Electrochemistry at One Nanoparticle.

PubMed

Mirkin, Michael V; Sun, Tong; Yu, Yun; Zhou, Min

2016-10-18

Electrochemistry at metal nanoparticles (NPs) is of significant current interest because of its applications in catalysis, energy conversion and storage, and sensors. The electrocatalytic activity of NPs depends strongly on their size, shape, and surface attachment. The use of a large number of particles in most reported kinetic experiments obscured the effects of these factors because of polydispersity and different NP orientations. Recent efforts to probe electrochemistry at single NPs included recording of the catalytically amplified current produced by random collisions of particles with the electrode surface, immobilizing an NP on the surface of a small electrode, and delivering individual NPs to electrode surfaces. Although the signals recorded in such experiments were produced by single NPs, the characterization issues and problems with separating an individual particle from other NPs present in the system made it difficult to obtain spatially and/or temporally resolved information about heterogeneous processes occurring at a specific NP. To carry out electrochemical experiments involving only one NP and characterize such an NP in situ, one needs nanoelectrochemical tools with the characteristic dimension smaller than or comparable to those of the particle of interest. This Account presents fundamentals of two complementary approaches to studying NP electrochemistry, i.e., probing single immobilized NPs with the tip of a scanning electrochemical microscope (SECM) and monitoring the collisions between one catalytic NP and a carbon nanopipette. The former technique can provide spatially resolved information about NP geometry and measure its electron transfer properties and catalytic activity under steady-state conditions. The emphasis here is on the extraction of quantitative physicochemical information from nanoelectrochemical data. By employing a polished disk-type nanoelectrode as an SECM tip, one can characterize a specific nanoparticle in situ and then

Conceptual Difficulties Experienced by Senior High School Students of Electrochemistry: Electrochemical (Galvanic) and Electrolytic Cells.

ERIC Educational Resources Information Center

Garnett, Pamela J.; Treagust, David F.

1992-01-01

This research used semistructured interviews to investigate students' (n=32) understanding of electrochemistry following a 7-9 week course of instruction. Three misconceptions were identified and incorporated with five previously reported into an alternative framework about electric current involving drifting electrons. Also noted was the tendency…

An Effective Approach to Teaching Electrochemistry.

ERIC Educational Resources Information Center

Birss, Viola I.; Truax, D. Rodney

1990-01-01

An approach which may be useful for teaching electrochemistry in freshman college chemistry courses is presented. Discussed are the potential problems with teaching this subject and solutions provided by this approach. (CW)

The birth of protein electrochemistry.

PubMed

Blanford, Christopher F

2013-12-11

The results from a final-year undergraduate project led to an $876M sale of a spin-out company 19 years later: the 1977 communication from Mark Eddowes and Allen Hill seeded the rich field of protein electrochemistry, the technology that underpins commercial glucose biosensors.

Boundary asymptotics for a non-neutral electrochemistry model with small Debye length

NASA Astrophysics Data System (ADS)

Lee, Chiun-Chang; Ryham, Rolf J.

2018-04-01

This article addresses the boundary asymptotics of the electrostatic potential in non-neutral electrochemistry models with small Debye length in bounded domains. Under standard physical assumptions motivated by non-electroneutral phenomena in oxidation-reduction reactions, we show that the electrostatic potential asymptotically blows up at boundary points with respect to the bulk reference potential as the scaled Debye length tends to zero. The analysis gives a lower bound for the blow-up rate with respect to the model parameters. Moreover, the maximum potential difference over any compact subset of the physical domain vanishes exponentially in the zero-Debye-length limit. The results mathematically confirm the physical description that electrolyte solutions are electrically neutral in the bulk and are strongly electrically non-neutral near charged surfaces.

Electrochemistry of Silicon: Instrumentation, Science, Materials and Applications

NASA Astrophysics Data System (ADS)

Lehmann, Volker

2002-04-01

Silicon has been and will most probably continue to be the dominant material in semiconductor technology. Although the defect-free silicon single crystal is one of the best understood systems in materails science, its electrochemistry to many people is still a kind of "alchemy". This view is partly due to the interdisciplinary aspects of the topic: Physics meets chemistry at the silicon-electrolyte interface. This book gives a comprehensive overview of this important aspect of silicon technology as well as examples of applications ranging from photonic crystals to biochips. It will serve materials scientists as well as engineers involved in silicon technology as a quick reference with its more than 150 technical tables and diagrams and ca. 1000 references cited for easy access of the original literature.

Electrochemistry and Storage

NASA Technical Reports Server (NTRS)

Thaller, L. H.

1984-01-01

The term electrochemistry implies the use of devices that convert chemical energy into electrical energy and sometimes vice versa. These devices are usually composed of some number of individual cells that are connected together to form a battery. In the cases where these devices cannot be electrically recharged they are usually referred to as primary batteries, whereas if these batteries can be charged and recharged repeatedly, they are called secondary batteries. The past and present uses of primary and secondary batteries in aerospace applications are discussed.

DNA-Mediated Electrochemistry

PubMed Central

Gorodetsky, Alon A.; Buzzeo, Marisa C.

2009-01-01

The base pair stack of DNA has been demonstrated as a medium for long range charge transport chemistry both in solution and at DNA-modified surfaces. This chemistry is exquisitely sensitive to structural perturbations in the base pair stack as occur with lesions, single base mismatches, and protein binding. We have exploited this sensitivity for the development of reliable electrochemical assays based on DNA charge transport at self-assembled DNA monolayers. Here we discuss the characteristic features, applications, and advantages of DNA-mediated electrochemistry. PMID:18980370

Redox-capacitor to connect electrochemistry to redox-biology.

PubMed

Kim, Eunkyoung; Leverage, W Taylor; Liu, Yi; White, Ian M; Bentley, William E; Payne, Gregory F

2014-01-07

It is well-established that redox-reactions are integral to biology for energy harvesting (oxidative phosphorylation), immune defense (oxidative burst) and drug metabolism (phase I reactions), yet there is emerging evidence that redox may play broader roles in biology (e.g., redox signaling). A critical challenge is the need for tools that can probe biologically-relevant redox interactions simply, rapidly and without the need for a comprehensive suite of analytical methods. We propose that electrochemistry may provide such a tool. In this tutorial review, we describe recent studies with a redox-capacitor film that can serve as a bio-electrode interface that can accept, store and donate electrons from mediators commonly used in electrochemistry and also in biology. Specifically, we (i) describe the fabrication of this redox-capacitor from catechols and the polysaccharide chitosan, (ii) discuss the mechanistic basis for electron exchange, (iii) illustrate the properties of this redox-capacitor and its capabilities for promoting redox-communication between biology and electrodes, and (iv) suggest the potential for enlisting signal processing strategies to "extract" redox information. We believe these initial studies indicate broad possibilities for enlisting electrochemistry and signal processing to acquire "systems level" redox information from biology.

Electrochemistry, biosensors and microfluidics: a convergence of fields.

PubMed

Rackus, Darius G; Shamsi, Mohtashim H; Wheeler, Aaron R

2015-08-07

Electrochemistry, biosensors and microfluidics are popular research topics that have attracted widespread attention from chemists, biologists, physicists, and engineers. Here, we introduce the basic concepts and recent histories of electrochemistry, biosensors, and microfluidics, and describe how they are combining to form new application-areas, including so-called "point-of-care" systems in which measurements traditionally performed in a laboratory are moved into the field. We propose that this review can serve both as a useful starting-point for researchers who are new to these topics, as well as being a compendium of the current state-of-the art for experts in these evolving areas.

Individuals Achieve More Accurate Results with Meters That Are Codeless and Employ Dynamic Electrochemistry

PubMed Central

Rao, Anoop; Wiley, Meg; Iyengar, Sridhar; Nadeau, Dan; Carnevale, Julie

2010-01-01

Background Studies have shown that controlling blood glucose can reduce the onset and progression of the long-term microvascular and neuropathic complications associated with the chronic course of diabetes mellitus. Improved glycemic control can be achieved by frequent testing combined with changes in medication, exercise, and diet. Technological advancements have enabled improvements in analytical accuracy of meters, and this paper explores two such parameters to which that accuracy can be attributed. Methods Four blood glucose monitoring systems (with or without dynamic electrochemistry algorithms, codeless or requiring coding prior to testing) were evaluated and compared with respect to their accuracy. Results Altogether, 108 blood glucose values were obtained for each system from 54 study participants and compared with the reference values. The analysis depicted in the International Organization for Standardization table format indicates that the devices with dynamic electrochemistry and the codeless feature had the highest proportion of acceptable results overall (System A, 101/103). Results were significant when compared at the 10% bias level with meters that were codeless and utilized static electrochemistry (p = .017) or systems that had static electrochemistry but needed coding (p = .008). Conclusions Analytical performance of these blood glucose meters differed significantly depending on their technologic features. Meters that utilized dynamic electrochemistry and did not require coding were more accurate than meters that used static electrochemistry or required coding. PMID:20167178

Individuals achieve more accurate results with meters that are codeless and employ dynamic electrochemistry.

PubMed

Rao, Anoop; Wiley, Meg; Iyengar, Sridhar; Nadeau, Dan; Carnevale, Julie

2010-01-01

Studies have shown that controlling blood glucose can reduce the onset and progression of the long-term microvascular and neuropathic complications associated with the chronic course of diabetes mellitus. Improved glycemic control can be achieved by frequent testing combined with changes in medication, exercise, and diet. Technological advancements have enabled improvements in analytical accuracy of meters, and this paper explores two such parameters to which that accuracy can be attributed. Four blood glucose monitoring systems (with or without dynamic electrochemistry algorithms, codeless or requiring coding prior to testing) were evaluated and compared with respect to their accuracy. Altogether, 108 blood glucose values were obtained for each system from 54 study participants and compared with the reference values. The analysis depicted in the International Organization for Standardization table format indicates that the devices with dynamic electrochemistry and the codeless feature had the highest proportion of acceptable results overall (System A, 101/103). Results were significant when compared at the 10% bias level with meters that were codeless and utilized static electrochemistry (p = .017) or systems that had static electrochemistry but needed coding (p = .008). Analytical performance of these blood glucose meters differed significantly depending on their technologic features. Meters that utilized dynamic electrochemistry and did not require coding were more accurate than meters that used static electrochemistry or required coding. 2010 Diabetes Technology Society.

Electrochemistry-based Approaches to Low Cost, High Sensitivity, Automated, Multiplexed Protein Immunoassays for Cancer Diagnostics

PubMed Central

Dixit, Chandra K.; Kadimisetty, Karteek; Otieno, Brunah A.; Tang, Chi; Malla, Spundana; Krause, Colleen E.; Rusling, James F.

2015-01-01

Early detection and reliable diagnostics are keys to effectively design cancer therapies with better prognoses. Simultaneous detection of panels of biomarker proteins holds great promise as a general tool for reliable cancer diagnostics. A major challenge in designing such a panel is to decide upon a coherent group of biomarkers which have higher specificity for a given type of cancer. The second big challenge is to develop test devices to measure these biomarkers quantitatively with high sensitivity and specificity, such that there are no interferences from the complex serum or tissue matrices. Lastly, integrating all these tests into a technology that doesn’t require exclusive training to operate, and can be used at point-of-care (POC) is another potential bottleneck in futuristic cancer diagnostics. In this article, we review electrochemistry-based tools and technologies developed and/or used in our laboratories to construct low-cost microfluidic protein arrays for highly sensitive detection of the panel of cancer-specific biomarkers with high specificity and at the same time have the potential to be translated into a POC. PMID:26525998

Electrochemistry-based approaches to low cost, high sensitivity, automated, multiplexed protein immunoassays for cancer diagnostics.

PubMed

Dixit, Chandra K; Kadimisetty, Karteek; Otieno, Brunah A; Tang, Chi; Malla, Spundana; Krause, Colleen E; Rusling, James F

2016-01-21

Early detection and reliable diagnostics are keys to effectively design cancer therapies with better prognoses. The simultaneous detection of panels of biomarker proteins holds great promise as a general tool for reliable cancer diagnostics. A major challenge in designing such a panel is to decide upon a coherent group of biomarkers which have higher specificity for a given type of cancer. The second big challenge is to develop test devices to measure these biomarkers quantitatively with high sensitivity and specificity, such that there are no interferences from the complex serum or tissue matrices. Lastly, integrating all these tests into a technology that does not require exclusive training to operate, and can be used at point-of-care (POC) is another potential bottleneck in futuristic cancer diagnostics. In this article, we review electrochemistry-based tools and technologies developed and/or used in our laboratories to construct low-cost microfluidic protein arrays for the highly sensitive detection of a panel of cancer-specific biomarkers with high specificity which at the same time has the potential to be translated into POC applications.

Students' understandings of electrochemistry

NASA Astrophysics Data System (ADS)

O'Grady-Morris, Kathryn

Electrochemistry is considered by students to be a difficult topic in chemistry. This research was a mixed methods study guided by the research question: At the end of a unit of study, what are students' understandings of electrochemistry? The framework of analysis used for the qualitative and quantitative data collected in this study was comprised of three categories: types of knowledge used in problem solving, levels of representation of knowledge in chemistry (macroscopic, symbolic, and particulate), and alternative conceptions. Although individually each of the three categories has been reported in previous studies, the contribution of this study is the inter-relationships among them. Semi-structured, task-based interviews were conducted while students were setting up and operating electrochemical cells in the laboratory, and a two-tiered, multiple-choice diagnostic instrument was designed to identify alternative conceptions that students held at the end of the unit. For familiar problems, those involving routine voltaic cells, students used a working-forwards problem-solving strategy, two or three levels of representation of knowledge during explanations, scored higher on both procedural and conceptual knowledge questions in the diagnostic instrument, and held fewer alternative conceptions related to the operation of these cells. For less familiar problems, those involving non-routine voltaic cells and electrolytic cells, students approached problem-solving with procedural knowledge, used only one level of representation of knowledge when explaining the operation of these cells, scored higher on procedural knowledge than conceptual knowledge questions in the diagnostic instrument, and held a greater number of alternative conceptions. Decision routines that involved memorized formulas and procedures were used to solve both quantitative and qualitative problems and the main source of alternative conceptions in this study was the overgeneralization of theory

Implementation of Case-Based Instruction on Electrochemistry at the 11th Grade Level

ERIC Educational Resources Information Center

Tarkin, Aysegul; Uzuntiryaki-Kondakci, Esen

2017-01-01

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

Metal-air batteries: from oxygen reduction electrochemistry to cathode catalysts.

PubMed

Cheng, Fangyi; Chen, Jun

2012-03-21

Because of the remarkably high theoretical energy output, metal-air batteries represent one class of promising power sources for applications in next-generation electronics, electrified transportation and energy storage of smart grids. The most prominent feature of a metal-air battery is the combination of a metal anode with high energy density and an air electrode with open structure to draw cathode active materials (i.e., oxygen) from air. In this critical review, we present the fundamentals and recent advances related to the fields of metal-air batteries, with a focus on the electrochemistry and materials chemistry of air electrodes. The battery electrochemistry and catalytic mechanism of oxygen reduction reactions are discussed on the basis of aqueous and organic electrolytes. Four groups of extensively studied catalysts for the cathode oxygen reduction/evolution are selectively surveyed from materials chemistry to electrode properties and battery application: Pt and Pt-based alloys (e.g., PtAu nanoparticles), carbonaceous materials (e.g., graphene nanosheets), transition-metal oxides (e.g., Mn-based spinels and perovskites), and inorganic-organic composites (e.g., metal macrocycle derivatives). The design and optimization of air-electrode structure are also outlined. Furthermore, remarks on the challenges and perspectives of research directions are proposed for further development of metal-air batteries (219 references).

Bipolar electrochemistry: from materials science to motion and beyond.

PubMed

Loget, Gabriel; Zigah, Dodzi; Bouffier, Laurent; Sojic, Neso; Kuhn, Alexander

2013-11-19

Bipolar electrochemistry, a phenomenon which generates an asymmetric reactivity on the surface of conductive objects in a wireless manner, is an important concept for many purposes, from analysis to materials science as well as for the generation of motion. Chemists have known the basic concept for a long time, but it has recently attracted additional attention, especially in the context of micro- and nanoscience. In this Account, we introduce the fundamentals of bipolar electrochemistry and illustrate its recent applications, with a particular focus on the fields of materials science and dynamic systems. Janus particles, named after the Roman god depicted with two faces, are currently in the heart of many original investigations. These objects exhibit different physicochemical properties on two opposite sides. This makes them a unique class of materials, showing interesting features. They have received increasing attention from the materials science community, since they can be used for a large variety of applications, ranging from sensing to photosplitting of water. So far the great majority of methods developed for the generation of Janus particles breaks the symmetry by using interfaces or surfaces. The consequence is often a low time-space yield, which limits their large scale production. In this context, chemists have successfully used bipolar electrodeposition to break the symmetry. This provides a single-step technique for the bulk production of Janus particles with a high control over the deposit structure and morphology, as well as a significantly improved yield. In this context, researchers have used the bipolar electrodeposition of molecular layers, metals, semiconductors, and insulators at one or both reactive poles of bipolar electrodes to generate a wide range of Janus particles with different size, composition and shape. In using bipolar electrochemistry as a driving force for generating motion, its intrinsic asymmetric reactivity is again the

Synthetic Organic Electrochemistry: Calling All Engineers.

PubMed

Yan, Ming; Kawamata, Yu; Baran, Phil S

2018-04-09

Unmet potential: Electrochemistry is the most simple and basic way of altering the redox-states of organic molecules. Despite extensive studies and its demonstrated promise, it has yet to take off in mainstream synthesis. The reason is due to engineering challenges in instrument design. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Novel Approaches in DNA Methylation Studies - MS-HRM Analysis and Electrochemistry].

PubMed

Bartošík, M; Ondroušková, E

Cytosine methylation in DNA is an epigenetic mechanism regulating gene expression and plays a vital role in cell differentiation or proliferation. Tumor cells often exhibit aberrant DNA methylation, e.g. hypermethylation of tumor suppressor gene promoters. New methods, capable of determining methylation status of specific DNA sequences, are thus being developed. Among them, MS-HRM (methylation-specific high resolution melting) and electrochemistry offer relatively inexpensive instrumentation, fast assay times and possibility of screening multiple samples/DNA regions simultaneously. MS-HRM is due to its sensitivity and simplicity an interesting alternative to already established techniques, including methylation-specific PCR or bisulfite sequencing. Electrochemistry, when combined with suitable electroactive labels and electrode surfaces, has been applied in several unique strategies for discrimination of cytosines and methylcytosines. Both techniques were successfully tested in analysis of DNA methylation within promoters of important tumor suppressor genes and could thus help in achieving more precise diagnostics and prognostics of cancer. Aberrant methylation of promoters has already been described in hundreds of genes associated with tumorigenesis and could serve as important biomarker if new methods applicable into clinical practice are sufficiently advanced.Key words: DNA methylation - 5-methylcytosine - HRM analysis - melting temperature - DNA duplex - electrochemistry - nucleic acid hybridizationThis work was supported by MEYS - NPS I - LO1413.The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study.The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 6. 5. 2016Accepted: 16. 5. 2016.

Bipolar electrochemistry.

PubMed

Fosdick, Stephen E; Knust, Kyle N; Scida, Karen; Crooks, Richard M

2013-09-27

A bipolar electrode (BPE) is an electrically conductive material that promotes electrochemical reactions at its extremities (poles) even in the absence of a direct ohmic contact. More specifically, when sufficient voltage is applied to an electrolyte solution in which a BPE is immersed, the potential difference between the BPE and the solution drives oxidation and reduction reactions. Because no direct electrical connection is required to activate redox reactions, large arrays of electrodes can be controlled with just a single DC power supply or even a battery. The wireless aspect of BPEs also makes it possible to electrosynthesize and screen novel materials for a wide variety of applications. Finally, bipolar electrochemistry enables mobile electrodes, dubbed microswimmers, that are able to move freely in solution. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analytical Electrochemistry: Theory and Instrumentation of Dynamic Techniques.

ERIC Educational Resources Information Center

Johnson, Dennis C.

1980-01-01

Emphasizes trends in the development of six topics concerning analytical electrochemistry, including books and reviews (34 references cited), mass transfer (59), charge transfer (25), surface effects (33), homogeneous reactions (21), and instrumentation (31). (CS)

Analytical Electrochemistry: Methodology and Applications of Dynamic Techniques.

ERIC Educational Resources Information Center

Heineman, William R.; Kissinger, Peter T.

1980-01-01

Reports developments involving the experimental aspects of finite and current analytical electrochemistry including electrode materials (97 cited references), hydrodynamic techniques (56), spectroelectrochemistry (62), stripping voltammetry (70), voltammetric techniques (27), polarographic techniques (59), and miscellany (12). (CS)

Integration of electrochemistry in micro-total analysis systems for biochemical assays: recent developments.

PubMed

Xu, Xiaoli; Zhang, Song; Chen, Hui; Kong, Jilie

2009-11-15

Micro-total analysis systems (microTAS) integrate different analytical operations like sample preparation, separation and detection into a single microfabricated device. With the outstanding advantages of low cost, satisfactory analytical efficiency and flexibility in design, highly integrated and miniaturized devices from the concept of microTAS have gained widespread applications, especially in biochemical assays. Electrochemistry is shown to be quite compatible with microanalytical systems for biochemical assays, because of its attractive merits such as simplicity, rapidity, high sensitivity, reduced power consumption, and sample/reagent economy. This review presents recent developments in the integration of electrochemistry in microdevices for biochemical assays. Ingenious microelectrode design and fabrication methods, and versatility of electrochemical techniques are involved. Practical applications of such integrated microsystem in biochemical assays are focused on in situ analysis, point-of-care testing and portable devices. Electrochemical techniques are apparently suited to microsystems, since easy microfabrication of electrochemical elements and a high degree of integration with multi-analytical functions can be achieved at low cost. Such integrated microsystems will play an increasingly important role for analysis of small volume biochemical samples. Work is in progress toward new microdevice design and applications.

Electroanalytical Evaluation of Nanoparticles by Nano-impact Electrochemistry

NASA Astrophysics Data System (ADS)

Karimi, Anahita

Applications of engineered nanoparticles in electronics, catalysis, solid oxide fuel cells, medicine and sensing continue to increase. Traditionally, nanoparticle systems are characterized by spectroscopic and microscopic techniques. These methods are cumbersome and expensive, which limit their routine use for screening purposes. Electrochemistry is a powerful, yet underutilized tool, for the detection and classification of nanoparticles. The first part of this dissertation investigates a recently developed electrochemical method -- nanoparticle collision electrochemistry -- for detection and characterization of nanoparticles. Three independent projects have been described to evaluate the use of this technique for characterizing nanoparticle based systems including: conjugation with biomolecules, interaction with environmental contaminants and fundamental investigation of conformational changes of nanoparticle capping ligands. The thesis reports the first use of nano-impact electrochemistry to quantitatively investigate bioconjugation and biomolecular recognition at conductive nanoparticles. Furthermore, we also demonstrate the potential of this method as a single step, reagentless and label-free technique for the ultra-sensitive detection of biomolecular targets. A fundamental study of biorecognition is important for the development of therapeutics and molecular diagnosis probes in the biomedical, biosensing and biotechnology fields. The second project describes the use of this method as a screening tool of particle reactivity. We study the interaction and adsorption of a toxic environmental metalloid (Arsenic) with metal oxide nanoparticles to extract mechanistic, speciation and loading information. We discuss the potential of this approach to complement or replace costly characterization techniques and enable routine study of nanoparticles and their reactivity. In the third project, we use the nano-impact method to study the pH-dependent conformational changes

2016 CEC Annual Workshop on Electrochemistry

DTIC Science & Technology

2016-08-31

Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 electrochemistry, electrolytes, lithium - ion batteries , electron transfer REPORT...the following topics: advanced electrolytes with applications, lithium - ion batteries , and electron transfer through films. CEC faculty members...11:40a-1:20p Lunch break. Lithium - ion Batteries Arumugam “Ram” Manthiram, Moderator 1:20-2:10p Steven J. Visco, PolyPlus Battery Company

Facilitating Conceptual Change in Students' Understanding of Electrochemistry.

ERIC Educational Resources Information Center

Niaz, Mansoor

2002-01-01

Constructs a teaching strategy to facilitate conceptual change in freshman students' understanding of electrochemistry. Provides students with the correct response along with alternative responses (teaching experiments), producing a conflicting situation that is conducive to an equilibration of their cognitive structures. Concludes that the…

LCEC: The Combination of Liquid Chromatography and Electrochemistry.

ERIC Educational Resources Information Center

Kissinger, Peter T.

1983-01-01

Use of combined liquid chromatography and finite-current electrochemistry (LCEC) procedures are discussed. Also discusses the relationship between electroactivity and molecular structure, selectivity in LCEC, and LCEC applications. Because of its selectivity and low detection limits, the procedures are most often applied in biomedical and…

Characterization of solution-phase and gas-phase reactions in on-line electrochemistry-thermospray tandem mass spectrometry.

PubMed

Volk, K J; Yost, R A; Brajter-Toth, A

1989-07-14

Electrochemistry was used on-line with high-performance liquid chromatography-thermospray tandem mass spectrometry to provide insight into the solution-phase decomposition reactions of electrochemically generated oxidation products. Products formed during electrooxidation were monitored as the electrode potential was varied. The solution reactions which follow the initial electron transfer at the electrode are affected by the vaporizer tip temperature of the thermospray probe and the composition of the thermospray buffer. Either hydrolysis or ammonolysis reactions of the initial electrochemical oxidation products can occur with pH 7 ammonium acetate buffer. Both the electrochemically generated and the synthesized disulfide of 6-thiopurine decompose under thermospray conditions to produce 6-thiopurine and purine-6-sulfinate. Solution-phase studies indicate that nucleophilic and electrophilic substitution reactions with purine-6-sulfinate result in the formation of purine, adenine, and hypoxanthine. Products were identified and characterized by tandem mass spectrometry. This work shows the first example of high-performance liquid chromatography used on-line with electrochemistry to separate stable oxidation products prior to analysis by thermospray tandem mass spectrometry. In addition, solution-phase and gas-phase studies with methylamine show that the site of the nucleophilic and electrophilic reactions is probably inside the thermospray probe. Most importantly, these results also show that the on-line combination of electrochemistry with thermospray tandem mass spectrometry provides valuable information about redox and associated chemical reactions of biological molecules such as the structures of intermediates or products as well as providing insight into reaction pathways.

Scanning thermo-ionic microscopy for probing local electrochemistry at the nanoscale

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

Eshghinejad, Ahmadreza; Nasr Esfahani, Ehsan; Wang, Peiqi

2016-05-28

Conventional electrochemical characterization techniques based on voltage and current measurements only probe faradaic and capacitive rates in aggregate. In this work we develop a scanning thermo-ionic microscopy (STIM) to probe local electrochemistry at the nanoscale, based on imaging of Vegard strain induced by thermal oscillation. It is demonstrated from both theoretical analysis and experimental validation that the second harmonic response of thermally induced cantilever vibration, associated with thermal expansion, is present in all solids, whereas the fourth harmonic response, caused by local transport of mobile species, is only present in ionic materials. The origin of STIM response is further confirmedmore » by its reduced amplitude with respect to increased contact force, due to the coupling of stress to concentration of ionic species and/or electronic defects. The technique has been applied to probe Sm-doped Ceria and LiFePO{sub 4}, both of which exhibit higher concentrations of mobile species near grain boundaries. The STIM gives us a powerful method to study local electrochemistry with high sensitivity and spatial resolution for a wide range of ionic systems, as well as ability to map local thermomechanical response.« less

2010 Gordon Research Conference, Electrochemistry, January 9-15, 2010

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

Creager, Stephen

Electrochemical science plays a crucial role in many important technologies and is intimately involved in many natural phenomena. Several new Gordon Research Conferences have appeared recently that are dedicated to electrochemical technologies, however electrochemistry as a discipline continues to thrive and provide the underpinnings of these technologies. The 2010 Electrochemistry GRC will focus on a wide range of fundamental electrochemical phenomena and materials and on their application in areas involving energy storage, information storage, chemical analysis, and motion actuation. The meeting will include sessions dedicated to the following specific topics: electrochemical energy storage (e.g. batteries; at least two sessions); electrochemicalmore » motion actuation (e.g. electrokinesis); electrocatalysis; electrochemistry in digital information storage; and bioelectrochemistry (including bioanalysis). An Open Session devoted to highlighting the activities of {approx}10 young investigators and non-North American visitors via brief 10-minute talks, and two open poster sessions highlighting the contributions of approximately 60 conference participants including graduate students, will be held. Altogether the conference is expected to include approximately 90 presentations. As has been the case in the recent past, the meeting will bring together participants from academia, national labs, and the private sector, including senior and junior-level scientists, postdoctoral scientists, and graduate students for informal interactions and exchange of ideas. An affiliated Gordon-Kenan Research Seminar (GRS) will also be held with the conference. Special efforts will be made to invite participation from members of underrepresented groups.« less

Chelating ionic liquids for reversible zinc electrochemistry.

PubMed

Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

2013-05-21

Advanced, high energy-density, metal-air rechargeable batteries, such as zinc-air, are of intense international interest due to their important role in energy storage applications such as electric and hybrid vehicles, and to their ability to deal with the intermittency of renewable energy sources such as solar and wind. Ionic liquids offer a number of ideal thermal and physical properties as potential electrolytes in such large-scale energy storage applications. We describe here the synthesis and characterisation of a family of novel "chelating" ILs designed to chelate and solubilize the zinc ions to create electrolytes for this type of battery. These are based on quaternary alkoxy alkyl ammonium cations of varying oligo-ether side chains and anions such as p-toluene sulfonate, bis(trifluoromethylsulfonyl)amide and dicyanoamides. This work shows that increasing the ether chain length in the cation from two to four oxygens can increase the ionic conductivity and reduce the melting point from 67 °C to 15 °C for the tosylate system. Changing the anion also plays a significant role in the nature of the zinc deposition electrochemistry. We show that zinc can be reversibly deposited from [N(222(20201))][NTf2] and [N(222(202020201))][NTf2] beginning at -1.4 V and -1.7 V vs. SHE, respectively, but not in the case of tosylate based ILs. This indicates that the [NTf2] is a weaker coordinating anion with the zinc cation, compared to the tosylate anion, allowing the coordination of the ether chain to dominate the behavior of the deposition and stripping of zinc ions.

Solid-state electrochemistry on the nanometer and atomic scales: the scanning probe microscopy approach

PubMed Central

Strelcov, Evgheni; Yang, Sang Mo; Jesse, Stephen; Balke, Nina; Vasudevan, Rama K.; Kalinin, Sergei V.

2016-01-01

Energy technologies of the 21st century require understanding and precise control over ion transport and electrochemistry at all length scales – from single atoms to macroscopic devices. This short review provides a summary of recent works dedicated to methods of advanced scanning probe microscopy for probing electrochemical transformations in solids at the meso-, nano- and atomic scales. Discussion presents advantages and limitations of several techniques and a wealth of examples highlighting peculiarities of nanoscale electrochemistry. PMID:27146961

Conceptual design and experiments of electrochemistry-flushing technology for the remediation of historically Cr(Ⅵ)-contaminated soil.

