WorldWideScience

Sample records for activation chemistry

  1. Environmental Chemistry Activities.

    Jackland, Thomas; And Others

    The authors of this curriculum supplement believe in a laboratory approach to chemistry and express the feeling that environmental chemistry provides the students an opportunity to apply theoretical chemistry to important practical problems. There are eighteen activities presented, each accompanied with behavioral objectives, one or more suggested…

  2. Student Active Learning Methods in Physical Chemistry

    Hinde, Robert J.; Kovac, Jeffrey

    2001-01-01

    We describe two strategies for implementing active learning in physical chemistry. One involves supplementing a traditional lecture course with heavily computer-based active-learning exercises carried out by cooperative groups in a department computer lab. The other uses cooperative learning almost exclusively, supplemented by occasional mini-lectures. Both approaches seemed to result in better student learning and a more positive attitude toward the subject. On the basis of our respective experiences using active learning techniques, we discuss some of the strengths of these techniques and some of the challenges we encountered using the active-learning approach in teaching physical chemistry.

  3. Using Art-Based Chemistry Activities to Improve Students' Conceptual Understanding in Chemistry

    Danipog, Dennis L.; Ferido, Marlene B.

    2011-01-01

    This study aimed to determine the effects of art-based chemistry activities (ABCA) on high school students' conceptual understanding in chemistry. The study used the pretest-posttest control group design. A total of 64 third-year high school students from two different chemistry classes participated in the study. One class was exposed to art-based…

  4. Activation analysis for food chemistry Pt. 3

    The nondestructive determination of K, Na, Ca, Mg, Cl and P content of animal tissues was reported. The IBR-30 (Dubna) reactor was used as the thermal neutron source for all the (n,ν) reactions needed for the analyses (tabulated), and as the source of fast neutrons for the (n,α) reaction of the P determination, too. Results and errors of the analyses (5-15%) were discussed comparing the reproducibility of the methods in case of different animal tissues, liver, bones, blood, etc. The nondestructive neutron activation multielemental analysis for food chemistry can be recommended in the case of a large scale monitoring program of food samples. (Sz.J.)

  5. Writing Chemistry Jingles as an Introductory Activity in a High School Chemistry Class

    Heid, Peter F.

    2011-01-01

    Starting the school year in an introductory high school chemistry class can be a challenge. The topic and approach is new to the students; many of the early chapters in the texts can be a bit tedious; and for many students the activities are uninspiring. My goal in the first few weeks of school is to hook the students on chemistry by getting them…

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

    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…

  7. Active Learning Applications in the History of Chemistry: Pre-Service Chemistry Teachers' Level of Knowledge and Views

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

    2014-01-01

    This study aims to investigate the effects of a History and Philosophy of Chemistry-I course based on active learning applications on the level of knowledge of pre-service chemistry teachers about the history of chemistry. The views of pre-service chemistry teachers about these activities were also investigated. The study was carried out with 38…

  8. Teaching chemistry with neutron activation analysis at Dalhousie University

    The Dalhousie University SLOWPOKE-2 Reactor (DUSR) has been operating since July 1976 and has proven to be an invaluable tool in many teaching programs. These reactors are inherently safe and are designed to serve teaching and research needs of the universities, research centers, hospitals, etc. Since the DUSR has been, from its inception, associated with the Trace Analysis Research Centre, which is the Analytical Chemistry Division of the Department of Chemistry, the main thrust of its use continues to be in the field of nuclear analytical chemistry. Both teaching and research programs involve trace element analysis by neutron activation

  9. Empowering Girls with Chemistry, Exercise and Physical Activity

    Clapham, Emily D.; Ciccomascolo, Lori E.; Clapham, Andrew J.

    2015-01-01

    Research suggests that a girl's career interests in the areas of science, technology, engineering and mathematics (STEM) declines between grades 6 and 8. Similarly, in middle school, there is a decrease in physical activity among girls. Researchers at the University of Rhode Island (URI) conducted a chemistry-based science camp that took place…

  10. Synthetic Methods, Chemistry, and the Anticonvulsant Activity of Thiadiazoles

    Bhawna Sharma

    2013-01-01

    Full Text Available The chemistry of heterocyclic compounds has been an interesting field of study for a long time. Heterocyclic nucleus 1,3,4-thiadiazole constitutes an important class of compounds for new drug development. The synthesis of novel thiadiazole derivatives and investigation of their chemical and biological behavior have gained more importance in recent decades. The search for antiepileptic compounds with more selective activity and lower toxicity continues to be an active area of intensive investigation in medicinal chemistry. During the recent years, there has been intense investigation of different classes of thiadiazole compounds, many of which possess extensive pharmacological activities, namely, antimicrobial activity, anticonvulsant, antifungal antidiabetic, anti-inflammatory, antioxidant, and antituberculosis activities, and so forth. The resistance towards available drugs is rapidly becoming a major worldwide problem. The need to design new compounds to deal with this resistance has become one of the most important areas of research today. Thiadiazole is a versatile moiety that exhibits a wide variety of biological activities. Thiadiazole moiety acts as “hydrogen binding domain” and “two-electron donor system.” It also acts as a constrained pharmacophore. On the basis of the reported literature, we study here thiadiazole compounds and their synthetic methods chemistry and anticonvulsant activity.

  11. Indoor Chemistry: Materials, Ventilation Systems, and Occupant Activities

    Morrison, G.C.; Corsi, R.L.; Destaillats, H.; Nazaroff, W.W.; Wells, J.R.

    2006-05-01

    Chemical processes taking place in indoor environments can significantly alter the nature and concentrations of pollutants. Exposure to secondary contaminants generated in these reactions needs to be evaluated in association with many aspects of buildings to minimize their impact on occupant health and well-being. Focusing on indoor ozone chemistry, we describe alternatives for improving indoor air quality by controlling chemical changes related to building materials, ventilation systems, and occupant activities.

  12. Chemistry

    Research and development activities dealing with the chemical problems related to design and ultimate operation of molten-salt reactor systems are described. An experimental test stand was constructed to expose metallurgical test specimens to Te2 vapor at defined temperatures and deposition rates. To better define the chemistry of fluoroborate coolant, several aspects are being investigated. The behavior of hydroxy and oxy compounds in molten NaBF4 is being investigated to define reactions and compounds that may be involved in corrosion and/or could be involved in methods for trapping tritium. Two corrosion products of Hastelloy N, Na3CrF6 and Na5Cr3F14, were identified from fluoroborate systems. The evaluation of fluoroborate and alternate coolants continued. Research on the behavior of hydrogen and its isotopes is summarized. The solubilities of hydrogen, deuterium, and helium in Li2BeF4 are very low. The sorption of tritium on graphite was found to be significant (a few milligrams of tritium per kilogram of graphite), possibly providing a means of sequestering a portion of the tritium produced. Development of analytical methods continued with emphasis on voltammetric and spectrophotometric techniques for the in-line analysis of corrosion products such as Fe2+ and Cr3+ and the determination of the U3+/U4+ ratio in MSBR fuel salt. Similar studies were conducted with the NaBF4--NaF coolant salt. Information developed during the previous operation of the CSTF has been assessed and used to formulate plans for evaluation of in-line analytical methods in future CSTF operations. Electroanalytical and spectrophotometric research suggests that an electroactive protonic species is present in molten NaBF4--NaF, and that this species rapidly equilibrates with a volatile proton-containing species. Data obtained from the CSTF indicated that tritium was concentrated in the volatile species. (JGB)

  13. Chemistry

    The chemical research and development efforts related to the design and ultimate operation of molten-salt breeder reactor systems are concentrated on fuel- and coolant-salt chemistry, including the development of analytical methods for use in these systems. The chemistry of tellurium in fuel salt is being studied to help elucidate the role of this element in the intergranular cracking of Hastelloy N. Studies were continued of the effect of oxygen-containing species on the equilibrium between dissolved UF3 and dissolved UF4, and, in some cases, between the dissolved uranium fluorides and graphite, and the UC2. Several aspects of coolant-salt chemistry are under investigation. Hydroxy and oxy compounds that could be formed in molten NaBF4 are being synthesized and characterized. Studies of the chemistry of chromium (III) compounds in fluoroborate melts were continued as part of a systematic investigation of the corrosion of structural alloys by coolant salt. An in-line voltammetric method for determining U4+/U3+ ratios in fuel salt was tested in a forced-convection loop over a six-month period. (LK)

  14. Using active learning methodologies in physical chemistry in CLIL contexts

    David Recatalá

    2016-03-01

    Full Text Available One of the main objectives of the European Higher Education Area (EHEA is to promote a change toward a student-centred education model. This fact has led to the implementation of novel methodologies based on active learning, aimed at engaging students’ interest. This implementation has been usually accompanied by significant changes in both the teaching and learning processes in European universities. Furthermore, teaching a subject through the medium of a foreign language has also been gaining attention over the past few years. More specifically, this approach commonly known as Content and Language Integrated Learning (CLIL has been employed for the simultaneous learning of content and English in a number of European countries. In this contribution we report on the active learning methods implemented in a Physical Chemistry course, as well as the efforts devoted to Content and English Language Integration in this subject. This research analyses a series of factors that can contribute to the global learning and teaching experience when both active learning and CLIL are implemented in the Physical Chemistry classroom. Some examples of them include changes in attitudes towards the subject, engagement and motivation during the course, perception of English learning, and in general, students’ satisfaction with the learning process.

  15. Present and future activities of the water chemistry research committees in JAES

    Research committee on water chemistry was established in 1982 in Japan Atomic Energy Society (JAES) and has continued its activities. Many internal and international activities of the water chemistry groups have been based on the Committee. The activity so far and the future prospect are described. As internal activities within the JAES, research committees and the resulting reports are enumerated. International activities, including supporting of the JAIF (Japan Atomic Industrial Forum) Conferences on Water Chemistry, are also mentioned. (Yamamoto, A.)

  16. Chemistry

    Research progress is reported in programs on fuel-salt chemistry, properties of compounds in the Li--Te system, Te spectroscopy UF4--H equilibria, porous electrode studies of molten salts, fuel salt-coolant salt reactions, thermodynamic properties of transition-metal fluorides, and properties of sodium fluoroborate. Developmental work on analytical methods is summarized including in-line analysis of molten MSBR fuel, analysis of coolant-salts for tritium, analysis of molten LiF--BeF2--ThF4 for Fe and analysis of LiF--BeF--ThF4 for Te

  17. Neutron activation analysis in teaching analytical chemistry at UCI

    The undergraduate curriculum in chemistry at the University of California at Irvine has included practice with experiments in radiochemistry and activation analysis since 1968, 3 years after the campus was founded. In 1969, a TRIGA nuclear reactor was installed that operates at 250 kW steady state or can pulse to ∼10 MW of peak power. This has been the main activation source, although experiments have also been carried out by students using a 14-MeV neutron generator (Kaman Sciences, Model 711) and a small (1-μCi) 252Cf source on loan from the US Department of Energy. The majority of the experience has been within a junior/senior-level elective course in radioisotope techniques. However, experiments were also introduced by this author into the required instrumental analysis course. A very worthwhile experience was gained when students were assigned an unknown material (sometimes an inexpensive standard reference material) and asked to determine the concentration of a single trace element by two or three different techniques (atomic absorption, polarography, or derivative spectrophotometry) in addition to instrumental neutron activation analysis (INAA)

  18. Combustion chemistry - activities in the CHEK research programme

    Dam-Johansen, K.; Johnsson, J.E.; Glarborg, P.; Frandsen, F.; Jensen, A.; Oestberg, M. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemical Engineering

    1997-10-01

    The combustion chemistry in the oxidation of fossil fuels and biofuels determines together with mixing and heat transfer the required size of a furnace, the emission of gaseous pollutants, and the formation of ash and deposits on surfaces. This presentation describes technologies for solid fuels combustion and gives a summary of the fuels, the pollutant chemistry and the inorganic chemistry in combustion processes. Emphasis is put on the work carried out in the CHEC (Combustion and Harmful Emission Control) Research Programme. (orig.)

  19. Chemistry, biogenesis, and biological activities of Cinnamomum zeylanicum.

    Jayaprakasha, G K; Rao, L Jagan Mohan

    2011-07-01

    The genus Cinnamomum comprises of several hundreds of species, which are distributed in Asia and Australia. Cinnamomum zeylanicum, the source of cinnamon bark and leaf oils, is an indigenous tree of Sri Lanka, although most oil now comes from cultivated areas. C. zeylanicum is an important spice and aromatic crop having wide applications in flavoring, perfumery, beverages, and medicines. Volatile oils from different parts of cinnamon such as leaves, bark, fruits, root bark, flowers, and buds have been isolated by hydro distillation/steam distillation and supercritical fluid extraction. The chemical compositions of the volatile oils have been identified by GC and GC-MS. More than 80 compounds were identified from different parts of cinnamon. The leaf oil has a major component called eugenol. Cinnamaldehyde and camphor have been reported to be the major components of volatile oils from stem bark and root bark, respectively. Trans-cinnamyl acetate was found to be the major compound in fruits, flowers, and fruit stalks. These volatile oils were found to exhibit antioxidant, antimicrobial, and antidiabetic activities. C. zeylanicum bark and fruits were found to contain proanthocyandins with doubly linked bis-flavan-3-ol units in the molecule. The present review provides a coherent presentation of scattered literature on the chemistry, biogenesis, and biological activities of cinnamon. PMID:21929331

  20. Cyclopenta[c]phenanthrenes--chemistry and biological activity.

    Brzuzan, Paweł; Góra, Maciej; Luczyński, Michał K; Woźny, Maciej

    2013-06-25

    Despite cyclopenta-fused polycyclic aromatic hydrocarbons (CP-PAHs) having been detected in the environment, the ability of these compounds to induce cellular and tissue responses remains poorly characterized. In this review, we look at the chemistry and biological activity of the cyclopenta[c]phenanthrenes (CP[c]Phs) as potential chemicals of concern in the process of risk assessment. The first part of the review deals with the environmental occurrence and chemistry of CP-PAHs, focusing on available methods of CP[c]Ph chemical synthesis. The most interesting structural feature of the CP[c]Ph is the presence of a pseudo fjord-region constructed by the cyclopentane ring. This compound can be treated either as a structurally similar one to B[c]Ph, or as a phenanthrene skeleton with an electrodonating alkyl substituent in the bay-region of the molecule. The second thread, providing available data on the adverse effects of CP[c]Ph compounds on cells and tissues of living organisms, mainly fish, improves our understanding of these possible environmental hazards. The data show that CP[c]Ph is less potent at inducing CYP1A gene expression in rainbow trout than benzo[a]pyrene (B[a]P), a well-known Ah-receptor agonist. Interestingly, the CP[c]Ph dependent up-regulation of CYP1A mRNA is positively correlated with the incidences of clastogenic changes in rainbow trout erythrocytes. CP[c]Ph has, comparably to B[a]P, a potential to repress expression of tumor suppressor p53, in the head kidney of rainbow trout. Furthermore, estrogen responsive genes in fish liver, ERα and VTG, are not induced by CP[c]Ph, suggesting that the compound has no endocrine disrupting potential. However, some CP[c]Phs show mutagenic activity when investigated in the Ames test, and exhibit genotoxic properties in in vitro micronucleus assay. The above characteristics suggest that CP-PAHs are chemicals of concern for which potential pathways of exposure should be further identified. PMID:23628509

  1. Evaluation of Potential Impacts of Microbial Activity on Drift Chemistry

    ''Evaluation of Potential Impacts of Microbial Activity on Drift Chemistry'' focuses on the potential for microbial communities that could be active in repository emplacement drifts to influence the in-drift bulk chemical environment. This report feeds analyses to support the inclusion or exclusion of features, events, and processes (FEPs) in the total system performance assessment (TSPA) for the license application (LA), but this work is not expected to generate direct feeds to the TSPA-LA. The purpose was specified by, and the evaluation was performed and is documented in accordance with, ''Technical Work Plan For: Near-Field Environment and Transport In-Drift Geochemistry Analyses'' (BSC 2004 [DIRS 172402], Section 2.1). This report addresses all of the FEPs assigned by the technical work plan (TWP), including the development of exclusion arguments for FEPs that are not carried forward to the TSPA-LA. Except for an editorial correction noted in Section 6.2, there were no other deviations from the TWP. This report documents the completion of all assigned tasks, as follows (BSC 2004 DIRS 172402, Section 1.2.1): (1) Perform analyses to evaluate the potential for microbial activity in the waste emplacement drift under the constraints of anticipated physical and chemical conditions. (2) Evaluate uncertainties associated with these analyses. (3) Determine whether the potential for microbes warrants a feed to TSPA-LA to account for predicted effects on repository performance. (4) Provide information to address the ''Yucca Mountain Review Plan, Final Report'' (NUREG-1804) (NRC 2003 [DIRS 163274]) and Key Technical Issues and agreements, as appropriate. (5) Develop information for inclusion or exclusion of FEPs

  2. Evaluation of Potential Impacts of Microbial Activity on Drift Chemistry

    Y. Wang

    2004-11-18

    ''Evaluation of Potential Impacts of Microbial Activity on Drift Chemistry'' focuses on the potential for microbial communities that could be active in repository emplacement drifts to influence the in-drift bulk chemical environment. This report feeds analyses to support the inclusion or exclusion of features, events, and processes (FEPs) in the total system performance assessment (TSPA) for the license application (LA), but this work is not expected to generate direct feeds to the TSPA-LA. The purpose was specified by, and the evaluation was performed and is documented in accordance with, ''Technical Work Plan For: Near-Field Environment and Transport In-Drift Geochemistry Analyses'' (BSC 2004 [DIRS 172402], Section 2.1). This report addresses all of the FEPs assigned by the technical work plan (TWP), including the development of exclusion arguments for FEPs that are not carried forward to the TSPA-LA. Except for an editorial correction noted in Section 6.2, there were no other deviations from the TWP. This report documents the completion of all assigned tasks, as follows (BSC 2004 DIRS 172402, Section 1.2.1): (1) Perform analyses to evaluate the potential for microbial activity in the waste emplacement drift under the constraints of anticipated physical and chemical conditions. (2) Evaluate uncertainties associated with these analyses. (3) Determine whether the potential for microbes warrants a feed to TSPA-LA to account for predicted effects on repository performance. (4) Provide information to address the ''Yucca Mountain Review Plan, Final Report'' (NUREG-1804) (NRC 2003 [DIRS 163274]) and Key Technical Issues and agreements, as appropriate. (5) Develop information for inclusion or exclusion of FEPs.

  3. An Assessment of a Physical Chemistry Online Activity

    Hamby Towns, Marcy; Kreke, Kelley; Sauder, Deborah; Stout, Roland; Long, George; Zielinski, Theresa Julia

    1998-12-01

    A questionnaire and list server archive were used to investigate the perception of students and faculty who took part in a physical chemistry online project. Students at four universities worked cooperatively in their own classrooms and collaborated as a larger team on the Internet via a list server to determine the best mathematical model to describe the PV behavior of a gas at a specified temperature. The strengths of the project were the interaction among students, the use of Mathcad and modern technology, and the experience of authentic problem-solving. The weaknesses were the problems with the technology, the facilitation of interaction, and the student's ability to ask questions to solve an ill-defined problem. The suggestions for improvements focused on facilitating interuniversity interaction between students, clarifying tasks and goals, and implementation of the online activities. We discuss how our evaluation of the project guided and informed the design of a subsequent online project, and our planning for future projects. In addition, we describe the professional learning community that evolved among faculty who participated in this project.

  4. Combustion chemistry. Activities in the CHEC research programme

    Dam-Johansen, K.; Johnsson, J.E.; Glarborg, P.; Frandsen, F.; Jensen, A.; Oestberg, M. [Technical Univ. of Denmark, Dept. of Chemical Engineering, Lyngby (Denmark)

    1996-12-01

    The combustion chemistry in the oxidation of fossil fuels and biofuels determines together with mixing and heat transfer the required size of a furnace, the emission of gaseous pollutants, and the formation of ash and deposits on surfaces. This paper describes technologies for solid fuels combustion and gives a summary of the fuels, the pollutant chemistry and the inorganic chemistry in combustion processes. Emphasis is put on the work carried out in the CHEC (Combustion and Harmful Emission Control Research Programme). (au) 173 refs.

  5. Comparative Analysis of Click Chemistry Mediated Activity-Based Protein Profiling in Cell Lysates

    Yinliang Yang

    2013-10-01

    Full Text Available Activity-based protein profiling uses chemical probes that covalently attach to active enzyme targets. Probes with conventional tags have disadvantages, such as limited cell permeability or steric hindrance around the reactive group. A tandem labeling strategy with click chemistry is now widely used to study enzyme targets in situ and in vivo. Herein, the probes are reacted in live cells, whereas the ensuing detection by click chemistry takes place in cell lysates. We here make a comparison of the efficiency of the activity-based tandem labeling strategy by using Cu(I-catalyzed and strain-promoted click chemistry, different ligands and different lysis conditions.

  6. Self-Directed Activity-Based Learning and Achievement in High School Chemistry

    Bassett, Meighan M.; Martinez, James; Martin, Ellice P.

    2014-01-01

    The effects of student-directed activity-based learning (SDABL) were examined in two high school chemistry classes. Students in the SDABL class were given pretest results, a list of standards to be mastered, and a chart of learning activities categorized by difficulty level. They selected activities to meet their needs and preferences.…

  7. Liaison activities with the Institute of Physical Chemistry, Russian Academy of Sciences: FY 1997

    Delegard, C.H.; Elovich, R.J.

    1997-09-01

    The Institute of Physical Chemistry of the Russian Academy of Sciences is conducting a program of fundamental and applied research into the chemistry of the actinides and technetium in alkaline media such as are present in the Hanford Site underground waste storage tanks. This work is being coordinated and the results disseminated through a technical liaison maintained at the Pacific Northwest National Laboratory. The technical liaison is performing laboratory studies on plutonium chemistry in alkaline media. The activities at the Institute of Physical Chemistry and through the liaison are pursued to improve understanding of the chemical behavior of key long-lived radioactive elements under current operating and proposed tank waste processing conditions. Both activities are supported by the Efficient Separations and Processing Crosscutting Program under the Office of Science and Technology of the U.S. Department of Energy.

  8. Liaison activities with the Institute of Physical Chemistry, Russian Academy of Sciences: FY 1997

    The Institute of Physical Chemistry of the Russian Academy of Sciences is conducting a program of fundamental and applied research into the chemistry of the actinides and technetium in alkaline media such as are present in the Hanford Site underground waste storage tanks. This work is being coordinated and the results disseminated through a technical liaison maintained at the Pacific Northwest National Laboratory. The technical liaison is performing laboratory studies on plutonium chemistry in alkaline media. The activities at the Institute of Physical Chemistry and through the liaison are pursued to improve understanding of the chemical behavior of key long-lived radioactive elements under current operating and proposed tank waste processing conditions. Both activities are supported by the Efficient Separations and Processing Crosscutting Program under the Office of Science and Technology of the U.S. Department of Energy

  9. Chemistry For Kids: Pre-Chemistry Acid Rain Activities for Kids.

    Barrow, Lloyd H.

    1985-01-01

    Presents two activities on acid rain for students in intermediate grades. Materials needed and procedures used are included. Also describes "chemical magic" shows performed by high school students for sixth-grade students in seven elementary schools in Altus, Oklahoma. (JN)

  10. Combinatorial chemistry

    Nielsen, John

    1994-01-01

    An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds.......An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds....

  11. "SimChemistry" as an Active Learning Tool in Chemical Education

    Bolton, Kim; Saalman, Elisabeth; Christie, Michael; Ingerman, Ake; Linder, Cedric

    2008-01-01

    The publicly available free computer program, "SimChemistry," was used as an active learning tool in the chemical engineering curriculum at the University College of Boras, Sweden. The activity involved students writing their own simulation programs on topics in the area of molecular structure and interactions. Evaluation of the learning…

  12. Offering Community Engagement Activities to Increase Chemistry Knowledge and Confidence for Teachers and Students

    Sewry, Joyce D.; Glover, Sarah R.; Harrison, Timothy G.; Shallcross, Dudley E.; Ngcoza, Kenneth M.

    2014-01-01

    Given the emphasis on community engagement in higher education, academic departments need to become more involved in the community. This paper discusses a number of outreach activities undertaken by the chemistry department at Rhodes University, South Africa. The activities range from service learning to community engagement with teachers and…

  13. Diversity of Secondary Metabolites from Marine Bacillus Species: Chemistry and Biological Activity

    Hee Jae Shin; Muhammad Abdul Mojid Mondol; Mohammad Tofazzal Islam

    2013-01-01

    Marine Bacillus species produce versatile secondary metabolites including lipopeptides, polypeptides, macrolactones, fatty acids, polyketides, and isocoumarins. These structurally diverse compounds exhibit a wide range of biological activities, such as antimicrobial, anticancer, and antialgal activities. Some marine Bacillus strains can detoxify heavy metals through reduction processes and have the ability to produce carotenoids. The present article reviews the chemistry and biological activi...

  14. Applications of neutron activation analysis in chemistry and pollution fields

    Some examples of applications of activation analysis are given such as: chemical analysis of precious metals, nuclear graphite and hydrocarbons; control of pollution of water and seawater, analysis of food and seafood, atmospheric, dust and hair for determination of impurities

  15. Medical chemistry of boron neutron capture agents having pharmacological activity

    Boron neutron capture therapy (BNCT) is a cancer treatment that selectively destroys cancer cells following administering a cancer-selective drug containing stable isotope boron-10 and neutron irradiation. In clinical trial of BNCT, disodium mercaptoundecahydro-closo-dodecaborate (BSH) and p-boronophenylalanine (BPA) have been used, however, development of a new drugs with high cancer selectivity and therapeutic efficiency is expected. Therefore, we review boron-containing drugs as a boron neutron capture agents having pharmacological activity, BNCT research on boron-modified porphyrin derivatives which have photosensitivity and neutron capture activity and our proposed neutron sensitizing agent. (author)

  16. Eliciting Metacognitive Experiences and Reflection in a Year 11 Chemistry Classroom: An Activity Theory Perspective

    Thomas, Gregory P.; McRobbie, Campbell J.

    2013-06-01

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

  17. Chemistry and Biological Activities of Flavonoids: An Overview

    Shashank Kumar

    2013-01-01

    Full Text Available There has been increasing interest in the research on flavonoids from plant sources because of their versatile health benefits reported in various epidemiological studies. Since flavonoids are directly associated with human dietary ingredients and health, there is need to evaluate structure and function relationship. The bioavailability, metabolism, and biological activity of flavonoids depend upon the configuration, total number of hydroxyl groups, and substitution of functional groups about their nuclear structure. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. Most recent researches have focused on the health aspects of flavonoids for humans. Many flavonoids are shown to have antioxidative activity, free radical scavenging capacity, coronary heart disease prevention, hepatoprotective, anti-inflammatory, and anticancer activities, while some flavonoids exhibit potential antiviral activities. In plant systems, flavonoids help in combating oxidative stress and act as growth regulators. For pharmaceutical purposes cost-effective bulk production of different types of flavonoids has been made possible with the help of microbial biotechnology. This review highlights the structural features of flavonoids, their beneficial roles in human health, and significance in plants as well as their microbial production.

  18. Electrostatic activation of prebiotic chemistry in substellar atmospheres

    Stark, Craig R; Diver, Declan A; Rimmer, Paul B

    2013-01-01

    Charged dust grains in the atmospheres of exoplanets may play a key role in the formation of prebiotic molecules, necessary to the origin of life. Dust grains submerged in an atmospheric plasma become negatively charged and attract a flux of ions that are accelerated from the plasma. The energy of the ions upon reaching the grain surface may be sufficient to overcome the activation energy of particular chemical reactions that would be unattainable via ion and neutral bombardment from classical, thermal excitation. As a result, prebiotic molecules or their precursors could be synthesised on the surface of dust grains that form clouds in exoplanetary atmospheres. This paper investigates the energization of the plasma ions, and the dependence on the plasma electron temperature, in the atmospheres of substellar objects such as gas giant planets. Calculations show that modest electron temperatures of $\\approx 1$ eV ($\\approx 10^{4}$ K) are enough to accelerate ions to sufficient energies that exceed the activation...

  19. Study the active site of flavonoid applying radiation chemistry

    Flavonoid are a large and important class of naturally occurring, low molecular weight benzo-γ-pyrone derivatives which are reported to have a myriad of biological activities, but the study on the active sites of flavonoids is still ambiguous. In this paper, rutin, quercetin and baicalin have been selected as model compounds. It is well known that rutin is used in inhibiting arteriosclerosis and baicalin is antibacterial and antiviral. They have similar basic structure, but their medicinal properties are so different, why? As most flavonoids contain carbonyl group, which can capture electron effectively, we predict that flavonoids can capture electron to form radical anion. The formation of anion radical may have influence on the mitochondrial electron transport chain. The difference in the ability of forming anion radical may cause the difference in their medicinal effects. (author)

  20. Processed Vietnamese ginseng: Preliminary results in chemistry and biological activity

    Le, Thi Hong Van; Lee, Seo Young; Kim, Tae Ryong; Kim, Jae Young; Kwon, Sung Won; NGUYEN, NGOC KHOI; Park, Jeong Hill; Nguyen, Minh Duc

    2013-01-01

    Background This study was carried out to investigate the effect of the steaming process on chemical constituents, free radical scavenging activity, and antiproliferative effect of Vietnamese ginseng. Methods Samples of powdered Vietnamese ginseng were steamed at 120°C for various times and their extracts were subjected to chemical and biological studies. Results Upon steaming, contents of polar ginsenosides, such as Rb1, Rc, Rd, Re, and Rg1, were rapidly decreased, whereas less polar ginsenos...

  1. Using active learning methodologies in physical chemistry in CLIL contexts

    David Recatalá

    2016-01-01

    One of the main objectives of the European Higher Education Area (EHEA) is to promote a change toward a student-centred education model. This fact has led to the implementation of novel methodologies based on active learning, aimed at engaging students’ interest. This implementation has been usually accompanied by significant changes in both the teaching and learning processes in European universities. Furthermore, teaching a subject through the medium of a foreign language has also been gain...

  2. Electrostatic activation of prebiotic chemistry in substellar atmospheres

    Stark, C. R.; Helling, Ch.; Diver, D.A.; Rimmer, P. B.

    2014-01-01

    Charged dust grains in the atmospheres of exoplanets may play a key role in the formation of prebiotic molecules, necessary to the origin of life. Dust grains submerged in an atmospheric plasma become negatively charged and attract a flux of ions that are accelerated from the plasma. The energy of the ions upon reaching the grain surface may be sufficient to overcome the activation energy of particular chemical reactions that would be unattainable via ion and neutral bombardment from classica...

  3. Antimicrobial activity of silver nanoparticles synthesized via green chemistry

    KAVAZ DOGA; LAMIDO SURAYYA MUHAMMAD; UMAR HUZAIFA

    2015-01-01

    Silver nanoparticles (AgNPs) synthesis is among the new areas of nanotechnological research and it’s a bit cost effective, pollution free and environmental friendly compared to other metals used to synthesized nanoparticles. The synthesized nanoparticle was characterized using Atomic Force Microscope (AFM), FTIR, EDX, UV-Vis, Zeta Sizer and anti-microbial activity studies was also carried out. These techniques of identification were for morphological, particle size and concentration of NPs fo...

  4. Chemistry and Biological Activities of Flavonoids: An Overview

    Shashank Kumar; Pandey, Abhay K

    2013-01-01

    There has been increasing interest in the research on flavonoids from plant sources because of their versatile health benefits reported in various epidemiological studies. Since flavonoids are directly associated with human dietary ingredients and health, there is need to evaluate structure and function relationship. The bioavailability, metabolism, and biological activity of flavonoids depend upon the configuration, total number of hydroxyl groups, and substitution of functional groups about...

  5. Amazon acai: chemistry and biological activities: a review.

    Yamaguchi, Klenicy Kazumy de Lima; Pereira, Luiz Felipe Ravazi; Lamarão, Carlos Victor; Lima, Emerson Silva; da Veiga-Junior, Valdir Florêncio

    2015-07-15

    Acai (acai or assai) is one of the Amazon's most popular functional foods and widely used in the world. There are many benefits to its alleged use in the growing market for nutraceuticals. The acai extracts have a range of polyphenolic components with antioxidant properties, some of those present in greater quantity are orientin, isoorientin and vanillic acid, as well as anthocyanins cyanidin-3-glucoside and cyanidin-3-rutinoside. The presence of these substances is linked mainly to the antioxidant, anti- inflammatory, anti-proliferative and cardioprotective activities. Importantly, there are two main species of the Euterpe genus which produce acai. There are several differences between them but they are still quite unknown, from literature to producers and consumers. In this review are highlighted the chemical composition, botanical aspects, pharmacological, marketing and nutrition of these species based on studies published in the last five years in order to unify the current knowledge and dissimilarities between them. PMID:25722148

  6. Ammonia removal using activated carbons: effect of the surface chemistry in dry and moist conditions

    Gonçalves, Maraisa; Sánchez García, Laura; Jardim, Erika de Oliveira; Silvestre Albero, Joaquín; Rodríguez Reinoso, Francisco

    2011-01-01

    The effect of surface chemistry (nature and amount of oxygen groups) in the removal of ammonia was studied using a modified resin-based activated carbon. NH3 breakthrough column experiments show that the modification of the original activated carbon with nitric acid, that is, the incorporation of oxygen surface groups, highly improves the adsorption behavior at room temperature. Apparently, there is a linear relationship between the total adsorption capacity and the amount of the more acidic ...

  7. Adsorption of atrazine on hemp stem-based activated carbons with different surface chemistry

    Lupul, Iwona; Yperman, Jan; Carleer, Robert; Gryglewicz, Grazyna

    2015-01-01

    Surface-modified hemp stem-based activated carbons (HACs) were prepared and used for the adsorption of atrazine from aqueous solution, and their adsorption performance was examined. A series of HACs were prepared by potassium hydroxide activation of hemp stems, followed by subsequent modification by thermal annealing, oxidation with nitric acid and amination. The resultant HACs differed in surface chemistry, while possessing similar porous structure. The surface group characteristics were exa...

  8. Neutron activation analysis in receptor modeling in environmental chemistry

    The release of air pollutants in high enough concentrations can have adverse health effects on the general public, particularly in urban areas. To develop strategies to manage the quality of air pollution, it is necessary to understand the flow of materials through the system, the sources and sinks, transformation, and transport pathways of the species of interest. An approach that is extensively being used in our laboratories, as well as in many others, is the use of receptor modeling. These models are based on the concepts of conservation of mass and a mass balance analysis, which in turn is based on the characterization of airborne particles into their constituents. From these methods, sources contributing to air quality are identified from the perspective of the receptor or ambient sampler. Separation of the ambient particles containing trace elements into distinct size classes allows the study of various sources to be identified. Another reason for the rapid development of receptor models has been the concurrent development of a variety of analytical techniques that permit greatly improved analyses to provide the needed input data. Two of the most powerful methods are instrumental neutron activation analysis (INAA) and X-ray fluorescence (XRF), including particle-induced X-ray emission. By using these methods along with sophisticated receptor modeling and size fractionation, the authors have been able to identify specific sources of local and regional air pollution

  9. Design performances and chemistry program supporting the FA3 /UKEPRTM activity management: experience and modeling balance

    EPRTM reactor accounts with an evolutionary design that provides the appropriate features to ensure the safety implementation of different chemistry and radiochemistry options. ALARP considerations have been taken into account by EDF-AREVA for making decisions relating to the activity management in the primary circuit of Flamanville 3-EPRTM and UK-EPRTM reactors. The water chemistry and radiochemistry concept implemented in FA3-EPRTM and UK-EPRTM reactors is the result of an exhaustive selection process based on the balance between the theoretical developments, the laboratory tests and the NPP experience concerning the diverse areas associated with: - The source term identification and characterization: The understanding of the origin and behavior of fission products/actinides, corrosion products and activation products constitutes the essential support for the selection of suitable parameters and criteria to monitor the system integrity, the tramp-uranium and radiation build-up and the discharges to the environment. - The source term quantification: The balance between the baseline data from PWR forerunner reactors and the assessments performed by modeling constitutes the major demonstration of the source term accuracy. This approach ensures that activity risks are understood and can be managed with the EPRTM design options. - The EPRTM design options evaluation: The sensitivity analysis results show the influence of the fuel management, the material choice and the chemistry conditioning on several domains such as the activity coolant and the fuel/ex-core crud management. EDF-AREVA demonstrates by means of this process that the design, sizing and chemistry conditioning of EPRTM reactor primary circuit are adapted to guarantee the correct activity management. The methodology developed, based on qualitative and quantitative assessments, intends to propose to the Nuclear Industry several alternatives for evaluating and/or improving the compliance with requirements

  10. Teaching chemistry concepts using differentiated instruction via tiered labs and activity menus

    Collins, Betsy C.

    Today's high school classrooms are composed of students with different levels of knowing and ways of understanding. Differentiating the type of work that they are asked to do to achieve the same objective is one way to meet each student's special circumstances on a somewhat equal playing field. By doing so, students are being challenged at their level rather than just blindly going through the same motions that they see others around them doing. Offering students choices to better understand a concept places the student in the driver seat of their educational journey. The purpose of this research project was to design and implement choice activities within the chemistry classroom to more appropriately teach and assess chemistry concepts and assess understanding of those concepts. These choice activities included tiered-laboratory investigations and activity menus. This project was implemented over the course of two trimesters in a high school chemistry classroom. Topics covered included calculating and interpreting density and applying significant figures, calculating and interpreting percent composition with the mole concept, and stoichiometry. The effectiveness of the tiered-labs and activity menus were evaluated using pre and post test comparisons, student surveys, and general in-class observations. Gains in conceptual understanding and student motivation were documented. These findings indicated that allowing choice and leveling of skills to achieve the same conceptual understanding promoted student learning and the overall enjoyment and motivation for learning.

  11. Recent activities of EC4 in the harmonization of clinical chemistry in the European Union.

    Sanders, G T; Jansen, R T; Beastall, G; Gurr, E; Kenny, D; Kohse, K P; Zérah, S

    1999-04-01

    This article describes the recent activities of the European Communities Confederation of Clinical Chemistry (EC4). Main goal of EC4 is harmonization of clinical chemistry in the European Union and Europe. EC4's actions connected to that are training and registration of professionals, and accreditation of laboratories. The 35000 professionals practising clinical chemistry in the EU have different backgrounds (medical, pharmaceutical, science-oriented, veterinary, or microbiological). Thus, for the harmonization of training of clinical chemists, EC4 has published a European Syllabus for Postgraduate Training, and instituted a European Union Register for Clinical Chemists. The Syllabus is an indication of the level of requirements in postgraduate training. The EC4 initiative to implement the European Register for Clinical Chemists is based on the 8 years vocational training necessary to obtain sufficient knowledge in clinical chemistry according to the European Syllabus. A guide to the EC4 Register has been published; registration leads to the title European Clinical Chemist (EurClinChem). The accreditation of laboratories must be based on a total quality management system. EC4 has described guidelines (essential criteria) which it judges appropriate for establishing the quality of medical laboratory service; it does not wish to fulfil the role of an accrediting body. Moreover, a working group has been set up to seek to harmonize the work of national accrediting bodies. Therefore, it is logical that EC4 monitors the activities of the different standardizing bodies that might influence the practice of clinical chemistry in the EU. Finally, some aspects concerning the future strategy of EC4 are brought forward. PMID:10369121

  12. Ant-mediated effects on spruce litter decomposition, solution chemistry, and microbial activity

    Stadler, B.; Schramm, Andreas; Kalbitz, K.

    2006-01-01

    effects of ants and aphid honeydew on litter solution of Norway spruce, microbial enzyme activities, and needle decomposition in a field and greenhouse experiment during summer 2003. In the field, low ant densities had relatively little effects on litter solution 30 cm away from a tree trunk, but...... %N were not affected by ants or honeydew. Our results suggest that ants have a distinct and immediate effect on solution composition and microbial activity in the litter layer indicating accelerated litter decay whereas the effect of honeydew was insignificant. Keywords: Ants; Decomposition; Formica...... polyctena; Honeydew; Litter solution chemistry; Microbial activity; Needle litter...

  13. Diversity of Secondary Metabolites from Marine Bacillus Species: Chemistry and Biological Activity

    Hee Jae Shin

    2013-08-01

    Full Text Available Marine Bacillus species produce versatile secondary metabolites including lipopeptides, polypeptides, macrolactones, fatty acids, polyketides, and isocoumarins. These structurally diverse compounds exhibit a wide range of biological activities, such as antimicrobial, anticancer, and antialgal activities. Some marine Bacillus strains can detoxify heavy metals through reduction processes and have the ability to produce carotenoids. The present article reviews the chemistry and biological activities of secondary metabolites from marine isolates. Side by side, the potential for application of these novel natural products from marine Bacillus strains as drugs, pesticides, carotenoids, and tools for the bioremediation of heavy metal toxicity are also discussed.

  14. The application of click chemistry in the synthesis of agents with anticancer activity

    Ma N

    2015-03-01

    Full Text Available Nan Ma,1–3 Ying Wang,3 Bing-Xin Zhao,3 Wen-Cai Ye,1,3 Sheng Jiang2 1Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, 2Laboratory of Medicinal Chemistry, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, 3Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou, People’s Republic of China Abstract: The copper(I-catalyzed 1,3-dipolar cycloaddition between alkynes and azides (click chemistry to form 1,2,3-triazoles is the most popular reaction due to its reliability, specificity, and biocompatibility. This reaction has the potential to shorten procedures, and render more efficient lead identification and optimization procedures in medicinal chemistry, which is a powerful modular synthetic approach toward the assembly of new molecular entities and has been applied in anticancer drugs discovery increasingly. The present review focuses mainly on the applications of this reaction in the field of synthesis of agents with anticancer activity, which are divided into four groups: topoisomerase II inhibitors, histone deacetylase inhibitors, protein tyrosine kinase inhibitors, and antimicrotubule agents. Keywords: topoisomerase II inhibitors, histone deacetylase inhibitors, protein tyrosine kinase inhibitors, antimicrotubule agents

  15. Hot Chemistry Laboratory decommissioning activities at IPEN/CNEN-SP, Brazil

    Camilo, Ruth L.; Lainetti, Paulo E.O. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: rcamilo@ipen.br, e-mail: lainetti@ipen.br

    2009-07-01

    IPEN's fuel cycle activities were accomplished in laboratory and pilot plant scale and most facilities were built in the 70-80 years. Nevertheless, radical changes of the Brazilian nuclear policy in the beginning of 90's determined the interruption of several fuel cycle activities and facilities shutdown. Since then, IPEN has faced the problem of the pilot plants decommissioning considering that there was no experience/expertise in this field at all. In spite of this, some laboratory and pilot plant decommissioning activities have been performed in IPEN in the last years, even without previous experience and training support. One of the first decommissioning activities accomplished in IPEN involved the Hot Chemistry Laboratory. This facility was built in the beginning of the 80's with the proposal of supporting research and development in the nuclear chemistry area. It was decided to settle a new laboratory in the place where the Hot Chemistry Laboratory was installed, being necessary its total releasing from the radioactive contamination point of view. The previous work in the laboratory involved the manipulation of samples of irradiated nuclear fuel, besides plutonium-239 and uranium-233 standard solutions. There were 5 glove-boxes in the facility but only 3 were used with radioactive material. The glove-boxes contained several devices and materials, besides the radioactive compounds, such as: electric and electronic equipment, metallic and plastic pieces, chemical reagents, liquid and solid radioactive wastes, etc. The laboratory's decommissioning process was divided in 12 steps. This paper describes the procedures, problems faced and results related to the Hot Chemistry Laboratory decommissioning operations and its reintegration as a new laboratory of the Chemical and Environmental Technology Center (CQMA) - IPEN-CNEN/SP. (author)

  16. Hot Chemistry Laboratory decommissioning activities at IPEN/CNEN-SP, Brazil

    IPEN's fuel cycle activities were accomplished in laboratory and pilot plant scale and most facilities were built in the 70-80 years. Nevertheless, radical changes of the Brazilian nuclear policy in the beginning of 90's determined the interruption of several fuel cycle activities and facilities shutdown. Since then, IPEN has faced the problem of the pilot plants decommissioning considering that there was no experience/expertise in this field at all. In spite of this, some laboratory and pilot plant decommissioning activities have been performed in IPEN in the last years, even without previous experience and training support. One of the first decommissioning activities accomplished in IPEN involved the Hot Chemistry Laboratory. This facility was built in the beginning of the 80's with the proposal of supporting research and development in the nuclear chemistry area. It was decided to settle a new laboratory in the place where the Hot Chemistry Laboratory was installed, being necessary its total releasing from the radioactive contamination point of view. The previous work in the laboratory involved the manipulation of samples of irradiated nuclear fuel, besides plutonium-239 and uranium-233 standard solutions. There were 5 glove-boxes in the facility but only 3 were used with radioactive material. The glove-boxes contained several devices and materials, besides the radioactive compounds, such as: electric and electronic equipment, metallic and plastic pieces, chemical reagents, liquid and solid radioactive wastes, etc. The laboratory's decommissioning process was divided in 12 steps. This paper describes the procedures, problems faced and results related to the Hot Chemistry Laboratory decommissioning operations and its reintegration as a new laboratory of the Chemical and Environmental Technology Center (CQMA) - IPEN-CNEN/SP. (author)

  17. Textbook Questions in Context-Based and Traditional Chemistry Curricula Analysed from a Content Perspective and a Learning Activities Perspective

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

    2013-01-01

    In this study, questions in context-based and traditional chemistry textbooks were analysed from two perspectives that are at the heart of chemistry curricula reforms: a content perspective and a learning activities perspective. To analyse these textbook questions, we developed an instrument for each perspective. In total, 971 textbook questions…

  18. Michaelis-Menten Kinetics and the Activation Energy Relate Soil Peroxidase Kinetics to the Lignin Chemistry

    Triebwasser-Freese, D.; Tharayil, N.; Preston, C. M.; Gerard, P.

