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Sample records for general chemistry expanding

  1. General Chemistry: Expanding the Learning Outcomes and Promoting Interdisciplinary Connections through the Use of a Semester-Long Project

    ERIC Educational Resources Information Center

    Wenzel, Thomas J.

    2006-01-01

    The laboratory component of a first-semester general chemistry course for science majors is described. The laboratory involves a semester-long project undertaken in a small-group format. Students are asked to examine whether plants grown in soil contaminated with lead take up more lead than those grown in uncontaminated soil. They are also asked…

  2. General chemistry: expanding the learning outcomes and promoting interdisciplinary connections through the use of a semester-long project.

    PubMed

    Wenzel, Thomas J

    2006-01-01

    The laboratory component of a first-semester general chemistry course for science majors is described. The laboratory involves a semester-long project undertaken in a small-group format. Students are asked to examine whether plants grown in soil contaminated with lead take up more lead than those grown in uncontaminated soil. They are also asked to examine whether the acidity of the rainwater affects the amount of lead taken up by the plants. Groups are then given considerable independence in the design and implementation of the experiment. Once the seeds are planted, which takes about 4 wk into the term, several shorter experiments are integrated in before it is time to harvest and analyze the plants. The use of a project and small working groups allows for the development of a broader range of learning outcomes than occurs in a "traditional" general chemistry laboratory. The nature of these outcomes and some of the student responses to the laboratory experience are described. This particular project also works well at demonstrating the connections among chemistry, biology, geology, and environmental studies.

  3. Chemistry as General Education

    NASA Astrophysics Data System (ADS)

    Tro, Nivaldo J.

    2004-01-01

    Science courses are common in most general education requirements. This paper addresses the role of chemistry classes in meeting these requirements. Chemistry professors have for many years questioned the appropriateness of the standard introductory chemistry course as general education, resulting in the growing popularity of specialized non-majors courses. I suggest that current non-major chemistry courses cover too much consumer chemistry and ignore some of the big contributions of chemistry to human knowledge. Majors chemistry courses, while they prepare students for majoring in science, do not address these issues either. Consequently, chemistry courses are often an ineffective and unpopular way to meet general education science requirements. Part of the reason for this dilemma is the lack of chemists who address the contributions of chemistry to human knowledge in general. I propose that faculty at liberal arts colleges engage in this important task and that non-majors chemistry textbooks incorporate questions and issues that relate chemistry to a broader view of human knowledge. If these things happen, perhaps chemistry courses will become more effective as general education.

  4. Chemistry as General Education

    ERIC Educational Resources Information Center

    Tro, Nivaldo J.

    2004-01-01

    The efficacy of different science and chemistry courses for science-major and non-major students, and the question of chemistry's contribution to general education are evaluated. Chemistry and science curriculum are too profession- and consumer-oriented, and to overcome this problem, it is advised that all disciplines must incorporate the major…

  5. General Chemistry for Engineers.

    ERIC Educational Resources Information Center

    Kybett, B. D.

    1982-01-01

    Discusses the relationship between molecular structure, intermolecular forces, and tensile strengths of a polymer and suggests that this is a logical way to introduce polymers into a general chemistry course. (Author/JN)

  6. General Chemistry, 1970 Edition.

    ERIC Educational Resources Information Center

    Dunham, Orson W.; Franke, Douglas C.

    This publication is a syllabus for a senior high school chemistry course designed for the average ability, nonscience major. The content of the syllabus is divided into three basic core areas: Area I: Similarities and Dissimilarities of Matter (9 weeks); Area II: Preparation and Separation of Substances (10 weeks); Area III: Structure and…

  7. General Chemistry Multimedia Problems

    NASA Astrophysics Data System (ADS)

    Whisnant, David M.

    2000-10-01

    Literature Cited

    1. Moore, J. W.; Jacobsen, J. J. Chemistry Comes Alive!, J. Chem. Educ. Software 2000, SP 18 2nd ed., SP 21 2nd ed., SP 23; SP 25; and additional video in press.
    2. Summerlin, L. R.; Borgford, C. F.; Ealy, J. B. Chemical Demonstrations, Volume 2; ACS: Washington, DC, 1987.

    3. Investigating expanded chemistry in CMAQ clouds

      EPA Science Inventory

      Clouds and fogs significantly impact the amount, composition, and spatial distribution of gas and particulate atmospheric species, not least of which through the chemistry that occurs in cloud droplets.ᅠ Atmospheric sulfate is an important component of fine aerosol mass an...

    4. General Chemistry for Waste Handlers.

      ERIC Educational Resources Information Center

      Sixtus, Michael E.

      This manual is intended for use in presenting a course which provides the content-specific general chemistry education required for the safety awareness and job enhancement of persons employed as waste handlers. The course, which was designed to be delivered to technicians at job sites in a lecture/demonstration format with several hands-on…

    5. General chemistry students' understanding of the chemistry underlying climate science

      NASA Astrophysics Data System (ADS)

      Versprille, Ashley N.

      The purpose of this study is to investigate first-semester general chemistry students' understanding of the chemistry underlying climate change. The first part of this study involves the collection of qualitative data from twenty-four first-semester general chemistry students from a large Midwestern research institution. The semi-structured interview protocol was developed based on alternative conceptions identified in the research literature and the essential principles of climate change outlined in the U.S. Climate Change Science Program (CCSP) document which pertain to chemistry (CCSP, 2003). The analysis and findings from the interviews indicate conceptual difficulties for students, both with basic climate literacy and underlying chemistry concepts. Students seem to confuse the greenhouse effect, global warming, and the ozone layer, and in terms of chemistry concepts, they lack a particulate level understanding of greenhouse gases and their interaction with electromagnetic radiation, causing them to not fully conceptualize the greenhouse effect and climate change. Based on the findings from these interviews, a Chemistry of Climate Science Diagnostic Instrument (CCSI) was developed for use in courses that teach chemistry with a rich context such as climate science. The CCSI is designed for professors who want to teach general chemistry, while also addressing core climate literacy principles. It will help professors examine their students' prior knowledge and alternative conceptions of the chemistry concepts associated with climate science, which could then inform their teaching and instruction.

    6. General Chemistry in Liberal Arts Colleges.

      ERIC Educational Resources Information Center

      Finholt, Albert E.

      1978-01-01

      Discusses some issues related to chemistry curricula in liberal arts colleges. Among these issues are the nature of a liberal arts curriculum, content of chemistry course, teaching methods, technological aids to teaching, use of the laboratory, and the future of general chemistry teaching in the liberal arts colleges. (HM)

    7. A Comprehensive General Chemistry Demonstration

      ERIC Educational Resources Information Center

      Sweeder, Ryan D.; Jeffery, Kathleen A.

      2013-01-01

      This article describes the use of a comprehensive demonstration suitable for a high school or first-year undergraduate introductory chemistry class. The demonstration involves placing a burning candle in a container adjacent to a beaker containing a basic solution with indicator. After adding a lid, the candle will extinguish and the produced…

    8. Peer Mentoring in the General Chemistry and Organic Chemistry Laboratories: The Pinacol Rearrangement--An Exercise in NMR and IR Spectroscopy for General Chemistry and Organic Chemistry Laboratories

      ERIC Educational Resources Information Center

      Arrington, Caleb A.; Hill, Jameica B.; Radfar, Ramin; Whisnant, David M.; Bass, Charles G.

      2008-01-01

      This article describes a discovery experiment for general chemistry and organic chemistry labs. Although the pinacol rearrangement has been employed in undergraduate organic laboratories before, in this application organic chemistry students act as mentors to students of general chemistry. Students work together using distillation--a new technique…

    9. 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…

    10. Synthesis of Aspirin: A General Chemistry Experiment.

      ERIC Educational Resources Information Center

      Olmsted, John III

      1998-01-01

      Describes the redesign of the first semester general chemistry laboratory at the college level. An organic component is included in the redesign and it provides students with explicit examples of several types of operations in which chemists engage. Contains 16 references. (DDR)

    11. Defining Conceptual Understanding in General Chemistry

      ERIC Educational Resources Information Center

      Holme, Thomas A.; Luxford, Cynthia J.; Brandriet, Alexandra

      2015-01-01

      Among the many possible goals that instructors have for students in general chemistry, the idea that they will better understand the conceptual underpinnings of the science is certainly important. Nonetheless, identifying with clarity what exemplifies student success at achieving this goal is hindered by the challenge of clearly articulating what…

    12. 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…

    13. A Flipped Classroom Redesign in General Chemistry

      ERIC Educational Resources Information Center

      Reid, Scott A.

      2016-01-01

      The flipped classroom continues to attract significant attention in higher education. Building upon our recent parallel controlled study of the flipped classroom in a second-term general chemistry course ("J. Chem. Educ.," 2016, 93, 13-23), here we report on a redesign of the flipped course aimed at scaling up total enrollment while…

    14. Electrochemistry in the General Chemistry Curriculum.

      ERIC Educational Resources Information Center

      Chambers, James Q.

      1983-01-01

      Outlines several ideas on introductory electrochemistry material suitable for college-level general chemistry. These include discussions of conductivity in solids and electrolytes, electrical quantities/properties, electrode potentials, and membrane potentials. Indicates that whatever strategy is used to present this material, the presentation…

    15. Measuring Student Performance in General Organic Chemistry

      ERIC Educational Resources Information Center

      Austin, Ara C.; Ben-Daat, Hagit; Zhu, Mary; Atkinson, Robert; Barrows, Nathan; Gould, Ian R.

      2015-01-01

      Student performance in general organic chemistry courses is determined by a wide range of factors including cognitive ability, motivation and cultural capital. Previous work on cognitive factors has tended to focus on specific areas rather than exploring performance across all problem types and cognitive skills. In this study, we have categorized…

  1. Expanding opportunities for mining bioactive chemistry from patents.

    PubMed

    Southan, Christopher

    2015-07-01

    Bioactive structures published in medicinal chemistry patents typically exceed those in papers by at least twofold and may precede them by several years. The Big-Bang of open automated extraction since 2012 has contributed to over 15 million patent-derived compounds in PubChem. While mapping between chemical structures, assay results and protein targets from patent documents is challenging, these relationships can be harvested using open tools and are beginning to be curated into databases.

  2. Expanding opportunities for mining bioactive chemistry from patents

    PubMed Central

    Southan, Christopher

    2015-01-01

    Bioactive structures published in medicinal chemistry patents typically exceed those in papers by at least twofold and may precede them by several years. The Big-Bang of open automated extraction since 2012 has contributed to over 15 million patent-derived compounds in PubChem. While mapping between chemical structures, assay results and protein targets from patent documents is challenging, these relationships can be harvested using open tools and are beginning to be curated into databases. PMID:26194581

  3. Predicting student success in General Chemistry

    NASA Astrophysics Data System (ADS)

    Figueroa, Daphne Elizabeth

    The goal of this research was to determine the predictors of student success in college level General Chemistry. The potential predictors were categorized as cognitive, non-cognitive, affective, or demographic factors. A broader goal of the study was to provide a reference for academic personnel to better judge the prerequisite skills, knowledge and attitudes that students should attain before enrolling in General Chemistry. Therefore, the study is relevant to chemical educators who are attempting to matriculate candidates for the scientific workforce and to chemical education researches who are interested in student success, student retention and curricular reform. The major hypotheses were that several factors from each category would emerge as significant predictors and that these would differ for students enrolled at three different post-secondary institutions: a community college, a private university and a public university. These hypotheses were tested using multiple regression techniques to analyze grade, student survey and post-test data collected from General Chemistry students at the three institutions. Over-all, twelve factors (six demographic, three cognitive and three affective) emerged as strong, significant predictors of student success. In addition, there were marked differences in which factors emerged based on the type of institution and on how student success was defined. Thus, the major hypotheses of the study were supported. Over-all, this study has significant implications for educational policy, theory, and practice. With regard to policy, there is a need for institutions and departments that offer General Chemistry to provide support for a diverse population of students. And, at the community college level, in particular, there is a need for better academic advising and more institutional support for underprepared students. In the classroom, the professor plays a critical role in influencing students' academic self-concept, which in turn

  4. Equal Spacing and Expanding Schedules in Children's Categorization and Generalization

    PubMed Central

    Vlach, Haley A.; Sandhofer, Catherine M.; Bjork, Robert A.

    2014-01-01

    In order to understand how generalization develops across the lifespan, researchers have examined the factors of the learning environment that promote the acquisition and generalization of categories. One such factor is the timing of learning events, which recent findings suggest may play a particularly important role in children's generalization. In the current study, we build upon these findings by examining the impact of equally spaced versus expanding learning schedules on children's ability to generalize from studied exemplars of a given category to new exemplars presented on a later test. We found no significant effects of learning schedule when the generalization test was administered immediately after the learning phase, but there was a clear difference when the generalization test was delayed by 24 hours: Children in the expanding condition significantly outperformed children in the equally spaced learning condition. These results suggest forgetting and retrieval dynamics may be lower-level cognitive mechanisms promoting generalization and have several implications for broad theories of learning, cognition, and development. PMID:24613074

  5. Synthesis of Aspirin: A General Chemistry Experiment

    NASA Astrophysics Data System (ADS)

    Olmsted, John A., III

    1998-10-01

    An experiment is described that is suitable for the early portion of the laboratory in a general chemistry course and integrates organic examples. It is the two-step synthesis of aspirin starting from oil of wintergreen. The mechanism for this synthesis provides examples of three major classes of chemical reactions: hydrolysis, condensation, and proton transfer. To understand the chemistry, the student must be able to recognize the common molecular framework shared by oil of wintergreen, salicylic acid, and aspirin and to identify the -OH and -CO2 sites where chemical changes occur. The experiment differs in three ways from traditional aspirin synthesis experiments for general chemistry. It is designed to be performed early rather than late; it starts from a naturally occurring material and requires two steps rather than one; and it utilizes FTIR spectroscopy to distinguish among oil of wintergreen starting material, salicylic acid intermediate, and aspirin product. The use of FTIR spectroscopy introduces students to a modern analytical technique that is currently used in research involving aspirin.

  6. Organic Chemistry Self Instructional Package 1: Review of General Chemistry.

    ERIC Educational Resources Information Center

    Zdravkovich, V.

    This booklet is one of a series of 17 developed at Prince George's Community College, Largo, Maryland. It provides an individualized, self-paced undergraduate organic chemistry instruction module designed to augment any course in organic chemistry but particularly those taught using the text "Organic Chemistry" by Morrison and Boyd. The…

  7. Cafeteria-Style Grading in General Chemistry

    NASA Astrophysics Data System (ADS)

    Goodwin, John A.; Gilbert, Brian D.

    2001-04-01

    Self-selected individual course-grade weighting schemes allow students personal choice of course components in the general chemistry sequence at Coastal Carolina University. With the availability of a wide range of commercial and academically produced pedagogical resources, students can select materials that best suit their own learning styles, social situations, and motivation level. Our students use a signed contract to indicate their preferred grade-weighting schemes for determination of the course grade. In doing so, they choose from course components that include peer-led team learning (PLTL) in the Workshop Chemistry (WSC) model, computer-assisted instruction (CAI) using the ChemSkill Builder (CSB) software, a variety of in-class quizzes and group problem-solving exercises, written exams, and the final written exam. Minimum percentage values are required of all components except WSC and CSB, which have been completely optional graded course components at CCU since the summer of 1999. Comparison of student success in the course and content learning suggests that the improvements observed with introduction of a gamut of activities increase even more when the cafeteria-style grading is implemented.

  8. Understanding the Impact of a General Chemistry Course on Students' Transition to Organic Chemistry

    ERIC Educational Resources Information Center

    Collins-Webb, Alexandra; Jeffery, Kathleen A.; Sweeder, Ryan D.

    2016-01-01

    The move from general chemistry to organic chemistry can be a challenge for students as it often involves a transition from quantitatively-oriented to mechanistically-oriented thinking. This study found that the design of the general chemistry course can change the student experience of this transition as assessed by a reflective survey. The…

  9. A Student Guide to Studying General Chemistry.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    This is a guide for introductory college chemistry students who are new to the subject of chemistry and who have been exposed to linear and second-order algebra equations and the concept of slope. The guide presents directions on the following topics: (1) How to prepare for lectures and take notes; (2) How to study chemistry outside of class using…

  10. Going Beyond, Going Further: Preparative Exercises in General Chemistry.

    ERIC Educational Resources Information Center

    Kauffman, George B.

    1987-01-01

    Proposes that preparative chemistry is an important and integral part of chemistry as a whole, and an excellent way to introduce students to descriptive chemistry. Provides an outline for students to follow for converting and transforming salts. Suggests a set of general guidelines for studying anion and cation transformations. (TW)

  11. A Timesharing Computer Program for a General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Cutler, Gary L.; Drum, Donald A.

    1975-01-01

    Describes an experiment in which general and physical chemistry students can determine the heat of vaporization of a volatile substance from experimental laboratory data using timesharing techniques. (MLH)

  12. 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…

  13. 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…

  14. Integrating Multiple Teaching Methods into a General Chemistry Classroom.

    ERIC Educational Resources Information Center

    Francisco, Joseph S.; Nicoll, Gayle; Trautmann, Marcella

    1998-01-01

    Four different methods of teaching--cooperative learning, class discussions, concept maps, and lectures--were integrated into a freshman-level general chemistry course to compare students' levels of participation. Findings support the idea that multiple modes of learning foster the metacognitive skills necessary for mastering general chemistry.…

  15. Attitude Counts: Self-Concept and Success in General Chemistry

    ERIC Educational Resources Information Center

    Lewis, Scott E.; Shaw, Janet L.; Heitz, Judith O.; Webster, Gail H.

    2009-01-01

    General chemistry is a required first step for students who wish to pursue a career in science or health professions. The course often has low rates of student success and as a result serves as a gateway limiting access to science fields. This study seeks to better understand factors that are related to student success in general chemistry by…

  16. 19. VIEW OF THE GENERAL CHEMISTRY LABORATORY IN BUILDING 881. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. VIEW OF THE GENERAL CHEMISTRY LABORATORY IN BUILDING 881. (4/12/62) - Rocky Flats Plant, General Manufacturing, Support, Records-Central Computing, Southern portion of Plant, Golden, Jefferson County, CO

  17. A general strategy for expanding polymerase function by droplet microfluidics

    PubMed Central

    Larsen, Andrew C.; Dunn, Matthew R.; Hatch, Andrew; Sau, Sujay P.; Youngbull, Cody; Chaput, John C.

    2016-01-01

    Polymerases that synthesize artificial genetic polymers hold great promise for advancing future applications in synthetic biology. However, engineering natural polymerases to replicate unnatural genetic polymers is a challenging problem. Here we present droplet-based optical polymerase sorting (DrOPS) as a general strategy for expanding polymerase function that employs an optical sensor to monitor polymerase activity inside the microenvironment of a uniform synthetic compartment generated by microfluidics. We validated this approach by performing a complete cycle of encapsulation, sorting and recovery on a doped library and observed an enrichment of ∼1,200-fold for a model engineered polymerase. We then applied our method to evolve a manganese-independent α-L-threofuranosyl nucleic acid (TNA) polymerase that functions with >99% template-copying fidelity. Based on our findings, we suggest that DrOPS is a versatile tool that could be used to evolve any polymerase function, where optical detection can be achieved by Watson–Crick base pairing. PMID:27044725

  18. A general strategy for expanding polymerase function by droplet microfluidics.

    PubMed

    Larsen, Andrew C; Dunn, Matthew R; Hatch, Andrew; Sau, Sujay P; Youngbull, Cody; Chaput, John C

    2016-04-05

    Polymerases that synthesize artificial genetic polymers hold great promise for advancing future applications in synthetic biology. However, engineering natural polymerases to replicate unnatural genetic polymers is a challenging problem. Here we present droplet-based optical polymerase sorting (DrOPS) as a general strategy for expanding polymerase function that employs an optical sensor to monitor polymerase activity inside the microenvironment of a uniform synthetic compartment generated by microfluidics. We validated this approach by performing a complete cycle of encapsulation, sorting and recovery on a doped library and observed an enrichment of ∼1,200-fold for a model engineered polymerase. We then applied our method to evolve a manganese-independent α-L-threofuranosyl nucleic acid (TNA) polymerase that functions with >99% template-copying fidelity. Based on our findings, we suggest that DrOPS is a versatile tool that could be used to evolve any polymerase function, where optical detection can be achieved by Watson-Crick base pairing.

  19. A phenomenographical study of student learning in general college chemistry

    NASA Astrophysics Data System (ADS)

    Mutch, Helen E.

    The United States is experiencing a severe shortage in technical majors such as engineering, chemistry, and math throughout higher education. It is therefore necessary to take a deeper look at why students are not choosing technical majors, what courses or concepts give students the most difficulty, and what makes them so difficult. One such course is general chemistry. General chemistry is a first year (freshman) course and can act as a filter, in which students who find the material too difficult change their minds on selecting a technical major. The purpose of this study was to better understand students' approaches to learning chemistry. In particular, this study examines a specific concept area called stoichiometry, a notoriously difficult concept in general chemistry. The research question for this study was: What categories can describe students' experiences with learning stoichiometry in a college-level chemistry course? This study used a phenomenographical research design to analyze students' perceptions of general chemistry concepts. Individual interviews were used to better understand thought processes and approaches to learning. In particular, this study focused on eight general chemistry students and their understanding of stoichiometry. The students, selected from a small four-year college in Maryland, were enrolled in a general college chemistry course within six months of the interviews. Students were asked general questions about how they approach learning in chemistry as well as very specific questions about their understanding of stoichiometry. This study distinguished between deep and surface learning approaches amongst the participants as they understand stoichiometry. The results of this study explain the difficulty students have with stoichiometry and also identify misconceptions the students have concerning chemistry.

  20. Comparing Recent Organizing Templates for Test Content between ACS Exams in General Chemistry and AP Chemistry

    ERIC Educational Resources Information Center

    Holme, Thomas

    2014-01-01

    Two different versions of "big ideas" rooted content maps have recently been published for general chemistry. As embodied in the content outline from the College Board, one of these maps is designed to guide curriculum development and testing for advanced placement (AP) chemistry. The Anchoring Concepts Content Map for general chemistry…

  1. Commentary: Reforming the General Chemistry Textbook

    NASA Astrophysics Data System (ADS)

    Gillespie, Ronald G.

    1997-05-01

    Most of use who teach chemistry want students to understand what we teach them. But many students, perhaps most, do not try to understand. Even if they set out trying to understand they usually soon conclude that it is too difficult, at least in the time they have available, and they resort, like the others, to learning the material. By learning they mean memorizingnames of substances, formulas, definitions of oxidation and reduction, shapes of orbitals, recipes for assigning oxidation numbers and doing pH calculations, etc., etc. Most students do not particularly object to doing this because it is what they did in high school and is what it means to study. Many will object to being expected to understand, as they find it easier to memorize and most of them have little understanding of what it means to understand. Surprising as it may seem to us, they see chemistry as very abstract, very difficult, and unrelated to real life. But this is perhaps not so surprising if we remember that for these students, chemistry consists of a large amount of apparently unrelated, irrelevant, and useless material that they have memorized rather than understood! Their main objective is to pass the course and get on to something they consider more interesting and more useful. They take from the course very little of value in other courses or in later life and little, if any, understanding of what chemistry is really aboutmerely a conviction that they will never understand it. Over many years I have noticed that when I meet people socially and reveal that I am a professor of chemistry, they are amazed. How could an otherwise normal-appearing sort of guy possibly understand that stuff? They often admit, somewhat apologetically, that chemistry was their worst subject at high school or university or that it was the most difficult of all the subjects they took. Why do I rarely meet anyone who tells me chemistry was fascinating or exciting, or at least interesting? Why do most students find

  2. Stratospheric General Circulation with Chemistry Model (SGCCM)

    NASA Technical Reports Server (NTRS)

    Rood, Richard B.; Douglass, Anne R.; Geller, Marvin A.; Kaye, Jack A.; Nielsen, J. Eric; Rosenfield, Joan E.; Stolarski, Richard S.

    1990-01-01

    In the past two years constituent transport and chemistry experiments have been performed using both simple single constituent models and more complex reservoir species models. Winds for these experiments have been taken from the data assimilation effort, Stratospheric Data Analysis System (STRATAN).

  3. Hydrated Cations in the General Chemistry Course.

    ERIC Educational Resources Information Center

    Kauffman, George B.; Baxter, John F., Jr.

    1981-01-01

    Presents selected information regarding the descriptive chemistry of the common metal ions and their compounds, including the concepts of process of solution, polar molecules, ionic size and charge, complex ions, coordination number, and the Bronsted-Lowry acid-base theory. (CS)

  4. Using Clinical Cases to Teach General Chemistry

    ERIC Educational Resources Information Center

    Dewprashad, Brahmadeo; Kosky, Charles; Vaz, Geraldine S.; Martin, Charlotte L.

    2004-01-01

    A clinical study was designed and used to show the relationship of health and medicine, in a typical clinical scenario, where many chemical principles are involved and that an integrated knowledge of chemistry and biology is essential to the understanding, diagnosing and treating of illnesses. A case study would be a positive learning experience…

  5. Expanded Choices for Vibration-Rotation Spectroscopy in the Physical Chemistry Teaching Laboratory

    NASA Astrophysics Data System (ADS)

    Schmitz, Joel R.; Dolson, David A.

    2015-06-01

    Many third-year physical chemistry laboratory students in the US analyze the vibration-rotation spectrum of HCl in support of lecture concepts in quantum theory and molecular spectroscopy. Contemporary students in physical chemistry teaching laboratories increasingly have access to FTIR spectrometers with 1/8th wn resolution, which allows for expanded choices of molecules for vibration-rotation spectroscopy. Here we present the case for choosing HBr/DBr for such a study, where the 1/8th wn resolution enables the bromine isotopic lines to be resolved. Vibration-rotation lines from the fundamental and first-overtone bands of four hydrogen bromide isotopomers are combined in a global analysis to determine molecular spectroscopic constants. Sample production, spectral appearance, analysis and results will be presented for various resolutions commonly available in teaching laboratories.

  6. 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…

  7. Service-Learning General Chemistry: Lead Paint Analyses.

    ERIC Educational Resources Information Center

    Kesner, Laya; Eyring, Edward M.

    1999-01-01

    Reports on a community-service project carried out by general chemistry students at the University of Utah. Students research lead poisoning then visit neighborhood homes to teach about lead poisoning, collect exterior paint samples, and analyze them as part of a chemistry experiment. Discusses service-learning and laboratory activities. (WRM)

  8. Connecting Achievement Motivation to Performance in General Chemistry

    ERIC Educational Resources Information Center

    Ferrell, Brent; Phillips, Michael M.; Barbera, Jack

    2016-01-01

    Student success in chemistry is inherently tied to motivational and other affective processes. We investigated three distinct constructs tied to motivation: self-efficacy, interest, and effort beliefs. These variables were measured twice over the course of a semester in three sections of a first-semester general chemistry course (n = 170). We…

  9. Generalized topological spaces in evolutionary theory and combinatorial chemistry.

    PubMed

    Stadler, Bärbel M R; Stadler, Peter F

    2002-01-01

    The search spaces in combinatorial chemistry as well as the sequence spaces underlying (molecular) evolution are conventionally thought of as graphs. Recombination, however, implies a nongraphical structure of the combinatorial search spaces. These structures, and their implications for search process itself, are heretofore not well understood in general. In this contribution we review a very general formalism from point set topology and discuss its application to combinatorial search spaces, fitness landscapes, evolutionary trajectories, and artificial chemistries.

  10. Report of the Polymer Core Course Committee: Polymer Chemistry for Introductory General Chemistry Courses.

    ERIC Educational Resources Information Center

    Carraher, Charles E., Jr.; And Others

    1983-01-01

    Lists polymer chemistry topics and depth of topics to be covered in general chemistry courses. Also lists topics using polymers as tools for delivering necessary concepts, discussing 11 topic areas. List of readings, information on textbook evaluation, and illustrative examination questions are included. (JN)

  11. 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.…

  12. General Chemistry Students' Understanding of Climate Change and the Chemistry Related to Climate Change

    ERIC Educational Resources Information Center

    Versprille, Ashley N.; Towns, Marcy H.

    2015-01-01

    While much is known about secondary students' perspectives of climate change, rather less is known about undergraduate students' perspectives. The purpose of this study is to investigate general chemistry students' understanding of the chemistry underlying climate change. Findings that emerged from the analysis of the 24 interviews indicate that…

  13. Using Computational Chemistry Activities to Promote Learning and Retention in a Secondary School General Chemistry Setting

    ERIC Educational Resources Information Center

    Ochterski, Joseph W.

    2014-01-01

    This article describes the results of using state-of-the-art, research-quality software as a learning tool in a general chemistry secondary school classroom setting. I present three activities designed to introduce fundamental chemical concepts regarding molecular shape and atomic orbitals to students with little background in chemistry, such as…

  14. 18. VIEW OF THE GENERAL CHEMISTRY LAB. THE LABORATORY PROVIDED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. VIEW OF THE GENERAL CHEMISTRY LAB. THE LABORATORY PROVIDED GENERAL ANALYTICAL AND STANDARDS CALIBRATION, AS WELL AS DEVELOPMENT OPERATIONS INCLUDING WASTE TECHNOLOGY DEVELOPMENT AND DEVELOPMENT AND TESTING OF MECHANICAL SYSTEMS FOR WEAPONS SYSTEMS. (4/4/66) - Rocky Flats Plant, General Manufacturing, Support, Records-Central Computing, Southern portion of Plant, Golden, Jefferson County, CO

  15. Expandable-graphite-derived graphene for next-generation battery chemistries

    NASA Astrophysics Data System (ADS)

    Zu, Chenxi; Li, Longjun; Qie, Long; Manthiram, Arumugam

    2015-06-01

    Lithium-sulfur and lithium-air batteries offer theoretical energy densities an order of magnitude higher than that of current lithium-ion batteries and are considered as promising candidates as the next-generation battery chemistries. For an efficient use of these new battery chemistries, careful selection of suitable electrode materials/structures is critical. Graphene, a unique two-dimensional nanomaterial, with its superior electronic conductivity, mechanical strength, and flexibility has been successfully applied in battery studies. Graphene, even with imperfect layers, will be of great interest to battery industrial applications if the manufacturing cost is reduced. Herein, we demonstrate the application of low-cost graphene sponge/sheets derived from expandable graphite in both lithium-sulfur and hybrid lithium-air batteries, respectively, as a cathode conductive matrix to accommodate the soluble polysulfides and as a catalyst for the oxygen reduction reaction. High utilization of active materials and good cycling stability are realized in lithium-sulfur and hybrid lithium-air batteries by employing this low-cost material, demonstrating its promise for use in next-generation battery chemistries.

  16. Astrochemistry: An Honors Approach to General Chemistry

    NASA Astrophysics Data System (ADS)

    Montgomery, M. M.; McClinton, D.

    2004-05-01

    Astrochemistry at the collegiate level offers gifted and high achieving students at the secondary education level to explore careers in science and math. This program reinforces the foundation of scientific instruction, yet provides for advanced specialized learning for the college-bound gifted student. Students examine basic chemical theories and their connections with the applications of physics to astronomy. In this program, students meet individuals in related career fields and tour local companies that use high technology. We present our program design that is funded by the Florida Department of Education, Govenor's Summer Program 2004. We also present our alternative teaching strategies including examples of our computer tutorials and our incorporation of the Process Oriented Guided Inquiry Learning (POGIL) approach, a newly funded NSF project that focuses on national dissemination of POGIL methods and materials. We present our reflection methods of student evaluations that are not related to grades. This program can be modified to offer college students a four-credit basic chemistry class, but with application to astronomy and physics.

  17. A generalized chemistry version of SPARK

    NASA Technical Reports Server (NTRS)

    Carpenter, Mark H.

    1988-01-01

    An extension of the reacting H2-air computer code SPARK is presented, which enables the code to be used on any reacting flow problem. Routines are developed calculating in a general fashion, the reaction rates, and chemical Jacobians of any reacting system. In addition, an equilibrium routine is added so that the code will have frozen, finite rate, and equilibrium capabilities. The reaction rate for the species is determined from the law of mass action using Arrhenius expressions for the rate constants. The Jacobian routines are determined by numerically or analytically differentiating the law of mass action for each species. The equilibrium routine is based on a Gibbs free energy minimization routine. The routines are written in FORTRAN 77, with special consideration given to vectorization. Run times for the generalized routines are generally 20 percent slower than reaction specific routines. The numerical efficiency of the generalized analytical Jacobian, however, is nearly 300 percent better than the reaction specific numerical Jacobian used in SPARK.

  18. Expanding Radical SAM Chemistry by Using Radical Addition Reactions and SAM Analogues.

    PubMed

    Ji, Xinjian; Li, Yongzhen; Xie, Liqi; Lu, Haojie; Ding, Wei; Zhang, Qi

    2016-09-19

    Radical S-adenosyl-l-methionine (SAM) enzymes utilize a [4Fe-4S] cluster to bind SAM and reductively cleave its carbon-sulfur bond to produce a highly reactive 5'-deoxyadenosyl (dAdo) radical. In almost all cases, the dAdo radical abstracts a hydrogen atom from the substrates or from enzymes, thereby initiating a highly diverse array of reactions. Herein, we report a change of the dAdo radical-based chemistry from hydrogen abstraction to radical addition in the reaction of the radical SAM enzyme NosL. This change was achieved by using a substrate analogue containing an olefin moiety. We also showed that two SAM analogues containing different nucleoside functionalities initiate the radical-based reactions with high efficiencies. The radical adduct with the olefin produced in the reaction was found to undergo two divergent reactions, and the mechanistic insights into this process were investigated in detail. Our study demonstrates a promising strategy in expanding radical SAM chemistry, providing an effective way to access nucleoside-containing compounds by using radical SAM-dependent reactions.

  19. LOGICAL REASONING ABILITY AND STUDENT PERFORMANCE IN GENERAL CHEMISTRY

    PubMed Central

    Bird, Lillian

    2010-01-01

    Logical reasoning skills of students enrolled in General Chemistry at the University of Puerto Rico in Río Piedras were measured using the Group Assessment of Logical Thinking (GALT) test. The results were used to determine the students’ cognitive level (concrete, transitional, formal) as well as their level of performance by logical reasoning mode (mass/volume conservation, proportional reasoning, correlational reasoning, experimental variable control, probabilistic reasoning and combinatorial reasoning). This information was used to identify particular deficiencies and gender effects, and to determine which logical reasoning modes were the best predictors of student performance in the general chemistry course. Statistical tests to analyze the relation between (a) operational level and final grade in both semesters of the course; (b) GALT test results and performance in the ACS General Chemistry Examination; and (c) operational level and student approach (algorithmic or conceptual) towards a test question that may be answered correctly using either strategy, were also performed. PMID:21373364

  20. LOGICAL REASONING ABILITY AND STUDENT PERFORMANCE IN GENERAL CHEMISTRY.

    PubMed

    Bird, Lillian

    2010-03-01

    Logical reasoning skills of students enrolled in General Chemistry at the University of Puerto Rico in Río Piedras were measured using the Group Assessment of Logical Thinking (GALT) test. The results were used to determine the students' cognitive level (concrete, transitional, formal) as well as their level of performance by logical reasoning mode (mass/volume conservation, proportional reasoning, correlational reasoning, experimental variable control, probabilistic reasoning and combinatorial reasoning). This information was used to identify particular deficiencies and gender effects, and to determine which logical reasoning modes were the best predictors of student performance in the general chemistry course. Statistical tests to analyze the relation between (a) operational level and final grade in both semesters of the course; (b) GALT test results and performance in the ACS General Chemistry Examination; and (c) operational level and student approach (algorithmic or conceptual) towards a test question that may be answered correctly using either strategy, were also performed.

  1. Expanding perfect fluid generalizations of the C metric

    SciTech Connect

    Wylleman, Lode; Beke, David

    2010-05-15

    Petrov type D gravitational fields, generated by a perfect fluid with spatially homogeneous energy density and with flow lines which form a nonshearing and nonrotating timelike congruence, are reexamined. It turns out that the anisotropic such spacetimes, which comprise the vacuum C metric as a limit case, can have nonzero expansion, contrary to the conclusion in the original investigation by Barnes [A. Barnes, Gen. Relativ. Gravit. 4, 105 (1973).]. Apart from the static members, this class consists of cosmological models with precisely one symmetry. The general line element is constructed and some important properties are discussed. It is also shown that purely electric Petrov type D vacuum spacetimes admit shear-free normal timelike congruences everywhere, even in the nonstatic regions. This result incited to deduce intrinsic, easily testable criteria regarding shear-free normality and staticity of Petrov type D spacetimes in general, which are added in an appendix.

  2. Expanding access to rheumatology care: the rheumatology general practice toolbox.

    PubMed

    Conway, R; Kavanagh, R; Coughlan, R J; Carey, J J

    2015-02-01

    Management guidelines for many rheumatic diseases are published in specialty rheumatology literature but rarely in general medical journals. Musculoskeletal disorders comprise 14% of all consultations in primary care. Formal post-graduate training in rheumatology is limited or absent for many primary care practitioners. Primary care practitioners can be trained to effectively treat complex diseases and have expressed a preference for interactive educational courses. The Rheumatology General Practice (GP) Toolbox is an intensive one day course designed to offer up to date information to primary care practitioners on the latest diagnostic and treatment guidelines for seven common rheumatic diseases. The course structure involves a short lecture on each topic and workshops on arthrocentesis, joint injection and DXA interpretation. Participants evaluated their knowledge and educational experience before, during and after the course. Thirty-two primary care practitioners attended, who had a median of 13 (IQR 6.5, 20) years experience in their specialty. The median number of educational symposia attended in the previous 5 years was 10 (IQR-5, 22.5), with a median of 0 (IQR 0, 1) in rheumatology. All respondents agreed that the course format was appropriate. Numerical improvements were demonstrated in participant's confidence in diagnosing and managing all seven common rheumatologic conditions, with statistically significant improvements (p < 0.05) in 11 of the 14 aspects assessed. The Rheumatology Toolbox is an effective educational method for disseminating current knowledge in rheumatology to primary care physicians and improved participant's self-assessed competence in diagnosis and management of common rheumatic diseases.

  3. One Instructor's Approach to Computer Assisted Instruction in General Chemistry.

    ERIC Educational Resources Information Center

    DeLorenzo, Ronald

    1982-01-01

    Discusses advantages of using computer-assisted instruction in a college general chemistry course. Advantages include using programs which generate random equations with double arrows (equilibrium systems) or generate alkane structural formula, asking for the correct IUPAC name of the structure. (Author/JN)

  4. Logical Reasoning Ability and Student Performance in General Chemistry

    ERIC Educational Resources Information Center

    Bird, Lillian

    2010-01-01

    Logical reasoning skills of students enrolled in a general chemistry course at the University of Puerto Rico in Rio Piedras were measured using the Group Assessment of Logical Thinking (GALT) test. The results were used to determine the students' cognitive level (concrete, transitional, formal) as well as their level of performance by logical…

  5. A General Chemistry Laboratory Course Designed for Student Discussion

    ERIC Educational Resources Information Center

    Obenland, Carrie A.; Kincaid, Kristi; Hutchinson, John S.

    2014-01-01

    We report a study of the general chemistry laboratory course at one university over four years. We found that when taught as a traditional laboratory course, lab experiences do not encourage students to deepen their understanding of chemical concepts. Although the lab instructor emphasized that the lab experiences were designed to enhance…

  6. A Novel Multipurpose Model Set for Teaching General Chemistry.

    ERIC Educational Resources Information Center

    Gupta, H. O.; Parkash, Brahm

    1999-01-01

    Reports on a low-cost and unique molecular model set capable of generating a large number of structures for teaching and learning general chemistry. An important component of the kit is an 11-hole ball that gives tetrahedral, octahedral, trigonal, trigonal bipyramidal, and square planar symmetries. (WRM)

  7. Presentation of Atomic Structure in Turkish General Chemistry Textbooks

    ERIC Educational Resources Information Center

    Niaz, Mansoor; Costu, Bayram

    2009-01-01

    Research in science education has recognized the importance of teaching atomic structure within a history and philosophy of science perspective. The objective of this study is to evaluate general chemistry textbooks published in Turkey based on the eight criteria developed in previous research. Criteria used referred to the atomic models of…

  8. Gendered Responses to Online Homework Use in General Chemistry

    ERIC Educational Resources Information Center

    Richards-Babb, Michelle; Jackson, Jennifer Kasi

    2011-01-01

    Online homework assignments have been shown to enhance student performance. Our research on gendered responses to these assignments adds new and useful information. We investigated differences between male and female students' responses to online homework in large-enrollment general chemistry courses. Replacing in class quizzes with online…

  9. A Program of Computational Chemistry Exercises for the First-Semester General Chemistry Course

    ERIC Educational Resources Information Center

    Feller, Scott E.; Dallinger, Richard F.; McKinney, Paul Caylor

    2004-01-01

    The computer systems available for molecular modeling are described, along with a discussion of a molecular modeling program created and supported by computational techniques for the first-semester general chemistry course. Various exercises are listed, which direct the learner from a beginner's course in software practice to more complex…

  10. Integrating the Liberal Arts and Chemistry: A Series of General Chemistry Assignments to Develop Science Literacy

    ERIC Educational Resources Information Center

    Miller, Diane M.; Chengelis Czegan, Demetra A.

    2016-01-01

    This paper describes assignments that have been implemented in a General Chemistry I course to promote science literacy. This course was chosen in particular because it reaches a broad audience, which includes nonscience majors. The assignment series begins with several discussions and tasks to develop information literacy, in which students find…

  11. Tropospheric ozone simulation with a chemistry-general circulation model: Influence of higher hydrocarbon chemistry

    NASA Astrophysics Data System (ADS)

    Roelofs, Geert-Jan; Lelieveld, Jos

    2000-09-01

    We present an improved version of the global chemistry-general circulation model of Roelofs and Lelieveld [1997]. The major model improvement is the representation of higher hydrocarbon chemistry, implemented by means of the Carbon Bond Mechanism 4 (CBM-4). Simulated tropospheric ozone concentrations at remote locations, which agreed well with observations in the previous model version, are not affected much by the chemistry of higher hydrocarbons. However, ozone formation in the polluted boundary layer is significantly enhanced, resulting in a more realistic simulation of surface ozone in regions such as North America, Europe, and Southeast Asia. Our model simulates a net global tropospheric ozone production of 73 Tg yr-1 when higher hydrocarbon chemistry is considered, and -36 Tg yr-1 without higher hydrocarbon chemistry. The simulated seasonality of surface CO agrees well with observations. However, the southern hemispheric maximum for O3 and CO associated with biomass burning emissions is delayed by 1 month compared to the observations, which demonstrates the need for a better representation of biomass burning emissions. Simulated peroxyacetyl nitrate (PAN) concentrations agree well with observed values, although the variability is underestimated. OH decreases strongly in the continental boundary layer due to its reaction with higher hydrocarbons. However, this is almost compensated by an increase of OH over oceans in the lower half of the troposphere. Consideration of higher hydrocarbon chemistry decreases the global annual tropospheric OH concentration by about 8% compared to a background tropospheric chemistry scheme. Further, the radiative forcing by anthropogenically increased tropospheric ozone on the northern hemisphere increases, especially in July. The forcing also increases on the southern hemisphere where biomass burning emissions produce tropospheric ozone, except between December and June, that is, outside the biomass burning season, when ozone

  12. Supramolecular chemistry-general principles and selected examples from anion recognition and metallosupramolecular chemistry.