PubMed

Li, Dong; Sun, Delin; Hu, Siyang; Hu, Jing; Yuan, Xingzhong

2016-02-01

A conceptual design and experiments, electrochemistry-flushing (E-flushing), using electrochemistry to enhance flushing efficiency for the remediation of Cr(Ⅵ)-contaminated soil is presented. The rector contained three compartments vertically superposed. The upper was airtight cathode compartment containing an iron-cathode. The middle was soil layer. The bottom was anode compartment containing an iron-anode and connected to a container by circulation pumps. H2 and OH(-) ions were produced at cathode. H2 increased the gas pressure in cathode compartment and drove flushing solution into soil layer forming flushing process. OH(-) ions entered into soil layer by eletromigration and hydraulic flow to enhance the desorption of Cr(Ⅵ). High potential gradient was applied to accelerate the electromigration of desorbed Cr(Ⅵ) ions and produced joule heat to increase soil temperature to enhance Cr(Ⅵ) desorption. In anode compartment, Fe(2+) ions produced at iron-anode reduced the desorbed Cr(Ⅵ) into Cr(3+) ions, which reacted with OH(-) ions forming Cr(OH)3. Experimental results show that Cr(Ⅵ) removal efficiency of E-flushing experiments was more than double of flushing experiments and reached the maximum of removal efficiency determined by desorption kinetics. All electrochemistry processes were positively used in E-flushing technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Alleviating the Common Confusion Caused by Polarity in Electrochemistry.

ERIC Educational Resources Information Center

Moran, P. J.; Gileadi, E.

1989-01-01

Discussed is some of the confusion encountered in electrochemistry due to misunderstandings of sign conventions and simple mathematical errors. Clarified are issues involving emf series, IUPAC sign conventions, calculation of cell potentials, reference electrodes, the polarity of electrodes in electrochemical devices, and overpotential. (CW)

Solid-state electrochemistry on the nanometer and atomic scales: the scanning probe microscopy approach

DOE PAGES

Strelcov, Evgheni; Yang, Sang Mo; Jesse, Stephen; ...

2016-04-21

Energy technologies of the 21st century require an understanding and precise control over ion transport and electrochemistry at all length scales – from single atoms to macroscopic devices. Our short review provides a summary of recent studies dedicated to methods of advanced scanning probe microscopy for probing electrochemical transformations in solids at the meso-, nano- and atomic scales. In this discussion we present the advantages and limitations of several techniques and a wealth of examples highlighting peculiarities of nanoscale electrochemistry.

Binding of Substrate Locks the Electrochemistry of CRY-DASH into DNA Repair.

PubMed

Gindt, Yvonne M; Messyasz, Adriana; Jumbo, Pamela I

2015-05-12

VcCry1, a member of the CRY-DASH family, may serve two diverse roles in vivo, including blue-light signaling and repair of UV-damaged DNA. We have discovered that the electrochemistry of the flavin adenine dinucleotide cofactor of VcCry1 is locked to cycle only between the hydroquinone and neutral semiquinone states when UV-damaged DNA is present. Other potential substrates, including undamaged DNA and ATP, have no discernible effect on the electrochemistry, and the kinetics of the reduction is unaffected by damaged DNA. Binding of the damaged DNA substrate determines the role of the protein and prevents the presumed photochemistry required for blue-light signaling.

Superoxide (Electro)Chemistry on Well-Defined Surfaces in Organic Environments

DOE PAGES

Genorio, Bostjan; Staszak-Jirkovský, Jakub; Assary, Rajeev S.; ...

2016-02-09

Efficient chemical transformations in energy conversion and storage systems depend on understanding superoxide anion (O 2 –) electrochemistry at atomic and molecular levels. Here, in this work, a combination of experimental and theoretical techniques are used for rationalizing, and ultimately understanding, the complexity of superoxide anion (electro)chemistry in organic environments. By exploring the O 2 + e – ↔ O 2 – reaction on well-characterized metal single crystals (Au, Pt, Ir), Pt single crystal modified with a single layer of graphene (Graphene@Pt(111)), and glassy carbon (GC) in 1,2 dimethoxyethane (DME) electrolytes, we demonstrate that (i) the reaction is an outer-spheremore » process; (ii) the reaction product O 2 – can “attack” any part of the DME molecule, i.e., the C–O bond via nucleophilic reaction and the C–H bond via radical hydrogen abstraction; (iii) the adsorption of carbon-based decomposition products and the extent of formation of a “solid electrolyte interface” (“SEI”) increases in the same order as the reactivity of the substrate, i.e., Pt(hkl)/Ir(hkl) » Au(hkl)/GC > Gaphene@Pt(111); and (iv) the formation of the “SEI” layer leads to irreversible superoxide electrochemistry on Pt(hkl) and Ir(hkl) surfaces. In conclusion, we believe this fundamental insight provides a pathway for the rational design of stable organic solvents that are urgently needed for the development of a new generation of reliable and affordable battery systems.« less

Direct Electrochemistry of Bilirubin Oxidase from Magnaporthe orizae on Covalently-Functionalized MWCNT for the Design of High-Performance Oxygen-Reducing Biocathodes.

PubMed

Gentil, Solène; Carrière, Marie; Cosnier, Serge; Gounel, Sébastien; Mano, Nicolas; Le Goff, Alan

2018-06-12

Herein, the direct electrochemistry of bilirubin oxidase from Magnaporthe orizae (MoBOD) was studied on CNTs functionalized by electrografting several types of diazonium salts. The functionalization induces favorable or unfavorable orientation of MoBOD, the latter being compared to the well-known BOD from Myrothecium verrucaria (MvBOD). On the same nanostructured electrodes, MoBOD can surpass MvBOD in terms of both current densities and minimal overpotentials. Added to the fact that MoBOD is also highly active at the gas-diffusion electrode (GDE), these findings make MoBOD one of the MCOs with the highest catalytic activity towards the oxygen reduction reaction (ORR). © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrochemistry of Some New Alkaline Battery Electrodes

DTIC Science & Technology

1976-02-01

1NýT;7 ~~ AFAPI 4TR- 75)aI Electrochemistry of Somwý New Alkaline V CI RG, 0OTNME Dr/ David F., ’Pickett, IM Wayue ’,Hisb’q Mr. R ic ha rd A I Mid...adding ZnO to the electi-olyte (saturated) and usi .j the interc:ell conrec;tor d isr:ussed earlier ,itLh el4cc.roploated zinc ag inst. the silver fo

Teaching Electrochemistry in the General Chemistry Laboratory through Corrosion Exercises

ERIC Educational Resources Information Center

Sanders, Richard W.; Crettol, Gregory L.; Brown, Joseph D.; Plummer, Patrick T.; Schendorf, Tara M.; Oliphant, Alex; Swithenbank, Susan B.; Ferrante, Robert F.; Gray, Joshua P.

2018-01-01

Electrochemistry is primarily taught in first-year undergraduate courses through batteries; this lab focuses instead on corrosion to apply electrochemical concepts of electrolytes, standard reduction potentials, galvanic cells, and other chemistry concepts including Le Chatelier's Principle and Henry's Law. Students investigate galvanic corrosion…

Strain Engineering to Modify the Electrochemistry of Energy Storage Electrodes

PubMed Central

Muralidharan, Nitin; Carter, Rachel; Oakes, Landon; Cohn, Adam P.; Pint, Cary L.

2016-01-01

Strain engineering has been a critical aspect of device design in semiconductor manufacturing for the past decade, but remains relatively unexplored for other applications, such as energy storage. Using mechanical strain as an input parameter to modulate electrochemical potentials of metal oxides opens new opportunities intersecting fields of electrochemistry and mechanics. Here we demonstrate that less than 0.1% strain on a Ni-Ti-O based metal-oxide formed on superelastic shape memory NiTi alloys leads to anodic and cathodic peak potential shifts by up to ~30 mV in an electrochemical cell. Moreover, using the superelastic properties of NiTi to enable strain recovery also recovers the electrochemical potential of the metal oxide, providing mechanistic evidence of strain-modified electrochemistry. These results indicate that mechanical energy can be coupled with electrochemical systems to efficiently design and optimize a new class of strain-modulated energy storage materials. PMID:27283872

Evaluation of Tris-Bipyridine Chromium Complexes for Flow Battery Applications: Impact of Bipyridine Ligand Structure on Solubility and Electrochemistry.

PubMed

Cabrera, Pablo J; Yang, Xingyi; Suttil, James A; Brooner, Rachel E M; Thompson, Levi T; Sanford, Melanie S

2015-11-02

This report describes the design, synthesis, solubility, and electrochemistry of a series of tris-bipyridine chromium complexes that exhibit up to six reversible redox couples as well as solubilities approaching 1 M in acetonitrile. We have systematically modified both the ligand structure and the oxidation state of these complexes to gain insights into the factors that impact solubility and electrochemistry. The results provide a set of structure-solubility-electrochemistry relationships to guide the future development of electrolytes for nonaqueous flow batteries. In addition, we have identified a promising candidate from the series of chromium complexes for further electrochemical and battery assessment.

High Surface Area Dendrite Nanoelectrodes for Electrochemistry

NASA Astrophysics Data System (ADS)

Nesbitt, Nathan; Glover, Jennifer; Goyal, Saurabh; Simidjiysky, Svetoslav; Naughton, Michael

2014-03-01

Solution-based electrodeposition of metal using a low ion concentration, surface passivation agents, and/or electrochemical crystal conditioning has allowed for the formation of high surface area metal electrodes, useful for Raman spectroscopy and electrochemical sensors. Additionally, high frequency electrical oscillations have been used to electrically connect co-planar electrodes, a process called directed electrochemical nanowire assembly (DENA). These approaches aim to control the crystal face that metal atoms in solution will nucleate onto, thus causing anisotropic growth of metal crystals. However, DENA has not been used to create high surface area electrodes, and no study has been conducted on the effect of micron-scale surface topography on the initial nucleation of metal crystals on the electrode surface. When DENA is used to create a high surface area electrode, such a texture has a strong impact on the subsequent topography of the three dimensional dendritic structures by limiting the areal density of crystals on the electrode surface. Such structures both demonstrate unique physics concerning the nucleation of metal dendrites, and offer a unique and highly facile fabrication method of high surface area electrodes, useful for chemical and biological sensing. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. (DGE-1258923).

Understanding Electrochemistry Concepts Using the Predict-Observe-Explain Strategy

ERIC Educational Resources Information Center

Karamustafaoglu, Sevilay; Mamlok-Naaman, Rachel

2015-01-01

The current study deals with freshman students who study at the Department of Science at the Faculty of Education. The aim of the study was to investigate the effect of teaching electrochemistry concepts using Predict-Observe-Explain (POE) strategy. The study was quasi-experimental design using 20 students each in the experimental group (EG) and…

LIGA-based microsystem manufacturing:the electrochemistry of through-mold depostion and material properties.

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

Kelly, James J.; Goods, Steven Howard

2005-06-01

The report presented below is to appear in ''Electrochemistry at the Nanoscale'', Patrik Schmuki, Ed. Springer-Verlag, (ca. 2005). The history of the LIGA process, used for fabricating dimensional precise structures for microsystem applications, is briefly reviewed, as are the basic elements of the technology. The principal focus however, is on the unique aspects of the electrochemistry of LIGA through-mask metal deposition and the generation of the fine and uniform microstructures necessary to ensure proper functionality of LIGA components. We draw from both previously published work by external researchers in the field as well as from published and unpublished studies frommore » within Sandia.« less

Construction and direct electrochemistry of orientation controlled laccase electrode.

PubMed

Li, Ying; Zhang, Jiwei; Huang, Xirong; Wang, Tianhong

2014-03-28

A laccase has multiple redox centres. Chemisorption of laccases on a gold electrode through a polypeptide tag introduced at the protein surface provides an isotropic orientation of laccases on the Au surface, which allows the orientation dependent study of the direct electrochemistry of laccase. In this paper, using genetic engineering technology, two forms of recombinant laccase which has Cys-6×His tag at the N or C terminus were generated. Via the Au-S linkage, the recombinant laccase was assembled orientationally on gold electrode. A direct electron transfer and a bioelectrocatalytic activity toward oxygen reduction were observed on the two orientation controlled laccase electrodes, but their electrochemical behaviors were found to be quite different. The orientation of laccase on the gold electrode affects both the electron transfer pathway and the electron transfer efficiency of O2 reduction. The present study is helpful not only to the in-depth understanding of the direct electrochemistry of laccase, but also to the development of laccase-based biofuel cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Cobalt-cadmium bimetallic porphyrin coordination polymers for electrochemistry application

NASA Astrophysics Data System (ADS)

Wang, C. Y.; Cui, G. Y.; Ding, D.; Zhou, B.

2018-01-01

In this paper, we used tetra (4-carboxyphenyl) porphyrin (H2TCPP) and metal cadmium, cobalt as reactants to synthesize metal porphyrin coordination polymers that they had different metal ratio. They were expressed as Co1Cd3TCPP, Co1Cd1TCPP, Co3Cd1TCPP, respectively. The results were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and inductively coupled plasma atomic emission spectrometer (ICP). Herein, a series of metal porphyrin coordination polymers has multiple metal active centers and constructs electrochemistry sensors. In order to increase the conductivity, multi-walled carbon nanotubes (MWCNTs) can be used to modify the electrodes. The polymer/MWCNTs/GCE electrode was studied by cyclic voltammetry and chronoamperometry as sensor for sodium nitrite. The performance of Co1Cd1TCPP/MWCNTs/GCE electrode is best, the sensitivity for sodium nitrite is 350.95 mA M-1 cm-2 and the. The results indicate that metal porphyrin coordination polymers have excellent performance. It also enriches the application of metal porphyrin coordination polymer in electrochemistry sensor.

Advanced Electrochemistry of Individual Metal Clusters Electrodeposited Atom by Atom to Nanometer by Nanometer.

PubMed

Kim, Jiyeon; Dick, Jeffrey E; Bard, Allen J

2016-11-15

Metal clusters are very important as building blocks for nanoparticles (NPs) for electrocatalysis and electroanalysis in both fundamental and applied electrochemistry. Attention has been given to understanding of traditional nucleation and growth of metal clusters and to their catalytic activities for various electrochemical applications in energy harvesting as well as analytical sensing. Importantly, understanding the properties of these clusters, primarily the relationship between catalysis and morphology, is required to optimize catalytic function. This has been difficult due to the heterogeneities in the size, shape, and surface properties. Thus, methods that address these issues are necessary to begin understanding the reactivity of individual catalytic centers as opposed to ensemble measurements, where the effect of size and morphology on the catalysis is averaged out in the measurement. This Account introduces our advanced electrochemical approaches to focus on each isolated metal cluster, where we electrochemically fabricated clusters or NPs atom by atom to nanometer by nanometer and explored their electrochemistry for their kinetic and catalytic behavior. Such approaches expand the dimensions of analysis, to include the electrochemistry of (1) a discrete atomic cluster, (2) solely a single NP, or (3) individual NPs in the ensemble sample. Specifically, we studied the electrocatalysis of atomic metal clusters as a nascent electrocatalyst via direct electrodeposition on carbon ultramicroelectrode (C UME) in a femtomolar metal ion precursor. In addition, we developed tunneling ultramicroelectrodes (TUMEs) to study electron transfer (ET) kinetics of a redox probe at a single metal NP electrodeposited on this TUME. Owing to the small dimension of a NP as an active area of a TUME, extremely high mass transfer conditions yielded a remarkably high standard ET rate constant, k 0 , of 36 cm/s for outer-sphere ET reaction. Most recently, we advanced nanoscale

Enzymatic Activity Detection via Electrochemistry for Enceladus

NASA Technical Reports Server (NTRS)

Studemeister, Lucy; Koehne, Jessica; Quinn, Richard

2017-01-01

Electrochemical detection of biological molecules is a pertinent topic and application in many fields such as medicine, environmental spills, and life detection in space. Proteases, a class of molecules of interest in the search for life, catalyze the hydrolysis of peptides. Trypsin, a specific protease, was chosen to investigate an optimized enzyme detection system using electrochemistry. This study aims at providing the ideal functionalization of an electrode that can reliably detect a signal indicative of an enzymatic reaction from an Enceladus sample.

Ultrasensitive thrombin detection based on direct electrochemistry of highly loaded hemoglobin spheres-encapsulated platinum nanoparticles as labels and electrocatalysts.

PubMed

Wu, Yongmei; Xu, Wenju; Bai, Lijuan; Yuan, Yali; Yi, Huayu; Chai, Yaqin; Yuan, Ruo

2013-12-15

For the first time, a sandwich-type electrochemical method was proposed for ultrasensitive thrombin (TB) detection based on direct electrochemistry of highly loaded hemoglobin spheres-encapsulated platinum nanoparticles (PtNPs@Hb) as labels and electrocatalysts. The prepared PtNPs@Hb not only exhibited good biocompatibility, excellent electrocatalytic activity, but also presented redox activity of Hb. Thus, it was employed for the fabrication of aptasensor without any extraneous redox mediators, leading to a simple preparation process for the aptasensor. The high loading of Hb spheres as redox mediators could enhance the electrochemical signal. Importantly, the synergetic electrocatalytic behavior of Hb and PtNPs toward H2O2 reduction greatly amplified the electrochemical signal, resulting in the high sensitivity of aptasensor. Consequently, under optimal conditions, the designed aptasensor exhibited a lower detection limit of 0.05 pM and wide dynamic linear range from 0.15 pM to 40 nM for TB detection. Additionally, the proposed mediator-free and signal-amplified electrochemical aptasensor showed great potential in portable and cost-effective TB sensing devices. Copyright © 2013 Elsevier B.V. All rights reserved.

Electrochemistry and Spectroelectrochemistry of Luminescent Europium Complexes

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

Lines, Amanda M.; Wang, Zheming; Clark, Sue B.

Fast, cost effective, and robust means of detecting and quantifying lanthanides are needed for supporting more efficient tracking within the nuclear, medicinal, and industrial fields. Spectroelectrochemistry (SEC) is a powerful technique combining electrochemistry and spectroscopy that can meet those needs. The primary limitation of SEC as a detection method for lanthanides is their low molar absorptivity in absorbance based measurements and low emission intensities in fluorescence based measurements; both lead to high limits of detection. These limitations can be circumvented by complexing the lanthanides with sensitizing ligands that enhance fluorescence, thereby dropping the limits of detection. Complexation may also stabilizemore » the metal ions in solution and improve the electrochemical reversibility, or Nernstian behavior, of the redox couples. To demonstrate this concept, studies were completed using europium in complexes with four different sensitizing ligands. Initial work indicates Eu in the four complexes studied does display the necessary characteristics for SEC analysis, which was successfully and reproducibly applied to all Eu complexes.« less

Photoelectroconversion by Semiconductors: A Physical Chemistry Experiment.

ERIC Educational Resources Information Center

Fan, Qinbai; And Others

1995-01-01

Presents an experiment designed to give students some experience with photochemistry, electrochemistry, and basic theories about semiconductors. Uses a liquid-junction solar cell and illustrates some fundamental physical and chemical principles related to light and electricity interconversion as well as the properties of semiconductors. (JRH)

Using a Teaching Model To Correct Known Misconceptions in Electrochemistry.

ERIC Educational Resources Information Center

Huddle, Penelope Ann; White, Margaret Dawn; Rogers, Fiona

2000-01-01

Describes a concrete teaching model designed to eliminate students' misconceptions about current flow in electrochemistry. The model uses a semi-permeable membrane rather than a salt bridge to complete the circuit and demonstrate the maintenance of cell neutrality. Concludes that use of the model led to improvement in students' understanding at…

The merger of electrochemistry and molecular electronics.

PubMed

McCreery, Richard L

2012-02-01

Molecular Electronics has the potential to greatly enhance existing silicon-based microelectronics to realize new functions, higher device density, lower power consumption, and lower cost. Although the investigation of electron transport through single molecules and molecular monolayers in "molecular junctions" is a recent development, many of the relevant concepts and phenomena are derived from electrochemistry, as practiced for the past several decades. The past 10+ years have seen an explosion of research activity directed toward how the structure of molecules affects electron transport in molecular junctions, with the ultimate objective of "rational design" of molecular components with new electronic functions, such as chemical sensing, interactions with light, and low-cost, low-power consumer electronics. In order to achieve these scientifically and commercially important objectives, the factors controlling charge transport in molecules "connected" to conducting contacts must be understood, and methods for massively parallel manufacturing of molecular circuits must be developed. This Personal Account describes the development of reproducible and robust molecular electronic devices, starting with modified electrodes used in electrochemistry and progressing to manufacturable molecular junctions. Although the field faced some early difficulties in reliability and characterization, the pieces are now in place for rapid advances in understanding charge transport at the molecular level. Inherent in the field of Molecular Electronics are many electrochemical concepts, including tunneling, redox exchange, activated electron transfer, and electron coupling between molecules and conducting contacts. Copyright © 2012 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

Layered transition metal dichalcogenide electrochemistry: journey across the periodic table.

PubMed

Chia, Xinyi; Pumera, Martin

2018-06-08

Studies on layered transition metal dichalcogenides (TMDs), in particular for Group VIB TMDs like MoS2 and WS2, have long reached a crescendo in the realms of electrochemical applications initiated by their remarkable catalytic and electronic properties. One area that garnered considerable attention is the fervent pursuit of layered TMDs as electrocatalysts for hydrogen evolution reaction (HER), driven by global efforts towards reducing carbon footprint and attaining hydrogen economy. This Tutorial Review captures the essence of electrochemistry of different classes of layered TMDs and metal chalcogenides across the period table and showcases their tuneable electrochemical and HER catalytic attributes that are governed by the elemental composition, structure and anisotropy. Of interest to the assiduously studied Group VIB TMDs, we describe the role of elemental constituents and material purity in aspects of surface composition and structure, on their electrochemistry. Across families of layered TMDs in the periodic table, we highlight the apparent trends in their electrochemical and electrocatalytic properties through diligent comparison. Inevitably, these trends vary according to the type of chalcogen or transition metal that constitutes the eventual TMD. Beyond layered TMDs, we discuss the electrochemistry and recent progress in HER electrocatalysis of other layered metal chalcogenides that are overshadowed by the success of Group VIB TMDs. At the pinnacle of the emergent applications of layered TMDs, it is prudent to demystify the intrinsic electrochemical behaviour that originates from the participation of the elemental constitution of transition metal or chalcogen. Moreover, knowledge of the catalytic and electronic properties of the various TMD families and emerging trends across the period or down the group is of paramount importance when introducing or refining their prospective uses. The annotations in this Tutorial Review are envisioned to promote

Membrane-entrapped microperoxidase as a 'solid-state' promoter in the electrochemistry of soluble metalloproteins.

PubMed Central

Brunori, M; Santucci, R; Campanella, L; Tranchida, G

1989-01-01

Immobilization of biological systems in solid matrices is presently of great interest, in view of the many potential advantages associated with both the higher stability of the immobilized macromolecules and the potential utilization for biotechnology. In the present paper the electrochemical behaviour of the undecapeptide from cytochrome c (called microperoxidase) tightly entrapped in cellulose triacetate membrane is reported; its utilization as 'solid-state' promoter in the electrochemistry of soluble metalloproteins is presented. The results obtained indicate that: (i) membrane-entrapped microperoxidase undergoes rapid reversible electron transfer at a glassy carbon electrode; (ii) the electrochemical process is diffusion-controlled; (iii) entrapped microperoxidase acts as 'solid-state' promoter in the electrochemistry of soluble cytochrome c and of azurin. PMID:2557833

DNA Electrochemistry and Electrochemical Sensors for Nucleic Acids.

PubMed

Ferapontova, Elena E

2018-06-12

Sensitive, specific, and fast analysis of nucleic acids (NAs) is strongly needed in medicine, environmental science, biodefence, and agriculture for the study of bacterial contamination of food and beverages and genetically modified organisms. Electrochemistry offers accurate, simple, inexpensive, and robust tools for the development of such analytical platforms that can successfully compete with other approaches for NA detection. Here, electrode reactions of DNA, basic principles of electrochemical NA analysis, and their relevance for practical applications are reviewed and critically discussed.

Electrochemistry coupled to (LC-)MS for the simulation of oxidative biotransformation reactions of PAHs.

PubMed

Wigger, Tina; Seidel, Albrecht; Karst, Uwe

2017-06-01

Electrochemistry coupled to liquid chromatography and mass spectrometry was used for simulating the biological and environmental fate of polycyclic aromatic hydrocarbons (PAHs) as well as for studying the PAH degradation behavior during electrochemical remediation. Pyrene and benzo[a]pyrene were selected as model compounds and oxidized within an electrochemical thin-layer cell equipped with boron-doped diamond electrode. At potentials of 1.2 and 1.6 V vs. Pd/H 2 , quinones were found to be the major oxidation products for both investigated PAHs. These quinones belong to a large group of PAH derivatives referred to as oxygenated PAHs, which have gained increasing attention in recent years due to their high abundance in the environment and their significant toxicity. Separation of oxidation products allowed the identification of two pyrene quinone and three benzo[a]pyrene quinone isomers, all of which are known to be formed via photooxidation and during mammalian metabolism. The good correlation between electrochemically generated PAH quinones and those formed in natural processes was also confirmed by UV irradiation experiments and microsomal incubations. At potentials higher than 2.0 V, further degradation of the initial oxidation products was observed which highlights the capability of electrochemistry to be used as remediation technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electrochemistry at Edge of Single Graphene Layer in a Nanopore

PubMed Central

Banerjee, Shouvik; Shim, Jiwook; Rivera, Jose; Jin, Xiaozhong; Estrada, David; Solovyeva, Vita; You, Xiuque; Pak, James; Pop, Eric; Aluru, Narayana; Bashir, Rashid

2013-01-01

We study the electrochemistry of single layer graphene edges using a nanopore-based structure consisting of stacked graphene and Al2O3 dielectric layers. Nanopores, with diameters ranging from 5 to 20 nm, are formed by an electron beam sculpting process on the stacked layers. This leads to unique edge structure which, along with the atomically thin nature of the embedded graphene electrode, demonstrates electrochemical current densities as high as 1.2 × 104 A/cm2. The graphene edge embedded structure offers a unique capability to study the electrochemical exchange at an individual graphene edge, isolated from the basal plane electrochemical activity. We also report ionic current modulation in the nanopore by biasing the embedded graphene terminal with respect to the electrodes in the fluid. The high electrochemical specific current density for a graphene nanopore-based device can have many applications in sensitive chemical and biological sensing, and energy storage devices. PMID:23249127

Impact electrochemistry on screen-printed electrodes for the detection of monodispersed silver nanoparticles of sizes 10-107 nm.

PubMed

Nasir, Muhammad Zafir Mohamad; Pumera, Martin

2016-10-12

Impact electrochemistry provides a useful alternative technique for the detection of silver nanoparticles in solutions. The combined use of impact electrochemistry on screen-printed electrodes (SPEs) for the successful detection of silver nanoparticles provides an avenue for future on-site, point-of-care detection devices to be made for environmental, medicinal and biological uses. Here we discuss the use of screen-printed electrodes for the detection of well-defined monodispersed silver nanoparticles of sizes 10, 20, 40, 80, and 107 nm.

Blood glucose meters employing dynamic electrochemistry are stable against hematocrit interference in a laboratory setting.

PubMed

Pfützner, Andreas; Musholt, Petra B; Schipper, Christina; Demircik, Filiz; Hengesbach, Carina; Flacke, Frank; Sieber, Jochen; Forst, Thomas

2013-11-01

Hematocrit (HCT) is known to be a confounding factor that interferes with many blood glucose (BG) measurement technologies, resulting in wrong readings. Dynamic electrochemistry has been identified as one possible way to correct for these potential deviations. The purpose of this laboratory investigation was to assess the HCT stability of four BG meters known to employ dynamic electrochemistry (BGStar and iBGStar, Sanofi; Wavesense Jazz, AgaMatrix; Wellion Linus, MedTrust) in comparison with three other devices (GlucoDock, Medisana; OneTouch Verio Pro, LifeScan; FreeStyle Freedom InsuLinx, Abbott-Medisense). Venous heparinized blood was immediately aliquoted after draw and manipulated to contain three different BG concentrations (60-90, 130-160, and 280-320 mg/dl) and five different HCT levels (25%, 35%, 45%, 55%, and 60%). After careful oxygenation to normal blood oxygen pressure, each of the resulting 15 different samples was measured six times with three devices and three strip lots of each meter. The YSI Stat 2300 served as laboratory reference method. Stability to HCT influence was assumed when less than 10% difference occurred between the highest and lowest mean glucose deviations in relation to HCT concentrations [hematocrit interference factor (HIF)]. Five of the investigated self-test meters showed a stable performance with the different HCT levels tested in this investigation: BGStar (HIF 4.6%), iBGStar (6.6%), Wavesense Jazz (4.1%), Wellion Linus (8.5%), and OneTouch Verio Pro (6.2%). The two other meters were influenced by HCT (FreeStyle InsuLinx 17.8%; GlucoDock 46.5%). In this study, meters employing dynamic electrochemistry, as used in the BGStar and iBGStar devices, were shown to correct for potential HCT influence on the meter results. Dynamic electrochemistry appears to be an effective way to handle this interfering condition. © 2013 Diabetes Technology Society.

Blood Glucose Meters Employing Dynamic Electrochemistry Are Stable against Hematocrit Interference in a Laboratory Setting

PubMed Central

Pfützner, Andreas; Musholt, Petra B.; Schipper, Christina; Demircik, Filiz; Hengesbach, Carina; Flacke, Frank; Sieber, Jochen; Forst, Thomas

2013-01-01

Background Hematocrit (HCT) is known to be a confounding factor that interferes with many blood glucose (BG) measurement technologies, resulting in wrong readings. Dynamic electrochemistry has been identified as one possible way to correct for these potential deviations. The purpose of this laboratory investigation was to assess the HCT stability of four BG meters known to employ dynamic electrochemistry (BGStar and iBGStar, Sanofi; Wavesense Jazz, AgaMatrix; Wellion Linus, MedTrust) in comparison with three other devices (GlucoDock, Medisana; OneTouch Verio Pro, LifeScan; FreeStyle Freedom InsuLinx, Abbott-Medisense). Methods Venous heparinized blood was immediately aliquoted after draw and manipulated to contain three different BG concentrations (60–90, 130–160, and 280–320 mg/dl) and five different HCT levels (25%, 35%, 45%, 55%, and 60%). After careful oxygenation to normal blood oxygen pressure, each of the resulting 15 different samples was measured six times with three devices and three strip lots of each meter. The YSI Stat 2300 served as laboratory reference method. Stability to HCT influence was assumed when less than 10% difference occurred between the highest and lowest mean glucose deviations in relation to HCT concentrations [hematocrit interference factor (HIF)]. Results Five of the investigated self-test meters showed a stable performance with the different HCT levels tested in this investigation: BGStar (HIF 4.6%), iBGStar (6.6%), Wavesense Jazz (4.1%), Wellion Linus (8.5%), and OneTouch Verio Pro (6.2%). The two other meters were influenced by HCT (FreeStyle InsuLinx 17.8%; GlucoDock 46.5%). Conclusions In this study, meters employing dynamic electrochemistry, as used in the BGStar and iBGStar devices, were shown to correct for potential HCT influence on the meter results. Dynamic electrochemistry appears to be an effective way to handle this interfering condition. PMID:24351179

Ferrocene-pyrimidine conjugates: Synthesis, electrochemistry, physicochemical properties and antiplasmodial activities.

PubMed

Chopra, Rakesh; de Kock, Carmen; Smith, Peter; Chibale, Kelly; Singh, Kamaljit

2015-07-15

The promise of hybrid antimalarial agents and the precedence set by the antimalarial drug ferroquine prompted us to design ferrocene-pyrimidine conjugates. Herein, we report the synthesis, electrochemistry and anti-plasmodial evaluation of ferrocenyl-pyrimidine conjugates against chloroquine susceptible NF54 strain of the malaria parasite Plasmodium falciparum. Also their physicochemical properties have been studied. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Effect of Cooperative Learning Strategies on Students' Understanding of Concepts in Electrochemistry

ERIC Educational Resources Information Center

Acar, Burcin; Tarhan, Leman

2007-01-01

The present study was conducted to investigate the degree of effectiveness of cooperative learning instruction over a traditional approach on 11th grade students' understanding of electrochemistry. The study involved forty-one 11th grade students from two science classes with the same teacher. To determine students' misconceptions concerning…

Capacity fade in high energy silicon-graphite electrodes for lithium-ion batteries

DOE PAGES

Dose, W. M.; Piernas-Munoz, M. J.; Maroni, V. A.; ...

