WorldWideScience

Sample records for shutdown chemistry practices

  1. Secondary chemistry of steam generator. Influence of hydrazine on corrosion potential. Optimisation of shutdown conditions and return to nominal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Foucault, M.; Long, A.; Combrade, P. [Framatome-ANP, Paris (France); Rodet, I.; Bouchacourt, M. [EdF-SEPTEN, Lyon (France)

    2002-07-01

    The oxygen and hydrazine contents of the secondary environment have a great importance in the build-up and the modification of the oxide layer formed on carbon steel or LAS surfaces of the secondary side of the SG. These modifications may have an important influence on general release, deposits in tube support plates. A program has been carried out to evaluate the influence of hydrazine on the structure and the composition of the oxide layer formed on carbon steel in different environmental conditions: nominal conditions, hot shutdown transient with high or low hydrazine concentration and come back to nominal conditions after a hot shut down. In order to reach the aim of this program, a special device has been built on with the following main characteristics: temperature up to 320 C, secondary environment with control of hydrazine and oxygen content, water-flow velocity up to 1 m/s, measurement of electrochemical potential on Carbon Steel samples. (authors)

  2. Irrigation Practice Affects Soil Phosphorus Chemistry

    Science.gov (United States)

    Ippolito, J.; Bjorneberg, D.

    2011-12-01

    It is expected, given the same water source applied to the same soil, that changes in soil chemistry would be subtle when comparing furrow and sprinkler irrigation practices. From four paired fields, we collected soil (after similar crops were harvested in September) from the 0-5 cm depth. Samples were analyzed for changes in soil P chemistry due to sprinkler or furrow irrigation using: 1) the Olsen soil test P extraction; 2) the alkaline phosphatase enzyme assay; 3) a sequential extraction technique which fractionated inorganic and organic soil P pools; and 4) a measure of the amorphous soil Al and Fe mineral phases. Olsen-extractable soil P was lower under sprinkler irrigation; however, this was not due to a reduction in microbial phosphatase activity. Soils under sprinkler irrigation contained lower inorganic P concentrations in soluble/Al-bound/Fe-bound and in the occluded phases, lesser amounts of organic P present in the moderately labile and non-labile fractions, and contained lower amorphous Fe concentrations. These results indicate that the method of water application affects soil chemistry and nutrient cycling.

  3. Physical Chemistry in Practice: Evaluation of DVD Modules

    Science.gov (United States)

    Dyer, James U.; Towns, Marcy; Weaver, Gabriela C.

    2007-01-01

    The Physical Chemistry in Practice (PCIP) DVD contains video programs (modules) and experimental data that present the research of scientists working in applications of physical chemistry. The DVD allows students to learn about cutting edge research in physical chemistry while making connections to the theoretical concepts learned in lecture.…

  4. Practical approaches to biological inorganic chemistry

    CERN Document Server

    Louro, Ricardo O

    2012-01-01

    The book reviews the use of spectroscopic and related methods to investigate the complex structures and mechanisms of biological inorganic systems that contain metals. Each chapter presents an overview of the technique including relevant theory, clearly explains what it is and how it works and then presents how the technique is actually used to evaluate biological structures. Practical examples and problems are included to illustrate each technique and to aid understanding. Designed for students and researchers who want to learn both the basics, and more advanced aspects of bioinorganic chemistry. It includes many colour illustrations enable easier visualization of molecular mechanisms and structures. It provides worked examples and problems that are included to illustrate and test the reader's understanding of each technique. It is written by a multi-author team who use and teach the most important techniques used today to analyse complex biological structures.

  5. Green analytical chemistry--theory and practice.

    Science.gov (United States)

    Tobiszewski, Marek; Mechlińska, Agata; Namieśnik, Jacek

    2010-08-01

    This tutorial review summarises the current state of green analytical chemistry with special emphasis on environmentally friendly sample preparation techniques. Green analytical chemistry is a part of the sustainable development concept; its history and origins are described. Miniaturisation of analytical devices and shortening the time elapsing between performing analysis and obtaining reliable analytical results are important aspects of green analytical chemistry. Solventless extraction techniques, the application of alternative solvents and assisted extractions are considered to be the main approaches complying with green analytical chemistry principles.

  6. Safety shutdown separators

    Science.gov (United States)

    Carlson, Steven Allen; Anakor, Ifenna Kingsley; Farrell, Greg Robert

    2015-06-30

    The present invention pertains to electrochemical cells which comprise (a) an anode; (b) a cathode; (c) a solid porous separator, such as a polyolefin, xerogel, or inorganic oxide separator; and (d) a nonaqueous electrolyte, wherein the separator comprises a porous membrane having a microporous coating comprising polymer particles which have not coalesced to form a continuous film. This microporous coating on the separator acts as a safety shutdown layer that rapidly increases the internal resistivity and shuts the cell down upon heating to an elevated temperature, such as 110.degree. C. Also provided are methods for increasing the safety of an electrochemical cell by utilizing such separators with a safety shutdown layer.

  7. [The shutdown point and the output volume limit (OVL) in the present situation of healthcare in Hungary (or a little economics for practicing physicians)].

    Science.gov (United States)

    Gresz, Miklós

    2008-09-07

    In the present situation of health care, financing has become so complicated that the treating doctor has to know not only his profession but also has to consider the different regulations, laws and book of rules. The work of the physician cannot be carried out only through the fact that he is a master of his art, that is healing. All healing practice, diagnostic abilities, intuition, empathy and other things are in vain: if he is not familiar with the basics of financing he can lead his institution to insolvency. This article tries to give a view of a small part of financing, the output volume limit (OVL) from another aspect. According to the basics of economy and general rules of leadership it tries to show up the practical difficulties of the output volume limit. The study enlightens that by defining the output volume limit one has to consider the shutdown point of the hospital and knowing this, the actual output volume limit should be defined in the way that it does not make the proper activity of the hospital completely impossible.

  8. chemistry in indigenous african knowledge and traditional practices1

    African Journals Online (AJOL)

    unesco

    research works and experiences in indigenous knowledge and Chemistry education in Africa. [AJCE, 2(3), July 2012). ... Chemistry was not an abstract idea to me, rather a practice, knowledge about doing certain things, skills and .... allocation for pedagogical innovations and for ongoing research. My knowledge and ...

  9. Enhancing first year chemistry student's participation in practical ...

    African Journals Online (AJOL)

    In this study, enhancing student's participation in practical analytical chemistry course at Haramaya University with various reasons was conducted. The data were collected from I year chemistry undergraduate students of class size 56 of which 23 were females and 33 were males. The class was arranged in to two groups ...

  10. enhancing first year chemistry student's participation in practical ...

    African Journals Online (AJOL)

    Temechegn

    ABSTRACT. In this study, enhancing student's participation in practical analytical chemistry course at. Haramaya University with various reasons was conducted. The data were collected from I year chemistry undergraduate students of class size 56 of which 23 were females and 33 were males. The class was arranged in to ...

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

    Science.gov (United States)

    Cullipher, Steven Gene

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

  12. Shutdown preparedness monitoring

    OpenAIRE

    Andreassen, Mats Gustav

    2011-01-01

    Statoil is a prominent Norwegian actor in the oil and gas industry at home and abroad. Maintaining the offshore installations has gradually become more important in line with the installations age, increased HMS demands and the fact that the offshore industry is extremely capital intensive. Management of shutdowns is an essential part of Statoil’s strategy for safe and efficient operation of assets or plants. The objective of the thesis is to investigate existing methods and tools tha...

  13. Water chemistry practice at German BWR plants

    Energy Technology Data Exchange (ETDEWEB)

    Stellwag, B. [Framatome ANP GmbH, Erlangen (Germany); Staudt, U. [VGB PowerTech e.V., Essen (Germany)

    2005-02-01

    As visual examinations carried out in 1994 detected cracks in a German boiling water reactor (BWR) plant due to intergranular stress corrosion cracking in core shroud components manufactured from Nb-stabilized CrNi steel 1.4550, safety-related assessments and in-service inspections were subsequently performed for the other six German BWRs. No cracks were found in the core shrouds of these plants. The second major event in the early 1990s was the detection of cracks at various German BWRs in piping systems made of Ti-stabilized CrNi steel 1.4541 caused by thermal sensitization in the heat-affected zone of welds. Comprehensive investigations resulted in a number of remedial measures (repair, replacement) implemented at piping in contact with reactor coolant of temperatures above 200 C. Thanks to the remedial measures and according to the analyses performed, cracking in the components in question due to the considered damage mechanisms need not be expected. German operators have therefore continued operating their BWR plants on normal water chemistry with an oxidizing environment. As a precaution, more stringent reactor coolant quality requirements have been specified and the limiting values of VGB Guideline R 401 J revised. This paper gives an overview of the trends in chemistry parameters at German BWR plants in the past 10 years. In addition, other relevant experience gained from the German BWR plants operating under normal water chemistry conditions is outlined: dose rates and collective doses, fuel performance, and results of periodic in-service inspections of major components of the reactor system. In the nearly 10 years of plant operation since implementation of the remedial measures, no cracks or other indications have been detected in any of the systems and components concerned. (orig.)

  14. Startup, Shutdown, & Malfunction (SSM) Emissions

    Science.gov (United States)

    EPA issued a final action to ensure states have plans in place that are fully consistent with the Clean Air Act and recent court decisions concerning startup, shutdown and malfunction (SSM) operations.

  15. Linking a Pharmaceutical Chemistry Workshop to Pharmacy Practice.

    Science.gov (United States)

    Morral, Jordi; Culshaw, Margaret; Morral, Kim; Conway, Barbara; Adams, Sylvia; Adams, Andrew

    2015-01-01

    This paper describes the design and implementation of a workshop to enhance pharmacy students' appreciation of the importance of chemistry for pharmacy practice. The workshop was designed to form part of the practical work of two modules taught in the second year of the MPharm degree. In this mandatory workshop, second year pharmacy students were required to spot in the dispensary drugs based on their chemical properties like chirality, their origin and chemical structure. The lecturers involved in the workshop showed examples of the application of chemistry in the day to day work of the dispensary (e.g. calculating the dose for a patient in millimoles or how small modifications from a natural product can change its ability to cross the blood-brain-barrier). Feedback from participating students was collected via two survey instruments to examine the impact of the intervention. The survey results showed a clear shift towards a more positive perception by students of the chemistry taught in the MPharm curriculum.

  16. Confirmation of shutdown cooling effects

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Kotaro, E-mail: ksato@nelted.co.jp; Tabuchi, Masato; Sugimura, Naoki; Tatsumi, Masahiro [Nuclear Engineering, Limited, 1-3-7 Tosabori Nishi-ku, Osaka-shi, Osaka 550-0001 (Japan)

    2015-12-31

    After the Fukushima accidents, all nuclear power plants in Japan have gradually stopped their operations and have long periods of shutdown. During those periods, reactivity of fuels continues to change significantly especially for high-burnup UO{sub 2} fuels and MOX fuels due to radioactive decays. It is necessary to consider these isotopic changes precisely, to predict neutronics characteristics accurately. In this paper, shutdown cooling (SDC) effects of UO{sub 2} and MOX fuels that have unusual operation histories are confirmed by the advanced lattice code, AEGIS. The calculation results show that the effects need to be considered even after nuclear power plants come back to normal operation.

  17. A Fast Shutdown Technique for Large Tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    E. Fredrickson; G.L. Schmidt; K. Hill; S.C. Jardin; et al

    1999-09-01

    A practical method is proposed for the fast shutdown of a large ignited tokamak. The method consists of injecting a rapid series of 30-50 deuterium pellets doped with a small ( 0.0005%) concentration of Krypton impurity, and simultaneously ramping the plasma current and shaping fields down over a period of several seconds using the poloidal field system. Detailed modeling with the Tokamak Simulation Code using a newly developed pellet mass deposition model shows that this method should terminate the discharge in a controlled and stable way without producing significant numbers of runaway electrons. A partial prototyping of this technique was accomplished in TFTR.

  18. Promoting Chemistry Learning through Undergraduate Work Experience in the Chemistry Lab: A Practical Approach

    Science.gov (United States)

    Yu, Hong-Bin

    2015-01-01

    Hiring undergraduate lab assistants in chemistry departments is common in college. However, few studies have focused on promoting undergraduate chemistry learning and thinking skills through this work experience in chemistry teaching laboratories. This article discusses the strategy we implemented in the lab assistant program. The…

  19. Practicing What We Preach: Assessing "Critical Thinking" in Organic Chemistry

    Science.gov (United States)

    Stowe, Ryan L.; Cooper, Melanie M.

    2017-01-01

    Organic chemistry is often promoted as a course designed to cultivate skill in scientific "ways of thinking." Expert organic chemists perceive their field as one in which plausible answers to complex questions are arrived at through analytical thought processes. They draw analogy between problem solving in organic chemistry and diagnosis…

  20. Thole's interacting polarizability model in computational chemistry practice

    NARCIS (Netherlands)

    deVries, AH; vanDuijnen, PT; Zijlstra, RWJ; Swart, M

    Thole's interacting polarizability model to calculate molecular polarizabilities from interacting atomic polarizabilities is reviewed and its major applications in computational chemistry are illustrated. The applications include prediction of molecular polarizabilities, use in classical expressions

  1. A Bridge between Two Cultures: Uncovering the Chemistry Concepts Relevant to the Nursing Clinical Practice

    Science.gov (United States)

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

    2012-01-01

    This study focused on the undergraduate course that covers basic topics in general, organic, and biological (GOB) chemistry at a mid-sized state university in the western United States. The central objective of the research was to identify the main topics of GOB chemistry relevant to the clinical practice of nursing. The collection of data was…

  2. Development and Validation of Teaching Practice Evaluation Instrument for Assessing Chemistry Students' Teaching Skills

    Science.gov (United States)

    Ezeudu, F. O.; Chiaha, G. T. U.; Eze, J. U.

    2013-01-01

    The study was designed to develop and factorially validate an instrument for measuring teaching practice skills of chemistry student-teachers in University of Nigeria, Nsukka. Two research questions guided the study. The design of the study was instrumentation. All the chemistry student-teachers in the Department of Science Education, University…

  3. Green Chemistry Teaching in Higher Education: A Review of Effective Practices

    Science.gov (United States)

    Andraos, John; Dicks, Andrew P.

    2012-01-01

    This account reviews published green chemistry teaching resources in print and online literature and our experiences in teaching the subject to undergraduate students. Effective practices in lecture and laboratory are highlighted and ongoing challenges are addressed, including areas in cutting edge green chemistry research that impact its teaching…

  4. small-scale chemistry for a hands-on approach to chemistry practical

    African Journals Online (AJOL)

    IICBA01

    Department of Chemistry, Norwegian University of Science and Technology, NTNU, Norway .... implemented as of 2008, 70% of the student enrolment in universities (and secondary schools alike) has to be in the ..... friendly, and both they and their students were smiling, signs of their motivation and happiness.

  5. A research approach to designing chemistry education using authentic practices

    NARCIS (Netherlands)

    Bulte, A.M.W.; Westbroek, H.B.; de Jong, O.; Pilot, A.

    2006-01-01

    We discuss how to reduce the incongruence between the outcomes (both cognitive and affective) of the conventional secondary chemistry curriculum and what is to be attained: the meaningful connection of students' learning to daily life and societal issues. This problem is addressed by a design study

  6. PCK to practice: Two experienced high school chemistry teachers' pedagological content knowledge in their teaching practice

    Science.gov (United States)

    Boesdorfer, Sarah B.

    Pedagogical content knowledge has been defined by Magnusson, Krajcik, and Borko (1999) and others for the purpose of understanding science teachers' knowledge and teaching practice. It is hoped that by improving our understanding of science teachers' PCK, we can improve the education and practice of science teachers. Research describing all domains of a teacher's PCK and its use in the practice of teaching has not been well established. The purpose of this study is to understand how two experienced secondary chemistry teachers' PCK manifests itself in their daily teaching practice. For each teacher, observations, interviews, and class documents were utilized to provide a detailed description of the five domains for PCK as defined by Magnusson et al. Both teachers were well regarded in their schools, but one teacher's PCK was found to be significantly more consistent with our current understanding of science teaching and learning. Along with the comparisons of the two teachers' knowledge, this research found that the teachers' knowledge and their enacted knowledge did not always correspond---suggesting the importance of observations for understanding PCK's influence on teaching practices. In addition, this study supports the importance of clearly defining a teacher's orientation toward science teaching in understanding a teacher's PCK. Both teachers' orientations toward science teaching were found to greatly influence their knowledge and actions in the other PCK domains. Finally, this study suggests that a teacher's knowledge of science curriculum should not be defined only as the knowledge of goals and objectives because this narrow definition of curriculum does not allow a complete understanding of the teacher's knowledge nor how their knowledge affects their practice. These conclusions have implications for future research and teacher educators.

  7. A pragmatic approach towards designing a second shutdown system for Tehran research reactor

    Directory of Open Access Journals (Sweden)

    Boustani Ehsan

    2016-01-01

    Full Text Available One second shutdown system is proposed for the Tehran Research Reactor to achieve the goal of higher safety in compliance with current operational requirements and regulations and improve the overall reliability of the reactor shutdown system. The proposed second shutdown system is a diverse, independent shutdown system compared to the existing rod based one that intends to achieve and maintain sub-criticality condition with an enough shutdown margin in many of abnormal situations. It is designed as much as practical based on neutron absorber solution injection into the existing core while the changes and interferences with the existing core structure are kept to a minimum. Core neutronic calculations were performed using MCNPX 2.6.0 and MTR_PC package for the current operational core equipped with the second shutdown system, and one experiment was conducted in the Tehran Research Reactor to test the neutronic calculations. A good agreement was seen between theoretical results and experimental ones. In addition, capability of the second shutdown system in the case of occurrence of design basis accident in the Tehran Research Reactor is demonstrated using PARET program.

  8. First LHC Shutdown: Coordination and Schedule Issues

    OpenAIRE

    Coupard, J; Foraz, K; Grillot, S

    2010-01-01

    The first LHC shutdown started in fall 2008, just after the incident on the 19th of September 2008. In addition to the typical work of a shutdown, a large number of interventions, related to the “consolidation after the incident” were performed in the LHC loop. Moreover the amount of work increased during the shutdown, following the recommendations and conclusions of the different working groups in charge of the safety of the personnel and of the machine. This paper will give an overview of t...

  9. Where are we with the current shutdown?

    OpenAIRE

    Coupard, J; Foraz, K

    2009-01-01

    The first shutdown of the LHC machine started on the 17th of November 2008. In addition to typical shut-down interventions and the works already foreseen (e.g. phase 1 collimator installation), some additional consolidation work is needed. On top of this comes the work caused by the 19 September incident and the subsequent tests carried out in November and December. This talk will give an overview of the activities currently planned and the key drivers for overall length of the shutdown, high...

  10. Teaching and learning of modelling in chemistry education : authentic practices as contexts for learning

    NARCIS (Netherlands)

    Prins, G.T.

    2010-01-01

    In science education, students should come to understand the nature and significance of models and the process of modelling. This study explores the potential benefits of using authentic modelling practices as contexts for learning in chemistry education. An authentic modelling practice is

  11. The "wonderful properties of glass": Liebig's Kaliapparat and the practice of chemistry in glass.

    Science.gov (United States)

    Jackson, Catherine M

    2015-03-01

    Everybody knows that glass is and always has been an important presence in chemical laboratories. Yet the very self-evidence of this notion tends to obscure a supremely important change in chemical practice during the early decades of the nineteenth century. This essay uses manuals of specifically chemical glassblowing published between about 1825 and 1835 to show that early nineteenth-century chemists began using glass in distinctly new ways and that their appropriation of glassblowing skill had profoundly important effects on the emerging discipline of chemistry. The new practice of chemistry in glass-exemplified in this essay by Justus Liebig's introduction of a new item of chemical glassware for organic analysis, the Kaliapparat--transformed not merely the material culture of chemistry but also its geography, its pedagogy, and, ultimately, its institutions. Moving chemistry into glass--a change so important that it warrants the term "glassware revolution"--had far-reaching consequences.

  12. Chemistry?!

    Indian Academy of Sciences (India)

    Chemistry is the science of matter and of its transformations, and life is its highest expression. It provides structures endowed with properties and develops processes for the synthesis of structures. It plays a primordial role in our understanding of material phe- nomena, in our capability to act upon them, to modify them, to.

  13. 40 CFR 63.1111 - Startup, shutdown, and malfunction.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Startup, shutdown, and malfunction. 63... Control Technology Standards § 63.1111 Startup, shutdown, and malfunction. (a) Startup, shutdown, and... develop a written startup, shutdown, and malfunction plan that describes, in detail, procedures for...

  14. Design, Development, and Psychometric Analysis of a General, Organic, and Biological Chemistry Topic Inventory Based on the Identified Main Chemistry Topics Relevant to Nursing Clinical Practice

    Science.gov (United States)

    Brown, Corina E.

    2013-01-01

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

  15. Spectroscopy 101: A Practical Introduction to Spectroscopy and Analysis for Undergraduate Organic Chemistry Laboratories

    Science.gov (United States)

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

    2017-01-01

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

  16. Learning Nuclear Chemistry through Practice: A High School Student Project Using PET in a Clinical Setting

    Science.gov (United States)

    Liguori, Lucia; Adamsen, Tom Christian Holm

    2013-01-01

    Practical experience is vital for promoting interest in science. Several aspects of chemistry are rarely taught in the secondary school curriculum, especially nuclear and radiochemistry. Therefore, we introduced radiochemistry to secondary school students through positron emission tomography (PET) associated with computer tomography (CT). PET-CT…

  17. Do Pre-Service Chemistry Teachers Reflect Their Beliefs about Constructivism in Their Teaching Practices?

    Science.gov (United States)

    Uzuntiryaki, Esen; Boz, Yezdan; Kirbulut, Demet; Bektas, Oktay

    2010-01-01

    This study aimed to explore pre-service chemistry teachers' beliefs about constructivism and the influence of their beliefs in their teaching practice. For this purpose, semi-structured interviews were carried out with eight pre-service teachers in order to understand their belief structures. Pre-service teachers' beliefs about constructivism were…

  18. Adapting authentic science practices into contexts for learning: The case of models and modelling in pre-university chemistry education

    NARCIS (Netherlands)

    Prins, G.T.; Pilot, A.

    2013-01-01

    This research study explores the potential benefits of using authentic modelling practices as contexts for learning in chemistry education. An authentic modelling practice is characterized as professionals sharing common purposes, working to a similar type of modelling procedure, while applying

  19. Shutdown system for a nuclear reactor

    Science.gov (United States)

    Groh, E.F.; Olson, A.P.; Wade, D.C.; Robinson, B.W.

    1984-06-05

    An ultimate shutdown system is provided for termination of neutronic activity in a nuclear reactor. The shutdown system includes bead chains comprising spherical containers suspended on a flexible cable. The containers are comprised of mating hemispherical shells which provide a ruggedized enclosure for reactor poison material. The bead chains, normally suspended above the reactor core on storage spools, are released for downward travel upon command from an external reactor monitor. The chains are capable of horizontal movement, so as to flow around obstructions in the reactor during their downward motion. 8 figs.

  20. Alternative Shutdown Panel. Amaraz Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Saenz de Santa Maria Valin, J.

    2016-07-01

    Between 2010 and 2014 the Nuclear Power Plant of Almaraz conducted one of the most complex projects in its history: The installation of an Alternative Shutdown Panel with the capability to stop the plant in case of fire in the Control room or in the Cable room. This project represented a great economic and organizational effort for the plant, but at the same time has been a great improvement in the safety of the installation, which was demonstrated by the achievement of a major milestone in the history of Almaraz: The actual shutdown from outside of the Control room. (Author)

  1. The 2013 US Government Shutdown (#Shutdown) and health: an emerging role for social media.

    Science.gov (United States)

    Merchant, Raina M; Ha, Yoonhee P; Wong, Charlene A; Schwartz, H Andrew; Sap, Maarten; Ungar, Lyle H; Asch, David A

    2014-12-01

    In October 2013, multiple United States (US) federal health departments and agencies posted on Twitter, "We're sorry, but we will not be tweeting or responding to @replies during the shutdown. We'll be back as soon as possible!" These "last tweets" and the millions of responses they generated revealed social media's role as a forum for sharing and discussing information rapidly. Social media are now among the few dominant communication channels used today. We used social media to characterize the public discourse and sentiment about the shutdown. The 2013 shutdown represented an opportunity to explore the role social media might play in events that could affect health.

  2. 40 CFR 52.271 - Malfunction, startup, and shutdown regulations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Malfunction, startup, and shutdown..., startup, and shutdown regulations. (a) The following regulations are disapproved because they would permit... malfunctions and/or fail to sufficiently limit startup and shutdown exemptions to those periods where it is...

  3. 40 CFR 63.1272 - Startups, shutdowns, and malfunctions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Startups, shutdowns, and malfunctions... Facilities § 63.1272 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods of...

  4. 40 CFR 63.762 - Startups, shutdowns, and malfunctions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Startups, shutdowns, and malfunctions... Facilities § 63.762 Startups, shutdowns, and malfunctions. (a) The provisions set forth in this subpart shall apply at all times except during startups or shutdowns, during malfunctions, and during periods of non...

  5. [Practical chemistry education provided by team-based learning (TBL) and peer evaluation].

    Science.gov (United States)

    Yasuhara, Tomohisa; Konishi, Motomi; Nishida, Takahiro; Kushihata, Taro; Sone, Tomomichi; Kurio, Wasako; Yamamoto, Yumi; Nishikawa, Tomoe; Yanada, Kazuo; Nakamura, Mitsutaka

    2014-01-01

    Learning chemistry is cumulative: basic knowledge and chemical calculation skills are required to gain understanding of higher content. However, we often suffer from students' lack of learning skills to acquire these concepts. One of the reasons is the lack of adequate training in the knowledge and skills of chemistry, and one of the reasons for this lack is the lack of adequate evaluation of training procedures and content. Team-based learning (TBL) is a strong method for providing training in the knowledge and skills of chemistry and reaffirms the knowledge and skills of students of various levels. In our faculty, TBL exercises are provided for first-year students concurrently with lectures in physical chemistry and analytical chemistry. In this study, we researched the adoption of a peer evaluation process for this participatory learning model. Questionnaires taken after TBL exercises in the previous year showed a positive response to TBL. Further, a questionnaire taken after TBL exercises in the spring semester of the current year also yielded a positive response not only to TBL but also to peer evaluation. In addition, a significant correlation was observed between the improvement of students' grades in chemistry classes and the feeling the percentage (20%) of peer evaluation in overall evaluation low (logistic regression analysis, p=0.022). On the basis of the findings, we argue that TBL provides a generic, practical learning environment including an effective focus on learning strategy and evaluation of knowledge, skills, and attitudes, and studies on the educational effects of TBL and peer evaluation.

  6. Development and Analysis of an Instrument to Assess Student Understanding of GOB Chemistry Knowledge Relevant to Clinical Nursing Practice

    Science.gov (United States)

    Brown, Corina E.; Hyslop, Richard M.; Barbera, Jack

    2015-01-01

    The General, Organic, and Biological Chemistry Knowledge Assessment (GOB-CKA) is a multiple-choice instrument designed to assess students' understanding of the chemistry topics deemed important to clinical nursing practice. This manuscript describes the development process of the individual items along with a psychometric evaluation of the…

  7. The FY2014 Government Shutdown: Economic Effects

    Science.gov (United States)

    2013-11-01

    Reaching the Debt Limit: Background and Potential Effects on Government Operations, coordinated by Mindy R. Levit . 3 Government spending’s contribution...Debt Limit: History and Recent Increases, by D. Andrew Austin and Mindy R. Levit . The FY2014 Government Shutdown: Economic Effects Congressional...the labor force through the furlough of non-excepted federal employees.17 Estimates of the number of federal employees furloughed vary widely, and

  8. 40 CFR 63.310 - Requirements for startups, shutdowns, and malfunctions.

    Science.gov (United States)

    2010-07-01

    ... occurred. (j) The owner or operator of a nonrecovery coke oven battery subject to the work practice... CATEGORIES National Emission Standards for Coke Oven Batteries § 63.310 Requirements for startups, shutdowns... or operator shall operate and maintain the coke oven battery and its pollution control equipment...

  9. Reporting unit size and measurement uncertainty: current Australian practice in clinical chemistry and haematology.

    Science.gov (United States)

    Hawkins, Robert C; Badrick, Tony

    2015-08-01

    In this study we aimed to compare the reporting unit size used by Australian laboratories for routine chemistry and haematology tests to the unit size used by learned authorities and in standard laboratory textbooks and to the justified unit size based on measurement uncertainty (MU) estimates from quality assurance program data. MU was determined from Royal College of Pathologists of Australasia (RCPA) - Australasian Association of Clinical Biochemists (AACB) and RCPA Haematology Quality Assurance Program survey reports. The reporting unit size implicitly suggested in authoritative textbooks, the RCPA Manual, and the General Serum Chemistry program itself was noted. We also used published data on Australian laboratory practices.The best performing laboratories could justify their chemistry unit size for 55% of analytes while comparable figures for the 50% and 90% laboratories were 14% and 8%, respectively. Reporting unit size was justifiable for all laboratories for red cell count, >50% for haemoglobin but only the top 10% for haematocrit. Few, if any, could justify their mean cell volume (MCV) and mean cell haemoglobin concentration (MCHC) reporting unit sizes.The reporting unit size used by many laboratories is not justified by present analytical performance. Using MU estimates to determine the reporting interval for quantitative laboratory results ensures reporting practices match local analytical performance and recognises the inherent error of the measurement process.

  10. Portraiture in the Large Lecture: Storying One Chemistry Professor's Practical Knowledge

    Science.gov (United States)

    Eddleton, Jeannine E.

    Practical knowledge, as defined by Freema Elbaz (1983), is a complex, practically oriented set of understandings which teachers use to actively shape and direct their work. The goal of this study is the construction of a social science portrait that illuminates the practical knowledge of a large lecture professor of general chemistry at a public research university in the southeast. This study continues Elbaz's (1981) work on practical knowledge with the incorporation of a qualitative and intentionally interventionist methodology which "blurs the boundaries of aesthetics and empiricism in an effort to capture the complexity, dynamics, and subtlety of human experience and organizational life," (Lawrence-Lightfoot & Davis, 1997). This collection of interviews, observations, writings, and reflections is designed for an eclectic audience with the intent of initiating conversation on the topic of the large lecture and is a purposeful attempt to link research and practice. Social science portraiture is uniquely suited to this intersection of researcher and researched, the perfect combination of methodology and analysis for a project that is both product and praxis. The following research questions guide the study. • Are aspects of Elbaz's practical knowledge identifiable in the research conversations conducted with a large lecture college professor? • Is practical knowledge identifiable during observations of Patricia's large lecture? Freema Elbaz conducted research conversations with Sarah, a high school classroom and writing resource teacher who conducted much of her teaching work one on one with students. Patricia's practice differs significantly from Sarah's with respect to subject matter and to scale.

  11. Rodded shutdown system for a nuclear reactor

    Science.gov (United States)

    Golden, Martin P.; Govi, Aldo R.

    1978-01-01

    A top mounted nuclear reactor diverse rodded shutdown system utilizing gas fed into a pressure bearing bellows region sealed at the upper extremity to an armature. The armature is attached to a neutron absorber assembly by a series of shafts and connecting means. The armature is held in an uppermost position by an electromagnet assembly or by pressurized gas in a second embodiment. Deenergizing the electromagnet assembly, or venting the pressurized gas, causes the armature to fall by the force of gravity, thereby lowering the attached absorber assembly into the reactor core.

  12. Technical Assessment: WRAP 1 HVAC Passive Shutdown

    Energy Technology Data Exchange (ETDEWEB)

    Ball, D.E.; Nash, C.R.; Stroup, J.L.

    1993-08-12

    As the result of careful interpretation of DOE Order 6430.lA and other DOE Orders, the HVAC system for WRAP 1 has been greatly simplified. The HVAC system is now designed to safely shut down to Passive State if power fails for any reason. The fans cease functioning, allowing the Zone 1 and Zone 2 HVAC Confinement Systems to breathe with respect to atmospheric pressure changes. Simplifying the HVAC system avoided overdesign. Construction costs were reduced by eliminating unnecessary equipment. This report summarizes work that was done to define the criteria, physical concepts, and operational experiences that lead to the passive shutdown design for WRAP 1 confinement HVAC systems.

  13. The self-evaluation of Slovenian prospective chemistry teachers' progress during their practical pedagogical training in primary schools.

    Science.gov (United States)

    Wissiak Grm, Katarina S; Savec, Vesna Ferk

    2014-01-01

    The present research deals with the self-evaluation of prospective chemistry teachers' progress during their practical pedagogical training (PPT) in primary schools. The sample consisted of 42 students from the 3rd and 4th years of the undergraduate programmes "Chemistry and Biology" or "Chemistry and Physics" at the Faculty of Education, University of Ljubljana. For the purpose of the investigation, the students completed questionnaires after each day of their practical pedagogical training, and at the end the entire training wrote reflective essays about their most significant experiences. Analysis of the results reveals that the students believe that practical pedagogical training makes a crucial contribution to their practical pedagogical education in the light of their future profession. The students also reported on their progress concerning the various skills that were developed.

  14. LHC Report: The shutdown work nearing completion

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    The work planned for the LHC injector chain during the winter shutdown is nearing completion. The PS Booster (PSB) and PS will be closed to access next week, and the control of machine access will be transferred to the CERN Control Centre in preparation for the resumption of machine operation. Hardware tests are being performed in all the machines.   Tests are under way in the LHC tunnel. The technical teams are putting the finishing touches to the work planned for the winter shutdown. At the Linac2, the PS Booster and the PS, work will be completed next week and hardware tests will be carried out soon after. POPS, the new powering system for the PS, will be commissioned for the first time in the coming days after the necessary preliminary tests have been carried out. At the SPS, various magnets have been replaced over recent weeks and the performance tests on the main power supply and other hardware tests will be able to start shortly. After that, the machine will be ready for operation with b...

  15. Shutdown Policies for MEMS-Based Storage Devices -- Analytical Models

    NARCIS (Netherlands)

    Khatib, M.G.; Engelen, Johannes Bernardus Charles; Hartel, Pieter H.

    MEMS-based storage devices should be energy ecient for deployment in mobile systems. Since MEMS-based storage devices have a moving me- dia sled, they should be shut down during periods of inactivity. However, shutdown costs energy, limiting the applicability of aggressive shutdown decisions. The

  16. Using Problem-Based Learning in a Chemistry Practical Class for Pharmacy Students and Engaging Them with Feedback.

    Science.gov (United States)

    Strohfeldt, Katja; Khutoryanskaya, Olga

    2015-11-25

    To introduce a new approach to problem-based learning (PBL) used in a medicinal chemistry practical class for pharmacy students. The chemistry practical class was based on independent studies by small groups of undergraduate students (4-5), who designed their own practical work, taking relevant professional standards into account. Students were guided by feedback and acquired a set of skills important for health-care professionals. The model was tailored to the application of PBL in a chemistry practical class setting for a large student cohort (150 students). The achievement of learning outcomes was based on the submission of relevant documentation, including a certificate of analysis, in addition to peer assessment. Some of the learning outcomes also were assessed in the final written examination. The practical was assessed at several time points using detailed marking schemes in order to provide the students with feedback. Students were required to engage with the feedback to succeed in the practical. A novel PBL chemistry laboratory course for pharmacy students was successful in that self-reflective learning and engagement with feedback were encouraged, and students enjoyed the challenging learning experience. Essential skills for health-care professionals were also promoted.

  17. Nuclear reactor shutdown control rod assembly

    Science.gov (United States)

    Bilibin, Konstantin

    1988-01-01

    A temperature responsive, self-actuated nuclear reactor shutdown control rod assembly 10. The upper end 18 of a lower drive line 17 fits within the lower end of an upper drive line 12. The lower end (not shown) of the lower drive line 17 is connected to a neutron absorber. During normal temperature conditions the lower drive line 17 is supported by detent means 22,26. When an overtemperature condition occurs thermal actuation means 34 urges ring 26 upwardly sufficiently to allow balls 22 to move radially outwardly thereby allowing lower drive line 17 to move downwardly toward the core of the nuclear reactor resulting in automatic reduction of the reactor powder.

  18. COMPUTING SERVICES DURING THE ANNUAL CERN SHUTDOWN

    CERN Multimedia

    2000-01-01

    As in previous years, computing services run by IT division will be left running unattended during the annual shutdown. The following points should be noted. No interruptions are scheduled for local and wide area networking and the ACB, e-mail and unix interactive services. Maintenance work is scheduled for the NICE home directory servers and the central Web servers. Users must, therefore, expect service interruptions. Unix batch services will be available but without access to HPSS or to manually mounted tapes. Dedicated Engineering services, general purpose database services and the Helpdesk will be closed during this period. An operator service will be maintained and can be reached at extension 75011 or by email to: computer.operations@cern.ch Users should be aware that, except where there are special arrangements, any major problems that develop during this period will most likely be resolved only after CERN has reopened. In particular, we cannot guarantee backups for Home Directory files for eithe...

  19. The Shutdown Dissociation Scale (Shut-D

    Directory of Open Access Journals (Sweden)

    Inga Schalinski

    2015-05-01

    Full Text Available The evolutionary model of the defense cascade by Schauer and Elbert (2010 provides a theoretical frame for a short interview to assess problems underlying and leading to the dissociative subtype of posttraumatic stress disorder. Based on known characteristics of the defense stages “fright,” “flag,” and “faint,” we designed a structured interview to assess the vulnerability for the respective types of dissociation. Most of the scales that assess dissociative phenomena are designed as self-report questionnaires. Their items are usually selected based on more heuristic considerations rather than a theoretical model and thus include anything from minor dissociative experiences to major pathological dissociation. The shutdown dissociation scale (Shut-D was applied in several studies in patients with a history of multiple traumatic events and different disorders that have been shown previously to be prone to symptoms of dissociation. The goal of the present investigation was to obtain psychometric characteristics of the Shut-D (including factor structure, internal consistency, retest reliability, predictive, convergent and criterion-related concurrent validity.A total population of 225 patients and 68 healthy controls were accessed. Shut-D appears to have sufficient internal reliability, excellent retest reliability, high convergent validity, and satisfactory predictive validity, while the summed score of the scale reliably separates patients with exposure to trauma (in different diagnostic groups from healthy controls.The Shut-D is a brief structured interview for assessing the vulnerability to dissociate as a consequence of exposure to traumatic stressors. The scale demonstrates high-quality psychometric properties and may be useful for researchers and clinicians in assessing shutdown dissociation as well as in predicting the risk of dissociative responding.

  20. Development of Chemistry Pre-Service Teachers During Practical Pedagogical Training: Self-Evaluation vs. Evaluation by School Mentors.

    Science.gov (United States)

    Ferk Savec, Vesna; Wissiak Grm, Katarina S

    2017-01-01

    The research presented in this article deals with the self-evaluation of 4th year pre-service chemistry teachers' progress during their second year practical pedagogical training in chemistry teaching at primary schools (students' age 13-15 years) in comparison to the perception of their progress by their school mentors. The sample consisted of 21 pre-service teachers and 21 school mentors, in-service chemistry teachers, at primary schools. For the purpose of following to pre-service chemistry teachers' development, the pre-service teachers as well as their mentors completed the "Questionnaire for monitoring students' progress", focusing on eight characteristics of professional development during practical pedagogical training. The results reveal that student-teachers were stricter in their self-evaluation in comparison to their school mentors after their first chemistry lecture at school during the practical pedagogical training; however, after their last lecture, the evaluations were similar for most of the characteristics. The development of five randomly selected student-teachers is presented in detail from their own perspectives, as well as from their school mentors' perspectives.

  1. Research into Practice: Visualising the Molecular World for a Deep Understanding of Chemistry

    Science.gov (United States)

    Tasker, Roy

    2014-01-01

    Why is chemistry so difficult? A seminal paper by Johnstone (1982) offered an explanation for why science in general, and chemistry in particular, is so difficult to learn. He proposed that an expert in chemistry thinks at three levels; the macro (referred to as the observational level in this article), the sub-micro (referred to as the molecular…

  2. Extraction of Nutraceuticals from Spirulina (Blue-Green Alga): A Bioorganic Chemistry Practice Using Thin-layer Chromatography

    Science.gov (United States)

    Herrera Bravo de Laguna, Irma; Toledo Marante, Francisco J.; Luna-Freire, Kristerson R.; Mioso, Roberto

    2015-01-01

    Spirulina is a blue-green alga (cyanobacteria) with high nutritive value. This work provides an innovative and original approach to the consideration of a bioorganic chemistry practice, using Spirulina for the separation of phytochemicals with nutraceutical characteristics via thin-layer chromatography (TLC) plates. The aim is to bring together…

  3. Using a Practical Instructional Development Process to Show That Integrating Lab and Active Learning Benefits Undergraduate Analytical Chemistry

    Science.gov (United States)

    Goacher, Robyn E.; Kline, Cynthia M.; Targus, Alexis; Vermette, Paul J.

    2017-01-01

    We describe how a practical instructional development process helped a first-year assistant professor rapidly develop, implement, and assess the impact on her Analytical Chemistry course caused by three changes: (a) moving the lab into the same semester as the lecture, (b) developing a more collaborative classroom environment, and (c) increasing…

  4. Physics and chemistry middle school teachers’ conceptions and practices about assessment

    Directory of Open Access Journals (Sweden)

    Marisa Sofia Monteiro Correia

    2014-08-01

    Full Text Available The main goal of this study is to characterize conceptions that Portuguese teachers of Physics and Chemistry have about learning assessment and how teachers incorporate assessment in their teaching practices within a curriculum reorganization. Three case studies of teachers with less than three years of service were carried out. Data was collected from semi-structured interviews, observations of lessons and documents supplied by the participants. This study’s findings indicate two conceptions of assessment: assessment of learning and assessment for learning. One of the participants shows a conception of assessment of learning, valuing a summative viewpoint of assessment. The other teachers revealed a conception of assessment for learning emphasizing a formative perspective of assessment, that as the role of regularizing and promoting improvement of learning. Relatively to the teachers’ practices, it seems clear that the assessment criteria are implicit, the feedback is sporadic and the students have a reduced role in the assessment process. All of the teachers demonstrate difficulties in assessment of attitudinal and procedural competences. Only one of the participants elaborates observation with registration to assess these competences. The tests constitute the main assessment instrument in the teachers' lessons, what is coherent with a teaching and learning conception that still remains traditional.