    2013-12-01

    Recently, it has been suggested that lignin exhibit a turnover rate of less than 6 years, suggesting that the enzymatic mechanisms mediating the decay of lignin are less understood. One factor that could be affecting the mean residence time of lignin in the soil is the catalytic efficiency of soil oxidoreductase enzymes. We characterized the spatial and seasonal transitions in the Michaelis-Menten kinetics and activation energy of the soil oxidoreductase enzyme, peroxidase, across three ecosystems of differing litter chemistries- pine, deciduous forest, and a cultivated field- and associate it to the soil lignin chemistries. To interpret the combined effect of Vmax and Km, the two parameters were integrated into one term which we defined as the catalytic efficiency. Generally, the peroxidases in pine soils exhibited the highest Vmax and Km, resulting in the lowest catalytic efficiency, followed by that in the deciduous soils. Meanwhile, the agricultural soils which exhibited the lowest Vmax and Km contained the highest catalytic efficiency of peroxidase. Through linear regression analysis of the kinetic parameters to the soil lignin chemistry, we discerned that the catalytic efficiency term best associated to the lignin monomer ratios (C/V, P/V, and SCV/V). The Activation Energy of peroxidase varied by depth, and seasons across the ecosystems. However, the Activation Energy of peroxidase did not relate to the lignin chemistry or quantity. Collectively, our results show that although the peroxidase Vmax and Km in the phenolic-poor soils are low, the degradation efficiency of peroxidases in this soils can be equivalent or exceed that of phenolic-rich soils. This study, through the characterization of Michaelis-Menten kinetics, provides a new insight into the mechanisms that could moderate the decomposition of lignin in soils.

  19. Ammonia removal using activated carbons: effect of the surface chemistry in dry and moist conditions.

    Gonçalves, Maraisa; Sánchez-García, Laura; Oliveira Jardim, Erika de; Silvestre-Albero, Joaquín; Rodríguez-Reinoso, Francisco

    2011-12-15

    The effect of surface chemistry (nature and amount of oxygen groups) in the removal of ammonia was studied using a modified resin-based activated carbon. NH(3) breakthrough column experiments show that the modification of the original activated carbon with nitric acid, that is, the incorporation of oxygen surface groups, highly improves the adsorption behavior at room temperature. Apparently, there is a linear relationship between the total adsorption capacity and the amount of the more acidic and less stable oxygen surface groups. Similar experiments using moist air clearly show that the effect of humidity highly depends on the surface chemistry of the carbon used. Moisture highly improves the adsorption behavior for samples with a low concentration of oxygen functionalities, probably due to the preferential adsorption of ammonia via dissolution into water. On the contrary, moisture exhibits a small effect on samples with a rich surface chemistry due to the preferential adsorption pathway via Brønsted and Lewis acid centers from the carbon surface. FTIR analyses of the exhausted oxidized samples confirm both the formation of NH(4)(+) species interacting with the Brønsted acid sites, together with the presence of NH(3) species coordinated, through the lone pair electron, to Lewis acid sites on the graphene layers. PMID:22049916

  20. The role of human activity and land use change in atmospheric chemistry and air quality

    In the this paper, I review the importance of a mineral of fossil fuel emissions atmospheric chemistry, air quality, and climate. I then review current estimates of the sources for each specie, deriving the fraction of each source that is due to specific land use practices or land cover categories. Understanding the current trends of those species with known increasing abundances and projecting increases into the future is possible if the estimated sources from human activity and land use change can be projected and if the known atmospheric sinks and the interactions in atmospheric chemistry and climate change are appropriately taken into account. Regional trends in the short-lived species can be projected as well, assuming the estimated sources and sinks are correct. However, significant uncertainties continue to surround the estimated budgets for most of these species. Uncertainties and the estimated ranges in different source strength estimates for each are also discussed

  1. Role of the surface chemistry of activated carbons in dye removal from aqueous solution

    Zhou, Hua-lei; Zhen, Wen-juan; Zhu, Qian; Wu, Xiao-bin; Chang, Zhi-dong; Li, Wen-jun

    2015-07-01

    Commercial activated carbons were modified by a series of chemical or physical treatments using H2O2, NH3, and heating under N2 flow without notably changing their pore structures. The resultant carbons were characterized by N2 adsorption and Bohem titration and then used to remove Ponceau 4R, methyl orange and brilliant blue from aqueous solutions. Surface chemistry was found to play a significantly different role in removing these three compounds. The removal of anionic Ponceau 4R increases with increasing carbon surface basicity due to the predominant dispersive interaction mechanism. In contrast, surface chemistry has little effect on the removal of anionic methyl orange, which can be explained by two parallel mechanisms involving electrostatic and dispersive interactions due to the basic amine group in a dye molecule. The influence of surface chemistry on the removal of amphoteric brilliant blue dye can also be ignored due to a weak interaction between the carbons and dye molecules, which is resulted from strong cohesive energy from electrostatic forces inside amphoteric dye molecules.

  2. Annual report 1985 Chemistry Department

    This report contains a brief survey of the main activities in the Chemistry Department. All particles and reports published and lectures given in 1985 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general. (author)

  3. Annual report 1984 Chemistry Department

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry , environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general. (author)

  4. Annual Report 1984. Chemistry Department

    Funck, Jytte; Nielsen, Ole John

    1985-01-01

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general.

  5. The Multi-Initiative Dissemination Project: Active-Learning Strategies for College Chemistry

    Burke, K. A.; Greenbowe, Thomas J.; Lewis, Eileen L.; Peace, G. Earl

    2002-06-01

    Aspects of the NSF-funded Multi-Initiative Dissemination Project (MID) are discussed in order to inform potential participants of the benefits of attending a MID workshop. The workshops are for two- and four-year college instructors who want to improve their students' understanding of science. Four of the NSF-funded chemistry systemic reform projects (ChemConnections, Molecular Science, New Traditions, and Peer-Led Team Learning) disseminate information and conduct hands-on activities with their session participants during the MID workshops. The MID workshops are funded from 2001 through 2003.

  6. Chemically active colloids near osmotic-responsive walls with surface-chemistry gradients

    Popescu, M N; Dietrich, S

    2016-01-01

    Chemically active colloids move by creating gradients in the composition of the surrounding solution and by exploiting the differences in their interactions with the various molecular species in solution. If such particles move near boundaries, e.g., the walls of the container confining the suspension, gradients in the composition of the solution are also created along the wall. This give rise to chemi-osmosis (via the interactions of the wall with the molecular species forming the solution), which drives flows coupling back to the colloid and thus influences its motility. Employing an approximate "point-particle" analysis, we show analytically that -- owing to this kind of induced active response (chemi-osmosis) of the wall -- such chemically active colloids can align with, and follow, gradients in the surface chemistry of the wall. In this sense, these artificial "swimmers" exhibit a primitive form of thigmotaxis with the meaning of sensing the proximity of a (not necessarily discontinuous) physical change ...

  7. [Influences of uncommon isoenzymes on determination of alkaline phosphatase activity by dry-chemistry analyzers].

    Tozawa, T; Hashimoto, M

    2001-04-01

    Dry-chemistry(DC) analysis may be influenced by some matrix effects for measuring uncommon isoenzyme forms. Placental and intestinal alkaline phosphatase(AP) are overestimated by the VITROS DC, compared with results obtained with the wet-chemistry(WC) method of Bretaudiere, et al. using 2-amino-2-methyl-1-propanol (AMP) buffer, however, no such discrepancy between AP results in any DC method and that with a routine WC method recommended by Japanese Society of Clinical Chemistry in that 2-ethylaminoethanol(EAE) buffer is used, has been demonstrated. The type of buffer used affects differently the rates of AP isoenzymes activities. We therefore examined whether the presence of uncommon AP isoenzyme forms in serum caused aberrant DC results for AP in comparison with a routine WC method using EAE buffer. Here, serum samples with only liver AP and bone AP(n : 32); high-molecular-mass AP(n : 11); placental AP(n : 12); intestinal AP(n : 13) and immunoglobulin (Ig) bound AP(n : 12) were analyzed for total AP activity on three different DC analyzers: VITROS 700XR, FUJIDRYCHEM 5000, SPOTCHEM 4410 and a WC analyzer: HITACHI 7350. Values obtained in all of the DCs for sera containing only liver/bone AP agreed with those with the WC method. For sera containing placental AP, the VITROS values were higher than those with the WC method, while the FUJIDRYCHEM values and the SPOTCHEM values were lower. The VITROS values and the FUJIDRYCHEM values for sera containing intestinal AP were lower than those with the WC method, while the SPOTCHEM values were higher. All of the DCs did not affect high-molecular-mass AP and Ig bound liver/bone AP types of macro AP, but underestimated Ig bound intestinal type. Ig bound intestinal AP may be sieved by DC multilayer elements. PMID:11391954

  8. Active Learning and Cooperative Learning in the Organic Chemistry Lecture Class

    Paulson, Donald R.

    1999-08-01

    Faculty in the physical sciences are one of the academic groups least receptive to the use of active learning strategies and cooperative learning in their classrooms. This is particularly so in traditional lecture classes. It is the objective of this paper to show how effective these techniques can be in improving student performance in classes. The use of active learning strategies and cooperative learning groups in my organic chemistry lecture classes has increased the overall pass rate in my classes by an astounding 20-30% over the traditional lecture mode. This has been accomplished without any reduction in "standards". The actual methods employed are presented as well as a discussion of how I came to radically change the way I teach my classes.

  9. Using Crater Lake chemistry to predict volcanic activity at Poás Volcano, Costa Rica

    Rowe, Gary L.; Ohsawa, Shinji; Takano, Bokuichiro; Brantley, Susan L.; Fernandez, Jose F.; Barquero, Jorge

    1992-08-01

    Monitoring of crater lake chemistry during the recent decline and disappearance of the crater lake of Poás Volcano revealed that large variations in SO4/Cl, F/Cl, and Mg/Cl ratios were caused by the enhanced release of HCl vapor from the lake surface due to increasing lake temperature and solution acidity. Variation in the concentration of polythionic acids (H2SxO6, x=4 6) was the most reliable predictor of renewed phreatic eruptive activity at the volcano, exhibiting sharp decreases three months prior to the initiation of phreatic eruptions in June 1987. Polythionic acids may offer a direct indicator of changing subsurface magmatic activity whereas chloride-based element ratios may be influenced by surface volatilization of HCl and subsequent recycling of acidic fluids in crater lake volcanoes.

  10. Activity of Water Chemistry Division of the Atomic Energy Society of Japan

    A water chemistry group in Japan started in 1982 as a special committee of the Atomic Energy Society of Japan (AESJ). In 2007 the committee has been upgraded as Water Chemistry Division. Current status of the Water Chemistry Division is briefly summarized. (author)

  11. The Importance of Computer Based Active Learning for Basic Chemistry in Vocational High Schools

    Tuğçe GÜNTER

    2011-01-01

    Full Text Available Chemistry is a very comprehensive discipline that researches atoms; molecules; the structure of matter in the form of element or compound; combinations, and physical and chemical properties of matter; macroscopic and microscopic transformations of matters; the energy and entropy released or absorbed in the course of these transformations; the structures and functions of carbohydrates, lipids, proteins, enzymes, vitamins and minerals in the body. This discipline includes numerous reactions at the macroscopic, microscopic and particulate levels, abstract concepts, three-dimensional structure of molecules, mathematics, and graphics. It is important for students to be trained as scientists to internalize -with meaningful learning - chemistry having much abstract concepts. Especially for students in associate degree programs in Vocational High Schools, taking this integrated course will provide them to be more creative in their future professional work; to cope with and overcome analytical problems; to be self-learners; to fill the gaps concerning chemical analysis originated from secondary education; and to gain critical thinking and self-evaluation skills regarding chemical problems. In the age of developing science and technology, “Computer-Based Active Learning Method” emerged with the introduction of multi-media into education and training. In this context, students will learn difficult and complex mathematical operations and graphics interpretations more meaningfully with computer-based simulations and analogies.

  12. Tracing the Physical Conditions in Active Galactic Nuclei with Time-Dependent Chemistry

    Meijerink, Rowin; Kamp, Inga; Aresu, Giambattista; Thi, Wing-Fai; Woitke, Peter

    2013-01-01

    We present an extension of the code ProDiMo that allows for a modeling of processes pertinent to active galactic nuclei and to an ambient chemistry that is time dependent. We present a proof-of-concept and focus on a few astrophysically relevant species, e.g., H+, H2+ and H3+; C+ and N+; C and O; CO and H2O; OH+, H2O+ and H3O+; HCN and HCO+. We find that the freeze-out of water is strongly suppressed and that this affects the bulk of the oxygen and carbon chemistry occurring in AGN. The commonly used AGN tracer HCN/HCO+ is strongly time-dependent, with ratios that vary over orders of magnitude for times longer than 10^4 years. Through ALMA observations this ratio can be used to probe how the narrow-line region evolves under large fluctuations in the SMBH accretion rate. Strong evolutionary trends, on time scales of 10^4-10^8 years, are also found in species such as H3O+, CO, and H2O. These reflect, respectively, time dependent effects in the ionization balance, the transient nature of the production of molecu...

  13. Osteoinductive activity of insulin-functionalized cell culture surfaces obtained using diazonium chemistry

    Mikulska, Anna; Filipowska, Joanna; Osyczka, Anna; Nowakowska, Maria; Szczubiałka, Krzysztof

    2014-12-01

    Polymeric surfaces suitable for cell culture (DR/Pec) were constructed from diazoresin (DR) and pectin (Pec) in a form of ultrathin films using the layer-by-layer (LbL) technique. The surfaces were functionalized with insulin using diazonium chemistry. Such functionalized surfaces were used to culture human mesenchymal stem cells (hMSCs) to assess their suitability for bone tissue engineering and regeneration. The activity of insulin immobilized on the surfaces (DR/Pec/Ins) was compared to that of insulin dissolved in the culture medium. Human MSC grown on insulin-immobilized DR/Pec surfaces displayed increased proliferation and higher osteogenic activity. The latter was determined by means of alkaline phosphatase (ALP) activity, which increases at early stages of osteoblasts differentiation. Insulin dissolved in the culture medium did not stimulate cell proliferation and its osteogenic activity was significantly lower. Addition of recombinant human bone morphogenetic protein 2 (rhBMP-2) to the culture medium further increased ALP activity in hMSCs indicating additive osteogenic action of immobilized insulin and rhBMP-2

  14. Final Report: Main Group Element Chemistry in Service of Hydrogen Storage and Activation

    David A. Dixon; Anthony J. Arduengo, III

    2010-09-30

    goal was met in terms of reducing the number of costly experiments and helping to focus the experimental effort on the potentially optimal targets. We have used computational chemistry approaches to predict the thermodynamic properties of a wide range of compounds containing boron, nitrogen, hydrogen, and other elements as appropriate including carbon. These calculations were done in most cases with high level molecular orbital theory methods that have small error bars on the order of ± 1 to 2 kcal/mol. The results were used to benchmark more approximate methods such as density functional theory for larger systems and for database development. We predicted reliable thermodynamics for thousands of compounds for release and regeneration schemes to aid/guide materials design and process design and simulation. These are the first reliable computed values for these compounds and for many represent the only available values. Overall, the computational results have provided us with new insights into the chemistry of main group and organic-base chemical hydrogen systems from the release of hydrogen to the regeneration of spent fuel. A number of experimental accomplishments were also made in this project. The experimental work on hydrogen storage materials centered on activated polarized σ- or π-bonded frameworks that hold the potential for ready dihydrogen activation, uptake, and eventually release. To this end, a large number of non-traditional valence systems including carbenes, cyanocarbons, and C-B and and B-N systems were synthesized and examined. During the course of these studies an important lead arose from the novel valency of a class of stable organic singlet bi-radical systems. A synthetic strategy to an “endless” hydrogen storage polymer has been developed based on our cyanocarbon chemistry. A key issue with the synthetic efforts was being able to link the kinetics of release with the size of the substituents as it was difficult to develop a low molecular

  15. Quantifying the impact of PWR primary side chemistry regime utilizing surface activity data

    The collection of gamma spectroscopic data, known as gamma scanning in the US, allows for identification and quantification of radionuclides contributing to shutdown dose rates. Based on such data, plants can quantitatively assess the impact of operational and chemistry changes and optimize their source term reduction programs.. To quantify the effect of PWR primary side chemistry on activity incorporation including zinc addition, a simplistic activity balance assessment of Co-58 activity incorporation and release rate constants was developed. Under steady state conditions, the sum of the net release rates of corrosion product radionuclides to the primary coolant from fuel cladding/crud and steam generator tubing and stainless steel surfaces must be equal to the net removal rates from the coolant. Release and re-incorporation of activated corrosion products can occur from each of the referenced primary surfaces, and isotopic (and mass) balances are developed based on the net value of these processes. Net deposition is expected locally in high duty boiling regions, but the reverse is expected in regions where the boiling rate has decreased as fuel burnup occurs during the cycle, i.e., there could be a net release of nickel and iron from such regions. Although transport rates of non-radioactive species such as iron and nickel can be modelled, it is difficult to validate the models since significant transport occurs during shutdowns, surface analysis results are currently only performed after shutdown. However, release of radionuclides from out-of-core surfaces has been shown to be minimal during the shutdown evolution; and non-destructive surface analyses performed following shutdown can be used to reasonably approximate surface activity during power operation prior to the shutdown. From these measurements, net deposition or release rates from out-of-core surfaces and the core during power operation can be estimated. The observed reductions in RCS piping surface

  16. Main Group Element Chemistry in Service of Hydrogen Storage and Activation. Final report

    goal was met in terms of reducing the number of costly experiments and helping to focus the experimental effort on the potentially optimal targets. We have used computational chemistry approaches to predict the thermodynamic properties of a wide range of compounds containing boron, nitrogen, hydrogen, and other elements as appropriate including carbon. These calculations were done in most cases with high level molecular orbital theory methods that have small error bars on the order of ± 1 to 2 kcal/mol. The results were used to benchmark more approximate methods such as density functional theory for larger systems and for database development. We predicted reliable thermodynamics for thousands of compounds for release and regeneration schemes to aid/guide materials design and process design and simulation. These are the first reliable computed values for these compounds and for many represent the only available values. Overall, the computational results have provided us with new insights into the chemistry of main group and organic-base chemical hydrogen systems from the release of hydrogen to the regeneration of spent fuel. A number of experimental accomplishments were also made in this project. The experimental work on hydrogen storage materials centered on activated polarized σ- or π-bonded frameworks that hold the potential for ready dihydrogen activation, uptake, and eventually release. To this end, a large number of non-traditional valence systems including carbenes, cyanocarbons, and C-B and and B-N systems were synthesized and examined. During the course of these studies an important lead arose from the novel valency of a class of stable organic singlet bi-radical systems. A synthetic strategy to an 'endless' hydrogen storage polymer has been developed based on our cyanocarbon chemistry. A key issue with the synthetic efforts was being able to link the kinetics of release with the size of the substituents as it was difficult to develop a low molecular weight

  17. Annual report 1988 Chemistry Department

    This report contains a brief survey of the main activities in the Chemistry Department. The names and abstracts of all articles and reports published and lectures given in 1988 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, chemical reactivity, mineral processing, and general. (author)

  18. Annual report 1986 chemistry department

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1986 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, radical chemistral, mineral processing, and general. (author)

  19. Annual report 1989 Chemistry Department

    This report contains a brief survey of the main activities in the Chemistry Department. The names and abstracts of all articles and reports published and lectures given in 1989 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, chemical reactivity, mineral processing, and general. (author)

  20. Understanding the chemistry behind the antioxidant activities of butylated hydroxytoluene (BHT): a review.

    Yehye, Wageeh A; Rahman, Noorsaadah Abdul; Ariffin, Azhar; Abd Hamid, Sharifah Bee; Alhadi, Abeer A; Kadir, Farkaad A; Yaeghoobi, Marzieh

    2015-08-28

    Hindered phenols find a wide variety of applications across many different industry sectors. Butylated hydroxytoluene (BHT) is a most commonly used antioxidant recognized as safe for use in foods containing fats, pharmaceuticals, petroleum products, rubber and oil industries. In the past two decades, there has been growing interest in finding novel antioxidants to meet the requirements of these industries. To accelerate the antioxidant discovery process, researchers have designed and synthesized a series of BHT derivatives targeting to improve its antioxidant properties to be having a wide range of antioxidant activities markedly enhanced radical scavenging ability and other physical properties. Accordingly, some structure-activity relationships and rational design strategies for antioxidants based on BHT structure have been suggested and applied in practice. We have identified 14 very sensitive parameters, which may play a major role on the antioxidant performance of BHT. In this review, we attempt to summarize the current knowledge on this topic, which is of significance in selecting and designing novel antioxidants using a well-known antioxidant BHT as a building-block molecule. Our strategy involved investigation on understanding the chemistry behind the antioxidant activities of BHT, whether through hydrogen or electron transfer mechanism to enable promising anti-oxidant candidates to be synthesized. PMID:26150290

  1. High pressure chemistry of red phosphorus by photo-activated simple molecules

    Ceppatelli, M.; Fanetti, S.; Bini, R.; Caporali, M.; Peruzzini, M.

    2014-05-01

    High pressure (HP) is very effective in reducing intermolecular distances and inducing unexpected chemical reactions. In addition the photo-activation of the reactants in HP conditions can lead to very efficient and selective processes. The chemistry of phosphorus is currently based on the white molecular form. The red polymeric allotrope, despite more stable and much less toxic, has not attracted much attention so far. However, switching from the white to the red form would benefit any industrial procedure, especially from an environmental point of view. On the other side, water and ethanol are renewable, environmental friendly and largely available molecules, usable as reactants and photo-activators in HP conditions. Here we report a study on the HP photo-induced reactivity of red phosphorus with water and ethanol, showing the possibility of very efficient and selective processes, leading to molecular hydrogen and valuable phosphorus compounds. The reactions have been studied by means of FTIR and Raman spectroscopy and pressure has been generated using membrane Diamond (DAC) and Sapphire (SAC) anvil cells. HP reactivity has been activated by the two-photon absorption of near-UV wavelengths and occurred in total absence of solvents, catalysts and radical initiators, at room T and mild pressure conditions (0.2-1.5 GPa).

  2. Synthesis and amylin receptor activity of glycomimetics of pramlintide using click chemistry.

    Yule, Lauren R; Bower, Rebekah L; Kaur, Harveen; Kowalczyk, Renata; Hay, Debbie L; Brimble, Margaret A

    2016-06-21

    Pramlintide (Symlin®), a synthetic analogue of the neuroendocrine hormone amylin, is devoid of the tendency to form cytotoxic amyloid fibrils and is currently used in patients with type I and type II diabetes mellitus as an adjunctive therapy with insulin or insulin analogues. As part of an on-going search for a pramlintide analogue with improved pharmacokinetic properties, we herein report the synthesis of mono- and di-glycosylated analogues of pramlintide and their activity at the AMY1(a) receptor. Introduction of N-glycosylated amino acids into the pramlintide sequence afforded the native N-linked glycomimetics whilst use of Cu(i)-catalysed azide-alkyne 1,3-dipolar cycloaddition (click) chemistry delivered 1,2,3-triazole linked glycomimetics. AMY1(a) receptor activity was retained by incorporation of single or multiple GlcNAc moieties at positions 21 and 35 of native pramlintide. Importantly, no difference in AMY1(a) activity was observed between native N-linked glycomimetics and 1,2,3-triazole linked glycomimetics demonstrating that the click variants can act as surrogates for the native N-glycosides in a biological setting. PMID:27139251

  3. High pressure chemistry of red phosphorus by photo-activated simple molecules

    High pressure (HP) is very effective in reducing intermolecular distances and inducing unexpected chemical reactions. In addition the photo-activation of the reactants in HP conditions can lead to very efficient and selective processes. The chemistry of phosphorus is currently based on the white molecular form. The red polymeric allotrope, despite more stable and much less toxic, has not attracted much attention so far. However, switching from the white to the red form would benefit any industrial procedure, especially from an environmental point of view. On the other side, water and ethanol are renewable, environmental friendly and largely available molecules, usable as reactants and photo-activators in HP conditions. Here we report a study on the HP photo-induced reactivity of red phosphorus with water and ethanol, showing the possibility of very efficient and selective processes, leading to molecular hydrogen and valuable phosphorus compounds. The reactions have been studied by means of FTIR and Raman spectroscopy and pressure has been generated using membrane Diamond (DAC) and Sapphire (SAC) anvil cells. HP reactivity has been activated by the two-photon absorption of near-UV wavelengths and occurred in total absence of solvents, catalysts and radical initiators, at room T and mild pressure conditions (0.2–1.5 GPa).

  4. Active chemistry control for coolant helium applying high-temperature gas-cooled reactors - HTR2008-58096

    Lifetime extension of high-temperature equipment such as the intermediate heat exchanger of high-temperature gas-cooled reactors (HTGRs) is important from the economical point of view. Since the replacing cost will cause the increasing of the running cost, it is important to reduce replacing times of the high-cost primary equipment during assumed reactor lifetime. In the past, helium chemistry has been controlled by the passive chemistry control technology in which chemical impurity in the coolant helium is removed as low concentration as possible, as does Japan's HTTR. Although the lifetime of high- temperature equipment almost depends upon the chemistry conditions in the coolant helium, it is necessary to establish an active chemistry control technology to maintain adequate chemical conditions. In this study, carbon deposition which could occur at the surface of the heat transfer tubes of the intermediate heat exchanger and decarburization of the high-temperature material of Hastelloy XR used at the heat transfer tubes were evaluated by referring the actual chemistry data obtained by the HTTR. The chemical equilibrium study contributed to clarify the algorism of the chemistry behaviours to be controlled. The created algorism is planned to be added to the instrumentation system of the helium purification systems. In addition, the chemical composition to be maintained during the reactor operation was proposed by evaluating not only core graphite oxidation but also carbon deposition and decarburization. It was identified when the chemical composition could not keep adequately, injection of 10 ppm carbon monoxide could effectively control the chemical composition to the designated stable area where the high-temperature materials could keep their structural integrity beyond the assumed duration. The proposed active chemistry control technology is expected to contribute economically to the purification systems of the future very high-temperature reactors. (authors)

  5. Teaching with the Case Study Method to Promote Active Learning in a Small Molecule Crystallography Course for Chemistry Students

    Campbell, Michael G.; Powers, Tamara M.; Zheng, Shao-Liang

    2016-01-01

    Implementing the case study method in a practical X-ray crystallography course designed for graduate or upper-level undergraduate chemistry students is described. Compared with a traditional lecture format, assigning small groups of students to examine literature case studies encourages more active engagement with the course material and…

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

    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…

  7. Temperature and substrate chemistry as major drivers of interregional variability of leaf microbial decomposition and cellulolytic activity in headwater streams.

    Fenoy, Encarnación; Casas, J Jesús; Díaz-López, Manuel; Rubio, Juan; Guil-Guerrero, J Luís; Moyano-López, Francisco J

    2016-11-01

    Abiotic factors, substrate chemistry and decomposers community composition are primary drivers of leaf litter decomposition. In soil, much of the variation in litter decomposition is explained by climate and substrate chemistry, but with a significant contribution of the specialisation of decomposer communities to degrade specific substrates (home-field advantage, HFA). In streams, however, HFA effects on litter decomposition have not been explicitly tested. We evaluated responses of microbial decomposition and β-glucosidase activity to abiotic factors, substrate and decomposer assemblages, using a reciprocal litter transplant experiment: 'ecosystem type' (mountain vs lowland streams) × 'litter chemistry' (alder vs reed). Temperature, pH and ionic concentration were higher in lowland streams. Decomposition for both species was faster in lowland streams. Decomposition of reed was more accelerated in lowland compared with mountain streams than that of alder, suggesting higher temperature sensitivity of decomposition in reed. Q10 (5°C-15°C) values of β-glucosidase activity were over 2. The alkaline pH and high ionic concentration of lowland streams depleted enzyme activity. We found similar relationships of decomposition or enzyme activity with abiotic factors for both species, suggesting limited support to the HFA hypothesis. Overall, our results suggest a prime role of temperature interacting with substrate chemistry on litter decomposition. PMID:27515735

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

    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…

  9. Tracing footprints of environmental events in tree ring chemistry using neutron activation analysis

    Sahin, Dagistan

    The aim of this study is to identify environmental effects on tree-ring chemistry. It is known that industrial pollution, volcanic eruptions, dust storms, acid rain and similar events can cause substantial changes in soil chemistry. Establishing whether a particular group of trees is sensitive to these changes in soil environment and registers them in the elemental chemistry of contemporary growth rings is the over-riding goal of any Dendrochemistry research. In this study, elemental concentrations were measured in tree-ring samples of absolutely dated eleven modern forest trees, grown in the Mediterranean region, Turkey, collected and dated by the Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology laboratory at Cornell University. Correlations between measured elemental concentrations in the tree-ring samples were analyzed using statistical tests to answer two questions. Does the current concentration of a particular element depend on any other element within the tree? And, are there any elements showing correlated abnormal concentration changes across the majority of the trees? Based on the detailed analysis results, the low mobility of sodium and bromine, positive correlations between calcium, zinc and manganese, positive correlations between trace elements lanthanum, samarium, antimony, and gold within tree-rings were recognized. Moreover, zinc, lanthanum, samarium and bromine showed strong, positive correlations among the trees and were identified as possible environmental signature elements. New Dendrochemistry information found in this study would be also useful in explaining tree physiology and elemental chemistry in Pinus nigra species grown in Turkey. Elemental concentrations in tree-ring samples were measured using Neutron Activation Analysis (NAA) at the Pennsylvania State University Radiation Science and Engineering Center (RSEC). Through this study, advanced methodologies for methodological, computational and

  10. Radiation chemistry of some novel antioxidants from turmeric and other natural products: physico-chemistry properties and antioxidant activities

    Using pulse radiolysis the free radical reactions of the structurally related phenols were studied with biologically relevant oxidants both in aqueous-organic solutions and neutral surfactant solutions. The resulting phenoxyl radicals were characterised by their lifetimes, absorption spectra, one-electron reduction potential and reaction with other antioxidants. The physicochemical properties of the phenoxyl radicals were compared with the antioxidant activities of these compounds

  11. Annual Report 1984. Chemistry Department

    Funck, Jytte; Nielsen, Ole John

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, an......, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general.......This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry...

  12. Bisphenol A removal from water by activated carbon. Effects of carbon characteristics and solution chemistry.

    Bautista-Toledo, I; Ferro-García, M A; Rivera-Utrilla, J; Moreno-Castilla, C; Vegas Fernández, F J

    2005-08-15

    The present study aimed to analyze the behavior of different activated carbons in the adsorption and removal of bisphenol A (2-2-bis-4-hydroxypheniyl propane) from aqueous solutions in order to identify the parameters that determine this process. Two commercial activated carbons and one prepared in our laboratory from almond shells were used; they were texturally and chemically characterized, obtaining the surface area, pore size distribution, mineral matter content, elemental analysis, oxygen surface groups, and pH of the point of zero charge (pH(PZC)), among other parameters. Adsorption isotherms of bisphenol A and adsorption capacities were obtained. The capacity of the carbons to remove bisphenol A was related to their characteristics. Thus, the adsorption of bisphenol A on activated carbon fundamentally depends on the chemical nature of the carbon surface and the pH of the solution. The most favorable experimental conditions for this process are those in which the net charge density of the carbon is zero and the bisphenol A is in molecular form. Under these conditions, the adsorbent-adsorbate interactions that govern the adsorption mechanism are enhanced. Influences of the mineral matter present in the carbon samples and the solution chemistry (pH and ionic strength) were also analyzed. The presence of mineral matter in carbons reduces their adsorption capacity because of the hydrophilic nature of the matter. The presence of electrolytes in the solution favor the adsorption process because of the screening effect produced between the positively charged carbon surface and the bisphenol A molecules, with a resulting increase in adsorbent-adsorbate interactions. PMID:16173588

  13. Hot-electron-mediated surface chemistry: toward electronic control of catalytic activity.

    Park, Jeong Young; Kim, Sun Mi; Lee, Hyosun; Nedrygailov, Ievgen I

    2015-08-18

    Energy dissipation at surfaces and interfaces is mediated by excitation of elementary processes, including phonons and electronic excitation, once external energy is deposited to the surface during exothermic chemical processes. Nonadiabatic electronic excitation in exothermic catalytic reactions results in the flow of energetic electrons with an energy of 1-3 eV when chemical energy is converted to electron flow on a short (femtosecond) time scale before atomic vibration adiabatically dissipates the energy (in picoseconds). These energetic electrons that are not in thermal equilibrium with the metal atoms are called "hot electrons". The detection of hot electron flow under atomic or molecular processes and understanding its role in chemical reactions have been major topics in surface chemistry. Recent studies have demonstrated electronic excitation produced during atomic or molecular processes on surfaces, and the influence of hot electrons on atomic and molecular processes. We outline research efforts aimed at identification of the intrinsic relation between the flow of hot electrons and catalytic reactions. We show various strategies for detection and use of hot electrons generated by the energy dissipation processes in surface chemical reactions and photon absorption. A Schottky barrier localized at the metal-oxide interface of either catalytic nanodiodes or hybrid nanocatalysts allows hot electrons to irreversibly transport through the interface. We show that the chemicurrent, composed of hot electrons excited by the surface reaction of CO oxidation or hydrogen oxidation, correlates well with the turnover rate measured separately by gas chromatography. Furthermore, we show that hot electron flows generated on a gold thin film by photon absorption (or internal photoemission) can be amplified by localized surface plasmon resonance. The influence of hot charge carriers on the chemistry at the metal-oxide interface are discussed for the cases of Au, Ag, and Pt

  14. Annual report 1987 Chemistry Department

    This report contains a brief survey of the main activities in the Chemistry Department. The names and abstracts of all articles and reports published and lectures given in 1987 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, radical chemistry, mineral processing, and general. 13 ills., (author)

  15. Annual report 1982 chemistry department

    The work going on in the Risoe National Laboratory, Chemistry Department is briefly surveyed by a presentation of all articles and reports published in 1982. The facilities and equipment are barely mentioned. The papers are divided into eight activities: 1. neutron activation analysis 2. analytical- and organic chemistry 3. environmental chemistry 4. polymer chemistry 5. geochemistry 6. radical chemistry 7. poitron annihilation 8. uranium process chemistry. (author)

  16. Identification of the biologically active liquid chemistry induced by a nonthermal atmospheric pressure plasma jet.

    Wende, Kristian; Williams, Paul; Dalluge, Joe; Gaens, Wouter Van; Aboubakr, Hamada; Bischof, John; von Woedtke, Thomas; Goyal, Sagar M; Weltmann, Klaus-Dieter; Bogaerts, Annemie; Masur, Kai; Bruggeman, Peter J

    2015-01-01

    The mechanism of interaction of cold nonequilibrium plasma jets with mammalian cells in physiologic liquid is reported. The major biological active species produced by an argon RF plasma jet responsible for cell viability reduction are analyzed by experimental results obtained through physical, biological, and chemical diagnostics. This is complemented with chemical kinetics modeling of the plasma source to assess the dominant reactive gas phase species. Different plasma chemistries are obtained by changing the feed gas composition of the cold argon based RF plasma jet from argon, humidified argon (0.27%), to argon/oxygen (1%) and argon/air (1%) at constant power. A minimal consensus physiologic liquid was used, providing isotonic and isohydric conditions and nutrients but is devoid of scavengers or serum constituents. While argon and humidified argon plasma led to the creation of hydrogen peroxide dominated action on the mammalian cells, argon-oxygen and argon-air plasma created a very different biological action and was characterized by trace amounts of hydrogen peroxide only. In particular, for the argon-oxygen (1%), the authors observed a strong negative effect on mammalian cell proliferation and metabolism. This effect was distance dependent and showed a half life time of 30 min in a scavenger free physiologic buffer. Neither catalase and mannitol nor superoxide dismutase could rescue the cell proliferation rate. The strong distance dependency of the effect as well as the low water solubility rules out a major role for ozone and singlet oxygen but suggests a dominant role of atomic oxygen. Experimental results suggest that O reacts with chloride, yielding Cl2(-) or ClO(-). These chlorine species have a limited lifetime under physiologic conditions and therefore show a strong time dependent biological activity. The outcomes are compared with an argon MHz plasma jet (kinpen) to assess the differences between these (at least seemingly) similar plasma sources

  17. Organic chemistry

    The activities of the mycotoxin research group are discussed. This includes the isolation and structure determination of mycotoxins, plant products, the biosyntheris of mycotoxins, the synthesis and characteristics of steroids, the synthesis and mechanistic aspects of heterocyclic chemistry and the functionality of steroids over long distances. Nmr spectra and mass spectroscopy are some of the techniques used

  18. An Active-Learning Assignment Requiring Pharmacy Students to Write Medicinal Chemistry Examination Questions

    Kolluru, Srikanth

    2012-01-01

    Objectives. To implement and assess the effectiveness of an assignment requiring doctor of pharmacy (PharmD) students to write examination questions for the medicinal chemistry sections of a pharmacotherapeutics course.

  19. Organization of a cognitive activity of students when teaching analytical chemistry

    А. Tapalova; O. Suleimenova

    2012-01-01

    Qualitative analysis allows using basic knowledge of general and inorganic chemistry for the solution of practical problems, disclosure the chemism of the processes that are fundamental for  the methods of analysis. Systematic qualitative analysis develops analytical thinking, establishes a scientific style of thinking of students.Сhemical analysis requires certain skills and abilities and develops the general chemical culture of the future teachers оn chemistry. The result can be evaluated i...

  20. Wave activity in the tropical tropopause layer in seven reanalysis and four chemistry climate model data sets

    Fujiwara, M.; Suzuki, J; Gettelman, A.; Hegglin, Michaela I.; H. Akiyoshi; Shibata, K

    2012-01-01

    Sub-seasonal variability including equatorial waves significantly influence the dehydration and transport processes in the tropical tropopause layer (TTL). This study investigates the wave activity in the TTL in 7 reanalysis data sets (RAs; NCEP1, NCEP2, ERA40, ERA-Interim, JRA25, MERRA, and CFSR) and 4 chemistry climate models (CCMs; CCSRNIES, CMAM, MRI, and WACCM) using the zonal wave number-frequency spectral analysis method with equatorially symmetric-antisymmetric decomposition. Analyses...

  1. "Green chemistry": os 12 princípios da química verde e sua inserção nas atividades de ensino e pesquisa Green chemistry: the 12 principles of green chemistry and it insertion in the teach and research activities

    Eder João Lenardão

    2003-01-01

    Full Text Available Green chemistry ¾ defined as the design, development, and application of chemical processes and products to reduce or eliminate the use and generation of substances hazardous to human health and the environment. This article summarizes the 12 principles of green chemistry, describing how they have been applied to the academic, industrial and research activities around the world.

  2. "Green chemistry": os 12 princípios da química verde e sua inserção nas atividades de ensino e pesquisa Green chemistry: the 12 principles of green chemistry and it insertion in the teach and research activities

    Eder João Lenardão; Rogério Antônio Freitag; Miguel J. Dabdoub; Antônio C. Ferreira Batista; Claudio da Cruz Silveira

    2003-01-01

    Green chemistry ¾ defined as the design, development, and application of chemical processes and products to reduce or eliminate the use and generation of substances hazardous to human health and the environment. This article summarizes the 12 principles of green chemistry, describing how they have been applied to the academic, industrial and research activities around the world.

  3. porewater chemistry experiment at Mont Terri rock laboratory. Reactive transport modelling including bacterial activity

    Document available in extended abstract form only. An in-situ test in the Opalinus Clay formation, termed pore water Chemistry (PC) experiment, was run for a period of five years. It was based on the concept of diffusive equilibration whereby traced water with a composition close to that expected in the formation was continuously circulated and monitored in a packed off borehole. The main original focus was to obtain reliable data on the pH/pCO2 of the pore water, but because of unexpected microbially- induced redox reactions, the objective was then changed to elucidate the biogeochemical processes happening in the borehole and to understand their impact on pH/pCO2 and pH in the low permeability clay formation. The biologically perturbed chemical evolution of the PC experiment was simulated with reactive transport models. The aim of this modelling exercise was to develop a 'minimal-' model able to reproduce the chemical evolution of the PC experiment, i.e. the chemical evolution of solute inorganic and organic compounds (organic carbon, dissolved inorganic carbon etc...) that are coupled with each other through the simultaneous occurrence of biological transformation of solute or solid compounds, in-diffusion and out-diffusion of solute species and precipitation/dissolution of minerals (in the borehole and in the formation). An accurate description of the initial chemical conditions in the surrounding formation together with simplified kinetics rule mimicking the different phases of bacterial activities allowed reproducing the evolution of all main measured parameters (e.g. pH, TOC). Analyses from the overcoring and these simulations evidence the high buffer capacity of Opalinus clay regarding chemical perturbations due to bacterial activity. This pH buffering capacity is mainly attributed to the carbonate system as well as to the clay surfaces reactivity. Glycerol leaching from the pH-electrode might be the primary organic source responsible for

  4. Organization of a cognitive activity of students when teaching analytical chemistry

    А. Tapalova

    2012-12-01

    Full Text Available Qualitative analysis allows using basic knowledge of general and inorganic chemistry for the solution of practical problems, disclosure the chemism of the processes that are fundamental for  the methods of analysis. Systematic qualitative analysis develops analytical thinking, establishes a scientific style of thinking of students.Сhemical analysis requires certain skills and abilities and develops the general chemical culture of the future teachers оn chemistry. The result can be evaluated in the course of self-control, peer review, and solving creative problems. Mastering the techniques of critical thinking (comparison, abstraction, generalization and their use in a particular chemical material - are necessary element in the formation of professional thinking of the future chemistry teacher.

  5. 64Cu Core-labeled Nanoparticles with High Specific Activity via Metal-Free Click Chemistry

    Zeng, Dexing; Lee, Nam S.; Liu, Yongjian; Zhou, Dong; Dence, Carmen S.; Wooley, Karen L.; Katzenellenbogen, John A.; Welch, Michael J.

    2012-01-01

    A novel strategy based on metal-free click chemistry was developed for the copper-64 radiolabeling of the core in shell-crosslinked nanoparticles (SCK-NPs). Compared with Cu(I)-catalyzed click chemistry, this metal-free strategy provides the following advantages for Cu-64 labeling of the core of SCK-NPs: (1) elimination of copper exchange between non-radioactive Cu in the catalyst and DOTA-chelated Cu-64; (2) elimination of the internal “click” reactions between the azide and acetylene groups...

  6. Derivatization chemistry of the double-decker dicobalt sandwich ion targeted to design biologically active substances

    Grüner, Bohumír; Švec, Petr; Hájková, Zuzana; Císařová, I.; Pokorná, Jana; Konvalinka, Jan

    2012-01-01

    Roč. 84, č. 11 (2012), s. 2243-2262. ISSN 0033-4545 R&D Projects: GA AV ČR IAAX00320901 Institutional support: RVO:61388980 ; RVO:61388963 Keywords : AIDS treatment * boranes * canastide ion * carboranes * dicarbollides * HIV -protease Subject RIV: CA - Inorganic Chemistry Impact factor: 3.386, year: 2012

  7. Supramolecular chemistry based on redox-active components and cucurbit[n]urils

    Andersson, Samir

    2010-01-01

    This thesis describes the host-guest chemistry between Cucurbit[7]uril (CB[7]) and CB[8] and a series of guests including bispyridinium cations, phenols and  napthalenes. These guests are bound to ruthenium polypyridine complexes or ruthenium based water oxidation catalysts (WOCs). The investigations are based upon utilizing the covalently linked photosensitizer and the electronic effects and chemical processes are investigated.