    PubMed

    Albrecht, Markus

    2007-12-01

    This review gives an introduction into supramolecular chemistry describing in the first part general principles, focusing on terms like noncovalent interaction, molecular recognition, self-assembly, and supramolecular function. In the second part those will be illustrated by simple examples from our laboratories. Supramolecular chemistry is the science that bridges the gap between the world of molecules and nanotechnology. In supramolecular chemistry noncovalent interactions occur between molecular building blocks, which by molecular recognition and self-assembly form (functional) supramolecular entities. It is also termed the "chemistry of the noncovalent bond." Molecular recognition is based on geometrical complementarity based on the "key-and-lock" principle with nonshape-dependent effects, e.g., solvatization, being also highly influential. Self-assembly leads to the formation of well-defined aggregates. Hereby the overall structure of the target ensemble is controlled by the symmetry features of the certain building blocks. Finally, the aggregates can possess special properties or supramolecular functions, which are only found in the ensemble but not in the participating molecules. This review gives an introduction on supramolecular chemistry and illustrates the fundamental principles by recent examples from our group.

  13. General conditions for scale-invariant perturbations in an expanding universe

    SciTech Connect

    Geshnizjani, Ghazal; Kinney, William H.; Dizgah, Azadeh Moradinezhad E-mail: whkinney@buffalo.edu

    2011-11-01

    We investigate the general properties of expanding cosmological models which generate scale-invariant curvature perturbations in the presence of a variable speed of sound. We show that in an expanding universe, generation of a super-Hubble, nearly scale-invariant spectrum of perturbations over a range of wavelengths consistent with observation requires at least one of three conditions: (1) accelerating expansion, (2) a speed of sound faster than the speed of light, or (3) super-Planckian energy density.

  14. General Chemistry Courses That Can Affect Achievement: An Action Research Study in Developing a Plan to Improve Undergraduate Chemistry Courses

    ERIC Educational Resources Information Center

    Shweikeh, Eman

    2014-01-01

    Over the past 50 years, considerable research has been dedicated to chemistry education. In evaluating principal chemistry courses in higher education, educators have noted the learning process for first-year general chemistry courses may be challenging. The current study investigated perceptions of faculty, students and administrators on…

  15. Bias Assessment of General Chemistry Analytes using Commutable Samples

    PubMed Central

    Koerbin, Gus; Tate, Jillian R; Ryan, Julie; Jones, Graham RD; Sikaris, Ken A; Kanowski, David; Reed, Maxine; Gill, Janice; Koumantakis, George; Yen, Tina; St John, Andrew; Hickman, Peter E; Simpson, Aaron; Graham, Peter

    2014-01-01

    Harmonisation of reference intervals for routine general chemistry analytes has been a goal for many years. Analytical bias may prevent this harmonisation. To determine if analytical bias is present when comparing methods, the use of commutable samples, or samples that have the same properties as the clinical samples routinely analysed, should be used as reference samples to eliminate the possibility of matrix effect. The use of commutable samples has improved the identification of unacceptable analytical performance in the Netherlands and Spain. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) has undertaken a pilot study using commutable samples in an attempt to determine not only country specific reference intervals but to make them comparable between countries. Australia and New Zealand, through the Australasian Association of Clinical Biochemists (AACB), have also undertaken an assessment of analytical bias using commutable samples and determined that of the 27 general chemistry analytes studied, 19 showed sufficiently small between method biases as to not prevent harmonisation of reference intervals. Application of evidence based approaches including the determination of analytical bias using commutable material is necessary when seeking to harmonise reference intervals. PMID:25678726

  16. A General Chemistry Laboratory Theme: Spectroscopic Analysis of Aspirin

    NASA Astrophysics Data System (ADS)

    Byrd, Houston; O'Donnell, Stephen E.

    2003-02-01

    In this paper, we describe the introduction of spectroscopy into the general chemistry laboratory using a series of experiments based on a common substance, aspirin. In the first lab the students synthesize and recrystallize aspirin and take melting points of their product, an aspirin standard, and salicylic acid. The students perform the remaining experiments on a rotating basis where the following four labs run simultaneously: structural characterization of the synthesized aspirin by IR and NMR; analysis of synthesized aspirin and commercial products by UV vis spectroscopy; analysis of synthesized aspirin and commercial products by HPLC; and analysis of calcium in commercial buffered aspirin tablets by AAS. In each of the analysis experiments, students collect, graph, and analyze their data using a spreadsheet. We have found that this series of labs has been very beneficial to our students. From the course evaluations, students indicate that they are beginning to understand how chemistry is applied outside of the classroom.

  17. Chemistry, Life, the Universe, and Everything: A New Approach to General Chemistry, and a Model for Curriculum Reform

    ERIC Educational Resources Information Center

    Cooper, Melanie; Klymkowsky, Michael

    2013-01-01

    The history of general chemistry is one of almost constant calls for reform, yet over the past 60 years little of substance has changed. Those reforms that have been implemented are almost entirely concerned with how the course is taught, rather than what is to be learned. Here we briefly discuss the history of the general chemistry curriculum and…

  18. Impact of General Chemistry on Student Achievement and Progression to Subsequent Chemistry Courses: A Regression Discontinuity Analysis

    ERIC Educational Resources Information Center

    Shultz, Ginger V.; Gottfried, Amy C.; Winschel, Grace A.

    2015-01-01

    General chemistry is a gateway course that impacts the STEM trajectory of tens of thousands of students each year, and its role in the introductory curriculum as well as its pedagogical design are the center of an ongoing debate. To investigate the role of general chemistry in the curriculum, we report the results of a posthoc analysis of 10 years…

  19. Learning beyond the Classroom: Using Text Messages to Measure General Chemistry Students' Study Habits

    ERIC Educational Resources Information Center

    Ye, Li; Oueini, Razanne; Dickerson, Austin P.; Lewis, Scott E.

    2015-01-01

    This study used a series of text message inquiries sent to General Chemistry students asking: "Have you studied for General Chemistry I in the past 48 hours? If so, how did you study?" This method for collecting data is novel to chemistry education research so the first research goals were to investigate the feasibility of the technique…

  20. A Closer Look at Phase Diagrams for the General Chemistry Course.

    ERIC Educational Resources Information Center

    Gramsch, Stephen A.

    2000-01-01

    Information concerning structural chemistry and phase equilibria contained in the full phase diagrams of common substances is a great deal richer than the general chemistry students are given to believe. Discusses ways of enriching the traditional presentation of phase diagrams in general chemistry courses. (Contains over 20 references.) (WRM)

  1. General chemistry courses that can affect achievement: An action research study in developing a plan to improve undergraduate chemistry courses

    NASA Astrophysics Data System (ADS)

    Shweikeh, Eman

    Over the past 50 years, considerable research has been dedicated to chemistry education. In evaluating principal chemistry courses in higher education, educators have noted the learning process for first-year general chemistry courses may be challenging. The current study investigated perceptions of faculty, students and administrators on chemistry education at three institutions in Southern California. Via action research, the study sought to develop a plan to improve student engagement in general chemistry courses. A mixed method was utilized to analyze different perceptions on key factors determining the level of commitment and engagement in general chemistry education. The approach to chemistry learning from both a faculty and student perspective was examined including good practices, experiences and extent of active participation. The research study considered well-known measures of effective education with an emphasis on two key components: educational practices and student behavior. Institutional culture was inclusively assessed where cognitive expectations of chemistry teaching and learning were communicated. First, the extent in which faculty members are utilizing the "Seven Principles for Good Practice in Undergraduate Education" in their instruction was explored. Second, student attitudes and approaches toward chemistry learning were examined. The focus was on investigating student understanding of the learning process and the structure of chemistry knowledge. The seven categories used to measure students' expectations for learning chemistry were: effort, concepts, math link, reality link, outcome, laboratory, and visualization. This analysis represents the views of 16 faculty and 140 students. The results validated the assertion that students need some competencies and skills to tackle the challenges of the chemistry learning process to deeply engage in learning. A mismatch exists between the expectations of students and those of the faculty

  2. Integrating Multiple Teaching Methods into a General Chemistry Classroom

    NASA Astrophysics Data System (ADS)

    Francisco, Joseph S.; Nicoll, Gayle; Trautmann, Marcella

    1998-02-01

    In addition to the traditional lecture format, three other teaching strategies (class discussions, concept maps, and cooperative learning) were incorporated into a freshman level general chemistry course. Student perceptions of their involvement in each of the teaching methods, as well as their perceptions of the utility of each method were used to assess the effectiveness of the integration of the teaching strategies as received by the students. Results suggest that each strategy serves a unique purpose for the students and increased student involvement in the course. These results indicate that the multiple teaching strategies were well received by the students and that all teaching strategies are necessary for students to get the most out of the course.

  3. Expanding the coordination chemistry of donor-stabilized group-14 metalenes.

    PubMed

    Cabeza, Javier A; García-Álvarez, Pablo; Polo, Diego

    2013-02-07

    The transformation of an amidinate germylene, equipped with just one accessible lone pair of electrons on the Ge atom, into a bidentate 4-electron donor κ(2)Ge,N-ligand, has been achieved for the first time, opening new doors to the non-carbene-like coordination chemistry of heavier carbene analogues.

  4. Exploring Dominant Types of Explanations Built by General Chemistry Students

    NASA Astrophysics Data System (ADS)

    Talanquer, Vicente

    2010-12-01

    The central goal of our study was to explore the nature of the explanations generated by science and engineering majors with basic training in chemistry to account for the colligative properties of solutions. The work was motivated by our broader interest in the characterisation of the dominant types of explanations that science college students use to make sense of phenomena under conditions of limited time and limited explicit knowledge about a topic. Explanations were collected in written form using two different quizzes that students completed under time constraints at the end of a two-semester general chemistry course. Our study revealed that students' ability to generate causal/mechanical explanations depended on the nature of the task. In general, students were more inclined or able to generate mechanistic explanations to account for boiling-point elevation and freezing-point depression than to make sense of osmotic flow. The analysis of the types of causal explanations built by the study participants suggests that students may be biased towards some causal models or explanatory modes characterised as causal-additive and causal-static in our work. A large proportion of the students built non-causal teleological explanations to account for osmotic flow. None of the participants in our study used a dynamic model of matter as the basis for their explanations of any of the relevant phenomena; the idea of an underlying random process that is taking place at all times giving rise to emergent properties and behaviours was completely absent from their intuitive reasoning under conditions of limited time and knowledge.

  5. Experimental and modeling studies of small molecule chemistry in expanding spherical flames

    NASA Astrophysics Data System (ADS)

    Santner, Jeffrey

    Accurate models of flame chemistry are required in order to predict emissions and flame properties, such that clean, efficient engines can be designed more easily. There are three primary methods used to improve such combustion chemistry models - theoretical reaction rate calculations, elementary reaction rate experiments, and combustion system experiments. This work contributes to model improvement through the third method - measurements and analysis of the laminar burning velocity at constraining conditions. Modern combustion systems operate at high pressure with strong exhaust gas dilution in order to improve efficiency and reduce emissions. Additionally, flames under these conditions are sensitized to elementary reaction rates such that measurements constrain modeling efforts. Measurement conditions of the present work operate within this intersection between applications and fundamental science. Experiments utilize a new pressure-release, heated spherical combustion chamber with a variety of fuels (high hydrogen content fuels, formaldehyde (via 1,3,5-trioxane), and C2 fuels) at pressures from 0.5--25 atm, often with dilution by water vapor or carbon dioxide to flame temperatures below 2000 K. The constraining ability of these measurements depends on their uncertainty. Thus, the present work includes a novel analytical estimate of the effects of thermal radiative heat loss on burning velocity measurements in spherical flames. For 1,3,5-trioxane experiments, global measurements are sufficiently sensitive to elementary reaction rates that optimization techniques are employed to indirectly measure the reaction rates of HCO consumption. Besides the influence of flame chemistry on propagation, this work also explores the chemistry involved in production of nitric oxide, a harmful pollutant, within flames. We find significant differences among available chemistry models, both in mechanistic structure and quantitative reaction rates. There is a lack of well

  6. A New Approach to the General Chemistry Laboratory

    NASA Astrophysics Data System (ADS)

    Bieron, Joseph F.; McCarthy, Paul J.; Kermis, Thomas W.

    1996-11-01

    Background Canisius College is a medium-sized liberal arts college with a longstanding tradition of maintaining an excellent chemistry program. We realized a few years ago, however, that this tradition was not being sustained by our General Chemistry laboratory course, which had not changed significantly in years. With the help of a grant from the National Science Foundation, our department has been able to design a new laboratory course built around several guiding principles. The design called for experiments to be grouped in units or clusters. Each cluster has a unifying theme or common thread, which gives some coherence to the experiments. The clusters and experiments are listed in the appendix and briefly explained below. Course Design Cluster A's topic is organic and polymer chemistry, and its main objective is to show that chemistry can be enjoyable and relevant to common experiences. Data collection is minimal and hands-on manipulation with observable products is emphasized. Cluster B is a case study of the chemistry of maintaining a swimming pool. The common theme is solution chemistry, and the experiments are designed to promote critical thinking. Cluster C encompasses both oxidation - reduction reactions and electrochemistry, and attempts to show the commonality of these important topics. Cluster D is a series of experiments on methods and techniques of analytical chemistry; in this group the analysis of unknown materials is undertaken. Cluster E is covered last in the second semester, and it stresses important concepts in chemistry at a slightly more advanced level. The emphasis is on the relationship of experiment to theory, and the cluster involves experiments in kinetics, equilibrium, and synthesis. Other guidelines that we considered important in our design were the use of computers (when appropriate), the introduction of microscale chemistry, and the use of instrumentation whenever possible. A separate cluster, labeled Mac, was developed to provide

  7. First 25-hydroxyvitamin D assay for general chemistry analyzers.

    PubMed

    Saida, Fakhri B; Chen, Xiaoru; Tran, Kiet; Dou, Chao; Yuan, Chong

    2015-03-01

    25-Hydroxyvitamin D [25(OH)D], the predominant circulating form of vitamin D, is an accurate indicator of the general vitamin D status of an individual. Because vitamin D deficiencies have been linked to several pathologies (including osteoporosis and rickets), accurate monitoring of 25(OH)D levels is becoming increasingly important in clinical settings. Current 25(OH)D assays are either chromatographic or immunoassay-based assays. These assays include HPLC, liquid chromatography-tandem mass spectrometry (LC-MS/MS), enzyme-immunosorbent, immunochemiluminescence, immunofluorescence and radioimmunoassay. All these assays use heterogeneous formats that require phase separation and special instrumentations. In this article, we present an overview of these assays and introduce the first homogeneous assay of 25(OH)D for use on general chemistry analyzers. A special emphasis is put on the unique challenges posed by the 25(OH)D analyte. These challenges include a low detection limit, the dissociation of the analyte from its serum transporter and the inactivation of various binding proteins without phase separation steps.

  8. 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…

  9. The Effects of Clickers and Online Homework on Students' Achievement in General Chemistry

    ERIC Educational Resources Information Center

    Gebru, Misganaw T.

    2012-01-01

    Retention of an introductory general chemistry course material is vital for student success in future chemistry and chemistry-related courses. This study investigated the effects of clickers versus online homework on students' long-term content retention, examined the effectiveness of online homework versus no graded homework on…

  10. Evaluation of Eleventh Grade Turkish Pupils' Comprehension of General Chemistry Concepts

    ERIC Educational Resources Information Center

    Belge Can, Hatice; Boz, Yezdan

    2011-01-01

    The main purpose of this study is to evaluate eleventh grade Turkish pupils' comprehension of various general chemistry concepts which in turn enables to investigate chemistry concepts which are easier and harder for students to comprehend. Examining the effect of gender and last semester chemistry course grades on pupils' comprehension of general…

  11. Oxidation of a biomarker for phenol carcinogen exposure: expanding the redox chemistry of 2'-deoxyguanosine.

    PubMed

    Weishar, Jennifer L; McLaughlin, Christopher K; Baker, Michael; Gabryelski, Wojciech; Manderville, Richard A

    2008-05-01

    A biomarker for phenolic carcinogen exposure, 8-(4''-hydroxyphenyl)-2'-deoxyguanosine, has been found to undergo oxidative coupling in the presence of Na2IrCl6 to afford ortho-ortho C-C-coupled polyphenols through the intermediacy of a phenoxyl radical. One can envision using such unique chemistry to oxidatively couple strands of DNA for the generation of new biomaterials. Our results also demonstrate the potential for phenolic adducts of DNA to undergo further oxidation reactions that may contribute to phenol-mediated cytotoxicity and genotoxicity.

  12. Cosmological Relativity: A General-Relativistic Theory for the Accelerating Expanding Universe

    NASA Astrophysics Data System (ADS)

    Carmeli, M.; Behar, S.

    Recent observations of distant supernovae imply, in defiance of expectations, that the universe growth is accelerating, contrary to what has always been assumed that the expansion is slowing down due to gravity. In this paper a general-relativistic cosmological theory that gives a direct relationship between distances and redshifts in an expanding universe is presented. The theory is actually a generalization of Hubble's law taking gravity into account by means of Einstein's theory of general relativity. The theory predicts that the universe can have three phases of expansion, decelerating, constant and accelerating, but it is shown that at present the first two cases are excluded, although in the past it had experienced them. Our theory shows that the universe now is definitely in the stage of accelerating expansion, confirming the recent experimental results.

  13. Sulfobetaine-Vinylimidazole Block Copolymers: A Robust Quantum Dot Surface Chemistry Expanding Bioimaging's Horizons.

    PubMed

    Tasso, Mariana; Giovanelli, Emerson; Zala, Diana; Bouccara, Sophie; Fragola, Alexandra; Hanafi, Mohamed; Lenkei, Zsolt; Pons, Thomas; Lequeux, Nicolas

    2015-11-24

    Long-term inspection of biological phenomena requires probes of elevated intra- and extracellular stability and target biospecificity. The high fluorescence and photostability of quantum dot (QD) nanoparticles contributed to foster their promise as bioimaging tools that could overcome limitations associated with traditional fluorophores. However, QDs' potential as a bioimaging platform relies upon a precise control over the surface chemistry modifications of these nano-objects. Here, a zwitterion-vinylimidazole block copolymer ligand was synthesized, which regroups all anchoring groups in one compact terminal block, while the rest of the chain is endowed with antifouling and bioconjugation moieties. By further application of an oriented bioconjugation approach with whole IgG antibodies, QD nanobioconjugates were obtained that display outstanding intra- and extracellular stability as well as biorecognition capacity. Imaging the internalization and intracellular dynamics of a transmembrane cell receptor, the CB1 brain cannabinoid receptor, both in HEK293 cells and in neurons, illustrates the breadth of potential applications of these nanoprobes.

  14. Expanding the fluorine chemistry of living systems using engineered polyketide synthase pathways

    PubMed Central

    Walker, Mark C.; Thuronyi, Benjamin W.; Charkoudian, Louise K.; Lowry, Brian; Khosla, Chaitan; Chang, Michelle C. Y.

    2014-01-01

    Organofluorines represent a rapidly expanding proportion of molecules used in pharmaceuticals, diagnostics, agrochemicals, and materials. Despite the prevalence of fluorine in synthetic compounds, the known biological scope is limited to a single pathway that produces fluoroacetate. Here, we demonstrate that this pathway can be exploited as a source of fluorinated building blocks for introduction of fluorine into natural product scaffolds. Specifically, we have constructed pathways involving two polyketide synthase systems and show that fluoroacetate can be used to incorporate fluorine into the polyketide backbone in vitro. We further show that fluorine can be introduced site-selectively and introduced into polyketide products in vivo. These results highlight the prospects for the production of complex fluorinated natural products using synthetic biology. PMID:24009388

  15. Chemical Remediation of Nickel(II) Waste: A Laboratory Experiment for General Chemistry Students

    ERIC Educational Resources Information Center

    Corcoran, K. Blake; Rood, Brian E.; Trogden, Bridget G.

    2011-01-01

    This project involved developing a method to remediate large quantities of aqueous waste from a general chemistry laboratory experiment. Aqueous Ni(II) waste from a general chemistry laboratory experiment was converted into solid nickel hydroxide hydrate with a substantial decrease in waste volume. The remediation method was developed for a…

  16. Predicting Inorganic Reaction Products: A Critical Thinking Exercise in General Chemistry

    ERIC Educational Resources Information Center

    DeWit, David G.

    2006-01-01

    A course module in general chemistry focusing on predicting the products of simple inorganic reactions is described. This component of the course is intended to be presented near the end of the last term of the general chemistry sequence and is designed to afford practice in applying the variety of principles encountered throughout the general…

  17. A Transition Program for Underprepared Students in General Chemistry: Diagnosis, Implementation, and Evaluation

    ERIC Educational Resources Information Center

    Shields, Shawn P.; Hogrebe, Mark C.; Spees, William M.; Handlin, Larry B.; Noelken, Greg P.; Riley, Julie M.; Frey, Regina F.

    2012-01-01

    We developed an online exam to diagnose students who are underprepared for college-level general chemistry and implemented a program to support them during the general chemistry sequence. This transition program consists of extended-length recitations, peer-led team-learning (PLTL) study groups, and peer-mentoring groups. We evaluated this…

  18. Building a Database for the Historical Analysis of the General Chemistry Curriculum Using ACS General Chemistry Exams as Artifacts

    ERIC Educational Resources Information Center

    Luxford, Cynthia J.; Linenberger, Kimberly J.; Raker, Jeffrey R.; Baluyut, John Y.; Reed, Jessica J.; De Silva, Chamila; Holme, Thomas A.

    2015-01-01

    As a discipline, chemistry enjoys a unique position. While many academic areas prepared "cooperative examinations" in the 1930s, only chemistry maintained the activity within what has become the ACS Examinations Institute. As a result, the long-term existence of community-built, norm-referenced, standardized exams provides a historical…

  19. Oxidative cyclizations in orthosomycin biosynthesis expand the known chemistry of an oxygenase superfamily

    SciTech Connect

    McCulloch, Kathryn M.; McCranie, Emilianne K.; Smith, Jarrod A.; Sarwar, Maruf; Mathieu, Jeannette L.; Gitschlag, Bryan L.; Du, Yu; Bachmann, Brian O.; Iverson, T. M.

    2015-08-03

    Orthosomycins are oligosaccharide antibiotics that include avilamycin, everninomicin, and hygromycin B and are hallmarked by a rigidifying interglycosidic spirocyclic ortho-δ-lactone (orthoester) linkage between at least one pair of carbohydrates. A subset of orthosomycins additionally contain a carbohydrate capped by a methylenedioxy bridge. The orthoester linkage is necessary for antibiotic activity but rarely observed in natural products. Orthoester linkage and methylenedioxy bridge biosynthesis require similar oxidative cyclizations adjacent to a sugar ring. In this paper, we have identified a conserved group of nonheme iron, α-ketoglutarate–dependent oxygenases likely responsible for this chemistry. High-resolution crystal structures of the EvdO1 and EvdO2 oxygenases of everninomicin biosynthesis, the AviO1 oxygenase of avilamycin biosynthesis, and HygX of hygromycin B biosynthesis show how these enzymes accommodate large substrates, a challenge that requires a variation in metal coordination in HygX. Excitingly, the ternary complex of HygX with cosubstrate α-ketoglutarate and putative product hygromycin B identified an orientation of one glycosidic linkage of hygromycin B consistent with metal-catalyzed hydrogen atom abstraction from substrate. These structural results are complemented by gene disruption of the oxygenases evdO1 and evdMO1 from the everninomicin biosynthetic cluster, which demonstrate that functional oxygenase activity is critical for antibiotic production. Finally, our data therefore support a role for these enzymes in the production of key features of the orthosomycin antibiotics.

  20. Oxidative cyclizations in orthosomycin biosynthesis expand the known chemistry of an oxygenase superfamily

    PubMed Central

    McCulloch, Kathryn M.; McCranie, Emilianne K.; Smith, Jarrod A.; Sarwar, Maruf; Mathieu, Jeannette L.; Gitschlag, Bryan L.; Du, Yu; Bachmann, Brian O.; Iverson, T. M.

    2015-01-01

    Orthosomycins are oligosaccharide antibiotics that include avilamycin, everninomicin, and hygromycin B and are hallmarked by a rigidifying interglycosidic spirocyclic ortho-δ-lactone (orthoester) linkage between at least one pair of carbohydrates. A subset of orthosomycins additionally contain a carbohydrate capped by a methylenedioxy bridge. The orthoester linkage is necessary for antibiotic activity but rarely observed in natural products. Orthoester linkage and methylenedioxy bridge biosynthesis require similar oxidative cyclizations adjacent to a sugar ring. We have identified a conserved group of nonheme iron, α-ketoglutarate–dependent oxygenases likely responsible for this chemistry. High-resolution crystal structures of the EvdO1 and EvdO2 oxygenases of everninomicin biosynthesis, the AviO1 oxygenase of avilamycin biosynthesis, and HygX of hygromycin B biosynthesis show how these enzymes accommodate large substrates, a challenge that requires a variation in metal coordination in HygX. Excitingly, the ternary complex of HygX with cosubstrate α-ketoglutarate and putative product hygromycin B identified an orientation of one glycosidic linkage of hygromycin B consistent with metal-catalyzed hydrogen atom abstraction from substrate. These structural results are complemented by gene disruption of the oxygenases evdO1 and evdMO1 from the everninomicin biosynthetic cluster, which demonstrate that functional oxygenase activity is critical for antibiotic production. Our data therefore support a role for these enzymes in the production of key features of the orthosomycin antibiotics. PMID:26240321

  1. Oxidative cyclizations in orthosomycin biosynthesis expand the known chemistry of an oxygenase superfamily

    DOE PAGES

    McCulloch, Kathryn M.; McCranie, Emilianne K.; Smith, Jarrod A.; ...

    2015-08-03

    Orthosomycins are oligosaccharide antibiotics that include avilamycin, everninomicin, and hygromycin B and are hallmarked by a rigidifying interglycosidic spirocyclic ortho-δ-lactone (orthoester) linkage between at least one pair of carbohydrates. A subset of orthosomycins additionally contain a carbohydrate capped by a methylenedioxy bridge. The orthoester linkage is necessary for antibiotic activity but rarely observed in natural products. Orthoester linkage and methylenedioxy bridge biosynthesis require similar oxidative cyclizations adjacent to a sugar ring. In this paper, we have identified a conserved group of nonheme iron, α-ketoglutarate–dependent oxygenases likely responsible for this chemistry. High-resolution crystal structures of the EvdO1 and EvdO2 oxygenases ofmore » everninomicin biosynthesis, the AviO1 oxygenase of avilamycin biosynthesis, and HygX of hygromycin B biosynthesis show how these enzymes accommodate large substrates, a challenge that requires a variation in metal coordination in HygX. Excitingly, the ternary complex of HygX with cosubstrate α-ketoglutarate and putative product hygromycin B identified an orientation of one glycosidic linkage of hygromycin B consistent with metal-catalyzed hydrogen atom abstraction from substrate. These structural results are complemented by gene disruption of the oxygenases evdO1 and evdMO1 from the everninomicin biosynthetic cluster, which demonstrate that functional oxygenase activity is critical for antibiotic production. Finally, our data therefore support a role for these enzymes in the production of key features of the orthosomycin antibiotics.« less

  2. Is Volume Conserved? A First General Chemistry Experiment.

    ERIC Educational Resources Information Center

    Olmsted, John

    1986-01-01

    Describes a freshman chemistry experiment designed to introduce scientific methodology, provide practice in measurement skills, and illustrate a fundamental chemical relationship (conservation of volume). Provides the experimental design, a materials and equipment list, sample calculations, and results. (JM)

  3. Teaching Lab Report Writing through Inquiry: A Green Chemistry Stoichiometry Experiment for General Chemistry

    ERIC Educational Resources Information Center

    Cacciatore, Kristen L.; Sevian, Hannah

    2006-01-01

    We present an alternative to a traditional first-year chemistry laboratory experiment. This experiment has four key features: students utilize stoichiometry, learn and apply principles of green chemistry, engage in authentic scientific inquiry, and discover why each part of a scientific lab report is necessary. The importance and essential…

  4. "The Chemicals Project": Connecting General Chemistry to Students' Lives

    NASA Astrophysics Data System (ADS)

    Stout, Roland

    2000-10-01

    "The Chemicals Project" described here strives to bring freshman chemistry alive for students by emphasizing its connection to the real world and to their own lives and experiences. Its major assignments deal with chemical phobias, recognizing the chemicals found in everyday life and chemical hazards (using Material Data Safety Sheets). The project is described in a cooperative learning format, employs portfolio grading, and includes a significant writing component. Ways of linking this project with the course lecture and student evaluations of the project are described. The bottom line: pre- and post-testing shows that it works. The Chemicals Project brings chemistry alive for students.

  5. Fostering Spatial Skill Acquisition by General Chemistry Students

    ERIC Educational Resources Information Center

    Carlisle, Deborah; Tyson, Julian; Nieswandt, Martina

    2015-01-01

    The study of chemistry requires the understanding and use of spatial relationships, which can be challenging for many students. Prior research has shown that there is a need to develop students' spatial reasoning skills. To that end, this study implemented guided activities designed to strengthen students' spatial skills, with the aim of improving…

  6. Service Learning Track in General Chemistry: Giving Students a Choice

    ERIC Educational Resources Information Center

    Donaghy, Kelley J.; Saxton, Kathleen J.

    2012-01-01

    Experiential learning is a foundation in chemistry courses from the introductory-level course to upper-level courses through laboratory experiences. Service learning is another type of experiential learning that is slowly gaining momentum in the sciences. There have been several reports in this "Journal" on this pedagogy with respect to student…

  7. Evaluation of Three Instructional Methods for Teaching General Chemistry.

    ERIC Educational Resources Information Center

    Jackman, Lance E.; And Others

    1987-01-01

    Reports on a study designed to determine the relative effectiveness of different instructional approaches on chemistry laboratory achievement. Investigated differences in achievement in spectrophotometry among college freshmen who received either traditional, learning cycle, or computer simulation instruction. Results indicated that students…

  8. Exploring Dominant Types of Explanations Built by General Chemistry Students

    ERIC Educational Resources Information Center

    Talanquer, Vicente

    2010-01-01

    The central goal of our study was to explore the nature of the explanations generated by science and engineering majors with basic training in chemistry to account for the colligative properties of solutions. The work was motivated by our broader interest in the characterisation of the dominant types of explanations that science college students…

  9. Incorporating More Individual Accountability in Group Activities in General Chemistry

    ERIC Educational Resources Information Center

    Cox, Charles T., Jr.

    2015-01-01

    A modified model of cooperative learning known as the GIG model (for group-individual-group) designed and implemented in a large enrollment freshman chemistry course. The goal of the model is to establish a cooperative environment while emphasizing greater individual accountability using both group and individual assignments. The assignments were…

  10. A General Chemistry Demonstration: Student Observations and Explanations.

    ERIC Educational Resources Information Center

    Silberman, Robert G.

    1983-01-01

    Out of 70 answers to questions concerning the chemistry involved in an "orange tornado" demonstration, only 10 were partially correct, others totally wrong or showing major errors in understanding, comprehension, and/or reasoning. Demonstration and reactions involved, selected incorrect answers, and a substantially correct answer are discussed.…

  11. Atoms-First Curriculum: A Comparison of Student Success in General Chemistry

    ERIC Educational Resources Information Center

    Esterling, Kevin M.; Bartels, Ludwig

    2013-01-01

    We present an evaluation of the impact of an atoms-first curriculum on student success in introductory chemistry classes and find that initially a lower fraction of students obtain passing grades in the first and second quarters of the general chemistry series. This effect is more than reversed for first-quarter students after one year of…

  12. Factors that Promote Success in Large Enrollment General Chemistry Courses Taught with Clickers

    ERIC Educational Resources Information Center

    MacArthur, James R.

    2010-01-01

    The environment of a large (greater than 300) enrollment first semester general chemistry course taught with clickers was characterized by statistical analysis of historical data, as well as through classroom observations and interviewing of professors and students. Four professors with experience teaching chemistry courses with clickers at this…

  13. Examining the Effects of Reflective Journals on Pre-Service Science Teachers' General Chemistry Laboratory Achievement

    ERIC Educational Resources Information Center

    Cengiz, Canan; Karatas, Faik Özgür

    2015-01-01

    The general chemistry laboratory is an appropriate place for learning chemistry well. It is also effective for stimulating higher-order thinking skills, including reflective thinking, a skill that is crucial for science teaching as well as learning. This study aims to examine the effects of feedback-supported reflective journal-keeping activities…

  14. Based on a True Story: Using Movies as Source Material for General Chemistry Reports

    ERIC Educational Resources Information Center

    Griep, Mark A.; Mikasen, Marjorie L.

    2005-01-01

    The story to improve student enthusiasm for writing reports about the chemistry behind events reported in the news and movies were chosen as the source material. The use of movies in the chemical classroom helps an instructor move the subject of chemistry from abstract, general themes to the personal and subjective arena of human interactions.

  15. Learning and Studying Strategies Used by General Chemistry Students with Different Affective Characteristics

    ERIC Educational Resources Information Center

    Chan, Julia Y. K.; Bauer, Christopher F.

    2016-01-01

    Students in general chemistry were partitioned into three groups by cluster analysis of six affective characteristics (emotional satisfaction, intellectual accessibility, chemistry self-concept, math self-concept, self-efficacy, and test anxiety). The at-home study strategies for exam preparation and in-class learning strategies differed among the…

  16. Preparation for College General Chemistry: More than Just a Matter of Content Knowledge Acquisition

    ERIC Educational Resources Information Center

    Cracolice, Mark S.; Busby, Brittany D.

    2015-01-01

    This study investigates the potential of five factors that may be predictive of success in college general chemistry courses: prior knowledge of common alternate conceptions, intelligence, scientific reasoning ability, proportional reasoning ability, and attitude toward chemistry. We found that both prior knowledge and scientific reasoning ability…

  17. Applying the Multilevel Framework of Discourse Comprehension to Evaluate the Text Characteristics of General Chemistry Textbooks

    ERIC Educational Resources Information Center

    Pyburn, Daniel T.; Pazicni, Samuel

    2014-01-01

    Prior chemistry education research has demonstrated a relationship between student reading skill and general chemistry course performance. In addition to student characteristics, however, the qualities of the learning materials with which students interact also impact student learning. For example, low-knowledge students benefit from texts that…

  18. The Representation of People of Color in Undergraduate General Chemistry Textbooks

    ERIC Educational Resources Information Center

    King, Denise; Domin, Daniel S.

    2007-01-01

    The presence of cultural basis within undergraduate general chemistry textbooks is examined by assessing the extent to and manner in which people of color are represented in textbook photographs. It is proposed that the images that students look upon in the textbooks help in their perceptions of chemistry as a whole.

  19. Problem Solving Videos for General Chemistry Review: Students' Perceptions and Use Patterns

    ERIC Educational Resources Information Center

    Richards-Babb, Michelle; Curtis, Reagan; Smith, Valerie J.; Xu, Mingming

    2014-01-01

    We examined the use of problem solving videos (PSVs) as a substitute for general chemistry exam review sessions. We investigated student perceptions of course aspects regarding usefulness for supporting their learning of chemistry content. We also examined "how" students used the PSVs to further their learning. Students ranked the PSVs…

  20. Teaching College General Chemistry: Techniques Designed To Communicate a Conceptual Framework

    NASA Astrophysics Data System (ADS)

    Duchovic, Ronald J.

    1998-07-01

    General chemistry at the college level is often perceived as a major hurdle by typical undergraduates. Both Freshmen and more advanced students undertake courses in general chemistry either ill-prepared or convinced that the subject matter is beyond their comprehension. With the exception of potential chemistry majors, the vast majority of general chemistry students enter the class simply to satisfy a graduation requirement of their degree program. Consequently, instructors must both communicate an understanding of the subject matter and overcome major barriers to the learning process itself. This paper discusses two techniques which have been utilized for five semesters in general chemistry courses and which attempt to surmount barriers to learning by emphasizing the conceptual framework of the science of chemistry. One of these techniques is the use of a repechage system (literally meaning "second chance") for all hour examinations during the term, while the second engages the students in writing exercises based on the laboratory portion of the course. This paper will discuss the techniques, their application and impact, and finally, the positive and negative aspects their utilization in a general chemistry course.

  1. 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.

  2. Imidazole as a pH Probe: An NMR Experiment for the General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Hagan, William J., Jr.; Edie, Dennis L.; Cooley, Linda B.

    2007-01-01

    The analysis describes an NMR experiment for the general chemistry laboratory, which employs an unknown imidazole solution to measure the pH values. The described mechanism can also be used for measuring the acidity within the isolated cells.

  3. Using Technology to Enhance the Effectiveness of General Chemistry Laboratory Courses

    ERIC Educational Resources Information Center

    Carvalho-Knighton, Kathleen M.; Keen-Rocha, Linda

    2007-01-01

    The effectiveness of two different laboratory techniques is compared to teach students majoring in science in a general chemistry laboratory. The results demonstrated that student laboratory activities with computer-interface systems could improve student understanding.

  4. The ACS Exams Institute Undergraduate Chemistry Anchoring Concepts Content Map I: General Chemistry

    ERIC Educational Resources Information Center

    Holme, Thomas; Murphy, Kristen

    2012-01-01

    To provide tools for programmatic assessment related to the use of ACS Exams in undergraduate chemistry courses, the ACS Exams Institute has built a content map that applies to the entire undergraduate curriculum. At the top two levels, the grain size of the content classification is large and spans the entire undergraduate curriculum. At the…

  5. Chemistry for DUMMIES: how to popularize and introduce chemistry to the general public.

    PubMed

    Montangero, Marc

    2012-01-01

    To mark the occasion of the International Year of Chemistry, each week in 2011 I posted a two-minute film demonstrating and explaining a simple and safe experiment to be carried out at home using everyday household products on the site www.chimie.ch/nuls.

  6. 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…

  7. Suggestions for Modifications in the Teaching of General Chemistry to Accommodate Learning Disabled Students: Alternative Techniques for Teaching General Chemistry to Learning Disabled Students in the University.

    ERIC Educational Resources Information Center

    Habib, H. S.

    A professor involved with the HELDS project (Higher Education for Learning Disabled Students) describes modifications in a general chemistry course. A syllabus lists program objectives for eight text chapters, evaluation components, and course rules. Two units are described in detail, with information presented on modifications made for LD…

  8. The Representation of People of Color in Undergraduate General Chemistry Textbooks

    NASA Astrophysics Data System (ADS)

    King, Denise; Domin, Daniel S.

    2007-02-01

    A content analysis of eleven college-level general chemistry textbooks was performed to ascertain the extent to which people of color are represented within the textbook photographs. The results of this study show that all of the textbooks' photographs within this investigation include people of color at a level well below their representation in American society. In addition, photographs containing images of people of color usually depict them in a context that has no relevance to chemistry or in a manner that propagates stereotypes. It is the conclusion of these authors that contemporary undergraduate general chemistry textbooks are laden with instructional bias with respect to people of color.

  9. TextRev: A Window into How General and Organic Chemistry Students Use Textbook Resources

    NASA Astrophysics Data System (ADS)

    Smith, Bradley D.; Jacobs, Dennis C.

    2003-01-01

    A paper-based survey of first-year general chemistry and second-year organic chemistry students included responses from approximately 3200 students at nine colleges and universities. The students answered questions about the time they spent using various textbook resources, and about the quality and helpfulness of each resource. Five important results emerged. Organic chemistry students report spending approximately 40% more time using textbook resources than do general chemistry students. For general chemistry students, the order of average self-reported hours per week using textbook resources correlates with anticipated grades in the following way, C > B > A; whereas the hours per week for organic students is independent of anticipated grade. Compared to general chemistry students, the organic chemistry students spend a smaller fraction of their time using the textbook and more time using the study guide or solutions manual. Both groups spend less than 7% of their time using the textbook’s Web site or the accompanying CD. Both groups find in-chapter example problems and end-of-chapter problems to be the most helpful textbook features.

  10. How Interstellar Chemistry (and Astrochemistry More Generally) Became Useful

    NASA Astrophysics Data System (ADS)

    Hartquist, T. W.; van Loo, S.; Falle, S. A. E. G.

    In 1986 Alex Dalgarno published a paper entitled Is Interstellar Chemistry Useful?1 By the middle 1970s, and perhaps even earlier, Alex had hoped that astronomical molecules would prove to: possess significant diagnostic utility; control many of the environments in which they exist; stimulate a wide variety of physicists and chemists who are at least as fascinated by the mechanisms forming and removing the molecules as by astronomy. His own research efforts have contributed greatly to the realization of that hope. This paper contains a few examples of: how molecules are used to diagnose large-scale dynamics in astronomical sources including star forming regions and supernovae; the ways in which molecular processes control the evolution of astronomical objects such as dense cores destined to become stars and very evolved giant stars; theoretical and laboratory investigations that elucidate the processes producing and removing astronomical molecules and allow their detection.

  11. Expanding the scope of strained-alkyne chemistry: a protection-deprotection strategy via the formation of a dicobalt-hexacarbonyl complex.

    PubMed

    Gobbo, Pierangelo; Romagnoli, Tommaso; Barbon, Stephanie M; Price, Jacquelyn T; Keir, Jennifer; Gilroy, Joe B; Workentin, Mark S

    2015-04-18

    A protection-deprotection strategy for strained alkynes used for bioorthogonal chemistry is reported. A strained alkyne can be protected with dicobalt-octacarbonyl and we demonstrate for the first time that a strained alkyne can be re-formed and isolated under mild reaction conditions for further bioorthogonal reactivity. The protection-deprotection strategy herein reported will expand the versatility of strained alkynes for the preparation of substrates in chemical biology and materials applications.

  12. Computer-based, Jeopardy™-like game in general chemistry for engineering majors

    NASA Astrophysics Data System (ADS)

    Ling, S. S.; Saffre, F.; Kadadha, M.; Gater, D. L.; Isakovic, A. F.

    2013-03-01

    We report on the design of Jeopardy™-like computer game for enhancement of learning of general chemistry for engineering majors. While we examine several parameters of student achievement and attitude, our primary concern is addressing the motivation of students, which tends to be low in a traditionally run chemistry lectures. The effect of the game-playing is tested by comparing paper-based game quiz, which constitutes a control group, and computer-based game quiz, constituting a treatment group. Computer-based game quizzes are Java™-based applications that students run once a week in the second part of the last lecture of the week. Overall effectiveness of the semester-long program is measured through pretest-postest conceptual testing of general chemistry. The objective of this research is to determine to what extent this ``gamification'' of the course delivery and course evaluation processes may be beneficial to the undergraduates' learning of science in general, and chemistry in particular. We present data addressing gender-specific difference in performance, as well as background (pre-college) level of general science and chemistry preparation. We outline the plan how to extend such approach to general physics courses and to modern science driven electives, and we offer live, in-lectures examples of our computer gaming experience. We acknowledge support from Khalifa University, Abu Dhabi

  13. Relationships of approaches to studying, metacognition, and intellectual development of general chemistry students

    NASA Astrophysics Data System (ADS)

    Egenti, Henrietta N.

    This study investigated approaches to studying, intellectual developments, and metacognitive skills of general chemistry students enrolled for the spring 2011 semester at a single campus of a multi-campus community college. The three instruments used were the Approaches and Study Skills Inventory for Students (ASSIST), the Learning Environment Preferences (LEP), and the Executive Process Questionnaire (EPQ). The subjects were 138 students enrolled in either general chemistry 1 or 2. The results revealed that the preferred approach to study was the strategic approach. The intellectual development of the students was predominantly Perry's position 2 (dualist) in transition to position 3 (multiplicity). Correlation statistics revealed that deep approach to studying is related to effective employment of metacognitive skills. Students with a deep approach to studying were likely to utilize effective metacognitive skills. Students with a surface approach to studying used no metacognitive skills or ineffective metacognitive skills. Multiple logistic regression analysis was conducted to ascertain which of the three variables, namely approaches to studying, ability to metacognate, or level of intellectual development, was the most salient in predicting the success of general chemistry students. No single variable was found to predict students’ success in general chemistry classes; however, a surface approach to studying predisposes general chemistry students to fail. The implication of this study is that students’ study approaches, intellectual developments, and metacognitive skills are requisite information to enable instructional remediation early in the semester.