  5. Grounding formative assessment in high-school chemistry classrooms: Connections between professional development and teacher practice

    Science.gov (United States)

    Cisterna Alburquerque, Dante Igor

    This study describes and analyzes the experiences of two high-school chemistry teachers who participated in a team-based professional development program to learn about and enact formative assessment in their classrooms. The overall purpose of this study is to explain how participation in this professional development influenced both teachers' classroom enactment of formative assessment practices. This study focuses on 1) teachers' participation in the professional development program, 2) teachers' enactment of formative assessment, and 3) factors that enabled or hindered enactment of formative assessment. Drawing on cultural-historical activity theory (CHAT) and using evidence from teacher lessons, teacher interviews, professional development meetings as data sources, this single embedded case study analyzes how these two teachers who participated in the same learning team and have similar characteristics (i.e., teaching in the same school, teaching the same courses and population of students, and using the same materials) differentially used the professional development learning about formative assessment as mediating tools to improve their classroom instruction. The learning team experience contributed to both teachers' development of a better understanding of formative assessment---especially in recognizing that their current grading and assessment practices were not appropriate to promote student learning---and the co-creation of artifacts to gather evidence of students' ideas. Although both teachers demonstrated understanding about how formative assessment may serve to promote student learning and had a set of tools available to utilize for formative assessment use, they did not enact these tools in the same way. One teacher appropriated formative assessment as mediating tool to verify if the students were following her explanations, and to check if the students were able to provide the correct response. The other teacher used the mediating tool to promote

  6. COMPUTING SERVICES DURING THE ANNUAL CERN SHUTDOWN

    CERN Multimedia

    2001-01-01

    As in previous years, computing services run by IT division will be left running unattended during the annual shutdown. The following points should be noted. No interruptions are scheduled for local and wide area networking and the ACB, e-mail and unix interactive services. Unix batch services will be available but without access to manually mounted tapes. Dedicated Engineering services, general purpose database services and the Helpdesk will be closed during this period. An operator service will be maintained and can be reached at extension 75011 or by Email to computer.operations@cern.ch. Users should be aware that, except where there are special arrangements, any major problems that develop during this period will most likely be resolved only after CERN has reopened. In particular, we cannot guarantee backups for Home Directory files (for Unix or Windows) or for email folders. Any changes that you make to your files during this period may be lost in the event of a disk failure. Please note that all t...

  7. The use of high impact practices (HIPs) on chemistry lesson design and implementation by pre-service teachers

    Science.gov (United States)

    Chamrat, Suthida; Apichatyotin, Nattaya; Puakanokhirun, Kittaporn

    2018-01-01

    The quality of lesson design is essential to learning effectiveness. Research shows some characteristics of lessons have strong effect on learning which were grouped into "High Impact Practices or HIPs. This research aims to examine the use of HIPs on chemistry lesson design as a part of Teaching Science Strand in Chemistry Concepts course. At the first round of lesson design and implementing in classroom, 14 chemistry pre-services teachers freely selected topics, designed and implemented on their own ideas. The lessons have been reflected by instructors and their peers. High Impact Practices were overtly used as the conceptual framework along with the After-Action Review and Reflection (AARR). The selected High Impact practice in this study consisted of 6 elements: well-designed lesson, vary cognitive demand/academic challenge, students center approach, opportunity of students to reflect by discussion or writing, the assignment of project based learning or task, and the lesson reflects pre-service teachers' Technological Pedagogical Content Knowledge (TPACK). The second round, pre-service teachers were encouraged to explicitly used 6 High Impact Practices in cooperated with literature review specified on focused concepts for bettering designed and implemented lessons. The data were collected from 28 lesson plans and 28 classroom observations to compare and discuss between the first and second lesson and implementation. The results indicated that High Impact Practices effect on the quality of delivered lesson. However, there are some elements that vary on changes which were detailed and discussed in this research article.

  8. Startup, Shutdown, & Malfunction (SSM) Emissions at Industrial Facilities

    Science.gov (United States)

    EPA issued a final action to ensure states have plans in place that are fully consistent with the Clean Air Act and recent court decisions concerning startup, shutdown and malfunction (SSM) operations.

  9. Applications of mathematical learning models to student performance on general chemistry: Microcomputer drill and practice programs

    Science.gov (United States)

    Zitzewitz, Barbara S.; Berger, Carl F.

    Four drill and practice programs in general chemistry (Butler & Hough, 1982) were altered to keep records of response, scores, and response times as students used the programs. Mathematical learning models were applied to the resulting score and time data. When data for groups of students using the same programs were analyzed using the polynomial fit model of Kerlinger and Pedhazur (1973), significant results were found and in most cases the linear fit provided the only significant explanation for the variance in the data. The performance of individual students on selected programs was also analyzed using a linear model, a simple exponential saturation model, and a more complex model which incorporated ability and motivation factors into the exponential saturation model (Aldridge, 1983). Most of the students improved their performance linearly with time and none exhibited patterns characteristic of the Aldridge model. In some cases, the simple exponential saturation model provided an explanation of the data as probable as that of the linear model. The implications of the findings for science teaching are discussed.

  10. 77 FR 71323 - Reconsideration of Certain New Source and Startup/Shutdown Issues: National Emission Standards...

    Science.gov (United States)

    2012-11-30

    ... AGENCY 40 CFR Parts 60 and 63 RIN 2060-AR62 Reconsideration of Certain New Source and Startup/Shutdown..., the requirements applicable during periods of startup and shutdown for MATS, the startup and shutdown... C. Startup and Shutdown Provisions V. Discussion of Provisions Subject to Reconsideration--Utility...

  11. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    Energy Technology Data Exchange (ETDEWEB)

    Maheras, Steven J.; Best, Ralph E.; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul E.

    2013-09-30

    This report fulfills the M2 milestone M2FT-13PN0912022, “Stranded Sites De-Inventorying Report.” In January 2013, the U.S. Department of Energy (DOE) issued the Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste (DOE 2013). Among the elements contained in this strategy is an initial focus on accepting used nuclear fuel from shutdown reactor sites. This focus is consistent with the recommendations of the Blue Ribbon Commission on America’s Nuclear Future, which identified removal of stranded used nuclear fuel at shutdown sites as a priority so that these sites may be completely decommissioned and put to other beneficial uses (BRC 2012). Shutdown sites are defined as those commercial nuclear power reactor sites where the nuclear power reactors have been shut down and the site has been decommissioned or is undergoing decommissioning. In this report, a preliminary evaluation of removing used nuclear fuel from 12 shutdown sites was conducted. The shutdown sites were Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, and San Onofre. These sites have no other operating nuclear power reactors at their sites and have also notified the U.S. Nuclear Regulatory Commission that their reactors have permanently ceased power operations and that nuclear fuel has been permanently removed from their reactor vessels. Shutdown reactors at sites having other operating reactors are not included in this evaluation.

  12. FPGA Implementation of the stepwise shutdown system

    Energy Technology Data Exchange (ETDEWEB)

    Lotjonen, L.

    2012-07-01

    This report elaborates the design process of applications for field-programmable gate array (FPGA) devices. Brief introductions to EPGA technology and the design process are first given and then the design phases are walked through with the aid of a case study. FPGA is a programmable logic device that is programmed by the customer rather than the manufacturer. They are also usually re-programmable which enables updating their programming and otherwise modifying the design. There are also one-time programmable FPGAs that can be used when security issues require it. FPGA is said to be 'hardware designed like software', which means that the design process resembles software development but the end-product is considered a hardware application because the execution of the functions is entirely different from a microprocessor. This duality can give both the flexibility of software and the reliability of hardware. The FPGA design and verification and validation (V and V) methods for NPP safety systems have not yet matured because the technology is rather new in the field. Software development methods and stanfards can be used to some extent but the hardware aspects bring new challenges that cannot be tacled using purely software methods. International efforts are being made to development formal and consistent design and V and V methodology regulations for FPGA devices. A preventive safety function called Stepwise Shutdown System (SWS) was implemented on an Actel M1 IGLOO field-programmable gate array (FPGA) device. SWS is used to drive a process into a normal state if the process measurements deviate from the desired operating values. This can happen in case of process disturbances. The SWS implementation processfrom the reguirements to the functional device is elaborated. The design is tested via simulation and hardware testing. The case study is to be further expanded as a part of a master's thesis. (orig.)

  13. Extraction and Antibacterial Properties of Thyme Leaf Extracts: Authentic Practice of Green Chemistry

    Science.gov (United States)

    Purcell, Sean C.; Pande, Prithvi; Lin, Yingxin; Rivera, Ernesto J.; Paw U, Latisha; Smallwood, Luisa M.; Kerstiens, Geri A.; Armstrong, Laura B.; Robak, MaryAnn T.; Baranger, Anne M.; Douskey, Michelle C.

    2016-01-01

    In this undergraduate analytical chemistry experiment, students quantitatively assess the antibacterial activity of essential oils found in thyme leaves ("Thymus vulgaris") in an authentic, research-like environment. This multi-week experiment aims to instill green chemistry principles as intrinsic to chemical problem solving. Students…

  14. Using Structure-Based Organic Chemistry Online Tutorials with Automated Correction for Student Practice and Review

    Science.gov (United States)

    O'Sullivan, Timothy P.; Hargaden, Gra´inne C.

    2014-01-01

    This article describes the development and implementation of an open-access organic chemistry question bank for online tutorials and assessments at University College Cork and Dublin Institute of Technology. SOCOT (structure-based organic chemistry online tutorials) may be used to supplement traditional small-group tutorials, thereby allowing…

  15. Effects of Lecture, Teacher Demonstrations, Discussion and Practical Work on 10th Graders' Attitudes to Chemistry and Understanding of Electrolysis

    Science.gov (United States)

    Thompson, Jerome; Soyibo, Kola

    2002-01-01

    This study investigated: (a) whether the use of the combination of lecture, teacher demonstrations, class discussion and student practical work in small groups significantly improved the experimental subjects' attitudes to chemistry and understanding of electrolysis more than their control group counterparts who were not exposed to practical work; and (b) whether there were statistically significant differences in their performance on electrolysis linked to their treatment, gender and post-test attitudes to chemistry. The sample was comprised of 138 Jamaican 10th graders in two high schools in St Catherine. The Attitudes to Chemistry Questionnaire and an Understanding of Electrolysis Test (UET) were used for data collection. The results showed that the experimental subjects' post-test attitudes to chemistry were statistically significantly better than those of their control group counterparts; the experimental groups' post-test mean scores on the multiple and structured items on the UET were statistically significantly better than those of the control groups; there was a positive, statistically significant but weak relationship between the experimental subjects' treatment and performance on the multiple and structured items, while the relationship between the control subjects' treatment and performance on both items was not significant.

  16. Second-Guessing Scientists and Engineers: Post Hoc Criticism and the Reform of Practice in Green Chemistry and Engineering.

    Science.gov (United States)

    Lynch, William T

    2015-10-01

    The article examines and extends work bringing together engineering ethics and Science and Technology Studies, which had built upon Diane Vaughan's analysis of the Challenger shuttle accident as a test case. Reconsidering the use of her term "normalization of deviance," the article argues for a middle path between moralizing against and excusing away engineering practices contributing to engineering disaster. To explore an illustrative pedagogical case and to suggest avenues for constructive research developing this middle path, it examines the emergence of green chemistry and green engineering. Green chemistry began when Paul Anastas and John Warner developed a set of new rules for chemical synthesis that sought to learn from missed opportunities to avoid environmental damage in the twentieth century, an approach that was soon extended to engineering as well. Examination of tacit assumptions about historical counterfactuals in recent, interdisciplinary discussions of green chemistry illuminate competing views about the field's prospects. An integrated perspective is sought, addressing how both technical practice within chemistry and engineering and the influence of a wider "social movement" can play a role in remedying environmental problems.

  17. A pragmatic approach towards designing a second shutdown system for Tehran research reactor

    OpenAIRE

    Boustani Ehsan; Khakshournia Samad; Khalafi Hossein

    2016-01-01

    One second shutdown system is proposed for the Tehran Research Reactor to achieve the goal of higher safety in compliance with current operational requirements and regulations and improve the overall reliability of the reactor shutdown system. The proposed second shutdown system is a diverse, independent shutdown system compared to the existing rod based one that intends to achieve and maintain sub-criticality condition with an enough shutdown margin in man...

  18. The Fast Flux Test Facility shutdown program plan

    Energy Technology Data Exchange (ETDEWEB)

    Guttenberg, S.; Jones, D.H.; Midgett, J.C.; Nielsen, D.L.

    1995-01-01

    The Fast Flux Test Facility (FFTF) is a 400 MWt sodium-cooled research reactor owned by the US Department of Energy (DOE) and operated by the Westinghouse Hanford Company (WHC) on the Hanford Site in southeastern Washington State. The decision was made by the DOE in December, 1993, to initiate shutdown of the FFTF. This paper describes the FFTF Transition Project Plan (1) (formerly the FFTF Shutdown Program Plan) which provides the strategy, major elements, and project baseline for transitioning the FFTF to an industrially and radiologically safe shutdown condition. The Plan, and its resource loaded schedule, indicate this transition can be achieved in a period of six to seven years at a cost of approximately $359 million. The transition activities include reactor defueling, fuel offload to dry cask storage, sodium drain and reaction, management of sodium residuals, shutdown of auxiliary systems, and preparation of appropriate environmental and regulatory documentation. Completion of these activities will involve resolution of many challenging and unique issues associated with shutdown of a large sodium reactor facility. At the conclusion of these activities, the FFTF will be in a safe condition for turnover to the Hanford Site Environmental Restoration Contractor for a long term surveillance and maintenance phase and decommissioning.

  19. CV activities on the LHC complex during the long shutdown

    CERN Document Server

    Deleval, S; Body, Y; Obrecht, M; Moccia, S; Peon, G

    2011-01-01

    The presentation gives an overview of the major projects and work foreseen to be performed during next long shutdown on cooling and ventilation plants. Several projects are needed following the experience of the last years when LHC was running, in particular the modifications in the water cooling circuits presently in overflow. Some other projects are linked to the CV consolidation plan. Finally, most of the work shall be done to respond to additional requests: SR buildings air conditioning, the need to be able to clean and maintain the LHC cooling towers without a complete stop of cooling circuits, the upgrade of the air conditioning of the CCC rack room cooling etc. For all these activities, the author will detail constraints and the impact on the schedule and on the operation of the plants that will however need to run for most of the shutdown duration. The consequence of postponing the long shutdown from 2012 to 2013 will be also covered.

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

    Science.gov (United States)

    Panther Bishoff, Jennifer

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

  1. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    Energy Technology Data Exchange (ETDEWEB)

    Maheras, Steven J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Best, Ralph E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ross, Steven B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buxton, Kenneth A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); England, Jeffery L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McConnell, Paul E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Massaro, Lawrence M. [Fermi Research Alliance (FRA), Batavia, IL (United States); Jensen, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-30

    A preliminary evaluation of removing spent nuclear fuel (SNF) from 13 shutdown nuclear power plant sites was performed. At these shutdown sites the nuclear power reactors have been permanently shut down and the sites have been decommissioned or are undergoing decommissioning. The shutdown sites were Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, San Onofre, and Vermont Yankee. The evaluation was divided into four components: Characterization of the SNF and greater-than-Class C low-level radioactive waste (GTCC waste) inventory A description of the on-site infrastructure at the shutdown sites An evaluation of the near-site transportation infrastructure and transportation experience at the shutdown sites An evaluation of the actions necessary to prepare for and remove SNF and GTCC waste. The primary sources for the inventory of SNF and GTCC waste were the U.S. Department of Energy (DOE) spent nuclear fuel inventory database, industry publications such as StoreFUEL, and government sources such as the U.S. Nuclear Regulatory Commission. The primary sources for information on the conditions of on-site infrastructure and near-site transportation infrastructure and experience included information collected during site visits, information provided by managers at the shutdown sites, Facility Interface Data Sheets compiled for DOE in 2005, Services Planning Documents prepared for DOE in 1993 and 1994, industry publications such as Radwaste Solutions, and Google Earth. State staff, State Regional Group representatives, a Tribal representative, and a Federal Railroad Administration representative have participated in nine of the shutdown site visits. Every shutdown site was found to have at least one off-site transportation mode option for removing its SNF and GTCC waste; some have multiple options. Experience removing large components during reactor decommissioning provided an

  2. Chemistry Teachers' Emerging Expertise in Inquiry Teaching: The Effect of a Professional Development Model on Beliefs and Practice

    Science.gov (United States)

    Rushton, Gregory T.; Lotter, Christine; Singer, Jonathan

    2011-02-01

    This study investigates the beliefs and practices of seven high school chemistry teachers as a result of their participation in a year-long inquiry professional development (PD) project. An analysis of oral interviews, written reflections, and in-class observations were used to determine the extent to which the PD affected the teachers' beliefs and practice. The data indicated that the teachers developed more complete conceptions of classroom inquiry, valued a "phenomena first" approach to scientific investigations, and viewed inquiry approaches as helpful for facilitating improved student thinking. Analysis of classroom observations with the Reformed Teaching Observation Protocol indicated that features of the PD were observed in the teachers' practice during the academic year follow-up. Implications for effective science teacher professional development models are discussed.

  3. Another Piece of the Puzzle: The Relationship between Beliefs and Practice in Higher Education Organic Chemistry

    Science.gov (United States)

    Farre, Andrea Soledad; Lorenzo, Maria Gabriela

    2009-01-01

    An original study about beliefs, conceptions and discourse analyses of organic chemistry teachers is presented. We used Likert questionnaires and discourse analysis to examine conceptions of the nature of science, learning and teaching at university level. A case study of four female teachers with varying experience and teacher training was…

  4. Analysis of a Superconductor: Development of a Practical Exam for the International Chemistry Olympiad

    Science.gov (United States)

    Nick, Sabine; Nather, Christian

    2007-01-01

    In July 2004 the 36th International Chemistry Olympiad was held in Kiel, Germany. Competition for medals included 236 students from 61 countries, accompanied by about 150 teachers and other mentors. During this Olympiad the students performed qualitative and quantitative analyses of a superconductor, based on lanthanum barium cuprate. In the…

  5. Effect of Virtual Analytical Chemistry Laboratory on Enhancing Student Research Skills and Practices

    Science.gov (United States)

    Bortnik, Boris; Stozhko, Natalia; Pervukhina, Irina; Tchernysheva, Albina; Belysheva, Galina

    2017-01-01

    This article aims to determine the effect of a virtual chemistry laboratory on university student achievement. The article describes a model of a laboratory course that includes a virtual component. This virtual component is viewed as a tool of student pre-lab autonomous learning. It presents electronic resources designed for a virtual laboratory…

  6. Avoiding compressor surge during emergency shutdown hybridturbine systems

    Energy Technology Data Exchange (ETDEWEB)

    Pezzini, Paolo [University of Genova, Italy; Tucker, David [U.S. DOE; Traverso, Alberto [University of Genova, Italy

    2013-01-01

    A new emergency shutdown procedure for a direct-fired fuel cell turbine hybrid power system was evaluated using a hardware-based simulation of an integrated gasifier/fuel cell/turbine hybrid cycle (IGFC), implemented through the Hybrid Performance (Hyper) project at the National Energy Technology Laboratory, U.S. Department of Energy (NETL). The Hyper facility is designed to explore dynamic operation of hybrid systems and quantitatively characterize such transient behavior. It is possible to model, test, and evaluate the effects of different parameters on the design and operation of a gasifier/fuel cell/gas turbine hybrid system and provide a means of quantifying risk mitigation strategies. An open-loop system analysis regarding the dynamic effect of bleed air, cold air bypass, and load bank is presented in order to evaluate the combination of these three main actuators during emergency shutdown. In the previous Hybrid control system architecture, catastrophic compressor failures were observed when the fuel and load bank were cut off during emergency shutdown strategy. Improvements were achieved using a nonlinear fuel valve ramp down when the load bank was not operating. Experiments in load bank operation show compressor surge and stall after emergency shutdown activation. The difficulties in finding an optimal compressor and cathode mass flow for mitigation of surge and stall using these actuators are illustrated.

  7. Design of Organic Transformations at Ambient Conditions: Our Sincere Efforts to the Cause of Green Chemistry Practice.

    Science.gov (United States)

    Brahmachari, Goutam

    2016-02-01

    This account summarizes our recent efforts in designing a good number of important organic transformations leading to the synthesis of biologically relevant compounds at room temperature and pressure. Currently, the concept of green chemistry is globally acclaimed and has already advanced quite significantly to emerge as a distinct branch of chemical sciences. Among the principles of green chemistry, one principle is dedicated to the "design of energy efficiency" - that is, to develop synthetic strategies that require less or the minimum amount of energy to carry out a specific reaction with optimum productivity - and the most effective way to save energy is to develop strategies/protocols that are capable enough to carry out the transformations at ambient temperature! As part of on-going developments in green synthetic strategies, the design of reactions under ambient conditions coupled with other green aspects is, thus, an area of current interest. The concept of developing reaction strategies at room temperature and pressure is now an emerging field of research in organic chemistry and is progressing steadily. This account is aimed to offer an overview of our recent research works directly related to this particular field of interest, and highlights the green chemistry practice leading to carbon-carbon and carbon-heteroatom bond-forming reactions of topical significance. Green synthetic routes to a variety of biologically relevant organic molecules (heterocyclic, heteroaromatic, alicyclic, acyclic, etc.) at room temperature and pressure are discussed. © 2015 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Shutdown: The Impact of Plant Shutdown, Extensive Employment Terminations and Layoffs on the Workers and the Community.

    Science.gov (United States)

    Eleen, John W.; Bernardine, Ashley G.

    This report discusses the social, economic, and human implications of plant shutdowns. As part of the data gathering process, personal interviews were held with civic leaders, company representatives, union leaders, and workers in order to gain insight into the causes and effect of the closing of plants. Sections of the report cover topics such…

  9. 77 FR 73968 - Reconsideration of Certain New Source and Startup/Shutdown Issues: National Emission Standards...

    Science.gov (United States)

    2012-12-12

    ... AGENCY 40 CFR Parts 60 and 63 RIN 2060-AR62 Reconsideration of Certain New Source and Startup/Shutdown... ``Reconsideration of Certain New Source and Startup/Shutdown Issues: National Emission Standards for Hazardous Air... November 30, 2012, proposed ``Reconsideration of Certain New Source and Startup/Shutdown Issues: National...

  10. 77 FR 75198 - Standard Format and Content for Post-Shutdown Decommissioning Activities Report

    Science.gov (United States)

    2012-12-19

    ... COMMISSION Standard Format and Content for Post-Shutdown Decommissioning Activities Report AGENCY: Nuclear... Format and Content for Post-shutdown Decommissioning Activities Report.'' This guide describes a method...) 1.185, ``Standard Format and Content for Post-shutdown Decommissioning Activities Report,'' which...

  11. Teaching Chemistry for All Its Worth: The Interaction Between Facts, Ideas, and Language in Lavoisier's and Priestley's Chemistry Practice: The Case of the Study of the Composition of Air

    Science.gov (United States)

    de Berg, Kevin

    2014-10-01

    Both Lavoisier and Priestley were committed to the role of experiment and observation in their chemistry practice. According to Lavoisier the physical sciences embody three important ingredients; facts, ideas, and language, and Priestley would not have disagreed with this. Ideas had to be consistent with the facts generated from experiment and observation and language needed to be precise and reflect the known chemistry of substances. While Priestley was comfortable with a moderate amount of hypothesis making, Lavoisier had no time for what he termed theoretical speculation about the fundamental nature of matter and avoided the use of the atomic hypothesis and Aristotle's elements in his Elements of Chemistry. In the preface to this famous work he claims he has good educational reasons for this position. While Priestley and Lavoisier used similar kinds of apparatus in their chemistry practice, they came to their task with completely different worldviews as regards the nature of chemical reactivity. This paper examines these worldviews as practiced in the famous experiment on the composition of air and the implications of this for chemistry education are considered.

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

    Science.gov (United States)

    Raker, Jeffrey R.; Towns, Marcy H.

    2012-01-01

    The development of curricular problems based on the practice of synthetic organic chemistry has not been explored in the literature. Such problems have broadly been hypothesized to promote student persistence and interest in STEM fields. This study reports seven ideas about how practice-based problems can be developed for sophomore-level organic…

  13. Perfectly Reasonable in a Practical World: Understanding Chemistry Teacher Responses to a Change Proposal

    Science.gov (United States)

    Westbroek, Hanna; Janssen, Fred; Doyle, Walter

    2017-12-01

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

  14. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    Energy Technology Data Exchange (ETDEWEB)

    Maheras, Steven J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Best, Ralph E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ross, Steven B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buxton, Kenneth A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); England, Jeffery L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McConnell, Paul E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Massaro, Lawrence M. [Federal Railroad Administration (FRA) (United States); Jensen, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-10-01

    This report presents a preliminary evaluation of removing used nuclear fuel (UNF) from 12 shutdown nuclear power plant sites. At these shutdown sites the nuclear power reactors have been permanently shut down and the sites have been decommissioned or are undergoing decommissioning. The shutdown sites are Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, and San Onofre. The evaluation was divided into four components: characterization of the UNF and greater-than-Class C low-level radioactive waste (GTCC waste) inventory; a description of the on-site infrastructure and conditions relevant to transportation of UNF and GTCC waste; an evaluation of the near-site transportation infrastructure and experience relevant to shipping transportation casks containing UNF and GTCC waste, including identification of gaps in information; and, an evaluation of the actions necessary to prepare for and remove UNF and GTCC waste. The primary sources for the inventory of UNF and GTCC waste are the U.S. Department of Energy (DOE) RW-859 used nuclear fuel inventory database, industry sources such as StoreFUEL and SpentFUEL, and government sources such as the U.S. Nuclear Regulatory Commission. The primary sources for information on the conditions of site and near-site transportation infrastructure and experience included observations and information collected during visits to the Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, and Zion sites; information provided by managers at the shutdown sites; Facility Interface Data Sheets compiled for DOE in 2005; Services Planning Documents prepared for DOE in 1993 and 1994; industry publications such as Radwaste Solutions; and Google Earth. State and Regional Group representatives, a Tribal representative, and a Federal Railroad Administration representative participated in six of the shutdown site

  15. The First Long Shutdown (LS1) for the LHC

    CERN Document Server

    Bordry, F; Foraz, K; Perrot, A L; Saban, R; Tock, J Ph

    2013-01-01

    The LHC has been delivering data to the physics experiments since the first collisions in 2009. The first long shutdown (LS1), which started on 14 February 2013, was triggered by the need to consolidate the magnet interconnections to allow the LHC to operate at the design energy of 14 TeV in the centre-of-mass. It has now become a major shutdown, which, in addition, includes other repairs, consolidation, upgrades and cabling across the whole accelerator complex and the associated experimental facilities. A detailed CERN-wide resource-loaded schedule was prepared aiming at resuming LHC physics in early 2015, while the rest of the CERN complex will gradually start up again in the second half of 2014.\

  16. Materials Chemistry

    CERN Document Server

    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...

  17. Reliability of Offshore Wind Turbine Drivetrains based on Measured Shut-down Events

    DEFF Research Database (Denmark)

    Natarajan, Anand; Buhl, Thomas

    2015-01-01

    The key objective of this paper is to investigate the frequency of normal shutdowns to be used in the design stage of wind turbines, based on measurements at an offshore wind farm and thereby quantify the irimpact on the fatigue loads on the drivetrain and tower top. The measured shut-downs...... observed on a fully instrumented multi megawatt wind turbine located in an offshore wind farm are correlated with corresponding observations of shutdowns on surrounding windturbines. The observed wind turbines have multiple shut-downs at high mean wind speeds. The normal shutdown is brought about....... A simulation model of the wind turbine is set up in the aeroelastic software HAWC2, based on which the observed shut-downs are simulated, along with normal operation. The simulated tower topmoments are compared with the measured loads, thereby quantifying the amplification in the loads due to the shutdown...

  18. EN/EL Activities during the next long Shutdown

    CERN Document Server

    Duval, F

    2011-01-01

    The EL group will participate in many activities during the next long shutdown. They are divided in four categories: • Projects which require an extension or modification of the distribution network. • Consolidation work of the electrical distribution infrastructure led by EN/EL. • Scheduled maintenance activities and, in addition, the maintenance activities postponed since the start of the LHC. • Many upgrades of EN/EL infrastructure following an evolution of the power request (from EN/EL or other groups). It should be noticed that so far, we know only a small part of the work for which we will be involved. Indeed, projects must be sufficiently defined by our colleagues before submitting us their request. Furthermore, it should be noted that the decision to delay from 2012 to 2013 the long shutdown will lead to a schedule change of some projects and will increase the risk of failure of EN/EL equipment due to a lack of maintenance. This postponement of the long shutdown will be preceded by an addition...

  19. 40 CFR 60.1695 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... requirements during periods of startup, shutdown, and malfunction? 60.1695 Section 60.1695 Protection of... Requirements § 60.1695 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

  20. 40 CFR 60.1220 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... during periods of startup, shutdown, and malfunction? 60.1220 Section 60.1220 Protection of Environment... Emission Limits § 60.1220 What happens to the emission limits during periods of startup, shutdown, and... waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or malfunction must...

  1. 40 CFR 62.15150 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... requirements during periods of startup, shutdown, and malfunction? 62.15150 Section 62.15150 Protection of... § 62.15150 What happens to the operating requirements during periods of startup, shutdown, and... municipal waste combustion unit startup, shutdown, or malfunction. (b) Each startup, shutdown, or...

  2. Strategic elements of steam cycle chemistry control practices at TXU's Comanche Peak steam electric station

    Energy Technology Data Exchange (ETDEWEB)

    Fellers, B.; Stevens, J.; Nichols, G. [TXU Electric (United States)

    2002-07-01

    Early industry experience defined the critical importance of Chemistry Control Practices to maintaining long-term performance of PWR steam generators. These lessons provided the impetus for a number of innovations and alternate practices at Comanche Peak. For example, advanced amine investigations and implementation of results provided record low iron transport and deposition. The benefits of the surface-active properties of dimethyl-amine exceeded initial expectations. Operation of pre-coat polishers and steam generator blowdown demineralizers in the amine cycle enabled optimization of amine concentrations and stable pH control. The strategy for coordinated control of oxygen and hydrazine dosing complemented the advanced amine program for protective oxide stabilization. Additionally, a proactive chemical cleaning was performed on Unit 1 to prevent degradations from general fouling of steam generator tube-tube support plate (TSP) and top-of-tubesheet (TTS) crevices. This paper shares the results of these innovations and practices. Also, the bases, theory, and philosophy supporting the strategic elements of program will be presented. (authors)

  3. Using Structured Chemistry Examinations (SCHemEs) as an Assessment Method to Improve Undergraduate Students' Generic, Practical, and Laboratory-Based Skills

    Science.gov (United States)

    Kirton, Stewart B.; Al-Ahmad, Abdullah; Fergus, Suzanne

    2014-01-01

    Increase in tuition fees means there will be renewed pressure on universities to provide "value for money" courses that provide extensive training in both subject-specific and generic skills. For graduates of chemistry this includes embedding the generic, practical, and laboratory-based skills associated with industrial research as an…

  4. Developing and Evaluating an Eighth Grade Curriculum Unit That Links Foundational Chemistry to Biological Growth. Paper #1: Selecting Core Ideas and Practices -- An Iterative Process

    Science.gov (United States)

    Roseman, Jo Ellen; Herrmann-Abell, Cari; Flanagan, Jean; Kruse, Rebecca; Howes, Elaine; Carlson, Janet; Roth, Kathy; Bourdelat-Parks, Brooke

    2013-01-01

    Researchers at AAAS and BSCS have developed a six-week unit that aims to help middle school students learn important chemistry ideas that can be used to explain growth and repair in animals and plants. By integrating core physical and life science ideas and engaging students in the science practices of modeling and constructing explanations, the…

  5. A Practice-Led Approach to Aligning Learning Theories with Learning and Teaching Strategies in Third Level Chemistry Education

    Directory of Open Access Journals (Sweden)

    Christine O'Connor

    2015-06-01

    Full Text Available Large class sizes and a diverse student cohort have resulted in challenges for academics in third level institutes both nationally and internationally. This is a result of widening of participation and the drive to create a knowledge-based society in Ireland for the future. The focus in this paper is on third level chemistry education and looking at the issues arising both in the class and laboratory and suggesting learning and teaching strategies in order to overcome them or to enhance efficiencies. The learning and teaching strategies suggested however may be applied across many disciplines. The learning theories that underpin these strategies are highlighted throughout the text to strengthen the pedagogical framework on which they are based. Behaviourism, constructivism, cognitivism and social constructivism are the four main learning theories that support the discussion. Exemplars from the literature and practice led, and all designed, developed and evaluated in the Dublin Institute of Technology (DIT. The role of learning technologies has been included where appropriate. There are many ways of addressing issues of teaching diverse groups at third level that are free and readily accessible, it is hoped that this paper will encourage academics to try a new educational approach in their practice.

  6. Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

    Energy Technology Data Exchange (ETDEWEB)

    Maheras, Steven J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Best, Ralph E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ross, Steven B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buxton, Kenneth A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); England, Jeffery L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McConnell, Paul E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Massaro, Lawrence M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-30

    A preliminary evaluation of removing spent nuclear fuel (SNF) from 13 shutdown nuclear power reactor sites was conducted. At these shutdown sites the nuclear power reactors have been permanently shut down and the sites have been decommissioned or are undergoing decommissioning. The shutdown sites were Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, San Onofre, and Vermont Yankee. The evaluation was divided into four components: (1) characterization of the SNF and greater-than-Class C low-level radioactive waste (GTCC waste) inventory, (2) a description of the on-site infrastructure and conditions relevant to transportation of SNF and GTCC waste, (3) an evaluation of the near-site transportation infrastructure and experience relevant to shipping transportation casks containing SNF and GTCC waste, including identification of gaps in information, and (4) an evaluation of the actions necessary to prepare for and remove SNF and GTCC waste. Every site was found to have at least one off-site transportation mode option for removing its SNF and GTCC waste; some have multiple options. Experience removing large components during reactor decommissioning provided an important source of information used to identify the transportation mode options for the sites. Especially important in conducting the evaluation were site visits, through which information was obtained that would not have been available otherwise. Extensive photographs taken during the site visits proved to be particularly useful in documenting the current conditions at or near the sites. It is expected that additional site visits will be conducted to add to the information presented in the evaluation.

  7. Research of Heated Oil Pipeline Shutdown and Restart Process Based on VB and MATLAB

    OpenAIRE

    Changjun Li; Xia Wu; Wenlong Jia

    2010-01-01

    During the operation of a heated oil transportation pipeline, the shutdown was caused by some pipeline accidents and repairing. In order to ensure the safety operation of the pipeline, determine the temperature drop and restart pressure was needed at different shutdown is important. This paper builds the heated oil pipeline temperature drop model after shutdown based on the unsteady heat transfer theory and restart model based on fluid transient flow theory. In order to solve the models, MATL...

  8. Towards a Practical Form of Epistemology: The Case of Green Chemistry

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Llored

    2012-12-01

    Full Text Available This paper explores how chemists are transforming their own current background in order to act upon the world without jeopardizing life. In this respect, I will envisage science as both a system of propositions and a set of engaged practices. The scrutiny of chemical innovations will allow me to query the concepts of paradigm and that of scientific community. In doing so, I will connect the philosophy of science with the philosophy of technology so as to think about our relation with the world.

  9. Global shutdown dose rate maps for a DEMO conceptual design

    Energy Technology Data Exchange (ETDEWEB)

    Leichtle, D., E-mail: dieter.leichtle@f4e.europa.eu [Karlsruhe Institute of Technology KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Pereslavtsev, P. [Karlsruhe Institute of Technology KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Sanz, J.; Catalan, J.P.; Juarez, R. [Universidad Nacional de Educación a Distancia(UNED), E.T.S. Ingenieros Industriales, C/ Juan del Rosal 12, 28040 Madrid (Spain)

    2015-10-15

    Highlights: • Application of R2S-method on high-resolution full torus sector mesh for DEMO. • Absorbed dose rates after shutdown for a variely of RH equipment at typical locations. • Idenification of radiation levels at several port based locations. - Abstract: For the calculations of highly reliable shutdown dose rate (SDR) maps in fusion devices like a DEMO plant, the Rigorous-2-step (R2S) method is nowadays routinely applied using high-resolution decay gamma sources from initial high-resolution neutron flux meshes activating all materials in the system. This approach has been utilized in the present paper with the objective to provide SDR results relevant for RH systems of a conceptual DEMO design developed in the EU. The primary objective was to assess specific locations of interest for RH equipment inside the vessel and along the extension of maintenance ports. To this end, a provisional DEMO MCNP model has been used, featuring HCLL-type blankets, tungsten/copper divertor, manifolds, vacuum vessel with ports and toroidal field coils. The operational scenario assumed 2.1 GW fusion power and a life-time of 20 years with plant availability of 30%, where removable parts will be extracted after 5.2 years. Results of absorbed dose rate distributions for several relevant materials are presented and discussed in terms of the different contributions from the various activated components.

  10. The String Shutdown Report December 97 - March 98

    CERN Document Server

    Casas-Cubillos, J; Favre, G; Herzog, R; Jacquemod, A; Missiaen, D; Saban, R; Struik, M

    1998-01-01

    The main reason for the shutdown was the installation of a tube containing a prototype auxiliary bus-bars cable. This tube runs in one of the beam tube apertures of the String from the front of MB1 to the rear of MB3 and is hydraulically connected to the cold mass of MB3. A ceramic leak tight feed-through was installed, for the first time in operational conditions, to route the signal wires for the temperature sensors and the voltage taps out of the 1.9 K helium bath. Leaks in the beam-screen capillary had prevented the connection of the beam screens to the cooling circuit. The opportunity of t his shutdown was taken to install a cryogenically cooled beam-screen in the other aperture of MB3. In addition, the calibration of temperature and positioning sensors took place. The SRB had to be re moved to install the long tube and the lines carrying cryogens had to be cut, therefore a pressure test and a leak test had to be carried-out.

  11. 40 CFR 65.6 - Startup, shutdown, and malfunction plan and procedures.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Startup, shutdown, and malfunction... (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE General Provisions § 65.6 Startup... Group 2A or Group 2B process vents. (b) Startup, shutdown, and malfunction plan—(1) Description and...

  12. 40 CFR 63.2852 - What is a startup, shutdown, and malfunction plan?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true What is a startup, shutdown, and... Production Compliance Requirements § 63.2852 What is a startup, shutdown, and malfunction plan? You must...)(2) malfunction period, or the § 63.2850(c)(2) or (d)(2) initial startup period. The SSM plan must...

  13. 40 CFR 62.14645 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false What happens during periods of startup... Limits § 62.14645 What happens during periods of startup, shutdown, and malfunction? (a) The emission limitations and operating limits apply at all times except during periods of CISWI unit startup, shutdown, or...

  14. 40 CFR 60.2918 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Performance Testing ...

  15. 40 CFR 60.3025 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... during periods of startup, shutdown, and malfunction? The emission limitations and operating limits apply at all times except during OSWI unit startups, shutdowns, or malfunctions. Model Rule—Performance...

  16. 40 CFR 60.2685 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... happens during periods of startup, shutdown, and malfunction? (a) The emission limitations and operating limits apply at all times except during CISWI unit startups, shutdowns, or malfunctions. (b) Each...

  17. CORAL and COOL during the LHC long shutdown

    CERN Multimedia

    Valassi, A; Dykstra, D; Goyal, N; Salnikov, A; Trentadue, R; Wache, M

    2013-01-01

    CORAL and COOL are two software packages used by the LHC experiments for managing detector conditions and other types of data using relational database technologies. They have been developed and maintained within the LCG Persistency Framework, a common project of the CERN IT department with ATLAS, CMS and LHCb. This presentation reports on the status of CORAL and COOL at the time of CHEP2013, covering the new features and enhancements in both packages, as well as the changes and improvements in the software process infrastructure. It also reviews the usage of the software in the experiments and the outlook for ongoing and future activities during the LHC long shutdown (LS1) and beyond.

  18. CORAL and COOL during the LHC long shutdown.

    CERN Document Server

    Valassi, Andrea; Dulstra, D; Goyal, N; Salnikov, A; Trentadue, R; Wache, M

    2014-01-01

    CORAL and COOL are two software packages used by the LHC experiments for managing detector conditions and other types of data using relational database technologies. They have been developed and maintained within the LCG Persistency Framework, a common project of the CERN IT department with ATLAS, CMS and LHCb. This presentation reports on the status of CORAL and COOL at the time of CHEP2013, covering the new features and enhancements in both packages, as well as the changes and improvements in the software process infrastructure. It also reviews the usage of the software in the experiments and the outlook for ongoing and future activities during the LHC long shutdown (LS1) and beyond.

  19. Industry shutdown rates and permanent layoffs: evidence from firm-worker matched data

    Directory of Open Access Journals (Sweden)

    Kim P. Huynh

    2017-06-01

    Full Text Available Abstract Firm shutdown creates a turbulent situation for workers as it leads directly to layoffs for its workers. An additional consideration is whether a firm’s shutdown within an industry creates turbulence for workers at other continuing firms. Using data drawn from the Longitudinal Worker File, a Canadian firm-worker matched employment database, we investigate the impact of industry shutdown rates on workers at continuing firm. This paper exploits variation in shutdown rates across industries and within an industry over time to explain the rate of permanent layoffs and the growth of workers’ earnings. We find an increase in industry shutdown rates increases the probability of permanent layoffs and decreases earnings growth for workers at continuing firms.

  20. Preliminary Evaluation of Removing Used Nuclear Fuel From Nine Shutdown Sites

    Energy Technology Data Exchange (ETDEWEB)

    Maheras, Steven J.; Best, Ralph; Ross, Steven B.; Buxton, Kenneth A.; England, Jeffery L.; McConnell, Paul

    2013-04-30

    The Blue Ribbon Commission on America’s Nuclear Future identified removal of stranded used nuclear fuel at shutdown sites as a priority so that these sites may be completely decommissioned and put to other beneficial uses. In this report, a preliminary evaluation of removing used nuclear fuel from nine shutdown sites was conducted. The shutdown sites included Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, and Zion. At these sites a total of 7649 used nuclear fuel assemblies and a total of 2813.2 metric tons heavy metal (MTHM) of used nuclear fuel are contained in 248 storage canisters. In addition, 11 canisters containing greater-than-Class C (GTCC) low-level radioactive waste are stored at these sites. The evaluation was divided in four components: • characterization of the used nuclear fuel and GTCC low-level radioactive waste inventory at the shutdown sites • an evaluation of the onsite transportation conditions at the shutdown sites • an evaluation of the near-site transportation infrastructure and experience relevant to the shipping of transportation casks containing used nuclear fuel from the shutdown sites • an evaluation of the actions necessary to prepare for and remove used nuclear fuel and GTCC low-level radioactive waste from the shutdown sites. Using these evaluations the authors developed time sequences of activities and time durations for removing the used nuclear fuel and GTCC low-level radioactive waste from a single shutdown site, from three shutdown sites located close to each other, and from all nine shutdown sites.