  8. "Chemistry Is in the News": Taxonomy of Authentic News Media-Based Learning Activities. Research Report

    Glaser, Rainer E.; Carson, Kathleen M.

    2005-01-01

    A brief history is given of approaches that aim at achieving a connectedness of the content of organic chemistry courses to real world issues. Recently, such approaches have relied more and more on online media resources, the tools of the Internet and the World Wide Web. We propose a six-level taxonomy of 'authentic news media-based learning…

  9. Island Explorations: Discovering Effects of Environmental Research-Based Lab Activities on Analytical Chemistry Students

    Tomasik, Janice Hall; LeCaptain, Dale; Murphy, Sarah; Martin, Mary; Knight, Rachel M.; Harke, Maureen A.; Burke, Ryan; Beck, Kara; Acevedo-Polakovich, I. David

    2014-01-01

    Motivating students in analytical chemistry can be challenging, in part because of the complexity and breadth of topics involved. Some methods that help encourage students and convey real-world relevancy of the material include incorporating environmental issues, research-based lab experiments, and service learning projects. In this paper, we…

  10. "JCE" Classroom Activity #110: Artistic Anthocyanins and Acid-Base Chemistry

    Lech, Jenna; Dounin, Vladimir

    2011-01-01

    Art and science are sometimes viewed as opposing subjects, but are united in many ways. With an increased awareness of the benefits of interdisciplinary studies in education, it is desirable to show students how different subjects impact one another. Visual arts are greatly connected to chemistry in several ways. Pigments are usually synthetically…

  11. Annual report 1983 Chemistry Department

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1983 are presented. The facilities and equipment are barely mentioned. The activities are divided into nine groups: 1. radioisotope chemistry 2. analytical- and organic chemistry 3. environmental chemistry 4. polymer chemistry 5. geochemistry and waste disposal 6. radical chemstry 7. positron annihilation 8. mineral processing 9. general. (author)

  12. Roles and chemical processes in preschool : A study of preschool teacher´s perception of roles within activities in the subject chemistry

    Klingberg, Linnéa

    2015-01-01

    The purpose of this study was to examine preschool teachers’ thoughts on roles within activities in the subject chemistry. The main focus has been their perceptions of their own and the children´s roles when planning and executing activities within the subject chemistry.   The method used to execute the study was semi-structured interviews, and all respondents have been certified preschool teachers. When analyzing the material I have used a constructivist perspective.   The study shows that t...

  13. Progress report on research and development activities. Annual report 1992 of the Institute of Hot Chemistry

    The point of main interest of the new R and D programme of the Institute of Hot Chemistry is: - Development of methods for the annihilaton of resistant chemical pollutants, especially of organohalogen compounds. The preliminary phase of orientation having been completed with the definition of research tasks in the course of the year 1992, the institute started R and D work for the given tasks within the scope of the PSA project, one of this year's major items being the application of chemical reactions in supercritical media as a basic process engineering approach, primarily for reactions in supercritical water. The studies into the formation and decomposition of organic pollutants in effluents of waste incineration plants have been continued. Other successful tasks continued in the period under review are basic research into the chemistry of the 4f and 5f elements and the solar neutrino measurement in the Gran Sasso underground laboratory within the framework of the international GALLEX project. (orig./BBR)

  14. Chemistry of zerumbone. 2. Regulation of ring bond cleavage and unique antibacterial activities of zerumbone derivatives.

    Kitayama, T; Yamamoto, K; Utsumi, R; Takatani, M; Hill, R K; Kawai, Y; Sawada, S; Okamoto, T

    2001-10-01

    Further investigation of the chemistry of the eleven-membered cyclic sesquiterpene, zerumbone, the major component of the wild ginger, Zingiber zerumbet Smith, has revealed a new selective epoxidation process, a further example of a novel Favorskii-initiated double ring contraction, and a regiospecific fragmentation of zerumbone dibromide derivatives. Several zerumbone derivatives were found to be selective inhibitors of the growth of gram-positive bacteria. PMID:11758909

  15. Distribution of Naturally Occurring Anthraquinones, Iridoids and Flavonoids from Morinda genus: Chemistry and Biological activity

    Phakhodee, Wong

    2012-01-01

    The present review covers chemistry and bioactivities of anthraquinones, iridoids, and flavonoids from the Morinda genus. The plants of Morinda species, belonging to the Rubiaceae family, have been used as traditional folk medicine with anti-bacterial, anti-fungal, anti-tumor, anti-helmin, analgesic, anti-inflammatory, and immune enhancing effects. They are rich sources of anthraquinones and iridoids. The relevant 2-methoxy-1,3,6-trihydroxyanthraquinone is one of the most potent quinone reduc...

  16. Liaison activities with the Institute of Physical Chemistry/Russian Academy of Science Fiscal Year 1995

    Investigations into the chemistry of alkaline Hanford Site tank waste (TTP RL4-3-20-04) were conducted in Fiscal Year 1995 at Westinghouse Hanford Company under the support of the Efficient Separations and Processing Crosscutting Program (EM-53). The investigation had two main subtasks: liaison with the Institute of Physical Chemistry of the Russian Academy of Science and further laboratory testing of the chemistry of thermal reconstitution of Hanford Site tank waste. Progress, which was achieved in the liaison subtask during Fiscal Year 1995, is summarized as follows: (1) A technical dialogue has been established with Institute scientists. (2) Editing was done on a technical literature review on the chemistry of transuranic elements and technetium in alkaline media written by researchers at the Institute. The report was issued in May 1995 as a Westinghouse Hanford Company document. (3) Four tasks from the Institute were selected for support by the U.S. Department of Energy. Work on three tasks commenced on 1 March 1995; the fourth task commenced on 1 April 1995. (4) Technical information describing the composition of Hanford Site tank waste was supplied to the Institute. (5) A program review of the four tasks was conducted at the Institute during a visit 25 August to 1 September, 1995. A lecture on the origin, composition, and proposed treatment of Hanford Site tank wastes was presented during this visit. Eight additional tasks were proposed by Institute scientists for support in Fiscal Year 1996. (6) A paper was presented at the Fifth International Conference on Radioactive Waste Management and Environmental Remediation (ICEM'95) in Berlin, Germany on 3 to 9 September, 1995 on the solubility of actinides in alkaline media

  17. Bad chemistry

    Petsko, Gregory A

    2004-01-01

    General chemistry courses haven't changed significantly in forty years. Because most basic chemistry students are premedical students, medical schools have enormous influence and could help us start all over again to create undergraduate chemistry education that works.

  18. The design of a bipodal bis(pentafluorophenoxy)aluminate supported on silica as an activator for ethylene polymerization using surface organometallic chemistry.

    Sauter, Dominique W; Popoff, Nicolas; Bashir, Muhammad Ahsan; Szeto, Kai C; Gauvin, Régis M; Delevoye, Laurent; Taoufik, Mostafa; Boisson, Christophe

    2016-04-01

    A new class of well-defined activating supports for olefin polymerization was obtained via the surface organometallic chemistry approach. High activities in slurry polymerization of ethylene along with industrial-grade physical properties of the resulting polyethylene were obtained when these activators were combined with metallocene complexes in the presence of triisobutylaluminium. PMID:26899986

  19. [Effect of macro-creatine kinase in serum on dry chemistry methods results for total creatine kinase activity].

    Tozawa, T; Hashimoto, M

    1999-02-01

    Most enzymes in serum that are measured in clinical laboratories can occur in macro-molecular forms in a significantly number of patients. Within dry chemistry (DC) multilayer film, physical barriers may prevent contact macro-molecular enzyme forms with the active reagent ingredients. Here, serum samples with macro-creatine kinase (macro-CK) type 1: CK-immunoglobulin complex or type 2: oligomer mitochondrial CK (CKm) were analyzed for total CK activity on three different DC analyzers: VITROS 700XR, FUJIDRYCHEM 5000, SPOTCHEM SP4410 and a classic wet chemistry (WC) analyzer: HITACHI 7350. Macro-CKs were detected and identified by electrophoresis on cellulose acetate. Serum with high amounts of oligomer CKm gave CK values by all of DC methods significantly lower than that by the WC method (p < 0.05). Oligomer CKm gradually converts into monomer forms in serum after storage. With increase in day after storage at 4 degrees C, there was a gradual shift in which percent of total CK activity for oligomer CKm decreased while the ratio of total CK activity, DC method/WC method increased. The principle of analytical method for CK activity determination is commonly to all of the DC methods, the WC method and the electrophoretic analysis. These suggest that oligomer CKm is sieved by DC multilayer film elements. In contrast, each of DC method produced highly corrected CK activities for sample containing CK-immunoglobulin complex. This difference in the effects of macro-CKs may depend upon physicochemical characteristics of analytical DC elements. PMID:10097631

  20. Mathematical problems for chemistry students

    Pota, Gyorgy

    2006-01-01

    Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistry students in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialists of the chemistry-related fields (physicists, mathematicians, biologists, etc.) into the world of the chemical applications. Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, other

  1. Effects of probiotic supplementation over 5 months on routine haematology and clinical chemistry measures in healthy active adults.

    Cox, A J; West, N P; Horn, P L; Lehtinen, M J; Koerbin, G; Pyne, D B; Lahtinen, S J; Fricker, P A; Cripps, A W

    2014-11-01

    Use of probiotic-containing foods and probiotic supplements is increasing; however, few studies document safety and tolerability in conjunction with defined clinical end points. This paper reports the effects of 150 days of supplementation with either a single- (Bifidobacterium animalis subsp. lactis Bl-04) or a double-strain (Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bi-07) probiotic on routine haematology and clinical chemistry measures in healthy active adults. Pre- to post-intervention changes in laboratory measures were determined and compared between supplement and placebo groups. Overall there were few differences in routine haematology and clinical chemistry measures between supplement and placebo groups post-intervention. Exceptions included plasma calcium (P=0.03) and urea (P=0.015); however, observed changes were small and within assay-specific laboratory reference ranges. These data provide evidence supporting the use of these probiotic supplements over a period of 5 months in healthy active adults without obvious safety or tolerability issues. PMID:25052229

  2. Effects of lead shot ingestion on delta-aminolevulinic acid dehydratase activity, hemoglobin concentration, and serum chemistry in bald eagles

    Hoffman, D.J.; Pattee, O.H.; Wiemeyer, Stanley N.; Mulhern, B.

    1981-01-01

    Lead shot ingestion by bald eagles (Haliaeetus leucocephalus) is considered to be widespread and has been implicated in the death of eagles in nature. It was recently demonstrated under experimental conditions that ingestion of as few as 10 lead shot resulted in death within 12 to 20 days. In the present study hematological responses to lead toxicity including red blood cell ALAD activity, hemoglobin concentration and 23 different blood serum chemistries were examined in five captive bald eagles that were unsuitable for rehabilitation and release. Eagles were dosed by force-feeding with 10 lead shot; they were redosed if regurgitation occurred. Red blood cell ALAD activity was inhibited by nearly 80% within 24 hours when mean blood lead concentration had increased to 0.8 parts per million (ppm). By the end of 1 week there was a significant decrease (20-25%) in hematocrit and hemoglobin, and the mean blood lead concentration was over 3 ppm. Within as little as 1-2 weeks after dosing, significant elevations in serum creatinine and serum alanine aminotransferase occurred, as well as a significant decrease in the ratio of serum aspartic aminotransferase to serum alanine aminotransferase. The mean blood lead concentration was over 5 ppm by the end of 2 weeks. These changes in serum chemistry may be indicative of kidney and liver alterations.

  3. HMI Department of Radiation Chemistry: Results of scientific activities in 1984

    In the radiation chemistry department of the Hahn-Meitner-Institute in Berlin, 4 subjects are treated largely the progress of which made in 1984 is herein reported: 1) Interface processes and energy conversion (reaction pathways of photoinduced charge carriers and their in energy conversion mechanisms); 2) Pulse radiolysis (generation and investigation of shortlived chemically quick-reacting particles); 3) Kinematics (reciprocal action with ion, atom and molecule collisions; clarification of the dynamics of chemical reactions; 4) Insulators and plastics/physical and chemical primary processes when these materials are subjected to high-energy radiation, light or UV light). A list of publications and lectures is added to complement the description of results gained from R and D work. (BR)

  4. Distribution of Naturally Occurring Anthraquinones, Iridoids and Flavonoids from Morinda genus: Chemistry and Biological activity

    Wong PHAKHODEE

    2012-09-01

    Full Text Available The present review covers chemistry and bioactivities of anthraquinones, iridoids, and flavonoids from the Morinda genus. The plants of Morinda species, belonging to the Rubiaceae family, have been used as traditional folk medicine with anti-bacterial, anti-fungal, anti-tumor, anti-helmin, analgesic, anti-inflammatory, and immune enhancing effects. They are rich sources of anthraquinones and iridoids. The relevant 2-methoxy-1,3,6-trihydroxyanthraquinone is one of the most potent quinone reductase enzyme inducers with no cytotoxicity with normal cells. Damnacanthol-3-O-b-D-primeveroside and lucidin-3-O-b-D-primeveroside displayed a significant reduction of the blood glucose levels in anti-diabetic tests. Additionally, iridoids, 9-epi-6a-methoxy geniposidic acid, scandoside methyl ester, asperulosidic acid, showed a more potent inhibitory effect of melanogenesis than the commercial available depigmented arbutin used in cosmetic industry.

  5. Surface chemistry of Au/TiO2: Thermally and photolytically activated reactions

    Panayotov, Dimitar A.; Morris, John R.

    2016-03-01

    The fascinating particle size dependence to the physical, photophysical, and chemical properties of gold has motivated thousands of studies focused on exploring the ability of supported gold nanoparticles to catalyze chemical transformations. In particular, titanium dioxide-supported gold (Au/TiO2) nanoparticles may provide the right combination of electronic structure, structural dynamics, and stability to affect catalysis in important practical applications from environmental remediation to selective hydrogenation to carbon monoxide oxidation. Harnessing the full potential of Au/TiO2 will require a detailed atomic-scale understanding of the thermal and photolytic processes that accompany chemical conversion. This review describes some of the unique properties exhibited by particulate gold before delving into how those properties affect chemistry on titania supports. Particular attention is given first to thermally driven reactions on single crystal system. This review then addresses nanoparticulate samples in an effort begin to bridge the so-called materials gap. Building on the foundation provided by the large body of work in the field of thermal catalysis, the review describes new research into light-driven catalysis on Au/TiO2. Importantly, the reader should bear in mind throughout this review that thermal chemistry and thermal effects typically accompany photochemistry. Distinguishing between thermally-driven stages of a reaction and photo-induced steps remains a significant challenge, but one that experimentalists and theorists are beginning to decipher with new approaches. Finally, a summary of several state-of-the-art studies describes how they are illuminating new frontiers in the quest to exploit Au/TiO2 as an efficient catalyst and low-energy photocatalyst.

  6. Complex chemistry

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-15

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  7. Complex chemistry

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  8. Litter chemistry prevails over litter consumers in mediating effects of past steel industry activities on leaf litter decomposition.

    Lucisine, Pierre; Lecerf, Antoine; Danger, Michaël; Felten, Vincent; Aran, Delphine; Auclerc, Apolline; Gross, Elisabeth M; Huot, Hermine; Morel, Jean-Louis; Muller, Serge; Nahmani, Johanne; Maunoury-Danger, Florence

    2015-12-15

    Soil pollution has adverse effects on the performance and life history traits of microorganisms, plants, and animals, yet evidence indicates that even the most polluted sites can support structurally-complex and dynamic ecosystems. The present study aims at determining whether and how litter decomposition, one of the most important soil ecological processes leaf, is affected in a highly trace-metal polluted site. We postulated that past steel mill activities resulting in soil pollution and associated changes in soil characteristics would influence the rate of litter decomposition through two non-exclusive pathways: altered litter chemistry and responses of decomposers to lethal and sub-lethal toxic stress. We carried out a litter-bag experiment using Populus tremula L. leaf litter collected at, and allowed to decompose in, a trace metal polluted site and in three unpolluted sites used as controls. We designed a fully-factorial transplant experimental design to assess effects of litter origin and exposure site on the rate of litter decomposition. We further determined initial litter chemistry, fungal biomass, mesofauna abundance in litter bags, and the soil macrofauna community. Irrespective of the site of litter exposure, litter originating from the polluted site had a two-fold faster decomposition than litter from the unpolluted sites. Litter chemistry, notably the lignin content, seemed most important in explaining the degradation rate of the leaf litter. Abundance of meso and macro-detritivores was higher at the polluted site than at the unpolluted sites. However, litter decomposition proceeded at similar rates in polluted and unpolluted sites. Our results show that trace metal pollution and associated soil and litter changes do not necessarily weaken consumer control on litter decomposition through lethal and sub-lethal toxic stress. PMID:26282755

  9. Mathematical Chemistry

    Trinajstić, Nenad; Gutman, Ivan

    2002-01-01

    A brief description is given of the historical development of mathematics and chemistry. A path leading to the meeting of these two sciences is described. An attempt is made to define mathematical chemistry, and journals containing the term mathematical chemistry in their titles are noted. In conclusion, the statement is made that although chemistry is an experimental science aimed at preparing new compounds and materials, mathematics is very useful in chemistry, among other things, to produc...

  10. Combinatorial chemistry and the Grid

    Frey, J G; Bradley, M.; Essex, J.W.; Hursthouse, M. B.; Lewis, S. M.; Luck, M.M.; Moreau, L; De Roure, D C; Surridge, M.; Welsh, A. H.

    2003-01-01

    Chemistry has always made extensive use of the developing computing technology and available computing power though activities such as modelling, simulation and chemical structure interpretational - activities conveniently summarised as computational chemistry. Developing procedures in chemical synthesis and characterisation, particularly in the arena of parallel and combinatorial methodology, have generated ever increasing demands on both Computational Chemistry and Computer Technology. Si...

  11. Annual report 1985 Chemistry Department

    This annual report describes the activities carried out in 1985 by the Chemistry Department in the following fields: Chemistry, Inorganic Chemistry, Physicochemistry (Interphases, Surfaces), General Chemical Analysis, Active Materials Analysis, X Ray Fluorescence Analysis, Mass Spectroscopy (Isotopic Analysis, Instrumentation) and Optical Spectroscopy. A list of publications is enclosed. (M.E.L.)

  12. Fructose Promotes Uptake and Activity of Oligonucleotides With Different Chemistries in a Context-dependent Manner in mdx Mice.

    Cao, Limin; Han, Gang; Lin, Caorui; Gu, Ben; Gao, Xianjun; Moulton, Hong M; Seow, Yiqi; Yin, HaiFang

    2016-01-01

    Antisense oligonucleotide (AO)-mediated exon-skipping therapeutics shows great promise in correcting frame-disrupting mutations in the DMD gene for Duchenne muscular dystrophy. However, insufficient systemic delivery limits clinical adoption. Previously, we showed that a glucose/fructose mixture augmented AO delivery to muscle in mdx mice. Here, we evaluated if fructose alone could enhance the activities of AOs with different chemistries in mdx mice. The results demonstrated that fructose improved the potency of AOs tested with the greatest effect on phosphorodiamidate morpholino oligomer (PMO), resulted in a 4.25-fold increase in the number of dystrophin-positive fibres, compared to PMO in saline in mdx mice. Systemic injection of lissamine-labeled PMO with fructose at 25 mg/kg led to increased uptake and elevated dystrophin expression in peripheral muscles, compared to PMO in saline, suggesting that fructose potentiates PMO by enhancing uptake. Repeated intravenous administration of PMO in fructose at 50 mg/kg/week for 3 weeks and 50 mg/kg/month for 5 months restored up to 20% of wild-type dystrophin levels in skeletal muscles with improved functions without detectable toxicity, compared to untreated mdx controls. Collectively, we show that fructose can potentiate AOs of different chemistries in vivo although the effect diminished over repeated administration. PMID:27351681

  13. Adsorption of a Textile Dye on Commercial Activated Carbon: A Simple Experiment to Explore the Role of Surface Chemistry and Ionic Strength

    Martins, Angela; Nunes, Nelson

    2015-01-01

    In this study, an adsorption experiment is proposed using commercial activated carbon as adsorbent and a textile azo dye, Mordant Blue-9, as adsorbate. The surface chemistry of the activated carbon is changed through a simple oxidation treatment and the ionic strength of the dye solution is also modified, simulating distinct conditions of water…

  14. Prebiotic chemistry and atmospheric warming of early Earth by an active young Sun

    Airapetian, V. S.; Glocer, A.; Gronoff, G.; Hébrard, E.; Danchi, W.

    2016-06-01

    Nitrogen is a critical ingredient of complex biological molecules. Molecular nitrogen, however, which was outgassed into the Earth’s early atmosphere, is relatively chemically inert and nitrogen fixation into more chemically reactive compounds requires high temperatures. Possible mechanisms of nitrogen fixation include lightning, atmospheric shock heating by meteorites, and solar ultraviolet radiation. Here we show that nitrogen fixation in the early terrestrial atmosphere can be explained by frequent and powerful coronal mass ejection events from the young Sun--so-called superflares. Using magnetohydrodynamic simulations constrained by Kepler Space Telescope observations, we find that successive superflare ejections produce shocks that accelerate energetic particles, which would have compressed the early Earth’s magnetosphere. The resulting extended polar cap openings provide pathways for energetic particles to penetrate into the atmosphere and, according to our atmospheric chemistry simulations, initiate reactions converting molecular nitrogen, carbon dioxide and methane to the potent greenhouse gas nitrous oxide as well as hydrogen cyanide, an essential compound for life. Furthermore, the destruction of N2, CO2 and CH4 suggests that these greenhouse gases cannot explain the stability of liquid water on the early Earth. Instead, we propose that the efficient formation of nitrous oxide could explain a warm early Earth.

  15. Research activity of institute of physical chemistry of Russian Academy of sciences in the field of nuclear fuel cycle

    The report is a brief review of the most important directions in research activity of the Institute of Physical Chemistry of RAS (Moscow) in the field of nuclear fuel cycle. The main attention is paid to researches and developments on liquid radioactive waste management including the removal of wastes to deep geological formations and the immobilization of the wastes. In particular, the data from the study on the properties of new, basaltic-like matrices for the immobilization are presented. The results of research on gas evolution from the systems modeling liquid high-level radioactive wastes are considered. The separation of some radionuclides from irradiated nuclear and the production of radiation sources by various methods are discussed. (author)

  16. Wave activity in the tropical tropopause layer in seven reanalysis and four chemistry climate model data sets

    Fujiwara, M.; Suzuki, J.; Gettelman, A.; Hegglin, M. I.; Akiyoshi, H.; Shibata, K.

    2012-06-01

    Sub-seasonal variability including equatorial waves significantly influence the dehydration and transport processes in the tropical tropopause layer (TTL). This study investigates the wave activity in the TTL in 7 reanalysis data sets (RAs; NCEP1, NCEP2, ERA40, ERA-Interim, JRA25, MERRA, and CFSR) and 4 chemistry climate models (CCMs; CCSRNIES, CMAM, MRI, and WACCM) using the zonal wave number-frequency spectral analysis method with equatorially symmetric-antisymmetric decomposition. Analyses are made for temperature and horizontal winds at 100 hPa in the RAs and CCMs and for outgoing longwave radiation (OLR), which is a proxy for convective activity that generates tropopause-level disturbances, in satellite data and the CCMs. Particular focus is placed on equatorial Kelvin waves, mixed Rossby-gravity (MRG) waves, and the Madden-Julian Oscillation (MJO). The wave activity is defined as the variance, i.e., the power spectral density integrated in a particular zonal wave number-frequency region. It is found that the TTL wave activities show significant difference among the RAs, ranging from ˜0.7 (for NCEP1 and NCEP2) to ˜1.4 (for ERA-Interim, MERRA, and CFSR) with respect to the averages from the RAs. The TTL activities in the CCMs lie generally within the range of those in the RAs, with a few exceptions. However, the spectral features in OLR for all the CCMs are very different from those in the observations, and the OLR wave activities are too low for CCSRNIES, CMAM, and MRI. It is concluded that the broad range of wave activity found in the different RAs decreases our confidence in their validity and in particular their value for validation of CCM performance in the TTL, thereby limiting our quantitative understanding of the dehydration and transport processes in the TTL.

  17. Chlorophyll fluorescence, Orbital and Photosynthesis: practical activities integrating concepts of Chemistry, Physics and Biology

    Elgion Lucio da Silva Loreto

    2013-11-01

    Full Text Available These laboratory activities explore the relationship between the reserve of energy that occur during photosynthesis and the chlorophyll fluorescence emission when in solution as opposed to absence of fluorescence when the chlorophyll are in intact chloroplasts. This proposal can be used as short demo or as  activities with longer duration, to show chlorophyll's properties associated with the photosynthesis. The materials proposed for the implementation of the activities are simple, and possible to building it by the students, enabling the development of various skills and experimental proposals. The protocols are based on observations and record key questions to continue the execution. During the activities, questions promotes pauses for moments of reflection and review of concepts. At the end are presented and discussed proposals for development of interdisciplinary projects.

  18. Green chemistry approach to the synthesis of potentially bioactive aminobenzylated Mannich bases through active hydrogen compounds

    S. L. VASOYA; P. T. CHOVATIA; D. H. PUROHIT; H. S. JOSHI

    2005-01-01

    An efficient and high yield method for the synthesis of aminobenzylated Mannich bases is described. The synthesis occurs in aqueous medium at 0 ºC. The compounds show moderate antitubercular and antimicrobial activities.

  19. Green chemistry approach to the synthesis of potentially bioactive aminobenzylated Mannich bases through active hydrogen compounds

    S. L. VASOYA

    2005-10-01

    Full Text Available An efficient and high yield method for the synthesis of aminobenzylated Mannich bases is described. The synthesis occurs in aqueous medium at 0 ºC. The compounds show moderate antitubercular and antimicrobial activities.

  20. TRICHLOROETHYLENE ADSORPTION BY ACTIVATED CARBON PRELOADED WITH HUMIC SUBSTANCES: EFFECTS OF SOLUTION CHEMISTRY. (R828157)

    AbstractTrichloroethylene (TCE) adsorption by activated carbon previously loaded ("preloaded") with humic substances was found to decrease with increasing concentrations of monovalent ions (NaCl), calcium (until solubility was exceeded), or dissolved oxygen in...

  1. 'Unconventional' coordination chemistry by metal chelating fragments in a metalloprotein active site.

    Martin, David P; Blachly, Patrick G; Marts, Amy R; Woodruff, Tessa M; de Oliveira, César A F; McCammon, J Andrew; Tierney, David L; Cohen, Seth M

    2014-04-01

    The binding of three closely related chelators: 5-hydroxy-2-methyl-4H-pyran-4-thione (allothiomaltol, ATM), 3-hydroxy-2-methyl-4H-pyran-4-thione (thiomaltol, TM), and 3-hydroxy-4H-pyran-4-thione (thiopyromeconic acid, TPMA) to the active site of human carbonic anhydrase II (hCAII) has been investigated. Two of these ligands display a monodentate mode of coordination to the active site Zn(2+) ion in hCAII that is not recapitulated in model complexes of the enzyme active site. This unprecedented binding mode in the hCAII-thiomaltol complex has been characterized by both X-ray crystallography and X-ray spectroscopy. In addition, the steric restrictions of the active site force the ligands into a 'flattened' mode of coordination compared with inorganic model complexes. This change in geometry has been shown by density functional computations to significantly decrease the strength of the metal-ligand binding. Collectively, these data demonstrate that the mode of binding by small metal-binding groups can be significantly influenced by the protein active site. Diminishing the strength of the metal-ligand bond results in unconventional modes of metal coordination not found in typical coordination compounds or even carefully engineered active site models, and understanding these effects is critical to the rational design of inhibitors that target clinically relevant metalloproteins. PMID:24635441

  2. Positronium chemistry

    Green, James

    1964-01-01

    Positronium Chemistry focuses on the methodologies, reactions, processes, and transformations involved in positronium chemistry. The publication first offers information on positrons and positronium and experimental methods, including mesonic atoms, angular correlation measurements, annihilation spectra, and statistical errors in delayed coincidence measurements. The text then ponders on positrons in gases and solids. The manuscript takes a look at the theoretical chemistry of positronium and positronium chemistry in gases. Topics include quenching, annihilation spectrum, delayed coincidence

  3. Implementation and Evaluation of Web-Based Learning Activities on Bonding and the Structure of Matter for 10-th Grade Chemistry

    Frailich, Marcel

    This study deals with the development, implementation, and evaluation of web-based activities associated with the topic of chemical bonding , as taught in 10th grade chemistry. A website was developed entitled: "Chemistry and the Chemical Industry in the Service of Mankind", its URL is: http://stwww.weizmann.ac.il/g-chem/learnchem (Kesner, Frailich, & Hofstein, 2003). The main goal of this study was to assess the educational effectiveness of website activities dealing with the chemical bonding concept. These activities include visualization tools, as well as topics relevant to daily life and industrial applications. The study investigated the effectiveness of a web-based learning environment regarding the understanding of chemical bonding concepts, students' perceptions of the classroom learning environment, their attitudes regarding the relevance of learning chemistry to everyday life, and their interest in chemistry studies. As mentioned before, in the present study we focused on activities (from the website), all of which deal with chemical bonding concept. The following are the reasons for the decision to focus on this topic: (1) Chemical bonding is a key concept that is taught in 10th grade chemistry in high school. It provides the basis for many other chemistry topics that are taught later, and (2) Chemical bonding is a difficult for students using existing tools (e. g., static models in books, ball-and- stick models), which are insufficient to demonstrate the abstract nature phenomena associated with this topic. The four activities developed for this study are (1) models of the atomic structure, (2) metals -- structure and properties, (3) ionic substances in everyday life and in industry, and (4) molecular substances -- structure, properties, and uses. The study analyzed both quantitative and qualitative research. The quantitative tools of the study included: A Semantic Differential questionnaire and a Chemistry Classroom Web-Based Learning Environment

  4. Adverse effects of erythromycin on the structure and chemistry of activated sludge

    Louvet, J.N.; Giammarino, C.; Potier, O. [Laboratoire des Sciences du Genie Chimique-CNRS, Nancy University, INPL, 1, rue Grandville, BP 20451, F-54001 Nancy Cedex (France); Pons, M.N., E-mail: marie-noelle.pons@ensic.inpl-nancy.f [Laboratoire des Sciences du Genie Chimique-CNRS, Nancy University, INPL, 1, rue Grandville, BP 20451, F-54001 Nancy Cedex (France)

    2010-03-15

    This study examines the effects of erythromycin on activated sludge from two French urban wastewater treatment plants (WWTPs). Wastewater spiked with 10 mg/L erythromycin inhibited the specific evolution rate of chemical oxygen demand (COD) by 79% (standard deviation 34%) and the specific N-NH{sub 4}{sup +} evolution rate by 41% (standard deviation 25%). A temporary increase in COD and tryptophan-like fluorescence, as well as a decrease in suspended solids, were observed in reactors with wastewater containing erythromycin. The destruction of activated sludge flocs was monitored by automated image analysis. The effect of erythromycin on nitrification was variable depending on the sludge origin. Erythromycin inhibited the specific nitrification rate in sludge from one WWTP, but increased the nitrification rate at the other facility. - Erythromycin toxicity on activated sludge is expected to reduce pollution removal.

  5. Adverse effects of erythromycin on the structure and chemistry of activated sludge

    This study examines the effects of erythromycin on activated sludge from two French urban wastewater treatment plants (WWTPs). Wastewater spiked with 10 mg/L erythromycin inhibited the specific evolution rate of chemical oxygen demand (COD) by 79% (standard deviation 34%) and the specific N-NH4+ evolution rate by 41% (standard deviation 25%). A temporary increase in COD and tryptophan-like fluorescence, as well as a decrease in suspended solids, were observed in reactors with wastewater containing erythromycin. The destruction of activated sludge flocs was monitored by automated image analysis. The effect of erythromycin on nitrification was variable depending on the sludge origin. Erythromycin inhibited the specific nitrification rate in sludge from one WWTP, but increased the nitrification rate at the other facility. - Erythromycin toxicity on activated sludge is expected to reduce pollution removal.

  6. Chemistry and Biological Activities of Terpenoids from Copaiba (Copaifera spp. Oleoresins

    Jamilly Kelly Oliveira Neves

    2012-03-01

    Full Text Available Copaiba oleoresins are exuded from the trunks of trees of the Copaifera species (Leguminosae-Caesalpinoideae. This oleoresin is a solution of diterpenoids, especially, mono- and di-acids, solubilized by sesquiterpene hydrocarbons. The sesquiterpenes and diterpenes (labdane, clerodane and kaurane skeletons are different for each Copaifera species and have been linked to several reported biological activities, ranging from anti-tumoral to embriotoxic effects. This review presents all the substances already described in this oleoresin, together with structures and activities of its main terpenoids.

  7. Chemistry and biological activities of terpenoids from copaiba (Copaifera spp.) oleoresins.

    Leandro, Lidiam Maia; Vargas, Fabiano de Sousa; Barbosa, Paula Cristina Souza; Neves, Jamilly Kelly Oliveira; da Silva, José Alexsandro; da Veiga-Junior, Valdir Florêncio

    2012-01-01

    Copaiba oleoresins are exuded from the trunks of trees of the Copaifera species (Leguminosae-Caesalpinoideae). This oleoresin is a solution of diterpenoids, especially, mono- and di-acids, solubilized by sesquiterpene hydrocarbons. The sesquiterpenes and diterpenes (labdane, clerodane and kaurane skeletons) are different for each Copaifera species and have been linked to several reported biological activities, ranging from anti-tumoral to embriotoxic effects. This review presents all the substances already described in this oleoresin, together with structures and activities of its main terpenoids. PMID:22466849

  8. Influence of volcanic activity on spring water chemistry at Popocatepetl Volcano, Mexico

    Martin-Del Pozzo, A.L.; Instituto de Geofisica, Ciudad Universitaria, Circuito Institutos, Universidad Nacional Autonoma de Mexico, 04510, Mexico Distrito Federal, Mexico; Aceves, F.; Instituto de Geofisica, Ciudad Universitaria, Circuito Institutos, Universidad Nacional Autonoma de Mexico, 04510, Mexico Distrito Federal, Mexico; Espinasa, R.; Instituto de Geofisica, Ciudad Universitaria, Circuito Institutos, Universidad Nacional Autonoma de Mexico, 04510, Mexico Distrito Federal, Mexico; Aguayo, A.; Instituto de Geofisica, Ciudad Universitaria, Circuito Institutos, Universidad Nacional Autonoma de Mexico, 04510, Mexico Distrito Federal, Mexico; Inguaggiato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Morales, P.; Instituto de GeologIa, Universidad Nacional Autonoma de Mexico, Mexico Distrito Federal, Mexico; Cienfuegos, E.; Instituto de GeologIa, Universidad Nacional Autonoma de Mexico, Mexico Distrito Federal, Mexico

    2002-01-01

    The results of the 7 years (1994-2000) of monthly monitoring of spring water before and during eruptions show response to volcanic activity. Low salinity and temperature characterize most of the springs, which are located on the flanks of Popocatepetl Volcano. The pH ranges from 5.8 to 7.8 and temperature from 3 to 36 jC. Oxygen and hydrogen isotopic data show that the water is of meteoric origin, but SO4 2 , Cl , F , HCO3 , B, and SO4 2- /Cl- variations precede main eruptive activity, ...

  9. Learning by Doing: The Objectification of Knowledge across Semiotic Modalities in Middle School Chemistry Lab Activities

    Wright, Laura J.

    2008-01-01

    This analysis follows students' action and interaction with a single scientific phenomenon (bubbling/gas) over the course of a curriculum unit in a middle school science classroom to examine how and what they learn when doing laboratory activities. Taking a situated approach to interaction, I place the process of objectification in its multimodal…

  10. The Chemistry of Self-Heating Food Products: An Activity for Classroom Engagement

    Oliver-Hoyo, Maria T.; Pinto, Gabriel; Llorens-Molina, Juan Antonio

    2009-01-01

    Two commercial self-heating food products have been used to apply chemical concepts such as stoichiometry, enthalpies of reactions and solutions, and heat transfer in a classroom activity. These products are the self-heating beverages sold in Europe and the Meals, Ready to Eat or MREs used primarily by the military in the United States. The main…

  11. How active ingredient localisation in plant tissues determines the targeted pest spectrum of different chemistries

    Buchholz, Anke; Trapp, Stefan

    2016-01-01

    information sets revealed that the intracellular localisation of active ingredients determines the performance of test compounds against different target pests because of different feeding behaviours: mites feed on mesophyll, and aphids and whiteflies mostly in the vascular system. Polar compounds have a slow...

  12. A Proposal for Teaching Undergraduate Chemistry Students Carbohydrate Biochemistry by Problem-Based Learning Activities

    Figueira, Angela C. M.; Rocha, Joao B. T.

    2014-01-01

    This article presents a problem-based learning (PBL) approach to teaching elementary biochemistry to undergraduate students. The activity was based on "the foods we eat." It was used to engage students' curiosity and to initiate learning about a subject that could be used by the future teachers in the high school. The experimental…

  13. Sensitization and protection in the radiation chemistry of biologically active DNA

    The results are reported of a study of the effects of the well-known sensitizers paranitroacetophenone (PNAP), triacetone-amine-N-oxyl (TAN) and oxygen, and of the protector cysteamine on the radiosensitivity of purified biologically active DNA of bacteriophages. Irradiation conditions are stated. The results are discussed. (U.K.)

  14. Division of Analytical Chemistry, 1998

    Hansen, Elo Harald

    1999-01-01

    The article recounts the 1998 activities of the Division of Analytical Chemistry (DAC- formerly the Working Party on Analytical Chemistry, WPAC), which body is a division of the Federation of European Chemical Societies (FECS). Elo Harald Hansen is the Danish delegate, representing The Danish...... Chemical Society/The Society for Analytical Chemistry....

  15. HMI scientific report - chemistry 1987

    Results of the R and D activities of the Radiation Chemistry Department, Hahn-Meitner-Institut, are reported, primarily dealing with the following subjects: Interface processes and energy conversion, high-energy photochemistry and radiation chemistry as well as trace elements chemistry. A list of publications and lectures is added and gives a view on results obtained in research and development. (EF)

  16. The chemistry and biological activity of herbs used in Flor-Essence herbal tonic and Essiac.

    Tamayo, C; Richardson, M A; Diamond, S; Skoda, I

    2000-02-01

    The herbal mixtures, Essiac and Flor-Essence, are sold as nutritional supplements and used by patients to treat chronic conditions, particularly cancer. Evidence of anticancer activity for the herbal teas is limited to anecdotal reports recorded for some 40 years in Canada. Individual case reports suggest that the tea improves quality of life, alleviates pain, and in some cases, impacts cancer progression among cancer patients. Experimental studies with individual herbs have shown evidence of biological activity including antioxidant, antioestrogenic, immunostimulant, antitumour, and antiocholeretic actions. However, research that demonstrates these positive effects in the experimental setting has not been translated to the clinical arena. Currently, no clinical studies of Essiac or Flor-essence are published, but a clinical study is being planned at the British Columbia Cancer Agency by the University of Texas-Center for Alternative Medicine (UT-CAM) and Tzu-Chi Institute for Complementary and Alternative Medicine. PMID:10641040

  17. Radiological and Environmental Research Division annual report. Fundamental molecular physics and chemistry, June 1975--September 1976. [Summaries of research activities at Argonne National Laboratory

    None

    1976-01-01

    A summary of research activities in the fundamental molecular physics and chemistry section at Argonne National Laboratory from July 1975 to September 1976 is presented. Of the 40 articles and abstracts given, 24 have been presented at conferences or have been published and will be separately abstracted. Abstracts of the remaining 16 items appear in this issue of ERA. (JFP)

  18. Chemistry and Biological Activities of Terpenoids from Copaiba (Copaifera spp.) Oleoresins

    Jamilly Kelly Oliveira Neves; José Alexsandro da Silva; Paula Cristina Souza Barbosa; Fabiano de Sousa Vargas; Lidiam Maia Leandro; Valdir Florêncio da Veiga-Junior

    2012-01-01

    Copaiba oleoresins are exuded from the trunks of trees of the Copaifera species (Leguminosae-Caesalpinoideae). This oleoresin is a solution of diterpenoids, especially, mono- and di-acids, solubilized by sesquiterpene hydrocarbons. The sesquiterpenes and diterpenes (labdane, clerodane and kaurane skeletons) are different for each Copaifera species and have been linked to several reported biological activities, ranging from anti-tumoral to embriotoxic effects. This review presents all the subs...

  19. Chemistry related to the actives sites of the [Fe]- and [FeFe]-hydrogenases

    Hill, Amanda D.

    2016-01-01

    Hydrogenases are an important group of enzymes found in a range of microorganisms. There are three phylogenetically distinct classes of hydrogenase all of which feature iron-containing complexes. The work contained in this thesis has two main focuses: the synthesis and characterization of novel mimics of the [Fe]-hydrogenase active site, and spectroscopic studies on the interaction of iron-sulfur clusters with CO and CN− relevant to the biosynthesis of the H-cluster of [FeFe]-hydrogenase. ...

  20. Mathematical problems for chemistry students

    Pota, Gyorgy

    2011-01-01

    Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistrystudents in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialistsof the chemistry-related fields (physicists, mathematicians, biologists, etc.) intothe world of the chemical applications.Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, others we

  1. Green Chemistry Approach for Efficient Synthesis of Schiff Bases of Isatin Derivatives and Evaluation of Their Antibacterial Activities

    Jnyanaranjan Panda

    2013-01-01

    Full Text Available Microwave-assisted organic synthesis, a green chemistry approach, is nowadays widely used in the drug synthesis. Microwave-assisted synthesis improves both throughput and turnaround time for medicinal chemists by offering the benefits of drastically reduced reaction times, increased yields, and pure products. Schiff bases are the important class of organic compounds due to their flexibility, and structural diversities due to the presence of azomethine group which is helpful for elucidating the mechanism of transformation and rasemination reaction in biological system. This novel compound could also act as valuable ligands for the development of new chemical entities. In the present work, some Schiff bases of Isatin derivatives was synthesized using microwave heating method. Schiff base of Isatin were synthesized by condensation of the keto group of Isatin with different aromatic primary amines. They were characterized by means of spectral data and subsequently subjected to the in vitro antibacterial activities against gram positive and gram negative strains of microbes. It was observed that the compound with electron withdrawing substituents exhibited good antibacterial activities against almost all the micro organisms.

  2. Changing the Chairs: Impact of Workshop Activities in Assisting Chemistry Department Chairs in Achieving Racial and Ethnic Diversity

    Greene, Jessica; Lewis, Priscilla A.; Richmond, Geraldine L.; Stockard, Jean

    2011-01-01

    To address the low levels of underrepresented minority (URM) faculty in top-ranked chemistry departments, the National Science Foundation, the U.S. Department of Energy, and the National Institutes of Health jointly sponsored a workshop for academic chemistry leaders in September 2007. The goal of the two-and-a-half-day workshop was to create an…

  3. Students' perceptions of teaching in context-based and traditional chemistry classrooms : Comparing content, learning activities, and interpersonal perspectives

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

    2014-01-01

    Context-based curriculum reforms in chemistry education are thought to bring greater diversity to the ways in which chemistry teachers organize their teaching. First and foremost, students are expected to perceive this diversity. However, empirical research on how students perceive their teacher's t

  4. Uptake of Reactive Black 5 by pumice and walnut activated carbon: Chemistry and adsorption mechanisms

    Heibati, B.; Rodriguez-Couto, S.; Amrane, A; M. Rafatullah; Hawari, A.; Al-Ghouti, M. A.

    2014-01-01

    The potential of using pumice and walnut wood activated carbon as low-cost adsorbents for the removal of the diazo dye Reactive Black 5 (RB5) from aqueous solutions was investigated. The Langmuir isotherm fit to the data specified the presence of two different natures of adsorption sites with different binding energies on the AC-W surface. Kinetic modelling showed that the adsorption behaviour and mechanism of RB5 for both adsorbents is believed to happen via surface adsorption followed by di...

  5. Molecular simulation of receptors of physiologically active compounds for purposes of medical chemistry

    Baskin, Igor I.; Palyulin, Vladimir A.; Zefirov, Nikolai S.

