne Gene

The present study investigated differences in the continuing development of National Board Certified Science Teachers' (NBCSTs) conceptions of inquiry across the disciplines of biology, chemistry, earth science, and physics. The central research question of the study was, "How does a NBCST's science discipline (biology, chemistry, earth science, or physics) influence their conceptions, enactment, and goals for inquiry-based teaching and learning?" A mixed methods approach was used that included an analysis of the National Board portfolio entry, Active Scientific Inquiry, for participants (n=48) achieving certification in the 2007 cohort. The portfolio entry provided detailed documentation of teachers' goals and enactment of an inquiry lesson taught in their classroom. Based on the results from portfolio analysis, participant interviews were conducted with science teachers (n=12) from the 2008 NBCST cohort who represented the science disciplines of biology, chemistry, earth science, and physics. The interviews provided a broader range of contexts to explore teachers' conceptions, enactment, and goals of inquiry. Other factors studied were disciplinary differences in NBCSTs' views of the nature of science, the relation between their science content knowledge and use of inquiry, and changes in their conceptions of inquiry as result of the NB certification process. Findings, based on a situated cognitive framework, suggested that differences exist between biology, chemistry, and earth science teachers' conceptions, enactment, and goals for inquiry. Further, individuals teaching in more than one discipline often held different conceptions of inquiry depending on the discipline in which they were teaching. Implications for the research community include being aware of disciplinary differences in studies on inquiry and exercising caution in generalizing findings across disciplines. In addition, teachers who teach in more than one discipline can highlight the contextual and culturally based nature of teachers' conceptions of inquiry. For the education community, disciplinary differences should be considered in the development of curriculum and professional development. An understanding of disciplinary trends can allow for more targeted and relevant representations of inquiry.
Relating Teacher PCK and Teacher Practice Using Classroom Observation

NASA Astrophysics Data System (ADS)

Barendsen, Erik; Henze, Ineke

2017-09-01

Science teachers' pedagogical content knowledge (PCK) has been researched in many studies, yet little empirical evidence has been found to determine how this knowledge actually informs teachers' actions in the classroom. To complement previous quantitative studies, there is a need for more qualitative studies to investigate the relationship between teacher knowledge (as formulated by the teacher) and classroom practice, especially in the context of an educational innovation. In this study we explored a possible way to investigate this relationship in an in-depth and systematic fashion. To this end, we conducted a case study with a chemistry teacher in the context of the implementation of a context-based science curriculum in The Netherlands. The teacher's PCK was captured using the Content Representation form by Loughran, Mulhall, and Berry. We used an observation table to monitor classroom interactions in such a way that the observations could be related to specific elements of teachers' PCK. Thus, we were able to give a detailed characterization of the correspondences and differences between the teacher's personal PCK and classroom practice. Such an elaborate description turned out to be a useful basis for discussing mechanisms explaining the relationship between teachers' knowledge and teachers' actions.
Polymeric Medical Sutures: An Exploration of Polymers and Green Chemistry

ERIC Educational Resources Information Center

Knutson, Cassandra M.; Schneiderman, Deborah K.; Yu, Ming; Javner, Cassidy H.; Distefano, Mark D.; Wissinger, Jane E.

2017-01-01

With new K-12 national science standards emerging, there is an increased need for experiments that integrate engineering into the context of society. Here we describe a chemistry experiment that combines science and engineering principles while introducing basic polymer and green chemistry concepts. Using medical sutures as a platform for…

The chemistry of PET imaging with zirconium-89.

PubMed

Dilworth, Jonathan R; Pascu, Sofia I

2018-04-23

This Tutorial Review aims to provide an overview of the use of zirconium-89 complexes in biomedical imaging. Over the past decade there have been many new papers in this field, ranging from chemistry through to preclinical and clinical applications. Here we attempt to summarise the main developments that have occurred in this period. The primary focus is on coordination chemistry but other aspects such as isotope production, isotope properties, handling and radiochemical techniques and characterisation of cold and labelled complexes are included. Selected results from animal and human clinical studies are presented in the context of the stabilities and properties of the labelled bioconjugates.
Implementation of an Online Chemistry Model to a Large Eddy Simulation Model (PALM-4U0

NASA Astrophysics Data System (ADS)

Mauder, M.; Khan, B.; Forkel, R.; Banzhaf, S.; Russo, E. E.; Sühring, M.; Kanani-Sühring, F.; Raasch, S.; Ketelsen, K.

2017-12-01

Large Eddy Simulation (LES) models permit to resolve relevant scales of turbulent motion, so that these models can capture the inherent unsteadiness of atmospheric turbulence. However, LES models are so far hardly applied for urban air quality studies, in particular chemical transformation of pollutants. In this context, BMBF (Bundesministerium für Bildung und Forschung) funded a joint project, MOSAIK (Modellbasierte Stadtplanung und Anwendung im Klimawandel / Model-based city planning and application in climate change) with the main goal to develop a new highly efficient urban climate model (UCM) that also includes atmospheric chemical processes. The state-of-the-art LES model PALM; Maronga et al, 2015, Geosci. Model Dev., 8, doi:10.5194/gmd-8-2515-2015), has been used as a core model for the new UCM named as PALM-4U. For the gas phase chemistry, a fully coupled 'online' chemistry model has been implemented into PALM. The latest version of the Kinetic PreProcessor (KPP) Version 2.3, has been utilized for the numerical integration of chemical species. Due to the high computational demands of the LES model, compromises in the description of chemical processes are required. Therefore, a reduced chemistry mechanism, which includes only major pollutants namely O3, NO, NO2, CO, a highly simplified VOC chemistry and a small number of products have been implemented. This work shows preliminary results of the advection, and chemical transformation of atmospheric pollutants. Non-cyclic boundaries have been used for inflow and outflow in east-west directions while periodic boundary conditions have been implemented to the south-north lateral boundaries. For practical applications, our approach is to go beyond the simulation of single street canyons to chemical transformation, advection and deposition of air pollutants in the larger urban canopy. Tests of chemistry schemes and initial studies of chemistry-turbulence, transport and transformations are presented.
Teaching Two Basic Nanotechnology Concepts in Secondary School by Using a Variety of Teaching Methods

ERIC Educational Resources Information Center

Blonder, Ron; Sakhnini, Sohair

2012-01-01

A nanotechnology module was developed for ninth grade students in the context of teaching chemistry. Two basic concepts in nanotechnology were chosen: (1) size and scale and (2) surface-area-to-volume ratio (SA/V). A wide spectrum of instructional methods (e.g., game-based learning, learning with multimedia, learning with models, project based…
Chemistry Teaching and Learning in the Context of a Problem Found at Home

ERIC Educational Resources Information Center

Vogelezang, Michiel

2012-01-01

Noticing the presence of colourless crystals in a glass of white wine was the starting point for some simple experiments to identify their chemical nature. The author did not succeed in identifying the chemical, but learned about the presence of an acid-base indicator. In retrospect, he was aware of the special chemical way he had considered the…
Investigating Quantum Mechanical Tunneling at the Nanoscale via Analogy: Development and Assessment of a Teaching Tool for Upper-Division Chemistry

ERIC Educational Resources Information Center

Muniz, Marc N.; Oliver-Hoyo, Maria T.

2014-01-01

We report a novel educational activity designed to teach quantum mechanical tunneling to upper-division undergraduate students in the context of nanochemistry. The activity is based on a theoretical framework for analogy and is split into three parts that are linked pedagogically through the framework: classical ball-and-ramp system, tunneling…
Fluorine Compounds and Dental Health: Applications of General Chemistry Topics

ERIC Educational Resources Information Center

Pinto, Gabriel

2009-01-01

An example about the use of everyday phenomena in teaching general chemistry is given. Students have a greater appreciation of the principles of chemistry if they can see the relevance to their lives. Fluorine compounds in dental applications (as topical or as systemic use) provide an excellent context in which to review core content of general…
Using Mathematical Software to Introduce Fourier Transforms in Physical Chemistry to Develop Improved Understanding of Their Applications in Analytical Chemistry

ERIC Educational Resources Information Center

Miller, Tierney C.; Richardson, John N.; Kegerreis, Jeb S.

2016-01-01

This manuscript presents an exercise that utilizes mathematical software to explore Fourier transforms in the context of model quantum mechanical systems, thus providing a deeper mathematical understanding of relevant information often introduced and treated as a "black-box" in analytical chemistry courses. The exercise is given to…
Medical Mycology and the Chemistry Classroom: Germinating Student Interest in Organic Chemistry

ERIC Educational Resources Information Center

Bliss, Joseph M.; Reid, Christopher W.

2013-01-01

Efforts to provide active research context to introductory courses in basic sciences are likely to better engage learners and provide a framework for relevant concepts. A simple teaching and learning experiment was conducted to use concepts in organic chemistry to solve problems in the life sciences. Bryant University is a liberal arts university…
Inhibition of the checkpoint protein PD-1 by the therapeutic antibody pembrolizumab outlined by quantum chemistry.

PubMed

Tavares, Ana Beatriz M L A; Lima Neto, José X; Fulco, Umberto L; Albuquerque, Eudenilson L

2018-01-30

Much of the recent excitement in the cancer immunotherapy approach has been generated by the recognition that immune checkpoint proteins, like the receptor PD-1, can be blocked by antibody-based drugs with profound effects. Promising clinical data have already been released pointing to the efficiency of the drug pembrolizumab to block the PD-1 pathway, triggering the T-lymphocytes to destroy the cancer cells. Thus, a deep understanding of this drug/receptor complex is essential for the improvement of new drugs targeting the protein PD-1. In this context, by employing quantum chemistry methods based on the Density Functional Theory (DFT), we investigate in silico the binding energy features of the receptor PD-1 in complex with its drug inhibitor. Our computational results give a better understanding of the binding mechanisms, being also an efficient alternative towards the development of antibody-based drugs, pointing to new treatments for cancer therapy.
Quantum-chemistry based calibration of the alkali metal cation series (Li(+)-Cs(+)) for large-scale polarizable molecular mechanics/dynamics simulations.

PubMed

Dudev, Todor; Devereux, Mike; Meuwly, Markus; Lim, Carmay; Piquemal, Jean-Philip; Gresh, Nohad

2015-02-15

The alkali metal cations in the series Li(+)-Cs(+) act as major partners in a diversity of biological processes and in bioinorganic chemistry. In this article, we present the results of their calibration in the context of the SIBFA polarizable molecular mechanics/dynamics procedure. It relies on quantum-chemistry (QC) energy-decomposition analyses of their monoligated complexes with representative O-, N-, S-, and Se- ligands, performed with the aug-cc-pVTZ(-f) basis set at the Hartree-Fock level. Close agreement with QC is obtained for each individual contribution, even though the calibration involves only a limited set of cation-specific parameters. This agreement is preserved in tests on polyligated complexes with four and six O- ligands, water and formamide, indicating the transferability of the procedure. Preliminary extensions to density functional theory calculations are reported. © 2014 Wiley Periodicals, Inc.
An exploratory study of proficient undergraduate Chemistry II students' application of Lewis's model

NASA Astrophysics Data System (ADS)

Lewis, Sumudu R.

This exploratory study was based on the assumption that proficiency in chemistry must not be determined exclusively on students' declarative and procedural knowledge, but it should be also described as the ability to use variety of reasoning strategies that enrich and diversify procedural methods. The study furthermore assumed that the ability to describe the structure of a molecule using Lewis's model and use it to predict its geometry as well as some of its properties is indicative of proficiency in the essential concepts of covalent bonding and molecule structure. The study therefore inquired into the reasoning methods and procedural techniques of proficient undergraduate Chemistry II students when solving problems, which require them to use Lewis's model. The research design included an original survey, designed by the researcher for this study, and two types of interviews, with students and course instructors. The purpose of the survey was two-fold. First and foremost, the survey provided a base for the student interview selection, and second it served as the foundation for the inquiry into the strategies the student use when solving survey problems. Twenty two students were interviewed over the course of the study. The interview with six instructors allowed to identify expected prior knowledge and skills, which the students should have acquired upon completion of the Chemistry I course. The data, including videos, audios, and photographs of the artifacts produced by students during the interviews, were organized and analyzed manually and using QSR NVivo 10. The research found and described the differences between proficient and non-proficient students' reasoning and procedural strategies when using Lewis's model to describe the structure of a molecule. One of the findings clearly showed that the proficient students used a variety of cues to reason, whereas other students used one memorized cue, or an algorithm, which often led to incorrect representations in cases where the algorithm cannot be applied. Additionally, the proficient students' understanding (i.e., representation, explanation and application) of the Valence Shell Electron-Pair Repulsion theory was accurate and precise, and they used the key terms in the correct context when explaining their reasoning. The results of this study can be of great importance to general chemistry and organic chemistry courses' instructors. This study identified students' baseline academic skills and abilities that lead to conceptual understanding of the essential concepts of covalent bonding and molecule structure, which instructors could use as a guide for developing instruction. Furthermore knowing the effective methods of reasoning the students use while applying Lewis's model, the instructors may be better informed and be able to better facilitate students' learning of Lewis' model and its application. Finally, the ideas and methods used in this study can be of value to chemistry education researchers to learn more about developing proficiency through reasoning methods in other chemistry concepts.
Introduction to Computational Chemistry: Teaching Hu¨ckel Molecular Orbital Theory Using an Excel Workbook for Matrix Diagonalization

ERIC Educational Resources Information Center

Litofsky, Joshua; Viswanathan, Rama

2015-01-01

Matrix diagonalization, the key technique at the heart of modern computational chemistry for the numerical solution of the Schrödinger equation, can be easily introduced in the physical chemistry curriculum in a pedagogical context using simple Hückel molecular orbital theory for p bonding in molecules. We present details and results of…
The Fragment Network: A Chemistry Recommendation Engine Built Using a Graph Database.

PubMed

Hall, Richard J; Murray, Christopher W; Verdonk, Marcel L

2017-07-27

The hit validation stage of a fragment-based drug discovery campaign involves probing the SAR around one or more fragment hits. This often requires a search for similar compounds in a corporate collection or from commercial suppliers. The Fragment Network is a graph database that allows a user to efficiently search chemical space around a compound of interest. The result set is chemically intuitive, naturally grouped by substitution pattern and meaningfully sorted according to the number of observations of each transformation in medicinal chemistry databases. This paper describes the algorithms used to construct and search the Fragment Network and provides examples of how it may be used in a drug discovery context.
A qualitative study of high school students' pre- and post-instructional conceptions in acid-base chemistry

NASA Astrophysics Data System (ADS)

Sheppard, Keith

This study investigated high school students' understanding of acid-base chemistry, prior to and after formal chemistry instruction. Sixteen students enrolled in a regular chemistry course were interviewed three times during the school year; before and after studying the topic of acids and bases and then while conducting a titration using a microcomputer-based laboratory (MBL). Oral, pictorial and graphical data were collected in a variety of acid-base practical tasks. The data were analyzed in two parts; first, common themes, ideas and alternative conceptions that students held were identified; second, profiles of each students were made to determine changes in their conceptions due to instruction. The findings showed that students had considerable difficulty with several areas of acid-base chemistry and did not develop an integrated conceptual understanding of the topic. Students were unable to describe acid-base concepts accurately and revealed a number of alternative conceptions, which remained unchanged by instruction. Specific areas of difficulty included the concepts of pH, neutralization, strength and the theoretical descriptions of acids and bases. Further, most students could not relate the concepts to actual solutions and were unable to describe acid-base phenomena at a sub-microscopic level. Student difficulties stemmed from a lack of understanding of some underlying and fundamental chemistry, such as the nature of chemical change and the particulate nature of matter. A number of factors were identified as contributing to these difficulties, and included the overstuffed nature of introductory chemistry itself, the emphasis in instruction on solving numerical problems and the dominant role played by the textbook. Further, the conceptual density of acid-base chemistry, the confusing nature of acid-base terminology and the lack of agreement about what material should be included in the chemistry curriculum were viewed as problematic. The study calls for a shift in introductory chemistry, from coverage of material to an emphasis on conceptual understanding, and suggests the use of more appropriate teaching strategies, the use of modern technologies, the inclusion of alternative modes of assessment and a re-evaluation of the chemistry introduced into the topic of acids and bases.
Heuristic Reasoning in Chemistry: Making decisions about acid strength

NASA Astrophysics Data System (ADS)

McClary, LaKeisha; Talanquer, Vicente

2011-07-01

The characterization of students' reasoning strategies is of central importance in the development of instructional strategies that foster meaningful learning. In particular, the identification of shortcut reasoning procedures (heuristics) used by students to reduce cognitive load can help us devise strategies to facilitate the development of more analytical ways of thinking. The central goal of this qualitative study was thus to investigate heuristic reasoning as used by organic chemistry college students, focusing our attention on their ability to predict the relative acid strength of chemical compounds represented using explicit composition and structural features (i.e., structural formulas). Our results indicated that many study participants relied heavily on one or more of the following heuristics to make most of their decisions: reduction, representativeness, and lexicographic. Despite having visual access to reach structural information about the substances included in each ranking task, many students relied on isolated composition features to make their decisions. However, the specific characteristics of the tasks seemed to trigger heuristic reasoning in different ways. Although the use of heuristics allowed students to simplify some components of the ranking tasks and generate correct responses, it often led them astray. Very few study participants predicted the correct trends based on scientifically acceptable arguments. Our results suggest the need for instructional interventions that explicitly develop college chemistry students' abilities to monitor their thinking and evaluate the effectiveness of analytical versus heuristic reasoning strategies in different contexts.
[Gutiérrez Bueno (1745-1822), textbooks and a new public for chemistry in the last third of the 18th century].

PubMed

García Belmar, A; Bertomeu Sánchez, J R

2001-01-01

This paper is a part of a general research project on the role that chemistry played in the transition of materia medica to experimental pharmacology during 19th century Spain. Within this general framework, the paper deals with the main characteristics of Spanish textbooks aimed at pharmaceutical and medical students. In a former study, published in this journal, we outlined the institutional context in which these books were read, written and published. Some of these issues are developed in the present paper through analysis of the "Curso de química" written by Pedro Gutiérrez Bueno. New light is shed on the public for chemistry during the late XVIII century Spain and their role in shaping the contents and organisation of chemistry textbooks.
Common-sense chemistry: The use of assumptions and heuristics in problem solving

NASA Astrophysics Data System (ADS)

Maeyer, Jenine Rachel

Students experience difficulty learning and understanding chemistry at higher levels, often because of cognitive biases stemming from common sense reasoning constraints. These constraints can be divided into two categories: assumptions (beliefs held about the world around us) and heuristics (the reasoning strategies or rules used to build predictions and make decisions). A better understanding and characterization of these constraints are of central importance in the development of curriculum and teaching strategies that better support student learning in science. It was the overall goal of this thesis to investigate student reasoning in chemistry, specifically to better understand and characterize the assumptions and heuristics used by undergraduate chemistry students. To achieve this, two mixed-methods studies were conducted, each with quantitative data collected using a questionnaire and qualitative data gathered through semi-structured interviews. The first project investigated the reasoning heuristics used when ranking chemical substances based on the relative value of a physical or chemical property, while the second study characterized the assumptions and heuristics used when making predictions about the relative likelihood of different types of chemical processes. Our results revealed that heuristics for cue selection and decision-making played a significant role in the construction of answers during the interviews. Many study participants relied frequently on one or more of the following heuristics to make their decisions: recognition, representativeness, one-reason decision-making, and arbitrary trend. These heuristics allowed students to generate answers in the absence of requisite knowledge, but often led students astray. When characterizing assumptions, our results indicate that students relied on intuitive, spurious, and valid assumptions about the nature of chemical substances and processes in building their responses. In particular, many interviewees seemed to view chemical reactions as macroscopic reassembling processes where favorability was related to the perceived ease with which reactants broke apart or products formed. Students also expressed spurious chemical assumptions based on the misinterpretation and overgeneralization of periodicity and electronegativity. Our findings suggest the need to create more opportunities for college chemistry students to monitor their thinking, develop and apply analytical ways of reasoning, and evaluate the effectiveness of shortcut reasoning procedures in different contexts.
Redox activation of metal-based prodrugs as a strategy for drug delivery

PubMed Central

Graf, Nora

2012-01-01

This review provides an overview of metal-based anticancer drugs and drug candidates. In particular, we focus on metal complexes that can be activated in the reducing environment of cancer cells, thus serving as prodrugs. There are many reports of Pt and Ru complexes as redox-activatable drug candidates, but other d-block elements with variable oxidation states have a similar potential to serve as prodrugs in this manner. In this context are compounds based on Fe, Co, or Cu chemistry, which are also covered. A trend in the field of medicinal inorganic chemistry has been toward molecularly targeted, metal-based drugs obtained by functionalizing complexes with biologically active ligands. Another recent activity is the use of nanomaterials for drug delivery, exploiting passive targeting of tumors with nanosized constructs made from Au, Fe, carbon, or organic polymers. Although complexes of all of the above mentioned metals will be described, this review focuses primarily on Pt compounds, including constructs containing nanomaterials. PMID:22289471
Cirrus cloud mimic surfaces in the laboratory: organic acids, bases and NOx heterogeneous reactions

NASA Astrophysics Data System (ADS)

Sodeau, J.; Oriordan, B.

2003-04-01

CIRRUS CLOUD MIMIC SURFACES IN THE LABORATORY:ORGANIC ACIDS, BASES AND NOX HETEROGENEOUS REACTIONS. B. ORiordan, J. Sodeau Department of Chemistry and Environment Research Institute, University College Cork, Ireland j.sodeau@ucc.ie /Fax: +353-21-4902680 There are a variety of biogenic and anthropogenic sources for the simple carboxylic acids to be found in the troposphere giving rise to levels as high as 45 ppb in certain urban areas. In this regard it is of note that ants of genus Formica produce some 10Tg of formic acid each year; some ten times that produced by industry. The expected sinks are those generally associated with tropospheric chemistry: the major routes studied, to date, being wet and dry deposition. No studies have been carried out hitherto on the role of water-ice surfaces in the atmospheric chemistry of carboxylic acids and the purpose of this paper is to indicate their potential function in the heterogeneous release of atmospheric species such as HONO. The deposition of formic acid on a water-ice surface was studied using FT-RAIR spectroscopy over a range of temperatures between 100 and 165K. In all cases ionization to the formate (and oxonium) ions was observed. The results were confirmed by TPD (Temperature Programmed Desorption) measurements, which indicated that two distinct surface species adsorb to the ice. Potential reactions between the formic acid/formate ion surface and nitrogen dioxide were subsequently investigated by FT-RAIRS. Co-deposition experiments showed that N2O3 and the NO+ ion (associated with water) were formed as products. A mechanism is proposed to explain these results, which involves direct reaction between the organic acid and nitrogen dioxide. Similar experiments involving acetic acid also indicate ionization on a water-ice surface. The results are put into the context of atmospheric chemistry potentially occuring on cirrus cloud surfaces.
"No one does this for fun": Contextualization and process writing in an organic chemistry laboratory course

NASA Astrophysics Data System (ADS)

Gay, Andrea

This study investigated the introduction of curriculum innovations into an introductory organic chemistry laboratory course. Pre-existing experiments in a traditional course were re-written in a broader societal context. Additionally, a new laboratory notebook methodology was introduced, using the Decision/Explanation/Observation/Inference (DEOI) format that required students to explicitly describe the purpose of procedural steps and the meanings of observations. Experts in organic chemistry, science writing, and chemistry education examined the revised curriculum and deemed it appropriate. The revised curriculum was introduced into two sections of organic chemistry laboratory at Columbia University. Field notes were taken during the course, students and teaching assistants were interviewed, and completed student laboratory reports were examined to ascertain the impact of the innovations. The contextualizations were appreciated for making the course more interesting; for lending a sense of purpose to the study of chemistry; and for aiding in students' learning. Both experts and students described a preference for more extensive connections between the experiment content and the introduced context. Generally, students preferred the DEOI method to journal-style laboratory reports believing it to be more efficient and more focused on thinking than stylistic formalities. The students claimed that the DEOI method aided their understanding of the experiments and helped scaffold their thinking, though some students thought that the method was over-structured and disliked the required pre-laboratory work. The method was used in two distinct manners; recursively writing and revising as intended and concept contemplation only after experiment completion. The recursive use may have been influenced by TA attitudes towards the revisions and seemed to engender a sense of preparedness. Students' engagement with the contextualizations and the DEOI method highlight the need for laboratory curricula that center on the best means to engage students in understanding, rather than simply providing the best examples for transmitting content.

Promoting the 21st century scientific literacy skills through innovative chemistry instruction

NASA Astrophysics Data System (ADS)

Rahayu, Sri

2017-12-01

Students need to be equipped with the 21st century skills/capabilities to ensure their competitiveness in the knowledge era. So, it is imperative that education at school should be changed in order to fulfill the need. However, there is not any specified approach on how to educate young students for the 21st century capabilities. Regardless the impediment for ts exist, we need to construct an innovative instruction that can develop the students' 21st century skills by incorporating the skills needed, based on contemporary theory of learning, necessary context of learning and appropriate assessment in a chemistry subject matter. This paper discuss the feasible skills to be promoted through chemistry course. Those skills/capabilities are scientific literacy, higher order thinking, communicationand collaboration and curiosity. The promoted are called the 21st century scientific literacy skills in which it emphasis on scientific literacy and embedded the other 21st century skills into the innovative chemistry instruction. The elements involve in the instruction such as inquiry and constructivist approach, nature of science, contemporary/socioscientific issues, critical thinking (higher order thinking).
Water chemistry in 179 randomly selected Swedish headwater streams related to forest production, clear-felling and climate.

PubMed

Löfgren, Stefan; Fröberg, Mats; Yu, Jun; Nisell, Jakob; Ranneby, Bo

2014-12-01

From a policy perspective, it is important to understand forestry effects on surface waters from a landscape perspective. The EU Water Framework Directive demands remedial actions if not achieving good ecological status. In Sweden, 44 % of the surface water bodies have moderate ecological status or worse. Many of these drain catchments with a mosaic of managed forests. It is important for the forestry sector and water authorities to be able to identify where, in the forested landscape, special precautions are necessary. The aim of this study was to quantify the relations between forestry parameters and headwater stream concentrations of nutrients, organic matter and acid-base chemistry. The results are put into the context of regional climate, sulphur and nitrogen deposition, as well as marine influences. Water chemistry was measured in 179 randomly selected headwater streams from two regions in southwest and central Sweden, corresponding to 10 % of the Swedish land area. Forest status was determined from satellite images and Swedish National Forest Inventory data using the probabilistic classifier method, which was used to model stream water chemistry with Bayesian model averaging. The results indicate that concentrations of e.g. nitrogen, phosphorus and organic matter are related to factors associated with forest production but that it is not forestry per se that causes the excess losses. Instead, factors simultaneously affecting forest production and stream water chemistry, such as climate, extensive soil pools and nitrogen deposition, are the most likely candidates The relationships with clear-felled and wetland areas are likely to be direct effects.
Physics and Its Interfaces with Medicinal Chemistry and Drug Design

NASA Astrophysics Data System (ADS)

Santos, Ricardo N.; Andricopulo, Adriano D.

2013-08-01

Medicinal chemistry is a multidisciplinary subject that integrates knowledge from a variety of fields of science, including, but not limited to, chemistry, biology, and physics. The area of drug design involves the cooperative work of scientists with a diverse range of backgrounds and technical skills, trying to tackle complex problems using an integration of approaches and methods. One important contribution to this field comes from physics through studies that attempt to identify and quantify the molecular interactions between small molecules (drugs) and biological targets (receptors), such as the forces that govern the interactions, the thermodynamics of the drug-receptor interactions, and so on. In this context, the interfaces of physics, medicinal chemistry, and drug design are of vital importance for the development of drugs that not only have the right chemistry but also the right intermolecular properties to interact at the macromolecular level, providing useful information about the principles and molecular mechanisms underlying the therapeutic action of drugs. This article highlights some of the most important connections between physics and medicinal chemistry in the design of new drugs.
Inquiry Teaching in High School Chemistry Classrooms: The Role of Knowledge and Beliefs

NASA Astrophysics Data System (ADS)

Roehrig, Gillian H.; Luft, Julie A.

2004-10-01

"Science as inquiry" is a key content standard in the National Science Education Standards, yet implementation of inquiry-based teaching is rare in secondary chemistry classrooms. This paper is the result of a study conducted to understand factors that effect the inquiry-based instruction of ten novice secondary chemistry teachers. The study focused on the influence of teaching beliefs and content knowledge on the instructional practices of these ten teachers. Case and cross-case comparisons revealed that chemistry teachers' intentions to implement inquiry teaching were strongly influenced by their teaching beliefs rather than their knowledge of chemistry. The quality of inquiry lessons, however, was found to depend on the teachers' knowledge of chemistry content. This study reinforces the need for chemistry-focused inservice training for beginning chemistry teachers that focuses on both inquiry teaching strategies and teaching beliefs.
Prebiotic Chemistry: Geochemical Context and Reaction Screening

PubMed Central

Cleaves, Henderson James

2013-01-01

The origin of life on Earth is widely believed to have required the reactions of organic compounds and their self- and/or environmental organization. What those compounds were remains open to debate, as do the environment in and process or processes by which they became organized. Prebiotic chemistry is the systematic organized study of these phenomena. It is difficult to study poorly defined phenomena, and research has focused on producing compounds and structures familiar to contemporary biochemistry, which may or may not have been crucial for the origin of life. Given our ignorance, it may be instructive to explore the extreme regions of known and future investigations of prebiotic chemistry, where reactions fail, that will relate them to or exclude them from plausible environments where they could occur. Come critical parameters which most deserve investigation are discussed. PMID:25369745
Argumentation in the Chemistry Laboratory: Inquiry and Confirmatory Experiments

ERIC Educational Resources Information Center

Katchevich, Dvora; Hofstein, Avi; Mamlok-Naaman, Rachel

2013-01-01

One of the goals of science education is to provide students with the ability to construct arguments--reasoning and thinking critically in a scientific context. Over the years, many studies have been conducted on constructing arguments in science teaching, but only few of them have dealt with studying argumentation in the laboratory. Our research…
Transfer of the Pedagogical Transformation Competence across Chemistry Topics

ERIC Educational Resources Information Center

Mavhunga, Elizabeth

2016-01-01

Pedagogical Content Knowledge (PCK) observed in one topic is commonly understood not to be transferable to another topic. This study asked, what can then be transferred in the context of learning and acquiring PCK? The study firstly posits the existence of a generic pedagogical competence that is developed in pre-service teachers to pedagogically…
Low-Cost Method for Quantifying Sodium in Coconut Water and Seawater for the Undergraduate Analytical Chemistry Laboratory: Flame Test, a Mobile Phone Camera, and Image Processing

ERIC Educational Resources Information Center

Moraes, Edgar P.; da Silva, Nilbert S. A.; de Morais, Camilo de L. M.; das Neves, Luiz S.; de Lima, Kassio M. G.

2014-01-01

The flame test is a classical analytical method that is often used to teach students how to identify specific metals. However, some universities in developing countries have difficulties acquiring the sophisticated instrumentation needed to demonstrate how to identify and quantify metals. In this context, a method was developed based on the flame…
Using Graphs of Gibbs Energy versus Temperature in General Chemistry Discussions of Phase Changes and Colligative Properties

ERIC Educational Resources Information Center

Hanson, Robert M.; Riley, Patrick; Schwinefus, Jeff; Fischer, Paul J.

2008-01-01

The use of qualitative graphs of Gibbs energy versus temperature is described in the context of chemical demonstrations involving phase changes and colligative properties at the general chemistry level. (Contains 5 figures and 1 note.)
Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

NASA Astrophysics Data System (ADS)

Thomas, Zahra; Abbott, Benjamin W.; Troccaz, Olivier; Baudry, Jacques; Pinay, Gilles

2016-03-01

Direct and indirect effects from human activity have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. Despite an abundance of studies investigating the impact of agricultural activity on water quality, our understanding of what determines the capacity of a watershed to remove or retain nutrients remains limited. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments by investigating the relationship between catchment characteristics, stream discharge, and water chemistry. We analyzed a 5-year, high-frequency water chemistry data set from three catchments in western France ranging from 2.3 to 10.8 km2. The relationship between hydrology and solute concentrations differed between the three catchments and was associated with hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness had relatively invariant carbon and nutrient chemistry across hydrologic conditions, indicating high resilience to human disturbance. Conversely, the catchments with smoother, thinner soils responded to both intra- and interannual hydrologic variation with high concentrations of phosphate (PO43-) and ammonium (NH4+) in streams during low flow conditions and strong increases in dissolved organic carbon (DOC), sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land-use configuration) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on water quality was both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent catchment buffering capacity and the probability of human disturbance provides a useful perspective for evaluating vulnerability of aquatic ecosystems and for managing systems to maintain agricultural production while minimizing leakage of nutrients.
Active Learning Applications in the History of Chemistry: Pre-Service Chemistry Teachers' Level of Knowledge and Views

ERIC Educational Resources Information Center

Sendur, Gülten; Polat, Merve; Toku, Abdullah; Kazanci, Coskun

2014-01-01

This study aims to investigate the effects of a History and Philosophy of Chemistry-I course based on active learning applications on the level of knowledge of pre-service chemistry teachers about the history of chemistry. The views of pre-service chemistry teachers about these activities were also investigated. The study was carried out with 38…
Joseph Priestley Across Theology, Education, and Chemistry: An Interdisciplinary Case Study in Epistemology with a Focus on the Science Education Context

NASA Astrophysics Data System (ADS)

de Berg, Kevin C.

2011-07-01

This paper discusses the findings of a search for the intellectual tools used by Joseph Priestley (1733-1804) in his chemistry, education, and theology documents. Priestley's enquiring democratic view of knowledge was applicable in all three areas and constitutes a significant part of his lifework. Current epistemological issues in science education are examined from the point of view of the nature of theory and experiment as observed in Priestley's writings and as espoused in modern philosophy of science. Science and religious faith issues in the context of science education are examined from the point of view of one's understanding of sacred texts, and the suggestion is made that a Priestleyan model of "the liberty to think for oneself" and "to hold knowledge with humility and virtue" could prove helpful in dealing with the known divergent opinions in relation to science, education, and religion.
Merging curriculum design with chemical epistemology: A case of teaching and learning chemistry through modeling

NASA Astrophysics Data System (ADS)

Erduran, Sibel

The central problem underlying this dissertation is the design of learning environments that enable the teaching and learning of chemistry through modeling. Significant role of models in chemistry knowledge is highlighted with a shift in emphasis from conceptual to epistemological accounts of models. Research context is the design and implementation of student centered Acids & Bases Curriculum, developed as part of Project SEPIA. Qualitative study focused on 3 curriculum activities conducted in one 7th grade class of 19 students in an urban, public middle school in eastern United States. Questions guiding the study were: (a) How can learning environments be designed to promote growth of chemistry knowledge through modeling? (b) What epistemological criteria facilitate learning of growth of chemistry knowledge through modeling? Curriculum materials, and verbal data from whole class conversations and student group interviews were analyzed. Group interviews consisted of same 4 students, selected randomly before curriculum implementation, and were conducted following each activity to investigate students' developing understandings of models. Theoretical categories concerning definition, properties and kinds of models as well as educational and chemical models informed curriculum design, and were redefined as codes in the analysis of verbal data. Results indicate more diversity of codes in student than teacher talk across all activities. Teacher concentrated on educational and chemical models. A significant finding is that model properties such as 'compositionality' and 'projectability' were not present in teacher talk as expected by curriculum design. Students did make reference to model properties. Another finding is that students demonstrate an understanding of models characterized by the seventeenth century Lemery model of acids and bases. Two students' developing understandings of models across curriculum implementation suggest that curriculum bears some change in students' understanding of models. The tension between students' everyday knowledge and teacher's scientific knowledge is highlighted relative to the patterns in codes observed in data. Implications for theory of learning, curriculum design and teacher education are discussed. It is argued that future educational research should acknowledge and incorporate perspectives from chemical epistemology.
An Environmentally Focused General Chemistry Laboratory

ERIC Educational Resources Information Center

Mihok, Morgan; Keiser, Joseph T.; Bortiatynski, Jacqueline M.; Mallouk, Thomas E.

2006-01-01

The environmentally focused general chemistry laboratory provides a format for teaching the concepts of the mainstream laboratory within an environmental context. The capstone integrated exercise emerged as the overwhelming favorite part of this laboratory and the experiment gave students an opportunity to do a self-directed project, using the…
Effectiveness of Case-Based Learning Instruction on Epistemological Beliefs and Attitudes toward Chemistry

ERIC Educational Resources Information Center

Cam, Aylin; Geban, Omer

2011-01-01

The purpose of the study was to investigate the effectiveness of case-based learning instruction over traditionally designed chemistry instruction on eleventh grade students' epistemological beliefs and their attitudes toward chemistry as a school subject. The subjects of this study consisted of 63 eleventh grade students from two intact classes…
Thermodynamics in Context: A Case Study of Contextualized Teaching for Undergraduates

ERIC Educational Resources Information Center

Holman, John; Pilling, Gwen

2004-01-01

Chemical thermodynamics that is often considered abstract and demanding could be made more accessible by taking a contextualized approach. The trial of a course designed for chemistry majors dealing with gas laws and the first law of thermodynamics in the existing course are illustrated.
Soil Studies: Applying Acid-Base Chemistry to Environmental Analysis.

ERIC Educational Resources Information Center

West, Donna M.; Sterling, Donna R.

2001-01-01

Laboratory activities for chemistry students focus attention on the use of acid-base chemistry to examine environmental conditions. After using standard laboratory procedures to analyze soil and rainwater samples, students use web-based resources to interpret their findings. Uses CBL probes and graphing calculators to gather and analyze data and…
Coherence of Physics and Chemistry Curricula in Terms of the Electron Concept

NASA Astrophysics Data System (ADS)

Elena, Ivanova

2016-08-01

One of the major contradictions in subject teaching is the contradiction between the unity of the world and the discrete separated generalized content of natural sciences that study natural phenomena. These are physics, chemistry, biology and more. One can eliminate the conflict if opens the content's interdisciplinary links set by the events that are studied by different disciplines. The corresponding contexts of the phenomenon content arise depending on the discipline, and they are not enough coordinated. Obviously, we need a mechanism that allows establishing interdisciplinary links in the content quickly and without losing the logic of the material and assess their coherence in academic disciplines. This article uses a quantitative method of coherence assessment elaborated by T.N. Gnitetskaya. The definition of the concept of the semantic state introduced by the authors is given in this article. The method is applied to coherence assessment of physics and chemistry textbooks. The coherence of two pairs of chemistry and physics textbooks by different authors in different combinations was calculated. The most cohered pairs of textbooks (chemistry-physics) were identified. One can recommend using the pair of textbooks for eighth grade that we offered that favors the development of holistic understandings of the world around us.
Frustration across the periodic table: heterolytic cleavage of dihydrogen by metal complexes.