  1. Doing the Research that Informs Practice: A Retrospective View of One Group's Attempt to Study The Teaching and Learning of Organic Chemistry.

    Science.gov (United States)

    Bodner, George M; Ferguson, Rob; Çalimsiz, Selçuk

    2017-07-04

    The idea that the focus of educational research should be on results that can inform the practice of teaching has been an implicit assumption for so many years that one would be hard-pressed to trace it back to an individual source. At one time, the people doing such research in STEM disciplines were faculty in schools or colleges of education who focused on K-12 classrooms and looked for ideas, concepts, and principles that would be valid across a range of STEM disciplines. Eventually, this research was done on college- or university-level students, as well, and there was a shift toward what has been called discipline-based educational research (DBER) that looks at the problems associated with the teaching and learning of a given discipline, such as chemistry. This paper will discuss the results of research on problem-solving in chemistry that has been done in our research group, with particular emphasis on the challenges of teaching and learning organic chemistry. The goal of this paper is to show what can happen when one listens carefully to students and begins to appreciate the difference between what we think we have taught and what the students learned. The examples we will use have the potential for convincing those of us who teach chemistry to rethink what we do in our classes to find better ways of helping our students understand the material we are trying to teach. Although this paper will focus on results from the second-year organic chemistry course, similar results have been observed in both inorganic and physical chemistry, as well as biochemistry courses. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. 40 CFR 60.1205 - What happens to the operating requirements during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... requirements during periods of startup, shutdown, and malfunction? 60.1205 Section 60.1205 Protection of... requirements during periods of startup, shutdown, and malfunction? (a) The operating requirements of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

  3. 40 CFR 62.15165 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... during periods of startup, shutdown, and malfunction? 62.15165 Section 62.15165 Protection of Environment... emission limits during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or...

  4. 40 CFR 60.1710 - What happens to the emission limits during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... during periods of startup, shutdown, and malfunction? 60.1710 Section 60.1710 Protection of Environment... during periods of startup, shutdown, and malfunction? (a) The emission limits of this subpart apply at all times except during periods of municipal waste combustion unit startup, shutdown, or malfunction...

  5. Air purging and shut-down system for diesel engines

    Energy Technology Data Exchange (ETDEWEB)

    Ricks, R.C.

    1992-03-17

    This patent describes an emergency shut-down system for the fuel system of an internal combustion engine having a fuel tank adapted to contain a liquid fuel therein, a main fuel pump connected to the fuel tank by a fuel line, and fuel distributing means for normally communicating the fuel to combustion chambers of the engine. It comprises monitor and control means for automatically alerting an operator that the fuel in the fuel tank has fallen below a predetermined level, providing the fuel distributing means and the combustion chambers with sufficient fuel to run the engine for a limited period of time, and deactivating the fuel distributing means to stop communication of fuel to the combustion chambers after the fuel has been expended, the monitor and control means including normally open pressure-responsive first switch means closeable in response to the pressure in the fuel line falling below a predetermined level, operator-visible first indicator means for alerting the operator that the pressure of the fuel has fallen below the predetermined level in response to closing of the first switch means, and a normally inactive auxiliary pump means for being activated to pump fuel through the fuel line in response to closing of the first switch means.

  6. Postinjury Fibrinolysis Shutdown: Rationale for Selective Tranexamic Acid

    Science.gov (United States)

    Moore, Ernest E.; Moore, Hunter B.; Gonzalez, Eduardo; Chapman, Michael P.; Hansen, Kirk C.; Sauaia, Angela; Silliman, Christopher C.; Banerjee, Anirban

    2015-01-01

    Postinjury systemic fibrinolysis has been recognized as a biologic process for more than 200 years, but the specific mechanisms of regulation and their clinical implications remain to be elucidated. By the 1950s, the plasminogen-plasmin-antiplasmin system was established as critical in preserving microvascular patency during blood clotting to maintain hemostasis. The challenges in modulating systemic fibrinolysis became evident soon thereafter. In the 1960s systemic fibrinolysis was identified by thrombelastography (TEG) during the anhepatic phase of liver transplantation, prompting the recommendation for intraoperative antifibrinolytics. But the administration of antifibrinolytic was associated with fatal postoperative pulmonary emboli. During the same period, there was experimental evidence that antifibrinolytics prevented irreversible hemorrhagic shock. More recently, a randomized trial indicated that plasmin inhibition during coronary artery bypass grafting was associated with increased mortality. The interest in antifibrinolytic therapy for trauma induced coagulopathy (TIC) is a relatively recent event, largely driven by the increasing use of viscoelastic hemostatic assays. The CRASH-2 trial, published in 2010, stimulated worldwide enthusiasm for tranexamic acid (TXA). However, the limitations of this study were soon acknowledged, raising concern for the unbridled use of TXA. Most recently, the documentation of fibrinolysis shutdown soon after injury has highlighted the potential adverse effects due to the untimely administration of TXA. A recent retrospective analysis in severely injured patients supports this hypothesis. But final clarity of this volatile topic awaits the completion of the current ongoing randomized clinical trials throughout the world. PMID:26002266

  7. A pragmatic approach towards designing a second shutdown system for Tehran research reactor

    National Research Council Canada - National Science Library

    Boustani Ehsan; Khakshournia Samad; Khalafi Hossein

    2016-01-01

    One second shutdown system is proposed for the Tehran Research Reactor to achieve the goal of higher safety in compliance with current operational requirements and regulations and improve the overall...

  8. Bad chemistry

    OpenAIRE

    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.

  9. Solution phase combinatorial chemistry.

    Science.gov (United States)

    Merritt, A T

    1998-06-01

    Combinatorial chemistry and parallel array synthesis techniques are now used extensively in the drug discovery process. Although published literature has been dominated by solid phase chemistry approaches, the use of solution phase techniques has also been widely explored. This review considers the advantages and disadvantages of choosing solution phase approaches in the various stages of drug discovery and optimisation, and assesses the practical issues related to these approaches. The uses of standard solution chemistry, the related liquid phase approach, and of supported materials to enhance solution phase chemistry are all illustrated by a comprehensive review of the published literature over the past three years.

  10. Green Chemistry Pedagogy

    Science.gov (United States)

    Kolopajlo, Larry

    2017-02-01

    This chapter attempts to show how the practice of chemistry teaching and learning is enriched by the incorporation of green chemistry (GC) into lectures and labs. To support this viewpoint, evidence from a wide range of published papers serve as a cogent argument that GC attracts and engages both science and nonscience students, enhances chemistry content knowledge, and improves the image of the field, while preparing the world for a sustainable future. Published pedagogy associated with green and sustainable chemistry is critically reviewed and discussed.

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

    Science.gov (United States)

    Sorgo, Andrej; Spernjak, Andreja

    2012-01-01

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

  12. 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

    Directory of Open Access Journals (Sweden)

    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.

  13. Techniques for detecting effects of urban and rural land-use practices on stream-water chemistry in selected watersheds in Texas, Minnesota,and Illinois

    Science.gov (United States)

    Walker, J.F.

    1993-01-01

    Although considerable effort has been expended during the past two decades to control nonpoint-source contamination of streams and lakes in urban and rural watersheds, little has been published on the effectiveness of various management practices at the watershed scale. This report presents a discussion of several parametric and nonparametric statistical techniques for detecting changes in water-chemistry data. The need for reducing the influence of natural variability was recognized and accomplished through the use of regression equations. Traditional analyses have focused on fixed-frequency instantaneous concentration data; this report describes the use of storm load data as an alternative.

  14. Mathematics for physical chemistry

    CERN Document Server

    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

  15. Using formative feedback to identify and support first-year chemistry students with missing or misconceptions. A Practice Report

    Directory of Open Access Journals (Sweden)

    Gwen Lawrie

    2013-08-01

    Full Text Available Students entering tertiary studies possess a diverse range of prior experiences in their academic preparation for tertiary chemistry so academics need tools to enable them to respond to issues in diversity in conceptual models possessed by entering students. Concept inventories can be used to provide formative feedback to help students identify concepts that they need to address to improve construction of subsequent understanding enabling their learning.Modular, formative learning activities that can be administered inside or outside of class in first year chemistry courses have been developed. These activities address key missing and mis-conceptions possessed by incoming student. Engagement in these learning activities by students and academics will help shift the culture of diagnostic and formative assessment within the tertiary context and address issues around the secondary/tertiary transition. This diagnostic/intervention framework is currently being trialed across five Australian tertiary institutions encompassing a large heterogeneous sample of students.

  16. Evaluation of a Design Principle for Fostering Students' Epistemological Views on Models and Modelling Using Authentic Practices as Contexts for Learning in Chemistry Education

    Science.gov (United States)

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

    2011-07-01

    Science education should foster students' epistemological view on models and modelling consistent with formal epistemology in science and technology practices. This paper reports the application of a curriculum unit in the classroom using an authentic chemical practice, 'Modelling drinking water treatment', as the context for learning. An authentic practice is defined as professionals working on an issue guided by common motives and purposes, according to a similar type of procedure and applying relevant knowledge. The epistemology on models and modelling in the practice was analysed and anchored in the curriculum unit. The knowledge involved was captured in a design principle 'content modelling'. A design principle provides heuristic guidelines to reach the intended pedagogic effects in the classroom. Throughout the field tests, research data were collected by means of classroom observations, interviews, audio-taped discussions, completed worksheets, and written questionnaires. Students were able to evaluate the advanced model features of goodness of fit and reliability, and, to a lesser extent, validity. However, reflection on the modelling approach applied can be improved. The findings were used to reconsider the current completion of the design principle 'content modelling'. This study contributes to the acquisition of a knowledge base concerning the use of authentic practices as contexts for learning in chemistry education as well as in science education in a broader sense.

  17. 46 CFR 154.540 - Quick-closing shut-off valves: Emergency shut-down system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Quick-closing shut-off valves: Emergency shut-down... shut-down system. The quick-closing shut-off valves under §§ 154.530, 154.532, and 154.538 must have an emergency shut-down system that: (a) Closes all the valves; (b) Is actuated by a single control in at least...

  18. Persistent Fibrinolysis Shutdown Is Associated with Increased Mortality in Severely Injured Trauma Patients.

    Science.gov (United States)

    Meizoso, Jonathan P; Karcutskie, Charles A; Ray, Juliet J; Namias, Nicholas; Schulman, Carl I; Proctor, Kenneth G

    2017-04-01

    Acute fibrinolysis shutdown is associated with early mortality after trauma; however, no previous studies have investigated the incidence of persistent fibrinolysis or its association with mortality. We tested the hypothesis that persistent fibrinolysis shutdown is associated with mortality in critically ill trauma patients. Thromboelastography was performed on ICU admission in 181 adult trauma patients and at 1 week in a subset of 78 patients. Fibrinolysis shutdown was defined as LY30 ≤ 0.8% and was considered transient if resolved by 1 week postinjury or persistent if not. Logistic regression adjusted for age, sex, hemodynamics, and Injury Severity Score (ISS). Median age was 52 years, 88% were male, and median ISS was 27, with 56% transient fibrinolysis shutdown, 44% persistent fibrinolysis shutdown and 12% mortality. Median LY30 was 0.23% (interquartile range [IQR] 0% to 1.20%) at admission and 0.10% (IQR 0% to 2.05%) at 1 week. Transient shutdown more often occurred after head injury (p = 0.019); persistent shutdown was more often associated with penetrating injury (29% vs 9%; p = 0.020), lower LY30 at ICU admission (0.10% vs 1.15%; p fibrinolysis shutdown was associated with admission LY30 (odds ratio [OR] 0.05; 95% CI 0.01 to 0.34; p = 0.002) and transfusion of packed RBCs (OR 0.81; 95% CI 0.68 to 0.97; p = 0.021) and platelets (OR 2.81; 95% CI 1.16 to 6.84; p = 0.022); moreover, it was an independent predictor of mortality (OR 8.48; 95% CI 1.35 to 53.18; p = 0.022). Persistent fibrinolysis shutdown is associated with late mortality after trauma. A high index of suspicion should be maintained, especially in patients with penetrating injury, reduced LY30 on admission, and/or receiving blood product transfusion. Judicious use of tranexamic acid is advised in this cohort. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  19. MCR2S unstructured mesh capabilities for use in shutdown dose rate analysis

    Energy Technology Data Exchange (ETDEWEB)

    Eade, T., E-mail: Tim.Eade@ccfe.ac.uk; Stonell, D.; Turner, A.

    2015-11-15

    Highlights: • Advancements in shutdown dose rate calculations will be needed as fusion moves from experimental reactors to full scale demonstration reactors in order to ensure the safety of personnel. • The MCR2S shutdown dose rate tool has been modified to allow shutdown dose rates calculations using an unstructured mesh. • The unstructured mesh capability of MCR2S was used on three shutdown dose rate models, a simple sphere, the ITER computational benchmark and the DEMO computational benchmark. • The results showed a reasonable agreement between an unstructured mesh approach and the CSG approach and highlighted the need to carefully choose the unstructured mesh resolution. - Abstract: As nuclear fusion progresses towards a sustainable energy source and the power of tokamak devices increases, a greater understanding of the radiation fields will be required. As well as on-load radiation fields, off-load or shutdown radiation field are an important consideration for the safety and economic viability of a commercial fusion reactor. Previously codes such as MCR2S have been written in order to predict the shutdown dose rates within, and in regions surrounding, a fusion reactor. MCR2S utilises a constructive solid geometry (CSG) model and a superimposed structured mesh to calculate 3-D maps of the shutdown dose rate. A new approach to MCR2S calculations is proposed and implemented using a single unstructured mesh to replace both the CSG model and the superimposed structured mesh. This new MCR2S approach has been demonstrated on three models of increasing complexity. These models were: a sphere, the ITER computational shutdown dose rate benchmark and the DEMO computational shutdown dose rate benchmark. In each case the results were compared to MCR2S calculations performed using MCR2S with CSG geometry and a superimposed structured mesh. It was concluded that the results from the unstructured mesh implementation of MCR2S compared well to the CSG structured mesh

  20. Development of Abnormal Operating Strategies for Station Blackout in Shutdown Operating Mode in Pressurized Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Duk-Joo; Lee, Seung-Chan; Sung, Je-Joong; Ha, Sang-Jun [KHNP CRI, Daejeon (Korea, Republic of); Hwang, Su-Hyun [FNC Tech. Co., Yongin (Korea, Republic of)

    2016-10-15

    Loss of all AC power is classified as one of multiple failure accident by regulatory guide of Korean accident management program. Therefore we need develop strategies for the abnormal operating procedure both of power operating and shutdown mode. This paper developed abnormal operating guideline for loss of all AC power by analysis of accident scenario in pressurized water reactor. This paper analyzed the loss of ultimate heat sink (LOUHS) in shutdown operating mode and developed the operating strategy of the abnormal procedure. Also we performed the analysis of limiting scenarios that operator actions are not taken in shutdown LOUHS. Therefore, we verified the plant behavior and decided operator action to taken in time in order to protect the fuel of core with safety. From the analysis results of LOUHS, the fuel of core maintained without core uncovery for 73 minutes respectively for opened RCS states after the SBO occurred. Therefore, operator action for the emergency are required to take in 73 minutes for opened RCS state. Strategy is to cooldown by using spent fuel pool cooling system. This method required to change the plant design in some plant. In RCS boundary closed state, first abnormal operating strategy in shutdown LOUHS is first abnormal operating strategy in shutdown LOUHS is to remove the residual heat of core by steam dump flow and auxiliary feedwater of SG.

  1. Effect of water chemistry upsets on the dynamics of corrective reagent dosing systems at thermal power stations

    Science.gov (United States)

    Voronov, V. N.; Yegoshina, O. V.; Bolshakova, N. A.; Yarovoi, V. O.; Latt, Aie Min

    2016-12-01

    Typical disturbances in the dynamics of a corrective reagent dosing system under unsteady-state conditions during the unsatisfactory operation of a chemical control system with some water chemistry upsets at thermal and nuclear power stations are considered. An experimental setup representing a physical model for the water chemistry control system is described. The two disturbances, which are most frequently encountered in water chemistry control practice, such as a breakdown or shutdown of temperature compensation during pH measurement and an increase in the heat-transfer fluid flow rate, have been modeled in the process of study. The study of the effect produced by the response characteristics of chemical control analyzers on the operation of a reagent dosing system under unsteady-state conditions is important for the operative control of a water chemistry regime state. The effect of temperature compensation during pH measurement on the dynamics of an ammonia-dosing system in the manual and automatic cycle chemistry control modes has been studied. It has been demonstrated that the reading settling time of a pH meter in the manual ammonia- dosing mode grows with a breakdown in temperature compensation and a simultaneous increase in the temperature of a heat-transfer fluid sample. To improve the efficiency of water chemistry control, some systems for the quality control of a heat-transfer fluid by a chemical parameter with the obligatory compensation of a disturbance in its flow rate have been proposed for use. Experimental results will possibly differ from industrial data due to a great length of sampling lines. For this reason, corrective reagent dosing systems must be adapted to the conditions of a certain power-generating unit in the process of their implementation.

  2. Shutdown dose rate assessment with the Advanced D1S method: Development, applications and validation

    Energy Technology Data Exchange (ETDEWEB)

    Villari, R., E-mail: rosaria.villari@enea.it [Associazione EURATOM-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Rome (Italy); Fischer, U. [Karlsruhe Institute of Technology KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Moro, F. [Associazione EURATOM-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Rome (Italy); Pereslavtsev, P. [Karlsruhe Institute of Technology KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Petrizzi, L. [European Commission, DG Research and Innovation K5, CDMA 00/030, B-1049 Brussels (Belgium); Podda, S. [Associazione EURATOM-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Rome (Italy); Serikov, A. [Karlsruhe Institute of Technology KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-10-15

    Highlights: Development of Advanced-D1S for shutdown dose rate calculations; Recent applications of the tool to tokamaks; Summary of the results of benchmarking with measurements and R2S calculations; Limitations and further development. Abstract: The present paper addresses the recent developments and applications of Advanced-D1S to the calculations of shutdown dose rate in tokamak devices. Results of benchmarking with measurements and Rigorous 2-Step (R2S) calculations are summarized and discussed as well as limitations and further developments. The outcomes confirm the essential role of the Advanced-D1S methodology and the evidence for its complementary use with the R2Smesh approach for the reliable assessment of shutdown dose rates and related statistical uncertainties in present and future fusion devices.

  3. Dynamic Analysis of a Floating Vertical Axis Wind Turbine Under Emergency Shutdown Using Hydrodynamic Brake

    DEFF Research Database (Denmark)

    Wang, K.; Hansen, Martin Otto Laver; Moan, T.

    2014-01-01

    Emergency shutdown is always a challenge for an operating vertical axis wind turbine. A 5-MW vertical axis wind turbine with a Darrieus rotor mounted on a semi-submersible support structure was examined in this study. Coupled non-linear aero-hydro-servo-elastic simulations of the floating vertical...... axis wind turbine were carried out for emergency shutdown cases over a range of environmental conditions based on correlated wind and wave data. When generator failure happens, a brake should be applied to stop the acceleration of the rotor to prevent the rotor from overspeeding and subsequent disaster...... the hydrodynamic brake and mechanical brake was also investigated. The application of the hydrodynamic brake is expected to be efficient for rotor shutdown and for reducing the platform motions and structural loads....

  4. Production test-105-55-P -- Reactivity of the B Pile under shutdown conditions. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Menegus, R.L.

    1946-07-26

    At the shutdown of the B Pile, 269 active tubes were discharged and ten poison columns were charged. As a result, the pile was let considerably below critical. The present test described in this report was set up to develop methods of detecting possible changes in reactivity by periodic measurements of neutron flux in the shutdown pile. The irradiation of indium foils in an empty process tube was found to provide a satisfactory method of monitoring the shutdown pile, and was sensitive than the proportional counter with was also tried. The accuracy with which the subcritical condition can be determined is roughly 20%. The uncertainty is due mostly to the irregular arrangement of metal and poison in the unit and the resulting difficulty in representing the neutron flux mathematically.

  5. Chemistry Dashboard

    Science.gov (United States)

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

  6. Experiments in physical chemistry

    CERN Document Server

    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

  7. Combinatorial chemistry

    DEFF Research Database (Denmark)

    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....

  8. TRACG-CFD analysis of ESBWR reactor water cleanup shutdown cooling system mixing coefficient

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, J. [UNAM, Facultad de Ingenieria, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Marquino, W.; Mistreanu, A.; Yang, J., E-mail: euqrop@hotmail.com [General Electric Hitachi Nuclear Energy, Wilmington, 28401 North Carolina (United States)

    2015-09-15

    The ESBWR is a 1520 nominal [M We] Generation III+ natural circulation boiling water reactor designed to high levels of safety utilizing features that have been successfully used before in operating BWRs, as well as standard features common to A BWR. In September of 2014, the US NRC has certified the ESBWR design for use in the USA. The RWCU/Sdc is an auxiliary system for the ESBWR nuclear island. Basic functions it performs include purifying the reactor coolant during normal operation and shutdown and providing shutdown cooling and cooldown to cold shutdown conditions. The performance of the RWCU system during shutdown cooling is directly related to the temperature of the water removed through the outlets, which is coupled with the vessel and F W temperatures through a thermal mixing coefficient. The complex three-dimensional (3-D) geometry of the BWR downcomer and lower plenum has a great impact on the flow mixing. Only a fine mesh technique like CFD can predict the 3-D temperature distribution in the RPV during shutdown and provide the RWCU/Sdc system inlet temperature. Plant shutdown is an unsteady event by nature and was modeled as a succession of CFD steady-state simulations. It is required to establish the mixing coefficient (which is a function of the heat balance and the core flow) during the operation of the RWCU system in the multiple shutdown cooling modes, and therefore a range of core flows needs to be estimated using quasi steady states obtained with TRACG. The lower end of that range is obtained from a system with minimal power decay heat and core flow; while the higher end corresponds to the power at the beginning of RWCU/Sdc operation when the cooldown is transferred to the RWCU/Sdc after the initial depressurization via the turbine bypass valves. Because the ESBWR RWCU/Sdc return and suction designs provide good mixing, the uniform mixing energy balance was found to be an adequate alternative for deriving the mixing coefficient. The CFD mass flow

  9. Commissioning of the Machine Protection Systems of the Large Hadron Collider Following its First Long Shutdown

    OpenAIRE

    Wollmann, Daniel; Schmidt, Ruediger; Uythoven, Jan; Wenninger, Jorg; Zerlauth, Markus

    2016-01-01

    During the first long shutdown of the Large Hadron Collider (LHC) extending for more than 18 months, most Machine Protection Systems (MPS) have undergone significant changes, and upgrades. A full re-commissioning of the MPS was performed at the end of the shutdown and during the LHC beam commissioning in 2015. To verify the correct functioning of all protection-relevant systems with beam, a step-wise intensity ramp-up was performed, reaching at the end of 2015 a record stored beam energy of ~...

  10. Combustion stability analysis of preburners in liquid propellant rocket engines during shutdown

    Science.gov (United States)

    Lim, Kair-Chuan; George, Paul E., II

    1987-01-01

    A linearized one-dimensional lumped-parameter model capable of predicting the occurrence of the low frequency combustion instability (chugging) experienced during preburner shutdown in the Space Shuttle Main Engines is discussed, and predictions are compared with NASA experimental results. Results from a parametric study of parameters including chamber pressure, fuel and oxygen temperatures, and the effective bulk modulus of the liquid oxidizer suggest that chugging is probably affected by conditions at shutdown through the fuel and oxidizer temperatures. It is suggested that chugging is initiated when the fuel, oxidizer, and helium temperature and flow rates pass into an unstable region, and that chugging may be terminated by decaying pressures.

  11. Extending students' practice of metacognitive regulation strategies in the undergraduate chemistry laboratory and investigation of Pb2+ binding to calmodulin with circular dichroism and molecular dynamics modeling

    Science.gov (United States)

    Valencia Navarro, Laura N.

    The following dissertation was composed of two projects in chemistry education and benchwork/computational biochemistry. The chemistry education research explored students' practice of metacognitive strategies while solving open-ended laboratory problems when engaged in an instructional environment, the Science Writing Heuristic (SWH), that was characterized as supporting metacognitive regulation strategy use. Through in-depth interviews with students, results demonstrated that students in the SWH environment, compared to non-SWH students, used metacognitive strategies to a greater degree and to a greater depth when solving open-ended laboratory problems. As students engaged in higher levels of metacognitive regulation, their elective use of peers became a prominent path for supporting the practice of metacognitive strategies. Students claimed that the structure of the SWH weekly laboratory experiments improved their ability to solve open-ended lab problems. This research not only provided a lens into students' descriptions of their regulation strategy practices in the laboratory, but it also supported that the way that a laboratory environment is arranged can affect these regulation strategy practices and their transfer to new situations. In the biochemical study on the binding of Pb2+ to calmodulin (CaM), data was acquired via circular dichroism (CD) and molecular dynamics modeling. CD signal data indicated a unique signal from Pb-CaM and a significantly smaller ratio theta208/theta222 for Pb-CaM than Ca-CaM. An analysis of secondary structure content indicated that alpha-helical structure decreased and random coil structure increased when CaM was saturated with Pb2+ compared to Ca2+ saturated CaM. A molecular dynamics simulation of Pb2+ binding to CaM showed that Pb2+ ions bound to sites outside of the known canonical binding sites including the linker region, and indicated change in secondary structure. These results support the theory of opportunistic binding

  12. Teachers' Practices in High School Chemistry Just Prior to the Adoption of the Next Generation Science Standards

    Science.gov (United States)

    Boesdorfer, Sarah B.; Staude, Kristin D.

    2016-01-01

    Effective professional development that influences teachers' classroom practices starts with what teachers know, understand, and do in their classroom. The Next Generation Science Standards (NGSS) challenge teachers to make changes to their classroom; to help teachers make these changes, it is necessary to know what they are doing in their…

  13. Estimation of shutdown heat generation rates in GHARR-1 due to ...

    African Journals Online (AJOL)

    Fission products decay power and residual fission power generated after shutdown of Ghana Research Reactor-1 (GHARR-1) by reactivity insertion accident were estimated by solution of the decay and residual heat equations. A Matlab program code was developed to simulate the heat generation rates by fission product ...

  14. Risk contribution from low power, shutdown, and other operational modes beyond full power

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, D.W.; Brown, T.D. [Sandia National Labs., Albuquerque, NM (United States); Chu, T.L.; Pratt, W.T. [Brookhaven National Lab., Upton, NY (United States); Robinson, R.C. Jr.

    1994-10-01

    During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected for study. The program consisted of two parallel projects performed by Brookhaven National Laboratory (Surry) and Sandia National Laboratories (Grand Gulf).

  15. 78 FR 49553 - Three Mile Island, Unit 2; Post Shutdown Decommissioning Activities Report

    Science.gov (United States)

    2013-08-14

    ...) for Three Mile Island, Unit 2 (TMI-2). The PSDAR provides an overview of GPUN's proposed... COMMISSION Three Mile Island, Unit 2; Post Shutdown Decommissioning Activities Report AGENCY: Nuclear... document. Mail comments to: Cindy Bladey, Chief, Rules, Announcements, and Directives Branch, Office of...

  16. 40 CFR 60.2120 - What happens during periods of startup, shutdown, and malfunction?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false What happens during periods of startup... 1, 2001 Emission Limitations and Operating Limits § 60.2120 What happens during periods of startup... during CISWI unit startups, shutdowns, or malfunctions. (b) Each malfunction must last no longer than 3...

  17. 78 FR 38001 - Reconsideration of Certain Startup/Shutdown Issues: National Emission Standards for Hazardous Air...

    Science.gov (United States)

    2013-06-25

    ..., FRL-9827-1] RIN 2060-AR62 Reconsideration of Certain Startup/Shutdown Issues: National Emission... published in the Federal Register the proposed rule, ``Reconsideration of Certain New Source and Startup....'' That proposal opened for reconsideration certain issues, including those related to startup and...

  18. 78 FR 38739 - Standard Format and Content for Post-Shutdown Decommissioning Activities Report

    Science.gov (United States)

    2013-06-27

    ..., DG-1272, in the Federal Register on December 19, 2012 (77 FR 75198), for a 60-day public comment... COMMISSION Standard Format and Content for Post-Shutdown Decommissioning Activities Report AGENCY: Nuclear... (NRC) is issuing Revision 1 of Regulatory Guide (RG) 1.185, ``Standard Format and Content for Post...

  19. Chemistry Technology

    Data.gov (United States)

    Federal Laboratory Consortium — Chemistry technology experts at NCATS engage in a variety of innovative translational research activities, including:Design of bioactive small molecules.Development...

  20. Mathematics for physical chemistry

    CERN Document Server

    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 ...

  1. Current organic chemistry

    National Research Council Canada - National Science Library

    1997-01-01

    Provides in depth reviews on current progress in the fields of asymmetric synthesis, organometallic chemistry, bioorganic chemistry, heterocyclic chemistry, natural product chemistry, and analytical...

  2. Evaluation of induced activity, decay heat and dose rate distribution after shutdown in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Maki, Koichi [Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.; Satoh, Satoshi; Hayashi, Katsumi; Yamada, Koubun; Takatsu, Hideyuki; Iida, Hiromasa

    1997-03-01

    Induced activity, decay heat and dose rate distributions after shutdown were estimated for 1MWa/m{sup 2} operation in ITER. The activity in the inboard blanket one day after shutdown is 1.5x10{sup 11}Bq/cm{sup 3}, and the average decay heating rate 0.01w/cm{sup 3}. The dose rate outside the 120cm thick concrete biological shield is two order higher than the design criterion of 5{mu}Sv/h. This indicates that the biological shield thickness should be enhanced by 50cm in concrete, that is, total thickness 170cm for workers to enter the reactor room and to perform maintenance. (author)

  3. Shutdown Dose Rate Analysis for the long-pulse D-D Operation Phase in KSTAR

    Directory of Open Access Journals (Sweden)

    Park Jin Hun

    2017-01-01

    Full Text Available KSTAR is a medium size fully superconducting tokamak. The deuterium-deuterium (D-D reaction in the KSTAR tokamak generates neutrons with a peak yield of 3.5x1016 per second through a pulse operation of 100 seconds. The effect of neutron generation from full D-D high power KSTAR operation mode to the machine, such as activation, shutdown dose rate, and nuclear heating, are estimated for an assurance of safety during operation, maintenance, and machine upgrade. The nuclear heating of the in-vessel components, and neutron activation of the surrounding materials have been investigated. The dose rates during operation and after shutdown of KSTAR have been calculated by a 3D CAD model of KSTAR with the Monte Carlo code MCNP5 (neutron flux and decay photon, the inventory code FISPACT (activation and decay photon and the FENDL 2.1 nuclear data library.

  4. Shutdown characteristics of the Mod-O wind turbine with aileron controls

    Science.gov (United States)

    Miller, D. R.; Corrigan, R. D.

    1984-01-01

    Horizontal-axis wind turbines utilize partial or full variable blade pitch to regulate rotor speed. The weight and costs of these systems indicated a need for alternate methods of rotor control. Aileron control is an alternative which has potential to meet this need. The NASA Lewis Research Center has been experimentally testing aileron control rotors on the Mod-U wind turbine to determine their power regulation and shutdown characteristics. Experimental and analytical shutdown test results are presented for a 38 percent chord aileron-control rotor. These results indicated that the 38 percent chord ailerons provided overspeed protection over the entire Mod-O operational windspeed range, and had a no-load equilibrium tip speed ratio of 1.9. Thus, the 38 percent chord ailerons had much improved aerodynamic braking capability when compared with the first aileron-control rotor having 20 percent chord ailerons.

  5. Shutdown-functionalized nonwoven separator with improved thermal and electrochemical properties for lithium-ion batteries

    Science.gov (United States)

    Kim, Youngkwon; Lee, Won-Yeol; Kim, Ki Jae; Yu, Ji-Sang; Kim, Young-Jun

    2016-02-01

    A shutdown-functionalized nonwoven separator (SFNS) with improved thermal and electrochemical stabilities is prepared by a simple dip coating method for use in lithium-ion battery (LiB) applications. The SFNS shows thermal stability at 200 °C, while providing shutdown functionality at approximately 140 °C, similar to commercial porous polyethylene separators. The surface-coated polymer prevents leakage current problems and in addition, shows air permeability values similar to that of bare nonwoven separators, while maintaining a thickness of about 20 μm, which is a desired attribute of effective separators for LiBs. The SFNS also shows increased electrolyte uptake and higher conductivity, compared to a bare polyethylene separator. Therefore, a cell with the SFNS exhibits higher discharge capacity and better cycle property than that with a porous polyethylene separator. These results suggest that SFNS is an effective separator for high-performance LiBs.

  6. CERN Vacuum-System Activities during the Long Shutdown 1: The LHC’s Injector Chain

    CERN Document Server

    Ferreira, J A

    2014-01-01

    During the long shutdown 1 (LS1), several maintenance, consolidation and upgrade activities have been carried out in LHC’s injector chain. Each machine has specific vacuum requirements and different history, which determine the present status of the vacuum components, their maintenance and consolidation needs. The present work presents the priorities agreed at the beginning of the LS1 period and their implementation. Of particular relevance are the interventions in radioactive controlled areas where several leaks due to stress corrosions stopped the operations in the past years. The strategy to reduce the collective dose is presented, in particular the use of remote controlled robots. An important part of the work performed during this period involves supporting other teams (acceptance tests, new equipment installation, etc.). Finally, as a result of the LS1 experience, a medium to long term strategy is depicted, focusing on the preparation of the next shutdown (LS2) and the integration of LINAC4 in the in...

  7. Containment closure time following loss of cooling under shutdown conditions of YGN units 3 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Seul, Kwang Won; Bang, Young Seok; Kim, Se Won; Kim, Hho Jung [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1998-12-31

    The YGN Units 3 and 4 plant conditions during shutdown operation were reviewed to identify the possible event scenarios following the loss of shutdown cooling. The thermal hydraulic analyses were performed for the five cases of RCS configurations under the worst event scenario, unavailable secondary cooling and no RCS inventory makeup, using the RELAP5/MOD3.2 code to investigate the plant behavior. From the analyses results, times to boil, times to core uncovery and times to core heat up were estimated to determine the containment closure time to prevent the uncontrolled release of fission products to atmosphere. These data provide useful information to the abnormal procedure to cope with the event. 6 refs., 7 figs., 2 tabs. (Author)

  8. Uncertainty evaluation of reliability of shutdown system of a medium size fast breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Zeliang, Chireuding; Singh, Om Pal, E-mail: singhop@iitk.ac.in; Munshi, Prabhat

    2016-11-15

    Highlights: • Uncertainty analysis of reliability of Shutdown System is carried out. • Monte Carlo method of sampling is used. • The effect of various reliability improvement measures of SDS are accounted. - Abstract: In this paper, results are presented on the uncertainty evaluation of the reliability of Shutdown System (SDS) of a Medium Size Fast Breeder Reactor (MSFBR). The reliability analysis results are of Kumar et al. (2005). The failure rate of the components of SDS are taken from International literature and it is assumed that these follow log-normal distribution. Fault tree method is employed to propagate the uncertainty in failure rate from components level to shutdown system level. The beta factor model is used to account different extent of diversity. The Monte Carlo sampling technique is used for the analysis. The results of uncertainty analysis are presented in terms of the probability density function, cumulative distribution function, mean, variance, percentile values, confidence intervals, etc. It is observed that the spread in the probability distribution of SDS failure rate is less than SDS components failure rate and ninety percent values of the failure rate of SDS falls below the target value. As generic values of failure rates are used, sensitivity analysis is performed with respect to failure rate of control and safety rods and beta factor. It is discovered that a large increase in failure rate of SDS rods is not carried to SDS system failure proportionately. The failure rate of SDS is very sensitive to the beta factor of common cause failure between the two systems of SDS. The results of the study provide insight in the propagation of uncertainty in the failure rate of SDS components to failure rate of shutdown system.

  9. Hangout with CERN: LHC, why the shutdown? (S02E06)

    CERN Multimedia

    Kahle, Kate

    2013-01-01

    The Large Hadron Collider has now entered its first long shutdown. But why? Why stop a machine that is working so well?CMS experiment physicist Seth Zenz is joined by head of LHC Operations, Mike Lamont, as well as CMS physicist Freya Blekman and ATLAS physicist Steven Goldfarb, with questions from Anne-Sophie Dirand from France and social media.Recorded live on 28th February 2013.

  10. An Approach to Increase Energy Efficiency Using Shutdown and Standby Machine Modes

    OpenAIRE

    Fysikopoulos, Apostolos; Pastras, Georgios; Vlachou, Aikaterini; Chryssolouris, George

    2014-01-01

    Part 1: Knowledge-Based Sustainability; International audience; Energy efficiency constitutes a very significant factor that requires its inclusion in the manufacturing decision making attributes developing a strategy to produce more with less. The idle state of a machine tool is an inefficient phase. A strategy to increase the energy efficiency of an already balanced production line, using machine tool stand-by or shut-down modes, during the idle phase, is being introduced. This strategy ide...

  11. Quantum chemistry

    CERN Document Server

    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,

  12. PCDD/F emissions during startup and shutdown of a hazardous waste incinerator.

    Science.gov (United States)

    Li, Min; Wang, Chao; Cen, Kefa; Ni, Mingjiang; Li, Xiaodong

    2017-08-01

    Compared with municipal solid waste incineration, studies on the PCDD/F emissions of hazardous waste incineration (HWI) under transient conditions are rather few. This study investigates the PCDD/F emission level, congener profile and removal efficiency recorded during startup and shutdown by collecting flue gas samples at the bag filter inlet and outlet and at the stack. The PCDD/F concentration measured in the stack gas during startup and shutdown were 0.56-4.16 ng I-TEQ Nm(-3) and 1.09-3.36 ng I-TEQ Nm(-3), respectively, far exceeding the present codes in China. The total amount of PCDD/F emissions, resulting from three shutdown-startup cycles of this HWI-unit is almost equal to that generated during one year under normal operating conditions. Upstream the filter, the PCDD/F in the flue gas is mainly in the particle phase; however, after being filtered PCDD/F prevails in the gas phase. The PCDD/F fraction in the gas phase even exceeds 98% after passing through the alkaline scrubber. Especially higher chlorinated PCDD/F accumulate on inner walls of filters and ducts during these startup periods and could be released again during normal operation, significantly increasing PCDD/F emissions. Copyright © 2017. Published by Elsevier Ltd.

  13. Outcomes of an international initiative for harmonization of low power and shutdown probabilistic safety assessment

    Directory of Open Access Journals (Sweden)

    Manna Giustino

    2010-01-01

    Full Text Available Many probabilistic safety assessment studies completed to the date have demonstrated that the risk dealing with low power and shutdown operation of nuclear power plants is often comparable with the risk of at-power operation, and the main contributors to the low power and shutdown risk often deal with human factors. Since the beginning of the nuclear power generation, human performance has been a very important factor in all phases of the plant lifecycle: design, commissioning, operation, maintenance, surveillance, modification, decommissioning and dismantling. The importance of this aspect has been confirmed by recent operating experience. This paper provides the insights and conclusions of a workshop organized in 2007 by the IAEA and the Joint Research Centre of the European Commission, on Harmonization of low power and shutdown probabilistic safety assessment for WWER nuclear power plants. The major objective of the workshop was to provide a comparison of the approaches and the results of human reliability analyses and gain insights in the enhanced handling of human factors.

  14. Upgrades of the ALICE TPC Front-End Electronics for Long Shutdown 1 and 2

    CERN Document Server

    Velure, Arild

    2015-01-01

    This paper presents the front-end electronics upgrades of the ALICE Time Projection Chamber detector for the coming years, with a focus on the upgrades for Long Shutdown 2. The Large Hadron Collider is currently in Long Shutdown 1 following a successful first run, and upgrades of the detectors are underway to support the higher particle interaction rates planned for the next run. For the Time Projection Chamber, the increase in data due to the higher interaction rate and higher energy will cause a bottleneck in the Readout Control Unit and a new board is in development which increases the data-link speed to the back-end. Another more general upgrade of the ALICE experiment is planned for Long Shutdown 2, foreseen to start in 2018. In this case the goal is to cope with an even higher interaction rate of 50 kHz for Pb-Pb collisions. The present Multi Wire Proportional Chambers of the Time Projection Chamber will then be replaced by Gas Electron Multiplier technology. At the same time, the front-end electronics ...

  15. Shutdown margin for high conversion BWRs operating in Th-{sup 233}U fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Shaposhnik, Y., E-mail: shaposhy@bgu.ac.il [NRCN – Nuclear Research Center Negev, POB 9001, Beer Sheva 84190 (Israel); Department of Nuclear Engineering, Ben-Gurion University of the Negev, POB 653, Beer Sheva 84105 (Israel); Shwageraus, E. [Department of Nuclear Engineering, Ben-Gurion University of the Negev, POB 653, Beer Sheva 84105 (Israel); Elias, E. [Faculty of Mechanical Engineering, Technion – Israel Institute of Technology, Technion City 32000, Haifa (Israel)

    2014-09-15

    Highlights: • BWR core operating in a closed self-sustainable Th-{sup 233}U fuel cycle. • Shutdown Margin in Th-RBWR design. • Fully coupled MC with fuel depletion and thermo-hydraulic feedback modules. • Thermal–hydraulic analysis includes MCPR observation. - Abstract: Several reactivity control system design options are explored in order to satisfy shutdown margin (SDM) requirements in a high conversion BWRs operating in Th-{sup 233}U fuel cycle (Th-RBWR). The studied core has an axially heterogeneous fuel assembly structure with a single fissile zone “sandwiched” between two fertile blanket zones. The utilization of an originally suggested RBWR Y-shape control rod in Th-RBWR is shown to be insufficient for maintaining adequate SDM to balance the high negative reactivity feedbacks, while maintaining fuel breeding potential, core power rating, and minimum Critical Power Ratio (CPR). Implementation of alternative reactivity control materials, reducing axial leakage through non-uniform enrichment distribution, use of burnable poisons, reducing number of pins as well as increasing pin diameter are also shown to be incapable of meeting the SDM requirements. Instead, an alternative assembly design, based on Rod Cluster Control Assembly with absorber rods was investigated. This design matches the reference ABWR core power and has adequate shutdown margin. The new concept was modeled as a single three-dimensional fuel assembly having reflective radial boundaries, using the BGCore system, which consists of the MCNP code coupled with fuel depletion and thermo-hydraulic feedback modules.