2018-02-09

A silicon-graphite blended anode is paired with a high capacity LiFePO 4 reference/counter electrode to track irreversibility and lithium inventory. The LiFePO 4 electrode provides a reliable, flat potential for dQ dV -1 analysis of Li xSi and Li xC electrochemical reactions. We can relate this electrochemistry to the morphological and physical changes taking place.

Capacity fade in high energy silicon-graphite electrodes for lithium-ion batteries

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

Dose, W. M.; Piernas-Munoz, M. J.; Maroni, V. A.

A silicon-graphite blended anode is paired with a high capacity LiFePO 4 reference/counter electrode to track irreversibility and lithium inventory. The LiFePO 4 electrode provides a reliable, flat potential for dQ dV -1 analysis of Li xSi and Li xC electrochemical reactions. We can relate this electrochemistry to the morphological and physical changes taking place.

Construction and direct electrochemistry of orientation controlled laccase electrode

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

Li, Ying; Zhang, Jiwei; Huang, Xirong, E-mail: xrhuang@sdu.edu.cn

2014-03-28

Highlights: • A recombinant laccase with Cys-6×His tag at the N or C terminus was generated. • Orientation controlled laccase electrodes were constructed via self assembly. • The electrochemical behavior of laccase electrodes was orientation dependent. • The C terminus tagged laccase was better for bioelectrocatalytic reduction of O{sub 2}. - Abstract: A laccase has multiple redox centres. Chemisorption of laccases on a gold electrode through a polypeptide tag introduced at the protein surface provides an isotropic orientation of laccases on the Au surface, which allows the orientation dependent study of the direct electrochemistry of laccase. In this paper, usingmore » genetic engineering technology, two forms of recombinant laccase which has Cys-6×His tag at the N or C terminus were generated. Via the Au-S linkage, the recombinant laccase was assembled orientationally on gold electrode. A direct electron transfer and a bioelectrocatalytic activity toward oxygen reduction were observed on the two orientation controlled laccase electrodes, but their electrochemical behaviors were found to be quite different. The orientation of laccase on the gold electrode affects both the electron transfer pathway and the electron transfer efficiency of O{sub 2} reduction. The present study is helpful not only to the in-depth understanding of the direct electrochemistry of laccase, but also to the development of laccase-based biofuel cells.« less

Computer-Animated Instruction and Students' Conceptual Change in Electrochemistry: Preliminary Qualitative Analysis

ERIC Educational Resources Information Center

Talib, Othman; Matthews, Robert; Secombe, Margaret

2005-01-01

This paper discusses the potential of applying computer-animated instruction (CAnI) as an effective conceptual change strategy in teaching electrochemistry in comparison to conventional lecture-based instruction (CLI). The core assumption in this study is that conceptual change in learners is an active, constructive process that is enhanced by the…

Electrochemistry in the mimicry of oxidative drug metabolism by cytochrome P450s.

PubMed

Nouri-Nigjeh, Eslam; Bischoff, Rainer; Bruins, Andries P; Permentier, Hjalmar P

2011-05-01

Prediction of oxidative drug metabolism at the early stages of drug discovery and development requires fast and accurate analytical techniques to mimic the in vivo oxidation reactions by cytochrome P450s (CYP). Direct electrochemical oxidation combined with mass spectrometry, although limited to the oxidation reactions initiated by charge transfer, has shown promise in the mimicry of certain CYP-mediated metabolic reactions. The electrochemical approach may further be utilized in an automated manner in microfluidics devices facilitating fast screening of oxidative drug metabolism. A wide range of in vivo oxidation reactions, particularly those initiated by hydrogen atom transfer, can be imitated through the electrochemically-assisted Fenton reaction. This reaction is based on O-O bond activation in hydrogen peroxide and oxidation by hydroxyl radicals, wherein electrochemistry is used for the reduction of molecular oxygen to hydrogen peroxide, as well as the reduction of Fe(3+) to Fe(2+). Metalloporphyrins, as surrogates for the prosthetic group in CYP, utilizing metallo-oxo reactive species, can also be used in combination with electrochemistry. Electrochemical reduction of metalloporphyrins in solution or immobilized on the electrode surface activates molecular oxygen in a manner analogous to the catalytical cycle of CYP and different metalloporphyrins can mimic selective oxidation reactions. Chemoselective, stereoselective, and regioselective oxidation reactions may be mimicked using electrodes that have been modified with immobilized enzymes, especially CYP itself. This review summarizes the recent attempts in utilizing electrochemistry as a versatile analytical and preparative technique in the mimicry of oxidative drug metabolism by CYP. © 2011 Bentham Science Publishers Ltd.

Electromagnetism Unit of an Introductory University Physics Course: The Influence of a Reform-Based Tutorial

ERIC Educational Resources Information Center

Barrett, Sarah Elizabeth; Hazari, Zahra; Fatholahzadeh, Baharak; Harrison, David M.

2012-01-01

Many students enrolled in university physics have little interest in the subject matter, a trend more pronounced in females. This study assesses students' conceptual understanding and interest during the electrochemistry unit of a physics course for nonphysics majors that was revised in light of consistently low ratings from its students. The…

Tungsten Oxides for Photocatalysis, Electrochemistry, and Phototherapy.

PubMed

Huang, Zhen-Feng; Song, Jiajia; Pan, Lun; Zhang, Xiangwen; Wang, Li; Zou, Ji-Jun

2015-09-23

The conversion, storage, and utilization of renewable energy have all become more important than ever before as a response to ever-growing energy and environment concerns. The performance of energy-related technologies strongly relies on the structure and property of the material used. The earth-abundant family of tungsten oxides (WOx ≤3 ) receives considerable attention in photocatalysis, electrochemistry, and phototherapy due to their highly tunable structures and unique physicochemical properties. Great breakthroughs have been made in enhancing the optical absorption, charge separation, redox capability, and electrical conductivity of WOx ≤3 through control of the composition, crystal structure, morphology, and construction of composite structures with other materials, which significantly promotes the efficiency of processes and devices based on this material. Herein, the properties and synthesis of WOx ≤3 family are reviewed, and then their energy-related applications are highlighted, including solar-light-driven water splitting, CO2 reduction, and pollutant removal, electrochromism, supercapacitors, lithium batteries, solar and fuel cells, non-volatile memory devices, gas sensors, and cancer therapy, from the aspect of function-oriented structure design and control. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrochemistry and Spectroelectrochemistry of the Pu (III/IV) and (IV/VI) Couples in Nitric Acid Systems

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

Lines, Amanda M.; Adami, Susan R.; Casella, Amanda J.

The solution chemistry of Pu in nitric acid is explored via electrochemistry and spectroelectrochemistry. By utilizing and comparing these techniques, an improved understanding of Pu behavior and its dependence on nitric acid concentration can be achieved. Here the Pu (III/IV) couple is characterized using cyclic voltammetry, square wave voltammetry, and a spectroelectrochemical Nernst step. Results indicate the formal reduction potential of the couple shifts negative with increasing acid concentration and reversible electrochemistry is no longer attainable above 6 M HNO3. Spectroelectrochemistry is also used to explore the irreversible oxidation of Pu(IV) to Pu(VI) and shine light on the mechanism andmore » acid dependence of the redox reaction.« less

An aptamer-based biosensing platform for highly sensitive detection of platelet-derived growth factor via enzyme-mediated direct electrochemistry.

PubMed

Deng, Kun; Xiang, Yang; Zhang, Liqun; Chen, Qinghai; Fu, Weiling

2013-01-08

In this work, a new label-free electrochemical aptamer-based sensor (aptasensor) was constructed for detection of platelet-derived growth factor (PDGF) based on the direct electrochemistry of glucose oxidase (GOD). For this proposed aptasensor, poly(diallyldimethylammonium chloride) (PDDA)-protected graphene-gold nanoparticles (P-Gra-GNPs) composite was firstly coated on electrode surface to form the interface with biocompatibility and huge surface area for the adsorption of GOD layer. Subsequently, gold nanoclusters (GNCs) were deposited on the surface of GOD to capture PDGF binding aptamer (PBA). Finally, GOD as a blocking reagent was employed to block the remaining active sites of the GNCs and avoid the nonspecific adsorption. With the direct electron transfer of double layer GOD membranes, the aptasensor showed excellent electrochemical response and the peak current decreased linearly with increasing logarithm of PDGF concentration from 0.005 nM to 60 nM with a relatively low limit of detection of 1.7 pM. The proposed aptasensor exhibited high specificity, good reproducibility and long-term stability, which provided a new promising technique for aptamer-based protein detection. Copyright © 2012 Elsevier B.V. All rights reserved.

Investigations by Protein Film Electrochemistry of Alternative Reactions of Nickel-Containing Carbon Monoxide Dehydrogenase.

PubMed

Wang, Vincent C-C; Islam, Shams T A; Can, Mehmet; Ragsdale, Stephen W; Armstrong, Fraser A

2015-10-29

Protein film electrochemistry has been used to investigate reactions of highly active nickel-containing carbon monoxide dehydrogenases (CODHs). When attached to a pyrolytic graphite electrode, these enzymes behave as reversible electrocatalysts, displaying CO2 reduction or CO oxidation at minimal overpotential. The O2 sensitivity of CODH is suppressed by adding cyanide, a reversible inhibitor of CO oxidation, or by raising the electrode potential. Reduction of N2O, isoelectronic with CO2, is catalyzed by CODH, but the reaction is sluggish, despite a large overpotential, and results in inactivation. Production of H2 and formate under highly reducing conditions is consistent with calculations predicting that a nickel-hydrido species might be formed, but the very low rates suggest that such a species is not on the main catalytic pathway.

Electrochemistry-Assisted Top-Down Characterization of Disulfide-Containing Proteins

PubMed Central

Zhang, Yun; Cui, Weidong; Zhang, Hao; Dewald, Howard D.; Chen, Hao

2013-01-01

Covalent disulfide bond linkage in a protein represents an important challenge for mass spectrometry (MS)-based top-down protein structure analysis as it reduces the backbone cleavage efficiency for MS/MS dissociation. This study presents a strategy for solving this critical issue via integrating electrochemistry (EC) online with top-down MS approach. In this approach, proteins undergo electrolytic reduction in an electrochemical cell to break disulfide bonds and then online ionized into gaseous ions for analysis by electron-capture dissociation (ECD) and collision-induced dissociation (CID). The electrochemical reduction of proteins allows to remove disulfide bond constraints and also leads to increased charge numbers of the resulting protein ions. As a result, sequence coverage was significantly enhanced, as exemplified by β-lactoglobulin A (24 vs. 73 backbone cleavages before and after electrolytic reduction, respectively) and lysozyme (5 vs. 66 backbone cleavages before and after electrolytic reduction, respectively). This methodology is fast and does not need chemical reductants, which would have an important impact in high-throughput proteomics research. PMID:22448817

Electrochemistry-assisted top-down characterization of disulfide-containing proteins.

PubMed

Zhang, Yun; Cui, Weidong; Zhang, Hao; Dewald, Howard D; Chen, Hao

2012-04-17

Covalent disulfide bond linkage in a protein represents an important challenge for mass spectrometry (MS)-based top-down protein structure analysis as it reduces the backbone cleavage efficiency for MS/MS dissociation. This study presents a strategy for solving this critical issue via integrating electrochemistry (EC) online with a top-down MS approach. In this approach, proteins undergo electrolytic reduction in an electrochemical cell to break disulfide bonds and then undergo online ionization into gaseous ions for analysis by electron-capture dissociation (ECD) and collision-induced dissociation (CID). The electrochemical reduction of proteins allows one to remove disulfide bond constraints and also leads to increased charge numbers of the resulting protein ions. As a result, sequence coverage was significantly enhanced, as exemplified by β-lactoglobulin A (24 vs 75 backbone cleavages before and after electrolytic reduction, respectively) and lysozyme (5 vs 66 backbone cleavages before and after electrolytic reduction, respectively). This methodology is fast and does not need chemical reductants, which would have an important impact in high-throughput proteomics research.

European Physical Society Conference on High Energy Physics

NASA Astrophysics Data System (ADS)

The European Physical Society Conference on High Energy Physics, organized by the High Energy and Particle Physics Division of the European Physical Society, is a major international conference that reviews biennially since 1971 the state of our knowledge of the fundamental constituents of matter and their interactions. The latest conferences in this series were held in Stockholm, Grenoble, Krakow, Manchester, Lisbon, and Aachen. Jointly organized by the Institute of High Energy Physics of the Austrian Academy of Sciences, the University of Vienna, the Vienna University of Technology, and the Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, the 23rd edition of this conference took place in Vienna, Austria. Among the topics covered were Accelerators, Astroparticle Physics, Cosmology and Gravitation, Detector R&D and Data Handling, Education and Outreach, Flavour Physics and Fundamental Symmetries, Heavy Ion Physics, Higgs and New Physics, Neutrino Physics, Non-Perturbative Field Theory and String Theory, QCD and Hadronic Physics, as well as Top and Electroweak Physics.

The edge- and basal-plane-specific electrochemistry of a single-layer graphene sheet

PubMed Central

Yuan, Wenjing; Zhou, Yu; Li, Yingru; Li, Chun; Peng, Hailin; Zhang, Jin; Liu, Zhongfan; Dai, Liming; Shi, Gaoquan

2013-01-01

Graphene has a unique atom-thick two-dimensional structure and excellent properties, making it attractive for a variety of electrochemical applications, including electrosynthesis, electrochemical sensors or electrocatalysis, and energy conversion and storage. However, the electrochemistry of single-layer graphene has not yet been well understood, possibly due to the technical difficulties in handling individual graphene sheet. Here, we report the electrochemical behavior at single-layer graphene-based electrodes, comparing the basal plane of graphene to its edge. The graphene edge showed 4 orders of magnitude higher specific capacitance, much faster electron transfer rate and stronger electrocatalytic activity than those of graphene basal plane. A convergent diffusion effect was observed at the sub-nanometer thick graphene edge-electrode to accelerate the electrochemical reactions. Coupling with the high conductivity of a high-quality graphene basal plane, graphene edge is an ideal electrode for electrocatalysis and for the storage of capacitive charges. PMID:23896697

In-Depth Characterization of Protein Disulfide Bonds by Online Liquid Chromatography-Electrochemistry-Mass Spectrometry

NASA Astrophysics Data System (ADS)

Switzar, Linda; Nicolardi, Simone; Rutten, Julie W.; Oberstein, Saskia A. J. Lesnik; Aartsma-Rus, Annemieke; van der Burgt, Yuri E. M.

2016-01-01

Disulfide bonds are an important class of protein post-translational modifications, yet this structurally crucial modification type is commonly overlooked in mass spectrometry (MS)-based proteomics approaches. Recently, the benefits of online electrochemistry-assisted reduction of protein S-S bonds prior to MS analysis were exemplified by successful characterization of disulfide bonds in peptides and small proteins. In the current study, we have combined liquid chromatography (LC) with electrochemistry (EC) and mass analysis by Fourier transform ion cyclotron resonance (FTICR) MS in an online LC-EC-MS platform to characterize protein disulfide bonds in a bottom-up proteomics workflow. A key advantage of a LC-based strategy is the use of the retention time in identifying both intra- and interpeptide disulfide bonds. This is demonstrated by performing two sequential analyses of a certain protein digest, once without and once with electrochemical reduction. In this way, the "parent" disulfide-linked peptide detected in the first run has a retention time-based correlation with the EC-reduced peptides detected in the second run, thus simplifying disulfide bond mapping. Using this platform, both inter- and intra-disulfide-linked peptides were characterized in two different proteins, ß-lactoglobulin and ribonuclease B. In order to prevent disulfide reshuffling during the digestion process, proteins were digested at a relatively low pH, using (a combination of) the high specificity proteases trypsin and Glu-C. With this approach, disulfide bonds in ß-lactoglobulin and ribonuclease B were comprehensively identified and localized, showing that online LC-EC-MS is a useful tool for the characterization of protein disulfide bonds.

High Energy Physics

Science.gov Websites

Untitled Document [Argonne Logo] [DOE Logo] High Energy Physics Home Division ES&H Personnel Collider Physics Cosmic Frontier Cosmic Frontier Theory & Computing Detector R&D Electronic Design Mechanical Design Neutrino Physics Theoretical Physics Seminars HEP Division Seminar HEP Lunch Seminar HEP

The Pre-exponential Factor in Electrochemistry.

PubMed

He, Zheng-Da; Chen, Yan-Xia; Santos, Elizabeth; Schmickler, Wolfgang

2018-07-02

Like many branches of science, not to mention culture in general, electrochemistry has a number of recurring topics: Areas of research that are popular for a certain time, then fade away as their possibilities seem to have been exhausted, only to return decades later as progress in experimental or theoretical techniques offer new possibilities for their investigation. A prime example are fuel cells, which have undergone five such cycles, but here we discuss a general concept of kinetics-the pre-exponential factor of a rate constant-which has undergone two such cycles. The first cycle was in the 1950-1980s, when the methods of electrochemical kinetics were developed, and the interpretation was based on transition-state theory. The second was triggered by the re-discovery of Kramers theory for reactions in condensed phases. This Minireview will show that the time has come for a third cycle based on recent progress in electrocatalysis. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrochemistry-based Battery Modeling for Prognostics

NASA Technical Reports Server (NTRS)

Daigle, Matthew J.; Kulkarni, Chetan Shrikant

2013-01-01

Batteries are used in a wide variety of applications. In recent years, they have become popular as a source of power for electric vehicles such as cars, unmanned aerial vehicles, and commericial passenger aircraft. In such application domains, it becomes crucial to both monitor battery health and performance and to predict end of discharge (EOD) and end of useful life (EOL) events. To implement such technologies, it is crucial to understand how batteries work and to capture that knowledge in the form of models that can be used by monitoring, diagnosis, and prognosis algorithms. In this work, we develop electrochemistry-based models of lithium-ion batteries that capture the significant electrochemical processes, are computationally efficient, capture the effects of aging, and are of suitable accuracy for reliable EOD prediction in a variety of usage profiles. This paper reports on the progress of such a model, with results demonstrating the model validity and accurate EOD predictions.

Molybdenum, molybdenum oxides, and their electrochemistry.

PubMed

Saji, Viswanathan S; Lee, Chi-Woo

2012-07-01

The electrochemical behaviors of molybdenum and its oxides, both in bulk and thin film dimensions, are critical because of their widespread applications in steels, electrocatalysts, electrochromic materials, batteries, sensors, and solar cells. An important area of current interest is electrodeposited CIGS-based solar cells where a molybdenum/glass electrode forms the back contact. Surprisingly, the basic electrochemistry of molybdenum and its oxides has not been reviewed with due attention. In this Review, we assess the scattered information. The potential and pH dependent active, passive, and transpassive behaviors of molybdenum in aqueous media are explained. The major surface oxide species observed, reversible redox transitions of the surface oxides, pseudocapacitance and catalytic reduction are discussed along with carefully conducted experimental results on a typical molybdenum glass back contact employed in CIGS-based solar cells. The applications of molybdenum oxides and the electrodeposition of molybdenum are briefly reviewed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li/Ag 2VO 2PO 4 batteries: the roles of composite electrode constituents on electrochemistry

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

Bock, David C.; Bruck, Andrea M.; Pelliccione, Christopher J.

2016-11-01

Silver vanadium phosphorous oxide, Ag 2V 2OPO 4, was used as a model system to systematically study the impact on the constituents of a composite electrode, including polymeric and conductive additives, on electrochemistry. Three different electrode compositions were investigated.

Li/Ag 2VO 2PO 4 batteries: the roles of composite electrode constituents on electrochemistry

DOE PAGES

Bock, David C.; Bruck, Andrea M.; Pelliccione, Christopher J.; ...

2016-11-01

In this study, we utilize silver vanadium phosphorous oxide, Ag 2VO 2PO 4, as a model system to systematically study the impact of the constituents of a composite electrode, including polymeric and conductive additives, on electrochemistry. Notably, although highly resistive, this bimetallic cathode can be discharged as a pure electroactive material in the absence of a conductive additive as it generates an in situ conductive matrix via a reduction displacement reaction resulting in the formation of silver metal nanoparticles. Also, three different electrode compositions were investigated: Ag 2VO 2PO 4 only, Ag 2VO 2PO 44 with binder, and Ag 2VOmore » 2PO 4 with binder and carbon. Constant current discharge, pulse testing and impedance spectroscopy measurements were used to characterize the electrochemical properties of the electrodes as a function of depth of discharge. In situ EDXRD was used to spatially resolve the discharge progression within the cathode by following the formation of Ag 0. Ex situ XRD and EXAFS modeling were used to quantify the amount of Ag 0 formed. Results indicate that the metal center reduced (V 5+ or Ag +) was highly dependent on composite composition (presence of PTFE, carbon), depth of discharge (Ag 0 nanoparticle formation), and spatial location within the cathode. The addition of a binder was found to increase cell polarization, and the percolation network provided by the carbon in the presence of PTFE was further increased with reduction and formation of Ag 0. Lastly, this study provides insight into the factors controlling the electrochemistry of resistive active materials in composite electrodes.« less

Li/Ag 2VO 2PO 4 batteries: the roles of composite electrode constituents on electrochemistry

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

Bock, David C.; Bruck, Andrea M.; Pelliccione, Christopher J.

In this study, we utilize silver vanadium phosphorous oxide, Ag 2VO 2PO 4, as a model system to systematically study the impact of the constituents of a composite electrode, including polymeric and conductive additives, on electrochemistry. Notably, although highly resistive, this bimetallic cathode can be discharged as a pure electroactive material in the absence of a conductive additive as it generates an in situ conductive matrix via a reduction displacement reaction resulting in the formation of silver metal nanoparticles. Also, three different electrode compositions were investigated: Ag 2VO 2PO 4 only, Ag 2VO 2PO 44 with binder, and Ag 2VOmore » 2PO 4 with binder and carbon. Constant current discharge, pulse testing and impedance spectroscopy measurements were used to characterize the electrochemical properties of the electrodes as a function of depth of discharge. In situ EDXRD was used to spatially resolve the discharge progression within the cathode by following the formation of Ag 0. Ex situ XRD and EXAFS modeling were used to quantify the amount of Ag 0 formed. Results indicate that the metal center reduced (V 5+ or Ag +) was highly dependent on composite composition (presence of PTFE, carbon), depth of discharge (Ag 0 nanoparticle formation), and spatial location within the cathode. The addition of a binder was found to increase cell polarization, and the percolation network provided by the carbon in the presence of PTFE was further increased with reduction and formation of Ag 0. Lastly, this study provides insight into the factors controlling the electrochemistry of resistive active materials in composite electrodes.« less

The Effects of Problem-Based Learning (PBL) on the Academic Achievement of Students Studying "Electrochemistry"

ERIC Educational Resources Information Center

Günter, Tugçe; Alpat, Sibel Kilinç

2017-01-01

This study investigates the effects of problem-based learning (PBL) on students' academic achievements in studying "Electrochemistry" within a course on Analytical Chemistry. The research was of a pretest-posttest control group quasi-experimental design and it was conducted with second year students in the Chemistry Teaching Program at…

Analysis of the electrochemistry of hemes with Ems spanning 800 mV

PubMed Central

Zheng, Zhong; Gunner, M. R.

2009-01-01

The free energy of heme reduction in different proteins is found to vary over more than 18 kcal/mol. It is a challenge to determine how proteins manage to achieve this enormous range of Ems with a single type of redox cofactor. Proteins containing 141 unique hemes of a-, b-, and c-type, with bis-His, His-Met, and aquo-His ligation were calculated using Multi-Conformation Continuum Electrostatics (MCCE). The experimental Ems range over 800 mV from −350 mV in cytochrome c3 to 450 mV in cytochrome c peroxidase (vs. SHE). The quantitative analysis of the factors that modulate heme electrochemistry includes the interactions of the heme with its ligands, the solvent, the protein backbone, and sidechains. MCCE calculated Ems are in good agreement with measured values. Using no free parameters the slope of the line comparing calculated and experimental Ems is 0.73 (R2 = 0.90), showing the method accounts for 73% of the observed Em range. Adding a +160 mV correction to the His-Met c-type hemes yields a slope of 0.97 (R2 = 0.93). With the correction 65% of the hemes have an absolute error smaller than 60 mV and 92% are within 120 mV. The overview of heme proteins with known structures and Ems shows both the lowest and highest potential hemes are c-type, whereas the b-type hemes are found in the middle Em range. In solution, bis-His ligation lowers the Em by ≈205 mV relative to hemes with His-Met ligands. The bis-His, aquo-His, and His-Met ligated b-type hemes all cluster about Ems which are ≈200 mV more positive in protein than in water. In contrast, the low potential bis-His c-type hemes are shifted little from in solution, whereas the high potential His-Met c-type hemes are raised by ≈300 mV from solution. The analysis shows that no single type of interaction can be identified as the most important in setting heme electrochemistry in proteins. For example, the loss of solvation (reaction field) energy, which raises the Em, has been suggested to be a major factor in

A Preliminary Study of Some of the Learning and Assessment Difficulties in Connection with O-Level Electrochemistry.

ERIC Educational Resources Information Center

Hillman, R. A. H.; And Others

1981-01-01

Describes a study which explored some difficulties related to technical and nontechnical vocabulary and the structure of the examination questions in electrochemistry. Includes results from a sample of 1,500 students in the fourth forms. (DS)

Synthesis of Cation and Water Free Cryptomelane Type OMS-2 Cathode Materials: The Impact of Tunnel Water on Electrochemistry

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

Poyraz, Altug S.; Huang, Jianping; Zhang, Bingjie

Cryptomelane type manganese dioxides (α-MnO 2, OMS-2) are interesting potential cathode materials due to the ability of their one dimensional (1D) tunnels to reversibly host various cations including Li +and an accessible stable 3+/4+ redox couple. Here, we synthesized metal cation free OMS-2 materials where the tunnels were occupied by only water and hydronium ions. Water was subsequently removed from the tunnels. Cation free OMS-2 and Dry-OMS-2 were used as cathodes in Li based batteries to investigate the role of tunnel water on their electrochemistry. The initial discharge capacity was higher for Dry-OMS-2 (252 mAh/g) compared to OMS-2 (194 mAh/g),more » however, after 100 cycles Dry-OMS-2 and OMS-2 delivered 137 mAh/g and 134 mAh/g, respectively. Li +ion diffusion was more facile for Dry-OMS as evidenced by rate capability, at 400 mA/g. Dry-OMS-2 delivered 135mAh/g whereas OMS-2 delivered ~115 mAh/g. This first report of the impact of tunnel water on the electrochemistry of OMS-2 type materials demonstrates that the presence of tunnel water in OMS-2 type materials negatively impacts the electrochemistry.« less

Effects of Jigsaw and Animation Techniques on Students' Understanding of Concepts and Subjects in Electrochemistry

ERIC Educational Resources Information Center

Doymus, Kemal; Karacop, Ataman; Simsek, Umit

2010-01-01

This study investigated the effect of jigsaw cooperative learning and animation versus traditional teaching methods on students' understanding of electrochemistry in a first-year general chemistry course. This study was carried out in three different classes in the department of primary science education during the 2007-2008 academic year. The…

Direct electrochemistry and electrocatalytic behavior of hemoglobin entrapped in Ag@C nanocables/gold nanoparticles nanocomposites film.

PubMed

Hu, Xiao-Wei; Mao, Chang-Jie; Song, Ji-Ming; Niu, He-Lin; Zhang, Sheng-Yi; Cui, Rong-Jing

2012-10-01

Direct electrochemistry of hemoglobin (Hb) was successfully fabricated by immobilizing Hb on the nanocomposites containing of Ag@C nanocables and Au nanoparticles (AuNPs) modified glassy carbon electrode (GCE). The immobilized Hb retained its biological activity and shown high catalytic activities to the reduction of H2O2 by circular dicroism (CD) spectrum, fourier transform infrared (FT-IR) spectrum and cyclic voltammetry (CV). Experimental conditions such as scan rate and pH Value were studied and optimized. The results indicated that the resulting biosensor are linear to the concentrations of H2O2 in the ranges of 6.67 x 10(-7)-2.40 x 10(5) M, and the detection limit is 2.02 x 10(-7) M. The electrochemical biosensor has also high stability and good reproducibility.

A Historical Analysis of the Daniell Cell and Electrochemistry Teaching in French and Tunisian Textbooks

ERIC Educational Resources Information Center

Boulabiar, Ahlem; Bouraoui, Kamel; Chastrette, Maurice; Abderrabba, Manef

2004-01-01

The condition in which the Daniell Cell was historically constructed is examined and the evolution of its presentation in French and Tunisian chemistry textbooks is analyzed. Based on the studies, several innovations to facilitate the teaching of the cell, and more generally, the teaching of electrochemistry and of ionic conduction are proposed.

A glucose biosensor based on direct electrochemistry of glucose oxidase immobilized on nitrogen-doped carbon nanotubes.

PubMed

Deng, Shengyuan; Jian, Guoqiang; Lei, Jianping; Hu, Zheng; Ju, Huangxian

2009-10-15

A novel biosensor for glucose was prepared by immobilizing glucose oxidase (GOx) on nitrogen-doped carbon nanotubes (CNx-MWNTs) modified electrode. The CNx-MWNTs membrane showed an excellent electrocatalytic activity toward the reduction of O(2) due to its diatomic side-on adsorption on CNx-MWNTs. The nitrogen doping accelerated the electron transfer from electrode surface to the immobilized GOx, leading to the direct electrochemistry of GOx. The biofunctional surface showed good biocompatibility, excellent electron-conductive network and large surface-to-volume ratio, which were characterized by scanning electron microscopy, contact angle and electrochemical impedance technique. The direct electron transfer of immobilized GOx led to stable amperometric biosensing for glucose with a linear range from 0.02 to 1.02 mM and a detection limit of 0.01 mM (S/N=3). These results indicated that CNx-MWNTs are good candidate material for construction of the third-generation enzyme biosensors based on the direct electrochemistry of immobilized enzymes.

In situ solid-state electrochemistry of mass-selected ions at well-defined electrode–electrolyte interfaces

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

Prabhakaran, Venkateshkumar; Johnson, Grant E.; Wang, Bingbing

2016-11-07

Molecular-level understanding of electrochemical processes occurring at electrode-electrolyte interfaces (EEI) is key to the rational development of high-performance and sustainable electrochemical technologies. This article reports the development and first application of solid-state in situ electrochemical probes to study redox and catalytic processes occurring at well-defined EEI generated using soft-landing of mass- and charge-selected cluster ions (SL). In situ electrochemical probes with excellent mass transfer properties are fabricated using carefully-designed nanoporous ionic liquid membranes. SL enables deposition of pure active species that are not obtainable with other techniques onto electrode surfaces with precise control over charge state, composition, and kinetic energy.more » SL is, therefore, a unique tool for studying fundamental processes occurring at EEI. For the first time using an aprotic electrochemical probe, the effect of charge state (PMo12O403-/2-) and the contribution of building blocks of Keggin polyoxometalate (POM) clusters to redox processes are characterized by populating EEI with novel POM anions generated by electrospray ionization and gas phase dissociation. Additionally, a proton conducting electrochemical probe has been developed to characterize the reactive electrochemistry (oxygen reduction activity) of bare Pt clusters (Pt40 ~1 nm diameter), thus demonstrating the capability of the probe for studying reactions in controlled gaseous environments. The newly developed in situ electrochemical probes combined with ion SL provide a versatile method to characterize the EEI in solid-state redox systems and reactive electrochemistry at precisely-defined conditions. This capability will advance molecular-level understanding of processes occurring at EEI that are critical to many energy-related technologies.« less

Direct electrochemistry and electrocatalysis of a glucose oxidase-functionalized bioconjugate as a trace label for ultrasensitive detection of thrombin.