PubMed

Bullock, R Morris; Chambers, Geoffrey M

2017-08-28

This perspective examines frustrated Lewis pairs (FLPs) in the context of heterolytic cleavage of H 2 by transition metal complexes, with an emphasis on molecular complexes bearing an intramolecular Lewis base. FLPs have traditionally been associated with main group compounds, yet many reactions of transition metal complexes support a broader classification of FLPs that includes certain types of transition metal complexes with reactivity resembling main group-based FLPs. This article surveys transition metal complexes that heterolytically cleave H 2 , which vary in the degree that the Lewis pairs within these systems interact. Many of the examples include complexes bearing a pendant amine functioning as the base with the metal functioning as the hydride acceptor. Consideration of transition metal compounds in the context of FLPs can inspire new innovations and improvements in transition metal catalysis.This article is part of the themed issue 'Frustrated Lewis pair chemistry'. © 2017 The Author(s).
Teaching Structural Formulas in Chemistry: How Students Relate Structural Formulas to the Solubility of Substances.

ERIC Educational Resources Information Center

Goedhart, Martin; van Duin, Yvonne

Structural formulas give professional chemists information about physical and chemical properties of corresponding compounds. In chemistry education at secondary schools, structural formulas are introduced in the context of chemical bonding. Structural formulas are not introduced as representations of the properties of chemical compounds. This…

Idealization in Chemistry: Pure Substance and Laboratory Product

ERIC Educational Resources Information Center

Fernández-González, Manuel

2013-01-01

This article analyzes the concept of idealization in chemistry and the role played by pure substance and laboratory product. This topic has evident repercussions in the educational contexts that are applied to the science classroom, which are highlighted throughout the text. A common structure for knowledge construction is proposed for both…
Developing Problem-Solving Skills through Retrosynthetic Analysis and Clickers in Organic Chemistry

ERIC Educational Resources Information Center

Flynn, Alison B.

2011-01-01

A unique approach to teaching and learning problem-solving and critical-thinking skills in the context of retrosynthetic analysis is described. In this approach, introductory organic chemistry students, who typically see only simple organic structures, undertook partial retrosynthetic analyses of real and complex synthetic targets. Multiple…
Conceptual Questions and Lack of Formal Reasoning: Are They Mutually Exclusive?

ERIC Educational Resources Information Center

Igaz, Csaba; Proksa, Miroslav

2012-01-01

Using specially designed conceptual question pairs, 9th grade students were tested on tasks (presented as experimental situations in pictorial form) that involved controlling the variables' scheme of formal reasoning. The question topics focused on these three chemical contexts: chemistry in everyday life, chemistry without formal concepts, and…
New Pathways for Teaching Chemistry: Reflective Judgment in Science.

ERIC Educational Resources Information Center

Finster, David C.

1992-01-01

The reflective judgment model offers a rich context for analysis of science and science teaching. It provides deeper understanding of the scientific process and its critical thinking and reveals fundamental connections between science and the other liberal arts. Classroom techniques from a college chemistry course illustrate the utility of the…
Potentialities beyond Deficit Perspectives: Globalization, Culture and Urban Science Education in the Bronx

ERIC Educational Resources Information Center

Pitts, Wesley

2011-01-01

The major focus of this ethnographic study is devoted to exploring the confluence of global and local referents of science education in the context of an urban chemistry laboratory classroom taught by a first-generation Filipino-American male teacher. This study investigates encounters between the teacher and four second-generation immigrant…
Exploring Grade 11 Students' Conceptual Pathways of the Particulate Nature of Matter in the Context of Multirepresentational Instruction

ERIC Educational Resources Information Center

Adadan, Emine; Trundle, Kathy Cabe; Irving, Karen E.

2010-01-01

This study investigated the conceptual pathways of 19 Grade 11 introductory chemistry students (age 16-17) as they participated in a multirepresentational instruction on the particulate nature of matter (PNM). This study was grounded in contemporary conceptual change theory, in particular, research on students' conceptual pathways that focuses on…
Bioorthogonal chemistry: applications in activity-based protein profiling.

PubMed

Willems, Lianne I; van der Linden, Wouter A; Li, Nan; Li, Kah-Yee; Liu, Nora; Hoogendoorn, Sascha; van der Marel, Gijs A; Florea, Bogdan I; Overkleeft, Herman S

2011-09-20

The close interaction between organic chemistry and biology goes back to the late 18th century, when the modern natural sciences began to take shape. After synthetic organic chemistry arose as a discipline, organic chemists almost immediately began to pursue the synthesis of naturally occurring compounds, thereby contributing to the understanding of their functions in biological processes. Research in those days was often remarkably interdisciplinary; in fact, it constituted chemical biology research before the phrase even existed. For example, histological dyes, both of an organic and inorganic nature, were developed and applied by independent researchers (Gram and Golgi) with the aim of visualizing cellular substructures (the bacterial cell wall and the Golgi apparatus). Over the years, as knowledge within the various fields of the natural sciences deepened, research disciplines drifted apart, becoming rather monodisciplinary. In these years, broadly ranging from the end of World War II to about the 1980s, organic chemistry continued to impact life sciences research, but contributions were of a more indirect nature. As an example, the development of the polymerase chain reaction, from which molecular biology and genetics research have greatly profited, was partly predicated on the availability of synthetic oligonucleotides. These molecules first became available in the late 1960s, the result of organic chemists pursuing the synthesis of DNA oligomers primarily because of the synthetic challenges involved. Today, academic natural sciences research is again becoming more interdisciplinary, and sometimes even multidisciplinary. What was termed "chemical biology" by Stuart Schreiber at the end of the last century can be roughly described as the use of intellectually chemical approaches to shed light on processes that are fundamentally rooted in biology. Chemical tools and techniques that are developed for biological studies in the exciting and rapidly evolving field of chemical biology research include contributions from many areas of the multifaceted discipline of chemistry, and particularly from organic chemistry. Researchers apply knowledge inherent to organic chemistry, such as reactivity and selectivity, to the manipulation of specific biomolecules in biological samples (cell extracts, living cells, and sometimes even animal models) to gain insight into the biological phenomena in which these molecules participate. In this Account, we highlight some of the recent developments in chemical biology research driven by organic chemistry, with a focus on bioorthogonal chemistry in relation to activity-based protein profiling. The rigorous demands of bioorthogonality have not yet been realized in a truly bioorthogonal reagent pair, but remarkable progress has afforded a range of tangible contributions to chemical biology research. Activity-based protein profiling, which aims to obtain information on the workings of a protein (or protein family) within the larger context of the full biological system, has in particular benefited from these advances. Both activity-based protein profiling and bioorthogonal chemistry have been around for approximately 15 years, and about 8 years ago the two fields very profitably intersected. We expect that each discipline, both separately and in concert, will continue to make important contributions to chemical biology research. © 2011 American Chemical Society
An Investigation into the Effectiveness of Problem-Based Learning in a Physical Chemistry Laboratory Course

ERIC Educational Resources Information Center

Gurses, Ahmet; Acikyildiz, Metin; Dogar, Cetin; Sozbilir, Mustafa

2007-01-01

The aim of this study was to investigate the effectiveness of a problem-based learning (PBL) approach in a physical chemistry laboratory course. The parameters investigated were students' attitudes towards a chemistry laboratory course, scientific process skills of students and their academic achievement. The design of the study was one group…
A Three-Way Street: MISR and MODIS Provide Context, SEAC4RS Provides Detail and Validation, Models Complete the Picture

NASA Technical Reports Server (NTRS)

Kahn, Ralph A.

2014-01-01

The Transported Smoke Survey had three objectives: to evaluate imager and polarimeter sensitivity to smoke properties (remote sensing validation); to study characteristics of transported smoke (chemistry/transport); and to assess rediative impact of smoke layers (radiation closure).
"Drug" Discovery with the Help of Organic Chemistry.

PubMed

Itoh, Yukihiro; Suzuki, Takayoshi

2017-01-01

The first step in "drug" discovery is to find compounds binding to a potential drug target. In modern medicinal chemistry, the screening of a chemical library, structure-based drug design, and ligand-based drug design, or a combination of these methods, are generally used for identifying the desired compounds. However, they do not necessarily lead to success and there is no infallible method for drug discovery. Therefore, it is important to explore medicinal chemistry based on not only the conventional methods but also new ideas. So far, we have found various compounds as drug candidates. In these studies, some strategies based on organic chemistry have allowed us to find drug candidates, through 1) construction of a focused library using organic reactions and 2) rational design of enzyme inhibitors based on chemical reactions catalyzed by the target enzyme. Medicinal chemistry based on organic chemical reactions could be expected to supplement the conventional methods. In this review, we present drug discovery with the help of organic chemistry showing examples of our explorative studies on histone deacetylase inhibitors and lysine-specific demethylase 1 inhibitors.
Recent Advances in Metal-Organic Frameworks for Heterogeneous Catalyzed Organic Transformations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabale, Sandip R.; Zheng, Jian; Vemuri, Venkata Rama Ses

2016-12-12

In this review, we have summarized the recent advances in MOF based heterogeneous catalytic chemistry. Catalytic performance of various configurations of MOFs such as active sites, post synthetic modification and MOF derived catalyst, has been summarized in the context of various organic transformation reactions. Post synthetic modification of MOFs via functionalization of organic linkers with active catalytic moieties was deliberated. Also, efficacy of carbonaceous catalysts derived from MOFs was discussed.
Placing Science into Its Human Context: Using Scientific Autobiography to Teach Chemistry

NASA Astrophysics Data System (ADS)

Carroll, Felix A.; Seeman, Jeffrey I.

2001-12-01

Scientific autobiography and biography can improve chemistry learning by helping students relate otherwise abstract concepts to important events in the lives of fellow human beings. In advanced courses, reading scientific autobiography and biography can help students see how scientific collaboration, advances in instrumentation, and major events in human lives influence the development of chemical ideas over time. In addition, studying many years of an individual's research program can demonstrate the progress of science, the connectivity of research findings, and the validity of experimental results over many decades. This paper describes the use of an autobiography of an eminent chemist in an advanced undergraduate chemistry course. This approach not only enhances the teaching of chemical concepts, but it also provides students with expanded opportunities for cooperative and self-directed learning activities.
Problem-based learning on quantitative analytical chemistry course

NASA Astrophysics Data System (ADS)

Fitri, Noor

2017-12-01

This research applies problem-based learning method on chemical quantitative analytical chemistry, so called as "Analytical Chemistry II" course, especially related to essential oil analysis. The learning outcomes of this course include aspects of understanding of lectures, the skills of applying course materials, and the ability to identify, formulate and solve chemical analysis problems. The role of study groups is quite important in improving students' learning ability and in completing independent tasks and group tasks. Thus, students are not only aware of the basic concepts of Analytical Chemistry II, but also able to understand and apply analytical concepts that have been studied to solve given analytical chemistry problems, and have the attitude and ability to work together to solve the problems. Based on the learning outcome, it can be concluded that the problem-based learning method in Analytical Chemistry II course has been proven to improve students' knowledge, skill, ability and attitude. Students are not only skilled at solving problems in analytical chemistry especially in essential oil analysis in accordance with local genius of Chemistry Department, Universitas Islam Indonesia, but also have skilled work with computer program and able to understand material and problem in English.
Thirty years through vanadium chemistry.

PubMed

Costa Pessoa, J

2015-06-01

The relevance of vanadium in biological systems is known for many years and vanadium-based catalysts have important industrial applications, however, till the beginning of the 80s research on vanadium chemistry and biochemistry did not receive much attention from the scientific community. The understanding of the broad bioinorganic implications resulting from the similarities between phosphate and vanadate(V) and the discovery of vanadium dependent enzymes gave rise to an enormous increase in interest in the chemistry and biological relevance of vanadium. Thereupon the last 30years corresponded to a period of enormous research effort in these fields, as well as in medicinal applications of vanadium and in the development of catalysts for use in fine-chemical synthesis, some of these inspired by enzymatic active sites. Since the 80s my group in collaboration with others made contributions, described throughout this text, namely in the understanding of the speciation of vanadium compounds in aqueous solution and in biological fluids, and to the transport of vanadium compounds in blood plasma and their uptake by cells. Several new types of vanadium compounds were also synthesized and characterized, with applications either as prospective therapeutic drugs or as homogeneous or heterogenized catalysts for the production of fine chemicals. The developments made are described also considering the international context of the evolution of the knowledge in the chemistry and bioinorganic chemistry of vanadium compounds during the last 30years. This article was compiled based on the Vanadis Award presentation at the 9th International Vanadium Symposium. Copyright © 2015 Elsevier Inc. All rights reserved.
Hispanic-American Students' Attitudes toward Enrolling in High School Chemistry: A Study of Planned Behavior and Belief-Based Change.

ERIC Educational Resources Information Center

Crawley, Frank E.; Koballa, Thomas R., Jr.

The study sought to: (1) identify the determinants that motivate Hispanic-American students to enroll in high school chemistry; and (2) determine if providing belief-based information to students and their parents/guardians increases chemistry registration. The Theory of Planned Behavior (TPB) and Elaboration Likelihood Model (ELM) guided the…
Case Studies in Systems Chemistry. Final Report. [Includes Complete Case Study, Carboxylic Acid Equilibria

ERIC Educational Resources Information Center

Fleck, George

This publication was produced as a teaching tool for college chemistry. The book is a text for a computer-based unit on the chemistry of acid-base titrations, and is designed for use with FORTRAN or BASIC computer systems, and with a programmable electronic calculator, in a variety of educational settings. The text attempts to present computer…
The Aspiring Adept: Robert Boyle and His Alchemical Quest (Lawrence M. Principe)

NASA Astrophysics Data System (ADS)

Kovac, Jeffrey

1999-10-01

Robert Boyle is widely regarded as the Father of Modern Chemistry, who broke once and for all from the irrational, misguided alchemy that preceded him. One of the goals of this carefully researched and argued new book by Lawrence M. Principe, Assistant Professor in the Department of Chemistry and the Institute for the History of Science, Medicine, and Technology at The Johns Hopkins University, is to refute the two errors in this characterization of Boyle and to understand his life, thought, and work in the intellectual and social context of his time. This book is not for the casual reader; it is a detailed scholarly treatise in the history of science, but it provides a fresh and interesting perspective on Boyle and on the development of chemistry in the 17th century. Boyle is usually characterized as a modern scientist and his most famous book, The Skeptical Chymist, as a critique of traditional alchemy. Principe demonstrates that this characterization is based on a selective and sometimes incorrect reading of Boyle's works. Like Newton, Boyle was deeply involved in traditional transmutational alchemy, reading the works of other alchemists, performing experiments, and even witnessing transmutations. Alchemy, however, was not a monolith and Boyle adhered to what Principe tentatively identifies as a uniquely English school of supernatural alchemy. According to Principe, The Skeptical Chymist was mainly a criticism of the Paracelsians interested in chemical medicine rather than a defense of what we would now regard as modern chemistry. To further support his characterization of Boyle and to better reveal Boyle's involvement in alchemyparticularly the transmutation of base metals to gold, termed chrysopoeiaPrincipe has reconstructed from some 20 fragments one of Boyle's alchemical manuscripts, his Dialogue on the Transmutation of Metals. The full text of this lost work is included as Appendix 1. Two other primary sources, Interview Accounts of Transmutations and Prefaces to Boyle's Other Chrysopoetic Writings, and Robert Boyle's Dialogue on the Converse with Angels Aided by the Philosophers Stone, are also printed, as Appendices 2 and 3. Both Robert Boyle and 17th-century chemistry emerge from this book as exceedingly complex. The development of chemistry cannot be regarded as either straightforward or linear. As Boyle's work exemplifies, ideas from traditional alchemy were important in the development of chemistry. For example, Boyle's corpuscularian hypothesis is partly derived from the alchemical corpuscularian traditionthe minima of Geber. Alchemy was part of the intellectual context in which both Boyle and Newton were raised and it played an important part in their thinking. For Boyle, alchemy was also closely linked to Christianity. He regarded the philosophers' stone as a powerful weapon against the growing atheism of his time. The possessor of the stone could summon angels and other spirits, thus providing support for crucial theological truths. Religion was as important a motivation as both natural philosophy and the potential for the development of potent medicines for Boyle's study of alchemy. This book is a rich source of information on Robert Boyle, alchemy, and the development of 17th century chemistry. It is not an easy book, however; it requires close attention and some background in the history of science. For those interested in the development of modern science, this is a valuable addition to the growing collection of excellent new books.
Survey Exploring Views of Scientists on Current Trends in Chemistry Education

NASA Astrophysics Data System (ADS)

Vamvakeros, Xenofon; Pavlatou, Evangelia A.; Spyrellis, Nicolas

2010-02-01

A survey exploring the views of scientists, chemists and chemical engineers, on current trends in Chemistry Education was conducted in Greece. Their opinions were investigated using a questionnaire focusing on curricula (the content and process of chemistry teaching and learning), as well as on the respondents’ general educational beliefs and their underlying epistemological views. The aim of this work was to investigate the respondents’ opinions and, if possible, to identify the areas where convergence or even consensus occurred. The results showed that some of the items on the research questionnaire produced a high degree of agreement with the respondents’ views, while a few others were exactly the opposite. These items are considered to be representative of more widespread views. In order to explore the diverging opinions, the items on the research questionnaire that showed great variance were analyzed to determine, whether or not there were significant inter-item correlations among subgroups of participants with different demographic characteristics. Postgraduate studies, professional occupation, age/experience, and career within or outside the wide educational sector were among the main factors that significantly influenced the research results. The study did not reveal any single belief framework underlying the opinions of the respondents. Nevertheless, three specific approach frameworks—ACADEMIC, CONSTRUCTIVIST and SCIENTIFIC REALISM—were analyzed to determine which had the highest degree of agreement. It was found that the SCIENTIFIC REALISM framework and the curriculum emphasis characteristic of the context-based CTSE (Chemistry, Technology, Society and Environment) prevailed, as they produced a significantly higher mean score. The ACADEMIC framework followed with a moderate mean score and the CONSTRUCTIVIST framework had a lower mean score.
Visualizing Molecular Chirality in the Organic Chemistry Laboratory Using Cholesteric Liquid Crystals

ERIC Educational Resources Information Center

Popova, Maia; Bretz, Stacey Lowery; Hartley, C. Scott

2016-01-01

Although stereochemistry is an important topic in second-year undergraduate organic chemistry, there are limited options for laboratory activities that allow direct visualization of macroscopic chiral phenomena. A novel, guided-inquiry experiment was developed that allows students to explore chirality in the context of cholesteric liquid crystals.…
A Review of Research on the Teaching and Learning of Thermodynamics at the University Level

ERIC Educational Resources Information Center

Bain, Kinsey; Moon, Alena; Mack, Michael R.; Towns, Marcy H.

2014-01-01

We review previous research on the teaching and learning of thermodynamics in upper-level, undergraduate settings. As chemistry education researchers we use physical chemistry as a context for understanding the literature. During our synthesis four themes of research emerged: factors that influence student success in learning thermodynamics,…

Ionic Liquids and Green Chemistry: A Lab Experiment

ERIC Educational Resources Information Center

Stark, Annegret; Ott, Denise; Kralisch, Dana; Kreisel, Guenter; Ondruschka, Bernd

2010-01-01

Although ionic liquids have been investigated as solvents for many applications and are starting to be used in industrial processes, only a few lab experiments are available to introduce students to these materials. Ionic liquids have been discussed in the context of green chemistry, but few investigations have actually assessed the degree of…
Field Trips Put Chemistry in Context for Non-Science Majors

ERIC Educational Resources Information Center

Peterman, Keith E.

2008-01-01

Field trips can provide excellent real-world learning situations for students in non-science major chemistry courses. The field trips described in this article are accessible, most trips can be completed within a scheduled three-hour laboratory time period, and they can be conducted at minimal cost. These field trips significantly enhanced student…
Spectroscopy 101: A Practical Introduction to Spectroscopy and Analysis for Undergraduate Organic Chemistry Laboratories

ERIC Educational Resources Information Center

Morrill, Lucas A.; Kammeyer, Jacquelin K.; Garg, Neil K.

2017-01-01

An undergraduate organic chemistry laboratory that provides an introduction to various spectroscopic techniques is reported. Whereas organic spectroscopy is most often learned and practiced in the context of reaction analyses, this laboratory experiment allows students to become comfortable with [superscript 1]H NMR, [superscript 13]C NMR, and IR…
Student Use of Energy Concepts from Physics in Chemistry Courses

ERIC Educational Resources Information Center

Nagel, Megan L.; Lindsey, Beth A.

2015-01-01

This paper describes an interdisciplinary investigation of students' usage of ideas about energy from physics in the context of introductory chemistry. We focus on student understanding of the idea that potential energy is a function of distance between interacting objects, a concept relevant to understanding potential energy in both physical and…
Solventless and One-Pot Synthesis of Cu(II) Phthalocyanine Complex: A Green Chemistry Experiment

ERIC Educational Resources Information Center

Sharma, R. K.; Sharma, Chetna; Sidhwani, Indu Tucker

2011-01-01

With the growing awareness of green chemistry, it is increasingly important for students to understand this concept in the context of laboratory experiments. Although microwave-assisted organic synthesis has become a common and invaluable technique in recent years, there have been few procedures published for microwave-assisted inorganic synthesis…
Engaging Students in Science Courses: Lessons of Change from the Arctic.

PubMed

Duffy, Lawrence K; Godduhn, Anna; Nicholas-Figueroa, Linda; Fabbri, Cindy E; van Muelken, Mary

2011-05-01

Where you live should have something to do with what you teach. In the Arctic, this idea of place-based education-teaching and sharing knowledge that is needed to live well- is central to the UARCTIC consortium and the 4 th International Polar Year educational reform effort. A place-based issue oriented context can engage students in chemistry concepts when it intersects with their experience and lives. This article examines the rationale and means of integrating local concerns such as world view, culture, traditional knowledge and policy into both general and specialized chemistry courses. More broadly, capacious place-based issues should be widely adapted by all curriculum reform efforts to demonstrate the connectivity between science and societal understanding of technological options. A case in point is the inclusion of indigenous perspectives in a non-majors general chemistry course when the concepts of scientific method, ice and water resources, genetic engineering, etc. are discussed. In a specialized course on radioactivity in the north, topics connected nuclear chemistry and radioactivity to people and energy. The local landscape should be central to science courses and involve issues relevant to stewardship, a component of the indigenous world view. The historical issues can be connected to current nuclear energy and uranium mining as they relate to the risks and benefits for the local community. This article will make the case that curriculum reform that focuses on real-world topics will not only engage students so that they perform well in class but also spark their interest so that they continue learning after the course is over.
Overview of actinide chemistry in the WIPP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borkowski, Marian; Lucchini, Jean - Francois; Richmann, Michael K

2009-01-01

The year 2009 celebrates 10 years of safe operations at the Waste Isolation Pilot Plant (WIPP), the only nuclear waste repository designated to dispose defense-related transuranic (TRU) waste in the United States. Many elements contributed to the success of this one-of-the-kind facility. One of the most important of these is the chemistry of the actinides under WIPP repository conditions. A reliable understanding of the potential release of actinides from the site to the accessible environment is important to the WIPP performance assessment (PA). The environmental chemistry of the major actinides disposed at the WIPP continues to be investigated as partmore » of the ongoing recertification efforts of the WIPP project. This presentation provides an overview of the actinide chemistry for the WIPP repository conditions. The WIPP is a salt-based repository; therefore, the inflow of brine into the repository is minimized, due to the natural tendency of excavated salt to re-seal. Reducing anoxic conditions are expected in WIPP because of microbial activity and metal corrosion processes that consume the oxygen initially present. Should brine be introduced through an intrusion scenario, these same processes will re-establish reducing conditions. In the case of an intrusion scenario involving brine, the solubilization of actinides in brine is considered as a potential source of release to the accessible environment. The following key factors establish the concentrations of dissolved actinides under subsurface conditions: (1) Redox chemistry - The solubility of reduced actinides (III and IV oxidation states) is known to be significantly lower than the oxidized forms (V and/or VI oxidation states). In this context, the reducing conditions in the WIPP and the strong coupling of the chemistry for reduced metals and microbiological processes with actinides are important. (2) Complexation - For the anoxic, reducing and mildly basic brine systems in the WIPP, the most important inorganic complexants are expected to be carbonate/bicarbonate and hydroxide. There are also organic complexants in TRU waste with the potential to strongly influence actinide solubility. (3) Intrinsic and pseudo-actinide colloid formation - Many actinide species in their expected oxidation states tend to form colloids or strongly associate with non actinide colloids present (e.g., microbial, humic and organic). In this context, the relative importance of actinides, based on the TRU waste inventory, with respect to the potential release of actinides from the WIPP, is greater for plutonium and americium, and to less extent for uranium and thorium. The most important oxidation states for WIPP-relevant conditions are III and IV. We will present an update of the literature on WIPP-specific data, and a summary of the ongoing research related to actinide chemistry in the WIPP performed by the Los Alamos National Laboratory (LANL) Actinide Chemistry and Repository Science (ACRSP) team located in Carlsbad, NM [Reed 2007, Lucchini 2007, and Reed 2006].« less
Digital biology and chemistry.

PubMed

Witters, Daan; Sun, Bing; Begolo, Stefano; Rodriguez-Manzano, Jesus; Robles, Whitney; Ismagilov, Rustem F

2014-09-07

This account examines developments in "digital" biology and chemistry within the context of microfluidics, from a personal perspective. Using microfluidics as a frame of reference, we identify two areas of research within digital biology and chemistry that are of special interest: (i) the study of systems that switch between discrete states in response to changes in chemical concentration of signals, and (ii) the study of single biological entities such as molecules or cells. In particular, microfluidics accelerates analysis of switching systems (i.e., those that exhibit a sharp change in output over a narrow range of input) by enabling monitoring of multiple reactions in parallel over a range of concentrations of signals. Conversely, such switching systems can be used to create new kinds of microfluidic detection systems that provide "analog-to-digital" signal conversion and logic. Microfluidic compartmentalization technologies for studying and isolating single entities can be used to reconstruct and understand cellular processes, study interactions between single biological entities, and examine the intrinsic heterogeneity of populations of molecules, cells, or organisms. Furthermore, compartmentalization of single cells or molecules in "digital" microfluidic experiments can induce switching in a range of reaction systems to enable sensitive detection of cells or biomolecules, such as with digital ELISA or digital PCR. This "digitizing" offers advantages in terms of robustness, assay design, and simplicity because quantitative information can be obtained with qualitative measurements. While digital formats have been shown to improve the robustness of existing chemistries, we anticipate that in the future they will enable new chemistries to be used for quantitative measurements, and that digital biology and chemistry will continue to provide further opportunities for measuring biomolecules, understanding natural systems more deeply, and advancing molecular and cellular analysis. Microfluidics will impact digital biology and chemistry and will also benefit from them if it becomes massively distributed.
Fluorine-containing nanoemulsions for MRI cell tracking

PubMed Central

Janjic, Jelena M.; Ahrens, Eric T.

2009-01-01

In this article we review the chemistry and nanoemulsion formulation of perfluorocarbons used for in vivo 19F MRI cell tracking. In this application, cells of interest are labeled in culture using a perfluorocarbon nanoemulsion. Labeled cells are introduced into a subject and tracked using 19F MRI or NMR spectroscopy. In the same imaging session, a high-resolution, conventional (1H) image can be used to place the 19F-labeled cells into anatomical context. Perfluorocarbon-based 19F cell tracking is a useful technology because of the high specificity for labeled cells, ability to quantify cell accumulations, and biocompatibility. This technology can be widely applied to studies of inflammation, cellular regenerative medicine, and immunotherapy. PMID:19920872
Using Beads and Divided Containers to Study Kinetic and Equilibrium Isotope Effects in the Laboratory and in the Classroom

ERIC Educational Resources Information Center

Campbell, Dean J.; Brewer, Emily R.; Martinez, Keri A.; Fitzjarrald, Tamara J.

2017-01-01

The purpose of this laboratory experiment is to study fundamental concepts of kinetics and equilibria and the isotope effects associated with both of these concepts. The concepts of isotopes in introductory and general chemistry courses are typically used within the contexts of atomic weights and radioactivity. Kinetic and equilibrium isotope…
Bioinorganic Life and Neural Activity: Toward a Chemistry of Consciousness?

PubMed

Chang, Christopher J

2017-03-21

Identifying what elements are required for neural activity as potential path toward consciousness, which represents life with the state or quality of awareness, is a "Holy Grail" of chemistry. As life itself arises from coordinated interactions between elements across the periodic table, the majority of which are metals, new approaches for analysis, binding, and control of these primary chemical entities can help enrich our understanding of inorganic chemistry in living systems in a context that is both universal and personal.
Implementation of Problem-Based Learning in Environmental Chemistry

ERIC Educational Resources Information Center

Jansson, Stina; So¨derstro¨m, Hanna; Andersson, Patrik L.; Nording, Malin L.

2015-01-01

Environmental Chemistry covers a range of topics within the discipline of chemistry, from toxicology to legislation, which warrants interdisciplinary study. Consequently, problem-based learning (PBL), a style of student-centered learning which facilitates the integration of multiple subjects, was investigated to determine if it would be a more…
How Do Students Understand Energy in Biology, Chemistry, and Physics? Development and Validation of an Assessment Instrument

ERIC Educational Resources Information Center

Opitz, Sebastian Tobias; Neumann, Knut; Bernholt, Sascha; Harms, Ute

2017-01-01

Science standards of different countries introduced disciplinary core ideas and crosscutting concepts--such as energy--to help students develop a more interconnected science understanding. As previous research has mostly addressed energy learning in specific disciplinary contexts, this study targets students' cross-disciplinary understanding of…
Metacognitive Monitoring and Learning Gain in Foundation Chemistry

ERIC Educational Resources Information Center

Mathabathe, Kgadi C.; Potgieter, Marietjie

2014-01-01

The ability to make realistic judgments of one's performance is a demonstration of the possession of strong metacognitive skills. In this study we investigate the relationship between accuracy of self-evaluation as an expression of metacognitive skill, and learning gain in stoichiometry. The context is an academic development programme at a South…
Reduced Order Modeling of Combustion Instability in a Gas Turbine Model Combustor

NASA Astrophysics Data System (ADS)

Arnold-Medabalimi, Nicholas; Huang, Cheng; Duraisamy, Karthik

2017-11-01

Hydrocarbon fuel based propulsion systems are expected to remain relevant in aerospace vehicles for the foreseeable future. Design of these devices is complicated by combustion instabilities. The capability to model and predict these effects at reduced computational cost is a requirement for both design and control of these devices. This work focuses on computational studies on a dual swirl model gas turbine combustor in the context of reduced order model development. Full fidelity simulations are performed utilizing URANS and Hybrid RANS-LES with finite rate chemistry. Following this, data decomposition techniques are used to extract a reduced basis representation of the unsteady flow field. These bases are first used to identify sensor locations to guide experimental interrogations and controller feedback. Following this, initial results on developing a control-oriented reduced order model (ROM) will be presented. The capability of the ROM will be further assessed based on different operating conditions and geometric configurations.
Chem-2-Chem: A One-to-One Supportive Learning Environment for Chemistry

NASA Astrophysics Data System (ADS)

Báez-Galib, Rosita; Colón-Cruz, Héctor; Resto, Wilfredo; Rubin, Michael R.

2005-12-01

The Chem-2-Chem (C2C) tutoring mentoring program was developed at the University of Puerto Rico at Cayey, an undergraduate institution serving Hispanic students, to increase student retention and help students achieve successful general chemistry course outcomes. This program provides a supportive learning environment designed to address students' academic and emotional needs in a holistic way. Advanced chemistry students offered peer-led, personalized, and individualized learning experiences through tutoring and mentoring to approximately 21% of students enrolled in the general chemistry course. Final grades from official class lists of all general chemistry course sections were analyzed using Student's t -test, paired t -test, and χ 2 analysis. Results during the seven semesters studied show an increase of 29% in successful course outcomes defined as final letter grades of A, B, and C obtained by Chem-2-Chem participants. For each final grade, highly statistically significant differences between participants and nonparticipants were detected. There were also statistically significant differences between successful course outcomes obtained by participants and nonparticipants for each of the semesters studied. This research supports recent trends in chemical education to provide a social context for learning experiences. This peer-led learning strategy can serve as an effective model to achieve excellence in science courses at a wide range of educational institutions.
Emphasizing the process of science using demonstrations in conceptual chemistry

NASA Astrophysics Data System (ADS)

Lutz, Courtney A.

The purpose of this project was to teach students a method for employing the process of science in a conceptual chemistry classroom when observing a demonstration of a discrepant event. Students observed six demonstrations throughout a trimester study of chemistry and responded to each demonstration by asking as many questions as they could think of, choosing one testable question to answer by making as many hypotheses as possible, and choosing one hypothesis to make predictions about observed results of this hypothesis when tested. Students were evaluated on their curiosity, confidence, knowledge of the process of science, and knowledge of the nature of science before and after the six demonstrations. Many students showed improvement in using or mastery of the process of science within the context of conceptual chemistry after six intensive experiences with it. Results of the study also showed students gained confidence in their scientific abilities after completing one trimester of conceptual chemistry. Curiosity and knowledge of the nature of science did not show statistically significant improvement according to the assessment tool. This may have been due to the scope of the demonstration and response activities, which focused on the process of science methodology instead of knowledge of the nature of science or the constraints of the assessment tool.
Exploring Mars for Evidence of Past or Present Life: Roles of Robotic and Human Missions

NASA Technical Reports Server (NTRS)

Farmer, Jack D.

1996-01-01

During the coming decade, robotic field science will play a fundamental role in exploring Mars for evidence of past life and/or prebiotic chemistry. To create a context for such exploration, we especially need to understand the mineralogy and chemistry of the Martian surface. We have learned that the preservation of biological signatures in rocks on Earth is favored by rapid mineralization processes that are restricted to a comparatively small number of geological settings. Thus, a detailed knowledge of surface mineralogy will provide valuable clues about past Martian environments as a necessary context for future exobiological exploration.
Capitalizing on Teacher Expertise: Motivations for Contemplating Transfer from Professional Development to the Classroom

NASA Astrophysics Data System (ADS)

van Duzor, Andrea Gay

2011-08-01

Of primary concern in professional development (PD) are the ways in which teachers transfer knowledge from PD to the classroom. This qualitative case study of a chemistry PD course for elementary teachers investigates the first step in the transfer process by examining why and how K-8 teachers consider transfer to the classroom. Motivations for considering transfer were the same whether teachers only proposed how they could use PD content or teachers actively utilized PD experiments and concepts in their own classrooms. Teacher learning of chemistry concepts, activities, and pedagogical strategies were motivating factors for considering transfer. Teachers appropriated and adapted PD materials based on the specific learning needs of their own students, the constraints of their teaching contexts, and their desired outcomes, including making science learning relevant for students. Understanding teachers' motivations and means of adaptations in considering PD can inform PD provider programs how to be more effective and responsive to teacher needs. Furthermore, teachers' active consideration of appropriations and adaptations highlights how teachers leverage their expertise in shaping their PD experiences.
Effectiveness of Case-Based Learning Instruction on Epistemological Beliefs and Attitudes Toward Chemistry

NASA Astrophysics Data System (ADS)

Çam, Aylin; Geban, Ömer

2011-02-01

The purpose of the study was to investigate the effectiveness of case-based learning instruction over traditionally designed chemistry instruction on eleventh grade students' epistemological beliefs and their attitudes toward chemistry as a school subject. The subjects of this study consisted of 63 eleventh grade students from two intact classes of an urban high school instructed with same teacher. Each teaching method was randomly assigned to one class. The experimental group received case-based learning and the control group received traditional instruction. At the experimental group, life cases were presented with small group format; at the control group, lecturing and discussion was carried out. The results showed that there was a significant difference between the experimental and control group with respect to their epistemological beliefs and attitudes toward chemistry as a school subject in favor of case-based learning method group. Thus, case base learning is helpful for development of students' epistemological beliefs and attitudes toward chemistry.

The problem of polysemy in the first thousand words of the General Service List: A corpus study of secondary chemistry texts

NASA Astrophysics Data System (ADS)

Clemmons, Karina

Vocabulary in a second language is an indispensable building block of all comprehension (Folse, 2006; Nation, 2006). Teachers in content area classes such as science, math, and social studies frequently teach content specific vocabulary, but are not aware of the obstacles that can occur when students do not know the basic words. Word lists such as the General Service List (GSL) were created to assist students and teachers (West, 1953). The GSL does not adequately take into account the high level of polysemy of many common English words, nor has it been updated by genre to reflect specific content domains encountered by secondary science students in today's high stakes classes such as chemistry. This study examines how many words of the first 1000 words of the GSL occurred in the secondary chemistry textbooks sampled, how often the first 1000 words of the GSL were polysemous, and specifically which multiple meanings occurred. A discussion of results includes word tables that list multiple meanings present, example phrases that illustrate the context surrounding the target words, suggestions for a GSL that is genre specific to secondary chemistry textbooks and that is ranked by meaning as well as type, and implications for both vocabulary materials and classroom instruction for ELLs in secondary chemistry classes. Findings are essential to second language (L2) researchers, materials developers, publishers, and teachers.
Pre-university Chemistry Students in a Mimicked Scholarly Peer Review

NASA Astrophysics Data System (ADS)

van Rens, Lisette; Hermarij, Philip; Pilot, Albert; Beishuizen, Jos; Hofman, Herman; Wal, Marjolein

2014-10-01

Peer review is a significant component in scientific research. Introducing peer review into inquiry processes may be regarded as an aim to develop student understanding regarding quality in inquiries. This study examines student understanding in inquiry peer reviews among pre-university chemistry students, aged 16-17, when they enact a design of a mimicked scholarly peer review. This design is based on a model of a human activity system. Twenty-five different schools in Brazil, Germany, Poland and The Netherlands participated. The students (n = 880) conducted in small groups (n = 428) open inquiries on fermentation. All groups prepared an inquiry report for peer review. These reports were published on a website. Groups were randomly paired in an internet symposium, where they posted review comments to their peers. These responses were qualitatively analyzed on small groups' level of understanding regarding seven categories: inquiry question, hypothesis, management of control variables, accurate measurement, presenting results, reliability of results, discussion and conclusion. The mimicked scholarly review prompted a collective practice. Student understanding was significantly well on presenting results, discussion and conclusion, and significantly less on inquiry question and reliability of results. An enacted design, based on a model of a human activity system, created student understanding of quality in inquiries as well as an insight in a peer-reviewing practice. To what extent this model can be applied in a broader context of design research in science education needs further study.
The Impact of Iodide-Mediated Ozone Deposition and Halogen Chemistry on Surface Ozone Concentrations Across the Continental United States

EPA Science Inventory

The air quality of many large coastal areas in the United States is affected by the confluence of polluted urban and relatively clean marine airmasses, each with distinct atmospheric chemistry. In this context, the role of iodide-mediated ozone (O3) deposition over seawater and m...
Development and Analysis of an Instrument to Assess Student Understanding of Foundational Concepts before Biochemistry Coursework

ERIC Educational Resources Information Center

Villafane, Sachel M.; Bailey, Cheryl P.; Loertscher, Jennifer; Minderhout, Vicky; Lewis, Jennifer E.