  16. Shutdown and low-power operation at commercial nuclear power plants in the United States. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    The report contains the results of the NRC Staff`s evaluation of shutdown and low-power operations at US commercial nuclear power plants. The report describes studies conducted by the staff in the following areas: Operating experience related to shutdown and low-power operations, probabilistic risk assessment of shutdown and low-power conditions and utility programs for planning and conducting activities during periods the plant is shut down. The report also documents evaluations of a number of technical issues regarding shutdown and low-power operations performed by the staff, including the principal findings and conclusions. Potential new regulatory requirements are discussed, as well as potential changes in NRC programs. A draft report was issued for comment in February 1992. This report is the final version and includes the responses to the comments along with the staff regulatory analysis of potential new requirements.

  17. Type and timing of childhood maltreatment and severity of shutdown dissociation in patients with schizophrenia spectrum disorder

    National Research Council Canada - National Science Library

    Schalinski, Inga; Teicher, Martin H

    2015-01-01

    .... Vulnerability to ongoing shutdown dissociation was assessed in 75 inpatients (46 M/29 F, M = 31 ± 10 years old) with schizophrenia spectrum disorder and related to number of traumatic events experienced or witnessed during childhood or adulthood...

  18. Nuclear Chemistry.

    Science.gov (United States)

    Chemical and Engineering News, 1979

    1979-01-01

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

  19. Green Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Podcasts in the Chemistry Teaching

    Directory of Open Access Journals (Sweden)

    Bruno Silva Leite

    2016-12-01

    Full Text Available Information and Communication Technologies (ICT provide facilities in teaching through education. There are many new tools and methodologies that use ICT as a knowledge-building support, but that are not always related to pedagogical practice. The Podcast is an important technology that can be used in the classroom. Using this tool, it can make the most interactive chemistry class, fleeing the classroom routine. However, it is necessary to point out that the podcast is just one feature that should be incorporated into education and not a substitute. This paper describes the development of Chemistry Podcasts by teachers and chemistry students in three disciplines in 2015. This study took place over a one-year period in a public University, in Pernambuco, Brazil. In the discipline of "Computer applied to the teaching of chemistry" participated 21 Chemistry teachers. In the disciplines of "Information and Communication Technologies in the teaching of chemistry" and "Informatics, Chemistry and Education" was composed of 54 undergraduate students in chemistry. Twelve podcasts were elaborated by students and five by teachers in this paper we present only nine. The results showed the contribution of podcasts produced by teachers and students in teaching and learning process chemistry. DOI: http://dx.doi.org/10.17807/orbital.v0i0.898

  1. Home Manufacture of Drugs: An Online Investigation and a Toxicological Reality Check of Online Discussions on Drug Chemistry.

    Science.gov (United States)

    Hearne, Evelyn; Alves, Emanuele Amorim; Van Hout, Marie Claire; Grund, Jean-Paul C

    2017-01-01

    Emerging trends in market dynamics and the use of new psychoactive substances are both a public health concern and a complex regulatory issue. One novel area of investigation is the availability of homemade opioids, amphetamines and dissociatives, and the potential fueling of interest in clandestine home manufacture of drugs via the Internet. We illustrate here how online communal folk pharmacology of homemade drugs on drug website forums may actually inform home manufacture practices or contribute to the reduction of harms associated with this practice. Discrepancies between online information around purification and making homemade drugs safer, and the synthesis of the same substances in a proper laboratory environment, exist. Moderation and shutdown of synthesis queries and discussions online are grounded in drug websites adhering to harm-reduction principles by facilitating discussions around purification of homemade drugs only. Drug discussion forums should consider reevaluating their policies on chemistry discussions in aiming to reach people who cannot or will not refrain from cooking their own drugs with credible information that may contribute to reductions in the harms associated with this practice.

  2. Radiation Chemistry

    Science.gov (United States)

    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.

  3. Polymer Chemistry

    Science.gov (United States)

    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.

  4. Organic Chemistry in Action! What Is the Reaction?

    Science.gov (United States)

    O'Dwyer, Anne; Childs, Peter

    2015-01-01

    The "Organic Chemistry in Action!" ("OCIA!") program is a set of teaching resources designed to facilitate the teaching and learning of introductory level organic chemistry. The "OCIA!" program was developed in collaboration with practicing and experienced chemistry teachers, using findings from Chemistry Education…

  5. “bologna declaration” pronouncement for africa's chemistry

    African Journals Online (AJOL)

    Temechegn

    Who said all the topics (theory and practical component) comprising the current inorganic chemistry 2 & 3 or organic chemistry 2 & 3, for example, cannot be studied or treated in full over the two semesters in a single year? The same question applies for physical chemistry 2 & 3 and analytical chemistry. 2 & 3 in another year ...

  6. Shutdown potential adjustment of modified carbene adducts as additives for lithium ion battery electrolytes

    Science.gov (United States)

    Janssen, Pia; Streipert, Benjamin; Krafft, Roman; Murmann, Patrick; Wagner, Ralf; Lewis-Alleyne, Lesley; Röschenthaler, Gerd-Volker; Winter, Martin; Cekic-Laskovic, Isidora

    2017-11-01

    To improve the intrinsic safety of lithium ion batteries (LIBs) by preventing cells from a thermal runaway, we studied two carbene adduct electrolyte additives. The recently synthesized compounds (1,3-dimethylimidazolidin-2-μm-trifluoroborate (NHC-BF3) and 1,3-dimethylimidazolidin-2-μm-tetrafluorotrifluoromethylphosphate (NHC-PF4CF3)) were investigated on LiNi1/3Co1/3Mn1/3O2 (NMC111) electrodes in Li metal and Li-ion cell setups as overcharge protection shutdown additives in 1M LiPF6 in EC:DEC (3:7, by wt.) electrolyte. By varying the NHC-ligand (-BF3, -PF5, -PF4CF3) in the molecule, the shutdown potential of the investigated carbene adduct electrolyte additives can be tailored for specific applications with different cut-off potentials. NHC-BF3 was identified as a promising candidate for the application with NMC111 electrodes up to 4.4 V vs. Li/Li+, whereas the carbene adduct NHC-PF4CF3 is ideal for the high-voltage application with the NMC-based electrode up to 4.6 V vs. Li/Li+. Next to electrochemical investigations in NMC111/Li and NMC111/graphite cells, Atomic Force Microscopy (AFM) and X-Ray Photoelectron Spectroscopy (XPS) were performed to verify the presence of a decomposition layer on the cathode, responsible for the shutdown effect. Furthermore, it has been proven that the investigated electrolyte additives have no influence on the cell performance under normal conditions in both, Li metal and Li-ion cell setups.

  7. Fibrinolysis shutdown phenotype masks changes in rodent coagulation in tissue injury versus hemorrhagic shock.

    Science.gov (United States)

    Moore, Hunter B; Moore, Ernest E; Lawson, Peter J; Gonzalez, Eduardo; Fragoso, Miguel; Morton, Alex P; Gamboni, Fabia; Chapman, Michael P; Sauaia, Angela; Banerjee, Anirban; Silliman, Christopher C

    2015-08-01

    Systemic hyperfibrinolysis (accelerated clot degradation) and fibrinolysis shutdown (impaired clot degradation) are associated with increased mortality compared with physiologic fibrinolysis after trauma. Animal models have not reproduced these changes. We hypothesize rodents have a shutdown phenotype that require an exogenous profibrinolytic to differentiate mechanisms that promote or inhibit fibrinolysis. Fibrinolysis resistance was assessed by thrombelastography (TEG) using exogenous tissue plasminogen activator (tPA) titrations in whole blood. There were 3 experimental groups: (1) tissue injury (laparotomy/bowel crush), (2) shock (hemorrhage to mean arterial pressure of 20 mmHg), and (3) control (arterial cannulation and tracheostomy). Baseline and 30-minute postintervention blood samples were collected, and assayed with TEG challenged with taurocholic acid (TUCA). Rats were resistant to exogenous tPA; the percent clot remaining 30 minutes after maximum amplitude (CL30) at 150 ng/mL (P = .511) and 300 ng/mL (P = .931) was similar to baseline, whereas 600 ng/mL (P = .046) provoked fibrinolysis. Using the TUCA challenge, the percent change in CL30 from baseline was increased in tissue injury compared with control (P = .048.), whereas CL30 decreased in shock versus control (P = .048). tPA increased in the shock group compared with tissue injury (P = .009) and control (P = .012). Rats have an innate fibrinolysis shutdown phenotype. The TEG TUCA challenge is capable of differentiating changes in clot stability with rats undergoing different procedures. Tissue injury inhibits fibrinolysis, whereas shock promotes tPA-mediated fibrinolysis. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Benchmarking of Monte Carlo based shutdown dose rate calculations for applications to JET.

    Science.gov (United States)

    Petrizzi, L; Batistoni, P; Fischer, U; Loughlin, M; Pereslavtsev, P; Villari, R

    2005-01-01

    The calculation of dose rates after shutdown is an important issue for operating nuclear reactors. A validated computational tool is needed for reliable dose rate calculations. In fusion reactors neutrons induce high levels of radioactivity and presumably high doses. The complex geometries of the devices require the use of sophisticated geometry modelling and computational tools for transport calculations. Simple rule of thumb laws do not always apply well. Two computational procedures have been developed recently and applied to fusion machines. Comparisons between the two methods showed some inherent discrepancies when applied to calculation for the ITER while good agreement was found for a 14 MeV point source neutron benchmark experiment. Further benchmarks were considered necessary to investigate in more detail the reasons for the different results in different cases. In this frame the application to the Joint European Torus JET machine has been considered as a useful benchmark exercise. In a first calculational benchmark with a representative D-T irradiation history of JET the two methods differed by no more than 25%. In another, more realistic benchmark exercise, which is the subject of this paper, the real irradiation history of D-T and D-D campaigns conducted at JET in 1997-98 were used to calculate the shut-down doses at different locations, irradiation and decay times. Experimental dose data recorded at JET for the same conditions offer the possibility to check the prediction capability of the calculations and thus show the applicability (and the constraints) of the procedures and data to the rather complex shutdown dose rate analysis of real fusion devices. Calculation results obtained by the two methods are reported below, comparison with experimental results give discrepancies ranging between 2 and 10. The reasons of that can be ascribed to the high uncertainty on the experimental data and the unsatisfactory JET model used in the calculation. A new

  9. Food carbohydrate chemistry

    National Research Council Canada - National Science Library

    Wrolstad, R. E

    2012-01-01

    .... Now in Food Carbohydrate Chemistry, author Wrolstad emphasizes the application of carbohydrate chemistry to understanding the chemistry, physical and functional properties of food carbohydrates...

  10. Small-scale chemistry for a hands-on approach to chemistry ...

    African Journals Online (AJOL)

    The purpose of this study was to investigate the possibility of using a small-scale chemistry (SSC) approach as a means of performing chemistry practical activities in Ethiopian secondary schools. A total of eight experiments from two topics, electrolysis and rate of reaction, in the Ethiopian grade 11 chemistry syllabus were ...

  11. Analytical Chemistry in Russia.

    Science.gov (United States)

    Zolotov, Yuri

    2016-09-06

    Research in Russian analytical chemistry (AC) is carried out on a significant scale, and the analytical service solves practical tasks of geological survey, environmental protection, medicine, industry, agriculture, etc. The education system trains highly skilled professionals in AC. The development and especially manufacturing of analytical instruments should be improved; in spite of this, there are several good domestic instruments and other satisfy some requirements. Russian AC has rather good historical roots.

  12. Summary of Beam Vacuum Activities Held during the LHC 2008-2009 Shutdown

    CERN Document Server

    Bregliozzi, Giuseppe; Jimenez, Jose

    2010-01-01

    At the start of the CERN Large Hadron Collider (LHC) 2008-2009 shutdown, all the LHC experimental vacuum chambers were vented to neon atmosphere. They were later pumped down shortly before beam circulation. Meanwhile, 2.3 km of vacuum beam pipes with NEG coatings were vented to air to allow the installation or repair of several components such as roman pot, magnets kicker, collimators, rupture disks and masks and reactivated thereafter. Beside these standard operations, “fast exchanges” of vacuum components and endoscopies inside cryogenic beam vacuum chambers were performed. This paper presents a summary of all the beam vacuum activities held during this period and the achieved vacuum performances

  13. Human Neutrophil Elastase Mediates Fibrinolysis Shutdown Through Competitive Degradation of Plasminogen and Generation of Angiostatin.

    Science.gov (United States)

    Barrett, Christopher D; Moore, Hunter B; Banerjee, Anirban; Silliman, Christopher C; Moore, Ernest E; Yaffe, Michael B

    2017-08-23

    A subset of trauma patients undergo fibrinolysis shutdown rather than pathologic hyperfibrinolysis, contributing to organ failure. The molecular basis for fibrinolysis shutdown in trauma is incompletely understood. Elastase released from primed/activated human neutrophils (HNE) has historically been described as fibrin(ogen)olytic. However, HNE can also degrade plasminogen (PLG) to angiostatin (ANG), retaining the Kringle domains but not the proteolytic function, and could thereby compete for generation of active plasmin by tPA. We hypothesized that HNE can drive fibrinolysis shutdown rather than fibrinolysis. Turbidometry was performed using light scatter (λ=620nm) in a purified fibrinogen + PLG system and in healthy citrate plasma clotted with Ca/thrombin -/+tPA, -/+HNE, and -/+ANG to evaluate HNE effects on fibrinolysis, quantified by time to transition midpoint (Tm). ΔTm from control is reported as percent of control ±95%CI. Purified HNE coincubated with PLG or tPA was analysed by western blot to identify cleavage products. Exogenous HNE was mixed ex-vivo with healthy volunteer blood (n=7) and used in TEG -/+tPA to evaluate effects on fibrinolysis. HNE did not cause measurable fibrinolysis on fibrin clots, clotted plasma, or whole blood as assessed by turbidometry or TEG in the absence of tPA. Upon tPA treatment, all 3 methods of evaluating fibrinolysis showed delays and decreases in fibrinolysis due to HNE relative to control: fibrin clot turbidometry ΔTm =110.7% (CI 105.0%-116.5%), clotted citrate plasma (n=6 healthy volunteers) ΔTm =126.1% (CI 110.4%-141.8%), and whole blood native TEG (n=7 healthy volunteers) with ΔLY30=28% (p=0.043). Western blot analysis of HNE-PLG co-incubation confirmed that HNE generates angiostatin K1-3, and plasma turbidity assays treated with angiostatin K1-3 delayed fibrinolysis. HNE degrades PLG and generates angiostatin K1-3, which predominates over HNE cleavage of fibrin(ogen). These findings suggest that neutrophil

  14. Requirements Analysis Study for Master Pump Shutdown System Project Development Specification [SEC 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    BEVINS, R.R.

    2000-03-24

    This document has been updated during the definitive design portion of the first phase of the W-314 Project to capture additional software requirements and is planned to be updated during the second phase of the W-314 Project to cover the second phase of the Project's scope. The objective is to provide requirement traceability by recording the analysis/basis for the functional descriptions of the master pump shutdown system. This document identifies the sources of the requirements and/or how these were derived. Each requirement is validated either by quoting the source or an analysis process involving the required functionality, performance characteristics, operations input or engineering judgment.

  15. Hyperfibrinolysis, physiologic fibrinolysis, and fibrinolysis shutdown: the spectrum of postinjury fibrinolysis and relevance to antifibrinolytic therapy.

    Science.gov (United States)

    Moore, Hunter B; Moore, Ernest E; Gonzalez, Eduardo; Chapman, Michael P; Chin, Theresa L; Silliman, Christopher C; Banerjee, Anirban; Sauaia, Angela

    2014-12-01

    Fibrinolysis is a physiologic process maintaining patency of the microvasculature. Maladaptive overactivation of this essential function (hyperfibrinolysis) is proposed as a pathologic mechanism of trauma-induced coagulopathy. Conversely, the shutdown of fibrinolysis has also been observed as a pathologic phenomenon. We hypothesize that there is a level of fibrinolysis between these two extremes that have a survival benefit for the severely injured patients. Thrombelastography and clinical data were prospectively collected on trauma patients admitted to our Level I trauma center from 2010 to 2013. Patients with an Injury Severity Score (ISS) of 15 or greater were evaluated. The percentage of fibrinolysis at 30 minutes by thrombelastography was used to stratify three groups as follows: hyperfibrinolysis (≥3%), physiologic (0.081-2.9%), and shutdown (0-0.08%). The threshold for hyperfibrinolysis was based on existing literature. The remaining groups were established on a cutoff of 0.8%, determined by the highest point of specificity and sensitivity for mortality on a receiver operating characteristic curve. One hundred eighty patients were included in the study. The median age was 42 years (interquartile range [IQR], 28-55 years), 70% were male, and 21% had penetrating injuries. The median ISS was 29 (IQR, 22-36), and the median base deficit was 9 mEq/L (IQR, 6-13 mEq/L). Distribution of fibrinolysis was as follows: shutdown, 64% (115 of 180); physiologic, 18% (32 of 180); and hyperfibrinolysis, 18% (33 of 180). Mortality rates were lower for the physiologic group (3%) compared with the hyperfibrinolysis (44%) and shutdown (17%) groups (p = 0.001). We have identified a U-shaped distribution of death related to the fibrinolysis system in response to major trauma, with a nadir in mortality, with level of fibrinolysis after 30 minutes between 0.81% and 2.9%. Exogenous inhibition of the fibrinolysis system in severely injured patients requires careful selection, as it

  16. Preliminary Calculations of Shutdown Dose Rate for the CTS Diagnostics System

    DEFF Research Database (Denmark)

    Klinkby, Esben Bryndt; Nonbøl, Erik; Lauritzen, Bent

    2015-01-01

    DTU and IST 2 are partners in the design of a collective Thomson Scattering (CTS) diagnostics for ITER through a contract with F4E. The CTS diagnostic utilizes probing radiation of ~60 GHz emitted into the plasma and, using a mirror, collects the scattered radiation by an array of receivers. Having...... on supplying input which affect the system design. Examples include: - Heatloads on plasma facing mirrors and preliminary stress and thermal analysis - Port plug cooling requirements and it's dependence on system design (in particular blanket cut-out) - Shutdown dose-rate calculations (relative analysis...

  17. Modeling startup and shutdown transient of the microlinear piezo drive via ANSYS

    Science.gov (United States)

    Azin, A. V.; Bogdanov, E. P.; Rikkonen, S. V.; Ponomarev, S. V.; Khramtsov, A. M.

    2017-02-01

    The article describes the construction-design of the micro linear piezo drive intended for a peripheral cord tensioner in the reflecting surface shape regulator system for large-sized transformable spacecraft antenna reflectors. The research target -the development method of modeling startup and shutdown transient of the micro linear piezo drive. This method is based on application software package ANSYS. The method embraces a detailed description of the calculation stages to determine the operating characteristics of the designed piezo drive. Based on the numerical solutions, the time characteristics of the designed piezo drive are determined.

  18. Vibration of a steam turbo-generator (TG) set during shutdown period

    OpenAIRE

    Sinha, Jyoti; Hahn, W; Elbhbah, Keri; Obi-Mgbam, Kelechi G.

    2016-01-01

    The steam turbo-generator (TG) sets in power plants during the shutdown period often operate at a very low speed with the aid of barring gear. This low speed is known as the barring speed and it is of the order upto 100 RPM. The purpose is to float the rotor in the fluid bearings so that the rotor heavy self-weight should not cause any damage to the bearings. The barring speed also maintains uniformity of temperature across the complete rotor when cooling down from operating condition to norm...

  19. Confectionary Chemistry.

    Science.gov (United States)

    Levine, Elise Hilf

    1996-01-01

    Presents activities and demonstrations that enable teachers to use various types of confections as tactile experiences to spark chemistry students' interest and generate enthusiasm for learning. Presents uses of candy in teaching about atomic structure, spontaneous nuclear decay, chemical formulas, fractoluminescence, the effect of a molecular…

  20. Chemistry Notes.

    Science.gov (United States)

    School Science Review, 1983

    1983-01-01

    Presents chemistry experiments, laboratory procedures, demonstrations, and classroom materials/activities. These include: experiments on colloids, processing of uranium ore, action of heat on carbonates; color test for phenols and aromatic amines; solvent properties of non-electrolytes; stereoscopic applications/methods; a valency balance;…

  1. Acute Fibrinolysis Shutdown after Injury Occurs Frequently and Increases Mortality: A Multicenter Evaluation of 2,540 Severely Injured Patients.

    Science.gov (United States)

    Moore, Hunter B; Moore, Ernest E; Liras, Ioannis N; Gonzalez, Eduardo; Harvin, John A; Holcomb, John B; Sauaia, Angela; Cotton, Bryan A

    2016-04-01

    Fibrinolysis is a physiologic process that maintains microvascular patency by breaking down excessive fibrin clot. Hyperfibrinolysis is associated with a doubling of mortality. Fibrinolysis shutdown, an acute impairment of fibrinolysis, has been recognized as a risk factor for increased mortality. The purpose of this study was to assess the incidence and outcomes of fibrinolysis phenotypes in 2 urban trauma centers. Injured patients included in the analysis were admitted between 2010 and 2013, were 18 years of age or older, and had an Injury Severity Score (ISS) > 15. Admission fibrinolysis phenotypes were determined by the clot lysis at 30 minutes (LY30): shutdown ≤ 0.8%, physiologic 0.9% to 2.9%, and hyperfibrinolysis ≥ 3%. Logistic regression was used to adjust for age, arrival blood pressure, ISS, mechanism, and facility. There were 2,540 patients who met inclusion criteria. Median age was 39 years (interquartile range [IQR] 26 to 55 years) and median ISS was 25 (IQR 20 to 33), with a mortality rate of 21%. Fibrinolysis shutdown was the most common phenotype (46%) followed by physiologic (36%) and hyperfibrinolysis (18%). Hyperfibrinolysis was associated with the highest death rate (34%), followed by shutdown (22%), and physiologic (14%, p Fibrinolysis shutdown is the most common phenotype on admission and is associated with increased mortality. These data provide additional evidence of distinct phenotypes of coagulation impairment and that individualized hemostatic therapy may be required. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  2. Transient Analysis of Loss of All AC Power While on Shutdown Cooling for WH 2-Loop Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Park, Da Hee; Lee, Kyung Jin; Hwang, Su Hyun [FNC Technology Co., Yongin (Korea, Republic of); Yoon, Duck Joo; Lee, Seung Chan [KHNP, Daejeon (Korea, Republic of)

    2016-10-15

    The analysis was performed to provide useful insights for operator guidelines to maintain critical safety functions during SBO for shutdown modes. For Shutdown State A, if the SG PORV is manually opened at 4,000 sec by operator and secondary external injection by operator was provided at 5hours, the core boiling is not expected and core is cooled well. For Shutdown State C, if RWST gravity feed by operator is provided at 4,000 sec, the core is not uncovered and core is cooled well. This study would be useful for improving a strategy to cope with loss of all AC power while on shutdown cooling. The purpose of this study is to provide strategies for maintaining core cooling and protecting the reactor core in the event of complete loss of all AC power while on Residual Heat Removal (RHR) cooling. In this study, in order to comprehend the Fukushima accident, the transient analysis was performed to provide insights into mitigating strategies for SBO while on a shutdown state using the RELAP5/MOD3.3 code.

  3. The slow birth of green chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Amato, I.

    1993-03-12

    Mainstream chemistry is beginning to look at environmental chemistry as an important solution to environmental problems. This can include research into developing cleaner-burning liquid fuels, cleaning up oil spills, or developing better process methods which engender less pollution, as opposed to previous practices of detecting pollutants without preventing their release to begin with. This article discusses the progress of this chemistry discipline, describes some of the ongoing research, and describes the future for environmental chemistry. An impetus for future growth will be generational change, as young scientists in training are beginning to push faculities into creating programs for environmental chemistry.

  4. Control assembly for controlling a fuel cell system during shutdown and restart

    Science.gov (United States)

    Venkataraman, Ramki; Berntsen, George; Carlson, Glenn L.; Farooque, Mohammad; Beachy, Dan; Peterhans, Stefan; Bischoff, Manfred

    2010-06-15

    A fuel cell system and method in which the fuel cell system receives and an input oxidant gas and an input fuel gas, and in which a fuel processing assembly is provided and is adapted to at least humidify the input fuel gas which is to be supplied to the anode of the fuel cell of the system whose cathode receives the oxidant input gas via an anode oxidizing assembly which is adapted to couple the output of the anode of the fuel cell to the inlet of the cathode of the fuel cell during normal operation, shutdown and restart of the fuel cell system, and in which a control assembly is further provided and is adapted to respond to shutdown of the fuel cell system during which input fuel gas and input oxidant gas cease to be received by the fuel cell system, the control assembly being further adapted to, when the fuel cell system is shut down: control the fuel cell system so as to enable a purging gas to be able to flow through the fuel processing assembly to remove humidified fuel gas from the processing assembly and to enable a purging gas to be able to flow through the anode of the fuel cell.

  5. U.S. Government shutdown degrades aviation radiation monitoring during solar radiation storm

    Science.gov (United States)

    Tobiska, W. Kent; Gersey, Brad; Wilkins, Richard; Mertens, Chris; Atwell, William; Bailey, Justin

    2014-01-01

    The U.S. Government shutdown from 1 to 17 October 2013 significantly affected U.S. and global aviation radiation monitoring. The closure occurred just as a S2 radiation storm was in progress with an average dose rate of 20 μSv h-1. We estimate that during the radiation event period, one-half million passengers were flying in the affected zone and, of this population, four would have received sufficient dose to contract fatal cancer in their lifetimes. The radiation environment can be treated like any other risk-prone weather event, e.g., rain, snow, icing, clear air turbulence, convective weather, or volcanic ash, and should be made available to flight crews in a timely way across the entire air traffic management system. The shutdown highlighted the need for active operational monitoring of the global radiation environment. Aviation radiation risk mitigation steps are simple and straightforward, i.e., fly at a lower altitude and/or use a more equatorward route. Public tools and media methods are also needed from the space weather scientific and operational communities to provide this information in a timely and accessible manner to the flying public.

  6. Performance Analysis on Passive Emergency Core Cooling System in the Low Power and Shutdown Operation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Soon Il; Hong, Soon Joon [FNC TECH. Yongin (Korea, Republic of); Kang, Sang Hee; Kim, Han Gon [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2016-05-15

    A Passive Emergency Core Cooling System (PECCS) is to be adopted as an improved safety design feature of APR+. During plant Shutdowns, certain maintenance and testing activities require a drain down of the RCS to a partially filled condition. And Shutdown Cooling System(SCS) is placed into service to accomplish Reactor coolant system(RCS) cooldown to refueling temperatures. If SCS operation is not re-established, core boiling and pressurization can produce rapid core uncovery. When unfavorable accidents such loss of SCS happen, the PECCS should be able to make up the core and then cool down the core. This study discusses the applicability of PECCS and the performance analysis during loss of SCS or RCS inventory. In this study, the applicability of PECCS and analysis performance during loss of SCS or RCS inventory were assessed. RELAP5 calculations show that PECCS can make up the core and then prevent the core from being damaged. Resultant analysis shows the role of the ADV for RCS depressurization, and SITs for RCS making up.

  7. Optimization of startup and shutdown operation of simulated moving bed chromatographic processes.

    Science.gov (United States)

    Li, Suzhou; Kawajiri, Yoshiaki; Raisch, Jörg; Seidel-Morgenstern, Andreas

    2011-06-24

    This paper presents new multistage optimal startup and shutdown strategies for simulated moving bed (SMB) chromatographic processes. The proposed concept allows to adjust transient operating conditions stage-wise, and provides capability to improve transient performance and to fulfill product quality specifications simultaneously. A specially tailored decomposition algorithm is developed to ensure computational tractability of the resulting dynamic optimization problems. By examining the transient operation of a literature separation example characterized by nonlinear competitive isotherm, the feasibility of the solution approach is demonstrated, and the performance of the conventional and multistage optimal transient regimes is evaluated systematically. The quantitative results clearly show that the optimal operating policies not only allow to significantly reduce both duration of the transient phase and desorbent consumption, but also enable on-spec production even during startup and shutdown periods. With the aid of the developed transient procedures, short-term separation campaigns with small batch sizes can be performed more flexibly and efficiently by SMB chromatography. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Supramolecular analytical chemistry.

    Science.gov (United States)

    Anslyn, Eric V

    2007-02-02

    A large fraction of the field of supramolecular chemistry has focused in previous decades upon the study and use of synthetic receptors as a means of mimicking natural receptors. Recently, the demand for synthetic receptors is rapidly increasing within the analytical sciences. These classes of receptors are finding uses in simple indicator chemistry, cellular imaging, and enantiomeric excess analysis, while also being involved in various truly practical assays of bodily fluids. Moreover, one of the most promising areas for the use of synthetic receptors is in the arena of differential sensing. Although many synthetic receptors have been shown to yield exquisite selectivities, in general, this class of receptor suffers from cross-reactivities. Yet, cross-reactivity is an attribute that is crucial to the success of differential sensing schemes. Therefore, both selective and nonselective synthetic receptors are finding uses in analytical applications. Hence, a field of chemistry that herein is entitled "Supramolecular Analytical Chemistry" is emerging, and is predicted to undergo increasingly rapid growth in the near future.

  9. Paper-Based Heavy Metal Sensors from the Concise Synthesis of an Anionic Porphyrin: A Practical Application of Organic Synthesis to Environmental Chemistry

    Science.gov (United States)

    Prabpal, Jutamat; Vilaivan, Tirayut; Praneenararat, Thanit

    2017-01-01

    Tetrakis(4-sulfonatophenyl)porphyrin (TSPP) was immobilized on patterned paper and used as a sensor for heavy metal ions in an advanced organic chemistry course. The resulting sensor could detect Hg[superscript 2+] and Cd[superscript 2+] ions colorimetrically, while Cu[superscript 2+] ion resulted in fluorescence quenching, thus demonstrating a…

  10. Analytical Thinking, Analytical Action: Using Prelab Video Demonstrations and e-Quizzes to Improve Undergraduate Preparedness for Analytical Chemistry Practical Classes

    Science.gov (United States)

    Jolley, Dianne F.; Wilson, Stephen R.; Kelso, Celine; O'Brien, Glennys; Mason, Claire E.

    2016-01-01

    This project utilizes visual and critical thinking approaches to develop a higher-education synergistic prelab training program for a large second-year undergraduate analytical chemistry class, directing more of the cognitive learning to the prelab phase. This enabled students to engage in more analytical thinking prior to engaging in the…

  11. Clinical Laboratory Practice Recommendations for the Use of Cardiac Troponin in Acute Coronary Syndrome: Expert Opinion from the Academy of the American Association for Clinical Chemistry and the Task Force on Clinical Applications of Cardiac Bio-Markers of the International Federation of Clinical Chemistry and Laboratory Medicine.

    Science.gov (United States)

    Wu, Alan H B; Christenson, Robert H; Greene, Dina N; Jaffe, Allan S; Kavsak, Peter A; Ordonez-Llanos, Jordi; Apple, Fred S

    2018-01-17

    This document is an essential companion to the third iteration of the National Academy of Clinical Biochemistry [NACB,8 now the American Association for Clinical Chemistry (AACC) Academy] Laboratory Medicine Practice Guidelines (LMPG) on cardiac markers. The expert consensus recommendations were drafted in collaboration with the International Federation of Clinical Chemistry and Laboratory Medicine Task Force on Clinical Applications of Bio-Markers (IFCC TF-CB). We determined that there is sufficient clinical guidance on the use of cardiac troponin (cTn) testing from clinical practice groups. Thus, in this expert consensus document, we focused on clinical laboratory practice recommendations for high-sensitivity (hs)-cTn assays. This document utilized the expert opinion class of evidence to focus on the following 10 topics: (a) quality control (QC) utilization, (b) validation of the lower reportable analytical limits, (c) units to be used in reporting measurable concentrations for patients and QC materials, (d) 99th percentile sex-specific upper reference limits to define the reference interval; (e) criteria required to define hs-cTn assays, (f) communication with clinicians and the laboratory's role in educating clinicians regarding the influence of preanalytic and analytic problems that can confound assay results, (g) studies on hs-cTn assays and how authors need to document preanalytical and analytical variables, (h) harmonizing and standardizing assay results and the role of commutable materials, (i) time to reporting of results from sample receipt and sample collection, and (j) changes in hs-cTn concentrations over time and the role of both analytical and biological variabilities in interpreting results of serial blood collections. © 2017 American Association for Clinical Chemistry.

  12. Development and initial validation of a project-based rubric to assess the systems-based practice competency of residents in the clinical chemistry rotation of a pathology residency.

    Science.gov (United States)

    Vitek, Carolyn R; Dale, Jane C; Homburger, Henry A; Bryant, Sandra C; Saenger, Amy K; Karon, Brad S

    2014-06-01

    Systems-based practice (SBP) is 1 of 6 core competencies required in all resident training programs accredited by the Accreditation Council for Graduate Medical Education. Reliable methods of assessing resident competency in SBP have not been described in the medical literature. To develop and validate an analytic grading rubric to assess pathology residents' analyses of SBP problems in clinical chemistry. Residents were assigned an SBP project based upon unmet clinical needs in the clinical chemistry laboratories. Using an iterative method, we created an analytic grading rubric based on critical thinking principles. Four faculty raters used the SBP project evaluation rubric to independently grade 11 residents' projects during their clinical chemistry rotations. Interrater reliability and Cronbach α were calculated to determine the reliability and validity of the rubric. Project mean scores and range were also assessed to determine whether the rubric differentiated resident critical thinking skills related to the SBP projects. Overall project scores ranged from 6.56 to 16.50 out of a possible 20 points. Cronbach α ranged from 0.91 to 0.96, indicating that the 4 rubric categories were internally consistent without significant overlap. Intraclass correlation coefficients ranged from 0.63 to 0.81, indicating moderate to strong interrater reliability. We report development and statistical analysis of a novel SBP project evaluation rubric. The results indicate the rubric can be used to reliably assess pathology residents' critical thinking skills in SBP.

  13. Growing your green chemistry mindset

    Science.gov (United States)

    Kosmas, Steven

    2017-08-01

    The purpose of this article is not to delineate the steps to move across the continuum to being a greener chemist, but to analyse the cognitive processes involved in fostering a green chemistry growth mindset (GCGM) [Dweck C. (2006) Mindset: The New Psychology of Success. New York, NY: Ballatine]. The focus is on changing the mindset, which inevitably will lead to a more mindful approach to chemistry practices before the laboratory begins. A green chemistry fixed mindset (GCFM) is closed to making improvements, since the attitude is that the techniques and processes in the laboratory are already employing a green chemistry mindset [Dweck C. (2006) Mindset: The New Psychology of Success. New York, NY: Ballatine]. The problem with the GCFM is that it precludes the possibility of making improvements. However, the GCGM employs a continuous, intentional focus on the attitude towards green chemistry, with the ultimate goal being a change in chemistry practices that is greener. The focus of this article will be on the GCGM.

  14. Theoretical chemistry periodicities in chemistry and biology

    CERN Document Server

    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

  15. 46 CFR 32.50-35 - Remote manual shutdown for internal combustion engine driven cargo pump on tank vessels-TB/ALL.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Remote manual shutdown for internal combustion engine... for Cargo Handling § 32.50-35 Remote manual shutdown for internal combustion engine driven cargo pump on tank vessels—TB/ALL. (a) Any tank vessel which is equipped with an internal combustion engine...

  16. Interstellar chemistry

    Science.gov (United States)

    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 observed is a challenge for complete understanding. The role and nature of reactions involving grain surfaces as well as new spectroscopic observations of interstellar and circumstellar regions are topics presented in this special feature. PMID:16894148

  17. The management of large cabling campaigns during the Long Shutdown 1 of LHC

    CERN Document Server

    Meroli, Stefano; Formenti, Fabio; Frans, Marten; Guillaume, Jean Claude; Ricci, Daniel

    2014-01-01

    The Large Hadron Collider at CERN entered into its first 18 month-long shutdown period in February 2013. During this period the entire CERN accelerator complex will undergo major consolidation and upgrade works, preparing the machines for LHC operation at nominal energy (7 TeV/beam). One of the most challenging activities concerns the cabling infrastructure (copper and optical fibre cables) serving the CERN data acquisition, networking and control systems. About 1000 kilometres of cables, distributed in different machine areas, will be installed, representing an investment of about 15 MCHF. This implies an extraordinary challenge in terms of project management, including resource and activity planning, work execution and quality control. The preparation phase of this project started well before its implementation, by defining technical solutions and setting financial plans for staff recruitment and material supply. Enhanced task coordination was further implemented by deploying selected competences to form a ...

  18. Spins, Stalls, and Shutdowns: Pitfalls of Qualitative Policing and Security Research

    Directory of Open Access Journals (Sweden)

    Randy K. Lippert

    2015-11-01

    Full Text Available This article explores key elements of qualitative research on policing and security agencies, including barriers encountered and strategies to prevent them. While it is oft-assumed that policing/security agencies are difficult to access due to their clandestine or bureaucratic nature, this article demonstrates this is not necessarily the case, as access was gained for three distinct qualitative research projects. Yet, access and subsequent research were not without pitfalls, which we term security spins, security stalls, and security shutdowns. We illustrate how each was encountered and argue these pitfalls are akin to researchers falling into risk categories, not unlike those used by policing/security agents in their work. Before concluding we discuss methodological strategies for scholars to avoid these pitfalls and to advance research that critically interrogates the immense policing/security realm. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1601108

  19. Production and Quality Assurance of Main Busbar Interconnection Splices during the LHC 2008-2009 Shutdown.

    CERN Document Server

    Bertinelli, F; Dalin, J-M; Fessia, P; Flora, R H; Heck, S; Pfeffer, H; Prin, H; Scheuerlein, C; Thonet, P; Tock, J-P; Williams, L

    2011-01-01

    The main busbar interconnection splices of the Large Hadron Collider are assembled by inductive soldering of the Rutherford type cables and the copper profiles of the stabilizer. Following the September 2008 incident, the assembly process and the quality assurance have been improved, with new measurement and diagnostics methods introduced. In the 2008-2009 shutdown the resistance both in the superconducting and in the normal conducting states have been the focus for improvements. The introduction of gamma radiography has allowed the visualization of voids between cable and stabilizer. It is now known that during the standard soldering heating cycle solder is lost from the busbar extremities adjacent to the splice profiles, leaving parts of the cable in poor contact with the stabilizer. A room temperature resistance measurement has been introduced as a simple, non-destructive test to measure the electrical continuity of the splice in its normal conducting state. An ultrasonic test has been performed systematic...

  20. Performance of Resistive Plate Chambers installed during the first long shutdown of the CMS experiment

    CERN Document Server

    Shopova, M.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Sultanov, G.; Rodozov, M.; Stoykova, S.; Assran, Y.; Sayed, A.; Radi, A.; Aly, S.; Singh, G.; Abbrescia, M.; Iaselli, G.; Maggi, M.; Pugliese, G.; Verwilligen, P.; Van Doninck, W.; Colafranceschi, S.; Sharma, A.; Benussi, L.; Bianco, S.; Piccolo, D.; Primavera, F.; Cimmino, A.; Crucy, S.; Rios, A.A.O.; Tytgat, M.; Zaganidis, N.; Gul, M.; Fagot, A.; Bhatnagar, V.; Singh, J.; Kumari, R.; Mehta, A.; Ahmad, A.; Awan, I.M.; Shahzad, H.; Hoorani, H.; Asghar, M.I.; Muhammad, S.; Ahmed, W.; Shah, M.A.; Cho, S.W.; Choi, S.Y.; Hong, B.; Kang, M.H.; Lee, K.S.; Lim, J.H.; Park, S.K.; Kim, M.S.; Laktineh, I.B.; Lagarde, F.; Gouzevitch, M.; Grenier, G.; Pedraza, I.; Bernardino, S. Carpinteyro; Estrada, C. Uribe; Carrillo Moreno, S.; Valencia, F. Vazquez; Pant, L.M.; Buontempo, S.; Cavallo, N.; Fabozzi, F.; Orso, I.; Lista, L.; Meola, S.; Merola, M.; Paolucci, P.; Thyssen, F.; Lanza, G.; Esposito, M.; Braghieri, A.; Magnani, A.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Montagna, P.; Ban, Y.; Qian, S.J.; Choi, M.; Choi, Y.; Goh, J.; Kim, D.; Dimitrov, A.; Litov, L.; Petkov, P.; Pavlov, B.; Bagaturia, I.; Lomidze, D.; Avila, C.; Cabrera, A.; Sanabria, J.C.; Crotty, I.; Vaitkus, J.

    2016-01-01

    The CMS experiment, located at the CERN Large Hadron Collider, has a redundant muon system composed by three different detector technologies: Cathode Strip Chambers (in the forward regions), Drift Tubes (in the central region) and Resistive Plate Chambers (both its central and forward regions). All three are used for muon reconstruction and triggering. During the first long shutdown (LS1) of the LHC (2013-2014) the CMS muon system has been upgraded with 144 newly installed RPCs on the forth forward stations. The new chambers ensure and enhance the muon trigger efficiency in the high luminosity conditions of the LHC Run2. The chambers have been successfully installed and commissioned. The system has been run successfully and experimental data has been collected and analyzed. The performance results of the newly installed RPCs will be presented.

  1. Requirements Analysis Study for Master Pump Shutdown System Project Development Specification [SEC 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    BEVINS, R.R.

    2000-09-20

    This study is a requirements document that presents analysis for the functional description for the master pump shutdown system. This document identifies the sources of the requirements and/or how these were derived. Each requirement is validated either by quoting the source or an analysis process involving the required functionality, performance characteristics, operations input or engineering judgment. The requirements in this study apply to the first phase of the W314 Project. This document has been updated during the definitive design portion of the first phase of the W314 Project to capture additional software requirements and is planned to be updated during the second phase of the W314 Project to cover the second phase of the project's scope.

  2. Evolution of the ATLAS Distributed Computing during the LHC long shutdown

    CERN Document Server

    Campana, S; The ATLAS collaboration

    2013-01-01

    The ATLAS Distributed Computing project (ADC) was established in 2007 to develop and operate a framework, following the ATLAS computing model, to enable data storage, processing and bookkeeping on top of the WLCG distributed infrastructure. ADC development has always been driven by operations and this contributed to its success. The system has fulfilled the demanding requirements of ATLAS, daily consolidating worldwide up to 1PB of data and running more than 1.5 million payloads distributed globally, supporting almost one thousand concurrent distributed analysis users. Comprehensive automation and monitoring minimized the operational manpower required. The flexibility of the system to adjust to operational needs has been important to the success of the ATLAS physics program. The LHC shutdown in 2013-2015 affords an opportunity to improve the system in light of operational experience and scale it to cope with the demanding requirements of 2015 and beyond, most notably a much higher trigger rate and event pileu...