PubMed

Bai, Lijuan; Yuan, Ruo; Chai, Yaqin; Yuan, Yali; Wang, Yan; Xie, Shunbi

2012-11-18

For the first time, a glucose oxidase-functionalized bioconjugate was prepared and served as a new trace label through its direct electrochemistry and electrocatalysis in a sandwich-type electrochemical aptasensor for ultrasensitive detection of thrombin.

Functionalization of carbon nanotubes with water-insoluble porphyrin in ionic liquid: direct electrochemistry and highly sensitive amperometric biosensing for trichloroacetic acid.

PubMed

Tu, Wenwen; Lei, Jianping; Ju, Huangxian

2009-01-01

A functional composite of single-walled carbon nanotubes (SWNTs) with hematin, a water-insoluble porphyrin, was first prepared in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF(6)]) ionic liquid. The novel composite in ionic liquid was characterized by scanning electron microscopy, ultraviolet absorption spectroscopy, and electrochemical impedance spectroscopy, and showed a pair of direct redox peaks of the Fe(III)/Fe(II) couple. The composite-[BMIM][PF(6)]-modified glassy carbon electrode showed excellent electrocatalytic activity toward the reduction of trichloroacetic acid (TCA) in neutral media due to the synergic effect among SWNTs, [BMIM][PF(6)], and porphyrin, which led to a highly sensitive and stable amperometric biosensor for TCA with a linear range from 9.0x10(-7) to 1.4x10(-4) M. The detection limit was 3.8x10(-7) M at a signal-to-noise ratio of 3. The TCA biosensor had good analytical performance, such as rapid response, good reproducibility, and acceptable accuracy, and could be successfully used for the detection of residual TCA in polluted water. The functional composite in ionic liquid provides a facile way to not only obtain the direct electrochemistry of water-insoluble porphyrin, but also construct novel biosensors for monitoring analytes in real environmental samples.

Epitaxial Fe(1-x)Gax/GaAs structures via electrochemistry for spintronics applications

NASA Astrophysics Data System (ADS)

Reddy, K. Sai Madhukar; Maqableh, Mazin M.; Stadler, Bethanie J. H.

2012-04-01

In this study, thin films of Fe83Ga17 (a giant magnetostrictive alloy) were grown on single-crystalline n-GaAs (001) and polycrystalline brass substrates via electrochemical synthesis from ferrous and gallium sulfate electrolytes. Extensive structural characterization using microdiffraction, high-resolution ω - 2θ, and rocking-curve analysis revealed that the films grown on GaAs(001) are highly textured with ⟨001⟩ orientation along the substrate normal, and the texture improved further upon annealing at 300 °C for 2 h in N2 environment. On the contrary, films grown on brass substrates exhibited ⟨011⟩ preferred orientation. Rocking-curve analysis done on Fe83Ga17/GaAs structures further confirmed that the ⟨001⟩ texture in the Fe83Ga17 thin film is a result of epitaxial nucleation and growth. The non-linear current-voltage plot obtained for the Fe-Ga/GaAs Schottky contacts was characteristic of tunneling injection, and showed improved behavior with annealing. Thus, this study demonstrates the feasibility of fabricating spintronic devices that incorporate highly magnetostrictive Fe(1-x)Gax thin films grown epitaxially via electrochemistry.

Topic-Specific Pedagogical Content Knowledge (TSPCK) in Redox and Electrochemistry of Experienced Teachers

NASA Astrophysics Data System (ADS)

O'Brien, Stephanie

Topic specific pedagogical content knowledge (TSPCK) is the basis by which knowledge of subject matter of a particular topic is conveyed to students. This includes students' prior knowledge, curricular saliency, what makes a topic easy or difficult to teach, representations, and teaching strategies. The goal of this study is to assess the pedagogical content knowledge of chemistry teachers in a professional learning community in the areas of redox and electrochemistry, as this has been regarded in previous literature as conceptually challenging for students to learn. By acquiring information regarding the PCK development of experienced chemistry teachers, the education and practice of all science teachers can be advanced. This study builds upon previous research that developed validated instruments to evaluate TSPCK. The research questions sought to determine which components of TSPCK were evidenced by the instructional design decisions teachers made, what shared patterns and trends were evident, and how TSPCK related to student learning outcomes. To answer the research questions subjects completed a background questionnaire, a TSPCK assessment, and interview tasks to elicit information about pedagogical decision making and processes that influenced student learning in their classrooms. The TSPCK exam and interview responses were coded to align with thematic constructs. To determine the effect of TSPCK on student learning gains, pre/post-assessment data on redox and electrochemistry were compared to teachers' TSPCK. The chemistry teachers displayed varying levels of TSPCK in redox and electrochemistry, as evidenced by their knowledge of student learning obstacles, curricular saliency, and teaching methodologies. There was evidence of experienced teachers lacking in certain areas of TSPCK, such as the ability to identify student misconceptions, suggesting the need for programmatic improvements in pre-service and in-service training to address the needs of current

Humidity Effect on Nanoscale Electrochemistry in Solid Silver Ion Conductors and the Dual Nature of Its Locality

DOE PAGES

Yang, Sangmo; Strelcov, Evgheni; Paranthaman, Mariappan Parans; ...

2015-01-07

Scanning probe microscopy (SPM) is a powerful tool to investigate electrochemistry in nanoscale volumes. While most SPM-based studies have focused on reactions at the tip-surface junction, charge and mass conservation requires coupled and intrinsically non-local cathodic and anodic processes that can be significantly affected by ambient humidity. Here, we explore the role of water in both cathodic and anodic processes, associated charge transport, and topographic volume changes depending on the polarity of tip bias. The first-order reversal curve current-voltage technique combined with simultaneous detection of the sample topography, referred to as FORC-IVz, was applied to a silver solid ion conductor.more » We found that the protons generated from water affect silver ionic conduction, silver particle formation and dissolution, and mechanical integrity of the material. This work highlights the dual nature (simultaneously local and non-local) of electrochemical SPM studies, which should be considered for comprehensive understanding of nanoscale electrochemistry.« less

Humidity effect on nanoscale electrochemistry in solid silver ion conductors and the dual nature of its locality.

PubMed

Yang, Sang Mo; Strelcov, Evgheni; Paranthaman, M Parans; Tselev, Alexander; Noh, Tae Won; Kalinin, Sergei V

2015-02-11

Scanning probe microscopy (SPM) is a powerful tool to investigate electrochemistry in nanoscale volumes. While most SPM-based studies have focused on reactions at the tip-surface junction, charge and mass conservation requires coupled and intrinsically nonlocal cathodic and anodic processes that can be significantly affected by ambient humidity. Here, we explore the role of water in both cathodic and anodic processes, associated charge transport, and topographic volume changes depending on the polarity of tip bias. The first-order reversal curve current-voltage technique combined with simultaneous detection of the sample topography, referred to as FORC-IVz, was applied to a silver solid ion conductor. We found that the protons generated from water affect silver ionic conduction, silver particle formation and dissolution, and mechanical integrity of the material. This work highlights the dual nature (simultaneously local and nonlocal) of electrochemical SPM studies, which should be considered for comprehensive understanding of nanoscale electrochemistry.

High Energy Physics

Science.gov Websites

Collider Physics Cosmic Frontier Cosmic Frontier Theory & Computing Detector R&D Electronic Design Theory Seminar Argonne >High Energy Physics Cosmic Frontier Theory & Computing Homepage General Cosmic Frontier Theory & Computing Group led the analysis to begin mapping dark matter. There have

Effectiveness of Interactive Multimedia Module with Pedagogical Agent (IMMPA) in the Learning of Electrochemistry: A Preliminary Investigation

ERIC Educational Resources Information Center

Lee, Tien Tien; Osman, Kamisah

2011-01-01

Electrochemistry is found to be a difficult topic to learn due to its abstract concepts that involve the macroscopic, microscopic and symbolic representation levels. Research showed that animation and simulation using Information and Communication Technology (ICT) can help students to visualize and hence enhance students' understanding in learning…

Direct electrochemistry and intramolecular electron transfer of ascorbate oxidase confined on L-cysteine self-assembled gold electrode.

PubMed

Patil, Bhushan; Kobayashi, Yoshiki; Fujikawa, Shigenori; Okajima, Takeyoshi; Mao, Lanqun; Ohsaka, Takeo

2014-02-01

A direct electrochemistry and intramolecular electron transfer of multicopper oxidases are of a great importance for the fabrication of these enzyme-based bioelectrochemical-devices. Ascorbate oxidase from Acremonium sp. (ASOM) has been successfully immobilized via a chemisorptive interaction on the l-cysteine self-assembled monolayer modified gold electrode (cys-SAM/AuE). Thermodynamics and kinetics of adsorption of ASOM on the cys-SAM/AuE were studied using cyclic voltammetry. A well-defined redox wave centered at 166±3mV (vs. Ag│AgCl│KCl(sat.)) was observed in 5.0mM phosphate buffer solution (pH7.0) at the fabricated ASOM electrode, abbreviated as ASOM/cys-SAM/AuE, confirming a direct electrochemistry, i.e., a direct electron transfer (DET) between ASOM and cys-SAM/AuE. The direct electrochemistry of ASOM was further confirmed by taking into account the chemical oxidation of ascorbic acid (AA) by O2 via an intramolecular electron transfer in the ASOM as well as the electrocatalytic oxidation of AA at the ASOM/cys-SAM/AuE. Thermodynamics and kinetics of the adsorption of ASOM on the cys-SAM/AuE have been elaborated along with its direct electron transfer at the modified electrodes on the basis of its intramolecular electron transfer and electrocatalytic activity towards ascorbic acid oxidation and O2 reduction. ASOM saturated surface area was obtained as 2.41×10(-11)molcm(-2) with the apparent adsorption coefficient of 1.63×10(6)Lmol(-1). The ASOM confined on the cys-SAM/AuE possesses its essential enzymatic function. © 2013.

DNA Electrochemistry with Tethered Methylene Blue

PubMed Central

Pheeney, Catrina G.

2012-01-01

Methylene blue (MB′), covalently attached to DNA through a flexible C12 alkyl linker, provides a sensitive redox reporter in DNA electrochemistry measurements. Tethered, intercalated MB′ is reduced through DNA-mediated charge transport; the incorporation of a single base mismatch at position 3, 10, or 14 of a 17-mer causes an attenuation of the signal to 62 ± 3% of the well-matched DNA, irrespective of position in the duplex. The redox signal intensity for MB′–DNA is found to be least 3-fold larger than that of Nile blue (NB)–DNA, indicating that MB′ is even more strongly coupled to the π-stack. The signal attenuation due to an intervening mismatch does, however, depend on DNA film density and the backfilling agent used to passivate the surface. These results highlight two mechanisms for reduction of MB′ on the DNA-modified electrode: reduction mediated by the DNA base pair stack and direct surface reduction of MB′ at the electrode. These two mechanisms are distinguished by their rates of electron transfer that differ by 20-fold. The extent of direct reduction at the surface can be controlled by assembly and buffer conditions. PMID:22512327

Film Self-Assembly of Oppositely Charged Macromolecules Triggered by Electrochemistry through a Morphogenic Approach.

PubMed

Dochter, Alexandre; Garnier, Tony; Pardieu, Elodie; Chau, Nguyet Trang Thanh; Maerten, Clément; Senger, Bernard; Schaaf, Pierre; Jierry, Loïc; Boulmedais, Fouzia

2015-09-22

The development of new surface functionalization methods that are easy to use, versatile, and allow local deposition represents a real scientific challenge. Overcoming this challenge, we present here a one-pot process that consists in self-assembling, by electrochemistry on an electrode, films made of oppositely charged macromolecules. This method relies on a charge-shifting polyanion, dimethylmaleic-modified poly(allylamine) (PAHd), that undergoes hydrolysis at acidic pH, leading to an overall switching of its charge. When a mixture of the two polyanions, PAHd and poly(styrenesulfonate) (PSS), is placed in contact with an electrode, where the pH is decreased locally by electrochemistry, the transformation of PAHd into a polycation (PAH) leads to the continuous self-assembly of a nanometric PAH/PSS film by electrostatic interactions. The pH decrease is obtained by the electrochemical oxidation of hydroquinone, which produces protons locally over nanometric distances. Using a negatively charged enzyme, alkaline phosphatase (AP), instead of PSS, this one-pot process allows the creation of enzymatically active films. Under mild conditions, self-assembled PAH/AP films have an enzymatic activity which is adjustable simply by controlling the self-assembly time. The selective functionalization of microelectrode arrays by PAH/AP was achieved, opening the route toward miniaturized biosensors.

The Effect of Process Oriented Guided Inquiry Learning (POGIL) on 11th Graders' Conceptual Understanding of Electrochemistry

ERIC Educational Resources Information Center

Sen, Senol; Yilmaz, Ayhan; Geban, Ömer

2016-01-01

The purpose of this study was to investigate the effect of Process Oriented Guided Inquiry Learning (POGIL) method compared to traditional teaching method on 11th grade students' conceptual understanding of electrochemistry concepts. Participants were 115 students from a public school in Turkey. Nonequivalent control group design was used. Two…

Electro-Fermentation - Merging Electrochemistry with Fermentation in Industrial Applications.

PubMed

Schievano, Andrea; Pepé Sciarria, Tommy; Vanbroekhoven, Karolien; De Wever, Heleen; Puig, Sebastià; Andersen, Stephen J; Rabaey, Korneel; Pant, Deepak

2016-11-01

Electro-fermentation (EF) merges traditional industrial fermentation with electrochemistry. An imposed electrical field influences the fermentation environment and microbial metabolism in either a reductive or oxidative manner. The benefit of this approach is to produce target biochemicals with improved selectivity, increase carbon efficiency, limit the use of additives for redox balance or pH control, enhance microbial growth, or in some cases enhance product recovery. We discuss the principles of electrically driven fermentations and how EF can be used to steer both pure culture and microbiota-based fermentations. An overview is given on which advantages EF may bring to both existing and innovative industrial fermentation processes, and which doors might be opened in waste biomass utilization towards added-value biorefineries. Copyright © 2016 Elsevier Ltd. All rights reserved.

The use of bipolar electrochemistry in nanoscience: Contact free methods for the site selective modification of nanostructured carbon materials

NASA Astrophysics Data System (ADS)

Ndungu, Patrick Gathura

Bipolar electrochemistry occurs when an isolated conductive substrate inside an electric field supports both oxidation and reduction reactions. The method requires no direct contact between the power supply and the substrate. In the following thesis bipolar electrochemistry has been used to deposit palladium onto isolated graphite platelets, carbon nanofibers (CNF), and carbon nanotubes (CNT), as well as, various metals, a semiconductor, and an electropolymer on CNTs. Initial work used pulsed DC electric fields to deposit palladium onto isolated graphite platelets. Transmission electron microscopy (TEM) studies on the platelets found palladium metal on one area, indicative of a bipolar mechanism, and palladium deposits that varied from surface bound to highly ramified deposits. No correlation was found between the frequency used to prepare the deposits and the palladium metal dispersion. The same field intensities and frequencies used on the graphite platelets were used to produce CNFs with palladium on one tip. The amount of palladium deposited on one tip of a CNF was controlled by adjusting how long the electric field was applied. Preliminary experiments to produce bulk quantities of CNFs with palladium bipolar electrodeposits used CNFs ball milled with silica, and CNFs suspended in tetrahydrofuran or methylene chloride. The palladium content, measured by atomic absorption spectroscopy, of the functionalized CNFs in silica showed no difference with increased CNF loading; however, TEM studies found a small number of functionalized chloride used suspensions with high loadings of CNFs which led to small percentages of CNFs with bipolar electrodeposited palladium. Finally CNTs obtained commercially and CNTs grown using chemical vapor deposition were successfully functionalized using bipolar electrodeposition. These experiments demonstrate a reliable and controlled method to modify nanostructured materials.

Impact of Interactive Multimedia Module with Pedagogical Agents on Students' Understanding and Motivation in the Learning of Electrochemistry

ERIC Educational Resources Information Center

Osman, Kamisah; Lee, Tien Tien

2014-01-01

The Electrochemistry topic is found to be difficult to learn due to its abstract concepts involving macroscopic, microscopic, and symbolic representation levels. Studies have shown that animation and simulation using information and communication technology (ICT) can help students to visualize and hence enhance their understanding in learning…

Electrochemistry of metalloproteins: protein film electrochemistry for the study of E. coli [NiFe]-hydrogenase-1.

PubMed

Evans, Rhiannon M; Armstrong, Fraser A

2014-01-01

Protein film electrochemistry is a technique which allows the direct control of redox-active enzymes, providing particularly detailed information on their catalytic properties. The enzyme is deposited onto a working electrode tip, and through control of the applied potential the enzyme activity is monitored as electrical current, allowing for direct study of inherent activity as electrons are transferred to and from the enzyme redox center(s). No mediators are used. Because the only enzyme present in the experiment is bound at the electrode surface, gaseous and liquid phase inhibitors can be introduced and removed whilst the enzyme remains in situ. Potential control means that kinetics and thermodynamics are explored simultaneously; the kinetics of a reaction can be studied as a function of potential. Steady-state catalytic rates are observed directly as current (for a given potential) and non-steady-state rates (such as interconversions between different forms of the enzyme) are observed from the change in current with time. The more active the enzyme, the higher the current and the better the signal-to-noise. In this chapter we outline the practical aspects of PFE for studying electroactive enzymes, using the Escherichia coli [NiFe]-hydrogenase 1 (Hyd-1) as an example.

Synthesis of Copper Birnessite, Cu xMnO y·nH 2O with Crystallite Size Control: Impact of Crystallite Size on Electrochemistry

DOE PAGES

Li, Yue Ru; Marschilok, Amy C.; Takeuchi, Esther S.; ...

2015-11-24

This report describes the first detailed electrochemical examination of a series of copper birnessite samples under lithium-based battery conditions, allowing a structure/function analysis of the electrochemistry and related material properties. To obtain the series of copper birnessite samples, a novel synthetic approach for the preparation of copper birnessite, Cu xMnO y·nH 2O is reported. The copper content (x) in Cu xMnO y·nH 2O, 0.28 >= x >= 0.20, was inversely proportional to crystallite size, which ranged from 12 to 19 nm. The electrochemistry under lithium-based battery conditions showed that the higher copper content (x = 0.28) and small crystallite sizemore » (similar to 12 nm) sample delivered similar to 194 mAh/g, about 20% higher capacity than the low copper content (x = 0.22) and larger crystallite size (similar to 19 nm) material. In addition, Cu xMnO y·nH 2O displays quasi-reversible electrochemistry in magnesium based electrolytes, indicating that copper birnessite could be a candidate for future application in magnesium-ion batteries.« less

Non-haloaluminate room-temperature ionic liquids in electrochemistry--a review.

PubMed

Buzzeo, Marisa C; Evans, Russell G; Compton, Richard G

2004-08-20

Some twenty-five years after they first came to prominence as alternative electrochemical solvents, room temperature ionic liquids (RTILs) are currently being employed across an increasingly wide range of chemical fields. This review examines the current state of ionic liquid-based electrochemistry, with particular focus on the work of the last decade. Being composed entirely of ions and possesing wide electrochemical windows (often in excess of 5 volts), it is not difficult to see why these compounds are seen by electrochemists as attractive potential solvents. Accordingly, an examination of the pertinent properties of ionic liquids is presented, followed by an assessment of their application to date across the various electrochemical disciplines, concluding with an outlook viewing current problems and directions.

Structural properties and electrochemistry of α-LiFeO2

NASA Astrophysics Data System (ADS)

Abdel-Ghany, A. E.; Mauger, A.; Groult, H.; Zaghib, K.; Julien, C. M.

2012-01-01

In this work, we study the physico-chemistry and electrochemistry of lithium ferrite synthesized by solid-state reaction. Characterization included X-ray diffraction (XRD), scanning electronic microscopy (SEM), Raman scattering (RS), Fourier transform infrared spectroscopy (FTIR), and SQUID magnetometry. XRD peaks gradually sharpen with increasing firing temperature; all the diffraction peaks can be indexed to the cubic α-LiFeO2 phase (Fm3m space group) with the refined cell parameter a = 4.155 Å. RS and FTIR spectra show the vibrational modes due to covalent Fe-O bonds and the Li-cage mode at low-frequency. The electrochemical properties of Li/LiFeO2 are revisited along with the post-mortem analysis of the positive electrode material using XRD and Raman experiments.

Electrochemistry of sulfur and polysulfides in ionic liquids.

PubMed

Manan, Ninie S A; Aldous, Leigh; Alias, Yatimah; Murray, Paul; Yellowlees, Lesley J; Lagunas, M Cristina; Hardacre, Christopher

2011-12-01

The electrochemistry of elemental sulfur (S(8)) and the polysulfides Na(2)S(4) and Na(2)S(6) has been studied for the first time in nonchloroaluminate ionic liquids. The cyclic voltammetry of S(8) in the ionic liquids is different to the behavior reported in some organic solvents, with two reductions and one oxidation peak observed. Supported by in situ UV-vis spectro-electrochemical experiments, the main reduction products of S(8) in [C(4)mim][DCA] ([C(4)mim] = 1-butyl-3-methylimidazolium; DCA = dicyanamide) have been identified as S(6)(2-) and S(4)(2-), and plausible pathways for the formation of these species are proposed. Dissociation and/or disproportionation of the polyanions S(6)(2-) and S(4)(2-) appears to be slow in the ionic liquid, with only small amounts of the blue radical species S(3)(•-) formed in the solutions at r.t., in contrast with that observed in most molecular solvents. © 2011 American Chemical Society

Physics Trends flyers & high school flyers

NASA Astrophysics Data System (ADS)

White, Susan C.

2016-03-01

Since 2000, we have published a series of flyers highlighting various data of interest to physics faculty members and students. For example, our Fall 2015 Physics Trends flyers display the employment sectors where physics bachelor's degree recipients work, the knowledge used frequently by mid-career PhD physicists working primarily in private sector jobs, and the proportion of women among physics faculty members. We have recently added a new resource for high school physics teachers: flyers focusing on high school physics. PDFs of both the Physics Trends and high school flyers are available for download at: www.aip.org/statistics/physics-trends and www.aip.org/statistics/highschool. We also have a limited number of printed copies of the Physics Trends flyers which we are happy to send to you upon request. We appreciate the responses from each of you who has helped us collect these data. Next month we will look at Hispanic representation among bachelor's degree recipients in physical sciences and engineering.

Minority participation in high school physics

NASA Astrophysics Data System (ADS)

White, Susan C.

2015-09-01

In the May 2014 issue of The Physics Teacher, we reported that 39% of high school seniors in the 2013 class took at least one high school physics course prior to graduation. (See TPT 52, 214-15.) This month we take a closer look at participation in high school physics by racial/ethnic group. As we see below, Asian students are most likely to take a high school physics course, while the participation of African-Americans and Hispanics remains below 30%. As we will see over the next few months, the lower participation can be explained, at least in part, by socioeconomic factors. About half of Hispanic seniors and almost 45% of African-American seniors were enrolled in schools where the student body was deemed as "worse off" than their peers by principals and teachers, and these "worse off" schools were less likely to offer physics. In October, we will look at high school physics enrollment by socioeconomic status of the student body.

Computing in high-energy physics

DOE PAGES

Mount, Richard P.

2016-05-31

I present a very personalized journey through more than three decades of computing for experimental high-energy physics, pointing out the enduring lessons that I learned. This is followed by a vision of how the computing environment will evolve in the coming ten years and the technical challenges that this will bring. I then address the scale and cost of high-energy physics software and examine the many current and future challenges, particularly those of management, funding and software-lifecycle management. Lastly, I describe recent developments aimed at improving the overall coherence of high-energy physics software.

Computing in high-energy physics

NASA Astrophysics Data System (ADS)

Mount, Richard P.

2016-04-01

I present a very personalized journey through more than three decades of computing for experimental high-energy physics, pointing out the enduring lessons that I learned. This is followed by a vision of how the computing environment will evolve in the coming ten years and the technical challenges that this will bring. I then address the scale and cost of high-energy physics software and examine the many current and future challenges, particularly those of management, funding and software-lifecycle management. Finally, I describe recent developments aimed at improving the overall coherence of high-energy physics software.

Computing in high-energy physics

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

Mount, Richard P.

I present a very personalized journey through more than three decades of computing for experimental high-energy physics, pointing out the enduring lessons that I learned. This is followed by a vision of how the computing environment will evolve in the coming ten years and the technical challenges that this will bring. I then address the scale and cost of high-energy physics software and examine the many current and future challenges, particularly those of management, funding and software-lifecycle management. Lastly, I describe recent developments aimed at improving the overall coherence of high-energy physics software.

Physical Activity Levels in Portuguese High School Physical Education

ERIC Educational Resources Information Center

Marmeleira, Jose Francisco Filipe; Aldeias, Nuno Micael Carrasqueira; da Graca, Pedro Miguel dos Santos Medeira

2012-01-01

The main aim of this study was to evaluate the physical activity (PA) levels of high school Portuguese students during physical education (PE) and investigate the association of PA levels with students' goal orientation and intrinsic motivation. Forty-six students from three high schools participated. Heart rate telemetry and pedometry were used…

Relative Effect of Lecture Method Supplemented with Music and Computer Animation on Senior Secondary School Students' Retention in Electrochemistry

ERIC Educational Resources Information Center

Akpoghol, T. V.; Ezeudu, F. O.; Adzape, J. N.; Otor, E. E.

2016-01-01

The study investigated the effects of Lecture Method Supplemented with Music (LMM) and Computer Animation (LMC) on senior secondary school students' retention in electrochemistry in Makurdi metropolis. Three research questions and three hypotheses guided the study. The design of the study was quasi experimental, specifically the pre-test,…

Electrochemistry of 1,1'-bis(2,4-dialkylphosphetanyl)ferrocene and 1,1'-bis(2,5-dialkylphospholanyl)ferrocene ligands: free phosphines, metal complexes, and chalcogenides.

PubMed

Mandell, Chelsea L; Kleinbach, Shannon S; Dougherty, William G; Kassel, W Scott; Nataro, Chip

2010-10-18

The oxidative electrochemistries of a series of chiral bisphosphinoferrocene ligands, 1,1'-bis(2,4-dialkylphosphetanyl)ferrocene (FerroTANE) and 1,1'-bis(2,5-dialkylphospholanyl)ferrocene (FerroLANE), were examined. The reversibility of the oxidation is sensitive to the steric bulk of the alkyl groups. New transition metal compounds and phosphine chalcogenides of these ligands were prepared and characterized. X-ray crystal structures of 10 of these compounds are reported. The percent buried volume (%V(bur)) is a recently developed measurement based on crystallographic data that examines the steric bulk of N-heterocyclic carbene and phosphine ligands. The %V(bur) for the FerroTANE and FerroLANE structures with methyl or ethyl substituents suggests these ligands are similar in steric properties to 1,1'-bis(diphenylphosphino)ferrocene (dppf). In addition the %V(bur) has been found to correlate well with the Tolman cone angle for phosphine chalcogenides. The oxidative electrochemistries of the transition metal complexes occur at more positive potentials than the free ligands. While a similar positive shift is seen for the oxidative electrochemistries of the phosphine chalcogenides, the oxidation of the phosphine selenides does not occur at the iron center, but rather oxidation occurs at the selenium atoms.

Effects of Lecture Method Supplemented with Music and Computer Animation on Senior Secondary School Students' Academic Achievement in Electrochemistry

ERIC Educational Resources Information Center

Akpoghol, T. V.; Ezeudu, F. O.; Adzape, J. N.; Otor, E. E.

2016-01-01

The study investigated the effects of Lecture Method Supplemented with Music (LMM) and Computer Animation (LMC) on senior secondary school students' academic achievement in electrochemistry in Makurdi metropolis. Six research questions and six hypotheses guided the study. The design of the study was quasi experimental, specifically the pre-test,…

Direct electrochemistry of glucose oxidase and biosensing for glucose based on boron-doped carbon nanotubes modified electrode.

PubMed

Deng, Chunyan; Chen, Jinhua; Chen, Xiaoli; Xiao, Chunhui; Nie, Lihua; Yao, Shouzhuo

2008-03-14

Due to their unique physicochemical properties, doped carbon nanotubes are now extremely attractive and important nanomaterials in bioanalytical applications. In this work, selecting glucose oxidase (GOD) as a model enzyme, we investigated the direct electrochemistry of GOD based on the B-doped carbon nanotubes/glassy carbon (BCNTs/GC) electrode with cyclic voltammetry. A pair of well-defined, quasi-reversible redox peaks of the immobilized GOD was observed at the BCNTs based enzyme electrode in 0.1M phosphate buffer solution (pH 6.98) by direct electron transfer between the protein and the electrode. As a new platform in glucose analysis, the new glucose biosensor based on the BCNTs/GC electrode has a sensitivity of 111.57 microA mM(-1)cm(-2), a linear range from 0.05 to 0.3mM and a detection limit of 0.01mM (S/N=3). Furthermore, the BCNTs modified electrode exhibits good stability and excellent anti-interferent ability to the commonly co-existed uric acid and ascorbic acid. These indicate that boron-doped carbon nanotubes are the good candidate material for the direct electrochemistry of the redox-active enzyme and the construction of the related enzyme biosensors.

Surface chemistry of bulk nanocrystalline pure iron and electrochemistry study in gas-flow physiological saline.

PubMed

Nie, F L; Zheng, Y F

2012-07-01

Conventional microcrystalline pure iron (MC-Fe) becomes a new candidate as biodegradable metals, which has the insufficient physical feature and inferior biodegradation behavior. Novel bulk nanocrystalline pure iron (NC-Fe) was fabricated via equal channel angular pressing technique in the present work to overcome these problems. The contact angle test with water and glycerol droplets shows a smaller angle (though >90°) of NC-Fe than that of MC-Fe, which implies a lower surface energy of NC-Fe. The surface roughness of NC-Fe increased greatly than that of MC-Fe. A further comparative study of corrosion and electrochemistry performance between NC-Fe and its original MC-Fe was investigated in physiological saline with different dissolved oxygen concentration, aiming to in vitro simulate the corrosion process of coronary stent occurred in physiological environment. The electrochemical impedance spectra analysis and anodic polarization measurements indicated that the NC-Fe exhibited higher corrosion resistance than that of the MC-Fe; meanwhile obvious enhanced corrosion resistance with the decrement of dissolved oxygen concentration was observed. Related equivalent circuit model and surface reconstruction process were further discussed, and the degradation mechanism of the MC-Fe and NC-Fe were finally established. Copyright © 2012 Wiley Periodicals, Inc.

The European Physical Society Conference on High Energy Physics

NASA Astrophysics Data System (ADS)

2017-07-01

The European Physical Society Conference on High Energy Physics (EPS- HEP) is one of the major international conferences that review the field. It takes place every other year since 1971. It is organized by the High Energy and Particle Physics Division of the European Physical Society in cooperation with an appointed European Local Institute of Research or an internationally recognized University or Academy Body. EPS-HEP 2017 was held on 5-12 July in Venice, Italy at Palazzo del Cinema and Palazzo del Casinò, located in the Lido island. The conference has been organized by the Istituto Nazionale di Fisica Nucleare (INFN) and by the Department of Physics and Astronomy of the University of Padova. Editorial Board: Paolo Checchia, Mauro Mezzetto, Giuseppina Salente, Michele Doro, Livia Conti, Caterina Braggio, Chiara Sirignano, Andrea Dainese, Martino Margoni, Roberto Rossin, Pierpaolo Mastrolia, Patrizia Azzi, Enrico Conti, Marco Zanetti, Luca Martucci, Sofia Talas Lucano Canton.