  14. General Procedure for the Easy Calculation of pH in an Introductory Course of General or Analytical Chemistry

    ERIC Educational Resources Information Center

    Cepriá, Gemma; Salvatella, Luis

    2014-01-01

    All pH calculations for simple acid-base systems used in introductory courses on general or analytical chemistry can be carried out by using a general procedure requiring the use of predominance diagrams. In particular, the pH is calculated as the sum of an independent term equaling the average pK[subscript a] values of the acids involved in the…

  15. Knowledge Surveys in General Chemistry: Confidence, Overconfidence, and Performance

    ERIC Educational Resources Information Center

    Bell, Priscilla; Volckmann, David

    2011-01-01

    Knowledge surveys have been used in a number of fields to assess changes in students' understanding of their own learning and to assist students in review. This study compares metacognitive confidence ratings of students faced with problems on the surveys with their actual knowledge as shown on the final exams in two courses of general chemistry…

  16. Using Chemistry and Color To Analyze Household Products: A 10-12 Hour Laboratory Project at the General Chemistry Level

    NASA Astrophysics Data System (ADS)

    Bosma, Wayne B.

    1998-02-01

    A general chemistry experiment is described in which the students use UV/Visible spectrometry as an analytical tool, for both compound identification and pH measurement. In the first portion of the experiment, the students compare spectra to determine which FD and C dyes are contained in household products. They furthermore use chromatography to separate the dyes in grape Kool-Aid, and analyze the products with the spectrometer. In the second portion of the experiment, the students use Beer's Law to determine the pH of solutions containing an acid/base indicator. The experiments are visually stimulating and provide a solid introduction to spectroscopy and perceived color.

  17. General Chemistry Collection for Students (CD-ROM), Abstract of Special Issue 16, 5th Edition

    NASA Astrophysics Data System (ADS)

    2001-06-01

    General Chemistry Collection contains the work of many authors. The time and effort of these dedicated chemistry educators in producing these programs is gratefully acknowledged by the editors, along with the authors' generosity in contributing their work to the chemistry education community by submission to JCE Software. Thanks are also due the many volunteer peer reviewers who give their time and expertise to help maintain and assure the high quality of JCE Software publications.

    Literature Cited

    1. General Chemistry Collection (Student Ed.), 4th ed. [CD-ROM]; J. Chem. Educ. Software 2000, SP 16.
    2. March, J. L.; Moore, J. W.; Jacobsen, J. J. ChemPages Laboratory [CD-ROM]; J. Chem. Educ. Software 2000, SP 24.
    3. Whisnant, D. M. General Chemistry Multimedia Problems [CD-ROM]; J. Chem. Educ. Software 2000, SP 27.
    4. Ophardt, C. E. Inorganic Molecules: A Visual Database [CD-ROM]; J. Chem. Educ. Software 1996, 8C1.
    5. Lisensky, G. C.; Ellis, A. B.; Blackwell, J. M.; Solid State Resources, 2nd ed. [CD-ROM]; J. Chem. Educ. Software 2000, SP 12.

  18. A General Chemistry and Precalculus First-Year Interest Group (FIG): Effect on Retention, Skills, and Attitudes

    ERIC Educational Resources Information Center

    Pence, Laura E.; Workman, Harry J.; Haruta, Mako E.

    2005-01-01

    The backdrop of the calculus reform movement created a fertile movement for the creation of overlap between general chemistry and precalculus as many of the goals emphasized key concepts from the chemistry lab. By using the graphing calculator in both precalculus and chemistry laboratory enhanced the students' comfort and competence with the…

  19. General Chemistry Collection for Students (CD-ROM), Abstract of Special Issue 16, 4th Edition

    NASA Astrophysics Data System (ADS)

    2000-07-01

    The General Chemistry Collection contains both new and previously published JCE Software programs that are intended for use by introductory-level chemistry students. These peer-reviewed programs for Macintosh and for Windows are available on a single CD-ROM for convenient distribution to and access by students, and the CD may be adopted for students to purchase as they would a textbook. General Chemistry Collection covers a broad range of topics providing students with interesting information, tutorials, and simulations that will be useful to them as they study chemistry for the first time. There are 22 programs included in the General Chemistry Collection 4th Edition. Their titles and the general chemistry topics they cover are listed in Table 1. Features in This Edition General Chemistry Collection, 4th edition includes:

    • Lessons for Introductory Chemistry and INQUAL-S, two new programs not previously published by JCE Software (abstracts appear below)
    • Writing Electron Dot Structures (1) and Viscosity Measurement: A Virtual Experiment for Windows (2), two programs published individually by JCE Software
    • Periodic Table Live! LE, a limited edition of Periodic Table Live!, 2nd Edition (3) (this replaces Chemistry Navigator (4) and Illustrated Periodic Table (5))
    • Many of the programs from previous editions (6)1
    Hardware and Software Requirements System requirements are given in Table 2. Some programs have additional requirements. See the individual program abstracts at JCE Online, or documentation included on the CD-ROM for more specific information. Licensing and Discounts for Adoptions The General Chemistry Collection is intended for use by individual students. Institutions and faculty members may adopt General Chemistry Collection 4th Edition as they would a textbook. We can arrange for CDs to be packaged with laboratory manuals or other course materials or to be sold for direct distribution to students through the campus

  20. 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…

  1. Introducing Scientific Literature to Honors General Chemistry Students: Teaching Information Literacy and the Nature of Research to First-Year Chemistry Students

    ERIC Educational Resources Information Center

    Ferrer-Vinent, Ignacio J.; Bruehl, Margaret; Pan, Denise; Jones, Galin L.

    2015-01-01

    This paper describes the methodology and implementation of a case study introducing the scientific literature and creative experiment design to honors general chemistry laboratory students. The purpose of this study is to determine whether first-year chemistry students can develop information literacy skills while they engage with the primary…

  2. Implementation of Argument-Driven Inquiry as an Instructional Model in a General Chemistry Laboratory Course

    ERIC Educational Resources Information Center

    Kadayifci, Hakki; Yalcin-Celik, Ayse

    2016-01-01

    This study examined the effectiveness of Argument-Driven Inquiry (ADI) as an instructional model in a general chemistry laboratory course. The study was conducted over the course of ten experimental sessions with 125 pre-service science teachers. The participants' level of reflective thinking about the ADI activities, changes in their science…

  3. Exploring Chemical Equilibrium with Poker Chips: A General Chemistry Laboratory Exercise

    ERIC Educational Resources Information Center

    Bindel, Thomas H.

    2012-01-01

    A hands-on laboratory exercise at the general chemistry level introduces students to chemical equilibrium through a simulation that uses poker chips and rate equations. More specifically, the exercise allows students to explore reaction tables, dynamic chemical equilibrium, equilibrium constant expressions, and the equilibrium constant based on…

  4. An Investigation of the Value of Using Concept Maps in General Chemistry.

    ERIC Educational Resources Information Center

    Nicoll, Gayle; Francisco, Joseph; Nakhleh, Mary B.

    2001-01-01

    Reports on a qualitative investigation of the effects of integrating concept maps into freshman-level general chemistry curriculum. Indicates that students in the experimental section had significantly more links and nodes in their concept maps than students in the traditional section. There were no significant differences between the two sections…

  5. Infrared and Raman Spectroscopy: A Discovery-Based Activity for the General Chemistry Curriculum

    ERIC Educational Resources Information Center

    Borgsmiller, Karen L.; O'Connell, Dylan J.; Klauenberg, Kathryn M.; Wilson, Peter M.; Stromberg, Christopher J.

    2012-01-01

    A discovery-based method is described for incorporating the concepts of IR and Raman spectroscopy into the general chemistry curriculum. Students use three sets of springs to model the properties of single, double, and triple covalent bonds. Then, Gaussian 03W molecular modeling software is used to illustrate the relationship between bond…

  6. Supporting Students' Learning to Learn in General Chemistry Using Moodle

    ERIC Educational Resources Information Center

    Gonza´lez, Maritza Lau; Haza, Ulises Ja´uregui; Gramagtes, Aurora Pe´rez; Leo´n, Gloria Farin~as; Le Bolay, Nadine

    2014-01-01

    A combination of regular classroom teaching with the use of resources available on the Moodle platform has been designed to foster the development of skills for learning to learn for students in an undergraduate general chemistry course. The use of the Moodle platform essentially aimed at strengthening the students' prior knowledge of…

  7. 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…

  8. Effects and Implications of Mini-Lectures on Learning in First-Semester General Chemistry

    ERIC Educational Resources Information Center

    Toto, Joe; Booth, Kathy

    2008-01-01

    This study describes the efficacy of a novel tool, mini-lecture movies, in teaching Web based general chemistry. The analysis shows a marked improvement in student learning, as evidenced by a corresponding increase in homework and final exam scores. Students with access to mini-lecture movies scored 11.2% (p = 0.016) higher than students who did…

  9. The Evaluation of Students' Written Reflection on the Learning of General Chemistry Lab Experiment

    ERIC Educational Resources Information Center

    Han, Ng Sook; Li, Ho Ket; Sin, Lee Choy; Sin, Keng Pei

    2014-01-01

    Reflective writing is often used to increase understanding and analytical ability. The lack of empirical evidence on the effect of reflective writing interventions on the learning of general chemistry lab experiment supports the examination of this concept. The central goal of this exploratory study was to evaluate the students' written…

  10. Argumentation and Participation Patterns in General Chemistry Peer-Led Sessions

    ERIC Educational Resources Information Center

    Kulatunga, Ushiri; Moog, Richard S.; Lewis, Jennifer E.

    2013-01-01

    This article focuses on the use of Toulmin's argumentation scheme to investigate the characteristics of student group argumentation in Peer-Led Guided Inquiry sessions for a General Chemistry I course. A coding scheme based on Toulmin's [Toulmin [1958] "The uses of argument." Cambridge: Cambridge University Press] argumentation…

  11. Assessing Conceptual and Algorithmic Knowledge in General Chemistry with ACS Exams

    ERIC Educational Resources Information Center

    Holme, Thomas; Murphy, Kristen

    2011-01-01

    In 2005, the ACS Examinations Institute released an exam for first-term general chemistry in which items are intentionally paired with one conceptual and one traditional item. A second-term, paired-questions exam was released in 2007. This paper presents an empirical study of student performances on these two exams based on national samples of…

  12. Reform in a General Chemistry Laboratory: How Do Students Experience Change in the Instructional Approach?

    ERIC Educational Resources Information Center

    Chopra, I.; O'Connor, J.; Pancho, R.; Chrzanowski, M.; Sandi-Urena, S.

    2017-01-01

    This qualitative study investigated the experience of a cohort of students exposed consecutively to two substantially different environments in their General Chemistry Laboratory programme. To this end, the first semester in a traditional expository programme was followed by a semester in a cooperative, problem-based, multi-week format. The focus…

  13. 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…

  14. The Testing Effect: An Intervention on Behalf of Low-Skilled Comprehenders in General Chemistry

    ERIC Educational Resources Information Center

    Pyburn, Daniel T.; Pazicni, Samuel; Benassi, Victor A.; Tappin, Elizabeth M.

    2014-01-01

    Past work has demonstrated that language comprehension ability correlates with general chemistry course performance with medium effect sizes. We demonstrate here that language comprehension's strong cognitive grounding can be used to inform effective and equitable pedagogies, namely, instructional interventions that differentially aid low-skilled…

  15. Identifying At-Risk Students in General Chemistry via Cluster Analysis of Affective Characteristics

    ERIC Educational Resources Information Center

    Chan, Julia Y. K.; Bauer, Christopher F.

    2014-01-01

    The purpose of this study is to identify academically at-risk students in first-semester general chemistry using affective characteristics via cluster analysis. Through the clustering of six preselected affective variables, three distinct affective groups were identified: low (at-risk), medium, and high. Students in the low affective group…

  16. Relationships of Approaches to Studying, Metacognition, and Intellectual Development of General Chemistry Students

    ERIC Educational Resources Information Center

    Egenti, Henrietta N.

    2012-01-01

    This study investigated approaches to studying, intellectual developments, and metacognitive skills of general chemistry students enrolled for the spring 2011 semester at a single campus of a multi-campus community college. The three instruments used were the Approaches and Study Skills Inventory for Students (ASSIST), the Learning Environment…

  17. Analysis of Classroom Response System Questions via Four Lenses in a General Chemistry Course

    ERIC Educational Resources Information Center

    Bruck, Aaron D.; Towns, Marcy H.

    2009-01-01

    General Chemistry lecture questions used in an electronic classroom response system (CRS) were analyzed using three theoretical frameworks and the pedagogical context in which they were presented. The analytical lenses included whether students were allowed to collaborate, Bloom's Taxonomy, a framework developed by Robinson and Nurrenbern, and an…

  18. Podcast Effectiveness as Scaffolding Support for Students Enrolled in First-Semester General Chemistry Laboratories

    ERIC Educational Resources Information Center

    Powell, Mary Cynthia Barton

    2010-01-01

    Podcasts covering essential first-semester general chemistry laboratory techniques and central concepts that aid in experimental design or data processing were prepared and made available for students to access on an as-needed basis on iPhones [arrow right] or iPod touches [arrow right]. Research focused in three areas: the extent of podcast…

  19. Amino Acid Complementarity: A Biochemical Exemplar of Stoichiometry for General and Health Sciences Chemistry

    ERIC Educational Resources Information Center

    Vitz, Ed

    2005-01-01

    The standard introduction to stoichiometry and simple exemplars can motivate students to learn the stoichiometric studies and the condensation reaction that occurs between amino acids to form the peptide bond. This topic can be integrated into general chemistry courses as an alternative to inclusion of a separate biochemistry course that could be…

  20. Using the Plan View to Teach Basic Crystallography in General Chemistry

    ERIC Educational Resources Information Center

    Cushman, Cody V.; Linford, Matthew R.

    2015-01-01

    The plan view is used in crystallography and materials science to show the positions of atoms in crystal structures. However, it is not widely used in teaching general chemistry. In this contribution, we introduce the plan view, and show these views for the simple cubic, body-centered cubic, face-centered cubic, hexagonal close packed, CsCl, NaCl,…

  1. Self-Assembled Student Interactions in Undergraduate General Chemistry Clicker Classrooms

    ERIC Educational Resources Information Center

    MacArthur, James R.; Jones, Loretta

    2013-01-01

    Student interviews, focus groups, and classroom observations were used in an exploratory study of the nature of student interactions in a large (300+ students) general chemistry course taught with clickers. These data suggest that students are self-assembling their learning environment: choosing ways in which to interact with one another during…

  2. Effect of Teaching Metacognitive Learning Strategies on Performance in General Chemistry Courses

    ERIC Educational Resources Information Center

    Cook, Elzbieta; Kennedy, Eugene; McGuire, Saundra Y.

    2013-01-01

    College students often find general chemistry to be a very challenging rite of passage on their way to degrees in various science, technology, and mathematics disciplines. As teachers, we make efforts to simultaneously patch gaps in students' prior knowledge and instill valuable learning strategies and sound study habits. In this paper, we…

  3. Looking beyond Lewis Structures: A General Chemistry Molecular Modeling Experiment Focusing on Physical Properties and Geometry

    ERIC Educational Resources Information Center

    Linenberger, Kimberly J.; Cole, Renee S.; Sarkar, Somnath

    2011-01-01

    We present a guided-inquiry experiment using Spartan Student Version, ready to be adapted and implemented into a general chemistry laboratory course. The experiment provides students an experience with Spartan Molecular Modeling software while discovering the relationships between the structure and properties of molecules. Topics discussed within…

  4. Playing with Light: Adventures in Optics and Spectroscopy for Honors and Majors General Chemistry

    ERIC Educational Resources Information Center

    van Staveren, Marie N.; Edwards, Kimberly D.; Apkarian, V. A.

    2012-01-01

    A lab was developed for use in an undergraduate honors and majors general chemistry laboratory to introduce students to optics, spectroscopy, and the underlying principles of quantum mechanics. This lab includes four mini-experiments exploring total internal reflection, the tunneling of light, spectra of sparklers and colored candles, and emission…

  5. Using Pooled Data and Data Visualization to Introduce Statistical Concepts in the General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Olsen, Robert J.

    2008-01-01

    I describe how data pooling and data visualization can be employed in the first-semester general chemistry laboratory to introduce core statistical concepts such as central tendency and dispersion of a data set. The pooled data are plotted as a 1-D scatterplot, a purpose-designed number line through which statistical features of the data are…

  6. A Retention Study at Burlington County College in General College Chemistry.

    ERIC Educational Resources Information Center

    Sollimo, Vincent J.

    A study was conducted at Burlington County College to investigate the relationship between the academic characteristics and course completion of students enrolled in General College Chemistry (CHE 105) in fall 1985. The study involved an examination of students' academic records and a survey of students who did not successfully pass the course. Of…

  7. Integrating Biology into the General Chemistry Laboratory: Fluorometric Analysis of Chlorophyll "a"

    ERIC Educational Resources Information Center

    Wesolowski, Meredith C.

    2014-01-01

    A laboratory experiment that introduces fluorometry of chlorophyll "a" at the general chemistry level is described. The use of thin-layer chromatography to isolate chlorophyll "a" from spirulina and leaf matter enables quantification of small amounts of chlorophyll "a" via fluorometry. Student results were reasonably…

  8. Inquiry-Based Arson Investigation for General Chemistry Using GC-MS

    ERIC Educational Resources Information Center

    Maurer, Marta K.; Bukowski, Michael R.; Menachery, Mary D.; Zatorsky, Adam R.

    2010-01-01

    We have developed a two-week guided-inquiry laboratory in which first-semester general chemistry students investigate a suspected arson using gas chromatography--mass spectrometry and paper chromatography. In the process of evaluating evidence from the crime scene, students develop and test hypotheses and learn the fundamentals of chromatography,…

  9. Team-Based Learning Reduces Attrition in a First-Semester General Chemistry Course

    ERIC Educational Resources Information Center

    Comeford, Lorrie

    2016-01-01

    Team-based learning (TBL) is an instructional method that has been shown to reduce attrition and increase student learning in a number of disciplines. TBL was implemented in a first-semester general chemistry course, and its effect on attrition was assessed. Attrition from sections before implementing TBL (fall 2008 to fall 2009) was compared with…

  10. A Computer Algebra Approach to Solving Chemical Equilibria in General Chemistry

    ERIC Educational Resources Information Center

    Kalainoff, Melinda; Lachance, Russ; Riegner, Dawn; Biaglow, Andrew

    2012-01-01

    In this article, we report on a semester-long study of the incorporation into our general chemistry course, of advanced algebraic and computer algebra techniques for solving chemical equilibrium problems. The method presented here is an alternative to the commonly used concentration table method for describing chemical equilibria in general…

  11. Assessment of Antioxidant Capacities in Foods: A Research Experience for General Chemistry Students

    ERIC Educational Resources Information Center

    Hoch, Matthew A.; Russell, Cianan B.; Steffen, Debora M.; Weaver, Gabriela C.; Burgess, John R.

    2009-01-01

    With the booming interest in health food and nutrition, investigations of the antioxidant capacities of various foods have come to the forefront of food science. This general chemistry laboratory curriculum provides students with an opportunity to design and implement their own experiments relating to antioxidants in food. The curriculum is six…

  12. Promoting Student Learning through Group Problem Solving in General Chemistry Recitations

    ERIC Educational Resources Information Center

    Mahalingam, Madhu; Schaefer, Fred; Morlino, Elisabeth

    2008-01-01

    We describe the implementation and effects of group problem solving in recitation sections associated with the general chemistry course at a small private science university. Recitation sections of approximately 45 students are used to supplement large (approximately 180 students) lecture sections. The primary goal of recitation is working in…

  13. Structure Determination of Unknown Organic Liquids Using NMR and IR Spectroscopy: A General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Pavel, John T.; Hyde, Erin C.; Bruch, Martha D.

    2012-01-01

    This experiment introduced general chemistry students to the basic concepts of organic structures and to the power of spectroscopic methods for structure determination. Students employed a combination of IR and NMR spectroscopy to perform de novo structure determination of unknown alcohols, without being provided with a list of possible…

  14. Students' Understanding of Analogy after a Core (Chemical Observations, Representations, Experimentation) Learning Cycle, General Chemistry Experiment

    ERIC Educational Resources Information Center

    Avargil, Shirly; Bruce, Mitchell R. M.; Amar, Franc¸ois G.; Bruce, Alice E.

    2015-01-01

    Students' understanding about analogy was investigated after a CORE learning cycle general chemistry experiment. CORE (Chemical Observations, Representations, Experimentation) is a new three-phase learning cycle that involves (phase 1) guiding students through chemical observations while they consider a series of open-ended questions, (phase 2)…

  15. Design and Implementation of a Studio-Based General Chemistry Course

    ERIC Educational Resources Information Center

    Gottfried, Amy C.; Sweeder, Ryan D.; Bartolin, Jeffrey M.; Hessler, Jessica A.; Reynolds, Benjamin P.; Stewart, Ian C.; Coppola, Brian P.; Holl, Mark Banaszak M.

    2007-01-01

    The design and implementation of a new value-added general chemistry course, which could use the studio instructional method to incorporate the existing educational research is reviewed. These teaching methods and activities were woven into the course to provide the students with ways of learning chemical concepts and practicing scientific…

  16. Examination of Bond Properties through Infrared Spectroscopy and Molecular Modeling in the General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Csizmar, Clifford M.; Force, Dee Ann; Warner, Don L.

    2012-01-01

    A concerted effort has been made to increase the opportunities for undergraduate students to address scientific problems employing the processes used by practicing chemists. As part of this effort, an infrared (IR) spectroscopy and molecular modeling experiment was developed for the first-year general chemistry laboratory course. In the…

  17. An Analysis of Undergraduate General Chemistry Students' Misconceptions of the Submicroscopic Level of Precipitation Reactions

    ERIC Educational Resources Information Center

    Kelly, Resa M.; Barrera, Juliet H.; Mohamed, Saheed C.

    2010-01-01

    This study examined how 21 college-level general chemistry students, who had received instruction that emphasized the symbolic level of ionic equations, explained their submicroscopic-level understanding of precipitation reactions. Students' explanations expressed through drawings and semistructured interviews revealed the nature of the…

  18. Using an Online, Self-Diagnostic Test for Introductory General Chemistry at an Open University

    ERIC Educational Resources Information Center

    Kennepohl, Dietmar; Guay, Matthew; Thomas, Vanessa

    2010-01-01

    A simple, online, self-diagnostic tool has been developed to allow students to independently and quickly measure their potential of success in a first-year general chemistry course. The online tool employs well-established performance predictors in areas such as student educational background, conceptual basics, critical thinking, mathematical…

  19. Web-Enhanced General Chemistry Increases Student Completion Rates, Success, and Satisfaction

    ERIC Educational Resources Information Center

    Amaral, Katie E.; Shank, John D.; Shibley, Ivan A., Jr.; Shibley, Lisa R.

    2013-01-01

    General Chemistry I historically had one of the highest failure and withdrawal rates at Penn State Berks, a four-year college within the Penn State system. The course was completely redesigned to incorporate more group work, the use of classroom response systems, peer mentors, and a stronger online presence via the learning management system…

  20. Transitioning from Expository Laboratory Experiments to Course-Based Undergraduate Research in General Chemistry

    ERIC Educational Resources Information Center

    Clark, Ted M.; Ricciardo, Rebecca; Weaver, Tyler

    2016-01-01

    General chemistry courses predominantly use expository experiments that shape student expectations of what a laboratory activity entails. Shifting within a semester to course-based undergraduate research activities that include greater decision-making, collaborative work, and "messy" real-world data necessitates a change in student…

  1. A spatial analysis of the expanding roles of nurses in general practice

    PubMed Central

    2012-01-01

    Background Changes to the workforce and organisation of general practice are occurring rapidly in response to the Australian health care reform agenda, and the changing nature of the medical profession. In particular, the last five years has seen the rapid introduction and expansion of a nursing workforce in Australian general practices. This potentially creates pressures on current infrastructure in general practice. Method This study used a mixed methods, ‘rapid appraisal’ approach involving observation, photographs, and interviews. Results Nurses utilise space differently to GPs, and this is part of the diversity they bring to the general practice environment. At the same time their roles are partly shaped by the ways space is constructed in general practices. Conclusion The fluidity of nursing roles in general practice suggests that nurses require a versatile space in which to maximize their role and contribution to the general practice team. PMID:22870933

  2. 'Seed + expand': a general methodology for detecting publication oeuvres of individual researchers.

    PubMed

    Reijnhoudt, Linda; Costas, Rodrigo; Noyons, Ed; Börner, Katy; Scharnhorst, Andrea

    2014-01-01

    The study of science at the individual scholar level requires the disambiguation of author names. The creation of author's publication oeuvres involves matching the list of unique author names to names used in publication databases. Despite recent progress in the development of unique author identifiers, e.g., ORCID, VIVO, or DAI, author disambiguation remains a key problem when it comes to large-scale bibliometric analysis using data from multiple databases. This study introduces and tests a new methodology called seed + expand for semi-automatic bibliographic data collection for a given set of individual authors. Specifically, we identify the oeuvre of a set of Dutch full professors during the period 1980-2011. In particular, we combine author records from a Dutch National Research Information System (NARCIS) with publication records from the Web of Science. Starting with an initial list of 8,378 names, we identify 'seed publications' for each author using five different approaches. Subsequently, we 'expand' the set of publications in three different approaches. The different approaches are compared and resulting oeuvres are evaluated on precision and recall using a 'gold standard' dataset of authors for which verified publications in the period 2001-2010 are available.

  3. Selected chapters from general chemistry in physics teaching with the help of e - learning

    NASA Astrophysics Data System (ADS)

    Feszterová, Melánia

    2017-01-01

    Education in the field of natural disciplines - Mathematics, Physics, Chemistry, Ecology and Biology takes part in general education at all schools on the territory of Slovakia. Its aim is to reach the state of balanced development of all personal characteristics of pupils, to teach them correctly identify and analyse problems, propose solutions and above all how to solve the problem itself. High quality education can be reached only through the pedagogues who have a good expertise knowledge, practical experience and high level of pedagogical abilities. The teacher as a disseminator of natural-scientific knowledge should be not only well-informed about modern tendencies in the field, but he/she also should actively participate in project tasks This is the reason why students of 1st year of study (bachelor degree) at the Department of Physics of Constantine the Philosopher University in Nitra attend lectures in the frame of subject General Chemistry. In this paper we present and describe an e - learning course called General Chemistry that is freely accessible to students. One of the aims of this course is to attract attention towards the importance of cross-curricular approach which seems to be fundamental in contemporary natural-scientific education (e.g. between Physics and Chemistry). This is why it is so important to implement a set of new topics and tasks that support development of abilities to realise cross-curricular goals into the process of preparation of future teachers of Physics.

  4. Argumentation as a Lens to Examine Student Discourse in Peer-Led Guided Inquiry for College General Chemistry

    ERIC Educational Resources Information Center

    Kulatunga, Ushiri Kumarihamy

    2013-01-01

    This dissertation work entails three related studies on the investigation of Peer-Led Guided Inquiry student discourse in a General Chemistry I course through argumentation. The first study, "Argumentation and participation patterns in general chemistry peer-led sessions," is focused on examining arguments and participation patterns in…

  5. Exploring General versus Task-Specific Assessments of Metacognition in University Chemistry Students: A Multitrait-Multimethod Analysis

    ERIC Educational Resources Information Center

    Wang, Chia-Yu

    2015-01-01

    The purpose of this study was to use multiple assessments to investigate the general versus task-specific characteristics of metacognition in dissimilar chemistry topics. This mixed-method approach investigated the nature of undergraduate general chemistry students' metacognition using four assessments: a self-report questionnaire, assessment of…

  6. Development and Preliminary Impacts of the Implementation of an Authentic Research-Based Experiment in General Chemistry

    ERIC Educational Resources Information Center

    Tomasik, Janice Hall; Cottone, Katelyn E.; Heethuis, Mitchell T.; Mueller, Anja

    2013-01-01

    Incorporating research-based lab activities into general chemistry at a large university can be challenging, considering the high enrollments and costs typically associated with the courses. Performing sweeping curricular overhauls of the general chemistry laboratory can be difficult, and in some cases discouraged, as many would rather maintain…

  7. Supramolecular chemistry—general principles and selected examples from anion recognition and metallosupramolecular chemistry

    NASA Astrophysics Data System (ADS)

    Albrecht, Markus

    2007-12-01

    This review gives an introduction into supramolecular chemistry describing in the first part general principles, focusing on terms like noncovalent interaction, molecular recognition, self-assembly, and supramolecular function. In the second part those will be illustrated by simple examples from our laboratories. Supramolecular chemistry is the science that bridges the gap between the world of molecules and nanotechnology. In supramolecular chemistry noncovalent interactions occur between molecular building blocks, which by molecular recognition and self-assembly form (functional) supramolecular entities. It is also termed the “chemistry of the noncovalent bond.” Molecular recognition is based on geometrical complementarity based on the “key-and-lock” principle with nonshape-dependent effects, e.g., solvatization, being also highly influential. Self- assembly leads to the formation of well-defined aggregates. Hereby the overall structure of the target ensemble is controlled by the symmetry features of the certain building blocks. Finally, the aggregates can possess special properties or supramolecular functions, which are only found in the ensemble but not in the participating molecules. This review gives an introduction on supramolecular chemistry and illustrates the fundamental principles by recent examples from our group.

  8. A Content Analysis of General Chemistry Laboratory Manuals for Evidence of Higher-Order Cognitive Tasks

    NASA Astrophysics Data System (ADS)

    Domin, Daniel S.

    1999-01-01

    The science laboratory instructional environment is ideal for fostering the development of problem-solving, manipulative, and higher-order thinking skills: the skills needed by today's learner to compete in an ever increasing technology-based society. This paper reports the results of a content analysis of ten general chemistry laboratory manuals. Three experiments from each manual were examined for evidence of higher-order cognitive activities. Analysis was based upon the six major cognitive categories of Bloom's Taxonomy of Educational Objectives: knowledge, comprehension, application, analysis, synthesis, and evaluation. The results of this study show that the overwhelming majority of general chemistry laboratory manuals provide tasks that require the use of only the lower-order cognitive skills: knowledge, comprehension, and application. Two of the laboratory manuals were disparate in having activities that utilized higher-order cognition. I describe the instructional strategies used within these manuals to foster higher-order cognitive development.

  9. Impact of testing styles and testing methods on achievement in general chemistry

    NASA Astrophysics Data System (ADS)

    Howell, Byron Edward

    2001-12-01

    This research conducted at a community college located in Northeast Texas studied testing style and testing methods in relation to achievement in general chemistry. Data was collected and examined from 212 participants. Of these, 143 completed both the MBTI and PEPS surveys. This provided 71 subjects designated as Sensor (S) types for the final phase of the study. The subjects were divided into two groups by performance on the PEPS. One group consisted of subjects that indicated a preference to communicate (test) using a formal/pencil-paper test format (linguistic testing style) and the other subjects indicated a preference to communicate (test) using a hands-on/movement test format (tactile testing style). All subjects were administered both a linguistic and tactile pretest prior to treatment and both a linguistic and tactile posttest after treatment. The data was analyzed using a 2 x 2 ANOVA for significant effects at the p < 0.05 level of confidence. The results indicated a significant interaction effect between the student testing style and test methods. While not conclusive, this study does indicate that the type of testing done in general chemistry may be favoring students with certain types of communication preferences (testing styles). Therefore students with many of the worker characteristics desired by the chemical industry may not be successful in general chemistry and choose a different career path.

  10. When West Meets East: Generalizing Theory and Expanding the Conceptual Toolkit of Criminology

    PubMed Central

    Messner, Steven F.

    2016-01-01

    This paper considers the ways in which established criminological theories born and nurtured in the West might need to be transformed to be applicable to the context of East Asian societies. The analyses focus on two theoretical perspectives—Situational Action Theory and Institutional Anomie Theory—that are located at opposite ends of the continuum with respect to levels of analysis. I argue that the accumulated evidence from cross-cultural psychology and criminological research in East Asian societies raises serious questions about the feasibility of simply transporting these perspectives from the West to the East. Instead, my analyses suggest that the formulation of theoretical explanations of crime that are truly universal will require criminologists to create and incorporate new concepts that are more faithful to the social realities of non-Western societies, societies such as those in East Asia and Asia more generally. PMID:27087864

  11. When West Meets East: Generalizing Theory and Expanding the Conceptual Toolkit of Criminology.

    PubMed

    Messner, Steven F

    2015-06-01

    This paper considers the ways in which established criminological theories born and nurtured in the West might need to be transformed to be applicable to the context of East Asian societies. The analyses focus on two theoretical perspectives-Situational Action Theory and Institutional Anomie Theory-that are located at opposite ends of the continuum with respect to levels of analysis. I argue that the accumulated evidence from cross-cultural psychology and criminological research in East Asian societies raises serious questions about the feasibility of simply transporting these perspectives from the West to the East. Instead, my analyses suggest that the formulation of theoretical explanations of crime that are truly universal will require criminologists to create and incorporate new concepts that are more faithful to the social realities of non-Western societies, societies such as those in East Asia and Asia more generally.

  12. Why has the bohr-sommerfeld model of the atom been ignoredby general chemistry textbooks?

    PubMed

    Niaz, Mansoor; Cardellini, Liberato

    2011-12-01

    Bohr's model of the atom is considered to be important by general chemistry textbooks. A major shortcoming of this model was that it could not explain the spectra of atoms containing more than one electron. In order to increase the explanatory power of the model, Sommerfeld hypothesized the existence of elliptical orbits. This study has the following objectives: 1) Formulation of criteria based on a history and philosophy of science framework; and 2) Evaluation of university-level general chemistry textbooks based on the criteria, published in Italy and U.S.A. Presentation of a textbook was considered to be "satisfactory" if it included a description of the Bohr-Sommerfeld model along with diagrams of the elliptical orbits. Of the 28 textbooks published in Italy that were analyzed, only five were classified as "satisfactory". Of the 46 textbooks published in U.S.A., only three were classified as "satisfactory". This study has the following educational implications: a) Sommerfeld's innovation (auxiliary hypothesis) by introducing elliptical orbits, helped to restore the viability of Bohr's model; b) Bohr-Sommerfeld's model went no further than the alkali metals, which led scientists to look for other models; c) This clearly shows that scientific models are tentative in nature; d) Textbook authors and chemistry teachers do not consider the tentative nature of scientific knowledge to be important; e) Inclusion of the Bohr-Sommerfeld model in textbooks can help our students to understand how science progresses.

  13. Distribution and budget of O3 in the troposphere calculated with a chemistry general circulation model

    NASA Astrophysics Data System (ADS)

    Roelofs, Geert-Jan; Lelieveld, Jos

    1995-10-01

    We present results of global tropospheric chemistry simulations with the coupled chemistry/atmospheric general circulation model ECHAM. Ultimately, the model will be used to study climate changes induced by anthropogenic influences on the chemistry of the atmosphere; meteorological parameters that are important for the chemistry, such as temperature, humidity, air motions, cloud and rain characteristics, and mixing processes are calculated on-line. The chemical part of the model describes background tropospheric CH4-CO-NOx-HOx photochemistry. Emissions of NO and CO, surface concentrations of CH4, and stratospheric concentrations of O3 and NOy are prescribed as boundary conditions. Calculations of the tropospheric O3 budget indicate that seasonal variabilities of the photochemical production and of injection from the stratosphere are represented realistically, although some aspects of the model still need improvement. Comparisons of calculated O3 surface concentrations and O3 profiles with available measurements show that the model reproduces O3 distributions in remote tropical and midlatitudinal sites. Also, the model matches typical profiles connected with deep convection in the Intertropical Convergence Zone (ITCZ). However, the model tends to underestimate O3 concentrations at the poles and in relatively polluted regions. These underestimates are caused by the poor representation of tropopause foldings in midlatitudes, which form a significant source of tropospheric O3 from the stratosphere, too weak transport to the poles, and the neglect of higher hydrocarbon chemistry. Also, mixing of polluted continental boundary layer air into the free troposphere may be underestimated. We discuss how these model deficiencies will be improved in the future.

  14. Introduction of Mass Spectrometry in an First-Semester General Chemistry Laboratory Course: Quantification of Mtbe or Dmso in Water

    ERIC Educational Resources Information Center

    Solow, Mike

    2004-01-01

    Quantification of a contaminant in water provides the first-year general chemistry students with a tangible application of mass spectrometry. The relevance of chemistry to assessing and solving environmental problems is highlighted for students when they perform mass spectroscopy experiments.

  15. Improving Students' Inquiry Skills and Self-Efficacy through Research-Inspired Modules in the General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Winkelmann, Kurt; Baloga, Monica; Marcinkowski, Tom; Giannoulis, Christos; Anquandah, George; Cohen, Peter

    2015-01-01

    Research projects conducted by faculty in STEM departments served as the inspiration for a new curriculum of inquiry-based, multiweek laboratory modules in the general chemistry 1 course. The purpose of this curriculum redesign was to improve students' attitudes about chemistry as well as their self-efficacy and skills in performing inquiry…

  16. From Bhopal to Cold Fusion: A Case-Study Approach to Writing Assignments in Honors General Chemistry

    ERIC Educational Resources Information Center

    Chamely-Wiik, Donna M.; Haky, Jerome E.; Galin, Jeffrey R.

    2012-01-01

    Faculty from the chemistry and English departments have developed a combined second-semester honors general chemistry and college writing course that fosters critical thinking through challenging writing assignments. Examples of case-study writing assignments and guidelines are provided that faculty at other institutions can adapt in similar…

  17. The Role of Self-Regulated Learning in Explaining Examination Performance of College Students in First-Semester General Chemistry

    ERIC Educational Resources Information Center

    Beckley, Scott

    2013-01-01

    Many college students struggle with first-semester general chemistry. Prior studies have shown that a student's prior knowledge of chemistry, a cognitive factor, does not account for the total variance when measured by examination scores. This study explored the role of self-regulated learning (SRL) to identify the degree of success or failure of…

  18. Factors that promote success in large enrollment general chemistry courses taught with clickers

    NASA Astrophysics Data System (ADS)

    MacArthur, James R.

    The environment of a large (>300) enrollment first semester general chemistry course taught with clickers was characterized by statistical analysis of historical data, as well as through classroom observations and interviewing of professors and students. Four professors with experience teaching chemistry courses with clickers at this university were selected through purposeful sampling and interviewed. A total of 23 classroom observations were conducted. Data was collected from eleven students through interviews, emails, and focus groups. At the conclusion of the interview, students were categorized as field dependent, field intermediate, or field independent using a hidden figure test. Focus groups were assigned to represent one primarily field dependent group and one primarily field independent group. Interview, email, and focus group transcripts were analyzed until a theory of student interactions emerged. Student interactions are self-assembled, and the success of these interactions seems to be driven by the behavior of resonators: students who move throughout the classroom seeking interactions which maximize student learning.

  19. Analysis of the effect of student cognizance of the learning cycle in general chemistry

    NASA Astrophysics Data System (ADS)

    Czapla, Matthew

    While the benefits of the using the Learning Cycle have been well researched, one area that has received surprisingly little investigation is the effect that student cognizance of the learning cycle has on student performance in chemistry. The Learning Cycle, with its strong theoretical roots in scientific practice and learning theory, offers a logical opportunity to educate students in the nature of science and metacognition. In addition, by examining the class holistically, students will have the opportunity to better link the lab and lecture components of the course. We hypothesized that since a keen understanding of the nature of science, strong metacognitive ability, and a holistic view of Learning Cycle classes have all been shown to increase student comprehension in general chemistry, students who were taught to understand the Learning Cycle would perform better than students who were not. Statistical analysis of survey and grade data will be presented.

  20. The Role of Water Chemistry in Marine Aquarium Design: A Model System for a General Chemistry Class

    ERIC Educational Resources Information Center

    Keaffaber, Jeffrey J.; Palma, Ramiro; Williams, Kathryn R.

    2008-01-01

    Water chemistry is central to aquarium design, and it provides many potential applications for discussion in undergraduate chemistry and engineering courses. Marine aquaria and their life support systems feature many chemical processes. A life support system consists of the entire recirculation system, as well as the habitat tank and all ancillary…

  1. Content Validation Studies of the AP Chemistry Examination.

    ERIC Educational Resources Information Center

    Taft, Hessy L.

    1990-01-01

    Described is a curriculum survey of general chemistry courses at the college level and an evaluation survey of the advanced placement chemistry examination. Results indicated that the AP chemistry course should remain broad in coverage and should expand its laboratory component. Analyses also indicated that the AP exam was appropriate and valid.…

  2. Impact of aircraft NOx emissions on tropospheric ozone calculated with a chemistry-general circulation model: Sensitivity to higher hydrocarbon chemistry

    NASA Astrophysics Data System (ADS)

    Kentarchos, A. S.; Roelofs, G. J.

    2002-07-01

    A three-dimensional chemistry-general circulation model has been employed to estimate the impact of current aircraft NOx emissions on tropospheric ozone. The model contains a representation of higher hydrocarbon chemistry, implemented by means of the Carbon Bond Mechanism 4 (CBM4), in order to investigate the potential effect of higher hydrocarbons on aircraft-induced ozone changes. Aircraft NOx emissions increase background NOX (= NO + NO2 + NO3 + 2N2O5 + HNO4) concentrations by 50-70 pptv in the upper troposphere over the Northern Hemisphere, and contribute up to 3 ppbv to upper tropospheric background ozone levels. When higher hydrocarbon chemistry is considered in the simulation, the aircraft-induced ozone perturbations are higher by ~12% during summer and the aircraft-induced ozone production efficiency per NOx molecule increases by ~20%, when compared to a simulation without higher hydrocarbon chemistry.

  3. 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.)

  4. Research and Teaching: Computational Methods in General Chemistry--Perceptions of Programming, Prior Experience, and Student Outcomes

    ERIC Educational Resources Information Center

    Wheeler, Lindsay B.; Chiu, Jennie L.; Grisham, Charles M.

    2016-01-01

    This article explores how integrating computational tools into a general chemistry laboratory course can influence student perceptions of programming and investigates relationships among student perceptions, prior experience, and student outcomes.

  5. Surface chemistry of grafted expanded poly(tetrafluoroethylene) membranes modifies the in vitro proinflammatory response in macrophages.

    PubMed

    Chandler-Temple, Adrienne; Kingshott, Peter; Wentrup-Byrne, Edeline; Cassady, A Ian; Grøndahl, Lisbeth

    2013-04-01

    A series of surface-modified expanded poly(tetrafluoroethylene) membranes showed varied levels of in vitro macrophage proinflammatory response. Membranes containing a mixture of phosphate and hydroxyl groups (as determined by X-ray photoelectron spectroscopy analysis) stimulate greater macrophage activation than samples containing a mixture of phosphate and carboxylic acid segments. The types of proteins that adsorbed irreversibly from serum onto the two samples with the highest and lowest cellular response were investigated using surface-matrix-assisted laser desorption ionisation time-of-flight mass spectrometry. Distinct differences in the number and type of proteins that adsorbed were observed between these samples. A correlation was found between the main protein components adsorbed onto the surfaces and the resulting in vitro proinflammatory response. This study strongly supports the hypothesis that the cellular response is not controlled directly by surface properties but is mediated by specific protein adsorption events. This in turn highlights the importance of better understanding and controlling the properties of intelligent surface-modified biomaterials.

  6. Modeling and analysis of aerosol processes in an interactive chemistry general circulation model

    NASA Astrophysics Data System (ADS)

    Verma, Sunita; Boucher, O.; Reddy, M. S.; Upadhyaya, H. C.; Le van, P.; Binkowski, F. S.; Sharma, O. P.