    2009-06-01

    The general strategy of the molecular simulation of biological receptors and their interaction with ligands is considered. The procedures for construction of 3D protein models, molecular docking, evaluation of model quality, determination of the free energy of protein binding with ligands are discussed. The methods of molecular design of new medicaments based on molecular models of biological targets: virtual screening and de novo design, are presented. Examples of the above-listed approaches for the simulation of a number of pharmacologically significant receptors, analysis of receptor-ligand interactions and design of new biologically active organic compounds are given.

  6. Chemistry and Biological Activities of Essential Oils from Melaleuca L. Species

    Luiz Claudio Almeida Barbosa

    2013-03-01

    Full Text Available Essential oils from species Melaleuca genus, especially M. alternifolia (Maiden & Betche Cheel, have been widely used worldwide in various industries. This review is a contribution to Melaleuca knowledge and describes five important essential oil-producing species and two subspecies of Melaleuca in terms of their essential oil chemical composition, medicinal applications, and leaf morphoanatomy. Some relationships between essential oil composition of these species and important biological activities are presented. Useful parameters for the certification of the essential oils are also highlighted.

  7. Chemistry and biological activities of essential oils from Melaleuca L. species

    Luiz Claudio Almeida Barbosa

    2013-03-01

    Full Text Available Essential oils from species Melaleuca genus, especially M. alternifolia (Maiden & Betche Cheel, have been widely used worldwide in various industries. This review is a contribution to Melaleuca knowledge and describes five important essential oil-producing species and two subspecies of Melaleuca in terms of their essential oil chemical composition, medicinal applications, and leaf morphoanatomy. Some relationships between essential oil composition of these species and important biological activities are presented. Useful parameters for the certification of the essential oils are also highlighted.

  8. Chemistry of ash-leachates to monitor volcanic activity: An application to Popocatepetl volcano, central Mexico

    Armienta, M.A., E-mail: victoria@geofisica.unam.mx [Universidad Nacional Autonoma de Mexico, Instituto de Geofisica, Circuito Exterior, C.U., Mexico 04510 D.F. (Mexico); De la Cruz-Reyna, S. [Universidad Nacional Autonoma de Mexico, Instituto de Geofisica, Circuito Exterior, C.U., Mexico 04510 D.F. (Mexico); Soler, A. [Grup de Mineralogia Aplicada i Medi Ambient, Dep. Cristal.lografia, Mineralogia i Diposits Minerals, Fac. Geologia, Universidad de Barcelona (Spain); Cruz, O.; Ceniceros, N.; Aguayo, A. [Universidad Nacional Autonoma de Mexico, Instituto de Geofisica, Circuito Exterior, C.U., Mexico 04510 D.F. (Mexico)

    2010-08-15

    Monitoring volcanic activity and assessing volcanic risk in an on-going eruption is a problem that requires the maximum possible independent data to reduce uncertainty. A quick, relatively simple and inexpensive method to follow the development of an eruption and to complement other monitoring parameters is the chemical analysis of ash leachates, particularly in the case of eruptions related to dome emplacement. Here, the systematic analysis of SO{sub 4}{sup 2-}, Cl{sup -} and F{sup -} concentrations in ash leachates is proposed as a valuable tool for volcanic activity monitoring. However, some results must be carefully assessed, as is the case for S/Cl ratios, since eruption of hydrothermally altered material may be confused with degassing of incoming magma. Sulfur isotopes help to identify SO{sub 4} produced by hydrothermal processes from magmatic SO{sub 2}. Lower S isotopic values correlated with higher F{sup -} percentages represent a better indicator of fresh magmatic influence that may lead to stronger eruptions and emplacement of new lava domes. Additionally, multivariate statistical analysis helps to identify different eruption characteristics, provided that the analyses are made over a long enough time to sample different stages of an eruption.

  9. Chemistry of ash-leachates to monitor volcanic activity: An application to Popocatepetl volcano, central Mexico

    Monitoring volcanic activity and assessing volcanic risk in an on-going eruption is a problem that requires the maximum possible independent data to reduce uncertainty. A quick, relatively simple and inexpensive method to follow the development of an eruption and to complement other monitoring parameters is the chemical analysis of ash leachates, particularly in the case of eruptions related to dome emplacement. Here, the systematic analysis of SO42-, Cl- and F- concentrations in ash leachates is proposed as a valuable tool for volcanic activity monitoring. However, some results must be carefully assessed, as is the case for S/Cl ratios, since eruption of hydrothermally altered material may be confused with degassing of incoming magma. Sulfur isotopes help to identify SO4 produced by hydrothermal processes from magmatic SO2. Lower S isotopic values correlated with higher F- percentages represent a better indicator of fresh magmatic influence that may lead to stronger eruptions and emplacement of new lava domes. Additionally, multivariate statistical analysis helps to identify different eruption characteristics, provided that the analyses are made over a long enough time to sample different stages of an eruption.

  10. Atmospheric Chemistry Measurements in Schools and Outreach Activities with Low-cost Air Quality Sensors

    Fleming, Z.; Monks, P. S.; McKenzie, K.

    2014-12-01

    The increasing range of low cost air quality sensors entering the market-place or being developed in-house in the last couple of years has led to many possibilities for using these instruments for public outreach activities or citizen science projects. A range of instruments sent out into local schools for the children to interpret and analyse the data and put the air quality in their area into context. A teaching package with tutorials has been developed to bring the data to life and link in with curriculum.The instruments have also been positioned around the city of Leicester in the UK to help understand the spatial variations in air quality and to assess the impact of retro-fitting buses on a busy bus route. The data is easily accessible online on a near real time basis and the various instruments can be compared with others around the country or the world from classrooms around the world.We will give an overview of the instrumentation with a comparison with commercial and cutting edge research instrumentation, the type of activities that were carried out and the public outreach forums where the data can be used.

  11. Pore-fluid chemistry along the main axis of an active lobe at the Congo deep-sea fan

    Croguennec, C.; Ruffine, L.; Guyader, V.; Le Bruchec, J.; Ruesch, B.; Caprais, J.; Cathalot, C.; de Prunelé, A.; Germain, Y.; Bollinger, C.; Dennielou, B.; Olu, K.; Rabouille, C.

    2013-12-01

    The distal lobes of the Congo deep-sea fan constitute a unique in situ laboratory to study early diagenesis of marine sediments. They are located at water depth of about 5000 m and result from the deposition of sediment transported by turbidity currents along the channel-levee systems and submarine canyon connected to the Congo River. Thus, a huge amount of organic matter, transported from the river to the lobes, undergoes decomposition processes involving different oxidants present within the sedimentary column. This drastically changes the chemistry of the pore fluids, allowing the occurence of a succession of biogeochemical processes. The present study is part of an ongoing project which aims at better understanding the role and the fate of organic matter transported to the lobe systems, as well as its implication in the distribution of the living communities encountered there. Thus, pore fluids have been sampled from 8 Calypso cores in order to determine the concentration of dissolved elements. Five sites have been investigated: four of them are located along the main axis of a currently active lobe, the last one being located on a lobe disconnected from the chenals. The analyses of methane, major (Cl, SO4, Mg, Ca, K, Na) and minor (Sr, Ba, B, Li, Mn) elements have been carried out along with total alkalinity determination. The resulting profiles show a highly heterogeneous pore-fluid chemistry. Sulphate concentration near the seawater/sediment interface varies from 3 to 29 mM, indicating intense sulphate reduction. Surprisingly the lowest values are found at the site which is disconnected from the active lobe. The manganese cycle is well defined for all cores. The core recovered at the more distal lobe exhibits very peculiar pore-fluid profiles which are likely related to a geological event, most likely sediment slide and remobilization. References: Babonneau, N., Savoye, B., Cremer, M. & Klein, B., 2002. Morphology and architecture of the present canyon and

  12. Evidence for linkages between ecoenzyme activity and soil organic matter chemistry following encroachment of leguminous woody plant into grasslands.

    Filley, Timothy; Stott, Diane; Boutton, Thomas; Creamer, Courtney; Olk, Dan

    2010-05-01

    The encroachment of woody plants into grasslands is a worldwide phenomenon. In the Rio Grande Plains of southern Texas, subtropical thorn woodlands dominated by the N-fixing tree Prosopis glandulosa have largely replaced native grasslands as a result of fire suppression and extensive cattle grazing. This land cover change has resulted in the increase of belowground stocks of C, N, and P, changes to the amount and chemical nature of soil-stabilized plant biopolymers, and the composition and activity of soil microbes. Given that extracellular enzymes produced by plants and microbes are the principal means by which complex compounds are degraded and that the production of such enzymes is triggered or suppressed by changes in substrate and nutrient availability we sought to relate how these fundamental changes in this ecosystem are reflected in the activity of soil stabilized ecoenzymes and soil organic matter (SOM) chemistry in this system. We investigated a chronosequence of woody encroachment (14-86 yrs) into a C4-dominant grassland. We related the potential activities of five extracellular enzymes (arylamidase, acid phosphatase, β-glucosidase, β-glucosaminidase (NAGase, polyphenoloxidase (PPO)) and a general marker for hydrolytic activity, fluorescein diacetate (FDA) to the molecular composition and concentration of total hydrolysable amino acids and amino sugars, sugars, as well as CuO extractable lignin and substituted fatty acid to. When normalized to dry weight soil all chemical components increase in concentration with cluster age and all clusters have greater concentrations than background grasslands. All enzymes activities exhibit higher potential activity in woody clusters than grasslands but only NAGase and FDA increase with cluster age when normalized to dry weight of soil. Conversely, when normalized to SOC only lignin phenols, hydroxyl proline, and glucose from cellulose are positively correlated with cluster age indicating a selective accrual with

  13. Conformation-activity studies on the interaction of berberine with acetylcholinesterase:Physical chemistry approach

    Jin Xiang; Changping Yu; Fang Yang; Ling Yang; Hong Ding

    2009-01-01

    Berberine has been reported as an acetylcholinesterase (AChE) inhibitor.With significantly low cytotoxicity,berberine will be developed for the clinical treatment of Alzheimer disease (AD) with higher efficacy and fewer side effects.This work investigated the structure change events of AChE that occur during the interaction with berberine by isothermal titration calorimetry (ITC),fluorescence titration,and circular dichroism (CD).The results show that the binding of berberine to AChE is mainly driven by a favorable entropy increase with a less weak affinity.Berberine causes a loss in enzymatic activity at a concentration much below the concentration which gradually exposed the tryptophan residues to a more hydrophilic environment and unfolded the protein,which indicates that the inhibition of AChE with berberine includes the main contributions of interaction and minor conformation change of the protein induced by the alkaloid.

  14. A review of chemistry and biological activities of the genus Aerva--a desert plant.

    Chawla, Payal; Chawla, Amit; Vasudeva, Neeru; Sharma, Surendra Kumar

    2012-01-01

    There are approximately 28 species of Aerva genus, but only a few species are medicinal of which A. persica, A. lanata and A. javanica are of great value. A number of flavonol glycosides (e.g., aervanone, kaempferol-3-galactoside, isorhamnetin-3-O-β-D-glucoside) have been reported from Aerva persica as major phytoconstituents and the minor constituents are β-cyanins (glycine betaine and trigonelline), sterols and carbohydrates. This plant is used as medicinal herb in several traditional systems of medicine all over the world, like diuretic, demulcent, purgative, emetic and tinder. Aerva plants are used to cure ulcer, lithiasis, dropsical affections, eye affection, toothache, headache, in disorders of abdomen and inflammation of internal organs. Roots and flowers are reported to possess hypoglycemic, antioxidant, anthelmintic, analgesic, antimalarial, antivenin activities and medicinal properties against rheumatism and kidney troubles. PMID:22568031

  15. Chemistry and Structure-Activity Relationship of the Styrylquinoline-Type HIV Integrase Inhibitors

    Didier Desmaële

    2010-04-01

    Full Text Available In spite of significant progress in anti-HIV-1 therapy, current antiviral chemo-therapy still suffers from deleterious side effects and emerging drug resistance. Therefore, the development of novel antiviral drugs remains a crucial issue for the fight against AIDS. HIV-1 integrase is a key enzyme in the replication cycle of the retrovirus since it catalyzes the integration of the reverse transcribed viral DNA into the chromosomal DNA. Efforts to develop anti-integrase drugs started during the early nineties, culminating with the recent approval of Raltegravir. The discovery and the development of the styrylquinoline inhibitor class was an important step in the overall process. In this review we have described the key synthetic issues and the structure-activity relationship of this family of integrase inhibitors. Crystallographic and docking studies that shed light on their mechanism of action are also examined.

  16. Layered Double Hydroxide Nanoclusters: Aqueous, Concentrated, Stable, and Catalytically Active Colloids toward Green Chemistry.

    Tokudome, Yasuaki; Morimoto, Tsuyoshi; Tarutani, Naoki; Vaz, Pedro D; Nunes, Carla D; Prevot, Vanessa; Stenning, Gavin B G; Takahashi, Masahide

    2016-05-24

    Increasing attention has been dedicated to the development of nanomaterials rendering green and sustainable processes, which occur in benign aqueous reaction media. Herein, we demonstrate the synthesis of another family of green nanomaterials, layered double hydroxide (LDH) nanoclusters, which are concentrated (98.7 g/L in aqueous solvent), stably dispersed (transparent sol for >2 weeks), and catalytically active colloids of nano LDHs (isotropic shape with the size of 7.8 nm as determined by small-angle X-ray scattering). LDH nanoclusters are available as colloidal building blocks to give access to meso- and macroporous LDH materials. Proof-of-concept applications revealed that the LDH nanocluster works as a solid basic catalyst and is separable from solvents of catalytic reactions, confirming the nature of nanocatalysts. The present work closely investigates the unique physical and chemical features of this colloid, the formation mechanism, and the ability to act as basic nanocatalysts in benign aqueous reaction systems. PMID:27124717

  17. Ceramics chemistry from the standpoint of the high activity level water treatment

    Towards closing the reactor accident of Fukushima Daiichi Nuclear Power Plants, the integrated activities are continued for remediation and for management of storing and disposal of radioactive wastes produced and large amount of remaining contaminated water to find out an adequate method for decontamination and preparing the manual for it. The paper introduces a cyclic water-injection cooling system in which such adsorbent materials as zeolite, insoluble ferrovanides, or ammonium molybdophosphate are employed as the adsorbent material. Selective adsorption characteristics of these adsorbents for cesium and strontium (structural analysis, correlation between adsorption rate and Cs partition distribution, high temperature phase transition of zeolite adsorbing Cs and Sr were examined and then solidification methods using borosilicate glass, high density concrete, and synthetic rocks for the waste disposal with their safety evaluation are presented. (S. Ohno)

  18. Rapid Bioorthogonal Chemistry Turn-on through Enzymatic or Long Wavelength Photocatalytic Activation of Tetrazine Ligation.

    Zhang, Han; Trout, William S; Liu, Shuang; Andrade, Gabriel A; Hudson, Devin A; Scinto, Samuel L; Dicker, Kevin T; Li, Yi; Lazouski, Nikifar; Rosenthal, Joel; Thorpe, Colin; Jia, Xinqiao; Fox, Joseph M

    2016-05-11

    Rapid bioorthogonal reactivity can be induced by controllable, catalytic stimuli using air as the oxidant. Methylene blue (4 μM) irradiated with red light (660 nm) catalyzes the rapid oxidation of a dihydrotetrazine to a tetrazine thereby turning on reactivity toward trans-cyclooctene dienophiles. Alternately, the aerial oxidation of dihydrotetrazines can be efficiently catalyzed by nanomolar levels of horseradish peroxidase under peroxide-free conditions. Selection of dihydrotetrazine/tetrazine pairs of sufficient kinetic stability in aerobic aqueous solutions is key to the success of these approaches. In this work, polymer fibers carrying latent dihydrotetrazines were catalytically activated and covalently modified by trans-cyclooctene conjugates of small molecules, peptides, and proteins. In addition to visualization with fluorophores, fibers conjugated to a cell adhesive peptide exhibited a dramatically increased ability to mediate contact guidance of cells. PMID:27078610

  19. Teacher Didactic Content Knowledge and its relation with the utilization of practical activities in chemistry classes: A study with expert teachers of the Angolan educational system

    Laurinda Baca; Marcos Onofre; Fátima Paixão

    2014-01-01

    This study was developed within the Angolan educational system, with chemistry expert teachers who teach the 7th grade (12 years old). Aiming to characterize the didactic content knowledge and relate it with the quality of teaching and with the development of practical activities that ensure the active participation of students in the construction of knowledge, we observed and analyzed the classes of a group of expert teachers, specifically in the content of chemical reactions and chemical...

  20. Genus Pouteria: chemistry and biological activity Gênero Pouteria: química e atividade biológica

    Cíntia A. M. Silva

    2009-06-01

    Full Text Available The genus Pouteria belongs to the family Sapotaceae and can be widely found around the World. These plants have been used as building material, as food, because the eatable fruits, as well as remedies in folk medicine. Some biological activities have been reported to species of this genus such as antioxidant, anti-inflammatory, antibacterial and antifungal. However, the real potential of this genus as source of new drugs or phytomedicines remains unknown. Therefore, a review of the so far known chemical composition and biological activities of this genus is presented to stimulate new studies about the species already reported moreover that species have no reference about chemistry or biological activities could be found until now.O gênero Pouteria pertence à família Sapotaceae e pode ser encontrado em muitos continentes. As plantas desse gênero têm sido utilizadas na construção civil, na alimentação e também na medicina popular. Algumas atividades biológicas são reportadas às espécies desse gênero, tais como, antioxidante, anti-inflamatória, antibacteriana e antifúngica, mas seu real potencial como fonte de novos fármacos ainda é pouco conhecido. Assim, uma revisão sobre a composição química e as atividades biológicas de Pouteria é apresentada, com o intuito de estimular a continuação dos estudos das espécies aqui citadas, e a investigação de outras espécies para as quais não foram encontrados relatos.

  1. Unique coupling of mono- and dioxygenase chemistries in a single active site promotes heme degradation.

    Matsui, Toshitaka; Nambu, Shusuke; Goulding, Celia W; Takahashi, Satoshi; Fujii, Hiroshi; Ikeda-Saito, Masao

    2016-04-01

    Bacterial pathogens must acquire host iron for survival and colonization. Because free iron is restricted in the host, numerous pathogens have evolved to overcome this limitation by using a family of monooxygenases that mediate the oxidative cleavage of heme into biliverdin, carbon monoxide, and iron. However, the etiological agent of tuberculosis, Mycobacterium tuberculosis, accomplishes this task without generating carbon monoxide, which potentially induces its latent state. Here we show that this unusual heme degradation reaction proceeds through sequential mono- and dioxygenation events within the single active center of MhuD, a mechanism unparalleled in enzyme catalysis. A key intermediate of the MhuD reaction is found to be meso-hydroxyheme, which reacts with O2 at an unusual position to completely suppress its monooxygenation but to allow ring cleavage through dioxygenation. This mechanistic change, possibly due to heavy steric deformation of hydroxyheme, rationally explains the unique heme catabolites of MhuD. Coexistence of mechanistically distinct functions is a previously unidentified strategy to expand the physiological outcome of enzymes, and may be applied to engineer unique biocatalysts. PMID:27006503

  2. Neutron activation analysis of saliva. Application in clinical chemistry, environmental and occupational toxicology

    The contents of 21 chemical elements (Ag, Br, Ca, Cl, Co, Cr, Cs, Fe, Hg, K, Mg, Mn, N, Na, P, Rb, Sb, Sc, Se, Sr, Zn) in mixed non-stimulated saliva of 52 relatively healthy people were assessed by activation using 14 MeV neutrons and nuclear reactor neutrons. The study included 45 women and 7 men, aged 18 to 35. the dependence of salivary compositions upon sex, age, time-of-day and time-of-year was studied. The saliva of 22 men, involved in the clean-up operation after the Chernobyl accident, was also studied. There existed clear circadian variations in the amount of Na, Sc and Cr contained in the saliva and a tendency to circadian variations for the amount of Cl, Co, Br and Rb. Neither sex, age, nor time-of-year influenced the contents of 21 chemical elements examined. The only exception to this finding was with Hg, whose content increases with age. the analysis of the cleaners' saliva made it possible to find considerable metabolic changes of Ca and some other chemical elements. (author). 21 refs., 6 tabs

  3. Social Chemistry

    Lichtfouse, Eric; Schwarzbauer, Jan; Robert, Didier

    2012-01-01

    International audience This article is both an essay to propose social chemistry as a new scientific discipline, and a preface of the book Environmental Chemistry for a Sustainable World. Environmental chemistry is a fast emerging discipline aiming at the understanding the fate of pollutants in ecosystems and at designing novel processes that are safe for ecosystems. Past pollution should be cleaned, future pollution should be predicted and avoided (Lichtfouse et al., 2005a). Such advices ...

  4. Computational chemistry

    Truhlar, Donald G.; McKoy, Vincent

    2000-01-01

    Computational chemistry has come of age. With significant strides in computer hardware and software over the last few decades, computational chemistry has achieved full partnership with theory and experiment as a tool for understanding and predicting the behavior of a broad range of chemical, physical, and biological phenomena. The Nobel Prize award to John Pople and Walter Kohn in 1998 highlighted the importance of these advances in computational chemistry. With massively parallel computers ...

  5. Bioinorganic Chemistry

    Bertini, Ivano; Gray, Harry B.; Lippard, Stephen J.; Valentine, Joan Selverstone

    1994-01-01

    This book covers material that could be included in a one-quarter or one-semester course in bioinorganic chemistry for graduate students and advanced undergraduate students in chemistry or biochemistry. We believe that such a course should provide students with the background required to follow the research literature in the field. The topics were chosen to represent those areas of bioinorganic chemistry that are mature enough for textbook presentation. Although each chapter presents material...

  6. Effects of pretreatment on the surface chemistry and pore size properties of nitrogen functionalized and alkylated granular activated carbon

    Chen, Jiajun; Zhai, Yunbo; Chen, Hongmei; Li, Caiting; Zeng, Guangming; Pang, Daoxiong; Lu, Pei

    2012-12-01

    In this paper, granular activated carbon (GAC) from coconut shell was pretreated by HNO3, H2O2 and urea-formaldehyde resin, respectively. Then the obtained materials were functionalized in the same way for nitrogen group, and then alkylated. Effects of pretreatment on the surface chemistry and pore size of modified GACs were studied. Surface area and micropore volume of modified GAC which pretreated by HNO3 were 723.88 m2/g and 0.229 cm3/g, respectively, while virgin GAC were 742.34 m2/g and 0.276 cm3/g. Surface area and micropore volume decrease of the modified GACs which pretreated by the others two methods were more drastically. The types of groups presented were analyzed by electrophoresis, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Nsbnd CH3 group and Cdbnd N group were detected on the surfaces of these three kinds of modified GACs. Results of XPS showed that the nitrogen functions of modified GAC which pretreated by H2O2 was 4.07%, it was more than that of the others two pretreatment methods. However, the modified GAC which pretreated by urea-formaldehyde resin was fixed more pyridine structure, which structure percentage was 45.88%, in addition, there were more basic groups or charge on the surface than the others.

  7. Green chemistry focus on optimization of silver nanoparticles using response surface methodology (RSM) and mosquitocidal activity: Anopheles stephensi (Diptera: Culicidae).

    Ondari Nyakundi, Erick; Padmanabhan, M Nalini

    2015-10-01

    There is an exigent necessity for development of environmental friendly bio-control agent(s) for elimination of mosquito due to increased resistance resurgence against synthetic control agents. Mosquito control strategy will lay a strong foundation to malaria exclusion or it can be curbed to certain level especially in the developing nations. In this study, silver nanoparticles were synthesized by green chemistry approach using Tridax procumbens leaf extract as a reducing agent. The reaction medium involved in the synthesis process was optimized by statistical experimental design using response surface methodology to obtain better yield, uniform size, shape and stability. Further, these synthesized nanoparticles were confirmed through UV-Visible, FT-IR spectroscopy, PSA and SEM Subsequently, the bioefficacy of these particles were investigated on Anopheles stephensi for larvicidal and pupicidal activity. Interestingly, time period of 90 min, temperature of 76±2 °C, pH 7.2±2, 2 mM silver nitrate (AgNO3), 3mM PEG and 2mM PVP showed excellent parameters for bioprocess design for large scale production of stabilized nanoparticles. A concentration of 5 ppm of PVP stabilized nanoparticles exhibited 100% mortality. Thus, the obtained results clearly suggest that silver nanoparticles stabilized by PEG and PVP may have important function as stabilizers, dispersants as well as larvicides for mosquito control. PMID:26010566

  8. Effects of biosolids and compost amendment on chemistry of soils contaminated with copper from mining activities.

    Sidhu, Virinder; Sarkar, Dibyendu; Datta, Rupali

    2016-03-01

    Several million metric tons of mining wastes, called stamp sands, were generated in the Upper Peninsula of Michigan during extensive copper (Cu) mining activities in the past. These materials, containing large amounts of Cu, were discharged into various offshoots of Lake Superior. Due to evidences of Cu toxicity on aquatic organisms, in due course, the materials were dredged and dumped on lake shores, thus converting these areas into vast, fallow lands. Erosion of these Cu-contaminated stamp sands back to the lakes is severely affecting aquatic life. A lack of uniform vegetation cover on stamp sands is facilitating this erosion. Understanding the fact that unless the stamp sands are fertilized to the point of sustaining vegetation growth, the problem with erosion and water quality degradation will continue, amending the stamp sands with locally available biosolids and composts, was considered. The purpose of the reported study was to assess potential effects of such organic fertilizer amendments on soil quality. As the first step of a combined laboratory and greenhouse study, a 2-month-long incubation experiment was performed to investigate the effects of biosolids and compost addition on the soil nutrient profile of stamp sands and organic matter content. Results showed that both biosolids and compost amendments resulted in significant increase in nitrogen and phosphorus concentrations and organic matter contents of stamp sands. Sequential extraction data demonstrated that Cu was mostly present as bound forms in stamp sands, and there was no significant increase in the plant available fraction of Cu because of fertilizer application. PMID:26894907

  9. Technetium chemistry

    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)

  10. Instructional strategies for online high school chemistry: Impact on student learning, success on labs, and active engagement

    McInerney, Jody R.

    A quasi-experimental mixed methods action research study was conducted at a K-12 virtual charter school with 103 high school chemistry students to investigate the relationship between participation in online synchronous lessons, student understanding of chemistry concepts and success on laboratory assignments. The study examined the impact of different instructional strategies on student success on chemistry labs as defined by lab completion rates, lab performance and concept understanding. The data show students who participated in the synchronous lessons were more successful in labs than those who did not. Different instructional strategies yielded different levels of student engagement and information gathered about student learning during synchronous lessons.

  11. Effects of pretreatment on the surface chemistry and pore size properties of nitrogen functionalized and alkylated granular activated carbon

    Chen Jiajun [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Zhai Yunbo, E-mail: ybzhai@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China); Chen Hongmei; Li Caiting; Zeng Guangming; Pang Daoxiong; Lu Pei [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082 (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The effects of pretreatment on the surface chemistry and pore sizes were studied. Black-Right-Pointing-Pointer Treated GAC was nitrogen functionalized and alkylated GAC also called modified GAC. Black-Right-Pointing-Pointer HNO{sub 3} pretreatment caused a slight decrease in surface area and microporosity. Black-Right-Pointing-Pointer The nitrogen percentage of modified GAC which pretreated by H{sub 2}O{sub 2} was 4.07%. Black-Right-Pointing-Pointer The pyridine of modified GAC which pretreated by urea-formaldehyde resin was 45.88%. - Abstract: In this paper, granular activated carbon (GAC) from coconut shell was pretreated by HNO{sub 3}, H{sub 2}O{sub 2} and urea-formaldehyde resin, respectively. Then the obtained materials were functionalized in the same way for nitrogen group, and then alkylated. Effects of pretreatment on the surface chemistry and pore size of modified GACs were studied. Surface area and micropore volume of modified GAC which pretreated by HNO{sub 3} were 723.88 m{sup 2}/g and 0.229 cm{sup 3}/g, respectively, while virgin GAC were 742.34 m{sup 2}/g and 0.276 cm{sup 3}/g. Surface area and micropore volume decrease of the modified GACs which pretreated by the others two methods were more drastically. The types of groups presented were analyzed by electrophoresis, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). N-CH{sub 3} group and C=N group were detected on the surfaces of these three kinds of modified GACs. Results of XPS showed that the nitrogen functions of modified GAC which pretreated by H{sub 2}O{sub 2} was 4.07%, it was more than that of the others two pretreatment methods. However, the modified GAC which pretreated by urea-formaldehyde resin was fixed more pyridine structure, which structure percentage was 45.88%, in addition, there were more basic groups or charge on the surface than the others.

  12. Alkali-activated fly ash. Relationship between mechanical strength gains and initial ash chemistry

    Palomo, A.

    2008-09-01

    Full Text Available Alkali-activated fly ash is the primary component of a new generation of high-strength, durable binders with excellent mechanical properties and durability (on occasion bettering traditional Portland cement performance. Moreover, development of these cements may contribute to mitigating CO2 emissions, since the base material is an industrial by-product. The present study was conducted to determine the effect of the composition of the initial materials (SiO2/Al2O3 and Na2O/Al2O3 ratios on the mechanical properties, nature and composition of the reaction products. The results obtained indicate that there is no linear relationship between these ratios and mechanical strength, but rather a series of optimal values above and below which strength declines. In the specific case of the ratios studied in the present paper, these values were: SiO2/Al2O3= 4.0 and Na2O/Al2O3= 1.0 (molar ratios.Las cenizas volantes activadas alcalinamente constituyen la base de una nueva generación de cementos con muy interesantes propiedades mecánicas, adherentes y durables (a veces incluso mejores que las de los cementos Portland tradicionales. Adicionalmente el desarrollo de estos cementos podría contribuir a mitigar las emisiones de CO2 a la atmósfera, ya que el material base de los mismos puede estar formado por subproductos industriales. En la presente investigación se realizó un estudio para determinar la influencia de la composición de los materiales iniciales (ratios SiO2/Al2O3 y Na2O/Al2O3 en las propiedades mecánicas y en la naturaleza y composición de los productos de reacción. Los resultados obtenidos indican que no existe una relación lineal de dichas ratios con las resistencias mecánicas, sino que existen unos valores óptimos, por encima y debajo de los cuales las resistencias mecánicas disminuyen. En el caso concreto de las ratios estudiadas en el presente trabajo estos valores serian: SiO2/Al2O3= 4,0 y Na2O/Al2O3= 1,0 (relaciones molares

  13. Nuclear Chemistry, exercises

    Those exercises have as objective to introduce the student in the basic concepts of nuclear chemistry: a) way of decline b) balances of mass used in nuclear reactions c) how to calculate activities, activity concentrations and specific activity d) radiotracers use in biomedical sciences pharmaceutical

  14. Chemistry of phosphorus ylides 31: Reaction of azidocoumarin with active phosphonium ylides, synthesis and antitumour activities of chromenones

    Soher S Maigali; Mansoura A Abd-El-Maksoud; Fouad M Soliman

    2013-11-01

    The reaction of 4- azidochromen-2-one (1) with the nucleophilic phosphacumulene ylides 2, 8, and 12 afforded the new heterocyclic triazoles, triazepines, aziridine, pyrrolone containing a coumarin moiety. Cycloaddition reactions took place first to give triazoline 3 and 9. The triazolines rearranged to the triazepines 4, 10, and 13 accompanied by elimination of triphenylphosphine leading to the phosphorus-free triazepines 5, 11, and moreover, aziridine 6 was produced via nitrogen extrusion from the triazoline 3, followed by ring expansion to the pyrrolone 7. On the other hand, the reaction of the azidocoumarin 1 with the phosphallene yield 15 behaves differently and afforded the triazine 17 and azetone 18. The antitumour activity of compounds 3, 4, 6, and 11 was evaluated, in vitro, against (breast: MCF-7 and liver: HPEG2) human solid tumour cell lines. They showed values closed to that recorded by the reference drug doxorubicin.

  15. 浅淡化学课堂教学的激活%Talking on the Teaching Activation of Chemistry Class

    匡煜华

    2015-01-01

    为了使得化学课堂的教学变得不再死板和沉闷,采用了“课堂引入”的方法,从而消除了化学基本概念与理论的抽象性和枯燥性,提高了学生在化学课堂的学习兴趣,最终取得了较好的课堂教学效果。%The method of“lead-in”is used in the class in order to make the chemistry teaching more lively and interesting;thus it can eliminate the abstractness and boredom of chemistry when the students are learning the basic concept and theory of chemistry. It can also increase the students’interest of chemistry learning, and finally teachers can get a better teaching effect.

  16. Good chemistry

    Petsko, Gregory A

    2004-01-01

    The subject matter in chemistry courses reflects almost nothing of the issues that chemists are interested in. It is important to formulate a set of topics - and a Medical College Admissions Test reflecting them - that would leave chemistry departments no choice but to change their teaching.

  17. The Application of SCC-DV-Xα Computational Method of Quantum Chemistry in Cement Chemistry

    2001-01-01

    It has been explored why quantum chemistry is applied to the research field of cement chemistry. The fundamental theory of SCC-DV-Xα computational method of quantum chemistry is synopsized. The results obtained by computational quantum chemistry method in recent years of valence-bond structures and hydration activity of some cement clinker minerals, mechanical strength and stabilization of some hydrates are summarized and evaluated. Finally the prospects of the future application of quantum chemistry to cement chemistry are depicted.

  18. [Our investigation on the chemistry of biologically active natural products. With the object of exploitation for structure determination methods, and elucidation of vital function].

    Komori, T

    1993-03-01

    Our investigation on the chemistry of biologically active natural products during the last 40 years since 1953 are reviewed in this paper. The following subjects are discussed: I. photochemical relationship between rhodopsin and compounds related to areca alkaloid, II. furanoid diterpenoid constituents from dioscoreaceae plants and colombo root, III. field desorption and fast atom bombardment mass spectrometry of biologically active natural glycosides and glycosphingolipids, IV. investigation of biologically active marine natural products, 1) constituents of steroid glycoside sulfates from Asteroidea, 2) spine toxins from Acanthaster planci, 3) constituents of triterpenoid glycoside sulfates from Holothuroidea, 4) constituents of isoprenoids from Opisthobranchia and Octocorallia, 5) constituents of glycosphingolipids from Asteroidea. PMID:8509990

  19. The Effect of Computer Supported Education and Internet Usage on Pre-Service Chemistry Teachers' Transferable Skills in Active Learning Environments

    İnci Morgil

    2006-12-01

    Full Text Available This study aims to investigate the effect of computer supported education and Internet usage on pre service chemistry teachers’ transferable skills in active learning environments. In the study, when the pre test and post test results are investigated, it can be seen that the mean score of technology using skills are lower than the other ones. This result reflects our countries’ reality related to the technology usage in education process. Most of the schools do not have adequate technology support.

  20. Quantum chemistry

    Lowe, John P

    1993-01-01

    Praised for its appealing writing style and clear pedagogy, Lowe's Quantum Chemistry is now available in its Second Edition as a text for senior undergraduate- and graduate-level chemistry students. The book assumes little mathematical or physical sophistication and emphasizes an understanding of the techniques and results of quantum chemistry, thus enabling students to comprehend much of the current chemical literature in which quantum chemical methods or concepts are used as tools. The book begins with a six-chapter introduction of standard one-dimensional systems, the hydrogen atom,

  1. Trace Chemistry

    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

  2. Materials Chemistry

    Fahlman, Bradley D

    2011-01-01

    The 2nd edition of Materials Chemistry builds on the strengths that were recognized by a 2008 Textbook Excellence Award from the Text and Academic Authors Association (TAA). Materials Chemistry addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment, providing a suitable breadth and depth coverage of the rapidly evolving materials field. The 2nd edition continues to offer innovative coverage and practical perspective throughout. After briefly defining materials chemistry and its history, seven chapters discuss solid-state chemistry, metals, semiconducting materials, organic "soft" materials, nanomaterials, and materials characterization. All chapters have been thoroughly updated and expanded with, for example, new sections on ‘soft lithographic’ patterning, ‘click chemistry’ polymerization, nanotoxicity, graphene, as well as many biomaterials applications. The polymer and ‘soft’ materials chapter represents the largest expansion for the 2nd edition. Each ch...

  3. Introductory Chemistry

    Baron, Mark; Gonzalez-Rodriguez, Jose; Stevens, Gary; Gray, Nathan; Atherton, Thomas; Winn, Joss

    2010-01-01

    Teaching and Learning resources for the 1st Year Introductory Chemistry course (Forensic Science). 30 credits. These are Open Educational Resources (OER), made available for re-use under a Creative Commons license.

  4. Analytical chemistry

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  5. Cluster Chemistry

    2011-01-01

    @@ Cansisting of eight scientists from the State Key Laboratory of Physical Chemistry of Solid Surfaces and Xiamen University, this creative research group is devoted to the research of cluster chemistry and creation of nanomaterials.After three-year hard work, the group scored a series of encouraging progresses in synthesis of clusters with special structures, including novel fullerenes, fullerene-like metal cluster compounds as well as other related nanomaterials, and their properties study.

  6. Green Chemistry

    Collison, Melanie

    2011-05-15

    Green chemistry is the science of chemistry used in a way that will not use or create hazardous substances. Dr. Rui Resendes is working in this field at GreenCentre Canada, an offshoot of PARTEQ Innovations in Kingston, Ontario. GreenCentre's preliminary findings suggest their licensed product {sup S}witchable Solutions{sup ,} featuring 3 classes of solvents and a surfactant, may be useful in bitumen oil sands extraction.

  7. Mineral Type and Solution Chemistry Affect the Structure and Composition of Actively Growing Bacterial Communities as Revealed by Bromodeoxyuridine Immunocapture and 16S rRNA Pyrosequencing.

    Kelly, L C; Colin, Y; Turpault, M-P; Uroz, S

    2016-08-01

    Understanding how minerals affect bacterial communities and their in situ activities in relation to environmental conditions are central issues in soil microbial ecology, as minerals represent essential reservoirs of inorganic nutrients for the biosphere. To determine the impact of mineral type and solution chemistry on soil bacterial communities, we compared the diversity, composition, and functional abilities of a soil bacterial community incubated in presence/absence of different mineral types (apatite, biotite, obsidian). Microcosms were prepared containing different liquid culture media devoid of particular essential nutrients, the nutrients provided only in the introduced minerals and therefore only available to the microbial community through mineral dissolution by biotic and/or abiotic processes. By combining functional screening of bacterial isolates and community analysis by bromodeoxyuridine DNA immunocapture and 16S rRNA gene pyrosequencing, we demonstrated that bacterial communities were mainly impacted by the solution chemistry at the taxonomic level and by the mineral type at the functional level. Metabolically active bacterial communities varied with solution chemistry and mineral type. Burkholderia were significantly enriched in the obsidian treatment compared to the biotite treatment and were the most effective isolates at solubilizing phosphorous or mobilizing iron, in all the treatments. A detailed analysis revealed that the 16S rRNA gene sequences of the OTUs or isolated strains assigned as Burkholderia in our study showed high homology with effective mineral-weathering bacteria previously recovered from the same experimental site. PMID:27138048

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

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

    2015-01-01

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

  9. Switching activation barriers: new insights in E-field driven processes at the interface: perspectives in physical chemistry and catalysis

    Susarrey Arce, A.

    2014-01-01

    The research described in this thesis aimed to explore new concepts in catalysis with the use of a homemade ATR-IR silicon-based microreactor. During this journey we have performed multidisciplinary research at the interface between physics and chemistry. New insights in the fabrication, integration

  10. Environmental chemistry. 3. ed.

    The book Environmental Chemistry deals with the basic aspects of environmental chemistry, the natural cycles of the environment, composition of atmosphere and various effects in it by pollutants due to human activities, like energy production, industrial endeavours etc. Details pertaining to the effect of various pollutants on ecosystem are also explained. A number of instrumented techniques in environmental chemical analysis including neutron activation analysis, spectroscopic methods are given. The correlation between energy and environment is dealt with consideration to the global aspects of it. Paper relevant to INIS database is indexed separately. (M.K.V.)

  11. Teacher Didactic Content Knowledge and its relation with the utilization of practical activities in chemistry classes: A study with expert teachers of the Angolan educational system

    Laurinda Baca

    2014-03-01

    Full Text Available This study was developed within the Angolan educational system, with chemistry expert teachers who teach the 7th grade (12 years old. Aiming to characterize the didactic content knowledge and relate it with the quality of teaching and with the development of practical activities that ensure the active participation of students in the construction of knowledge, we observed and analyzed the classes of a group of expert teachers, specifically in the content of chemical reactions and chemical equations. In a quasi-experimental design methodology, the used technique was the observation from the capture of images in the classes. An element we paid particular attention in the analysis of the classes was the implementation of strategies that involve practical activities, since the didactic research has amply demonstrated that they are likely to generate active learning in science education, with particular emphasis in chemistry. The results revealed that the expert teachers often use practical activities in their classrooms, using group work procedures, work front and questions oral and written.

  12. Radiation Chemistry

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  13. Process chemistry {ampersand} statistics quality assurance plan

    Meznarich, H.K.

    1996-08-01

    This document provides quality assurance guidelines and quality control requirements for Process Chemistry and Statistics. This document is designed on the basis of Hanford Analytical Services Quality Assurance Plan (HASQAP) technical guidelines and is used for governing process chemistry activities.

  14. Quantum chemistry

    Lowe, John P

    2006-01-01

    Lowe's new edition assumes little mathematical or physical sophistication and emphasizes an understanding of the techniques and results of quantum chemistry. It can serve as a primary text in quantum chemistry courses, and enables students and researchers to comprehend the current literature. This third edition has been thoroughly updated and includes numerous new exercises to facilitate self-study and solutions to selected exercises.* Assumes little initial mathematical or physical sophistication, developing insights and abilities in the context of actual problems* Provides thorough treatment

  15. Polymer Chemistry

    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.

  16. Radiopharmaceutical Chemistry of Targeted Radiopharmaceutics. Synthesis of 211At-Labeled Radiopharmaceuticals at High Activities for Clinical Use

    Targeted α-particle radiotherapy is an appealing approach to cancer treatment because of the potential for delivering curative doses of radiation to tumor with minimal damage to normal tissue due to a range equivalent to only a few cell diameters. Compared with β-emitters they have significant advantages from a radiobiological perspective. The LET of 211At α-particles is more than 400 times higher than the β-particles emitted by 90Y, in addition the distance between ionizing events is almost the same as that between the two strands of DNA, yielding a high probability of creating non-repairable DNA damage. It gives the ability to kill cancer cells not compromised by hypoxia, dose rate effects or cell cycle position, enhancing their attractiveness for targeted radiotherapy. However, translation of the concept to the clinic has been slow, many obstacles had to be surmounted before clinical studies could be initiated, the first clinical evaluation of a 211At- labeled mAb was made in 2001. This study circumvents many of the challenges to entering clinical studies with 211At. But several problems were encountered in maintaining efficient labeling with escalating radiation dose of alpha-particle likely related to radiolysis. The impact of the radiolysis produced by the α-particle over the labeling chemistry is much higher in comparison with typical β-emitters due to a deposition of energy in the solvent in a highly localized manner two orders of magnitude per unit volume higher than 90Y or 131I. Due to these difficulties a comprehensive basic science study about the radiolytic effects of astatine alpha-particles over the synthesis of 211At-labeled radiopharmaceuticals was carried out. Its main goal was overcoming the problem of the synthesis of 211At-labeled radiopharmaceuticals at the high activities necessaries for therapy and also to extend the shelf life of astatine elutions. Briefly this study held several steps, the first one was to study the role of solvent

  17. HMI scientific report - chemistry 1988

    Results of the R and D activities are reported, dealing with the following subjects: Interface processes and energy conversion, high-energy photochemistry and radiation chemistry as well as trace elements chemistry. A list of publications and lectures is added and gives a view on results obtained in research and development. (EF)

  18. Revitalizing chemistry laboratory instruction

    McBride, Phil Blake

    This dissertation involves research in three major domains of chemical education as partial fulfillment of the requirements for the Ph.D. program in chemistry at Miami University with a major emphasis on chemical education, and concurrent study in organic chemistry. Unit I, Development and Assessment of a Column Chromatography Laboratory Activity, addresses the domain of Instructional Materials Development and Testing. This unit outlines the process of developing a publishable laboratory activity, testing and revising that activity, and subsequently sharing that activity with the chemical education community. A laboratory activity focusing on the separation of methylene blue and sodium fluorescein was developed to demonstrate the effects of both the stationary and mobile phase in conducting a separation. Unit II, Bringing Industry to the Laboratory, addresses the domain of Curriculum Development and Testing. This unit outlines the development of the Chemistry of Copper Mining module, which is intended for use in high school or undergraduate college chemistry. The module uses the learning cycle approach to present the chemistry of the industrial processes of mining copper to the students. The module includes thirteen investigations (three of which are web-based and ten which are laboratory experiments) and an accompanying interactive CD-ROM, which provides an explanation of the chemistry used in copper mining with a virtual tour of an operational copper mine. Unit III, An Alternative Method of Teaching Chemistry. Integrating Lecture and the Laboratory, is a project that addresses the domain of Research in Student Learning. Fundamental Chemistry was taught at Eastern Arizona College as an integrated lecture/laboratory course that met in two-hour blocks on Monday, Wednesday, and Friday. The students taking this integrated course were compared with students taking the traditional 1-hour lectures held on Monday, Wednesday, and Friday, with accompanying 3-hour lab on

  19. Nuclear analytical chemistry

    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

  20. Nuclear analytical chemistry

    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.