  3. Evolution of the ATLAS Distributed Computing system during the LHC Long shutdown

    CERN Document Server

    Campana, S; The ATLAS collaboration

    2014-01-01

    The ATLAS Distributed Computing project (ADC) was established in 2007 to develop and operate a framework, following the ATLAS computing model, to enable data storage, processing and bookkeeping on top of the WLCG distributed infrastructure. ADC development has always been driven by operations and this contributed to its success. The system has fulfilled the demanding requirements of ATLAS, daily consolidating worldwide up to 1PB of data and running more than 1.5 million payloads distributed globally, supporting almost one thousand concurrent distributed analysis users. Comprehensive automation and monitoring minimized the operational manpower required. The flexibility of the system to adjust to operational needs has been important to the success of the ATLAS physics program. The LHC shutdown in 2013-2015 affords an opportunity to improve the system in light of operational experience and scale it to cope with the demanding requirements of 2015 and beyond, most notably a much higher trigger rate and event pileu...

  4. LS1 “First Long Shutdown of LHC and its Injector Chains”

    CERN Multimedia

    Foraz, K; Barberan, M; Bernardini, M; Coupard, J; Gilbert, N; Hay, D; Mataguez, S; McFarlane, D

    2014-01-01

    The LHC and its Injectors were stopped in February 2013, in order to maintain, consolidate and upgrade the different equipment of the accelerator chain, with the goal of achieving LHC operation at the design energy of 14 TeV in the centre-of-mass. Prior to the start of this First Long Shutdown (LS1), a major effort of preparation was performed in order to optimize the schedule and the use of resources across the different machines, with the aim of resuming LHC physics in early 2015. The rest of the CERN complex will restart beam operation in the second half of 2014. This paper presents the schedule of the LS1, describes the organizational set-up for the coordination of the works, the main activities, the different main milestones, which have been achieved so far, and the decisions taken in order to mitigate the issues encountered.

  5. The Chernobyl plant shutdown; L'arret de la centrale de Tchernobyl

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    The Chernobylsk-1 reactor, operational in september 1977 has been stopped in november 1996; the Chernobylsk-2 reactor started in november 1978 is out of order since 1991 following a fire. The Chernobylsk-3 reactor began in 1981. During the last three years it occurs several maintenance operations that stop it. In june 2000, the Ukrainian authorities decided to stop it definitively on the 15. of december (2000). This file handles the subject. it is divided in four chapters: the first one gives the general context of the plant shutdown, the second chapter studies the supporting projects to stop definitively the nuclear plant, the third chapter treats the question of the sarcophagus, and the fourth and final chapter studies the consequences of the accident and the contaminated territories. (N.C.)

  6. Fast shut-down protection system for radio frequency breakdown and multipactor testing

    Science.gov (United States)

    Graves, T. P.; Hanson, P.; Michaelson, J. M.; Farkas, A. D.; Hubble, A. A.

    2014-02-01

    Radio frequency (RF) breakdown such as multipactor or ionization breakdown is a device-limiting phenomenon for on-orbit spacecraft used for communication, navigation, or other RF payloads. Ground testing is therefore part of the qualification process for all high power components used in these space systems. This paper illustrates a shut-down protection system to be incorporated into multipactor/ionization breakdown ground testing for susceptible RF devices. This 8 channel system allows simultaneous use of different diagnostic classes and different noise floors. With initiation of a breakdown event, diagnostic signals increase above a user-specified level, which then opens an RF switch to eliminate RF power from the high power amplifier. Examples of this system in use are shown for a typical setup, illustrating the reproducibility of breakdown threshold voltages and the lack of multipactor conditioning. This system can also be utilized to prevent excessive damage to RF components in tests with sensitive or flight hardware.

  7. Low-power and shutdown models for the accident sequence precursor (ASP) program

    Energy Technology Data Exchange (ETDEWEB)

    Sattison, M.B.; Thatcher, T.A.; Knudsen, J.K. [Idaho National Engineering Lab., Idaho Falls, ID (United States)] [and others

    1997-02-01

    The US Nuclear Regulatory Commission (NRC) has been using full-power. Level 1, limited-scope risk models for the Accident Sequence Precursor (ASP) program for over fifteen years. These models have evolved and matured over the years, as have probabilistic risk assessment (PRA) and computer technologies. Significant upgrading activities have been undertaken over the past three years, with involvement from the Offices of Nuclear Reactor Regulation (NRR), Analysis and Evaluation of Operational Data (AEOD), and Nuclear Regulatory Research (RES), and several national laboratories. Part of these activities was an RES-sponsored feasibility study investigating the ability to extend the ASP models to include contributors to core damage from events initiated with the reactor at low power or shutdown (LP/SD), both internal events and external events. This paper presents only the LP/SD internal event modeling efforts.

  8. Shutdown dose rate analysis with CAD geometry, Cartesian/tetrahedral mesh, and advanced variance reduction

    Energy Technology Data Exchange (ETDEWEB)

    Biondo, Elliott D., E-mail: biondo@wisc.edu; Davis, Andrew, E-mail: davisa@engr.wisc.edu; Wilson, Paul P.H., E-mail: wilsonp@engr.wisc.edu

    2016-05-15

    Highlights: • A CAD-based shutdown dose rate analysis workflow has been implemented. • Cartesian and superimposed tetrahedral mesh are fully supported. • Biased and unbiased photon source sampling options are available. • Hybrid Monte Carlo/deterministic techniques accelerate photon transport. • The workflow has been validated with the FNG-ITER benchmark problem. - Abstract: In fusion energy systems (FES) high-energy neutrons born from burning plasma activate system components to form radionuclides. The biological dose rate that results from photons emitted by these radionuclides after shutdown—the shutdown dose rate (SDR)—must be quantified for maintenance planning. This can be done using the Rigorous Two-Step (R2S) method, which involves separate neutron and photon transport calculations, coupled by a nuclear inventory analysis code. The geometric complexity and highly attenuating configuration of FES motivates the use of CAD geometry and advanced variance reduction for this analysis. An R2S workflow has been created with the new capability of performing SDR analysis directly from CAD geometry with Cartesian or tetrahedral meshes and with biased photon source sampling, enabling the use of the Consistent Adjoint Driven Importance Sampling (CADIS) variance reduction technique. This workflow has been validated with the Frascati Neutron Generator (FNG)-ITER SDR benchmark using both Cartesian and tetrahedral meshes and both unbiased and biased photon source sampling. All results are within 20.4% of experimental values, which constitutes satisfactory agreement. Photon transport using CADIS is demonstrated to yield speedups as high as 8.5·10{sup 5} for problems using the FNG geometry.

  9. Shutdown dose rate contribution from diagnostics in ITER upper port 18

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, M.S., E-mail: munseong@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); Pak, S.; An, Y.H.; Seon, C.R.; Lee, H.G. [National Fusion Research Institute, Daejeon (Korea, Republic of); Bertalot, L.; Krasilnikov, V. [ITER Organization, St Paul-lez-Durance (France); Zvonkov, A. [Agency ITER-RF, Moscow (Russian Federation)

    2016-11-01

    Highlights: • The Shutdown Dose Rate in the interspace of ITER upper port 18 was evaluated. • VUV spectrometer is the dominant contributor to the average SDR. • The existence and size of the blanket cooling pipes impacts significantly on SDR. - Abstract: D-T operation of ITER plasma will produce high-energy fusion neutrons those can activate materials around the place where human-access is necessary. The interspace of the diagnostic port is one of the area where human-access is necessary for the maintenance of diagnostic systems installed at the port, so it is important to evaluate a dose rate of the interspace area in order to comply with ALARA principle. The shutdown dose rate (SDR) in the interspace of ITER upper port 18 was evaluated by the Direct 1-Step (D1S) method using MCNP5 code. This port contains three diagnostics: Vacuum Ultra-Violet (VUV) Spectrometer, Neutron Activation System (NAS), and Upper Vertical Neutron Camera (UVNC). The contribution of each diagnostic in the port was evaluated by running separate upper port MCNP models those contain individual diagnostic only, and the total dose rate contribution was evaluated with the model which was fully integrated with all the diagnostics. The effect of the opening around the upper port plug and of the other ports was also investigated. The purpose of this assessment is to provide the shielding design basis for the preliminary design of the diagnostic integration in the port. The method and result of the calculation will be presented in this paper.

  10. Risk contribution from low power, shutdown, and other operational modes beyond full power

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, D.W.; Brown, T.D. [Sandia National Labs., Albuquerque, NM (United States); Chu, T.L. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1995-04-01

    During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented.

  11. Risk contribution from low power, shutdown, and other operational modes beyond full power

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, D.W.; Brown, T.D.; Chu, T.L.; Pratt, W.T.

    1995-01-01

    During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented.

  12. Simulation of runaway electron generation during plasma shutdown by impurity injection

    Energy Technology Data Exchange (ETDEWEB)

    Feher, Tamas

    2011-03-15

    Disruptions are dangerous instabilities in tokamaks that should be avoided or mitigated. One possible disruption mitigation method is to inject impurities into the plasma to shut it down in a controlled way. Runaway Electrons (REs) can be generated after the plasma is cooled down by the impurities and these electrons can damage the tokamak. In this work a simulation code is developed to investigate different disruption mitigation scenarios. The response of the bulk plasma, more precisely the temperature evolution of electrons, deuterium and impurity ions are described by energy balance equations in a 1D cylindrical plasma model. The induction and resistive diffusion of electric field is calculated. RE generation rates are used to calculate the runaway current. The Dreicer, hot-tail and avalanche effect is taken into account and a simple model for RE losses is also included. RE generation is studied in JET-like plasmas during pellet injection. Carbon pellets cause effective cooling but these scenarios are prone to runaway generation. A mixture of argon and deuterium gas could be used for safe shutdown without RE generation. In ITER the hot-tail RE generation process becomes important, and the simulation is therefore extended to take this into account. Shutdown scenarios with different concentration of neon and argon impurities were tested in ITER-like plasmas. To simplify the problem the impurity injection into the plasma is not modeled in these cases, only the response of the bulk plasma. The avalanche process cannot be suppressed in a simple way and would produce high runaway current. It can be avoided if some runaway loss phenomenon is included in the simulations, like diffusion due to magnetic perturbations

  13. Shielding optimisation of the ITER ICH&CD antenna for shutdown dose rate

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Andrew, E-mail: andrew.turner@ccfe.ac.uk [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Leichtle, Dieter [Fusion for Energy, Josep Pla 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain); Lamalle, Philippe; Levesy, Bruno [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St., Paul-lez-Durance (France); Meunier, Lionel [Fusion for Energy, Josep Pla 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain); Polunovskiy, Eduard [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St., Paul-lez-Durance (France); Sartori, Roberta [Fusion for Energy, Josep Pla 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain); Shannon, Mark [CCFE, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom)

    2015-10-15

    Highlights: • Neutronics analysis on the ITER ICH&CD system conducted to reduce shutdown dose rate. • Several designs for shielding the port plug gaps were modelled. • Shielding significantly reduced interspace dose rate but still exceed project requirements. • Design optimisation of the ICH port is continuing. • Significant contributions from other ports require an integrated modelling approach. - Abstract: The Ion Cyclotron Heating and Current Drive (ICH&CD) system will reside in ITER equatorial port plugs 13 and 15. Shutdown dose rates (SDDR) within the port interspace are required to be less than 100 μSv/h at 10{sup 6} s cooling. A significant contribution to the SDDR results from neutrons streaming down gaps around the port frame, and the mitigation of this streaming is the main subject of these analyses. An updated MCNP model of the antenna was created and integrated into an ITER reference model. Shielding plates were defined in the port gaps, and scoping studies conducted to assess their effectiveness in several configurations, based on which a front dog-leg arrangement was selected for high resolution 3-D activation analysis using MCR2S. It was concluded that the selected configuration reduced the SDDR from ∼500 μSv/h to 220 μSv/h but were still in excess of dose rate requirements. Approximately 30% of this was due to cross-talk from neighbouring ports. In addition, increased dose rates were observed in the port interspace along the lines of sight of the removable vacuum transmission lines. Design optimisation is continuing, however an integrated approach is needed with regard to ITER port plug design and the shielding of surrounding systems.

  14. Experimental investigation of a new method for advanced fast reactor shutdown cooling

    Science.gov (United States)

    Pakholkov, V. V.; Kandaurov, A. A.; Potseluev, A. I.; Rogozhkin, S. A.; Sergeev, D. A.; Troitskaya, Yu. I.; Shepelev, S. F.

    2017-07-01

    We consider a new method for fast reactor shutdown cooling using a decay heat removal system (DHRS) with a check valve. In this method, a coolant from the decay heat exchanger (DHX) immersed into the reactor upper plenum is supplied to the high-pressure plenum and, then, inside the fuel subassemblies (SAs). A check valve installed at the DHX outlet opens by the force of gravity after primary pumps (PP-1) are shut down. Experimental studies of the new and alternative methods of shutdown cooling were performed at the TISEY test facility at OKBM. The velocity fields in the upper plenum of the reactor model were obtained using the optical particle image velocimetry developed at the Institute of Applied Physics (Russian Academy of Sciences). The study considers the process of development of natural circulation in the reactor and the DHRS models and the corresponding evolution of the temperature and velocity fields. A considerable influence of the valve position in the displacer of the primary pump on the natural circulation of water in the reactor through the DHX was discovered (in some modes, circulation reversal through the DHX was obtained). Alternative DHRS designs without a shell at the DHX outlet with open and closed check valve are also studied. For an open check valve, in spite of the absence of a shell, part of the flow is supplied through the DHX pipeline and then inside the SA simulators. When simulating power modes of the reactor operation, temperature stratification of the liquid was observed, which increased in the cooling mode via the DHRS. These data qualitatively agree with the results of tests at BN-600 and BN-800 reactors.

  15. Shutdown-induced tensile stress in monolithic miniplates as a possible cause of plate pillowing at very high burnup

    Energy Technology Data Exchange (ETDEWEB)

    Medvedev, Pavel G [Idaho National Laboratory; Ozaltun, Hakan [Idaho National Laboratory; Robinson, Adam Brady [Idaho National Laboratory; Rabin, Barry H [Idaho National Laboratory

    2014-04-01

    Post-irradiation examination of Reduced Enrichment for Research and Test Reactors (RERTR)-12 miniplates showed that in-reactor pillowing occurred in at least 4 plates, rendering performance of these plates unacceptable. To address in-reactor failures, efforts are underway to define the mechanisms responsible for in-reactor pillowing, and to suggest improvements to the fuel plate design and operational conditions. To achieve these objectives, the mechanical response of monolithic fuel to fission and thermally-induced stresses was modeled using a commercial finite element analysis code. Calculations of stresses and deformations in monolithic miniplates during irradiation and after the shutdown revealed that the tensile stress generated in the fuel increased from 2 MPa to 100 MPa at shutdown. The increase in tensile stress at shutdown possibly explains in-reactor pillowing of several RERTR-12 miniplates irradiated to the peak local burnup of up to 1.11x1022 fissions/cm3 . This paper presents the modeling approach and calculation results, and compares results with post-irradiation examinations and mechanical testing of irradiated fuel. The implications for the safe use of the monolithic fuel in research reactors are discussed, including the influence of fuel burnup and power on the magnitude of the shutdown-induced tensile stress.

  16. Type and timing of childhood maltreatment and severity of shutdown dissociation in patients with schizophrenia spectrum disorder.

    Directory of Open Access Journals (Sweden)

    Inga Schalinski

    Full Text Available Dissociation, particularly the shutting down of sensory, motor and speech systems, has been proposed to emerge in susceptible individuals as a defensive response to traumatic stress. In contrast, other individuals show signs of hyperarousal to acute threat. A key question is whether exposure to particular types of stressful events during specific stages of development can program an individual to have a strong dissociative response to subsequent stressors. Vulnerability to ongoing shutdown dissociation was assessed in 75 inpatients (46 M/29 F, M = 31 ± 10 years old with schizophrenia spectrum disorder and related to number of traumatic events experienced or witnessed during childhood or adulthood. The Maltreatment and Abuse Chronology of Exposure (MACE scale was used to collect retrospective recall of exposure to ten types of maltreatment during each year of childhood. Severity of shutdown dissociation was related to number of childhood but not adult traumatic events. Random forest regression with conditional trees indicated that type and timing of childhood maltreatment could predictably account for 31% of the variance (p < 0.003 in shutdown dissociation, with peak vulnerability occurring at 13-14 years of age and with exposure to emotional neglect followed by various forms of emotional abuse. These findings suggest that there may be windows of vulnerability to the development of shutdown dissociation. Results support the hypothesis that experienced events are more important than witnessed events, but challenge the hypothesis that "life-threatening" events are a critical determinant.

  17. Estimation of the economic impact of temperature changes induced by a shutdown of the thermohaline circulation: an application of FUND

    NARCIS (Netherlands)

    Link, P.M.; Tol, R.S.J.

    2011-01-01

    The integrated assessment model FUND 2.8n is applied in an assessment to estimate the magnitude of the general market and non-market impacts of temperature changes caused by a possible shutdown of the thermohaline circulation (THC). The monetized impacts of this change in environmental conditions

  18. 78 FR 79709 - Duke Energy Florida, Inc., Crystal River Unit 3 Nuclear Generating Plant Post-Shutdown...

    Science.gov (United States)

    2013-12-31

    ...] [FR Doc No: 2013-31317] NUCLEAR REGULATORY COMMISSION [Docket No. 50-302; NRC-2013-0283] Duke Energy Florida, Inc., Crystal River Unit 3 Nuclear Generating Plant Post-Shutdown Decommissioning Activities Report AGENCY: Nuclear Regulatory Commission (NRC). ACTION: Notice of receipt; availability; public...

  19. Virtually going green: The role of quantum computational chemistry in reducing pollution and toxicity in chemistry

    Science.gov (United States)

    Stevens, Jonathan

    2017-07-01

    Continuing advances in computational chemistry has permitted quantum mechanical calculation to assist in research in green chemistry and to contribute to the greening of chemical practice. Presented here are recent examples illustrating the contribution of computational quantum chemistry to green chemistry, including the possibility of using computation as a green alternative to experiments, but also illustrating contributions to greener catalysis and the search for greener solvents. Examples of applications of computation to ambitious projects for green synthetic chemistry using carbon dioxide are also presented.

  20. contextualization and interdisciplinarity in chemistry teaching

    African Journals Online (AJOL)

    Temechegn

    teachers practices and chemistry high school textbooks, have not changed in two decades. [African. Journal of ... interdisciplinary fashion could improve the chemistry learning by high school students. However, ... other areas, the lack of appropriate pedagogical resources and the reduced time (number of hours, per week ...

  1. An X-ray microsource based system for crystal screening and beamline development during synchrotron shutdown periods

    Science.gov (United States)

    Miller, Mitchell D.; Deacon, Ashley M.

    2007-01-01

    Crystallographic end-stations require a significant investment in state-of-the-art equipment, as well as a significant effort in software development. The equipment often sits idle during annual maintenance shutdowns. In order to utilize the existing hardware and software during these shutdowns, we installed a sealed-tube microsource X-ray generator in the beamline 9-2 hutch at Stanford Synchrotron Radiation Laboratory. A multi-layer optic provides good flux and spectral purity. The small physical size of the source, the long optic to focus distance (635 mm) and the short source to optic distance (65 mm) allowed the use of existing beamline components, without any significant modification. The system replaces a short section of beam pipe upstream of the beam conditioning slits and shutter. The system can be installed and removed from the beamline in less than 1 day. The Joint Center for Structural Genomics (JCSG) and SSRL Structural Molecular Biology group developed the Stanford Automated Mounting (SAM) system and installed it on beamlines at SSRL. The JCSG relies on this system to test crystals for diffraction. The installation of the X-ray microsource in beamline 9-2 allowed crystal screening to continue during SSRL shutdowns. Using a standard screening protocol of two 10 minute exposures, separated by a 90° phi rotation, the system was capable of screening up to 400 crystals per week and was left to run unattended for up to 4 days. Over 8200 crystals were screened during the last four SSRL shutdown periods. An X-ray generator can also be useful for ongoing beamline development. Shutdown periods provide easier access to the experimental hardware, however, some tests require beam. The X-ray microsource offers the ability to conduct these tests during periods when users are not scheduled. PMID:19005562

  2. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    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).

  3. Immobilization chemistries.

    Science.gov (United States)

    Todt, Sascha; Blohm, Dietmar H

    2009-01-01

    Among the parameters which influence the success of a microarray experiment, the attachment of the nucleic acid captures to the support surface plays a decisive role.This article attempts to review the main concepts and ideas of the multiple variants which exist in terms of the immobilization chemistries used in nucleic acid microarray technology. Starting from the attachment of unmodified nucleic acids to modified glass slides by adsorption, further strategies for the coupling of nucleic acid capture molecules to a variety of support materials are surveyed with a focus on the reactive groups involved in the respective process.After a brief introduction, an overview is given about microarray substrates with special emphasis on the approaches used for the activation of these - usually chemically inert - materials. In the next sections strategies for the "undefined" and "defined" immobilization of captures on the substrates are described. While the latter approach tries to accomplish the coupling via a defined reactive moiety of the molecule to be immobilized, the former mentioned techniques involve multiply occurring reactive groups in the capture.The article finishes with an example for microarray manufacture, the production of aminopropyltriethoxysilane (APTES) functionalized glass substrates to which PDITC homobifunctional linker molecules are coupled; on their part providing reactive functional groups for the covalent immobilization of pre-synthesized, amino-modified oligonucleotides.This survey does not seek to be comprehensive rather it tries to present and provide key examples for the basic techniques, and to enable orientation if more detailed studies are needed. This review should not be considered as a guide to how to use the different chemistries described, but instead as a presentation of various principles and approaches applied in the still evolving field of nucleic acid microarray technology.

  4. A short textbook of colloid chemistry

    CERN Document Server

    Jirgensons, B

    1962-01-01

    A Short Textbook of Colloid Chemistry, Second Revised Edition details the factual aspect of colloid chemistry that includes the basic facts, established empirical and mathematical relationships, and practical applications. The chapters of the title are organized into two parts. In the first part, the text discusses the general concepts of colloid chemistry, such as the history and scope, basic terms, and basic methods in experiment with colloids. Part Two covers the technical aspect of colloid chemistry, such as the optical properties, electrical properties, and viscosity. The book will be of

  5. Public perception of chemistry

    OpenAIRE

    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 ...

  6. USSR Report Chemistry

    National Research Council Canada - National Science Library

    1986-01-01

    Contents: Adsorption, Chemistry,Alkaloids, Analytical Chemistry, Catalysis,Chemical Industry,,Coal Gasification, Combustion, Electrochemistry,Explosives and Explosions, Fertilizers, Free Radicals, Inorganic...

  7. Science Update: Inorganic Chemistry.

    Science.gov (United States)

    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)

  8. Evaluation of a Design Principle for Fostering Students' Epistemological Views on Models and Modelling Using Authentic Practices as Contexts for Learning in Chemistry Education

    Science.gov (United States)

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

    2011-01-01

    Science education should foster students' epistemological view on models and modelling consistent with formal epistemology in science and technology practices. This paper reports the application of a curriculum unit in the classroom using an authentic chemical practice, "Modelling drinking water treatment", as the context for learning.…

  9. students' anxiety towards the learning of chemistry in some ...

    African Journals Online (AJOL)

    Preferred Customer

    Chemistry is a human endeavor that relies on basic human qualities like creativity, insights, reasoning, and skills. .... The major employment for chemistry is classroom teaching. I am scared by chemistry practical ... they don't know where to work and 90% believed that classroom teaching is the major employment opened to ...

  10. development of low-cost educational materials for chemistry

    African Journals Online (AJOL)

    unesco

    worldwide to design and implement Chemistry curricula to reflect this practical nature of. Chemistry. In Africa, whereas there had ... The teaching of Chemistry in Africa has been dominated by theoretical lectures and that has been limiting our students' ... for teaching and learning purposes. Such materials include improvised ...

  11. Shutdown dose rate analysis of European test blanket modules shields in ITER Equatorial Port #16

    Energy Technology Data Exchange (ETDEWEB)

    Juárez, Rafael, E-mail: rjuarez@ind.uned.es [Departamento de Ingeniería Energética, ETSII-UNED, Calle Juan del Rosal 12, Madrid 28040 (Spain); Sauvan, Patrick; Perez, Lucia [Departamento de Ingeniería Energética, ETSII-UNED, Calle Juan del Rosal 12, Madrid 28040 (Spain); Panayotov, Dobromir; Vallory, Joelle; Zmitko, Milan; Poitevin, Yves [Fusion for Energy (F4E), Torres Diagonal Litoral B3, Josep Pla 2, Barcelona 08019 (Spain); Sanz, Javier [Departamento de Ingeniería Energética, ETSII-UNED, Calle Juan del Rosal 12, Madrid 28040 (Spain)

    2016-11-01

    Highlights: • Nuclear analysis for European TBMs and shields, in ITER Equatorial Port #16, has been conducted in support of the ‘Concept Design Review’ from ITER. • The objective of the work is the characterization of the Shutdown Dose Rates at Equatorial Port #16 interspace. • The role played by the TBM and TBM shields, the equatorial port gaps and the vacuum vessel permeation, in terms of neutron flux transmission is assessed. • The role played by the TBM, TBM shields, Port Plug Frame, Pipe Forest and the machine in terms of activation is also investigated. - Abstract: ‘Fusion for Energy’ (F4E) is designing, developing, and implementing the European Helium-Cooled Lead-Lithium (HCLL) and Helium-Cooled Pebble-Bed (HCPB) Test Blanket Systems (TBSs) for ITER (Nuclear Facility INB-174). An essential element of the Conceptual Design Review (CDR) of these TBSs is the demonstration of capability of Test Blanket Modules (TBM) and their shields to fulfil their function and comply with the design requirements. One of the TBM shields highly relevant design aspects is the project target for shutdown dose rates (SDDR) in the interspace. We investigated two functions of the TBMs and TBM shields—the neutron flux attenuation along the shields, and the reduction of the activation of the components contributing to SDDR. It is shown that TBMs and TBM shields reduce significantly the neutron flux in the port plug (PP). In terms of neutron flux attenuation, the TBM shield provides sufficient neutron flux reduction, being responsible for 5 × 10{sup 6} n/cm{sup 2} s at port interspace, while the EPP gaps and BSM gaps are responsible for 5 × 10{sup 7} n/cm{sup 2} s each. When considering closed upper, lower and lateral neighbour equatorial ports (thus, excluding the cross-talk between ports), a SDDR of 121 μSv/h averaged near the port closure flange was obtained, out of which, only 4 μSv/h are due to the activation of TBMs and TBM shields. Maximum SDDR in the range

  12. Derivation of main drivers affecting the possibility of human errors during low power and shutdown operation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ar Ryum; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of); Park, Jin Kyun; Kim, Jae Whan [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    In order to estimate the possibility of human error and identify its nature, human reliability analysis (HRA) methods have been implemented. For this, various HRA methods have been developed so far: techniques for human error rate prediction (THERP), cause based decision tree (CBDT), the cognitive reliability and error analysis method (CREAM) and so on. Most HRA methods have been developed with a focus on full power operation of NPPs even though human performance may more largely affect the safety of the system during low power and shutdown (LPSD) operation than it would when the system is in full power operation. In this regard, it is necessary to conduct a research for developing HRA method to be used in LPSD operation. For the first step of the study, main drivers which affect the possibility of human error have been developed. Drivers which are commonly called as performance shaping factors (PSFs) are aspects of the human's individual characteristics, environment, organization, or task that specifically decrements or improves human performance, thus respectively increasing or decreasing the likelihood of human errors. In order to estimate the possibility of human error and identify its nature, human reliability analysis (HRA) methods have been implemented. For this, various HRA methods have been developed so far: techniques for human error rate prediction (THERP), cause based decision tree (CBDT), the cognitive reliability and error analysis method (CREAM) and so on. Most HRA methods have been developed with a focus on full power operation of NPPs even though human performance may more largely affect the safety of the system during low power and shutdown (LPSD) operation than it would when the system is in full power operation. In this regard, it is necessary to conduct a research for developing HRA method to be used in LPSD operation. For the first step of the study, main drivers which affect the possibility of human error have been developed. Drivers

  13. The Probabilistic Safety Analysis during low power and shutdown, framework to improve safety; El APS a baja potencia en parada, marco para la mejora de la seguridad

    Energy Technology Data Exchange (ETDEWEB)

    Nos, V.

    2014-02-01

    Historically Probabilistic Safety Analysis (PSA) has been focused exclusively at full power operation, nevertheless, operational experience has revealed that events occurred during low power and shutdown can also present threats for the safety of the plant. Through qualitative assessment (NUMARC 91-06) about the configuration in shutdown have been internationally accepted, the benefits of Low Power and Shutdown PSA have been demonstrated as fundamental framework of quantitative understanding for improving safety and risk management in the above mentioned operative conditions of the plant. (Author)

  14. What History Tells Us about the Distinct Nature of Chemistry.

    Science.gov (United States)

    Chang, Hasok

    2018-01-08

    Attention to the history of chemistry can help us recognise the characteristics of chemistry that have helped to maintain it as a separate scientific discipline with a unique identity. Three such features are highlighted in this paper. First, chemistry has maintained a distinct type of theoretical thinking, independent from that of physics even in the era of quantum chemistry. Second, chemical research has always been shaped by its ineliminable practical relevance and usefulness. Third, the lived experience of chemistry, spanning the laboratory, the classroom and everyday life, is distinctive in its multidimensional sensuousness. Furthermore, I argue that the combination of these three features makes chemistry an exemplary science.

  15. Time Delay for the Initiation of an Emergency Shutdown at the Peruvian Nuclear Reactor RP-10

    Energy Technology Data Exchange (ETDEWEB)

    Ramon, A.; Ovalle, E.; Canaza, D.; Salazar, A.; Zapata, A.; Felix, J.; Arrieta, R.; Vela, M. [Instituto Peruano de Energia Nuclear, Av. Canada 1470, San Borja, Lima (Peru)

    2008-07-01

    In this paper we show the measurement of the time delay for the initiation of an emergency shutdown state at the RP-10 Reactor. This time delay is the one corresponding to the delay between the detection of a signal of any fixed limit and the start of a protective action to get the reactor in a safety state. The experimental method used is based on monitoring two signals in an oscilloscope, one signal is the elected initiate event and the other is the de-energizing of electromagnets of the security bars. The time delay for each safety and control rods, was measured for seven energizing current values in a range of 36 - 52 mA. The results showed that the minimum value is (84 {+-} 1.26) ms and the maximum is (108 {+-} 1.60) ms. In all cases it is noted that, the delay time is less than the limit values prefixed down in the reactor safety report. (authors)

  16. Optimization of a landfill gas collection shutdown based on an adapted first-order decay model.

    Science.gov (United States)

    Lagos, Daniel A; Héroux, Martin; Gosselin, Ryan; Cabral, Alexandre R

    2017-05-01

    LandGEM's equation was reformulated to include two types of refuse, fast decaying refuse (FDR) and slow decaying refuse (SDR), whose fractions and key modeling parameters k and L0 were optimized independently for three periods in the life of the Montreal-CESM landfill. Three scenarios were analyzed and compared to actual biogas collection data: (1) Two-Variable Scenario, where k and L0 were optimized for a single type of refuse; (2) Six-Variable Scenario, where three sets of k and L0 were optimized for the three periods and for a single type of refuse; and (3) Seven-Variable Scenario, whereby optimization was performed for two sets of k and L0, one associated with FDR and the second with SDR, and for the fraction of FDR during each of the three periods. Results showed that the lowest error from the error minimization technique was obtained with the Six-Variable Scenario. However, this scenario's estimation of gas generation was found to be rather unlikely. The Seven-Variable Scenario, which allowed for considerations about changes in landfilling trends, offered a more reliable prediction tool for landfill gas generation and optimal shutdown time of the biogas collection system, when the minimum technological threshold would be attained. The methodology could potentially be applied mutatis mutandis to other landfills, by considering their specific waste disposal and gas collection histories. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Control of radio-iodine at the German reprocessing plant WAK during operation and after shutdown

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, F.J.; Herrmann, B.; Kuhn, K.D. [Wiederaufarbeitungsanlage Karlsruhe (Germany)] [and others

    1997-08-01

    During 20 years of operation 207 metric tons of oxide fuel from nuclear power reactors with 19 kg of iodine-129 had been reprocessed in the WAK plant near Karlsruhe. In January 1991 the WAK Plant was shut down. During operation iodine releases of the plant as well as the iodine distribution over the liquid and gaseous process streams had been determined. Most of the iodine is evolved into the dissolver off-gas in volatile form. The remainder is dispersed over many aqueous, organic and especially gaseous process and waste streams. After shut down of the plant in January 1991, iodine measurements in the off-gas streams have been continued up to now. Whereas the iodine-129 concentration in the dissolver off-gas dropped during six months after shutdown by three orders of magnitude, the iodine concentrations in the vessel ventilation system of the PUREX process and the cell vent system decreased only by a factor of 10 during the same period. Iodine-129 releases of the liquid high active waste storage tanks did not decrease distinctly. The removal efficiencies of the silver impregnated iodine filters in the different off-gas streams of the WAK plant depend on the iodine concentration in the off-gas. The reason of the observed dependence of the DF on the iodine-129 concentration might be due to the presence of organic iodine compounds which are difficult to remove. 13 refs., 3 figs.

  18. Shut-down dose rate analyses for the ITER electron cyclotron-heating upper launcher

    Energy Technology Data Exchange (ETDEWEB)

    Weinhorst, Bastian; Serikov, Arkady; Fischer, Ulrich; Lu, Lei [Institute for Neutron Physics and Reactor Technology INR (Germany); Karlsruhe Institute of Technology KIT (Germany); Spaeh, Peter; Strauss, Dirk [Institute for Applied Materials IAM (Germany); Karlsruhe Institute of Technology KIT (Germany)

    2014-10-15

    The electron cyclotron resonance heating upper launcher (ECHUL) is going to be installed in the upper port of the ITER tokamak thermonuclear fusion reactor for plasma mode stabilization (neoclassical tearing modes and the sawtooth instability). The paper reports the latest neutronic modeling and analyses which have been performed for the ITER reference front steering launcher design. It focuses on the port accessibility after reactor shut-down for which dose rate (SDDR) distributions on a fine regular mesh grid were calculated. The results are compared to those obtained for the ITER Dummy Upper Port. The calculations showed that the heterogeneous ECHUL design gives rise to enhanced radiation streaming as compared to the homogenous dummy upper port. Therefore the used launcher geometry was upgraded to a more recent development stage. The inter-comparison shows a significant improvement of the launchers shielding properties but also the necessity to further upgrade the shielding performance. Furthermore, the analysis for the homogenous dummy upper port, which represents optimal shielding inside the launcher, demonstrates that the shielding upgrade also needs to include the launcher's environment.

  19. Summary of Information Presented at an NRC-Sponsored Low-Power Shutdown Public Workshop, April 27, 1999, Rockville, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, Timothy A.; Whitehead, Donnie W.; Lois, Erasmia

    1999-07-01

    This report summarizes a public workshop that was held on April 27, 1999, in Rockville, Maryland. The workshop was conducted as part of the US Nuclear Regulatory Commission's (NRC) efforts to further develop its understanding of the risks associated with low power and shutdown operations at US nuclear power plants. A sufficient understanding of such risks is required to support decision-making for risk-informed regulation, in particular Regulatory Guide 1.174, and the development of a consensus standard. During the workshop the NRC staff discussed and requested feedback from the public (including representatives of the nuclear industry, state governments, consultants, private industry, and the media) on the risk associated with low-power and shutdown operations.

  20. Human reliability analysis in low power and shut-down probabilistic safety assessment: Outcomes of an international initiative

    Directory of Open Access Journals (Sweden)

    Manna Giustino

    2012-01-01

    Full Text Available Since the beginning of the nuclear power generation, human performance has been a very important factor in all phases of the plant lifecycle: design, commissioning, operation, maintenance, surveillance, modification, and decommissioning. This aspect has been confirmed by the operating experience. A workshop was organized by the IAEA and the Joint Research Centre of the European Commission, on Harmonization of low power and shutdown probabilistic safety assessment for WWER nuclear power plants. One of the major objectives of the Workshop was to provide a comparison of the approaches and results of human reliability analyses for WWER 440 and WWER 1000, and gain insights for future application of human reliability analyses in Low Power and Shutdown scenarios. This paper provides the insights and conclusions of the workshops concerning human reliability analyses and human factors.

  1. Chemistry in Our Life

    Indian Academy of Sciences (India)

    IAS Admin

    toothpaste, soaps and cosmetics, (7) plastics and polymers, (8) chemistry in health and disease, (9) chemistry of building, (10) fire chemistry and (11) chemistry of electricity. To write on these topics at a popular level for lay persons, without bringing in chemical for- mulas, structures or equations, is extremely difficult.

  2. Preliminary review of critical shutdown heat removal items for common cause failure susceptibility on LMFBR's. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Allard, L.T.; Elerath, J.G.

    1976-02-01

    This document presents a common cause failure analysis for Critical LMFBR Shutdown Heat Removal Systems. The report is intended to outline a systematic approach to defining areas with significant potential for common causes of failure, and ultimately provide inputs to the reliability prediction model. A preliminary evaluation of postulatd single initiating causes resulting in multiple failures of LMFBR-SHRS items is presented in Appendix C. This document will be periodically updated to reflect new information and activity.

  3. Trending Fibrinolytic Dysregulation: Fibrinolysis Shutdown in the Days After Injury Is Associated With Poor Outcome in Severely Injured Children.

    Science.gov (United States)

    Leeper, Christine M; Neal, Matthew D; McKenna, Christine J; Gaines, Barbara A

    2017-09-01

    To trend fibrinolysis after injury and determine the influence of traumatic brain injury (TBI) and massive transfusion on fibrinolysis status. Admission fibrinolytic derangement is common in injured children and adults, and is associated with poor outcome. No studies examine fibrinolysis days after injury. Prospective study of severely injured children at a level 1 pediatric trauma center. Rapid thromboelastography was obtained on admission and daily for up to 7 days. Standard definitions of hyperfibrinolysis (HF; LY30 ≥3), fibrinolysis shutdown (SD; LY30 ≤0.8), and normal (LY30 = 0.9-2.9) were applied. Antifibrinolytic use was documented. Outcomes were death, disability, and thromboembolic complications. Wilcoxon rank-sum and Fisher exact tests were performed. Exploratory subgroups included massively transfused and severe TBI patients. In all, 83 patients were analyzed with median (interquartile ranges) age 8 (4-12) and Injury Severity Score 22 (13-34), 73.5% blunt mechanism, 47% severe TBI, 20.5% massively transfused. Outcomes were 14.5% mortality, 43.7% disability, and 9.8% deep vein thrombosis. Remaining in or trending to SD was associated with death (P = 0.007), disability (P = 0.012), and deep vein thrombosis (P = 0.048). Median LY30 was lower on post-trauma day (PTD)1 to PTD4 in patients with poor compared with good outcome; median LY30 was lower on PTD1 to PTD3 in TBI patients compared with non-TBI patients. HF without associated shutdown was not related to poor outcome, but extreme HF (LY30 >30%, n = 3) was lethal. Also, 50% of massively transfused patients in hemorrhagic shock demonstrated SD physiology on admission. All with HF (fc31.2%) corrected after hemostatic resuscitation without tranexamic acid. Fibrinolysis shutdown is common postinjury and predicts poor outcomes. Severe TBI is associated with sustained shutdown. Empiric antifibrinolytics for children should be questioned; thromboelastography-directed selective use should be considered for

  4. Discovery of practical production processes for arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides: Beginning of a new era of “super-trifluoromethyl” arene chemistry and its industry

    Directory of Open Access Journals (Sweden)

    Teruo Umemoto

    2012-03-01

    Full Text Available Various arylsulfur pentafluorides, ArSF5, have long been desired in both academic and industrial areas, and ArSF5 compounds have attracted considerable interest in many areas such as medicines, agrochemicals, and other new materials, since the highly stable SF5 group is considered a “super-trifluoromethyl group” due to its significantly higher electronegativity and lipophilicity. This article describes the first practical method for the production of various arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides, from the corresponding diaryl disulfides or aryl thiols. The method consists of two steps: (Step 1 treatment of a diaryl disulfide or an aryl thiol with chlorine in the presence of an alkali metal fluoride, and (step 2 treatment of the resulting arylsulfur chlorotetrafluoride with a fluoride source, such as ZnF2, HF, and Sb(III/V fluorides. The intermediate arylsulfur chlorotetrafluorides were isolated by distillation or recrystallization and characterized. The aspects of these new reactions are revealed and reaction mechanisms are discussed. As the method offers considerable improvement over previous methods in cost, yield, practicality, applicability, and large-scale production, the new processes described here can be employed as the first practical methods for the economical production of various arylsulfur pentafluorides and their higher homologues, which could then open up a new era of “super-trifluoromethyl” arene chemistry and its applications in many areas.

  5. Enhancing Efficiency of Safeguards at Facilities that are Shutdown or Closed-Down, including those being Decommissioned

    Energy Technology Data Exchange (ETDEWEB)

    Moran, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stern, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Colley, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Marzo, M. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-12-15

    International Atomic Energy Agency (IAEA) safeguards involves verification activities at a wide range of facilities in a variety of operational phases (e.g., under construction, start-up, operating, shutdown, closed-down, and decommissioned). Safeguards optimization for each different facility type and operational phase is essential for the effectiveness of safeguards implementation. The IAEA’s current guidance regarding safeguards for the different facility types in the various lifecycle phases is provided in its Design Information Examination (DIE) and Verification (DIV) procedure. 1 Greater efficiency in safeguarding facilities that are shut down or closed down, including those being decommissioned, could allow the IAEA to use a greater portion of its effort to conduct other verification activities. Consequently, the National Nuclear Security Administration’s Office of International Nuclear Safeguards sponsored this study to evaluate whether there is an opportunity to optimize safeguards approaches for facilities that are shutdown or closed-down. The purpose of this paper is to examine existing safeguards approaches for shutdown and closed-down facilities, including facilities being decommissioned, and to seek to identify whether they may be optimized.