Phun Physics 4 Phemales: Physics Camp for High School Girls

NASA Astrophysics Data System (ADS)

Kwon, Chuhee; Gu, Jiyeong; Henriquez, Laura

2014-03-01

The department of Physics and Astronomy with the department of Science Education at California State University, Long Beach hosted summer program of ``Phun Physics 4 Phemales (PP4P)'' during summer 2012 and summer 2013 with the support from APS public outreach program. PP4P summer camp was hosted along with a two-week summer science camp, Young Scientists Camp, which has been institutionalized for the last 14 years since 1999. More than 2,500 3rd -8th grade students and 250 teachers have participated in the program. PP4P program provided the tools and support that female high school students need to pursue careers in physics and/or science, technology, engineering and math (STEM) field. This girls-only camp created connections among the girls and built confidence. In addition PP4P program introduced students to key principles in physics by a hands-on lab environment and demonstrated the real-world social impact of physics. In summer 2012, high school girls worked on physics experimental project on electronics and in summer 2013 they worked on the mechanics. I would share our experience in this program and the impact on the female high school students. This work was supported by 2012 Public Outreach and Informing the Public Grants from American Physical Society.

Preparing High School Physics Teachers.

ERIC Educational Resources Information Center

Green, Ben A., Jr.; And Others

Reported are (1) the status of preparation of physics teachers, and (2) recommendations for improving programs preparing physics teachers. The seriously declining high school physics enrollments are attributed, in part, to the shortage, or absence, of competent teachers. The effect this might have on the future supply of physicists is a major…

High School Physics, Two-Year Colleges, and Physics Majors

ERIC Educational Resources Information Center

White, Susan C.

2013-01-01

We have just completed the data collection for our 2012-13 Nationwide Survey of High School Physics and expect to have results to report in the spring. In the interim, we will take a look at physics in two-year colleges (TYCs). In 2007, we surveyed undergraduate seniors in degree-granting physics departments, and we asked these students if they…

High school physics and socioeconomics

NASA Astrophysics Data System (ADS)

White, Susan C.

2015-11-01

In our September column, we noted that Hispanic and African-American seniors were less likely to have taken a high school physics course than their peers, and we suggested that socioeconomic status (SES) played a role in the lower participation. In the figure, we display the proportion of seniors, of physics teachers, and of physics enrollments at schools by SES. While the number of seniors is roughly one-third in each group, physics enrollments differ dramatically by SES. Furthermore, the disparity in enrollments is greater than the disparity in physics teachers; this means that the teachers teaching physics at "better off" schools teach more physics than the physics teachers at "worse off" schools. Thus, a physics teacher at a "better off" school is more likely to teach a majority of their classes in physics.

Quantum Sensing for High Energy Physics

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

Ahmed, Zeeshan; et al.

Report of the first workshop to identify approaches and techniques in the domain of quantum sensing that can be utilized by future High Energy Physics applications to further the scientific goals of High Energy Physics.

Mathematical modeling of synthesis gas fueled electrochemistry and transport including H2/CO co-oxidation and surface diffusion in solid oxide fuel cell

NASA Astrophysics Data System (ADS)

Bao, Cheng; Jiang, Zeyi; Zhang, Xinxin

2015-10-01

Fuel flexibility is a significant advantage of solid oxide fuel cell (SOFC). A comprehensive macroscopic framework is proposed for synthesis gas (syngas) fueled electrochemistry and transport in SOFC anode with two main novelties, i.e. analytical H2/CO electrochemical co-oxidation, and correction of gas species concentration at triple phase boundary considering competitive absorption and surface diffusion. Staring from analytical approximation of the decoupled charge and mass transfer, we present analytical solutions of two defined variables, i.e. hydrogen current fraction and enhancement factor. Giving explicit answer (rather than case-by-case numerical calculation) on how many percent of the current output contributed by H2 or CO and on how great the water gas shift reaction plays role on, this approach establishes at the first time an adaptive superposition mechanism of H2-fuel and CO-fuel electrochemistry for syngas fuel. Based on the diffusion equivalent circuit model, assuming series-connected resistances of surface diffusion and bulk diffusion, the model predicts well at high fuel utilization by keeping fixed porosity/tortuosity ratio. The model has been validated by experimental polarization behaviors in a wide range of operation on a button cell for H2-H2O-CO-CO2-N2 fuel systems. The framework could be helpful to narrow the gap between macro-scale and meso-scale SOFC modeling.

Precision Crystal Calorimeters in High Energy Physics

ScienceCinema

Ren-Yuan Zhu

2017-12-09

Precision crystal calorimeters traditionally play an important role in high energy physics experiments. In the last two decades, it faces a challenge to maintain its precision in a hostile radiation environment. This paper reviews the performance of crystal calorimeters constructed for high energy physics experiments and the progress achieved in understanding crystal’s radiation damage as well as in developing high quality scintillating crystals for particle physics. Potential applications of new generation scintillating crystals of high density and high light yield, such as LSO and LYSO, in particle physics experiments is also discussed.

High school students' perceptions of physics

NASA Astrophysics Data System (ADS)

Checkley, Doug

There are far fewer high school students enrolled in physics than in chemistry or biology courses within the province of Alberta (Alberta Education, 2007). Students are also completing the highest level math course in larger numbers than those taking physics. It appears that a fear of physics exists within students in our province; this fear seems to be related to a level of difficulty the students associate with physics. Many students either opt to not take physics or enter the course with the expectation of failure. In this study I explored the impact of physics' reputation upon a group of students who chose not to take physics. In addition, I attempted to determine whether the perception of the difficulty of high school physics is accurate. This was done by investigating the perceptions of several students who took physics. I surveyed students from one high school in a small urban school district using group interviews. The students were in grades 10 to 12 and divided into groups of Science 10, Physics 20 and Physics 30 students. The students were interviewed to gain a deeper understanding of what perceptions they have about physics and why they may have them, hoping to identify factors that affect their academic decision to take or not take physics classes. For the students interviewed, I found that the biggest influence on their decisions to take or not take physics was related to their future aspirations. The students were also heavily influenced by their perceptions of physics. The students who took physics claimed that physics was not as difficult as they had believed it to be and they reported that it was interesting, enjoyable and relevant. Those students who had chosen to not take physics perceived it would be difficult, irrelevant and boring. Therefore, a major difference of perception exists between the students who took physics and those that did not.

Conceptual Difficulties Experienced by Prospective Teachers in Electrochemistry: Half-Cell Potential, Cell Potential, and Chemical and Electrochemical Equilibrium in Galvanic Cells.

ERIC Educational Resources Information Center

Ozkaya, Ali Riza

2002-01-01

A previous study of prospective teachers found that students from different countries and different levels of electrochemistry hold common misconceptions, indicating that concepts were presented to them poorly. Reports on how prospective teachers' scientifically incorrect ideas were used to form assertion-reason-type questions and how these…

Electrochemistry for the Generation of Renewable Chemicals: One-Pot Electrochemical Deoxygenation of Xylose to δ-Valerolactone.

PubMed

James, Olusola O; Sauter, Waldemer; Schröder, Uwe

2017-05-09

In this study, the electrochemical conversion of xylose to δ-valerolactone via carbonyl intermediates is demonstrated. The conversion was achieved in aqueous media and at ambient conditions. This study also demonstrates that the feedstock for production of renewable chemicals and biofuels through electrochemistry can be extended to primary carbohydrate molecules. This is the first report on a one-pot electrochemical deoxygenation of xylose to δ-valerolactone. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanopore Electrochemistry: A Nexus for Molecular Control of Electron Transfer Reactions

PubMed Central

2018-01-01

Pore-based structures occur widely in living organisms. Ion channels embedded in cell membranes, for example, provide pathways, where electron and proton transfer are coupled to the exchange of vital molecules. Learning from mother nature, a recent surge in activity has focused on artificial nanopore architectures to effect electrochemical transformations not accessible in larger structures. Here, we highlight these exciting advances. Starting with a brief overview of nanopore electrodes, including the early history and development of nanopore sensing based on nanopore-confined electrochemistry, we address the core concepts and special characteristics of nanopores in electron transfer. We describe nanopore-based electrochemical sensing and processing, discuss performance limits and challenges, and conclude with an outlook for next-generation nanopore electrode sensing platforms and the opportunities they present. PMID:29392173

Flare physics at high energies

NASA Technical Reports Server (NTRS)

Ramaty, R.

1990-01-01

High-energy processes, involving a rich variety of accelerated particle phenomena, lie at the core of the solar flare problem. The most direct manifestation of these processes are high-energy radiations, gamma rays, hard X-rays and neutrons, as well as the accelerated particles themselves, which can be detected in interplanetary space. In the study of astrophysics from the moon, the understanding of these processes should have great importance. The inner solar system environment is strongly influenced by activity on the sun; the physics of solar flares is of great intrinsic interest; and much high-energy astrophysics can be learned from investigations of flare physics at high energies.

Expedient preparation of nazlinine and a small library of indole alkaloids using flow electrochemistry as an enabling technology.

PubMed

Kabeshov, Mikhail A; Musio, Biagia; Murray, Philip R D; Browne, Duncan L; Ley, Steven V

2014-09-05

An expedient synthesis of the indole alkaloid nazlinine is reported. Judicious choice of flow electrochemistry as an enabling technology has permitted the rapid generation of a small library of unnatural relatives of this biologically active molecule. Furthermore, by conducting the key electrochemical Shono oxidation in a flow cell, the loading of electrolyte can be significantly reduced to 20 mol % while maintaining a stable, broadly applicable process.

ZnO/Cu nanocomposite: a platform for direct electrochemistry of enzymes and biosensing applications.

PubMed

Yang, Chi; Xu, Chunxiang; Wang, Xuemei

2012-03-06

Unique structured nanomaterials can facilitate the direct electron transfer between redox proteins and the electrodes. Here, in situ directed growth on an electrode of a ZnO/Cu nanocomposite was prepared by a simple corrosion approach, which enables robust mechanical adhesion and electrical contact between the nanostructured ZnO and the electrodes. This is great help to realize the direct electron transfer between the electrode surface and the redox protein. SEM images demonstrate that the morphology of the ZnO/Cu nanocomposite has a large specific surface area, which is favorable to immobilize the biomolecules and construct biosensors. Using glucose oxidase (GOx) as a model, this ZnO/Cu nanocomposite is employed for immobilization of GOx and the construction of the glucose biosensor. Direct electron transfer of GOx is achieved at ZnO/Cu nanocomposite with a high heterogeneous electron transfer rate constant of 0.67 ± 0.06 s(-1). Such ZnO/Cu nanocomposite provides a good matrix for direct electrochemistry of enzymes and mediator-free enzymatic biosensors.

Quantum Sensing for High Energy Physics

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

van Bibber, Karl; Boshier, Malcolm; Demarteau, Marcel

The Coordinating Panel for Advanced Detectors (CPAD) of the APS Division of Particles and Fields organized a first workshop on Quantum Sensing for High Energy Physics (HEP) in early December 2017 at Argonne National Laboratory. Participants from universities and national labs were drawn from the intersecting fields of Quantum Information Science (QIS), high energy physics, atomic, molecular and optical physics, condensed matter physics, nuclear physics and materials science. Quantum-enabled science and technology has seen rapid technical advances and growing national interest and investments over the last few years. The goal of the workshop was to bring the various communities togethermore » to investigate pathways to integrate the expertise of these two disciplines to accelerate the mutual advancement of scientific progress.« less

Influence of High School Physical Education on University Student's Physical Activity

ERIC Educational Resources Information Center

Kimball, Jessica; Jenkins, Jayne; Wallhead, Tristan

2009-01-01

The purpose of this study was to use the Lifelong Physical Activity (LLPA) framework to examine the influence of high school physical education (PE) on university students' level of physical activity (PA). Participants included 365 undergraduate students from the Rocky Mountain West of the USA enrolled in a university physical activity course.…

The Importance of High School Physics Teachers for Female Students' Physics Identity and Persistence

NASA Astrophysics Data System (ADS)

Hazari, Zahra; Brewe, Eric; Goertzen, Renee Michelle; Hodapp, Theodore

2017-02-01

Given the historic and continued underrepresentation of women in physics, it is important to understand the role that high school physics might play in attracting female students to physics careers. Drawing on data from over 900 female undergraduates in physics, we examine when these women became interested in physics careers and different sources of recognition (important for physics identity development) that may have affected their choices at certain time points. The results provide optimism since many of these female students, even those not previously intending science careers, began to intend physics careers in high school and recognition from high school physics teachers had a significant effect on predicting these intentions.

Bringing Technology into High School Physics Classrooms

NASA Astrophysics Data System (ADS)

Zettili, Nouredine

2005-04-01

In an effort to help high school physics teachers bring technology into their classrooms, we at JSU have been offering professional development to secondary education teachers. This effort is part of Project IMPACTSEED (IMproving Physics And Chemistry Teaching in SEcondary Education), a No-Child Left Behind (NCLB) grant funded by the Alabama Commission on Higher Education, serving high school physics teachers in Northeast Alabama. This project is motivated by a major pressing local need: A large number of high school physics teachers teach out of field. To achieve IMPACTSEED's goals, we have forged a functional collaboration with school districts from about ten counties. This collaboration is aimed at achieving a double aim: (a) to make physics and chemistry understandable and fun to learn within a hands-on, inquiry-based setting; (b) to overcome the fear- factor for physics and chemistry among students. Through a two-week long summer institute, a series of weekend technology workshops, and onsite support, we have been providing year-round support to the physics/chemistry teachers in this area. This outreach initiative has helped provide our students with a physics/chemistry education that enjoys a great deal of continuity and consistency from high school to college.

An Analysis of Metaphors Used by High School Students to Describe Physics, Physics Lesson and Physics Teacher

ERIC Educational Resources Information Center

Çetin, Ali

2016-01-01

The purpose of this study was to describe high school students' "physics", physics lesson" and "physics teacher" conceptions by using metaphors. 313 students participated in the study from different high school types in Siirt, Turkey. A metaphorical perception form constructed by researcher was individually conducted,…

2006 Electrochemistry Gordon Research Conference - February 12-17-2006

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

Abruna, Hector D.

The Gordon Research Conference (GRC) on Electrochemistry was held at Santa Ynez Valley Marriott, Buellton California from February 12-17, 2006. The Conference was well-attended with 113 participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. In designing the formal speakers program, emphasis was placed on current unpublished research and discussion of the future target areas in this field. There was a conscious effort to stimulate lively discussion about the key issues in the field today. Time formore » formal presentations was limited in the interest of group discussions. In order that more scientists could communicate their most recent results, poster presentation time was scheduled. Attached is a copy of the formal schedule and speaker program and the poster program. In addition to these formal interactions, "free time" was scheduled to allow informal discussions. Such discussions are fostering new collaborations and joint efforts in the field.« less

78 FR 50405 - High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-19

... DEPARTMENT OF ENERGY High Energy Physics Advisory Panel AGENCY: Office of Science, Department of..., General Services Administration, notice is hereby given that the High Energy Physics Advisory Panel will... Sciences Directorate (NSF), on long-range planning and priorities in the national high-energy physics...

76 FR 53119 - High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-25

... DEPARTMENT OF ENERGY High Energy Physics Advisory Panel AGENCY: Department of Energy. ACTION... hereby given that the High Energy Physics Advisory Panel will be renewed for a two-year period, beginning...-range planning and priorities in the national High Energy Physics program. Additionally, the renewal of...

Direct electrochemistry of Shewanella loihica PV-4 on gold nanoparticles-modified boron-doped diamond electrodes fabricated by layer-by-layer technique.

PubMed

Wu, Wenguo; Xie, Ronggang; Bai, Linling; Tang, Zuming; Gu, Zhongze

2012-05-01

Microbial Fuel Cells (MFCs) are robust devices capable of taping biological energy, converting pollutants into electricity through renewable biomass. The fabrication of nanostructured electrodes with good bio- and electrochemical activity, play a profound role in promoting power generation of MFCs. Au nanoparticles (AuNPs)-modified Boron-Doped Diamond (BDD) electrodes are fabricated by layer-by-layer (LBL) self-assembly technique and used for the direct electrochemistry of Shewanella loihica PV-4 in an electrochemical cell. Experimental results show that the peak current densities generated on the Au/PAH multilayer-modified BDD electrodes increased from 1.25 to 2.93 microA/cm(-2) as the layer increased from 0 to 6. Different cell morphologies of S. loihica PV-4 were also observed on the electrodes and the highest density of cells was attached on the (Au/PAH)6/BDD electrode with well-formed three-dimensional nanostructure. The electrochemistry of S. loihica PV-4 was enhanced on the (Au/PAH)4/BDD electrode due to the appropriate amount of AuNPsand thickness of PAH layer.

Graphene oxide electrochemistry: the electrochemistry of graphene oxide modified electrodes reveals coverage dependent beneficial electrocatalysis

PubMed Central

Smith, Graham C.

2017-01-01

The modification of electrode surfaces is widely implemented in order to try and improve electron transfer kinetics and surface interactions, most recently using graphene related materials. Currently, the use of ‘as is’ graphene oxide (GO) has been largely overlooked, with the vast majority of researchers choosing to reduce GO to graphene or use it as part of a composite electrode. In this paper, ‘as is’ GO is explored and electrochemically characterized using a range of electrochemical redox probes, namely potassium ferrocyanide(II), N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD), dopamine hydrochloride and epinephrine. Furthermore, the electroanalytical efficacy of GO is explored towards the sensing of dopamine hydrochloride and epinephrine via cyclic voltammetry. The electrochemical response of GO is benchmarked against pristine graphene and edge plane-/basal plane pyrolytic graphite (EPPG and BPPG respectively) alternatives, where the GO shows an enhanced electrochemical/electroanalytical response. When using GO as an electrode material, the electrochemical response of the analytes studied herein deviate from that expected and exhibit altered electrochemical responses. The oxygenated species encompassing GO strongly influence and dominate the observed voltammetry, which is crucially coverage dependent. GO electrocatalysis is observed, which is attributed to the presence of beneficial oxygenated species dictating the response in specific cases, demonstrating potential for advantageous electroanalysis to be realized. Note however, that crucial coverage based regions are observed at GO modified electrodes, owing to the synergy of edge plane sites and oxygenated species. We report the true beneficial electrochemistry of GO, which has enormous potential to be beneficially used in various electrochemical applications ‘as is’ rather than be simply used as a precursor to making graphene and is truly a fascinating member of the graphene family. PMID

Dispersion of nanocrystalline Fe 3O 4 within composite electrodes: Insights on battery-related electrochemistry

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

David C. Bock; Takeuchi, Kenneth J.; Pelliccione, Christopher J.

2016-04-20

Aggregation of nanosized materials in composite lithium-ion-battery electrodes can be a significant factor influencing electrochemical behavior. In this study, aggregation was controlled in magnetite, Fe 3O 4, composite electrodes via oleic acid capping and subsequent dispersion in a carbon black matrix. A heat treatment process was effective in the removal of the oleic acid capping agent while preserving a high degree of Fe 3O 4 dispersion. Electrochemical testing showed that Fe 3O 4 dispersion is initially beneficial in delivering a higher functional capacity, in agreement with continuum model simulations. However, increased capacity fade upon extended cycling was observed for themore » dispersed Fe 3O 4 composites relative to the aggregated Fe 3O 4 composites. X-ray absorption spectroscopy measurements of electrodes post cycling indicated that the dispersed Fe 3O 4 electrodes are more oxidized in the discharged state, consistent with reduced reversibility compared with the aggregated sample. Higher charge-transfer resistance for the dispersed sample after cycling suggests increased surface-film formation on the dispersed, high-surface-area nanocrystalline Fe 3O 4 compared to the aggregated materials. Furthermore, this study provides insight into the specific effects of aggregation on electrochemistry through a multiscale view of mechanisms for magnetite composite electrodes.« less

Dispersion of Nanocrystalline Fe 3 O 4 within Composite Electrodes: Insights on Battery-Related Electrochemistry

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

Bock, David C.; Pelliccione, Christopher J.; Zhang, Wei

2016-04-20

Aggregation of nanosized materials in composite lithium-ion-battery electrodes can be a significant factor influencing electrochemical behavior. In this study, aggregation was controlled in magnetite, Fe 3O 4, composite electrodes via oleic acid capping and subsequent dispersion in a carbon black matrix. A heat treatment process was effective in the removal of the oleic acid capping agent while preserving a high degree of Fe 3O 4 dispersion. Electrochemical testing showed that Fe 3O 4 dispersion is initially beneficial in delivering a higher functional capacity, in agreement with continuum model simulations. However, increased capacity fade upon extended cycling was observed for themore » dispersed Fe 3O 4 composites relative to the aggregated Fe 3O 4 composites. X-ray absorption spectroscopy measurements of electrodes post cycling indicated that the dispersed Fe 3O 4 electrodes are more oxidized in the discharged state, consistent with reduced reversibility compared with the aggregated sample. Higher charge-transfer resistance for the dispersed sample after cycling suggests increased surface-film formation on the dispersed, high-surface-area nanocrystalline Fe 3O 4 compared to the aggregated materials. This study provides insight into the specific effects of aggregation on electrochemistry through a multiscale view of mechanisms for magnetite composite electrodes.« less

High energy physics at UC Riverside

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

NONE

1997-07-01

This report discusses progress made for the following two tasks: experimental high energy physics, Task A, and theoretical high energy physics, Task B. Task A1 covers hadron collider physics. Information for Task A1 includes: personnel/talks/publications; D0: proton-antiproton interactions at 2 TeV; SDC: proton-proton interactions at 40 TeV; computing facilities; equipment needs; and budget notes. The physics program of Task A2 has been the systematic study of leptons and hadrons. Information covered for Task A2 includes: personnel/talks/publications; OPAL at LEP; OPAL at LEP200; CMS at LHC; the RD5 experiment; LSND at LAMPF; and budget notes. The research activities of the Theorymore » Group are briefly discussed and a list of completed or published papers for this period is given.« less

UPR/Mayaguez High Energy Physics

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

Mendez, Hector

This year the University of Puerto Rico at Mayaguez (UPRM) High Energy Physics (HEP) group continued with the ongoing research program outlined in the grant proposal. The program is centered on the Compact Muon Solenoid (CMS) experiment at the proton-proton (pp) collisions at the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland. The main research focus is on data analysis and on the preparation for the High Luminosity (HL) LHC or experiment detector upgrade. The physics data analysis included Higgs Doublet Search and measurement of the (1) Λ 0 b branching fraction, (2) B meson mass, and (3) hyperonmore » θ - b lifetime. The detector upgrade included work on the preparations for the Forward Pixel (FPIX) detector Silicon Sensor Testing in a production run at Fermilab. In addition, the group has taken responsibilities on the Software Release through our former research associate Dr. Eric Brownson who acted until last December as a Level Two Offline Manager for the CMS Upgrade. In support of the CMS data analysis activities carried out locally, the UPRM group has built and maintains an excellent Tier3 analysis center in Mayaguez. This allowed us to analyze large data samples and to continue the development of algorithms for the upgrade tracking robustness we started several years ago, and we plan to resume in the near future. This project involves computer simulation of the radiation damage to be suffered at the higher luminosities of the upgraded LHC. This year we continued to serve as a source of outstanding students for the field of high energy physics. Three of our graduate students finished their MS work in May, 2014, Their theses research were on data analysis of heavy quark b-physics. All of them are currently enrolled at Ph.D. physics program across the nation. One of them (Hector Moreno) at New Mexico University (Hector Moreno), one at University of New Hampshire (Sandra Santiesteban) and one at University of Puerto Rico-Rio Piedras (Carlos Malca

Examples from Astronomy for High School Physics

NASA Astrophysics Data System (ADS)

Dieterich, Sergio

2016-01-01

A formal course in physics is increasingly becoming a standard requirement in the high school curriculum. With that dissemination comes the challenge of reaching and motivating a population that is more diverse in their academic abilities and intrinsic motivation. The abstract nature of pure physics is often made more accessible when motivated by examples from everyday life, and providing copious mathematical as well as conceptual examples has become standard practice in high school physics textbooks. Astronomy is a naturally captivating subject and astronomical examples are often successful in capturing the curiosity of high school students as well as the general population. This project seeks to diversify the range of pedagogical materials available to the high school physics instructor by compiling and publishing specific examples where an astronomical concept can be used to motivate the physics curriculum. This collection of examples will consist of both short problems suitable for daily homework assignments as well as longer project style activities. Collaborations are encouraged and inquiries should be directed to sdieterich at carnegiescience dot edu.This work is funded by the NSF Astronomy and Astrophysics Postdoctoral Fellowship Program through NSF grant AST-1400680.

Korean Physical Society's Physics Camp for High School Girls

NASA Astrophysics Data System (ADS)

Park, Youngah; Yoon, Jin-Hee

2005-10-01

The Women's Committee of the Korean Physical Society organized physics camps during the summers of 2002, 2003, and 2004 for high school girls. The camps give the girls an opportunity to meet and interact with working physicists and enhance smart-girl networking. About 40 students in 10 teams visited excellent laboratories in universities and research institutes located in diverse areas of the country. The girls explored the work going on in each laboratory for a few days and participated in some basic experiments when possible. Afterward they gathered at the on-site camp for oral and poster presentations about what they learned and what they did in the laboratories they visited. Their presentations were evaluated and prizes awarded for outstanding teams. These camps were successful in terms of attracting many enthusiastic girl students and enhancing their interest in physics. The camps also showed the Korean physics community the importance of this kind of activity. To attract many girl students from various regions of the country, the Korean Physical Society co-organized the physics camp with the WISE (Women in Science and Engineering) Center, which has a network system for girl students interested in science and mathematics. The 2004 KPS-ASML-WISE Physics camp was supported by the ASML Foundation in the Netherlands.

High School Physics Courses & Enrollments: Results from the 2012-13 Nationwide Survey of High School Physics Teachers. Focus On

ERIC Educational Resources Information Center

White, Susan; Tesfaye, Casey Langer

2014-01-01

This report examines enrollments in high school physics during the 2012-13 school year. Based on data from the most recent survey (which includes both public and private high schools in the U.S.), it is estimated that 39% of the class of 2013 took high school physics before graduating. During the 2012-13 school year, 1.38 million students were…

Connecting High School Physics Experiences, Outcome Expectations, Physics Identity, and Physics Career Choice: A Gender Study

ERIC Educational Resources Information Center

Hazari, Zahra; Sonnert, Gerhard; Sadler, Philip M.; Shanahan, Marie-Claire

2010-01-01

This study explores how students' physics identities are shaped by their experiences in high school physics classes and by their career outcome expectations. The theoretical framework focuses on physics identity and includes the dimensions of student performance, competence, recognition by others, and interest. Drawing data from the Persistence…

Improving High School Physics Through An Outreach Initiative

NASA Astrophysics Data System (ADS)

Zettili, Nouredine

2006-04-01

We want to discuss our outreach initiative at Jacksonville State University designed to help improve the teaching of physics at a number of high schools in Northeast Alabama. This initiative is part of Project IMPACTSEED (IMproving Physics And Chemistry Teaching in SEcondary Education), a No-Child Left Behind grant funded by the Alabama Commission on Higher Education. This project is motivated by a major pressing local need: A large number of high school physics teachers teach out of field. IMPACTSEED is designed to achieve a double aim: (a) to make physics and chemistry understandable and fun to learn within a hands-on, inquiry-based setting; (b) to overcome the fear-factor for physics and chemistry among students. Through a two-week long summer institute, a series of weekend workshops designed to help bring technology into physics classrooms, onsite support, and a hotline, we have been providing year-round support to the physics/chemistry teachers in this area. IMPACTSEED aims at providing our students with a physics/chemistry education that enjoys a great deal of continuity and consistency from high school to college.

Improvement of capabilities of the Distributed Electrochemistry Modeling Tool for investigating SOFC long term performance

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

Gonzalez Galdamez, Rinaldo A.; Recknagle, Kurtis P.

2012-04-30

This report provides an overview of the work performed for Solid Oxide Fuel Cell (SOFC) modeling during the 2012 Winter/Spring Science Undergraduate Laboratory Internship at Pacific Northwest National Laboratory (PNNL). A brief introduction on the concept, operation basics and applications of fuel cells is given for the general audience. Further details are given regarding the modifications and improvements of the Distributed Electrochemistry (DEC) Modeling tool developed by PNNL engineers to model SOFC long term performance. Within this analysis, a literature review on anode degradation mechanisms is explained and future plans of implementing these into the DEC modeling tool are alsomore » proposed.« less

HIGH ENERGY PHYSICS: CERN Link Breathes Life Into Russian Physics.

PubMed

Stone, R

2000-10-13

Without fanfare, 600 Russian scientists here at CERN, the European particle physics laboratory, are playing key roles in building the Large Hadron Collider (LHC), a machine that will explore fundamental questions such as why particles have mass, as well as search for exotic new particles whose existence would confirm supersymmetry, a popular theory that aims to unify the four forces of nature. In fact, even though Russia is not one of CERN's 20 member states, most top high-energy physicists in Russia are working on the LHC. Some say their work could prove the salvation of high-energy physics back home.

Direct electrochemistry of nitrate reductase from the fungus Neurospora crassa.

PubMed

Kalimuthu, Palraj; Ringel, Phillip; Kruse, Tobias; Bernhardt, Paul V

2016-09-01

We report the first direct (unmediated) catalytic electrochemistry of a eukaryotic nitrate reductase (NR). NR from the filamentous fungus Neurospora crassa, is a member of the mononuclear molybdenum enzyme family and contains a Mo, heme and FAD cofactor which are involved in electron transfer from NAD(P)H to the (Mo) active site where reduction of nitrate to nitrite takes place. NR was adsorbed on an edge plane pyrolytic graphite (EPG) working electrode. Non-turnover redox responses were observed in the absence of nitrate from holo NR and three variants lacking the FAD, heme or Mo cofactor. The FAD response is due to dissociated cofactor in all cases. In the presence of nitrate, NR shows a pronounced cathodic catalytic wave with an apparent Michaelis constant (KM) of 39μM (pH7). The catalytic cathodic current increases with temperature from 5 to 35°C and an activation enthalpy of 26kJmol(-1) was determined. In spite of dissociation of the FAD cofactor, catalytically activity is maintained. Copyright © 2016. Published by Elsevier B.V.

Gender Differences in Introductory University Physics Performance: The Influence of High School Physics Preparation and Affect

NASA Astrophysics Data System (ADS)

Hazari, Zahra

2006-12-01

The attrition of females studying physics after high school has been a continuing concern for the physics education community. If females are well prepared, feel confident, and do well in introductory college physics, they may be inclined to study physics further. This quantitative study uses HLM to identify factors from high school physics preparation (content, pedagogy, and assessment) and the affective domain that predict female and male performance in introductory college physics. The study includes controls for student demographic and academic background characteristics, and the final dataset consists of 1973 surveys from 54 introductory college physics classes. The results highlight high school physics and affective experiences that differentially predict female and male performance. These experiences include: learning requirements, computer graphing/analysis, long written problems, everyday world examples, community projects cumulative tests/quizzes, father's encouragement, family's belief that science leads to a better career, and the length of time students believe that high school physics would help in university physics. There were also experiences that similarly predict female and male performance. The results paint a dynamic picture of the factors from high school physics and the affective domain that influence the future physics performance of females and males. The implication is that there are many aspects to the teaching of physics in high school that, although widely used and thought to be effective, need reform in their implementation in order to be fully beneficial to females and/or males in college.