  1. Chemistry Cook-Off

    McCormick, Cynthia

    2012-01-01

    For this activity, high school chemistry students compete in a cooking contest. They must determine the chemical and physical changes that occur in the food they prepare, present their recipe as a step-by-step procedure similar to a lab procedure, identify chemicals in the food, and present all measurements in both metric and English units. The…

  2. Reinventing Chemistry

    Whitesides, George McClelland

    2015-01-01

    Chemistry is in a period of change, from an era focused on molecules and reactions, to one in which manipulations of systems of molecules and reactions will be essential parts of controlling larger systems. This Essay traces paths from the past to possible futures.

  3. Chemistry Notes

    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…

  4. Coordination Chemistry of Polyaromatic Thiosemicarbazones 2: Synthesis and Biological Activity of Zinc, Cobalt, and Copper Complexes of 1-(Naphthalene-2-yl)ethanone Thiosemicarbazone

    Marc-Andre LeBlanc; Antonio Gonzalez-Sarrías; Beckford, Floyd A.; P. Canisius Mbarushimana; Seeram, Navindra P.

    2011-01-01

    A novel thiosemicarbazone from 2-acetonaphthone (represented as acnTSC) has been synthesized and its basic coordination chemistry with zinc(II), cobalt(II), and copper(II) explored. The complexes were characterized by elemental analysis and various spectroscopic techniques and are best formulated as [M(acnTSC)2Cl2] with the metal likely in an octahedral environment. The anticancer activity of the complexes was determined against a panel of human colon cancer cells (HCT-116 and Caco-2). The co...

  5. International global atmospheric chemistry (IGAC) program global emissions inventory activity (GEIA). Proceedings of the IGAC/GEIA workshop on global emission inventory

    Pacyna, J.M. [Norwegian Inst. for Air Research, Lillestroem (Norway); Graedel, T.E. [AT and T Bell Labs., Murray Hill, NJ (United States)

    1992-10-01

    In accordance with the work plan of the International Geosphere-Biosphere Program (IGBP)/International Global Atmospheric Chemistry (IGAC) Global Emission Inventory was organized by the GEIA Secretariat and the Norwegian Institute for Air Research (NILU). The workshop was attended by 34 participants from 9 countries and 3 international organizations. The overall goals of the workshop were to review the progress of work within individual GEIA projects and to plan further activity, as well as to discuss new projects. Major focus was placed on projects related to emissions of acidic components, such as SO{sub 2} and NO{sub x}, and other nitrogen compounds, and volatile organic compounds (VOCs)

  6. Chemistry in Second Life

    Bradley Jean-Claude

    2009-10-01

    Full Text Available Abstract This review will focus on the current level on chemistry research, education, and visualization possible within the multi-user virtual environment of Second Life. We discuss how Second Life has been used as a platform for the interactive and collaborative visualization of data from molecules and proteins to spectra and experimental data. We then review how these visualizations can be scripted for immersive educational activities and real-life collaborative research. We also discuss the benefits of the social networking affordances of Second Life for both chemists and chemistry students.

  7. I Chemistry Conference of West Bahia

    Boaz Oliveira

    2014-11-01

    Full Text Available The I Chemistry Conference of West Bahia [1] aimed the meeting of the academic community of west Bahia state developing research activities at graduate level and postgraduate ones in several chemistry areas, mainly the analytic chemistry, natural products, theoretical chemistry, medicinal chemistry, chemistry teaching, spectroscopy, materials science, photochemistry and catalysis. Through the plenary lectures, short courses and poster presentation, invited researchers from other institutions and mainly students could share experiences as well as plan collaborations from multi and interdisciplinar nature, enabling a greater scientific aggrandizement of the research developed by emergent groups distributed along the inland cities of Brazil.

  8. Fine chemistry

    The 1988 progress report of the Fine Chemistry laboratory (Polytechnic School, France) is presented. The research programs are centered on the renewal of the organic chemistry most important reactions and on the invention of new, highly efficient and highly selective reactions, by applying low cost reagents and solvents. An important research domain concerns the study and fabrication of new catalysts. They are obtained by means of the reactive sputtering of the metals and metal oxydes thin films. The Monte Carlo simulations of the long-range electrostatic interaction in a clay and the obtention of acrylamides from anhydrous or acrylic ester are summarized. Moreover, the results obtained in the field of catalysis are also given. The published papers and the congress communications are included

  9. Diversity and Periodicity: An Inorganic Chemistry Module.

    Huheey, James

    This book is one in a series of Interdisciplinary Approaches to Chemistry (IAC) designed to help students discover that chemistry is a lively science and actively used to pursue solutions to the important problems of today. It is expected for students to see how chemistry takes place continuously all around and to readily understand the daily…

  10. Organometallic chemistry

    Bashkin, James K.; M.L.H. Green; Dr. M. L. H. Green

    1982-01-01

    Transition metal organometallic chemistry is a rapidly expanding field, which has an important relationship to industrial problems of petrochemical catalysis. This thesis describes studies of fundamental organometallic reaction processes, such as C-H and C-C bond formation and cleavage, and investigations of the structure and bonding of organometallic compounds. A number of techniques were used to pursue these studies, including synthesis, X-ray crystallography, and semi-em...

  11. Disk Chemistry*

    Thi Wing-Fai

    2015-01-01

    The chemical species in protoplanetary disks react with each other. The chemical species control part of the thermal balance in those disks. How the chemistry proceeds in the varied conditions encountered in disks relies on detailed microscopic understanding of the reactions through experiments or theoretical studies. This chapter strives to summarize and explain in simple terms the different types of chemical reactions that can lead to complex species. The first part of the chapter deals wit...

  12. Interstellar chemistry

    Klemperer, William

    2006-01-01

    In the past half century, radioastronomy has changed our perception and understanding of the universe. In this issue of PNAS, the molecular chemistry directly observed within the galaxy is discussed. For the most part, the description of the molecular transformations requires specific kinetic schemes rather than chemical thermodynamics. Ionization of the very abundant molecular hydrogen and atomic helium followed by their secondary reactions is discussed. The rich variety of organic species o...

  13. Analytical chemistry

    The division for Analytical Chemistry continued to try and develope an accurate method for the separation of trace amounts from mixtures which, contain various other elements. Ion exchange chromatography is of special importance in this regard. New separation techniques were tried on certain trace amounts in South African standard rock materials and special ceramics. Methods were also tested for the separation of carrier-free radioisotopes from irradiated cyclotron discs

  14. Computational chemistry

    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.

  15. Green chemistry

    A grand challenge facing government, industry, and academia in the relationship of our technological society to the environment is reinventing the use of materials. To address this challenge, collaboration from an interdisciplinary group of stakeholders will be necessary. Traditionally, the approach to risk management of materials and chemicals has been through inerventions intended to reduce exposure to materials that are hazardous to health and the environment. In 1990, the Pollution Prevention Act encouraged a new tact-elimination of hazards at the source. An emerging approach to this grand challenge seeks to embed the diverse set of environmental perspectives and interests in the everyday practice of the people most responsible for using and creating new materials--chemists. The approach, which has come to be known as Green Chemistry, intends to eliminate intrinsic hazard itself, rather than focusing on reducing risk by minimizing exposure. This chapter addresses the representation of downstream environmental stakeholder interests in the upstream everyday practice that is reinventing chemistry and its material inputs, products, and waste as described in the '12 Principles of Green Chemistry'

  16. Green chemistry

    The depletion of world fossil fuel reserves and the involvement of greenhouse gases in the global warming has led to change the industrial and energy policies of most developed countries. The goal is now to reserve petroleum to the uses where it cannot be substituted, to implement renewable raw materials obtained from plants cultivation, and to consider the biodegradability of molecules and of manufactured objects by integrating the lifetime concept in their expected cycle of use. The green chemistry includes the design, development and elaboration of chemical products and processes with the aim of reducing or eliminating the use and generation of harmful compounds for the health and the environment, by adapting the present day operation modes of the chemical industry to the larger framework of the sustainable development. In addition to biofuels, this book reviews the applications of green chemistry in the different industrial processes in concern. Part 1 presents the diversity of the molecules coming from renewable carbon, in particular lignocellulose and the biotechnological processes. Part 2 is devoted to materials and treats of the overall available technological solutions. Part 3 focusses on functional molecules and chemical intermediates, in particular in sugar- and fats-chemistry. Part 4 treats of biofuels under the aspects of their production and use in today's technologies. The last part deals with the global approaches at the environmental and agricultural levels. (J.S.)

  17. Approaching isomerism in organic and inorganic compounds: activity based on the use of problem situations during initial chemistry teacher training

    José Euzébio Simões Neto

    2016-08-01

    Full Text Available This study sought investigate: i the understanding of isomerism by future chemistry teachers during initial training; and ii the construction of isomer concepts after an approach centered on problem situations (SP’s. Two problem situations related to isomerism (historical context and medicinal applications were elaborated. A textual learning material developed for this purpose and concrete molecular models were used of system resources in the problem situation resolution process. Data were colleted using a questionnaire, field observation and semi-structured interview, and analyzed according to the ideas presented by Meirieu (1998. The two SP’s had obstacles, transposable to only a few of the nine groups that responded. Inadequate use of the isomer concept was observed in many of the responses considered scarcely satisfactory or unsatisfactory.

  18. Validation and application of a solid phase chemistry method for preparation of high effective specific activity technetium-99m radiopharmaceuticals

    Solid phase chemistry with UltraLinkTM Iodoacetyl gel was investigated as a method for removing excess ligand present in preparations of diaminedithiol (DADT) 99mTc radiopharmaceuticals. The process was optimized and tested under 99mTc labeling conditions with 2,2,4,9,9-pentamethyl-4,7-diaza-1,10-decanedithiol (N-methyl-DADT), 1, and 4-(1-(2'-methoxyphenyl) piperazinylbutyl)-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanedithiol (DADT-4C-MPP), 2, a serotonin receptor-binding ligand. The results illustrated that this gel removed ≥99.9% excess ligand used in labeling reactions, and was comparable to the level of purification usually obtained by the more labor intensive method of HPLC

  19. Surface chemistry

    Desai, KR

    2008-01-01

    The surface Chemistry of a material as a whole is crucially dependent upon the Nature and type of surfaces exposed on crystallites. It is therefore vitally important to independently Study different, well - defined surfaces through surface analytical techniques. In addition to composition and structure of surface, the subject also provides information on dynamic light scattering, micro emulsions, colloid Stability control and nanostructures. The present book endeavour to bring before the reader that the understanding and exploitation of Solid state phenomena depended largely on the ability to

  20. Hypercarbon chemistry

    This text points out the emerging significance of higher-valent carbon compounds. It describes the compounds of carbon with coordination numbers greater than four and explores the delocalized bonds of π aromatic molecules as a basis for rational description of orbitals; localized multicentered orbitals; the interactions of metallic ions with other atoms and molecules; the skeletal electron counts as a guide for synthesis; and the isolobal concept. Illustrated are the ways in which these subjects bring together structure and reactivity in the great diversity of novel carbon chemistry and its relationship to that of boron, lithium, hydrogen, the metals, and others

  1. Theoretical chemistry periodicities in chemistry and biology

    Eyring, Henry

    1978-01-01

    Theoretical Chemistry: Periodicities in Chemistry and Biology, Volume 4 covers the aspects of theoretical chemistry. The book discusses the stably rotating patterns of reaction and diffusion; the chemistry of inorganic systems exhibiting nonmonotonic behavior; and population cycles. The text also describes the mathematical modeling of excitable media in neurobiology and chemistry; oscillating enzyme reactions; and oscillatory properties and excitability of the heart cell membrane. Selected topics from the theory of physico-chemical instabilities are also encompassed. Chemists, mechanical engin

  2. Radioanalytical chemistry in Denmark

    Publications from Denmark in the field of radioanalytical chemistry are presented in 2 groups, one involving neutron activation and similar techniques, and one for other radioanalytical work. Altogether 258 references including books are given for the period 1936-1977, and the overall doubling time is 5.2 years. A significant deviation from a purely exponential growth was caused by the Second World War. (author)

  3. Coordination Chemistry of Polyaromatic Thiosemicarbazones 2: Synthesis and Biological Activity of Zinc, Cobalt, and Copper Complexes of 1-(Naphthalene-2-ylethanone Thiosemicarbazone

    Marc-Andre LeBlanc

    2011-01-01

    Full Text Available A novel thiosemicarbazone from 2-acetonaphthone (represented as acnTSC has been synthesized and its basic coordination chemistry with zinc(II, cobalt(II, and copper(II explored. The complexes were characterized by elemental analysis and various spectroscopic techniques and are best formulated as [M(acnTSC2Cl2] with the metal likely in an octahedral environment. The anticancer activity of the complexes was determined against a panel of human colon cancer cells (HCT-116 and Caco-2. The compounds bind to DNA via an intercalative mode with binding constants of 9.7×104 M-1, 1.8×105 M-1, and 9.5×104 M-1 for the zinc, cobalt, and copper complexes, respectively.

  4. Coordination Chemistry of Polyaromatic Thiosemicarbazones 2: Synthesis and Biological Activity of Zinc, Cobalt, and Copper Complexes of 1-(Naphthalene-2-yl)ethanone Thiosemicarbazone

    LeBlanc, Marc-Andre; Gonzalez-Sarrías, Antonio; Beckford, Floyd A.; Mbarushimana, P. Canisius; Seeram, Navindra P.

    2012-01-01

    A novel thiosemicarbazone from 2-acetonaphthone (represented as acnTSC) has been synthesized and its basic coordination chemistry with zinc(II), cobalt(II), and copper(II) explored. The complexes were characterized by elemental analysis and various spectroscopic techniques and are best formulated as [M(acnTSC)2Cl2] with the metal likely in an octahedral environment. The anticancer activity of the complexes was determined against a panel of human colon cancer cells (HCT-116 and Caco-2). The compounds bind to DNA via an intercalative mode with binding constants of 9.7 × 104 M−1, 1.8 × 105 M−1, and 9.5 × 104 M−1 for the zinc, cobalt, and copper complexes, respectively. PMID:22303515

  5. Synthesis via “click chemistry" of new triazole analogues derivatives of grandisin and veraguensin neolignans with potential trypanocidal and leishmanicidal activity

    Tatiana C Bortolo

    2012-06-01

    Full Text Available Using the concept of bioisosterism, new triazole analogs were designed from the molecular modification of grandisin and veraguensin neolignans   which have a furan group that is a bioisóstere of 1,2,3-triazoles ring. In order to obtain more potent compounds, with fewer side effects, and better physical and chemical characteristics in combating leishmaniasis and chagas disease, this research group synthesized, via "Click Chemistry", eight new triazole analogues of neolignans. Thus reactions 1,3-dipolar cycloaddition of Huisgen were performed between terminal acetylenes and azides previously synthesized. The catalytic system CuSO4.5H2O/Ascorbate Sodium / CH2Cl2/H2O was used and, under this reaction conditions eight triazole analogues were synthesized in good yields. Trypanocidal activity test showed positive for the eight molecules.

  6. The radiation chemistry of macromolecules

    1973-01-01

    The Radiation Chemistry of Macromolecules, Volume II is a collection of papers that discusses radiation chemistry of specific systems. Part 1 deals with radiation chemistry of substituted vinyl polymers, particularly polypropylene (PP) as its structure is intermediate between polyethylene and polyisobutylene. This part also discusses polypropylene oxide (PPOx) for it can be prepared in the atactic, isotactic, and optically active forms. One paper focuses on the fundamental chemical processes and the changes in physical properties that give rise to many different applications of polystyrene. An

  7. [JSPS Asia and Africa scientific platform program development for the medicinal chemistry based on biologically active natural products in the subtropical zone].

    Saito, Naoki; Morita, Takashi

    2009-04-01

    In 2005, the independent administrative institution the "Japan Society for the Promotion of Sciences (JSPS)" initiated the "Asia and Africa Science Platform Program", which is a new project aimed to create high potential research hubs in selected fields within the Asian and African region, while fostering the next generation of leading researchers. Another goal is to establish sustainable collaborative relationships among universities and research institutes in Japan and other Asian and African countries. In this project, we consider natural sources existing in partner countries to be the most important factor in the production of medicine. We will search for target compounds and analyze their structures by screening biologically active natural products. Additionally, we will design functional molecules and create process for retrieving a large supply of target compounds based on a bioprospecting strategy. Thailand, Indonesia, and India share the vision of enhancing collaborative efforts. By conducting this researche, we will focus on academic research that is necessary for the development of the pharmaceutical and medical products industry in partner countries. There are four selected research topics as followeds: 1) Development of New Antitumor Agents based on Marine Natural Products; 2) Development of New Anticoagulants and Anti-VEGF; 3) Molecular Epidemiological Investigation of Emerging Infectious Diseases and Development of Novel Diagnosis and Therapeutic Agents; and 4) Medicinal Chemistry on Biologically Active Natural Products from the Traditional Condiments and Medicines. The exchanges might take the form of joint research seminars. The first Medicinal Chemistry Seminar of the AA Scientific Platform Program was co-organized with the 23th Annual Research Conference on Pharmaceutical Sciences, Thailand at Chulalongkorn University, Bangkok, on December 14-15, 2006. The 2nd JSPS seminar was co-organized with the 1st Bioactive Natural Products from Marine

  8. The influence of modified water chemistries on metal oxide films, activity build-up and stress corrosion cracking of structural materials in nuclear power plants

    The primary coolant oxidises the surfaces of construction materials in nuclear power plants. The properties of the oxide films influence significantly the extent of incorporation of actuated corrosion products into the primary circuit surfaces, which may cause additional occupational doses for the maintenance personnel. The physical and chemical properties of the oxide films play also an important role in different forms of corrosion observed in power plants. This report gives a short overview of the factors influencing activity build-up and corrosion phenomena in nuclear power plants. Furthermore, the most recent modifications in the water chemistry to decrease these risks are discussed. A special focus is put on zinc water chemistry, and a preliminary discussion on the mechanism via which zinc influences activity build-up is presented. Even though the exact mechanisms by which zinc acts are not yet known, it is assumed that Zn may block the diffusion paths within the oxide film. This reduces ion transport through the oxide films leading to a reduced rate of oxide growth. Simultaneously the number of available adsorption sites for 60Co is also reduced. The current models for stress corrosion cracking assume that the anodic and the respective cathodic reactions contributing to crack growth occur partly on or in the oxide films. The rates of these reactions may control the crack propagation rate and therefore, the properties of the oxide films play a crucial role in determining the susceptibility of the material to stress corrosion cracking. Finally, attention is paid also on the novel techniques which can be used to mitigate the susceptibility of construction materials to stress corrosion cracking. (orig.)

  9. The influence of modified water chemistries on metal oxide films, activity build-up and stress corrosion cracking of structural materials in nuclear power plants

    Maekelae, K.; Laitinen, T.; Bojinov, M. [VTT Manufacturing Technology, Espoo (Finland)

    1999-03-01

    The primary coolant oxidises the surfaces of construction materials in nuclear power plants. The properties of the oxide films influence significantly the extent of incorporation of actuated corrosion products into the primary circuit surfaces, which may cause additional occupational doses for the maintenance personnel. The physical and chemical properties of the oxide films play also an important role in different forms of corrosion observed in power plants. This report gives a short overview of the factors influencing activity build-up and corrosion phenomena in nuclear power plants. Furthermore, the most recent modifications in the water chemistry to decrease these risks are discussed. A special focus is put on zinc water chemistry, and a preliminary discussion on the mechanism via which zinc influences activity build-up is presented. Even though the exact mechanisms by which zinc acts are not yet known, it is assumed that Zn may block the diffusion paths within the oxide film. This reduces ion transport through the oxide films leading to a reduced rate of oxide growth. Simultaneously the number of available adsorption sites for {sup 60}Co is also reduced. The current models for stress corrosion cracking assume that the anodic and the respective cathodic reactions contributing to crack growth occur partly on or in the oxide films. The rates of these reactions may control the crack propagation rate and therefore, the properties of the oxide films play a crucial role in determining the susceptibility of the material to stress corrosion cracking. Finally, attention is paid also on the novel techniques which can be used to mitigate the susceptibility of construction materials to stress corrosion cracking. (orig.) 127 refs.

  10. The Advantages Perceived by School Teachers in Engaging Their Students in University-Based Chemistry Outreach Activities

    Tuah, Jauyah; Harrison, Timothy G.; Shallcross, Dudley E.

    2009-01-01

    The value teachers put on university-based outreach activities designed for 14-16 year olds that involves both practical and lecture activities are discussed. A variety of good reasons for attending are provided by the teachers but the role of a School Teacher Fellow in mapping the events to the curriculum is shown to be vital to the success of…

  11. Thermal modification of activated carbon surface chemistry improves its capacity as redox mediator for azo dye reduction.

    Pereira, L; Pereira, R; Pereira, M F R; van der Zee, F P; Cervantes, F J; Alves, M M

    2010-11-15

    The surface chemistry of a commercial AC (AC(0)) was selectively modified, without changing significantly its textural properties, by chemical oxidation with HNO(3) (AC(HNO3)) and O(2) (AC(O2)), and thermal treatments under H(2) (AC(H2)) or N(2) (AC(N2)) flow. The effect of modified AC on anaerobic chemical dye reduction was assayed with sulphide at different pH values 5, 7 and 9. Four dyes were tested: Acid Orange 7, Reactive Red 2, Mordant Yellow 10 and Direct Blue 71. Batch experiments with low amounts of AC (0.1 g L(-1)) demonstrated an increase of the first-order reduction rate constants, up to 9-fold, as compared with assays without AC. Optimum rates were obtained at pH 5 except for MY10, higher at pH 7. In general, rates increased with increasing the pH of point zero charge (pH(pzc)), following the trend AC(HNO3) < AC(O2) < AC(0) < AC(N2) < AC(H2). The highest reduction rate was obtained for MY10 with AC(H2) at pH 7, which corresponded to the double, as compared with non-modified AC. In a biological system using granular biomass, AC(H2) also duplicated and increase 4.5-fold the decolourisation rates of MY10 and RR2, respectively. In this last experiment, reaction rate was independent of AC concentration in the tested range 0.1-0.6 g L(-1). PMID:20800966

  12. Combustion chemistry

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    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).

  13. Cyclodextrin chemistry

    The chemistry of cyclodextrins was studied. This study included synthesising some cyclodextrin derivatives, preparing selected inclusion complexes with cyclodextrin and investigating the effects of gamma irradiation on cyclodextrins and certain linear oligosaccharides. This report presents a brief review of the structure and properties of cyclodextrins, the synthesis of cyclodextrin derivatives, their complexation and applications. This is followed by a description of the synthesis of some cyclodextrin derivatives and the preparation of inclusion complexes of cyclodextrin with some organic compounds. Finally, the effects of gamma irradiation on cyclodextrins, some of their derivatives and certain structurally related carbohydrates are discussed. The gamma irradiation studies were carried out for two reasons: to study the effects of gamma irradiation on cyclodextrins and their derivatives; and to investigate selectivity during the gamma irradiation of cyclodextrin derivatives

  14. Chemistry in all its States

    Ruiz-Hitzky, Eduardo

    2015-01-01

    1 • The Microwave Oven: from the Kitchen to Synthesis Chemistry “A microwave oven is a domestic appliance that is mainly used to heat up food quickly, by agitating the water molecules contained in the food under the effect of a microwave radiation” (Wikipedia). From the outset, this technology was mainly used in the kitchen and sometimes in highly precise industrial applications. However, for the last twenty years or so microwave has also been used in chemistry laboratories, to activate chem...

  15. Design, synthesis, and anticancer activity of novel berberine derivatives prepared via CuAAC “click” chemistry as potential anticancer agents

    Jin X

    2014-08-01

    Full Text Available Xin Jin1,2,* Tian-Hua Yan,3,* Lan Yan,1 Qian Li,4 Rui-Lian Wang,1 Zhen-Lin Hu,1 Yuan-Ying Jiang,1 Qing-Yan Sun,1 Yong-Bing Cao1 1School of Pharmacy, Second Military Medical University, Shanghai, People's Republic of China; 2School of Pharmacy, FuJian University of Traditional Chinese Medicine, Fuzhou, People's Republic of China; 3Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing, People's Republic of China; 4Diakite Biological Technology Co., Ltd, Shanghai, People's Republic of China *These authors contributed equally to this work Abstract: A series of novel derivatives of phenyl-substituted berberine triazolyls has been designed and synthesized via copper-catalyzed azide-alkyne cycloaddition click chemistry in an attempt to develop antitumor agents. All of the compounds were evaluated for anticancer activity against a panel of three human cancer cell lines, including MCF-7 (breast, SW-1990 (pancreatic, and SMMC-7721 (liver and the noncancerous human umbilical vein endothelial cell (HUVEC cell lines. The results indicated that most of the compounds displayed notable anticancer activities against the MCF-7 cells compared with berberine. Among these derivatives, compound 16 showed the most potent inhibitory activity against the SW-1990 and SMMC-7721 cell lines, with half-maximal inhibitory concentration (IC50 values of 8.54±1.97 µM and 11.87±1.83 µM, respectively. Compound 36 exhibited the most potent inhibitory activity against the MCF-7 cell line, with an IC50 value of 12.57±1.96 µM. Compound 16 and compound 36 exhibited low cytotoxicity in the HUVEC cell line, with IC50 values of 25.49±3.24 µM and 30.47±3.47 µM. Furthermore, compounds 14, 15, 16, 17, 18, 32, and 36 exhibited much better selectivity than berberine toward the normal cell line HUVEC. Keywords: berberine, anticancer, click chemistry, structure–activity relationship

  16. Modification of Activated Carbon by Means of Microwave Heating and Its Effects on the Pore Texture and Surface Chemistry

    Bing Li

    2013-02-01

    Full Text Available Two kinds of typical Activated Carbons (coal based AC and coconut shell based AC were modified in a flow of N0 gas has been carried out using a microwave device operating at 2450 MHz and different input power, instead of a conventional furnace. The samples were analyzed by means of low temperatureN0 adsorption, elemental analysis and Boehm titration. The results show that microwave heating is an effective means of activated carbon modification. The temperature of activated carbon increases rapidly under microwave heating and then gradual increase to a quasi-stationary temperature. The pore texture of activated carbon changes slightly after microwave treatment and the two activated carbons still keep rich pore structure. The oxygen functional groups decompose and evolve with the form of CO and CO2. This in turn gives rise to a significant decrease in oxygen content. These changes of oxygen contents increase as the microwave input power increases. During microwave treatment, a gradual decrease in the surface acidic functional groups is observed. More important, with the removal of the surface acidic groups, the number of the basic group increased gradually, the activated carbon with oxygen functional groups become basic properties material.

  17. Science Update: Inorganic Chemistry

    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)

  18. Why Teach Environmental Chemistry?

    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)

  19. Public perception of chemistry

    Stražar, Alenka

    2015-01-01

    The thesis deals with the perception of chemistry among the public, which reflects the stereotypes that people have about chemistry. It presents the existing classification of stereotypes about chemistry and their upgrade. An analysis of movies that reflect the existing perception of chemistry in the public is written. Literature on selected aspects of the application of chemistry in movies is collected and analyzed. A qualification of perception of chemistry in the movies is presented based ...

  20. Science Update: Inorganic Chemistry.

    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)

  1. Searching for halo-alkalophilic proteases maintaining stability and activity in hydrophilic aprotic solvents as biocatalysts in carbohydrate chemistry

    Pedersen, Lars Haastrup; Mørkholt, Camilla Kær; Nielsen, Carsten Bue

    2012-01-01

    and other carbohydrates (1, 2). Therefore, we are searching for new bacterial halo-alkaline proteases from extreme environments in Denmark. So far we have identified a number of interesting isolates showing proteolytic activity at pH 7 and 10. Whole genome Illumina Hiseq 2000 amplicon sequencing, de novo...

  2. Surface chemistry and catalytic activity of Ni/Al2O3 irradiated with high-energy electron beam

    The radiation effects induced effects by electron beam (EB) treatment on the catalytic activity of Ni/γ-Al2O3 were studied for the carbon dioxide reforming of methane with different EB energy and absorbed radiation dose. Transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to determine the change in structure and surface states of Ni/γ-Al2O3 catalyst before and after the EB treatment. Higher energy EB treatment is useful for increasing the proportion of the active sites (such as Ni0 and NiAl2O4-phase) on the surface. The increase of Ni/Al-ratio indicates that the Ni dispersion on the surface increased with the EB-treatment, resulting in an increase of the active sites, which leads to improving the catalytic activity. XPS measurement also showed a decrease of the surface carbon with EB dose. The maximum 20% increase in the conversion of CO2/CH4-mixture into CO/H2 gas was observed for the catalyst treated with 2 MeV energy and 600 kGy dose of EB relative to untreated

  3. Migration chemistry

    Migration chemistry, the influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour of pollutants in the environment, is an interplay between the actual natur of the pollutant and the characteristics of the environment, such as pH, redox conditions and organic matter content. The wide selection of possible pollutants in combination with varying geological media, as well as the operation of different chemical -, biochemical - and physico-chemical reactions compleactes the prediction of the influence of these processes on the mobility of pollutants. The report summarizes a wide range of potential pollutants in the terrestrial environment as well as a variety of chemical -, biochemical - and physico-chemical reactions, which can be expected to influence the migration behaviour, comprising diffusion, dispersion, convection, sorption/desorption, precipitation/dissolution, transformations/degradations, biochemical reactions and complex formation. The latter comprises the complexation of metal ions as well as non-polar organics to naturally occurring organic macromolecules. The influence of the single types of processes on the migration process is elucidated based on theoretical studies. The influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour is unambiguous, as the processes apparently control the transport of pollutants in the terrestrial environment. As the simple, conventional KD concept breaks down, it is suggested that the migration process should be described in terms of the alternative concepts chemical dispersion, average-elution-time and effective retention. (AB) (134 refs.)

  4. Reduction of 68Ge activity containing liquid waste from 68Ga PET chemistry in nuclear medicine and radiopharmacy by solidification

    E. de Blois (Erik); H.S. Chan; K. Roy (Kamalika); E.P. Krenning (Eric); W.A.P. Breeman (Wouter)

    2011-01-01

    textabstractPET with68Ga from the TiO2- or SnO2- based68Ge/68Ga generators is of increasing interest for PET imaging in nuclear medicine. In general, radionuclidic purity (68Ge vs.68Ga activity) of the eluate of these generators varies between 0.01 and 0.001%. Liquid waste containing low amounts of6

  5. Synthesis, chemistry, and catalytic activity of complexes of lanthanide and actinide metals in unusual oxidation states and coordination environments. Progress report, February 1, 1981-January 31, 1982

    The objectives of this research project are: (1) to demonstrate experimentally that the lanthanide and actinide metals have a more extensive chemistry than is presently known; (2) to develop a better understanding of the special features of the f orbital elements which will allow the design of f orbital complexes possessing unique chemical and physical properties; (3) to provide a basis for seeking unusual catalytic transformations involving these elements; and (4) to synthesize and explore the chemical and physical properties of mixed metal complexes which contain both lanthanide and transition metals. During the past year progress was made in each area. Some of the specific results are: (1) the first activation of CO by an organolanthanide complex was demonstrated; (2) the first, crystallograhically characterized, molecular lanthanide hydride complexes, the bridged dimers, [(C5H4R)2LnH(THF)]2 (R=H, CH3; Ln=Lu, Er, Y), were synthesized by hydrogenolysis of the appropriate (C5H4R)2Ln(C(CH3)3)(THF) complex; (3) [(C5H5)2(THF)ErH]2 was found to catalyze the homogeneous hydrogenation of alkynes; (4) the first trimetallic organolanthanide complex was synthesized; (5) the first polyhydridic organolanthanide complex was synthesized; (6) U(III) hydride was found to catalytically activate molecular hydrogen in alkene and alkyne hydrogenation reactions

  6. Students' Perceptions of Teaching in Context-Based and Traditional Chemistry Classrooms: Comparing Content, Learning Activities, and Interpersonal Perspectives

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

    2014-01-01

    Context-based curriculum reforms in chemistry education are thought to bring greater diversity to the ways in which chemistry teachers organize their teaching. First and foremost, students are expected to perceive this diversity. However, empirical research on how students perceive their teacher's teaching in context-based chemistry…

  7. Storytelling with Chemistry and Related Hands-on Activities: Informal Learning Experiences to Prevent "Chemophobia" and Promote Young Children's Scientific Literacy

    Morais, Carla

    2015-01-01

    The dissemination of chemistry has been experienced as a difficult task, largely because of the negative image that the public has of this science, but also because of its inherent complexity and its own semantics and symbolism. Science centers, as informal learning environments, can contribute to a more effective dissemination of chemistry to an…

  8. Determining the Quantum Efficiency for Activation of an Organometallic Photoinitiator for Cationic Polymerization: An Experiment for the Physical or Inorganic Chemistry Laboratory

    Hayes, David M.; Mahar, Maura; Schnabel, R. Chris; Shah, Paras; Lees, Alistair J.; Jakubek, Vladimir

    2007-01-01

    We present a new laboratory experiment on the photochemistry of organometallic [eta][superscript 5],[eta][superscript 6]-mixed-sandwich compounds, which is suitable for both the physical chemistry and inorganic chemistry laboratory. Specifically, students use 1,10-phenanthroline to trap the intermediate formed when…

  9. A new diamantane functionalized tris(aryloxide) ligand system for small molecule activation chemistry at reactive uranium complexes

    Lam, O.P.; Heinemann, F.W.; Meyer, K. [Department of Chemistry and Pharmacy, Inorganic Chemistry, University Erlangen-Nuremberg, Erlangen (Germany); Lam, O.P. [University of California, San Diego, Department of Chemistry and Biochemistry, La Jolla, CA (United States)

    2010-06-15

    The diamantane functionalized triazacyclononane ligand ({sup Dia}ArOH){sub 3}tacn (L{sub 3}) has been synthesized and the reactivity of its U(III) metallated product [(({sup Dia}ArO){sub 3}tacn)U] (1) has been explored. Complex 1 promotes dichloromethane and azido-trimethyl-silane activation to generate U(IV) complex [(({sup Dia}ArO){sub 3}tacn)U(Cl)] (2) and U(V) complex [(({sup Dia}ArO){sub 3}tacn)U(NTMS)] (3), respectively. Spectroscopic investigations of complexes 1, 2, and 3 will be discussed, along with molecular structures where possible. (authors)

  10. A new diamantane functionalized tris(aryloxide) ligand system for small molecule activation chemistry at reactive uranium complexes

    The diamantane functionalized triazacyclononane ligand (DiaArOH)3tacn (L3) has been synthesized and the reactivity of its U(III) metallated product [((DiaArO)3tacn)U] (1) has been explored. Complex 1 promotes dichloromethane and azido-trimethyl-silane activation to generate U(IV) complex [((DiaArO)3tacn)U(Cl)] (2) and U(V) complex [((DiaArO)3tacn)U(NTMS)] (3), respectively. Spectroscopic investigations of complexes 1, 2, and 3 will be discussed, along with molecular structures where possible. (authors)

  11. Experimentally calibrated computational chemistry of tryptophan hydroxylase: Trans influence, hydrogen-bonding, and 18-electron rule govern O-2-activation

    Haahr, Lærke Tvedebrink; Kepp, Kasper Planeta; Boesen, Jane;

    2010-01-01

    Insight into the nature of oxygen activation in tryptophan hydroxylase has been obtained from density functional computations. Conformations of O2-bound intermediates have been studied with oxygen trans to glutamate and histidine, respectively. An O2-adduct with O2 trans to histidine (Ohis) and a...... peroxo intermediate with peroxide trans to glutamate (Pglu) were found to be consistent (0.57–0.59 mm/s) with experimental Mössbauer isomer shifts (0.55 mm/s) and had low computed free energies. The weaker trans influence of histidine is shown to give rise to a bent O2 coordination mode with O2 pointing...

  12. Atmospheric pseudohalogen chemistry

    D. J. Lary

    2004-09-01

    Full Text Available There are at least three reasons why hydrogen cyanide is likely to be significant for atmospheric chemistry. The first is well known, HCN is a product and marker of biomass burning. However, if a detailed ion chemistry of lightning is considered then it is almost certain than in addition to lightning producing NOx, it also produces HOx and HCN. Unlike NOx and HOx, HCN is long-lived and could therefore be a useful marker of lightning activity. Observational evidence is considered to support this view. Thirdly, the chemical decomposition of HCN leads to the production of small amounts of CN and NCO. NCO can be photolyzed in the visible portion of the spectrum yielding N atoms. The production of N atoms is significant as it leads to the titration of nitrogen from the atmosphere via N+N→N2. Normally the only modelled source of N atoms is NO photolysis which happens largely in the UV Schumann-Runge bands. However, NCO photolysis occurs in the visible and so could be involved in titration of atmospheric nitrogen in the lower stratosphere and troposphere. HCN emission inventories are worthy of attention. The CN and NCO radicals have been termed pseudohalogens since the 1920s. They are strongly bound, univalent, radicals with an extensive and varied chemistry. The products of the atmospheric oxidation of HCN are NO, CO and O3. N+CH4 and N+CH3OH are found to be important sources of HCN. Including the pseudohalogen chemistry gives a small increase in ozone and total reactive nitrogen (NOy.

  13. A model for gas phase chemistry in interstellar clouds. II - Nonequilibrium effects and effects of temperature and activation energies

    Prasad, S. S.; Huntress, W. T., Jr.

    1980-01-01

    The chemical evolution of diffuse and dense interstellar clouds is examined via the time-dependent model outlined by Prasad and Huntress (1980). This paper presents specific results for CH, CO, CH4, O2, CH2O, CN, C2, C2H, HC3N, and NH3. Comparison with observations and predictions of other contemporary models show that cloud temperature plays a very important role through the inverse temperature dependence of radiative association reactions and through activation energies in neutral reactions and selected ion-molecule reactions. The observed fractional abundance of CN with respect to H2 and more accurate recent laboratory data on CN + O and CN + O2 reactions suggest that there is an unidentified, yet efficient, mechanism for conversion of O and O2 into polyatomic species. C2H and HC3N are synthesized early in the history of dense clouds. The value of the fractional abundance of C2H remains high, because as the cloud cools down the activation energy in the C2H + O reaction closes down this most important loss channel. A rapidly decreasing fractional abundance of O with time can also accomplish the same result. The value of the fractional abundance of HC3N remains high because it is an unreactive molecule and probably does not condense readily onto grains.

  14. Technical Consultation of the International Space Station (ISS) Internal Active Thermal Control System (IATCS) Cooling Water Chemistry

    Gentz, Steven J.; Rotter, Hank A.; Easton, Myriam; Lince, Jeffrey; Park, Woonsup; Stewart, Thomas; Speckman, Donna; Dexter, Stephen; Kelly, Robert

    2005-01-01

    The Internal Active Thermal Control System (IATCS) coolant exhibited unexpected chemical changes during the first year of on-orbit operation following the launch and activation in February 2001. The coolant pH dropped from 9.3 to below the minimum specification limit of 9.0, and re-equilibrated between 8.3 and 8.5. This drop in coolant pH was shown to be the result of permeation of CO2 from the cabin into the coolant via Teflon flexible hoses which created carbonic acid in the fluid. This unexpected diffusion was the result of having a cabin CO2 partial pressure higher than the ground partial pressure (average 4.0 mmHg vs. less than 0.2 mmHg). This drop in pH was followed by a concurrent increasing coolant nickel concentration. No other metal ions were observed in the coolant and based on previous tests, the source of nickel ion was thought to be the boron nickel (BNi) braze intermetallics used in the construction of HXs and cold plates. Specifically, BNi2 braze alloy was used for the IATCS IFHX and BNi3 braze alloy was used for the IATCS Airlock Servicing and Performance Checkout Unit (SPCU) HX and cold plates. Given the failure criticality of the HXs, a Corrosion Team was established by the IATCS CWG to determine the impact of the nickel corrosion on hardware performance life.

  15. A Systematic Study of Structure and E-H Bond Activation Chemistry by Sterically Encumbered Germylene Complexes.

    Usher, Matthew; Protchenko, Andrey V; Rit, Arnab; Campos, Jesús; Kolychev, Eugene L; Tirfoin, Rémi; Aldridge, Simon

    2016-08-01

    A series of new germylene compounds has been synthesized offering systematic variation in the σ- and π-capabilities of the α-substituent and differing levels of reactivity towards E-H bond activation (E=H, B, C, N, Si, Ge). Chloride metathesis utilizing [(terphenyl)GeCl] proves to be an effective synthetic route to complexes of the type [(terphenyl)Ge(ERn )] (1-6: ERn =NHDipp, CH(SiMe3 )2 , P(SiMe3 )2 , Si(SiMe3 )3 or B(NDippCH)2 ; terphenyl=C6 H3 Mes2 -2,6=Ar(Mes) or C6 H3 Dipp2 -2,6=Ar(Dipp) ; Dipp=C6 H3 iPr2 -2,6, Mes=C6 H2 Me3 -2,4,6), while the related complex [{(Me3 Si)2 N}Ge{B(NDippCH)2 }] (8) can be accessed by an amide/boryl exchange route. Metrical parameters have been probed by X-ray crystallography, and are consistent with widening angles at the metal centre as more bulky and/or more electropositive substituents are employed. Thus, the widest germylene units (θ>110°) are found to be associated with strongly σ-donating boryl or silyl ancillary donors. HOMO-LUMO gaps for the new germylene complexes have been appraised by DFT calculations. The aryl(boryl)-germylene system [Ar(Mes) Ge{B(NDippCH)2 }] (6-Mes), which features a wide C-Ge-B angle (110.4(1)°) and (albeit relatively weak) ancillary π-acceptor capabilities, has the smallest HOMO-LUMO gap (119 kJ mol(-1) ). These features result in 6-Mes being remarkably reactive, undergoing facile intramolecular C-H activation involving one of the mesityl ortho-methyl groups. The related aryl(silyl)-germylene system, [Ar(Mes) Ge{Si(SiMe3 )3 }] (5-Mes) has a marginally wider HOMO-LUMO gap (134 kJ mol(-1) ), rendering it less labile towards decomposition, yet reactive enough to oxidatively cleave H2 and NH3 to give the corresponding dihydride and (amido)hydride. Mixed aryl/alkyl, aryl/amido and aryl/phosphido complexes are unreactive, but amido/boryl complex 8 is competent for the activation of E-H bonds (E=H, B, Si) to give hydrido, boryl and silyl products. The results of these reactivity studies

  16. Optimization of molecular and crystalline forms of drugs, agrochemicals, pesticides in relation to activity, bioavailability, patentability and to the fabrication of polymorphs, solvates, co-crystals with green chemistry methods

    Nanna, Saverio

    2015-01-01

    This doctorate was funded by the Regione Emilia Romagna, within a Spinner PhD project coordinated by the University of Parma, and involving the universities of Bologna, Ferrara and Modena. The aim of the project was: - Production of polymorphs, solvates, hydrates and co-crystals of active pharmaceutical ingredients (APIs) and agrochemicals with green chemistry methods; - Optimization of molecular and crystalline forms of APIs and pesticides in relation to activity, bioavailability an...

  17. Fuel Chemistry Division: progress report for 1987

    The progress of research and development activities of the Fuel Chemistry Division of the Bhabha Atomic Research Centre, Bombay, during 1987 is reported in the form of summaries which are arranged under the headings: Fuel Development Chemistry, Chemistry of Actinides, Chemical Quality Control of Fuel, and Studies related to Nuclear Material Accounting. A list of publications by the members of the Division during the report period is given at the end of the report. (M.G.B.). refs., 15 figs., 85 tabs

  18. Creating a Context for Chemistry

    Truman Schwartz, A.