  6. Shutdown dose rates at ITER equatorial ports considering radiation cross-talk from torus cryopump lower port

    Energy Technology Data Exchange (ETDEWEB)

    Juárez, Rafael, E-mail: rjuarez@ind.uned.es [Departamento de Ingeniería Energética, ETSII-UNED, Calle Juan del Rosal 12, Madrid 28040 (Spain); Pampin, Raul [F4E, Torres Diagonal Litoral B3, Josep Pla 2, Barcelona 08019 (Spain); Levesy, Bruno [ITER Organization, 13115 Route de Vinon sur Verdon, St Paul Lez Durance (France); Moro, Fabio [ENEA, Via Enrico Fermi 45, Frascati, Rome (Italy); Suarez, Alejandro [ITER Organization, 13115 Route de Vinon sur Verdon, St Paul Lez Durance (France); Sanz, Javier [Departamento de Ingeniería Energética, ETSII-UNED, Calle Juan del Rosal 12, Madrid 28040 (Spain)

    2015-11-15

    Shutdown dose rates for planned maintenance purposes is an active research field in ITER. In this work the radiation (neutron and gamma) cross-talk between ports in the most conservative case foreseen in ITER is investigated: the presence of a torus cryopump lower port, mostly empty for pumping efficiency reasons. There will be six of those ports: #4, #6, #10, #12, #16 and #18. The equatorial ports placed above them will receive a significant amount of additional radiation affecting the shutdown dose rates during in situ maintenance activities inside the cryostat, and particularly in the port interspace area. In this study a general situation to all the equatorial ports placed above torus cryopump lower ports is considered: a generic diagnostics equatorial port placed above the torus cryopump lower port (LP#4). In terms of shutdown dose rates at equatorial port interspace after 10{sup 6} s of cooling time, 405 μSv/h has been obtained, of which 160 μSv/h (40%) are exclusively due to radiation cross-talk from a torus cryopump lower port. Equatorial port activation due to only “local neutrons” contributes 166 μSv/h at port interspace, showing that radiation cross-talk from such a lower port is a phenomenon comparable in magnitude to the neutron leakage though the equatorial port plug.

  7. With its magnet rolled back during a shut-down of the Proton Synchrotron in 1969, the body of the 2 m hydrogen bubble chamber becomes visible

    CERN Multimedia

    CERN PhotoLab

    1969-01-01

    The 2 m hydrogen bubble chamber is undergoing modifications during the annual PS shutdown. For this, the two halves of the magnet, which normally hide the chamber, safety tanks, cooling pipes etc, are rolled back.

  8. A Study on the Risk Reduction Effect by MLCS (Mid-loop Level Control System) of EUAPR using the Low-Power and Shutdown PSA Result

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Keunsung; Choi, Sunmi [KHNP CRI, Daejeon (Korea, Republic of); Kim, Eden [FNC Technology Co., Yongin (Korea, Republic of)

    2016-10-15

    The EU-APR design has been developed in order to expand and diversify the global nuclear power market of APR1400. For the improvement of shutdown risk for the EUAPR, the mid-loop level control system (MLCS) is considered during mid-loop operation for the EU-APR, which is not incorporated into SKN 3 and 4 (APR1400 Type) in Korea. Commonly, the risk associated with the NPP can be identified through the PSA. Thus, this paper discusses the low power and shutdown (LPSD) risk reduction effect by MLCS using the Low-Power and Shutdown PSA Result. LPSD level 1 PSA models for EU-APR have been developed. The risk reduction effect by MLCS is discussed. Because the loss of shutdown cooling function during mid-loop is one of the most vulnerable events, the MLCS have a significant influence on CDF in LPSD PSA. The shutdown risk of domestic power plants would likely be reduced if the MLCS is adopted in all operating NPPs in Korea during the mid-loop operation. It is expected that this work will contribute to reduce shutdown risk of domestic power plants.

  9. Green chemistry: A tool in Pharmaceutical Chemistry

    OpenAIRE

    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...

  10. Interpretations of de-orbit, deactivation, and shutdown guidelines applicable to GEO satellites

    Science.gov (United States)

    Honda, L.; Perkins, J.; Sun, Sheng

    As the population of space debris in orbit around the Earth grows, the probability for catastrophic collisions increases. Many agencies such as the IADC, FCC, and UN have proposed space debris mitigation guidelines or recommendations. For example, a minimum increase in perigee altitude of 235km + (1000 Cr A / m) where Cr is the solar radiation pressure coefficient, A/m is the aspect area to dry mass ratio, and 235 km is the sum of the upper altitude of the geostationary orbit (GEO) protected region (200 km) and the maximum descent of a re-orbited spacecraft due to lunar-solar & geopotential perturbations (35 km) with an eccentricity less than or equal to 0.003. While this particular recommendation is reasonably straightforward, the assumptions an operator chooses may change the result by 25 km. Other recommendations are more ambiguous. For example, once the space vehicle has been de-orbited to the required altitude, all on-board stored energy sources must be discharged by venting propellants and pressurants, discharging batteries and disabling the ability to charge them, and performing other appropriate measures. “ Vented” is not usually defined. In addition, the broadcasting capability of the spacecraft must be disabled. Boeing and its customers are working together to devise de-orbit and deactivation sequences that meet the spirit of the recommendations. This paper derives and proposes a generic minimum deorbit altitude, appropriate depletion and venting pressures based on tank design, propellant and pressurant type, and an acceptable shutdown procedure and final configuration that avoid interference with those still in the GEO belt well into the future. The goal of this paper is to open a dialogue with the global community to establish reasonable guidelines that are straightforward, safe, and achievable before an absolute requirement is set.

  11. Evolution of the ATLAS distributed computing system during the LHC long shutdown

    Science.gov (United States)

    Campana, S.; Atlas Collaboration

    2014-06-01

    The ATLAS Distributed Computing project (ADC) was established in 2007 to develop and operate a framework, following the ATLAS computing model, to enable data storage, processing and bookkeeping on top of the Worldwide LHC Computing Grid (WLCG) distributed infrastructure. ADC development has always been driven by operations and this contributed to its success. The system has fulfilled the demanding requirements of ATLAS, daily consolidating worldwide up to 1 PB of data and running more than 1.5 million payloads distributed globally, supporting almost one thousand concurrent distributed analysis users. Comprehensive automation and monitoring minimized the operational manpower required. The flexibility of the system to adjust to operational needs has been important to the success of the ATLAS physics program. The LHC shutdown in 2013-2015 affords an opportunity to improve the system in light of operational experience and scale it to cope with the demanding requirements of 2015 and beyond, most notably a much higher trigger rate and event pileup. We will describe the evolution of the ADC software foreseen during this period. This includes consolidating the existing Production and Distributed Analysis framework (PanDA) and ATLAS Grid Information System (AGIS), together with the development and commissioning of next generation systems for distributed data management (DDM/Rucio) and production (Prodsys-2). We will explain how new technologies such as Cloud Computing and NoSQL databases, which ATLAS investigated as R&D projects in past years, will be integrated in production. Finally, we will describe more fundamental developments such as breaking job-to-data locality by exploiting storage federations and caches, and event level (rather than file or dataset level) workload engines.

  12. Practical application of biological variation and Sigma metrics quality models to evaluate 20 chemistry analytes on the Beckman Coulter AU680.

    Science.gov (United States)

    Tran, Mai Thi Chi; Hoang, KienTrung; Greaves, Ronda F

    2016-11-01

    This study aimed to evaluate the imprecision and bias data generated for 20 routine chemistry analytes against both the biological variation fitness for purpose (FFP) and Sigma metrics (SM) criteria. Twenty serum/plasma analytes were evaluated on the Beckman Coulter AU680. Third party commercial lyophilized internal quality control samples of human origin were used for day-to-day imprecision calculations. Commercial external quality assurance (EQA) samples were used to determine the systematic error between the test method result and the instrument group mean result from the EQA program for each analyte. Biological variation data was used to calculate the minimum, desirable and optimal imprecision and bias for determination of FFP. The desirable total allowable error was determined from biological variation data and applied to the SM calculation. The outcomes of both quality approaches were then compared. The day-to-day imprecision of most tested analytes (except sodium and chloride) were smaller than the allowable imprecision (ranging from minimum to optimum). Most analytes achieved at least minimum bias. The SM varied with analyte concentration with six analytes producing low Sigma values. Comparing the quality processes eleven analytes produced a green light for both FFP and SM. There was some difference seen in interpretation for the other nine analytes. The individual interpretation of bias and imprecision using FFP criteria allowed for the clear determination of the major source of error. Whereas, SM provided a summative evaluation of method performance. But the selection of total allowable error (TEa) is fundamental to this interpretation and harmonisation of the TEa calculation is needed. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  13. Beryllium chemistry and processing

    CERN Document Server

    Walsh, Kenneth A

    2009-01-01

    This book introduces beryllium; its history, its chemical, mechanical, and physical properties including nuclear properties. The 29 chapters include the mineralogy of beryllium and the preferred global sources of ore bodies. The identification and specifics of the industrial metallurgical processes used to form oxide from the ore and then metal from the oxide are thoroughly described. The special features of beryllium chemistry are introduced, including analytical chemical practices. Beryllium compounds of industrial interest are identified and discussed. Alloying, casting, powder processing, forming, metal removal, joining and other manufacturing processes are covered. The effect of composition and process on the mechanical and physical properties of beryllium alloys assists the reader in material selection. The physical metallurgy chapter brings conformity between chemical and physical metallurgical processing of beryllium, metal, alloys, and compounds. The environmental degradation of beryllium and its all...

  14. Constitutional dynamic chemistry: bridge from supramolecular chemistry to adaptive chemistry.

    Science.gov (United States)

    Lehn, Jean-Marie

    2012-01-01

    Supramolecular chemistry aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the investigation of chemical systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems. Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.The merging of the features: -information and programmability, -dynamics and reversibility, -constitution and structural diversity, points to the emergence of adaptive and evolutive chemistry, towards a chemistry of complex matter.

  15. Handbook of computational quantum chemistry

    CERN Document Server

    Cook, David B

    2005-01-01

    Quantum chemistry forms the basis of molecular modeling, a tool widely used to obtain important chemical information and visual images of molecular systems. Recent advances in computing have resulted in considerable developments in molecular modeling, and these developments have led to significant achievements in the design and synthesis of drugs and catalysts. This comprehensive text provides upper-level undergraduates and graduate students with an introduction to the implementation of quantum ideas in molecular modeling, exploring practical applications alongside theoretical explanations.Wri

  16. Kinetic model framework for aerosol and cloud surface chemistry and gas-particle interactions ─ Part 2: Exemplary practical applications and numerical simulations

    Directory of Open Access Journals (Sweden)

    M. Ammann

    2007-12-01

    Full Text Available A kinetic model framework with consistent and unambiguous terminology and universally applicable rate equations and parameters for aerosol and cloud surface chemistry and gas-particle interactions has been presented in the preceding companion paper by Pöschl, Rudich and Ammann (Pöschl et al., 2007, abbreviated PRA. It allows to describe mass transport and chemical reaction at the gas-particle interface and to link aerosol and cloud surface processes with gas phase and particle bulk processes. Here we present multiple exemplary model systems and calculations illustrating how the general mass balance and rate equations of the PRA framework can be easily reduced to compact sets of equations which enable a mechanistic description of time and concentration dependencies of trace gas uptake and particle composition in systems with one or more chemical components and physicochemical processes. Time-dependent model scenarios show the effects of reversible adsorption, surface-bulk transport, and chemical aging on the temporal evolution of trace gas uptake by solid particles and solubility saturation of liquid particles. They demonstrate how the transformation of particles and the variation of trace gas accommodation and uptake coefficients by orders of magnitude over time scales of microseconds to days can be explained and predicted from the initial composition and basic kinetic parameters of model systems by iterative calculations using standard spreadsheet programs. Moreover, they show how apparently inconsistent experimental data sets obtained with different techniques and on different time scales can be efficiently linked and mechanistically explained by application of consistent model formalisms and terminologies within the PRA framework. Steady-state model scenarios illustrate characteristic effects of gas phase composition and basic kinetic parameters on the rates of mass transport and chemical reactions. They demonstrate how adsorption and

  17. Coordination Chemistry of Life Processes: Bioinorganic Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. Coordination Chemistry of Life Processes: Bioinorganic Chemistry. R N Mukherjee. General Article Volume 4 Issue 9 September 1999 pp 53-62. Fulltext. Click here to view fulltext PDF. Permanent link:

  18. Environmental chemistry: Volume A

    Energy Technology Data Exchange (ETDEWEB)

    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. A dictionary of chemistry

    National Research Council Canada - National Science Library

    Daintith, John

    2008-01-01

    "Fully revised and updated, the sixth edition of this popular dictionary covers all aspects of chemistry from physical chemistry to biochemisty, and boasts broader coverage in forensics, metallurgy, and geology...

  20. Organometallic Chemistry of Molybdenum.

    Science.gov (United States)

    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)

  1. Advanced Chemistry Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Description/History: Chemistry laboratoryThe Advanced Chemistry Laboratory (ACL) is a unique facility designed for working with the most super toxic compounds known...

  2. How sonochemistry contributes to green chemistry?

    Science.gov (United States)

    Chatel, Gregory

    2018-01-01

    Based on the analyses of papers from the literature, and especially those published in Ultrasonics Sonochemistry journal, the contribution of sonochemistry to green chemistry area has been discussed here. Important reminders and insights on the good practices and considerations have been made to understand and demonstrate how sonochemistry can continue to efficiently contribute to green chemistry area in the further studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. The Birth of Modern Chemistry

    OpenAIRE

    Rayner, Thomas Allan; Mackevica, Aiga

    2009-01-01

    Alchemy was a science practiced for more than two millennia up till the end of 18th century when it was replaced by modern chemistry, which is practiced up till this very day. The purpose of this report is to look into this shift and investigate whether this shift can be classified as a paradigm shift according to the famous philosopher Thomas Kuhn, who came up with a theory on the structure of scientific revolutions. In order to come to draw any kind of conclusions, the report...

  4. Chemistry is Evergreen

    Indian Academy of Sciences (India)

    Srimath

    RESONANCE ⎜ March 2009. GENERAL ⎜ ARTICLE. Keywords. Green fluorescent protein,. FRET. Chemistry is Evergreen. 2008 Nobel Prize in Chemistry. Swagata Dasgupta. Swagata Dasgupta is an. Associate Professor in the. Department of Chemistry at IIT Kharagpur. Her research interests revolve around proteins and ...

  5. Green Chemistry and Education.

    Science.gov (United States)

    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)

  6. American Association for Clinical Chemistry

    Science.gov (United States)

    ... Find the answer to your question IN CLINICAL CHEMISTRY Hs-cTnI as a Gatekeeper for Further Cardiac ... Online Harmonization.net Commission on Accreditation in Clinical Chemistry American Board of Clinical Chemistry Clinical Chemistry Trainee ...

  7. Francis-99: Transient CFD simulation of load changes and turbine shutdown in a model sized high-head Francis turbine

    Science.gov (United States)

    Mössinger, Peter; Jester-Zürker, Roland; Jung, Alexander

    2017-01-01

    With increasing requirements for hydropower plant operation due to intermittent renewable energy sources like wind and solar, numerical simulations of transient operations in hydraulic turbo machines become more important. As a continuation of the work performed for the first workshop which covered three steady operating conditions, in the present paper load changes and a shutdown procedure are investigated. The findings of previous studies are used to create a 360° model and compare measurements with simulation results for the operating points part load, high load and best efficiency. A mesh motion procedure is introduced, allowing to represent moving guide vanes for load changes from best efficiency to part load and high load. Additionally an automated re-mesh procedure is added for turbine shutdown to ensure reliable mesh quality during guide vane closing. All three transient operations are compared to PIV velocity measurements in the draft tube and pressure signals in the vaneless space. Simulation results of axial velocity distributions for all three steady operation points, during both load changes and for the shutdown correlated well with the measurement. An offset at vaneless space pressure is found to be a result of guide vane corrections for the simulation to ensure similar velocity fields. Short-time Fourier transformation indicating increasing amplitudes and frequencies at speed-no load conditions. Further studies will discuss the already measured start-up procedure and investigate the necessity to consider the hydraulic system dynamics upstream of the turbine by means of a 1D3D coupling between the 3D flow field and a 1D system model.

  8. The New Color of Chemistry: Green Chemistry

    Directory of Open Access Journals (Sweden)

    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. Surface chemistry essentials

    CERN Document Server

    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

  10. Complex of technologies and prototype systems for eco-friendly shutdown of the power-generating, process, capacitive, and transport equipment

    Science.gov (United States)

    Smorodin, A. I.; Red'kin, V. V.; Frolov, Y. D.; Korobkov, A. A.; Kemaev, O. V.; Kulik, M. V.; Shabalin, O. V.

    2015-07-01

    A set of technologies and prototype systems for eco-friendly shutdown of the power-generating, process, capacitive, and transport equipment is offered. The following technologies are regarded as core technologies for the complex: cryogenic technology nitrogen for displacement of hydrogen from the cooling circuit of turbine generators, cryo blasting of the power units by dioxide granules, preservation of the shutdown power units by dehydrated air, and dismantling and severing of equipment and structural materials of power units. Four prototype systems for eco-friendly shutdown of the power units may be built on the basis of selected technologies: Multimode nitrogen cryogenic system with four subsystems, cryo blasting system with CO2 granules for thermal-mechanical and electrical equipment of power units, and compressionless air-drainage systems for drying and storage of the shutdown power units and cryo-gas system for general severing of the steam-turbine power units. Results of the research and pilot and demonstration tests of the operational units of the considered technological systems allow applying the proposed technologies and systems in the prototype systems for shutdown of the power-generating, process, capacitive, and transport equipment.

  11. The New Color of Chemistry: Green Chemistry

    OpenAIRE

    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...

  12. Radiation chemistry and its application

    Energy Technology Data Exchange (ETDEWEB)

    Majima, Tetsuro [Osaka Univ., Osaka (Japan)

    2013-07-01

    Effects of radiation to human body have been seriously discussed nowadays. These are important issues for the realization of sustainable society. It should be emphasized that various reactive intermediates generated by radiation play important roles in each cases. Radiation chemical studies will provide various reaction-mechanistic aspects on these important issues. Our research group has continuously carried out reaction-mechanistic studies using radiation chemical methods. From these studies, we have obtained a variety of results on basic molecular systems, reactions, materials that are close to practical application, biological systems and so on. Reactive species are generated from the radiation reactions in solution, and can be used as one-electron oxidative and reductive reagent to give selectively radical cation and anion of solute molecules such as various organic and inorganic molecules. Therefore, the radiation chemistry has contributed significantly to chemistry in which one-electron oxidation and reduction play the important role. The kinetics of such redox processes and the following reduction play the important role. The kinetics of such redox processes and the following reactions can be studied in real time with the transition absorption measurement by the pulse radiolysis technique. Even though the target compounds cannot be oxidized and reduced in chemical or electrochemical oxidation and reduction, their one-electron redox can be performed by the electron beam radiation. Therefore, radiation chemistry is very useful technique for basic science. Moreover, application potentials of radiation chemistry are so high for various research subjects. Moreover, application potentials of radiation chemistry are so high for various research subjects.

  13. Understanding the hydrologic impacts of wastewater treatment plant discharge to shallow groundwater: Before and after plant shutdown

    Science.gov (United States)

    Hubbard, Laura E.; Keefe, Steffanie H.; Kolpin, Dana W.; Barber, Larry B.; Duris, Joseph W.; Hutchinson, Kasey J.; Bradley, Paul M.

    2016-01-01

    Effluent-impacted surface water has the potential to transport not only water, but wastewater-derived contaminants to shallow groundwater systems. To better understand the effects of effluent discharge on in-stream and near-stream hydrologic conditions in wastewater-impacted systems, water-level changes were monitored in hyporheic-zone and shallow-groundwater piezometers in a reach of Fourmile Creek adjacent to and downstream of the Ankeny (Iowa, USA) wastewater treatment plant (WWTP). Water-level changes were monitored from approximately 1.5 months before to 0.5 months after WWTP closure. Diurnal patterns in WWTP discharge were closely mirrored in stream and shallow-groundwater levels immediately upstream and up to 3 km downstream of the outfall, indicating that such discharge was the primary control on water levels before shutdown. The hydrologic response to WWTP shutdown was immediately observed throughout the study reach, verifying the far-reaching hydraulic connectivity and associated contaminant transport risk. The movement of WWTP effluent into alluvial aquifers has implications for potential WWTP-derived contamination of shallow groundwater far removed from the WWTP outfall.

  14. Ab initio valence calculations in chemistry

    CERN Document Server

    Cook, D B

    1974-01-01

    Ab Initio Valence Calculations in Chemistry describes the theory and practice of ab initio valence calculations in chemistry and applies the ideas to a specific example, linear BeH2. Topics covered include the Schrödinger equation and the orbital approximation to atomic orbitals; molecular orbital and valence bond methods; practical molecular wave functions; and molecular integrals. Open shell systems, molecular symmetry, and localized descriptions of electronic structure are also discussed. This book is comprised of 13 chapters and begins by introducing the reader to the use of the Schrödinge

  15. A descriptive model of the molten salt reactor experiment after shutdown: Review of FY 1995 progress

    Energy Technology Data Exchange (ETDEWEB)

    Williams, D.F.; Del Cul, G.D.; Toth, L.M.

    1996-01-01

    During FY 1995 considerable progress was made toward gaining a better understanding of the chemistry and transport processes that continue to govern the behavior of the Molten Salt Reactor Experiment (MSRE). As measurements in the MSRE proceed, laboratory studies continue, and better analyses are available, our understanding of the state of the MSRE and the best path toward remediation improves. Because of the immediate concern about the deposit in the auxiliary charcoal bed (ACB), laboratory studies in the past year focused on carbon-fluorine chemistry. Secondary efforts were directed toward investigation of gas generation from MSRE salts by both radiolytic and nonradiolytic pathways. In addition to the laboratory studies, field measurements at the MSRE provided the basis for estimating the inventory of uranium and fluorine in the ACB. Analysis of both temperature and radiation measurements provided independent and consistent estimates of about 2.6 kg of uranium deposited in the top of the ACB. Further analysis efforts included a refinement in the estimates of the fuel- salt source term, the deposited decay energy, and the projected rate of radiolytic gas generation. This report also provides the background material necessary to explain new developments and to review areas of particular interest. The detailed history of the MSRE is extensively documented and is cited where appropriate. This work is also intended to update and complement the more recent MSRE assessment reports.

  16. laboratory activities and students practical performance

    African Journals Online (AJOL)

    unesco

    ABSTRACT. The major objective of this study was to offer an overview of the current situation in the course practical organic chemistry I of Haramaya University. All first year second semester chemistry students, laboratory instructors and Practical Organic Chemistry I course material were involved as the main source of data.

  17. Human Reliability Analysis. Applicability of the HRA-concept in maintenance shutdown; Analys av maensklig tillfoerlitlighet. HRA-begreppets tillaempbarhet vid revisionsavstaellning

    Energy Technology Data Exchange (ETDEWEB)

    Obenius, Aino (MTO Psykologi AB, Stockholm (SE))

    2007-08-15

    Probabilistic Safety Analysis (PSA) is performed for Swedish nuclear power plants in order to make predictions and improvements of system safety. The analysis of the Three Mile Island and Chernobyl accidents contributed to broaden the approach to nuclear power plant safety. A system perspective focusing on the interaction between aspects of Man, Technology and Organization (MTO) emerged in addition to the development of Human Factors knowledge. To take the human influence on the technical system into consideration when performing PSAs, a Human Reliability Analysis (HRA) is performed. PSA is performed for different stages and plant operating states, and the current state of Swedish analyses is Low power and Shutdown (LPSD), also called Shutdown PSA (SPSA). The purpose of this master's thesis is to describe methods and basic models used when analysing human reliability for the LPSD state. The following questions are at issue: 1. How can the LPSD state be characterised and defined? 2. What is important to take into consideration when performing a LPSD HRA? 3. How can human behaviour be modelled for a LPSD risk analysis? 4. According to available empirical material, how are the questions above treated in performed analysis of human operation during LPSD? 5. How does the result of the questions above affect the way methods for analysis of LPSD could and/or should be developed? The procedure of this project has mainly consisted of literature studies of available theory for modelling of human behaviour and risk analysis of the LPSD state. This study regards analysis of planned outages when maintenance, fuel change, tests and inspections are performed. The outage period is characterised by planned maintenance activities performed in rotating 3-shifts, around the clock, as well as many of the persons performing work tasks on the plant being external contractors. The working conditions are characterised by stress due to heat, radiation and physically demanding or

  18. Development of Abnormal Operating Strategies for Loss of Ultimate Heat Sink (LOUHS) at Shutdown Mode in Westinghouse Type Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Duk-Joo; Lee, Seung-Chan; Sung, Je-Joong; Ha, Sang Jun [KHNP CRI, Daejeon (Korea, Republic of); Hwang, Su-Hyun [FNC Tech. Co., Yongin (Korea, Republic of)

    2016-10-15

    Loss of all AC power is classified as one of multiple failure accident by regulatory guide of Korean accident management program. Therefore we need develop strategies for the abnormal operating procedure both of power operating and shutdown mode. This paper developed abnormal operating guideline for loss of all AC power by analysis of accident scenario in pressurized water reactor. This paper analyzed the extended SBO in shutdown operating mode and developed the operating strategy of the abnormal operation procedure. Operator action for the emergency are not required to take in 500 minutes and 60 minutes in intact and opened RCS state respectively.

  19. Which systems (except main circuits) should be commissioned/tested for 7 TeV operation before the long shutdown?

    OpenAIRE

    Pojer, M

    2011-01-01

    The key driver of the long 2012/13 shutdown is the consolidation of the 13 kA splices. Once the machine will be back to operation, the increase of energy to 7 TeV should be possible. Are all circuits and systems ready for 7 TeV operation? This paper focuses on what else could limit LHC high energy operation and how we can know that in advance. A period of dedicated testing at the end of operation and before the long shutdown could give a precious knowledge on the status of the machine.

  20. Journal of Business Chemistry

    OpenAIRE

    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...

  1. Orbital interactions in chemistry

    CERN Document Server

    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

  2. USSR Report, Chemistry

    National Research Council Canada - National Science Library

    1986-01-01

    This USSR Report on Chemistry contains articles on Aerosols, Adsorption, Biochemistry, Catalysis, Chemical Industry, Coal Gasification, Electrochemistry, Explosives and Explosions, Fertilizers, Food...

  3. Advances in quantum chemistry

    CERN Document Server

    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

  4. Canopy Chemistry (OTTER)

    Data.gov (United States)

    National Aeronautics and Space Administration — Canopy characteristics: leaf chemistry, specific leaf area, LAI, PAR, IPAR, NPP, standing biomass--see also: Meteorology (OTTER) for associated meteorological...

  5. Elements of environmental chemistry

    National Research Council Canada - National Science Library

    Hites, R. A; Raff, Jonathan D

    2012-01-01

    ... more. Extensively revised, updated, and expanded, this second edition includes new chapters on atmospheric chemistry, climate change, and polychlorinated biphenyls and dioxins, and brominated flame retardants...

  6. Computational Chemistry for Kids

    National Research Council Canada - National Science Library

    Naef, Olivier

    2000-01-01

    This article aims to show that computational chemistry is not exclusively restricted to molecular energy and structure calculations but also includes chemical process control and reaction simulation...

  7. Contribution from philosophy of chemistry to chemistry education: In a case of ionic liquids as technochemistry

    Science.gov (United States)

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

    2017-08-01

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

  8. A Human Reliability Analysis of Pre-Accident Human Errors in the Low Power and Shutdown PSA of the KSNP

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Daeil; Jang, Seungchul

    2007-03-15

    Korea Atomic Energy Research Institute, using the ANS Low Power /Shutdown (LPSD)PRA Standard, evaluated the LPSD PSA model of the KSNP, Younggwang (YGN) Units 5 and 6, and identified the items to be improved. The evaluation results of human reliability analysis (HRA) of the pre-accident human errors in the LPSD PSA model of the KSNP showed that 13 items among 15 items of supporting requirements for those in the ANS PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for pre-accident human errors in the LPSD PSA model for the KSNP to improve its quality. We considered potential pre-accident human errors for all manual valves and control/instrumentation equipment of the systems modeled in the KSNP LPSD PSA model except reactor protection system/ engineering safety features actuation system. We reviewed 160 manual valves and 56 control/instrumentation equipment. The number of newly identified pre-accident human errors is 101. Among them, the number of those related to testing/maintenance tasks is 56. The number of those related to calibration tasks is 45. The number of those related to only shutdown operation is 10. It was shown that the pre-accident human errors related to only shutdown operation contributions to the core damage frequency of LPSD PSA model for the KSNP was negligible.The self-assessment results for the new HRA results of pre-accident human errors using the ANS LPSD PRA Standard show that above 80% items of its supporting requirements for post-accident human errors were graded as its Category II or III. It is expected that the HRA results for the pre-accident human errors presented in this study will be greatly helpful to improve the PSA quality for the domestic nuclear power plants because they have sufficient PSA quality to meet the Category II of supporting requirements for the postaccident human errors in the ANS LPSD PRA Standard.

  9. Modern Trends in Inorganic Chemistry

    Indian Academy of Sciences (India)

    Unknown

    projections of research in frontier areas of inorganic chemistry, includ- ing organometallics, bio-inorganic chemistry, catalysis and materials chemistry. We do hope that the wide range of topics covered in this Issue reflect the current trends of research in inorganic chemistry in India and prac- titioners of inorganic chemistry ...

  10. ict in teaching and learning chemistry activities on the ipad

    African Journals Online (AJOL)

    IICBA01

    ABSTRACT. The purpose of this workshop is to equip chemistry educators with practical activities and logistical training to incorporate Information and Communication Technologies (ICT) into their chemistry curriculum. During this workshop, participants will gain hands-on experience using technology such as iPads and a ...

  11. Plasma chemistry for inorganic materials

    Science.gov (United States)

    Matsumoto, O.

    1980-01-01

    Practical application of plasma chemistry to the development of inorganic materials using both low temperature and warm plasmas are summarized. Topics cover: the surface nitrification and oxidation of metals; chemical vapor deposition; formation of minute oxide particles; the composition of oxides from chloride vapor; the composition of carbides and nitrides; freezing high temperature phases by plasma arc welding and plasma jet; use of plasma in the development of a substitute for petroleum; the production of silicon for use in solar cell batteries; and insulating the inner surface of nuclear fusion reactor walls.

  12. Diversity in Medicinal Chemistry.

    Science.gov (United States)

    Peralta, David

    2018-01-08

    The wide world of medicinal chemistry: We look back at our activities in 2017, particularly the expansion of the journal's scope to nanomedicine and why we need a more inclusive medicinal chemistry journal. Additionally, we look at upcoming special issues and developments for ChemPubSoc Europe in 2018. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Chemistry in Microfluidic Channels

    Science.gov (United States)

    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…

  14. Exercises in Computational Chemistry

    DEFF Research Database (Denmark)

    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)....

  15. The Breath of Chemistry

    DEFF Research Database (Denmark)

    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...

  16. Movies in Chemistry Education

    Science.gov (United States)

    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…

  17. Chemistry of americium

    Energy Technology Data Exchange (ETDEWEB)

    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)

  18. Chemistry is Evergreen

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 3. Chemistry is Everygreen - 2008 Nobel Prize in Chemistry. Swagata Dasgupta. General Article Volume 14 Issue 3 March 2009 pp 248-258. Fulltext. Click here to view fulltext PDF. Permanent link:

  19. SCAR - Post-Accident Simulator SIPA with safety analysis code CATHARE-2 and PWR cold shutdown state simulation

    Energy Technology Data Exchange (ETDEWEB)

    Farvacque, M.; Faydide, B. [CEA Grenoble, 38 (France). Dept. de Thermohydraulique et de Physique; Iffenecker, F.; Pentori, B. [Electricite de France, 75 - Paris (France); Dufeil, Ph.; Raimond, E. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Clamart (France)

    2003-07-01

    The use of Cathare in the simulators of pressurized water reactors has been effective since the beginning of the nineties. Scar project is the second stage of the Cathare strategy for the simulators, its main objective is the extension of the field of simulation to the accident situations in cold shutdown states. Work was carried out in 3 major areas: modelling, optimization and integration in the simulator. Throughout the project, the developments were part of a 3 stages validation strategy: -) elementary tests of the developments of new model on the N4 (1450 MW PWR); -) analytical tests and systems to ensure non regression of the validation of the physical laws of the Cathare code during the modifications carried out within the optimization stage; and -) overall tests of the SIPA-CP1 (900 MW PWR) simulator, controlled automatically by programmed scenarios including the transients which are carried out in PWR, the transients of the Regulatory Guides and the accident transients.

  20. The application of knowledge management and TRIZ for solving the safe shutdown capability of fire alarms in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chia-Nan; Chen, Hsin-Po; Hsueh, Ming-Hsien; Chin, Fong-Li [National Kaohsiung Univ. of Applied Sciences, Kaohsiung City, Taiwan (China). Dept. of Industrial Engineering and Management

    2017-11-15

    The Fukushima nuclear disaster in 2011 has raised widespread concern over the safety of nuclear power plants. This study employed knowledge management in conjunction with the Teoriya Resheniya Izobreatatelskih Zadatch (TRIZ) method in the formulation of a database to facilitate the evaluation of post-fire safe shutdown capability with the aim of safeguarding nuclear facilities in the event of fire. The proposed approach is meant to bring facilities in line with US Nuclear Regulatory Commission (NRC) standards. When implemented in a case study of an Asian nuclear power plant, our method proved highly effective in the detection of 22 cables that fell short of regulatory requirements, thereby reducing 850,000 paths to 0. This study could serve as reference for industry and academia in the development of systematic approaches to the upgrading of nuclear power plants.

  1. Dynamic responses of a semi-type offshore floating wind turbine during normal state and emergency shutdown

    Science.gov (United States)

    Hu, Zhi-qiang; Li, Liang; Wang, Jin; Hu, Qiu-hao; Shen, Ma-cheng

    2016-03-01

    This paper addresses joint wind-wave induced dynamic responses of a semi-type offshore floating wind turbine (OFWT) under normal states and fault event conditions. The analysis in this paper is conducted in time domain, using an aero-hydro-servo-elastic simulation code-FAST. Owing to the unique viscous features of the reference system, the original viscous damping model implemented in FAST is replaced with a quadratic one to gain an accurate capture of viscous effects. Simulation cases involve free-decay motion in still water, steady motions in the presence of regular waves and wind as well as dynamic response in operational sea states with and without wind. Simulations also include the cases for transient responses induced by fast blade pitching after emergency shutdown. The features of platform motions, local structural loads and a typical mooring line tension force under a variety of excitations are obtained and investigated.

  2. The first use of {sup 236}U in the general environment and near a shutdown nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Quinto, F. [Vienna Environmental Research Accelerator (VERA), Fakultaet fuer Physik - Isotopenforschung, Universitaet Wien, Waehringer Strasse 17, Wien A-1090 (Austria); Dipartimento di Scienze Ambientali, Seconda Universita di Napoli, via Vivaldi 43, 81100 Caserta (Italy); Center for Isotope Research on Cultural and Environmental Heritage (CIRCE) (Italy)], E-mail: francesca.quinto@unina2.it; Steier, P. [Vienna Environmental Research Accelerator (VERA), Fakultaet fuer Physik - Isotopenforschung, Universitaet Wien, Waehringer Strasse 17, Wien A-1090 (Austria); Wallner, G. [Institut fuer Anorganische Chemie, Universitaet Wien, Waehringer Strasse 42, Wien A-1090 (Austria); Wallner, A. [Vienna Environmental Research Accelerator (VERA), Fakultaet fuer Physik - Isotopenforschung, Universitaet Wien, Waehringer Strasse 17, Wien A-1090 (Austria); Srncik, M. [Institut fuer Anorganische Chemie, Universitaet Wien, Waehringer Strasse 42, Wien A-1090 (Austria); Bichler, M. [Atominstitut der Osterreichischen Universitaeten (ATI), Osterreichischen Universitaeten, Stadionallee 2, Wien A-1020 (Austria); Kutschera, W. [Vienna Environmental Research Accelerator (VERA), Fakultaet fuer Physik - Isotopenforschung, Universitaet Wien, Waehringer Strasse 17, Wien A-1090 (Austria); Terrasi, F.; Petraglia, A.; Sabbarese, C. [Dipartimento di Scienze Ambientali, Seconda Universita di Napoli, via Vivaldi 43, 81100 Caserta (Italy); Center for Isotope Research on Cultural and Environmental Heritage (CIRCE) (Italy)

    2009-10-15

    We present a first effort to investigate {sup 236}U in the environment near a shutdown nuclear power plant far away from highly contaminated sites, by using accelerator mass spectrometry. The detection limit of about 1 pg {sup 236}U allowed us to identify a minimal increase of the {sup 236}U/{sup 238}U isotopic ratio correlated to a peak of {sup 137}Cs in river sediments downstream of the nuclear power plant, and to detect anthropogenic {sup 236}U also upstream, where it is probably not related to the power plant but to global fallout. The {sup 236}U content shoved variations of the {sup 236}U/{sup 238}U isotopic ratio in relation to the chemical-physical characteristics of the sediments. This demonstrates the potential of {sup 236}U as an environmental tracer, and as an indicator for releases from nuclear facilities.

  3. The Affordances of Fiction for Teaching Chemistry

    Science.gov (United States)

    Yerrick, Randy K.; Simons, Tiffany

    2017-01-01

    As science fiction has a way of capturing the human imagination that few other genres can rival, this study sought to investigate the effects of using science fiction on the performance and interest of high school chemistry students. An action research approach was used to guide the first author's practice as she studied two college preparatory…

  4. Chemistry without Borders: Careers, Research, and Entrepreneurship

    Science.gov (United States)

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

  5. Solid Acid Catalysts in Green Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 10. Solid Acid Catalysts in Green Chemistry - Some Practical Examples. Leena Rao. General Article Volume 12 Issue 10 October 2007 pp 30-36. Fulltext. Click here to view fulltext PDF. Permanent link:

  6. Solid Acid Catalysts in Green Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 8. Solid Acid Catalysts in Green Chemistry - Emerging Eco-Friendly Practices in Chemical Industry. Leena Rao. General Article Volume 12 Issue 8 August 2007 pp 65-75 ...

  7. Avoiding general chemistry textbooks' misrepresentations of ...

    African Journals Online (AJOL)

    It is reported that there is a terminology problem as many authors state that practical equilibrium constants, viz. Kpand Kc, are unit-less quantities. Also, in many chemistry textbooks Kpplays the role of the thermodynamic equilibrium constant, Kº. Thus, after reviewing the proper definition of each of the terms analyzed, one ...

  8. Green polymer chemistry: biocatalysis and biomaterials

    Science.gov (United States)

    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...

  9. Learning Organic Chemistry Through Natural Products

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 9. Learning Organic Chemistry Through Natural Products A Practical Approach. N R Krishnaswamy. Series Article Volume 1 Issue 9 September 1996 pp 25-33. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. Computational Chemistry Capacity Building in an Underprivileged ...

    African Journals Online (AJOL)

    Its applications comprise a variety of fields, from drug design to the design of compounds with desired properties (e.g., catalysts with specific actions) and to ample overlaps with nanotechnology. However, despite its relevance, the presence of computational chemistry research in Sub-Saharan Africa is still scarce, practically ...

  11. Transuranic Computational Chemistry.

    Science.gov (United States)

    Kaltsoyannis, Nikolas

    2018-02-26

    Recent developments in the chemistry of the transuranic elements are surveyed, with particular emphasis on computational contributions. Examples are drawn from molecular coordination and organometallic chemistry, and from the study of extended solid systems. The role of the metal valence orbitals in covalent bonding is a particular focus, especially the consequences of the stabilization of the 5f orbitals as the actinide series is traversed. The fledgling chemistry of transuranic elements in the +II oxidation state is highlighted. Throughout, the symbiotic interplay of experimental and computational studies is emphasized; the extraordinary challenges of experimental transuranic chemistry afford computational chemistry a particularly valuable role at the frontier of the periodic table. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Biosynthetic inorganic chemistry.

    Science.gov (United States)

    Lu, Yi

    2006-08-25

    Inorganic chemistry and biology can benefit greatly from each other. Although synthetic and physical inorganic chemistry have been greatly successful in clarifying the role of metal ions in biological systems, the time may now be right to utilize biological systems to advance coordination chemistry. One such example is the use of small, stable, easy-to-make, and well-characterized proteins as ligands to synthesize novel inorganic compounds. This biosynthetic inorganic chemistry is possible thanks to a number of developments in biology. This review summarizes the progress in the synthesis of close models of complex metalloproteins, followed by a description of recent advances in using the approach for making novel compounds that are unprecedented in either inorganic chemistry or biology. The focus is mainly on synthetic "tricks" learned from biology, as well as novel structures and insights obtained. The advantages and disadvantages of this biosynthetic approach are discussed.

  13. Korean Kimchi Chemistry: A Multicultural Chemistry Connection

    Science.gov (United States)

    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,…

  14. Modern analytical chemistry in the contemporary world

    Science.gov (United States)

    Šíma, Jan

    2016-12-01

    Students not familiar with chemistry tend to misinterpret analytical chemistry as some kind of the sorcery where analytical chemists working as modern wizards handle magical black boxes able to provide fascinating results. However, this approach is evidently improper and misleading. Therefore, the position of modern analytical chemistry among sciences and in the contemporary world is discussed. Its interdisciplinary character and the necessity of the collaboration between analytical chemists and other experts in order to effectively solve the actual problems of the human society and the environment are emphasized. The importance of the analytical method validation in order to obtain the accurate and precise results is highlighted. The invalid results are not only useless; they can often be even fatal (e.g., in clinical laboratories). The curriculum of analytical chemistry at schools and universities is discussed. It is referred to be much broader than traditional equilibrium chemistry coupled with a simple description of individual analytical methods. Actually, the schooling of analytical chemistry should closely connect theory and practice.

  15. The Chemistry behind Special Effects in Film and Television

    Science.gov (United States)

    Short, Daniel B.; Badger, Paul D.

    2013-01-01

    The chemistry behind practical special effects in the film and television industry is discussed, along with examples of commonly used chemical demonstrations that simulate them in the laboratory. (Contains 3 figures.)

  16. Pheromone Chemistry of the Smaller European Elm Bark Beetle.

    Science.gov (United States)

    Beck, Keith

    1978-01-01

    Discusses the aggregation pheromone of the smaller European elm bark beetle, Scolytus multistriatus (Marsham), with emphasis on information that could be used in the classroom as a practical application of organic chemistry. (Author/GA)

  17. Teaching chemistry to students with learning difficulties: exemplary ...

    African Journals Online (AJOL)

    pushed-outs' because they are 'left-outs' during the instructional process. Thus, this study attempted to provide compilation of the exemplary adaptive instructional practices for assisting struggling learners in regular chemistry classrooms.