    2007-02-01

    An "online" aerosol dynamics and chemistry module is included in the Laboratoire de Météorologie Dynamique general circulation model (LMDZ), so that the chemical species are advected at each dynamical time step and evolve through chemical and physical processes that have been parameterized consistently with the meteorology. These processes include anthropogenic and biogenic emissions, over 50 gas/aqueous phase chemical reactions, transport due to advection, vertical diffusion and convection, dry deposition and wet scavenging. We have introduced a size-resolved representation of aerosols which undergo various processes such as coagulation, nucleation and dry and wet scavenging. The model considers 16 prognostic tracers: water vapor, liquid water, dimethyl sulfide (DMS), hydrogen sulfide (H2S), dimethyl sulphoxide (DMSO), methanesulphonic acid (MSA), sulfur dioxide (SO2), nitrogen oxides (NOX), carbon monoxide (CO), nitric acid (HNO3), ozone (O3), hydrogen peroxide (H2O2), sulfate mass and number for Aitken and accumulation modes. The scheme accounts for two-way interactions between tropospheric chemistry and aerosols. The oxidants and chemical species fields that represent the sulfate aerosol formation are evolved interactively with the model dynamics. A detailed description on the coupled climate-chemistry interactive module is presented with the evaluation of chemical species in winter and summer seasons. Aqueous phase reactions in cloud accounted for 71% of sulfate production rate, while only 45% of the sulfate burden in the troposphere is derived from in-cloud oxidation.

  7. Assessing student perspectives of the laboratory, self-efficacy in chemistry, and attitudes towards science in an undergraduate first-semester general chemistry laboratory

    NASA Astrophysics Data System (ADS)

    Olave, Marcella

    Research is lacking in the general chemistry laboratory that explores the concerted affective predictor variables of student perspectives of the laboratory, self-efficacy in chemistry, and student attitudes towards science. There is little research on the assessment of variables in the affective domain to determine student experiences in the chemistry laboratory. Student experiences in this study were assessed by determining congruence between student perspectives of their actual and preferred general chemistry laboratory environment using the SLEI, and student attitudes towards careers as a scientist using the SAI II. Correlations between scales from the SLEI, SAI II along with the CCSS that measures self-efficacy in college chemistry were identified. A sample of eighty college students enrolled in a first-semester general chemistry laboratory responded to the SLEI, SAI II, and CCSS. A t test indicated there were no significant differences with student cohesiveness, integration, material environment, and rule clarity between the actual and preferred SLEI signifying congruence. There were significant differences between students actual and preferred perception of open-endedness (t = -3.59, df = 28, p = 0.00). Student attitudes towards careers as a scientist could not be determined using pretests and posttests of the SAI II due to a ceiling effect. There were positive significant correlations found between the scales of material environment, integration from the SLEI and the scale of student attitudes towards careers as a scientist using the SAI II. There were also positive significant correlations between self-efficacy for everyday applications, and self-efficacy for cognitive skills from the CCSS with the scale of student attitudes towards careers as a scientist. This study is of significance since it is the first study exploring congruence between the actual and preferred student perspectives of the laboratory using the SLEI in a first semester general chemistry

  8. Implementation of a PETN failure model using ARIA's general chemistry framework

    SciTech Connect

    Hobbs, Michael L.

    2017-01-01

    We previously developed a PETN thermal decomposition model that accurately predicts thermal ignition and detonator failure [1]. This model was originally developed for CALORE [2] and required several complex user subroutines. Recently, a simplified version of the PETN decomposition model was implemented into ARIA [3] using a general chemistry framework without need for user subroutines. Detonator failure was also predicted with this new model using ENCORE. The model was simplified by 1) basing the model on moles rather than mass, 2) simplifying the thermal conductivity model, and 3) implementing ARIA’s new phase change model. This memo briefly describes the model, implementation, and validation.

  9. Teaching Is Learning--Maximum Incentive, Minimum Discipline in Student Groups Teaching General Chemistry

    NASA Astrophysics Data System (ADS)

    Benvenuto, Mark

    2001-02-01

    A novel form of teaching and test scoring has been developed, in which student group work and test performance are linked to bonus points on weekly quizzes. A class of 71 students was divided into 12 groups of five or six students. The groups taught sections of a general chemistry class, and their test grades were adjusted upward on the basis of the scores achieved for each quiz or test. The scoring technique involves the possibility of only upward adjustments, to maximize positive reinforcement for good test performance. Work requirements resulting from this technique, for both the students and the faculty member, are discussed.

  10. Evaluation of the atmospheric chemistry general circulation model ECHAM5/MESSy1

    NASA Astrophysics Data System (ADS)

    Joeckel, P.; Tost, H.; Pozzer, A.; Bruehl, C.; Buchholz, J.; Ganzeveld, L.; Hoor, P.; Kerkweg, A.; Lawrence, M. G.; Metzger, S.; Sander, R.; Steil, B.; Stiller, G.; Tanarhte, M.; Taraborrelli, D.; van Aardenne, J.; Lelieveld, J.

    2006-12-01

    We present the new Modular Earth Submodel System (MESSy) coupled to the 5th generation European Centre Hamburg GCM, ECHAM5. MESSy describes atmospheric chemistry and meteorological processes in a modular framework, following strict coding standards. This approach is chosen to face the challenges associated with increasing model complexity. The resulting model system is portable, user-friendly and easily expandable. The system enables the testing of different modules of the same processes (e.g. convection) under otherwise identical numerical conditions. In a first model evaluation simulation we apply a 90-layer model setup up to 0.01 hPa at T42 spectral resolution to simulate the dynamics and chemistry, both coupled via radiation, of the lower and middle atmosphere. A Newtonian relaxation technique was applied in the troposphere to weakly nudge the model towards the analysed (ECMWF) meteorology during the period 1998-2005. This technique allows a direct comparison of model results with observations. It is shown that the tropospheric wave forcing of the stratosphere in the model suffices to reproduce the Quasi- Biennial Oscillation and major stratospheric warming events leading e.g. to the vortex split over Antarctica in 2002. The model realistically simulates stratosphere-troposphere exchange processes as shown by comparisons with satellite and in situ measurements. The main characteristics of the trace gas distributions are reproduced well. In summary, the model consistently simulates the state of the atmosphere from the surface to the mesosphere without the need to prescribe artifical boundary conditions, e.g., such as ozone at the tropopause.

  11. Getting Real: A General Chemistry Laboratory Program Focusing on "Real World" Substances

    NASA Astrophysics Data System (ADS)

    Kerber, Robert C.; Akhtar, Mohammad J.

    1996-11-01

    working with these materials, we present chemical structures wherever possible, but do not emphasize organic nomenclature or functional group chemistry beyond identifying, as appropriate, acidic and basic groups and other key structural features. 3. As can be appreciated from Table 1, the course organization is overtly based on the nature of the materials themselveshousehold "chemicals", food and beverages, pills, and plasticsrather than on abstract chemical principles. Organizing the course on the basis of the materials studied emphasizes their relevance to students and focuses interest on the actual results obtained by the individual students. Nevertheless, a coherent sequence of development of laboratory techniques and gradually increasing opportunity for less tightly directed student experiences is maintained. Laboratory exercises cover most of the usual topics, including stoichiometry, qualitative analysis, quantitative analyses by acid-base and redox titrations, and colorimetry. We have not, however, found or devised exercises dealing with thermochemistry or electrochemistry; readers' suggestions in these areas would be welcome. 4. The instruments, equipment, and techniques used in the laboratory initially were the same as previously used, so that we have been able to introduce this program without initial capital expenditure. The exercises rely substantially upon mass measurements and titrations, with pH meters and colorimeters brought into use as the year progresses. We are now in the process of introducing Fourier transform infrared (FTIR) methods into the laboratories. This will add a very powerful tool to the students' repertoire. Its use will greatly expand the opportunities for directed-inquiry investigations of real-world samples in the context of the course. 5. Some of the exercises in Table 1 will be recognized by readers of this Journal as standard ones, found in many lab manuals or available as commercial modules (2). To provide a comprehensive focus on

  12. The Effects of Fasting and General Anesthesia on Serum Chemistries in KCG Miniature Pigs

    PubMed Central

    Tanaka, Hozumi; Igarashi, Takashi; Lefor, Alan T; Kobayashi, Eiji

    2009-01-01

    Investigators are obligated to optimize the perioperative care of experimental animals, but little is known about the effects of anesthesia and surgery on serum chemistries in KCG pigs. The objective of this study was to examine the influence of fasting and surgery under general anesthesia on 27 serum chemistries in KCG miniature pigs to improve management. Crossbred KCG minipigs were used at a mean of 12.3 mo of age (range, 8.6 to 14.9) and 33.4 kg of body weight (range, 24.0 to 40.2). Serum chemistries were evaluated at the start and end of a 24 h fasting period in fasted animals (n = 6). No significant differences were observed between the starting and postfasting studies. Partial hemilaminectomy of the lumbar spine was carried out in 2 groups of animals. Those given sevoflurane anesthesia (n = 7) had significant decreases in serum albumin, potassium, inorganic phosphorus, γ-glutamyltransferase peptidase, cholinesterase, and glucose postoperatively compared with preoperative values. Animals given isoflurane (n = 7) anesthesia had significantly decreased total protein, albumin, triglyceride, phospholipids, sodium, potassium, calcium, alanine aminotransferase, alkaline phoshatase and glucose after surgery compared with levels before surgery. In a separate experiment (n = 7), serum glucose and insulin also decreased during the postoperative period after isoflurane anesthesia. These results demonstrate that select serum electrolytes, glucose, and insulin of KCG miniature pigs are altered after general anesthesia. Investigators must be aware of the effects of anesthetic agents on experimental animals to provide optimal care and for interpretation of experimental data. PMID:19245748

  13. Effects on Student Achievement in General Chemistry following Participation in an Online Preparatory Course: ChemPrep, a Voluntary, Self-Paced, Online Introduction to Chemistry

    ERIC Educational Resources Information Center

    Botch, Beatrice; Day, Roberta; Vining, William; Stewart, Barbara; Rath, Kenneth; Peterfreund, Alan; Hart, David

    2007-01-01

    ChemPrep was developed to be a stand-alone preparatory short-course to help students succeed in general chemistry. It is Web-based and delivered using the OWL system. Students reported that the ChemPrep materials (short information pages, parameterized questions with detailed feedback, tutorials, and answers to questions through the OWL message…

  14. Cooperative Learning and Enhanced Communication: Effects on Student Performance, Retention, and Attitudes in General Chemistry

    NASA Astrophysics Data System (ADS)

    Dougherty, R. C.; Bowen, C. W.; Berger, T.; Rees, W.; Mellon, E. K.; Pulliam, E.

    1995-09-01

    This report discusses the retention and performance of three sections of general chemistry that utilized different levels of cooperative learning and enhanced communication. The structured cooperative section (S-coop) required that students belonged to study groups, had group homework and group quizzes and had course credit driven electronic mail. The unstructured cooperative section (U-coop) encouraged students to form optional informal groups and provided for optional enhanced communication by paper mail. The control section used a standard lecture format without any cooperative learning or enhanced communication options. The student retention (C or better) was S-coop 85 %, U-coop 76 %, and Control 59 % (all differences were statistically significant). On the final exam the percent correct for common questions was S-coop 58%, U-coop 60%, and Control 55%. Adjusted for the difference in retention there was no significant difference between the two cooperative sections. The results of the Student Instructional Rating System for the three sections had the following percentage of students agreeing that the instructor was an effective teacher: S-coop 74%; U-coop 99%; and Control 80%. In all cases the differences were statistically significant. We conclude that a structured cooperative learning environment with enhanced communication can improve overall student retention and performance in general chemistry.

  15. What Do Conceptual Holes in Assessment Say about the Topics We Teach in General Chemistry?

    ERIC Educational Resources Information Center

    Luxford, Cynthia J.; Holme, Thomas A.

    2015-01-01

    Introductory chemistry has long been considered a service course by various departments that entrust chemistry departments with teaching their students. As a result, most introductory courses include a majority of students who are not chemistry majors, and many are health and science related majors who are required to take chemistry. To identify…

  16. Development of the formal reasoning abilities of college students in a general chemistry guided-inquiry laboratory

    NASA Astrophysics Data System (ADS)

    Monteyne, Kereen

    Reform efforts in science education have been galvanized around the idea that instruction based on inquiry will increase science achievement and promote the development of higher-order thinking skills. The problem with many inquiry-oriented curriculum materials at the college level that aim to increase conceptual understanding of science is the implicit assumption that students are already skilled in higher-order thinking. Research has shown that only 25% of college freshmen consistently apply these skills. The purpose of this research study is to compare the effectiveness of a formal-reasoning-centered to a chemistry-concept-centered general chemistry guided-inquiry laboratory curriculum. Each curriculum was delivered during twelve laboratory meetings over a period of one semester to a sample of 91 college students enrolled in a first-term general chemistry course. Measures used in this study include the ability to use formal reasoning skills, the ability to abstract use of formal reasoning from context, understanding of chemistry concepts, and perception of learning gains (attitude). The results of this research show that a formal-reasoning-centered curriculum is more effective than a chemistry-concept-centered curriculum on specific-transfer measures of formal reasoning using a chemistry context. No differences between the two curricula were found on specific- or nonspecific-transfer measures of formal reasoning using a general (non-chemistry) context. Students using a formal-reasoning-centered curriculum were more able to abstract use of formal reasoning from context. No differences between the curricula were found on measures of understanding chemistry concepts. Students using a chemistry-concept-centered curriculum reported more positive attitudes towards laboratory-based instruction.

  17. 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.

  18. General Chemistry Students' Understanding of the Chemistry Underlying Climate Science and the Development of a Two-Tiered Multiple-Choice Diagnostic Instrument

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    As part of the NSF funded Visualizing the Chemistry of Climate Change (VC3) project, we have developed a chemistry of climate science diagnostic instrument for use in general chemistry courses based on twenty-four student interviews. We have based our interview protocol on misconceptions identified in the research literature and the essential principles of climate change outlined in the CCSP document that pertain to chemistry (CCSP, 2009). The undergraduate student interviews elicited their understanding of the greenhouse effect, global warming, climate change, greenhouse gases, climate, and weather, and the findings from these interviews informed and guided the development of the multiple-choice diagnostic instrument. Our analysis and findings from the interviews indicate that students seem to confuse the greenhouse effect, global warming, and the ozone layer and in terms of chemistry concepts, the students lack a particulate level understanding of greenhouse gases causing them to not fully conceptualize the greenhouse effect and climate change. Details of the findings from the interviews, development of diagnostic instrument, and preliminary findings from the full implementation of the diagnostic instrument will be shared.

  19. Introductory Molecular Orbital Theory: An Honors General Chemistry Computational Lab as Implemented Using Three-Dimensional Modeling Software

    ERIC Educational Resources Information Center

    Ruddick, Kristie R.; Parrill, Abby L.; Petersen, Richard L.

    2012-01-01

    In this study, a computational molecular orbital theory experiment was implemented in a first-semester honors general chemistry course. Students used the GAMESS (General Atomic and Molecular Electronic Structure System) quantum mechanical software (as implemented in ChemBio3D) to optimize the geometry for various small molecules. Extended Huckel…

  20. Climate Change Concepts and POGIL: Using climate change to teach general chemistry

    NASA Astrophysics Data System (ADS)

    King, D. B.; Lewis, J. E.; Anderson, K.; Latch, D.; Sutheimer, S.; Webster, G.; Middlecamp, C.; Moog, R.

    2013-12-01

    Climate change is a topic that can be used to engage students in a variety of courses and disciplines. Through an NSF-funded project, we have written a set of in-class POGIL (Process Oriented Guided Inquiry Learning) activities that use climate change topics to teach general chemistry concepts. POGIL is a pedagogical approach that uses group activities to teach content and process skills. In these group activities an initial model and a series of critical thinking questions are used to guide students through the introduction to or application of course content. Students complete the activities on their own, with the faculty member as a facilitator of learning, rather than a provider of information. Through assigned group roles and intentionally designed activity structure, process skills, such as teamwork, communication, and information processing, are developed during completion of the activity. While POGIL activities were initially developed for chemistry courses, this approach has now been used to create materials for use in other fields, such as biology, math, engineering and computer science. An additional component of this project is the incorporation of questions that relate to socio-scientific issues, e.g., the economic and social effects of climate change policies. The goal is for students to use evidence-based arguments in situations where opinion-based arguments are common. Key components (i.e., models and the corresponding critical thinking questions) of one activity will be presented. We will also report preliminary feedback based on initial classroom testing of several of the activities.

  1. Podcast effectiveness as scaffolding support for students enrolled in first-semester general chemistry laboratories

    NASA Astrophysics Data System (ADS)

    Powell, Mary Cynthia Barton

    Podcasts covering essential first-semester general chemistry laboratory techniques and central concepts that aid in experimental design or data processing were prepared and made available for students to access on an as-needed basis on iPhones→ or iPod touches→. Research focused in three areas: the extent of podcast usage, the numbers and types of interactions between instructors and research teams, and student performance on graded assignments. Data analysis indicates that the podcast treatment research teams accessed a podcast 2.86 times on average during each week that podcasts were available. Comparison of interaction data for the lecture treatment research teams and podcast treatment research teams reveals that interactions with instructors were statistically significantly fewer for teams that had podcast access rather than a pre-laboratory lecture. The implication of the results is that student research teams were able to gather laboratory information more effectively when it was presented in an on-demand podcast format. Finally, statistical analysis of data on student performance on graded assignments indicates no significant differences between outcome measures for the treatment groups when compared as cohorts. The only statistically significant difference is between students judged to be highly motivated; for this sub-group the students in the podcast treatment group earned a course average that was statistically significantly higher than those in the lecture treatment group. This research study provides some of the first data collected on the effectiveness of podcasts delivered as needed in a first-semester general chemistry laboratory setting.

  2. Exploring students' interactions, arguments, and reflections in general chemistry laboratories with different levels of inquiry

    NASA Astrophysics Data System (ADS)

    Xu, Haozhi

    Students' learning in inquiry-based investigations has drawn considerable attention of the science education community. Inquiry activities can be viewed as knowledge construction processes in which students are expected to develop conceptual understanding and critical thinking abilities. Our study aimed to explore the effect of experiments with different levels of inquiry on students' interactions in the laboratory setting, as well as on students' written arguments and reflections. Our results are based on direct observations of group work in college general chemistry laboratories and analysis of associated written lab reports. The analysis of students' interactions in the laboratory was approached from three major analytic dimensions: Functional analysis, cognitive processing, and social processing. According to our results, higher levels of inquiry were associated with an increase in the relative frequency of episodes where students were engaged in proposing ideas versus asking and answering each others' questions. Higher levels of inquiry also favored episodes in which experimental work was approached in a more exploratory (versus procedural) manner. However, no major changes were observed in the extent to which students were engaged in either interpretive discussions of central scientific concepts and ideas. As part of our study we were also interested in characterizing the effects of experiments involving different levels of inquiry on the structure and adequacy of university general chemistry students' written arguments, as well as on the nature of their reflections about laboratory work. Our findings indicate that the level of inquiry of the observed experiments had no significant impact on the structure or adequacy of arguments generated by students. However, the level of inquiry of the experiments seemed to have a major impact on several areas of students' written reflections about laboratory work. In general, our results elicit trends and highlight issues

  3. Effects on Student Achievement in General Chemistry Following Participation in an Online Preparatory Course. ChemPrep, a Voluntary, Self-Paced, Online Introduction to Chemistry

    NASA Astrophysics Data System (ADS)

    Botch, Beatrice; Day, Roberta; Vining, William; Stewart, Barbara; Rath, Kenneth; Peterfreund, Alan; Hart, David

    2007-03-01

    ChemPrep was developed to be a stand-alone preparatory short-course to help students succeed in general chemistry. It is Web-based and delivered using the OWL system. Students reported that the ChemPrep materials (short information pages, parameterized questions with detailed feedback, tutorials, and answers to questions through the OWL message system) permitted them to work independently without the need for textbook or lecture. On average, students who completed ChemPrep had higher grades in the subsequent GenChem, Nursing, and Honors chemistry courses, with a greater percentage achieving a grade of C- or higher. Participation in ChemPrep was voluntary, and more women than men responded. Students in the Honors course enrolled in ChemPrep in higher percentages than students in GenChem and Nursing. SAT and departmental math placement exam scores were used as proxy measures of prior achievement and ability. Based on these, Honors chemistry ChemPrep users were on par with their peers but performed better in the course than non-users. In GenChem and Nursing chemistry courses, ChemPrep helped students of high prior achievement and ability perform better than their achievement scores would predict. Weaker or less motivated students did not respond to the voluntary offerings of ChemPrep in the same numbers as stronger or more motivated students, and we are seeking alternate ways to reach this population.

  4. Development and evaluation of a thermochemistry concept inventory for college-level general chemistry

    NASA Astrophysics Data System (ADS)

    Wren, David A.

    The research presented in this dissertation culminated in a 10-item Thermochemistry Concept Inventory (TCI). The development of the TCI can be divided into two main phases: qualitative studies and quantitative studies. Both phases focused on the primary stakeholders of the TCI, college-level general chemistry instructors and students. Each phase was designed to collect evidence for the validity of the interpretations and uses of TCI testing data. A central use of TCI testing data is to identify student conceptual misunderstandings, which are represented as incorrect options of multiple-choice TCI items. Therefore, quantitative and qualitative studies focused heavily on collecting evidence at the item-level, where important interpretations may be made by TCI users. Qualitative studies included student interviews (N = 28) and online expert surveys (N = 30). Think-aloud student interviews (N = 12) were used to identify conceptual misunderstandings used by students. Novice response process validity interviews (N = 16) helped provide information on how students interpreted and answered TCI items and were the basis of item revisions. Practicing general chemistry instructors (N = 18), or experts, defined boundaries of thermochemistry content included on the TCI. Once TCI items were in the later stages of development, an online version of the TCI was used in expert response process validity survey (N = 12), to provide expert feedback on item content, format and consensus of the correct answer for each item. Quantitative studies included three phases: beta testing of TCI items (N = 280), pilot testing of the a 12-item TCI (N = 485), and a large data collection using a 10-item TCI ( N = 1331). In addition to traditional classical test theory analysis, Rasch model analysis was also used for evaluation of testing data at the test and item level. The TCI was administered in both formative assessment (beta and pilot testing) and summative assessment (large data collection), with

  5. Removal of Aromatic Pollutant Surrogate from Water by Recyclable Magnetite-Activated Carbon Nanocomposite: An Experiment for General Chemistry

    ERIC Educational Resources Information Center

    Furlan, Ping Y.; Melcer, Michael E.

    2014-01-01

    A general chemistry laboratory experiment using readily available chemicals is described to introduce college students to an exciting class of nanocomposite materials. In a one-step room temperature synthetic process, magnetite nanoparticles are embedded onto activated carbon matrix. The resultant nanocomposite has been shown to combine the…

  6. Enhancing Student Performance in First-Semester General Chemistry Using Active Feedback through the World Wide Web

    ERIC Educational Resources Information Center

    Chambers, Kent A.; Blake, Bob

    2007-01-01

    The World Wide Web recently launched a new interactive feedback system for the instructors, so that can better understanding about their students and their problems. The feedback, in combination with tailored lectures is expected to enhance student performance in the first semester of general chemistry.

  7. Examining the Effectiveness of a Semi-Self-Paced Flipped Learning Format in a College General Chemistry Sequence

    ERIC Educational Resources Information Center

    Hibbard, Lisa; Sung, Shannon; Wells, Breche´

    2016-01-01

    Flipped learning has come to the forefront in education. It maximizes learning by moving content delivery online, where learning can be self-paced, allowing for class time to focus on student-centered active learning. This five-year cross-sectional study assessed student performance in a college general chemistry for majors sequence taught by a…

  8. Using Animations in Identifying General Chemistry Students' Misconceptions and Evaluating Their Knowledge Transfer Relating to Particle Position in Physical Changes

    ERIC Educational Resources Information Center

    Smith, K. Christopher; Villarreal, Savannah

    2015-01-01

    This article reports on the types of views and misconceptions uncovered after assessing 155 freshman general chemistry students on the concept of particle position during the reversible physical change of melting, using the Melting Cycle Instrument, which illustrates particulate-level representations of a melting-freezing cycle. Animations…

  9. Impact of the Flipped Classroom on Student Performance and Retention: A Parallel Controlled Study in General Chemistry

    ERIC Educational Resources Information Center

    Ryan, Michael D.; Reid, Scott A.

    2016-01-01

    Despite much recent interest in the flipped classroom, quantitative studies are slowly emerging, particularly in the sciences. We report a year-long parallel controlled study of the flipped classroom in a second-term general chemistry course. The flipped course was piloted in the off-semester course in Fall 2014, and the availability of the…

  10. Access to Knowledge and Critical Thinking in General Chemistry via Social Constructivism: Pedagogical and Curricular Opportunities for Minority Science Majors.

    ERIC Educational Resources Information Center

    Pushkin, David B.; Colon-Gonzalez, Maria H.

    This research study examines the nature of socio-cognitive influences on general chemistry students' learning and success. In this study, "learning" means gaining critical thinking skills and "success" means good academic grades. From a social constructivist and postmodern perspective, learning and success are considered functions of enculturation…

  11. Practical Work in Biology, Chemistry and Physics at Lower Secondary and General Upper Secondary Schools in Slovenia

    ERIC Educational Resources Information Center

    Sorgo, Andrej; Spernjak, Andreja

    2012-01-01

    Syllabi in the science subjects, biology, chemistry and physics at lower and general upper secondary school are compared in the light of their underlying philosophies, goals, objectives and recognized importance in science teaching. Even though all syllabi were prepared within the same framework, great differences among syllabi concerning…

  12. Flame Emission Spectrometry in General Chemistry Labs: Solubility Product (K[subscript sp]) of Potassium Hydrogen Phthalate

    ERIC Educational Resources Information Center

    Nyasulu, Frazier W.; Cusworth, William, III; Lindquist, David; Mackin, John

    2007-01-01

    In this general chemistry laboratory, flame emission spectrometry is used to determine the potassium ion concentration in saturated solutions of potassium hydrogen phthalate (KHP) in the 0-65 [degree]C temperature range. From these data the solubility products (K[subscript sp]), the Gibbs free energies of solution ([Delta][subscript…

  13. Learning How Students Learn: An Exploration of Self-Regulation Strategies in a Two-Year College General Chemistry Class

    ERIC Educational Resources Information Center

    Miller, Dionne A.

    2015-01-01

    This study investigated how students in an urban 2-year college used self-regulation strategies in a General Chemistry I course and whether their use was correlated with both performance and the ability to correctly predict performance on a course exam. The 142 students enrolled in all 10 sections of the course were asked to complete the Motivated…

  14. The Use of Gas Chromatography and Mass Spectrometry to Introduce General Chemistry Students to Percent Mass and Atomic Mass Calculations

    ERIC Educational Resources Information Center

    Pfennig, Brian W.; Schaefer, Amy K.

    2011-01-01

    A general chemistry laboratory experiment is described that introduces students to instrumental analysis using gas chromatography-mass spectrometry (GC-MS), while simultaneously reinforcing the concepts of mass percent and the calculation of atomic mass. Working in small groups, students use the GC to separate and quantify the percent composition…

  15. Estimating the One-Electron Reduction Potential for Vanadium (V) by Chemical Techniques: An Experiment for General Chemistry.

    ERIC Educational Resources Information Center

    Wentworth, R. A. D.

    1985-01-01

    Describes an experiment which requires only qualitative observations, is suitable for general chemistry students, prompts an understanding of thermodynamic spontaneity, gives chemical meaning to electrode potentials, requires non-electrochemical equipment, and allows estimates of the standard potential for the reduction of Vanadium (V) to V (IV).…

  16. The Use of Molecular Modeling as "Pseudoexperimental" Data for Teaching VSEPR as a Hands-On General Chemistry Activity

    ERIC Educational Resources Information Center

    Martin, Christopher B.; Vandehoef, Crissie; Cook, Allison

    2015-01-01

    A hands-on activity appropriate for first-semester general chemistry students is presented that combines traditional VSEPR methods of predicting molecular geometries with introductory use of molecular modeling. Students analyze a series of previously calculated output files consisting of several molecules each in various geometries. Each structure…

  17. Features of Representations in General Chemistry Textbooks: A Peek through the Lens of the Cognitive Load Theory

    ERIC Educational Resources Information Center

    Nyachwaya, James M.; Gillaspie, Merry

    2016-01-01

    The goals of this study were (1) determine the prevalence of various features of representations in five general chemistry textbooks used in the United States, and (2) use cognitive load theory to draw implications of the various features of analyzed representations. We adapted the Graphical Analysis Protocol (GAP) (Slough et al., 2010) to look at…

  18. Safety in the Chemical Laboratory: Reduction of Experimental Scale in High School and College General Chemistry Laboratories.

    ERIC Educational Resources Information Center

    Bennett, Carole A.; And Others

    1989-01-01

    Notes the careful observation of chemical reactivity phenomena has been and should be an important part of the general chemistry laboratory curriculum. Stresses reduction of experimental scale will help to ensure, in times of rampant chemophobia, that it remains so. Provides several examples of the methodology. (MVL)

  19. Implementation of Gas Chromatography and Microscale Distillation into the General Chemistry Laboratory Curriculum as Vehicles for Examining Intermolecular Forces

    ERIC Educational Resources Information Center

    Csizmar, Clifford M.; Force, Dee Ann; Warner, Don L.

    2011-01-01

    As part of an NSF-funded Course Curriculum and Laboratory Improvement (CCLI) project that seeks, in part, to increase student exposure to scientific instrumentation, a gas chromatography experiment has been integrated into the second-semester general chemistry laboratory curriculum. The experiment uses affordable, commercially available equipment…

  20. 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…

  1. Introduction of Differential Scanning Calorimetry in a General Chemistry Laboratory Course: Determination of Thermal Properties of Organic Hydrocarbons

    ERIC Educational Resources Information Center

    D'Amelia, Ronald; Franks, Thomas; Nirode, William F.

    2007-01-01

    In first-year general chemistry undergraduate courses, thermodynamics and thermal properties such as melting points and changes in enthalpy ([Delta]H) and entropy ([Delta]S) of phase changes are frequently discussed. Typically, classical calorimetric methods of analysis are used to determine [Delta]H of reactions. Differential scanning calorimetry…

  2. Two Methods of Determining Total Phenolic Content of Foods and Juices in a General, Organic, and Biological (GOB) Chemistry Lab

    ERIC Educational Resources Information Center

    Shaver, Lee Alan; Leung, Sam H.; Puderbaugh, Amy; Angel, Stephen A.

    2011-01-01

    The determination of total phenolics in foods and fruit juices was used successfully as a laboratory experiment in our undergraduate general, organic, and biological (GOB) chemistry course. Two different colorimetric methods were used over three years and comparative student results indicate that a ferrous ammonium sulfate (FAS) indicator…

  3. Identification of Unknown Chloride Salts Using a Combination of Qualitative Analysis and Titration with Silver Nitrate: A General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Maines, Laina L.; Bruch, Martha D.

    2012-01-01

    General chemistry students often have difficulty writing balanced equations and performing stoichiometry calculations for precipitation reactions, in part because of difficulty understanding the symbolic notation used to represent chemical reactions. We have developed a problem-based experiment to improve student learning of these concepts, and…

  4. Incrementally Approaching an Inquiry Lab Curriculum: Can Changing a Single Laboratory Experiment Improve Student Performance in General Chemistry?

    ERIC Educational Resources Information Center

    Cacciatore, Kristen L.; Sevian, Hannah

    2009-01-01

    Many institutions are responding to current research about how students learn science by transforming their general chemistry laboratory curricula to be inquiry-oriented. We present a comparison study of student performance after completing either a traditional or an inquiry stoichiometry experiment. This single laboratory experience was the only…

  5. Use of a PhET Interactive Simulation in General Chemistry Laboratory: Models of the Hydrogen Atom

    ERIC Educational Resources Information Center

    Clark, Ted M.; Chamberlain, Julia M.

    2014-01-01

    An activity supporting the PhET interactive simulation, Models of the Hydrogen Atom, has been designed and used in the laboratory portion of a general chemistry course. This article describes the framework used to successfully accomplish implementation on a large scale. The activity guides students through a comparison and analysis of the six…

  6. A Service-Learning Project Based on a Research Supportive Curriculum Format in the General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Kalivas, John H.

    2008-01-01

    This article describes a two-semester general chemistry laboratory teaching approach to assist students in gaining experience with science-process skills. The ultimate goal is successful completion of a second-semester service-learning project requiring use of their newly developed science-process skills. The project entails creating an…

  7. Effect of Clickers "versus" Online Homework on Students' Long-Term Retention of General Chemistry Course Material

    ERIC Educational Resources Information Center

    Gebru, Misganaw T.; Phelps, Amy J.; Wulfsberg, Gary

    2012-01-01

    This study reports the effects of student response systems (clickers) "versus" online homework on students' long-term retention of General Chemistry I course material. Long-term content retention was measured by a comprehensive yearlong American Chemical Society (ACS) GC97 exam administered seven months after students had completed the General…

  8. The Influence of Self-Efficacy and Motivational Factors on Academic Performance in General Chemistry Course: A Modeling Study

    ERIC Educational Resources Information Center

    Alci, Bulent

    2015-01-01

    This study aims to determine the predictive and explanatory model in terms of university students' academic performance in "General Chemistry" course and their motivational features. The participants were 169 university students in the 1st grade at university. Of the participants, 132 were female and 37 were male students. Regarding…

  9. TextRev: A Window into How General and Organic Chemistry Students Use Textbook Resources.

    ERIC Educational Resources Information Center

    Smith, Bradley D.; Jacobs, Dennis C.

    2003-01-01

    Points out the important use of textbooks and their ancillary resources in lower-division chemistry courses and the scientific misconceptions found in them. Introduces the TextRev Project which is a new resource for data collection and analysis. Investigates how first and second year chemistry students use and value their textbooks and their study…

  10. A dry deposition parameterization for sulfur oxides in a chemistry and general circulation model

    NASA Astrophysics Data System (ADS)

    Ganzeveld, Laurens; Lelieveld, Jos; Roelofs, Geert-Jan

    1998-03-01

    A dry deposition scheme, originally developed to calculate the deposition velocities for the trace gases O3, NO2, NO, and HNO3 in the chemistry and general circulation European Centre Hamburg Model (ECHAM), is extended to sulfur dioxide (SO2) and sulfate (SO42-). In order to reduce some of the shortcomings of the previous model version a local surface roughness and a more realistic leaf area index (LAI), derived from a high-resolution ecosystem database are introduced. The current model calculates the deposition velocities from the aerodynamic resistance, a quasi-laminary boundary layer resistance and a surface resistance of the surface cover, e.g., snow/ice, bare soil, vegetation, wetted surfaces, and ocean. The SO2 deposition velocity over vegetated surfaces is calculated as a function of the vegetation activity, the canopy wetness, turbulent transport through the canopy to the soil, and uptake by the soil. The soil resistance is explicitly calculated from the relative humidity and the soil pH, derived from a high-resolution global soil pH database. The snow/ice resistance of SO2 is a function of temperature. The SO2 deposition velocity over the oceans is controlled by turbulence. The sulfate deposition velocity is calculated considering diffusion, impaction, and sedimentation. Over sea surfaces the effect of bubble bursting, causing the breakdown of the quasi-laminary boundary layer, scavenging of the sulfate aerosol by sea spray, and aerosol growth due to high local relative humidities are considered. An integrated sulfate deposition velocity is calculated, applying a unimodal mass size distribution over land and a bimodal mass size distribution over sea. The calculated sulfate deposition velocity is about an order of magnitude larger than that based on a monodisperse aerosol, which is often applied in chemistry-transport models. Incorporation of the new dry deposition scheme in the ECHAM model yields significant relative differences (up to ˜50%) in mass flux

  11. Introduction of Differential Scanning Calorimetry in a General Chemistry Laboratory Course: Determination of Heat Capacity of Metals and Demonstration of Law of Dulong and Petit

    ERIC Educational Resources Information Center

    D'Amelia, Ronald P.; Stracuzzi, Vincent; Nirode, William F.

    2008-01-01

    Today's general chemistry students are introduced to many of the principles and concepts of thermodynamics. In first-year general chemistry undergraduate courses, thermodynamic properties such as heat capacity are frequently discussed. Classical calorimetric methods of analysis and thermal equilibrium experiments are used to determine heat…

  12. Identifying and Dealing with Hazardous Materials and Procedures in the General Chemistry Laboratory.

    ERIC Educational Resources Information Center

    Katz, David A.

    1982-01-01

    A survey of freshman chemistry laboratory manuals identified 15 questionable laboratory procedures, including the use of potentially hazardous chemicals. Alternatives are suggested for each hazard discussed (such as using a substitute solvent for benzene). (SK)

  13. Evaluation of a Mineral Dust Simulation in the Atmospheric-Chemistry General Circulation Model-EMAC

    NASA Astrophysics Data System (ADS)

    Abdel Kader, M.; Astitha, M.; Lelieveld, J.

    2012-04-01

    This study presents an evaluation of the atmospheric mineral dust cycle in the Atmospheric Chemistry General Circulation Model (AC-GCM) using new developed dust emissions scheme. The dust cycle, as an integral part of the Earth System, plays an important role in the Earth's energy balance by both direct and indirect ways. As an aerosol, it significantly impacts the absorption and scattering of radiation in the atmosphere and can modify the optical properties of clouds and snow/ice surfaces. In addition, dust contributes to a range of physical, chemical and bio-geological processes that interact with the cycles of carbon and water. While our knowledge of the dust cycle, its impacts and interactions with the other global-scale bio-geochemical cycles has greatly advanced in the last decades, large uncertainties and knowledge gaps still exist. Improving the dust simulation in global models is essential to minimize the uncertainties in the model results related to dust. In this study, the results are based on the ECHAM5 Modular Earth Submodel System (MESSy) AC-GCM simulations using T106L31 spectral resolution (about 120km ) with 31 vertical levels. The GMXe aerosol submodel is used to simulate the phase changes of the dust particles between soluble and insoluble modes. Dust emission, transport and deposition (wet and dry) are calculated on-line along with the meteorological parameters in every model time step. The preliminary evaluation of the dust concentration and deposition are presented based on ground observations from various campaigns as well as the evaluation of the optical properties of dust using AERONET and satellite (MODIS and MISR) observations. Preliminarily results show good agreement with observations for dust deposition and optical properties. In addition, the global dust emissions, load, deposition and lifetime is in good agreement with the published results. Also, the uncertainties in the dust cycle that contribute to the overall model performance

  14. Take-Home Challenges: Extending Discovery-Based Activities beyond the General Chemistry Classroom

    NASA Astrophysics Data System (ADS)

    Mason, P. K.; Sarquis, A. M.

    1996-04-01

    In an effort to more effectively integrate the experimental nature of chemistry into our students' experiences, we are developing and implementing discovery-based activities into both the laboratory and lecture components of general chemistry. Below we describe and provide an example of a "take-home challenge" intended to supplement the lecture component of the course. These take-home challenges involve the student in chemistry exploration outside of class and extend the context of content and experimentation into a nontraditional laboratory environment. Over 25 take-home challenges have been developed to date. Preliminary evaluation of the impact of the take-home challenges shows that students reporting themselves as receiving a B or C grade in the course find the challenges very useful in helping them gain a conceptual understanding of the phenomena addressed. Students earning an A grade report little or no impact on their learning. Prepared as one-page handouts, each take-home challenge begins with a scene-setting introduction followed by pertinent background information, a list of materials to be collected, and any appropriate safety precautions. The exploration component of the activity integrates leading questions with the procedural instructions to help guide the students through the discovery process and challenge them to stretch their understanding of the chemistry. After completing a take-home challenge activity, students submit written reports containing responses to the questions posed, observations of data collected, and their responses to the challenge. The accompanying sample take-home challenge activity is provided as a novel adaptation of the belch phenomenon that challenges students to experiment in order to explain the factors that account for the observed behavior. Persons interested in field testing the take-home challenges with their classes should contact the authors. Belch Bottle Challenge: What factors are responsible for the behavior of a

  15. Results of an interactively coupled atmospheric chemistry A~é general circulation model: Comparison with observations

    NASA Astrophysics Data System (ADS)

    Hein, R.; Dameris, M.; Schnadt, C.; Land, C.; Grewe, V.; Köhler, I.; Ponater, M.; Sausen, R.; Steil, B.; Landgraf, J.; Brühl, C.

    2001-04-01

    The coupled climate-chemistry model ECHAM4.L39(DLR)/CHEM is presented which enables a simultaneous treatment of meteorology and atmospheric chemistry and their feedbacks. This is the first model which interactively combines a general circulation model with a chemical model, employing most of the important reactions and species necessary to describe the stratospheric and upper tropospheric ozone chemistry, and which is computationally fast enough to allow long-term integrations with currently available computer resources. This is possible as the model time-step used for the chemistry can be chosen as large as the integration time-step for the dynamics. Vertically the atmosphere is discretized by 39 levels from the surface up to the top layer which is centred at 10 hPa, with a relatively high vertical resolution of approximately 700 m near the extra-tropical tropopause. We present the results of a control simulation representing recent conditions (1990) and compare it to available observations. The focus is on investigations of stratospheric dynamics and chemistry relevant to describe the stratospheric ozone layer. ECHAM4.L39(DLR)/CHEM reproduces main features of stratospheric dynamics in the arctic vortex region, including stratospheric warming events. This constitutes a major improvement compared to earlier model versions. However, apparent shortcomings in Antarctic circulation and temperatures persist. The seasonal and interannual variability of the ozone layer is simulated in accordance with observations. Activation and deactivation of chlorine in the polar stratospheric vortices and their inter-hemispheric differences are reproduced. Considering methane oxidation as part of the dynamic-chemistry feedback results in an improved representation of the spatial distribution of stratospheric water vapour concentrations. The current model constitutes a powerful tool to investigate, for instance, the combined direct and indirect effects of anthropogenic trace gas

  16. Utilization of the seven principles for good practice in undergraduate education in general chemistry by community college instructors

    NASA Astrophysics Data System (ADS)

    Panther Bishoff, Jennifer

    In recent years, higher education has undergone many changes. The advent of assessment, accountability, and a newfound focus on teaching have required faculty to examine how they are teaching. Administrators and faculty are beginning to recognize that learning is not a "one size fits all" enterprise. To this end, Chickering and Gamson developed an inventory that examined faculty utilization of the Seven Principles of Good Practice in Undergraduate Education. The seven principles included by the authors included faculty-student interaction, cooperative learning, active learning, giving prompt feedback, emphasizing time on task, communicating high expectations, and respecting diverse talents and ways of learning. It was determined by Chickering and Gamson, as well as many other researchers, that these seven principles were hallmarks of successful undergraduate education. Community colleges are important institutions to study, as many students begin their higher education at two-year colleges. Most students are also required to take one or more science classes for their general education requirements; therefore, many students must take at least one general chemistry course. Both community colleges and chemistry are rarely studied in literature, which makes this study important. Community college general chemistry instructors were surveyed using an online version of Chickering and Gamson's Faculty Inventory for the Seven Principles of Good Practice in Undergraduate Education. Responses were analyzed, and it was discovered that not only did instructors utilize the principles to a different extent, but there were also differences between genders as well as between the specific actions related to each principle.