2011-01-01

Biochemistry is a challenging subject because student learning depends on the application of previously learned concepts from general chemistry and biology to new, biological contexts. This article describes the development of a multiple-choice instrument intended to measure five concepts from general chemistry and three from biology that are…
Multicultural Chemistry and the Nature of Science: But What about Knowledge?

ERIC Educational Resources Information Center

Tan, Michael

2012-01-01

In response to Goff, Boesdorfer, and Hunter's article on the use of a multicultural approach to teaching chemistry and the nature of science, I forward this critical reflective essay to discuss more general curriculum aspects of the relationship between the nature of science and science education in school contexts. Taking a social realist…
Teachers' Reasoning: Classroom Visual Representational Practices in the Context of Introductory Chemical Bonding

ERIC Educational Resources Information Center

Patron, Emelie; Wikman, Susanne; Edfors, Inger; Johansson-Cederblad, Brita; Linder, Cedric

2017-01-01

Visual representations are essential for communication and meaning-making in chemistry, and thus the representational practices play a vital role in the teaching and learning of chemistry. One powerful contemporary model of classroom learning, the variation theory of learning, posits that the way an object of learning gets handled is another vital…
Design, Development, and Psychometric Analysis of a General, Organic, and Biological Chemistry Topic Inventory Based on the Identified Main Chemistry Topics Relevant to Nursing Clinical Practice

ERIC Educational Resources Information Center

Brown, Corina E.

2013-01-01

This two-stage study focused on the undergraduate nursing course that covers topics in general, organic, and biological (GOB) chemistry. In the first stage, the central objective was to identify the main concepts of GOB chemistry relevant to the clinical practice of nursing. The collection of data was based on open-ended interviews of both nursing…
Implementation of Case-Based Instruction on Electrochemistry at the 11th Grade Level

ERIC Educational Resources Information Center

Tarkin, Aysegul; Uzuntiryaki-Kondakci, Esen

2017-01-01

This study aims to compare the effectiveness of case-based instruction over traditional instruction in improving 11th grade students' understanding of electrochemistry concepts, attitudes toward chemistry, chemistry self-efficacy beliefs, and motivation to learn chemistry. In total, 113 students (47 males and 66 females) from three high schools…
Turkish Prospective Chemistry Teachers' Alternative Conceptions about Acids and Bases

ERIC Educational Resources Information Center

Boz, Yezdan

2009-01-01

The purpose of this study was to obtain prospective chemistry teachers' conceptions about acids and bases concepts. Thirty-eight prospective chemistry teachers were the participants. Data were collected by means of an open-ended questionnaire and semi-structured interviews. Analysis of data indicated that most prospective teachers did not have…
The Contribution of Constructivist Instruction Accompanied by Concept Mapping in Enhancing Pre-Service Chemistry Teachers' Conceptual Understanding of Chemistry in the Laboratory Course

ERIC Educational Resources Information Center

Aydin, Sevgi; Aydemir, Nurdane; Boz, Yezdan; Cetin-Dindar, Ayla; Bektas, Oktay

2009-01-01

The present study aimed to evaluate whether a chemistry laboratory course called "Laboratory Experiments in Science Education" based on constructivist instruction accompanied with concept mapping enhanced pre-service chemistry teachers' conceptual understanding. Data were collected from five pre-service chemistry teachers at a university…
Guided-inquiry based laboratory instruction: Investigation of critical thinking skills, problem solving skills, and implementing student roles in chemistry

NASA Astrophysics Data System (ADS)

Gupta, Tanya

Recent initiatives in the laboratory curriculum have encouraged an inquiry-based approach to learning and teaching in the laboratory. It has been argued that laboratory instruction should not just be hands-on, but it should portray the essence of inquiry through the process of experiential learning and reflective engagement in collaboration with peers and in facilitation by the instructor. A student-centered active learning approach may be an effective way to enhance student understanding of concepts in the laboratory. The dissertation research work explores the impact of laboratory instruction and its relevance for college-level chemistry. Each chapter is different from the preceding chapter in terms of the purpose of the study and the research questions asked. However, the overarching idea is to address the importance of guided-inquiry based laboratory instruction in chemistry and its relevance in helping students to make connections with the chemistry content and in imparting skills to students. Such skills include problem solving, collaborative group work and critical thinking. The first research study (Chapter 2) concerns the impact of first year co-requisite general chemistry laboratory instruction on the problem-solving skills of students. The second research study (Chapter 3) examines the impact of implementing student roles also known as Student-Led Instructor Facilitated Guided-Inquiry based Laboratories, SLIFGIL) by modifying the Science Writing Heuristic approach of laboratory instruction. In the third research study (Chapter 4), critical thinking skills of first semester general chemistry laboratory students were compared to advanced (third or fourth year) chemistry laboratory students based on the analysis of their laboratory reports.
Gold Nanoparticles for Biology and Medicine

PubMed Central

Giljohann, David A.; Seferos, Dwight S.; Daniel, Weston L.; Massich, Matthew D.; Patel, Pinal C.

2014-01-01

Gold colloids have fascinated scientists for over a century and are now heavily utilized in chemistry, biology, engineering, and medicine. Today these materials can be synthesized reproducibly, modified with seemingly limitless chemical functional groups, and, in certain cases, characterized with atomic-level precision. This Review highlights recent advances in the synthesis, bioconjugation, and cellular uses of gold nanoconjugates. There are now many examples of highly sensitive and selective assays based upon gold nanoconjugates. In recent years, focus has turned to therapeutic possibilities for such materials. Structures which behave as gene-regulating agents, drug carriers, imaging agents, and photoresponsive therapeutics have been developed and studied in the context of cells and many debilitating diseases. These structures are not simply chosen as alternatives to molecule-based systems, but rather for their new physical and chemical properties, which confer substantive advantages in cellular and medical applications. PMID:20401880
Evaluating the efficacy of a chemistry video game

NASA Astrophysics Data System (ADS)

Shapiro, Marina

A quasi-experimental design pre-test/post-test intervention study utilizing a within group analysis was conducted with 45 undergraduate college chemistry students that investigated the effect of implementing a game-based learning environment into an undergraduate college chemistry course in order to learn if serious educational games (SEGs) can be used to achieve knowledge gains of complex chemistry concepts and to achieve increase in students' positive attitude toward chemistry. To evaluate if students learn chemistry concepts by participating in a chemistry game-based learning environment, a one-way repeated measures analysis of variance (ANOVA) was conducted across three time points (pre-test, post-test, delayed post-test which were chemistry content exams). Results showed that there was an increase in exam scores over time. The results of the ANOVA indicated a statistically significant time effect. To evaluate if students' attitude towards chemistry increased as a result of participating in a chemistry game-based learning environment a paired samples t-test was conducted using a chemistry attitudinal survey by Mahdi (2014) as the pre- and post-test. Results of the paired-samples t-test indicated that there was no significant difference in pre-attitudinal scores and post-attitudinal scores.
Chemistry for Student Nurses: Applications-Based Learning

ERIC Educational Resources Information Center

El-Farargy, Nancy

2009-01-01

New chemistry materials were devised for pre university National Certificate (NC) nursing students studying chemistry at a further education college. Previously, preliminary work showed that students felt that the chemistry taught to them was irrelevant, boring and difficult. It was hoped that through an applications-led style curriculum…
Is case-based learning an effective teaching strategy to challenge students' alternative conceptions regarding chemical kinetics?

NASA Astrophysics Data System (ADS)

Yalçınkaya, Eylem; Taştan-Kırık, Özgecan; Boz, Yezdan; Yıldıran, Demet

2012-07-01

Background: Case-based learning (CBL) is simply teaching the concept to the students based on the cases. CBL involves a case, which is a scenario based on daily life, and study questions related to the case, which allows students to discuss their ideas. Chemical kinetics is one of the most difficult concepts for students in chemistry. Students have generally low levels of conceptual understanding and many alternative conceptions regarding it. Purpose: This study aimed to explore the effect of CBL on dealing with students' alternative conceptions about chemical kinetics. Sample: The sample consists of 53 high school students from one public high school in Turkey. Design and methods : Nonequivalent pre-test and post-test control group design was used. Reaction Rate Concept Test and semi-structured interviews were used for data collection. Convenience sampling technique was followed. For data analysis, the independent samples t-test and ANOVA was performed. Results : Both concept test and interview results showed that students instructed with cases had better understanding of core concepts of chemical kinetics and had less alternative conceptions related to the subject matter compared to the control group students, despite the fact that it was impossible to challenge all the alternative conceptions in the experimental group. Conclusions: CBL is an effective teaching method for challenging students' alternative conceptions in the context of chemical kinetics. Since using cases in small groups and whole class discussions has been found to be an effective way to cope with the alternative conceptions, it can be applied to other subjects and grade levels in high schools with a higher sample size. Furthermore, the effect of this method on academic achievement, motivation and critical thinking skills are other variables that can be investigated for future studies in the subject area of chemistry.
Synthesis Road Map Problems in Organic Chemistry

ERIC Educational Resources Information Center

Schaller, Chris P.; Graham, Kate J.; Jones, T. Nicholas

2014-01-01

Road map problems ask students to integrate their knowledge of organic reactions with pattern recognition skills to "fill in the blanks" in the synthesis of an organic compound. Students are asked to identify familiar organic reactions in unfamiliar contexts. A practical context, such as a medicinally useful target compound, helps…
Art, Meet Chemistry; Chemistry, Meet Art: Case Studies, Current Literature, and Instrumental Methods Combined to Create a Hands-On Experience for Nonmajors and Instrumental Analysis Students

ERIC Educational Resources Information Center

Nivens, Delana A.; Padgett, Clifford W.; Chase, Jeffery M.; Verges, Katie J.; Jamieson, Deborah S.

2010-01-01

Case studies and current literature are combined with spectroscopic analysis to provide a unique chemistry experience for art history students and to provide a unique inquiry-based laboratory experiment for analytical chemistry students. The XRF analysis method was used to demonstrate to nonscience majors (art history students) a powerful…
Paint Analysis Using Visible Reflectance Spectroscopy: An Undergraduate Forensic Lab

ERIC Educational Resources Information Center

Hoffman, Erin M.; Beussman, Douglas J.

2007-01-01

The study of forensic science is found throughout undergraduate programs in growing numbers, both as stand-alone courses as well as specific examples within existing courses. Part of the driving force for this trend is the ability to apply common chemistry techniques to everyday situations, all couched in the context of a mystery that must be…
Assessing Secondary Science Students' Knowledge of Molecule Movement, Concentration Gradients, and Equilibrium through Multiple Contexts

ERIC Educational Resources Information Center

Raven, Sara

2015-01-01

Background: Studies have shown that students' knowledge of osmosis and diffusion and the concepts associated with these processes is often inaccurate. This is important to address, as these concepts not only provide the foundation for more advanced topics in biology and chemistry, but are also threaded throughout both state and national science…
Roles of Terminology, Experience, and Energy Concepts in Student Conceptions of "Freezing" and "Boiling"

ERIC Educational Resources Information Center

Jasien, Paul G.

2013-01-01

A discussion of some student conceptions of the solid-liquid and liquid-vapor phase transitions is presented. Data from open-ended, short-answer questions were collected from first-semester general chemistry students and then discussed in the context of previous studies. The responses gave insight into the various student conceptions about these…

Effect of Culture on High-School Students' Question-Asking Ability Resulting from an Inquiry-Oriented Chemistry Laboratory

ERIC Educational Resources Information Center

Dkeidek, Iyad; Mamlok-Naaman, Rachel; Hofstein, Avi

2011-01-01

In order to cope with complex issues in the science-technology-environment-society context, one must develop students' high-order learning skills, such as question-asking ability (QAA), critical thinking, evaluative thinking, decision-making, and problem-solving capabilities within science education. In this study, we are concerned with evaluating…
Potentialities beyond deficit perspectives: globalization, culture and urban science education in the Bronx

NASA Astrophysics Data System (ADS)

Pitts, Wesley

2011-03-01

The major focus of this ethnographic study is devoted to exploring the confluence of global and local referents of science education in the context of an urban chemistry laboratory classroom taught by a first-generation Filipino-American male teacher. This study investigates encounters between the teacher and four second-generation immigrant female students of color, as well as encounters among the four students. The pervasive spread of neoliberal ideology of accountability and sanctions both globally and locally, particularly in public high schools in the Bronx, New York City fuel situations for teaching and learning science that are encoded with the referents of top-down control. In the face of theses challenges, classroom participants must become aware of productive ways to build solidarity and interstitial culture across salient social boundaries, such as age, gender, ethnicity and role, to create and sustain successful teaching and learning of chemistry. Empirical evidence for solidarity was guided by physical and verbal displays of synchrony, mutual focus, entrainment, and emotional energy, body gestures, and prosody markers. This study shows that classroom participants used a combination of prosody markers to appropriate resources to decrease breaches in face-to-face encounters and, at the same time, create and sustain participation and solidarity to successfully complete an acid-base experiment.
Beyond Hydrophobicity: Aqueous Interfaces, Interactions, and Reactions

NASA Astrophysics Data System (ADS)

Perkins, Russell James

Many important chemical reactions from all branches of chemistry occur with water as a solvent. Furthermore, in environmental chemistry, biochemistry, and synthetic chemistry, key reactions occur in heterogeneous aqueous systems, where interfacial effects are particularly important. Despite the importance of aqueous environments and the tremendous amount of work done to study them, there are aspects that require further explanation and remain controversial. I have performed experimental studies to help elucidate the fundamental characteristics of aqueous systems, while examining specific phenomena across several fields. The genetic disorder phenylketonuria (PKU) can result in increased levels of the aromatic amino acid phenylalanine in human serum. Much of my work has focused on the driving forces behind partitioning of aromatic small molecules, including phenylalanine, into air-water or membrane-water interfacial regions, and the consequences of partitioning on interfacial properties. Drastically different behaviors for structurally similar aromatic molecules are observed, differences that cannot be explained by hydrophobic effects. These observations can be explained, however, through the development of a more detailed picture of interactions and partitioning, including the formation of interfacial aggregates. For phenylalanine, this partitioning appears to result in drastic changes in membrane morphology and permeability. This is a likely molecular-level cause for the damage associated with the disease state of PKU. Aqueous systems are further complicated by the reactivity of water. It often serves not only the role of a solvent, but also a reactant, a product, and/or a catalyst. I explore this reactivity using an organic molecule with relevance to environmental chemistry, zymonic acid. Zymonic acid forms spontaneously from pyruvic acid, an important atmospheric species. While zymonic acid exists as a single species in solid form when dissolved in DMSO, once in aqueous solution it quickly reacts with water and equilibrates with at least four other forms. I studied the details and kinetics of these equilibria via time-dependent NMR. Several surprising mechanistic details were uncovered, including a direct enol to geminal diol conversion and base-catalyzed lactone ring formation. The consequences of zymonic acid's behavior are investigated in the context of environmental and prebiotic chemistry.
On the Making of Quantum Chemistry in Germany

NASA Astrophysics Data System (ADS)

Karachalios, Andreas

During the 1990s several historians of science have studied the emergence of quantum chemistry as an autonomous discipline in different national contexts (Nye, 1993; Simões, 1993; Simões, forthcoming; Gavroglu and Simões, 1994; Karachalios, 1997a). Beyond these disciplinary studies, a number of contributions to special aspects of this theme have appeared (Schweber, 1990; Gavroglu, 1995; Simões and Gavroglu, 1997, 1999a,b; Schwarz et al., 1999). In this literature the birth of quantum chemistry has generally been associated with two dates: the 1927 paper of Walter Heitler and Fritz London and the year 1931 in which Linus Pauling and John Clarke Slater independently explained the tetrahedral orientation of the four bonds of the carbon atom. To these dates we might also add a third: in 1928 London published a paper, 'Zur Quantentheorie der homöopolaren Valenzzahlen' (London, 1928), in which he gave a quantum mechanical explanation of the classical chemical notion of valency. There he showed a relationship between the valency numbers and the spectroscopical multiplicity, namely that valency=multiplicity-1. This relation established a bridge between physical and chemical facts. Taken together, these developments constitute important events for the international development of quantum chemistry.
Hands-On Practical Chemistry for All: Why and How?

NASA Astrophysics Data System (ADS)

Bradley, John D.; Durbach, S.; Bell, B.; Mungarulire, J.; Kimel, H.

1998-11-01

Practical work in chemistry is invariably described as essential in chemical education, and a variety of aims is claimed for it. Yet in schools around the world it is frequently absent from the real curriculum. Although some of the explanations advanced for this conundrum are little more than excuses, there is truth in the cost explanation. In this article we report on our development of a system based on microscale chemistry kits for individual students. These reusable kits comprise a number of components specially designed around a Comboplate made of optically clear plastic. The kits are supplied in individual zip-lock bags with a variety of configurations to suit different grades and curricula. Chemicals are supplied as solids and prepared solutions in quantities suitable for a whole class for one year, and student worksheets are available. The total system is cost-effective, safe, environmentally friendly, and versatile. The system has been very well received in both wealthy and poor contexts and countries by both teachers and students. It is so convenient and user-friendly it appeals to teachers. For students, pride of ownership is tapped by the individual kits. Their portability facilitates fieldwork and also distance learning. The system, developed through academic-industrial cooperation, may well achieve a global revolution in chemistry teaching and learning.
Free Radical Addition Polymerization Kinetics without Steady-State Approximations: A Numerical Analysis for the Polymer, Physical, or Advanced Organic Chemistry Course

ERIC Educational Resources Information Center

Iler, H. Darrell; Brown, Amber; Landis, Amanda; Schimke, Greg; Peters, George

2014-01-01

A numerical analysis of the free radical addition polymerization system is described that provides those teaching polymer, physical, or advanced organic chemistry courses the opportunity to introduce students to numerical methods in the context of a simple but mathematically stiff chemical kinetic system. Numerical analysis can lead students to an…
Quantitative Analysis in the General Chemistry Laboratory: Training Students to Analyze Individual Results in the Context of Collective Data

ERIC Educational Resources Information Center

Ling, Chris D.; Bridgeman, Adam J.

2011-01-01

Titration experiments are ideal for generating large data sets for use in quantitative-analysis activities that are meaningful and transparent to general chemistry students. We report the successful implementation of a sophisticated quantitative exercise in which the students identify a series of unknown acids by determining their molar masses…
An Evaluation of the Chemical Origin of Life as a Context for Teaching Undergraduate Chemistry

ERIC Educational Resources Information Center

Venkataraman, Bhawani

2011-01-01

The chemical origin of life on earth has been used as a conceptual framework in an introductory, undergraduate chemistry course. The course explores the sequence of events through which life is believed to have emerged, from atoms to molecules to macromolecular systems, and uses this framework to teach basic chemical concepts. The results of this…
Using Metaphor Theory to Examine Conceptions of Energy in Biology, Chemistry, and Physics

ERIC Educational Resources Information Center

Lancor, Rachael

2014-01-01

Energy is one of the most important unifying themes in science. Yet the way energy is conceptualized varies depending on context. In this paper, the discourse used to explain the role of energy in systems from biology, chemistry, and physics is examined from the perspective of metaphor theory. Six substance metaphors for energy are identified in…
Assessing recall, conceptualization, and transfer capabilities of novice biochemistry students' across learning style preferences as revealed by self-explanations

NASA Astrophysics Data System (ADS)

Hilsenbeck-Fajardo, Jacqueline L.

2009-08-01

The research described herein is a multi-dimensional attempt to measure student's abilities to recall, conceptualize, and transfer fundamental and dynamic protein structure concepts as revealed by their own diagrammatic (pictorial) representations and written self-explanations. A total of 120 participants enrolled in a 'Fundamentals of Biochemistry' course contributed to this mixed-methodological study. The population of interest consisted primarily of pre-nursing and sport and exercise science majors. This course is typically associated with a high (<30%) combined drop/failure rate, thus the course provided the researcher with an ideal context in which to apply novel transfer assessment strategies. In the past, students within this population have reported very little chemistry background. In the following study, student-generated diagrammatic representations and written explanations were coded thematically using a highly objective rubric that was designed specifically for this study. Responses provided by the students were characterized on the macroscopic, microscopic, molecular-level, and integrated scales. Recall knowledge gain (i.e., knowledge that was gained through multiple-choice questioning techniques) was quantitatively correlated to learning style preferences (i.e., high-object, low-object, and non-object). Quantitative measures revealed that participants tended toward an object (i.e., snapshot) -based visualization preference, a potentially limiting factor in their desire to consider dynamic properties of fundamental biochemical contexts such as heat-induced protein denaturation. When knowledge transfer was carefully assessed within the predefined context, numerous misconceptions pertaining to the fundamental and dynamic nature of protein structure were revealed. Misconceptions tended to increase as the transfer model shifted away from the context presented in the original learning material. Ultimately, a fundamentally new, novel, and unique measure of knowledge transfer was developed as a main result of this study. It is envisioned by the researcher that this new measure of learning is applicable specifically to physical and chemical science education-based research in the form of deep transfer on the atomic-level scale.
Medicinal Chemistry Projects Requiring Imaginative Structure-Based Drug Design Methods.

PubMed

Moitessier, Nicolas; Pottel, Joshua; Therrien, Eric; Englebienne, Pablo; Liu, Zhaomin; Tomberg, Anna; Corbeil, Christopher R

2016-09-20

Computational methods for docking small molecules to proteins are prominent in drug discovery. There are hundreds, if not thousands, of documented examples-and several pertinent cases within our research program. Fifteen years ago, our first docking-guided drug design project yielded nanomolar metalloproteinase inhibitors and illustrated the potential of structure-based drug design. Subsequent applications of docking programs to the design of integrin antagonists, BACE-1 inhibitors, and aminoglycosides binding to bacterial RNA demonstrated that available docking programs needed significant improvement. At that time, docking programs primarily considered flexible ligands and rigid proteins. We demonstrated that accounting for protein flexibility, employing displaceable water molecules, and using ligand-based pharmacophores improved the docking accuracy of existing methods-enabling the design of bioactive molecules. The success prompted the development of our own program, Fitted, implementing all of these aspects. The primary motivation has always been to respond to the needs of drug design studies; the majority of the concepts behind the evolution of Fitted are rooted in medicinal chemistry projects and collaborations. Several examples follow: (1) Searching for HDAC inhibitors led us to develop methods considering drug-zinc coordination and its effect on the pKa of surrounding residues. (2) Targeting covalent prolyl oligopeptidase (POP) inhibitors prompted an update to Fitted to identify reactive groups and form bonds with a given residue (e.g., a catalytic residue) when the geometry allows it. Fitted-the first fully automated covalent docking program-was successfully applied to the discovery of four new classes of covalent POP inhibitors. As a result, efficient stereoselective syntheses of a few screening hits were prioritized rather than synthesizing large chemical libraries-yielding nanomolar inhibitors. (3) In order to study the metabolism of POP inhibitors by cytochrome P450 enzymes (CYPs)-for toxicology studies-the program Impacts was derived from Fitted and helped us to reveal a complex metabolism with unforeseen stereocenter isomerizations. These efforts, combined with those of other docking software developers, have strengthened our understanding of the complex drug-protein binding process while providing the medicinal chemistry community with useful tools that have led to drug discoveries. In this Account, we describe our contributions over the past 15 years-within their historical context-to the design of drug candidates, including BACE-1 inhibitors, POP covalent inhibitors, G-quadruplex binders, and aminoglycosides binding to nucleic acids. We also remark the necessary developments of docking programs, specifically Fitted, that enabled structure-based design to flourish and yielded multiple fruitful, rational medicinal chemistry campaigns.
Computations and interpretations: The growth of quantum chemistry, 1927-1967

NASA Astrophysics Data System (ADS)

Park, Buhm Soon

1999-10-01

This dissertation is a contribution to the historical study of scientific disciplines in the twentieth century. It seeks to examine the development of quantum chemistry during the four decades after its inception in 1927. This development was manifest in theories, tools, scientists, and institutions, all of which constituted the disciplinary identity of quantum chemistry. To characterize its identity, I deal with the origins of key ideas and concepts; the change of computational tools from desk calculators to digital computers; the formation of a network among research groups and individuals; and the institutionalization of annual meetings. The dissertation's thesis is three-fold. First, in the pre- World War II years, there were individual contributions to the development of theories in quantum chemistry, but the founding fathers worked in their disciplinary contexts of physics or chemistry with little interest in building a quantum chemistry community. Second, the introduction of electronic digital computers in the postwar years affected the resurgence of the ab initio approach-the attempt to solve the Schrödinger equation without recourse to empirical data-and also the emergence of a community of quantum chemists. But the use of computers did not give rise to a consensus over the aims, methods, or content of the discipline. Third, quantum chemistry exerted a significant influence upon the transformation of chemical education and research in general, thanks to ``chemical translators,'' who sought to explain the gist of quantum chemistry in a language that chemists could understand. In sum, quantum chemistry has been a discipline characterized by diverse traditions, and the whole of chemistry has been under the influence of computations and interpretations made by quantum chemists.
Jordanian Chemistry Teachers' Views on Teaching Practices and Educational Reform

ERIC Educational Resources Information Center

Al-Amoush, Siham A.; Markic, Silvija; Eilks, Ingo

2012-01-01

This study evaluates experienced teachers' views of chemistry teaching and learning and educational reform in Jordan. The main focus is an investigation of applied teaching practices in chemistry education, including educators' perception of the intentions and effects of ongoing educational reforms. The study is based on semi-structured interviews…
Students' Written Arguments in General Chemistry Laboratory Investigations

ERIC Educational Resources Information Center

Choi, Aeran; Hand, Brian; Greenbowe, Thomas

2013-01-01

This study aimed to examine the written arguments developed by college freshman students using the Science Writing Heuristic approach in inquiry-based general chemistry laboratory classrooms and its relationships with students' achievement in chemistry courses. Fourteen freshman students participated in the first year of the study while 19…
A self-study of designing and implementing an inquiry-based chemistry course for elementary education majors

NASA Astrophysics Data System (ADS)

Larson, Teresa

2011-12-01

This self-study examines my experiences with implementing an inquiry-based version of a chemistry course (Chemistry 299) designed for elementary education majors. The inquiry-based curriculum design and teaching strategies that I implement in Chemistry 299 is the focus of this study. Since my previous education and professional experiences were in the physical sciences, I position myself in this study as a scientist who engages in self-study as a form of professional development for the purpose of developing an inquiry-based curriculum and instructional practices. My research provides an inside perspective of the curriculum development process. This process involves implementing the inquiry-oriented ideas and knowledge I acquired in my graduate studies to design the curriculum and influence my teaching practice. My analysis of the curriculum and my instruction is guided by two questions: What are the strengths and weaknesses of the inquiry-based Chemistry 299 curriculum design? What does the process of developing my inquiry-based teaching practice entail and what makes is challenging? Schwab's (1973) The Practical 3: Translation into Curriculum serves as the theoretical framework for this study because of the emphasis Schwab places on combining theoretical and practical knowledge in the curriculum development process and because of the way he characterizes the curriculum. The findings in this study are separated into curriculum and instruction domains. First, the Chemistry 299 curriculum was designed to make the epistemological practices of scientists "accessible" to students by emphasizing epistemic development with respect to their ideas about scientific inquiry and science learning. Using student learning as a gauge for progress, I identify specific design elements that developed transferable inquiry skills as a means to support scientific literacy and pre-service teacher education. Second, the instruction-related findings built upon the insight I gained through my analysis of the curriculum. The data reveals four areas of inner conflict I dealt with throughout the study that related to underlying beliefs I held about science teaching and learning. The implications of the study position the Chemistry 299 curriculum in the field and speak to issues related to developing science courses for elementary education majors and professional development for scientists.
ChemicalTagger: A tool for semantic text-mining in chemistry.

PubMed

Hawizy, Lezan; Jessop, David M; Adams, Nico; Murray-Rust, Peter

2011-05-16

The primary method for scientific communication is in the form of published scientific articles and theses which use natural language combined with domain-specific terminology. As such, they contain free owing unstructured text. Given the usefulness of data extraction from unstructured literature, we aim to show how this can be achieved for the discipline of chemistry. The highly formulaic style of writing most chemists adopt make their contributions well suited to high-throughput Natural Language Processing (NLP) approaches. We have developed the ChemicalTagger parser as a medium-depth, phrase-based semantic NLP tool for the language of chemical experiments. Tagging is based on a modular architecture and uses a combination of OSCAR, domain-specific regex and English taggers to identify parts-of-speech. The ANTLR grammar is used to structure this into tree-based phrases. Using a metric that allows for overlapping annotations, we achieved machine-annotator agreements of 88.9% for phrase recognition and 91.9% for phrase-type identification (Action names). It is possible parse to chemical experimental text using rule-based techniques in conjunction with a formal grammar parser. ChemicalTagger has been deployed for over 10,000 patents and has identified solvents from their linguistic context with >99.5% precision.
Nanowire-based thermoelectrics

NASA Astrophysics Data System (ADS)

Ali, Azhar; Chen, Yixi; Vasiraju, Venkata; Vaddiraju, Sreeram

2017-07-01

Research on thermoelectrics has seen a huge resurgence since the early 1990s. The ability of tuning a material’s electrical and thermal transport behavior upon nanostructuring has led to this revival. Nevertheless, thermoelectric performances of nanowires and related materials lag far behind those achieved with thin-film superlattices and quantum dot-based materials. This is despite the fact that nanowires offer many distinct advantages in enhancing the thermoelectric performances of materials. The simplicity of the strategy is the first and foremost advantage. For example, control of the nanowire diameters and their surface roughnesses will aid in enhancing their thermoelectric performances. Another major advantage is the possibility of obtaining high thermoelectric performances using simpler nanowire chemistries (e.g., elemental and binary compound semiconductors), paving the way for the fabrication of thermoelectric modules inexpensively from non-toxic elements. In this context, the topical review provides an overview of the current state of nanowire-based thermoelectrics. It concludes with a discussion of the future vision of nanowire-based thermoelectrics, including the need for developing strategies aimed at the mass production of nanowires and their interface-engineered assembly into devices. This eliminates the need for trial-and-error strategies and complex chemistries for enhancing the thermoelectric performances of materials.
A Case Study on German First Year Chemistry Student Teachers' Beliefs about Chemistry Teaching, and Their Comparison with Student Teachers from Other Science Teaching Domains

ERIC Educational Resources Information Center

Markic, Silvija; Eilks, Ingo

2008-01-01

This paper gives insights into the beliefs of 85 German first year chemistry student teachers about chemistry teaching and learning at the beginning of their teacher education. The study is based on student teachers' drawings of themselves in a typical classroom situation and four open questions. The approach evaluated: (I) Beliefs about Classroom…
The Living Textbook of Nuclear Chemistry: A Peer-Reviewed, Web-Based, Education Resource

ERIC Educational Resources Information Center

Loveland, W.; Gallant, A.; Joiner, C.

2004-01-01

The recent developments in nuclear chemistry education are presented and an attempt is made to collect supplemental materials relating to the study and practice of nuclear chemistry. The Living Textbook of Nuclear Chemistry functions as an authoritative Web site with supplemental material for teaching nuclear and radiochemistry.
Population-Based Pediatric Reference Intervals in General Clinical Chemistry: A Swedish Survey.

PubMed

Ridefelt, Peter

2015-01-01

Very few high quality studies on pediatric reference intervals for general clinical chemistry and hematology analytes have been performed. Three recent prospective community-based projects utilising blood samples from healthy children in Sweden, Denmark and Canada have substantially improved the situation. The Swedish survey included 701 healthy children. Reference intervals for general clinical chemistry and hematology were defined.

Effects of Computer Based Learning on Students' Attitudes and Achievements towards Analytical Chemistry

ERIC Educational Resources Information Center

Akcay, Hüsamettin; Durmaz, Asli; Tüysüz, Cengiz; Feyzioglu, Burak

2006-01-01

The aim of this study was to compare the effects of computer-based learning and traditional method on students' attitudes and achievement towards analytical chemistry. Students from Chemistry Education Department at Dokuz Eylul University (D.E.U) were selected randomly and divided into three groups; two experimental (Eg-1 and Eg-2) and a control…
The Efficacy of Problem-Based Learning in an Analytical Laboratory Course for Pre-Service Chemistry Teachers

ERIC Educational Resources Information Center

Yoon, Heojeong; Woo, Ae Ja; Treagust, David; Chandrasegaran, A. L.

2014-01-01

The efficacy of problem-based learning (PBL) in an analytical chemistry laboratory course was studied using a programme that was designed and implemented with 20 students in a treatment group over 10 weeks. Data from 26 students in a traditional analytical chemistry laboratory course were used for comparison. Differences in the creative thinking…
Measuring meaningful learning in the undergraduate chemistry laboratory

NASA Astrophysics Data System (ADS)

Galloway, Kelli R.

The undergraduate chemistry laboratory has been an essential component in chemistry education for over a century. The literature includes reports on investigations of singular aspects laboratory learning and attempts to measure the efficacy of reformed laboratory curriculum as well as faculty goals for laboratory learning which found common goals among instructors for students to learn laboratory skills, techniques, experimental design, and to develop critical thinking skills. These findings are important for improving teaching and learning in the undergraduate chemistry laboratory, but research is needed to connect the faculty goals to student perceptions. This study was designed to explore students' ideas about learning in the undergraduate chemistry laboratory. Novak's Theory of Meaningful Learning was used as a guide for the data collection and analysis choices for this research. Novak's theory states that in order for meaningful learning to occur the cognitive, affective, and psychomotor domains must be integrated. The psychomotor domain is inherent in the chemistry laboratory, but the extent to which the cognitive and affective domains are integrated is unknown. For meaningful learning to occur in the laboratory, students must actively integrate both the cognitive domain and the affective domains into the "doing" of their laboratory work. The Meaningful Learning in the Laboratory Instrument (MLLI) was designed to measure students' cognitive and affective expectations and experiences within the context of conducting experiments in the undergraduate chemistry laboratory. Evidence for the validity and reliability of the data generated by the MLLI were collected from multiple quantitative studies: a one semester study at one university, a one semester study at 15 colleges and universities across the United States, and a longitudinal study where the MLLI was administered 6 times during two years of general and organic chemistry laboratory courses. Results from these studies revealed students' narrow cognitive expectations for learning that go largely unmet by their experiences and diverse affective expectations and experiences. Concurrently, a qualitative study was carried out to describe and characterize students' cognitive and affective experiences in the undergraduate chemistry laboratory. Students were video recorded while performing one of their regular laboratory experiments and then interviewed about their experiences. The students' descriptions of their learning experiences were characterized by their overreliance on following the experimental procedure correctly rather than developing process-oriented problem solving skills. Future research could use the MLLI to intentionally compare different types of laboratory curricula or environments.
The essential roles of chemistry in high-throughput screening triage

PubMed Central

Dahlin, Jayme L; Walters, Michael A

2015-01-01

It is increasingly clear that academic high-throughput screening (HTS) and virtual HTS triage suffers from a lack of scientists trained in the art and science of early drug discovery chemistry. Many recent publications report the discovery of compounds by screening that are most likely artifacts or promiscuous bioactive compounds, and these results are not placed into the context of previous studies. For HTS to be most successful, it is our contention that there must exist an early partnership between biologists and medicinal chemists. Their combined skill sets are necessary to design robust assays and efficient workflows that will weed out assay artifacts, false positives, promiscuous bioactive compounds and intractable screening hits, efforts that ultimately give projects a better chance at identifying truly useful chemical matter. Expertise in medicinal chemistry, cheminformatics and purification sciences (analytical chemistry) can enhance the post-HTS triage process by quickly removing these problematic chemotypes from consideration, while simultaneously prioritizing the more promising chemical matter for follow-up testing. It is only when biologists and chemists collaborate effectively that HTS can manifest its full promise. PMID:25163000
Inorganic sulfur-nitrogen compounds: from gunpowder chemistry to the forefront of biological signaling.

PubMed

Cortese-Krott, Miriam M; Butler, Anthony R; Woollins, J Derek; Feelisch, Martin

2016-04-14

The reactions between inorganic sulfur and nitrogen-bearing compounds to form S-N containing species have a long history and, besides assuming importance in industrial synthetic processes, are of relevance to microbial metabolism; waste water treatment; aquatic, soil and atmospheric chemistry; and combustion processes. The recent discovery that hydrogen sulfide and nitric oxide exert often similar, sometimes mutually dependent effects in a variety of biological systems, and that the chemical interaction of these two species leads to formation of S-N compounds brought this chemistry to the attention of physiologists, biochemists and physicians. We here provide a perspective about the potential role of S-N compounds in biological signaling and briefly review their chemical properties and bioactivities in the context of the chronology of their discovery. Studies of the biological role of NO revealed why its chemistry is ideally suited for the tasks Nature has chosen for it; realising how the distinctive properties of sulfur can enrich this bioactivity does much to revive 'die Freude am experimentellen Spiel' of the pioneers in this field.
Nature and magnitude of aromatic base stacking in DNA and RNA: Quantum chemistry, molecular mechanics, and experiment.

PubMed

Sponer, Jiří; Sponer, Judit E; Mládek, Arnošt; Jurečka, Petr; Banáš, Pavel; Otyepka, Michal

2013-12-01

Base stacking is a major interaction shaping up and stabilizing nucleic acids. During the last decades, base stacking has been extensively studied by experimental and theoretical methods. Advanced quantum-chemical calculations clarified that base stacking is a common interaction, which in the first approximation can be described as combination of the three most basic contributions to molecular interactions, namely, electrostatic interaction, London dispersion attraction and short-range repulsion. There is not any specific π-π energy term associated with the delocalized π electrons of the aromatic rings that cannot be described by the mentioned contributions. The base stacking can be rather reasonably approximated by simple molecular simulation methods based on well-calibrated common force fields although the force fields do not include nonadditivity of stacking, anisotropy of dispersion interactions, and some other effects. However, description of stacking association in condensed phase and understanding of the stacking role in biomolecules remain a difficult problem, as the net base stacking forces always act in a complex and context-specific environment. Moreover, the stacking forces are balanced with many other energy contributions. Differences in definition of stacking in experimental and theoretical studies are explained. Copyright © 2013 Wiley Periodicals, Inc.
Investigating Pre-Service Chemistry Teachers' Problem Solving Strategies: Towards Developing a Framework in Teaching Stoichiometry

ERIC Educational Resources Information Center

Espinosa, Allen A.; Nueva España, Rebecca C.; Marasigan, Arlyne C.