Who's Teaching What in High School Physics?

ERIC Educational Resources Information Center

White, Susan; Tyler, John

2015-01-01

During the 2012-13 school year, approximately 27,000 teachers taught at least one physics course in a U.S. high school. About one-third of those teachers have earned a degree in physics or physics education; the vast majority of the others have earned degrees in a variety of other science fields. About 53,000 physics classes were taught, ranging…

The Association Between Participation in High School Physical Education and Physical Fitness in Young Men

DTIC Science & Technology

2004-08-13

control education to be introduced at the high school level, to enable young adults to make good choices about their fitness and health . The...NAVAL HEALTH RESEARCH CENTER THE ASSOCIATION BETWEEN PARTICIPATION IN HIGH SCHOOL PHYSICAL EDUCATION AND PHYSICAL FITNESS IN YOUNG MEN...duration of physical activity programs for high school- aged students. Keywords: injury, military High School and Fitness in Young Men 3 The

AAPT/NSTA High School Physics Examination.

ERIC Educational Resources Information Center

Nelson, James

1983-01-01

Discusses development of the American Association of Physics Teachers and National Science Teachers Association (AAPT/NSTA) high school physics examination. Includes sample examination questions and distribution of topics: mechanics (30 percent), waves/optics/sound (20 percent), heat/kinetic theory (10 percent), electricity/magnetism (25 percent),…

High-Productivity Computing in Computational Physics Education

NASA Astrophysics Data System (ADS)

Tel-Zur, Guy

2011-03-01

We describe the development of a new course in Computational Physics at the Ben-Gurion University. This elective course for 3rd year undergraduates and MSc. students is being taught during one semester. Computational Physics is by now well accepted as the Third Pillar of Science. This paper's claim is that modern Computational Physics education should deal also with High-Productivity Computing. The traditional approach of teaching Computational Physics emphasizes ``Correctness'' and then ``Accuracy'' and we add also ``Performance.'' Along with topics in Mathematical Methods and case studies in Physics the course deals a significant amount of time with ``Mini-Courses'' in topics such as: High-Throughput Computing - Condor, Parallel Programming - MPI and OpenMP, How to build a Beowulf, Visualization and Grid and Cloud Computing. The course does not intend to teach neither new physics nor new mathematics but it is focused on an integrated approach for solving problems starting from the physics problem, the corresponding mathematical solution, the numerical scheme, writing an efficient computer code and finally analysis and visualization.

Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise.

PubMed

Rapp, Teresa L; Phillips, Susan R; Dmochowski, Ivan J

2016-12-13

The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, light-driven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes that provide a sterically bulky, photolabile moiety for transiently "caging" biologically active molecules. Photouncaging involves the use of visible (1-photon) or near-IR (2-photon) light to break one or more bonds between ruthenium and coordinated ligand(s), which can occur on short time scales and in high quantum yields. In this work we demonstrate the use of a model "caged" acetonitrile complex, Ru(2,2'-bipyridine) 2 (acetonitrile) 2 , or RuMeCN in an advanced synthesis and physical chemistry laboratory. Students made RuMeCN in an advanced synthesis laboratory course and performed UV-vis spectroscopy and electrochemistry. The following semester students investigated RuMeCN photolysis kinetics in a physical chemistry laboratory. These two exercises may also be combined to create a 2-week module in an advanced undergraduate laboratory course.

Kinetics and Photochemistry of Ruthenium Bisbipyridine Diacetonitrile Complexes: An Interdisciplinary Inorganic and Physical Chemistry Laboratory Exercise

PubMed Central

2016-01-01

The study of ruthenium polypyridyl complexes can be widely applied across disciplines in the undergraduate curriculum. Ruthenium photochemistry has advanced many fields including dye-sensitized solar cells, photoredox catalysis, light-driven water oxidation, and biological electron transfer. Equally promising are ruthenium polypyridyl complexes that provide a sterically bulky, photolabile moiety for transiently “caging” biologically active molecules. Photouncaging involves the use of visible (1-photon) or near-IR (2-photon) light to break one or more bonds between ruthenium and coordinated ligand(s), which can occur on short time scales and in high quantum yields. In this work we demonstrate the use of a model “caged” acetonitrile complex, Ru(2,2′-bipyridine)2(acetonitrile)2, or RuMeCN in an advanced synthesis and physical chemistry laboratory. Students made RuMeCN in an advanced synthesis laboratory course and performed UV–vis spectroscopy and electrochemistry. The following semester students investigated RuMeCN photolysis kinetics in a physical chemistry laboratory. These two exercises may also be combined to create a 2-week module in an advanced undergraduate laboratory course. PMID:28649139

Electrochemistry in Near-Critical and Supercritical Fluids. 4. Nitrogen Heterocycles, Nitrobenzene, and Solvated Electrons in Ammonia at Temperatures to 150C.

DTIC Science & Technology

1986-09-01

of pyraz ne quinoxaline, phenazine and solvated electrons in near-critical and supercritical ammonia was investigated by cycU-i Voltanimetry and...Crooks and Allen J. Bard Department of Chemistry, University of Texas Austin, Texas 78712 ABSTRACT The electrochemistry of pyrazine, quinoxaline, phenazine ...in liquid ammonia at -40° C. The reductions of pyrazine, quinoxaline and phenazine at room temperature, and in the supercritical fluid (SCF), occur

Energetics of the Semiconductor-Electrolyte Interface.

ERIC Educational Resources Information Center

Turner, John A.

1983-01-01

The use of semiconductors as electrodes for electrochemistry requires an understanding of both solid-state physics and electrochemistry, since phenomena associated with both disciplines are seen in semiconductor/electrolyte systems. The interfacial energetics of these systems are discussed. (JN)

Structure and electrochemistry of proteins harboring iron-sulfur clusters of different nuclearities. Part II. [4Fe-4S] and [3Fe-4S] iron-sulfur proteins.

PubMed

Zanello, Piero

2018-06-01

In the context of the plethora of proteins harboring iron-sulfur clusters we have already reviewed structure/electrochemistry of metalloproteins expressing single types of iron-sulfur clusters (namely: {Fe(Cys) 4 }, {[Fe 2 S 2 ](Cys) 4 }, {[Fe 2 S 2 ](Cys) 3 (X)} (X = Asp, Arg, His), {[Fe 2 S 2 ](Cys) 2 (His) 2 }, {[Fe 3 S 4 ](Cys) 3 }, {[Fe 4 S 4 ](Cys) 4 } and {[Fe 4 S 4 ](S γ Cys ) 3 (nonthiolate ligand)} cores) and their synthetic analogs. More recently we are focussing on structure/electrochemistry of metalloproteins harboring iron-sulfur centres of different nuclearities. Having started such a subject with proteins harboring [4Fe-4S] and [2Fe-2S] clusters, we now depict the state of art of proteins containing [4Fe-4S] and [3Fe-4S] clusters. Copyright © 2018 Elsevier Inc. All rights reserved.

Observation of nanometer-sized electro-active defects in insulating layers by fluorescence microscopy and electrochemistry.

PubMed

Renault, Christophe; Marchuk, Kyle; Ahn, Hyun S; Titus, Eric J; Kim, Jiyeon; Willets, Katherine A; Bard, Allen J

2015-06-02

We report a method to study electro-active defects in passivated electrodes. This method couples fluorescence microscopy and electrochemistry to localize and size electro-active defects. The method was validated by comparison with a scanning probe technique, scanning electrochemical microscopy. We used our method for studying electro-active defects in thin TiO2 layers electrodeposited on 25 μm diameter Pt ultramicroelectrodes (UMEs). The permeability of the TiO2 layer was estimated by measuring the oxidation of ferrocenemethanol at the UME. Blocking of current ranging from 91.4 to 99.8% was achieved. Electro-active defects with an average radius ranging between 9 and 90 nm were observed in these TiO2 blocking layers. The distribution of electro-active defects over the TiO2 layer is highly inhomogeneous and the number of electro-active defect increases for lower degree of current blocking. The interest of the proposed technique is the possibility to quickly (less than 15 min) image samples as large as several hundreds of μm(2) while being able to detect electro-active defects of only a few tens of nm in radius.

Guidelines for High School Physics Programs

ERIC Educational Resources Information Center

American Association of Physics Teachers (NJ1), 2002

2002-01-01

The American Association of Physics Teachers (AAPT) developed this document as a resource for high school administrators, parents, and teachers who are interested in developing guidelines for physics curriculum and instruction in their school(s). These guidelines reflect the goals of the AAPT, with an emphasis on instructional strategies and…

Magnesium-ion battery-relevant electrochemistry of MgMn 2O 4: crystallite size effects and the notable role of electrolyte water content

DOE PAGES

Yin, Jiefu; Brady, Alexander B.; Takeuchi, Esther S.; ...

2017-03-06

MgMn 2O 4 nanoparticles with crystallite sizes of 11 (MMO-1) and 31 nm (MMO-2) were synthesized and their magnesium-ion battery-relevant electrochemistry was investigated. Here, MMO-1 delivered an initial capacity of 220 mA h g –1 (678 mW h g –1). Electrolyte water content had a profound effect on cycle retention.

Integration of electrochemistry with ultra-performance liquid chromatography/mass spectrometry.

PubMed

Cai, Yi; Zheng, Qiuling; Liu, Yong; Helmy, Roy; Loo, Joseph A; Chen, Hao

2015-01-01

This study presents the development of ultra-performance liquid chromatography (UPLC) mass spectrometry (MS) combined with electrochemistry (EC) for the first time and its application for the structural analysis of proteins/peptides that contain disulfide bonds. In our approach, a protein/peptide mixture sample undergoes a fast UPLC separation and subsequent electrochemical reduction in an electrochemical flow cell followed by online MS and tandem mass spectrometry (MS/MS) analyses. The electrochemical cell is coupled to the mass spectrometer using our recently developed desorption electrospray ionization (DESI) interface. Using this UPLC/EC/DESI-MS method, peptides that contain disulfide bonds can be differentiated from those without disulfide bonds, as the former are electroactive and reducible. MS/MS analysis of the disulfide-reduced peptide ions provides increased information on the sequence and disulfide-linkage pattern. In a reactive DESI- MS detection experiment in which a supercharging reagent was used to dope the DESI spray solvent, increased charging was obtained for the UPLC-separated proteins. Strikingly, upon online electrolytic reduction, supercharged proteins (e.g., α-lactalbumin) showed even higher charging, which will be useful in top- down protein structure MS analysis as increased charges are known to promote protein ion dissociation. Also, the separation speed and sensitivity are enhanced by approximately 1(~)2 orders of magnitude by using UPLC for the liquid chromatography (LC)/EC/MS platform, in comparison to the previously used high- performance liquid chromatography (HPLC). This UPLC/EC/DESI-MS method combines the power of fast UPLC separation, fast electrochemical conversion, and online MS structural analysis for a potentially valuable tool for proteomics research and bioanalysis.

Synthesis, characterization and electrochemistry studies of iron(III) complex with curcumin ligand.

PubMed

Özbolat, Gülüzar; Yegani, Arash Alizadeh; Tuli, Abdullah

2018-05-11

Iron overload is a serious clinical condition for humans and is a key target in drug development. The aim of this study was to investigate the coordination of iron(III) ions with curcumin ligand that may be used in the treatment of iron overload. Iron(III) complex of curcumin was synthesized and structurally characterized in its solid and solution state by FT-IR, UV-Vis, elemental analysis, and magnetic susceptibility. Electrochemical behaviour of the ligand and the complexes were examined using cyclic voltammetry. The cytotoxic activities of the ligand and the iron(III) complex were evaluated by the MTT assay. Curcumin reacted with iron in high concentrations at physiological pH at room temperature. Subsequently, a brown-red complex was formed. Data regarding magnetic susceptibility showed that the complexes with a 1:2 (metal/ligand) mole ratio had octahedral geometry. The complex showed higher anti-oxidant effect towards the cell line ECV304 at IC 50 values of 4.83 compared to curcumin. The complex exhibited very high cytotoxic activity and showed a cytotoxic effect that was much better than that of the ligand. The potentials for redox were calculated as 0.180 V and 0.350 V, respectively. The electrochemistry studies showed that Fe 3+ /Fe 2+ couple redox process occurred at low potentials. This value was within the range of compounds that are expected to show superoxide dismutase activity. This finding indicates that the iron complex is capable of removing free radicals. The observed cytotoxicity could be pursued to obtain a potential drug. Further studies investigating the use of curcumin for this purpose are needed. © 2018 John Wiley & Sons Australia, Ltd.

The electrode/ionic liquid interface: electric double layer and metal electrodeposition.

PubMed

Su, Yu-Zhuan; Fu, Yong-Chun; Wei, Yi-Min; Yan, Jia-Wei; Mao, Bing-Wei

2010-09-10

The last decade has witnessed remarkable advances in interfacial electrochemistry in room-temperature ionic liquids. Although the wide electrochemical window of ionic liquids is of primary concern in this new type of solvent for electrochemistry, the unusual bulk and interfacial properties brought about by the intrinsic strong interactions in the ionic liquid system also substantially influence the structure and processes at electrode/ionic liquid interfaces. Theoretical modeling and experimental characterizations have been indispensable in reaching a microscopic understanding of electrode/ionic liquid interfaces and in elucidating the physics behind new phenomena in ionic liquids. This Minireview describes the status of some aspects of interfacial electrochemistry in ionic liquids. Emphasis is placed on high-resolution and molecular-level characterization by scanning tunneling microscopy and vibrational spectroscopies of interfacial structures, and the initial stage of metal electrodeposition with application in surface nanostructuring.

The Importance of High School Physics Teachers for Female Students' Physics Identity and Persistence

ERIC Educational Resources Information Center

Hazari, Zahra; Brewe, Eric; Goertzen, Renee Michelle; Hodapp, Theodore

2017-01-01

Given the historic and continued underrepresentation of women in physics, it is important to understand the role that high school physics might play in attracting female students to physics careers. Drawing on data from over 900 female undergraduates in physics, we examine when these women became interested in physics careers and different sources…

Material science and Condensed matter Physics. 8th International Conference. Abstracts.

NASA Astrophysics Data System (ADS)

Kulyuk, L. L.; Paladi, Florentin; Canter, Valeriu; Nikorich, Valentina; Filippova, Irina

2016-08-01

The book includes the abstracts of the communications presented at the 8th International Conference on Materials Science and Condensed Matter Physics (MSCMP 2016), a traditional biennial meeting organized by the Institute of Applied Physics of the Academy of Sciences of Moldova (IAP).A total of 346 abstracts has been included in the book. The Conference programm included plenary lectures, topical keynote lectures, contributed oral and poster presentations distributed into 7 sections: * Condensed Matter Theory; * Advanced Bulk Materials; * Design and Structural Characterization of Materials; * Solid State Nanophysics and Nanotechnology; * Energy Conversion and Storage. Solid State Devices; * Surface Engineering and Applied Electrochemistry; * Digital and Optical holography: Materials and Methods. The abstracts are arranged according to the sections mentioned above. The Abstracts book includes a table of matters at the beginning of the book and an index of authors at the finish of the book.

Light Emission Mechanisms in CuInS 2 Quantum Dots Evaluated by Spectral Electrochemistry

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

Fuhr, Addis S.; Yun, Hyeong Jin; Makarov, Nikolay S.

Luminescent CuInS 2 (CIS) quantum dots (QDs) exhibit highly efficient intragap emission and long, hundreds-of-nanoseconds radiative lifetimes. These spectral properties, distinct from structurally similar II–VI QDs, can be explained by the involvement of intragap defect states containing a localized hole capable of coupling with a conduction band electron for a radiative transition. However, the absolute energies of the intragap and band-edge states, the structure of the emissive defect(s), and the role and origin of nonemissive decay channels still remain poorly understood. Here, we address these questions by applying methods of spectral electrochemistry. Cyclic voltammetry measurements reveal a well-defined intragap statemore » whose redox potential is close to that of the Cu x defect state (where x = 1+ or 2+). The energy offset of this state from the valence band accounts well for the apparent photoluminescence Stokes shift observed in optical spectra. These results provide direct evidence that Cu-related defects serve as emission centers responsible for strong intragap emission from CIS QDs. We then use in situ spectroelectrochemistry to reveal two distinct emission pathways based on the differing oxidation states of Cu defects, which can be controlled by altering QD stoichiometry (1+ for stoichiometric QDs and 2+ for Cu-deficient QDs).« less

Forensic electrochemistry: indirect electrochemical sensing of the components of the new psychoactive substance "Synthacaine".

PubMed

Cumba, Loanda R; Kolliopoulos, Athanasios V; Smith, Jamie P; Thompson, Paul D; Evans, Peter R; Sutcliffe, Oliver B; do Carmo, Devaney R; Banks, Craig E

2015-08-21

"Synthacaine" is a New Psychoactive Substance which is, due to its inherent psychoactive properties, reported to imitate the effects of cocaine and is therefore consequently branded as "legal cocaine". The only analytical approach reported to date for the sensing of "Synthacaine" is mass spectrometry. In this paper, we explore and evaluate a range of potential analytical techniques for its quantification and potential use in the field screening "Synthacaine" using Raman spectroscopy, presumptive (colour) testing, High Performance Liquid Chromatography (HPLC) and electrochemistry. HPLC analysis of street samples reveals that "Synthacaine" comprises a mixture of methiopropamine (MPA) and 2-aminoindane (2-AI). Raman spectroscopy and presumptive (colour) tests, the Marquis, Mandelin, Simon's and Robadope test, are evaluated towards a potential in-the-field screening approach but are found to not be able to discriminate between the two when they are both present in the same sample, as is the case in the real street samples. We report for the first time a novel indirect electrochemical protocol for the sensing of MPA and 2-AI which is independently validated in street samples with HPLC. This novel electrochemical approach based upon one-shot disposable cost effective screen-printed graphite macroelectrodes holds potential for in-the-field screening for "Synthacaine".

Tetramer model of leukoemeraldine-emeraldine electrochemistry in the presence of trihalogenoacetic acids. DFT approach.

PubMed

Barbosa, Nuno Almeida; Grzeszczuk, Maria; Wieczorek, Robert

2015-01-15

First results of the application of the DFT computational approach to the reversible electrochemistry of polyaniline are presented. A tetrameric chain was used as the simplest model of the polyaniline polymer species. The system under theoretical investigation involved six tetramer species, two electrons, and two protons, taking part in 14 elementary reactions. Moreover, the tetramer species were interacting with two trihalogenoacetic acid molecules. Trifluoroacetic, trichloroacetic, and tribromoacetic acids were found to impact the redox transformation of polyaniline as shown by cyclic voltammetry. The theoretical approach was considered as a powerful tool for investigating the main factors of importance for the experimental behavior. The DFT method provided molecular structures, interaction energies, and equilibrium energies of all of the tetramer-acid complexes. Differences between the energies of the isolated tetramer species and their complexes with acids are discussed in terms of the elementary reactions, that is, ionization potentials and electron affinities, equilibrium constants, electrode potentials, and reorganization energies. The DFT results indicate a high impact of the acid on the reorganization energy of a particular elementary electron-transfer reaction. The ECEC oxidation path was predicted by the calculations. The model of the reacting system must be extended to octamer species and/or dimeric oligomer species to better approximate the real polymer situation.

Light Emission Mechanisms in CuInS 2 Quantum Dots Evaluated by Spectral Electrochemistry

DOE PAGES

Fuhr, Addis S.; Yun, Hyeong Jin; Makarov, Nikolay S.; ...

2017-09-07

Luminescent CuInS 2 (CIS) quantum dots (QDs) exhibit highly efficient intragap emission and long, hundreds-of-nanoseconds radiative lifetimes. These spectral properties, distinct from structurally similar II–VI QDs, can be explained by the involvement of intragap defect states containing a localized hole capable of coupling with a conduction band electron for a radiative transition. However, the absolute energies of the intragap and band-edge states, the structure of the emissive defect(s), and the role and origin of nonemissive decay channels still remain poorly understood. Here, we address these questions by applying methods of spectral electrochemistry. Cyclic voltammetry measurements reveal a well-defined intragap statemore » whose redox potential is close to that of the Cu x defect state (where x = 1+ or 2+). The energy offset of this state from the valence band accounts well for the apparent photoluminescence Stokes shift observed in optical spectra. These results provide direct evidence that Cu-related defects serve as emission centers responsible for strong intragap emission from CIS QDs. We then use in situ spectroelectrochemistry to reveal two distinct emission pathways based on the differing oxidation states of Cu defects, which can be controlled by altering QD stoichiometry (1+ for stoichiometric QDs and 2+ for Cu-deficient QDs).« less

High School Physics Textbooks, Resources and Teacher Resourcefulness: Results from the 2012-13 Nationwide Survey of High School Physics Teachers. Focus On

ERIC Educational Resources Information Center

Tesfaye, Casey Langer; White, Susan

2014-01-01

What textbooks are physics teachers using? How highly do they rate those textbooks? What other types of materials do teachers use? The textbooks and other resources used by high school physics teachers in the US have evolved along with the changing demands of physics classes and the evolving set of options available to teachers. In this report,…

Electrochemistry of moexipril: experimental and computational approach and voltammetric determination.

PubMed

Taşdemir, Hüdai I; Kiliç, E

2014-09-01

The electrochemistry of moexipril (MOE) was studied by electrochemical methods with theoretical calculations performed at B3LYP/6-31 + G (d)//AM1. Cyclic voltammetric studies were carried out based on a reversible and adsorption-controlled reduction peak at -1.35 V on a hanging mercury drop electrode (HMDE). Concurrently irreversible diffusion-controlled oxidation peak at 1.15 V on glassy carbon electrode (GCE) was also employed. Potential values are according to Ag/AgCI, (3.0 M KCI) and measurements were performed in Britton-Robinson buffer of pH 5.5. Tentative electrode mechanisms were proposed according to experimental results and ab-initio calculations. Square-wave adsorptive stripping voltammetric methods have been developed and validated for quantification of MOE in pharmaceutical preparations. Linear working range was established as 0.03-1.35 microM for HMDE and 0.2-20.0 microM for GCE. Limit of quantification (LOQ) was calculated to be 0.032 and 0.47 microM for HMDE and GCE, respectively. Methods were successfully applied to assay the drug in tablets by calibration and standard addition methods with good recoveries between 97.1% and 106.2% having relative standard deviation less than 10%.

Gender differences in introductory university physics performance: The influence of high school physics preparation and affect

NASA Astrophysics Data System (ADS)

Hazari, Zahra Sana

The attrition of females studying physics after high school is a concern to the science education community. Most undergraduate science programs require introductory physics coursework. Thus, success in introductory physics is necessary for students to progress to higher levels of science study. Success also influences attitudes; if females are well-prepared, feel confident, and do well in introductory physics, they may be inclined to study physics further. This quantitative study using multilevel modeling focused on determining factors from high school physics preparation (content, pedagogy, and assessment) and the affective domain that influenced female and male performance in introductory university physics. The study controlled for some university/course level characteristics as well as student demographic and academic background characteristics. The data consisted of 1973 surveys from 54 introductory physics courses within 35 universities across the US. The results highlight high school physics and affective experiences that differentially influenced female and male performance. These experiences include: learning requirements, computer graphing/analysis, long written problems, everyday world examples, community projects, cumulative tests/quizzes, father's encouragement, family's belief that science leads to a better career, and the length of time students believed that high school physics would help in university physics. There were also experiences that had a similar influence on female and male performance. Positively related to performance were: covering fewer topics for longer periods of time, the history of physics as a recurring topic, physics-related videos, and test/quiz questions that involved calculations and/or were drawn from standardized tests. Negatively related to performance were: student-designed projects, reading/discussing labs the day before performing them, microcomputer based laboratories, discussion after demonstrations, and family

75 FR 63450 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-15

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Department of Energy.../NSF High Energy Physics Advisory Panel (HEPAP). Federal Advisory Committee Act (Pub. L. 92-463, 86... 20852. FOR FURTHER INFORMATION CONTACT: John Kogut, Executive Secretary; High Energy Physics Advisory...

Effective Practices for Training and Inspiring High School Physics Teachers

NASA Astrophysics Data System (ADS)

Magee-Sauer, Karen

It is well-documented that there is a nationwide shortage of highly qualified high school physics teachers. Not surprising, institutions of higher education report that the most common number of physics teacher graduates is zero with the majority of institutions graduating less than two physics teachers per year. With these statistics in mind, it is critical that institutions take a careful look at how they recruit, train, and contribute to the retention of high school physics teachers. PhysTEC is a partnership between the APS and AAPT that is dedicated to improving and promoting the education of high school physics teachers. Primarily funded by the NSF and its partnering organizations, PhysTEC has identified key components that are common to successful physics teacher preparation programs. While creating a successful training program in physics, it is also important that students have the opportunity for a ``do-able'' path to certification that does not add further financial debt. This talk will present an overview of ``what works'' in creating a path for physics majors to a high school physics teaching career, actions and activities that help train and inspire pre-service physics teachers, and frameworks that provide the support for in-service teachers. Obstacles to certification and the importance of a strong partnership with colleges of education will be discussed. Several examples of successful physics high school teacher preparation programs will be presented. This material is part of the Physics Teacher Education Coalition project, which is based upon work supported by the National Science Foundation under Grant Nos. 0808790, 0108787, and 0833210.

78 FR 46330 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Office of Science... High Energy Physics Advisory Panel (HEPAP). Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat... CONTACT: John Kogut, Executive Secretary; High Energy Physics Advisory Panel; U.S. Department of Energy...

76 FR 19986 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-11

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Department of Energy.../NSF High Energy Physics Advisory Panel (HEPAP). The Federal Advisory Committee Act (Pub. L. 92-463, 86... FURTHER INFORMATION CONTACT: John Kogut, Executive Secretary; High Energy Physics Advisory Panel; U.S...

On the importance of identifying, characterizing, and predicting fundamental phenomena towards microbial electrochemistry applications.

PubMed

Torres, César Iván

2014-06-01

The development of microbial electrochemistry research toward technological applications has increased significantly in the past years, leading to many process configurations. This short review focuses on the need to identify and characterize the fundamental phenomena that control the performance of microbial electrochemical cells (MXCs). Specifically, it discusses the importance of recent efforts to discover and characterize novel microorganisms for MXC applications, as well as recent developments to understand transport limitations in MXCs. As we increase our understanding of how MXCs operate, it is imperative to continue modeling efforts in order to effectively predict their performance, design efficient MXC technologies, and implement them commercially. Thus, the success of MXC technologies largely depends on the path of identifying, understanding, and predicting fundamental phenomena that determine MXC performance. Copyright © 2013 Elsevier Ltd. All rights reserved.

77 FR 4027 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-26

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Department of Energy.../NSF High Energy Physics Advisory Panel (HEPAP). The Federal Advisory Committee Act (Pub. L. 92-463, 86... Secretary; High Energy Physics Advisory Panel; U.S. Department of Energy; SC-25/ Germantown Building, 1000...

76 FR 8358 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-14

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Department of Energy.../NSF High Energy Physics Advisory Panel (HEPAP). Federal Advisory Committee Act (Pub. L. 92-463, 86... Secretary; High Energy Physics Advisory Panel; U.S. Department of Energy; SC-25/ Germantown Building, 1000...

75 FR 57463 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-21

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Department of Energy.../NSF High Energy Physics Advisory Panel (HEPAP). Federal Advisory Committee Act (Pub. L. 92-463, 86... Secretary; High Energy Physics Advisory Panel; U.S. Department of Energy; SC-25/ Germantown Building, 1000...

78 FR 69839 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-21

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Department of Energy.../NSF High Energy Physics Advisory Panel (HEPAP). The Federal Advisory Committee Act (Pub. L. 92-463, 86... CONTACT: John Kogut, Executive Secretary; High Energy Physics Advisory Panel; U.S. Department of Energy...

77 FR 33449 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-06

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Office of Science... High Energy Physics Advisory Panel (HEPAP). The Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat..., Executive Secretary; High Energy Physics Advisory Panel; U.S. Department of Energy; SC-25/ Germantown...

76 FR 41234 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-13

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Department of Energy.../NSF High Energy Physics Advisory Panel (HEPAP). The Federal Advisory Committee Act (Pub. L. 92-463, 86... Secretary; High Energy Physics Advisory Panel; U.S. Department of Energy; SC-25/ Germantown Building, 1000...

78 FR 12043 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-21

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Office of Science... High Energy Physics Advisory Panel (HEPAP). The Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat... INFORMATION CONTACT: John Kogut, Executive Secretary; High Energy Physics Advisory Panel; U.S. Department of...

Recent Advances in Modeling Transition Metal Oxides for Photo-electrochemistry

NASA Astrophysics Data System (ADS)

Caspary Toroker, Maytal

Computational research offers a wide range of opportunities for materials science and engineering, especially in the energy arena where there is a need for understanding how material composition and structure control energy conversion, and for designing materials that could improve conversion efficiency. Potential inexpensive materials for energy conversion devices are metal oxides. However, their conversion efficiency is limited by at least one of several factors: a too large band gap for efficiently absorbing solar energy, similar conduction and valence band edge characters that may lead to unfavorably high electron-hole recombination rates, a valence band edge that is not positioned well for oxidizing water, low stability, low electronic conductivity, and low surface reactivity. I will show how we model metal oxides with ab-initio methods, primarily DFT +U. Our previous results show that doping with lithium, sodium, or hydrogen could improve iron (II) oxide's electronic properties, and alloying with zinc or nickel could improve iron (II) oxide's optical properties. Furthermore, doping nickel (II) oxide with lithium could improve several key properties including solar energy absorption. In this talk I will highlight new results on our understanding of the mechanism of iron (III) oxide's surface reactivity. Our theoretical insights bring us a step closer towards understanding how to design better materials for photo-electrochemistry. References: 1. O. Neufeld and M. Caspary Toroker, ``Pt-doped Fe2O3 for enhanced water splitting efficiency: a DFT +U study'', J. Phys. Chem. C 119, 5836 (2015). 2. M. Caspary Toroker, ``Theoretical Insights into the Mechanism of Water Oxidation on Non-stoichiometric and Ti - doped Fe2O3 (0001)'', J. Phys. Chem. C, 118, 23162 (2014). This research was supported by the Morantz Energy Research Fund, the Nancy and Stephen Grand Technion Energy Program, the I-CORE Program of the Planning and Budgeting Committee, and The Israel Science

A Study on Linking High-School Physics and Perfect Teaching Reformation of College Physics

ERIC Educational Resources Information Center

Liu, Xiaolai; Li, Qun; Gao, Jiangtao

2011-01-01

For the students who have just entered colleges, learning university physics would be a challenge. This paper discusses how to make students who have just finished senior high school physics won't feel difficult in learning university physics and how to guide and cultivate the students' interest in the study of physics so to stimulate the…

75 FR 17701 - High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-07

... DEPARTMENT OF ENERGY High Energy Physics Advisory Panel AGENCY: Department of Energy, Office of... Physics Advisory Panel (HEPAP). Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770) requires... Energy Physics Advisory Panel; U.S. Department of Energy; SC-25/ Germantown Building, 1000 Independence...

Laboratory for Nuclear Science. High Energy Physics Program

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

Milner, Richard

High energy and nuclear physics research at MIT is conducted within the Laboratory for Nuclear Science (LNS). Almost half of the faculty in the MIT Physics Department carry out research in LNS at the theoretical and experimental frontiers of subatomic physics. Since 2004, the U.S. Department of Energy has funded the high energy physics research program through grant DE-FG02-05ER41360 (other grants and cooperative agreements provided decades of support prior to 2004). The Director of LNS serves as PI. The grant supports the research of four groups within LNS as “tasks” within the umbrella grant. Brief descriptions of each group aremore » given here. A more detailed report from each task follows in later sections. Although grant DE-FG02-05ER41360 has ended, DOE continues to fund LNS high energy physics research through five separate grants (a research grant for each of the four groups, as well as a grant for AMS Operations). We are pleased to continue this longstanding partnership.« less

[High blood pressure and physical exercise].