  17. Productive whole-class discussions: A qualitative analysis of peer leader behaviors in general chemistry

    NASA Astrophysics Data System (ADS)

    Eckart, Teresa Mcclain

    The intention of this research was to describe behaviors and characteristics of General Chemistry I peer leaders using a pedagogical reform method referred to as Peer-led Guided Inquiry (PLGI), and to discuss the ways in which these peer leaders created productive whole-class discussions. This reform technique engaged students to work on guided inquiry activities while working cooperatively in small groups, led by undergraduate peer leaders. These sessions were video recorded and transcribed. The data was evaluated using grounded theory methods of analysis. This study examined the dialog between students and peer leaders, paying specific attention to question types and observed patterns of interactions. The research took shape by examining the kinds of questions asked by peer leaders and the purposes these questions served. In addition to looking at questions, different kinds of behaviors displayed by peer leaders during their small group sessions were also observed. A close examination of peer leader questions and behaviors aided in developing an answer to the overall research question regarding what factors are associated with productive whole-class discussions. Five major categories of peer leader behaviors evolved from the data and provided a means to compare and contrast productive whole-class discussions. While no category single-handedly determined if a discussion was good or bad, there was a tendency for peer leaders who exhibited positive traits in at least three of the following categories to have consistently better whole-class discussions: Procedural Practices, Supervisory Qualities, Questioning Techniques, Feedback/Responses, and Interpersonal Skills. Furthermore, each of the major categories is tied directly to Interpersonal, Communication, and Leadership skills and their interactions with each other. This study also addressed applications that each of these categories has on instructional practices and their need in peer leader training. In addition

  18. New reactions of germylenes with ketones and assessment of studio general chemistry

    NASA Astrophysics Data System (ADS)

    Sweeder, Ryan David

    New reaction modes of germylenes with ketones are presented. The germylene, Ge[CH(SiMe3)2]2 (1), will undergo reversible [4+2] addition with alkyl or aryl phenones to form a conjugated triene. Anthraquinone or 1,4-naphthylquinone will undergo a similar triene formation, but an insertion by a second molecule of 1 yields a product stable to reversion. In these cases, the second equivalent of germylene acts as a trap for the initially formed conjugated triene. A similar germylene, Ge[N(SiMe3)2]2 ( 2), reacts in analogous fashion with anthraquinone or 1,4-naphthylquinone indicating that it too engages in an equilibrium with phenones. The equilibrium for 2 with phenones lies heavily toward free 2 and phenone as no triene is detected via UV/Vis or NMR spectroscopies. Successful catalytic hydrogenation of the conjugate triene formed from the reaction of 1 with benzophenone is also presented. Other non-phenone ketones react with 1 via either CH or OH insertion. Three acetyl-containing ketones (acetone, butanone and cyclopropyl methyl ketone) have been observed to undergo CH insertion with 1 in the presence of one equivalent of MgCl2. The absence of MgCl 2 yields apparent OH insertion into the enol tautomer of the ketone. All secondary ketones examined undergo OH insertion even in the presence of MgCl2. The development, assessment and a description of a studio version of general chemistry are presented. This new course was implemented in the Fall 2002 semester at the University of Michigan. Content-based interviews focusing on equilibrium indicated that the students from the studio course had a better understanding of the underlying principles of equilibrium than their non-studio counterparts. The students enrolled in the studio course also gave more non-prompted explanations for a chemical reaction demonstrated during the interview, suggesting that they were more capable of transferring their chemical knowledge to new systems. The Motivated Strategies for Learning

  19. Getting Real: A General Chemistry Laboratory Program Focusing on "Real World" Substances.

    ERIC Educational Resources Information Center

    Kerber, Robert C.; Akhtar, Mohammad J.

    1996-01-01

    Describes a freshman laboratory program designed to interface between the substances that surround students in their ordinary lives and abstract principles presented in chemistry classrooms. Course organization is based on the nature of the materials themselves, which include household chemicals such as hydrogen peroxide, food and beverages, pills…

  20. The Use of Video Demonstrations and Particulate Animation in General Chemistry

    ERIC Educational Resources Information Center

    Velazquez-Marcano, Alexandra; Williamson, Vickie M.; Ashkenazi, Guy; Tasker, Roy; Williamson, Kenneth C.

    2004-01-01

    Different visualization techniques have been used for teaching chemistry concepts. Previous studies have shown that when molecular animations and video demonstrations are used, students seem to better correlate all three levels of representation: macroscopic, submicroscopic, and symbolic. This thinking process allows the students to improve their…

  1. 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…

  2. Design, Implementation, and Evaluation of a Flipped Format General Chemistry Course

    ERIC Educational Resources Information Center

    Weaver, Gabriela C.; SturtevantHannah G.

    2015-01-01

    Research has consistently shown that active problem-solving in a collaborative environment supports more effective learning than the traditional lecture approach. In this study, a flipped classroom format was implemented and evaluated in the chemistry majors' sequence at Purdue University over a period of three years. What was formerly lecture…

  3. 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…

  4. Investigating Macroscopic, Submicroscopic, and Symbolic Connections in a College-Level General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Thadison, Felicia Culver

    2011-01-01

    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…

  5. Green, Enzymatic Syntheses of Divanillin and Diapocynin for the Organic, Biochemistry, or Advanced General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Nishimura, Rachel T.; Giammanco, Chiara H.; Vosburg, David A.

    2010-01-01

    Environmentally benign chemistry is an increasingly important topic both in the classroom and the laboratory. In this experiment, students synthesize divanillin from vanillin or diapocynin from apocynin, using horseradish peroxidase and hydrogen peroxide in water. The dimerized products form rapidly at ambient temperature and are isolated by…

  6. A General Chemistry Assignment Analyzing Environmental Contamination for the Depue, IL, National Superfund Site

    ERIC Educational Resources Information Center

    Saslow Gomez, Sarah A.; Faurie-Wisniewski, Danielle; Parsa, Arlen; Spitz, Jeff; Spitz, Jennifer Amdur; Loeb, Nancy C.; Geiger, Franz M.

    2015-01-01

    The classroom exercise outlined here is a self-directed assignment that connects students to the environmental contamination problem surrounding the DePue Superfund site. By connecting chemistry knowledge gained in the classroom with a real-world problem, students are encouraged to personally connect with the problem while simultaneously…

  7. Connecting Solubility, Equilibrium, and Periodicity in a Green, Inquiry Experiment for the General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Cacciatore, Kristen L.; Amado, Jose; Evans, Jason J.; Sevian, Hannah

    2008-01-01

    We present a novel first-year chemistry laboratory experiment that connects solubility, equilibrium, and chemical periodicity concepts. It employs a unique format that asks students to replicate experiments described in different sample lab reports, each lacking some essential information, rather than follow a scripted procedure. This structure is…

  8. Online Grading of Calculations in General Chemistry Laboratory Write-Ups

    ERIC Educational Resources Information Center

    Silva, Alexsandra; Gonzales, Robert; Brennan, Daniel P.

    2010-01-01

    In the past, there were frequently complaints about the grading of laboratory reports in our laboratory chemistry courses. This article discussed the implementation of an online submission of laboratory acquired data using LON-CAPA (The Learning Online Network with Computer-Assisted Personalized Approach), which is an open source management and…

  9. Piloting Blended Strategies to Resolve Laboratory Capacity Issues in a First-Semester General Chemistry Course

    ERIC Educational Resources Information Center

    Burchett, Shayna; Hayes, Jack; Pfaff, Annalise; Satterfield, Emmalou T.; Skyles, Amy; Woelk, Klaus

    2016-01-01

    Laboratory capacity is an issue that has plagued education for more than a century. New buildings, late night classes, and virtual laboratories have offered transitory relief at great expense. Missouri University of Science and Technology is employing blended strategies to increase capacity and student success. Blended strategies expand learning…

  10. Exploring General Versus Task-Specific Assessments of Metacognition in University Chemistry Students: A Multitrait-Multimethod Analysis

    NASA Astrophysics Data System (ADS)

    Wang, Chia-Yu

    2015-08-01

    The purpose of this study was to use multiple assessments to investigate the general versus task-specific characteristics of metacognition in dissimilar chemistry topics. This mixed-method approach investigated the nature of undergraduate general chemistry students' metacognition using four assessments: a self-report questionnaire, assessment of concurrent metacognitive skills, confidence judgment, and calibration accuracy. Data were analyzed using a multitrait-multimethod correlation matrix, supplemented with regression analyses, and qualitative interpretation. Significant correlations among task performance, calibration accuracy, and concurrent metacognition within a task suggest a converging relationship. Confidence judgment, however, was not associated with task performance or the other metacognitive measurements. The results partially support hypotheses of both general and task-specific metacognition. However, general and task-specific properties of metacognition were detected using different assessments. Case studies were constructed for two participants to illustrate how concurrent metacognition varied within different task demands. Considerations of how each assessment may appropriate different metacognitive constructs and the importance of the alignment of analytical constructs when using multiple assessments are discussed. These results may help lead to improvements in metacognition assessment and may provide insights into designs of effective metacognitive instruction.

  11. Argumentation as a Lens to Examine Student Discourse in Peer-Led Guided Inquiry for College General Chemistry

    NASA Astrophysics Data System (ADS)

    Kulatunga, Ushiri Kumarihamy

    This dissertation work entails three related studies on the investigation of Peer-Led Guided Inquiry student discourse in a General Chemistry I course through argumentation. The first study, Argumentation and participation patterns in general chemistry peer-led sessions, is focused on examining arguments and participation patterns in small student groups without peer leader intervention. The findings of this study revealed that students were mostly engaged in co-constructed arguments, that a discrepancy in the participation of the group members existed, and students were able to correct most of the incorrect claims on their own via argumentation. The second study, Exploration of peer leader verbal behaviors as they intervene with small groups in college general chemistry, examines the interactive discourse of the peer leaders and the students during peer leader intervention. The relationship between the verbal behaviors of the peer leaders and the student argumentation is explored in this study. The findings of this study demonstrated that peer leaders used an array of verbal behaviors to guide students to construct chemistry concepts, and that a relationship existed between student argument components and peer leader verbal behaviors. The third study, Use of Tolumin's Argumentation Scheme for student discourse to gain insight about guided inquiry activities in college chemistry , is focused on investigating the relationship between student arguments without peer leader intervention and the structure of published guided inquiry ChemActivities. The relationship between argumentation and the structure of the activities is explored with respect to prompts, questions, and the segmented Learning Cycle structure of the ChemActivities. Findings of this study revealed that prompts were effective in eliciting arguments, that convergent questions produced more arguments than directed questions, and that the structure of the Learning Cycle successfully scaffolded arguments. A

  12. Dry deposition parameterization in a chemistry general circulation model and its influence on the distribution of reactive trace gases

    NASA Astrophysics Data System (ADS)

    Ganzeveld, Laurens; Lelieveld, Jos

    1995-10-01

    A dry deposition scheme has been developed for the chemistry general circulation model to improve the description of the removal of chemically reactive trace gases at the earth's surface. The chemistry scheme simulates background CH4-CO-NOx- HOx photochemistry and calculates concentrations of, for example, HNO3, NOx, and O3. A resistance analog is used to parameterize the dry deposition velocity for these gases. The aerodynamic resistance is calculated from the model boundary layer stability, wind speed, and surface roughness, and a quasi-laminar boundary layer resistance is incorporated. The stomatal resistance is explicitly calculated and combined with representative cuticle and mesophyll resistances for each trace gas. The new scheme contributes to internal consistency in the model, in particular with respect to diurnal and seasonal cycles in both the chemistry and the planetary boundary layer processes and surface characteristics that control dry deposition. Evaluation of the model indicates satisfactory agreement between calculated and observed deposition velocities. Comparison of the results with model simulations in which the deposition velocity was kept constant indicates significant relative differences in deposition fluxes and surface layer trace gas concentrations up to about ±35%. Shortcomings are discussed, for example, violation of the constant flux approach for the surface layer, the lacking canopy description, and effects of surface water layers.

  13. A study of two measures of spatial ability as predictors of success in different levels of general chemistry

    NASA Astrophysics Data System (ADS)

    Carter, Carolyn S.; Larussa, Mary A.; Bodner, George M.

    Preliminary data (Bodner and McMillen, 1986) suggested a correlation between spatial ability and performance in a general chemistry course for science and engineering majors. This correlation was seen not only on highly spatial tasks such as predicting the structures of ionic solids (r = 0.29), but also on tasks such as multiple-choice stoichiometry questions (r = 0.32) that might not be expected to involve spatial skills. To further investigate the relationship between spatial ability and performance in introductory chemistry courses, two spatial tests were given to 1648 students in a course for science and engineering majors (Carter, 1984) and 850 students in a course for students from nursing and agriculture (La-Russa, 1985) at Purdue. Scores on the spatial tests consistently contributed a small but significant amount to success on measures of performance in chemistry. Correlations were largest, however, for subscores that grouped questions that tested problem solving skills rather than rote memory or the application of simple algorithms, and correlations were also large for verbally complex questions thaty required the students to disembed and restructure relevant information.

  14. Nanocrystal conversion chemistry: A unified and materials-general strategy for the template-based synthesis of nanocrystalline solids

    SciTech Connect

    Vasquez, Yolanda; Henkes, Amanda E.; Chris Bauer, J.; Schaak, Raymond E.

    2008-07-15

    The concept of nanocrystal conversion chemistry, which involves the use of pre-formed nanoparticles as templates for chemical transformation into derivative solids, has emerged as a powerful approach for designing the synthesis of complex nanocrystalline solids. The general strategy exploits established synthetic capabilities in simple nanocrystal systems and uses these nanocrystals as templates that help to define the composition, crystal structure, and morphology of product nanocrystals. This article highlights key examples of 'conversion chemistry' approaches to the synthesis of nanocrystalline solids using a variety of techniques, including galvanic replacement, diffusion, oxidation, and ion exchange. The discussion is organized according to classes of solids, highlighting the diverse target systems that are accessible using similar chemical concepts: metals, oxides, chalcogenides, phosphides, alloys, intermetallic compounds, sulfides, and nitrides. - Graphical abstract: Nanocrystal conversion chemistry uses pre-formed nanoparticles as templates for chemical transformation into derivative solids, helping to define the composition, crystal structure, and morphology of product nanocrystals that have more complex features than their precursor templates. This article highlights the application of this concept to diverse classes of solids, including metals, oxides, chalcogenides, phosphides, alloys, intermetallics, sulfides, and nitrides.

  15. Efficient tree tensor network states (TTNS) for quantum chemistry: generalizations of the density matrix renormalization group algorithm.

    PubMed

    Nakatani, Naoki; Chan, Garnet Kin-Lic

    2013-04-07

    We investigate tree tensor network states for quantum chemistry. Tree tensor network states represent one of the simplest generalizations of matrix product states and the density matrix renormalization group. While matrix product states encode a one-dimensional entanglement structure, tree tensor network states encode a tree entanglement structure, allowing for a more flexible description of general molecules. We describe an optimal tree tensor network state algorithm for quantum chemistry. We introduce the concept of half-renormalization which greatly improves the efficiency of the calculations. Using our efficient formulation we demonstrate the strengths and weaknesses of tree tensor network states versus matrix product states. We carry out benchmark calculations both on tree systems (hydrogen trees and π-conjugated dendrimers) as well as non-tree molecules (hydrogen chains, nitrogen dimer, and chromium dimer). In general, tree tensor network states require much fewer renormalized states to achieve the same accuracy as matrix product states. In non-tree molecules, whether this translates into a computational savings is system dependent, due to the higher prefactor and computational scaling associated with tree algorithms. In tree like molecules, tree network states are easily superior to matrix product states. As an illustration, our largest dendrimer calculation with tree tensor network states correlates 110 electrons in 110 active orbitals.

  16. CLUSTER CHEMISTRY

    SciTech Connect

    Muetterties, Earl L.

    1980-05-01

    Metal cluster chemistry is one of the most rapidly developing areas of inorganic and organometallic chemistry. Prior to 1960 only a few metal clusters were well characterized. However, shortly after the early development of boron cluster chemistry, the field of metal cluster chemistry began to grow at a very rapid rate and a structural and a qualitative theoretical understanding of clusters came quickly. Analyzed here is the chemistry and the general significance of clusters with particular emphasis on the cluster research within my group. The importance of coordinately unsaturated, very reactive metal clusters is the major subject of discussion.

  17. The effect of participation in an extended inquiry project on general chemistry student laboratory interactions, confidence, and process skills

    NASA Astrophysics Data System (ADS)

    Krystyniak, Rebecca A.

    2001-12-01

    This study explored the effect of participation by second-semester general chemistry students in an extended open-inquiry laboratory investigation on their use of science process skills and confidence in performing specific aspects of laboratory investigations. In addition, verbal interactions of a student lab team among team members and with their instructor over three open-inquiry laboratory sessions and two non-inquiry sessions were investigated. Instruments included the Test of Integrated Skills (TIPS), a 36-item multiple-choice instrument, and the Chemistry Laboratory Survey (CLS), a researcher co-designed 20-item 8-point instrument. Instruments were administered at the beginning and close of the semester to 157 second-semester general chemistry students at the two universities; students at only one university participated in open-inquiry activity. A MANCOVA was performed to investigate relationships among control and experimental students, TIPS, and CLS post-test scores. Covariates were TIPS and CLS pre-test scores and prior high school and college science experience. No significant relationships were found. Wilcoxen analyses indicated both groups showed increase in confidence; experimental-group students with below-average TIPS pre-test scores showed a significant increase in science process skills. Transcribed audio tapes of all laboratory-based verbal interactions were analyzed. Coding categories, developed using the constant comparison method, led to an inter-rater reliability of .96. During open-inquiry activities, the lab team interacted less often, sought less guidance from their instructor, and talked less about chemistry concepts than during non-inquiry activities. Evidence confirmed that students used science process skills and engaged in higher-order thinking during both types of activities. A four-student focus shared their experiences with open-inquiry activities, indicating that they enjoyed the experience, viewed it as worthwhile, and believed

  18. Major Challenges for the Modern Chemistry in Particular and Science in General

    PubMed Central

    Uskokovíc, Vuk

    2013-01-01

    In the past few hundred years, science has exerted an enormous influence on the way the world appears to human observers. Despite phenomenal accomplishments of science, science nowadays faces numerous challenges that threaten its continued success. As scientific inventions become embedded within human societies, the challenges are further multiplied. In this critical review, some of the critical challenges for the field of modern chemistry are discussed, including: (a) interlinking theoretical knowledge and experimental approaches; (b) implementing the principles of sustainability at the roots of the chemical design; (c) defining science from a philosophical perspective that acknowledges both pragmatic and realistic aspects thereof; (d) instigating interdisciplinary research; (e) learning to recognize and appreciate the aesthetic aspects of scientific knowledge and methodology, and promote truly inspiring education in chemistry. In the conclusion, I recapitulate that the evolution of human knowledge inherently depends upon our ability to adopt creative problem-solving attitudes, and that challenges will always be present within the scope of scientific interests. PMID:24465151

  19. The Abbott Architect c8000: analytical performance and productivity characteristics of a new analyzer applied to general chemistry testing.

    PubMed

    Pauli, Daniela; Seyfarth, Michael; Dibbelt, Leif

    2005-01-01

    Applying basic potentiometric and photometric assays, we evaluated the fully automated random access chemistry analyzer Architect c8000, a new member of the Abbott Architect system family, with respect to both its analytical and operational performance and compared it to an established high-throughput chemistry platform, the Abbott Aeroset. Our results demonstrate that intra- and inter-assay imprecision, inaccuracy, lower limit of detection and linear range of the c8000 generally meet actual requirements of laboratory diagnosis; there were only rare exceptions, e.g. assays for plasma lipase or urine uric acid which apparently need to be improved by additional rinsing of reagent pipettors. Even with plasma exhibiting CK activities as high as 40.000 U/l, sample carryover by the c8000 could not be detected. Comparison of methods run on the c8000 and the Aeroset revealed correlation coefficients of 0.98-1.00; if identical chemistries were applied on both analyzers, slopes of regression lines approached unity. With typical laboratory workloads including 10-20% STAT samples and up to 10% samples with high analyte concentrations demanding dilutional reruns, steady-state throughput numbers of 700 to 800 tests per hour were obtained with the c8000. The system generally responded to STAT orders within 2 minutes yielding analytical STAT order completion times of 5 to 15 minutes depending on the type and number of assays requested per sample. Due to its extended test and sample processing capabilities and highly comfortable software, the c8000 may meet the varying needs of clinical laboratories rather well.

  20. Color Changes in Indicator Solutions. An Intriguing and Elucidative General Chemistry Experiment

    NASA Astrophysics Data System (ADS)

    Silva, César R.; Pereira, Renato B.; Sabadini, Edvaldo

    2001-07-01

    The simple dilution of an aqueous solution of the indicator (In) bromocresol green is proposed as an intriguing experiment for students of chemistry. As the solution is diluted with water, its color changes strikingly from reddish to pale blue. These changes are related to changes in the absorption bands in the visible electronic spectra. The pKIn can be determined through the Henderson-Hasselbalch equation by plotting the pH values as a function of log([In-]/[HIn]). The concentration, in mol L-1, of the HIn species can be determined by measuring the absorbance at 440 nm and using the e value determined from the Beer's law plot. [In-] is calculated from the difference between the initial HIn concentration and the observed [HIn]. Students will be able to conclude that the dissociated fraction of a weak acid increases with dilution.

    See Letter re: this article.

  1. A Study of Concept Mapping as an Instructional Intervention in an Undergraduate General Chemistry Calorimetry Laboratory

    NASA Astrophysics Data System (ADS)

    Stroud, Mary W.

    This investigation, rooted in both chemistry and education, considers outcomes occurring in a small-scale study in which concept mapping was used as an instructional intervention in an undergraduate calorimetry laboratory. A quasi-experimental, multiple-methods approach was employed since the research questions posed in this study warranted the use of both qualitative and quantitative perspectives and evaluations. For the intervention group of students, a convenience sample, post-lab concept maps, written discussions, quiz responses and learning surveys were characterized and evaluated. Archived quiz responses for non-intervention students were also analyzed for comparison. Students uniquely constructed individual concept maps containing incorrect, conceptually correct and "scientifically thin" calorimetry characterizations. Students more greatly emphasized mathematical relationships and equations utilized during the calorimetry experiment; the meaning of calorimetry concepts was demonstrated to a lesser extent.

  2. Promoting the Relevance & Value of Chemistry: the General Chemistry Program of the U.S. Coast Guard Academy. Report 06-92.

    ERIC Educational Resources Information Center

    Redig, K. A.; And Others

    Many students face chemistry courses with a sense of fear and foreboding because it is a required course. Yet at the same time, fundamentals of chemistry have become intertwined in countless professions to say nothing of its growing importance in our everyday lives. Educators must bridge this dichotomy between attitude and importance. This paper…

  3. The role of self-regulated learning in explaining examination performance of college students in first-semester general chemistry

    NASA Astrophysics Data System (ADS)

    Beckley, Scott

    Many college students struggle with first-semester general chemistry. Prior studies have shown that a student's prior knowledge of chemistry, a cognitive factor, does not account for the total variance when measured by examination scores. This study explored the role of self-regulated learning (SRL) to identify the degree of success or failure of students with two outcome variables (i.e., American Chemical Society Comprehensive First-Term General Chemistry Examination (Form 2009) and hour-examination averages). The SRL construct consists of three interrelated components (i.e., cognitive, metacognitive, and motivational). SRL theory focuses on the idea of reciprocal determinism, in which the impact of one component of self-regulation affects the other two components. In the quantitative portion of this mixed methods study, eight measures of SRL were used to determine the `level' of self-regulation for each student. SRL variables were used in regression analysis and provided additional and unique variances. Cluster analysis techniques identified two distinct groups of students (i.e., adaptive and maladaptive). Generally, adaptive learners were associated with higher levels of SRL and success in the course; maladaptive learners had lower levels of SRL and struggled with the course demands. For the qualitative portion of the study, student volunteers (n = 8) were interviewed to gauge their views on the role of instruction in influencing their examination performances. The findings indicated that perceptions of teaching methods, demands of the course, course structure, feedback, and assessments were associated with the students' levels of self-regulation. Interviews revealed four SRL styles. Rote memorizers tended to fragment instruction and then memorize each fragment, while algorithmic memorizers tended to imitate the step-by-step problem-solving strategies of the instructor or the textbook. Globalizers were intrinsically motivated to learn the material but tended to

  4. Quantitative Clinical Chemistry Proteomics (qCCP) using mass spectrometry: general characteristics and application.

    PubMed

    Lehmann, Sylvain; Hoofnagle, Andrew; Hochstrasser, Denis; Brede, Cato; Glueckmann, Matthias; Cocho, José A; Ceglarek, Uta; Lenz, Christof; Vialaret, Jérôme; Scherl, Alexander; Hirtz, Christophe

    2013-05-01

    Proteomics studies typically aim to exhaustively detect peptides/proteins in a given biological sample. Over the past decade, the number of publications using proteomics methodologies has exploded. This was made possible due to the availability of high-quality genomic data and many technological advances in the fields of microfluidics and mass spectrometry. Proteomics in biomedical research was initially used in 'functional' studies for the identification of proteins involved in pathophysiological processes, complexes and networks. Improved sensitivity of instrumentation facilitated the analysis of even more complex sample types, including human biological fluids. It is at that point the field of clinical proteomics was born, and its fundamental aim was the discovery and (ideally) validation of biomarkers for the diagnosis, prognosis, or therapeutic monitoring of disease. Eventually, it was recognized that the technologies used in clinical proteomics studies [particularly liquid chromatography-tandem mass spectrometry (LC-MS/MS)] could represent an alternative to classical immunochemical assays. Prior to deploying MS in the measurement of peptides/proteins in the clinical laboratory, it seems likely that traditional proteomics workflows and data management systems will need to adapt to the clinical environment and meet in vitro diagnostic (IVD) regulatory constraints. This defines a new field, as reviewed in this article, that we have termed quantitative Clinical Chemistry Proteomics (qCCP).

  5. Investigating the effectiveness of implementing the Science Writing Heuristic on student performance in general chemistry

    NASA Astrophysics Data System (ADS)

    Poock, Jason Ray

    This research investigated the effectiveness at how the Science Writing Heuristic in the freshman chemistry laboratory for science and engineering majors at Iowa State University during the fall and spring semesters of the 2002--2003 academic year, was implemented. The Science Writing Heuristic (SWH) consists of two components, writing to learn strategies and conducting the laboratory session in a student-centered, guided-inquiry fashion. The writing component replaced the standard laboratory report with a series of questions that guided the students' critical thinking along the lines of scientific investigation. The writing process helped students construct knowledge. Also critical to the successful implementation of the SWH was conducting the laboratory experiments in a student-centered, guided-inquiry fashion. Through the SWH the students became engaged in meaningful scientific dialogue that promoted knowledge construction. For the SWH to be properly implemented, a classroom dynamic between the teacher and the students should be established. The teacher provides the framework within which the laboratory experiment is conducted and the students respond to that guidance by becoming engaged in the learning process. Results of the study showed that student scores improved when the teacher properly implemented the SWH, when the students responded positively to the implementation of the SWH, and when there was a proper classroom dynamic created between the teacher and the students. This study revealed that successful implementation of the SWH was beneficial to females and low ability students. This research also demonstrated a connection between the implementation of a learning strategy in the laboratory component of a course and the subsequent benefit in student performance in the lecture component of the course.

  6. Textbook Treatments of Electrostatic Potential Maps in General and Organic Chemistry

    ERIC Educational Resources Information Center

    Hinze, Scott R.; Williamson, Vickie M.; Deslongchamps, Ghislain; Shultz, Mary Jane; Williamson, Kenneth C.; Rapp, David N.

    2013-01-01

    Electrostatic potential maps (EPMs) allow for representation of key molecular-level information in a relatively simple and inexpensive format. As these visualizations become more prevalent in instruction, it is important to determine how students are exposed to them and supported in their use. A systematic review of current general and organic…

  7. Choice of Study Resources in General Chemistry by Students Who Have Little Time to Study

    ERIC Educational Resources Information Center

    Bunce, Diane M.; Komperda, Regis; Dillner, Debra K.; Lin, Shirley; Schroeder, Maria J.; Hartman, JudithAnn R.

    2017-01-01

    Students with an insufficient amount of time to study are becoming more prevalent in the general college population as many who enroll in college have competing responsibilities (full-time jobs, childcare, etc.). Such students are likely to choose study resources that they consider to be both effective and efficient. Students at the U.S. Naval…

  8. Picture this: The value of multiple visual representations for student learning of quantum concepts in general chemistry

    NASA Astrophysics Data System (ADS)

    Allen, Emily Christine

    Mental models for scientific learning are often defined as, "cognitive tools situated between experiments and theories" (Duschl & Grandy, 2012). In learning, these cognitive tools are used to not only take in new information, but to help problem solve in new contexts. Nancy Nersessian (2008) describes a mental model as being "[loosely] characterized as a representation of a system with interactive parts with representations of those interactions. Models can be qualitative, quantitative, and/or simulative (mental, physical, computational)" (p. 63). If conceptual parts used by the students in science education are inaccurate, then the resulting model will not be useful. Students in college general chemistry courses are presented with multiple abstract topics and often struggle to fit these parts into complete models. This is especially true for topics that are founded on quantum concepts, such as atomic structure and molecular bonding taught in college general chemistry. The objectives of this study were focused on how students use visual tools introduced during instruction to reason with atomic and molecular structure, what misconceptions may be associated with these visual tools, and how visual modeling skills may be taught to support students' use of visual tools for reasoning. The research questions for this study follow from Gilbert's (2008) theory that experts use multiple representations when reasoning and modeling a system, and Kozma and Russell's (2005) theory of representational competence levels. This study finds that as students developed greater command of their understanding of abstract quantum concepts, they spontaneously provided additional representations to describe their more sophisticated models of atomic and molecular structure during interviews. This suggests that when visual modeling with multiple representations is taught, along with the limitations of the representations, it can assist students in the development of models for reasoning about

  9. The atmospheric chemistry general circulation model ECHAM5/MESSy1: consistent simulation of ozone from the surface to the mesosphere

    NASA Astrophysics Data System (ADS)

    Jöckel, P.; Tost, H.; Pozzer, A.; Brühl, C.; Buchholz, J.; Ganzeveld, L.; Hoor, P.; Kerkweg, A.; Lawrence, M. G.; Sander, R.; Steil, B.; Stiller, G.; Tanarhte, M.; Taraborrelli, D.; van Aardenne, J.; Lelieveld, J.

    2006-11-01

    The new Modular Earth Submodel System (MESSy) describes atmospheric chemistry and meteorological processes in a modular framework, following strict coding standards. It has been coupled to the ECHAM5 general circulation model, which has been slightly modified for this purpose. A 90-layer model setup up to 0.01 hPa was used at spectral T42 resolution to simulate the lower and middle atmosphere. With the high vertical resolution the model simulates the Quasi-Biennial Oscillation. The model meteorology has been tested to check the influence of the changes to ECHAM5 and the radiation interactions with the new representation of atmospheric composition. In the simulations presented here a Newtonian relaxation technique was applied in the tropospheric part of the domain to weakly nudge the model towards the analysed meteorology during the period 1998-2005. This allows an efficient and direct evaluation with satellite and in-situ data. It is shown that the tropospheric wave forcing of the stratosphere in the model suffices to reproduce major stratospheric warming events leading e.g. to the vortex split over Antarctica in 2002. Characteristic features such as dehydration and denitrification caused by the sedimentation of polar stratospheric cloud particles and ozone depletion during winter and spring are simulated well, although ozone loss in the lower polar stratosphere is slightly underestimated. The model realistically simulates stratosphere-troposphere exchange processes as indicated by comparisons with satellite and in situ measurements. The evaluation of tropospheric chemistry presented here focuses on the distributions of ozone, hydroxyl radicals, carbon monoxide and reactive nitrogen compounds. In spite of minor shortcomings, mostly related to the relatively coarse T42 resolution and the neglect of inter-annual changes in biomass burning emissions, the main characteristics of the trace gas distributions are generally reproduced well. The MESSy submodels and the

  10. The atmospheric chemistry general circulation model ECHAM5/MESSy1: consistent simulation of ozone from the surface to the mesosphere

    NASA Astrophysics Data System (ADS)

    Jöckel, P.; Tost, H.; Pozzer, A.; Brühl, C.; Buchholz, J.; Ganzeveld, L.; Hoor, P.; Kerkweg, A.; Lawrence, M. G.; Sander, R.; Steil, B.; Stiller, G.; Tanarhte, M.; Taraborrelli, D.; van Aardenne, J.; Lelieveld, J.

    2006-07-01

    The new Modular Earth Submodel System (MESSy) describes atmospheric chemistry and meteorological processes in a modular framework, following strict coding standards. It has been coupled to the ECHAM5 general circulation model, which has been slightly modified for this purpose. A 90-layer model version up to 0.01 hPa was used at T42 resolution (~2.8 latitude and longitude) to simulate the lower and middle atmosphere. The model meteorology has been tested to check the influence of the changes to ECHAM5 and the radiation interactions with the new representation of atmospheric composition. A Newtonian relaxation technique was applied in the tropospheric part of the domain to weakly nudge the model towards the analysed meteorology during the period 1998-2005. It is shown that the tropospheric wave forcing of the stratosphere in the model suffices to reproduce the Quasi-Biennial Oscillation and major stratospheric warming events leading e.g. to the vortex split over Antarctica in 2002. Characteristic features such as dehydration and denitrification caused by the sedimentation of polar stratospheric cloud particles and ozone depletion during winter and spring are simulated accurately, although ozone loss in the lower polar stratosphere is slightly underestimated. The model realistically simulates stratosphere-troposphere exchange processes as indicated by comparisons with satellite and in situ measurements. The evaluation of tropospheric chemistry presented here focuses on the distributions of ozone, hydroxyl radicals, carbon monoxide and reactive nitrogen compounds. In spite of minor shortcomings, mostly related to the relatively coarse T42 resolution and the neglect of interannual changes in biomass burning emissions, the main characteristics of the trace gas distributions are generally reproduced well. The MESSy submodels and the ECHAM5/MESSy1 model output are available through the internet on request.

  11. Expanding Mg-Zn hybrid chemistry: inorganic salt effects in addition reactions of organozinc reagents to trifluoroacetophenone and the implications for a synergistic lithium-magnesium-zinc activation.

    PubMed

    Armstrong, David R; Clegg, William; García-Álvarez, Pablo; Kennedy, Alan R; McCall, Matthew D; Russo, Luca; Hevia, Eva

    2011-07-18

    Numerous organic transformations rely on organozinc compounds made through salt-metathesis (exchange) reactions from organolithium or Grignard reagents with a suitable zinc precursor. By combining X-ray crystallography, NMR spectroscopy and DFT calculations, this study sheds new light on the constitution of the organometallic species involved in this important synthetic tool. Investigations into the metathesis reactions of equimolar amounts of Grignard reagents (RMgX) and ZnCl(2) in THF led to the isolation of novel magnesium-zinc hybrids, [{(thf)(2)Mg(μ-Cl)(3)ZnR}(2)] (R=Et, tBu, nBu or o-OMe-C(6)H(4)), which exhibit an unprecedented structural motif in mixed magnesium-zinc chemistry. Furthermore, theoretical modelling of the reaction of EtMgCl with ZnCl(2) reveals that formation of the mixed-metal compound is thermodynamically preferred to that of the expected homometallic products, RZnCl and MgCl(2). This study also assesses the alkylating ability of hybrid 3 towards the sensitive ketone trifluoroacetophenone, revealing a dramatic increase in the chemoselectivity of the reaction when LiCl is introduced as an additive. This observation, combined with recent related breakthroughs in synthesis, points towards the existence of a trilateral Li/Mg/Zn synergistic effect.

  12. Effectiveness of Podcasts Delivered on Mobile Devices as a Support for Student Learning During General Chemistry Laboratories

    NASA Astrophysics Data System (ADS)

    Powell, Cynthia B.; Mason, Diana S.

    2013-04-01

    Chemistry instructors in teaching laboratories provide expert modeling of techniques and cognitive processes and provide assistance to enrolled students that may be described as scaffolding interaction. Such student support is particularly essential in laboratories taught with an inquiry-based curriculum. In a teaching laboratory with a high instructor-to-student ratio, mobile devices can provide a platform for expert modeling and scaffolding during the laboratory sessions. This research study provides data collected on the effectiveness of podcasts delivered as needed in a first-semester general chemistry laboratory setting. Podcasts with audio and visual tracks covering essential laboratory techniques and central concepts that aid in experimental design or data processing were prepared and made available for students to access on an as-needed basis on iPhones® or iPod touches®. Research focused in three areas: the extent of podcast usage, the numbers and types of interactions between instructors and student laboratory teams, and student performance on graded assignments. Data analysis indicates that on average the podcast treatment laboratory teams accessed a podcast 2.86 times during the laboratory period during each week that podcasts were available. Comparison of interaction data for the lecture treatment laboratory teams and podcast treatment laboratory teams reveals that scaffolding interactions with instructors were statistically significantly fewer for teams that had podcast access rather than a pre-laboratory lecture. The implication of the results is that student laboratory teams were able to gather laboratory information more effectively when it was presented in an on-demand podcast format than in a pre-laboratory lecture format. Finally, statistical analysis of data on student performance on graded assignments indicates no significant differences between outcome measures for the treatment groups when compared as cohorts. The only statistically

  13. Adsorbate-induced lifting of substrate relaxation is a general mechanism governing titania surface chemistry

    NASA Astrophysics Data System (ADS)

    Silber, David; Kowalski, Piotr M.; Traeger, Franziska; Buchholz, Maria; Bebensee, Fabian; Meyer, Bernd; Wöll, Christof

    2016-09-01

    Under ambient conditions, almost all metals are coated by an oxide. These coatings, the result of a chemical reaction, are not passive. Many of them bind, activate and modify adsorbed molecules, processes that are exploited, for example, in heterogeneous catalysis and photochemistry. Here we report an effect of general importance that governs the bonding, structure formation and dissociation of molecules on oxidic substrates. For a specific example, methanol adsorbed on the rutile TiO2(110) single crystal surface, we demonstrate by using a combination of experimental and theoretical techniques that strongly bonding adsorbates can lift surface relaxations beyond their adsorption site, which leads to a significant substrate-mediated interaction between adsorbates. The result is a complex superstructure consisting of pairs of methanol molecules and unoccupied adsorption sites. Infrared spectroscopy reveals that the paired methanol molecules remain intact and do not deprotonate on the defect-free terraces of the rutile TiO2(110) surface.

  14. Adsorbate-induced lifting of substrate relaxation is a general mechanism governing titania surface chemistry.

    PubMed

    Silber, David; Kowalski, Piotr M; Traeger, Franziska; Buchholz, Maria; Bebensee, Fabian; Meyer, Bernd; Wöll, Christof

    2016-09-30

    Under ambient conditions, almost all metals are coated by an oxide. These coatings, the result of a chemical reaction, are not passive. Many of them bind, activate and modify adsorbed molecules, processes that are exploited, for example, in heterogeneous catalysis and photochemistry. Here we report an effect of general importance that governs the bonding, structure formation and dissociation of molecules on oxidic substrates. For a specific example, methanol adsorbed on the rutile TiO2(110) single crystal surface, we demonstrate by using a combination of experimental and theoretical techniques that strongly bonding adsorbates can lift surface relaxations beyond their adsorption site, which leads to a significant substrate-mediated interaction between adsorbates. The result is a complex superstructure consisting of pairs of methanol molecules and unoccupied adsorption sites. Infrared spectroscopy reveals that the paired methanol molecules remain intact and do not deprotonate on the defect-free terraces of the rutile TiO2(110) surface.

  15. Adsorbate-induced lifting of substrate relaxation is a general mechanism governing titania surface chemistry

    PubMed Central

    Silber, David; Kowalski, Piotr M.; Traeger, Franziska; Buchholz, Maria; Bebensee, Fabian; Meyer, Bernd; Wöll, Christof

    2016-01-01

    Under ambient conditions, almost all metals are coated by an oxide. These coatings, the result of a chemical reaction, are not passive. Many of them bind, activate and modify adsorbed molecules, processes that are exploited, for example, in heterogeneous catalysis and photochemistry. Here we report an effect of general importance that governs the bonding, structure formation and dissociation of molecules on oxidic substrates. For a specific example, methanol adsorbed on the rutile TiO2(110) single crystal surface, we demonstrate by using a combination of experimental and theoretical techniques that strongly bonding adsorbates can lift surface relaxations beyond their adsorption site, which leads to a significant substrate-mediated interaction between adsorbates. The result is a complex superstructure consisting of pairs of methanol molecules and unoccupied adsorption sites. Infrared spectroscopy reveals that the paired methanol molecules remain intact and do not deprotonate on the defect-free terraces of the rutile TiO2(110) surface. PMID:27686286

  16. Simulation of a dust episode over Eastern Mediterranean using a high-resolution atmospheric chemistry general circulation model

    NASA Astrophysics Data System (ADS)

    Abdel Kader, Mohamed; Zittis, Georgios; Astitha, Marina; Lelieveld, Jos; Tymvios, Fillipos

    2013-04-01

    An extended episode of low visibility took place over the Eastern Mediterranean in late September 2011, caused by a strong increase in dust concentrations, analyzed from observations of PM10 (Particulate Matter with <10μm in diameter). A high-resolution version of the atmospheric chemistry general circulation model EMAC (ECHAM5/Messy2.41 Atmospheric Chemistry) was used to simulate the emissions, transport and deposition of airborne desert dust. The model configuration involves the spectral resolution of T255 (0.5°, ~50Km) and 31 vertical levels in the troposphere and lower stratosphere. The model was nudged towards ERA40 reanalysis data to represent the actual meteorological conditions. The dust emissions were calculated online at each model time step and the aerosol microphysics using the GMXe submodel (Global Modal-aerosol eXtension). The model includes a sulphur chemistry mechanism to simulate the transformation of the dust particles from the insoluble (at emission) to soluble modes, which promotes dust removal by precipitation. The model successfully reproduces the dust distribution according to observations by the MODIS satellite instruments and ground-based AERONET stations. The PM10 concentration is also compared with in-situ measurements over Cyprus, resulting in good agreement. The model results show two subsequent dust events originating from the Negev and Sahara deserts. The first dust event resulted from the transport of dust from the Sahara on the 21st of September and lasted only briefly (hours) as the dust particles were efficiently removed by precipitation simulated by the model and observed by the TRMM (Tropical Rainfall Measuring Mission) satellites. The second event resulted from dust transport from the Negev desert to the Eastern Mediterranean during the period 26th - 30th September with a peak concentration at 2500m elevation. This event lasted for four days and diminished due to dry deposition. The observed reduced visibility over Cyprus

  17. Assessment of two physical parameterization schemes for desert dust emissions in an atmospheric chemistry general circulation model

    NASA Astrophysics Data System (ADS)

    Astitha, M.; Abdel Kader, M.; Pozzer, A.; Lelieveld, J.

    2012-04-01

    Atmospheric particulate matter and more specific desert dust has been the topic of numerous research studies in the past due to the wide range of impacts in the environment and climate and the uncertainty of characterizing and quantifying these impacts in a global scale. In this work we present two physical parameterizations of the desert dust production that have been incorporated in the atmospheric chemistry general circulation model EMAC (ECHAM5/MESSy2.41 Atmospheric Chemistry). The scope of this work is to assess the impact of the two physical parameterizations in the global distribution of desert dust and highlight the advantages and disadvantages of using either technique. The dust concentration and deposition has been evaluated using the AEROCOM dust dataset for the year 2000 and data from the MODIS and MISR satellites as well as sun-photometer data from the AERONET network was used to compare the modelled aerosol optical depth with observations. The implementation of the two parameterizations and the simulations using relatively high spatial resolution (T106~1.1deg) has highlighted the large spatial heterogeneity of the dust emission sources as well as the importance of the input parameters (soil size and texture, vegetation, surface wind speed). Also, sensitivity simulations with the nudging option using reanalysis data from ECMWF and without nudging have showed remarkable differences for some areas. Both parameterizations have revealed the difficulty of simulating all arid regions with the same assumptions and mechanisms. Depending on the arid region, each emission scheme performs more or less satisfactorily which leads to the necessity of treating each desert differently. Even though this is a quite different task to accomplish in a global model, some recommendations are given and ideas for future improvements.

  18. "Lorenzo's Oil" as a Vehicle for Teaching Chemistry Content, Processes of Science, and Sociology of Science in a General Education Chemistry Classroom

    ERIC Educational Resources Information Center

    Wink, Donald

    2011-01-01

    The film "Lorenzo's Oil" depicts the challenges faced by the parents of a child with adrenoleukodystrophy, a neurological disorder that, they were told, was certainly fatal. The film contains a significant amount of chemistry, including concepts of fatty acid metabolism, enzyme inhibition, and the purification of substances. The film also raises…

  19. Yielding Unexpected Results: Precipitation of Ba[subscript3](PO[subscript4])[subscript2] and Implications for Teaching Solubility Principles in the General Chemistry Curriculum

    ERIC Educational Resources Information Center

    Hazen, Jeffery L.; Cleary, David A.