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

  19. Physical chemistry and the environment

    From the ozone hole and the greenhouse effect to plastics recycling and hazardous waste disposal, society faces a number of issues, the solutions to which require an unprecedented understanding of the properties of molecules. We are coming to realize that the environment is a coupled set of chemical systems, its dynamics determining the welfare of the biosphere and of humans in particular. These chemical systems are governed by fundamental molecular interactions, and they present chemists with an unparalleled challenge. The application of current concepts of molecular behavior and of up-to-date experimental and computational techniques can provide us with insights into the environment that are needed to mitigate past damage, to anticipate the impact of current human activity, and to avoid future insults to the environment. Environmental chemistry encompasses a number of separate, yet interlocking, areas of research. In all of these areas progress is limited by an inadequate understanding of the underlying chemical processes involved. Participation of all chemical approaches -- experimental, theoretical and computational -- and of all disciplines of chemistry -- organic, inorganic, physical, analytical and biochemistry -- will be required to provide the necessary fundamental understanding. The Symposium on ''Physical Chemistry and the Environment'' was designed to bring the many exciting and challenging physical chemistry problems involved in environmental chemistry to the attention of a larger segment of the physical chemistry community

  20. The Chemistry and Biological Activities of Natural Products from Northern African Plant Families: From Taccaceae to Zygophyllaceae.

    Ntie-Kang, Fidele; Njume, Leonel E; Malange, Yvette I; Günther, Stefan; Sippl, Wolfgang; Yong, Joseph N

    2016-04-01

    Traditional medicinal practices have a profound influence on the daily lives of people living in developing countries, particularly in Africa, since the populations cannot generally afford the cost of Western medicines. We have undertaken to investigate the correlation between the uses of plants in Traditional African medicine and the biological activities of the derived natural products, with the aim to validate the use of traditional medicine in Northern African communities. The literature is covered for the period 1959-2015 and part III of this review series focuses on plant families with names beginning with letters T to Z. The authors have focused on curating data from journals in natural products and phytomedicine. Within each journal home page, a query search based on country name was conducted. All articles "hits" were then verified, one at a time, that the species was harvested within the Northern African geographical regions. The current data partly constitutes the bases for the development of the Northern African natural compounds database. The review discusses 284 plant-based natural compounds from 34 species and 11 families. It was observed that the ethnobotanical uses of less than 40 % of the plant species surveyed correlated with the bioactivities of compounds identified. PMID:26931529

  1. Industrial Chemistry and School Chemistry: Making Chemistry Studies More Relevant

    Hofstein, Avi; Kesner, Miri

    2006-01-01

    In this paper, we present the development and implementation over the period of more than 15 years of learning materials focusing on industrial chemistry as the main theme. The work was conducted in the Department of Science Teaching at the Weizmann Institute of Science, Israel. The project's general goal was to teach chemistry concepts in the…

  2. Chemistry, phase formation, and catalytic activity of thin palladium-containing oxide films synthesized by plasma-assisted physical vapor deposition

    Anders, Andre

    2010-11-26

    The chemistry, microstructure, and catalytic activity of thin films incorporating palladium were studied using scanning and transmission electron microscopies, X-ray diffraction, spectrophotometry, 4-point probe and catalytic tests. The films were synthesized using pulsed filtered cathodic arc and magnetron sputter deposition, i.e. techniques far from thermodynamic equilibrium. Catalytic particles were formed by thermally cycling thin films of the Pd-Pt-O system. The evolution and phase formation in such films as a function of temperature were discussed in terms of the stability of PdO and PtO2 in air. The catalytic efficiency was found to be strongly affected by the chemical composition, with oxidized palladium definitely playing a major role in the combustion of methane. Reactive sputter deposition of thin films in the Pd-Zr-Y-O system allowed us forming microstructures ranging from nanocrystalline zirconia to palladium nanoparticles embedded in a (Zr,Y)4Pd2O matrix. The sequence of phase formation is put in relation to simple thermodynamic considerations.

  3. Publicising chemistry in a multicultural society through chemistry outreach

    Joyce D. Sewry

    2011-11-01

    Full Text Available Given the emphasis in Higher Education on community engagement in South Africa and the importance of international collaboration, we discuss a joint approach to chemistry outreach in two countries on two continents with widely differing target school audiences. We describe the history of the partnership between the chemistry departments at Rhodes University and the University of Bristol and provide an outline of the chemistry content of their outreach initiatives, the modes of delivery, the advantages to both departments and their students for involvement in various levels of outreach, the challenges they still face and additional opportunities that such work facilitated. The lecture demonstration ‘A Pollutant’s Tale’ was presented to thousands of learners all over the world, including learners at resource-deprived schools in South Africa. Challenges to extend outreach activities in South Africa include long travelling distances, as well as a lack of facilities (such as school halls and electricity at schools. Outreach activities not only impacted on the target audience of young learners, they also impacted upon the postgraduate and other chemistry students taking part in these initiatives. This collaboration strengthened both institutions and their outreach work and may also lead to chemistry research collaborations between the academics involved.

  4. Combining Chemistry

    The last advances inside the field of the chemical synthesis involve mainly two classes of methods, the parallel and that of separation and it mixes. Each one of them offers different possibilities in the obtaining of the looked for substance. In this article it is described in succinct form the procedures that are continued in each case, the same thing that their advantages and disadvantages. In the synthesis process, especially in pharmacology, the main interest of the chemists is centered in finding indications of clinical activity in the compounds that synthesize. In the realization of this work class it leaves initially of the basic structure of a substance, in general derived of natural products as bacteria, mushrooms, etc; With well-known clinical activity the one which once selected, and fully identified, it takes as molecule mother or series head with the purpose of making different transformations in their structure it stops then to check if the new compound presents a bigger or smaller activity that the initial. Although this synthesis method has been refined with the use of different tests that they are made in a form but quick and reliable; the appearance of new illnesses and the necessity of quick treatments on the part of the drugs, the necessity of quick and efficient production of medications has increased with great biological activity that they allow to assure a better acting

  5. From Matter to Life:Chemistry?Chemistry!

    Jean-Marie; LEHN

    2007-01-01

    1 Results Animate as well as inanimate matter,living organisms as well as materials,are formed of molecules and of the organized entities resulting from the interaction of molecules with each other.Chemistry provides the bridge between the molecules of inanimate matter and the highly complex molecular architectures and systems which make up living organisms. Synthetic chemistry has developed a very powerful set of methods for constructing ever more complex molecules.Supramolecular chemistry seeks to con...

  6. Green chemistry: A tool in Pharmaceutical Chemistry

    Smita Talaviya; Falguni Majumdar

    2012-01-01

    Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceut...

  7. Dapson in heterocyclic chemistry, part VIII: synthesis, molecular docking and anticancer activity of some novel sulfonylbiscompounds carrying biologically active 1,3-dihydropyridine, chromene and chromenopyridine moieties

    Al-Said Mansour S

    2012-07-01

    Full Text Available Abstract Several new sulfonebiscompounds having a biologically active 1,2-dihydropyridine-2-one 3–19, acrylamide 20, chromene 21, 22 and chromenopyridine 23, 24 moieties were synthesized and evaluated as potential anticancer agents. The structures of the products were confirmed via elemental analyses and spectral data. The screening tests showed that many of the biscompounds obtained exhibited good anticancer activity against human breast cell line (MCF7 comparable to doxorubicin which was used as reference drug. Compounds 11, 17 and 24 showed IC50 values 35.40 μM, 29.86 μM and 30.99 μM, respectively. In order to elucidate the mechanism of action of the synthesized compounds as anticancer agents, docking on the active site of farnesyltransferase and arginine methyltransferase was also performed and good results were obtained.

  8. Mound Laboratory activities in chemical and physical research: July--December 1976. [Isotope separation; metal hydride research, separation chemistry and separation research

    1977-05-04

    The status of the following programs is reported: isotope separation of carbon, argon, helium, krypton, neon, xenon, oxygen, and sulfur; metal hydride research; separation chemistry; and separation research. (LK)

  9. ADVANCES IN ORGANIC, BIOORGANIC AND NATURAL PRODUCTS CHEMISTRY IN THE INSTITUTE OF CHEMISTRY OF THE ACADEMY OF SCIENCES OF MOLDOVA

    Vlad, Pavel F.; Fliur Z. Macaev

    2009-01-01

    This overview deals with the advances in the investigation in the fi eld of organic, bioorganic and naturalproducts chemistry as well as the biologically active compounds in the Institute of Chemistry of the Academy of Sciences of Moldova.

  10. Chemistry Rocks: Redox Chemistry as a Geologic Tool.

    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)

  11. Crevice chemistry estimation from bulk water chemistry

    Since the first PWR plant in Japan started commercial operation in 1970, 22 plants are running in Japan as of the end of 1994. The main purpose of secondary water chemistry control is to minimize the corrosion possibility of the secondary system equipment, especially steam generators (SG). To achieve this objective, much effort has been concentrated on improving secondary water chemistry control. As a result of this effort, the recent secondary water chemistry in Japanese plants is well maintained in every stage of operation. However, to ensure and improve the reliability of SG, it is necessary to control crevice environments, which are located at tube/tube support plate intersections and under the sludge pile on the tube sheet. According to recent crevice monitoring examination results, the concentration behavior impurities in SG bulk water at the crevice is different for each species, and SG bulk water and crevice chemical compositions are not always equal. From these results, to control the crevice chemistry, improving bulk water chemistry control methods and a new type of molar ratio control index is needed. This paper introduces a brief summary of a recent crevice chemistry evaluation technique and bulk water chemistry control method, which is employed for crevice chemistry control, based on crevice monitoring examination results

  12. Advances in BWR water chemistry

    This paper reviews recent advances in Boiling Water Reactor (BWR) water chemistry control with examples of plant experiences at U.S. designed BWRs. Water chemistry advances provide some of the most effective methods for mitigating materials degradation, reducing fuel performance concerns and lowering radiation fields. Mitigation of stress corrosion cracking (SCC) of materials remains a high priority and improved techniques that have been demonstrated in BWRs will be reviewed, specifically hydrogen injection combined with noble metal chemical addition (NMCA) and the newer on-line noble metal application process (OLNC). Hydrogen injection performance, an important part of SCC mitigation, will also be reviewed for the BWR fleet, highlighting system improvements that have enabled earlier injection of hydrogen including the potential for hydrogen injection during plant startup. Water chemistry has been significantly improved by the application of pre-filtration and optimized use of ion exchange resins in the CP (condensate polishing) and reactor water cleanup (RWCU) systems. EPRI has monitored and supported water treatment improvements to meet water chemistry goals as outlined in the EPRI BWR Water Chemistry Guidelines, particularly those for SCC mitigation of reactor internals and piping, minimization of fuel risk due to corrosion and crud deposits and chemistry control for radiation field reduction. In recent years, a significant reduction has occurred in feedwater corrosion product input, particularly iron. A large percentage of plants are now reporting <0.1 ppb feedwater iron. The impacts to plant operation and chemistry of lower feedwater iron will be explored. Depleted zinc addition is widely practiced across the fleet and the enhanced focus on radiation reduction continues to emphasize the importance of controlling radiation source term. In addition, shutdown chemistry control is necessary to avoid excessive release of activated corrosion products from fuel

  13. Department of Chemistry, progress report

    The research activities in Department of Chemistry during the last 3 years from 1986 to 1988 were compiled. The researches and works of Department of Chemistry are mainly those concerned with important basic matters and items which are committed to the further development of the nuclear fuels and materials, to the establishment of the nuclear fuel cycle, and to the acquisition of data for the environmental safety studies. Intensive efforts were also made on chemical analysis service of various fuels and nuclear materials. (author)

  14. Molten fluoride fuel salt chemistry

    The chemistry of molten fluorides is traced from their development as fuels in the Molten Salt Reactor Experiment with important factors in their selection being discussed. Key chemical characteristics such as solubility, redox behavior, and chemical activity are explained as they relate to the behavior of molten fluoride fuel systems. Fission product behavior is described along with processing experience. Development requirements for fitting the current state of the chemistry to modern nuclear fuel system are described. It is concluded that while much is known about molten fluoride behavior, processing and recycle of the fuel components is a necessary factor if future systems are to be established

  15. Green chemistry: A tool in Pharmaceutical Chemistry

    Smita Talaviya

    2012-07-01

    Full Text Available Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceuticals is to utilize eco-friendly, non-hazardous, reproducible and efficient solvents and catalysts in synthesis of drug molecules, drug intermediates and in researches involving synthetic chemistry. Microwave synthesis is also an important tool of green chemistry by being an energy efficient process.

  16. Organometallic Chemistry of Molybdenum.

    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)

  17. CHINESE JOURNAL OF CHEMISTRY

    2000-01-01

    @@Chinese Journal of Chemistry is an international journal published in English by the Chinese Chemical Society with its editorial office hosted by Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.

  18. Environmental chemistry: Volume A

    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.

  19. Frontiers in Gold Chemistry

    Mohamed, Ahmed A.

    2015-01-01

    Basic chemistry of gold tells us that it can bond to sulfur, phosphorous, nitrogen, and oxygen donor ligands. The Frontiers in Gold Chemistry Special Issue covers gold complexes bonded to the different donors and their fascinating applications. This issue covers both basic chemistry studies of gold complexes and their contemporary applications in medicine, materials chemistry, and optical sensors. There is a strong belief that aurophilicity plays a major role in the unending applications of g...

  20. Green Chemistry and Education.

    Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

    2000-01-01

    Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)

  1. Facets of coordination chemistry

    Agarwala, BV

    1993-01-01

    A concise account of coordination chemistry since its inception is given here together with some of the newer significant facets. This book covers a broad spectrum of various topics on Environment, Cyclic Voltammetry, Chromatography, Metal Complexes of biological interest, Alkoxides, NMR spectroscopy and others. These are useful to the scientific community engaged in the field of Inorganic Chemistry and Analytical Chemistry.

  2. Complex Protostellar Chemistry

    Nuth, Joseph A., III; Johnson, Natasha M.

    2012-01-01

    Two decades ago, our understanding of the chemistry in protostars was simple-matter either fell into the central star or was trapped in planetary-scale objects. Some minor chemical changes might occur as the dust and gas fell inward, but such effects were overwhelmed by the much larger scale processes that occurred even in bodies as small as asteroids. The chemistry that did occur in the nebula was relatively easy to model because the fall from the cold molecular cloud into the growing star was a one-way trip down a well-known temperature-pressure gradient; the only free variable was time. However, just over 10 years ago it was suggested that some material could be processed in the inner nebula, flow outward, and become incorporated into comets (1, 2). This outward flow was confirmed when the Stardust mission returned crystalline mineral fragments (3) from Comet Wild 2 that must have been processed close to the Sun before they were incorporated into the comet. In this week's Science Express, Ciesla and Sandford (4) demonstrate that even the outermost regions of the solar nebula can be a chemically active environment. Their finding could have consequences for the rest of the nebula.

  3. Materials Chemistry Studies

    In 2006, a new research group has been created at the SCK-CEN in order to focus more specifically on chemical issues relevant to the studies of materials. The integrated staff personnel has a long experience in many different fields of expertise such as radiochemistry (fuel cycles and radioisotopes), organic chemistry, electrochemistry (analytical techniques and corrosion) and sonochemistry. The previously running activities are now being reoriented according to a well-defined work programme. Each research line that was previously running had specific objectives. Fuel cycle studies were axed on the partitioning of lanthanides and actinides in aqueous solutions. Support to corrosion studies was devoted to the development of a new method for the treatment of electrochemical noise data for the detection and the classification of local corrosion events. New objectives for the future put a strong accent on radioisotopes for the pharmaceutical industry as well as the use of non-aqueous chemistry as a tool for several applications among which the treatment and the separation of radioisotopes, analytical measurements as well as the chemical control of impurities in liquid metals

  4. Tropospheric Halogen Chemistry

    von Glasow, R.; Crutzen, P. J.

    2003-12-01

    processes. Early work by Cauer (1951) had shown that Cl/Na and Cl/Mg ratios were lower in air than in seawater, indicating loss of chlorine by "acid displacement" from sea salt by the strong acids, H2SO4 (Eriksson (1959a, b) and HNO3 (Robbins et al., 1959). Already the first measurements of bromine in aerosols by Duce et al. (1963) showed that bromine, like chlorine, was lost from the sea salt particles, whereas iodine was strongly enriched ( Duce et al., 1965). Research since the early 1980s has shown that photochemical processes are actively involved.Interest in the chemistry of atmospheric halogens took a steep upward surge after it was postulated that the release of industrially produced halocarbons, in particular the chlorofluorocarbons (CFCs), CFCl3, and CF2Cl2, could cause severe depletions in stratospheric ozone (Molina and Rowland, 1974) by the reactions involving the CFC photolytic product radicals, Cl and ClO, as catalysts. The first stratospheric measurements of ClO did indeed show its presence in significant quantities in the stratosphere so that by the end of the 1970s USA, Canada, and the Scandinavian countries issued laws against the use of CFC gases as propellants in spray cans. In the mid-1980s the springtime stratospheric ozone hole over Antarctica was discovered by Farman et al. (1985), involving heterogeneous reactions on polar stratospheric clouds that lead to chlorine activation ( Solomon et al., 1986). Ten years later, in 1996, a complete phaseout ofthe production of the CFCs and a number of other chlorine- or bromine-containing chemicals came into effect for all nations in the developed world. In this contribution we will, however, concentrate on the impact of reactive chlorine, bromine, and iodine on tropospheric ozone chemistry.Halogens have the potential to be important in many facets of tropospheric chemistry. A multitude of gas phase reactions and gas-particle interactions occur that include coupling with the sulfur cycle and reactions with

  5. Optically active tetra-tert-butyl-P(5)-deltacyclene epimers: preparation, spectroscopy, dynamic equilibriums, H/D exchange, and transition-metal complex chemistry.

    Rohwer, Lars; Höhn, Christine; Autschbach, Jochen; Bauer, Walter; Heinemann, Frank W; Huguet Torrell, Sergi; Keller, Irene; Shubina, Tatyana E; Steffen, Jacob; Zenneck, Ulrich

    2014-05-01

    On the basis of isolated diastereomeric triorganylstannyl-P5 -deltacyclenes 7' and 7'', almost pure enantiomers of their destannylation products 8' and 8'' are now available. These stereochemically inert cage chiral species contain a configurationally labile P1H1 group that defines two epimers 8 a and 8 b of each of the enantiomers, which are connected by a rapid equilibrium. Mirror-symmetric circular dichroism (CD) spectra of the enantiomeric cages are compatible with the identification of epimers. A simulation of the CD spectrum of the major epimer 8'a relates the cage chirality of the system to the observed chiroptical effects. Both cage epimers and two of the phosphorus cage atoms are active as ligands with respect to [M(CO)5 ] fragments of Cr, Mo, and W. Four almost isoenergetic regio- and stereoisomers of the resulting mononuclear complexes are formed for these metals, but only one of the isomers per metal crystallized in the case of the racemic series of the complexes. The enantiopure versions of cages and cage complexes, however, did not crystallize at all, a well-known phenomenon for chiral compounds. CD spectra of the optically active complex isomer mixtures are close to identical with the CD spectra of the related free cages and point again to the chiral cages as the dominant source of the CD effects of the complexes. [(Benzene)RuCl2 ] complexes of the cage ligand 8 behave totally differently. Only a single species 12=[(benzene)RuCl2 ⋅8 b] is formed in almost quantitative yield and the minor epimer 8 b plays the role of the ligand exclusively. The reaction works as well for the separated enantiomeric cage versions to yield the highly enriched enantiomers 12' and 12'' separately. An efficient kinetic resolution process was identified as the main reason for this finding. It is based on a high stereo- and regiochemical flexibility of the PC cage ligand that is capable of adjusting to the specific requirements of a suitable transition

  6. Targeting Mitogen-Activated Protein Kinase-Activated Protein Kinase 2 (MAPKAPK2, MK2): Medicinal Chemistry Efforts To Lead Small Molecule Inhibitors to Clinical Trials.

    Fiore, Mario; Forli, Stefano; Manetti, Fabrizio

    2016-04-28

    The p38/MAPK-activated kinase 2 (MK2) pathway is involved in a series of pathological conditions (inflammation diseases and metastasis) and in the resistance mechanism to antitumor agents. None of the p38 inhibitors entered advanced clinical trials because of their unwanted systemic side effects. For this reason, MK2 was identified as an alternative target to block the pathway but avoiding the side effects of p38 inhibition. However, ATP-competitive MK2 inhibitors suffered from low solubility, poor cell permeability, and scarce kinase selectivity. Fortunately, non-ATP-competitive inhibitors of MK2 have been already discovered that allowed circumventing the selectivity issue. These compounds showed the additional advantage to be effective at lower concentrations in comparison to the ATP-competitive inhibitors. Therefore, although the significant difficulties encountered during the development of these inhibitors, MK2 is still considered as an attractive target to treat inflammation and related diseases to prevent tumor metastasis and to increase tumor sensitivity to chemotherapeutics. PMID:26502061

  7. American Association for Clinical Chemistry

    ... indispensable patient care tool. Learn more IN CLINICAL CHEMISTRY ddPCR Quantification of Lymphoma Mutations Researchers have developed ... Online Harmonization.net Commission on Accreditation in Clinical Chemistry American Board of Clinical Chemistry Clinical Chemistry Trainee ...

  8. The New Color of Chemistry: Green Chemistry

    Zuhal GERÇEK

    2012-01-01

    Full Text Available Green chemistry which is the new application of chemistry rules provides solutions to problems that mankind is faced with climate changes, sustainable agriculture, energy, toxics, depletion of natural sources e.g. designing new chemicals and processes that production and utilization of hazardous matters. So, it is the indispensible tool for sustainable development. Current and future chemists should consider the human health and ecological issues in their professional life. In order to provide a solution for this requirement, green chemistry rules and under standings should be primarily taken in the university curriculum and at all educational levels.

  9. Annual Report of Institute of Nuclear Chemistry and Technology 2002

    The INCT 2002 Annual Report is the review of scientific activities in all branches being developed in the Institute of Nuclear Chemistry and Technology, Warsaw. The studies are connected in general with the following fields: radiation chemistry and physics, radiation technologies, radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general, radiobiology, process engineering, material engineering, structural studies and diagnostics, nucleonic control systems and accelerators

  10. Progress report 1983-1984 Reactor Chemistry Department

    Description of the activity developed by the Reactor Chemistry Department of the National Atomic Energy Commission during the period 1983-1984 in its four divisions: Chemical Control; Moderator and Refrigerant Chemistry; Radiation Chemistry and Nuclear Power Plant's Service. A list of the publications made by the personnel during this period is also included. (M.E.L.)

  11. Surface chemistry essentials

    Birdi, K S

    2013-01-01

    Surface chemistry plays an important role in everyday life, as the basis for many phenomena as well as technological applications. Common examples range from soap bubbles, foam, and raindrops to cosmetics, paint, adhesives, and pharmaceuticals. Additional areas that rely on surface chemistry include modern nanotechnology, medical diagnostics, and drug delivery. There is extensive literature on this subject, but most chemistry books only devote one or two chapters to it. Surface Chemistry Essentials fills a need for a reference that brings together the fundamental aspects of surface chemistry w

  12. Fundamentals of reactor chemistry

    In the Nuclear Engineering School of JAERI, many courses are presented for the people working in and around the nuclear reactors. The curricula of the courses contain also the subject material of chemistry. With reference to the foreign curricula, a plan of educational subject material of chemistry in the Nuclear Engineering School of JAERI was considered, and the fundamental part of reactor chemistry was reviewed in this report. Since the students of the Nuclear Engineering School are not chemists, the knowledge necessary in and around the nuclear reactors was emphasized in order to familiarize the students with the reactor chemistry. The teaching experience of the fundamentals of reactor chemistry is also given. (author)

  13. Chemistry Division : Annual progress report of 1974

    Research and development activities (during 1974) of the Chemistry Division of the Bhabha Atomic Research Centre, Bombay, are described. Some of the activities of particular interest to nuclear science and technology are: (1) chemistry-based problems of the operating power reactors such as development of a decontaminating solution for power reactors, correlation of iodine-131 levels in the primary heat transport system of a reactor with its operation (2) release of fission gases like xenon from ceramic fuels and (3) radiation chemistry of nitrate solutions (M.G.B.)

  14. Advances in analytical chemistry

    Arendale, W. F.; Congo, Richard T.; Nielsen, Bruce J.

    1991-01-01

    Implementation of computer programs based on multivariate statistical algorithms makes possible obtaining reliable information from long data vectors that contain large amounts of extraneous information, for example, noise and/or analytes that we do not wish to control. Three examples are described. Each of these applications requires the use of techniques characteristic of modern analytical chemistry. The first example, using a quantitative or analytical model, describes the determination of the acid dissociation constant for 2,2'-pyridyl thiophene using archived data. The second example describes an investigation to determine the active biocidal species of iodine in aqueous solutions. The third example is taken from a research program directed toward advanced fiber-optic chemical sensors. The second and third examples require heuristic or empirical models.

  15. Progress report 1987-1988. Reactor Chemistry Department

    Review of the activities performed by the Reactor Chemistry Department of the National Atomic Energy Commission of Argentina during 1987-1988. This department provides services and assistance in all matters related to water chemistry and nuclear reactors chemistry, in all their phases: design, construction, commissioning and decommissioning. The appendix includes information on the Reactor Chemistry Department staff, its publications, services, seminars, courses and conferences performed during 1987-1988. (Author)

  16. The New Color of Chemistry: Green Chemistry

    Zuhal GERÇEK

    2012-01-01

    Green chemistry which is the new application of chemistry rules provides solutions to problems that mankind is faced with climate changes, sustainable agriculture, energy, toxics, depletion of natural sources e.g. designing new chemicals and processes that production and utilization of hazardous matters. So, it is the indispensible tool for sustainable development. Current and future chemists should consider the human health and ecological issues in their professional life. In order to provid...

  17. Philosophy of Chemistry or Philosophy with Chemistry?

    Bernadette Bensaude-Vincent

    2014-01-01

    Chemistry deserves more philosophical attention not so much to do justice to a long-neglected science or to enhance its cultural prestige, but to undermine a number of taken-for-granted assumptions about scientific rationality and more importantly to diversify our metaphysical views of nature and reality. In brief, this paper does not make the case for a philosophy of chemistry. It rather urges philosophers of science to listen to chemists and discuss what they learn from them. Because over t...

  18. N-4-Acyl derivatives as lipophilic prodrugs of cidofovir and its 5-azacytosine analogue, (S)-HPMP-5-azaC: Chemistry and antiviral activity

    Krečmerová, Marcela; Pohl, Radek; Masojídková, Milena; Balzarini, J.; Snoeck, R.; Andrei, G.

    2014-01-01

    Roč. 22, č. 10 (2014), s. 2896-2906. ISSN 0968-0896 R&D Projects: GA MPO FR-TI4/625 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonate * antivirals * 5-azacytosine * prodrug Subject RIV: CC - Organic Chemistry Impact factor: 2.793, year: 2014

  19. Radiological and Environmental Research Division annual report: Fundamental Molecular Physics and Chemistry, October 1977-September 1978. [Summary of research activities at Argonne National Laboratory

    Rowland, R. E.; Inokuti, Mitio [eds.

    1978-01-01

    Research presented includes 32 papers, six of which have appeared previously in ERA, and 26 appear in this issue of ERA. Molecular physics and chemistry including photoionization, molecular properties, oscillator strengths, scattering, shape resonances, and photoelectrons are covered. A list of publications is included. (JFP)

  20. Creating and Teaching a Web-Based, University-Level Introductory Chemistry Course that Incorporates Laboratory Exercises and Active Learning Pedagogies

    Phipps, Linda R.

    2013-01-01

    An introductory, nonscience-majors chemistry course was converted to a Web-based course. The differences in student populations, teaching strategies, laboratory methods, and learning outcomes are described. Practical information is also given on the use of software and other online technology to implement course conversion. (Contains 2 tables.)

  1. Analytical Chemistry Section Chemistry Research Group, Winfrith. Report for 1982 and 1983

    This report reviews the principal activities of the Analytical Chemistry Section of Chemistry Research Group, Winfrith, during 1982 and 1983. The objectives of the report are to outline the range of chemical analysis support services available at Winfrith, indicate the research areas from which samples currently originate, and identify instrumental techniques where significant updating has occurred. (author)

  2. Green Goggles: Designing and Teaching a General Chemistry Course to Nonmajors Using a Green Chemistry Approach

    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.…

  3. Journal of Business Chemistry

    2013-01-01

    The Journal of Business Chemistry examines issues associated with leadership and management for chemists and managers working in chemical research or industry. This journal is devoted to improving and developing the field of Business Chemistry. The Journal of Business Chemistry publishes peer-reviewed papers (including case studies) and essays. Areas for possible publication in include: leadership issues in the chemical and biochemical industry, such as teamwork, team building, mentoring, coa...

  4. Mathematical Thinking in Chemistry

    José L. Villaveces; Guillermo Restrepo

    2012-01-01

    Mathematical chemistry is often thought to be a 20th-century subdiscipline of chemistry, but in this paper we discuss several early chemical ideas and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl's description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cases we discuss are Plato's triangles, Geoffro...

  5. Elementary physical chemistry

    Linder, Bruno

    2010-01-01

    This book is designed for a one-semester course, for undergraduates, not necessarily chemistry majors, who need to know something about physical chemistry. The emphasis is not on mathematical rigor, but subtleties and conceptual difficulties are not hidden. It covers the essential topics in physical chemistry, including the state of matter, thermodynamics, chemical kinetics, phase and chemical equilibria, introduction to quantum theory, and molecular spectroscopy.

  6. Orbital interactions in chemistry

    Albright, Thomas A; Whangbo, Myung-Hwan

    2013-01-01

    Explains the underlying structure that unites all disciplines in chemistry Now in its second edition, this book explores organic, organometallic, inorganic, solid state, and materials chemistry, demonstrating how common molecular orbital situations arise throughout the whole chemical spectrum. The authors explore the relationships that enable readers to grasp the theory that underlies and connects traditional fields of study within chemistry, thereby providing a conceptual framework with which to think about chemical structure and reactivity problems. Orbital Interactions

  7. Diverse applications of radiation chemistry

    Radiation chemistry began as early radiotherapists needed a reliable and appropriate dosimeter. The iron sulphate dosimeter, using ferrous iron in sulphuric acid and oxidation by irradiation, was a nasty brew of chemicals but it was sensitive, reliable and conveniently had the same density as human tissue. Water irradiation chemistry studies were driven by the need to understand the fundamental processes in radiotherapy; to control the corrosion problems in the cooling/ heat exchange systems of nuclear reactors and to find stable solvents and reagents for use in spent fuel element processing. The electrical and mechanical stability of materials in high radiation fields stimulated the attention of radiation chemists to the study of defects in solids. The coupled use of radiation and Electron Spin Resonance (ESR) enabled the identity of defect structures to be probed. This research led to the development of the sensitive Thermoluminescent Dosimeters, TLD's and a technique for dating of archaeological pottery artefacts. Radiation chemistry in the area of medicine is very active with fundamental studies of the mechanism of DNA strand breakage and the development of radiation sensitisers and protectors for therapeutic purposes. The major area of polymer radiation chemistry is one which Australia commands great international respect

  8. The Chemistry Institute

    Fontecave, Marc

    2015-01-01

    Chemistry at the Collège de France has received particular attention over the last few years. After the departures of Profs Jean-Marie Lehn and Jacques Livage, new ambition for developing this discipline has led to the creation of several Chairs: Prof. Marc Fontecave’s Chair of Chemistry of Biological Processes in 2008, Prof. Clément Sanchez’ Chair of Chemistry of Hybrid Materials in 2011, and the Chair of Chemistry of Materials and Energy, which Prof. Jean-Marie Tarascon has held since 2014....

  9. Advances in quantum chemistry

    Sabin, John R

    2013-01-01

    Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features detailed reviews written by leading international researchers. This volume focuses on the theory of heavy ion physics in medicine.Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features

  10. DOE fundamentals handbook: Chemistry

    This handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of chemistry. This volume contains the following modules: reactor water chemistry (effects of radiation on water chemistry, chemistry parameters), principles of water treatment (purpose; treatment processes [ion exchange]; dissolved gases, suspended solids, and pH control; water purity), and hazards of chemicals and gases (corrosives [acids, alkalies], toxic compounds, compressed gases, flammable/combustible liquids)

  11. Group theory and chemistry

    Bishop, David M

    1993-01-01

    Group theoretical principles are an integral part of modern chemistry. Not only do they help account for a wide variety of chemical phenomena, they simplify quantum chemical calculations. Indeed, knowledge of their application to chemical problems is essential for students of chemistry. This complete, self-contained study, written for advanced undergraduate-level and graduate-level chemistry students, clearly and concisely introduces the subject of group theory and demonstrates its application to chemical problems.To assist chemistry students with the mathematics involved, Professor Bishop ha

  12. Actinide Sciences at ITN - Basic Studies in Chemistry with Potential Interest for Partitioning, Fuel Fabrication and More

    The current activities in the area of actinide chemistry at ITN, comprising basic research studies in inorganic and organometallic chemistry, catalysis, gas-phase ion chemistry, thermochemistry, and solid state chemistry, are briefly described. Actinide (and lanthanide) chemistry studies at ITN will be pursued connecting basic research with potential applications in nuclear and non-nuclear areas. (authors)

  13. Intermediate-energy nuclear chemistry workshop

    This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities

  14. Intermediate-energy nuclear chemistry workshop

    Butler, G.W.; Giesler, G.C.; Liu, L.C.; Dropesky, B.J.; Knight, J.D.; Lucero, F.; Orth, C.J.

    1981-05-01

    This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities.

  15. Water chemistry and materials degradation in LWR'S

    Water chemistry plays a major role in corrosion, in erosion corrosion and in activity transport in NPPs; it impacts upon the operational safety of LWRs in two main ways: integrity of pressure boundary materials and activity transport and out-of-core radiation fields. A good control of water chemistry can significantly reduce these problems and improve plant safety, but economic pressures are leading to more rigorous operating conditions: fuel burnups are to be increased, higher efficiencies are to be achieved by running at higher temperatures and plant lifetimes are to be extended. Typical water chemistry specifications used in PWR and BWR plants are presented and the chemistry optimization is discussed. The complex interplay of metallurgical, mechanical and environmental factors in environmental sensitive cracking is shown, with details on studies for carbon steels, stainless steels and nickel base alloys. 20 refs., 8 figs., 4 tabs

  16. Open access and medicinal chemistry

    Swain Chris

    2007-01-01

    Abstract Chemistry Central is a new open access website for chemists publishing peer-reviewed research in chemistry from a range of open access journals. A new addition, Chemistry Central Journal, will cover all of chemistry and will be broken down into discipline-specific sections, and Im delighted that Medicinal Chemistry will be a key discipline in this new journal.

  17. Medicinal Chemistry and the Pharmacy Curriculum

    Faruk Khan, M.O.; Deimling, Michael J.; Philip, Ashok

    2011-01-01

    The origins and advancements of pharmacy, medicinal chemistry, and drug discovery are interwoven in nature. Medicinal chemistry provides pharmacy students with a thorough understanding of drug mechanisms of action, structure-activity relationships (SAR), acid-base and physicochemical properties, and absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles. A comprehensive understanding of the chemical basis of drug action equips pharmacy students with the ability to answ...

  18. The Breath of Chemistry

    Josephsen, Jens

    The present preliminary text is a short thematic presentation in biological inorganic chemistry meant to illustrate general and inorganic (especially coordination) chemistry in biochemistry. The emphasis is on molecular models to explain features of the complicated mechanisms essential to breathing...

  19. Movies in Chemistry Education

    Pekdag, Bulent; Le Marechal, Jean-Francois

    2010-01-01

    This article reviews numerous studies on chemistry movies. Movies, or moving pictures, are important elements of multimedia and signify a privileged or motivating means of presenting knowledge. Studies on chemistry movies show that the first movie productions in this field were devoted to university lectures or documentaries. Shorter movies were…

  20. Physical Chemistry of Molecular

    2011-01-01

    @@ Established in 2009, the group consists of six researchers and more than 70 research assistants and graduate students from the CAS Key Laboratory of Molecular Nanostructures and Nanotechnologies at the CAS Institute of Chemistry.Its research focuses on the physical chemistry involved in molecular assembly, molecular nanostructures, functional nanomaterials and conceptual nano-devices.

  1. Chemistry of americium

    Schulz, W.W.

    1976-01-01

    Essential features of the descriptive chemistry of americium are reviewed. Chapter titles are: discovery, atomic and nuclear properties, collateral reading, production and uses, chemistry in aqueous solution, metal, alloys, and compounds, and, recovery, separation, purification. Author and subject indexes are included. (JCB)

  2. Exercises in Computational Chemistry

    Spanget-Larsen, Jens

    2016-01-01

    A selection of HyperChem© PC-exercises in computational chemistry. Answers to most questions are appended (Roskilde University 2014-16).......A selection of HyperChem© PC-exercises in computational chemistry. Answers to most questions are appended (Roskilde University 2014-16)....

  3. Titanocene sulfide chemistry

    Horáček, Michal

    2016-01-01

    Roč. 314, MAY 2016 (2016), s. 83-102. ISSN 0010-8545 R&D Projects: GA ČR(CZ) GAP207/12/2368 Institutional support: RVO:61388955 Keywords : titanocene sulfide chemistry * photolysis * titanocene hydrosulfides Ti-(SH)n Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 12.239, year: 2014

  4. Chemistry in Microfluidic Channels

    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…

  5. From Metalloproteins to Coordination Chemistry: A Learning Exercise to Teach Transition Metal Chemistry

    Reglinski, John; Graham, Duncan; Kennedy, Alan R.; Gibson, Lorraine T.

    2004-01-01

    An exercise is organized to reinforce the fundamental rules of coordination chemistry through a biological study of metalloproteins. The work, which is divided into four well-defined activities, involves a major application of computer databases to address chemical problems.

  6. Mathematical Thinking in Chemistry

    José L. Villaveces

    2012-05-01

    Full Text Available Mathematical chemistry is often thought to be a 20th-century subdiscipline of chemistry, but in this paper we discuss several early chemical ideas and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl's description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cases we discuss are Plato's triangles, Geoffroy's affinity table, Lavoisier's classification of substances and their relationships, Mendeleev's periodic table, Cayley's enumeration of alkanes, Sylvester's association of algebra and chemistry, and Wiener's relationship between molecular structure and boiling points. These examples show that mathematical chemistry has much more than a century of history.

  7. Fuel Chemistry Division annual progress report for 1990

    The progress report gives brief descriptions of the various activities of the Fuel Chemistry Division of Bhabha Atomic Research Centre, Bombay for the year 1990. The descriptions of activities are arranged under the headings: Fuel Development Chemistry, Chemistry of Actinides, Quality Control of Nuclear Fuels, and studies related to Nuclear Materials Accounting. At the end of the report, a list of papers published in journals and presented at various conferences/symposia is also given. (author). 7 figs., 52 tabs

  8. Korean Kimchi Chemistry: A Multicultural Chemistry Connection

    Murfin, Brian

    2009-01-01

    Connecting science with different cultures is one way to interest students in science, to relate science to their lives, and at the same time to broaden their horizons in a variety of ways. In the lesson described here, students make kimchi, a delicious and popular Korean dish that can be used to explore many important chemistry concepts,…

  9. Third Chemistry Conference on Recent Trends in Chemistry

    The third chemistry conference 2011 on recent trends in chemistry was held from October 17-19, 2001 at Islamabad, Pakistan. More than 65 papers and oral presentation. The scope of the conference was wide open and provides and opportunity for participation of broad spectrum of chemists. This forum provided a platform for the dissemination of the latest research followed by discussion pertaining to new trends in chemistry. This con fence covered different aspects of subjects including analytical chemistry, environmental chemistry, polymer chemistry, industrial chemistry, biochemistry and nano chemistry etc. (A.B.)

  10. System approach to chemistry course

    Lorina E. Kruglova; Valentina G. Derendyaeva

    2010-01-01

    The article considers the raise of chemistry profile for engineers and constructors training, discloses the system approach to chemistry course and singles out the most important modules from the course of general chemistry for construction industry.

  11. Radiation chemistry and the environment

    The rather strong and many-sided pollution of the environment (atmosphere, water resources, soil) as a consequence of human activities is summarized. The solution of the arised problems by application of radiation chemistry methods and the utilization of modern environmentally ''clean'' and economical technologies, founded on electron beam processing, are mentioned. Some basic environmental problems and their solution are briefly discussed: i) Removal of CO2 from flue gases and its radiation induced utilization. ii) Principals for degradation of aqueous pollutants by electron beam processing in the presence of ozone (synergistic effect). The radiation chemistry as a modern and manifold discipline with very broad applications can also essentially contribute in the conservation of the environment

  12. Concept Maps in Chemistry Education

    Regis, Alberto; Albertazzi, Pier Giorgio; Roletto, Ezio

    1996-11-01

    This article presents and illustrates a proposed application of concept maps in chemistry teaching in high schools. The students were provided with the "concept lables" necessary for map building in three different ways. The analysis of the students' maps at different stages of the learning process led to the recognition of the three types of cognitive events which seem to correspond to the same number of restructuring stages in the conceptual organization. This can enable the teacher to characterize the changes produced in the learners' conceptions by teaching / learning activities. Three examples of the use of concept maps in chemistry teaching are reported and discussed with reference to: atomic structure, oxidation-reduction and thermodynamics.

  13. Water chemistry experiences with VVERs at Kudankulam

    Kudankulam Nuclear Power Project - 1 and 2 (Kudankulam NPP - 1 and 2) are pressurised water cooled VVERs of 1000 MWe each. Kudankulam NPP Unit - 1 is presently on its first cycle of operation and Kudankulam NPP Unit - 2 is on the advanced stage of commissioning with the successful completion of hot run related Functional tests. Water Chemistry aspects during various phases of commissioning of Kudankulam NPP Unit - 1 such as Hot Run, Boric acid flushing, initial fuel Loading (IFL), First approach to Criticality (FAC) are discussed. The main objectives of the use of controlled primary water chemistry programme during the hot functional tests are reviewed. The importance of the relevant water chemistry parameters were ensured to have the quality of the passive layer formed on the primary coolant system surfaces. The operational experiences during the 1st cycle of operation of primary water chemistry, radioactivity transport and build-up are presented. The operational experience of some VVER units in the field of the primary water chemistry, radioactivity transport and build-up are presented as a comparison to VVER at Kudankulam NPP. The effects of the initial passivated layer formed on metal surfaces during hot run, activated corrosion products levels in the primary coolant under controlled water chemistry regime and the contamination/radiation situation are discussed. This report also includes the water chemistry related issues of secondary water systems. (author)

  14. Moderator Chemistry Program

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department's moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation

  15. Moderator Chemistry Program

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department's moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  16. Moderator Chemistry Program

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department`s moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  17. Atmospheric and aerosol chemistry

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  18. Chemistry in water reactors

    The international conference Chemistry in Water Reactors was arranged in Nice 24-27/04/1994 by the French Nuclear Energy Society. Examples of technical program areas were primary chemistry, operational experience, fundamental studies and new technology. Furthermore there were sessions about radiation field build-up, hydrogen chemistry, electro-chemistry, condensate polishing, decontamination and chemical cleaning. The conference gave the impression that there are some areas that are going to be more important than others during the next few years to come. Cladding integrity: Professor Ishigure from Japan emphasized that cladding integrity is a subject of great concern, especially with respect to waterside corrosion, deposition and release of crud. Chemistry control: The control of the iron/nickel concentration quotient seems to be not as important as previously considered. The future operation of a nuclear power plant is going to require a better control of the water chemistry than achievable today. One example of this is solubility control via regulation in BWR. Trends in USA: means an increasing use of hydrogen, minimization of SCC/IASCC, minimization of radiation fields by thorough chemistry control, guarding fuel integrity by minimization of cladding corrosion and minimization of flow assisted corrosion. Stellite replacement: The search for replacement materials will continue. Secondary side crevice chemistry: Modeling and practical studies are required to increase knowledge about the crevice chemistry and how it develops under plant operation conditions. Inhibitors: Inhibitors for IGSCC and IGA as well for the primary- (zinc) as for the secondary side (Ti) should be studied. The effects and mode of operation of the inhibitors should be documented. Chemical cleaning: of heat transfer surfaces will be an important subject. Prophylactic cleaning at regular intervals could be one mode of operation

  19. Fuel Chemistry Division annual progress report for 1986

    The research and development activities of the Fuel Chemistry Division during 1986 are reported in the form of summaries. These activities mainly deal with nuclear fuel development, the chemistry of actinides and solid and solution state, analytical methods for chemical quality control of fuels and other related materials. (M.G.B.)