PubMed

Sosner, P; Gremeaux, V; Bosquet, L; Herpin, D

2014-06-01

High blood pressure is a frequent pathology with many cardiovascular complications. As highlighted in guidelines, the therapeutic management of hypertension relies on non-pharmacological measures, which are diet and regular physical activity, but both patients and physicians are reluctant to physical activity prescription. To acquire the conviction that physical activity is beneficial, necessary and possible, we can take into account some fundamental and clinical studies, as well as the feedback of our clinical practice. Physical inactivity is a major risk factor for cardiovascular morbidity and mortality, and hypertension contributes to increase this risk. Conversely, regular practice of physical activity decreases very significantly the risk by up to 60%. The acute blood pressure changes during exercise and post-exercise hypotension differs according to the dynamic component (endurance or aerobic and/or strength exercises), but the repetition of the sessions leads to the chronic hypotensive benefit of physical activity. Moreover, physical activity prescription must take into account the assessment of global cardiovascular risk, the control of the hypertension, and the opportunities and desires of the patient in order to promote good adherence and beneficial lifestyle change. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Physical activity barriers and motivators among high-risk employees.

PubMed

Paguntalan, John C; Gregoski, Mathew

2016-11-22

Worksite wellness programs offer an ideal setting to target high-risk sedentary workers to improve health status. Lack of physical activity is associated with increased risk for coronary heart disease and mortality. Despite the risks, the number of sedentary workers is increasing. This study examined the perceived barriers and motivators for physical activity among employees at high-risk for coronary heart disease. A purposive sample of 24 high-risk workers participating in a wellness program in rural South Carolina were enrolled in the study. Qualitative data was obtained through semi-structured face-to-face interviews. Grounded theory was used to analyze qualitative data, and identify overarching themes. Physical limitations due to pain and weakness, lack of motivation, and lack of time emerged as the main barriers to physical activity. Family relationships were reported as the strongest motivator along with social support and potential health benefits. Findings highlight the unique experience of high-risk workers with physical activity. The findingsunderscore the need to design and implement effective interventions specifically designed to meet the needs of high-risk employees.

Study on tribological and electrochemistry properties of metal materials in H2O2 solutions

NASA Astrophysics Data System (ADS)

Yuan, Chengqing; Yu, Li; Li, Jian; Yan, Xinping

2012-03-01

Hydrogen peroxide (H2O2) is a kind of ideal green propellant. It is crucial to study the wear behavior and failure modes of the metal materials under the strong oxidizing environment of H2O2. This study aims to investigate the wear of rubbing pairs of 2Cr13 stainless steel against 1045 metal in H2O2 solutions, which has a great effect on wear, the decomposition and damage mechanism of materials. The comparison analysis of the friction coefficients, wear mass loss, worn surface topographies and current densities was conducted under different concentrations of H2O2 solutions. There were significant differences in the tribological and electrochemistry properties of the rubbing pairs in different H2O2 solutions.

Experimental High Energy Physics Research

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

Hohlmann, Marcus

This final report summarizes activities of the Florida Tech High Energy Physics group supported by DOE under grant #DE-SC0008024 during the period June 2012 – March 2015. We focused on one of the main HEP research thrusts at the Energy Frontier by participating in the CMS experiment. We were exploiting the tremendous physics opportunities at the Large Hadron Collider (LHC) and prepared for physics at its planned extension, the High-Luminosity LHC. The effort comprised a physics component with analysis of data from the first LHC run and contributions to the CMS Phase-2 upgrades in the muon endcap system (EMU) formore » the High-Luminosity LHC. The emphasis of our hardware work was the development of large-area Gas Electron Multipliers (GEMs) for the CMS forward muon upgrade. We built a production and testing site for such detectors at Florida Tech to complement future chamber production at CERN. The first full-scale CMS GE1/1 chamber prototype ever built outside of CERN was constructed at Florida Tech in summer 2013. We conducted two beam tests with GEM prototype chambers at CERN in 2012 and at FNAL in 2013 and reported the results at conferences and in publications. Principal Investigator Hohlmann served as chair of the collaboration board of the CMS GEM collaboration and as co-coordinator of the GEM detector working group. He edited and authored sections of the detector chapter of the Technical Design Report (TDR) for the GEM muon upgrade, which was approved by the LHCC and the CERN Research Board in 2015. During the course of the TDR approval process, the GEM project was also established as an official subsystem of the muon system by the CMS muon institution board. On the physics side, graduate student Kalakhety performed a Z' search in the dimuon channel with the 2011 and 2012 CMS datasets that utilized 20.6 fb⁻¹ of p-p collisions at √s = 8 TeV. For the dimuon channel alone, the 95% CL lower limits obtained on the mass of a Z' resonance are 2770 GeV for

Application of three-dimensional reduced graphene oxide-gold composite modified electrode for direct electrochemistry and electrocatalysis of myoglobin.

PubMed

Shi, Fan; Xi, Jingwen; Hou, Fei; Han, Lin; Li, Guangjiu; Gong, Shixing; Chen, Chanxing; Sun, Wei

2016-01-01

In this paper a three-dimensional (3D) reduced graphene oxide (RGO) and gold (Au) composite was synthesized by electrodeposition and used for the electrode modification with carbon ionic liquid electrode (CILE) as the substrate electrode. Myoglobin (Mb) was further immobilized on the surface of 3D RGO-Au/CILE to obtain an electrochemical sensing platform. Direct electrochemistry of Mb on the modified electrode was investigated with a pair of well-defined redox waves appeared on cyclic voltammogram, indicating the realization of direct electron transfer of Mb with the modified electrode. The results can be ascribed to the presence of highly conductive 3D RGO-Au composite on the electrode surface that accelerate the electron transfer rate between the electroactive center of Mb and the electrode. The Mb modified electrode showed excellent electrocatalytic activity to the reduction of trichloroacetic acid in the concentration range from 0.2 to 36.0 mmol/L with the detection limit of 0.06 mmol/L (3σ). Copyright © 2015 Elsevier B.V. All rights reserved.

Electrochemistry coupled online to liquid chromatography-mass spectrometry for fast simulation of biotransformation reactions of the insecticide chlorpyrifos.

PubMed

Mekonnen, Tessema F; Panne, Ulrich; Koch, Matthias

2017-05-01

An automated method is presented for fast simulation of (bio)transformation products (TPs) of the organophosphate insecticide chlorpyrifos (CPF) based on electrochemistry coupled online to liquid chromatography-mass spectrometry (EC-LC-MS). Oxidative TPs were produced by a boron doped diamond (BDD) electrode, separated by reversed phase HPLC and online detected by electrospray ionization-mass spectrometry (ESI-MS). Furthermore, EC oxidative TPs were investigated by HPLC-tandem mass spectrometry (LC-MS/MS) and FT-ICR high resolution mass spectrometry (HRMS) and compared to in vitro assay metabolites (rat and human liver microsomes). Main phase I metabolites of CPF: chlorpyrifos oxon (CPF oxon), trichloropyridinol (TCP), diethylthiophosphate (DETP), diethylphosphate (DEP), desethyl chlorpyrifos (De-CPF), and desethyl chlorpyrifos oxon (De-CPF oxon), were successfully identified by the developed EC-LC-MS method. The EC-LC-MS method showed similar metabolites compared to the in vitro assay with possibilities of determining reactive species. Our results reveal that online EC-(LC)-MS brings an advantage on time of analysis by eliminating sample preparation steps and matrix complexity compared to conventional in vivo or in vitro methods.

The Mathematics of High School Physics

NASA Astrophysics Data System (ADS)

Kanderakis, Nikos

2016-10-01

In the seventeenth and eighteenth centuries, mathematicians and physical philosophers managed to study, via mathematics, various physical systems of the sublunar world through idealized and simplified models of these systems, constructed with the help of geometry. By analyzing these models, they were able to formulate new concepts, laws and theories of physics and then through models again, to apply these concepts and theories to new physical phenomena and check the results by means of experiment. Students' difficulties with the mathematics of high school physics are well known. Science education research attributes them to inadequately deep understanding of mathematics and mainly to inadequate understanding of the meaning of symbolic mathematical expressions. There seem to be, however, more causes of these difficulties. One of them, not independent from the previous ones, is the complex meaning of the algebraic concepts used in school physics (e.g. variables, parameters, functions), as well as the complexities added by physics itself (e.g. that equations' symbols represent magnitudes with empirical meaning and units instead of pure numbers). Another source of difficulties is that the theories and laws of physics are often applied, via mathematics, to simplified, and idealized physical models of the world and not to the world itself. This concerns not only the applications of basic theories but also all authentic end-of-the-chapter problems. Hence, students have to understand and participate in a complex interplay between physics concepts and theories, physical and mathematical models, and the real world, often without being aware that they are working with models and not directly with the real world.

Cyberinfrastructure for high energy physics in Korea

NASA Astrophysics Data System (ADS)

Cho, Kihyeon; Kim, Hyunwoo; Jeung, Minho; High Energy Physics Team

2010-04-01

We introduce the hierarchy of cyberinfrastructure which consists of infrastructure (supercomputing and networks), Grid, e-Science, community and physics from bottom layer to top layer. KISTI is the national headquarter of supercomputer, network, Grid and e-Science in Korea. Therefore, KISTI is the best place to for high energy physicists to use cyberinfrastructure. We explain this concept on the CDF and the ALICE experiments. In the meantime, the goal of e-Science is to study high energy physics anytime and anywhere even if we are not on-site of accelerator laboratories. The components are data production, data processing and data analysis. The data production is to take both on-line and off-line shifts remotely. The data processing is to run jobs anytime, anywhere using Grid farms. The data analysis is to work together to publish papers using collaborative environment such as EVO (Enabling Virtual Organization) system. We also present the global community activities of FKPPL (France-Korea Particle Physics Laboratory) and physics as top layer.

Inciting High-School interest in physics.

NASA Astrophysics Data System (ADS)

Zhang, Jiandi

2008-03-01

We report on our outreach effort on material-physics education program as one part of my NSF Career award project. This is a program incorporated with the NSF funded Physics Learning Center at FIU, focusing on the material physics enrichment both high school students and teachers. We particularly pay attention to minority students by taking the advantage of FIU's composition and location. The program offers a special/session-style workshop, demonstrations, research lab touring, as well as summer research activities. The goal is to enrich teacher's ability of instruction to their students and inspire students to pursue scientific careers. The detailed outreach activities will be discussed.

Synthesis of graphene supported Li2SiO3 as a high performance anode material for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Yang, Shuai; Wang, Qiufen; Miao, Juan; Zhang, Jingyang; Zhang, Dafeng; Chen, Yumei; Yang, Hong

2018-06-01

The Li2SiO3-graphene composite is successfully synthesized through an easy hydrothermal method. The structures and morphologies of the produced samples are characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrum, Brunauer-Emmett-Teller formalism, scanning electron microscope, transmission electron microscope, and electrochemistry methods. The result shows a well crystalline of the Li2SiO3-GE composite. The existence of graphene doesn't change the crystalline of Li2SiO3. In addition, the Li2SiO3 compound with an average diameter of 20 nm can be seen on the surface of graphene with uniform distribution. After the composite with graphene, the composite displays large surface area which ensures the well electrochemistry of the composite. Finally, the Li2SiO3-graphene composite delivers a high initial capacity of 878.3 mAh g-1 at 1C as well as a high recovery capacity of 400 mAh g-1 after 200 cycles. When charged and discharged at high rate, the Li2SiO3-doping graphene composite still exhibits a high specific capacity of 748.3 mAh g-1 (at 2C, and 576 mAh g-1 at 5C) and well cycling performance. The well synthesized composite possesses well structure and well electrochemistry performance.

The Distinguishing Characteristics of High Schools with High and Low Enrollments in Physics.

ERIC Educational Resources Information Center

Van Koevering, Thomas E.

This paper presents the procedures, results, and conclusions of a study designed to determine if high schools with either high or low enrollments in physics exhibit any distinguishing characteristics that are measurable. The study involved 48 schools, 51 physics teachers, and 3767 students in the State of Michigan. Questionnaires were administered…

Integration of Electrochemistry with Ultra Performance Liquid Chromatography/Mass Spectrometry (UPLC/MS)

PubMed Central

Cai, Yi; Zheng, Qiuling; Liu, Yong; Helmy, Roy; Loo, Joseph A.; Chen, Hao

2015-01-01

This study presents the development of ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) combined with electrochemistry (EC) for the first time and its application for the structural analysis of disulfide bond-containing proteins/peptides. In our approach, a protein/peptide mixture sample undergoes fast UPLC separation and subsequent electrochemical reduction in an electrochemical flow cell followed by online MS and MS/MS analyses. The electrochemical cell is coupled to MS using our recently developed desorption electrospray ionization (DESI) interface. Using this UPLC/EC/DESI-MS method, disulfide bond-containing peptides can be differentiated from those without disulfide bonds as the former are electroactive and reducible. Tandem MS analysis of the disulfide-reduced peptide ions provides increased sequence and disulfide linkage pattern information. In a reactive DESI-MS detection experiment in which a supercharging reagent was used to dope the DESI spray solvent, increased charging was obtained for the UPLC-separated proteins. Strikingly, upon online electrolytic reduction, supercharged proteins (e.g., α-lactalbumin) showed even higher charging, which would be useful in top-down protein structure analysis as increased charges are known to promote protein ion dissociation. Also, the separation speed and sensitivity are enhanced by approximately 1~2 orders of magnitude by using UPLC for the LC/EC/MS platform, in comparison to the previously used high performance liquid chromatography (HPLC). This UPLC/EC/DESI-MS method combines the power of fast UPLC separation, fast electrochemical conversion and online MS structural analysis for a potentially valuable tool for proteomics research and bioanalysis. PMID:26307715

"Physics Stories": How the Early Technologies of High Voltage and High Vacuum Led to "Modern Physics"

NASA Astrophysics Data System (ADS)

Greenslade, Thomas B.

2018-05-01

Some of you may remember the 1979 television series "Connections" that was written and narrated by James Burke, a British science writer. Burke's technique was to choose a number of seemingly unrelated ideas and show how they led to developments in science and technology. This is an enjoyable business, even if some of the connections seem to be stretched at times, and led to a book by Burke. In a number of talks that I have given over the years, I have made somewhat less fanciful connections that suggest how the technologies of high vacuum and high voltage led to what used to be called "modern physics." Today we might limit the "modern" era to the years from 1890 to 1920 that gave the first workable theories of small-scale physics.

The Army's High Priority Physical Fitness Program.

ERIC Educational Resources Information Center

Drews, Fred R.

1984-01-01

This article explores the importance of physical fitness in the United States Army. The development of expanded fitness assessment and programs is related to health and the prevention of coronary heart disease. Improved physical training programs, improved nutrition, and fundamental research are necessary for maintaining a highly fit and healthy…

Social capital and physical activity among Croatian high school students.

PubMed

Novak, D; Doubova, S V; Kawachi, I

2016-06-01

To examine factors associated with regular physical activity in Croatian adolescents. A cross-sectional survey among high school students was carried out in the 2013/14 school year. A survey was conducted among 33 high schools in Zagreb City, Croatia. Participants were students aged 17-18 years. The dependent variables were regular moderate to vigorous physical activity (MVPA) and overall physical activity measured by the short version of International Physical Activity Questionnaire and defined as 60 min or more of daily physical activity. The independent variables included family, neighborhood, and high school social capital. Other study covariates included: socio-economic status, self-rated health, psychological distress and nutritional status. The associations between physical activity and social capital variables were assessed separately for boys and girls through multiple logistic regression and inverse probability weighting in order to correct for missing data bias. A total of 1689 boys and 1739 girls responded to the survey. A higher percentage of boys reported performing regular vigorous and moderate physical activity (59.4%) and overall physical activity (83.4%), comparing with the girls (35.4% and 70%, respectively). For boys, high family social capital and high informal social control were associated with increased odds of regular MVPA (1.49, 95%CI: 1.18 - 1.90 and 1.26, 95%CI: 1.02 - 1.56, respectively), compared to those with low social capital. For girls, high informal social control was associated with regular overall physical activity (OR 1.38, 95% CI: 1.09 - 1.76). High social capital is associated with regular MVPA in boys and regular overall activity in girls. Intervention and policies that leverage community social capital might serve as an avenue for promotion of physical activity in youth. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Ultrasensitive signal-on DNA biosensor based on nicking endonuclease assisted electrochemistry signal amplification.

PubMed

Liu, Zhongyuan; Zhang, Wei; Zhu, Shuyun; Zhang, Ling; Hu, Lianzhe; Parveen, Saima; Xu, Guobao

2011-11-15

Combining the advantages of signal-on strategy and nicking endonuclease assisted electrochemistry signal amplification (NEAESA), a new sensitive and signal-on electrochemical DNA biosensor for the sequence specific DNA detection based on NEAESA has been developed for the first time. A Hairpin-shape probe (HP), containing the target DNA recognition sequence, is thiol-modified at 5' end and immobilized on gold electrode via Au-S bonding. Subsequently, the HP modified electrode is hybridized with target DNA to form a duplex. Then the nicking endonuclease is added and nicks the HP strand in the duplex. After nicking, 3'-ferrocene (Fc)-labeled part complementary probe (Fc-PCP) is introduced on the electrode surface by hybridizing with the thiol-modified HP fragment, which results in the generation of electrochemical signal. Hence, the DNA biosensor is constructed successfully. The present DNA biosensor shows a wide linear range of 5.0×10(-13)-5.0×10(-8)M for detecting target DNA, with a low detection limit of 0.167pM. The proposed strategy does not require any amplifying labels (enzymes, DNAzymes, nanoparticles, etc.) for biorecognition events, which avoids false-positive results to occur frequently. Moreover, the strategy has the benefits of simple preparation, convenient operation, good selectivity, and high sensitivity. With the advantages mentioned above, this simple and sensitive strategy has the potential to be integrated in portable, low cost and simplified devices for diagnostic applications. Copyright © 2011 Elsevier B.V. All rights reserved.

``But you're just a physics booster!'' -- Why political advocacy for high school physics is crucial

NASA Astrophysics Data System (ADS)

Cottle, Paul

2010-10-01

There is no shortage of research-based arguments supporting the importance of high school physics. A study from the University of South Florida demonstrates the importance of high school physics for the preparation of future STEM professionals [1]. A white paper from the National Academy of Education [2] states that the usual biology-chemistry-physics sequence in high school is ``out of order'' and points out that students in 9th grade biology classes are taught concepts that make no sense to them because they ``know little about atoms and next to nothing about the chemistry and physics that can help them make sense of these structures and their functions.'' Nevertheless, in Florida the high school physics-taking rate has been declining for several years and a large fraction of the International Baccalaureate programs do not even offer IB Physics. I will argue that physicists must collectively advocate in the political arena for the expansion and improvement of high school physics. I will also provide a few examples of collective actions by scientists that may have influenced the formulation of the new high school graduation requirements in Florida. Finally, I will argue that we must lobby our colleagues in the Colleges of Education to devote their scarce resources to recruiting and training teachers in the physical sciences. [4pt] [1] W. Tyson, R. Lee, K.M. Borman, and M.A. Hanson, {Journal of Education for Students Placed at Risk} 12, 243 (2007). [0pt] [2] National Academy of Education White Paper ``Science and Mathematics Education,'' (http://www.naeducation.org/Science/and/Mathematics/Education/White/Paper.pdf).

UNIVERSITY OF ARIZONA HIGH ENERGY PHYSICS PROGRAM

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

Rutherfoord, John P.; Johns, Kenneth A.; Shupe, Michael A.

2013-07-29

The High Energy Physics Group at the University of Arizona has conducted forefront research in elementary particle physics. Our theorists have developed new ideas in lattice QCD, SUSY phenomenology, string theory phenomenology, extra spatial dimensions, dark matter, and neutrino astrophysics. The experimentalists produced significant physics results on the ATLAS experiment at CERN's Large Hadron Collider and on the D0 experiment at the Fermilab Tevatron. In addition, the experimentalists were leaders in detector development and construction, and on service roles in these experiments.

77 FR 64799 - DOE/NSF High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-23

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel AGENCY: Department of Energy... Physics Advisory Panel (HEPAP). Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770) requires... Kogut, Executive Secretary; High Energy Physics Advisory Panel; U.S. Department of Energy; SC-25...

Assessment of Electrochemical Concepts: A Comparative Study Involving Senior High-School Students in Indonesia and Japan

ERIC Educational Resources Information Center

Rahayu, Sri; Treagust, David F.; Chandrasegaran, A. L.; Kita, Masakazu; Ibnu, Suhadi

2011-01-01

Background and purpose: This study investigated Indonesian and Japanese senior high-school students' understanding of electrochemistry concepts. Sample: The questionnaire was administered to 244 Indonesian and 189 Japanese public senior high-school students. Design and methods: An 18-item multiple-choice questionnaire relating to five conceptual…

Tunnel Structured α-MnO 2 with Different Tunnel Cations (H + , K + , Ag + ) as Cathode Materials in Rechargeable Lithium Batteries: The Role of Tunnel Cation on Electrochemistry

DOE PAGES

Poyraz, Altug S.; Huang, Jianping; Cheng, Shaobo; ...

2017-07-12

α-MnO 2 type manganese dioxide is an interesting prospective cathode material for reversible lithium insertion owing to its cation accessible tunnels (0.46nm x 0.46nm), high voltage, and low cost. The tunneled structure is synthetically formed by the assistance of cations acting as structure directing agents where the cations may remain in the tunnel. The electrochemistry of this family of materials is strongly dependent on the morphological and physicochemical (i.e. surface area, crystallite size, and average manganese oxidation state) properties as well as tunnel occupancy. For this work, we prepared a set of materials Mn 8O 16·0.81H 2O, K 0.81Mn 8Omore » 16·0.78H 2O and Ag 1.33Mn 8O 16·0.95H 2O with similar nanorod morphology, crystallite size, surface area, and tunnel water content. This set of samples allowed us to investigate the role of tunnel cations in the electrochemistry of α-MnO 2 type manganese dioxide in a lithium based environment while minimizing the effects of the other parameters. The electrochemistry was evaluated using cyclic voltammetry, galvanostatic cycling, rate capability, and galvanostatic intermittent titration type testing. Mn 8O 16·0.81H 2O showed higher loaded voltages, improved capacity retention, and higher specific energy relative to K 0.81Mn 8O 16·0.78H 2O and Ag 1.33Mn 8O 16·0.95H 2O. After 100 cycles, Mn 8O 16·0.81H 2O delivered ~200% more capacity than Ag 1.33Mn 8O 16·0.95H 2O (64 vs. 129 mAh/g) and ~35% more capacity than K 0.81Mn 8O 16·0.78H 2O (85 vs. 129 mAh/g). Mn 8O 16·0.81H 2O also showed higher effective lithium diffusion coefficients (DLi+) and higher rate capability compared to K 0.81Mn 8O 16·0.78H 2O and Ag 1.33Mn 8O 16·0.95H 2O suggesting faster Li+ ion diffusion in the absence of large metal tunnel cations.« less

Tunnel Structured α-MnO 2 with Different Tunnel Cations (H + , K + , Ag + ) as Cathode Materials in Rechargeable Lithium Batteries: The Role of Tunnel Cation on Electrochemistry

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

Poyraz, Altug S.; Huang, Jianping; Cheng, Shaobo

α-MnO 2 type manganese dioxide is an interesting prospective cathode material for reversible lithium insertion owing to its cation accessible tunnels (0.46nm x 0.46nm), high voltage, and low cost. The tunneled structure is synthetically formed by the assistance of cations acting as structure directing agents where the cations may remain in the tunnel. The electrochemistry of this family of materials is strongly dependent on the morphological and physicochemical (i.e. surface area, crystallite size, and average manganese oxidation state) properties as well as tunnel occupancy. For this work, we prepared a set of materials Mn 8O 16·0.81H 2O, K 0.81Mn 8Omore » 16·0.78H 2O and Ag 1.33Mn 8O 16·0.95H 2O with similar nanorod morphology, crystallite size, surface area, and tunnel water content. This set of samples allowed us to investigate the role of tunnel cations in the electrochemistry of α-MnO 2 type manganese dioxide in a lithium based environment while minimizing the effects of the other parameters. The electrochemistry was evaluated using cyclic voltammetry, galvanostatic cycling, rate capability, and galvanostatic intermittent titration type testing. Mn 8O 16·0.81H 2O showed higher loaded voltages, improved capacity retention, and higher specific energy relative to K 0.81Mn 8O 16·0.78H 2O and Ag 1.33Mn 8O 16·0.95H 2O. After 100 cycles, Mn 8O 16·0.81H 2O delivered ~200% more capacity than Ag 1.33Mn 8O 16·0.95H 2O (64 vs. 129 mAh/g) and ~35% more capacity than K 0.81Mn 8O 16·0.78H 2O (85 vs. 129 mAh/g). Mn 8O 16·0.81H 2O also showed higher effective lithium diffusion coefficients (DLi+) and higher rate capability compared to K 0.81Mn 8O 16·0.78H 2O and Ag 1.33Mn 8O 16·0.95H 2O suggesting faster Li+ ion diffusion in the absence of large metal tunnel cations.« less

Formation of high molecular weight products from benzene during boundary lubrication

NASA Technical Reports Server (NTRS)

Morales, W.

1985-01-01

High molecular weight products were detected on the wear track of an iron disk at the end of a sliding friction and wear test using benzene as a lubricant. Size exclusion chromagography in conjunction with UV analysis gave evidence that the high molecular weight products are polyphenyl ether type substances. Organic electrochemistry was used to elucidate the possible surface reaction mechanisms.

Application of N-doped graphene modified carbon ionic liquid electrode for direct electrochemistry of hemoglobin.

PubMed

Sun, Wei; Dong, Lifeng; Deng, Ying; Yu, Jianhua; Wang, Wencheng; Zhu, Qianqian

2014-06-01

Nitrogen-doped graphene (NG) was synthesized and used for the investigation on direct electrochemistry of hemoglobin (Hb) with a carbon ionic liquid electrode as the substrate electrode. Due to specific characteristics of NG such as excellent electrocatalytic property and large surface area, direct electron transfer of Hb was realized with enhanced electrochemical responses appearing. Electrochemical behaviors of Hb on the NG modified electrode were carefully investigated with the electrochemical parameters calculated. The Hb modified electrode exhibited excellent electrocatalytic reduction activity toward different substrates, such as trichloroacetic acid and H2O2, with wider dynamic range and lower detection limit. These findings show that NG can be used for the preparation of chemically modified electrodes with improved performance and has potential applications in electrochemical sensing. Copyright © 2014 Elsevier B.V. All rights reserved.

Fabrication of graphene-platinum nanocomposite for the direct electrochemistry and electrocatalysis of myoglobin.

PubMed

Sun, Wei; Li, Linfang; Lei, Bingxin; Li, Tongtong; Ju, Xiaomei; Wang, Xiuzheng; Li, Guangjiu; Sun, Zhenfan

2013-05-01

In this paper a platinum (Pt) nanoparticle decorated graphene (GR) nanosheet was synthesized and used for the investigation on direct electrochemistry of myoglobin (Mb). By integrating GR-Pt nanocomposite with Mb on the surface of carbon ionic liquid electrode (CILE), a new electrochemical biosensor was fabricated. UV-Vis absorption and FT-IR spectra indicated that Mb remained its native structure in the nanocomposite film. Electrochemical behaviors of Nafion/Mb-GR-Pt/CILE were investigated with a pair of well-defined redox peak appeared, which indicated that direct electron transfer of Mb was realized on the underlying electrode with the usage of the GR-Pt nanocomposite. The fabricated electrode showed good electrocatalytic activity to the reduction of trichloroacetic acid in the linear range from 0.9 to 9.0 mmol/L with the detection limit as 0.32 mmol/L (3σ), which showed potential application for fabricating novel electrochemical biosensors and bioelectronic devices. Copyright © 2012 Elsevier B.V. All rights reserved.

AAPT Guidelines for High School Physics Programs.

ERIC Educational Resources Information Center

Mays, Katherine

The quality of a high school's physics program is determined in part by the quality of preparation and the overall workload of its teachers, along with the provision for adequate budgets, facilities, and support services. The guidelines presented in this booklet were prepared by a task force of the American Association of Physics Teachers (AAPT)…

The physical activity climate in Minnesota middle and high schools.

PubMed

Samuelson, Anne; Lytle, Leslie; Pasch, Keryn; Farbakhsh, Kian; Moe, Stacey; Sirard, John Ronald

2010-11-01

This article describes policies, practices, and facilities that form the physical activity climate in Minneapolis/St. Paul, Minnesota metro area middle and high schools and examines how the physical activity climate varies by school characteristics, including public/private, school location and grade level. Surveys examining school physical activity practices, policies and environment were administered to principals and physical education department heads from 115 middle and high schools participating in the Transdisciplinary Research on Energetics and Cancer-Identifying Determinants of Eating and Activity (TREC-IDEA) study. While some supportive practices were highly prevalent in the schools studied (such as prohibiting substitution of other classes for physical education); other practices were less common (such as providing opportunity for intramural (noncompetitive) sports). Public schools vs. private schools and schools with a larger school enrollment were more likely to have a school climate supportive of physical activity. Although schools reported elements of positive physical activity climates, discrepancies exist by school characteristics. Of note, public schools were more than twice as likely as private schools to have supportive physical activity environments. Establishing more consistent physical activity expectations and funding at the state and national level is necessary to increase regular school physical activity.

A comparative study of middle school and high school students' views about physics and learning physics

NASA Astrophysics Data System (ADS)

Ding, Lin

2013-01-01

Previous studies of student epistemological beliefs about physics and learning physics focused on college and post-college students in Western countries. However, little is known about early-grade students in Asian countries. This paper reports Chinese middle and high school students' views about the nature of physics and learning physics, measured by the Colorado Learning Attitudes Survey about Science (CLASS). Two variables—school level and gender—are examined for a series of comparative analyses. Results show that although middle school students received fewer years of education in physics, they demonstrated more expert-like conceptions about this subject matter than high school students. Also, male students in general exhibited more expert-like views than their female counterparts. While such a gender difference remained constant across both middle and high schools, for the most part it was a small-size difference.

Research in High Energy Physics

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

Wilson, Robert John; Toki, Walter; Harton, John

This report summarizes research performed within the Department of Energy Office of Science's Intensity Frontier and Cosmic Frontier High Energy Physics research subprograms during the period 2014-17. The major research thrusts in the Intensity Frontier involved two currently active neutrino experiments T2K and NOvA; participation in development for the new Short-Baseline Neutrino program at Fermilab (SBN), which will begin full operation within the next one to two years; and physics tools, analysis and detector prototyping for the future Deep Underground Neutrino Experiment (DUNE). The major research thrusts in the Cosmic Frontier involved the Pierre Auger Observatory and the Directional Recoilmore » Identification From Tracks (DRIFT) dark matter search experiment.« less

Experiences of a high-school physics textbook author

NASA Astrophysics Data System (ADS)

Zitzewitz, Paul W.

2004-05-01

For the past twenty years I have been involved writing a widely used high school physics textbook. I will discuss my experiences with the many forces that shape such a book, including state requirements, the publisher, editors, free-lance writers, reviewers, high school teachers, and students. Attempts to incorporate the results of physics education research and the changing role of technology in the production process will also be discussed.