    2014-01-01

    Precipitation of barium phosphate from aqueous solutions of a barium salt and a phosphate salt forms the basis for a number of conclusions drawn in general chemistry. For example, the formation of a solid white precipitate is offered as evidence that barium phosphate is insoluble. Furthermore, analysis of the supernatant is used to illustrate the…

  20. 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…

  1. Introducing NMR to a General Chemistry Audience: A Structural-Based Instrumental Laboratory Relating Lewis Structures, Molecular Models, and [superscript 13]C NMR Data

    ERIC Educational Resources Information Center

    Pulliam, Curtis R.; Pfeiffer, William F.; Thomas, Alyssa C.

    2015-01-01

    This paper describes a first-year general chemistry laboratory that uses NMR spectroscopy and model building to emphasize molecular shape and structure. It is appropriate for either a traditional or an atoms-first curriculum. Students learn the basis of structure and the use of NMR data through a cooperative learning hands-on laboratory…

  2. Separation and Identification of a Mixture of Group 6 Transition-Metal Carbonyl Compounds Using GC-MS in the General Chemistry Curriculum

    ERIC Educational Resources Information Center

    Fong, Lawrence K.

    2004-01-01

    Students in the general chemistry course are advised to scrutinize data obtained by gas chromatograph (GC) for segregation, and mass spectroscopy (MS) for recognizing combination of group 6 transition-metal carbonyl compounds. The GC-MS method arouses students' interest, as it can be applied to real-world situations, such as the routine…

  3. A Focus on Problems of National Interest in the College General Chemistry Laboratory: The Effects of the Problem-Oriented Method Compared with Those of the Traditional Approach.

    ERIC Educational Resources Information Center

    Neman, Robert Lynn

    This study was designed to assess the effects of the problem-oriented method compared to those of the traditional approach in general chemistry at the college level. The problem-oriented course included topics such as air and water pollution, drug addiction and analysis, tetraethyl-lead additives, insecticides in the environment, and recycling of…

  4. Multiple-Choice Exams and Guessing: Results from a One-Year Study of General Chemistry Tests Designed to Discourage Guessing

    ERIC Educational Resources Information Center

    Campbell, Mark L.

    2015-01-01

    Multiple-choice exams, while widely used, are necessarily imprecise due to the contribution of the final student score due to guessing. This past year at the United States Naval Academy the construction and grading scheme for the department-wide general chemistry multiple-choice exams were revised with the goal of decreasing the contribution of…

  5. Discovering [superscript 13]C NMR, [superscript 1]H NMR, and IR Spectroscopy in the General Chemistry Laboratory through a Sequence of Guided-Inquiry Exercises

    ERIC Educational Resources Information Center

    Iler, H. Darrell; Justice, David; Brauer, Shari; Landis, Amanda

    2012-01-01

    This sequence of three guided-inquiry labs is designed for a second-semester general chemistry course and challenges students to discover basic theoretical principles associated with [superscript 13]C NMR, [superscript 1]H NMR, and IR spectroscopy. Students learn to identify and explain basic concepts of magnetic resonance and vibrational…

  6. Bringing out the "Main Characters" in General Chemistry: Can Creating a Sense of Narrative in the Classroom and for the Textbook Aid Long-Term Memory?

    ERIC Educational Resources Information Center

    Chang, Junyoung; Churchill, David

    2011-01-01

    A new approach for teaching general chemistry is presented and discussed. Importantly, a storyline approach is provided in which the same chemical item or concept is reintroduced and embellished from chapter to chapter. The intention is to bring more connectivity between the various seemingly unrelated chapters. This might lead to a more…

  7. Alka-Seltzer Fizzing--Determination of Percent by Mass of NaHCO3 in Alka-Seltzer Tablets: An Undergraduate General Chemistry Experiment.

    ERIC Educational Resources Information Center

    Chen, Yueh-Huey; Yaung, Jing-Fun

    2002-01-01

    Presents a general chemistry stoichiometry experiment using materials involved in everyday life. From this activity, students learn that a chemical reaction occurs when an Alka-Seltzer tablet is dropped into water. Students also practice plotting experimental data through the use of a graphing program. Interpretation of the graph helps them…

  8. Online Homework Put to the Test: A Report on the Impact of Two Online Learning Systems on Student Performance in General Chemistry

    ERIC Educational Resources Information Center

    Eichler, Jack F.; Peeples, Junelyn

    2013-01-01

    Two different online homework systems were administered to students in a first-quarter general chemistry course. This study used a multiple regression model to control for the students' academic and socioeconomic background, and it was found that students who completed the online homework activities performed significantly better on a common…

  9. Using the science writing heuristic approach as a tool for assessing and promoting students' conceptual understanding and perceptions in the general chemistry laboratory

    NASA Astrophysics Data System (ADS)

    Mohammad, Elham Ghazi

    This thesis reports on a study that examined the impact of implementing SWH (inquiry-based approach) in a general chemistry lab on non-science-major students' understanding of chemistry concepts and students' perceptions toward writing in science and implementing SWH. This study was conducted in a large university in the Midwest of the United States in a college freshman chemistry laboratory for non-science-major students. The research framework is presented including the following: the qualitative research design with the observation as data collection method for this design and the criteria for teacher level of implementation and the ranking mechanism; and the quantitative research design with data collection and analysis methods including pre- and post-conceptual exams, lecture question, open-ended surveys. This research was based on a quasi-experimental mixed-method design a focus on student performance on higher order conceptual questions, and open-ended survey at the end of semester about their perception toward writing to learn ad implementing SWH. Results from the qualitative and quantitative component indicated that implementing SWH approach has notably enhanced both male and female conceptual understanding and perception toward chemistry and implementing SWH. It is known that there is gender gap in science, where female have lower perception and self confident toward science. Interestingly, my findings have showed that implementing SWH helped closing the gap between male and female who started the semester with a statistically significant lower level of conceptual understanding of chemistry concepts among females than males.

  10. Transition Metal Complexes of Expanded Porphyrins

    PubMed Central

    Sessler, Jonathan L.; Tomat, Elisa

    2008-01-01

    Over the last two decades, the rapid development of new synthetic routes for the preparation of expanded porphyrin macrocycles has allowed exploration of a new frontier consisting of “porphyrin-like” coordination chemistry. In this Account, we summarize our exploratory forays into the still relatively poorly explored area of oligopyrrolic macrocycle metalation chemistry. Specifically, we describe our successful formation of both mono- and binuclear complexes and in doing so highlight the diversity of coordination modes available to expanded porphyrin-type ligands. The nature of the inserted cation, the emerging role of tautomeric equilibria, and the importance of hydrogen-bonding interactions in regulating this chemistry are also discussed. PMID:17397134

  11. A Strategy for Incorporating Hands-On GC-MS into the General Chemistry Lecture and Laboratory Courses.

    ERIC Educational Resources Information Center

    Reeves, Perry C.; Pamplin, Kim L.

    2001-01-01

    Describes strategies to introduce students in a first year chemistry course to the gas chromatograph coupled with a mass spectrometer (GC-MS) and provides students with hands-on experiences in its use. (ASK)

  12. 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.

  13. Frontiers in polymer chemistry.

    PubMed

    Schlüter, A Dieter

    2013-01-01

    The article shows how the initial concept of Staudinger on linear macromolecules was expanded topologically by increasing the cross-section diameter of polymer chains and by introducing sheet polymers with planar rather than the commonly known linear repeat units. The two concrete projects addressed are the synthesis of dendronized and of two-dimensional polymers. It is explained how these novel macromolecules were achieved and which obstacles had to be overcome but also where these frontiers in polymer chemistry might lead to new insights in polymer science in general and novel applications in particular. The article also provides insights into analytical issues because both target macromolecules are in an extraordinarily high molar mass range and contrast/sensitivity issues can turn rather serious in particular for the two-dimensional polymers.

  14. Comparison of High School Dual-Enrollment and Traditional First-Term General/Organic/Biochemistry College Chemistry Class Outcomes

    ERIC Educational Resources Information Center

    Zuidema, Daniel R.; Eames, Kevin J.

    2014-01-01

    Student performance in a high school dual-enrollment chemistry course was compared with student performance in the corresponding traditional college course. The two courses were taught by the same instructor and evaluated using the same American Chemical Society (ACS) standardized examination. Interestingly, the high school dual-enrollment…

  15. Effectiveness of Podcasts Delivered on Mobile Devices as a Support for Student Learning during General Chemistry Laboratories

    ERIC Educational Resources Information Center

    Powell, Cynthia B.; Mason, Diana S.

    2013-01-01

    Chemistry instructors in teaching laboratories provide expert modeling of techniques and cognitive processes and provide assistance to enrolled students that may be described as scaffolding interaction. Such student support is particularly essential in laboratories taught with an inquiry-based curriculum. In a teaching laboratory with a high…

  16. The Application and Evaluation of a Two-Concept Diagnostic Instrument with Students Entering College General Chemistry

    ERIC Educational Resources Information Center

    Heredia, Keily; Xu, Xiaoying; Lewis, Jennifer E.

    2012-01-01

    The Particulate Nature of Matter and Chemical Bonding Diagnostic Instrument (Othman J., Treagust D. F. and Chandrasegaran A. L., (2008), "Int. J. Sci. Educ.," 30(11), 1531-1550) is used to investigate college students' understanding of two chemistry concepts: particulate nature of matter and chemical bonding. The instrument, originally…

  17. The A[subscript 1c] Blood Test: An Illustration of Principles from General and Organic Chemistry

    ERIC Educational Resources Information Center

    Kerber, Robert C.

    2007-01-01

    The glycated hemoglobin blood test, usually designated as the A[subscript 1c] test, is a key measure of the effectiveness of glucose control in diabetics. The chemistry of glucose in the bloodstream, which underlies the test and its impact, provides an illustration of the importance of chemical equilibrium and kinetics to a major health problem.…

  18. Teaching Thermodynamics and Kinetics to Advanced General Chemistry Students and to Upper-Level Undergraduate Students Using PV Diagrams

    ERIC Educational Resources Information Center

    Iyengar, Srinivasan S.; deSouza, Romualdo T.

    2014-01-01

    We describe how complex concepts in macroscopic chemistry, namely, thermodynamics and kinetics, can be taught at considerable depth both at the first-year undergraduate as well as upper levels. We begin with a careful treatment of PV diagrams, and by pictorially integrating the appropriate area in a PV diagram, we introduce work. This starting…

  19. Assessing the Impact of New Research-Inspired General Chemistry Laboratory Experiments Using the Awareness of and Attitudes toward Scientific Research Inventory

    NASA Astrophysics Data System (ADS)

    Anzovino, Mary Elizabeth

    This work has three main components: 1.) The development of new research-inspired general chemistry laboratory experiments, 2.) The development of a new survey instrument to assess students' awareness of and attitudes toward scientific research, 3.) The utilization of that survey to assess the impacts of the new experiments. The value of undergraduate research experiences, both within and outside a course context, has been demonstrated in the literature. However, it is simply not feasible for all undergraduate students to participate in extracurricular research. Additionally, in many cases, integration of research modules into an undergraduate course is not realistic either. It is therefore necessary to assess the impacts of less complete, but still potentially significant, integration of research into the undergraduate curriculum via content drawn from current research at the University of Wisconsin--Madison. Two such experiments have been developed, in the areas of surfactants (synthesis and analysis) and reaction kinetics. Although a vast array of survey instruments exist to assess student attitudes toward science in general and specific fields such as chemistry, none of these instruments address scientific research. The Awareness of and Attitudes toward Scientific Research Inventory (AASRI) has been designed to fill this gap in the literature. The AASRI data exhibited evidence of good validity and reliability, suggesting that it is a useful assessment. A quasi-experimental study was conducted to evaluate the impact of the new research-inspired experiments in the general chemistry curriculum. The AASRI was used as a pre- and post-test for students who did and did not complete the new experiments. Although no significant differences were found between the groups, the data collected in the pre-test and post-test of both classes demonstrated evidence of good validity and reliability, and it is possible that a simple increase in the number of interventions would

  20. A Kinetics Experiment To Demonstrate the Role of a Catalyst in a Chemical Reaction: A Versatile Exercise for General or Physical Chemistry Students

    NASA Astrophysics Data System (ADS)

    Copper, Christine L.; Koubek, Edward

    1998-01-01

    A kinetics experiment for general or physical chemistry students is presented. The common iodine clock reaction is modified and the initial rate method is used to observe the role of catalyst in the reactions through activation energy calculations. An experimental procedure is designed such that students can determine the order with respect to each reactant and evaluate the mechanism that has been previously reported for this reaction. Furthermore, students use experimental results to calculate the rate constants of the uncatalyzed and catalyzed (independent of the uncatalyzed) reactions.

  1. Environmental chemistry. 5th edition

    SciTech Connect

    Manahan, S.E. . Dept. of Chemistry)

    1991-01-01

    This book is organized around several major sections: aquatic Chemistry, atmospheric chemistry, the geosphere and hazardous wastes, toxicological chemistry, and resources and energy. Specific topics discussed in the book include a general introduction to environment chemistry, basic principles of aquatic chemistry, water pollution and water treatment, the essential role of microorganisms in aquatic chemical phenomena, atmospheric chemistry, a discussion of major threats to the global atmosphere (particularly greenhouse gases and ozone-depleting chemicals), the geosphere and hazardous substances, soil chemistry, and the nature and sources of hazardous wastes. The environmental chemistry of hazardous wastes, their treatment, minimization, and recycling, and the effects of these hazardous substances in also presented.

  2. Global trend analysis of surface CO simulated using the global atmospheric chemistry general circulation model, EMAC (ECHAM5/MESSy)

    NASA Astrophysics Data System (ADS)

    Yoon, Jongmin; Pozzer, Andrea; Lelieveld, Jos

    2013-04-01

    Carbon monoxide (CO) is an important trace gas in tropospheric chemistry. It directly influences the concentration of tropospheric hydroxyl radical (OH), and therefore regulates the lifetimes of various tropospheric trace gases. Since anthropogenic activity produces about 60% of the annual global emission of the tropospheric CO, temporal trend analysis of surface CO is needed to understand the increasing (decreasing) influence of humans on the cleansing capacity of the atmosphere. In this study, the global trend of surface CO from 2001 to 2010 was estimated using the EMAC (ECHAM5/MESSy for Atmospheric Chemistry) model. The simulation is based on the emission scenario based on RCP8.5 (Representative Concentration Pathways). The global EMAC simulations of monthly surface CO are evaluated with monthly MOPITT (Measurements Of Pollution In The Troposphere) observations (i.e. MOP03TM), and the spatial correlations range from 0.87 to 0.97. The simulated trends are compared with the data from a global surface CO monitoring network, the World Data Centre for Greenhouse Gases (WDCGG), which includes also the NOAA/CMDL (Climate Monitoring and Diagnostic Laboratory of the National Oceanic and Atmospheric Administration) Cooperative Air Sampling Network. Over the United States and Western Europe, the significant decreases of surface CO are estimated at -49.7±2.7 and -38.6±2.7 ppbv per decade. In contrast, the surface CO increased by +12.4±10.2 and +7.2±3.7 ppbv per decade over South America and South Africa, respectively.

  3. Unconventional microfluidics: expanding the discipline.

    PubMed

    Nawaz, Ahmad Ahsan; Mao, Xiaole; Stratton, Zackary S; Huang, Tony Jun

    2013-04-21

    Since its inception, the discipline of microfluidics has been harnessed for innovations in the biomedicine/chemistry fields-and to great effect. This success has had the natural side-effect of stereotyping microfluidics as a platform for medical diagnostics and miniaturized lab processes. But microfluidics has more to offer. And very recently, some researchers have successfully applied microfluidics to fields outside its traditional domains. In this Focus article, we highlight notable examples of such "unconventional" microfluidics applications (e.g., robotics, electronics). It is our hope that these early successes in unconventional microfluidics prompt further creativity, and inspire readers to expand the microfluidics discipline.

  4. Unconventional microfluidics: expanding the discipline

    PubMed Central

    Nawaz, Ahmad Ahsan; Mao, Xiaole; Stratton, Zackary S.; Huang, Tony Jun

    2014-01-01

    Since its inception, the discipline of microfluidics has been harnessed for innovations in the biomedicine/chemistry fields—and to great effect. This success has had the natural side-effect of stereotyping microfluidics as a platform for medical diagnostics and miniaturized lab processes. But microfluidics has more to offer. And very recently, some researchers have successfully applied microfluidics to fields outside its traditional domains. In this Focus article, we highlight notable examples of such “unconventional” microfluidics applications (e.g., robotics, electronics). It is our hope that these early successes in unconventional microfluidics prompt further creativity, and inspire readers to expand the microfluidics discipline. PMID:23478651

  5. Two-Year Community College Chemistry: Joules

    ERIC Educational Resources Information Center

    Bardole, Ellen, Ed.; Bardole, Jay, Ed.

    1978-01-01

    Discusses a self-paced individualized general chemistry laboratory, the Doctor of Arts program, the Educational Resources Information Center (ERIC) system, and problems existing in chemistry education. (SL)

  6. Early metal bis(phosphorus-stabilised)carbene chemistry.

    PubMed

    Liddle, Stephen T; Mills, David P; Wooles, Ashley J

    2011-05-01

    Since the discovery of covalently-bound mid- and late-transition metal carbenes there has been a spectacular explosion of interest in their chemistry, but their early metal counterparts have lagged behind. In recent years, bis(phosphorus-stabilised)carbenes have emerged as valuable ligands for metals across the periodic table, and their use has in particular greatly expanded covalently-bound early metal carbene chemistry. In this tutorial review we introduce the reader to bis(phosphorus-stabilised)carbenes, and cover general preparative methods, structure and bonding features, and emerging reactivity studies of early metal derivatives (groups 1-4 and the f-elements).

  7. USSR Report, Chemistry, No. 98

    DTIC Science & Technology

    2007-11-02

    The report contains information on USSR Chemistry in generally in civil technology with particular attention to biochemistry, Catalysts, Coal ... gasification , combustion, Fertilizers, petroleum processing technology. The report also covers important issues related to polymerization, wood chemistry and Elastomer production.

  8. Polymer Chemistry in High School.

    ERIC Educational Resources Information Center

    Stucki, Roger

    1984-01-01

    Discusses why polymer chemistry should be added to the general chemistry curriculum and what topics are appropriate (listing traditional with related polymer topics). Also discusses when and how these topics should be taught. (JN)

  9. ESTABLISHING A STEREOSCOPIC TECHNIQUE FOR DETERMINING THE KINEMATIC PROPERTIES OF SOLAR WIND TRANSIENTS BASED ON A GENERALIZED SELF-SIMILARLY EXPANDING CIRCULAR GEOMETRY

    SciTech Connect

    Davies, J. A.; Perry, C. H.; Harrison, R. A.; Trines, R. M. G. M.; Lugaz, N.; Möstl, C.; Liu, Y. D.; Steed, K.

    2013-11-10

    The twin-spacecraft STEREO mission has enabled simultaneous white-light imaging of the solar corona and inner heliosphere from multiple vantage points. This has led to the development of numerous stereoscopic techniques to investigate the three-dimensional structure and kinematics of solar wind transients such as coronal mass ejections (CMEs). Two such methods—triangulation and the tangent to a sphere—can be used to determine time profiles of the propagation direction and radial distance (and thereby radial speed) of a solar wind transient as it travels through the inner heliosphere, based on its time-elongation profile viewed by two observers. These techniques are founded on the assumption that the transient can be characterized as a point source (fixed φ, FP, approximation) or a circle attached to Sun-center (harmonic mean, HM, approximation), respectively. These geometries constitute extreme descriptions of solar wind transients, in terms of their cross-sectional extent. Here, we present the stereoscopic expressions necessary to derive propagation direction and radial distance/speed profiles of such transients based on the more generalized self-similar expansion (SSE) geometry, for which the FP and HM geometries form the limiting cases; our implementation of these equations is termed the stereoscopic SSE method. We apply the technique to two Earth-directed CMEs from different phases of the STEREO mission, the well-studied event of 2008 December and a more recent event from 2012 March. The latter CME was fast, with an initial speed exceeding 2000 km s{sup –1}, and highly geoeffective, in stark contrast to the slow and ineffectual 2008 December CME.

  10. Anion-π Catalysis of Enolate Chemistry: Rigidified Leonard Turns as a General Motif to Run Reactions on Aromatic Surfaces.

    PubMed

    Cotelle, Yoann; Benz, Sebastian; Avestro, Alyssa-Jennifer; Ward, Thomas R; Sakai, Naomi; Matile, Stefan

    2016-03-18

    To integrate anion-π, cation-π, and ion pair-π interactions in catalysis, the fundamental challenge is to run reactions reliably on aromatic surfaces. Addressing a specific question concerning enolate addition to nitroolefins, this study elaborates on Leonard turns to tackle this problem in a general manner. Increasingly refined turns are constructed to position malonate half thioesters as close as possible on π-acidic surfaces. The resulting preorganization of reactive intermediates is shown to support the disfavored addition to enolate acceptors to an absolutely unexpected extent. This decisive impact on anion-π catalysis increases with the rigidity of the turns. The new, rigidified Leonard turns are most effective with weak anion-π interactions, whereas stronger interactions do not require such ideal substrate positioning to operate well. The stunning simplicity of the motif and its surprisingly strong relevance for function should render the introduced approach generally useful.

  11. Chemistry in Microfluidic Channels

    ERIC Educational Resources Information Center

    Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

    2011-01-01

    General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…

  12. Simulating organic species with the global atmospheric chemistry general circulation model ECHAM5/MESSy1: a comparison of model results with observations

    NASA Astrophysics Data System (ADS)

    Pozzer, A.; Jöckel, P.; Tost, H.; Sander, R.; Ganzeveld, L.; Kerkweg, A.; Lelieveld, J.

    2007-01-01

    The atmospheric-chemistry general circulation model ECHAM5/MESSy1 is evaluated with observations of different organic ozone precursors. This study continues a prior analysis which focused primarily on the representation of atmospheric dynamics and ozone. We use the results of the same reference simulation and apply a statistical analysis using data from numerous field campaigns. The results serve as a basis for future improvements of the model system. ECHAM5/MESSy1 generally reproduces the spatial distribution and the seasonal cycle of carbon monoxide (CO) very well. However, for the background in the northern hemisphere we obtain a negative bias (mainly due to an underestimation of emissions from fossil fuel combustion), and in the high latitude southern hemisphere a yet unexplained positive bias. The model results agree well with observations of alkanes, whereas severe problems in the simulation of alkenes are present. For oxygenated compounds the results are ambiguous: The model results are in good agreement with observations of formaldehyde, but systematic biases are present for methanol and acetone. The discrepancies between the model results and the observations are explained (partly) by means of sensitivity studies.

  13. Simulating organic species with the global atmospheric chemistry general circulation model ECHAM5/MESSy1: a comparison of model results with observations

    NASA Astrophysics Data System (ADS)

    Pozzer, A.; Jöckel, P.; Tost, H.; Sander, R.; Ganzeveld, L.; Kerkweg, A.; Lelieveld, J.

    2007-05-01

    The atmospheric-chemistry general circulation model ECHAM5/MESSy1 is evaluated with observations of different organic ozone precursors. This study continues a prior analysis which focused primarily on the representation of atmospheric dynamics and ozone. We use the results of the same reference simulation and apply a statistical analysis using data from numerous field campaigns. The results serve as a basis for future improvements of the model system. ECHAM5/MESSy1 generally reproduces the spatial distribution and the seasonal cycle of carbon monoxide (CO) very well. However, for the background in the Northern Hemisphere we obtain a negative bias (mainly due to an underestimation of emissions from fossil fuel combustion), and in the high latitude Southern Hemisphere a yet unexplained positive bias. The model results agree well with observations of alkanes, whereas severe problems in the simulation of alkenes and isoprene are present. For oxygenated compounds the results are ambiguous: The model results are in good agreement with observations of formaldehyde, but systematic biases are present for methanol and acetone. The discrepancies between the model results and the observations are explained (partly) by means of sensitivity studies.

  14. Ozone, Water Vapor and Nox Variability In The Upper Troposphere-lower Stratosphere In The Coupled Chemistry-general Circulation Model Lmdzt-inca

    NASA Astrophysics Data System (ADS)

    Jourdain, L.; Hauglustaine, D.; Brunner, D.; Staehelin, J.; Klonecki, A.

    In this study, we analyze the distribution and variability of O3, H2O and NOx around the tropopause region at northern midlatitudes. Our analysis is based on the coupled chemistry-general circulation model LMDzT-INCA used in conjunction with the NOx measurements from the NOXAR experiment in 1995 and 1996 and the O3 and H2O data collected during MOZAIC in 1996. We have performed a two year simulation in wich the model winds are regularly relaxed toward ECMWF analyses to allow a more direct comparison between model outputs and observations. The sensivity of the simulated distributions to the model vertical resolution is investigated using two versions with 19 and 50 levels. The spatial and temporal variability of O3 and H2O around the tropopause region are generally correctly reproduced by the model. However in summer, in the model, the tropopause is too high in altitude. The impact of convection and lightning emissions on the NOx variability is investigated. The discrepancies between measurements and model simulations arise mainly from the occurence and location of convective events which are responsible for a large part of the variability in the UTLS. The impact of this NOx variability on the radical concentration and ozone production is also discussed.

  15. What Expands in an Expanding Universe?

    PubMed

    Pacheco, José A De Freitas

    2015-01-01

    In the present investigation, the possible effects of the expansion of the Universe on systems bonded either by gravitational or electromagnetic forces, are reconsidered. It will be shown that the acceleration (positive or negative) of the expanding background, is the determinant factor affecting planetary orbits and atomic sizes. In the presently accepted cosmology (ΛCDM) all bonded systems are expanding at a decreasing rate that tends to be zero as the universe enters in a de Sitter phase. It is worth mentioning that the estimated expansion rates are rather small and they can be neglected for all practical purposes.

  16. Metalloporphyrins as Oxidation Catalysts: Moving toward "Greener" Chemistry in the Inorganic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Clark, Rose A.; Stock, Anne E.; Zovinka, Edward P.

    2012-01-01

    Training future chemists to be aware of the environmental impact of their work is of fundamental importance to global society. To convince chemists to embrace sustainability, the integration of green chemistry across the entire chemistry curriculum is a necessary step. This experiment expands the reach of green chemistry techniques into the…

  17. Generality of the 18-n Rule: Intermetallic Structural Chemistry Explained through Isolobal Analogies to Transition Metal Complexes.

    PubMed

    Yannello, Vincent J; Fredrickson, Daniel C

    2015-12-07

    Intermetallic phases exhibit a vast structural diversity in which electron count is known to be one controlling factor. However, chemical bonding theory has yet to establish how electron counts and structure are interrelated for the majority of these compounds. Recently, a simple bonding picture for transition metal (T)-main group (E) intermetallics has begun to take shape based on isolobal analogies to molecular T complexes. This bonding picture is summarized in the 18-n rule: each T atom in a T-E intermetallic phase will need 18-n electrons to achieve a closed-shell 18-electron configuration, where n is the number of electron pairs it shares with other T atoms in multicenter interactions isolobal to T-T bonds. In this Article, we illustrate the generality of this rule with a survey over a wide range of T-E phases. First, we illustrate how three structural progressions with changing electron counts can be accounted for, both geometrically and electronically, with the 18-n rule: (1) the transition between the fluorite and complex β-FeSi2 types for TSi2 phases; (2) the sequence from the marcasite type to the arsenopyrite type and back to the marcasite type for TSb2 compounds; and (3) the evolution from the AuCu3 type to the ZrAl3 and TiAl3 types for TAl3 phases. We then turn to a broader survey of the applicability of the 18-n rule through a study of the following 34 binary structure types: PtHg4, CaF2 (fluorite), Fe3C, CoGa3, Co2Al5, Ru2B3, β-FeSi2, NiAs, Ni2Al3, Rh4Si5, CrSi2, Ir3Ga5, Mo3Al8, MnP, TiSi2, Ru2Sn3, TiAl3, MoSi2, CoSn, ZrAl3, CsCl, FeSi, AuCu3, ZrSi2, Mn2Hg5, FeS2 (oP6, marcasite), CoAs3 (skutterudite), PdSn2, CoSb2, Ir3Ge7, CuAl2, Re3Ge7, CrP2, and Mg2Ni. Through these analyses, the 18-n rule is established as a framework for interpreting the stability of 341 intermetallic phases and anticipating their properties.

  18. Evaluation of Questions in General Chemistry Textbooks According to the Form of the Questions and the Question-Answer Relationship (QAR): The Case of Intra-and Intermolecular Chemical Bonding

    ERIC Educational Resources Information Center

    Pappa, Eleni T.; Tsaparlis, Georgios

    2011-01-01

    One way of checking to what extent instructional textbooks achieve their aim is to evaluate the questions they contain. In this work, we analyze the questions that are included in the chapters on chemical bonding of ten general chemistry textbooks. We study separately the questions on intra- and on intermolecular bonding, with the former…

  19. Chemical Characterization and Source Apportionment of Size Fractionated Atmospheric Aerosols, and, Evaluating Student Attitudes and Learning in Large Lecture General Chemistry Classes

    NASA Astrophysics Data System (ADS)

    Allen, Gregory Harold

    between the OOA2 and WBOA factors and smoke levels indicates that these factors can be used to identify the influence of biomass burning on ambient aerosols. The effectiveness of using the ChemWiki instead of a traditional textbook was investigated during the spring quarter of 2014. Student performance was measured using common midterms, a final, and a pre/post content exams. We also employed surveys, the Colorado Learning Attitudes about Science Survey (CLASS) for Chemistry, and a weekly time-on-task survey to quantify students' attitudes and study habits. The effectiveness of the ChemWiki compared to a traditional textbook was examined using multiple linear regression analysis with a standard non-inferiority testing framework. Results show that the performance of students in the section who were assigned readings from the ChemWiki was non-inferior to the performance of students in the section who were assigned readings from the traditional textbook, indicating that the ChemWiki does not substantially differ from the standard textbook in terms of student learning outcomes. The results from the surveys also suggest that the two classes were similar in their beliefs about chemistry and overall average time spent studying. These results indicate that the ChemWiki is a viable cost-saving alternative to traditional textbooks. The impact of using active learning techniques in a large lecture general chemistry class was investigated by assessing student performance and attitudes during the fall 2014 and winter 2015 quarters. One instructor applied active learning strategies while the remaining instructors employed more traditional lecture styles. Student performance, learning, learning environments, and attitudes were measured using a standardized pre/post exams, common final exams, classroom observations, and the CLASS chemistry instrument in large lecture general chemistry courses. Classroom observation data showed that the active learning class was the most student centered

  20. Kelvin waves and ozone Kelvin waves in the quasi-biennial oscillation and semiannual oscillation: A simulation by a high-resolution chemistry-coupled general circulation model

    NASA Astrophysics Data System (ADS)

    Watanabe, Shingo; Takahashi, Masaaki

    2005-09-01

    Equatorial Kelvin waves and ozone Kelvin waves were simulated by a T63L250 chemistry-coupled general circulation model with a high vertical resolution (300 m). The model produces a realistic quasi-biennial oscillation (QBO) and a semiannual oscillation (SAO) in the equatorial stratosphere. The QBO has a period slightly longer than 2 years, and the SAO shows rapid reversals from westerly to easterly regimes and gradual descents of westerlies. Results for the zonal wave number 1 slow and fast Kelvin waves are discussed. Structure of the waves and phase relationships between temperature and ozone perturbations coincide well with satellite observations made by LIMS, CLAES, and MLS. They are generally in phase (antiphase) in the lower (upper) stratosphere as theoretically expected. The fast Kelvin waves in the temperature and ozone are dominant in the upper stratosphere because the slow Kelvin waves are effectively filtered by the QBO westerly. In this simulation, the fast Kelvin waves encounter their critical levels in the upper stratosphere when zonal asymmetry of the SAO westerly is enhanced by an intrusion of the extratropical planetary waves. In addition to the critical level filtering effect, modulations of wave properties by background winds are evident near easterly and westerly shears associated with the QBO and SAO. Enhancement of wave amplitude in the QBO westerly shear is well coincident with radiosonde observations. Increase/decrease of vertical wavelength in the QBO easterly/westerly is obvious in this simulation, which is consistent with the linear wave theory. Shortening of wave period due to the descending QBO westerly shear zone is demonstrated for the first time. Moreover, dominant periods during the QBO westerly phase are longer than those during the QBO easterly phase for both the slow and fast Kelvin waves.

  1. Smaragdyrins: emeralds of expanded porphyrin family.

    PubMed

    Pareek, Yogita; Ravikanth, M; Chandrashekar, T K

    2012-10-16

    Porphyrins are tetrapyrrolic 18 π electron conjugated macrocycles with wide applications that range from materials to medicine. Expanded porphyrins, synthetic analogues of porphyrins that contain more than 18 π electrons in the conjugated pathway, have an increased number of pyrroles or other heterocyles or multiple meso-carbon bridges. The expanded porphyrins have attracted tremendous attention because of unique features such as anion binding or transport that are not present in porphyrins. Expanded porphyrins exhibit wide applications that include their use in the coordination of large metal ions, as contrasting agents in magnetic resonance imaging (MRI), as sensitizers for photodynamic therapy (PDT) and as materials for nonlinear optical (NLO) studies. Pentaphyrin 1, sapphyrin 2, and smaragdyrin 3 are expanded porphyrins that include five pyrroles or heterocyclic rings. They differ from each other in the number of bridging carbons and direct bonds that connect the five heterocyclic rings. Sapphyrins were the first stable expanded porphyrins reported in the literature and remain one of the most extensively studied macrocycles. The strategies used to synthesize sapphyrins are well established, and these macrocycles are versatile anion binding agents. They possess rich porphyrin-like coordination chemistry and have been used in diverse applications. This Account reviews developments in smaragdyrin chemistry. Although smaragdyrins were discovered at the same time as sapphyrins, the chemistry of smaragdyrins remained underdeveloped because of synthetic difficulties and their comparative instability. Earlier efforts resulted in the isolation of stable β-substituted smaragdyrins and meso-aryl isosmaragdyrins. Recently, researchers have synthesized stable meso-aryl smaragdyrins by [3 + 2] oxidative coupling reactions. These results have stimulated renewed research interest in the exploration of these compounds for anion and cation binding, energy transfer

  2. The effect of matching learning styles and instructional strategies on academic achievement and student enjoyment of science lessons in a high school general chemistry course

    NASA Astrophysics Data System (ADS)

    Fundi, Shaaban Kitindi

    This study explored the matching hypothesis by examining the effect of matching students' learning style preferences with teachers' instructional strategies on students' academic performance and lesson enjoyment in a high school general chemistry course. To achieve the study aims, the researcher utilized a single-participant study design with a baseline phase and four treatment phases. Determination of students' learning style preferences involved using the Visual, Audial, Read/Write, and Kinesthetic (VARK) Learning Style Inventory. During the one-week baseline phase, students received instruction using regular instructional strategies, followed by four treatment phases: visual intervention, audial intervention, read/write intervention, and a kinesthetic intervention. Each intervention phase lasted one week. During each phase, the researcher measured academic achievement using three teacher-created quiz scores. Student enjoyment was measured using the Test of Science-Related Attitudes (TOSRA). A total of 14 students completed the VARK Questionnaire. Of these, eight students (2 boys and 6 girls) exhibited a multimodal learning style were subsequently excluded from study participation. An additional student was excluded due to excessive absenteeism, leaving five students who completed all phases of the study. Results indicated that matching students' learning style preferences with teachers' instructional strategies did not improve students' academic performance as measured by teacher-created quizzes. However, weekly switching of the instructional strategies did improve student enjoyment of chemistry lessons. Student enjoyment increased for all participants in all intervention phases regardless of whether or not instruction matched students' learning style preferences compared to baseline phase. The results of this study do not support the matching hypothesis. The students in this study, preferred to learn with multiple teaching strategies. Alternating instructional

  3. Assessment of General Chemistry Instruction

    ERIC Educational Resources Information Center

    Bergin, Adam; Sharp, Kevan; Gatlin, Todd A.; Villalta-Cerdas, Adrian; Gower, Austin; Sandi-Urena, Santiago

    2013-01-01

    Commercial online instructor evaluations have gained traction in influencing students' decisions on professor and course selections at universities. RateMyProfessors.com (RMP) is the most popular of such evaluation tools and houses a wealth of information from the students' viewpoint. The purpose of this study was to determine whether RMP data…

  4. Discovery of a general method of solving the Schrödinger and dirac equations that opens a way to accurately predictive quantum chemistry.

    PubMed

    Nakatsuji, Hiroshi

    2012-09-18

    Just as Newtonian law governs classical physics, the Schrödinger equation (SE) and the relativistic Dirac equation (DE) rule the world of chemistry. So, if we can solve these equations accurately, we can use computation to predict chemistry precisely. However, for approximately 80 years after the discovery of these equations, chemists believed that they could not solve SE and DE for atoms and molecules that included many electrons. This Account reviews ideas developed over the past decade to further the goal of predictive quantum chemistry. Between 2000 and 2005, I discovered a general method of solving the SE and DE accurately. As a first inspiration, I formulated the structure of the exact wave function of the SE in a compact mathematical form. The explicit inclusion of the exact wave function's structure within the variational space allows for the calculation of the exact wave function as a solution of the variational method. Although this process sounds almost impossible, it is indeed possible, and I have published several formulations and applied them to solve the full configuration interaction (CI) with a very small number of variables. However, when I examined analytical solutions for atoms and molecules, the Hamiltonian integrals in their secular equations diverged. This singularity problem occurred in all atoms and molecules because it originates from the singularity of the Coulomb potential in their Hamiltonians. To overcome this problem, I first introduced the inverse SE and then the scaled SE. The latter simpler idea led to immediate and surprisingly accurate solution for the SEs of the hydrogen atom, helium atom, and hydrogen molecule. The free complement (FC) method, also called the free iterative CI (free ICI) method, was efficient for solving the SEs. In the FC method, the basis functions that span the exact wave function are produced by the Hamiltonian of the system and the zeroth-order wave function. These basis functions are called complement

  5. Functionalized expanded porphyrins

    DOEpatents

    Sessler, Jonathan L; Pantos, Patricia J

    2013-11-12

    Disclosed are functionalized expanded porphyrins that can be used as spectrometric sensors for high-valent actinide cations. The disclosed functionalized expanded porphyrins have the advantage over unfunctionalized systems in that they can be immobilized via covalent attachment to a solid support comprising an inorganic or organic polymer or other common substrates. Substrates comprising the disclosed functionalized expanded porphyrins are also disclosed. Further, disclosed are methods of making the disclosed compounds (immobilized and free), methods of using them as sensors to detect high valent actinides, devices that comprise the disclosed compounds, and kits.

  6. Biophysical chemistry.

    PubMed

    Häussinger, Daniel; Pfohl, Thomas

    2010-01-01

    Biophysical chemistry at the Department of Chemistry, University of Basel, covers the NMR analysis of protein-protein interaction using paramagnetic tags and sophisticated microscopy techniques investigating the dynamics of biological matter.

  7. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Presents background information, laboratory procedures, classroom materials/activities, and chemistry experiments. Topics include sublimation, electronegativity, electrolysis, experimental aspects of strontianite, halide test, evaluation of present and future computer programs in chemistry, formula building, care of glass/saturated calomel…

  8. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

    Described are eight chemistry experiments and demonstrations applicable to introductory chemistry courses. Activities include: measure of lattice enthalpy, Le Chatelier's principle, decarboxylation of soap, use of pocket calculators in pH measurement, and making nylon. (SL)

  9. Chemistry Dashboard

    EPA Pesticide Factsheets

    The Chemistry Dashboard is part of a suite of dashboards developed by EPA to help evaluate the safety of chemicals. The Chemistry Dashboard provides access to a variety of information on over 700,000 chemicals currently in use.

  10. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Thirteen ideas are presented that may be of use to chemistry teachers. Topics covered include vitamin C, industrial chemistry, electrical conductivity, electrolysis, alkali metals, vibration modes infra-red, dynamic equilibrium, and some new demonstrations in gaseous combinations. (PS)

  11. Expanding the Universe

    NASA Astrophysics Data System (ADS)

    Sterken, Christiaan; Leedjärv, Laurits; Tempel, Elmo

    2011-12-01

    Proceedings of the International Conference EXPANDING THE UNIVERSE, On the occasion of the 200th anniversary of the Tartu Observatory, Tartu, Estonia 2011 April 27-29. C. Sterken, L. Leedjarv, E. Tempel (Eds.)

  12. Efficient model chemistries for peptides. I. General framework and a study of the heterolevel approximation in RHF and MP2 with Pople split-valence basis sets.

    PubMed

    Echenique, Pablo; Alonso, José Luis

    2008-07-15

    We present an exhaustive study of more than 250 ab initio potential energy surfaces (PESs) of the model dipeptide HCO-L-Ala-NH(2). The model chemistries (MCs) investigated are constructed as homo- and heterolevels involving possibly different RHF and MP2 calculations for the geometry and the energy. The basis sets used belong to a sample of 39 representants from Pople's split-valence families, ranging from the small 3-21G to the large 6-311++G(2df,2pd). The reference PES to which the rest are compared is the MP2/6-311++G(2df,2pd) homolevel, which, as far as we are aware, is the most accurate PES in the literature. All data sets have been analyzed according to a general framework, which can be extended to other complex problems and which captures the nearness concept in the space of MCs. The great number of MCs evaluated has allowed us to significantly explore this space and show that the correlation between accuracy and computational cost of the methods is imperfect, thus justifying a systematic search for the combination of features in a MC that is optimal to deal with peptides. Regarding the particular MCs studied, the most important conclusion is that the potentially very cost-saving heterolevel approximation is a very efficient one to describe the whole PES of HCO-L-Ala-NH(2). Finally, we show that, although RHF may be used to calculate the geometry if a MP2 single-point energy calculation follows, pure RHF//RHF homolevels are not recommendable for this problem.

  13. Altitude distribution of tropospheric ozone over the Northern Hemisphere during 1996, simulated with a chemistry-general circulation model at two different horizontal resolutions

    NASA Astrophysics Data System (ADS)

    Kentarchos, A. S.; Roelofs, G. J.; Lelieveld, J.

    2001-01-01

    The spatial/temporal variability of the vertical distribution of tropospheric ozone in the Northern Hemisphere (NH) over a period of 1 year (1996) is studied with a coupled chemistry-general circulation model. The model is used at two different horizontal resolutions (T30: 3.75°×3.75° and T63: 1.875°×1.875°) and is nudged towards European Centre for Medium Range Weather Forecasts analyses for 1996, using a four-dimensional assimilation technique (newtonian relaxation), to enable direct comparisons of observations and model results. Overall, the model reproduces satisfactorily the magnitude and seasonal variability of the vertical ozone distribution observed at six selected locations. Discrepancies occur, however, at remote locations in the subtropical Atlantic and tropical Pacific where ozone concentrations throughout the free troposphere are overestimated by the fourth version of the European Centre Hamburg Model (ECHAM4)-T30. A considerable improvement is evident at T63, which can be attributed, at least partially, to less efficient transport of ozone precursors from the polluted continents at higher resolution. In the upper troposphere/tropopause region, short-term ozone variations are better reproduced at higher resolution. The origin of tropospheric ozone is examined by decomposing its seasonal variation in the model into ozone from the stratosphere and ozone produced within the troposphere. Differences in the NH annual tropospheric ozone budget for 1996, between T30 and T63 mean amounts are relatively small. The tropospheric ozone budget is dominated by photochemical production and destruction (2716 and 2684 Tg, respectively), while the net ozone flux from the stratosphere is estimated to be 436 Tg, and dry deposition is estimated to be 487 Tg.