  20. Academic Position "Associate Professor in Chemistry Education" of the Department of Physical Chemistry, University of Sofia: Dr. Milena Kirova [In Bulgarian

    B.V. Toshev

    2013-05-01

    Full Text Available This is a review of research activity of Dr. Milena Kirova who applies for the academic position “Associate Professor in Chemistry Education” at the Department of Physical Chemistry, University of Sofia.

  1. Mathematics for physical chemistry

    Mortimer, Robert G

    2013-01-01

    Mathematics for Physical Chemistry is the ideal supplementary text for practicing chemists and students who want to sharpen their mathematics skills while enrolled in general through physical chemistry courses. This book specifically emphasizes the use of mathematics in the context of physical chemistry, as opposed to being simply a mathematics text. This 4e includes new exercises in each chapter that provide practice in a technique immediately after discussion or example and encourage self-study. The early chapters are constructed around a sequence of mathematical topics, wit

  2. Computational quantum chemistry website

    This report contains the contents of a web page related to research on the development of quantum chemistry methods for computational thermochemistry and the application of quantum chemistry methods to problems in material chemistry and chemical sciences. Research programs highlighted include: Gaussian-2 theory; Density functional theory; Molecular sieve materials; Diamond thin-film growth from buckyball precursors; Electronic structure calculations on lithium polymer electrolytes; Long-distance electronic coupling in donor/acceptor molecules; and Computational studies of NOx reactions in radioactive waste storage

  3. Gas phase ion chemistry

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 1 covers papers on the advances of gas phase ion chemistry. The book discusses the advances in flow tubes and the measurement of ion-molecule rate coefficients and product distributions; the ion chemistry of the earth's atmosphere; and the classical ion-molecule collision theory. The text also describes statistical methods in reaction dynamics; the state selection by photoion-photoelectron coincidence; and the effects of temperature and pressure in the kinetics of ion-molecule reactions. The energy distribution in the unimolecular decomposition of ions, as well

  4. Experiments in physical chemistry

    Wilson, J M; Denaro, A R

    1968-01-01

    Experiments in Physical Chemistry, Second Edition provides a compilation of experiments concerning physical chemistry. This book illustrates the link between the theory and practice of physical chemistry. Organized into three parts, this edition begins with an overview of those experiments that generally have a simple theoretical background. Part II contains experiments that are associated with more advanced theory or more developed techniques, or which require a greater degree of experimental skill. Part III consists of experiments that are in the nature of investigations wherein these invest

  5. DOE fundamentals handbook: Chemistry

    The Chemistry Handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of chemistry. The handbook includes information on the atomic structure of matter; chemical bonding; chemical equations; chemical interactions involved with corrosion processes; water chemistry control, including the principles of water treatment; the hazards of chemicals and gases, and basic gaseous diffusion processes. This information will provide personnel with a foundation for understanding the chemical properties of materials and the way these properties can impose limitations on the operation of equipment and systems

  6. Bentonite porewater chemistry

    Porewater composition in a compacted bentonite is dependent on the composition of the surrounding groundwater, and on the characteristics of the bentonite itself. Two mechanisms through which bentonite influences the respective porewater composition are distinguished: surface chemical reactions (ion exchange, surface complexation) on smectite and dissolution of minerals and soluble impurities included in bentonite. This report provides the results of different activities related to the definition of porewater chemistry through the use of geochemical models: 1) review of thermodynamic model on ion exchange reaction, 2) modeling of bentonite-water interactions under aerobic conditions, 3) performance of sensitivity analyses of key parameters in the bentonite model, 4) model simulation of bentonite porewater chemistry in the engineered barrier system under repository conditions. Experimental information of bentonite-water interaction allowed the determination of soluble impurities in the bentonite, and the knowledge of these impurities is important for predictive modeling. For the impurities of Kunigel-V1, 0.38% of CaSO4, 0.0011% of NaCl and 0.0044% of KCl were determined. The sensitivity analyses resulted in that the presence of calcite, CaSO4 and pyrite strongly influences the pH in the compacted bentonite, and the pH in compacted bentonite is buffered by the acid/base equilibria at the Na-smectite surface as well. Through the model calculations, some remarks on the expected trends for the long term behavior can be made like that the pH in compacted bentonite is expected to increase with increasing number of water exchange cycles, as long as CaCO3 contributes to the pH buffering capacity, due to slow depletion of the soluble impurities in the bentonite. The pH of the porewater, however, lies in all cases (but in the presence of CaCo3) between 5.6 and 9.5. Based on the findings discussed above, a large number of calculations were carried out to support the definition

  7. CAREM-25: considerations about primary coolant chemistry

    World operating experience, in conjunction with basic studies has been modifying chemistry specifications for the primary coolant of water cooled nuclear reactors along with the reactor type and structural materials involved in the design. For the reactor CAREM-25, the following sources of information have been used: 1) Experience gained by the Chemistry Department of the National Atomic Energy Commission (CNEA, Argentina); 2) Participation of the Chemistry Department (CNEA) in international cooperation projects; 3) Guidelines given by EPRI, Siemens-KWU, AECL, etc. Given the main objectives: materials integrity, low radiation levels and personnel safety, which are in turn a balance between the lowest corrosion and activity transport achievable and considering that the CAREM-25 is a pressurized vessel integrated reactor, a group of guidelines for the chemistry and additives for the primary coolant have been given in the present work. (author)

  8. Assessing the impact of integrating POGIL in Elementary Organic Chemistry

    Shatila, Ahmad

    Organic chemistry is a difficult subject to teach especially to non-chemistry majors. CHE 251, Elementary Organic Chemistry, is an introductory course in organic chemistry given to non-chemistry majors. It is usually taught the traditional way using lectures as the main method of presentation. In the fall of 2006, POGIL (Process Oriented Guided Inquiry Learning) activities were introduced in this course. POGIL is a program that integrates guided inquiry and cooperative learning in chemistry education. The purpose of this research study was to determine the effect of using POGIL activities in elementary organic chemistry. CHE 251, Elementary Organic Chemistry, was taught using a mixture of traditional teaching, lecturing, and POGIL activities. This was assessed by looking at the effect of using POGIL activities on student achievement. Furthermore, the study investigated possible effects of POGIL activities on students' attitudes toward chemistry. Archival data on 28 students enrolled in the fall 2004 semester were used in this study. In addition, 27 students enrolled in the 2006 semester participated in the study by completing an attitudinal survey that was developed by the researcher. Finally, 9 students enrolled in the 2006 semester were interviewed to give additional insight to the study. The quantitative data concerning achievement revealed no significant difference between groups, students who used POGIL did not differ from students who did not. Further, the quantitative data concerning confidence levels of students in understanding and applying organic chemistry before and after going through the POGIL activities revealed no significant difference. This study showed that students in general (88.8% of surveyed students) liked POGIL activities and preferred them over lecturing. Students thought that POGIL activities helped them better understand and learn chemistry. Furthermore, students acknowledged the benefits of guided inquiry and cooperative learning, the

  9. Water chemistry and behavior of materials in PWRs and BWRs

    Water chemistry plays a major role in corrosion and in activity transport in NPP's. Although a full understanding of all mechanisms involved in corrosion does not exist, controlling of the water chemistry has achieved good results in recent years. Water chemistry impacts upon the operational safety of LWR's in two main ways: integrity of pressure boundary materials and, activity transport and out-of-core radiation fields. This paper will describe application of water chemistry control in operating reactors to prevent corrosion. Some problems experienced in LWR's will be reviewed for the design of the nuclear heating reactors (NHR). (author). 18 refs, 10 figs, 5 tabs

  10. Chemistry at large

    Sanders, Jeremy K. M.

    2007-01-01

    A new book introduces young researchers to supramolecular chemistry, starting from the basics and working up to the more complicated aspects of the topic. While the text is inspiring for new graduates, it lacks a critical view.

  11. General Chemistry for Engineers.

    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)

  12. Bringing chemistry to life

    Boyce, Michael; Bertozzi, Carolyn R.

    2011-01-01

    Bioorthogonal chemistry allows a wide variety of biomolecules to be specifically labeled and probed in living cells and whole organisms. Here we discuss the history of bioorthogonal reactions and some of the most interesting and important advances in the field.

  13. Supplemental instruction in chemistry

    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.

  14. Beauty in chemistry

    Peter Atkins

    2006-03-01

    Full Text Available Though hard going for the general reader and highly personal in its selectivity, Elegant Solutions: Ten Beautiful Experiments in Chemistry provides reflections of a thoughtful author that will delight chemists

  15. Beauty in chemistry

    Peter Atkins

    2006-01-01

    Though hard going for the general reader and highly personal in its selectivity, Elegant Solutions: Ten Beautiful Experiments in Chemistry provides reflections of a thoughtful author that will delight chemists

  16. Magnetism in Chemistry

    Brookes, R. W.; McFadyen, W. D.

    1975-01-01

    Discusses the technical aspects of paramagnetism and an electrostatic model called Crystal Field Theory (CFT), very often used in the case of transition metal compounds. Suggests that this discussion be included as an option for college chemistry courses. (MLH)

  17. Enzymes in Analytical Chemistry.

    Fishman, Myer M.

    1980-01-01

    Presents tabular information concerning recent research in the field of enzymes in analytic chemistry, with methods, substrate or reaction catalyzed, assay, comments and references listed. The table refers to 128 references. Also listed are 13 general citations. (CS)

  18. Comparison of control of Listeria by nitric oxide redox chemistry from murine macrophages and NO donors: insights into listeriocidal activity of oxidative and nitrosative stress.

    Ogawa, R; Pacelli, R; Espey, M G; Miranda, K M; Friedman, N; Kim, S M; Cox, G; Mitchell, J B; Wink, D A; Russo, A

    2001-02-01

    The physiological function of nitric oxide (NO) in the defense against pathogens is multifaceted. The exact chemistry by which NO combats intracellular pathogens such as Listeria monocytogenes is yet unresolved. We examined the effects of NO exposure, either delivered by NO donors or generated in situ within ANA-1 murine macrophages, on L. monocytogenes growth. Production of NO by the two NONOate compounds PAPA/NO (NH2(C3H6)(N[N(O)NO]C3H7) and DEA/NO (Na(C2H5)2N[N(O)NO]) resulted in L. monocytogenes cytostasis with minimal cytotoxicity. Reactive oxygen species generated from xanthine oxidase/hypoxanthine were neither bactericidal nor cytostatic and did not alter the action of NO. L. monocytogenes growth was also suppressed upon internalization into ANA-1 murine macrophages primed with interferon-gamma (INF-gamma) + tumor necrosis factor-alpha (TNF-alpha or INF-gamma + lipid polysaccharide (LPS). Growth suppression correlated with nitrite formation and nitrosation of 2,3-diaminonaphthalene elicited by stimulated murine macrophages. This nitrosative chemistry was not dependent upon nor mediated by interaction with reactive oxygen species (ROS), but resulted solely from NO and intermediates related to nitrosative stress. The role of nitrosation in controlling L. monocytogenes was further examined by monitoring the effects of exposure to NO on an important virulence factor, Listeriolysin O, which was inhibited under nitrosative conditions. These results suggest that nitrosative stress mediated by macrophages is an important component of the immunological arsenal in controlling L. monocytogenes infections. PMID:11165873

  19. Atmospheric chemistry in volcanic plumes.

    von Glasow, Roland

    2010-04-13

    Recent field observations have shown that the atmospheric plumes of quiescently degassing volcanoes are chemically very active, pointing to the role of chemical cycles involving halogen species and heterogeneous reactions on aerosol particles that have previously been unexplored for this type of volcanic plumes. Key features of these measurements can be reproduced by numerical models such as the one employed in this study. The model shows sustained high levels of reactive bromine in the plume, leading to extensive ozone destruction, that, depending on plume dispersal, can be maintained for several days. The very high concentrations of sulfur dioxide in the volcanic plume reduces the lifetime of the OH radical drastically, so that it is virtually absent in the volcanic plume. This would imply an increased lifetime of methane in volcanic plumes, unless reactive chlorine chemistry in the plume is strong enough to offset the lack of OH chemistry. A further effect of bromine chemistry in addition to ozone destruction shown by the model studies presented here, is the oxidation of mercury. This relates to mercury that has been coemitted with bromine from the volcano but also to background atmospheric mercury. The rapid oxidation of mercury implies a drastically reduced atmospheric lifetime of mercury so that the contribution of volcanic mercury to the atmospheric background might be less than previously thought. However, the implications, especially health and environmental effects due to deposition, might be substantial and warrant further studies, especially field measurements to test this hypothesis. PMID:20368458

  20. Department of Nuclear Physical Chemistry

    The research program at the Department of Nuclear Physical Chemistry of the Niewodniczanski Institute of Nuclear Physics is described. The Department consist of three laboratories. First - Laboratory of Physical Chemistry of Separation Processes on which the activity is concentrated on separation of radioactive isotopes from particle bombarded target. The main interest is production and separation of neutron deficient isotopes for medical diagnostic and therapy. The investigation program includes measurements of nuclear reaction cross sections,, band resolution technique, preparation of radioactive sources, detection of non-radioactive trace elements. An independent project on desulphurization of flue gases is also carried out in the Laboratory. In the second one - Laboratory of Chemistry and Radiochemistry - the systematic studies of physicochemical properties of transition elements in solutions are carried out. The results of the performed experiments were used for the elaboration of new rapid and selective methods for various elements. Some of these results have been applied for separation of trans actinide elements at U-400 cyclotron of JINR Dubna. The third one laboratory - Environmental Radioactivity Laboratory -conducts continuous monitoring of radioactivity contamination of atmosphere. The investigation of different radionuclides concentration in natural environment, mainly in the forest had been carried out. (author)

  1. Forensic Chemistry Training

    Zuhal GERÇEK

    2012-01-01

    Increasing the types of terrorism and crime nowadays, the importance of the forensic sciences can be bett er understood. Forensic science is the application of the wide spectrum of science to answer the question of legal system. It contains the application of the principles, techniques and methods of basic sciences and its main aim is the determination of the physical facts which are important in legal situations. Forensic chemistry is the branch of chemistry which performs the chemical analy...

  2. Applications of supramolecular chemistry

    Schneider, Hans-Jörg

    2012-01-01

    ""The time is ripe for the present volume, which gathers thorough presentations of the numerous actually realized or potentially accessible applications of supramolecular chemistry by a number of the leading figures in the field. The variety of topics covered is witness to the diversity of the approaches and the areas of implementation…a broad and timely panorama of the field assembling an eminent roster of contributors.""-Jean-Marie Lehn, 1987 Noble Prize Winner in Chemistry

  3. Fundamentals of quantum chemistry

    House, J E

    2004-01-01

    An introduction to the principles of quantum mechanics needed in physical chemistry. Mathematical tools are presented and developed as needed and only basic calculus, chemistry, and physics is assumed. Applications include atomic and molecular structure, spectroscopy, alpha decay, tunneling, and superconductivity. New edition includes sections on perturbation theory, orbital symmetry of diatomic molecules, the Huckel MO method and Woodward/Hoffman rules as well as a new chapter on SCF and Hartree-Fock methods. * This revised text clearly presents basic q

  4. Impact of surface chemistry

    Somorjai, Gabor A.; Li, Yimin

    2010-01-01

    The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized.

  5. Quantitative analysis chemistry

    This book is about quantitative analysis chemistry. It is divided into ten chapters, which deal with the basic conception of material with the meaning of analysis chemistry and SI units, chemical equilibrium, basic preparation for quantitative analysis, introduction of volumetric analysis, acid-base titration of outline and experiment examples, chelate titration, oxidation-reduction titration with introduction, titration curve, and diazotization titration, precipitation titration, electrometric titration and quantitative analysis.

  6. Gas phase ion chemistry

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 2 covers the advances in gas phase ion chemistry. The book discusses the stabilities of positive ions from equilibrium gas-phase basicity measurements; the experimental methods used to determine molecular electron affinities, specifically photoelectron spectroscopy, photodetachment spectroscopy, charge transfer, and collisional ionization; and the gas-phase acidity scale. The text also describes the basis of the technique of chemical ionization mass spectrometry; the energetics and mechanisms of unimolecular reactions of positive ions; and the photodissociation

  7. EPA Environmental Chemistry Laboratory

    1993-01-01

    The Environmental Protection Agency's (EPA) Chemistry Laboratory (ECL) is a national program laboratory specializing in residue chemistry analysis under the jurisdiction of the EPA's Office of Pesticide Programs in Washington, D.C. At Stennis Space Center, the laboratory's work supports many federal anti-pollution laws. The laboratory analyzes environmental and human samples to determine the presence and amount of agricultural chemicals and related substances. Pictured, ECL chemists analyze environmental and human samples for the presence of pesticides and other pollutants.

  8. Chemistry and nuclear technology

    The underlying principles of nuclear sciece and technology as based on the two basic phenomena, namely, radioactivity and nuclear reactions, with their relatively large associated energy changes, are outlined. The most important contributions by chemists in the overall historical development are mentioned and the strong position chemistry has attained in these fields is indicated. It is concluded that chemistry as well as many other scientific discplines (apart from general benefits) have largely benefitted from these nuclear developments

  9. X-ray fluorescence in Member States (Spain): Main activities related to the use of XRF techniques at the Analytical and Environmental Chemistry Research Group of the University of Girona (UdG)

    The Analytical and Environmental Chemistry Group (QAA) is a consolidated research group of the Department of Chemistry of the University of Girona (North- East Spain). The main research topics of the group are related to the development and application of analytical methodologies for the determination of inorganic and organic species in different kind of environmental, clinical and industrial samples. From the beginning of the 2000’s, one of the research focuses of the group, is the use of X-ray fluorescence spectrometry (XRF) for the determination of trace amounts of metals and metalloids mostly in samples related to the environmental and industrial fields. For instance, in collaboration with the Institute of Earth Sciences “Jaume Almera” (ICTJA-CSIC, Spain), we have developed and successfully applied several analytical approaches based on the use of EDXRF (Energy dispersive XRF), WDXRF (Wavelength dispersive XRF) and PEDXRF (Polarised EDXRF) for the determination of metals at trace levels in complex liquid samples such as sea water or electroplating waters in vegetation samples collected around mining environments or in active pharmaceutical ingredients. At present, the evaluation of the analytical possibilities of TXRF (Total reflection XRF) in the chemical analysis field is also one of the research topics of QAA. In this sense, several contributions related to the use of this technique for element determination in liquid and solid samples have been developed. A summary of these contributions is summarized in the last section of this review

  10. Annual Report of Institute of Nuclear Chemistry and Technology 1997

    NONE

    1998-10-01

    The report is the collection of short communications being the review of the scientific activity of Institute of Nuclear Chemistry and Technology - Warsaw in 1997. The papers are gathered in several branches as follows: radiation chemistry and physics; radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general; radiobiology; nuclear technologies and methods. The annual report of INCT-1997 contains also the general information about INCT as well as the full list of scientific papers being published by the staff in 1997

  11. A study of why we need Environmental chemistry?

    Tushar kumar Gandhi

    2013-01-01

    Environmental chemistry is the scientific study of the chemical and biochemical phenomena that occur in natural places. It should not be confused with green chemistry, which seeks to reduce potential pollution at its source. It can be defined as the study of the sources, reactions, transport, effects, and fates of chemical species in the air, soil, and water environments; and the effect of human activity on these. Environmental chemistry is an interdisciplinary science that includes atmospher...

  12. Annual Report of Institute of Nuclear Chemistry and Technology 2001

    The INCT 2001 Annual Report is the review of scientific activities in all branches being developed in the Institute of Nuclear Chemistry and Technology in Warsaw. The studies are connected in general with the following fields: radiation chemistry and physics, radiation technologies, radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general, radiobiology, process engineering, material engineering, structural studies and diagnostics, nucleonic control systems and accelerators and nuclear analytical methods

  13. Annual Report of Institute of Nuclear Chemistry and Technology 1999

    The INCT 1999 Annual Report is the review of scientific activities in all branches being developed in the Institute of Nuclear Chemistry and Technology, Warsaw. The studies are connected in general with the following fields: radiation chemistry and physics, radiation technologies, radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general, radiobiology, process engineering, material engineering, structural studies and diagnostics and nucleonic control systems and accelerators

  14. Water Chemistry Division Progress Report (April 1983 - April 1985)

    The research and development work of the Water Chemistry Division during the period from April 1983 to April 1985 is reported in the form of individual summaries. The activities of the Division cover the following fields: water and steam chemistry, high temperature studies, single crystal structure by x-ray diffraction, vriable temperature, x-ray powder studies, thermal analysis and thermophysical properties of rare earth compounds and uranium chemistry. (author)

  15. Annual Report 2004 of Institute of Nuclear Chemistry and Technology

    The INCT 2004 Annual Report is the review of scientific activities in all branches being developed in the Institute of Nuclear Chemistry and Technology Warsaw. The studies are connected in general with the following fields: radiation chemistry and physics, radiation technologies, radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general, radiobiology, process engineering, material engineering, structural studies and diagnostics, nucleonic control systems and accelerators, radiobiology and nuclear analytical methods

  16. Annual Report of Institute of Nuclear Chemistry and Technology 1997

    The report is the collection of short communications being the review of the scientific activity of Institute of Nuclear Chemistry and Technology - Warsaw in 1997. The papers are gathered in several branches as follows: radiation chemistry and physics; radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general; radiobiology; nuclear technologies and methods. The annual report of INCT-1997 contains also the general information about INCT as well as the full list of scientific papers being published by the staff in 1997

  17. Photoredox Catalysis in Organic Chemistry

    2016-01-01

    In recent years, photoredox catalysis has come to the forefront in organic chemistry as a powerful strategy for the activation of small molecules. In a general sense, these approaches rely on the ability of metal complexes and organic dyes to convert visible light into chemical energy by engaging in single-electron transfer with organic substrates, thereby generating reactive intermediates. In this Perspective, we highlight the unique ability of photoredox catalysis to expedite the development of completely new reaction mechanisms, with particular emphasis placed on multicatalytic strategies that enable the construction of challenging carbon–carbon and carbon–heteroatom bonds. PMID:27477076

  18. Photoredox Catalysis in Organic Chemistry.

    Shaw, Megan H; Twilton, Jack; MacMillan, David W C

    2016-08-19

    In recent years, photoredox catalysis has come to the forefront in organic chemistry as a powerful strategy for the activation of small molecules. In a general sense, these approaches rely on the ability of metal complexes and organic dyes to convert visible light into chemical energy by engaging in single-electron transfer with organic substrates, thereby generating reactive intermediates. In this Perspective, we highlight the unique ability of photoredox catalysis to expedite the development of completely new reaction mechanisms, with particular emphasis placed on multicatalytic strategies that enable the construction of challenging carbon-carbon and carbon-heteroatom bonds. PMID:27477076

  19. Advanced radiation chemistry research: Current status

    Radiation chemistry is a branch of chemistry that studies chemical transformations in materials exposed to high-energy radiations. It is based on the use of ionizing radiation as the initiator or catalyst in chemical reactions. The most significant advantage of radiation chemistry lies in its ability to be used in the production and study of almost any reactive atomic and molecular species playing a part in chemical reaction, synthesis, industrial processes, or in biological systems. Over the the last few years a number of meetings have taken place, under the auspices of the IAEA, in order to evaluate recent developments in radiation chemistry as well as the trends indicated by the results obtained. Radiation chemists from different countries have participated at these meetings. The present publication, a companion to the previous publication - New Trends and Development in Radiation Chemistry, IAEA-TECDOC-527 (1989) - includes some of the important contributions presented at these meetings. It is hoped that it will provide a useful overview of current activities and of emerging trends in this field, thus promoting better understanding of potential contributions of radiation chemistry to other fields of knowledge as well as to practical applications in industry, medicine and agriculture. Refs, figs and tabs

  20. Making a Natural Product Chemistry Course Meaningful with a Mini Project Laboratory

    Hakim, Aliefman; Liliasari; Kadarohman, Asep; Syah, Yana Maolana

    2016-01-01

    This paper discusses laboratory activities that can improve the meaningfulness of natural product chemistry course. These laboratory activities can be useful for students from many different disciplines including chemistry, pharmacy, and medicine. Students at the third-year undergraduate level of chemistry education undertake the project to…

  1. The influence of redox chemistry and pH on chemically active forms of arsenic in sewage sludge-amended soil

    Carbonell-Barrachina, A.; Jugsujinda, A.; DeLaune, R.D.; Patrick, W.H. Jr. [Louisiana State Univ., Baton Rouge, LA (United States). Wetland Biogeochemistry Inst.; Burlo, F. [Univ. Miguel Hernandez, Alicante (Spain). Div. Tecnologia de Alimentos; Sirisukhodom, S. [Mahidol Univ., Bangkok (Thailand). Environmental Health Science Dept.; Anurakpongsatorn, P. [Kasetsart Univ., Bangkok (Thailand). Dept. of Environmental Science

    1999-07-01

    Chemical fractionation procedures were used to quantify the effect of the sediment redox and pH conditions on the adsorption and solubility of arsenic (As) in municipal sewage sludge and sewage sludge-amended soil. Sludge and sludge-amended soil were incubated in microcosms in which Eh-pH conditions were controlled. Samples were sequentially extracted to determine As in various chemical forms (water soluble, exchangeable, bound to carbonates, bound to iron (Fe) and manganese (Mn) oxides, bound to insoluble organics and sulfides) and the chemically inactive fraction (mineral residues). In both sewage sludge and sludge-amended soil, As chemistry was governed by large molecular humic matter and sulfides and Fe and Mn-oxides. Solubility of As remained low and constant under both aerobic and anaerobic conditions in sludge-amended soil. After dissolution of Fe and Mn-oxides, As{sup 5+} was released into sludge solution, reduced to As{sup 3+} and likely precipitated as sulfide. Therefore, an organic amendment rich in sulfur compounds, such as sewage sludge, would drastically reduce the potential risks derived from As pollution under highly anoxic conditions by precipitation of this toxic metalloid as insoluble and immobile sulfides.

  2. 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.

    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. PMID:21656589

  3. Chemistry beyond positivism.

    Brandt, Werner W

    2003-05-01

    Chemistry is often thought to be quite factual, and therefore might be considered close to the "positivist" ideal of a value-free science. A closer look, however, reveals that the field is coupled to the invisible realm of values, meanings, and purpose in various ways, and chemists interact with that realm loosely and unevenly. Tacit knowledge is one important locus of such interactions. We are concerned in this essay with two questions. What is the nature of the knowledge when we are in the early stages of discovery? and In what ways does the hidden reality we are seeking affect our search for an understanding of it? The first question is partly answered by Polanyi's theory of tacit knowledge, while the second one leads us to realize the limitations of our language when discussing "reality"-or certain chemical experimental results. A strictly positivist approach is of little use, but so is the opposite, the complete disregard of facts. The contrast between positivism and non-formulable aspects of scientific reasoning amounts to a paradox that needs to be analyzed and can lead to a "connected" chemistry. This in turn resembles networks described by Schweber and is more concerned than the chemistry "as it is" with aspects such as the image of chemistry, the challenges chemists face as citizens, and chemistry in liberal education. PMID:12796119

  4. Analytical Chemistry Division annual progress report: For period ending December 31, 1987

    This report is divided into analytical spectroscopy; radioactive materials analysis; inorganic chemistry; organic chemistry; ORNL environmental programs; quality assurance, safety, and training; supplementary activities; and presentation of research results

  5. Analytical Chemistry Division annual progress report: For period ending December 31, 1987

    1988-05-01

    This report is divided into analytical spectroscopy; radioactive materials analysis; inorganic chemistry; organic chemistry; ORNL environmental programs; quality assurance, safety, and training; supplementary activities; and presentation of research results.

  6. Collaborative Physical Chemistry Projects Involving Computational Chemistry

    Whisnant, David M.; Howe, Jerry J.; Lever, Lisa S.

    2000-02-01

    The physical chemistry classes from three colleges have collaborated on two computational chemistry projects using Quantum CAChe 3.0 and Gaussian 94W running on Pentium II PCs. Online communication by email and the World Wide Web was an important part of the collaboration. In the first project, students used molecular modeling to predict benzene derivatives that might be possible hair dyes. They used PM3 and ZINDO calculations to predict the electronic spectra of the molecules and tested the predicted spectra by comparing some with experimental measurements. They also did literature searches for real hair dyes and possible health effects. In the final phase of the project they proposed a synthetic pathway for one compound. In the second project the students were asked to predict which isomer of a small carbon cluster (C3, C4, or C5) was responsible for a series of IR lines observed in the spectrum of a carbon star. After preliminary PM3 calculations, they used ab initio calculations at the HF/6-31G(d) and MP2/6-31G(d) level to model the molecules and predict their vibrational frequencies and rotational constants. A comparison of the predictions with the experimental spectra suggested that the linear isomer of the C5 molecule was responsible for the lines.

  7. Reaction chemistry of cerium

    NONE

    1997-01-01

    It is truly ironic that a synthetic organic chemist likely has far greater knowledge of the reaction chemistry of cerium(IV) than an inorganic colleague. Cerium(IV) reagents have long since been employed as oxidants in effecting a wide variety of organic transformations. Conversely, prior to the late 1980s, the number of well characterized cerium(IV) complexes did not extend past a handful of known species. Though in many other areas, interest in the molecular chemistry of the 4f-elements has undergone an explosive growth over the last twenty years, the chemistry of cerium(IV) has for the most part been overlooked. This report describes reactions of cerium complexes and structure.

  8. Chemistry of plutonium revealed

    In 1941 one goal of the Manhattan Project was to unravel the chemistry of the synthetic element plutonium as rapidly as possible. In this paper the work carried out at Berkeley from the spring of 1942 to the summer of 1945 is described briefly. The aqueous chemistry of plutonium is quite remarkable. Important insights were obtained from tracer experiments, but the full complexity was not revealed until macroscopic amounts (milligrams) became available. Because processes for separation from fission products were based on aqueous solutions, such solution chemistry was emphasized, particularly precipitation and oxidation-reduction behavior. The latter turned out to be unusually intricate when it was discovered that two more oxidation states existed in aqueous solution than had previously been suspected. Further, an equilibrium was rapidly established among the four aqueous oxidation states, while at the same time any three were not in equilibrium. These and other observations made while doing a crash study of a previously unknown element are reported

  9. Introductory quantum chemistry

    This book on quantum chemistry is primarily intended for university students at the senior undergraduate level. It serves as an aid to the basic understanding of the important concepts of quantum mechanics introduced in the field of chemistry. Various chapters of the book are devoted to the following : (i) Waves and quanta, (ii) Operator concept in quantum chemistry, (iii) Wave mechanics of some simple systems, (iv) Perturbation theory, (v) Many-electron atoms and angular momenta (vi) Molecular orbital theory and its application to the electronic structure of diatomic molecules, (vii) Chemical bonding in polyatomic molecules and (viii) Chemical applications of Hellmann-Feynman theorem. At the end of each chapter, a set of problems is given and the answers to these problems are given at the end of the book. (A.K.)

  10. Mathematics for physical chemistry

    Mortimer, Robert G

    2005-01-01

    Mathematics for Physical Chemistry, Third Edition, is the ideal text for students and physical chemists who want to sharpen their mathematics skills. It can help prepare the reader for an undergraduate course, serve as a supplementary text for use during a course, or serve as a reference for graduate students and practicing chemists. The text concentrates on applications instead of theory, and, although the emphasis is on physical chemistry, it can also be useful in general chemistry courses. The Third Edition includes new exercises in each chapter that provide practice in a technique immediately after discussion or example and encourage self-study. The first ten chapters are constructed around a sequence of mathematical topics, with a gradual progression into more advanced material. The final chapter discusses mathematical topics needed in the analysis of experimental data.* Numerous examples and problems interspersed throughout the presentations * Each extensive chapter contains a preview, objectives, and ...

  11. Dynamic Combinatorial Chemistry

    Lisbjerg, Micke

    This thesis is divided into seven chapters, which can all be read individually. The first chapter, however, contains a general introduction to the chemistry used in the remaining six chapters, and it is therefore recommended to read chapter one before reading the other chapters. Chapter 1...... is a general introductory chapter for the whole thesis. The history and concepts of dynamic combinatorial chemistry are described, as are some of the new and intriguing results recently obtained. Finally, the properties of a broad range of hexameric macrocycles are described in detail. Chapter 2 gives...

  12. Cloud chemistry on Jupiter

    Carlson, B. E.; Prather, M. J.; W. B. Rossow

    1987-01-01

    Aqueous chemistry on Uranus affects the atmospheric abundances of NH3 and H2S below the methane cloud base. Here a complete thermochemical equilibrium model for the H2O-NH3-H2S system is presented. Inclusion of H2S increases the aqueous removal of NH3 to 20-30 percent, but aqueous chemistry alone cannot account for the depletion of NH3 in the 150-200-K region of the atmosphere required to fit microwave observations. Formation of NH4SH clouds can account for the observed depletion provided the...

  13. Chemistry of Transactinides

    Kratz, J. V.

    In this chapter, the chemical properties of the man-made transactinide elements rutherfordium, Rf (element 104), dubnium, Db (element 105), seaborgium, Sg (element 106), bohrium, Bh (element 107), hassium, Hs (element 108), and copernicium, Cn (element 112) are reviewed, and prospects for chemical characterizations of even heavier elements are discussed. The experimental methods to perform rapid chemical separations on the time scale of seconds are presented and comments are given on the special situation with the transactinides where chemistry has to be studied with single atoms. It follows a description of theoretical predictions and selected experimental results on the chemistry of elements 104 through 108, and element 112.

  14. Solvent effects in chemistry

    Buncel, Erwin

    2015-01-01

    This book introduces the concepts, theory and experimental knowledge concerning solvent effects on the rate and equilibrium of chemical reactions of all kinds.  It begins with basic thermodynamics and kinetics, building on this foundation to demonstrate how a more detailed understanding of these effects may be used to aid in determination of reaction mechanisms, and to aid in planning syntheses. Consideration is given to theoretical calculations (quantum chemistry, molecular dynamics, etc.), to statistical methods (chemometrics), and to modern day concerns such as ""green"" chemistry, where ut

  15. Nanophotonics and supramolecular chemistry

    Ariga, Katsuhiko; Komatsu, Hirokazu; Hill, Jonathan P.

    2013-10-01

    Supramolecular chemistry has become a key area in emerging bottom-up nanoscience and nanotechnology. In particular, supramolecular systems that can produce a photonic output are increasingly important research targets and present various possibilities for practical applications. Accordingly, photonic properties of various supramolecular systems at the nanoscale are important in current nanotechnology. In this short review, nanophotonics in supramolecular chemistry will be briefly summarized by introducing recent examples of control of photonic responses of supramolecular systems. Topics are categorized according to the fundamental actions of their supramolecular systems: (i) self-assembly; (ii) recognition; (iii) manipulation.

  16. Computational organometallic chemistry

    In this article, the author highlights the tremendous impact that density functional theory has had on computational chemistry over the last decade. This robust and efficient theoretical technique (for which John Pople and Walter Kohn were awarded the Nobel Prize in 1998) has opened up many new possibilities for chemists, allowing to study large systems with a degree of reliability hitherto uncontemplated. Examples which illustrate how both density functional theory and hybrid method have been successfully used in solving difficult problems in quantum chemistry of catalysis are briefly discussed

  17. Spins in chemistry

    McWeeny, Roy

    2004-01-01

    Originally delivered as a series of lectures, this volume systematically traces the evolution of the ""spin"" concept from its role in quantum mechanics to its assimilation into the field of chemistry. Author Roy McWeeny presents an in-depth illustration of the deductive methods of quantum theory and their application to spins in chemistry, following the path from the earliest concepts to the sophisticated physical methods employed in the investigation of molecular structure and properties. Starting with the origin and development of the spin concept, the text advances to an examination of sp

  18. Atmospheric pseudohalogen chemistry

    Lary, D. J.

    2004-01-01

    There are at least three reasons why hydrogen cyanide is likely to be significant for atmospheric chemistry. The first is well known, HCN is a product and marker of biomass burning. However, if a detailed ion chemistry of lightning is considered then it is almost certain than in addition to lightning producing NOx, it also produces HOx and HCN. Unlike NOx and HOx, HCN is long-lived and could therefore ...

  19. Chemistry WebBook

    SRD 69 NIST Chemistry WebBook (Web, free access)   The NIST Chemistry WebBook contains: Thermochemical data for over 7000 organic and small inorganic compounds; thermochemistry data for over 8000 reactions; IR spectra for over 16,000 compounds; mass spectra for over 33,000 compounds; UV/Vis spectra for over 1600 compounds; electronic and vibrational spectra for over 5000 compounds; constants of diatomic molecules(spectroscopic data) for over 600 compounds; ion energetics data for over 16,000 compounds; thermophysical property data for 74 fluids.

  20. Chemistry in microelectronics

    Le Tiec, Yannick

    2013-01-01

    Microelectronics is a complex world where many sciences need to collaborate to create nano-objects: we need expertise in electronics, microelectronics, physics, optics and mechanics also crossing into chemistry, electrochemistry, as well as biology, biochemistry and medicine. Chemistry is involved in many fields from materials, chemicals, gases, liquids or salts, the basics of reactions and equilibrium, to the optimized cleaning of surfaces and selective etching of specific layers. In addition, over recent decades, the size of the transistors has been drastically reduced while the functionalit

  1. The chemistry of silicon

    Rochow, E G; Emeléus, H J; Nyholm, Ronald

    1975-01-01

    Pergamon Texts in Organic Chemistry, Volume 9: The Chemistry of Silicon presents information essential in understanding the chemical properties of silicon. The book first covers the fundamental aspects of silicon, such as its nuclear, physical, and chemical properties. The text also details the history of silicon, its occurrence and distribution, and applications. Next, the selection enumerates the compounds and complexes of silicon, along with organosilicon compounds. The text will be of great interest to chemists and chemical engineers. Other researchers working on research study involving s

  2. Progress in physical chemistry

    Hempelmann, Rolf

    2008-01-01

    Progress in Physical Chemistry is a collection of recent ""Review Articles"" published in the ""Zeitschrift für Physikalische Chemie"". The second volume of Progress in Physical Chemistry is a collection of thematically closely related minireview articles written by the members of the Collaborative Research Centre (SFB) 277 of the German Research Foundation (DFG). These articles are based on twelve years of intense coordinated research efforts. Central topics are the synthesis and the characterization of interface-dominated, i.e. nanostructured materials, mainly in the solid state but also as

  3. Chemistry and lithography

    Okoroanyanwu, Uzodinma

    2011-01-01

    This is a unique book, combining chemistry and physics with technology and history in a way that is both enlightening and lively. No other book in the field of lithography has as much breadth. Highly recommended for anyone interested in the broad application of chemistry to lithography. --Chris Mack, Gentleman Scientist. This book provides a comprehensive treatment of the chemical phenomena in lithography in a manner that is accessible to a wide readership. The book presents topics on the optical and charged particle physics practiced in lithography, with a broader view of how the marriage bet

  4. Frontiers in nuclear chemistry

    This book contains articles on the landmarks in nuclear and radiochemistry which takes through scientific history spanning over five decades from the times of Roentgen to the middle of this century. Articles on nuclear fission and back end of the nuclear fuel cycle give an insight into the current status of this subject. Reviews on frontier areas like lanthanides, actinides, muonium chemistry, accelerator based nuclear chemistry, fast radiochemical separations and nuclear medicine bring out the multidisciplinary nature of nuclear sciences. This book also includes an article on environmental radiochemistry and safety. Chapters relevant to INIS are indexed separately

  5. Survey of Water Chemistry and Corrosion of NPP

    Status of water chemistry of nuclear power plant and materials corrosion has been surveyed. For PWR, system chemistry of primary coolant and secondary coolant as well as the related corrosion of materials was surveyed. For BWR, system chemistry as whole has been surveyed with its accompanying corrosion problems. Radiolysis of coolant water and activation of corrosion products also was surveyed. Future NPP such as supercritical water cooled reactor and fusion reactor has also been surveyed for their water chemistry and corrosion problems. As a result, proposal for some research items has been suggested. Some related corrosion research techniques and electrochemical fundamentals are also presented

  6. Survey of Water Chemistry and Corrosion of NPP

    Jung, Ki Sok; Hong, Bong Geon

    2008-06-15

    Status of water chemistry of nuclear power plant and materials corrosion has been surveyed. For PWR, system chemistry of primary coolant and secondary coolant as well as the related corrosion of materials was surveyed. For BWR, system chemistry as whole has been surveyed with its accompanying corrosion problems. Radiolysis of coolant water and activation of corrosion products also was surveyed. Future NPP such as supercritical water cooled reactor and fusion reactor has also been surveyed for their water chemistry and corrosion problems. As a result, proposal for some research items has been suggested. Some related corrosion research techniques and electrochemical fundamentals are also presented.

  7. The Intelligent CAI System for Chemistry Based on Automated Reasoning

    王晓京; 张景中

    1999-01-01

    A new type of intelligent CAI system for chemistry is developed in this paper based on automated reasoning with chemistry knowledge.The system has shown its ability to solve chemistry problems,to assist students and teachers in studies and instruction with the automated reasoning functions.Its open mode of the knowledge base and its unique style of the interface between the system and human provide more opportunities for the users to acquire living knowledge through active participation.The automated reasoning based on basic chemistry knowledge also opened a new approach to the information storage and management of the ICAI system for sciences.

  8. Green Chemistry: Innovations for a Cleaner World. [Videotape].

    American Chemical Society, Washington, DC.

    This video was developed through a cooperative agreement between the American Chemical Society (ACS)'s Education and International Activities Division and the U.S. Environmental Protection Agency's Green Chemistry Program, Office of Pollution Prevention and Toxics. "Green Chemistry" focuses on chemical products and processes that reduce or…

  9. Soil Studies: Applying Acid-Base Chemistry to Environmental Analysis.

    West, Donna M.; Sterling, Donna R.

    2001-01-01

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

  10. Recent advances in the chemistry and biology of pyridopyrimidines.

    Buron, F; Mérour, J Y; Akssira, M; Guillaumet, G; Routier, S

    2015-05-01

    The interest in pyridopyrimidine cores for pharmaceutical products makes this scaffold a highly useful building block for organic chemistry. These derivatives have found applications in various areas of medicine such as anticancer, CNS, fungicidal, antiviral, anti-inflammatory, antimicrobial, and antibacterial therapies. This review mainly focuses on the progress achieved since 2004 in the chemistry and biological activity of pyridopyrimidines. PMID:25794791

  11. Progress in Kdo-glycoside chemistry

    Kosma, Paul

    2016-01-01

    Glycosylation chemistry of 3-deoxy-D-manno-oct-2-ulosonic acid units has been considerably developed within the last decade. This review covers major achievements with respect to improved yields and anomeric selectivity as well as suppression of the elimination side reaction via selection of dedicated protecting groups and appropriate activation of the anomeric center. PMID:27274586

  12. Green polymer chemistry: biocatalysis and biomaterials

    This overview briefly surveys the practice of green chemistry in polymer science. Eight related themes can be discerned from the current research activities: 1) biocatalysis, 2) bio-based building blocks and agricultural products, 3) degradable polymers, 4) recycling of polymer products and catalys...

  13. Using the ACS Journals Search to Validate Assumptions about Writing in Chemistry and Improve Chemistry Writing Instruction

    Robinson, Marin S.; Stoller, Fredricka L.; Jones, James K.

    2008-01-01

    This article illustrates how faculty and students can use the ACS Journals Search to examine assumptions about writing in chemistry. We examined common writing practices in chemistry including (i) the use of nominalizations, active and passive voice, and personal pronouns, (ii) words to avoid (e.g., researcher, very), (iii) words to use (e.g.,…

  14. Conflicts in Chemistry: The Case of Plastics, a Role-Playing Game for High School Chemistry Students

    Cook, Deborah H.

    2014-01-01

    Conflicts in Chemistry: The Case of Plastics, an innovative role-playing activity for high school students, was developed by the Chemical Heritage Foundation to promote increased public understanding of chemistry. The pilot program included three high school teachers and their students at three different schools and documented implementation and…

  15. How to teach chemistry? Is Chemistry a new universal language

    López Guerrero, María del Mar; López Guerrero, Gema

    2015-01-01

    Chemistry has been developed greatly throughout the 20th century. Chemistry is included in the curriculum of elementary and secondary education. In general, students are not interested in science, and because of this ,students tend not to make an effort to learn and understand the meaning of concepts and the chemistry language that are being taught to them. If we consider that there is a little bit analogy between chemistry and foreign languages, we should learn the s...