2016-01-01

The present study investigated pre-service chemistry teachers' problem solving strategies and alternative conceptions in solving stoichiometric problems and later on formulate a teaching framework based from the result of the study. The pre-service chemistry teachers were given four stoichiometric problems with increasing complexity and they need…
The Influence of Web-Based Chemistry Learning on Students' Perceptions, Attitudes, and Achievements

ERIC Educational Resources Information Center

Frailich, Marcel; Kesner, Miri; Hofstein, Avi

2007-01-01

The goal of this study was to investigate whether integrating a website into chemistry teaching influences 10th-grade students' perceptions of the classroom learning environment, their attitudes regarding the relevance of chemistry, and their understanding of the concept of chemical bonding. Two groups participated in this study: an experimental…
The Impact of a Teaching-Learning Program Based on a Brain-Based Learning on the Achievement of the Female Students of 9th Grade in Chemistry

ERIC Educational Resources Information Center

Shabatat, Kawthar; Al-Tarawneh, Mohammed

2016-01-01

This study aimed at recognizing the impact of teaching-learning program based on a brain-based learning on the achievement of female students of 9th grade in chemistry, to accomplish the goal of this study the researchers designed instruments of: instructional plans, pre achievement and past achievement exams to use them for the study-validity and…
Assessing Motivation to Learn Chemistry: Adaptation and Validation of Science Motivation Questionnaire II with Greek Secondary School Students

ERIC Educational Resources Information Center

Salta, Katerina; Koulougliotis, Dionysios

2015-01-01

In educational research, the availability of a validated version of an original instrument in a different language offers the possibility for valid measurements obtained within the specific educational context and in addition it provides the opportunity for valid cross-cultural comparisons. The present study aimed to adapt the Science Motivation…
The Relation between Students' Math and Reading Ability and Their Mathematics, Physics, and Chemistry Examination Grades in Secondary Education

ERIC Educational Resources Information Center

Korpershoek, Hanke; Kuyper, Hans; van der Werf, Greetje

2015-01-01

Word problems are math- or science-related problems presented in the context of a story or real-life scenario. Literature suggests that, to solve these problems, advanced reading skills are required, in addition to content-related skills in, for example, mathematics. In the present study, we investigated the relation between students' reading…
Implementation of Large-Scale Science Curricula: A Study in Seven European Countries

ERIC Educational Resources Information Center

Pilling, G. M.; Waddington, D. J.

2005-01-01

The Salters Chemistry courses, context-led curricula for 13-16 and 17-18 year old students, first developed by the Science Education Group at the University of York in the UK, have now been translated and/or adapted in seven other European countries. This paper describes and discusses the different reasons for taking up the courses, the ways in…
Cycloadditions in modern polymer chemistry.

PubMed

Delaittre, Guillaume; Guimard, Nathalie K; Barner-Kowollik, Christopher

2015-05-19

Synthetic polymer chemistry has undergone two major developments in the last two decades. About 20 years ago, reversible-deactivation radical polymerization processes started to give access to a wide range of polymeric architectures made from an almost infinite reservoir of functional building blocks. A few years later, the concept of click chemistry revolutionized the way polymer chemists approached synthetic routes. Among the few reactions that could qualify as click, the copper-catalyzed azide-alkyne cycloaddition (CuAAC) initially stood out. Soon, many old and new reactions, including cycloadditions, would further enrich the synthetic macromolecular chemistry toolbox. Whether click or not, cycloadditions are in any case powerful tools for designing polymeric materials in a modular fashion, with a high level of functionality and, sometimes, responsiveness. Here, we wish to describe cycloaddition methodologies that have been reported in the last 10 years in the context of macromolecular engineering, with a focus on those developed in our laboratories. The overarching structure of this Account is based on the three most commonly encountered cycloaddition subclasses in organic and macromolecular chemistry: 1,3-dipolar cycloadditions, (hetero-)Diels-Alder cycloadditions ((H)DAC), and [2+2] cycloadditions. Our goal is to briefly describe the relevant reaction conditions, the advantages and disadvantages, and the realized polymer applications. Furthermore, the orthogonality of most of these reactions is highlighted because it has proven highly beneficial for generating unique, multifunctional polymers in a one-pot reaction. The overview on 1,3-dipolar cycloadditions is mostly centered on the application of CuAAC as the most travelled route, by far. Besides illustrating the capacity of CuAAC to generate complex polymeric architectures, alternative 1,3-dipolar cycloadditions operating without the need for a catalyst are described. In the area of (H)DA cycloadditions, beyond the popular maleimide/furan couple, we present chemistries based on more reactive species, such as cyclopentadienyl or thiocarbonylthio moieties, particularly stressing the reversibility of these systems. In these two greater families, as well as in the last section on [2+2] cycloadditions, we highlight phototriggered chemistries as a powerful tool for spatially and temporally controlled materials synthesis. Clearly, cycloaddition chemistry already has and will continue to transform the field of polymer chemistry in the years to come. Applying this chemistry enables better control over polymer composition, the development of more complicated polymer architectures, the simplification of polymer library production, and the discovery of novel applications for all of these new polymers.
Distributed scaffolding: Wiki collaboration among Latino high school chemistry students

NASA Astrophysics Data System (ADS)

O'Sullivan, Edwin Duncan, Jr.

The primary purpose of this study was to evaluate if wiki collaboration among Latino high school chemistry students can help reduce the science achievement gap between Latino and White students. The study was a quasi-experimental pre/post control group mixed-methods design. It used three intact sections of a high school chemistry course. The first research question asked if there is a difference in academic achievement between a treatment and control group on selected concepts from the topics of bonding, physical changes, and chemical changes, when Latino high school chemistry students collaborate on a quasi-natural wiki project. Overall results for all three activities (Bonding, Physical Changes, and Chemical Changes) indicated no significant difference between the wiki and control group. However, students performing the chemical changes activity did significantly better than their respective control group. Furthermore, there was a significant association, with large effect size, between group membership and ability to overcome the misconception that aqueous ionic reactants in precipitation reactions exist as molecular pairs of ions. Qualitative analysis of classroom and computer lab dialogue, discussion board communication, student focus groups, teacher interviews, and wiki content attributes the better performance of the chemical changes wiki group to favorable differences in intersubjectivity and calibrated assistance, as well as learning about submicroscopic representations of precipitation reactions in multiple contexts. Furthermore, the nonsignificant result overall points to an aversion to peer editing as a possible cause. Drawing considerably on Vygotsky and Piaget, the results are discussed within the context of how distributed scaffolding facilitated medium levels of cognitive conflict. The second research question asked what the characteristics of distributed metacognitive scaffolding are when Latino high school chemistry students collaborate on a quasi-natural wiki project. Results suggested a higher frequency of metacognitive scaffolding by the teacher, over peers, for content knowledge and making connections knowledge. Teacher metacognitive scaffolding often took the form of posting discussion board questions designed to stimulate student reflection on their content or creativity. On the other hand, both teacher and peer metacognitive scaffolding for general goals knowledge and strategy knowledge was relatively infrequent. Recommendations are offered for improving teacher and peer metacognitive scaffolding.
Blending Problem-Based Learning and Peer-Led Team Learning, in an Open Ended "Home-Grown" Pharmaceutical Chemistry Case Study

ERIC Educational Resources Information Center

Veale, Clinton G. L.; Krause, Rui W. M.; Sewry, Joyce D.

2018-01-01

Pharmaceutical chemistry, medicinal chemistry and the drug discovery process require experienced practitioners to employ reasoned speculation in generating creative ideas, which can be used to evolve promising molecules into drugs. The ever-evolving world of pharmaceutical chemistry requires university curricula that prepare graduates for their…
How do video-based demonstration assessment tasks affect problem-solving process, test anxiety, chemistry anxiety and achievement in general chemistry students?

NASA Astrophysics Data System (ADS)

Terrell, Rosalind Stephanie

2001-12-01

Because paper-and-pencil testing provides limited knowledge about what students know about chemical phenomena, we have developed video-based demonstrations to broaden measurement of student learning. For example, students might be shown a video demonstrating equilibrium shifts. Two methods for viewing equilibrium shifts are changing the concentration of the reactants and changing the temperature of the system. The students are required to combine the data collected from the video and their knowledge of chemistry to determine which way the equilibrium shifts. Video-based demonstrations are important techniques for measuring student learning because they require students to apply conceptual knowledge learned in class to a specific chemical problem. This study explores how video-based demonstration assessment tasks affect problem-solving processes, test anxiety, chemistry anxiety and achievement in general chemistry students. Several instruments were used to determine students' knowledge about chemistry, students' test and chemistry anxiety before and after treatment. Think-aloud interviews were conducted to determine students' problem-solving processes after treatment. The treatment group was compared to a control group and a group watching video demonstrations. After treatment students' anxiety increased and achievement decreased. There were also no significant differences found in students' problem-solving processes following treatment. These negative findings may be attributed to several factors that will be explored in this study.
The 2009 Nobel Prize in Chemistry: Thomas A. Steitz and the structure of the ribosome.

PubMed

Zhao, Peter

2011-06-01

Over the past 200 years, there have been countless groundbreaking discoveries in biology and medicine at Yale University. However, one particularly noteworthy discovery with profoundly important and broad consequences happened here in just the past two decades. In 2009, Thomas Steitz, the Sterling Professor of Molecular Biophysics & Biochemistry, was awarded the Nobel Prize in Chemistry for "studies of the structure and function of the ribosome," along with Venkatraman Ramakrishnan of the MRC Laboratory of Molecular Biology and Ada E. Yonath of the Weizmann Institute of Science. This article covers the historical context of Steitz's important discovery, the techniques his laboratory used to study the ribosome, and the impact that this research has had, and will have, on the future of biological and medical research.
Development and implementation of an empirical frequency map for use in MD simulations of isotope-edited proteins, and, Development, implementation, and evaluation of an online student portal as a textbook replacement in an advanced general chemistry course

NASA Astrophysics Data System (ADS)

Shorb, Justin Matthew

The first portion of this thesis describes an extension of work done in the Skinner group to develop an empirical frequency map for N-methylacetamide (NMA) in water. NMA is a peptide bond capped on either side by a methyl group and is therefore a common prototypical molecule used when studying complicated polypeptides and proteins. This amide bond is present along the backbone of every protein as it connects individual component amino acids. This amide bond also has a strong observable frequency in the IR due to the Amide-I mode (predominantly carbon-oxygen stretching motion). This project describes the simplification of the prior model for mapping the frequency of the Amide-I mode from the electric field due to the environment and develops a parallel implementation of this algorithm for use in larger biological systems, such as the trans-membrane portion of the tetrameric polypeptide bundle protein CD3zeta. The second portion of this thesis describes the development, implementation and evaluation of an online textbook within the context of a cohesive theoretical framework. The project begins by describing what is meant when discussing a digital textbook, including a survey of various types of digital media being used to deliver textbook-like content. This leads into the development of a theoretical framework based on constructivist pedagogical theory, hypertext learning theory, and chemistry visualization and representation frameworks. The implementation and design of ChemPaths, the general chemistry online text developed within the Chemistry Education Digital Library (ChemEd DL) is then described. The effectiveness of ChemPaths being used as a textbook replacement in an advanced general chemistry course is evaluated within the developed theoretical framework both qualitatively and quantitatively.
Nanopore-CMOS Interfaces for DNA Sequencing

PubMed Central

Magierowski, Sebastian; Huang, Yiyun; Wang, Chengjie; Ghafar-Zadeh, Ebrahim

2016-01-01

DNA sequencers based on nanopore sensors present an opportunity for a significant break from the template-based incumbents of the last forty years. Key advantages ushered by nanopore technology include a simplified chemistry and the ability to interface to CMOS technology. The latter opportunity offers substantial promise for improvement in sequencing speed, size and cost. This paper reviews existing and emerging means of interfacing nanopores to CMOS technology with an emphasis on massively-arrayed structures. It presents this in the context of incumbent DNA sequencing techniques, reviews and quantifies nanopore characteristics and models and presents CMOS circuit methods for the amplification of low-current nanopore signals in such interfaces. PMID:27509529
Nanopore-CMOS Interfaces for DNA Sequencing.

PubMed

Magierowski, Sebastian; Huang, Yiyun; Wang, Chengjie; Ghafar-Zadeh, Ebrahim

2016-08-06

DNA sequencers based on nanopore sensors present an opportunity for a significant break from the template-based incumbents of the last forty years. Key advantages ushered by nanopore technology include a simplified chemistry and the ability to interface to CMOS technology. The latter opportunity offers substantial promise for improvement in sequencing speed, size and cost. This paper reviews existing and emerging means of interfacing nanopores to CMOS technology with an emphasis on massively-arrayed structures. It presents this in the context of incumbent DNA sequencing techniques, reviews and quantifies nanopore characteristics and models and presents CMOS circuit methods for the amplification of low-current nanopore signals in such interfaces.

Overcoming heterologous protein interdependency to optimize P450-mediated Taxol precursor synthesis in Escherichia coli

PubMed Central

Biggs, Bradley Walters; Lim, Chin Giaw; Sagliani, Kristen; Shankar, Smriti; Stephanopoulos, Gregory; Ajikumar, Parayil Kumaran

2016-01-01

Recent advances in metabolic engineering have demonstrated the potential to exploit biological chemistry for the synthesis of complex molecules. Much of the progress to date has leveraged increasingly precise genetic tools to control the transcription and translation of enzymes for superior biosynthetic pathway performance. However, applying these approaches and principles to the synthesis of more complex natural products will require a new set of tools for enabling various classes of metabolic chemistries (i.e., cyclization, oxygenation, glycosylation, and halogenation) in vivo. Of these diverse chemistries, oxygenation is one of the most challenging and pivotal for the synthesis of complex natural products. Here, using Taxol as a model system, we use nature’s favored oxygenase, the cytochrome P450, to perform high-level oxygenation chemistry in Escherichia coli. An unexpected coupling of P450 expression and the expression of upstream pathway enzymes was discovered and identified as a key obstacle for functional oxidative chemistry. By optimizing P450 expression, reductase partner interactions, and N-terminal modifications, we achieved the highest reported titer of oxygenated taxanes (∼570 ± 45 mg/L) in E. coli. Altogether, this study establishes E. coli as a tractable host for P450 chemistry, highlights the potential magnitude of protein interdependency in the context of synthetic biology and metabolic engineering, and points to a promising future for the microbial synthesis of complex chemical entities. PMID:26951651
Overcoming heterologous protein interdependency to optimize P450-mediated Taxol precursor synthesis in Escherichia coli.

PubMed

Biggs, Bradley Walters; Lim, Chin Giaw; Sagliani, Kristen; Shankar, Smriti; Stephanopoulos, Gregory; De Mey, Marjan; Ajikumar, Parayil Kumaran

2016-03-22

Recent advances in metabolic engineering have demonstrated the potential to exploit biological chemistry for the synthesis of complex molecules. Much of the progress to date has leveraged increasingly precise genetic tools to control the transcription and translation of enzymes for superior biosynthetic pathway performance. However, applying these approaches and principles to the synthesis of more complex natural products will require a new set of tools for enabling various classes of metabolic chemistries (i.e., cyclization, oxygenation, glycosylation, and halogenation) in vivo. Of these diverse chemistries, oxygenation is one of the most challenging and pivotal for the synthesis of complex natural products. Here, using Taxol as a model system, we use nature's favored oxygenase, the cytochrome P450, to perform high-level oxygenation chemistry in Escherichia coli. An unexpected coupling of P450 expression and the expression of upstream pathway enzymes was discovered and identified as a key obstacle for functional oxidative chemistry. By optimizing P450 expression, reductase partner interactions, and N-terminal modifications, we achieved the highest reported titer of oxygenated taxanes (∼570 ± 45 mg/L) in E. coli. Altogether, this study establishes E. coli as a tractable host for P450 chemistry, highlights the potential magnitude of protein interdependency in the context of synthetic biology and metabolic engineering, and points to a promising future for the microbial synthesis of complex chemical entities.
The Mismatch between Students' Mental Models of Acids/Bases and Their Sources and Their Teacher's Anticipations Thereof

ERIC Educational Resources Information Center

Lin, Jing-Wen; Chiu, Mei-Hung

2010-01-01

The aim of this study is to compare the characteristics and sources of students' mental models of acids and bases with a teacher's anticipations and, based on this comparison, to explore some possible explanations why motivated students might fail to learn from a subject-knowledgeable chemistry teacher. The study involves a chemistry teacher and…
Life-Cycle Thinking in Inquiry-Based Sustainability Education--Effects on Students' Attitudes towards Chemistry and Environmental Literacy

ERIC Educational Resources Information Center

Juntunen, Marianne; Aksela, Maija

2013-01-01

The aim of the present study is to improve the quality of students' environmental literacy and sustainability education in chemistry teaching by combining the socio-scientific issue of life-cycle thinking with inquiry-based learning approaches. This case study presents results from an inquiry-based life-cycle thinking project: an interdisciplinary…
Sustainable Chemistry at Sungkyunkwan University.

PubMed

Park, Nam-Gyu

2015-07-20

Special Issue: Sustainable Chemistry at Sungkyunkwan University. Sustainable chemistry is key to the development of efficient renewable energies, which will become more and more important in order to combat global warming. In this Editorial, guest editor Prof. Nam-Gyu Park describes the context of this Special Issue on top-quality research towards sustainability performed at Sungkyunkwan University (SKKU) in Korea. Scientists at SKKU work on, for example, photovoltaic solar cells to generate low-cost electricity, lithium batteries and capacitors to store electricity, piezoelectric nanogenerators, thermoelectric devices, hydrogen generation, and fuel cells. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
The Effects of Problem-Based Learning (PBL) on the Academic Achievement of Students Studying "Electrochemistry"

ERIC Educational Resources Information Center

Günter, Tugçe; Alpat, Sibel Kilinç

2017-01-01

This study investigates the effects of problem-based learning (PBL) on students' academic achievements in studying "Electrochemistry" within a course on Analytical Chemistry. The research was of a pretest-posttest control group quasi-experimental design and it was conducted with second year students in the Chemistry Teaching Program at…
Effects of Combined Hands-on Laboratory and Computer Modeling on Student Learning of Gas Laws: A Quasi-Experimental Study

ERIC Educational Resources Information Center

Liu, Xiufeng

2006-01-01

Based on current theories of chemistry learning, this study intends to test a hypothesis that computer modeling enhanced hands-on chemistry laboratories are more effective than hands-on laboratories or computer modeling laboratories alone in facilitating high school students' understanding of chemistry concepts. Thirty-three high school chemistry…
An Investigation of the Effects of Relevant Samples and a Comparison of Verification versus Discovery Based Lab Design

ERIC Educational Resources Information Center

Rieben, James C., Jr.

2010-01-01

This study focuses on the effects of relevance and lab design on student learning within the chemistry laboratory environment. A general chemistry conductivity of solutions experiment and an upper level organic chemistry cellulose regeneration experiment were employed. In the conductivity experiment, the two main variables studied were the effect…
Using Rasch Measurement to Validate an Instrument for Measuring the Quality of Classroom Teaching in Secondary Chemistry Lessons

ERIC Educational Resources Information Center

He, Peng; Liu, Xiufeng; Zheng, Changlong; Jia, Mengying

2016-01-01

This study intends to develop a standardized instrument for measuring classroom teaching and learning in secondary chemistry lessons. Based on previous studies and interviews with expert teachers, the progression of five quality levels was constructed hypothetically to represent the quality of chemistry lessons in Chinese secondary schools. The…
The Effectiveness of Interacting with Scientific Animations in Chemistry Using Mobile Devices on Grade 12 Students' Spatial Ability and Scientific Reasoning Skills

ERIC Educational Resources Information Center

Al-Balushi, Sulaiman M.; Al-Musawi, Ali S.; Ambusaidi, Abdullah K.; Al-Hajri, Fatemah H.

2017-01-01

The purpose of the current study was to investigate the effectiveness of interacting with animations using mobile devices on grade 12 students' spatial and reasoning abilities. The study took place in a grade 12 context in Oman. A quasi-experimental design was used with an experimental group of 32 students and a control group of 28 students. The…
Mass Spectrometry in Studies of Protein Thiol Chemistry and Signaling: Opportunities and Caveats

PubMed Central

Devarie Baez, Nelmi O.; Reisz, Julie A.; Furdui, Cristina M.

2014-01-01

Mass spectrometry (MS) has become a powerful and widely utilized tool in the investigation of protein thiol chemistry, biochemistry, and biology. Very early biochemical studies of metabolic enzymes have brought to light the broad spectrum of reactivity profiles that distinguish cysteine thiols with functions in catalysis and protein stability from other cysteine residues in proteins. The development of MS methods for the analysis of proteins using electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI) coupled with the emergence of high-resolution mass analyzers have been instrumental in advancing studies of thiol modifications, both in single proteins and within the cellular context. This article reviews MS instrumentation and methods of analysis employed in investigations of thiols and their reactivity toward a range of small biomolecules. A selected number of studies are detailed to highlight the advantages brought about by the MS technologies along with the caveats associated with these analyses. PMID:25261734
Using an in Silico Approach to Teach 3D Pharmacodynamics of the Drug-Target Interaction Process Focusing on Selective COX2 Inhibition by Celecoxib

ERIC Educational Resources Information Center

Tavares, Maurício T.; Primi, Marina C.; Silva, Nuno A. T. F.; Carvalho, Camila F.; Cunha, Micael R.; Parise-Filho, Roberto

2017-01-01

Teaching the molecular aspects of drug-target interactions and selectivity is not always an easy task. In this context, the use of alternative and engaging approaches could help pharmacy and chemistry students better understand this important topic of medicinal chemistry. Herein a 4 h practical exercise that uses freely available software as a…
New Hydrophobic IOL Materials and Understanding the Science of Glistenings.

PubMed

Tetz, Manfred; Jorgensen, Matthew R

2015-01-01

An introduction to the history of intraocular lenses (IOLs) is given, leading up to modern hydrophobic examples. The roles of hydrophobicity, hygroscopy, materials chemistry, and edge design are discussed in the context of IOLs. The four major types of IOL materials are compared in terms of their chemistry and biocompatibility. An example of a modern "hydrophobic" acrylic polymer with higher water content is discussed in detail.
Promoting Student Development of Models and Scientific Inquiry Skills in Acid-Base Chemistry: An Important Skill Development in Preparation for AP Chemistry

ERIC Educational Resources Information Center

Hale-Hanes, Cara

2015-01-01

In this study, two groups of 11th grade chemistry students (n = 210) performed a sequence of hands-on and virtual laboratories that were progressively more inquiry-based. One-half of the students did the laboratory sequence with the addition of a teacher-led discussion connecting student data to student-generated visual representations of…
Exploring the Structure and Function of the Chemistry Self-Concept Inventory with High School Chemistry Students

ERIC Educational Resources Information Center

Nielsen, Sara E.; Yezierski, Ellen

2015-01-01

Though the Chemistry Self-Concept Inventory (CSCI) was developed to study one aspect of the affective domain in college chemistry students, the instrument on which it was based, the Self-Description Questionnaire III, was developed for use with late adolescents. As such, we explored data generated from administering the CSCI to high school…
Students' Learning with the Connected Chemistry (CC1) Curriculum: Navigating the Complexities of the Particulate World

ERIC Educational Resources Information Center

Levy, Sharona T.; Wilensky, Uri

2009-01-01

The focus of this study is students' learning with a Connected Chemistry unit, CC1 (denotes Connected Chemistry, chapter 1), a computer-based environment for learning the topics of gas laws and kinetic molecular theory in chemistry (Levy and Wilensky 2009). An investigation was conducted into high-school students' learning with Connected…
Effects of Students' Pre- and Post-Laboratory Concept Maps on Students' Attitudes toward Chemistry Laboratory in University General Chemistry

ERIC Educational Resources Information Center

Kilic, Ziya; Kaya, Osman Nafiz; Dogan, Alev

2004-01-01

The purpose of this study was to investigate the effects of scientific discussions based on student-constructed pre- and post-laboratory concept maps on students' attitudes toward chemistry laboratory in the university general chemistry. As part of instruction, during the first four laboratory sessions, students were taught how to construct and…
Computer-Based Molecular Modelling: Finnish School Teachers' Experiences and Views

ERIC Educational Resources Information Center

Aksela, Maija; Lundell, Jan

2008-01-01

Modern computer-based molecular modelling opens up new possibilities for chemistry teaching at different levels. This article presents a case study seeking insight into Finnish school teachers' use of computer-based molecular modelling in teaching chemistry, into the different working and teaching methods used, and their opinions about necessary…
Ligand-directed tosyl chemistry for in situ native protein labeling and engineering in living systems: from basic properties to applications.

PubMed

Tsukiji, Shinya; Hamachi, Itaru

2014-08-01

The ability to introduce any chemical probe to any endogenous target protein in its native environment, that is in cells and in vivo, is anticipated to provide various new exciting tools for biological and biomedical research. Although still at the prototype stage, the ligand-directed tosyl (LDT) chemistry is a novel type of affinity labeling technique that we developed for such a dream. This chemistry allows for modifying native proteins by various chemical probes with high specificity in various biological settings ranging from in vitro (in test tubes) to in living cells and in vivo. Since the first report, the list of proteins that are successfully labeled by the LDT chemistry has been increasing. A growing number of studies have demonstrated its utility to create semisynthetic proteins directly in cellular contexts. The in situ generated semisynthetic proteins are applicable for various types of analysis and imaging of intracellular biological processes. In this review, we summarize the basic properties of the LDT chemistry and its applications toward in situ engineering and analysis of native proteins in living systems. Current limitations and future challenges of this area are also described. Copyright © 2014 Elsevier Ltd. All rights reserved.
Water and complex organic chemistry in the cold dark cloud Barnard 5: Observations and Models

NASA Astrophysics Data System (ADS)

Wirström, Eva; Charnley, Steven B.; Taquet, Vianney; Persson, Carina M.

2015-08-01

Studies of complex organic molecule (COM) formation have traditionally been focused on hot cores in regions of massive star formation, where chemistry is driven by the elevated temperatures - evaporating ices and allowing for endothermic reactions in the gas-phase. As more sensitive instruments have become available, the types of objects known to harbour COMs like acetaldehyde (CH3CHO), dimethyl ether (CH3OCH3), methyl formate (CH3OCHO), and ketene (CH2CO) have expanded to include low mass protostars and, recently, even pre-stellar cores. We here report on the first in a new category of objects harbouring COMs: the cold dark cloud Barnard 5 where non-thermal ice desorption induce complex organic chemistry entirely unrelated to local star-formation.Methanol, which only forms efficiently on the surfaces of dust grains, provide evidence of efficient non-thermal desorption of ices in the form of prominent emission peaks offset from protostellar activity and high density tracers in cold molecular clouds. A study with Herschel targeting such methanol emission peaks resulted in the first ever detection of gas-phase water offset from protostellar activity in a dark cloud, at the so called methanol hotspot in Barnard 5.To model the effect a transient injection of ices into the gas-phase has on the chemistry of a cold, dark cloud we have included gas-grain interactions in an existing gas-phase chemical model and connected it to a chemical reaction network updated and expanded to include the formation and destruction paths of the most common COMs. Results from this model will be presented.Ground-based follow-up studies toward the methanol hotspot in B5 have resulted in the detection of a number of COMs, including CH2CO, CH3CHO, CH3OCH3, and CH3OCHO, as well as deuterated methanol (CH2DOH). Observations have also confirmed that COM emission is extended and not localised to a core structure. The implications of these observational and theoretical studies of B5 will be discussed in the context of the gas-grain interaction in dark clouds and its relation to the chemistry of the earliest phases of low-mass star formation.

Understanding "Green Chemistry" and "Sustainability": An Example of Problem-Based Learning (PBL)

ERIC Educational Resources Information Center

Günter, Tugçe; Akkuzu, Nalan; Alpat, Senol

2017-01-01

Background: This study uses problem-based learning (PBL) to ensure that students comprehend the significance of green chemistry better by experiencing the stages of identifying the problem, developing hypotheses, and providing solutions within the problem-solving process. Purpose: The aim of this study is to research the effect of PBL implemented…
Xenobiology: State-of-the-Art, Ethics, and Philosophy of New-to-Nature Organisms.

PubMed

Schmidt, Markus; Pei, Lei; Budisa, Nediljko

The basic chemical constitution of all living organisms in the context of carbon-based chemistry consists of a limited number of small molecules and polymers. Until the twenty-first century, biology was mainly an analytical science and has now reached a point where it merges with engineering science, paving the way for synthetic biology. One of the objectives of synthetic biology is to try to change the chemical compositions of living cells, that is, to create an artificial biological diversity, which in turn fosters a new sub-field of synthetic biology, xenobiology. In particular, the genetic code in living systems is based on highly standardized chemistry composed of the same "letters" or nucleotides as informational polymers (DNA, RNA) and the 20 amino acids which serve as basic building blocks for proteins. The universality of the genetic code enables not only vertical gene transfer within the same species but also horizontal gene transfer across biological taxa, which require a high degree of standardization and interconnectivity. Although some minor alterations of the standard genetic code are found in nature (e.g., proteins containing non-conical amino acids exist in nature, and some organisms use alternated coding systems), all structurally deep chemistry changes within living systems are generally lethal, making the creation of artificial biological system an extremely difficult challenge.In this context, one of the great challenges for bioscience is the development of a strategy for expanding the standard basic chemical repertoire of living cells. Attempts to alter the meaning of the genetic information stored in DNA as an informational polymer by changing the chemistry of the polymer (i.e., xeno-nucleic acids) or by changes in the genetic code have already yielded successful results. In the future this should enable the partial or full redirection of the biological information flow to generate "new" version(s) of the genetic code derived from the "old" biological world.In addition to the scientific challenges, the attempt to increase biochemical diversity also raises important ethical and philosophical issues. Although promotors of this branch of synthetic biology highlight the many potential applications to come (e.g., novel tools for diagnostics and fighting infection diseases), such developments could also bring risks affecting social, political, and other structures of nearly all societies.
On the Prevalence of Alternative Conceptions on Acid-Base Chemistry among Secondary Students: Insights from Cognitive and Confidence Measures

ERIC Educational Resources Information Center

Hoe, Kai Yee; Subramaniam, R.

2016-01-01

This study presents an analysis of alternative conceptions (ACs) on acid--base chemistry harbored by grade 9 students in Singapore. The ACs were obtained by the development and validation of a 4-tier diagnostic instrument. It is among the very few studies in the science education literature that have focused on examining results based also on…
Implementation of a Research-Based Lab Module in a High School Chemistry Curriculum: A Study of Classroom Dynamics

ERIC Educational Resources Information Center

Pilarz, Matthew

2013-01-01

For this study, a research-based lab module was implemented in two high school chemistry classes for the purpose of examining classroom dynamics throughout the process of students completing the module. A research-based lab module developed for use in undergraduate laboratories by the Center for Authentic Science Practice in Education (CASPiE) was…
Understanding `green chemistry' and `sustainability': an example of problem-based learning (PBL)

NASA Astrophysics Data System (ADS)

Günter, Tuğçe; Akkuzu, Nalan; Alpat, Şenol

2017-10-01

Background: This study uses problem-based learning (PBL) to ensure that students comprehend the significance of green chemistry better by experiencing the stages of identifying the problem, developing hypotheses, and providing solutions within the problem-solving process.
Biosourced polymetallic catalysis: A surprising and efficient means to promote the Knoevenagel condensation

NASA Astrophysics Data System (ADS)

Deyris, Pierre-Alexandre; Bert, Valérie; Diliberto, Sébastien; Boulanger, Clotilde; Petit, Eddy; Legrand, Yves-Marie; Grison, Claude

2018-03-01

Zn hyperaccumulator (Arabidobsis halleri) and Zn accumulator Salix ‘Tordis’ (Salix schwerinii x S. viminalis) have shown their interest in the phytoextraction of polluted brownfields. Herein, we explore an innovative methodology based on the chemical valorization of Zn-rich biomass produced by these metallophyte plants. The approach is based on the direct use of polymetallic salts derived from plants as “Lewis acid” catalysts in organic chemistry. The formed ecocatalysts were characterized via ICP-MS, XRD, FT-IR in order to elucidate the chemical composition, structure and behavior of the formed materials. The Doebner-Knoevenagel reaction was chosen as model reaction to study their synthetic potential. Significant differences to conventional catalysts such as zinc (II) chloride are observed. They can principally be related to a mixture of unusual mineral species. DFT calculations were carried out on these salts in the context of the Gutmann theory. They allow the rationalization of experimental results. Finally, these new bio-based polymetallic catalysts illustrated the interest of this concept for green and sustainable catalysis.
A conflict of analysis: analytical chemistry and milk adulteration in Victorian Britain.

PubMed

Steere-Williams, Jacob

2014-08-01

This article centres on a particularly intense debate within British analytical chemistry in the late nineteenth century, between local public analysts and the government chemists of the Inland Revenue Service. The two groups differed in both practical methodologies and in the interpretation of analytical findings. The most striking debates in this period were related to milk analysis, highlighted especially in Victorian courtrooms. It was in protracted court cases, such as the well known Manchester Milk Case in 1883, that analytical chemistry was performed between local public analysts and the government chemists, who were often both used as expert witnesses. Victorian courtrooms were thus important sites in the context of the uneven professionalisation of chemistry. I use this tension to highlight what Christopher Hamlin has called the defining feature of Victorian public health, namely conflicts of professional jurisdiction, which adds nuance to histories of the struggle of professionalisation and public credibility in analytical chemistry.
The Effects of Problem-Based Learning on Metacognitive Awareness and Attitudes toward Chemistry of Prospective Teachers with Different Academic Backgrounds

ERIC Educational Resources Information Center

Tosun, Cemal; Senocak, Erdal

2013-01-01

The aim of this study was to reveal the effects of Problem-based Learning (PBL) on the metacognitive awareness and attitudes toward chemistry of teacher candidates with different academic backgrounds. The study was carried out on one group using both pre-and post-test experimental studies. The findings of the study were obtained through…
Staying in the Science Stream: Patterns of Participation in A-Level Science Subjects in the UK

ERIC Educational Resources Information Center

Smith, Emma

2011-01-01

This paper describes patterns of participation and attainment in A-level physics, chemistry and biology from 1961 to 2009. The A level has long been seen as an important gateway qualification for higher level study, particularly in the sciences. This long-term overview examines how recruitment to these three subjects has changed in the context of…
Scope & Limitations of Fmoc Chemistry SPPS-Based Approaches to the Total Synthesis of Insulin Lispro via Ester Insulin

PubMed Central

Dhayalan, Balamurugan; Mandal, Kalyaneswar; Rege, Nischay; Weiss, Michael A.; Eitel, Simon H.; Meier, Thomas; Schoenleber, Ralph O.; Kent, Stephen B.H.

2017-01-01

We have systematically explored three approaches based on Fmoc chemistry SPPS for the total chemical synthesis of the key depsipeptide intermediate for the efficient total chemical synthesis of insulin. The approaches used were: stepwise Fmoc chemistry SPPS; the ‘hybrid method’, in which maximally-protected peptide segments made by Fmoc chemistry SPPS are condensed in solution; and, native chemical ligation using peptide-thioester segments generated by Fmoc chemistry SPPS. A key building block in all three approaches was a Glu[Oβ(Thr)] ester-linked dipeptide equipped with a set of orthogonal protecting groups compatible with Fmoc chemistry SPPS. The most effective method for the preparation of the 51 residue ester-linked polypeptide chain of ester insulin was the use of unprotected peptide-thioester segments, prepared from peptide-hydrazides synthesized by Fmoc chemistry SPPS, and condensed by native chemical ligation. High resolution X-ray crystallography confirmed the disulfide pairings and three-dimensional structure of synthetic insulin lispro prepared from ester insulin lispro by this route. Further optimization of these pilot studies should yield an effective total chemical synthesis of insulin lispro (Humalog) based on peptide synthesis by Fmoc chemistry SPPS. PMID:27905149
Copper-free click chemistry in living animals

PubMed Central

Chang, Pamela V.; Prescher, Jennifer A.; Sletten, Ellen M.; Baskin, Jeremy M.; Miller, Isaac A.; Agard, Nicholas J.; Lo, Anderson; Bertozzi, Carolyn R.

2010-01-01

Chemical reactions that enable selective biomolecule labeling in living organisms offer a means to probe biological processes in vivo. Very few reactions possess the requisite bioorthogonality, and, among these, only the Staudinger ligation between azides and triarylphosphines has been employed for direct covalent modification of biomolecules with probes in the mouse, an important model organism for studies of human disease. Here we explore an alternative bioorthogonal reaction, the 1,3-dipolar cycloaddition of azides and cyclooctynes, also known as “Cu-free click chemistry,” for labeling biomolecules in live mice. Mice were administered peracetylated N-azidoacetylmannosamine (Ac4ManNAz) to metabolically label cell-surface sialic acids with azides. After subsequent injection with cyclooctyne reagents, glycoconjugate labeling was observed on isolated splenocytes and in a variety of tissues including the intestines, heart, and liver, with no apparent toxicity. The cyclooctynes tested displayed various labeling efficiencies that likely reflect the combined influence of intrinsic reactivity and bioavailability. These studies establish Cu-free click chemistry as a bioorthogonal reaction that can be executed in the physiologically relevant context of a mouse. PMID:20080615
Development of a PERCA Instrument for Ambient Peroxy Radical Measurements

NASA Astrophysics Data System (ADS)

Dusanter, S.; Duncianu, M.; Lahib, A.; Tomas, A.; Stevens, P. S.

2017-12-01

Peroxy radicals (HO2 and RO2) are key species in atmospheric chemistry, which together with the hydroxyl radical (OH), lead to the oxidation of volatile organic compounds and the formation of secondary pollutants such as ozone and secondary organic aerosols. Monitoring these short-lived species during intensive field campaigns and comparing the measured concentrations to model outputs allows assessing the reliability of chemical mechanisms implemented in atmospheric models. However, ambient measurements of peroxy radicals are still considered challenging and only a few techniques have been used for field measurements. The PEroxy Radical Chemical Amplifier (PERCA) approach, whose principle is based on amplification and a conversion of ambient peroxy radicals into nitrogen dioxide (NO2), has recently seen renewed interests due to the availability of sensitive NO2 monitors. We will present (i) the construction of a PERCA instrument, (ii) experiments conducted to quantify the radical chain length for HO2 and several RO2 radicals, including those produced during the OH-oxidation of isoprene, and (iii) a comparison of the conventional CO/NO and recently proposed ethane/NO amplification chemistries. In this context, box modelling of the PERCA chemistry will be discussed.
A Course in Chemistry of Silicates for Beginning Undergraduate Students: An Interdisciplinary Study

ERIC Educational Resources Information Center

Dunstone, John

1973-01-01

The course was designed: (1) to broaden the base for chemistry majors to build their courses; (2) to illustrate how some chemistry principles are applied to real situations; and (3) to serve as an introduction to geochemistry for geology majors. (DF)
Unraveling the chemical identity of meat pigments.