  14. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Presents background information, laboratory procedures, classroom materials/activities, and experiments for chemistry. Topics include superheavy elements, polarizing power and chemistry of alkali metals, particulate carbon from combustion, tips for the chemistry laboratory, interesting/colorful experiments, behavior of bismuth (III) iodine, and…

  15. Forensic chemistry.

    PubMed

    Bell, Suzanne

    2009-01-01

    Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is incorporating a broader spectrum of chemical sciences. Existing forensic practices are being revisited as the purview of forensic chemistry extends outward from drug analysis and toxicology into such diverse areas as combustion chemistry, materials science, and pattern evidence.

  16. Silicon microfabricated beam expander

    SciTech Connect

    Othman, A. Ibrahim, M. N.; Hamzah, I. H.; Sulaiman, A. A.; Ain, M. F.

    2015-03-30

    The feasibility design and development methods of silicon microfabricated beam expander are described. Silicon bulk micromachining fabrication technology is used in producing features of the structure. A high-precision complex 3-D shape of the expander can be formed by exploiting the predictable anisotropic wet etching characteristics of single-crystal silicon in aqueous Potassium-Hydroxide (KOH) solution. The beam-expander consist of two elements, a micromachined silicon reflector chamber and micro-Fresnel zone plate. The micro-Fresnel element is patterned using lithographic methods. The reflector chamber element has a depth of 40 µm, a diameter of 15 mm and gold-coated surfaces. The impact on the depth, diameter of the chamber and absorption for improved performance are discussed.

  17. Radiation Chemistry in Organized Assemblies.

    ERIC Educational Resources Information Center

    Thomas, J. K.; Chen, T. S.

    1981-01-01

    Expands the basic concepts regarding the radiation chemistry of simple aqueous systems to more complex, but well defined, organized assemblies. Discusses the differences in behavior in comparison to simple systems. Reviews these techniques: pulse radiolysis, laser flash, photolysis, and steady state irradiation by gamma rays or light. (CS)

  18. Expand Your Hiring Horizons.

    ERIC Educational Resources Information Center

    Leske, Lucy Apthorp; Archer-Martin, Nancy

    1999-01-01

    To succeed in recruiting development officers, colleges and universities must use more aggressive methods to reach alumni, people with ties to the campus, and local business people; expand their selection criteria, perhaps including candidates with little or no experience; streamline the hiring process; and train new professionals. (MSE)

  19. Expanding Views on Transition.

    ERIC Educational Resources Information Center

    Repetto, Jeanne B.; Correa, Vivian I.

    1996-01-01

    This position paper proposes an expanded definition of transition, based on common components of early childhood and secondary perspectives. It advocates for a seamless model of transition service delivery for students with disabilities, including program planning, from birth through age 21. The model addresses curriculum, location of services,…

  20. Expanded Roles for HRD.

    ERIC Educational Resources Information Center

    1998

    This document contains three papers from a symposium on expanded roles for human resource development (HRD). "The Roles of Consultants in Gainsharing Firms: Empirical Results" (Eunsang Cho, Gary N. McLean) reports findings that consultants are moderately involved at the separation, preparation, evaluation, and design stages and have low…

  1. ExpandED Options: Learning beyond High School Walls

    ERIC Educational Resources Information Center

    ExpandED Schools, 2014

    2014-01-01

    Through ExpandED Options by TASC, New York City high school students get academic credit for learning career-related skills that lead to paid summer jobs. Too many high school students--including those most likely to drop out--are bored or see classroom learning as irrelevant. ExpandED Options students live the connection between mastering new…

  2. Supplemental instruction in chemistry

    NASA Astrophysics Data System (ADS)

    Lundeberg, Mary A.

    This study was designed to measure some effects of supplemental instruction in chemistry. Supplemental instruction is a peer-led cooperative learning program that encourages students to develop conceptual understanding by articulating both understandings and misconceptions in a think-aloud fashion. Supplemental instruction was offered three hours weekly outside of class and lab time for students in four classes of General Organic and Biological Chemistry. Over a two-year period 108 students volunteered to participate in this program; 45 students did not participate. As measured by final grades in chemistry and responses to a questionnaire, supplemental instruction was effective in increasing students' achievement in chemistry. Further research is needed to determine the in-depth effects of supplemental instruction on students' learning, problem solving, and self-esteem.

  3. Technetium chemistry

    SciTech Connect

    Burns, C.; Bryan, J.; Cotton, F.; Ott, K.; Kubas, G.; Haefner, S.; Barrera, J.; Hall, K.; Burrell, A.

    1996-04-01

    Technetium chemistry is a young and developing field. Despite the limited knowledge of its chemistry, technetium is the workhorse for nuclear medicine. Technetium is also a significant environmental concern because it is formed as a byproduct of nuclear weapons production and fission-power generators. Development of new technetium radio-pharmaceuticals and effective environmental control depends strongly upon knowledge of basic technetium chemistry. The authors performed research into the basic coordination and organometallic chemistry of technetium and used this knowledge to address nuclear medicine and environmental applications. This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL).

  4. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Twelve new chemistry expermiments are described. Broad areas covered include atomic structure, solubility, gaseous diffusion, endothermic reactions, alcohols, equilibrium, atomic volumes, and some improvised apparatus. (PS)

  5. Ion Exchange and Thin Layer Chromatographic Separation and Identification of Amino Acids in a Mixture: An Experiment for General Chemistry and Biotechnology Laboratories

    ERIC Educational Resources Information Center

    Brunauer, Linda S.; Caslavka, Katelyn E.; Van Groningen, Karinne

    2014-01-01

    A multiday laboratory exercise is described that is suitable for first-year undergraduate chemistry, biochemistry, or biotechnology students. Students gain experience in performing chromatographic separations of biomolecules, in both a column and thin layer chromatography (TLC) format. Students chromatographically separate amino acids (AA) in an…

  6. Towards expanding megasonic cleaning capability

    NASA Astrophysics Data System (ADS)

    Han, Zhenxing; Ferstl, Berthold; Oetter, Günter; Dietze, Uwe; Samayoa, Martin; Dattilo, Davide

    2016-10-01

    Megasonic cleaning remains the industry's workhorse technology for particle removal on advanced 193i and extreme ultraviolet (EUV) photomasks. Several megasonic cleaning technologies and chemistries have been proposed and implemented over the years in diverse production environments. The operational range of these process technologies, over a wide array of applications, is ultimately defined by measurable capability limits. As geometries continue to scale-down and new materials are introduced, existing cleaning technologies will naturally fade out of range and new capability is ultimately required. This paper presents a novel fundamental approach for expanding cleaning capability by use of high-frequency megasonics and tenside-based additives (BASF SELECTIPUR C-series). To this end, a sonoluminescence-based experimental test bench was configured to characterize and study the effects of various process parameters on cleaning performance, with a particular emphasis on cavitation-induced damage and enhancement of particle removal capabilities. The results from the fundamental studies provide a path forward towards delivering new cleaning capability by enabling high-frequency megasonic systems and tenside-based additives.

  7. Characterizing the successful student in general chemistry and physical science classes in terms of Jung's personality types as identified by the Myers-Briggs Type Indicator

    NASA Astrophysics Data System (ADS)

    Riley, Wayne David

    1998-11-01

    A student's success in a science class can depend upon previous experiences, motivation, and the level of interest in the subject. Since psychological type is intrinsic to a person's whole being, it can be influential upon the student's motivation and interests. Thus, a study of student psychological types versus the level of success in a class, as measured by a percentage, has potential to uncover certain personality characteristics which may be helpful to or which may hinder a student's learning environment. This study was initiated, using the Myers-Briggs Type Indicator, to evaluate any correlation between a student's personality type and his/her performance in a science class. A total of 1041 students from three classes: Chemistry 121/122, Chemistry 112, Physical Science 100, volunteered for the study. An analysis of variance (ANOVA) was used to determine the levels of significance among sixteen personality types' averages. The results reveal that for the Chemistry 1121/122 course, the average score of the INTJ personality type was 5.1 to 12.6 points higher than every other personality type. The ANOVA identifies 3 personality types with averages significantly below the INTJ at the p < 0.05 significance level. The ANOVA analysis for the Chemistry 112 course identified significances between student scores at p = 0.08. The significance level for the differences among scores for the Physical Science 100 course was determined at a level of p = 0.02. Significance levels for p < 0.05 and <0.01 were identified between several groups in this course. The data suggest, that although personality type may not predict a particular student's success in a science class, students with certain personality traits may be favored in a chemistry class due the structure of the instruction and the presentation of the subject matter.

  8. Medicinal Chemistry/Pharmacology in Sophomore Organic Chemistry.

    ERIC Educational Resources Information Center

    Harrison, Aline M.

    1989-01-01

    Discussed is a series of lectures designed to illustrate the use of general organic chemical principles in molecular biology, introduce current research in interdisciplinary areas to the beginner, increase interest in organic chemistry, and bridge the gap between traditional organic chemistry, biology, and the consumer. An outline is presented.…

  9. 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.

  10. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Outlines laboratory procedures, demonstrations, teaching suggestions, and content information related to chemistry. Topics include polarizing power; calorimetry and momentum; microcomputers in school chemistry; a constant-volume dispenser for liquids, floating magnets, and crystal lattices; preparation of chromium; and solvent polarity and…

  11. Discovering the Expanding Universe

    NASA Astrophysics Data System (ADS)

    Nussbaumer, Harry; Bieri, Lydia; Sandage, Foreword by Allan

    2009-03-01

    Acknowledgments; Foreword; 1. Introduction; 2. Cosmological concepts at the end of the Middle Ages; 3. Nebulae as a new astronomical phenomenon; 4. On the construction of the Heavens; 5. Island universes turn into astronomical facts: a universe of galaxies; 6. The early cosmology of Einstein and de Sitter; 7. The dynamical universe of Friedmann; 8. Redshifts: how to reconcile Slipher and de Sitter?; 9. Lemaître discovers the expanding universe; 10. Hubble's contribution of 1929; 11. The breakthrough for the expanding universe; 12. Hubble's anger about de Sitter; 13. Robertson and Tolman join the game; 14. The Einstein-de Sitter universe; 15. Are Sun and Earth older than the universe?; 16. In search of alternative tracks; 17. The seed for the Big Bang; 18. Summary and Postscript; Appendix; References; Index.

  12. Expandable LED array interconnect

    DOEpatents

    Yuan, Thomas Cheng-Hsin; Keller, Bernd

    2011-03-01

    A light emitting device that can function as an array element in an expandable array of such devices. The light emitting device comprises a substrate that has a top surface and a plurality of edges. Input and output terminals are mounted to the top surface of the substrate. Both terminals comprise a plurality of contact pads disposed proximate to the edges of the substrate, allowing for easy access to both terminals from multiple edges of the substrate. A lighting element is mounted to the top surface of the substrate. The lighting element is connected between the input and output terminals. The contact pads provide multiple access points to the terminals which allow for greater flexibility in design when the devices are used as array elements in an expandable array.

  13. Grazing incidence beam expander

    NASA Astrophysics Data System (ADS)

    Akkapeddi, P. R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V. K.

    1985-01-01

    A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

  14. Expanding the HAWC Observatory

    SciTech Connect

    Mori, Johanna

    2016-08-17

    The High Altitude Water Cherenkov Gamma-Ray Observatory is expanding its current array of 300 water tanks to include 350 outrigger tanks to increase sensitivity to gamma rays above 10 TeV. This involves creating and testing hardware with which to build the new tanks, including photomultiplier tubes, high voltage supply units, and flash analog to digital converters. My responsibilities this summer included preparing, testing and calibrating that equipment.

  15. Chemistry for whom? Gender awareness in teaching and learning chemistry

    NASA Astrophysics Data System (ADS)

    Andersson, Kristina

    2016-11-01

    Marie Ståhl and Anita Hussénius have defined what discourses dominate national tests in chemistry for Grade 9 in Sweden by using feminist, critical didactic perspectives. This response seeks to expand the results in Ståhl and Hussénius's article Chemistry inside an epistemological community box!—Discursive exclusions and inclusions in the Swedish national tests in chemistry, by using different facets of gender awareness. The first facet—Gender awareness in relations to the test designers' own conceptions—highlighted how the gender order where women are subordinated men becomes visible in the national tests as a consequence of the test designers internalized conceptions. The second facet—Gender awareness in relation to chemistry—discussed the hierarchy between discourses within chemistry. The third facet—Gender awareness in relation to students—problematized chemistry in relation to the students' identity formation. In summary, I suggest that the different discourses can open up new ways to interpret chemistry and perhaps dismantle the hegemonic chemistry discourse.

  16. Chemistry Is Fun.

    ERIC Educational Resources Information Center

    Yaniv, D; And Others

    1982-01-01

    Encouraging scientific thinking through open-ended experiments, allowing students access to common chemical instrumentation, and introduction to laboratory techniques are goals of a high school science laboratory program. Course content (general, inorganic, and organic chemistry), limitations, and course evaluation are discussed. (Author/JN)

  17. Circumstellar chemistry

    NASA Technical Reports Server (NTRS)

    Glassgold, Alfred E.; Huggins, Patrick J.

    1987-01-01

    The study of the outer envelopes of cool evolved stars has become an active area of research. The physical properties of CS envelopes are presented. Observations of many wavelengths bands are relevant. A summary of observations and a discussion of theoretical considerations concerning the chemistry are summarized. Recent theoretical considerations show that the thermal equilibrium model is of limited use for understanding the chemistry of the outer CS envelopes. The theoretical modeling of the chemistry of CS envelopes provides a quantitive test of chemical concepts which have a broader interest than the envelopes themselves.

  18. Beginning Chemistry Can Be Relevant

    ERIC Educational Resources Information Center

    Corwin, James F.

    1971-01-01

    Reviews ways of applying laboratory work in general and analytical chemistry to supermarket products. Describes ways water and air pollution analysis can illustrate acid-base reactions, redox reactions, precipitimetry, and colorimetry. (PR)

  19. Preventive Ethics Through Expanding Education.

    PubMed

    Ho, Anita; MacDonald, Lisa Mei-Hwa; Unger, David

    2016-03-01

    Healthcare institutions have been making increasing efforts to standardize consultation methodology and to accredit both bioethics training programs and the consultants accordingly. The focus has traditionally been on the ethics consultation as the relevant unit of ethics intervention. Outcome measures are studied in relation to consultations, and the hidden assumption is that consultations are the preferred or best way to address day-to-day ethical dilemmas. Reflecting on the data from an internal quality improvement survey and the literature, we argue that having general ethics education as a key function of ethics services may be more important in meeting the contemporaneous needs of acute care settings. An expanded and varied ethics education, with attention to the time constraints of healthcare workers' schedules, was a key recommendation brought forward by survey respondents. Promoting ethical reflection and creating a culture of ethics may serve to prevent ethical dilemmas or mitigate their effects.

  20. Expanding Human Cognition and Communication

    SciTech Connect

    Spohrer, Jim; Pierce, Brian M.; Murray, Cherry A.; Golledge, Reginald G.; Horn, Robert E.; Turkle, Sherry; Yonas, Gerold; Glicken Turnley, Jessica; Pollack, Jordan; Burger, Rudy; Robinett, Warren; Wilson, Larry Todd; Bainbridge, W. S.; Canton, J.; Kuekes, P.; Loomis, J.; Penz, P.

    2013-01-01

    To be able to chart the most profitable future directions for societal transformation and corresponding scientific research, five multidisciplinary themes focused on major goals have been identified to fulfill the overall motivating vision of convergence described in the previous pages. The first, “Expanding Human Cognition and Communication,” is devoted to technological breakthroughs that have the potential to enhance individuals’ mental and interaction abilities. Throughout the twentieth century, a number of purely psychological techniques were offered for strengthening human character and personality, but evaluation research has generally failed to confirm the alleged benefits of these methods (Druckman and Bjork 1992; 1994). Today, there is good reason to believe that a combination of methods, drawing upon varied branches of converging science and technology, would be more effective than attempts that rely upon mental training alone.

  1. 40 CFR 158.2290 - Residue chemistry.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Residue chemistry. 158.2290 Section... REQUIREMENTS FOR PESTICIDES Antimicrobial Pesticide Data Requirements § 158.2290 Residue chemistry. (a) General... determine the residue chemistry data requirements for antimicrobial pesticide products. Notes that apply...

  2. Expanding the Boundaries of Adult Religious Education

    ERIC Educational Resources Information Center

    Isaac, E. Paulette

    2012-01-01

    Religious institutions wear many hats. In addition to meeting spiritual needs, they also serve as educational, cultural, political, and social centers. Like the world in general, many of them have responded to societal changes. They have expanded their contextual, geographical, and physical boundaries. Also, as demonstrated throughout this…

  3. Catalytic Chemistry.

    ERIC Educational Resources Information Center

    Borer, Londa; And Others

    1996-01-01

    Describes an approach for making chemistry relevant to everyday life. Involves the study of kinetics using the decomposition of hydrogen peroxide by vegetable juices. Allows students to design and carry out experiments and then draw conclusions from their results. (JRH)

  4. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1980

    1980-01-01

    Describes equipment, activities, and experiments useful in chemistry instruction, including among others, a rapid method to determine available chlorine in bleach, simple flame testing apparatus, and a simple apparatus demonstrating the technique of flash photolysis. (SK)

  5. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1973

    1973-01-01

    Several ideas are proposed for chemistry teachers to try in their classrooms. Subjects included are polymerization of acrylate, polymerization of styrene, conductivity, pollution, preparation of chlorine, redox equations, chemiluminescence, and molecular sieves. (PS)

  6. Nuclear Chemistry.

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1979

    1979-01-01

    Provides a brief review of the latest developments in nuclear chemistry. Nuclear research today is directed toward increased activity in radiopharmaceuticals and formation of new isotopes by high-energy, heavy-ion collisions. (Author/BB)

  7. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Describes 13 activities, experiments and demonstrations, including the preparation of iron (III) chloride, simple alpha-helix model, investigating camping gas, redox reactions of some organic compounds, a liquid crystal thermometer, and the oxidation number concept in organic chemistry. (JN)

  8. Precolumbian Chemistry.

    ERIC Educational Resources Information Center

    Robinson, Janet Bond

    1995-01-01

    Describes the content and development of a curriculum that provides an approach to descriptive chemistry and the history of technology through consideration of the pottery, metallurgy, pigments, dyes, agriculture, and medicine of pre-Columbian people. (DDR)

  9. Stratospheric chemistry

    SciTech Connect

    Brune, W.H. )

    1991-01-01

    Advances in stratospheric chemistry made by investigators in the United States from 1987 to 1990 are reviewed. Subject areas under consideration include photochemistry of the polar stratosphere, photochemistry of the global stratosphere, and assessments of inadvertent modification of the stratosphere by anthropogenic activity. Particular attention is given to early observations and theories, gas phase chemistry, Antarctic observations, Arctic observations, odd-oxygen, odd-hydrogen, odd-nitrogen, halogens, aerosols, modeling of stratospheric ozone, and reactive nitrogen effects.

  10. Analytical Chemistry at the Interface Between Materials Science and Biology

    SciTech Connect

    O'Brien, Janese C.

    2000-09-21

    Likedlessentid sciences, anal~cd chetis~continues toreinvent itself. Moving beyond its traditional roles of identification and quantification, analytical chemistry is now expanding its frontiers into areas previously reserved to other disciplines. This work describes several research efforts that lie at the new interfaces between analytical chemistry and two of these disciplines, namely materials science and biology. In the materials science realm, the search for new materials that may have useful or unique chromatographic properties motivated the synthesis and characterization of electrically conductive sol-gels. In the biology realm, the search for new surface fabrication schemes that would permit or even improve the detection of specific biological reactions motivated the design of miniaturized biological arrays. Collectively, this work represents some of analytical chemistry’s newest forays into these disciplines. The introduction section to this dissertation provides a literature review on several of the key aspects of this work. In advance of the materials science discussion, a brief introduction into electrochemically-modulated liquid chromatography (EMLC) and sol-gel chemistry is provided. In advance of the biological discussions, brief overviews of scanning force microscopy (SFM) and the oxidative chemistry used to construct our biological arrays are provided. This section is followed by four chapters, each of which is presented as a separate manuscript, and focuses on work that describes some of our cross-disciplinary efforts within materials science and biology. This dissertation concludes with a general summary and future prospectus.

  11. Uranium triamidoamine chemistry.

    PubMed

    Gardner, Benedict M; Liddle, Stephen T

    2015-07-07

    Triamidoamine (Tren) complexes of the p- and d-block elements have been well-studied, and they display a diverse array of chemistry of academic, industrial and biological significance. Such in-depth investigations are not as widespread for Tren complexes of uranium, despite the general drive to better understand the chemical behaviour of uranium by virtue of its fundamental position within the nuclear sector. However, the chemistry of Tren-uranium complexes is characterised by the ability to stabilise otherwise reactive, multiply bonded main group donor atom ligands, construct uranium-metal bonds, promote small molecule activation, and support single molecule magnetism, all of which exploit the steric, electronic, thermodynamic and kinetic features of the Tren ligand system. This Feature Article presents a current account of the chemistry of Tren-uranium complexes.

  12. Mechanically expandable annular seal

    DOEpatents

    Gilmore, R.F.

    1983-07-19

    A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces is described. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluid tight barrier. A counter rotation removes the barrier. 6 figs.

  13. Mechanically expandable annular seal

    DOEpatents

    Gilmore, Richard F.

    1983-01-01

    A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluidtight barrier. A counterrotation removes the barrier.

  14. Expanding hollow metal rings

    DOEpatents

    Peacock, Harold B.; Imrich, Kenneth J.

    2009-03-17

    A sealing device that may expand more planar dimensions due to internal thermal expansion of a filler material. The sealing material is of a composition such that when desired environment temperatures and internal actuating pressures are reached, the sealing materials undergoes a permanent deformation. For metallic compounds, this permanent deformation occurs when the material enters the plastic deformation phase. Polymers, and other materials, may be using a sealing mechanism depending on the temperatures and corrosivity of the use. Internal pressures are generated by either rapid thermal expansion or material phase change and may include either liquid or solid to gas phase change, or in the gaseous state with significant pressure generation in accordance with the gas laws. Sealing material thickness and material composition may be used to selectively control geometric expansion of the seal such that expansion is limited to a specific facing and or geometric plane.

  15. Chemistry and cosmology.

    PubMed

    Black, John H

    2006-01-01

    The simplest elements, hydrogen and helium, offer a remarkably rich chemistry, which has controlled crucial features of the early evolution of the universe. Theoretical models of the origin of structure (stars, galaxies, clusters of galaxies, etc.) now incorporate this chemistry in some detail. In addition to the origin of structure, cosmologists are concerned with observational tests of competing world models. Primordial chemistry may give rise to some of the earliest departures from thermodynamic equilibrium in the universe. These effects may be observable as broad-band spectroscopic distortions of the cosmic background radiation, which otherwise exhibits a nearly perfect blackbody spectrum. The chemical history of the expanding universe is followed through a detailed calculation of the evolution of the abundances of H, H+, H-, H2, H2+, H3+, and other minor species. It is shown that continuous absorption by the small concentration of H- can produce a distortion in the cosmic background spectrum with a maximum at a frequency near nu/c = 9 cm-1 (wavelength 1.1 mm). The predicted effect lies only a factor of 5 below current limits. Its detection would provide an important test of our understanding of the recombination epoch of the universe.

  16. C-IFS-CB05-BASCOE: stratospheric chemistry in the Integrated Forecasting System of ECMWF

    NASA Astrophysics Data System (ADS)

    Huijnen, Vincent; Flemming, Johannes; Chabrillat, Simon; Errera, Quentin; Christophe, Yves; Blechschmidt, Anne-Marlene; Richter, Andreas; Eskes, Henk

    2016-09-01

    We present a model description and benchmark evaluation of an extension of the tropospheric chemistry module in the Integrated Forecasting System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF) with stratospheric chemistry, referred to as C-IFS-CB05-BASCOE (for brevity here referred to as C-IFS-TS). The stratospheric chemistry originates from the one used in the Belgian Assimilation System for Chemical ObsErvations (BASCOE), and is here combined with the modified CB05 chemistry module for the troposphere as currently used operationally in the Copernicus Atmosphere Monitoring Service (CAMS). In our approach either the tropospheric or stratospheric chemistry module is applied, depending on the altitude of each individual grid box with respect to the tropopause. An evaluation of a 2.5-year long C-IFS-TS simulation with respect to various satellite retrieval products and in situ observations indicates good performance of the system in terms of stratospheric ozone, and a general improvement in terms of stratospheric composition compared to the C-IFS predecessor model version. Possible issues with transport processes in the stratosphere are identified. This marks a key step towards a chemistry module within IFS that encompasses both tropospheric and stratospheric composition, and could expand the CAMS analysis and forecast capabilities in the near future.

  17. The Expanding Universe

    NASA Astrophysics Data System (ADS)

    Heacox, William D.

    2015-11-01

    Introducing the Universe; Part I. Conceptual Foundations: 1. Newtonian cosmology; 2. General relativity; 3. Relativistic cosmology; Part II. General Relativity: 4. General covariance; 5. Equivalence principle; 6. Space-time curvature; 7. Einstein field equations of gravitation; Part III. Universal Expansion: 8. Cosmological field equations; 9. Cosmography; 10. Expansion dynamics; Part IV. Expansion Models: 11. Radiation; 12. Matter; 13. Dark energy; 14. Observational constraints; 15. Concordance cosmological model; Part V. Expansion History: 16. Particle era; 17. Plasma era; 18. Galaxy era; 19. Afterword: the new modern cosmology; Part VI: Appendices; Bibliography; Index.

  18. Investigating the Relationship between Faculty Cognitive Expectations about Learning Chemistry and the Construction of Exam Questions

    ERIC Educational Resources Information Center

    Sanabria-Rios, David; Bretz, Stacey Lowery

    2010-01-01

    We have investigated chemistry faculty's cognitive expectations about learning chemistry and their influence upon the construction of exam questions in a general chemistry curriculum. Faculty cognitive expectations for learning chemistry were measured using QUIMX. Learning objectives and exam questions for a year-long general chemistry sequence…

  19. Clinical chemistry through Clinical Chemistry: a journal timeline.

    PubMed

    Rej, Robert

    2004-12-01

    The establishment of the modern discipline of clinical chemistry was concurrent with the foundation of the journal Clinical Chemistry and that of the American Association for Clinical Chemistry in the late 1940s and early 1950s. To mark the 50th volume of this Journal, I chronicle and highlight scientific milestones, and those within the discipline, as documented in the pages of Clinical Chemistry. Amazing progress has been made in the field of laboratory diagnostics over these five decades, in many cases paralleling-as well as being bolstered by-the rapid pace in the development of computer technologies. Specific areas of laboratory medicine particularly well represented in Clinical Chemistry include lipids, endocrinology, protein markers, quality of laboratory measurements, molecular diagnostics, and general advances in methodology and instrumentation.

  20. Significant steps in the evolution of analytical chemistry--is the today's analytical chemistry only chemistry?

    PubMed

    Karayannis, Miltiades I; Efstathiou, Constantinos E

    2012-12-15

    In this review the history of chemistry and specifically the history and the significant steps of the evolution of analytical chemistry are presented. In chronological time spans, covering the ancient world, the middle ages, the period of the 19th century, and the three evolutional periods, from the verge of the 19th century to contemporary times, it is given information for the progress of chemistry and analytical chemistry. During this period, analytical chemistry moved gradually from its pure empirical nature to more rational scientific activities, transforming itself to an autonomous branch of chemistry and a separate discipline. It is also shown that analytical chemistry moved gradually from the status of exclusive serving the chemical science, towards serving, the environment, health, law, almost all areas of science and technology, and the overall society. Some recommendations are also directed to analytical chemistry educators concerning the indispensable nature of knowledge of classical analytical chemistry and the associated laboratory exercises and to analysts, in general, why it is important to use the chemical knowledge to make measurements on problems of everyday life.

  1. Student academic achievement in college chemistry

    NASA Astrophysics Data System (ADS)

    Tabibzadeh, Kiana S.

    General Chemistry is required for variety of baccalaureate degrees, including all medical related fields, engineering, and science majors. Depending on the institution, the prerequisite requirement for college level General Chemistry varies. The success rate for this course is low. The purpose of this study is to examine the factors influencing student academic achievement and retention in General Chemistry at the college level. In this study student achievement is defined by those students who earned grades of "C" or better. The dissertation contains in-depth studies on influence of Intermediate Algebra as a prerequisite compared to Fundamental Chemistry for student academic achievement and student retention in college General Chemistry. In addition the study examined the extent and manner in which student self-efficacy influences student academic achievement in college level General Chemistry. The sample for this part of the study is 144 students enrolled in first semester college level General Chemistry. Student surveys determined student self-efficacy level. The statistical analyses of study demonstrated that Fundamental Chemistry is a better prerequisite for student academic achievement and student retention. The study also found that student self-efficacy has no influence on student academic achievement. The significance of this study will be to provide data for the purpose of establishing a uniform and most suitable prerequisite for college level General Chemistry. Finally the variables identified to influence student academic achievement and enhance student retention will support educators' mission to maximize the students' ability to complete their educational goal at institutions of higher education.

  2. Polymer Chemistry

    NASA Technical Reports Server (NTRS)

    Williams, Martha; Roberson, Luke; Caraccio, Anne

    2010-01-01

    This viewgraph presentation describes new technologies in polymer and material chemistry that benefits NASA programs and missions. The topics include: 1) What are Polymers?; 2) History of Polymer Chemistry; 3) Composites/Materials Development at KSC; 4) Why Wiring; 5) Next Generation Wiring Materials; 6) Wire System Materials and Integration; 7) Self-Healing Wire Repair; 8) Smart Wiring Summary; 9) Fire and Polymers; 10) Aerogel Technology; 11) Aerogel Composites; 12) Aerogels for Oil Remediation; 13) KSC's Solution; 14) Chemochromic Hydrogen Sensors; 15) STS-130 and 131 Operations; 16) HyperPigment; 17) Antimicrobial Materials; 18) Conductive Inks Formulations for Multiple Applications; and 19) Testing and Processing Equipment.

  3. Chemistry Experiments

    NASA Technical Reports Server (NTRS)

    Brasseur, Guy; Remsberg, Ellis; Purcell, Patrick; Bhatt, Praful; Sage, Karen H.; Brown, Donald E.; Scott, Courtney J.; Ko, Malcolm K. W.; Tie, Xue-Xi; Huang, Theresa

    1999-01-01

    The purpose of the chemistry component of the model comparison is to assess to what extent differences in the formulation of chemical processes explain the variance between model results. Observed concentrations of chemical compounds are used to estimate to what degree the various models represent realistic situations. For readability, the materials for the chemistry experiment are reported in three separate sections. This section discussed the data used to evaluate the models in their simulation of the source gases and the Nitrogen compounds (NO(y)) and Chlorine compounds (Cl(y)) species.

  4. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1980

    1980-01-01

    Presents 12 chemistry notes for British secondary school teachers. Some of these notes are: (1) a simple device for testing pH-meters; (2) portable fume cupboard safety screen; and (3) Mass spectroscopy-analysis of a mass peak. (HM)

  5. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

    Describes several chemistry projects, including solubility, formula for magnesium oxide, dissociation of dinitrogen tetroxide, use of 1-chloro-2, 4-dinitrobenzene, migration of ions, heats of neutralizations, use of pocket calculators, sonic cleaning, oxidation states of manganese, and cell potentials. Includes an extract from Chemical Age on…

  6. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Short articles on the alkylation of aniline, the preparation and properties of perbromate, using scrap copper in chemistry instruction, a safe method of burning hydrogen, and the use of an ion-charge model as an alternative to the mole concept in secondary school instruction. (AL)

  7. Confectionary Chemistry.

    ERIC Educational Resources Information Center

    Levine, Elise Hilf

    1996-01-01

    Presents activities and demonstrations that enable teachers to use various types of confections as tactile experiences to spark chemistry students' interest and generate enthusiasm for learning. Presents uses of candy in teaching about atomic structure, spontaneous nuclear decay, chemical formulas, fractoluminescence, the effect of a molecular…

  8. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Short articles on the kinetics of the hydrogen peroxide-iodide ion reaction, simulation of fluidization catalysis, the use of Newman projection diagrams to represent steric relationships in organic chemistry, the use of synthetic substrates for proteolytic enzyme reactions, and two simple clock reactions"--hydrolysis of halogenoalkanes and…

  9. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Presents chemistry experiments, laboratory procedures, demonstrations, teaching suggestions, and classroom materials/activities. These include: game for teaching ionic formulas; method for balancing equations; description of useful redox series; computer programs (with listings) for water electrolysis simulation and for determining chemical…

  10. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Presents chemistry experiments, laboratory procedures, demonstrations, and classroom materials/activities. These include: experiments on colloids, processing of uranium ore, action of heat on carbonates; color test for phenols and aromatic amines; solvent properties of non-electrolytes; stereoscopic applications/methods; a valency balance;…

  11. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Presents procedures, experiments, demonstrations, teaching suggestions, and information on a variety of chemistry topics including, for example, inert gases, light-induced reactions, calculators, identification of substituted acetophenones, the elements, analysis of copper minerals, extraction of metallic strontium, equilibrium, halogens, and…

  12. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1978

    1978-01-01

    Describes some laboratory apparatus, chemistry experiments and demonstrations, such as a Kofler block melting point apparatus, chromatographic investigation of the phosphoric acid, x-ray diffraction, the fountain experiment, endothermic sherbet, the measurement of viscosity, ionization energies and electronic configurations. (GA)

  13. Cocrystal Controlled Solid-State Synthesis: A Green Chemistry Experiment for Undergraduate Organic Chemistry

    ERIC Educational Resources Information Center

    Cheney, Miranda L.; Zaworotko, Michael J.; Beaton, Steve; Singer, Robert D.

    2008-01-01

    Green chemistry has become an important area of concern for all chemists from practitioners in the pharmaceutical industry to professors and the students they teach and is now being incorporated into lectures of general and organic chemistry courses. However, there are relatively few green chemistry experiments that are easily incorporated into…

  14. Chemistry, Poetry, and Artistic Illustration: An Interdisciplinary Approach to Teaching and Promoting Chemistry

    ERIC Educational Resources Information Center

    Furlan, Ping Y.; Kitson, Herbert; Andes, Cynthia

    2007-01-01

    This article describes a successful interdisciplinary collaboration among chemistry, humanities and English faculty members, who utilized poetry and artistic illustration to help students learn, appreciate, and enjoy chemistry. Students taking general chemistry classes were introduced to poetry writing and museum-type poster preparation during one…

  15. The Artful Universe Expanded

    NASA Astrophysics Data System (ADS)

    Barrow, John D.

    2005-07-01

    Our love of art, writes John Barrow, is the end product of millions of years of evolution. How we react to a beautiful painting or symphony draws upon instincts laid down long before humans existed. Now, in this enhanced edition of the highly popular The Artful Universe , Barrow further explores the close ties between our aesthetic appreciation and the basic nature of the Universe. Barrow argues that the laws of the Universe have imprinted themselves upon our thoughts and actions in subtle and unexpected ways. Why do we like certain types of art or music? What games and puzzles do we find challenging? Why do so many myths and legends have common elements? In this eclectic and entertaining survey, Barrow answers these questions and more as he explains how the landscape of the Universe has influenced the development of philosophy and mythology, and how millions of years of evolutionary history have fashioned our attraction to certain patterns of sound and color. Barrow casts the story of human creativity and thought in a fascinating light, considering such diverse topics as our instinct for language, the origins and uses of color in nature, why we divide time into intervals as we do, the sources of our appreciation of landscape painting, and whether computer-generated fractal art is really art. Drawing on a wide variety of examples, from the theological questions raised by St. Augustine and C.S. Lewis to the relationship between the pure math of Pythagoras and the music of the Beatles, The Artful Universe Expanded covers new ground and enters a wide-ranging debate about the meaning and significance of the links between art and science.

  16. Expanding contraceptive options.

    PubMed

    1989-01-01

    The goals of Family Health International (FHI) have been to introduce a variety of birth control options to people in developing countries, and to provide information to the user on the advantages and disadvantages of each method. FHI has worked with many developing countries in clinical trials of established as well as new contraceptive methods. These trials played an important part in making 2 sterilization procedures, laparoscopy and minilaparotomy popular for women. Further research improved the methods and have made them the most popular in the world, chosen by 130 million users. FHI is doing clinical trials on a new IUD, that is a copper bearing T-shaped device called the TCu380A. they have collected data on over 10,000 women using IUD's and early analysis indicates TCu380A is more effective than others. FHI is also evaluating devices such as Norplant that will prevent pregnancy up to 5 years by implanting the capsules in the arm. More than 8,000 women are being tested to determine the acceptability of implants in different geographical locations. Other research groups are doing work in 10 additional countries: Bangladesh will expand its program to 24,000 women and Nepal to 8,000 women. Trials are also being conducted on progestogen pills, since they do not lesson the volume of milk in breast feeding. FHI has also worked to introduce creative community-based distribution channels. In one case, specially trained health workers delivered contraceptives door-to-door in over 150,000 households. They found that 2 of 3 women accepted the pills and in a follow up survey 90% were still using them. FHI is now focusing on ways to improve moving new contraceptives from clinical testing on everyday use. They will coordinate training programs, educational material, media campaigns, and efforts with other international organizations, government agencies, and family planning groups.

  17. Microscale Chemistry and Green Chemistry: Complementary Pedagogies

    NASA Astrophysics Data System (ADS)

    Singh, Mono M.; Szafran, Zvi; Pike, R. M.

    1999-12-01

    This paper describes the complementary nature of microscale chemistry and green chemistry. Green chemistry emphasizes the concepts of atom economy, source reduction, pathway modification, solvent substitution, and pollution prevention as means of improving the environmental impact of industrial chemistry. Microscale chemistry serves as a tool for incorporating green chemistry ideas across the curriculum in educational institutions. Examples are drawn from microscale laboratory experiments to illustrate the pedagogic connection between the two areas.

  18. Advanced expander test bed engine

    NASA Technical Reports Server (NTRS)

    Mitchell, J. P.

    1992-01-01

    The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high pressure expander cycle concept, study system interactions, and conduct studies of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

  19. Advanced expander test bed program

    NASA Technical Reports Server (NTRS)

    Masters, A. I.; Mitchell, J. C.

    1991-01-01

    The Advanced Expander Test Bed (AETB) is a key element in NASA's Chemical Transfer Propulsion Program for development and demonstration of expander cycle oxygen/hydrogen engine technology component technology for the next space engine. The AETB will be used to validate the high-pressure expander cycle concept, investigate system interactions, and conduct investigations of advanced missions focused components and new health monitoring techniques. The split-expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust.

  20. A three-dimensional chemistry/general circulation model simulation of anthropogenically derived ozone in the troposphere and its radiative climate forcing

    NASA Astrophysics Data System (ADS)

    Roelofs, Geert-Jan; Lelieveld, Jos; van Dorland, Rob

    1997-10-01

    We present results from the tropospheric chemistry/climate European Center Hamburg Model by comparing two simulations that consider a preindustrial and a contemporary emission scenario. Photochemical O3 production from anthropogenically emitted precursors contributes about 30% to the present-day tropospheric O3 content, which is roughly equal to the natural photochemical production. Transports of stratospheric O3 into the troposphere contribute about 40%. As a result of anthropogenic emissions, the O3 maximum over remote northern hemisphere (NH) areas has shifted from winter to spring, when photochemical production of O3 is relatively efficient. Over NH continents the preindustrial seasonal variability is relatively weak whereas a distinct surface O3 summer maximum appears in the contemporary simulation. In the (sub)tropical southern hemisphere (SH), anthropogenic biomass burning emissions cause an increase of O3 mixing ratios in the dry season (September-November). We calculate a relative increase in O3 mixing ratios due to anthropogenic emissions of about 30% in the pristine SH middle and high latitudes to about 100% in the polluted NH boundary layer. The model simulations suggest that the absolute increase of tropospheric O3 maximizes in the middle troposphere. Through convection, upper tropospheric O3 mixing ratios are significantly affected in the tropical regions and, during summer, in the middle and high NH latitudes. Under these conditions the radiative forcing of climate by increasing O3 is relatively large. We calculate a global and annual average radiative forcing by tropospheric O3 perturbations of 0.42 W m-2, i.e., 0.51 W m-2 in the NH and 0.33 W m-2 in the SH.

  1. Polynitrogen Chemistry

    DTIC Science & Technology

    2013-09-24

    4N3, while As(C6H5)4N3 presents a borderline case.23 Theoretical Calculations High-level theoretical studies of nitrogen, oxygen, selenium and...Dixon, D. A.; Christe, K. O., "Thermochemical Properties of Selenium Fluorides, Oxides, and Oxofluorides," Inorganic Chemistry, p. 2472, vol. 51, (2012...34Thermochemical Properties of Selenium Fluorides, Oxides, and Oxofluorides," Inorg. Chem., p. 2472, vol. 51, (2012). 26. K. S. Thanthiriwatte, M. Vasiliu

  2. Computational chemistry

    NASA Technical Reports Server (NTRS)

    Arnold, J. O.

    1987-01-01

    With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

  3. Benchmarking Problems Used in Second Year Level Organic Chemistry Instruction

    ERIC Educational Resources Information Center

    Raker, Jeffrey R.; Towns, Marcy H.

    2010-01-01

    Investigations of the problem types used in college-level general chemistry examinations have been reported in this Journal and were first reported in the "Journal of Chemical Education" in 1924. This study extends the findings from general chemistry to the problems of four college-level organic chemistry courses. Three problem…

  4. A general solution-chemistry route to the synthesis LiMPO{sub 4} (M=Mn, Fe, and Co) nanocrystals with [010] orientation for lithium ion batteries

    SciTech Connect

    Su Jing; Wei Bingqing; Rong Jiepeng; Yin Wenyan; Ye Zhixia; Tian Xianqing; Ren Ling; Cao Minhua; Hu Changwen

    2011-11-15

    A general and efficient solvothermal strategy has been developed for the preparation of lithium transition metal phosphate microstructures (LiMnPO{sub 4}, LiFePO{sub 4}, and LiCoPO{sub 4}), employing ethanol as the solvent, LiI as the Li source, metal salts as the M sources, H{sub 3}PO{sub 4} as the phosphorus source, and poly(vinyl pyrrolidone) (PVP) as the carbon source and template. This route features low cost, environmental benign, and one-step process for the cathode material production of Li-ion batteries without any complicated experimental setups and sophisticated operations. The as-synthesized LiMPO{sub 4} microstructures exhibit unique, well-shaped and favorable structures, which are self-assembled from microplates or microrods. The b axis is the preferred crystal growth orientation of the products, resulting in a shorter lithium ion diffusion path. The LiFePO{sub 4} microstructures show an excellent cycling stability without capacity fading up to 50 cycles when they are used as a cathode material in lithium-ion batteries. - Graphical abstract: A general and efficient solvothermal strategy has been developed for the preparation of lithium transition metal phosphate microstructures under solvothermal conditions in the presence of PVP. Highlights: > A general and efficient solvothermal strategy has been developed for the preparation of LiMPO{sub 4} microstructures. > This route features low cost, environmental benign, and one-step process. > The LiMPO{sub 4} microstructures exhibit unique, well-shaped, and favorable structures. > The LiFePO{sub 4} microstructures show an excellent cycling stability up to 50 cycles as a cathode material of lithium-ion batteries.

  5. A Statistical Evaluation: Peer-led Team Learning in an Organic Chemistry Course.

    ERIC Educational Resources Information Center

    Lyle, Kenneth S.; Robinson, William R.