  16. Array processors in chemistry

    Ostlund, N.S.

    1980-01-01

    The field of attached scientific processors (''array processors'') is surveyed, and an attempt is made to indicate their present and possible future use in computational chemistry. The current commercial products from Floating Point Systems, Inc., Datawest Corporation, and CSP, Inc. are discussed.

  17. Chromatin chemistry goes cellular.

    W. Fischle; D. Schwarzer; Mootz, H.

    2015-01-01

    Analysing post-translational modifications of histone proteins as they occur within chromatin is challenging due to their large number and chemical diversity. A major step forward has now been achieved by using split intein chemistry to engineer functionalized histones within cells.

  18. Chemistry in Protoplanetary Disks

    Henning, Thomas; Semenov, Dmitry

    2013-01-01

    This comprehensive review summarizes our current understanding of the evolution of gas, solids and molecular ices in protoplanetary disks. Key findings related to disk physics and chemistry, both observationally and theoretically, are highlighted. We discuss which molecular probes are used to derive gas temperature, density, ionization state, kinematics, deuterium fractionation, and study organic matter in protoplanetary disks.

  19. Chemistry Education and Mythology

    Sule Aycan

    2005-01-01

    This study aimed to investigate the effect of mythological story in teaching chemistry. To this end the students in the class were divided into two homogenous groups. While the first group was thought in a traditional way, using a mythological story thought the second group. The story used was based on a Mountain just opposite the faculty.

  20. Symmetry in chemistry

    Jaffé, Hans H

    1977-01-01

    This book, devoted exclusively to symmetry in chemistry and developed in an essentially nonmathematical way, is a must for students and researchers. Topics include symmetry elements and operations, multiple symmetry operations, multiplication tables and point groups, group theory applications, and crystal symmetry. Extensive appendices provide useful tables.

  1. The chemistry of glycerin

    This book dedicated to chemistry of polyatomic alcohols, in particular, to glycerin and its numerous derivatives. These compounds are very widespread in the natural objects and carry out several functions in alive organism. Big part of these matters are arrange in industry production of base organic synthesis

  2. Online Organic Chemistry

    Janowicz, Philip A.

    2010-01-01

    This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online…

  3. Nobel Prize in Chemistry

    2000-01-01

    The Royal Swedish Academy has awarded the 1999 Nobel Prize in Chemistry to Ahmed H. Zewail (California Institute of Technology, Pasadena, CA) "for his studies of the transition states of chemical reactions using femtosecond spectroscopy". Zewail's work has taken the study of the rates and mechanisms of chemical reactions to the ultimate degree of detail - the time scale of bond making and bond breaking.

  4. Chemistry and Heritage

    Vittoria Barbarulo, Maria

    2014-05-01

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

  5. Metaphorical Models in Chemistry.

    Rosenfeld, Stuart; Bhusan, Nalini

    1995-01-01

    What happens when students of chemistry fail to recognize the metaphorical status of certain models and interpret them literally? Suggests that such failures lead students to form perceptions of phenomena that can be misleading. Argues that the key to making good use of metaphorical models is a recognition of their metaphorical status. Examines…

  6. Spatially Resolved Artificial Chemistry

    Fellermann, Harold

    2009-01-01

    made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction...

  7. The Chemistry of Griseofulvin

    Petersen, Asger Bjørn; Rønnest, Mads Holger; Larsen, Thomas Ostenfeld;

    2014-01-01

    Specific synthetic routes are presented in schemes to illustrate the chemistry, and the analogs are presented in a table format to give an accessible overview of the structures. Several patents have been published regarding the properties of griseofulvin and its derivatives including synthesis...

  8. Chemistry Education and Mythology

    Sule Aycan

    2005-01-01

    Full Text Available This study aimed to investigate the effect of mythological story in teaching chemistry. To this end the students in the class were divided into two homogenous groups. While the first group was thought in a traditional way, using a mythological story thought the second group. The story used was based on a Mountain just opposite the faculty.

  9. Forensic Chemistry Training

    Zuhal GERÇEK

    2012-01-01

    Full Text Available Increasing the types of terrorism and crime nowadays, the importance of the forensic sciences can be bett er understood. Forensic science is the application of the wide spectrum of science to answer the question of legal system. It contains the application of the principles, techniques and methods of basic sciences and its main aim is the determination of the physical facts which are important in legal situations. Forensic chemistry is the branch of chemistry which performs the chemical analysis of evidences that used in the courts. Forensic chemist is the professional chemist who analyzes the evidences from crime scene and reaches a result by application of tests. Th us, they have to have a special education. In forensic laboratories candidates who have chemistry/biochemistry undergraduate degree and took biology and forensic chemistry lectures are preferred. It is necessary to design graduate and undergraduate education to train a forensic chemist. Science education should be at the core of the undergraduate education. In addition to this strong laboratory education on both science and forensic science should be given. Th e graduate program of forensic science example should contain forensic science subjects, strong academic lectures on special subjects and research and laboratory components.

  10. Analytical Chemistry Laboratory

    Anderson, Mark

    2013-01-01

    The Analytical Chemistry and Material Development Group maintains a capability in chemical analysis, materials R&D failure analysis and contamination control. The uniquely qualified staff and facility support the needs of flight projects, science instrument development and various technical tasks, as well as Cal Tech.

  11. Evaluating Environmental Chemistry Textbooks.

    Hites, Ronald A.

    2001-01-01

    A director of the Indiana University Center for Environmental Science Research reviews textbooks on environmental chemistry. Highlights clear writing, intellectual depth, presence of problem sets covering both the qualitative and quantitative aspects of the material, and full coverage of the topics of concern. Discusses the director's own approach…

  12. Chemistry between the stars

    Gammon, R. H.

    1976-01-01

    A unit is presented for the secondary school teacher of physics, chemistry, astronomy, or earth sciences. Included are a list of reference materials, teaching aids, and projects. Discussion questions and a glossary are also provided. Concepts developed are: the nature of interstellar space, spectroscopy, molecular signals from space and interstellar molecules and other areas of astronomy.

  13. 金丝桃属植物中的金丝桃素:化学、植物来源和生物活性%Hypericin in hypericum: chemistry, botanical sources and biological activities

    黄林芳; 陈士林

    2012-01-01

    Hypericin,a secondary metabolite first reported in 1830,is a natural photosensitizing naphtodianthrone and is mainly from the natural plant sources of genus Hypericum.Hypericin exhibits a wide variety of biological and pharmacological activities,such as antiviral,antidepressant,antitumor,antimicrobial,and antioxidant activity.Hypericin can also be utilized in photodynamic diagnosis.Accumulating evidence is pointing to the effects of hypericin with potential pharmaceutical and clinical interests in the past decades.The present review gives a comprehensive outline of the chemistry,botanical occurrence and biological activities of this powerful compound.%金丝桃素是金丝桃属植物中一种重要的次生代谢产物,1830年首次被正式报道,它是一种天然光敏型的二蒽酮类化合物.金丝桃素具有抗病毒,抗抑郁、抗肿瘤、抗菌、抗氧化等广泛的生物和药理活性,并用于光动力治疗.在过去的几十年中越来越多的证据表明金丝桃素具有很大的药用潜力年和临床价值.本篇综述了金丝桃素的化学、植物来源和生物活性.

  14. Chemistry and sustainable environment (abstract)

    Chemistry is one of the oldest branches of science; the human beings had ever come across. It has consistently contributed towards meeting the human needs from the dawn of civilization. However, its role has multiplied since the inception of industrial revolution. Although anthropogenic activities have made the human life comfortable and even luxurious yet their impacts on the physical, biological and socio-economic environments had been destructive. Numerous kinds of chemicals have engulfed us and our environment. Modern chemistry has leading role in sculpting the present as well as future of human lifestyle. It is serving the man and other biodiversity by providing countless products in every sphere of life. At the same time it is playing villain role in the destruction of environment at an alarming rate. Today the world is confronted with heinous environmental issues hitherto unknown to the living beings mostly triggered by chemicals. Thousands of chemicals are used in industrial products, agricultural chemicals, persistent organic pollutants, freezers, pharmaceuticals, chemical and radiological warfare, construction industry, synthetic materials, electrical goods, medical gadgets etc. Some natural sources of chemicals are acid rains, volcanic eruptions, eutrophication and photochemical smog. The fact of matter is that chemicals are being consistently added into atmosphere, biosphere and lithosphere. For the sustainable environment it is imperative that the chemicals must not be added into human environment beyond its carrying capacity. It is responsibility of chemists to introduce environmentally benign and biodegradable chemicals. All types of chemistry need to be green and environment friendly. The scientists and engineers should develop chemicals and technologies which do not harm the living creatures during any stage of their life-cycle. (author)

  15. Green chemistry of carbon nanomaterials.

    Basiuk, Elena V; Basiuk, Vladimir A

    2014-01-01

    The global trend of looking for more ecologically friendly, "green" techniques manifested itself in the chemistry of carbon nanomaterials. The main principles of green chemistry emphasize how important it is to avoid the use, or at least to reduce the consumption, of organic solvents for a chemical process. And it is precisely this aspect that was systematically addressed and emphasized by our research group since the very beginning of our work on the chemistry of carbon nanomaterials in early 2000s. The present review focuses on the results obtained to date on solvent-free techniques for (mainly covalent) functionalization of fullerene C60, single-walled and multi-walled carbon nanotubes (SWNTs and MWNTs, respectively), as well as nanodiamonds (NDs). We designed a series of simple and fast functionalization protocols based on thermally activated reactions with chemical compounds stable and volatile at 150-200 degrees C under reduced pressure, when not only the reactions take place at a high rate, but also excess reagents are spontaneously removed from the functionalized material, thus making its purification unnecessary. The main two classes of reagents are organic amines and thiols, including bifunctional ones, which can be used in conjunction with different forms of nanocarbons. The resulting chemical processes comprise nucleophilic addition of amines and thiols to fullerene C60 and to defect sites of pristine MWNTs, as well as direct amidation of carboxylic groups of oxidized nanotubes (mainly SWNTs) and ND. In the case of bifunctional amines and thiols, reactions of the second functional group can give rise to cross-linking effects, or be employed for further derivatization steps. PMID:24730288

  16. Colloid and interface chemistry for nanotechnology

    Kralchevsky, Peter

    2013-01-01

    Colloid and interface science dealt with nanoscale objects for nearly a century before the term nanotechnology was coined. An interdisciplinary field, it bridges the macroscopic world and the small world of atoms and molecules. Colloid and Interface Chemistry for Nanotechnology is a collection of manuscripts reflecting the activities of research teams that have been involved in the networking project Colloid and Interface Chemistry for Nanotechnology (2006-2011), Action D43, the European Science Foundation. The project was a part of the intergovernmental framework for Cooperation in Science an

  17. Liquefaction chemistry and kinetics: Hydrogen utilization studies

    Rothenberger, K.S.; Warzinski, R.P.; Cugini, A.V. [Pittsburgh Energy Technology Center, PA (United States)] [and others

    1995-12-31

    The objectives of this project are to investigate the chemistry and kinetics that occur in the initial stages of coal liquefaction and to determine the effects of hydrogen pressure, catalyst activity, and solvent type on the quantity and quality of the products produced. The project comprises three tasks: (1) preconversion chemistry and kinetics, (2) hydrogen utilization studies, and (3) assessment of kinetic models for liquefaction. The hydrogen utilization studies work will be the main topic of this report. However, the other tasks are briefly described.

  18. Facile design of biomaterials by 'click' chemistry

    Hvilsted, Søren

    2012-01-01

    chemistry is elaborated. The present state of creating functional and biologically active surfaces by click chemistry is presented. Finally, conducting surfaces based on an azide‐functionalized polymer with prospective biological sensor potential are introduced. Copyright © 2012 Society of Chemical Industry......The advent of the so‐called ‘click chemistry’ a decade ago has significantly improved the chemical toolbox for producing novel biomaterials. This review focuses primarily on the application of Cu(I)‐catalysed azide–alkyne 1,3‐cycloadditon in the preparation of numerous, diverse biomaterials and...

  19. Striving toward a More "Precise" Chemistry

    YAO Jiannian

    2011-01-01

    @@ On multiple temporal and spatial scales, chemistry explores the composition, structure and form of matter, its physical properties and biological activity as well as the chemical changes and synthesis reactions, striving to describe the colorful world of matter and reveal the molecular secrets of matter transformations and life processes using its theories and its unique language.As a fundamental and creative discipline of science, chemistry not only helps us to understand the nature of substances and make high-performing materials to serve economic development, but is distinctively characterized by the ability to invent novel and marvelous matters.

  20. Conserved structural chemistry for incision activity in structurally non-homologous apurinic/apyrimidinic endonuclease APE1 and endonuclease IV DNA repair enzymes.

    Tsutakawa, Susan E.; Shin, David S.; Mol, Clifford D.; Izum, Tadahide; Arvai, Andrew S.; Mantha, Anil K.; Szczesny, Bartosz; Ivanov, Ivaylo N.; Hosfield, David J.; Maiti, Buddhadev; Pique, Mike E.; Frankel, Kenneth A.; Hitomi, Kenichi; Cunningham, Richard P.; Mitra, Sankar; Tainer, John A.

    2013-03-22

    Non-coding apurinic/apyrimidinic (AP) sites in DNA form spontaneously and as DNA base excision repair intermediates are the most common toxic and mutagenic in vivo DNA lesion. For repair, AP sites must be processed by 5' AP endonucleases in initial stages of base repair. Human APE1 and bacterial Nfo represent the two conserved 5' AP endonuclease families in the biosphere; they both recognize AP sites and incise the phosphodiester backbone 5' to the lesion, yet they lack similar structures and metal ion requirements. Here, we determined and analyzed crystal structures of a 2.4 ? resolution APE1-DNA product complex with Mg(2+) and a 0.92 Nfo with three metal ions. Structural and biochemical comparisons of these two evolutionarily distinct enzymes characterize key APE1 catalytic residues that are potentially functionally similar to Nfo active site components, as further tested and supported by computational analyses. We observe a magnesium-water cluster in the APE1 active site, with only Glu-96 forming the direct protein coordination to the Mg(2+). Despite differences in structure and metal requirements of APE1 and Nfo, comparison of their active site structures surprisingly reveals strong geometric conservation of the catalytic reaction, with APE1 catalytic side chains positioned analogously to Nfo metal positions, suggesting surprising functional equivalence between Nfo metal ions and APE1 residues. The finding that APE1 residues are positioned to substitute for Nfo metal ions is supported by the impact of mutations on activity. Collectively, the results illuminate the activities of residues, metal ions, and active site features for abasic site endonucleases.

  1. The Medicinal Chemistry of Dengue Virus.

    Behnam, Mira A M; Nitsche, Christoph; Boldescu, Veaceslav; Klein, Christian D

    2016-06-23

    The dengue virus and related flaviviruses are an increasing global health threat. In this perspective, we comment on and review medicinal chemistry efforts aimed at the prevention or treatment of dengue infections. We include target-based approaches aimed at viral or host factors and results from phenotypic screenings in cellular assay systems for viral replication. This perspective is limited to the discussion of results that provide explicit chemistry or structure-activity relationship (SAR), or appear to be of particular interest to the medicinal chemist for other reasons. The discovery and development efforts discussed here may at least partially be extrapolated toward other emerging flaviviral infections, such as West Nile virus. Therefore, this perspective, although not aimed at flaviviruses in general, should also be able to provide an overview of the medicinal chemistry of these closely related infectious agents. PMID:26771861

  2. The phosphorus and the transition metals chemistry

    The 1988 progress report, concerning the Polytechnic School unit (France), which studies the phosphorus and the transition metals chemistry, is presented. The laboratory activities are related to the following topics: the phosporus heterocyclic chemistry, the phosphorus-carbon double bonds chemistry, the new transition metals phosphorus compounds, the phosphonates and their uses. Some practical applications of homogeneous catalysis and new materials synthesis are investigated. The main results obtained are: the discovery of the tetra-phosphafulvalenes, the utilization of a new synthesis method of the phosphorus-carbon double bonds and the stabilization of the α-phosphonyled carbanions by the lithium diisopropylamidourea. The papers, the congress communications and the thesis are also shown

  3. Conference 'Chemistry of hydrides' Proceedings

    This collection of thesis of conference of Chemistry hydrides presents the results of investigations concerning of base questions of chemistry of nonorganic hydrides, including synthesis questions, studying of physical and chemical properties, thermodynamics, analytical chemistry, investigation of structure, equilibriums in the systems of metal-hydrogen, behaviour of nonorganic hydrides in non-water mediums and applying investigations in the chemistry area and technology of nonorganic hydrides

  4. Heterogenous phase as a mean in combinatorial chemistry

    Combinatorial chemistry is a rapid and inexpensive technique for the synthesis of hundreds of thousands of organic compounds of potential medicinal activity. In the past few decades a large number of combinatorial libraries have been constructed, and significantly supplement the chemical diversity of the traditional collections of the potentially active medicinal compounds. Solid phase synthesis was used to enrich the combinatorial chemistry libraries, through the use of solid supports (resins) and their modified forms. Most of the new libraries of compounds appeared recently, were synthesized by the use of solid-phase. Solid-phase combinatorial chemistry (SPCC) is now considered as an outstanding branch in pharmaceutical chemistry research and used extensively as a tool for drug discovery within the context of high-throughput chemical synthesis. The best pure libraries synthesized by the use of solid phase combinatorial chemistry (SPCC) may well be those of intermediate complexity that are free of artifact-causing nuisance compounds. (author)

  5. Flipped Classroom Modules for Large Enrollment General Chemistry Courses: A Low Barrier Approach to Increase Active Learning and Improve Student Grades

    Eichler, Jack F.; Peeples, Junelyn

    2016-01-01

    In the face of mounting evidence revealing active learning approaches result in improved student learning outcomes compared to traditional passive lecturing, there is a growing need to change the way instructors teach large introductory science courses. However, a large proportion of STEM faculty continues to use traditional instructor-centered…

  6. Surface chemistry and catalytic activity of Ni/Al{sub 2}O{sub 3} irradiated with high-energy electron beam

    Jun, Jin [Department of Optometry and Optic Science, Dongshin University, 252 Daeho-Dong, Naju 520-714 (Korea, Republic of)], E-mail: jinjun@dsu.ac.kr; Dhayal, Marshal [Liquid Crystal and Self Assembled Monolayer Section, National Physical Laboratory, Dr. KS Krisnan Marg, New Delhi 120011 (India); Shin, Joong-Hyeok [Department of Environmental Engineering, Dongshin University, 252 Daeho-Dong, Naju 520-714 (Korea, Republic of); Han, Young Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Getoff, Nikola [Department of Nutrition, Section Radiation Biology, University of Vienna, Althanstr. 14, A-1090 Vienna (Austria)

    2008-05-30

    The radiation effects induced effects by electron beam (EB) treatment on the catalytic activity of Ni/{gamma}-Al{sub 2}O{sub 3} were studied for the carbon dioxide reforming of methane with different EB energy and absorbed radiation dose. Transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to determine the change in structure and surface states of Ni/{gamma}-Al{sub 2}O{sub 3} catalyst before and after the EB treatment. Higher energy EB treatment is useful for increasing the proportion of the active sites (such as Ni{sup 0} and NiAl{sub 2}O{sub 4}-phase) on the surface. The increase of Ni/Al-ratio indicates that the Ni dispersion on the surface increased with the EB-treatment, resulting in an increase of the active sites, which leads to improving the catalytic activity. XPS measurement also showed a decrease of the surface carbon with EB dose. The maximum 20% increase in the conversion of CO{sub 2}/CH{sub 4}-mixture into CO/H{sub 2} gas was observed for the catalyst treated with 2 MeV energy and 600 kGy dose of EB relative to untreated.

  7. School Chemistry: An Historical and Philosophical Approach

    Izquierdo-Aymerich, Mercè

    2013-07-01

    Since at least the eighteenth century scientific knowledge (then natural philosophy) was produced in groups of experts and specialists and was transmitted in schools, where, future experts and specialists were trained. The design of teaching has always been a complex process particularly in recent years when educational aims (for example, teaching scientific competence to everyone, not just to experts and specialists) present significant challenges. These challenges are much more than a simple reorganisation of the scientific knowledge pre-determined by the existing teaching tradition for different educational level. In the context of chemical education, the new teaching approaches should bring about not only the transmission of chemical knowledge but also a genuine chemical activity so as to ensure that students can acquire chemical thinking. Chemistry teaching should be revised according to contemporary demands of schooling. In order to move forward towards new teaching proposals, we must identify the genuine questions that generate `chemical criteria' and we should focus on them for teaching. We think that a good strategy is to look for those criteria in the philosophy and history of chemistry, from the perspective of didactics of science. This paper will examine the following questions: (1) How can school science be designed as a world-modelling activity by drawing on the philosophy of science. (2) How can `stories' about the emergence of chemical entities be identified by looking at the history of chemistry? (3) How can modelling strategies be structured in school chemistry activities?

  8. Predictors of General Chemistry Grades.

    Ozsogomonyan, Ardas; Loftus, Drew

    1979-01-01

    Chemistry pretest scores, high school chemistry grades and, to a greater extent, math SAT scores were useful predictors of college general chemistry grades. Regression analysis of all these predictors combined was used to construct an expectancy table which is being used to identify and advise underprepared students. (BB)

  9. Copper Nanoparticles in Click Chemistry.

    Alonso, Francisco; Moglie, Yanina; Radivoy, Gabriel

    2015-09-15

    The challenges of the 21st century demand scientific and technological achievements that must be developed under sustainable and environmentally benign practices. In this vein, click chemistry and green chemistry walk hand in hand on a pathway of rigorous principles that help to safeguard the health of our planet against negligent and uncontrolled production. Copper-catalyzed azide-alkyne cycloaddition (CuAAC), the paradigm of a click reaction, is one of the most reliable and widespread synthetic transformations in organic chemistry, with multidisciplinary applications. Nanocatalysis is a green chemistry tool that can increase the inherent effectiveness of CuAAC because of the enhanced catalytic activity of nanostructured metals and their plausible reutilization capability as heterogeneous catalysts. This Account describes our contribution to click chemistry using unsupported and supported copper nanoparticles (CuNPs) as catalysts prepared by chemical reduction. Cu(0)NPs (3.0 ± 1.5 nm) in tetrahydrofuran were found to catalyze the reaction of terminal alkynes and organic azides in the presence of triethylamine at rates comparable to those achieved under microwave heating (10-30 min in most cases). Unfortunately, the CuNPs underwent dissolution under the reaction conditions and consequently could not be recovered. Compelling experimental evidence on the in situ generation of highly reactive copper(I) chloride and the participation of copper(I) acetylides was provided. The supported CuNPs were found to be more robust and efficient catalyst than the unsupported counterpart in the following terms: (a) the multicomponent variant of CuAAC could be applied; (b) the metal loading could be substantially decreased; (c) reactions could be conducted in neat water; and (d) the catalyst could be recovered easily and reutilized. In particular, the catalyst composed of oxidized CuNPs (Cu2O/CuO, 6.0 ± 2.0 nm) supported on carbon (CuNPs/C) was shown to be highly versatile and very

  10. I. Developing methods for the analysis of chemistry students' inscriptions, II. Exploring the regioselectivity of 1,3-dipolar cycloadditions of munchnones, III. Stereochemical investigations of C-H activation reactions involving germylene and stannylene/aryl iodide reagents

    Kiste, Alan L.

    I. Analyzing and comparing student-generated inscriptions in chemistry is crucial to gaining insight into students' understanding about chemistry concepts. Thus, we developed two methods of analyzing student-generated inscriptions: features analysis and thematic analysis. We have also demonstrated how these methods are able to discern differences between both how students inscribe their understandings and the content of those inscriptions, regardless of (1) how those inscriptions were created (i.e. computer vs. pencil-and-paper), (2) the nature of the inscriptions (verbal vs. pictorial), and (3) the expertise of the students. The ability to analyze inscriptions regardless of the medium allows the examination of multiple inscriptions in educational research applications as well as in the design and development of educational materials. Also, inscriptions can be compared across contexts, allowing the comparison of student-generated inscriptions derived from various educational interventions. Finally, the ability to compare inscriptions regardless of the level of expertise allows novice/expert comparisons as well as longitudinal comparison over time. II. Predicting the regiochemistry of 1,3-dipolar cycloadditions of munchnones and acetylenic dipolarophiles is difficult based on frontier molecular orbital theory (FMO) alone. We have proposed that, in addition to FMO considerations, steric factors influencing the non-covalent interactions between reactive centers in the transition state also influence the regioselectivity of these reactions. We have developed a scheme to use a tether-based regiocontrol strategy to synthesize 2,4-disubstituted pyrroles using N-(2-thiazolinyl) secondary amino acid derivatives. Attempts to synthesize these amino acid derivatives have been, so far, unsuccessful. III. To provide additional information about the mechanism of C-H activation reactions of stannylenes and germylenes, and to demonstrate the utility of these reactions, we explored

  11. Effects of Microporosity and Surface Chemistry on Separation Performances of N-Containing Pitch-Based Activated Carbons for CO2/N2 Binary Mixture

    Lee, Min-Sang; Park, Mira; Kim, Hak Yong; Park, Soo-Jin

    2016-03-01

    In this study, N-containing pitch-based activated carbons (NPCs) were prepared using petroleum pitch with a low softening point and melamine with a high nitrogen content. The major advantage of the preparation method is that it enables variations in chemical structures and textural properties by steam activation at high temperatures. The adequate micropore structures, appropriate chemical modifications, and high adsorption enthalpies of NPCs are favorable for CO2 adsorption onto carbon surfaces. Furthermore, the structure generates a considerable gas/N-containing carbon interfacial area, and provides selective access to CO2 molecules over N2 molecules by offering an increased number of active sites on the carbon surfaces. The highest CO2/N2 selectivity, i.e., 47.5, and CO2 adsorption capacity for a CO2/N2 (0.15:0.85) binary gas mixture, i.e., 5.30 wt%, were attained at 298 K. The NPCs also gave reversible and durable CO2-capturing performances. All the results suggest that NPCs are promising CO2 sorbents, which can meet the challenges of current CO2 capture and separation techniques.

  12. Effects of Microporosity and Surface Chemistry on Separation Performances of N-Containing Pitch-Based Activated Carbons for CO2/N2 Binary Mixture

    Lee, Min-Sang; Park, Mira; Kim, Hak Yong; Park, Soo-Jin

    2016-01-01

    In this study, N-containing pitch-based activated carbons (NPCs) were prepared using petroleum pitch with a low softening point and melamine with a high nitrogen content. The major advantage of the preparation method is that it enables variations in chemical structures and textural properties by steam activation at high temperatures. The adequate micropore structures, appropriate chemical modifications, and high adsorption enthalpies of NPCs are favorable for CO2 adsorption onto carbon surfaces. Furthermore, the structure generates a considerable gas/N-containing carbon interfacial area, and provides selective access to CO2 molecules over N2 molecules by offering an increased number of active sites on the carbon surfaces. The highest CO2/N2 selectivity, i.e., 47.5, and CO2 adsorption capacity for a CO2/N2 (0.15:0.85) binary gas mixture, i.e., 5.30 wt%, were attained at 298 K. The NPCs also gave reversible and durable CO2-capturing performances. All the results suggest that NPCs are promising CO2 sorbents, which can meet the challenges of current CO2 capture and separation techniques. PMID:26987683

  13. Carbohydrates in Supramolecular Chemistry.

    Delbianco, Martina; Bharate, Priya; Varela-Aramburu, Silvia; Seeberger, Peter H

    2016-02-24

    Carbohydrates are involved in a variety of biological processes. The ability of sugars to form a large number of hydrogen bonds has made them important components for supramolecular chemistry. We discuss recent advances in the use of carbohydrates in supramolecular chemistry and reveal that carbohydrates are useful building blocks for the stabilization of complex architectures. Systems are presented according to the scaffold that supports the glyco-conjugate: organic macrocycles, dendrimers, nanomaterials, and polymers are considered. Glyco-conjugates can form host-guest complexes, and can self-assemble by using carbohydrate-carbohydrate interactions and other weak interactions such as π-π interactions. Finally, complex supramolecular architectures based on carbohydrate-protein interactions are discussed. PMID:26702928

  14. Radiation chemistry of oils

    Full text : Primary investigations have been conducted at the end of the 1950th years in the area of radiation chemistry of the oils, the physical-chemical properties of crude oil have been investigated the influence of ionizing rays. This report by M. Malikzadeh is about the results of investigations carried out in the field of development of radiation chemistry. The power of the radiation dose and temperature-thermal effect of the collapse of Phentadekan -Oil, and oil fractions (200-400 degrees Celsium, 230-310 degrees Celsium) of radiation-thermal separation of olefins - Conversion of hydrogen from the transormation of black oil, bitumen and tar Kinetics of the above-mentioned processes was studied, the technical-economic indicators of the products were determined

  15. Medicinal chemistry for 2020.

    Satyanarayanajois, Seetharama D; Hill, Ronald A

    2011-10-01

    Rapid advances in our collective understanding of biomolecular structure and, in concert, of biochemical systems, coupled with developments in computational methods, have massively impacted the field of medicinal chemistry over the past two decades, with even greater changes appearing on the horizon. In this perspective, we endeavor to profile some of the most prominent determinants of change and speculate as to further evolution that may consequently occur during the next decade. The five main angles to be addressed are: protein-protein interactions; peptides and peptidomimetics; molecular diversity and pharmacological space; molecular pharmacodynamics (significance, potential and challenges); and early-stage clinical efficacy and safety. We then consider, in light of these, the future of medicinal chemistry and the educational preparation that will be required for future medicinal chemists. PMID:22004084

  16. Aqueous chemistry of iodine

    The chemistry of iodine has been examined in aqueous solutions of pH 6 to 10 containing 2500 ppM boron as H3BO3 at temperatures up to 1500C using absorption spectrophotometry to identify and monitor the iodine species present. Kinetic rate constants for the disproportionation of the HOI intermediate, 3HOI= IO3- + 2I- + 3H+, have been measured as a function of pH even though no direct spectral evidence for HOI itself has been observed. An HOI partition coefficient >104 has been estimated; results of ionic strength tests are consistent with HOI being present as an uncharged triatomic species in solution. Redox and radiation effects on the aqueous iodine chemistry have also been described. 11 refs., 2 figs., 3 tabs

  17. Chemistry space–time

    David A. Winkler

    2015-12-01

    Full Text Available As Einstein identified so clearly, space and time are intimately related. We discuss the relationship between time and Euclidean space using spectroscopic and radioastronomical studies of interstellar chemistry as an example. Given the finite speed of light, we are clearly studying chemical reactions occurring tens of thousands of years ago that may elucidate the primordial chemistry of this planet several billion years ago. We also explore space of a different kind – chemical space, with many more dimensions than the four we associate as space–time. Vast chemical spaces also need very efficient (computational methods for their exploration to overcome this ‘curse of dimensionality’. We discuss methods by which the time to explore these new spaces can be very substantially reduced, opening the discovery useful new materials that are the key to our future.

  18. Heterogeneous atmospheric chemistry

    Schryer, D. R.

    1982-01-01

    The present conference on heterogeneous atmospheric chemistry considers such topics concerning clusters, particles and microparticles as common problems in nucleation and growth, chemical kinetics, and catalysis, chemical reactions with aerosols, electron beam studies of natural and anthropogenic microparticles, and structural studies employing molecular beam techniques, as well as such gas-solid interaction topics as photoassisted reactions, catalyzed photolysis, and heterogeneous catalysis. Also discussed are sulfur dioxide absorption, oxidation, and oxidation inhibition in falling drops, sulfur dioxide/water equilibria, the evidence for heterogeneous catalysis in the atmosphere, the importance of heterogeneous processes to tropospheric chemistry, soot-catalyzed atmospheric reactions, and the concentrations and mechanisms of formation of sulfate in the atmospheric boundary layer.

  19. Organic Chemistry in Space

    Charnley, Steven

    2009-01-01

    Astronomical observations, theoretical modeling, laboratory simulation and analysis of extraterrestrial material have enhanced our knowledge of the inventory of organic matter in the interstellar medium (ISM) and on small bodies such as comets and asteroids (Ehrenfreund & Charnley 2000). Comets, asteroids and their fragments, meteorites and interplanetary dust particles (IDPs), contributed significant amounts of extraterrestrial organic matter to the young Earth. This material degraded and reacted in a terrestrial prebiotic chemistry to form organic structures that may have served as building blocks for life on the early Earth. In this talk I will summarize our current understanding of the organic composition and chemistry of interstellar clouds. Molecules of astrobiological relevance include the building blocks of our genetic material: nucleic acids, composed of subunits such as N-heterocycles (purines and pyrimidines), sugars and amino acids. Signatures indicative of inheritance of pristine and modified interstellar material in comets and meteorites will also be discussed.

  20. Quo vadis, analytical chemistry?

    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. PMID:26631024

  1. Supramolecular chemistry and technology

    HENRIQUE E. TOMA

    2000-03-01

    Full Text Available Supramolecular chemistry deals with the association of several chemical species, in an organized way and according to well defined purposes. Based on a molecular engineering approach, supramolecular structures can be designed from pre-formed building blocks, providing a promising route from chemistry to molecular nanotechnology. New supramolecular systems have been assembled in our laboratory with the use of bridging unities such as tetrapyridylporphyrins, porphyrazines and polypyrazines, connecting transition metal complexes and clusters. These systems display a very exciting electrochemical and catalytic behavior, and interact with DNA, generating ¹O2 and leading to efficient oxidative clivage for photodynamic terapy applications. Molecular interfaces have been developed, exhibiting photocurrent response in the presence of visible-UV light, and rectifying properties in the presence of electroactive species. Successful applications of the supramolecular species in chemical and bio-sensors have been developed.

  2. Muons in chemistry

    Clayden, N. J.

    2013-12-01

    Positive muons have long been used as extrinsic probes in chemistry, offering unique properties for the investigation of local magnetism, dynamics, transport and radical kinetics. Exciting new developments in muon beam lines offer the opportunity of extending these studies selectively to surfaces permitting, for example, the detection of increased mobility of polymer chains at the surface of a polymer film. So called pump and probe methods, involving external perturbations by laser irradiation to manipulate vibrational and electronic states, can be followed by muon pulses allowing the probing of the properties of these states. Muoniated radical probes are finding greater use in soft matter. Selectivity is achieved in these complex systems through an appropriate target molecule giving the chance to measure partitioning and interfacial transfer in surfactant systems. Improvements in sample environments allow the observation of muons in increasingly extreme combinations of temperature and pressure, such as supercritical water, allowing the characterization of the chemistry in these systems.

  3. Tropical Soil Chemistry

    Borggaard, Ole K.

    A new book that is particularly relevant as tropical countries experience increased pressure on land resources to improve agricultural production. To ensure sustainable land use, the potentials and limitations of different kinds of tropical soils must be known in relation to crop production...... soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics...... and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors...

  4. ANT International chemistry update and best practices

    There is an increasing number of Nuclear Power Plants (NPP) in various countries. Their chemistry practices are different due to the variety of designs and experiences while in the past the view was more monolithic. This is allowing a very rich experience that is extremely difficult to fully be aware of. ANT International is now collecting and evaluating these data as well as related R and D Information. This allows interested parties to have an easier access to the various sources of information. The chemistry experts associated to ANT International have been gathering a comprehensive detailed view of: The numerous laboratory data gained all over the world during the past decades; The extensive plant operating experiences with various types of chemistry strategies, crosschecked for various types of reactors designs and materials; An experienced international knowledge able to give the comprehensive overview that young engineers now in charge of many other activities are unable to fully cover. This paper gives the core conclusions of the detailed ANT International reports and results that have recently been gathered in the area of chemistry. It particularly covers: The primary water chemistry and its relation with radionuclides, dose rates and fuel behaviour; The secondary water chemistry focusing on its rationale selection depending on materials, design and other constraints; The start up and shutdown chemistry with it large variety of practices hardly understandable even for some experts; and, The maintenance remedies such as decontamination, steam generator cleaning and its alternate options. Various types of Reactor designs (PWR, VVER, BWR, CANDU®) are considered. The different materials, for example the impact of steam generator tubing and its evolution on the secondary water chemistry rationale or on the radioactivity built-up in the primary coolant, are described. The ways to improve the plant operation with a long term reliability as well as the most

  5. Annual Report 2003 of the Institute of Nuclear Chemistry and Technology

    The INCT 2003 Annual Report is the review of scientific activities in all branches being developed in the Institute of Nuclear Chemistry and Technology Warsaw. The studies are connected in general with the following fields: radiation chemistry and physics, radiation technologies, radiochemistry, stable isotopes, nuclear analytical methods, chemistry in general, radiobiology, process engineering, material engineering, structural studies, nucleonic control systems and accelerators

  6. First-Year Chemistry in the Context of the Periodic Table.

    Woodgate, Sheila D.

    1995-01-01

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

  7. Solvents and sustainable chemistry

    Welton, Tom

    2015-01-01

    Solvents are widely recognized to be of great environmental concern. The reduction of their use is one of the most important aims of green chemistry. In addition to this, the appropriate selection of solvent for a process can greatly improve the sustainability of a chemical production process. There has also been extensive research into the application of so-called green solvents, such as ionic liquids and supercritical fluids. However, most examples of solvent technologies that give improved...

  8. Chemistry of sex attraction.

    Roelofs, W L

    1995-01-01

    The chemical communication system used to attract mates involves not only the overt chemical signals but also indirectly a great deal of chemistry in the emitter and receiver. As an example, in emitting female moths, this includes enzymes (and cofactors, mRNA, genes) of the pheromone biosynthetic pathways, hormones (and genes) involved in controlling pheromone production, receptors and second messengers for the hormones, and host plant cues that control release of the hormone. In receiving ma...

  9. Current ADC Linker Chemistry

    Jain, Nareshkumar; Smith, Sean W.; Ghone, Sanjeevani; Tomczuk, Bruce

    2015-01-01

    The list of ADCs in the clinic continues to grow, bolstered by the success of first two marketed ADCs: ADCETRIS® and Kadcyla®. Currently, there are 40 ADCs in various phases of clinical development. However, only 34 of these have published their structures. Of the 34 disclosed structures, 24 of them use a linkage to the thiol of cysteines on the monoclonal antibody. The remaining 10 candidates utilize chemistry to surface lysines of the antibody. Due to the inherent heterogeneity of conjugati...

  10. Advances in electroanalytical chemistry

    Wang, Yijun; Compton, Richard

    2012-01-01

    This thesis concerns several advances in electroanalytical chemistry which are separated into four parts: the electrochemical investigation of diffusional behaviour, the mechanistic and kinetic study of electrochemistry with room temperature ionic liquids (RTILs), the study of weakly-supported electrochemistry and a comparison of the Butler-Volmer and Marcus-Hush kinetic theories of electron transfer. A study of the diffusional behaviour of electroactive species is essential for further s...

  11. Art and Chemistry

    Walter, Philippe

    2015-01-01

    Philippe Walter’s teaching, which he delivered as holder of the Liliane Bettencourt Annual Chair of Technological Innovation, was completed with two lectures on “practical work” to deal with a real case. The conditions and challenges of interdisciplinary research combining analytical chemistry, art history and archaeology were thus discussed in relation to specific works. The Holy Family, Constantin Abraham (1785-1855) by Raphaël (aka), Sanzio Raffaello (1483-1520), hard porcelain, Sèvres, C...

  12. Chemistry of silybin

    Biedermann, David; Vavříková, Eva; Cvak, L.; Křen, Vladimír

    2014-01-01

    Roč. 31, č. 9 (2014), s. 1138-1157. ISSN 0265-0568 R&D Projects: GA ČR(CZ) GAP301/11/0662; GA MŠk LH13097; GA MŠk(CZ) LD14096; GA MŠk(CZ) LD13042 Institutional support: RVO:61388971 Keywords : silybin * Silybum marianum * separation Subject RIV: CC - Organic Chemistry Impact factor: 10.107, year: 2014

  13. Medicinal chemistry for 2020

    Satyanarayanajois, Seetharama D.; Hill, Ronald A

    2011-01-01

    Rapid advances in our collective understanding of biomolecular structure and, in concert, of biochemical systems, coupled with developments in computational methods, have massively impacted the field of medicinal chemistry over the past two decades, with even greater changes appearing on the horizon. In this perspective, we endeavor to profile some of the most prominent determinants of change and speculate as to further evolution that may consequently occur during the next decade. The five ma...

  14. Learning Chemistry from Bacteria

    Clardy, Jon

    2013-01-01

    Dr. Jon Clardy Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University All animals, including humans, originated and evolved on a planet already teeming with bacteria, and the two kingdoms of life have been competing and cooperating through their joint history. Although bacteria are most familiar as pathogens, some bacteria produce small molecules that are essential for the biology of animals and other eukaryotes. This lecture explores some of...

  15. Actinide separative chemistry

    Actinide separative chemistry has focused very heavy work during the last decades. The main was nuclear spent fuel reprocessing: solvent extraction processes appeared quickly a suitable, an efficient way to recover major actinides (uranium and plutonium), and an extensive research, concerning both process chemistry and chemical engineering technologies, allowed the industrial development in this field. We can observe for about half a century a succession of Purex plants which, if based on the same initial discovery (i.e. the outstanding properties of a molecule, the famous TBP), present huge improvements at each step, for a large part due to an increased mastery of the mechanisms involved. And actinide separation should still focus R and D in the near future: there is a real, an important need for this, even if reprocessing may appear as a mature industry. We can present three main reasons for this. First, actinide recycling appear as a key-issue for future nuclear fuel cycles, both for waste management optimization and for conservation of natural resource; and the need concerns not only major actinide but also so-called minor ones, thus enlarging the scope of the investigation. Second, extraction processes are not well mastered at microscopic scale: there is a real, great lack in fundamental knowledge, useful or even necessary for process optimization (for instance, how to design the best extracting molecule, taken into account the several notifications and constraints, from selectivity to radiolytic resistivity?); and such a need for a real optimization is to be more accurate with the search of always cheaper, cleaner processes. And then, there is room too for exploratory research, on new concepts-perhaps for processing quite new fuels- which could appear attractive and justify further developments to be properly assessed: pyro-processes first, but also others, like chemistry in 'extreme' or 'unusual' conditions (supercritical solvents, sono-chemistry, could be

  16. Quantum mechanics in chemistry

    Schatz, George C

    2002-01-01

    Intended for graduate and advanced undergraduate students, this text explores quantum mechanical techniques from the viewpoint of chemistry and materials science. Dynamics, symmetry, and formalism are emphasized. An initial review of basic concepts from introductory quantum mechanics is followed by chapters examining symmetry, rotations, and angular momentum addition. Chapter 4 introduces the basic formalism of time-dependent quantum mechanics, emphasizing time-dependent perturbation theory and Fermi's golden rule. Chapter 5 sees this formalism applied to the interaction of radiation and matt

  17. Chemistry in Bioinformatics

    Mitchell John; Murray-Rust Peter; Rzepa Henry

    2005-01-01

    Abstract Chemical information is now seen as critical for most areas of life sciences. But unlike Bioinformatics, where data is openly available and freely re-usable, most chemical information is closed and cannot be re-distributed without permission. This has led to a failure to adopt modern informatics and software techniques and therefore paucity of chemistry in bioinformatics. New technology, however, offers the hope of making chemical data (compounds and properties) free during the auth...

  18. Food chemistry. 2. ed.

    This second edition of the textbook deals with all essential aspects of food chemistry. The revision improved in particular the chapters on food preservation, including irradiation of food, food additives, and pollutants and residues, including radionuclides. The chapter on the German legal regime for foodstuffs has been updated to cover the recent amendments of the law, and the information on processes applied in food technology has been largely enhanced. (VHE) With 153 figs., 78 tabs

  19. Green chemistry: development trajectory

    Examples of applications of green chemistry methods in heavy organic synthesis are analyzed. Compounds, which can be produced by the processing of the biomass, and the criteria for the selection of the most promising products are summarized. The current status of the ethanol production and processing is considered. The possibilities of the use of high fatty acid triglycerides, glycerol, succinic acid, and isoprene are briefly discussed. The bibliography includes 67 references

  20. Green chemistry: development trajectory

    Moiseev, I. I.

    2013-07-01

    Examples of applications of green chemistry methods in heavy organic synthesis are analyzed. Compounds, which can be produced by the processing of the biomass, and the criteria for the selection of the most promising products are summarized. The current status of the ethanol production and processing is considered. The possibilities of the use of high fatty acid triglycerides, glycerol, succinic acid, and isoprene are briefly discussed. The bibliography includes 67 references.