  18. Annual Report 1984. Chemistry Department

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    Shweikeh, Eman

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

  20. 78 FR 60260 - Order of the Commodity Futures Trading Commission Relating to the Continuation, Shutdown, and...

    Science.gov (United States)

    2013-10-01

    ... financial integrity of futures markets; (3) price discovery; (4) sound risk management practices; and (5... efficiency and financial integrity of the futures markets, and price discovery. The order also notifies... regulations.. This category includes regulation 1.10 and 5.12 filings (financial reports of futures commission...

  1. Safety in the Chemical Laboratory: Fire Safety and Fire Control in the Chemistry Laboratory.

    Science.gov (United States)

    Wilbraham, A. C.

    1979-01-01

    Discusses fire safety and fire control in the chemistry laboratory. The combustion process, extinguishing equipment, extinguisher maintenance and location, and fire safety and practices are included. (HM)

  2. The Living Textbook of Nuclear Chemistry: A Peer-Reviewed, Web-Based, Education Resource

    Science.gov (United States)

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

    2004-01-01

    The recent developments in nuclear chemistry education are presented and an attempt is made to collect supplemental materials relating to the study and practice of nuclear chemistry. The Living Textbook of Nuclear Chemistry functions as an authoritative Web site with supplemental material for teaching nuclear and radiochemistry.

  3. Gas phase ion chemistry

    CERN Document Server

    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. Spatially Resolved Artificial Chemistry

    DEFF Research Database (Denmark)

    Fellermann, Harold

    2009-01-01

    Although spatial structures can play a crucial role in chemical systems and can drastically alter the outcome of reactions, the traditional framework of artificial chemistry is a well-stirred tank reactor with no spatial representation in mind. Advanced method development in physical chemistry has...... 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...

  5. Biginelli and Mannich multicomponent reactions in the undergraduate organic chemistry laboratory: a didactic approach to green chemistry principles

    OpenAIRE

    Marcelo Volpatto Marques; Tula Beck Bisol; Marcus Mandolesi Sá

    2012-01-01

    The introduction of Mannich and Biginelli multicomponent reactions in a practical Organic Chemistry course is presented in this article. Procedures described in the literature were adapted for use under the simple conditions available in undergraduate laboratories and were selected on the basis of Green Chemistry principles and practicality of synthesis. The reactions are easy to carry out and all products are readily isolated as crystalline solids with yields ranging from moderate to high.

  6. Chemistry with a Peel.

    Science.gov (United States)

    Borer, Londa; Larsen, Eric

    1997-01-01

    Presents experiments that introduce natural product chemistry into high school classrooms. In the laboratory activities, students isolate and analyze the oil in orange peels. Students also perform a steam distillation and learn about terpenes. (DDR)

  7. Indicators: Soil Chemistry

    Science.gov (United States)

    The chemical makeup of the soil can provide information on wetland condition, wetland water quality and services being provided by the wetland ecosystem. Analyzing soil chemistry reveals if the soil is contaminated with a toxic chemical or heavy metal.

  8. Microfluidics in inorganic chemistry.

    Science.gov (United States)

    Abou-Hassan, Ali; Sandre, Olivier; Cabuil, Valérie

    2010-08-23

    The application of microfluidics in chemistry has gained significant importance in the recent years. Miniaturized chemistry platforms provide controlled fluid transport, rapid chemical reactions, and cost-saving advantages over conventional reactors. The advantages of microfluidics have been clearly established in the field of analytical and bioanalytical sciences and in the field of organic synthesis. It is less true in the field of inorganic chemistry and materials science; however in inorganic chemistry it has mostly been used for the separation and selective extraction of metal ions. Microfluidics has been used in materials science mainly for the improvement of nanoparticle synthesis, namely metal, metal oxide, and semiconductor nanoparticles. Microfluidic devices can also be used for the formulation of more advanced and sophisticated inorganic materials or hybrids.

  9. Supplemental instruction in chemistry

    Science.gov (United States)

    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.

  10. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 7. Electrostatics in Chemistry - Molecular Electrostatic Potential: Visualization and Topography. Shridhar R Gadre Pravin K Bhadane. Series Article Volume 4 Issue 7 July 1999 pp 14-23 ...

  11. Applications of supramolecular chemistry

    CERN Document Server

    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

  12. Fundamentals of quantum chemistry

    CERN Document Server

    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

  13. Gas phase ion chemistry

    CERN Document Server

    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

  14. Tropical Soil Chemistry

    DEFF Research Database (Denmark)

    Borggaard, Ole K.

    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...... 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...

  15. Impact of surface chemistry

    Science.gov (United States)

    Somorjai, Gabor A.; Li, Yimin

    2011-01-01

    The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized. PMID:20880833

  16. Green analytical chemistry - the use of surfactants as a replacement of organic solvents in spectroscopy

    Science.gov (United States)

    Pharr, Daniel Y.

    2017-07-01

    This chapter gives an introduction to the many practical uses of surfactants in analytical chemistry in replacing organic solvents to achieve greener chemistry. Taking a holistic approach, it covers some background of surfactants as chemical solvents, their properties and as green chemicals, including their environmental effects. The achievements of green analytical chemistry with micellar systems are reviewed in all the major areas of analytical chemistry where these reagents have been found to be useful.

  17. Click Chemistry in Functional Aliphatic Polycarbonates.

    Science.gov (United States)

    Dai, Yu; Zhang, Xiaojin; Xia, Fan

    2017-10-01

    Click chemistry, one of the most important methods in conjugation, plays an extremely significant role in the synthesis of functional aliphatic polycarbonates, which are a group of biodegradable polymers containing carbonate bonds in their main chains. To date, more than 75 articles have been reported on the topic of click chemistry in functional aliphatic polycarbonates. However, these efforts have not yet been highlighted. Six categories of click reactions (alkyne-azide reaction, thiol-ene reaction, Michael addition, epoxy-amine/thiol reaction, Diels-Alder reaction, and imine formation) that have been afforded for further post-polymerization modification of polycarbonates are reviewed. Through this review, a comprehensive understanding of functional aliphatic polycarbonates aims to afford insight on the design of polycarbonates for further post-polymerization modification via click chemistry and the expectation of the practical application. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Two computational approaches for Monte Carlo based shutdown dose rate calculation with applications to the JET fusion machine

    Energy Technology Data Exchange (ETDEWEB)

    Petrizzi, L.; Batistoni, P.; Migliori, S. [Associazione EURATOM ENEA sulla Fusione, Frascati (Roma) (Italy); Chen, Y.; Fischer, U.; Pereslavtsev, P. [Association FZK-EURATOM Forschungszentrum Karlsruhe (Germany); Loughlin, M. [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxfordshire, OX (United Kingdom); Secco, A. [Nice Srl Via Serra 33 Camerano Casasco AT (Italy)

    2003-07-01

    In deuterium-deuterium (D-D) and deuterium-tritium (D-T) fusion plasmas neutrons are produced causing activation of JET machine components. For safe operation and maintenance it is important to be able to predict the induced activation and the resulting shut down dose rates. This requires a suitable system of codes which is capable of simulating both the neutron induced material activation during operation and the decay gamma radiation transport after shut-down in the proper 3-D geometry. Two methodologies to calculate the dose rate in fusion devices have been developed recently and applied to fusion machines, both using the MCNP Monte Carlo code. FZK has developed a more classical approach, the rigorous 2-step (R2S) system in which MCNP is coupled to the FISPACT inventory code with an automated routing. ENEA, in collaboration with the ITER Team, has developed an alternative approach, the direct 1 step method (D1S). Neutron and decay gamma transport are handled in one single MCNP run, using an ad hoc cross section library. The intention was to tightly couple the neutron induced production of a radio-isotope and the emission of its decay gammas for an accurate spatial distribution and a reliable calculated statistical error. The two methods have been used by the two Associations to calculate the dose rate in five positions of JET machine, two inside the vacuum chamber and three outside, at cooling times between 1 second and 1 year after shutdown. The same MCNP model and irradiation conditions have been assumed. The exercise has been proposed and financed in the frame of the Fusion Technological Program of the JET machine. The scope is to supply the designers with the most reliable tool and data to calculate the dose rate on fusion machines. Results showed that there is a good agreement: the differences range between 5-35%. The next step to be considered in 2003 will be an exercise in which the comparison will be done with dose-rate data from JET taken during and

  19. Reserves for shutdown/dismantling and disposal in nuclear technology. Theses and recommendations on reform options; Rueckstellungen fuer Stilllegung/Rueckbau und Entsorgung im Atombereich. Thesen und Empfehlungen zu Reformoptionen

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Bettina [Forum Oekologisch-Soziale Marktwirtschaft e.V. (FOeS), Berlin (Germany). Green Budget Germany (GBG)

    2012-04-11

    The study on reserves for shutdown, dismantling and disposal of nuclear facilities covers the following topics: cost for shutdown, dismantling and disposal and amount and transparency of nuclear reserves, solution by y stock regulated by public law for long-term liabilities, and improvement of the protection in the event of insolvency for the remaining EVU reserves for short- and intermediate-term liabilities. The appendix includes estimations and empirical values for the cost of shutdown and dismantling, estimation of disposal costs, and a summary of Swiss studies on dismantling and disposal and transfer to Germany.

  20. Implementing a Student-Designed Green Chemistry Laboratory Project in Organic Chemistry

    Science.gov (United States)

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

    2014-01-01

    A multiweek organic chemistry laboratory project is described that emphasizes sustainable practices in experimental design. An emphasis on student-driven development of the project is meant to mirror the independent nature of research. Students propose environmentally friendly modifications of several reactions. With instructor feedback, students…

  1. Shutdown channels and fitted interlocks in atomic reactors; Chaines de securite et verrouillages installes sur les piles atomiques

    Energy Technology Data Exchange (ETDEWEB)

    Furet, J.; Landauer, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    This catalogue consists of tables (one per reactor) giving the following information: number and type of detectors, range of the shutdown channels, nature of the associated electronics, thresholds setting off the alarms, fitted interlocks. These cards have been drawn up with a view to an examination of the reactors safety by the 'Reactor Safety Sub-Commission', they take into account the latest decisions. The reactors involved in this review are: Azur, Cabri, Castor-Pollux, Cesar-Marius-2, Edf-2, EL3, EL4, Eole, G1, G2-G3, Harmonie, Isis, Masurca, Melusine, Minerve, Osiris, Pegase, Peggy, PAT, Rapsodie, SENA, Siloe, Siloette, Triton-Nereide, and Ulysse. (authors) [French] Ce catalogue est compose d'un ensemble de tableaux (a raison de un tableau par pile) donnant les renseignements suivants: nombre et nature des detecteurs, dynamique des chaines, nature de l'electronique associee, seuils provoquant des actions de securite, verrouillages installes. Ces fiches ont ete etablies en vue de l'examen de la securite des piles par la 'Sous-Commission de Surete des Piles', et tiennent compte des decisions de celle-ci. Les reacteurs concernes sont: Azur, Cabri, Cator-Pollux, Cesar-Marius-2, Edf-2, EL3, EL4, Eole, G1, G2-G3, Harmonie, Isis, Masurca, Melusine, Minerve, Osiris, Pegase, Peggy, PAT, Rapsodie, SENA, Siloe, Siloette, Triton-Nereide, et Ulysse. (auteurs)

  2. Inactivating the spindle checkpoint kinase Bub1 during embryonic development results in a global shutdown of proliferation

    Directory of Open Access Journals (Sweden)

    Taylor Stephen S

    2009-09-01

    Full Text Available Abstract Background Bub1 is a component of the spindle assembly checkpoint, a surveillance mechanism that maintains chromosome stability during M-phase. Bub1 is essential during the early stages of embryogenesis, with homozygous BUB1-null mice dying shortly after day E3.5. Bub1 is also required later during embryogenesis; inactivation of BUB1 on day E10.5 appears to rapidly block all further development. However, the mechanism(s responsible for this phenotype remain unclear. Findings Here we show that inactivating BUB1 on day E10.5 stalls embryogenesis within 48 hours. This is accompanied by a global shutdown of proliferation, widespread apoptosis and haemorrhaging. Conclusion Our results suggest that Bub1 is required throughout the developing embryo for cellular proliferation. Therefore, Bub1 has been shown to be essential in all scenarios analyzed thus far in mice: proliferation of cultured fibroblasts, spermatogenesis, oogenesis and both early and late embryonic development. This likely reflects the fact that Bub1 has dual functions during mitosis, being required for both SAC function and chromosome alignment.

  3. Comparisons of RELAP5-3D Analyses to Experimental Data from the Natural Convection Shutdown Heat Removal Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bucknor, Matthew; Hu, Rui; Lisowski, Darius; Kraus, Adam

    2016-04-17

    The Reactor Cavity Cooling System (RCCS) is an important passive safety system being incorporated into the overall safety strategy for high temperature advanced reactor concepts such as the High Temperature Gas- Cooled Reactors (HTGR). The Natural Convection Shutdown Heat Removal Test Facility (NSTF) at Argonne National Laboratory (Argonne) reflects a 1/2-scale model of the primary features of one conceptual air-cooled RCCS design. The project conducts ex-vessel, passive heat removal experiments in support of Department of Energy Office of Nuclear Energy’s Advanced Reactor Technology (ART) program, while also generating data for code validation purposes. While experiments are being conducted at the NSTF to evaluate the feasibility of the passive RCCS, parallel modeling and simulation efforts are ongoing to support the design, fabrication, and operation of these natural convection systems. Both system-level and high fidelity computational fluid dynamics (CFD) analyses were performed to gain a complete understanding of the complex flow and heat transfer phenomena in natural convection systems. This paper provides a summary of the RELAP5-3D NSTF model development efforts and provides comparisons between simulation results and experimental data from the NSTF. Overall, the simulation results compared favorably to the experimental data, however, further analyses need to be conducted to investigate any identified differences.

  4. Reliability of activation cross sections for estimation of shutdown dose rate in the ITER port cell and port interspace

    Directory of Open Access Journals (Sweden)

    García Raquel

    2017-01-01

    Full Text Available This paper explores the quality of available activation cross section (XS data for accurate Shutdown Dose Rate (SDDR prediction in the ITER Port Cell and Port Interspace areas, where different maintenance activities are foreseen. For this purpose the EAF library (2007 and 2010 versions has been investigated, as it is typically used by the ITER community. Based on both reports/papers on SDDR in ITER and own calculations, major nuclides contributing to the SDDR coming from the activation of i relevant materials placed in ITER and ii candidate materials for the bioshield plug as L2N and barite concretes, are identified. Then, relevant production pathways are obtained. EAF XS quality for all pathways is checked following the procedure used for validating and testing the successive EAF versions. Also, possible improvements from using the TENDL-2015 library are assessed by comparing EAF and TENDL XS with available differential experimental data from EXFOR. Results point out that most of the activation XS related to materials currently placed in ITER are reliable, and only a few need improvement. Also, many of the XS related to both L2N and barite concretes need further work for validation.

  5. Reliability of activation cross sections for estimation of shutdown dose rate in the ITER port cell and port interspace

    Science.gov (United States)

    García, Raquel; García, Mauricio; Ogando, Francisco; Pampin, Raúl; Sanz, Javier

    2017-09-01

    This paper explores the quality of available activation cross section (XS) data for accurate Shutdown Dose Rate (SDDR) prediction in the ITER Port Cell and Port Interspace areas, where different maintenance activities are foreseen. For this purpose the EAF library (2007 and 2010 versions) has been investigated, as it is typically used by the ITER community. Based on both reports/papers on SDDR in ITER and own calculations, major nuclides contributing to the SDDR coming from the activation of i) relevant materials placed in ITER and ii) candidate materials for the bioshield plug as L2N and barite concretes, are identified. Then, relevant production pathways are obtained. EAF XS quality for all pathways is checked following the procedure used for validating and testing the successive EAF versions. Also, possible improvements from using the TENDL-2015 library are assessed by comparing EAF and TENDL XS with available differential experimental data from EXFOR. Results point out that most of the activation XS related to materials currently placed in ITER are reliable, and only a few need improvement. Also, many of the XS related to both L2N and barite concretes need further work for validation.

  6. Technical Specification action statements requiring shutdown. A risk perspective with application to the RHR/SSW systems of a BWR

    Energy Technology Data Exchange (ETDEWEB)

    Mankamo, T. [Avaplan Oy, Espoo (Finland); Kim, I.S.; Samanta, P.K. [Brookhaven National Lab., Upton, NY (United States)

    1993-11-01

    When safety systems fail during power operation, the limiting conditions for operation (LCOs) and associated action statements of technical specifications typically require that the plant be shut down within the limits of allowed outage time (AOT). However, when a system needed to remove decay heat, such as the residual heat removal (RHR) system, is inoperable or degraded, shutting down the plant may not necessarily be preferable, from a risk perspective, to continuing power operation over a usual repair time, giving priority to the repairs. The risk impact of the basic operational alternatives, i.e., continued operation or shutdown, was evaluated for failures in the RHR and standby service water (SSW) systems of a boiling-water reactor (BWR) nuclear power plant. A complete or partial failure of the SSW system fails or degrades not only the RHR system but other front-line safety systems supported by the SSW system. This report presents the methodology to evaluate the risk impact of LCOs and associated AOT; the results of risk evaluation from its application to the RHR and SSW systems of a BWR; the findings from the risk-sensitivity analyses to identify alternative operational policies; and the major insights and recommendations to improve the technical specifications action statements.

  7. Chemistry beyond positivism.

    Science.gov (United States)

    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.

  8. Storage of wind power by post-utilization of shut-down mines. Final report; Windenergiespeicherung durch Nachnutzung stillgelegter Bergwerke. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Beck, H.P.; Schmidt, M. (eds.)

    2011-08-31

    The contribution under consideration examines the potential of energy storages in the electrical power grid in Germany for the grid integration of wind energy by the pre-utilization of shut-down mines by means of underground hydrodynamic pumped storage power plant. This requires retrofitting measures of shut-down mines. For this purpose, six mining regions in Germany have been identified for the construction of underground pumped storage power plants. Examplary, two mines (the former mines Grund in the Harz Mountain and Poehla in the Erz Mountains) were investigated in terms of post-utilization for an underground pumped storage power plant. In both cases, a realization appears technically possible. The major challenges are at the site Poehla due to the supply of raw materials, access to these mines and environmental as well as acceptance issues.

  9. Impacts of nuclear plant shutdown on coal-fired power generation and infant health in the Tennessee Valley in the 1980s

    Science.gov (United States)

    Severnini, Edson

    2017-04-01

    The Fukushima nuclear accident in March 2011 generated deep public anxiety and uncertainty about the future of nuclear energy. However, differently to fossil fuel plants, nuclear plants produce virtually no greenhouse gas emissions or air pollutants during power generation. Here we show the effect on air pollution and infant health in the context of the temporary closure of nuclear plants by the Tennessee Valley Authority (TVA) in the 1980s. After the Three Mile Island accident in 1979, the US Nuclear Regulatory Commission intensified inspections throughout the nation, leading to the shutdown of two large nuclear power plants in the TVA area. In response to that shutdown, electricity generation shifted one to one to coal-fired power plants within TVA, increasing particle pollution in counties where they were located. Consequently, infant health may have deteriorated in the most affected places, indicating deleterious effects to public health.

  10. Comparing Non-Steady State Emissions under Start-Up and Shut-Down Operating Conditions with Steady State Emissions for Several Industrial Sectors: A Literature Review

    OpenAIRE

    Juwairia Obaid; Ashraf Ramadan; Ali Elkamel; William Anderson

    2017-01-01

    This study investigates the emissions of various industrial facilities under start-up, shut-down, and normal operations. The industries that have been investigated include power and/or heat generation, energy-from-waste generation, nuclear power generation, sulphuric acid production, ethylene production, petrochemical production, and waste incineration. The study investigated multiple facilities worldwide for each of these industrial categories. The different potential contaminants characteri...

  11. Conceptual design study, Phase 1, Task 7.3. Shutdown heat removal system. Working group final report. Volume 2. Overall results

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1979-11-01

    Task 7.3 of the Conceptual Design Study (CDS) had the objective of choosing an optimal Shutdown Heat Removal System (SHRS) for the CDS plant. A working group was formed with the primary objective of defining a SHRS consensus position. This position could define specific recommended system concepts or it could identify the work and information needed to establish the preferred SHRS for the CDS plant. This report documents the recommended SHRS position for CDS.

  12. Collaborative Physical Chemistry Projects Involving Computational Chemistry

    Science.gov (United States)

    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.

  13. Reaction chemistry of cerium

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Air Composition and Chemistry

    Science.gov (United States)

    Brimblecombe, Peter

    1996-01-01

    This book is about the atmosphere and humanity's influence on it. For this new edition, Brimblecombe has rewritten and updated much of the book. In the early chapters, he discusses the geochemical, biological and maritime sources of the trace gases. Next, he examines the chemistry of atmospheric gases, suspended particles, and rainfall. After dealing with the natural atmosphere, he examines the sources of air pollution and its effects, with all scenarios updated from the last edition. Scenarios include decline in health, damage to plants and animals, indoor pollution, and acid rain. The final chapters, also revised, are concerned with the chemistry and evolution of the atmospheres of the planets of the solar system. Students with an interest in chemistry and the environmental sciences will find this book highly valuable.

  15. Simulation of station blackout scenario in low-power and shutdown condition of Westinghouse two-loop plant with RELAP5 code

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Se Yun; Ha, Sang Jun [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    A station blackout scenario in low power and shutdown condition of Westinghouse two-loop plant is simulated with RELAP5 code. To evaluate plant safety in station blackout scenario for low-power and shutdown condition, the transient calculation with RELAP5 code has been carried out for a Westinghouse two-loop plant. Without core cooling, the boiling in core and spent fuel pit occurs. The core uncovery is observed about 160 hours and the peak cladding temperature exceeds 1206K at 161.1. Station blackout is the complete loss of alternating current (AC) electrical power to the essential and nonessential switchgear buses in a nuclear power plant. Because many safety systems required for reactor core cooling and containment heat removal depend on AC power, the consequences of a station blackout could be severe. Especially, station blackout in low-power and shutdown condition is one of the current issues. Therefore, the evaluation of plant safety with safety analysis code is opportune.

  16. Students’ experienced coherence between chemistry and biology in context-based secondary science education

    NARCIS (Netherlands)

    Boer, H.J.; Prins, Gjalt; Goedhart, M.J.; Boersma, Kerst

    2014-01-01

    In current biology and chemistry secondary school practice, coherence between the subjects chemistry and biology is underexposed or even ignored. This is incongruent with the current scientific practice, in which the emphasis is shifting towards inter- and multidisciplinarity. These problems have

  17. Lecture Notes and Guidance for Course 21220 (Non-aqueous Inorganic Chemistry)

    DEFF Research Database (Denmark)

    1998-01-01

    The lecture notes contain the theoretical as well as the practical background material necessary for mastering the special laboratory techniques used in non-aqueous inorganic chemistry (cfr. Course Descriptions, DTU).......The lecture notes contain the theoretical as well as the practical background material necessary for mastering the special laboratory techniques used in non-aqueous inorganic chemistry (cfr. Course Descriptions, DTU)....

  18. Laboratory Activities and Students Practical Performance: The Case ...

    African Journals Online (AJOL)

    The major objective of this study was to offer an overview of the current situation in the course practical organic chemistry I of Haramaya University. All first year second semester chemistry students, laboratory instructors and Practical Organic Chemistry I course material were involved as the main source of data. The main ...

  19. Spins in chemistry

    CERN Document Server

    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

  20. Solvent effects in chemistry

    CERN Document Server

    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

  1. Chemistry WebBook

    Science.gov (United States)

    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.

  2. Dynamic Combinatorial Chemistry

    DEFF Research Database (Denmark)

    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...

  3. Chemistry of Transactinides

    Science.gov (United States)

    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.

  4. Chemistry in second life.

    Science.gov (United States)

    Lang, Andrew S I D; Bradley, Jean-Claude

    2009-10-23

    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.

  5. The chemistry of silicon

    CERN Document Server

    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

  6. Atmospheric pseudohalogen chemistry

    OpenAIRE

    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 ...

  7. Progress in physical chemistry

    CERN Document Server

    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

  8. Chemistry in Second Life

    Directory of Open Access Journals (Sweden)

    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.

  9. Chemistry in microelectronics

    CERN Document Server

    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

  10. Save Time and Money through Chemistry (by Ken Carpenter)

    Science.gov (United States)

    Hazari, Al

    1998-01-01

    Useful Chemistry Publishing: Dayton, OH, 1997. 261 pp. Figs. and tables. ISBN: 0965566714. $24.95 (soft cover only). Would you like to learn about the 5 W's of everyday chemistry and chemicals? Who(m) should you see to learn to identify and appraise jewelry? What should you eat for breakfast? When should you get up from your sleep? Where is cholesterol in the human body? Why do pool owners add hydrochloric acid? Then read Save Time and Money through Chemistry, by Ken Carpenter. This book is loaded with practical and useful chemistry information that every person who took chemistry in high school or college wishes he or she had been introduced or exposed to. I know I do.

  11. Experimentação em química de compostos organometálicos: preparação do cloreto de dicarbonilciclopentadienilferro(II Practical in organometallic chemistry: preparation of dicarbonylcyclopentadienyliron(II chloride

    Directory of Open Access Journals (Sweden)

    Zaine Teixeira

    2007-04-01

    Full Text Available In this work, we describe a new method for obtaining [Fe(CO2[(eta5-C5H5Cl] employing simple techniques and low-cost reagents. It is worth mentioning that this method is faster than others reported in the literature. It was applied in laboratory classes for undergraduate students, exploring different concepts in organometallic chemistry and discussing the steps involved in the synthetic route.

  12. Ethics in Science: The Unique Consequences of Chemistry.

    Science.gov (United States)

    Kovac, Jeffrey

    2015-01-01

    This article discusses the ethical issues unique to the science and practice of chemistry. These issues arise from chemistry's position in the middle between the theoretical and the practical, a science concerned with molecules that are of the right size to directly affect human life. Many of the issues are raised by the central activity of chemistry--synthesis. Chemists make thousands of new substances each year. Many are beneficial, but others are threats. Since the development of the chemical industry in the nineteenth century, chemistry has contributed to the deterioration of the environment but has also helped to reduce pollution. Finally, we discuss the role of codes of ethics and whether the current codes of conduct for chemists are adequate for the challenges of today's world.

  13. Chemistry: Experiments, Demonstrations and Other Activities Suggested for Chemistry.

    Science.gov (United States)

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    This publication is a handbook used in conjunction with the course of study in chemistry developed through the New York State Education Department and The University of the State of New York. It contains experiments, demonstrations, and other activities for a chemistry course. Areas covered include the science of chemistry, the atomic structure of…

  14. Connected Chemistry--Incorporating Interactive Simulations into the Chemistry Classroom.

    Science.gov (United States)

    Stieff, Mike; Wilensky, Uri

    2003-01-01

    Describes a novel modeling and simulation package and assesses its impact on students' understanding of chemistry. Connected Chemistry was implemented inside the NetLogo modeling environment. Using Connected Chemistry, students employed problem -solving techniques characterized by stronger attempts at conceptual understanding and logical…

  15. Myrrh--Commiphora chemistry.

    Science.gov (United States)

    Hanus, Lumír O; Rezanka, Tomás; Dembitsky, Valery M; Moussaieff, Arieh

    2005-06-01

    Myrrh and opopanax has been used throughout history in incense and as a perfume. Since Bible times it has been used for the treatment of wounds. The first attempts to identify content compounds were almost 100 years ago. In this review we discuss the present state of knowledge in the chemistry of substances of Commiphora spp.

  16. Elements of Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 1. Elements of Chemistry. Antoine-Laurent Lavoisier. Classics Volume 17 Issue 1 January 2012 pp 92-100. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/017/01/0092-0100. Author Affiliations.

  17. Chemistry and Heritage

    Science.gov (United States)

    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.

  18. Concept of Green Chemistry

    Indian Academy of Sciences (India)

    Srimath

    Chemistry has provided valuable materials in the form of medi- cines, food products, cosmetics, dyes, paints, agrochemicals, biomolecules, high-tech substances like polymers, liquid crystals and nanoparticles. Chemists have used their knowledge and skill to prepare a large number of new materials which are far better.

  19. Chemistry at the Nanoscale

    Indian Academy of Sciences (India)

    Program, School of Medicine and Dentistry, University of. Rochester, New York. His research interests are in studying the structure, function, interaction and the chemistry of biomolecules as well as their assemblies and networks. Ram Ramaswamy teaches in the Schools of Physical. Sciences (SPS) and. Computational and.

  20. Chemistry in the Troposphere.

    Science.gov (United States)

    Chameides, William L.; Davis, Douglas D.

    1982-01-01

    Topics addressed in this review of chemistry in the troposphere (layer of atmosphere extending from earth's surface to altitude of 10-16km) include: solar radiation/winds; earth/atmosphere interface; kinetic studies of atmospheric reactions; tropospheric free-radical photochemistry; instruments for nitric oxide detection; sampling…

  1. News: Green Chemistry & Technology

    Science.gov (United States)

    A series of 21 articles focused on different features of green chemistry in a recent issue of Chemical Reviews. Topics extended over a wide range to include the design of sustainable synthetic processes to biocatalysis. A selection of perspectives follows as part of this colu

  2. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    For an excellent summary of the field of supramolecular chemistry, readers are referred to the article by J-M Lehn in Resonance, VaLl,. No.3, p.39, 1996. Electrostatics plays an important role in weak intermolecular interactions. The present series is aimed at understanding these electrostatic aspects. This article presents the.

  3. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    Electrostatics in Chemistry. 3. Molecular Electrostatic Potential: Visualization and Topography. Shridhar R Gadre and Pravin K Bhadane. 1 1. Basic Principles, Resona- nce, Vol.4, No.2, 11-19, 1999. 2. Electrostatic Potentials of. Atoms, Ions and Molecules,. Resonance, Vol.4, No.5, 40-51,. 1999. Topographical features of the ...

  4. The Chemistry of Griseofulvin

    DEFF Research Database (Denmark)

    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...

  5. Tunnelling Effects in Chemistry

    Indian Academy of Sciences (India)

    IAS Admin

    Tunnelling Effects in Chemistry. Molecules in the Strange Quantum World. Sharmistha Karmakar, Deepthi Jose and Ayan Datta. (left) Sharmistha Karmakar is doing her PhD in the group of. Ayan Datta, IACS,. Kolkata. Her research interests are modelling molecules with strong optical absorbtion and emission properties.

  6. Analytical Chemistry Laboratory

    Science.gov (United States)

    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.

  7. Forensic Chemistry Training

    Directory of Open Access Journals (Sweden)

    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.

  8. Chemistry: The Middle Kingdom

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 7. Chemistry: The Middle Kingdom. Gautam R Desiraju. General Article Volume 12 Issue 7 July 2007 pp 44-60. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/012/07/0044-0060. Keywords.

  9. Symmetry in chemistry

    CERN Document Server

    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.

  10. Array processors in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Teaching Chemistry. through Riddles

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 7. Teaching Chemistry through Riddles. Mala Das Sharma. Classroom Volume 9 Issue 7 July 2004 pp 74-76. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/07/0074-0076. Author Affiliations.

  12. Arrows in Chemistry

    Indian Academy of Sciences (India)

    IAS Admin

    reaction conditions, reagents and catalysts used in the chemical reaction are written on the chemical reaction arrow. For example,. Arrows in chemistry can be broadly classified as 'reaction arrows' and 'electron arrows'. While the former is used to describe the state or progress of a chemical reaction, the latter is used to.

  13. Tunnelling Effects in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 2. Tunnelling Effects in Chemistry: Molecules in the Strange Quantum World. Sharmistha Karmakar Deepthi Jose Ayan Datta. General Article Volume 19 Issue 2 February 2014 pp 160-174 ...

  14. Chemistry in a Nutshell.

    Science.gov (United States)

    Rupnow, John; And Others

    1995-01-01

    Presents an activity that involves making peanut butter in the laboratory as a way to teach students the chemistry concepts of emulsification, solubility, and formulation. Enables students to realize that they can actually create or modify the physical and sensory characteristics of peanut butter and taste the differences in their work. (JRH)

  15. Nobel Prize in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 4. Nobel Prize in Chemistry – 2003 The Gateway for Perfect Health. S M Srideshikan S K Srivatsa. General Article Volume 9 Issue 4 April 2004 pp 61-70. Fulltext. Click here to view fulltext PDF. Permanent link:

  16. Chemistry of Materials

    Indian Academy of Sciences (India)

    solid materials particularly metal oxides of various kinds. Then started intense activity in other classes of materials, including organics. It is no surprise that in the last few years, the two main streams of chemistry are directed towards biology and advanced materials. It is also not difficult to understand why chemists are getting ...

  17. Arrows in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 1. Arrows in Chemistry. Abirami Lakshminarayanan. General Article Volume 15 Issue 1 January 2010 pp 51-63. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/015/01/0051-0063. Keywords. Arrows ...

  18. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 2. Electrostatics in Chemistry - Basic Principles. Shridhar R Gadre Pravin K Bhadane. Series Article Volume 4 Issue 2 February 1999 pp 8-19. Fulltext. Click here to view fulltext PDF. Permanent link:

  19. Chemistry: The Middle Kingdom

    Indian Academy of Sciences (India)

    2005-02-10

    Feb 10, 2005 ... Chemistry occupies a unique middle position between physics and mathematics on the one side and biology, .... The late nineteenth century saw the zenith of the industrial revolution, the emergence of capitalism and colo- .... of the processes occurring in living systems. Chemists were slow to recognize the ...

  20. Colour chemistry in water

    OpenAIRE

    Cardona, Maria

    2015-01-01

    Atmospheric carbon dioxide (CO2) levels have increased dramatically in the last few decades. Famous for causing global warming, CO2 is also resulting in the acidification of seas and oceans. http://www.um.edu.mt/think/colour-chemistry-in-water/

  1. African mistletoes (loranthaceae); ethnopharmacology, chemistry ...

    African Journals Online (AJOL)

    African mistletoes (loranthaceae); ethnopharmacology, chemistry and medicinal values: An update. ... little is known about their biology (taxonomy, host/plant relationship, ecology, toxicology, physiological characteristics, etc.) and chemistry (chemical constituents' profile). Some pharmacological studies carried out on the ...

  2. Polymer Chemistry in High School.

    Science.gov (United States)

    Stucki, Roger

    1984-01-01

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

  3. Principles of Chemistry (by Michael Munowitz)

    Science.gov (United States)

    Kovac, Reviewed By Jeffrey

    2000-05-01

    principles. This is a very conceptual book. Each chapter has two parts, which are distinguished by having different-colored pages: white and gray. The first part of every chapter is a lovely conceptual development of the "big picture". In these white pages, there are no sample problems, no tables of data, just elegant prose liberally illustrated with graphs and diagrams. Mathematical and chemical equations and chemical structures are presented as needed, but the goal is to provide the reader with a conceptual understanding. I found these introductory "lectures", as Munowitz terms them, to be enchanting. The second part of each chapter is a review and guide to problems, what Munowitz calls the "recitation" section. These pages are gray. This second section gives a brief summary of the material, which is followed by a series of worked examples that apply the concepts to practical problems. This structure reflects the author's pedagogical philosophy--begin with the general and move to the specific--and his view of chemistry as a combination of "lofty principles and gritty practicality". Following the worked examples, of course, are exercises for the student, ranging from simple drill problems to more sophisticated applications of the principles. I was a little disappointed, however, that there were so few conceptual exercises. Although Munowitz describes the second part of each chapter as a review and applications, he does put new material into the sample problems. For example, in Chapter 3 the concept of oxidation numbers is introduced and sample problems on the assignment of oxidation numbers are presented. Then, in example 3-3, the concept of formal charge is presented as a contrast to the oxidation number even though this idea had not been previously introduced. The dual structure of white and gray pages makes this book unique but also very long. The combined length of the white sections is about 800 pages, but an approximately 25-page conceptual section is always followed

  4. Tracking of fuel particles after pin failure in nominal, loss-of-flow and shutdown conditions in the MYRRHA reactor

    Energy Technology Data Exchange (ETDEWEB)

    Buckingham, Sophia; Planquart, Philippe [von Karman Institute, Chaussée de Waterloo 72, B-1640 Rhode-St-Genèse (Belgium); Van Tichelen, Katrien [SCK- CEN, Boeretang 200, 2400 Mol (Belgium)

    2017-02-15

    Highlights: • Quantification of the design and safety of the MYRRHA reactor in the event of a pin failure. • Simulation of different accident scenarios in both forced and natural convection regime. • The accumulation areas at the free-surface in case of the least dense particles depend on the flow regime. • The densest particles form an important deposit at the bottom of the vessel. • Further study of the risk of core blockage requires a detailed model of the core. - Abstract: This work on fuel dispersion aims at quantifying the design and safety of the MYRRHA nuclear reactor. A number of accidents leading to the release of a secondary phase into the primary coolant loop are investigated. Among these scenarios, an incident leading to the failure of one or more of the fuel pins is simulated while the reactor is operating in nominal conditions, but also in natural convection regime either during accident transients such as loss-of-flow or during the normal shut-down of the reactor. Two single-phase CFD models of the MYRRHA reactor are constructed in ANSYS Fluent to represent the reactor in nominal and natural convection conditions. An Euler–Lagrange approach with one-way coupling is used for the flow and particle tracking. Firstly, a steady state RANS solution is obtained for each of the three conditions. Secondly, the particles are released downstream from the core outlet and particle distributions are provided over the coolant circuit. Their size and density are defined such that test cases represent potential extremes that may occur. Analysis of the results highlights different particle behaviors, depending essentially on gravity forces and kinematic effects. Statistical distributions highlight potential accumulation regions that may form at the free-surfaces, on top of the upper diaphragm plate or at the bottom of the vessel. These results help to localize regions of fuel accumulation in order to provide insight for development of strategies for

  5. Mathematical problems for chemistry students

    CERN Document Server

    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

  6. Pharmacy and Chemistry in the Eighteenth Century: What Lessons for the History of Science?

    Science.gov (United States)

    Simon, Jonathan

    2014-01-01

    This essay questions the continuity of chemistry across the eighteenth century based on an analysis of its relationship to pharmacy in France. Comparing a text by Nicolas Lémery (1675) with one by Antoine Baumé (1773), the article argues for a key transformation in chemistry across this period. The elimination of the practical side of pharmacy (indications and dosages) from chemistry texts is symptomatic of a reorientation of chemistry toward more theoretical or philosophical concerns. The essay considers several possible explanations for this change in orientation, including developments within pharmacy, but in the end privileges an approach in terms of the changing publics for chemistry in eighteenth-century France.

  7. Aqueous Solution Chemistry of Plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Clark, David L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-28

    Things I have learned working with plutonium: Chemistry of plutonium is complex; Redox equilibria make Pu solution chemistry particularly challenging in the absence of complexing ligands; Understanding this behavior is key to successful Pu chemistry experiments; There is no suitable chemical analog for plutonium.

  8. Six Pillars of Organic Chemistry

    Science.gov (United States)

    Mullins, Joseph J.

    2008-01-01

    This article describes an approach to teaching organic chemistry, which is to have students build their knowledge of organic chemistry upon a strong foundation of the fundamental concepts of the subject. Specifically, the article focuses upon a core set of concepts that I call "the six pillars of organic chemistry": electronegativity, polar…

  9. MINIATURIZING CHEMISTRY THE ECOLOGICAL ALTERNATIVE

    African Journals Online (AJOL)

    unesco

    Education in Chemistry (U.K.). • African Journal of Chemical Education (Ethiopia). • Educacion Quimica (Mexico). A list of books on the field is given in the appendix of this paper. WHERE DID IT START AND WHERE IS IT BEING USED? The adoption of Microscale Chemistry for the teaching of Chemistry in Africa and Asia is.

  10. Division of Analytical Chemistry, 1998

    DEFF Research Database (Denmark)

    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....

  11. Scientific Information Analysis of Chemistry Dissertations Using Thesaurus of Chemistry

    Directory of Open Access Journals (Sweden)

    Taghi Rajabi

    2017-09-01

    Full Text Available : Concept maps of chemistry can be obtained from thesaurus of chemistry. Analysis of information in the field of chemistry is done at graduate level, based on comparing and analyzing chemistry dissertations by using these maps. Therefore, the use of thesaurus for analyzing scientific information is recommended. Major advantage of using this method, is that it is possible to obtain a detailed map of all academic researches across all branches of science. The researches analysis results in chemical science can play a key role in developing strategic research policies, educational programming, linking universities to industries and postgraduate educational programming. This paper will first introduce the concept maps of chemistry. Then, emerging patterns from the concept maps of chemistry will be used to analyze the trend in the academic dissertations in chemistry, using the data collected and stored in our database at Iranian Research Institute for Information Science and Technology (IranDoc over the past 10 years (1998-2009.

  12. "Molecules-in-Medicine": Peer-Evaluated Presentations in a Fast-Paced Organic Chemistry Course for Medical Students

    Science.gov (United States)

    Kadnikova, Ekaterina N.

    2013-01-01

    To accentuate the importance of organic chemistry in development of contemporary pharmaceuticals, a three-week unit entitled "Molecules-in-Medicine" was included in the curriculum of a comprehensive one-semester four-credit organic chemistry course. After a lecture on medicinal chemistry concepts and pharmaceutical practices, students…

  13. A practical approach for linearity assessment of calibration curves under the International Union of Pure and Applied Chemistry (IUPAC) guidelines for an in-house validation of method of analysis.

    Science.gov (United States)

    Sanagi, M Marsin; Nasir, Zalilah; Ling, Susie Lu; Hermawan, Dadan; Ibrahim, Wan Aini Wan; Naim, Ahmedy Abu

    2010-01-01

    Linearity assessment as required in method validation has always been subject to different interpretations and definitions by various guidelines and protocols. However, there are very limited applicable implementation procedures that can be followed by a laboratory chemist in assessing linearity. Thus, this work proposes a simple method for linearity assessment in method validation by a regression analysis that covers experimental design, estimation of the parameters, outlier treatment, and evaluation of the assumptions according to the International Union of Pure and Applied Chemistry guidelines. The suitability of this procedure was demonstrated by its application to an in-house validation for the determination of plasticizers in plastic food packaging by GC.