    2003-01-01

    Reports the status of peer-led learning, also known as Workshop Chemistry. This National Science Foundation (NSF) systemic-reform initiative focuses on general chemistry, organic chemistry, and biochemistry. (DDR)

  6. Expanding roles for atorvastatin.

    PubMed

    Singh, Vibhuti; Deedwania, Prakash

    2008-06-01

    Atherosclerosis, especially when manifested as coronary artery disease (CAD), continues to be the number one cause of mortality and morbidity in developed nations and will soon become so in developing countries. Survivors of an acute heart attack have an increased risk of illness and death that is 1.5-15 times greater than in the general population. Sudden death occurs in myocardial infarction (MI) survivors at a rate 4-6 times greater than in the general population. After an initial recognized MI, 25% of male and 38% of female survivors die within 1 year. Within 6 years after a recognized MI, 18% of men and 35% of women will have a second MI, 7% of men and 6% of women will suffer sudden death, and 22% of men and 46% of women will be disabled with heart failure. Aggressive secondary prevention, therefore, is the key to containing and reversing the "malignant" natural history of CAD, since patients with CAD or CAD risk equivalents are already in the "high risk" category according to the Adult Treatment Panel III (ATP III) of the National Cholesterol Education rogram (NCEP). Treatment of dyslipidemia, especially the reduction of low-density lipoprotein (LDL) cholesterol levels to below 100 mg/dl, was recommended by the 2001 NCEP-ATP Guidelines. In 2004, based on the increasing evidence from several major clinical trials between 2001 and 2004, the NCEP-ATP reaffirmed its LDL goal of < 100 mg/dl in patients with CAD or coronary disease risk equivalents (including multiple risk factors), with an optional LDL goal of < 70 mg/dl in very-high-risk patients (including patients with established coronary heart disease plus other highrisk conditions) Findings from major studies, such as the Treating to New Targets (TNT) study, the Scandinavian Simvastatin Survival Study (4S), the Collaborative Atorvastatin Diabetes Study (CARDS), the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial and, more recently, the Lipid-Lowering Arm of the Anglo

  7. Monolithical aspherical beam expanding systems

    NASA Astrophysics Data System (ADS)

    Fuchs, U.; Matthias, Sabrina

    2014-10-01

    Beam expanding is a common task, where Galileo telescopes are preferred. However researches and customers have found limitations when using these systems. A new monolithical solution which is based on the usage of only one aspherical component will be presented. It will be shown how to combine up to five monolithical beam expanding systems and to keep the beam quality at diffraction limitation. Insights will be given how aspherical beam expanding systems will help using larger incoming beams and reducing the overall length of such a system. Additionally an add-on element for divergence and wavelength adaption will be presented.

  8. Quo vadis, analytical chemistry?

    PubMed

    Valcárcel, Miguel

    2016-01-01

    This paper presents an open, personal, fresh approach to the future of Analytical Chemistry in the context of the deep changes Science and Technology are anticipated to experience. Its main aim is to challenge young analytical chemists because the future of our scientific discipline is in their hands. A description of not completely accurate overall conceptions of our discipline, both past and present, to be avoided is followed by a flexible, integral definition of Analytical Chemistry and its cornerstones (viz., aims and objectives, quality trade-offs, the third basic analytical reference, the information hierarchy, social responsibility, independent research, transfer of knowledge and technology, interfaces to other scientific-technical disciplines, and well-oriented education). Obsolete paradigms, and more accurate general and specific that can be expected to provide the framework for our discipline in the coming years are described. Finally, the three possible responses of analytical chemists to the proposed changes in our discipline are discussed.

  9. [Gaubius and medical chemistry].

    PubMed

    van Gijn, Jan; Gijselhart, Joost P

    2011-01-01

    Hieronymus David Gaub (1705-1780) was the son of a protestant cloth merchant in Heidelberg. Disliking a pietistic boarding school in Halle, Germany, he came to stay with a paternal uncle who was a physician in Amsterdam. Hieronymus studied medicine in Harderwijk and in Leiden, under the guidance of Herman Boerhaave (1668-1738). In 1731 he was appointed reader (and in 1734 professor) in chemistry at the Leiden medical faculty. After Boerhaave's death he also taught medicine, but without access to hospital beds. Gaubius correctly envisaged that chemistry would become an important discipline in medicine, but was limited by the technical constraints of his time. In his textbook of general pathology (1758) he attributed disease to disturbances of not only fluids, but also solid parts, although symptoms remained the basis of his classification. The book would remain influential for several decades, until the advent of pathological anatomy.

  10. Nuclear analytical chemistry

    SciTech Connect

    Brune, D.; Forkman, B.; Persson, B.

    1984-01-01

    This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection.

  11. General theory for multiple input-output perturbations in complex molecular systems. 1. Linear QSPR electronegativity models in physical, organic, and medicinal chemistry.

    PubMed

    González-Díaz, Humberto; Arrasate, Sonia; Gómez-SanJuan, Asier; Sotomayor, Nuria; Lete, Esther; Besada-Porto, Lina; Ruso, Juan M

    2013-01-01

    In general perturbation methods starts with a known exact solution of a problem and add "small" variation terms in order to approach to a solution for a related problem without known exact solution. Perturbation theory has been widely used in almost all areas of science. Bhor's quantum model, Heisenberg's matrix mechanincs, Feyman diagrams, and Poincare's chaos model or "butterfly effect" in complex systems are examples of perturbation theories. On the other hand, the study of Quantitative Structure-Property Relationships (QSPR) in molecular complex systems is an ideal area for the application of perturbation theory. There are several problems with exact experimental solutions (new chemical reactions, physicochemical properties, drug activity and distribution, metabolic networks, etc.) in public databases like CHEMBL. However, in all these cases, we have an even larger list of related problems without known solutions. We need to know the change in all these properties after a perturbation of initial boundary conditions. It means, when we test large sets of similar, but different, compounds and/or chemical reactions under the slightly different conditions (temperature, time, solvents, enzymes, assays, protein targets, tissues, partition systems, organisms, etc.). However, to the best of our knowledge, there is no QSPR general-purpose perturbation theory to solve this problem. In this work, firstly we review general aspects and applications of both perturbation theory and QSPR models. Secondly, we formulate a general-purpose perturbation theory for multiple-boundary QSPR problems. Last, we develop three new QSPR-Perturbation theory models. The first model classify correctly >100,000 pairs of intra-molecular carbolithiations with 75-95% of Accuracy (Ac), Sensitivity (Sn), and Specificity (Sp). The model predicts probabilities of variations in the yield and enantiomeric excess of reactions due to at least one perturbation in boundary conditions (solvent, temperature

  12. (Pesticide chemistry)

    SciTech Connect

    Barnthouse, L.W.

    1990-09-04

    This report summarizes a trip by L. W. Barnthouse of the Environmental Sciences Division (ESD), Oak Ridge National Laboratory (ORNL), to Hamburg, Federal Republic of Germany (FRG), where he participated in the 7th International Congress of Pesticide Chemistry. He chaired a workshop on experimental systems for determining effects of pesticides on nontarget organisms and gave an oral presentation at a symposium on pesticide risk assessment. Before returning to the United States, Dr. Barnthouse visited the Netherlands Institute for Sea Research in Texel, the Netherlands.

  13. Academic excellence workshops in chemistry and physics

    NASA Astrophysics Data System (ADS)

    Mills, Susan Rose

    In the mid-1970's, Uri Treisman, at the University of California, Berkeley, developed an academic excellence workshop program that had important successes in increasing minority student achievement and persistence in calculus. The present dissertation research is an in-depth study of chemistry and physics workshops at the California State Polytechnic University, Pomona. Data for the first, longitudinal component of this study were obtained by tracking to Spring 1998 all workshop minority students, i.e., Latino, African American, and Native American workshop students, a random sample of non-workshop minority students, and a random sample of non-targeted students, i.e., Anglo and Asian students, enrolled in first-quarter General Chemistry or Physics during specific quarters of 1992 or 1993. Data for the second component were obtained by administering questionnaires, conducting interviews, and observing science students during Fall, 1996. Workshop participation was a significant predictor of first-quarter course grade for minority students in both chemistry and physics, while verbal and mathematics Scholastic Aptitude Test (SAT) scores were not significant predictors of beginning course grade for minority science students. The lack of predictive ability of the SAT and the importance of workshop participation in minority students' beginning science course performance are results with important implications for educators and students. In comparing pre-college achievement measures for workshop and non-targeted students, non-targeted students' mathematics SAT scores were significantly higher than chemistry and physics workshop students' scores. Nonetheless, workshop participation "leveled the field" as workshop and non-targeted students performed similarly in beginning science courses. Positive impacts of workshop participation on achievement, persistence, efficiency, social integration, and self-confidence support the continued and expanded funding of workshop programs

  14. Advanced expander test bed program

    NASA Technical Reports Server (NTRS)

    Riccardi, D. P.; Mitchell, J. C.

    1993-01-01

    The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high-pressure expander cycle concept, investigate system interactions, and conduct investigations of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust. Contract work began 27 Apr. 1990. During 1992, a major milestone was achieved with the review of the final design of the oxidizer turbopump in Sep. 1992.

  15. An Atmospheric General Circulation Model with Chemistry for the CRAY T3E: Design, Performance Optimization and Coupling to an Ocean Model

    NASA Technical Reports Server (NTRS)

    Farrara, John D.; Drummond, Leroy A.; Mechoso, Carlos R.; Spahr, Joseph A.

    1998-01-01

    The design, implementation and performance optimization on the CRAY T3E of an atmospheric general circulation model (AGCM) which includes the transport of, and chemical reactions among, an arbitrary number of constituents is reviewed. The parallel implementation is based on a two-dimensional (longitude and latitude) data domain decomposition. Initial optimization efforts centered on minimizing the impact of substantial static and weakly-dynamic load imbalances among processors through load redistribution schemes. Recent optimization efforts have centered on single-node optimization. Strategies employed include loop unrolling, both manually and through the compiler, the use of an optimized assembler-code library for special function calls, and restructuring of parts of the code to improve data locality. Data exchanges and synchronizations involved in coupling different data-distributed models can account for a significant fraction of the running time. Therefore, the required scattering and gathering of data must be optimized. In systems such as the T3E, there is much more aggregate bandwidth in the total system than in any particular processor. This suggests a distributed design. The design and implementation of a such distributed 'Data Broker' as a means to efficiently couple the components of our climate system model is described.

  16. Chemistry-Climate Interactions in the Goddard Institute for Space Studies General Circulation Model. 2; New Insights into Modeling the Pre-Industrial Atmosphere

    NASA Technical Reports Server (NTRS)

    Grenfell, J. Lee; Shindell, D. T.; Koch, D.; Rind, D.; Hansen, James E. (Technical Monitor)

    2002-01-01

    We investigate the chemical (hydroxyl and ozone) and dynamical response to changing from present day to pre-industrial conditions in the Goddard Institute for Space Studies General Circulation Model (GISS GMC). We identify three main improvements not included by many other works. Firstly, our model includes interactive cloud calculations. Secondly we reduce sulfate aerosol which impacts NOx partitioning hence Ox distributions. Thirdly we reduce sea surface temperatures and increase ocean ice coverage which impact water vapor and ground albedo respectively. Changing the ocean data (hence water vapor and ozone) produces a potentially important feedback between the Hadley circulation and convective cloud cover. Our present day run (run 1, control run) global mean OH value was 9.8 x 10(exp 5) molecules/cc. For our best estimate of pre-industrial conditions run (run 2) which featured modified chemical emissions, sulfate aerosol and sea surface temperatures/ocean ice, this value changed to 10.2 x 10(exp 5) molecules/cc. Reducing only the chemical emissions to pre-industrial levels in run 1 (run 3) resulted in this value increasing to 10.6 x 10(exp 5) molecules/cc. Reducing the sulfate in run 3 to pre-industrial levels (run 4) resulted in a small increase in global mean OH (10.7 x 10(exp 5) molecules/cc). Changing the ocean data in run 4 to pre-industrial levels (run 5) led to a reduction in this value to 10.3 x 10(exp 5) molecules/cc. Mean tropospheric ozone burdens were 262, 181, 180, 180, and 182 Tg for runs 1-5 respectively.

  17. Why Teach Environmental Chemistry?

    ERIC Educational Resources Information Center

    Gardner, Marjorie H.

    1974-01-01

    Discusses the importance of teaching environmental chemistry in secondary school science classes, and outlines five examples of environmental chemistry problems that focus on major concepts of chemistry and have critical implications for human survival and well-being. (JR)

  18. Science Update: Inorganic Chemistry

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1978-01-01

    This first in a series of articles describing the state of the art of various branches of chemistry reviews inorganic chemistry, including bioinorganic, photochemistry, organometallic, and solid state chemistries. (SL)

  19. A Reply to ''Reinterpretation of Students' Ideas When Reasoning about Particle Model Illustrations. A Response to ''Using Animations in Identifying General Chemistry Students' Misconceptions and Evaluating Their Knowledge Transfer Relating to Particle Position in Physical Changes'' by Smith and Villarreal (2015)''

    ERIC Educational Resources Information Center

    Smith, K. Christopher; Villarreal, Savannah

    2015-01-01

    In this reply to Elon Langbeheim's response to an article recently published in this journal, authors Smith and Villarreal identify several types of general chemistry students' misconceptions concerning the concept of particle position during physical change. They focus their response on one of the misconceptions identified as such: Given a solid…

  20. Combustion chemistry

    SciTech Connect

    Brown, N.J.

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  1. Chemistry: Coping with Change...Creatively.

    ERIC Educational Resources Information Center

    Barron, Marcelline A.

    Developed for mathematics-shy high school chemistry students, this laboratory manual is suitable for use with any chemistry textbook. Seventy-three experiments, based on a theme of change, are grouped into 5 general areas: (1) 9 experiments focusing on skills needed in observing reality; (2) 19 experiments interpreting how reality changes,…

  2. Environmental Chemistry in the Undergraduate Laboratory.

    ERIC Educational Resources Information Center

    Wenzel, Thomas J.; Austin, Rachel N.

    2001-01-01

    Discusses the importance of environmental chemistry and the use of laboratory exercises in analytical and general chemistry courses. Notes the importance of lab work in heightening student interest in coursework including problem-based learning in undergraduate curricula, ready adaptability of environmental coursework to existing curricula, and…

  3. Science Update: Inorganic Chemistry.

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1981-01-01

    Describes areas of inorganic chemistry which have changed dramatically in the past year or two, including photochemistry, electrochemistry, organometallic complexes, inorganic reaction theory, and solid state chemistry. (DS)

  4. Organometallic chemistry: A new metathesis

    NASA Astrophysics Data System (ADS)

    Hennessy, Elisabeth T.; Jacobsen, Eric N.

    2016-08-01

    Carbonyls and alkenes, two of the most common functional groups in organic chemistry, generally do not react with one another. Now, a simple Lewis acid has been shown to catalyse metathesis between alkenes and ketones in a new carbonyl olefination reaction.

  5. Chemistry Perfumes Your Daily Life

    ERIC Educational Resources Information Center

    Fortineau, Anne-Dominique

    2004-01-01

    A synopsis on the history of perfumery is presented, along with the various processes accessible for obtaining natural perfume constituents, and creation of synthetic chemicals. The important contribution of organic chemists in the invention of perfumes, aspects of fragrance chemistry, and general information on the perfume industry are…

  6. 40 CFR 161.150 - General.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Product Chemistry Data Requirements § 161.150 General. (a) Applicability. This subpart describes the product chemistry data that are required to support the...

  7. 40 CFR 161.150 - General.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... FOR REGISTRATION OF ANTIMICROBIAL PESTICIDES Product Chemistry Data Requirements § 161.150 General. (a) Applicability. This subpart describes the product chemistry data that are required to support the...

  8. General Relativity and Energy

    ERIC Educational Resources Information Center

    Jackson, A. T.

    1973-01-01

    Reviews theoretical and experimental fundamentals of Einstein's theory of general relativity. Indicates that recent development of the theory of the continually expanding universe may lead to revision of the space-time continuum of the finite and unbounded universe. (CC)

  9. Trace Chemistry

    NASA Technical Reports Server (NTRS)

    Radhakrishnan, Krishnan; Whitefield, Philip

    1999-01-01

    The goals of the trace chemistry group were to identify the processes relevant to aerosol and aerosol precursor formation occurring within aircraft gas turbine engines; that is, within the combustor, turbine, and nozzle. The topics of discussion focused on whether the chemistry of aerosol formation is homogeneous or heterogeneous; what species are important for aerosol and aerosol precursor formation; what modeling/theoretical activities to pursue; what experiments to carry out that both support modeling activities and elucidate fundamental processes; and the role of particulates in aerosol and aerosol precursor formation. The consensus of the group was that attention should be focused on SO2, SO3, and aerosols. Of immediate concern is the measurement of the concentration of the species SO3, SO2, H2SO4 OH, HO2, H2O2, O, NO, NO2, HONO, HNO3, CO, and CO2 and particulates in various engines, both those currently in use and those in development. The recommendation was that concentration measurements should be made at both the combustor exit and the engine exit. At each location the above species were classified into one of four categories of decreasing importance, Priority I through IV, as follows: Combustor exit: Priority I species - SO3:SO2 ratio, SO3, SO2, and particulates; Priority II species: OH and O; Priority III species - NO and NO2; and Priority IV species - CO and CO2. For the Engine exit: Priority I species - SO3:SO2 ratio, SO3, SO2,H2SO4, and particulates; Priority II species: OH,HO2, H2O2, and O; Priority III species - NO, NO2, HONO, and HNO3; and Priority IV species - CO and CO2. Table I summarizes the anticipated concentration range of each of these species. For particulate matter, the quantities of interest are the number density, size distribution, and composition. In order to provide data for validating multidimensional reacting flow models, it would be desirable to make 2-D, time-resolved measurements of the concentrations of the above species and

  10. Two Multipurpose Thermochemical Experiments for General Chemistry.

    ERIC Educational Resources Information Center

    Wentworth, R. A. D.

    1988-01-01

    Describes two experiments designed to provide concepts on the difference between heat and temperature and also bond energy. Investigates both a neutralization experiment and a ligation experiment. Notes inexpensive chemicals are used along with simple equipment. Discusses the sharing of lab results for a single class value. (MVL)

  11. Teaching General Chemistry: A Materials Science Companion.

    ERIC Educational Resources Information Center

    Ellis, Arthur B.; And Others

    Many teachers and other educators have expressed a concern regarding the lack of student interest in many of the traditional science courses. To help rectify this problem a collaborative effort among educators and others concerned has led to the development of instructional materials that are more relevant to the lives of students. This document…

  12. Ideal Gas Laws: Experiments for General Chemistry

    ERIC Educational Resources Information Center

    Deal, Walter J.

    1975-01-01

    Describes a series of experiments designed to verify the various relationships implicit in the ideal gas equation and shows that the success of the Graham's law effusion experiments can be explained by elementary hydrodynamics. (GS)

  13. Have a Chemistry Field Day in Your Area.

    ERIC Educational Resources Information Center

    Mattson, Bruce M.; And Others

    1989-01-01

    Describes a full day of chemistry fun and competition for high school chemistry students. Notes teams have five students from each high school. Lists five competitive events for each team: titration, qualitative analysis, balancing equations, general chemistry quiz, and quantitative analysis with atomic absorption spectroscopy. (MVL)

  14. Expandable Shelter/Container Report.

    DTIC Science & Technology

    1973-06-01

    without removing whatever payload might be in the contai ner. Equ i pment located in the expanded porti on of the ES/C durin g norma l operat i ons is...and Supply BattalIon , Div isi on Support Coianand. In addition , divisional avIation battalions have an A Irc raft Maintenance Company. The TOE

  15. Common Ground: Expanding Our Horizons.

    ERIC Educational Resources Information Center

    McDevitt, Michele J.

    In "Common Ground: Dialogue, Understanding, and the Teaching of Composition," Kurt Spellmeyer seeks to familiarize students and teachers with the linguistic and cultural no-man's-land separating them. Reinstating the value of two writing conventions often used by traditional students--expressive and commonplaces--can help expand on the…

  16. Finite simple groups as expanders

    PubMed Central

    Kassabov, Martin; Lubotzky, Alexander; Nikolov, Nikolay

    2006-01-01

    We prove that there exist k ∈ ℕ and 0 < ε ∈ ℝ such that every non-abelian finite simple group G, which is not a Suzuki group, has a set of k generators for which the Cayley graph Cay(G; S) is an ε-expander. PMID:16601101

  17. Expanding the eukaryotic genetic code

    SciTech Connect

    Chin, Jason W; Cropp, T Ashton; Anderson, J Christopher; Schultz, Peter G

    2012-02-14

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  18. Expanding the eukaryotic genetic code

    SciTech Connect

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2013-01-22

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  19. Expanding the eukaryotic genetic code

    SciTech Connect

    Chin, Jason W; Cropp, T Ashton; Anderson, J Christopher; Schultz, Peter G

    2012-05-08

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  20. The Expanding Frontier of Pluralism.

    ERIC Educational Resources Information Center

    King, Edmund

    1983-01-01

    Looks at the expanding frontier of pluralism in terms of reappraising the relationship of formal education to the advent of the constant change (occupational and social) accelerated by the microprocessor revolution and readjusting provisions in educational systems to meet the different needs of different populations. (AH)

  1. Expanding the eukaryotic genetic code

    DOEpatents

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2009-12-01

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  2. Expanding the eukaryotic genetic code

    DOEpatents

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2009-10-27

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  3. Expanding the eukaryotic genetic code

    DOEpatents

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2017-02-28

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  4. Expanding the eukaryotic genetic code

    DOEpatents

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2010-09-14

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  5. Expanding the eukaryotic genetic code

    DOEpatents

    Chin, Jason W.; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G.

    2009-11-17

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  6. Expanding the Universe of Education.

    ERIC Educational Resources Information Center

    Parsons, Elizabeth

    1996-01-01

    Definitions of "education" and "rural" are debunked and expanded. The three major tasks of rural education are educating people to understand their own needs, the unavoidable changes that will transform rural Australia within their lifetimes, and the range of technologies that can enhance their well-being. Presents a strategy…

  7. Expanding Frontiers of Humanoid Robotics

    DTIC Science & Technology

    2000-08-01

    From the IEEE Intelligent Systems Special Issue on Humanoid Robotics , July/August 2000 GUEST EDITORS’ Expanding Frontiers of Humanoid Robotics ...Mark L. Swinson, DARPA David J. Bruemmer, Strategic Analysis Mobile robots pose a unique set of challenges to artificial intelligence researchers...the constraints of logical correctness but also some assortment of crosscutting, physical constraints. Particularly interesting among these robots

  8. Expanding the eukaryotic genetic code

    SciTech Connect

    Chin, Jason W; Cropp, T. Ashton; Anderson, J. Christopher; Schultz, Peter G

    2015-02-03

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  9. Monolithical aspherical beam expanding systems

    NASA Astrophysics Data System (ADS)

    Fuchs, U.

    2014-02-01

    In complex laser systems, such as those for material processing, and in basically all laboratory applications passive optical components are indispensable. Matching beam diameters is a common task, where Galileo type telescopes are preferred for beam expansion. Nevertheless researches and customers have found various limitations when using these systems. Some of them are the complicated adjustment, very small diameter for the incoming beam (1/e2), fixed and non-modifiable magnifications. Above that, diffraction-limitation is only assured within the optical design and not for the real world setup of the beam expanding system. Therefore, we will discuss limitations of currently used beam expanding systems to some extent. We will then present a new monolithical solution, which is based on the usage of only one aspherical component. It will be shown theoretically how the beam quality can be significantly improved by using aspherical lenses. As it is in the nature of things aspheres are working diffraction limited in the design, it will be shown how to combine up to five monolithical beam expanding systems and to keep the beam quality at diffraction limitation. Data of the culminated wavefront error will be presented. Last but not least insights will be given how beam expanding systems based on aspheres will help to use larger incoming beams and to reduce the overall length of such a system.

  10. Ferroelectric based catalysis: Switchable surface chemistry

    NASA Astrophysics Data System (ADS)

    Kakekhani, Arvin; Ismail-Beigi, Sohrab

    2015-03-01

    We describe a new class of catalysts that uses an epitaxial monolayer of a transition metal oxide on a ferroelectric substrate. The ferroelectric polarization switches the surface chemistry between strongly adsorptive and strongly desorptive regimes, circumventing difficulties encountered on non-switchable catalytic surfaces where the Sabatier principle dictates a moderate surface-molecule interaction strength. This method is general and can, in principle, be applied to many reactions, and for each case the choice of the transition oxide monolayer can be optimized. Here, as a specific example, we show how simultaneous NOx direct decomposition (into N2 and O2) and CO oxidation can be achieved efficiently on CrO2 terminated PbTiO3, while circumventing oxygen (and sulfur) poisoning issues. One should note that NOx direct decomposition has been an open challenge in automotive emission control industry. Our method can expand the range of catalytically active elements to those which are not conventionally considered for catalysis and which are more economical, e.g., Cr (for NOx direct decomposition and CO oxidation) instead of canonical precious metal catalysts. Primary support from Toyota Motor Engineering and Manufacturing, North America, Inc.

  11. An update on chemistry analyzers.

    PubMed

    Vap, L M; Mitzner, B

    1996-09-01

    This update of six chemistry analyzers available to the clinician discusses several points that should be considered prior to the purchase of equipment. General topics include how to best match an instrument to clinic needs and the indirect costs associated with instrument operation. Quality assurance recommendations are discussed and common terms are defined. Specific instrument features, principles of operation, performance, and costs are presented. The information provided offers potential purchasers an objective approach to the evaluation of a chemistry analyzer for the veterinary clinic.

  12. Implications of coccolithophores expanding to polar waters

    NASA Astrophysics Data System (ADS)

    Winter, A.; Henderiks, J.; Beaufort, L.

    2008-12-01

    There is much debate about the response of coccolithophores to decreased carbonate saturation state and decreased pH in the ocean as a result of increased CO2 partial pressure. It is still not known whether coccolithophores act as a sink or source for CO CO2. Nor is it known whether calcification will be reduced or increased in response to climate change. A proper understanding of the relationship between calcification and climate change is important not only because coccolithophores play an important role in determining the PIC:POC ratio of particle export into the deep ocean but also because climate change may affect the overall biodiversity of phytoplankton and the marine food chain. Because ocean acidification strongly affects polar regions, initially it seems unlikely that coccolithophores should prefer polar waters or even be a major component of phytoplankton in these regions. Yet there is much recent evidence that coccolithophores are increasingly expanding their range into polar oceans. This observation could be pivotal in improving our understanding of the mechanisms and rates of climatic adaptation by natural coccolithophore populations. We postulate that coccolithophores may be more sensitive to recent environmental changes, such as SSTs and salinity, than to factors more directly linked to changing ocean carbonate chemistry

  13. Dissipation and nonlocality in a general expanding braneworld universe

    SciTech Connect

    Remazeilles, Mathieu

    2009-02-15

    We study the evolution of both scalar and tensor cosmological perturbations in a Randall-Sundrum braneworld having an arbitrary expansion history. We adopt a four dimensional point of view where the degrees of freedom on the brane constitute an open quantum system coupled to an environment composed of the bulk gravitons. Because of the expansion of the universe, the brane degrees of freedom and the bulk degrees of freedom interact as they propagate forward in time. Brane excitations may decay through the emission of bulk gravitons which may escape to future infinity, leading to a sort of dissipation from the four dimensional point of view of an observer on the brane. Bulk gravitons may also be reflected off of the curved bulk and reabsorbed by the brane, thereby transformed into quanta on the brane, leading to a sort of nonlocality from the four dimensional point of view. The dissipation and the nonlocality are encoded into the retarded bulk propagator. We estimate the dissipation rates of the bound state as well as of the matter degrees of freedom at different cosmological epochs and for different sources of matter on the brane. We use a near-brane limit of the bulk geometry for the study when purely nonlocal bulk effects are encountered.

  14. Historical Notes on the Expanding Universe

    NASA Technical Reports Server (NTRS)

    Way, Michael J.; Belenkyi, Ari; Nussbaumer, Harry; Peacock, John

    2014-01-01

    The article Measuring the Hubble constant by Mario Livio and Adam Riess (Physics Today, October 2013, page 41) reviewed studies of the expanding universe from the 1920s to the present. Although the history of the subject underwent considerable compression to fit the length of a magazine article, we think it may leave a misleading impression of some of the key steps to our current understanding. We therefore offer the following clarifications. Most significantly, papers by Arthur Eddington and by Willem de Sitter in 1930, who successfully promoted Georges Lematres 1927 article for the Scientific Society of Brussels, effected a paradigm shift in interpretation of extragalactic redshifts in 1930. Before then, the astronomical community was generally unaware of the existence of nonstatic cosmological solutions and did not broadly appreciate that redshifts could be thought of locally as Doppler shifts in an expanding matter distribution. Certainly, in 1929 Edwin Hubble referred only to the de Sitter solution of 1917. At the time, the relation between distance and redshift predicted in that model was generally seen purely as a manifestation of static spacetime curvature.

  15. Part 6: The Literature of Inorganic Chemistry, Revised.

    ERIC Educational Resources Information Center

    Douville, Judith A.

    2002-01-01

    Presents a list of resources on inorganic chemistry that includes general surveys, nomenclature, dictionaries, handbooks, compilations, and treatises. Selected for use by academic and student chemists. (DDR)

  16. The law's interface with expanding technology

    NASA Technical Reports Server (NTRS)

    Green, H. P.

    1972-01-01

    The role of the law in technology assessment is described in generalized terms of a legal system as it confronts expanding technology. The functions of a technology assessment are considered to be twofold; provide for legislative action designed to channel technological advance along lines which are regarded as optimal from the standpoint of society's interests; and encourage and promote legislative action which will deal decisively with the potential disruptions and injuries caused by technology at a much earlier stage of the growth of the technology than is feasible under the present legal system. It is concluded that since new law always has a disruptive effect on expectations and commitments arrived at under old law, it is generally desirable that new legislation should make the least possible change in the law consistant with accomplishing the desired objective.

  17. Cometary MHD and chemistry

    NASA Technical Reports Server (NTRS)

    Wegmann, R.; Schmidt, H. U.; Huebner, W. F.; Boice, D. C.

    1987-01-01

    An MHD and chemical comet-coma model was developed, applying the computer program of Huebner (1985) for the detailed chemical evolution of a spherically expanding coma and the program of Schmidt and Wegman (1982) and Wegman (1987) for the MHD flow of plasma and magnetic field in a comet to the Giotto-mission data on the ion abundances measured by the HIS ion mass spectrometer. The physics and chemistry of the coma are modeled in great detail, including photoprocesses, gas-phase chemical kinetics, energy balance with a separate electron temperature, multifluid hydrodynamics with a transition to free molecular flow, fast-streaming atomic and molecular hydrogen, counter and cross streaming of the ionized species relative to the neutral species in the coma-solar wind interaction region with momentum exchange by elastic collisions, mass-loading through ion pick-up, and Lorentz forces of the advected magnetic field. The results, both inside and outside of the contact surface, are discussed and compared with the relevant HIS ion mass spectra.

  18. Helical screw expander evaluation project

    NASA Astrophysics Data System (ADS)

    McKay, R.

    1982-03-01

    A one MW helical rotary screw expander power system for electric power generation from geothermal brine was evaluated. The technology explored in the testing is simple, potentially very efficient, and ideally suited to wellhead installations in moderate to high enthalpy, liquid dominated field. A functional one MW geothermal electric power plant that featured a helical screw expander was produced and then tested with a demonstrated average performance of approximately 45% machine efficiency over a wide range of test conditions in noncondensing, operation on two-phase geothermal fluids. The Project also produced a computer equipped data system, an instrumentation and control van, and a 1000 kW variable load bank, all integrated into a test array designed for operation at a variety of remote test sites. Data are presented for the Utah testing and for the noncondensing phases of the testing in Mexico. Test time logged was 437 hours during the Utah tests and 1101 hours during the Mexico tests.

  19. Helical screw expander evaluation project

    NASA Technical Reports Server (NTRS)

    Mckay, R.

    1982-01-01

    A one MW helical rotary screw expander power system for electric power generation from geothermal brine was evaluated. The technology explored in the testing is simple, potentially very efficient, and ideally suited to wellhead installations in moderate to high enthalpy, liquid dominated field. A functional one MW geothermal electric power plant that featured a helical screw expander was produced and then tested with a demonstrated average performance of approximately 45% machine efficiency over a wide range of test conditions in noncondensing, operation on two-phase geothermal fluids. The Project also produced a computer equipped data system, an instrumentation and control van, and a 1000 kW variable load bank, all integrated into a test array designed for operation at a variety of remote test sites. Data are presented for the Utah testing and for the noncondensing phases of the testing in Mexico. Test time logged was 437 hours during the Utah tests and 1101 hours during the Mexico tests.

  20. Seal-less cryogenic expander

    SciTech Connect

    Faria, L.E.; Christopher, E.H.

    1987-12-08

    In an expander for use in a split Stirling cycle refrigeration system of the type wherein a displacer moves with reciprocating motion inside an expander housing, and wherein a plunger force and a regenerator force are formed on the displacer, the plunger force cyclically varying and having a time of minimum and maximum plunger force amplitude, and the regenerator force cyclically varying and having a time of minimum and maximum regenerator force amplitude, the improvement is described comprising: (a) means for maintaining displacer forces, such that the maximum plunger force amplitude is substantially equal to the maximum regenerator force amplitude; and (b) means for adjusting a time difference, the time difference being the time between the time of maximum plunger force and the time of maximum regenerator force such that a measure of the cooling power of the refrigeration system is maximized.

  1. Echinocandins: The Expanding Antifungal Armamentarium.

    PubMed

    Aguilar-Zapata, Daniel; Petraitiene, Ruta; Petraitis, Vidmantas

    2015-12-01

    The echinocandins are large lipopeptide molecules that, since their discovery approximately 41 years ago, have emerged as important additions to the expanding armamentarium against invasive fungal diseases. Echinocandins exert in vitro and in vivo fungicidal action against most Candida species and fungistatic action against Aspergillus species. However, the population of patients at risk for developing invasive fungal infections continues to increase. New therapeutic strategies using echinocandins are needed to improve clinical outcomes in patients with invasive fungal disease.

  2. Entropy in an expanding universe

    NASA Astrophysics Data System (ADS)

    Frautschi, S.

    1982-08-01

    The evolution of organized structures from initial chaos in the expanding universe is demonstrated to be reconcilable with the second law of thermodynamics, and the effects of expansion and gravity on this problem are emphasized. Numerical estimates of the major sources of entropy increase are calculated, including the entropy increase in stars, the earth, black hole formation and decay, quantum tunneling of matter into black holes, positronium formation and decay, etc. An expanding 'causal' region is defined in which the entropy, though increasing, tends to fall further and further behind its maximum possible value, thus allowing for the development of order. That is, the classical heat death argument does not hold, because an expanding universe never achieves equilibrium and never reaches a constant temperature. Also considered are questions of whether entropy will continue increasing without limit in the future, and whether such increase in the form of Hawking radiation or radiation from positronium might enable life to maintain itself permanently. Attempts to find a scheme for preserving life based on solid structures fail because events such as quantum tunneling recurrently disorganize matter on a very long but fixed time scale.

  3. Entropy in an expanding universe.

    PubMed

    Frautschi, S

    1982-08-13

    The question of how the observed evolution of organized structures from initial chaos in the expanding universe can be reconciled with the laws of statistical mechanics is studied, with emphasis on effects of the expansion and gravity. Some major sources of entropy increase are listed. An expanding "causal" region is defined in which the entropy, though increasing, tends to fall further and further behind its maximum possible value, thus allowing for the development of order. The related questions of whether entropy will continue increasing without limit in the future, and whether such increase in the form of Hawking radiation or radiation from positronium might enable life to maintain itself permanently, are considered. Attempts to find a scheme for preserving life based on solid structures fail because events such as quantum tunneling recurrently disorganize matter on a very long but fixed time scale, whereas all energy sources slow down progressively in an expanding universe. However, there remains hope that other modes of life capable of maintaining themselves permanently can be found.

  4. Chemistry Rocks: Redox Chemistry as a Geologic Tool.

    ERIC Educational Resources Information Center

    Burns, Mary Sue

    2001-01-01

    Applies chemistry to earth science, uses rocks in chemistry laboratories, and teaches about transition metal chemistry, oxidation states, and oxidation-reduction reactions from firsthand experiences. (YDS)

  5. Mars aqueous chemistry experiment

    NASA Technical Reports Server (NTRS)

    Clark, Benton C.; Mason, Larry W.

    1993-01-01

    The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

  6. "On Course" for Supporting Expanded Participation and Improving Scientific Reasoning in Undergraduate Thesis Writing

    ERIC Educational Resources Information Center

    Dowd, Jason E.; Roy, Christopher P.; Thompson, Robert J., Jr.; Reynolds, Julie A.

    2015-01-01

    The Department of Chemistry at Duke University has endeavored to expand participation in undergraduate honors thesis research while maintaining the quality of the learning experience. Accomplishing this goal has been constrained by limited departmental resources (including faculty time) and increased diversity in students' preparation to engage in…

  7. Constitutional dynamic chemistry: bridge from supramolecular chemistry to adaptive chemistry.

    PubMed

    Lehn, Jean-Marie

    2012-01-01

    Supramolecular chemistry aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the investigation of chemical systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems. Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.The merging of the features: -information and programmability, -dynamics and reversibility, -constitution and structural diversity, points to the emergence of adaptive and evolutive chemistry, towards a chemistry of complex matter.

  8. Chemistry of the actinide elements. Second edition

    SciTech Connect

    Katz, J.J.; Seaborg, G.T.; Morss, L.R.

    1987-01-01

    This is an exhaustive, updated discourse on the chemistry of Actinides, Volume 1 contains a systematic coverage of the elements Ac, Th, Pa, U, Np, and Pu, which constitutes Part 1 of the work. The characterization of each element is discussed in terms of its nuclear properties, occurrence, preparation, atomic and metallic properties, chemistry of specific compounds, and solution chemistry. The first part of Volume 2 follows the same format as Volume 1 but is confined to the elements Am, Cm, Bk, Cf, and Es, plus a more condensed coverage of the Transeinsteinium elements (Fm, Md, No, Lw, and 104-109). Part 2 of this volume is devoted to a discussion of the actinide elements in general, with a specific focus on electronic spectra, thermodynamic and magnetic properties, the metallic state, structural chemistry, solution kinetics, organometallic chemistry for /sigma/- and /pi/-bonded compounds, and some concluding remarks on the superheavy elements.

  9. Predicted versus Actual Performance in Undergraduate Organic Chemistry and Implications for Student Advising

    ERIC Educational Resources Information Center

    Pursell, David P.

    2007-01-01

    Performance as measured by grades in the first and second semesters of organic chemistry was predicted using pre-college measures (SAT scores, high school rank, validation exams) and college measures (general chemistry GPA, overall college GPA prior to beginning organic chemistry, first-semester organic chemistry GPA). Data indicate that overall…

  10. Teaching Green and Sustainable Chemistry: A Revised One-Semester Course Based on Inspirations and Challenges

    ERIC Educational Resources Information Center

    Marteel-Parrish, Anne E.

    2014-01-01

    An elective course, "Toward the Greening of Our Minds": Green and Sustainable Chemistry, has been offered at Washington College since 2005. This new course without laboratory is designed for chemistry and biology majors and minors who have previously taken two semesters of general chemistry and organic chemistry. Due to the popularity of…

  11. Towards molecular imaging and treatment of disease with radionuclides: the role of inorganic chemistry.

    PubMed

    Blower, Phil

    2006-04-14

    Molecular imaging and radiotherapy using radionuclides is a rapidly expanding field of medicine and medical research. This article highlights the development of the role of inorganic chemistry in designing and producing the radiopharmaceuticals on which this interdisciplinary science depends.

  12. Semigroup Actions of Expanding Maps

    NASA Astrophysics Data System (ADS)

    Carvalho, Maria; Rodrigues, Fagner B.; Varandas, Paulo

    2017-01-01

    We consider semigroups of Ruelle-expanding maps, parameterized by random walks on the free semigroup, with the aim of examining their complexity and exploring the relation between intrinsic properties of the semigroup action and the thermodynamic formalism of the associated skew-product. In particular, we clarify the connection between the topological entropy of the semigroup action and the growth rate of the periodic points, establish the main properties of the dynamical zeta function of the semigroup action and relate these notions to recent research on annealed and quenched thermodynamic formalism. Meanwhile, we examine how the choice of the random walk in the semigroup unsettles the ergodic properties of the action.

  13. Shell may expand detergent alcohols

    SciTech Connect

    1996-10-23

    Shell Chemical is studying plans to expand detergent alcohols capacity in the US, CW has learned. The company is considering adding capacity for about 80 million lbs/year. If the project is approved, it would be implemented at the company`s Geismar, LA site. Shell will make a final decision on whether to proceed with the project within six months. It has been rumored to be considering a capacity addition as a result of tightening supply of natural and synthetic detergent alcohols.

  14. Advanced Expander Test Bed Engine

    DTIC Science & Technology

    1992-03-01

    performance data will be provided to NASA -LeRC for verifying the ROCETS computer model and evaluating various RLI0 modifications. 22 SECTION IV CURRENT...RL10 modeling data for the ROCETS computer program. 23 NASA Report Documentation Page Nafi~aj AfWflWuIC Wd Sow@ Ad-lvhlsto, 1 eport No. 2. Government... NASA have identified the need for a new Space Transfer Vehicle (STV) Propulsion System. The new system will be an oxygen/hydrogen expander cycle engine

  15. Bias in clinical chemistry.

    PubMed

    Theodorsson, Elvar; Magnusson, Bertil; Leito, Ivo

    2014-01-01

    Clinical chemistry uses automated measurement techniques and medical knowledge in the interest of patients and healthy subjects. Automation has reduced repeatability and day-to-day variation considerably. Bias has been reduced to a lesser extent by reference measurement systems. It is vital to minimize clinically important bias, in particular bias within conglomerates of laboratories that measure samples from the same patients. Small and variable bias components will over time show random error properties and conventional random-error based methods for calculating measurement uncertainty can then be applied. The present overview of bias presents the general principles of error and uncertainty concepts, terminology and analysis, and suggests methods to minimize bias and measurement uncertainty in the interest of healthcare.

  16. USSR Report, Chemistry.

    DTIC Science & Technology

    2007-11-02

    This chemistry Report from the USSR contains articles mainly on Adsorption, Analytical Chemistry, Biochemistry, Catalysis, Chemical Industry, Coal ... Gasification , Electrochemistry, Fertilizers, Food Technology, Inorganic Compounds, Nitrogen Compounds and Organometallic Compounds.

  17. Chemistry for Potters.

    ERIC Educational Resources Information Center

    Denio, Allen A.

    1980-01-01

    Relates pottery making to chemistry by providing chemical information about clay, its origin, composition, properties, and changes that occur during firing; also describes glaze compositions, examples of redox chemistry, salt glazing, crystalline glazes, and problems in toxicity. (CS)

  18. Organometallic Chemistry of Molybdenum.

    ERIC Educational Resources Information Center

    Lucas, C. Robert; Walsh, Kelly A.

    1987-01-01

    Suggests ways to avoid some of the problems students have learning the principles of organometallic chemistry. Provides a description of an experiment used in a third-year college chemistry laboratory on molybdenum. (TW)

  19. Special Report: Brain Chemistry.

    ERIC Educational Resources Information Center

    Krassner, Michael B.

    1983-01-01

    Chemical actions in the brain result in cognitive, emotional, neuroendocrine, neuromuscular, and/or neurocirculatory effects. Developments in understanding brain chemistry are discussed, considering among others, neurotransmitter chemistry, neuropeptides, drugs and the brain, antidepressants, and actions of minor tranquilizers. (JN)

  20. Environmental chemistry: Volume A

    SciTech Connect

    Yen, T.F.

    1999-08-01

    This is an extensive introduction to environmental chemistry for engineering and chemical professionals. The contents of Volume A include a brief review of basic chemistry prior to coverage of litho, atmo, hydro, pedo, and biospheres.