PubMed

Pegg, R B; Shahidi, F

1997-10-01

This review examines the chemistry of nitrite curing of meat and meat products as it relates to the development of cured meat color and provides a detailed account of how nitrite-free processed meats could be prepared using the preformed cooked cured-meat pigment (CCMP). Thus, a chemical description of meat color, both raw and cooked, and characterization of nitrosylheme pigments follows. Based on electron paramagnetic resonance (EPR), visible and infrared spectroscopic studies, evidence has been provided to support the hypothesis that the chemical structure of the preformed CCMP is identical to that of the pigment prepared in situ after thermal processing of nitrite-cured meat and is in fact a mononitrosylheme complex. An appendix, which describes the basic principles of EPR spectroscopy used in the context of this review, is attached.
Chemistry and Heritage

NASA Astrophysics Data System (ADS)

Vittoria Barbarulo, Maria

2014-05-01

Chemistry is the central science, as it touches every aspect of the society we live in and it is intertwined with many aspects of our culture; in particular, the strong link between Chemistry and Archaeology and Art History is being explored, offering a penetrating insight into an area of growing interest from an educational point of view. A series of vital and vibrant examples (i.e., ancient bronzes composition, colour changes due to natural pigment decomposition, marble degradation) has been proposed, on one hand, to improve student understanding of the relationship between cultural and scientific issues arising from the examination, the conservation, and the maintenance of cultural Heritage, on the other, to illustrate the role of the underlying Chemistry. In some case studies, a survey of the most relevant atmospheric factors, which are involved in the deterioration mechanisms, has also been presented to the students. First-hand laboratory experiences have been providing an invaluable means of discovering the full and varied world of Chemistry. Furthermore, the promotion of an interdisciplinary investigation of a famous painting or fresco, involving the study of its nature and significance, the definition of its historical context, any related literature, the chemical knowledge of the materials used, may be an excellent occasion to experiment the Content and Language Integrated Learning (CLIL). The aim of this approach is to convey the important message that everyone has the responsibility to care for and preserve Heritage for the benefit of present and future generations.
Tropospheric impacts of volcanic halogen emissions: first simulations of reactive halogen chemistry in the Eyjafjallajökull eruption plume

NASA Astrophysics Data System (ADS)

Roberts, Tjarda

2013-04-01

Volcanic plumes are regions of high chemical reactivity. Instrumented research aircraft that probed the 2010 Icelandic Eyjafjallajökull eruption plume identified in-plume ozone depletion and reactive halogens (Cl, BrO), the latter also detected by satellite. These measurements add to growing evidence that volcanic plumes support rapid reactive halogen chemistry, with predicted impacts including depletion of atmospheric oxidants and mercury deposition. However, attempts to simulate volcanic plume halogen chemistry and predict impacts are subject to considerable uncertainties. e.g. in rate constants for HOBr reactive uptake (see this session: EGU2013-6076), or in the high-temperature initialisation. Model studies attempting to replicate volcanic plume halogen chemistry are restricted by a paucity of field data that is required both for model tuning and verification, hence reported model 'solutions' are not necessarily unique. To this end, the aircraft, ground-based and satellite studies of the Eyjafjallajökull eruption provide a valuable combination of datasets for improving our understanding of plume chemistry and impacts. Here, PlumeChem simulations of Eyjafjallajökull plume reactive halogen chemistry and impacts are presented and verified by observations for the first time. Observed ozone loss, a function of plume strength and age, is quantitatively reproduced by the model. Magnitudinal agreement to reported downwind BrO and Cl is also shown. The model predicts multi-day impacts, with reactive bromine mainly as BrO, HOBr and BrONO2 during daytime, and Br2 and BrCl at night. BrO/SO2 is reduced in more dispersed plumes due to enhanced partitioning to HOBr, of potential interest to satellite studies of BrO downwind of volcanoes. Additional predicted impacts of Eyjafjallajökull volcanic plume halogen chemistry include BrO-mediated depletion of HOx that reduces the rate of SO2 oxidation to H2SO4, hence the formation of sulphate aerosol. The model predicts NOx is rapidly converted into nitric acid (via BrONO2). Such HNO3-formation might contribute towards new particle formation, noting reported very high in-plume particle nucleation rates in Eyjafjallajökull plume. Thus, plume halogen chemistry influences on aerosol formation and growth are emphasized regarding studies of climatic and health impacts of volcanic aerosol. As the plume disperses, in-plume ozone concentrations partially recover due to entrainment of O3-rich background air. However, the cumulative net impact on ozone depletion continues. Whilst the global tropospheric impact of Eyjafjallajokull is small, up-scaling of the model findings in the context of present day global volcanic degassing and recent historic eruptions indicates potential for significant impacts of global volcanic halogen emissions on tropospheric ozone, particularly during periods of enhanced volcanic activity. Notably, this model-observation study of Eyjafjallajökull plume exhibits contrasts to a related model-observation study that quantified ozone loss in Redoubt volcano eruption plume (Kelly et al., JVGR in press). Meteorological and volcanological causes for these differences in plume halogen evolution (hence impacts) are discussed. This has implications for wider atmospheric modelling efforts to quantify global impacts from volcanic halogen emissions and highlights the useful role of fully-flexible and computationally inexpensive models such as PlumeChem to inform larger (regional or global) model studies regarding model initialisation and particularly near-source plume chemistry.
The quadruple bottom line: the advantages of incorporating Green Chemistry into the undergraduate chemistry major

NASA Astrophysics Data System (ADS)

Bodner, George M.

2017-08-01

When the author first became involved with the Green Chemistry movement, he noted that his colleagues in industry who were involved in one of the ACS Green Chemistry Institute® industrial roundtables emphasized the take-home message they described as the "triple bottom line." They noted that introducing Green Chemistry in industrial settings had economic, social, and environmental benefits. As someone who first went to school at age 5, and has been "going to school" most days for 65 years, it was easy for the author to see why introducing Green Chemistry into academics had similar beneficial effects within the context of economic, social and environmental domains at the college/university level. He was prepared to understand why faculty who had taught traditional courses often saw the advantage of incorporating Green Chemistry into the courses they teach. What was not as obvious is why students who were encountering chemistry for the first time were often equally passionate about the Green Chemistry movement. Recent attention has been paid, however, to a model that brings clarity to the hitherto vague term of "relevance" that might explain why integrating Green Chemistry into the undergraduate chemistry classroom can achieve a "quadruple bottom-line" for students because of potentially positive effects of adding a domain of "relevance" to the existing economic, social, and environmental domains.
Towards "Bildung"-Oriented Chemistry Education

ERIC Educational Resources Information Center

Sjöström, Jesper

2013-01-01

This paper concerns "Bildung"-oriented chemistry education, based on a reflective and critical discourse of chemistry. It is contrasted with the dominant type of chemistry education, based on the mainstream discourse of chemistry. "Bildung"-oriented chemistry education includes not only content knowledge in chemistry, but also…
Bioactive Natural Product and Superacid Chemistry for Lead Compound Identification: A Case Study of Selective hCA III and L-Type Ca2+ Current Inhibitors for Hypotensive Agent Discovery.

PubMed

Carreyre, Hélène; Carré, Grégoire; Ouedraogo, Maurice; Vandebrouck, Clarisse; Bescond, Jocelyn; Supuran, Claudiu T; Thibaudeau, Sébastien

2017-05-31

Dodoneine (Ddn) is one of the active compounds identified from Agelanthus dodoneifolius , which is a medicinal plant used in African pharmacopeia and traditional medicine for the treatment of hypertension. In the context of a scientific program aiming at discovering new hypotensive agents through the original combination of natural product discovery and superacid chemistry diversification, and after evidencing dodoneine's vasorelaxant effect on rat aorta, superacid modifications allowed us to generate original analogues which showed selective human carbonic anhydrase III (hCA III) and L-type Ca 2+ current inhibition. These derivatives can now be considered as new lead compounds for vasorelaxant therapeutics targeting these two proteins.
Can They Succeed? Exploring At-Risk Students' Study Habits in College General Chemistry

ERIC Educational Resources Information Center

Ye, Li; Shuniak, Constantine; Oueini, Razanne; Robert, Jenay; Lewis, Scott

2016-01-01

A well-established literature base identifies a portion of students enrolled in post-secondary General Chemistry as at-risk of failing the course based on incoming metrics. Learning about the experiences and factors that lead to this higher failure rate is essential toward improving retention in this course. This study examines the relationship…

Thai Undergraduate Chemistry Practical Learning Experiences Using the Jigsaw IV Method

ERIC Educational Resources Information Center

Jansoon, Ninna; Somsook, Ekasith; Coll, Richard K.

2008-01-01

The research reported in this study consisted of an investigation of student learning experiences in Thai chemistry laboratories using the Jigsaw IV method. A hands-on experiment based on the Jigsaw IV method using a real life example based on green tea beverage was designed to improve student affective variables for studying topics related to…
Evaluation of a Design Principle for Fostering Students' Epistemological Views on Models and Modelling Using Authentic Practices as Contexts for Learning in Chemistry Education

ERIC Educational Resources Information Center

Prins, Gjalt T.; Bulte, Astrid M. W.; Pilot, Albert

2011-01-01

Science education should foster students' epistemological view on models and modelling consistent with formal epistemology in science and technology practices. This paper reports the application of a curriculum unit in the classroom using an authentic chemical practice, "Modelling drinking water treatment", as the context for learning.…
Measuring Meaningful Learning in the Undergraduate General Chemistry and Organic Chemistry Laboratories: A Longitudinal Study

ERIC Educational Resources Information Center

Galloway, Kelli R.; Bretz, Stacey Lowery

2015-01-01

Understanding how students learn in the undergraduate chemistry teaching laboratory is an essential component to developing evidence-based laboratory curricula. The Meaningful Learning in the Laboratory Instrument (MLLI) was developed to measure students' cognitive and affective expectations and experiences for learning in the chemistry…
ChemicalTagger: A tool for semantic text-mining in chemistry

PubMed Central

2011-01-01

Background The primary method for scientific communication is in the form of published scientific articles and theses which use natural language combined with domain-specific terminology. As such, they contain free owing unstructured text. Given the usefulness of data extraction from unstructured literature, we aim to show how this can be achieved for the discipline of chemistry. The highly formulaic style of writing most chemists adopt make their contributions well suited to high-throughput Natural Language Processing (NLP) approaches. Results We have developed the ChemicalTagger parser as a medium-depth, phrase-based semantic NLP tool for the language of chemical experiments. Tagging is based on a modular architecture and uses a combination of OSCAR, domain-specific regex and English taggers to identify parts-of-speech. The ANTLR grammar is used to structure this into tree-based phrases. Using a metric that allows for overlapping annotations, we achieved machine-annotator agreements of 88.9% for phrase recognition and 91.9% for phrase-type identification (Action names). Conclusions It is possible parse to chemical experimental text using rule-based techniques in conjunction with a formal grammar parser. ChemicalTagger has been deployed for over 10,000 patents and has identified solvents from their linguistic context with >99.5% precision. PMID:21575201
Knot theory in modern chemistry.

PubMed

Horner, Kate E; Miller, Mark A; Steed, Jonathan W; Sutcliffe, Paul M

2016-11-21

Knot theory is a branch of pure mathematics, but it is increasingly being applied in a variety of sciences. Knots appear in chemistry, not only in synthetic molecular design, but also in an array of materials and media, including some not traditionally associated with knots. Mathematics and chemistry can now be used synergistically to identify, characterise and create knots, as well as to understand and predict their physical properties. This tutorial review provides a brief introduction to the mathematics of knots and related topological concepts in the context of the chemical sciences. We then survey the broad range of applications of the theory to contemporary research in the field.
Social aspects of classroom learning: Results of a discourse analysis in an inquiry-oriented physical chemistry class

NASA Astrophysics Data System (ADS)

Becker, Nicole M.

Engaging students in classroom discourse offers opportunities for students to participate in the construction of joint understandings, to negotiate relationships between different types of evidence, and to practice making evidence-based claims about science content. However, close attention to social aspects of learning is critical to creating inquiry-oriented classroom environments in which students learn with understanding. This study examined the social influences that contribute to classroom learning in an inquiry-oriented undergraduate physical chemistry class using the Process Oriented Guided Inquiry Learning (POGIL) approach. A qualitative approach to analyzing classroom discourse derived from Toulmin's (1968) model of argumentation was used to document patterns in classroom reasoning that reflect normative aspects of social interaction. Adapting the constructs of social and sociomathematical norms from the work of Yackel and Cobb (1996), I describe social aspects of the classroom environment by discussing normative aspects of social interaction (social norms) and discipline-specific criteria related to reasoning and justification in chemistry contexts, referred to here as sociochemical norms. This work discusses four social norms and two sociochemical norms that were documented over a five-week period of observation in Dr. Black's POGIL physical chemistry class. In small group activities, the socially established expectations that students explain reasoning, negotiate understandings of terminology and symbolic representations, and arrive at a consensus on critical thinking questions shaped small group interactions and reasoning. In whole class discussion, there was an expectation that students share reasoning with the class, and that the instructor provide feedback on student reasoning in ways that extended student contributions and elaborated relationships between macroscopic, particulate, and symbolic-level ideas. The ways in which the class constructed evidence-based claims about chemistry content reflected the influence of sociochemical norms that were enacted through classroom discourse. Two sociochemical norms were documented in both whole class and small group activities: first, the class used particulate-level evidence to make claims about chemical and physical properties; second, particular ways of using mathematical reasoning to justify claims about thermodynamics content became normative for the class. These similarities and differences between social and sociochemical norms in small group and whole class discussion highlight ways in which instructor facilitation can support productive interactions in classroom activities.
Assessing Chemistry-Learning Competencies of Students in Isolated Rural Senior High Schools by Using the National Examination: A Case Study of Simeulue Island, Indonesia

ERIC Educational Resources Information Center

Adlim, M-; Soewarno, S.; Ali, Hasbi; Ibrahim, Armia; Umar, Hasmunir; Ismail, Khairil; Gani, Usman A.; Hasan, Ishak; Yasin, Burhanuddin

2014-01-01

This study explored learning competency based on the Indonesian National Examination focusing especially on chemistry performance and the circumstances of senior high school students and teachers in rural areas of Simeulue Island, Indonesia. The National Examination total score and chemistry score for students in rural areas were consistently…
Controls on dripwater chemistry of Oregon Caves National Monument, northwestern United States

NASA Astrophysics Data System (ADS)

Rushdi, Ahmed I.; Ersek, Vasile; Mix, Alan C.; Clark, Peter U.

2018-02-01

Cave dripwater chemistry of Oregon Caves National Monument (OCNM) was studied, where the parameters pH, total alkalinity, calcium, magnesium, strontium, sodium and barium were analyzed at quasi-monthly intervals from 2005 to 2007. Different statistical analyses have been used to investigate the variability of the chemical parameters in the different sites in the OCNM cave system. The dripwater varies in response to seasonal changes in rainfall. The drip rates range from zero in summer to continuous flow in winter, closely following the rainfall intensity. Spatial variations of dripwater chemistry, which is nonlinearly related to dripwater discharge likely, reflect the chemical composition of bedrock and overlying soil, and the residence time of the ground water within the aquifer. The residence time of infiltrated water in bedrock cracks control the dissolution carbonate bedrock, reprecipitation of calcium carbonate and the degree of saturation of dripwater with respect to calcium carbonate minerals. Spatiotemporal fluctuations of dripwater Mg/Ca and Sr/Ca ratios are controlled by dissolution of carbonate bedrock and the degree of calcite reprecipitation in bedrock cracks. This suggests that trace elements in speleothem deposits at the OCNM may serve as paleoclimatological proxies for precipitation, if interpreted within the context of understanding local bedrock chemistry.
An Evaluation of Lightning Flash Rate Parameterizations Based on Observations of Colorado Storms during DC3

NASA Astrophysics Data System (ADS)

Basarab, B.; Fuchs, B.; Rutledge, S. A.

2013-12-01

Predicting lightning activity in thunderstorms is important in order to accurately quantify the production of nitrogen oxides (NOx = NO + NO2) by lightning (LNOx). Lightning is an important global source of NOx, and since NOx is a chemical precursor to ozone, the climatological impacts of LNOx could be significant. Many cloud-resolving models rely on parameterizations to predict lightning and LNOx since the processes leading to charge separation and lightning discharge are not yet fully understood. This study evaluates predicted flash rates based on existing lightning parameterizations against flash rates observed for Colorado storms during the Deep Convective Clouds and Chemistry Experiment (DC3). Evaluating lightning parameterizations against storm observations is a useful way to possibly improve the prediction of flash rates and LNOx in models. Additionally, since convective storms that form in the eastern plains of Colorado can be different thermodynamically and electrically from storms in other regions, it is useful to test existing parameterizations against observations from these storms. We present an analysis of the dynamics, microphysics, and lightning characteristics of two case studies, severe storms that developed on 6 and 7 June 2012. This analysis includes dual-Doppler derived horizontal and vertical velocities, a hydrometeor identification based on polarimetric radar variables using the CSU-CHILL radar, and insight into the charge structure using observations from the northern Colorado Lightning Mapping Array (LMA). Flash rates were inferred from the LMA data using a flash counting algorithm. We have calculated various microphysical and dynamical parameters for these storms that have been used in empirical flash rate parameterizations. In particular, maximum vertical velocity has been used to predict flash rates in some cloud-resolving chemistry simulations. We diagnose flash rates for the 6 and 7 June storms using this parameterization and compare to observed flash rates. For the 6 June storm, a preliminary analysis of aircraft observations of storm inflow and outflow is presented in order to place flash rates (and other lightning statistics) in the context of storm chemistry. An approach to a possibly improved LNOx parameterization scheme using different lightning metrics such as flash area will be discussed.
Chemical leasing in the context of sustainable chemistry.

PubMed

Moser, Frank; Karavezyris, Vassilios; Blum, Christopher

2015-05-01

Chemical leasing is a new and innovative approach of selling chemicals. It aims at reducing the risks emanating from hazardous substances and ensuring long-term economic success within a global system of producing and using chemicals. This paper explores how, through chemical leasing, the consumption of chemicals, energy, resources and the generation of related wastes can be reduced. It also analyses the substitution of hazardous chemicals as a tool to protect environmental, health and safety and hence ensure compliance with sustainability criteria. For this, we are proposing an evaluation methodology that seeks to provide an answer to the following research questions: (1) Does the application of chemical leasing promote sustainability in comparison to an existing chemicals production and management system? 2. If various chemical leasing project types are envisaged, which is the most promising in terms of sustainability? The proposed methodology includes a number of basic goals and sub-goals to assess the sustainability for eight different chemical leasing case studies that have been implemented both at the local and the national levels. The assessment is limited to the relative assessment of specific case studies and allows the comparisons of different projects in terms of their relative contribution to sustainable chemistry. The findings of our assessment demonstrate that chemical leasing can be regarded as promoting sustainable chemistry in five case studies with certainty. However, on the grounds of our assessment, we cannot conclude with certainty that chemical leasing has equivalent contribution to sustainable chemistry in respect of three further case studies.
A Study of Faculty Approaches to Teaching Undergraduate Physical Chemistry Courses

NASA Astrophysics Data System (ADS)

Mack, Michael Ryan

Chemistry education researchers have not adequately studied teaching and learning experiences at all levels in the undergraduate chemistry curriculum leaving gaps in discipline-based STEM education communities understanding about how the upper- division curricula works (National Research Council, 2012b; Towns, 2013). This study explored faculty approaches to teaching in upper-division physical chemistry course settings using an interview-based methodology. Two conceptualizations of approaches to teaching emerged from a phenomenographic analysis of interview transcripts: (1) faculty beliefs about the purposes for teaching physical chemistry and (2) their conceptions of their role as an instructor in these course settings. Faculty who reported beliefs predominantly centered on helping students develop conceptual knowledge and problem-solving skills in physical chemistry often worked with didactic models of teaching, which emphasized the transfer of expert knowledge to students. When faculty expressed beliefs that were more inclusive of conceptual, epistemic, and social learning goals in science education they often described more student-centered models of teaching and learning, which put more responsibilities on them to facilitate students' interactive engagement with the material and peers during regularly scheduled class time. Knowledge of faculty thinking, as evinced in a rich description of their accounts of their experience, provides researchers and professional developers with useful information about the potential opportunities or barriers that exist for helping faculty align their beliefs and goals for teaching with research-based instructional strategies.
Asymmetric translation between multiple representations in chemistry

NASA Astrophysics Data System (ADS)

Lin, Yulan I.; Son, Ji Y.; Rudd, James A., II

2016-03-01

Experts are more proficient in manipulating and translating between multiple representations (MRs) of a given concept than novices. Studies have shown that instruction using MR can increase student understanding of MR, and one model for MR instruction in chemistry is the chemistry triplet proposed by Johnstone. Concreteness fading theory suggests that presenting concrete representations before abstract representations can increase the effectiveness of MR instruction; however, little work has been conducted on varying the order of different representations during instruction and the role of concreteness in assessment. In this study, we investigated the application of concreteness fading to MR instruction and assessment in teaching chemistry. In two experiments, undergraduate students in either introductory psychology courses or general chemistry courses were given MR instruction on phase changes using different orders of presentation and MR assessment questions based on the representations in the chemistry triplet. Our findings indicate that the order of presentation based on levels of concreteness in MR chemistry instruction is less important than implementation of comprehensive MR assessments. Even after MR instruction, students display an asymmetric understanding of the chemical phenomenon on the MR assessments. Greater emphasis on MR assessments may be an important component in MR instruction that effectively moves novices toward more expert MR understanding.
The PRIME Partnership: 9th Graders, Graduate Students and Integrated, Inquiry-Based Science

NASA Astrophysics Data System (ADS)

Gaffney, A. M.; Miguelez, S.

2001-12-01

The PRIME program (Partnership for Research in Inquiry-based Math, science and engineering Education) is a collaboration between the UW Colleges of Education and Engineering and several Seattle-area school districts. This project, funded by the NSF GK-12 program, pairs UW graduate students from math, science and engineering disciplines with local middle school teachers. The graduate student spends a year working with the teacher, on projects designed to meet the needs and interests of the specific partnership and classroom. In the partnership, the graduate student spends 15 hours per week in the classroom, interacting with the students, as well as additional planning time outside of the classroom. Goals of the PRIME program are enriched learning by middle school students, professional development for middle school teachers, improved communication and teaching skills for the graduate students, and strengthened partnerships between the University of Washington and local school districts. The goal of our partnership was to develop an inquiry-based, 9th grade unit that integrates the pre-existing Earth Science and Chemistry units, and to assess the effectiveness of teaching Chemistry in the context of Earth Science. We have observed that students often become engaged and excited when they do hands-on activities that utilize the intrinsic understanding that they have of concepts that draw upon experiences in their daily lives. When science is taught and learned in one such context - in the context of the natural world - the students may gain a more solid fundamental understanding of the science that they learn. The day-to-day activities for this unit vary widely. We started each topic with a question designed to get the students thinking independently and to identify the preconceptions that the students brought into the classroom. Discussions of students' preconceptions served as a justification and springboard for the subsequent activities and experiments. Examples of questions used to spark student thought are: "What do you think the inside of the Earth looks like?," "What makes a volcano erupt?," and "Do mountains last forever?." We evaluated the effectiveness of this approach through a combination of classroom observations, formal and informal interviews, and surveys
Chemical biology on the genome.

PubMed

Balasubramanian, Shankar

2014-08-15

In this article I discuss studies towards understanding the structure and function of DNA in the context of genomes from the perspective of a chemist. The first area I describe concerns the studies that led to the invention and subsequent development of a method for sequencing DNA on a genome scale at high speed and low cost, now known as Solexa/Illumina sequencing. The second theme will feature the four-stranded DNA structure known as a G-quadruplex with a focus on its fundamental properties, its presence in cellular genomic DNA and the prospects for targeting such a structure in cels with small molecules. The final topic for discussion is naturally occurring chemically modified DNA bases with an emphasis on chemistry for decoding (or sequencing) such modifications in genomic DNA. The genome is a fruitful topic to be further elucidated by the creation and application of chemical approaches. Copyright © 2014 Elsevier Ltd. All rights reserved.
Study of fission-product segregation in used CANDU fuel by X-ray photoelectron spectroscopy (XPS) II

NASA Astrophysics Data System (ADS)

Hocking, William H.; Duclos, A. Michael; Johnson, Lawrence H.

1994-03-01

A thorough investigation of the grain-boundary chemistry of used CANDU fuel from one intact element has been conducted by X-ray photoelectron spectroscopy (XPS). Selected findings from more extensive XPS measurements on other used CANDU fuels exposed to storage conditions are included for comparison. Cesium, rubidium, tellurium and barium have been commonly observed, often reaching high degrees of surface enrichment, although their relative abundances can vary widely with a complex dependence on the fuel irradiation history. Lower concentrations of cadmium, molybdenum, strontium and iodine have also been occasionally detected. Except for iodine, chemical-shift data are indicative of oxidized species, possibly uranates. Segregation at monolayer-level coverages has been demonstrated by sequential XPS analysis and argon-ion sputtering. Calculations based on an idealized thin-film model are consistent with the depth profiles. The interpretation of these results is discussed in the context of previous studies, especially on LWR fuels.
Problem-Based Learning in Teaching Chemistry: Enthalpy Changes in Systems

ERIC Educational Resources Information Center

Ayyildiz, Yildizay; Tarhan, Leman

2018-01-01

Background: Problem-based learning (PBL) as a teaching strategy has recently become quite widespread in especially chemistry classes. Research has found that students, from elementary through college, have many alternative conceptions regarding "enthalpy changes in systems." Although there are several studies focused on identifying…
Assessing the Effect of Web-Based Learning Tools on Student Understanding of Stoichiometry Using Knowledge Space Theory

ERIC Educational Resources Information Center

Arasasingham, Ramesh D.; Taagepera, Mare; Potter, Frank; Martorell, Ingrid; Lonjers, Stacy

2005-01-01

Student achievement in web-based learning tools is assessed by using in-class examination, pretests, and posttests. The study reveals that using mastering chemistry web software in large-scale instruction provides an overall benefit to introductory chemistry students.
Chemistry Teachers' Perceived Benefits and Challenges of Inquiry-Based Instruction in Inclusive Chemistry Classrooms

ERIC Educational Resources Information Center

Mumba, F.; Banda, A.; Chabalengula, V. M.

2015-01-01

Studies on inquiry-based instruction in inclusive science teaching have mainly focused on elementary and middle school levels. Little is known about inquiry-based instruction in high school inclusive science classes. Yet, such classes have become the norm in high schools, fulfilling the instructional needs of students with mild disabilities. This…
Thai Grade 11 Students' Alternative Conceptions for Acid-Base Chemistry

ERIC Educational Resources Information Center

Artdej, Romklao; Ratanaroutai, Thasaneeya; Coll, Richard Kevin; Thongpanchang, Tienthong

2010-01-01

This study involved the development of a two-tier diagnostic instrument to assess Thai high school students' understanding of acid-base chemistry. The acid-base diagnostic test (ABDT) comprising 18 items was administered to 55 Grade 11 students in a science and mathematics programme during the second semester of the 2008 academic year. Analysis of…
Conceptual Understanding of Acids and Bases Concepts and Motivation to Learn Chemistry

ERIC Educational Resources Information Center

Cetin-Dindar, Ayla; Geban, Omer

2017-01-01

The purpose of this study was to investigate the effect of 5E learning cycle model oriented instruction (LCMI) on 11th-grade students' conceptual understanding of acids and bases concepts and student motivation to learn chemistry. The study, which lasted for 7 weeks, involved two groups: An experimental group (LCMI) and a control group (the…

Designing Undergraduate-Level Organic Chemistry Instructional Problems: Seven Ideas from a Problem-Solving Study of Practicing Synthetic Organic Chemists

ERIC Educational Resources Information Center

Raker, Jeffrey R.; Towns, Marcy H.

2012-01-01

The development of curricular problems based on the practice of synthetic organic chemistry has not been explored in the literature. Such problems have broadly been hypothesized to promote student persistence and interest in STEM fields. This study reports seven ideas about how practice-based problems can be developed for sophomore-level organic…
Scope and Limitations of Fmoc Chemistry SPPS-Based Approaches to the Total Synthesis of Insulin Lispro via Ester Insulin.

PubMed

Dhayalan, Balamurugan; Mandal, Kalyaneswar; Rege, Nischay; Weiss, Michael A; Eitel, Simon H; Meier, Thomas; Schoenleber, Ralph O; Kent, Stephen B H

2017-01-31

We have systematically explored three approaches based on 9-fluorenylmethoxycarbonyl (Fmoc) chemistry solid phase peptide synthesis (SPPS) for the total chemical synthesis of the key depsipeptide intermediate for the efficient total chemical synthesis of insulin. The approaches used were: stepwise Fmoc chemistry SPPS; the "hybrid method", in which maximally protected peptide segments made by Fmoc chemistry SPPS are condensed in solution; and, native chemical ligation using peptide-thioester segments generated by Fmoc chemistry SPPS. A key building block in all three approaches was a Glu[O-β-(Thr)] ester-linked dipeptide equipped with a set of orthogonal protecting groups compatible with Fmoc chemistry SPPS. The most effective method for the preparation of the 51 residue ester-linked polypeptide chain of ester insulin was the use of unprotected peptide-thioester segments, prepared from peptide-hydrazides synthesized by Fmoc chemistry SPPS, and condensed by native chemical ligation. High-resolution X-ray crystallography confirmed the disulfide pairings and three-dimensional structure of synthetic insulin lispro prepared from ester insulin lispro by this route. Further optimization of these pilot studies could yield an efficient total chemical synthesis of insulin lispro (Humalog) based on peptide synthesis by Fmoc chemistry SPPS. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Earthquakes: hydrogeochemical precursors

USGS Publications Warehouse

Ingebritsen, Steven E.; Manga, Michael

2014-01-01

Earthquake prediction is a long-sought goal. Changes in groundwater chemistry before earthquakes in Iceland highlight a potential hydrogeochemical precursor, but such signals must be evaluated in the context of long-term, multiparametric data sets.
Investigating Students' Interest in Chemistry through Self-Generated Questions

ERIC Educational Resources Information Center

Demirdogen, Betul; Cakmakci, Gultekin

2014-01-01

This study investigates Turkish students' (age 15 or older) interest in chemistry by analysing 1027 of their self-generated chemistry-related questions, which had been submitted to a popular science magazine. These questions were classified based on the field of interest, the cognitive level of the question, and the stimulating impetus for asking…
Intuitive Judgments Govern Students' Answering Patterns in Multiple-Choice Exercises in Organic Chemistry

ERIC Educational Resources Information Center

Graulich, Nicole

2015-01-01

Research in chemistry education has revealed that students going through their undergraduate and graduate studies in organic chemistry have a fragmented conceptual knowledge of the subject. Rote memorization, rule-based reasoning, and heuristic strategies seem to strongly influence students' performances. There appears to be a gap between what we…
The Influence of PBL on Students' Self-Efficacy Beliefs in Chemistry

ERIC Educational Resources Information Center

Mataka, Lloyd M.; Grunert Kowalske, Megan

2015-01-01

A convergent mixed methods research study was used to investigate whether or not undergraduate students who participated in a problem-based learning (PBL) laboratory environment improved their self-efficacy beliefs in chemistry. The Chemistry Attitude and Experience Questionnaire (CAEQ) was used as a pre- and post-test to determine changes in…
A Degree Is Not Enough: A Quantitative Study of Aspects of Pre-Service Science Teachers' Chemistry Content Knowledge

ERIC Educational Resources Information Center

Kind, Vanessa

2014-01-01

Aspects of chemistry content knowledge held by 265 UK-based pre-service teachers (PSTs) were probed using 28 diagnostic questions in five chemistry concept areas, "Particle theory and changes of state", "Mass conservation" (taught to 11-14-year-olds), and "Chemical bonding", "Mole calculations" and…
The Role of Student Major in Grade Perception in Chemistry Courses

ERIC Educational Resources Information Center

Karatjas, Andrew; Webb, Jeffrey

2017-01-01

The Kruger-Dunning effect was studied as it related to performance in chemistry courses based on student differences in academic background. Student major was chosen as the classification to look at the effect of students with different interests/specializations. Chemistry majors tended to predict lower performance than biology majors, while…
Large-Scale Parallel Simulations of Turbulent Combustion using Combined Dimension Reduction and Tabulation of Chemistry

DTIC Science & Technology

2012-05-22

tabulation of the reduced space is performed using the In Situ Adaptive Tabulation ( ISAT ) algorithm. In addition, we use x2f mpi – a Fortran library...for parallel vector-valued function evaluation (used with ISAT in this context) – to efficiently redistribute the chemistry workload among the...Constrained-Equilibrium (RCCE) method, and tabulation of the reduced space is performed using the In Situ Adaptive Tabulation ( ISAT ) algorithm. In addition
Increased robustness of single-molecule counting with microfluidics, digital isothermal amplification, and a mobile phone versus real-time kinetic measurements.

PubMed

Selck, David A; Karymov, Mikhail A; Sun, Bing; Ismagilov, Rustem F

2013-11-19

Quantitative bioanalytical measurements are commonly performed in a kinetic format and are known to not be robust to perturbation that affects the kinetics itself or the measurement of kinetics. We hypothesized that the same measurements performed in a "digital" (single-molecule) format would show increased robustness to such perturbations. Here, we investigated the robustness of an amplification reaction (reverse-transcription loop-mediated amplification, RT-LAMP) in the context of fluctuations in temperature and time when this reaction is used for quantitative measurements of HIV-1 RNA molecules under limited-resource settings (LRS). The digital format that counts molecules using dRT-LAMP chemistry detected a 2-fold change in concentration of HIV-1 RNA despite a 6 °C temperature variation (p-value = 6.7 × 10(-7)), whereas the traditional kinetic (real-time) format did not (p-value = 0.25). Digital analysis was also robust to a 20 min change in reaction time, to poor imaging conditions obtained with a consumer cell-phone camera, and to automated cloud-based processing of these images (R(2) = 0.9997 vs true counts over a 100-fold dynamic range). Fluorescent output of multiplexed PCR amplification could also be imaged with the cell phone camera using flash as the excitation source. Many nonlinear amplification schemes based on organic, inorganic, and biochemical reactions have been developed, but their robustness is not well understood. This work implies that these chemistries may be significantly more robust in the digital, rather than kinetic, format. It also calls for theoretical studies to predict robustness of these chemistries and, more generally, to design robust reaction architectures. The SlipChip that we used here and other digital microfluidic technologies already exist to enable testing of these predictions. Such work may lead to identification or creation of robust amplification chemistries that enable rapid and precise quantitative molecular measurements under LRS. Furthermore, it may provide more general principles describing robustness of chemical and biological networks in digital formats.
Estimating reliable paediatric reference intervals in clinical chemistry and haematology.

PubMed

Ridefelt, Peter; Hellberg, Dan; Aldrimer, Mattias; Gustafsson, Jan

2014-01-01

Very few high-quality studies on paediatric reference intervals for general clinical chemistry and haematology analytes have been performed. Three recent prospective community-based projects utilising blood samples from healthy children in Sweden, Denmark and Canada have substantially improved the situation. The present review summarises current reference interval studies for common clinical chemistry and haematology analyses. ©2013 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
Biosourced Polymetallic Catalysis: A Surprising and Efficient Means to Promote the Knoevenagel Condensation

PubMed Central

Deyris, Pierre-Alexandre; Bert, Valérie; Diliberto, Sébastien; Boulanger, Clotilde; Petit, Eddy; Legrand, Yves-Marie; Grison, Claude

2018-01-01

Zn hyperaccumulator (Arabidobsis halleri) and Zn accumulator Salix “Tordis” (Salix schwerinii × Salix viminalis) have shown their interest in the phytoextraction of polluted brownfields. Herein, we explore a novel methodology based on the chemical valorization of Zn-rich biomass produced by these metallophyte plants. The approach is based on the use of polymetallic salts derived from plants as bio-based catalysts in organic chemistry. The formed ecocatalysts were characterized via ICP-MS, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) in order to precise the chemical composition, structure, and behavior of the formed materials. The Doebner-Knoevenagel reaction was chosen as model reaction to study their synthetic potential. Significant differences to usual catalysts such as zinc (II) chloride are observed. They can principally be related to a mixture of unusual mineral species. DFT calculations were carried out on these salts in the context of the Gutmann theory. They allow the rationalization of experimental results. Finally, these new bio-based polymetallic catalysts illustrated the interest of this concept for green and sustainable catalysis. PMID:29637065
Biosourced Polymetallic Catalysis: A Surprising and Efficient Means to Promote the Knoevenagel Condensation.

PubMed

Deyris, Pierre-Alexandre; Bert, Valérie; Diliberto, Sébastien; Boulanger, Clotilde; Petit, Eddy; Legrand, Yves-Marie; Grison, Claude

2018-01-01

Zn hyperaccumulator ( Arabidobsis halleri ) and Zn accumulator Salix "Tordis" ( Salix schwerinii × Salix viminalis ) have shown their interest in the phytoextraction of polluted brownfields. Herein, we explore a novel methodology based on the chemical valorization of Zn-rich biomass produced by these metallophyte plants. The approach is based on the use of polymetallic salts derived from plants as bio-based catalysts in organic chemistry. The formed ecocatalysts were characterized via ICP-MS, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) in order to precise the chemical composition, structure, and behavior of the formed materials. The Doebner-Knoevenagel reaction was chosen as model reaction to study their synthetic potential. Significant differences to usual catalysts such as zinc (II) chloride are observed. They can principally be related to a mixture of unusual mineral species. DFT calculations were carried out on these salts in the context of the Gutmann theory. They allow the rationalization of experimental results. Finally, these new bio-based polymetallic catalysts illustrated the interest of this concept for green and sustainable catalysis.
PRECIPITATION CHEMISTRY OF MAGNESIUM SULFITE HYDRATES IN MAGNESIUM OXIDE SCRUBBING

EPA Science Inventory

The report gives results of laboratory studies defining the precipitation chemistry of MgSO3 hydrates. The results apply to the design of Mg-based scrubbing processes for SO2 removal from combustion flue gas. In Mg-based scrubbing processes, MgSO3 precipitates as either trihydrat...
Inquiry-Based Laboratory Activities in Electrochemistry: High School Students' Achievements and Attitudes

NASA Astrophysics Data System (ADS)

Acar Sesen, Burcin; Tarhan, Leman

2013-02-01

This study aimed to investigate the effects of inquiry-based laboratory activities on high school students' understanding of electrochemistry and attitudes towards chemistry and laboratory work. The participants were 62 high school students (average age 17 years) in an urban public high school in Turkey. Students were assigned to experimental ( N = 30) and control groups ( N = 32). The experimental group was taught using inquiry-based laboratory activities developed by the researchers and the control group was instructed using traditional laboratory activities. The results of the study indicated that instruction based on inquiry-based laboratory activities caused a significantly better acquisition of scientific concepts related to electrochemistry, and produced significantly higher positive attitudes towards chemistry and laboratory. In the light of the findings, it is suggested that inquiry-based laboratory activities should be developed and applied to promote students' understanding in chemistry subjects and to improve their positive attitudes.
How Do Undergraduate Students Conceptualize Acid-Base Chemistry? Measurement of a Concept Progression

ERIC Educational Resources Information Center

Romine, William L.; Todd, Amber N.; Clark, Travis B.