  14. Towards "Bildung"-Oriented Chemistry Education

    Science.gov (United States)

    Sjöström, Jesper

    2013-01-01

    This paper concerns "Bildung"-oriented chemistry education, based on a reflective and critical discourse of chemistry. It is contrasted with the dominant type of chemistry education, based on the mainstream discourse of chemistry. "Bildung"-oriented chemistry education includes not only content knowledge in chemistry, but also…

  15. Chemistry of naphthalene diimides.

    Science.gov (United States)

    Bhosale, Sheshanath V; Jani, Chintan H; Langford, Steven J

    2008-02-01

    This tutorial review surveys recent developments in the chemistry of naphthalene diimides (NDIs) and explores their application in the fields of material and supramolecular science. It begins with a discussion of their general uses, methods of syntheses and their electronic and spectroscopic properties. Of interest to their application in the fields of conducting thin films and molecular sensors is the structure-function relationships that exist either as co-components of supramolecular ensembles as in the case of "nanotubes", or as the sole components in molecular wires. Also discussed are advances in NDI research within the areas of energy and electron transfer (covalent and non-covalent systems) and in host-guest chemistry including foldamer, mechanically-interlocked and ligand-gated ion channel examples. Finally, we explore the developments in the recent field of core-substituted NDIs, their photophysical properties and applications in artificial photosynthesis. We conclude with our views on the prospects of NDIs for future research endeavours.

  16. Organic Chemistry in Space

    Science.gov (United States)

    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.

  17. Chemistry and Art.

    Science.gov (United States)

    Lipscher, Juraj

    2018-02-01

    This review summarizes possibilities of including scientific methods for investigation of art objects into the secondary school chemistry curriculum. We discuss methods such as X-ray radiography, infrared reflectography, neutron activation autoradiography, X-ray fluorescence, and Raman spectroscopy and provide recent examples of their use. The results obtained, especially when combined with modern digital image processing algorithms, are indeed impressive. The second part of the paper is devoted to suggestions for actual use in teaching. The activities in the classroom can be centered around scientific investigation of a single painting, properties and use of a single pigment, or utilizing parallels in the history of Chemistry and history of Art. Finally, scientific methods for detecting art fraud including actual historical examples are especially motivating for the students and various teaching activities can be designed around this aspect.

  18. Chemistry space–time

    Directory of Open Access Journals (Sweden)

    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.

  19. Bubble and foam chemistry

    CERN Document Server

    Pugh, Robert J

    2016-01-01

    This indispensable guide will equip the reader with a thorough understanding of the field of foaming chemistry. Assuming only basic theoretical background knowledge, the book provides a straightforward introduction to the principles and properties of foams and foaming surfactants. It discusses the key ideas that underpin why foaming occurs, how it can be avoided and how different degrees of antifoaming can be achieved, and covers the latest test methods, including laboratory and industrial developed techniques. Detailing a variety of different kinds of foams, from wet detergents and food foams, to polymeric, material and metal foams, it connects theory to real-world applications and recent developments in foam research. Combining academic and industrial viewpoints, this book is the definitive stand-alone resource for researchers, students and industrialists working on foam technology, colloidal systems in the field of chemical engineering, fluid mechanics, physical chemistry, and applied physics.

  20. Carbohydrates in Supramolecular Chemistry.

    Science.gov (United States)

    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.

  1. Quo vadis, analytical chemistry?

    Science.gov (United States)

    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.

  2. Quantum mechanics in chemistry

    CERN Document Server

    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

  3. Green chemistry: development trajectory

    Science.gov (United States)

    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.

  4. Genetic algorithm in chemistry.

    OpenAIRE

    da Costa, PA; Poppi, RJ

    1999-01-01

    Genetic algorithm is an optimization technique based on Darwin evolution theory. In last years its application in chemistry is increasing significantly due the special characteristics for optimization of complex systems. The basic principles and some further modifications implemented to improve its performance are presented, as well as a historical development. A numerical example of a function optimization is also shown to demonstrate how the algorithm works in an optimization process. Final...

  5. Chemistry of superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Schaedel, M. [Japan Atomic Energy Agency, Tokai, Ibaraki (Japan). Advanced Science Research Center; GSI Helmholtz Center for Heavy Ion Research, Darmstadt (Germany)

    2012-07-01

    The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

  6. The Need for Innovative Methods of Teaching and Learning Chemistry in Higher Education--Reflections from a Project of the European Chemistry Thematic Network

    Science.gov (United States)

    Eilks, Ingo; Byers, Bill

    2010-01-01

    This paper summarizes the work and conclusions of a working group established by the European Chemistry Thematic Network (ECTN). The aim of the working group was to identify potential areas for innovative approaches to the teaching and learning of chemistry in Higher Education, and to survey good practice throughout the EU. The paper starts by…

  7. A Human Reliability Analysis of Post- Accident Human Errors in the Low Power and Shutdown PSA of KSNP

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Daeil; Kim, J. H.; Jang, S. C

    2007-03-15

    Korea Atomic Energy Research Institute, using the ANS low power and shutdown (LPSD) probabilistic risk assessment (PRA) Standard, evaluated the LPSD PSA model of the KSNP, Yonggwang Units 5 and 6, and identified the items to be improved. The evaluation results of human reliability analysis (HRA) of the post-accident human errors in the LPSD PSA model for the KSNP showed that 10 items among 19 items of supporting requirements for those in the ANS PRA Standard were identified as them to be improved. Thus, we newly carried out a HRA for post-accident human errors in the LPSD PSA model for the KSNP. Following tasks are the improvements in the HRA of post-accident human errors of the LPSD PSA model for the KSNP compared with the previous one: Interviews with operators in the interpretation of the procedure, modeling of operator actions, and the quantification results of human errors, site visit. Applications of limiting value to the combined post-accident human errors. Documentation of information of all the input and bases for the detailed quantifications and the dependency analysis using the quantification sheets The assessment results for the new HRA results of post-accident human errors using the ANS LPSD PRA Standard show that above 80% items of its supporting requirements for post-accident human errors were graded as its Category II. The number of the re-estimated human errors using the LPSD Korea Standard HRA method is 385. Among them, the number of individual post-accident human errors is 253. The number of dependent post-accident human errors is 135. The quantification results of the LPSD PSA model for the KSNP with new HEPs show that core damage frequency (CDF) is increased by 5.1% compared with the previous baseline CDF It is expected that this study results will be greatly helpful to improve the PSA quality for the domestic nuclear power plants because they have sufficient PSA quality to meet the Category II of Supporting Requirements for the post

  8. Comparing Non-Steady State Emissions under Start-Up and Shut-Down Operating Conditions with Steady State Emissions for Several Industrial Sectors: A Literature Review

    Directory of Open Access Journals (Sweden)

    Juwairia Obaid

    2017-02-01

    Full Text Available This study investigates the emissions of various industrial facilities under start-up, shut-down, and normal operations. The industries that have been investigated include power and/or heat generation, energy-from-waste generation, nuclear power generation, sulphuric acid production, ethylene production, petrochemical production, and waste incineration. The study investigated multiple facilities worldwide for each of these industrial categories. The different potential contaminants characteristic of each industry type have been investigated and the emissions of these contaminants under non-steady state have been compared to the steady state emissions. Where available, trends have been developed to identify the circumstances, i.e., the industrial sector and contaminant, under which the assessment and consideration of emissions from start-up and shut-down events is necessary for each industry. These trends differ by industrial sector and contaminant. For example, the study shows that sulphur dioxide (SO2 emissions should be assessed for the start-up operations of sulphuric acid production plants, but may not need to be assessed for the start-up operations of a conventional power generation facility. The trends developed as part of this research paper will help air permit applicants to effectively allocate their resources when assessing emissions related to non-steady state operations. Additionally, it will ensure that emissions are assessed for the worst-case scenario. This is especially important when emissions under start-up and shut-down operations have the potential to exceed enforceable emission limits. Thus, assessing emissions for the worst-case scenario can help in preventing the emissions from adversely impacting public health and the environment.

  9. Facing the nuclear power phaseout - Swedish experiences of enterprise shutdown and organisational development; Infoer kaernkraftavveckling - svenska erfarenheter av foeretagsnedlaeggningar och foeraendringsarbete

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist, K. [Castor AB, Stockholm (Sweden)

    1998-02-01

    The aim of this study is to make an overview of problems and experiences connected to decommissioning and organisational changes of Swedish enterprises and public agencies from a safety perspective. The central point is the view of decommissioning of nuclear power plants as a process of change. In practice decommissioning includes both downsizing and organisational development. The question is which problems can arise and which strategy of change is most adequate from the standpoint of safety. The report starts with a summary of the most important experiences of the process of decommissioning of enterprises during the sixties to eighties concerning the consequences for the individuals and the labour market. After that follows the main results from earlier investigations of shut-down of nuclear power plants regarding the staff. The restructuring and downsizing of the public sector during the nineties have given rise to a large amount of material on staffing issues. The knowledge and experiences drawn from the organisational change processes of Swedish working life during the nineties are then summarised. At last some conclusions for decommissioning of nuclear power plants are discussed. The period before and after the termination of power generation is connected with great strain. The vulnerability of the staff increases and the faith in management can easily be destroyed, which can affect safety and the decommissioning work. The feeling of security increases if the staff continuously is kept informed and within certain limits can influence the course of events. A learning strategy is preferable in comparison to an expert oriented strategy because it is impossible to gain complete control over the technically and socially complex process of decommissioning. Instead of detailed and central planning of the process it will be safer to work in a participative way and to include all the staff in the preparations from the very beginning. By a learning way of working is

  10. Spotlight on medicinal chemistry education.

    Science.gov (United States)

    Pitman, Simone; Xu, Yao-Zhong; Taylor, Peter; Turner, Nicholas; Coaker, Hannah; Crews, Kasumi

    2014-05-01

    The field of medicinal chemistry is constantly evolving and it is important for medicinal chemists to develop the skills and knowledge required to succeed and contribute to the advancement of the field. Future Medicinal Chemistry spoke with Simone Pitman (SP), Yao-Zhong Xu (YX), Peter Taylor (PT) and Nick Turner (NT) from The Open University (OU), which offers an MSc in Medicinal Chemistry. In the interview, they discuss the MSc course content, online teaching, the future of medicinal chemistry education and The OU's work towards promoting widening participation. SP is a Qualifications Manager in the Science Faculty at The OU. She joined The OU in 1993 and since 1998 has been involved in the Postgraduate Medicinal Chemistry provision at The OU. YX is a Senior Lecturer in Bioorganic Chemistry at The OU. He has been with The OU from 2001, teaching undergraduate courses of all years and chairing the master's course on medicinal chemistry. PT is a Professor of Organic Chemistry at The OU and has been involved with the production and presentation of The OU courses in Science and across the university for over 30 years, including medicinal chemistry modules at postgraduate level. NT is a Lecturer in Analytical Science at The OU since 2009 and has been involved in the production of analytical sciences courses, as well as contributing to the presentation of a number of science courses including medicinal chemistry.

  11. Mathematics Competency for Beginning Chemistry Students Through Dimensional Analysis.

    Science.gov (United States)

    Pursell, David P; Forlemu, Neville Y; Anagho, Leonard E

    2017-01-01

    Mathematics competency in nursing education and practice may be addressed by an instructional variation of the traditional dimensional analysis technique typically presented in beginning chemistry courses. The authors studied 73 beginning chemistry students using the typical dimensional analysis technique and the variation technique. Student quantitative problem-solving performance was evaluated. Students using the variation technique scored significantly better (18.3 of 20 points, p mathematics competency and problem-solving ability in both education and practice. [J Nurs Educ. 2017;56(1):22-26.]. Copyright 2017, SLACK Incorporated.

  12. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry

    OpenAIRE

    Marek Tobiszewski; Mariusz Marć; Agnieszka Gałuszka; Jacek Namieśnik

    2015-01-01

    The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-establis...

  13. Mars aqueous chemistry experiment

    Science.gov (United States)

    Clark, Benton C.; Mason, Larry W.

    1993-01-01

    The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

  14. Physical chemistry II essentials

    CERN Document Server

    REA, The Editors of

    1992-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Physical Chemistry II includes reaction mechanisms, theoretical approaches to chemical kinetics, gravitational work, electrical and magnetic work, surface work, kinetic theory, collisional and transport properties of gases, statistical mechanics, matter and waves, quantum mechanics, and rotations and vibrations of atoms and molecules.

  15. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A.G.; Stordal, F.; Knudsen, S. [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  16. Chemistry and Science Fiction

    Science.gov (United States)

    Stocker, Jack H.

    1998-11-01

    This lively collection looks at science as filtered through literature, film, and television. It discusses classic works in science fiction and provides an in-depth look at the chemistry depicted in popular culture, particularly in Start Trek , Star Wars , and Doctor Who . It includes an examination by Nebula Award winner Connie Willis of how science fiction authors use science, and reprints two tongue-in-cheek short stories by Isaac Asimov. The book also includes suggestions for using science fiction as an educational resource.

  17. Chemistry in space

    CERN Document Server

    Rehder, Dieter

    2010-01-01

    The dynamic field of extraterrestrial chemistry brings together ideas of chemistr, astrophysics, and biology to the study of molecules between stars, around stars, and on plantes. This book serves as an introduction to chemial processes under ?unearthly? and hence usually extreme conditions (temperature, pressure, high or low density, bombardment by cosmic rays), and their impact on the early development of our solar system, as well as providing a deeper understanding of processes in earthly regions where conditions approach those of extraterrestrial areas.A unique and extraordinary perspe

  18. Introduction to Coordination Chemistry

    CERN Document Server

    Lawrance, Geoffrey Alan

    2010-01-01

    Introduction to Coordination Chemistry examines and explains how metals and molecules that bind as ligands interact, and the consequences of this assembly process. This book describes the chemical and physical properties and behavior of the complex assemblies that form, and applications that may arise as a result of these properties. Coordination complexes are an important but often hidden part of our world?even part of us?and what they do is probed in this book. This book distills the essence of this topic for undergraduate students and for research scientists.

  19. Principles of quantum chemistry

    CERN Document Server

    George, David V

    2013-01-01

    Principles of Quantum Chemistry focuses on the application of quantum mechanics in physical models and experiments of chemical systems.This book describes chemical bonding and its two specific problems - bonding in complexes and in conjugated organic molecules. The very basic theory of spectroscopy is also considered. Other topics include the early development of quantum theory; particle-in-a-box; general formulation of the theory of quantum mechanics; and treatment of angular momentum in quantum mechanics. The examples of solutions of Schroedinger equations; approximation methods in quantum c

  20. Radiochemistry and nuclear chemistry

    CERN Document Server

    Choppin, Gregory; RYDBERG, JAN; Ekberg, Christian

    2013-01-01

    Radiochemistry or nuclear chemistry is the study of radiation from an atomic and molecular perspective, including elemental transformation and reaction effects, as well as physical, health and medical properties. This revised edition of one of the earliest and best-known books on the subject has been updated to bring into teaching the latest developments in research and the current hot topics in the field. To further enhance the functionality of this text, the authors have added numerous teaching aids, examples in MathCAD with variable quantities and options, hotlinks to relevant text secti

  1. Quantum chemistry an introduction

    CERN Document Server

    Kauzmann, Walter

    2013-01-01

    Quantum Chemistry: An Introduction provides information pertinent to the fundamental aspects of quantum mechanics. This book presents the theory of partial differentiation equations by using the classical theory of vibrations as a means of developing physical insight into this essential branch of mathematics.Organized into five parts encompassing 16 chapters, this book begins with an overview of how quantum mechanical deductions are made. This text then describes the achievements and limitations of the application of quantum mechanics to chemical problems. Other chapters provide a brief survey

  2. Nuclear Chemistry and Services

    Energy Technology Data Exchange (ETDEWEB)

    Vandevelde, L

    2002-04-01

    The objectives, the programme, and the achievements of R and D at the Belgian Nuclear Research Centre SCK-CEN in the field of nuclear chemistry and analytical techniques are summarized. Major achievement in 2001 included the completion of a project on the measurement of critical radionuclides in reactor waste fluxes (the ARIANE project), the radiochemical characterisation of beryllium material originating from the second matrix of the BR2 reactor as well as to a the organisation of a workshop on the analysis of thorium and its isotopes in workplace materials.

  3. Advances in Phosphasilene Chemistry.

    Science.gov (United States)

    Nesterov, Vitaly; Breit, Nora C; Inoue, Shigeyoshi

    2017-09-07

    Heavier alkene analogues possess unique electronic properties and reactivity, encouraging multidisciplinary research groups to utilize them in the rational design of novel classes of compounds and materials. Phosphasilenes are heavier imine analogues, containing highly reactive Si=P double bonds. Recent achievements in this field are closely related to the progress in the chemistry of stable low-coordinate silicon compounds. In this Review, we have attempted to summarize in a comprehensive way the available data on the structures, syntheses, electronic and chemical properties of these compounds, with an emphasis on recent achievements. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Analytical chemistry in space

    CERN Document Server

    Wainerdi, Richard E

    1970-01-01

    Analytical Chemistry in Space presents an analysis of the chemical constitution of space, particularly the particles in the solar wind, of the planetary atmospheres, and the surfaces of the moon and planets. Topics range from space engineering considerations to solar system atmospheres and recovered extraterrestrial materials. Mass spectroscopy in space exploration is also discussed, along with lunar and planetary surface analysis using neutron inelastic scattering. This book is comprised of seven chapters and opens with a discussion on the possibilities for exploration of the solar system by

  5. NUCLEAR CHEMISTRY ANNUAL REPORT 1970

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1971-05-01

    Papers are presented for the following topics: (1) Nuclear Structure and Nuclear Properties - (a) Nuclear Spectroscopy and Radioactivity; (b) Nuclear Reactions and Scattering; (c) Nuclear Theory; and (d) Fission. (2) Chemical and Atomic Physics - (a) Atomic and Molecular Spectroscopy; and (b) Hyperfine Interactions. (3) Physical, Inorganic, and Analytical Chemistry - (a) X-Ray Crystallography; (b) Physical and Inorganic Chemistry; (c) Radiation Chemistry; and (d) Chemical Engineering. (4) Instrumentation and Systems Development.

  6. The physical basis of chemistry

    CERN Document Server

    Warren, Warren S

    2000-01-01

    If the text you're using for general chemistry seems to lack sufficient mathematics and physics in its presentation of classical mechanics, molecular structure, and statistics, this complementary science series title may be just what you're looking for. Written for the advanced lower-division undergraduate chemistry course, The Physical Basis of Chemistry, Second Edition, offers students an opportunity to understand and enrich the understanding of physical chemistry with some quantum mechanics, the Boltzmann distribution, and spectroscopy. Posed and answered are questions concerning eve

  7. Green Chemistry for Chemical Synthesis

    National Research Council Canada - National Science Library

    Chao-Jun Li; Barry M. Trost

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize...

  8. Information theory in analytical chemistry

    National Research Council Canada - National Science Library

    Eckschlager, Karel; Danzer, Klaus

    1994-01-01

    Contents: The aim of analytical chemistry - Basic concepts of information theory - Identification of components - Qualitative analysis - Quantitative analysis - Multicomponent analysis - Optimum analytical...

  9. Solid state chemistry an introduction

    CERN Document Server

    Smart, Lesley E

    2012-01-01

    ""Smart and Moore are engaging writers, providing clear explanations for concepts in solid-state chemistry from the atomic/molecular perspective. The fourth edition is a welcome addition to my bookshelves. … What I like most about Solid State Chemistry is that it gives simple clear descriptions for a large number of interesting materials and correspondingly clear explanations of their applications. Solid State Chemistry could be used for a solid state textbook at the third or fourth year undergraduate level, especially for chemistry programs. It is also a useful resource for beginning graduate

  10. Identification of human-induced initiating events in the low power and shutdown operation using the commission error search and assessment method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Chan; Kim, Jong Hyun [KEPCO International Nuclear Graduate School (KINGS), Ulsan (Korea, Republic of)

    2015-03-15

    Human-induced initiating events, also called Category B actions in human reliability analysis, are operator actions that may lead directly to initiating events. Most conventional probabilistic safety analyses typically assume that the frequency of initiating events also includes the probability of human-induced initiating events. However, some regulatory documents require Category B actions to be specifically analyzed and quantified in probabilistic safety analysis. An explicit modeling of Category B actions could also potentially lead to important insights into human performance in terms of safety. However, there is no standard procedure to identify Category B actions. This paper describes a systematic procedure to identify Category B actions for low power and shutdown conditions. The procedure includes several steps to determine operator actions that may lead to initiating events in the low power and shutdown stages. These steps are the selection of initiating events, the selection of systems or components, the screening of unlikely operating actions, and the quantification of initiating events. The procedure also provides the detailed instruction for each step, such as operator's action, information required, screening rules, and the outputs. Finally, the applicability of the suggested approach is also investigated by application to a plant example.

  11. Complex Protostellar Chemistry

    Science.gov (United States)

    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.

  12. Organometallic Neptunium Chemistry.

    Science.gov (United States)

    Arnold, Polly L; Dutkiewicz, Michał S; Walter, Olaf

    2017-09-13

    Fifty years have passed since the foundation of organometallic neptunium chemistry, and yet only a handful of complexes have been reported, and even fewer have been fully characterized. Yet, increasingly, combined synthetic/spectroscopic/computational studies are demonstrating how covalently bonding, soft, carbocyclic organometallic ligands provide an excellent platform for advancing the fundamental understanding of the differences in orbital contributions and covalency in f-block metal-ligand bonding. Understanding the subtleties is the key to the safe handling and separations of the highly radioactive nuclei. This review describes the complexes that have been synthesized to date and presents a critical assessment of the successes and difficulties in their analysis and the bonding information they have provided. Because of increasing recent efforts to start new Np-capable air-sensitive inorganic chemistry laboratories, the importance of radioactivity, the basics of Np decay and its ramifications (including the radiochemical synthesis of one organometallic compound), and the available anhydrous starting materials are also surveyed. The review also highlights a range of instances in which important differences in the chemical behavior between Np and its closest neighbors, uranium and plutonium, are found.

  13. Chemistry in Context: Analysis of Thematic Chemistry Videos Available Online

    Science.gov (United States)

    Christensson, Camilla; Sjöström, Jesper

    2014-01-01

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

  14. A Quantum Chemistry Concept Inventory for Physical Chemistry Classes

    Science.gov (United States)

    Dick-Perez, Marilu; Luxford, Cynthia J.; Windus, Theresa L.; Holme, Thomas

    2016-01-01

    A 14-item, multiple-choice diagnostic assessment tool, the quantum chemistry concept inventory or QCCI, is presented. Items were developed based on published student misconceptions and content coverage and then piloted and used in advanced physical chemistry undergraduate courses. In addition to the instrument itself, data from both a pretest,…

  15. Chemistry for Whom? Gender Awareness in Teaching and Learning Chemistry

    Science.gov (United States)

    Andersson, Kristina

    2017-01-01

    Marie Ståhl and Anita Hussénius have defined what discourses dominate national tests in chemistry for Grade 9 in Sweden by using feminist, critical didactic perspectives. This response seeks to expand the results in Ståhl and Hussénius's article "Chemistry inside an epistemological community box!--Discursive exclusions and inclusions in the…

  16. Topical report: Natural convection shutdown heat removal test facility (NSTF) evaluation for generating additional reactor cavity cooling system (RCCS) data.

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, M. T.; Kilsdonk, D. J.; Tzanos, C.P.; Lomperski, S.; Aeschlimann, R.W.; Pointer, D.; Nuclear Engineering Division

    2005-09-01

    As part of the Department of Energy (DOE) Generation IV roadmapping activity, the Very High Temperature gas cooled Reactor (VHTR) has been selected as the principal concept for hydrogen production and other process-heat applications such as district heating and potable water production. On this basis, the DOE has selected the VHTR for additional R&D with the ultimate goal of demonstrating emission-free electricity and hydrogen production with this advanced reactor concept. One of the key passive safety features of the VHTR is the potential for decay heat removal by natural circulation of air in a Reactor Cavity Cooling System (RCCS). The air-cooled RCCS concept is notably similar to the Reactor Vessel Auxiliary Cooling System (RVACS) that was developed for the General Electric PRISM sodium-cooled fast reactor. As part of the DOE R&D program that supported the development of this fast reactor concept, the Natural Convection Shutdown Heat Removal Test Facility (NSTF) was developed at ANL to provide proof-of-concept data for the RVACS under prototypic natural convection flow, temperature, and heat flux conditions. Due to the similarity between RVACS and the RCCS, current VHTR R&D plans call for the utilization of the NSTF to provide RCCS model development and validation data, in addition to supporting design validation and optimization activities. Both air-cooled and water-cooled RCCS designs are to be included. In support of this effort, ANL has been tasked with the development of an engineering plan for mechanical and instrumentation modifications to NSTF to ensure that sufficiently detailed temperature, heat flux, velocity and turbulence profiles are obtained to adequately qualify the codes under the expected range of air-cooled RCCS flow conditions. Next year, similar work will be carried out for the alternative option of a water-cooled RCCS design. Analysis activities carried out in support of this experiment planning task have shown that: (a) in the RCCS, strong

  17. Nuclear Chemistry and Chemistry of f-Elements in Chemistry Curriculum at Secondary Schools

    OpenAIRE

    Distler, Petr

    2016-01-01

    This master's degree thesis, called Nuclear Chemistry and Chemistry of f-Elements in Chemistry Curriculum at Secondary Schools, conducts a research of the most commonly used high school textbooks. Within the textbook research, topics such as atomic nucleus composition, radioactivity, and f-elements were studied in order to evaluate to what extent contemporary textbooks meet to the curriculum requirements. Based on the textbook research, the new teaching texts, materials, and teaching tasks in...

  18. The effectiveness of a standards-based integrated chemistry and mathematics curriculum on improving the academic achievement in chemistry for high school students in Southern California

    Science.gov (United States)

    Mupanduki, Blessing T.

    The purpose of this study was to determine whether integrating chemistry and mathematics curricula and teaching practices significantly improves academic achievement in chemistry among high school students in Southern California. The study was conducted during the 2008--2009 academic year. A quasi-experimental research design was used to explore the effects of a standards-based integrated chemistry and mathematics curriculum (Integrated CHEMAT) and teaching practices on student academic achievement when compared to a traditional standards-based chemistry curriculum (Regular CHEM) and teaching practices. Academic achievement was based on a researcher-created Chemistry Achievement Assessment (CHAAS). The sample population involved in the research included 136 high school chemistry students attending high school in a Southern California rural school district. The research involved 2 groups of 68 students each: the experimental group and the control group. The data were analyzed using SPSS independent samples t-test, one-way multivariate analysis of covariance (MANCOVA), and profile analysis. Statistical significance was determined at the .05 and .001 levels. Significant differences were found when analyzing the effects of the standards-based integrated chemistry and mathematics curriculum and teaching practices. All 3 statistical analysis procedures (the independent samples t-test, MANCOVA, and profile analysis) indicated that students in the integrated CHEMAT program scored significantly higher than the students in the regular CHEM program in achievement scores based on the results of the CHAAS.

  19. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry

    Directory of Open Access Journals (Sweden)

    Marek Tobiszewski

    2015-06-01

    Full Text Available The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-established and recently developed green analytical chemistry metrics, including NEMI labeling and analytical Eco-scale, are presented. Additionally, this paper focuses on the possibility of the use of multivariate statistics in evaluation of environmental impact of analytical procedures. All the above metrics are compared and discussed in terms of their advantages and disadvantages. The current needs and future perspectives in green chemistry metrics are also discussed.

  20. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry.

    Science.gov (United States)

    Tobiszewski, Marek; Marć, Mariusz; Gałuszka, Agnieszka; Namieśnik, Jacek

    2015-06-12

    The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-established and recently developed green analytical chemistry metrics, including NEMI labeling and analytical Eco-scale, are presented. Additionally, this paper focuses on the possibility of the use of multivariate statistics in evaluation of environmental impact of analytical procedures. All the above metrics are compared and discussed in terms of their advantages and disadvantages. The current needs and future perspectives in green chemistry metrics are also discussed.

  1. From organic chemistry to fat and oil chemistry*

    Directory of Open Access Journals (Sweden)

    Deffense Etienne

    2009-01-01

    Full Text Available With his work on animal fat and identification of fatty acids, Chevreul was a pioneer in organic chemistry. As Chevreul, I had a passion for organic chemistry too. It was then, an honour and a pleasure to present in 2008 at EFL in Athens this presentation entitled “From organic chemistry to fat and oil chemistry” because my background in organic chemistry helped me all along my professional career to understand and implement new developments related to oil and fat technology and processing. Among the topics which I worked out, I highlighted more particularly the following subjects: the degumming chemistry of oil and fat; the improvement of physical refining; a new chemical analytical tool for the dry fractionation; new development in the dry fractionation

  2. Introducing Undergraduates to Research Using a Suzuki-Miyaura Cross-Coupling Organic Chemistry Miniproject

    Science.gov (United States)

    Oliveira, Deyvid G. M.; Rosa, Clarissa H.; Vargas, Bruna P.; Rosa, Diego S.; Silveira, Ma´rcia V.; de Moura, Neusa F.; Rosa, Gilber R.

    2015-01-01

    A five-week miniproject is described for an upper-division experimental organic chemistry course. The activities include synthesis of a phenylboronic acid via a Grignard reaction and its use in a Suzuki-Miyaura cross-coupling reaction. Technical skills and concepts normally presented in practical organic chemistry courses are covered, including…

  3. Organic Chemistry Students' Ideas about Nucleophiles and Electrophiles: The Role of Charges and Mechanisms

    Science.gov (United States)

    Anzovino, Mary E.; Bretz, Stacey Lowery

    2015-01-01

    Organic chemistry students struggle with reaction mechanisms and the electron-pushing formalism (EPF) used by practicing organic chemists. Faculty have identified an understanding of nucleophiles and electrophiles as one conceptual prerequisite to mastery of the EPF, but little is known about organic chemistry students' knowledge of nucleophiles…

  4. Ensuring Sustainability of Tomorrow through Green Chemistry Integrated with Sustainable Development Concepts (SDCS)

    Science.gov (United States)

    Karpudewan, Mageswary; Ismail, Zurida; Roth, Wolff-Michael

    2012-01-01

    The purpose of this article is to describe a best practice: an approach to teaching chemistry that our quantitative research has shown to produce large differences between experimental and control groups in terms of achievement, pro-environmental attitudes, values, and motivation. Our interest in teaching chemistry by focusing on sustainable…

  5. ICT in teaching and learning chemistry activities on the iPad ...

    African Journals Online (AJOL)

    The purpose of this workshop is to equip chemistry educators with practical activities and logistical training to incorporate Information and Communication Technologies (ICT) into their chemistry curriculum. During this workshop, participants will gain hands-on experience using technology such as iPads and a variety of ...

  6. Past, Present, and Future of AP Chemistry: A Brief History of Course and Exam Alignment Efforts

    Science.gov (United States)

    Magrogan, Serena

    2014-01-01

    As part of the Advanced Placement (AP) Program's commitment to continually enhance alignment with current best practices in college-level learning, the AP Program is currently evaluating and redesigning courses and exams, one of which launched during the 2013-2014 academic school year: AP chemistry. The history of the AP chemistry course and…

  7. 75 FR 36421 - Draft Guidance for Industry on Chemistry, Manufacturing, and Controls Postapproval Manufacturing...

    Science.gov (United States)

    2010-06-25

    ... HUMAN SERVICES Food and Drug Administration Draft Guidance for Industry on Chemistry, Manufacturing, and... reported in annual reports. Specifically, the draft guidance describes chemistry, manufacturing, and... the many advances in quality management practices in manufacturing and to enable the agency to more...

  8. Constituição de professores universitários de disciplinas sobre ensino de Química Development of university teachers in the chemistry teaching discipline

    Directory of Open Access Journals (Sweden)

    Rejane Maria Ghisolfi da Silva

    2005-12-01

    Full Text Available This paper focuses on the teaching development practice in the field of chemistry covering such disciplines as chemistry teaching practice, chemistry teaching instrumentation and chemistry teaching methodology and/or didactics, thereby describing and analysing the logics of the development practice and the role of teachers as well as the epistemological identity configurations (knowledges which are proper to said identity within this discipline field.

  9. Significant steps in the evolution of analytical chemistry--is the today's analytical chemistry only chemistry?

    Science.gov (United States)

    Karayannis, Miltiades I; Efstathiou, Constantinos E

    2012-12-15

    In this review the history of chemistry and specifically the history and the significant steps of the evolution of analytical chemistry are presented. In chronological time spans, covering the ancient world, the middle ages, the period of the 19th century, and the three evolutional periods, from the verge of the 19th century to contemporary times, it is given information for the progress of chemistry and analytical chemistry. During this period, analytical chemistry moved gradually from its pure empirical nature to more rational scientific activities, transforming itself to an autonomous branch of chemistry and a separate discipline. It is also shown that analytical chemistry moved gradually from the status of exclusive serving the chemical science, towards serving, the environment, health, law, almost all areas of science and technology, and the overall society. Some recommendations are also directed to analytical chemistry educators concerning the indispensable nature of knowledge of classical analytical chemistry and the associated laboratory exercises and to analysts, in general, why it is important to use the chemical knowledge to make measurements on problems of everyday life. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Tropospheric Halogen Chemistry

    Science.gov (United States)

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

    2003-12-01

    Halogens are very reactive chemicals that are known to play an important role in anthropogenic stratospheric ozone depletion chemistry, first recognized by Molina and Rowland (1974). However, they also affect the chemistry of the troposphere. They are of special interest because they are involved in many reaction cycles that can affect the oxidation power of the atmosphere indirectly by influencing the main oxidants O3 and its photolysis product OH and directly, e.g., by reactions of the Cl radical with hydrocarbons (e.g., CH4).Already by the middle of the nineteenth century, Marchand (1852) reported the presence of bromine and iodine in rain and other natural waters. He also mentions the benefits of iodine in drinking water through the prevention of goitres and cretinism. In a prophetic monograph "Air and Rain: The Beginnings of a Chemical Climatology," Smith (1872) describes measurements of chloride in rain water, which he states to originate partly from the oceans by a process that he compares with the bursting of "soap bubbles" which produces "small vehicles" that transfer small spray droplets of seawater to the air. From deviations of the sulfate-to-chloride ratio in coastal rain compared to seawater, Smith concluded that chemical processes occur once the particles are airborne.For almost a century thereafter, however, atmospheric halogens received little attention. One exception was the work by Cauer (1939), who reported that iodine pollution has been significant in Western and Central Europe due to the inefficient burning of seaweed, causing mean gas phase atmospheric concentrations as high as or greater than 0.5 μg m-3. In his classical textbook Air Chemistry and Radioactivity, Junge (1963) devoted less than three pages to halogen gas phase chemistry, discussing chlorine and iodine. As reviewed by Eriksson (1959a, b), the main atmospheric source of halogens is sea salt, derived from the bursting of bubbles of air which are produced by ocean waves and other

  11. Applicative chemistry of tanning metallic heterocomplexes

    CERN Document Server

    Gaidau, Carmen

    2013-01-01

    The chemistry of heterocomplex compounds is a fascinating field for experts in chemical synthesis and structural analysis, and for technologists specializing in leather processing. This volume describes the vast theoretical and practical possibilities of exploiting the action synergism of metals with different collagen cross-linking capacity. The possibility of reducing chromium content from leather tanning agents by replacing it with other tanning metals has significant environmental implications and minimum changes in terms of quality and production costs of natural leather, and is a viable

  12. Low temperature nitrogen chemistry. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Glarborg, P.; Dam-Johansen, K.; Kristensen, P.G.; Alzueta, M.; Roejel, H.

    1997-04-01

    The results of a two tasks program on Natural Gas Reburning are reported. The work involved an experimental and theoretical study of the reburning and hybrid reburning/SNCR chemistry in the 1000-1500 K range. The interactions between hydrocarbon and nitrogen chemistry under fuel-rich conditions were investigated in order to assess the NO{sub x} reduction potential of low temperature reburning. The effect of reburn fuel(carbon monoxide, methane, acetylene, ethylene, ethane, and methane/ethane mixture), temperature, stoichiometry, reactant dilution, reaction time, and inlet NO level were studied. The results indicate a significant NO reduction potential even below 1400 K, but extrapolation to practical conditions are complicated by inadequate knowledge of the detailed chemistry as well as of the effect of mixing. The possibilities of enhancing the conversion to N{sub 2} instead of NO by adding selective reducing agents (hybrid reburning/SNCR) were evaluated. Our results indicate little synergistic effect between reburn and SNCR. The most simple configuration, where the selective reducing agent is injected together with the burnout air, is not expected to be effective, unless the N-agent is injected in form of an aqueous solution. A chemical kinetic model for reburning and reburn/SNCR is listed and can be obtained by e-mail from pgl(commerical at)kt.dtu.dk.(au) 145 refs.

  13. Dynamic imine chemistry.

    Science.gov (United States)

    Belowich, Matthew E; Stoddart, J Fraser

    2012-03-21

    Formation of an imine--from an amine and an aldehyde--is a reversible reaction which operates under thermodynamic control such that the formation of kinetically competitive intermediates are, in the fullness of time, replaced by the thermodynamically most stable product(s). For this fundamental reason, the imine bond has emerged as an extraordinarily diverse and useful one in the hands of synthetic chemists. Imine bond formation is one of a handful of reactions which define a discipline known as dynamic covalent chemistry (DCC), which is now employed widely in the construction of exotic molecules and extended structures on account of the inherent 'proof-reading' and 'error-checking' associated with these reversible reactions. While both supramolecular chemistry and DCC operate under the regime of reversibility, DCC has the added advantage of constructing robust molecules on account of the formation of covalent bonds rather than fragile supermolecules resulting from noncovalent bonding interactions. On the other hand, these products tend to require more time to form--sometimes days or even months--but their formation can often be catalysed. In this manner, highly symmetrical molecules and extended structures can be prepared from relatively simple precursors. When DCC is utilised in conjunction with template-directed protocols--which rely on the use of noncovalent bonding interactions between molecular building blocks in order to preorganise them into certain relative geometries as a prelude to the formation of covalent bonds under equilibrium control--an additional level of control of structure and topology arises which offers a disarmingly simple way of constructing mechanically-interlocked molecules, such as rotaxanes, catenanes, Borromean rings, and Solomon knots. This tutorial review focuses on the use of dynamic imine bonds in the construction of compounds and products formed with and without the aid of additional templates. While synthesis under thermodynamic

  14. Compressed Sensing for Chemistry

    Science.gov (United States)

    Sanders, Jacob Nathan

    Many chemical applications, from spectroscopy to quantum chemistry, involve measuring or computing a large amount of data, and then compressing this data to retain the most chemically-relevant information. In contrast, compressed sensing is an emergent technique that makes it possible to measure or compute an amount of data that is roughly proportional to its information content. In particular, compressed sensing enables the recovery of a sparse quantity of information from significantly undersampled data by solving an ℓ 1-optimization problem. This thesis represents the application of compressed sensing to problems in chemistry. The first half of this thesis is about spectroscopy. Compressed sensing is used to accelerate the computation of vibrational and electronic spectra from real-time time-dependent density functional theory simulations. Using compressed sensing as a drop-in replacement for the discrete Fourier transform, well-resolved frequency spectra are obtained at one-fifth the typical simulation time and computational cost. The technique is generalized to multiple dimensions and applied to two-dimensional absorption spectroscopy using experimental data collected on atomic rubidium vapor. Finally, a related technique known as super-resolution is applied to open quantum systems to obtain realistic models of a protein environment, in the form of atomistic spectral densities, at lower computational cost. The second half of this thesis deals with matrices in quantum chemistry. It presents a new use of compressed sensing for more efficient matrix recovery whenever the calculation of individual matrix elements is the computational bottleneck. The technique is applied to the computation of the second-derivative Hessian matrices in electronic structure calculations to obtain the vibrational modes and frequencies of molecules. When applied to anthracene, this technique results in a threefold speed-up, with greater speed-ups possible for larger molecules. The

  15. Chemistry of Covalent Organic Frameworks.

    Science.gov (United States)

    Waller, Peter J; Gándara, Felipe; Yaghi, Omar M

    2015-12-15

    Linking organic molecules by covalent bonds into extended solids typically generates amorphous, disordered materials. The ability to develop strategies for obtaining crystals of such solids is of interest because it opens the way for precise control of the geometry and functionality of the extended structure, and the stereochemical orientation of its constituents. Covalent organic frameworks (COFs) are a new class of porous covalent organic structures whose backbone is composed entirely of light elements (B, C, N, O, Si) that represent a successful demonstration of how crystalline materials of covalent solids can be achieved. COFs are made by combination of organic building units covalently linked into extended structures to make crystalline materials. The attainment of crystals is done by several techniques in which a balance is struck between the thermodynamic reversibility of the linking reactions and their kinetics. This success has led to the expansion of COF materials to include organic units linked by these strong covalent bonds: B-O, C-N, B-N, and B-O-Si. Since the organic constituents of COFs, when linked, do not undergo significant change in their overall geometry, it has been possible to predict the structures of the resulting COFs, and this advantage has facilitated their characterization using powder X-ray diffraction (PXRD) techniques. It has also allowed for the synthesis of COF structures by design and for their formation with the desired composition, pore size, and aperture. In practice, the modeled PXRD pattern for a given expected COF is compared with the experimental one, and depending on the quality of the match, this is used as a starting point for solving and then refining the crystal structure of the target COF. These characteristics make COFs an attractive class of new porous materials. Accordingly, they have been used as gas storage materials for energy applications, solid supports for catalysis, and optoelectronic devices. A large and

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  17. News from Online: Green Chemistry

    Science.gov (United States)

    Uffelman, Erich S.

    2004-01-01

    Green chemistry closely relates to energy and environmental problems, and includes the promotion of environmental friendly products and systems within the framework of renewable resources. Various websites on green chemistry are reviewed, one of which lists the 12 commandments of this particular subject.

  18. Chemistry Teachers' Views of Creativity

    Science.gov (United States)

    Akkanat, Çigdem; Gökdere, Murat

    2015-01-01

    The purpose of this study was to determine chemistry teachers' views of creativity. In this study, phenomenology method, one of the qualitative research patterns, was used. The participants of this study were 13 chemistry teachers working in Amasya. A semi-structured interview form was used for data collection. By using NVivo 9 qualitative…

  19. How fast is ultrafast chemistry

    OpenAIRE

    Bagchi, Biman

    1995-01-01

    The field of ultrafast chemistry has seen a string of remarkable discoveries in the recent years. In this article we briefly discuss some of the problems solved recently. The understanding that has emerged from these studies has important consequences non only in chemistry but also in diverse biological processes.

  20. Modern Trends in Inorganic Chemistry

    Indian Academy of Sciences (India)

    Administrator

    The series of symposia on 'Modern Trends in Inorganic Chemistry' (MTIC), which began in 1985 at the Indian Association for Cultivation of Science, Calcutta has evolved into a forum for the Inorganic Chemistry fraternity of the country to meet every two years and discuss the current status and future projections of research in.