2016-01-01

We developed and validated a new instrument, called "Measuring Concept progressions in Acid-Base chemistry" (MCAB) and used it to better understand the progression of undergraduate students' understandings about acid-base chemistry. Items were developed based on an existing learning progression for acid-base chemistry. We used the Rasch…
School Chemistry: The Need for Transgression

NASA Astrophysics Data System (ADS)

Talanquer, Vicente

2013-07-01

Studies of the philosophy of chemistry over the past 15 years suggest that chemistry is a hybrid science which mixes scientific pursuits with technological applications. Dominant universal characterizations of the nature of science thus fail to capture the essence of the discipline. The central goal of this position paper is to encourage reflection about the extent to which dominant views about quality science education based on universal views of scientific practices may constrain school chemistry. In particular, we discuss how these predominant ideas restrict the development of chemistry curricula and instructional approaches that may better support the learning of the ideas and practices that studies of the philosophy of chemistry suggest are at the core of the discipline. Our analysis suggests that philosophical studies about the nature of chemistry invite us to transgress traditional educational boundaries between science and technology, inquiry and design, content and process, and to reconceptualize school chemistry as a paradigmatic techno scientific subject. To support these changes, chemical education researchers should expand the scope of their investigations to better understand how students and teachers reason about and engage in more authentic ways of chemical thinking and doing.
Problem-based learning in teaching chemistry: enthalpy changes in systems

NASA Astrophysics Data System (ADS)

Ayyildiz, Yildizay; Tarhan, Leman

2018-01-01

Problem-based learning (PBL) as a teaching strategy has recently become quite widespread in especially chemistry classes. Research has found that students, from elementary through college, have many alternative conceptions regarding enthalpy changes in systems. Although there are several studies focused on identifying student alternative conceptions and misunderstandings of this subject, studies on preventing the formation of these alternative conceptions are limited.
Species‐ and habitat‐specific otolith chemistry patterns inform riverine fisheries management

USGS Publications Warehouse

Radigan, William; Carlson, Andrew K.; Kientz, Jeremy; Chipps, Steven R.; Fincel, Mark J.; Graeb, Brian D. S.

2018-01-01

Geology and hydrology are drivers of water chemistry and thus important considerations for fish otolith chemistry research. However, other factors such as species and habitat identity may have predictive ability, enabling selection of appropriate elemental signatures prior to costly, perhaps unnecessary water/age‐0 fish sampling. The goal of this study was to develop a predictive methodology for using species and habitat identity to design efficient otolith chemistry studies. Duplicate water samples and age‐0 fish were collected from 61 sites in 4 Missouri River reservoirs for walleye Sander vitreus and one impoundment (Lake Sharpe, South Dakota) for other fishes (bluegill Lepomis macrochirus, black crappie Pomoxis nigromaculatus, gizzard shad Dorosoma cepedianum, largemouth bass Micropterus salmoides, smallmouth bass M. dolomieu, white bass Morone chrysops, white crappie P. annularis, and yellow perch Perca flavescens). Water chemistry (barium:calcium [Ba:Ca], strontium:calcium [Sr:Ca]) was temporally stable, spatially variable, and highly correlated with otolith chemistry for all species except yellow perch. Classification accuracies based on bivariate Ba:Ca and Sr:Ca signatures were high (84% across species) yet varied between floodplain and main‐channel habitats in a species‐specific manner. Thus, to maximize the reliability of otolith chemistry, researchers can use species classifications presented herein to inform habitat selection (e.g., study reservoir‐oriented species such as white bass in main‐channel environments) and habitat‐based classifications to inform species selection (e.g., focus floodplain studies on littoral species such as largemouth bass). Overall, species and habitat identity are important considerations for efficient, effective otolith chemistry studies that inform and advance fisheries and aquatic resource management.
An investigation into the effectiveness of problem-based learning in a physical chemistry laboratory course

NASA Astrophysics Data System (ADS)

Gürses, Ahmet; Açıkyıldız, Metin; Doğar, Çetin; Sözbilir, Mustafa

2007-04-01

The aim of this study was to investigate the effectiveness of a problem-based learning (PBL) approach in a physical chemistry laboratory course. The parameters investigated were students’ attitudes towards a chemistry laboratory course, scientific process skills of students and their academic achievement. The design of the study was one group pre-test post-test. Four experiments, covering the topics adsorption, viscosity, surface tension and conductivity were performed using a PBL approach in the fall semester of the 2003/04 academic year at Kazim Karabekir Education Faculty of Atatürk University. Each experiment was done over a three week period. A total of 40 students, 18 male and 22 female, participated in the study. Students took the Physical Chemistry Laboratory Concept Test (PCLCT), Attitudes towards Chemistry Laboratory (ATCL) questionnaire and Science Process Skills Test (SPST) as pre and post-tests. In addition, the effectiveness of the PBL approach was also determined through four different scales; Scales Specific to Students’ Views of PBL. A statistically significant difference between the students’ academic achievement and scientific process skills at p

The land-use legacy effect: Towards a mechanistic understanding of time-lagged water quality responses to land use/cover.

PubMed

Martin, Sherry L; Hayes, Daniel B; Kendall, Anthony D; Hyndman, David W

2017-02-01

Numerous studies have linked land use/land cover (LULC) to aquatic ecosystem responses, however only a few have included the dynamics of changing LULC in their analysis. In this study, we explicitly recognize changing LULC by linking mechanistic groundwater flow and travel time models to a historical time series of LULC, creating a land-use legacy map. We then illustrate the utility of legacy maps to explore relationships between dynamic LULC and lake water chemistry. We tested two main concepts about mechanisms linking LULC and lake water chemistry: groundwater pathways are an important mechanism driving legacy effects; and, LULC over multiple spatial scales is more closely related to lake chemistry than LULC over a single spatial scale. We applied statistical models to twelve water chemistry variables, ranging from nutrients to relatively conservative ions, to better understand the roles of biogeochemical reactivity and solubility on connections between LULC and aquatic ecosystem response. Our study illustrates how different areas can have long groundwater pathways that represent different LULC than what can be seen on the landscape today. These groundwater pathways delay the arrival of nutrients and other water quality constituents, thus creating a legacy of historic land uses that eventually reaches surface water. We find that: 1) several water chemistry variables are best fit by legacy LULC while others have a stronger link to current LULC, and 2) single spatial scales of LULC analysis performed worse for most variables. Our novel combination of temporal and spatial scales was the best overall model fit for most variables, including SRP where this model explained 54% of the variation. We show that it is important to explicitly account for temporal and spatial context when linking LULC to ecosystem response. Copyright © 2016. Published by Elsevier B.V.
Nanometer-Scale Chemistry of a Calcite Biomineralization Template: Implications for Skeletal Composition and Nucleation.

PubMed

Branson, Oscar; Bonnin, Elisa A; Perea, Daniel E; Spero, Howard J; Zhu, Zihua; Winters, Maria; Hönisch, Bärbel; Russell, Ann D; Fehrenbacher, Jennifer S; Gagnon, Alexander C

2016-11-15

Plankton, corals, and other organisms produce calcium carbonate skeletons that are integral to their survival, form a key component of the global carbon cycle, and record an archive of past oceanographic conditions in their geochemistry. A key aspect of the formation of these biominerals is the interaction between organic templating structures and mineral precipitation processes. Laboratory-based studies have shown that these atomic-scale processes can profoundly influence the architecture and composition of minerals, but their importance in calcifying organisms is poorly understood because it is difficult to measure the chemistry of in vivo biomineral interfaces at spatially relevant scales. Understanding the role of templates in biomineral nucleation, and their importance in skeletal geochemistry requires an integrated, multiscale approach, which can place atom-scale observations of organic-mineral interfaces within a broader structural and geochemical context. Here we map the chemistry of an embedded organic template structure within a carbonate skeleton of the foraminifera Orbulina universa using both atom probe tomography (APT), a 3D chemical imaging technique with Ångström-level spatial resolution, and time-of-flight secondary ionization mass spectrometry (ToF-SIMS), a 2D chemical imaging technique with submicron resolution. We quantitatively link these observations, revealing that the organic template in O. universa is uniquely enriched in both Na and Mg, and contributes to intraskeletal chemical heterogeneity. Our APT analyses reveal the cation composition of the organic surface, offering evidence to suggest that cations other than Ca 2+ , previously considered passive spectator ions in biomineral templating, may be important in defining the energetics of carbonate nucleation on organic templates.
Argumentation in the Chemistry Laboratory: Inquiry and Confirmatory Experiments

NASA Astrophysics Data System (ADS)

Katchevich, Dvora; Hofstein, Avi; Mamlok-Naaman, Rachel

2013-02-01

One of the goals of science education is to provide students with the ability to construct arguments—reasoning and thinking critically in a scientific context. Over the years, many studies have been conducted on constructing arguments in science teaching, but only few of them have dealt with studying argumentation in the laboratory. Our research focuses on the process in which students construct arguments in the chemistry laboratory while conducting various types of experiments. It was found that inquiry experiments have the potential to serve as an effective platform for formulating arguments, owing to the features of this learning environment. The discourse during inquiry-type experiments was found to be rich in arguments, whereas that during confirmatory-type experiments was found to be sparse in arguments. The arguments, which were developed during the discourse of an open inquiry experiment, focus on the hypothesis-building stage, analysis of the results, and drawing appropriate conclusions.
Genetic Algorithm Approaches to Prebiobiotic Chemistry Modeling

NASA Technical Reports Server (NTRS)

Lohn, Jason; Colombano, Silvano

1997-01-01

We model an artificial chemistry comprised of interacting polymers by specifying two initial conditions: a distribution of polymers and a fixed set of reversible catalytic reactions. A genetic algorithm is used to find a set of reactions that exhibit a desired dynamical behavior. Such a technique is useful because it allows an investigator to determine whether a specific pattern of dynamics can be produced, and if it can, the reaction network found can be then analyzed. We present our results in the context of studying simplified chemical dynamics in theorized protocells - hypothesized precursors of the first living organisms. Our results show that given a small sample of plausible protocell reaction dynamics, catalytic reaction sets can be found. We present cases where this is not possible and also analyze the evolved reaction sets.
A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions

NASA Technical Reports Server (NTRS)

Reid, Concha M.; Bennett, William R.

2010-01-01

NASAs Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair Lunar Lander and the Extravehicular Activities (EVA) advanced Lunar surface spacesuit. These customers require safe, reliable batteries with extremely high specific energy as compared to state-of-the-art. The specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery-level at 0 degrees Celsius ( C) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation between 0 and 30 C and 200 cycles are targeted. Electrode materials that were considered include layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. Advanced cell chemistry options were evaluated with respect to multiple quantitative and qualitative attributes while considering their projected performance at the end of the available development timeframe. Following a rigorous ranking process, a chemistry that combines a lithiated nickel manganese cobalt oxide Li(LiNMC)O2 cathode with a silicon-based composite anode was selected as the technology that can potentially offer the best combination of safety, specific energy, energy density, and likelihood of success.
"Chemistry for All, Instead of Chemistry Just for the Elite": Lessons Learned from Detracked Chemistry Classrooms

ERIC Educational Resources Information Center

Watanabe, Maika; Nunes, Nicole; Mebane, Sheryl; Scalise, Kathleen; Claesgens, Jennifer

2007-01-01

Within the already limited literature on instructional practices in detracked classrooms, there are even fewer research-based studies of detracked science classrooms. This article attempts to address this gap in the research literature, delving into the unique challenges and instructional responses to teaching detracked science. The authors report…
Students' Understandings of Acid Strength: How Meaningful Is Reliability When Measuring Alternative Conceptions

ERIC Educational Resources Information Center

Bretz, Stacey Lowery; McClary, LaKeisha

2015-01-01

Most organic chemistry reactions occur by a mechanism that includes acid-base chemistry, so it is important that students develop and learn to use correct conceptions of acids and acid strength. Recent studies have described undergraduate organic chemistry students' cognitive resources related to the Brønsted-Lowry acid model and the Lewis acid…
The Development of Innovative Chemistry Learning Material for Bilingual Senior High School Students in Indonesia

ERIC Educational Resources Information Center

Situmorang, Manihar; Sitorus, Marham; Hutabarat, Wesly; Situmorang, Zakarias

2015-01-01

The development of innovative chemistry learning material for bilingual Senior High School (SHS) students in Indonesia is explained. The study is aimed to obtain an innovative chemistry learning material based on national curriculum in Indonesia to be used as a learning media in the teaching and learning activities. The learning material is…
Pedagogy-Based-Technology and Chemistry Students' Performance in Higher Institutions: A Case of Debre Berhan University

ERIC Educational Resources Information Center

Demissie, Tesfaye; Ochonogor, Chukunoye E.; Engida, Temechegn

2011-01-01

Many students have difficulty in learning abstract and complex lessons of chemistry. This study investigated how students develop their understandings of abstract and complex lessons in chemistry with the aid of visualizing tools: animation, simulation and video that allow them to build clear concepts. Animation, simulation and video enable…
The Role of Green Chemistry Activities in Fostering Secondary School Students' Understanding of Acid-Base Concepts and Argumentation Skills

ERIC Educational Resources Information Center

Karpudewan, Mageswary; Roth, Wolff Michael; Sinniah, Devananthini

2016-01-01

In a world where environmental degradation is taking on alarming levels, understanding, and acting to minimize, the individual environmental impact is an important goal for many science educators. In this study, a green chemistry curriculum--combining chemistry experiments with everyday, environmentally friendly substances with a student-centered…
Simulation studies of DNA at the nanoscale: Interactions with proteins, polycations, and surfaces

NASA Astrophysics Data System (ADS)

Elder, Robert M.

Understanding the nanoscale interactions of DNA, a multifunctional biopolymer with sequence-dependent properties, with other biological and synthetic substrates and molecules is essential to advancing these technologies. This doctoral thesis research is aimed at understanding the thermodynamics and molecular-level structure when DNA interacts with proteins, polycations, and functionalized surfaces. First, we investigate the ability of a DNA damage recognition protein (HMGB1a) to bind to anti-cancer drug-induced DNA damage, seeking to explain how HMGB1a differentiates between the drugs in vivo. Using atomistic molecular dynamics simulations, we show that the structure of the drug-DNA molecule exhibits drug- and base sequence-dependence that explains some of the experimentally observed differential recognition of the drugs in various sequence contexts. Then, we show how steric hindrance from the drug decreases the deformability of the drug-DNA molecule, which decreases recognition by the protein, a concept that can be applied to rational drug design. Second, we study how polycation architecture and chemistry affect polycation-DNA binding so as to design optimal polycations for high efficiency gene (DNA) delivery. Using a multiscale computational approach involving atomistic and coarse-grained simulations, we examine how rearranging polylysine from a linear to a grafted architecture, and several aspects of the grafted architecture, affect polycation-DNA binding and the structure of polycation-DNA complexes. Next, going beyond lysine we examine how oligopeptide chemistry and sequence in the grafted architecture affects polycation-DNA binding and find that strategic placement of hydrophobic peptides might be used to tailor binding strength. Third, we study the adsorption and conformations of single-stranded DNA (an amphiphilic biopolymer) on model hydrophilic and hydrophobic surfaces. Short ssDNA oligomers adsorb to both surfaces with similar strength, with the strength of adsorption to the hydrophobic surface depending on the composition of the DNA strands, i.e. purine or pyrimidine bases. Additionally, DNA-surface and DNA-water interactions near the surfaces govern the adsorption. For longer ssDNA oligomers, the effects of surface chemistry and temperature on ssDNA conformations are rather small, but either the hydrophilic surface or increased temperature favor slightly more compact conformations due to energetic and entropic effects, respectively.
Volta-Based Cells Materials Chemical Multiple Representation to Improve Ability of Student Representation

NASA Astrophysics Data System (ADS)

Helsy, I.; Maryamah; Farida, I.; Ramdhani, M. A.

2017-09-01

This study aimed to describe the application of teaching materials, analyze the increase in the ability of students to connect the three levels of representation and student responses after application of multiple representations based teaching materials chemistry. The method used quasi one-group pretest-posttest design to 71 students. The results showed the application of teaching materials carried 88% with very good category. A significant increase ability to connect the three levels of representation of students after the application of multiple representations based teaching materials chemistry with t-value > t-crit (11.402 > 1.991). Recapitulation N-gain pretest and posttest showed relatively similar for all groups is 0.6 criterion being achievement. Students gave a positive response to the application of multiple representations based teaching materials chemistry. Students agree teaching materials used in teaching chemistry (88%), and agrees teaching materials to provide convenience in connecting the three levels of representation (95%).
Assessment of chemistry models for compressible reacting flows

NASA Astrophysics Data System (ADS)

Lapointe, Simon; Blanquart, Guillaume

2014-11-01

Recent technological advances in propulsion and power devices and renewed interest in the development of next generation supersonic and hypersonic vehicles have increased the need for detailed understanding of turbulence-combustion interactions in compressible reacting flows. In numerical simulations of such flows, accurate modeling of the fuel chemistry is a critical component of capturing the relevant physics. Various chemical models are currently being used in reacting flow simulations. However, the differences between these models and their impacts on the fluid dynamics in the context of compressible flows are not well understood. In the present work, a numerical code is developed to solve the fully coupled compressible conservation equations for reacting flows. The finite volume code is based on the theoretical and numerical framework developed by Oefelein (Prog. Aero. Sci. 42 (2006) 2-37) and employs an all-Mach-number formulation with dual time-stepping and preconditioning. The numerical approach is tested on turbulent premixed flames at high Karlovitz numbers. Different chemical models of varying complexity and computational cost are used and their effects are compared.
The future of South East Asian rainforests in a changing landscape and climate.

PubMed

Hector, Andy; Fowler, David; Nussbaum, Ruth; Weilenmann, Maja; Walsh, Rory P D

2011-11-27

With a focus on the Danum Valley area of Sabah, Malaysian Borneo, this special issue has as its theme the future of tropical rainforests in a changing landscape and climate. The global environmental context to the issue is briefly given before the contents and rationale of the issue are summarized. Most of the papers are based on research carried out as part of the Royal Society South East Asia Rainforest Research Programme. The issue is divided into five sections: (i) the historical land-use and land management context; (ii) implications of land-use change for atmospheric chemistry and climate change; (iii) impacts of logging, forest fragmentation (particularly within an oil palm plantation landscape) and forest restoration on ecosystems and their functioning; (iv) the response and resilience of rainforest systems to climatic and land-use change; and (v) the scientific messages and policy implications arising from the research findings presented in the issue.
Implementation and Evaluation of Web-Based Learning Activities on Bonding and the Structure of Matter for 10-th Grade Chemistry

NASA Astrophysics Data System (ADS)

Frailich, Marcel

This study deals with the development, implementation, and evaluation of web-based activities associated with the topic of chemical bonding , as taught in 10th grade chemistry. A website was developed entitled: "Chemistry and the Chemical Industry in the Service of Mankind", its URL is: http://stwww.weizmann.ac.il/g-chem/learnchem (Kesner, Frailich, & Hofstein, 2003). The main goal of this study was to assess the educational effectiveness of website activities dealing with the chemical bonding concept. These activities include visualization tools, as well as topics relevant to daily life and industrial applications. The study investigated the effectiveness of a web-based learning environment regarding the understanding of chemical bonding concepts, students' perceptions of the classroom learning environment, their attitudes regarding the relevance of learning chemistry to everyday life, and their interest in chemistry studies. As mentioned before, in the present study we focused on activities (from the website), all of which deal with chemical bonding concept. The following are the reasons for the decision to focus on this topic: (1) Chemical bonding is a key concept that is taught in 10th grade chemistry in high school. It provides the basis for many other chemistry topics that are taught later, and (2) Chemical bonding is a difficult for students using existing tools (e. g., static models in books, ball-and- stick models), which are insufficient to demonstrate the abstract nature phenomena associated with this topic. The four activities developed for this study are (1) models of the atomic structure, (2) metals -- structure and properties, (3) ionic substances in everyday life and in industry, and (4) molecular substances -- structure, properties, and uses. The study analyzed both quantitative and qualitative research. The quantitative tools of the study included: A Semantic Differential questionnaire and a Chemistry Classroom Web-Based Learning Environment Inventory to assess students' perceptions regarding the relevance of chemistry to their life and attitude towards chemistry studies, a Feedback questionnaire that examined the students' response after performing the website activities, and an achievement test that assessed their knowledge and understanding of the concept of chemical bonding. The qualitative research included observations and interviews of both students and teachers. About twenty eight observations were made while the students preformed the Internet activities. Eighteen students and seven teachers from the experimental group, and two teachers from the comparison group were interviewed. The quantitative research reveals that the experimental group outperformed the comparison group significantly, in the achievement post-test, which examines students' understanding of chemical bonding concept. We also found from the attitude questionnaires that in most of the categories, the experimental groupdemonstrated more positive attitudes compared to comparison group. Those results are in alignment with interviews that were analyzed in which teachers and students in the experimental group suggested that the visualization tools helped students to better understand the chemical bonding concept. In addition, we found that web-based learning was a significant addition to the teacher's explanations in class, since it provided scaffolding and supported the students' learning process, and indeed promoted cooperative and active learning within a community of learners using a constructivist approach. Furthermore, the students were satisfied with the activities conducted on the website and enjoyed their chemistry learning Also, they showed significant higher awareness to the relevance of chemistry to daily life. The teachers were also satisfied with the web-based activities because they were more aware to students' difficulties in understanding the chemical bonding concept, and the visual tools help them to demonstrate abstract phenomena to their students. Moreover, the website activities caused teachers to make reflection on their instruction strategies and improve them. (Abstract shortened by UMI.)
Remote sensing of atmospheric chemistry; Proceedings of the Meeting, Orlando, FL, Apr. 1-3, 1991

NASA Technical Reports Server (NTRS)

Mcelroy, James L. (Editor); Mcneal, Robert J. (Editor)

1991-01-01

The present volume on remote sensing of atmospheric chemistry discusses special remote sensing space observations and field experiments to study chemical change in the atmosphere, network monitoring for detection of stratospheric chemical change, stratospheric chemistry studies, and the combining of model, in situ, and remote sensing in atmospheric chemistry. Attention is given to the measurement of tropospheric carbon monoxide using gas filter radiometers, long-path differential absorption measurements of tropospheric molecules, air quality monitoring with the differential optical absorption spectrometer, and a characterization of tropospheric methane through space-based remote sensing. Topics addressed include microwave limb sounder experiments for UARS and EOS, an overview of the spectroscopy of the atmosphere using an FIR emission experiment, the detection of stratospheric ozone trends by ground-based microwave observations, and a FIR Fabry-Perot spectrometer for OH measurements.
A Game-Based Approach to an Entire Physical Chemistry Course

ERIC Educational Resources Information Center

Daubenfeld, Thorsten; Zenker, Dietmar

2015-01-01

We designed, implemented, and evaluated a game-based learning approach to increase student motivation and achievement for an undergraduate physical chemistry course. By focusing only on the most important game aspects, the implementation was realized with a production ratio of 1:8 (study load in hours divided by production effort in hours).…
Students' Perceptions of a Project-Based Organic Chemistry Laboratory Environment: A Phenomenographic Approach

ERIC Educational Resources Information Center

Burrows, Nikita L.; Nowak, Montana K.; Mooring, Suazette R.

2017-01-01

Students can perceive the laboratory environment in a variety of ways that can affect what they take away from the laboratory course. This qualitative study characterizes undergraduate students' perspectives of a project-based Organic Chemistry laboratory using the theoretical framework of phenomenography. Eighteen participants were interviewed in…
Effect of Problem-Based Learning on Students' Achievement in Chemistry

ERIC Educational Resources Information Center

Aidoo, Benjamin; Boateng, Sampson Kwadwo; Kissi, Philip Siaw; Ofori, Isaac

2016-01-01

The study investigated the effect of problem-based learning (PBL) on students' achievement in chemistry. Learners' low achievement in Science in South Africa has been a concern to government, stakeholders, school principals and parents over the years as a result of poor teaching techniques, students' attitudes, lack of teaching and learning…
Incorporating Course-Based Undergraduate Research Experiences into Analytical Chemistry Laboratory Curricula

ERIC Educational Resources Information Center

Kerr, Melissa A.; Yan, Fei

2016-01-01

A continuous effort within an undergraduate university setting is to improve students' learning outcomes and thus improve students' attitudes about a particular field of study. This is undoubtedly relevant within a chemistry laboratory. This paper reports the results of an effort to introduce a problem-based learning strategy into the analytical…

STREAMWATER ACID-BASED CHEMISTRY AND CRITICAL LOADS OF ATMOSPHERIC SULFUR DEPOSITION IN SHENANDOAH NATIONAL PARK, VIRGINIA

EPA Science Inventory

A modeling study was conducted to evaluate the acid-base chemistry of streams within Shenandoah National Park, Virginia and to project future responses to sulfur (S) and nitrogen (N) atmospheric emissions controls. Many of the major stream systems in the Park have acid neutraliz...
Validity And Practicality of Experiment Integrated Guided Inquiry-Based Module on Topic of Colloidal Chemistry for Senior High School Learning

NASA Astrophysics Data System (ADS)

Andromeda, A.; Lufri; Festiyed; Ellizar, E.; Iryani, I.; Guspatni, G.; Fitri, L.

2018-04-01

This Research & Development study aims to produce a valid and practical experiment integrated guided inquiry based module on topic of colloidal chemistry. 4D instructional design model was selected in this study. Limited trial of the product was conducted at SMAN 7 Padang. Instruments used were validity and practicality questionnaires. Validity and practicality data were analyzed using Kappa moment. Analysis of the data shows that Kappa moment for validity was 0.88 indicating a very high degree of validity. Kappa moments for the practicality from students and teachers were 0.89 and 0.95 respectively indicating high degree of practicality. Analysis on the module filled in by students shows that 91.37% students could correctly answer critical thinking, exercise, prelab, postlab and worksheet questions asked in the module. These findings indicate that the integrated guided inquiry based module on topic of colloidal chemistry was valid and practical for chemistry learning in senior high school.
Validity of Scientific Based Chemistry Android Module to Empower Science Process Skills (SPS) in Solubility Equilibrium

NASA Astrophysics Data System (ADS)

Antrakusuma, B.; Masykuri, M.; Ulfa, M.

2018-04-01

Evolution of Android technology can be applied to chemistry learning, one of the complex chemistry concept was solubility equilibrium. this concept required the science process skills (SPS). This study aims to: 1) Characteristic scientific based chemistry Android module to empowering SPS, and 2) Validity of the module based on content validity and feasibility test. This research uses a Research and Development approach (RnD). Research subjects were 135 s1tudents and three teachers at three high schools in Boyolali, Central of Java. Content validity of the module was tested by seven experts using Aiken’s V technique, and the module feasibility was tested to students and teachers in each school. Characteristics of chemistry module can be accessed using the Android device. The result of validation of the module contents got V = 0.89 (Valid), and the results of the feasibility test Obtained 81.63% (by the student) and 73.98% (by the teacher) indicates this module got good criteria.
Nitrosation of thiols and thioethers in the gas phase: a combined theoretical and experimental study.

PubMed

Gerbaux, Pascal; Wantier, Pascale; Flammang, Robert

2004-03-01

Recent studies have demonstrated the biological importance of the interaction of nitric oxide with proteins such as cytochrome-c or hemoglobin. In particular, the possibility that the nitrosonium cation, NO(+), could reversibly bind to sulfide atom type was proposed. At pH values of biological relevance, nitrosation was proposed to occur through the action of NO(+) carriers such as nitrosothiols or nitrosamines. In this context, the gas phase chemistry of protonated nitrosothiols is studied in the present work by a combination of mass spectrometry and computational methods.
CallWall: tracking resident calls to improve clinical utilization of pathology laboratories.

PubMed

Buck, Thomas P; Connor, Ian M; Horowitz, Gary L; Arnaout, Ramy A

2011-07-01

Clinical pathology (CP) laboratories are used for millions of tests each year. These lead to thousands of calls to CP residents. However, although laboratory utilization is a frequent topic of study, clinical utilization--the content of the interactions between clinicians and CP residents--is not. Because it reflects questions about laboratory utilization, clinical utilization could suggest ways to improve both training and care by reducing diagnostic error. To build and implement a secure, scalable Web-based system to allow CP residents at any hospital to track the calls they receive, the interaction's context, and the action taken as a result, with evidence where applicable, and to use this system to report on clinical utilization at a major academic hospital. Entries were analyzed from a nearly year-long period to describe the clinical utilization of CP at a large academic teaching hospital. Sixteen residents logged 847 calls during 10 months, roughly evenly distributed among transfusion medicine, chemistry, microbiology, and hematopathology. Calls covered 94 different analytes in chemistry and 71 different organisms or tests in microbiology. Analysis revealed areas where CP can improve clinical care through educating the clinical services, for example, about ordering Rh immune globulin, testosterone testing, and diagnosis of tick-borne diseases. Documenting calls also highlighted patterns among residents. Clinical utilization is a potentially rich knowledge base for improving patient care and resident training. Our resident call-tracking system is a useful way for measuring clinical utilization and mining it for actionable information.
Sunlight-initiated chemistry of aqueous pyruvic acid: building complexity in the origin of life.

PubMed

Griffith, Elizabeth C; Shoemaker, Richard K; Vaida, Veronica

2013-10-01

Coupling chemical reactions to an energy source is a necessary step in the origin of life. Here, we utilize UV photons provided by a simulated sun to activate aqueous pyruvic acid and subsequently prompt chemical reactions mimicking some of the functions of modern metabolism. Pyruvic acid is interesting in a prebiotic context due to its prevalence in modern metabolism and its abiotic availability on early Earth. Here, pyruvic acid (CH3COCOOH, a C3 molecule) photochemically reacts to produce more complex molecules containing four or more carbon atoms. Acetoin (CH3CHOHCOCH3), a C4 molecule and a modern bacterial metabolite, is produced in this chemistry as well as lactic acid (CH3CHOHCOOH), a molecule which, when coupled with other abiotic chemical reaction pathways, can provide a regeneration pathway for pyruvic acid. This chemistry is discussed in the context of plausible environments on early Earth such as near the ocean surface and atmospheric aerosol particles. These environments allow for combination and exchange of reactants and products of other reaction environments (such as shallow hydrothermal vents). The result could be a contribution to the steady increase in chemical complexity requisite in the origin of life.
Eliciting Metacognitive Experiences and Reflection in a Year 11 Chemistry Classroom: An Activity Theory Perspective

NASA Astrophysics Data System (ADS)

Thomas, Gregory P.; McRobbie, Campbell J.

2013-06-01

Concerns regarding students' learning and reasoning in chemistry classrooms are well documented. Students' reasoning in chemistry should be characterized by conscious consideration of chemical phenomenon from laboratory work at macroscopic, molecular/sub-micro and symbolic levels. Further, students should develop metacognition in relation to such ways of reasoning about chemistry phenomena. Classroom change eliciting metacognitive experiences and metacognitive reflection is necessary to shift entrenched views of teaching and learning in students. In this study, Activity Theory is used as the framework for interpreting changes to the rules/customs and tools of the activity systems of two different classes of students taught by the same teacher, Frances, who was teaching chemical equilibrium to those classes in consecutive years. An interpretive methodology involving multiple data sources was employed. Frances explicitly changed her pedagogy in the second year to direct students attention to increasingly consider chemical phenomena at the molecular/sub-micro level. Additionally, she asked students not to use the textbook until toward the end of the equilibrium unit and sought to engage them in using their prior knowledge of chemistry to understand their observations from experiments. Frances' changed pedagogy elicited metacognitive experiences and reflection in students and challenged them to reconsider their metacognitive beliefs about learning chemistry and how it might be achieved. While teacher change is essential for science education reform, students are not passive players in change efforts and they need to be convinced of the viability of teacher pedagogical change in the context of their goals, intentions, and beliefs.
Hispanic-American Students' Attitudes toward Enrolling in High School Chemistry: A Study of Planned Behavior and Belief-Based Change.

ERIC Educational Resources Information Center

Crawley, Frank E.; Koballa, Thomas R., Jr.

1992-01-01

Inquired 69 students' beliefs about registering for high school chemistry. The information was used to develop a questionnaire and persuasive messages. Among 598 target students, chemistry enrollment was higher than expected for those receiving in-class student-only materials and lower than expected for those receiving student/parent take-home…
Impact of surface chemistry

PubMed Central

Somorjai, Gabor A.; Li, Yimin

2011-01-01

The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized. PMID:20880833
A Novel Course of Chemistry as a Scientific Discipline: How Do Prospective Teachers Perceive Nature of Chemistry through Visits to Research Groups?

ERIC Educational Resources Information Center

Vesterinen, Veli-Matti; Aksela, Maija

2009-01-01

To achieve sufficient pedagogical content knowledge on nature of chemistry related issues, teachers need structured opportunities for reflection and discussion. One way to provide those opportunities is through teacher-scientist interaction. This study is based on reflective essays of thirty prospective teachers who participated in a new course…
The Relationship between Teacher-Related Factors and Students' Attitudes towards Secondary School Chemistry Subject in Bureti District, Kenya

ERIC Educational Resources Information Center

Chepkorir, Salome; Cheptonui, Edna Marusoi; Chemutai, Agnes

2014-01-01

This paper examines the relationship between teacher-related factors and student's attitudes towards Chemistry subject in secondary schools in Kenya. The paper is based on a study conducted in Bureti District in Kericho County, Kenya. This paper highlights issues on the teaching methods used by chemistry teachers, the teachers' availability to…
Closing the Gap between Beliefs and Practice: Change of Pre-Service Chemistry Teachers' Orientations during a PCK-Based NOS Course

ERIC Educational Resources Information Center

Demirdögen, Betül; Uzuntiryaki-Kondakçi, Esen

2016-01-01

The purpose of this case study was to investigate how pre-service chemistry teachers' science teaching orientations change during a two-semester intervention designed to enhance their pedagogical content knowledge (PCK) for teaching the nature of science (NOS). Moreover, the way that pre-service chemistry teachers translated their change in…
Incorporating a Soap Industry Case Study to Motivate and Engage Students in the Chemistry of Daily Life

ERIC Educational Resources Information Center

Chowdhury, Mohammad A.

2013-01-01

The global trend of the declining interest in chemistry education is a major concern. Over the last few decades, significant efforts and improvements have been made in various areas of chemistry education research to increase student motivation and engagement based on classroom and laboratory practices. However, little research has been conducted…
Textbook-Bundled Metacognitive Tools: A Study of LearnSmart's Efficacy in General Chemistry

ERIC Educational Resources Information Center

Thadani, Vandana; Bouvier-Brown, Nicole C.

2016-01-01

College textbook publishers increasingly bundle sophisticated technology-based study tools with their texts. These tools appear promising, but empirical work on their efficacy is needed. We examined whether LearnSmart, a study tool bundled with McGraw-Hill's textbook "Chemistry" (Chang & Goldsby, 2013), improved learning in an…
Inquiry Practices in Malaysian Secondary Classroom and Model of Inquiry Teaching Based on Verbal Interaction

ERIC Educational Resources Information Center

Li, Winnie Sim Siew; Arshad, Mohammad Yusof

2015-01-01

Purpose: Inquiry teaching has been suggested as one of the important approaches in teaching chemistry. This study investigates the inquiry practices among chemistry teachers. Method: A combination of quantitative and qualitative study was applied in this study to provide detailed information about inquiry teaching practices. Questionnaires,…
Ecological literacy through critical/place-based pedagogy in the environmental studies program at a small liberal arts college

NASA Astrophysics Data System (ADS)

Beeman-Cadwallader, Nicole

In 2007 Pioneer High School, a public school in Whittier, California changed the sequence of its science courses from the Traditional Biology-Chemistry-Physics (B-C-P) to Biology-Physics-Chemistry (B-P-C), or "Physics Second." The California Standards Tests (CSTs) scores in Physics and Chemistry from 2004-2012 were used to determine if there were any effects of the Physics Second sequencing on student achievement in those courses. The data was also used to determine whether the Physics Second sequence had an effect on performance in Physics and Chemistry based on gender. Independent t tests and chi-square analysis of the data determined an improvement in student performance in Chemistry but not Physics. The 2x2 Factorial ANOVA analysis revealed that in Physics male students performed better on the CSTs than their female peers. In Chemistry, it was noted that male and female students performed equally well. Neither finding was a result ofthe change to the "Physics Second" sequencing.
Increasing character value and conservation behavior through integrated ethnoscience chemistry in chemistry learning: A Case Study in The Department of Science Universitas Negeri Semarang.

NASA Astrophysics Data System (ADS)

Sudarmin; Sumarni, Woro

2018-04-01

The purpose of this study was to obtain a factual picture of the improvement of students' conservation character and conservation behavior through the application integrated ethnoscience chemistry learning. This research was a case study on students majoring in the Department Of Science Mathematics and Natural Science Faculty Universitas Negeri Semarang. The subjects of the study were 30 students attending ethnoscience course in one of the teacher education institutions in the even semester of the academic year of 2016/2017. The subjects were given chemistry learning integrated into ethnoscience for eight weeks. The technique of data collection was done by using attitude scale arranged based on Likert scale. The data were analyzed by using qualitative descriptive. The results showed that the integrated ethnoscience chemistry learning contributed positively to the improvement of the character value and conservation behavior
DNA Charge Transport within the Cell

PubMed Central

Grodick, Michael A.; Muren, Natalie B.; Barton, Jacqueline K.

2015-01-01

The unique characteristics of DNA charge transport (CT) have prompted an examination of roles for this chemistry within a biological context. Not only can DNA CT facilitate long range oxidative damage of DNA, but redox-active proteins can couple to the DNA base stack and participate in long range redox reactions using DNA CT. DNA transcription factors with redox-active moieties such as SoxR and p53 can use DNA CT as a form of redox sensing. DNA CT chemistry also provides a means to monitor the integrity of the DNA, given the sensitivity of DNA CT to perturbations in base stacking as arise with mismatches and lesions. Enzymes that utilize this chemistry include an interesting and ever-growing class of DNA-processing enzymes involved in DNA repair, replication, and transcription that have been found to contain 4Fe-4S clusters. DNA repair enzymes containing 4Fe-4S clusters, that include Endonuclease III (EndoIII), MutY, and DinG from bacteria, as well as XPD from archaea, have been shown to be redox-active when bound to DNA, share a DNA-bound redox potential, and can be reduced and oxidized at long range via DNA CT. Interactions between DNA and these proteins in solution, in addition to genetics experiments within E. coli, suggest that DNA-mediated CT can be used as a means of cooperative signaling among DNA repair proteins that contain 4Fe-4S clusters as a first step in finding DNA damage, even within cells. Based on these data, we can consider also how DNA-mediated CT may be used as a means of signaling to coordinate DNA processing across the genome. PMID:25606780
Vertical columns of NO2, HONO, HCHO, CHOCHO and aerosol extinction: diurnal and seasonal variations in context of CalNex and CARES

NASA Astrophysics Data System (ADS)

Ortega, I.; Coburn, S.; Oetjen, H.; Sinreich, R.; Thalman, R. M.; Waxman, E.; Volkamer, R.

2011-12-01

We present results from two ground-based University of Colorado Multi Axis Differential Optical Absorption Spectroscopy (CU-MAX-DOAS) instruments that were deployed during the CALNEX and CARES 2010 field campaigns. Ground based CU-MAX-DOAS measurements were carried out through Dec 2010, and measured vertical column abundances of nitrogen dioxide (NO2), nitrous acid (HONO), formaldehyde (HCHO), glyoxal (CHOCHO), and aerosol extinction, which is determined indirectly from observing the oxygen dimers (O4). The measurements were acquired on the top of Millikan library at Caltech, Pasadena, CA, at the Fontana Arrows site located 60 Km east of Caltech, and for a limited period also downwind of Sacramento at T1 site during CARES. In the South Coast Air Basin, the MAX-DOAS instruments at both sites collected an extended time series of use to test satellites, and atmospheric chemistry models. We determine the state of the planetary boundary layer by comparing the columns observations with in-situ sensors, and place the CALNEX and CARES measurements intensive into seasonal context.
Teaching Gases through Problem-Based Learning

ERIC Educational Resources Information Center

Baran, Mukadder

2016-01-01

The purpose of this study was to investigate not only the applicability of the method of Problem-Based Learning (PBL) to the lesson subject of "Gasses" within the scope of the 9th grade course of Chemistry in Hakkari Gazi High School but also the influence of this method on the students' achievement levels in chemistry and on their…

Web-Based Undergraduate Chemistry Problem-Solving: The Interplay of Task Performance, Domain Knowledge and Web-Searching Strategies

ERIC Educational Resources Information Center

She, Hsiao-Ching; Cheng, Meng-Tzu; Li, Ta-Wei; Wang, Chia-Yu; Chiu, Hsin-Tien; Lee, Pei-Zon; Chou, Wen-Chi; Chuang, Ming-Hua

2012-01-01

This study investigates the effect of Web-based Chemistry Problem-Solving, with the attributes of Web-searching and problem-solving scaffolds, on undergraduate students' problem-solving task performance. In addition, the nature and extent of Web-searching strategies students used and its correlation with task performance and domain knowledge also…
Examining Chemistry Teachers' Use of Curriculum Materials: In View of Teachers' Pedagogical Content Knowledge

ERIC Educational Resources Information Center

Chen, Bo; Wei, Bing

2015-01-01

This paper aimed to explore how pedagogical content knowledge (PCK) of teachers influenced their adaptations of the curriculum materials of the new senior secondary chemistry curriculum, a standards-based science curriculum, in China. This study was based on the premise that the interaction of the teacher with the curriculum materials determines…
Investigating macroscopic, submicroscopic, and symbolic connections in a college-level general chemistry laboratory

NASA Astrophysics Data System (ADS)

Thadison, Felicia Culver

Explanations of chemical phenomena rely on understanding the behavior of submicroscopic particles. Because this level is "invisible," it is described using symbols such as models, diagrams and equations. For this reason, students often view chemistry as a "difficult" subject. The laboratory offers a unique opportunity for the students to experience chemistry macroscopically as well as symbolically. The purpose of this investigation was to determine how chemistry lab students explained chemical phenomenon on the macroscopic, submicroscopic, and representational/symbolic level. The participants were undergraduate students enrolled in an introductory level general chemistry lab course. Students' background information (gender, the number of previous chemistry courses), scores on final exams, and final average for the course were collected. Johnstone's triangle of representation guided the design and implementation of this study. A semi-structured interview was also conducted to bring out student explanations. The questionnaires required students to draw a molecule of water, complete acid base reaction equations, represent, submicroscopically, the four stages of an acid-base titration, and provide definitions of various terms. Students were able represent the submicroscopic level of water. Students were not able to represent the submicroscopic level of the reaction between an acid and a base. Students were able to represent the macroscopic level of an acid base reaction. Students were able to symbolically represent the reaction of an acid and a base. These findings indicate that students can use all three levels of chemical representation. However, students showed an inability to connect the levels in relation to acid-base chemistry. There was no relationship between a student's ability to use the levels and his or her final score in the course.
A Reconstruction of Development of the Periodic Table Based on History and Philosophy of Science and Its Implications for General Chemistry Textbooks

ERIC Educational Resources Information Center

Brito, Angmary; Rodriguez, Maria A.; Niaz, Mansoor

2005-01-01

The objectives of this study are: (a) elaboration of a history and philosophy of science (HPS) framework based on a reconstruction of the development of the periodic table; (b) formulation of seven criteria based on the framework; and (c) evaluation of 57 freshman college-level general chemistry textbooks with respect to the presentation of the…
A Comparative Study of the Effects of a Concept Mapping Enhanced Laboratory Experience on Turkish High School Students' Understanding of Acid-Base Chemistry

ERIC Educational Resources Information Center

Ozmen, Haluk; Demircioglu, Gokhan; Coll, Richard K.

2009-01-01

The research reported here consists of the introduction of an intervention based on a series of laboratory activities combined with concept mapping. The purpose of this intervention was to enhance student understanding of acid-base chemistry for tenth grade students' from two classes in a Turkish high school. An additional aim was to enhance…
Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLuckey, Scott

2016-08-30

The overall objectives of this research effort were to expand the capabilities of spectroscopic and ion chemistry tools for the structural characterization of polyatomic ions of relevance to the broad mission of the Department of Energy. Mass spectrometry currently plays an important role in virtually all of the molecular sciences by virtue of the value of the accurate measurement of mass and the structural information that can be derived from various structural probes based on, for example, ion chemistry, ion mobility, and ion spectroscopy. Mass spectrometry has long played important roles in supporting the missions of the Department of Energymore » and its predecessor agencies, particularly in the area of isotopic analysis of nuclides. Molecular mass spectrometry has played increasingly important roles is many aspects of the production and use of energy as the nation has diversified its energy portfolio. There is an ongoing need for the expansion of the measurement capabilities associated with molecular mass spectrometry that involves both technological developments as well as improved understanding of the chemical and physical processes that take place upon ionization and ion analysis in a mass spectrometer. Advances in mass spectrometry have impacted science broadly and further advances will be required to meet the needs of current energy and environmental research. This program has historically focused on the structural characterization of polyatomic ions, usually within the context of a tandem mass spectrometry experiment. A wide variety of physical and chemical processes can take place within a mass spectrometer and advantage can be taken of such processes to enhance the quality and quantity of information that can be derived for a given chemical system of interest. For example, ions can undergo interactions with neutral molecules/atoms, light, surfaces, electrons, or oppositely charged ions. The outcomes of all such interactions can be sensitive to the structures of the ions and are therefore candidates for probes of ion structure. This program has historically focused on the chemistry and physics associated with ion/neutral interactions at both low and high translational energies, and ion/ion reactions. The former area has involved the study of ion/molecule reactions at thermal energies and the extensive study of collisional activation under a wide variety of conditions. A major area of emphasis has been collisional activation in electrodynamic ion traps. The study of gas-phase ion/ion reactions within the context of tandem mass spectrometry was initiated in this program and has grown to be a major research area in this group. Most of the focus in ion/ion chemistry has been on proton transfer and electron transfer reactions and some of the work in the previous budget period was directed, in particular, to fundamental aspects of electron transfer. Recently, the discovery of selective covalent ion/ion reactions has opened up new vistas for research that will expand significantly the capabilities of tandem mass spectrometry for the structural characterization of polyatomic ions.« less
Development of Chemistry Triangle Oriented Module on Topic of Reaction Rate for Senior High School Level Grade XI Chemistry Learning.

NASA Astrophysics Data System (ADS)

Sari, D. R.; Hardeli; Bayharti

2018-04-01

This study aims to produce chemistry triangle oriented module on topic of reaction rate, and to reveal the validity and practicality level of the generated module. The type of research used is EducationalDesign Research (EDR) with development model is Plompmodel. This model consists of three phases, which are preliminary research, prototyping phase, and assessment phase. The instrument used in this research is questionnaire validity and practicality. The data of the research were analyzed by using Kappa Cohen formula. The chemistry triangle oriented module validation sheet was given to 5 validators consisting of 3 chemistry lecturers and 2 high school chemistry teachers, while the practicality sheet was given to 2 chemistry teachers, 6 students of SMAN 10 Padang grade XII MIA 5 on the small groupevaluation and 25 students of SMAN 10 Padang grade XII MIA 6 on the field test. Based on the questionnaire validity analysis, the validity level of the module is very high with the value of kappa moment 0.87. The level of practicality based on teacher questionnaire response is very high category with a kappa moment value 0.96. Based on the questionnaire of student responses on small group evaluation, the level of practicality is very high category with a kappa moment 0.81, and the practicality is very high category with kappa moment value 0.83 based on questionnaire of student response on field test.
Chemical climatology of the southeastern United States, 1999-2013

NASA Astrophysics Data System (ADS)

Hidy, G. M.; Blanchard, C. L.; Baumann, K.; Edgerton, E.; Tanenbaum, S.; Shaw, S.; Knipping, E.; Tombach, I.; Jansen, J.; Walters, J.

2014-11-01

A series of experiments (the Southern Oxidant and Aerosol Study - SOAS) took place in central Alabama in June-July, 2013 as part of the broader Southern Atmosphere Study (SAS). These projects were aimed at studying oxidant photochemistry and formation and impacts of aerosols at a detailed process level in a location where high biogenic organic vapor emissions interact with anthropogenic emissions, and the atmospheric chemistry occurs in a subtropical climate in North America. The majority of the ground-based experiments were located at the Southeastern Aerosol Research and Characterization (SEARCH) Centreville (CTR) site near Brent, Alabama, where extensive, unique aerometric measurements of trace gases and particles and meteorology were made beginning in the early 1990s through 2013. The SEARCH network data permits a characterization of the temporal and spatial context of the SOAS findings. Our earlier analyses of emissions and air quality trends are extended through 2013 to provide a perspective for continued decline in ambient concentrations, and the implications of these changes to regional sulfur oxide, nitrogen-ozone, and carbon chemistry. The narrative supports the SAS program in terms of long-term average chemistry (chemical climatology) and short-term comparisons of early summer average spatial variability across the southeastern US at high temporal (hourly) resolution. The long-term measurements show that the SOAS experiments took place during the second wettest and coolest year in the 2000-2013 period, with lower than average solar radiation. The pollution levels at CTR and other SEARCH sites were the lowest since full measurements began in 1999. Changes in anthropogenic gas and particle emissions between 1999 and 2013 account for the decline in pollutant concentrations at the monitoring sites in the region. The data provide an opportunity to contrast SOAS results with temporally and spatially variable conditions in support of the development of tests for the robustness of SOAS findings.
Assessing Changes in High School Students' Conceptual Understanding through Concept Maps before and after the Computer-Based Predict-Observe-Explain (CB-POE) Tasks on Acid-Base Chemistry at the Secondary Level

ERIC Educational Resources Information Center

Yaman, Fatma; Ayas, Alipasa

2015-01-01

Although concept maps have been used as alternative assessment methods in education, there has been an ongoing debate on how to evaluate students' concept maps. This study discusses how to evaluate students' concept maps as an assessment tool before and after 15 computer-based Predict-Observe-Explain (CB-POE) tasks related to acid-base chemistry.…
The Examination of Secondary Education Chemistry Curricula Published between 1957-2007 in Terms of the Dimensions of Rationale, Goals, and Subject-Matter

ERIC Educational Resources Information Center

Pekdag, Bulent; Erol, Hilal

2013-01-01

Fifteen secondary education chemistry curricula published from 1957 until 2007 were examined based on the dimensions of rationale, goals, and subject matter. An examination of documents in the scope of qualitative research was carried out in the study. The goals included in the examined chemistry curricula were analyzed according to the cognitive,…
Education in Environmental Chemistry: Setting the Agenda and Recommending Action. A Workshop Report Summary

NASA Astrophysics Data System (ADS)

Zoller, Uri

2005-08-01

Worldwide, the essence of the current reform in science education is a paradigm shift from algorithmic, lower-order cognitive skills (LOCS) teaching to higher-order cognitive skills (HOCS) learning. In the context of education in environmental chemistry (EEC), the ultimate goal is to educate students to be science technology environment society (STES)-literate, capable of evaluative thinking, decision making, problem solving and taking responsible action accordingly. Educators need to translate this goal into effective courses that can be implemented: this includes developing teaching strategies and assessment methodologies that are consonant with the goal of HOCS learning. An international workshop—"Environmental Chemistry Education in Europe: Setting the Agenda"—yielded two main recommendations for those undertaking educational reform in science education, particularly to promote meaningful EEC. The first recommendation concerns integration of environmental sciences into core chemistry courses as well as the development and implementation of HOCS-promoting teaching strategies and assessment methodologies in chemical education. The second emphasizes the development of students' HOCS for transfer, followed by performance assessment of HOCS. This requires changing the way environmental chemistry is typically taught, moving from a narrowly focused approach (applied analytical, ecotoxicological, or environmental engineering chemistry) to an interdisciplinary and multidisciplinary approach.
Describing the direct and indirect radiative effects of atmospheric aerosols over Europe by using coupled meteorology-chemistry simulations: a contribution from the AQMEII-Phase II exercise

NASA Astrophysics Data System (ADS)

Jimenez-Guerrero, Pedro; Balzarini, Alessandra; Baró, Rocío; Curci, Gabriele; Forkel, Renate; Hirtl, Marcus; Honzak, Luka; Langer, Matthias; Pérez, Juan L.; Pirovano, Guido; San José, Roberto; Tuccella, Paolo; Werhahn, Johannes; Zabkar, Rahela

2014-05-01

The study of the response of the aerosol levels in the atmosphere to a changing climate and how this affects the radiative budget of the Earth (direct, semi-direct and indirect effects) is an essential topic to build confidence on climate science, since these feedbacks involve the largest uncertainties nowadays. Air quality-climate interactions (AQCI) are, therefore, a key, but uncertain contributor to the anthropogenic forcing that remains poorly understood. To build confidence in the AQCI studies, regional-scale integrated meteorology-atmospheric chemistry models (i.e., models with on-line chemistry) that include detailed treatment of aerosol life cycle and aerosol impacts on radiation (direct effects) and clouds (indirect effects) are in demand. In this context, the main objective of this contribution is the study and definition of the uncertainties in the climate-chemistry-aerosol-cloud-radiation system associated to the direct radiative forcing and the indirect effect caused by aerosols over Europe, using an ensemble of fully-coupled meteorology-chemistry model simulations with the WRF-Chem model run under the umbrella of AQMEII-Phase 2 international initiative. Simulations were performed for Europe for the entire year 2010. According to the common simulation strategy, the year was simulated as a sequence of 2-day time slices. For better comparability, the seven groups applied the same grid spacing of 23 km and shared common processing of initial and boundary conditions as well as anthropogenic and fire emissions. With exception of a simulation with different cloud microphysics, identical physics options were chosen while the chemistry options were varied. Two model set-ups will be considered here: one sub-ensemble of simulations not taking into account any aerosol feedbacks (the baseline case) and another sub-ensemble of simulations which differs from the former by the inclusion of aerosol-radiation feedback. The existing differences for meteorological variables (mainly 2-m temperature and precipitation) and air quality levels (mainly ozone an PM10) between both sub-ensembles of WRF-Chem simulations have been characterized. In the case of ozone and PM10, an increase in solar radiation and temperature has generally resulted in an enhanced photochemical activity and therefore a negative feedback (areas with low aerosol concentrations present more than 50 W m-2 higher global radiation for cloudy conditions). However, simulated feedback effects between aerosol concentrations and meteorological variables and on pollutant distributions strongly depend on the model configuration and the meteorological situation. These results will help providing improved science-based foundations to better assess the impacts of climate variability, support the development of effective climate change policies and optimize private decision-making.
Origins of life systems chemistry

NASA Astrophysics Data System (ADS)

Sutherland, J.

2015-10-01

By reconciling previously conflicting views about the origin of life - in which one or other cellular subsystem emerges first, and then 'invents' the others - a new modus operandi for its study is suggested. Guided by this, a cyanosulfidic protometabolism is uncovered which uses UV light and the stoichiometric reducing power of hydrogen sulfide to convert hydrogen cyanide, and a couple of other prebiotic feedstock molecules which can be derived therefrom, into nucleic acid, peptide and lipid building blocks. Copper plays several key roles in this chemistry, thus, for example, copper(I) catalysed cross coupling and copper(II) driven oxidative crosscoupling reactions generate key feedstock molecules. Geochemical scenarios consistent with this protometabolism are outlined. Finally, the transition of a system from the inanimate to the animate state is considered in the context of there being intermediate stages of partial 'aliveness'.
Discovering Watson's Crick in High School Chemistry.

ERIC Educational Resources Information Center

Whitman, Mark

1984-01-01

High school chemistry students begin the school year by reading and studying "The Double Helix" by James B. Watson. Rationale, objectives, and instructional strategies for this assignment are discussed. Sample discussion questions based on the book are included. (JN)
Potential Changes in Prospective Chemistry Teachers' Beliefs about Teaching and Learning--A Cross-Level Study

ERIC Educational Resources Information Center

Markic, Silvija; Eilks, Ingo

2013-01-01

This paper presents a cross-level study of German student teachers' beliefs about teaching and learning chemistry. It covers different stages of their teacher training program. The study is based upon drawings of teaching situations, which were analyzed using an evaluation pattern developed using grounded theory. The qualitative scales analyze…
National Chemistry Teacher Safety Survey

NASA Astrophysics Data System (ADS)

Plohocki, Barbra A.

This study evaluated the status of secondary school instructional chemistry laboratory safety using a survey instrument which focused on Teacher background Information, Laboratory Safety Equipment, Facility Safety, General Safety, and a Safety Content Knowledge Survey. A fifty question survey instrument based on recent research and questions developed by the researcher was mailed to 500 secondary school chemistry teachers who participated in the 1993 one-week Woodrow Wilson National Fellowship Foundation Chemistry Institute conducted at Princeton University, New Jersey. The data received from 303 respondents was analyzed by t tests and Analysis of Variance (ANOVA). The level of significance for the study was set at ~\\ <.05. There was no significant mean difference in test performance on the Safety Content Knowledge Survey and secondary school chemistry teachers who have had undergraduate and/or graduate safety training and those who have not had undergraduate and/or graduate safety training. Secondary school chemistry teachers who attended school district sponsored safety inservices did not score higher on the Safety Content Knowledge Survey than teachers who did not attend school district sponsored safety inservice sessions. The type of school district (urban, suburban, or rural) had no significant correlation to the type of laboratory safety equipment found in the instructional chemistry laboratory. The certification area (chemistry or other type of certificate which may or may not include chemistry) of the secondary school teacher had no significant correlation to the type of laboratory equipment found in the instructional chemistry laboratory. Overall, this study indicated a majority of secondary school chemistry teachers were interested in attending safety workshops applicable to chemistry safety. Throughout this research project, many teachers indicated they were not adequately instructed on the collegiate level in science safety and had to rely on common sense and self-study in their future teaching careers.
Rediscovery in a Course for Nonscientists: Use of Molecular Models to Solve Classical Structural Problems

ERIC Educational Resources Information Center

Wood, Gordon W.

1975-01-01

Describes exercises using simple ball and stick models which students with no chemistry background can solve in the context of the original discovery. Examples include the tartaric acid and benzene problems. (GS)
Thai Grade 11 students' alternative conceptions for acid-base chemistry

NASA Astrophysics Data System (ADS)

Artdej, Romklao; Ratanaroutai, Thasaneeya; Coll, Richard Kevin; Thongpanchang, Tienthong

2010-07-01

This study involved the development of a two-tier diagnostic instrument to assess Thai high school students' understanding of acid-base chemistry. The acid-base diagnostic test (ABDT) comprising 18 items was administered to 55 Grade 11 students in a science and mathematics programme during the second semester of the 2008 academic year. Analysis of students' responses from this study followed the methodology outlined by Çalik and Ayas. The research findings suggest that the ABDT, the multiple choice diagnostic instrument, enables researchers and teachers to classify students' understanding at different levels. Most students exhibited alternative conceptions for several concepts: acid-base theory, dissociation of strong acids or bases, and dissociation of weak acids/bases. Interestingly, one of the concepts that students appeared to find most difficult, and for which they exhibited the most alternative conceptions, was acid-base theory. Some alternative conceptions revealed in this study differ from earlier reports, such as the concept of electrolyte and non-electrolyte solutions as well as the concentration changes of H3O+and OH- in water. These research findings present valuable information for facilitating better understanding of acid-base chemistry by providing insight into the preventable and correctable alternative conceptions exhibited by students.
Chemical Understanding and Graphing Skills in an Honors Case-Based Computerized Chemistry Laboratory Environment: The Value of Bidirectional Visual and Textual Representations

ERIC Educational Resources Information Center

Dori, Yehudit J.; Sasson, Irit

2008-01-01

The case-based computerized laboratory (CCL) is a chemistry learning environment that integrates computerized experiments with emphasis on scientific inquiry and comprehension of case studies. The research objective was to investigate chemical understanding and graphing skills of high school honors students via bidirectional visual and textual…
The Effectiveness of the Chemistry Problem Based Learning (PBL) via FB among Pre-University Students

ERIC Educational Resources Information Center

Sunar, Mohd Shahir Mohamed; Shaari, Ahmad Jelani

2017-01-01

The impact of social media, such as Facebook in various fields including education is undeniable. The main objective of this study is to examine the effect of the interaction between students' learning styles and learning approaches on their achievements in the chemistry subject using the Problem-Based Learning (PBL) method through Facebook. The…

Impact of Active Teaching Methods Implemented on Therapeutic Chemistry Module: Performance and Impressions of First-Year Pharmacy Students

ERIC Educational Resources Information Center

Derfoufi, Sanae; Benmoussa, Adnane; El Harti, Jaouad; Ramli, Youssef; Taoufik, Jamal; Chaouir, Souad

2015-01-01

This study investigates the positive impact of the Case Method implemented during a 4- hours tutorial in "therapeutic chemistry module." We view the Case Method as one particular approach within the broader spectrum of problem based or inquiry based learning approaches. Sixty students were included in data analysis. A pre-test and…
Anion Solvation in Carbonate-Based Electrolytes

DOE PAGES

von Wald Cresce, Arthur; Gobet, Mallory; Borodin, Oleg; ...

2015-11-16

The correlation between Li + solvation and interphasial chemistry on anodes firmly established in Li-ion batteries, the effect of cation–solvent interaction has gone beyond bulk thermodynamic and transport properties and become an essential element that determines the reversibility of electrochemistry and kinetics of Li-ion intercalation chemistries. Now, most studies are dedicated to the solvation of Li +, and the solvation of anions in carbonate-based electrolytes and its possible effect on the electrochemical stability of such electrolytes remains little understood. Moreover, as a mirror effort to prior Li + solvation studies, this work focuses on the interactions between carbonate-based solvents andmore » two anions (hexafluorophosphate, PF 6–, and tetrafluoroborate, BF 4–) that are most frequently used in Li-ion batteries. The possible correlation between such interaction and the interphasial chemistry on cathode surface is also explored.« less
A Polymer Chemistry Point of View on Mucoadhesion and Mucopenetration.

PubMed

Schattling, Philipp; Taipaleenmäki, Essi; Zhang, Yan; Städler, Brigitte

2017-09-01

Although oral is the preferred route of administration of pharmaceutical formulations, the long-standing challenge for medically active compounds to efficiently cross the mucus layer barrier limits its wider applicability. Efforts in nanomedicine to overcome this hurdle consider mucoadhesive and mucopenetrating drug carriers by selectively designing (macromolecular) building blocks. This review highlights and critically discusses recent strategies developed in this context including poly(ethylene glycol)-based modifications, cationic and thiolated polymers, as well as particles with high charge density, zeta-potential shifting ability, or mucolytic properties. The latest advances in ex vivo test platforms are also reviewed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Elementary and brief introduction of hadronic chemistry

NASA Astrophysics Data System (ADS)

Tangde, Vijay M.

2013-10-01

The discipline, today known as Quantum Chemistry for atomic and subatomic level interactions has no doubt made a significant historical contributions to the society. Despite of its significant achievements, quantum chemistry is also known for its widespread denial of insufficiencies it inherits. An Italian-American Scientist Professor Ruggero Maria Santilli during his more than five decades of dedicated and sustained research has denounced the fact that quantum chemistry is mostly based on mere nomenclatures without any quantitative scientific contents. Professor R M Santilli first formulated the iso-, geno- and hyper-mathematics [1-4] that helped in understanding numerous diversified problems and removing inadequacies in most of the established and celebrated theories of 20th century physics and chemistry. This involves the isotopic, genotopic, etc. lifting of Lie algebra that generated Lie admissible mathematics to properly describe irreversible processes. The studies on Hadronic Mechanics in general and chemistry in particular based on Santilli's mathematics[3-5] for the first time has removed the very fundamental limitations of quantum chemistry [2, 6-8]. In the present discussion, we have briefly reviewed the conceptual foundations of Hadronic Chemistry that imparts the completeness to the Quantum Chemistry via an addition of effects at distances of the order of 1 fm (only) which are assumed to be Non-linear, Non-local, Non-potential, Non-hamiltonian and thus Non-unitary and its application in development of a new chemical species called Magnecules.
How sonochemistry contributes to green chemistry?

PubMed

Chatel, Gregory

2018-01-01

Based on the analyses of papers from the literature, and especially those published in Ultrasonics Sonochemistry journal, the contribution of sonochemistry to green chemistry area has been discussed here. Important reminders and insights on the good practices and considerations have been made to understand and demonstrate how sonochemistry can continue to efficiently contribute to green chemistry area in the further studies. Copyright © 2017 Elsevier B.V. All rights reserved.
Nanometer-Scale Chemistry of a Calcite Biomineralization Template: Implications for Skeletal Composition and Nucleation

PubMed Central

Bonnin, Elisa A.; Perea, Daniel E.; Spero, Howard J.; Zhu, Zihua; Winters, Maria; Hönisch, Bärbel; Russell, Ann D.; Fehrenbacher, Jennifer S.; Gagnon, Alexander C.

2016-01-01

Plankton, corals, and other organisms produce calcium carbonate skeletons that are integral to their survival, form a key component of the global carbon cycle, and record an archive of past oceanographic conditions in their geochemistry. A key aspect of the formation of these biominerals is the interaction between organic templating structures and mineral precipitation processes. Laboratory-based studies have shown that these atomic-scale processes can profoundly influence the architecture and composition of minerals, but their importance in calcifying organisms is poorly understood because it is difficult to measure the chemistry of in vivo biomineral interfaces at spatially relevant scales. Understanding the role of templates in biomineral nucleation, and their importance in skeletal geochemistry requires an integrated, multiscale approach, which can place atom-scale observations of organic-mineral interfaces within a broader structural and geochemical context. Here we map the chemistry of an embedded organic template structure within a carbonate skeleton of the foraminifera Orbulina universa using both atom probe tomography (APT), a 3D chemical imaging technique with Ångström-level spatial resolution, and time-of-flight secondary ionization mass spectrometry (ToF-SIMS), a 2D chemical imaging technique with submicron resolution. We quantitatively link these observations, revealing that the organic template in O. universa is uniquely enriched in both Na and Mg, and contributes to intraskeletal chemical heterogeneity. Our APT analyses reveal the cation composition of the organic surface, offering evidence to suggest that cations other than Ca2+, previously considered passive spectator ions in biomineral templating, may be important in defining the energetics of carbonate nucleation on organic templates. PMID:27794119
Perception of the importance of chemistry research papers and comparison to citation rates.

PubMed

Borchardt, Rachel; Moran, Cullen; Cantrill, Stuart; Chemjobber; Oh, See Arr; Hartings, Matthew R

2018-01-01

Chemistry researchers are frequently evaluated on the perceived significance of their work with the citation count as the most commonly-used metric for gauging this property. Recent studies have called for a broader evaluation of significance that includes more nuanced bibliometrics as well as altmetrics to more completely evaluate scientific research. To better understand the relationship between metrics and peer judgements of significance in chemistry, we have conducted a survey of chemists to investigate their perceptions of previously published research. Focusing on a specific issue of the Journal of the American Chemical Society published in 2003, respondents were asked to select which articles they thought best matched importance and significance given several contexts: highest number of citations, most significant (subjectively defined), most likely to share among chemists, and most likely to share with a broader audience. The answers to the survey can be summed up in several observations. The ability of respondents to predict the citation counts of established research is markedly lower than the ability of those counts to be predicted by the h-index of the corresponding author of each article. This observation is conserved even when only considering responses from chemists whose expertise falls within the subdiscipline that best describes the work performed in an article. Respondents view both cited papers and significant papers differently than papers that should be shared with chemists. We conclude from our results that peer judgements of importance and significance differ from metrics-based measurements, and that chemists should work with bibliometricians to develop metrics that better capture the nuance of opinions on the importance of a given piece of research.
Including Non-Traditional Instrumentation in Undergraduate Environmental Chemistry Courses

ERIC Educational Resources Information Center

Jenkins, J. David; Orvis, Jessica N.; Smith, C. Jimmy; Manley, Citabria; Rice, Jeanette K. 2

2004-01-01

Non-traditional instrumentation was obtained for Georgia Southern undergraduates to attain fundamental environmental education through unique laboratory experiences. In this context, the method for including a direct mercury analyzer into both major and non-major environmental laboratories is reported.
Reducing Carbon Dioxide Emissions: Using the Mole Concept.

ERIC Educational Resources Information Center

Myers, Alan

2002-01-01

Provides an application of quantitative chemistry concepts in the context of motor vehicle emissions. Shows how carbon dioxide emissions from cars may be reduced by up to 25% by reducing motorway speeds from 70-75 mph to 60 mph. (Author/MM)
Improving our chemistry: challenges and opportunities in the interdisciplinary study of floral volatiles.

PubMed

Raguso, R A; Thompson, J N; Campbell, D R

2015-07-01

The field of chemical ecology was established, in large part, through collaborative studies between biologists and chemists with common interests in the mechanisms that mediate chemical communication in ecological and evolutionary contexts. Pollination is one highly diverse and important category of such interactions, and there is growing evidence that floral volatiles play important roles in mediating pollinator behaviour and its consequences for plant reproductive ecology and evolution. Here we outline next-generation questions emerging in the study of plants and pollinators, and discuss the potential for strengthening collaboration between biologists and chemists in answering such questions.
Puzzling through General Chemistry: A Light-Hearted Approach to Engaging Students with Chemistry Content

ERIC Educational Resources Information Center

Boyd, Susan L.

2007-01-01

Several puzzles are designed to be used by chemistry students as learning tools and teach them basic chemical concepts. The topics of the puzzles are based on the chapters from Chemistry, The Central Science used in general chemistry course and the puzzles are in various forms like crosswords, word searches, number searches, puzzles based on…
Using Chemistry Teaching Aids Based Local Wisdom as an Alternative Media for Chemistry Teaching and Learning

ERIC Educational Resources Information Center

Priyambodo, Erfan; Wulaningrum, Safira

2017-01-01

Students have difficulties in relating the chemistry phenomena they learned and the life around them. It is necessary to have teaching aids which can help them to relate between chemistry with the phenomena occurred in everyday life, which is chemistry's teaching aids based on local wisdom. There are 3 teaching aids which used in chemistry…
Chemistry Outreach Project to High Schools Using a Mobile Chemistry Laboratory, ChemKits, and Teacher Workshops

ERIC Educational Resources Information Center

Long, Gary L.; Bailey, Carol A.; Bunn, Barbara B.; Slebodnick, Carla; Johnson, Michael R.; Derozier, Shad

2012-01-01

The Chemistry Outreach Program (ChOP) of Virginia Tech was a university-based outreach program that addressed the needs of high school chemistry classes in underfunded rural and inner-city school districts. The primary features of ChOP were a mobile chemistry laboratory (MCL), a shipping-based outreach program (ChemKits), and teacher workshops.…
Evaluating Student Motivation in Organic Chemistry Courses: Moving from a Lecture-Based to a Flipped Approach with Peer-Led Team Learning

ERIC Educational Resources Information Center

Liu, Yujuan; Raker, Jeffrey R.; Lewis, Jennifer E.

2018-01-01

Academic Motivation Scale-Chemistry (AMS-Chemistry), an instrument based on the self-determination theory, was used to evaluate students' motivation in two organic chemistry courses, where one course was primarily lecture-based and the other implemented flipped classroom and peer-led team learning (Flip-PLTL) pedagogies. Descriptive statistics…
The Effect of Learning Cycle Constructivist-Based Approach on Students' Academic Achievement and Attitude towards Chemistry in Secondary Schools in North-Eastern Part of Nigeria

ERIC Educational Resources Information Center

Jack, Gladys Uzezi

2017-01-01

This study investigated the effect of learning cycle constructivist-based approach on secondary schools students' academic achievement and their attitude towards chemistry. The design used was a pre-test, post-test non randomized control group quasi experimental research design. The design consisted of two instructional groups (learning cycle…
A Rational Reconstruction of the Kinetic Molecular Theory of Gases Based on History and Philosophy of Science and Its Implications for Chemistry Textbooks.

ERIC Educational Resources Information Center

Niaz, Mansoor

2000-01-01

Describes a study that was designed to develop a framework for examining the way in which chemistry textbooks describe the kinetic theory and related issues. The framework was developed by a rational reconstruction of the kinetic molecular theory of gases based on historians and philosophers of science. (Contains 102 references.)(Author/LRW)
Pi-metal complexes of tetrapyrrolic systems. A novel coordination mode in "porphyrin-like" chemistry.

PubMed

Cuesta, Luciano; Sessler, Jonathan L

2009-09-01

The coordination chemistry of porphyrins and related tetrapyrrolic ligands has traditionally centered around the ability of these systems to form pyrrole N-ligated complexes via the formation of sigma bonds, either within the N(4) core or displaced above it. In fact, such sigma-complexes are known with almost every metal cation in the periodic table. However, a growing number of pi-complexes derived from tetrapyrrolic ligands have been reported in recent years. The underlying coordination mode, while still novel in the context of "porphyrin-like" chemistry, is already being recognized for the effects it can impart over the reactivity, as well as the spectroscopic, redox, electronic, and optical properties of various oligopyrrolic macrocycles. This critical review summarizes accomplishments made in this fast-emerging field (59 references).
Contribution from philosophy of chemistry to chemistry education: In a case of ionic liquids as technochemistry

NASA Astrophysics Data System (ADS)

Mudzakir, Ahmad; Hernani, Widhiyanti, Tuszie; Sudrajat, Devi Pratiwi

2017-08-01

Traditional chemistry education is commonly handing down of concepts, principles, and theories, such as mechanical properties, the relationship between structure and properties as well as chemical structure and chemical bonding theory, to students without engaging them in the processes of chemical inquiry. This practice leads to the lack of opportunity for the students to construct an appropriate understanding of these concepts, principles, and theories. Students are also rarely facilitated in modeling the structure and function of matter themselves. This situation shows that the philosophy of chemistry has not received as much attention from chemistry educators. The main idea of this paper is to embed philosophy of chemistry through the implementation of technochemistry in chemistry education. One of the most interesting and rapidly developing areas of modern chemistry, technologies and engineering is Ionic Liquids (ILs) as an emerging knowledge on technochemistry which can be applied to chemistry education. The developments between academic researchers and industrial developments in the ILs area are conducted in parallel. In order to overcome the existing problems of scientific development in chemistry education, the science and technology of ILs can be used for reconceptualizing the teaching and learning of chemistry to embrace the epistemology in chemistry. This study promises a potential contribution by philosophy of chemistry. The main objectives of this study are to develop: (i) a perspective based on philosophy of science considerations (rational reconstruction) in order to understand ionic liquids and (ii) teaching materials that can be used to enhance pre-service teacher's view of nature of science and technology (VNOST). The method used in the study is analytical-descriptive (elementarization), i.e. the first step in the model of educational reconstruction (MER). This study concludes that the development of the concepts and their applications of ionic liquids follow the inductive process. Experimental observations lead to scientific concepts which later can facilitate to elaborate explanatory theories.
Molecular Electron Density Theory: A Modern View of Reactivity in Organic Chemistry.

PubMed

Domingo, Luis R

2016-09-30

A new theory for the study of the reactivity in Organic Chemistry, named Molecular Electron Density Theory (MEDT), is proposed herein. MEDT is based on the idea that while the electron density distribution at the ground state is responsible for physical and chemical molecular properties, as proposed by the Density Functional Theory (DFT), the capability for changes in electron density is responsible for molecular reactivity. Within MEDT, the reactivity in Organic Chemistry is studied through a rigorous quantum chemical analysis of the changes of the electron density as well as the energies associated with these changes along the reaction path in order to understand experimental outcomes. Studies performed using MEDT allow establishing a modern rationalisation and to gain insight into molecular mechanisms and reactivity in Organic Chemistry.
Chemical Laws, Idealization and Approximation

NASA Astrophysics Data System (ADS)

Tobin, Emma

2013-07-01

This paper examines the notion of laws in chemistry. Vihalemm ( Found Chem 5(1):7-22, 2003) argues that the laws of chemistry are fundamentally the same as the laws of physics they are all ceteris paribus laws which are true "in ideal conditions". In contrast, Scerri (2000) contends that the laws of chemistry are fundamentally different to the laws of physics, because they involve approximations. Christie ( Stud Hist Philos Sci 25:613-629, 1994) and Christie and Christie ( Of minds and molecules. Oxford University Press, New York, pp. 34-50, 2000) agree that the laws of chemistry are operationally different to the laws of physics, but claim that the distinction between exact and approximate laws is too simplistic to taxonomise them. Approximations in chemistry involve diverse kinds of activity and often what counts as a scientific law in chemistry is dictated by the context of its use in scientific practice. This paper addresses the question of what makes chemical laws distinctive independently of the separate question as to how they are related to the laws of physics. From an analysis of some candidate ceteris paribus laws in chemistry, this paper argues that there are two distinct kinds of ceteris paribus laws in chemistry; idealized and approximate chemical laws. Thus, while Christie ( Stud Hist Philos Sci 25:613-629, 1994) and Christie and Christie ( Of minds and molecules. Oxford University Press, New York, pp. 34--50, 2000) are correct to point out that the candidate generalisations in chemistry are diverse and heterogeneous, a distinction between idealizations and approximations can nevertheless be used to successfully taxonomise them.

Are Creative Comparisons Developed by Prospective Chemistry Teachers Evidence of Their Conceptual Understanding? The Case of Inter- and Intramolecular Forces

ERIC Educational Resources Information Center

Sendur, Gulten

2014-01-01

The aim of this study is to determine prospective chemistry teachers' creative comparisons about the basic concepts of inter- and intramolecular forces, and to uncover the relationship between these creative comparisons and prospective teachers' conceptual understanding. Based on a phenomenological research method, this study was conducted with…
Use of Chemistry Software to Teach and Assess Model-Based Reaction and Equation Knowledge

ERIC Educational Resources Information Center

Pyatt, Kevin

2014-01-01

This study investigated the challenges students face when learning chemical reactions in a first-year chemistry course and the effectiveness of a curriculum and software implementation that was used to teach and assess student understanding of chemical reactions and equations. This study took place over a two year period in a public suburban…
Sense codon emancipation for proteome-wide incorporation of noncanonical amino acids: rare isoleucine codon AUA as a target for genetic code expansion

PubMed Central

Bohlke, Nina; Budisa, Nediljko

2014-01-01

One of the major challenges in contemporary synthetic biology is to find a route to engineer synthetic organisms with altered chemical constitution. In terms of core reaction types, nature uses an astonishingly limited repertoire of chemistries when compared with the exceptionally rich and diverse methods of organic chemistry. In this context, the most promising route to change and expand the fundamental chemistry of life is the inclusion of amino acid building blocks beyond the canonical 20 (i.e. expanding the genetic code). This strategy would allow the transfer of numerous chemical functionalities and reactions from the synthetic laboratory into the cellular environment. Due to limitations in terms of both efficiency and practical applicability, state-of-the-art nonsense suppression- or frameshift suppression-based methods are less suitable for such engineering. Consequently, we set out to achieve this goal by sense codon emancipation, that is, liberation from its natural decoding function – a prerequisite for the reassignment of degenerate sense codons to a new 21st amino acid. We have achieved this by redesigning of several features of the post-transcriptional modification machinery which are directly involved in the decoding process. In particular, we report first steps towards the reassignment of 5797 AUA isoleucine codons in Escherichia coli using efficient tools for tRNA nucleotide modification pathway engineering. PMID:24433543
On the chemical ladder of esters. Detection and formation of ethyl formate in the W51 e2 hot molecular core

NASA Astrophysics Data System (ADS)

Rivilla, V. M.; Beltrán, M. T.; Martín-Pintado, J.; Fontani, F.; Caselli, P.; Cesaroni, R.

2017-03-01

Context. In recent years, the detection of organic molecules with increasing complexity and potential biological relevance is opening the possibility to understand the formation of the building blocks of life in the interstellar medium. One of the families of molecules of substantial astrobiological interest are the esters. The simplest ester, methyl formate (CH3OCHO), is rather abundant in star-forming regions. The next step in the chemical complexity of esters is ethyl formate, C2H5OCHO. Despite the increase in sensitivity of current telescopes, the detection of complex molecules with more than ten atoms such as C2H5OCHO is still a challenge. Only two detections of this species have been reported so far, which strongly limits our understanding of how complex molecules are formed in the interstellar medium. New detections towards additional sources with a wide range of physical conditions are crucial to differentiate between competing chemical models based on dust grain surface and gas-phase chemistry. Aims: We have searched for ethyl formate towards the W51 e2 hot molecular core, one of the most chemically rich sources in the Galaxy and one of the most promising regions to study prebiotic chemistry, especially after the recent discovery of the P-O bond, key in the formation of DNA. Methods: We have analyzed a spectral line survey towards the W51 e2 hot molecular core, which covers 44 GHz in the 1, 2 and 3 mm bands, carried out with the IRAM 30 m telescope. Results: We report the detection of the trans and gauche conformers of ethyl formate. A local thermodynamic equilibrium analysis indicates that the excitation temperature is 78 ± 10 K and that the two conformers have similar source-averaged column densities of (2.0 ± 0.3) × 10-16 cm-2 and an abundance of 10-8. We compare for the first time the observed molecular abundances of ethyl formate with different competing chemical models based on grain surface and gas-phase chemistry. Conclusions: We propose that grain-surface chemistry may have a dominant role in the formation of ethyl formate (and other complex organic molecules) in hot molecular cores, rather than reactions in the gas phase. Based on observations carried out with the IRAM 30 m Telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).
Learning Stoichiometry: A Comparison of Text and Multimedia Formats

ERIC Educational Resources Information Center

Evans, Karen L.; Yaron, David; Leinhardt, Gaea

2008-01-01

Even after repeated instruction, first year college chemistry students are often unable to apply stoichiometry knowledge to equilibrium and acid-base chemistry problems. The dynamic and interactive capabilities of online technology may facilitate stoichiometry instruction that promotes more meaningful learning. This study compares a…
Canonical Pedagogical Content Knowledge by Cores for Teaching Acid-Base Chemistry at High School

ERIC Educational Resources Information Center

Alvarado, Clara; Cañada, Florentina; Garritz, Andoni; Mellado, Vicente

2015-01-01

The topic of acid-base chemistry is one of the oldest in general chemistry courses and it has been almost continuously in academic discussion. The central purpose of documenting the knowledge and beliefs of a group of ten Mexican teachers with experience in teaching acid-base chemistry in high school was to know how they design, prepare and…
Automatic Differentiation in Quantum Chemistry with Applications to Fully Variational Hartree-Fock.

PubMed

Tamayo-Mendoza, Teresa; Kreisbeck, Christoph; Lindh, Roland; Aspuru-Guzik, Alán

2018-05-23

Automatic differentiation (AD) is a powerful tool that allows calculating derivatives of implemented algorithms with respect to all of their parameters up to machine precision, without the need to explicitly add any additional functions. Thus, AD has great potential in quantum chemistry, where gradients are omnipresent but also difficult to obtain, and researchers typically spend a considerable amount of time finding suitable analytical forms when implementing derivatives. Here, we demonstrate that AD can be used to compute gradients with respect to any parameter throughout a complete quantum chemistry method. We present DiffiQult , a Hartree-Fock implementation, entirely differentiated with the use of AD tools. DiffiQult is a software package written in plain Python with minimal deviation from standard code which illustrates the capability of AD to save human effort and time in implementations of exact gradients in quantum chemistry. We leverage the obtained gradients to optimize the parameters of one-particle basis sets in the context of the floating Gaussian framework.
Automatic Differentiation in Quantum Chemistry with Applications to Fully Variational Hartree–Fock

PubMed Central

2018-01-01

Automatic differentiation (AD) is a powerful tool that allows calculating derivatives of implemented algorithms with respect to all of their parameters up to machine precision, without the need to explicitly add any additional functions. Thus, AD has great potential in quantum chemistry, where gradients are omnipresent but also difficult to obtain, and researchers typically spend a considerable amount of time finding suitable analytical forms when implementing derivatives. Here, we demonstrate that AD can be used to compute gradients with respect to any parameter throughout a complete quantum chemistry method. We present DiffiQult, a Hartree–Fock implementation, entirely differentiated with the use of AD tools. DiffiQult is a software package written in plain Python with minimal deviation from standard code which illustrates the capability of AD to save human effort and time in implementations of exact gradients in quantum chemistry. We leverage the obtained gradients to optimize the parameters of one-particle basis sets in the context of the floating Gaussian framework.
Student participation in World Wide Web-based curriculum development of general chemistry

NASA Astrophysics Data System (ADS)

Hunter, William John Forbes

1998-12-01

This thesis describes an action research investigation of improvements to instruction in General Chemistry at Purdue University. Specifically, the study was conducted to guide continuous reform of curriculum materials delivered via the World Wide Web by involving students, instructors, and curriculum designers. The theoretical framework for this study was based upon constructivist learning theory and knowledge claims were developed using an inductive analysis procedure. This results of this study are assertions made in three domains: learning chemistry content via the World Wide Web, learning about learning via the World Wide Web, and learning about participation in an action research project. In the chemistry content domain, students were able to learn chemical concepts that utilized 3-dimensional visualizations, but not textual and graphical information delivered via the Web. In the learning via the Web domain, the use of feedback, the placement of supplementary aids, navigation, and the perception of conceptual novelty were all important to students' use of the Web. In the participation in action research domain, students learned about the complexity of curriculum. development, and valued their empowerment as part of the process.
Surface chemistry of InP ridge structures etched in Cl{sub 2}-based plasma analyzed with angular XPS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bouchoule, Sophie, E-mail: sophie.bouchoule@lpn.cnrs.fr; Cambril, Edmond; Guilet, Stephane

2015-09-15

Two x-ray photoelectron spectroscopy configurations are proposed to analyze the surface chemistry of micron-scale InP ridge structures etched in chlorine-based inductively coupled plasma (ICP). Either a classical or a grazing configuration allows to retrieve information about the surface chemistry of the bottom surface and sidewalls of the etched features. The procedure is used to study the stoichiometry of the etched surface as a function of ridge aspect ratio for Cl{sub 2}/Ar and Cl{sub 2}/H{sub 2} plasma chemistries. The results show that the bottom surface and the etched sidewalls are P-rich, and indicate that the P-enrichment mechanism is rather chemically driven.more » Results also evidence that adding H{sub 2} to Cl{sub 2} does not necessarily leads to a more balanced surface stoichiometry. This is in contrast with recent experimental results obtained with the HBr ICP chemistry for which fairly stoichiometric surfaces have been obtained.« less
Improve Outcomes Study subjects Chemistry Teaching and Learning Strategies through independent study with the help of computer-based media

NASA Astrophysics Data System (ADS)

Sugiharti, Gulmah

2018-03-01

This study aims to see the improvement of student learning outcomes by independent learning using computer-based learning media in the course of STBM (Teaching and Learning Strategy) Chemistry. Population in this research all student of class of 2014 which take subject STBM Chemistry as many as 4 class. While the sample is taken by purposive as many as 2 classes, each 32 students, as control class and expriment class. The instrument used is the test of learning outcomes in the form of multiple choice with the number of questions as many as 20 questions that have been declared valid, and reliable. Data analysis techniques used one-sided t test and improved learning outcomes using a normalized gain test. Based on the learning result data, the average of normalized gain values for the experimental class is 0,530 and for the control class is 0,224. The result of the experimental student learning result is 53% and the control class is 22,4%. Hypothesis testing results obtained t count> ttable is 9.02> 1.6723 at the level of significance α = 0.05 and db = 58. This means that the acceptance of Ha is the use of computer-based learning media (CAI Computer) can improve student learning outcomes in the course Learning Teaching Strategy (STBM) Chemistry academic year 2017/2018.
Development of Scientific Approach Based on Discovery Learning Module

NASA Astrophysics Data System (ADS)

Ellizar, E.; Hardeli, H.; Beltris, S.; Suharni, R.

2018-04-01

Scientific Approach is a learning process, designed to make the students actively construct their own knowledge through stages of scientific method. The scientific approach in learning process can be done by using learning modules. One of the learning model is discovery based learning. Discovery learning is a learning model for the valuable things in learning through various activities, such as observation, experience, and reasoning. In fact, the students’ activity to construct their own knowledge were not optimal. It’s because the available learning modules were not in line with the scientific approach. The purpose of this study was to develop a scientific approach discovery based learning module on Acid Based, also on electrolyte and non-electrolyte solution. The developing process of this chemistry modules use the Plomp Model with three main stages. The stages are preliminary research, prototyping stage, and the assessment stage. The subject of this research was the 10th and 11th Grade of Senior High School students (SMAN 2 Padang). Validation were tested by the experts of Chemistry lecturers and teachers. Practicality of these modules had been tested through questionnaire. The effectiveness had been tested through experimental procedure by comparing student achievement between experiment and control groups. Based on the findings, it can be concluded that the developed scientific approach discovery based learning module significantly improve the students’ learning in Acid-based and Electrolyte solution. The result of the data analysis indicated that the chemistry module was valid in content, construct, and presentation. Chemistry module also has a good practicality level and also accordance with the available time. This chemistry module was also effective, because it can help the students to understand the content of the learning material. That’s proved by the result of learning student. Based on the result can conclude that chemistry module based on discovery learning and scientific approach in electrolyte and non-electrolyte solution and Acid Based for the 10th and 11th grade of senior high school students were valid, practice, and effective.
Racing chemistry: A century of challenges and progress.

PubMed

Kremmer, Christopher

2017-09-01

Horseracing has been called 'one of the first quintessentially modern sports'. Its urge towards standardization, its mathematically set odds, its concern with weights, and its pioneering embrace of drug-testing reflect an empirical temperament crucial to its transformation from a gentleman's pastime to a global industry funded by wagering. Ironically, in the late nineteenth century, it was modern science itself, and in particular the purification and synthesis of the drugs of nature, that turned the doping of racing animals - a practice recorded in antiquity - into an organized criminal enterprise. This paper presents original research into the history of racing chemistry in Australia in the context of developments in the field worldwide. Using a case-study approach based on extensive archival materials, it reveals unpublished diaries kept by an analyst working at Sydney Racing Laboratory in the 1950s that document conflicts between scientists over identification of performance drugs in racing animals. The author presents evidence that augments and revises earlier narratives concerning the history of the establishment of laboratory control at Australian racetracks and the removal of the country's first official analyst for racing, Miss Jean Kimble. The Kimble case illustrates the inevitable political, professional, and personal pressures that bear upon drug-testing in sports, and also conflicts between scientists over standards and priorities. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Some strategies to improve performance in school chemistry, based on two cognitive factors

NASA Astrophysics Data System (ADS)

Danili, Eleni; Reid, Norman

2004-02-01

The background to this study are the difficulties facing the majority of Greek pupils in understanding chemistry concepts and, therefore, performing well in the National Examinations. The aim was to explore the problems and to suggest ways in which the situation might be improved. Working with 105 Greek pupils aged 15 to 16, the first stage of the enquiry confirmed that both working memory space and extent of field dependency were two psychological factors affecting performance. This is at least part of the nature of the problem. In the second stage, an attempt was made to explore how the problems might be reduced. New teaching materials were constructed to minimize any limitations to learning caused by working memory space and problems associated with being field dependent. The use of the new materials was compared to the normal teaching process working with 210 Greek pupils aged 15 to16. It was found that there was a significant difference in the average improvement of the experimental group and the control group, in favour of the experimental group. This result was independent of the effect of the teacher, and of the interaction of teaching method and teacher. It is suggested that approaches to learning must take into account cognitive factors in the learners in the context of information processing understandings of learning. If this is done, learning is much more effective.
Oxygen Activation and Radical Transformations in Heme Proteins and Metalloporphyrins

PubMed Central

2017-01-01

As a result of the adaptation of life to an aerobic environment, nature has evolved a panoply of metalloproteins for oxidative metabolism and protection against reactive oxygen species. Despite the diverse structures and functions of these proteins, they share common mechanistic grounds. An open-shell transition metal like iron or copper is employed to interact with O2 and its derived intermediates such as hydrogen peroxide to afford a variety of metal–oxygen intermediates. These reactive intermediates, including metal-superoxo, -(hydro)peroxo, and high-valent metal–oxo species, are the basis for the various biological functions of O2-utilizing metalloproteins. Collectively, these processes are called oxygen activation. Much of our understanding of the reactivity of these reactive intermediates has come from the study of heme-containing proteins and related metalloporphyrin compounds. These studies not only have deepened our understanding of various functions of heme proteins, such as O2 storage and transport, degradation of reactive oxygen species, redox signaling, and biological oxygenation, etc., but also have driven the development of bioinorganic chemistry and biomimetic catalysis. In this review, we survey the range of O2 activation processes mediated by heme proteins and model compounds with a focus on recent progress in the characterization and reactivity of important iron–oxygen intermediates. Representative reactions initiated by these reactive intermediates as well as some context from prior decades will also be presented. We will discuss the fundamental mechanistic features of these transformations and delineate the underlying structural and electronic factors that contribute to the spectrum of reactivities that has been observed in nature as well as those that have been invented using these paradigms. Given the recent developments in biocatalysis for non-natural chemistries and the renaissance of radical chemistry in organic synthesis, we envision that new enzymatic and synthetic transformations will emerge based on the radical processes mediated by metalloproteins and their synthetic analogs. PMID:29286645
Quantifying emerging local anthropogenic emissions in the Arctic region: the ACCESS aircraft campaign experiment

NASA Astrophysics Data System (ADS)

Roiger, Anke; Thomas, Jennie L.; Schlager, Hans; Law, Kathy; Kim, Jin; Reiter, Anja; Schäfler, Andreas; Weinzierl, Bernadett; Rose, Maximilian; Raut, Jean-Christophe; Marelle, Louis

2014-05-01

Arctic change has opened the region to new industrial activities, most notably transit shipping and resource extraction. The impacts that Arctic industrialization will have on pollutants and Arctic climate are not well understood. In order to understand how shipping and offshore oil/gas extraction impact on Arctic tropospheric chemistry and composition, we conducted the ACCESS (Arctic Climate Change, Economy, and Society, a European Union Seventh Framework Programme project) aircraft campaign. The campaign was conducted in July 2012 using the DLR Falcon research aircraft, based in Andenes, Norway. The Falcon was equipped with a suite of trace gas and aerosol instruments (black carbon, ozone, as well as other trace species) to characterize these emissions and their atmospheric chemistry. The Falcon performed nine scientific flights to study emissions from different ships (e.g. cargo, passenger, and fishing vessels) and a variety of offshore extraction facilities (e.g. drilling rigs, production and storage platforms) off the Norwegian Coast. Distinct differences in chemical and aerosol composition were found in emissions from these increasing pollution sources. We also studied the composition of biomass burning plumes imported from Siberian wildfires to put the emerging local pollution within a broader context. In addition to our measurements, we used a regional chemical transport model to study the influence of emerging pollution sources on gas and aerosol concentrations in the region. We will present an overview on the measured trace gas and aerosol properties of the different emission sources and discuss the impact of future local anthropogenic activities on the Arctic air composition by combining measurements with model simulations.
Argument-Driven Inquiry as a Way to Help Undergraduate Students Write to Learn by Learning to Write in Chemistry

NASA Astrophysics Data System (ADS)

Sampson, Victor; Phelps Walker, Joi

2012-07-01

This exploratory study examined how undergraduate students' ability to write in science changed over time as they completed a series of laboratory activities designed using a new instructional model called argument-driven inquiry. The study was conducted in a single section of an undergraduate general chemistry lab course offered at a large two-year community college located in the southeast USA. The intervention took place over a 15-week semester and consisted of six laboratory activities. During each laboratory activity, the undergraduates wrote investigation reports, participated in a double-blind group peer review of the reports, and revised their reports based on the reviews. The reports written during each laboratory activity were used to examine changes in the students' writing skills over time and to identify aspects of scientific writing that were the most difficult for the undergraduates in this context. The reviews produced by the students during each report were used to evaluate how well undergraduates engage in the peer-review process. The results of a quantitative and qualitative analysis of the reports and reviews indicate that the participants made significant improvements in their ability to write in science and were able to evaluate the quality of their peers' writing with a relatively high degree of accuracy, but they also struggled with several aspects of scientific writing. The conclusions and implications of the study include recommendations for helping undergraduate students learn to write by writing to learn in science and new directions for future research.
Quality improvement on chemistry practicum courses through implementation of 5E learning cycle

NASA Astrophysics Data System (ADS)

Merdekawati, Krisna

2017-03-01

Two of bachelor of chemical education's competences are having practical skills and mastering chemistry material. Practicum courses are organized to support the competency achievement. Based on observation and evaluation, many problems were found in the implementation of practicum courses. Preliminary study indicated that 5E Learning Cycle can be used as an alternative solution in order to improve the quality of chemistry practicum course. The 5E Learning Cycle can provide positive influence on the achievement of the competence, laboratory skills, and students' understanding. The aim of the research was to describe the feasibility of implementation of 5E Learning Cycle on chemistry practicum courses. The research was based on phenomenology method in qualitative approach. The participants of the research were 5 person of chemistry laboratory manager (lecturers at chemistry and chemistry education department). They concluded that the 5E Learning Cycle could be implemented to improve the quality of the chemistry practicum courses. Practicum guides and assistant competences were organized to support the implementation of 5E Learning Cycle. It needed training for assistants to understand and implement in the stages of 5E Learning Cycle. Preparation of practical guidelines referred to the stages of 5E Learning Cycle, started with the introduction of contextual and applicable materials, then followed with work procedures that accommodate the stage of engagement, exploration, explanation, extension, and evaluation
Chemistry Students' Erroneous Conceptions of Limiting Reagent.

ERIC Educational Resources Information Center

Mammen, K. J.

1996-01-01

Describes a study of 32 University of Transkei (South Africa) freshmen's conceptualization of "limiting reagent," a basic concept in chemistry, based on student responses to two written test questions and clinical interviews. Results indicated that a high percentage of students had misconceptions and could not apply the concept…
Chemistry without Borders: Careers, Research, and Entrepreneurship

USDA-ARS?s Scientific Manuscript database

This book is based on two symposia of the American Chemical Society (ACS): 1) “The Transnational Practice of Chemistry and Allied Sciences and Engineering: Study, Research and Careers without Borders” held at the Spring National Meeting in Denver in March 2015, and 2) “International Entrepreneurship...

A gist of comprehensive review of hadronic chemistry and its applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tangde, Vijay M.

20{sup th} century theories of Quantum Mechanics and Quantum Chemistry are exactly valid only when considered to represent the atomic structures. While considering the more general aspects of atomic combinations these theories fail to explain all the related experimental data from first unadulterated axiomatic principles. According to Quantum Chemistry two valence electrons should repel each other and as such there is no mathematical representation of a strong attractive forces between such valence electrons. In view of these and other insufficiencies of Quantum Chemistry, an Italian-American Scientist Professor Ruggero Maria Santilli during his more than five decades of dedicated and sustainedmore » research has denounced the fact that quantum chemistry is mostly based on mere nomenclatures. Professor R M Santilli first formulated the iso-, geno- and hyper- mathematics [1, 2, 3, 4] that helped in understanding numerous diversified problems and removing inadequacies in most of the established and celebrated theories of 20th century physics and chemistry. This involves the isotopic, genotopic, etc. lifting of Lie algebra that generated Lie admissible mathematics to properly describe irreversible processes. The studies on Hadronic Mechanics in general and chemistry in particular based on Santilli’s mathematics[3, 4, 5] for the first time has removed the very fundamental limitations of quantum chemistry [2, 6, 7, 8]. In the present discussion, a comprehensive review of Hadronic Chemistry is presented that imparts the completeness to the Quantum Chemistry via an addition of effects at distances of the order of 1 fm (only) which are assumed to be Non-linear, Non-local, Non-potential, Non-hamiltonian and thus Non-unitary, stepwise successes of Hadronic Chemistry and its application in development of a new chemical species called Magnecules.« less
Improving substance information in USEtox® , part 1: Discussion on data and approaches for estimating freshwater ecotoxicity effect factors.

PubMed

Saouter, Erwan; Aschberger, Karin; Fantke, Peter; Hauschild, Michael Z; Bopp, Stephanie K; Kienzler, Aude; Paini, Alicia; Pant, Rana; Secchi, Michela; Sala, Serenella

2017-12-01

The scientific consensus model USEtox ® is recommended by the European Commission as the reference model to characterize life cycle chemical emissions in terms of their potential human toxicity and freshwater aquatic ecotoxicity impacts in the context of the International Reference Life Cycle Data System Handbook and the Environmental Footprint pilot phase looking at products (PEF) and organizations (OEF). Consequently, this model has been systematically used within the PEF/OEF pilot phase by 25 European Union industry sectors, which manufacture a wide variety of consumer products. This testing phase has raised some questions regarding the derivation of and the data used for the chemical-specific freshwater ecotoxicity effect factor in USEtox. For calculating the potential freshwater aquatic ecotoxicity impacts, USEtox bases the effect factor on the chronic hazard concentration (HC50) value for a chemical calculated as the arithmetic mean of all logarithmized geometric means of species-specific chronic median lethal (or effect) concentrations (L[E]C50). We investigated the dependency of the USEtox effect factor on the selection of ecotoxicological data source and toxicological endpoints, and we found that both influence the ecotoxicity ranking of chemicals and may hence influence the conclusions of a PEF/OEF study. We furthermore compared the average measure (HC50) with other types of ecotoxicity effect indicators, such as the lowest species EC50 or no-observable-effect concentration, frequently used in regulatory risk assessment, and demonstrated how they may also influence the ecotoxicity ranking of chemicals. We acknowledge that these indicators represent different aspects of a chemical's ecotoxicity potential and discuss their pros and cons for a comparative chemical assessment as performed in life cycle assessment and in particular within the PEF/OEF context. Environ Toxicol Chem 2017;36:3450-3462. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
The medicinal chemistry of liver X receptor (LXR) modulators.

PubMed

Tice, Colin M; Noto, Paul B; Fan, Kristi Yi; Zhuang, Linghang; Lala, Deepak S; Singh, Suresh B

2014-09-11

LXRs have been of interest as targets for the treatment of atherosclerosis for over a decade. In recent years, LXR modulators have also garnered interest for potential use in the treatment of inflammation, Alzheimer's disease (AD), dermatological conditions, hepatic steatosis, and oncology. To date, no LXR modulator has successfully progressed beyond phase I clinical trials. In this Perspective, we summarize published medicinal chemistry efforts in the context of the available crystallographic data, druglikeness, and isoform selectivity. In addition, we discuss the challenges that need to be overcome before an LXR modulator can reach clinical use.
An investigation of the effects of relevant samples and a comparison of verification versus discovery based lab design

NASA Astrophysics Data System (ADS)

Rieben, James C., Jr.

This study focuses on the effects of relevance and lab design on student learning within the chemistry laboratory environment. A general chemistry conductivity of solutions experiment and an upper level organic chemistry cellulose regeneration experiment were employed. In the conductivity experiment, the two main variables studied were the effect of relevant (or "real world") samples on student learning and a verification-based lab design versus a discovery-based lab design. With the cellulose regeneration experiment, the effect of a discovery-based lab design vs. a verification-based lab design was the sole focus. Evaluation surveys consisting of six questions were used at three different times to assess student knowledge of experimental concepts. In the general chemistry laboratory portion of this study, four experimental variants were employed to investigate the effect of relevance and lab design on student learning. These variants consisted of a traditional (or verification) lab design, a traditional lab design using "real world" samples, a new lab design employing real world samples/situations using unknown samples, and the new lab design using real world samples/situations that were known to the student. Data used in this analysis were collected during the Fall 08, Winter 09, and Fall 09 terms. For the second part of this study a cellulose regeneration experiment was employed to investigate the effects of lab design. A demonstration creating regenerated cellulose "rayon" was modified and converted to an efficient and low-waste experiment. In the first variant students tested their products and verified a list of physical properties. In the second variant, students filled in a blank physical property chart with their own experimental results for the physical properties. Results from the conductivity experiment show significant student learning of the effects of concentration on conductivity and how to use conductivity to differentiate solution types with the use of real world samples. In the organic chemistry experiment, results suggest that the discovery-based design improved student retention of the chain length differentiation by physical properties relative to the verification-based design.
Profile of laboratory instruction in secondary school level chemistry and indication for reform

NASA Astrophysics Data System (ADS)

Wang, Mei

This study is a profile of the laboratory component of instruction in secondary school level chemistry. As one of several companion studies, the purpose of the study is to investigate present practices related to instruction as a means of producing reform that improve cognitive and non-cognitive learning outcomes. Five hundred-forty students, from 18 chemistry classes taught by 12 teachers in ten high schools were involved in this study. Three schools included public and private schools, urban school, suburban schools, and rural schools. Three levels or types of chemistry courses were offered in these schools: school regular chemistry for college bound students, Chemistry in the Community or "ChemCom" for non-college bound students, and a second year of chemistry or advanced placement chemistry. Laboratory sessions in each of these three levels of courses were observed, videotaped, and later analyzed using the Modified Revised Science Teachers Behaviors Inventory (MR-STBI). The 12 chemistry teachers, eight science supervisors, and selected students were interviewed to determine their professional backgrounds and other factors that might influence how they teach, how they think, and how they learn. The following conclusions developed from the research are: (1) The three levels of chemistry courses are offered across high schools of varying sizes and locations. (2) Teachers perceive that students come to chemistry classes poorly prepared to effectively carry out laboratory experiences and/or investigations. (3) While students indicated that they are able to effectively use math skills in analyzing the results of chemistry laboratory experiments, teachers, in general, are not satisfied with the level at which students are prepared to use these skills, or to use writing skills. (4) Students working in pairs, is the typical approach. Group cooperation is sometimes used in carrying out the laboratory component of chemistry instruction in the ChemCom and AP chemistry courses. (5) Computers and other technology were not observed in use commonly in laboratory component of instruction in any levels of chemistry courses. (6) The results of MR-STBI (Modified Revised Science Teachers Behavior Inventory) indicates that the rank order of use of the teaching behaviors in laboratory based instruction among the three types of chemistry courses are similar. (7) A summary of recommended practices for use in teaching each of the three levels of high school chemistry courses is presented in Chapter 5.
Metacognitive Analysis of Pre-Service Teachers of Chemistry in Posting Questions

NASA Astrophysics Data System (ADS)

Santoso, T.; Yuanita, L.

2017-04-01

Questions addressed to something can induce metacognitive function to monitor a person’s thinking process. This study aims to describe the structure of the level of student questions based on thinking level and chemistry understanding level and describe how students use their metacognitive knowledge in asking. This research is a case study in chemistry learning, followed by 87 students. Results of the analysis revealed that the structure of thinking level of student question consists of knowledge question, understanding and application question, and high thinking question; the structure of chemistry understanding levels of student questions are a symbol, macro, macro-micro, macro-process, micro-process, and the macro-micro-process. The level Questioning skill of students to scientific articles more qualified than the level questioning skills of students to the teaching materials. The analysis result of six student interviews, a student question demonstrate the metacognitive processes with categories: (1) low-level metacognitive process, which is compiled based on questions focusing on a particular phrase or change the words; (2) intermediate level metacognitive process, submission of questions requires knowledge and understanding, and (3) high-level metacognitive process, the student questions posed based on identifying the central topic or abstraction essence of scientific articles.
Promoting a structural view of biology for varied audiences: an overview of RCSB PDB resources and experiences.

PubMed

Dutta, Shuchismita; Zardecki, Christine; Goodsell, David S; Berman, Helen M

2010-10-01

The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB) supports scientific research and education worldwide by providing an essential resource of information on biomolecular structures. In addition to serving as a deposition, data-processing and distribution center for PDB data, the RCSB PDB offers resources and online materials that different audiences can use to customize their structural biology instruction. These include resources for general audiences that present macromolecular structure in the context of a biological theme, method-based materials for researchers who take a more traditional approach to the presentation of structural science, and materials that mix theme-based and method-based approaches for educators and students. Through these efforts the RCSB PDB aims to enable optimal use of structural data by researchers, educators and students designing and understanding experiments in biology, chemistry and medicine, and by general users making informed decisions about their life and health.
Contrasting controls of pH climatology in an open coast versus urban fjord estuary

EPA Science Inventory

Interactions of physical, chemical, and biological processes in the coastal zone can result in a highly variable carbonate chemistry regime. This characteristic variability in coastal areas has garnered renewed interest within the context of ocean acidification, yet the relative...
Computer Series, 61: Bits & Pieces, 24.

ERIC Educational Resources Information Center

Moore, John W., Ed.

1985-01-01

Describes: (1) laboratory information science in the clinical chemistry curriculum; (2) testing Boyle's Law, a context for statistical methods in undergraduate laboratories; (3) acquiring chemical concepts using microcomputers as tutees; and (4) using Data Interchange Format files for Apple microcomputers. Includes feedback from a previous article…
Assessing the Development of Chemistry Students' Conceptual and Visual Understanding of Dimensional Analysis via Supplemental Use of Web-Based Software

ERIC Educational Resources Information Center

Ellis, Jennifer T.

2013-01-01

This study was designed to evaluate the effects of a proprietary software program on students' conceptual and visual understanding of dimensional analysis. The participants in the study were high school general chemistry students enrolled in two public schools with different demographics (School A and School B) in the Chattanooga, Tennessee,…
The Effects of a Chemistry Course with Integrated Information Communication Technologies on University Students' Learning and Attitudes

ERIC Educational Resources Information Center

Su, King-Dow

2008-01-01

The purpose of this study was to evaluate the instructional effects of using animations, static figures, PowerPoint bulletins, and e-plus software as chemistry texts with the aid of computer-based technology. This study analyzed the characteristics of students involved in three multimedia courses and their achievement and attitude toward chemistry…
Determining the Antifungal Agent Clioquinol by HPLC, the Not so Pure Preparation: A Laboratory-Based Case Study for an Instrumental Analytical Chemistry Course

ERIC Educational Resources Information Center

Schaber, Peter M.; Hobika, Geoffrey

2018-01-01

The case study approach provides students with a better appreciation of how scientists solve problems and conduct themselves in the "real world". When applied to the undergraduate chemistry laboratory, this approach also challenges critical thinking skills and creativity in ways "cook book" experiments very often do not. This…
Beyond Academic Tracking: Using Cluster Analysis and Self-Organizing Maps to Investigate Secondary Students' Chemistry Self-Concept

ERIC Educational Resources Information Center

Nielsen, Sara E.; Yezierski, Ellen J.

2016-01-01

Academic tracking, placing students in different classes based on past performance, is a common feature of the American secondary school system. A longitudinal study of secondary students' chemistry self-concept scores was conducted, and one feature of the study was the presence of academic tracking. Though academic tracking is one way to group…
Incorporating Modeling and Simulations in Undergraduate Biophysical Chemistry Course to Promote Understanding of Structure-Dynamics-Function Relationships in Proteins

ERIC Educational Resources Information Center

Hati, Sanchita; Bhattacharyya, Sudeep

2016-01-01

A project-based biophysical chemistry laboratory course, which is offered to the biochemistry and molecular biology majors in their senior year, is described. In this course, the classroom study of the structure-function of biomolecules is integrated with the discovery-guided laboratory study of these molecules using computer modeling and…
Analysis of stratospheric ozone, temperature, and minor constituent data

NASA Technical Reports Server (NTRS)

Stolarski, Richard S.; Douglass, Anne R.; Jackman, Charles H.; Kaye, Jack A.; Rood, Richard B.

1990-01-01

The objective of this research is to use available satellite measurements of temperature and constituent concentrations to test the conceptual picture of stratospheric chemistry and transport. This was originally broken down into two sub-goals: first, to use the constituent data to search for critical tests of our understanding of stratospheric chemistry and second, to examine constituent transport processes emphasizing interactions with chemistry on various time scales. A third important goal which has evolved is to use the available solar backscattered ultraviolet (SBUV) and Total Ozone Mapping Spectrometer (TOMS) data from Nimbus 7 to describe the morphology of recent changes in Antarctic and global ozone with emphasis on searching for constraints to theories. The major effort now being pursued relative to the two original goals is our effort as a theoretical team for the Arctic Airborne Stratospheric Expedition (AASE). Our effort for the AASE is based on the 3D transport and chemistry model at Goddard. Our goal is to use this model to place the results from the mission data in a regional and global context. Specifically, we set out to make model runs starting in late December and running through March of 1989, both with and without heterogeneous chemistry. The transport is to be carried out using dynamical fields from a 4D data assimilation model being developed under separate funding from this task. We have successfully carried out a series of single constituent transport experiments. One of the things demonstrated by these runs was the difficulty in obtaining observed low N2O abundances in the vortex without simultaneously obtaining very high ozone values. Because the runs start in late December, this difficulty arises in the attempt to define consistent initial conditions for the 3D model. To accomplish a consistent set of initial conditions, we are using the 2D photochemistry-transport model of Jackman and Douglass and mapping in potential temperature, potential vorticity space as developed by Schoeberl and coworkers.
An Analysis of Teaching Competence in Science Teachers Involved in the Design of Context-Based Curriculum Materials

ERIC Educational Resources Information Center

De Putter-Smits, Lesley G. A.; Taconis, Ruurd; Jochems, Wim; Van Driel, Jan

2012-01-01

The committees for the current Dutch context-based innovation in secondary science education employed teachers to design context-based curriculum materials. A study on the learning of science teachers in design teams for context-based curriculum materials is presented in this paper. In a correlation study, teachers with (n = 5 and 840 students)…
Nitrogen Removal by Streams and Rivers of the Upper Mississippi River Basin

EPA Science Inventory

Our study, based on chemistry and channel dimensions data collected at 893 randomly-selected stream and river sites in the Mississippi River basin, demonstrated the interaction of stream chemistry, stream size, and NO3-N uptake metrics across a range of stream sizes and across re...
Understanding Quantum Numbers in General Chemistry Textbooks

ERIC Educational Resources Information Center

Niaz, Mansoor; Fernandez, Ramon

2008-01-01

Quantum numbers and electron configurations form an important part of the general chemistry curriculum and textbooks. The objectives of this study are: (1) Elaboration of a framework based on the following aspects: (a) Origin of the quantum hypothesis, (b) Alternative interpretations of quantum mechanics, (c) Differentiation between an orbital and…
What People Eat--A Chemistry Program Based on Nutrition

ERIC Educational Resources Information Center

Raw, Isaias; And Others

1975-01-01

Describes a chemistry curriculum for college freshmen that uses laboratory study of the chemical composition of meals eaten by students as the central activity from which theoretical and practical learning are derived. Presents a meal analysis flow diagram and a table of concepts included in the program. (GS)
Some Properties of Poly(Methyl Methacrylate) Studied by Radiation Degradation: An Interdisciplinary Student Experiment.

ERIC Educational Resources Information Center

Hill, D. J. T.; O'Donnell, J. H.

1981-01-01

Describes an interdisciplinary student experiment based upon the radiation effects on polymers, integrating some of the fundamentals of radiation chemistry, polymer chemistry, and material science. Also demonstrates how the information gained in the experiment has direct commercial application in product manufacture or processing. (CS)

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