Scientific Argumentation in Public Physics Lectures: Bringing Contemporary Physics into High-School Teaching

ERIC Educational Resources Information Center

Kapon, S.; Ganiel, U.; Eylon, B.

2009-01-01

This article presents an approach to integrating public e-lectures on contemporary physics into a traditional high-school syllabus. This approach was used in a long-distance professional development course for in-service physics teachers. Each lecture was related to a specific obligatory syllabus chapter, and was accompanied by learner-centred…

78 FR 14087 - DOE/NSF High Energy Physics Advisory Panel: Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-04

... DEPARTMENT OF ENERGY DOE/NSF High Energy Physics Advisory Panel: Correction AGENCY: Office of..., the Department of Energy (DOE) published a notice of open meeting for the DOE/NSF High Energy Physics... FURTHER INFORMATION CONTACT: John Kogut, Executive Secretary; High Energy Physics Advisory Panel; U.S...

Direct electrochemistry of glucose oxidase and glucose biosensing on a hydroxyl fullerenes modified glassy carbon electrode.

PubMed

Gao, Yun-Fei; Yang, Tian; Yang, Xiao-Lu; Zhang, Yu-Shuai; Xiao, Bao-Lin; Hong, Jun; Sheibani, Nader; Ghourchian, Hedayatollah; Hong, Tao; Moosavi-Movahedi, Ali Akbar

2014-10-15

Direct electrochemistry of glucose oxidase (GOD) was achieved when GOD-hydroxyl fullerenes (HFs) nano-complex was immobilized on a glassy carbon (GC) electrode and protected with a chitosan (Chit) membrane. The ultraviolet-visible absorption spectrometry (UV-vis), transmission electron microscopy (TEM), and circular dichroism spectropolarimeter (CD) methods were utilized for additional characterization of the GOD, GOD-HFs and Chit/GOD-HFs. Chit/HFs may preserve the secondary structure and catalytic properties of GOD. The cyclic voltammograms (CVs) of the modified GC electrode showed a pair of well-defined quasi-reversible redox peaks with the formal potential (E°') of 353 ± 2 mV versus Ag/AgCl at a scan rate of 0.05 V/s. The heterogeneous electron transfer constant (ks) was calculated to be 2.7 ± 0.2s(-1). The modified electrode response to glucose was linear in the concentrations ranging from 0.05 to 1.0mM, with a detection limit of 5 ± 1 μM. The apparent Michaelis-Menten constant (Km(app)) was 694 ± 8 μM. Thus, the modified electrode could be applied as a third generation biosensor for glucose with high sensitivity, selectivity and low detection limit. Copyright © 2014 Elsevier B.V. All rights reserved.

Fifth International Conference on High Energy Density Physics

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

Beg, Farhat

The Fifth International Conference on High Energy Density Physics (ICHED 2015) was held in the Catamaran Hotel in San Diego from August 23-27, 2015. This meeting was the fifth in a series which began in 2008 in conjunction with the April meeting of the American Physical Society (APS). The main goal of this conference has been to bring together researchers from all fields of High Energy Density Science (HEDS) into one, unified meeting.

High Energy Density Physics and Exotic Acceleration Schemes

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

Cowan, T.; /General Atomics, San Diego; Colby, E.

2005-09-27

The High Energy Density and Exotic Acceleration working group took as our goal to reach beyond the community of plasma accelerator research with its applications to high energy physics, to promote exchange with other disciplines which are challenged by related and demanding beam physics issues. The scope of the group was to cover particle acceleration and beam transport that, unlike other groups at AAC, are not mediated by plasmas or by electromagnetic structures. At this Workshop, we saw an impressive advancement from years past in the area of Vacuum Acceleration, for example with the LEAP experiment at Stanford. And wemore » saw an influx of exciting new beam physics topics involving particle propagation inside of solid-density plasmas or at extremely high charge density, particularly in the areas of laser acceleration of ions, and extreme beams for fusion energy research, including Heavy-ion Inertial Fusion beam physics. One example of the importance and extreme nature of beam physics in HED research is the requirement in the Fast Ignitor scheme of inertial fusion to heat a compressed DT fusion pellet to keV temperatures by injection of laser-driven electron or ion beams of giga-Amp current. Even in modest experiments presently being performed on the laser-acceleration of ions from solids, mega-amp currents of MeV electrons must be transported through solid foils, requiring almost complete return current neutralization, and giving rise to a wide variety of beam-plasma instabilities. As keynote talks our group promoted Ion Acceleration (plenary talk by A. MacKinnon), which historically has grown out of inertial fusion research, and HIF Accelerator Research (invited talk by A. Friedman), which will require impressive advancements in space-charge-limited ion beam physics and in understanding the generation and transport of neutralized ion beams. A unifying aspect of High Energy Density applications was the physics of particle beams inside of solids, which is

Electrochemistry and capillary condensation theory reveal the mechanism of corrosion in dense porous media.

PubMed

Stefanoni, Matteo; Angst, Ueli M; Elsener, Bernhard

2018-05-09

Corrosion in carbonated concrete is an example of corrosion in dense porous media of tremendous socio-economic and scientific relevance. The widespread research endeavors to develop novel, environmentally friendly cements raise questions regarding their ability to protect the embedded steel from corrosion. Here, we propose a fundamentally new approach to explain the scientific mechanism of corrosion kinetics in dense porous media. The main strength of our model lies in its simplicity and in combining the capillary condensation theory with electrochemistry. This reveals that capillary condensation in the pore structure defines the electrochemically active steel surface, whose variability upon changes in exposure relative humidity is accountable for the wide variability in measured corrosion rates. We performed experiments that quantify this effect and find good agreement with the theory. Our findings are essential to devise predictive models for the corrosion performance, needed to guarantee the safety and sustainability of traditional and future cements.

Availability of high school physics and socioeconomics

NASA Astrophysics Data System (ADS)

White, Susan C.

2015-10-01

We noted last month that Hispanic and African-American seniors were less likely to have taken a high school physics course than their peers, and we suggested that socioeconomic status (SES) played a role in the lower participation. Often the proportion of students receiving free and reduced-price meals (FRMs) is used as a measure of SES in secondary education; however, we found that this measure did not differentiate very well between schools at the upper end of the socioeconomic spectrum. To help us understand both ends of the SES scale, we ask principals and teachers to assess the economic situation of their students relative to others in the area. We have found that this tracks well with FRMs on the low end and helps us distinguish between schools on the upper end. This figure displays the number of seniors in public high schools attending a school where physics is never offered by SES. While the number of seniors is roughly one-third in each SES group, over half of the seniors attending a school where physics is not offered are at "worse off" schools. Next month we will look more closely at physics by SES.

Sophisticated Epistemologies of Physics versus High-Stakes Tests: How Do Elite High School Students Respond to Competing Influences about How to Learn Physics?

ERIC Educational Resources Information Center

Yerdelen-Damar, Sevda; Elby, Andrew

2016-01-01

This study investigates how elite Turkish high school physics students claim to approach learning physics when they are simultaneously (i) engaged in a curriculum that led to significant gains in their epistemological sophistication and (ii) subject to a high-stakes college entrance exam. Students reported taking surface (rote) approaches to…

Development of an Attitude Scale towards High School Physics Lessons

ERIC Educational Resources Information Center

Yavas, Pervin Ünlü; Çagan, Sultan

2017-01-01

The aim of this study was to develop a Likert type attitude scale for high school students with regard to high school physics lessons. The research was carried out with high school students who were studying in Ankara. First, the opinions of 105 high school students about physics lessons were obtained and then 55 scale items were determined from…

High School Physics Availability: Results from the 2012-13 Nationwide Survey of High School Physics Teachers. Focus On

ERIC Educational Resources Information Center

White, Susan; Tesfaye, Casey Langer

2014-01-01

In this report, the authors share their analysis of the data from over 3,500 high schools in the U.S. beginning with an examination of the availability of physics in U.S. high schools. The schools in their sample are a nationally-representative random sample of the almost 25,000 high schools in forty-nine of the fifty states. Table 1 shows the…

The Readiness of High School Students to Pursue First Year Physics

ERIC Educational Resources Information Center

Ramnarain, U.; Molefe, P.

2012-01-01

A high failure rate at first year physics is often attributed to the lack of readiness of high school students to pursue such studies. This research explores this issue and reports on the perceptions of five physics lecturers at a South African university on the preparedness of high school students for first year physics. Qualitative data was…

Experience, gender, and performance: Connecting high school physics experience and gender differences to introductory college physics performance

NASA Astrophysics Data System (ADS)

Tai, Robert H.

Current science educational practice is coming under heavy criticism based on the dismaying results of the Third International Mathematics and Science Study of 1998, the latest in a series of large scale surveys; and from research showing the appallingly low representation of females in science-related fields. These critical evaluations serve to draw attention to science literacy in general and lack of persistence among females in particular, two issues that relate closely to the "preparation for future study" goal held by many high school science teachers. In other words, these teachers often seek to promote future success and to prevent future failure in their students' academic careers. This thesis studies the connection between the teaching practices recommended by reformers and researchers for high school teachers, and their students' subsequent college physics performance. The teaching practices studied were: laboratory experiences, class discussion experiences, content coverage, and reliance on textbooks. This study analyzed a survey of 1500 students from 16 different lecture-format college physics courses at 14 different universities. Using hierarchical linear modeling, this study accounted for course-level variables (Calculus-based/Non-calculus course type, professor's gender, and university selectivity). This study controlled for the student's parents education, high school science/mathematics achievement, high school calculus background, and racial background. In addition, the interactions between gender and both pedagogical/curricular and course-level variables were analyzed. The results indicated that teaching fewer topics in greater depth in high school physics appeared to be helpful to college physics students. An interaction between college course type and content coverage showed that students in Calculus-based physics reaped even greater benefits from a depth-oriented curriculum. Also students with fewer labs per month in high school physics

Electrochemistry-mass spectrometry for in-vitro determination of selected chemotherapeutics and their electrochemical products in comparison to in-vivo approach.

PubMed

Szultka-Mlynska, Malgorzata; Buszewski, Boguslaw

2016-11-01

samples from patients after antibiotic drugs have been administered.. Overall, the comparison of electrochemistry to in-vivo experiments shows the high potential of EC-MS as a fast analytical tool in the prediction of electrochemical conversion that could be applied to therapeutic drug monitoring and pharmacokinetic studies as well. Copyright © 2016 Elsevier B.V. All rights reserved.

99Tc and Re incorporated into metal oxide polyoxometalates: oxidation state stability elucidated by electrochemistry and theory.

PubMed

McGregor, Donna; Burton-Pye, Benjamin P; Mbomekalle, Israel M; Aparicio, Pablo A; Romo, Susanna; López, Xavier; Poblet, Josep M; Francesconi, Lynn C

2012-08-20

The radioactive element technetium-99 ((99)Tc, half-life = 2.1 × 10(5) years, β(-) of 253 keV), is a major byproduct of (235)U fission in the nuclear fuel cycle. (99)Tc is also found in radioactive waste tanks and in the environment at National Lab sites and fuel reprocessing centers. Separation and storage of the long-lived (99)Tc in an appropriate and stable waste-form is an important issue that needs to be addressed. Considering metal oxide solid-state materials as potential storage matrixes for Tc, we are examining the redox speciation of Tc on the molecular level using polyoxometalates (POMs) as models. In this study we investigate the electrochemistry of Tc complexes of the monovacant Wells-Dawson isomers, α(1)-P(2)W(17)O(61)(10-) (α1) and α(2)-P(2)W(17)O(61)(10-) (α2) to identify features of metal oxide materials that can stabilize the immobile Tc(IV) oxidation state accessed from the synthesized Tc(V)O species and to interrogate other possible oxidation states available to Tc within these materials. The experimental results are consistent with density functional theory (DFT) calculations. Electrochemistry of K(7-n)H(n)[Tc(V)O(α(1)-P(2)W(17)O(61))] (Tc(V)O-α1), K(7-n)H(n)[Tc(V)O(α(2)-P(2)W(17)O(61))] (Tc(V)O-α2) and their rhenium analogues as a function of pH show that the Tc-containing derivatives are always more readily reduced than their Re analogues. Both Tc and Re are reduced more readily in the lacunary α1 site as compared to the α2 site. The DFT calculations elucidate that the highest oxidation state attainable for Re is VII while, under the same electrochemistry conditions, the highest oxidation state for Tc is VI. The M(V)→ M(IV) reduction processes for Tc(V)O-α1 are not pH dependent or only slightly pH dependent suggesting that protonation does not accompany reduction of this species unlike the M(V)O-α2 (M = (99)Tc, Re) and Re(V)O-α1 where M(V/IV) reduction process must occur hand in hand with protonation of the terminal M═O to

Direct electrochemistry of hemoglobin immobilized in CuO nanowire bundles.

PubMed

Li, Yueming; Zhang, Qian; Li, Jinghong

2010-11-15

It is one of main challenges to find the suitable materials to enhance the direct electron transfer between the electrode and redox protein for direct electrochemistry field. Nano-structured metal oxides have attracted considerable interest because of unique properties, well biocompatibility, and good stability. In this paper, the copper oxide nanowire bundles (CuO NWBs) were prepared via a template route, and the bioelectrochemical performances of hemoglobin (Hb) on the CuO NWBs modified glass carbon electrodes (denoted as Hb-CuO NWBs/GC) were studied. TEM and XRD were used to characterize the morphology and structure of the as synthesized CuO NWBs. Fourier transform-infrared spectroscopy (FT-IR) proved that Hb in the CuO NWBs matrix could retain its native secondary structure. A pair of well-defined and quasi-reversible redox peaks at approximately -0.325 V (vs. Ag/AgCl saturated KCl) were shown in the cyclic voltammogram curve for the Hb-CuO NWBs/GC electrode, which indicated the direct electrochemical behavior. The Hb-CuO NWBs/GC electrode also displayed a good electrocatalytic activity toward the reduction of hydrogen peroxide. These results indicate that the CuO NWBs are good substrates for immobilization of biomolecules and might be promising in the fields of (bio) electrochemical analysis. Copyright © 2010 Elsevier B.V. All rights reserved.

75 FR 6651 - Office of Science; High Energy Physics Advisory Panel

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-10

... DEPARTMENT OF ENERGY Office of Science; High Energy Physics Advisory Panel AGENCY: Department of... Physics Advisory Panel (HEPAP). Federal Advisory Committee Act (Public Law 92- 463, 86 Stat. 770) requires...; High Energy Physics Advisory Panel; U.S. Department of Energy; SC-25/ Germantown Building, 1000...

End-of-Discharge and End-of-Life Prediction in Lithium-Ion Batteries with Electrochemistry-Based Aging Models

NASA Technical Reports Server (NTRS)

Daigle, Matthew; Kulkarni, Chetan S.

2016-01-01

As batteries become increasingly prevalent in complex systems such as aircraft and electric cars, monitoring and predicting battery state of charge and state of health becomes critical. In order to accurately predict the remaining battery power to support system operations for informed operational decision-making, age-dependent changes in dynamics must be accounted for. Using an electrochemistry-based model, we investigate how key parameters of the battery change as aging occurs, and develop models to describe aging through these key parameters. Using these models, we demonstrate how we can (i) accurately predict end-of-discharge for aged batteries, and (ii) predict the end-of-life of a battery as a function of anticipated usage. The approach is validated through an experimental set of randomized discharge profiles.

An Investigation into Physics Teaching in Senior High Schools

ERIC Educational Resources Information Center

Buabeng, Isaac; Ossei-Anto, Theophilus Aquinas; Ampiah, Joseph Ghartey

2014-01-01

This study sought to examine the activities that go on in physics classrooms in Senior High Schools in Ghana. Specifically, the study sought to investigate the pattern of interaction and instructional methods used for teaching physics and level of coverage of physics syllabus. The survey design was employed for the study in which questionnaire was…

Particle Physics in High School: A Diagnose Study

PubMed Central

Solbes, Jordi

2016-01-01

The science learning process improves when the contents are connected to students’ lives. Particle physics has had a great impact in our society in the last years and has changed the theoretical picture about matter fundamental dynamics. Thus, we think that academic contents about matter components and interactions should be updated. With this study we aim to characterize the level of knowledge of high school students about this topic. We built a test with questions about classical atomic models, particle physics, recent discoveries, social implications and students opinions about it. Contrary to our first suspicion, students’ answers show a high variability. They have new physics ideas and show a great interest towards modern concepts. We suggest including an updated view of this topic as part of the curriculum. PMID:27253377

Particle Physics in High School: A Diagnose Study.

PubMed

Tuzón, Paula; Solbes, Jordi

2016-01-01

The science learning process improves when the contents are connected to students' lives. Particle physics has had a great impact in our society in the last years and has changed the theoretical picture about matter fundamental dynamics. Thus, we think that academic contents about matter components and interactions should be updated. With this study we aim to characterize the level of knowledge of high school students about this topic. We built a test with questions about classical atomic models, particle physics, recent discoveries, social implications and students opinions about it. Contrary to our first suspicion, students' answers show a high variability. They have new physics ideas and show a great interest towards modern concepts. We suggest including an updated view of this topic as part of the curriculum.

Simulating Electrochemistry of Hydrothermal Vents on Enceladus and Other Ocean Worlds

NASA Astrophysics Data System (ADS)

Barge, L. M.; Krause, F. C.; Jones, J. P.; Billings, K.; Sobron, P.

2017-12-01

Gradients generated in hydrothermal systems provide a significant source of free energy for chemosynthetic life, and may play a role in present-day habitability on ocean worlds such as Enceladus that are thought to host hydrothermal activity. Hydrothermal vents are similar in some ways to typical fuel cell devices: redox/pH gradients between seawater and hydrothermal fluid are analogous to the oxidant and fuel reservoirs; conductive natural mineral deposits are analogous to electrodes; and, in hydrothermal chimneys, the porous chimney wall can function as a separator or ion-exchange membrane. Electrochemistry, founded on quantitative study of redox and other chemical disequilibria as well as the chemistry of interfaces, is uniquely suited to studying these systems. We have performed electrochemical studies to better understand the catalytic potential of seafloor minerals and vent chimneys, using samples from a black smoker vent chimney as an initial demonstration. Fuel cell experiments with electrodes made from black smoker chimney material accurately simulated the redox reactions that occur in a geological setting with this particular catalyst. Similar methods with other geo-catalysts (natural or synthetic) could be utilized to test which redox reactions or metabolisms could be driven in other hydrothermal systems, including putative vent systems on other worlds.

Electrochemistry of Cytochrome P450 BM3 in Sodium Dodecyl Sulfate Films

PubMed Central

Udit, Andrew K.; Hill, Michael G.; Gray, Harry B.

2008-01-01

Direct electrochemistry of the cytochrome P450 BM3 heme domain (BM3) was achieved by confining the protein within sodium dodecyl sulfate (SDS) films on the surface of basal-plane graphite (BPG) electrodes. Cyclic voltammetry revealed the heme FeIII/II redox couple at −330 mV (vs. Ag/AgCl, pH 7.4). Up to 10 V/s, the peak current was linear with scan rate, allowing us to treat the system as surface-confined within this regime. The standard heterogeneous rate constant determined at 10 V/s was estimated to be 10 s−1. Voltammograms obtained for the BM3-SDS-BPG system in the presence of dioxygen exhibited catalytic waves at the onset of FeIII reduction. The altered heme reduction potential of the BM3-SDS-graphite system indicates that SDS is likely bound in the enzyme active-site region. Compared to other P450-surfactant systems, we find redox potentials and electron transfer rates that differ by ~ 100 mV and > 10-fold, respectively, indicating that the nature of the surfactant environment has a significant effect on the observed heme redox properties. PMID:17129070

Reaching the Critical Mass: The Twenty Year Surge in High School Physics. Findings from the 2005 Nationwide Survey of High School Physics Teachers. AIP Report. Number R-442

ERIC Educational Resources Information Center

Neuschatz, Michael; McFarling, Mark; White, Susan

2008-01-01

This report traces the growth of high school physics in American school over the past twenty years. Highlights of the report include: (1) Enrollments in high school physics continue to grow; (2) Increase in number and proportion of physics teachers; (3) Number of students taking honors, advance placement or second-year physics course has nearly…

Goals.

ERIC Educational Resources Information Center

Phillips, David A.; Phillips, Prudence

1985-01-01

Presents two discussions which focus on the rationale for and goals of teaching electrochemistry at high school and college levels. The first is "Electrochemistry" by Ronald Perkins and the second is "Goals in Teaching Electrochemistry" by J. T. Maloy. (JN)

Super-SERS-active and highly effective antimicrobial Ag nanodendrites

NASA Astrophysics Data System (ADS)

Li, H. B.; Liu, P.; Liang, Y.; Xiao, J.; Yang, G. W.

2012-07-01

We have developed simple and green electrochemistry to synthesize Ag nanostructures with high purity, good crystallinity and smooth surface for applications as super-SERS (surface-enhanced Raman scattering), SERS-active substrates and with highly effective antimicrobial activities. This synthesis takes place in a clean and slow reaction environment without any chemical additives, which ensures an ultrahigh active surface of the as-synthesized Ag nanostructures owing to their purity, good crystallinity and smooth morphology. Using this method, we synthesized nearly perfect Ag nanodendrites (NDs), which exhibit super-SERS sensitivity when they are used to detect the SERS spectra of rhodamine 6G at concentrations as low as 5 × 10-16 M, and have an ultrahigh electromagnetic (EM) enhancement factor of the order of 1013, breaking through the theoretical limit of EM enhancement. Meanwhile, the as-synthesized Ag NDs possess highly effective antimicrobial activities for Escherichia coli, Candida albicans and Staphylococcus aureus, which are over 10 times that of silver nanoparticles. Additionally, the basic physics and chemistry involved in the fabrication of Ag nanostructures are pursued. These investigations show that silver nanostructures with highly active surfaces can make the most of Ag nanostructures functioning as super-SERS-active substrates and multiple antibiotics.

Martian Dust Devil Electron Avalanche Process and Associated Electrochemistry

NASA Technical Reports Server (NTRS)

Jackson, Telana L.; Farrell, William M.; Delory, Gregory T.; Nithianandam, Jeyasingh

2010-01-01

Mars' dynamic atmosphere displays localized dust devils and larger, global dust storms. Based on terrestrial analog studies, electrostatic modeling, and laboratory work these features will contain large electrostatic fields formed via triboelectric processes. In the low-pressure Martian atmosphere, these fields may create an electron avalanche and collisional plasma due to an increase in electron density driven by the internal electrical forces. To test the hypothesis that an electron avalanche is sustained under these conditions, a self-consistent atmospheric process model is created including electron impact ionization sources and electron losses via dust absorption, electron dissociation attachment, and electron/ion recombination. This new model is called the Dust Devil Electron Avalanche Model (DDEAM). This model solves simultaneously nine continuity equations describing the evolution of the primary gaseous chemical species involved in the electrochemistry. DDEAM monitors the evolution of the electrons and primary gas constituents, including electron/water interactions. We especially focus on electron dynamics and follow the electrons as they evolve in the E field driven collisional gas. When sources and losses are self-consistently included in the electron continuity equation, the electron density grows exponentially with increasing electric field, reaching an equilibrium that forms a sustained time-stable collisional plasma. However, the character of this plasma differs depending upon the assumed growth rate saturation process (chemical saturation versus space charge). DDEAM also shows the possibility of the loss of atmospheric methane as a function of electric field due to electron dissociative attachment of the hydrocarbon. The methane destruction rates are presented and can be included in other larger atmospheric models.

PREFACE: High Energy Particle Physics Workshop (HEPPW2015)

NASA Astrophysics Data System (ADS)

Cornell, Alan S.; Mellado, B.

2015-10-01

The motivation for this workshop began with the discovery of the Higgs boson three years ago, and the realisation that many problems remain in particle physics, such as why there is more matter than anti-matter, better determining the still poorly measured parameters of the strong force, explaining possible sources for dark matter, naturalness etc. While the newly discovered Higgs boson seems to be compatible with the Standard Model, current experimental accuracy is far from providing a definitive statement with regards to the nature of this new particle. There is a lot of room for physics beyond the Standard Model to emerge in the exploration of the Higgs boson. Recent measurements in high-energy heavy ion collisions at the LHC have shed light on the complex dynamics that govern high-density quark-gluon interactions. An array of results from the ALICE collaboration have been highlighted in a recent issue of CERN courier. The physics program of high-energy heavy ion collisions promises to further unveil the intricacies of high-density quark-gluon plasma physics. The great topicality of high energy physics research has also seen a rapid increase in the number of researchers in South Africa pursuing such studies, both experimentally through the ATLAS and ALICE colliders at CERN, and theoretically. Young researchers and graduate students largely populate these research groups, with little experience in presenting their work, and few support structures (to their knowledge) to share experiences with. Whilst many schools and workshops have sought to educate these students on the theories and tools they will need to pursue their research, few have provided them with a platform to present their work. As such, this workshop discussed the various projects being pursued by graduate students and young researchers in South Africa, enabling them to develop networks for future collaboration and discussion. The workshop took place at the iThemba Laboratories - North facility, in

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

None

Progress in the fields of nuclear chemistry, isolation and chemical properties of synthetic elements, chemical separation of isotopes, radiation chemistry, organic chemistry, chemistry of aquecus systems, electrochemistry of corrosion, nonaqueous systems at high temperature, and chemical physics for the year ending June 20, 1961, is reported. Separate abstracts were prepared for each topic. (M.C.G.)

Prospective Physics Teachers' Views on Their Knowledge about the New Concepts in Turkish High School Physics Curricula

ERIC Educational Resources Information Center

Kapucu, Serkan; Yildirim, Ufuk

2012-01-01

The purpose of this study was to a) investigate prospective physics teachers' views on their knowledge about new physics concepts introduced in Turkish High School Physics Curricula; b) investigate the sources of their acquired knowledge about these new physics concepts; and c) explore if there were differences in views on knowledge about these…

High school students' scientific epistemological beliefs, self-efficacy in learning physics and attitudes toward physics: a structural equation model

NASA Astrophysics Data System (ADS)

Kapucu, Serkan; Bahçivan, Eralp

2015-05-01

Background: There are some theoretical evidences that explain the relationships between core beliefs (i.e., epistemological beliefs) and peripheral beliefs (self-efficacy in learning) in the literature. The close relationships of such type of beliefs with attitudes are also discussed by some researchers. Constructing a model that investigates these relationships by considering theoretical and empirical evidences can empower researchers to discuss these relationships more comprehensively. Purpose: The purpose of this study is to explore the relationships among Turkish high school students' scientific epistemological beliefs, self-efficacy in learning physics and their attitudes toward physics. Sample: A total of 632 high school students participated in this study; however, 269 female and 229 male (a total of 498) high school students' data were used. Design and methods: Three distinct instruments that measure scientific epistemological beliefs, self-efficacy in learning physics and attitudes toward physics were combined into a unique questionnaire form and it was distributed to high school students. To explore the relationships among these variables, structural equation modeling was used. Results: The results showed that scientific epistemological belief dimensions uncovered by the nature of knowing (source and justification) significantly and positively related to both self-efficacy in learning physics and attitudes toward other important physics dimensions. Additionally, self-efficacy in learning physics significantly and positively predicted attitudes toward multiple physics dimensions (importance, comprehension and requirement). However, epistemological belief dimensions related to the nature of knowledge (certainty and development) did not have significant impact on self-efficacy in learning physics or attitudes toward physics. Conclusions: This study concludes that there are positive and significant relationships among Turkish high school students' scientific

Profiles of Change: Lessons for Improving High School Physical Education

ERIC Educational Resources Information Center

Doolittle, Sarah

2014-01-01

This feature has told stories of high school physical educators who have refused to accept the status quo of high school physical education programs. They have identified problems, initiated innovations in their own classes, implemented changes beyond their classes, and moved toward institutionalizing improvements throughout their programs and…

Research in High Energy Physics. Final report

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

Conway, John S.

2013-08-09

This final report details the work done from January 2010 until April 2013 in the area of experimental and theoretical high energy particle physics and cosmology at the University of California, Davis.

Using Physical Organic Chemistry To Shape the Course of Electrochemical Reactions.

PubMed

Moeller, Kevin D

2018-05-09

While organic electrochemistry can look quite different to a chemist not familiar with the technique, the reactions are at their core organic reactions. As such, they are developed and optimized using the same physical organic chemistry principles employed during the development of any other organic reaction. Certainly, the electron transfer that triggers the reactions can require a consideration of new "wrinkles" to those principles, but those considerations are typically minimal relative to the more traditional approaches needed to manipulate the pathways available to the reactive intermediates formed downstream of that electron transfer. In this review, three very different synthetic challenges-the generation and trapping of radical cations, the development of site-selective reactions on microelectrode arrays, and the optimization of current in a paired electrolysis-are used to illustrate this point.

High School Physics Teacher Outreach Programs at California State University Long Beach

NASA Astrophysics Data System (ADS)

Kwon, Chuhee; Pickett, Galen; Henriques, Laura

2013-03-01

One of the goals of the CSULB PhysTEC project has been to establish a physics teaching community that partners CSULB faculty, high school teachers, pre-service teachers, and physics students. In two years, we have created a solid sustainable Physics Teacher Network with local high school teachers. We will discuss the successful outreach programs for high school physics teachers at CSULB and the detailed logistics. Teacher-In-Residence (TIR), high school physics teachers working with the CSULB PhysTEC team, has provided invaluable input for designing and implementing outreach events. The department organizes biannual open house for local high school teachers and their students. The open house event is attended by pre-service teachers, physics undergraduate and graduate students, and faculty. We also host the monthly demo-sharing day that physics teachers bring and share topical demos, which has about 30 - 50 attendees each month. The CSULB PhysTEC project also distributes a monthly newsletter for local physics teachers with upcoming events and information about teaching, and this newsletter is organized and written by TIR. This work is supported by the PhysTEC grant.

Nonfaradaic nanoporous electrochemistry for conductometry at high electrolyte concentration.

PubMed

Bae, Je Hyun; Kang, Chung Mu; Choi, Hyoungseon; Kim, Beom Jin; Jang, Woohyuk; Lim, Sung Yul; Kim, Hee Chan; Chung, Taek Dong

2015-02-17

Nanoporous electrified surfaces create a unique nonfaradaic electrochemical behavior that is sensitively influenced by pore size, morphology, ionic strength, and electric field modulation. Here, we report the contributions of ion concentration and applied ac frequency to the electrode impedance through an electrical double layer overlap and ion transport along the nanopores. Nanoporous Pt with uniform pore size and geometry (L2-ePt) responded more sensitively to conductivity changes in aqueous solutions than Pt black with poor uniformity despite similar real surface areas and enabled the previously difficult quantitative conductometry measurements at high electrolyte concentrations. The nanopores of L2-ePt were more effective in reducing the electrode impedance and exhibited superior linear responses to not only flat Pt but also Pt black, leading to successful conductometric detection in ion chromatography without ion suppressors and at high ionic strengths.

Fast single run of vanilla fingerprint markers on microfluidic-electrochemistry chip for confirmation of common frauds.

PubMed

Avila, Mónica; Zougagh, Mohammed; Escarpa, Alberto; Ríos, Angel

2009-10-01

A new strategy based on the fast separation of the fingerprint markers of Vanilla planifolia extracts and vanilla-related samples on microfluidic-electrochemistry chip is proposed. This methodology allowed the detection of all required markers for confirmation of common frauds in this field. The elution order was strategically connected with sequential sample screening and analyte confirmation steps, where first ethyl vanillin was detected to distinguish natural from adultered samples; second, vanillin as prominent marker in V. planifolia, but frequently added in its synthetic form; and third, the final detection of the fingerprint markers (p-hydroxybenzaldehyde, vanillic acid, and p-hydroxybenzoic acid) of V. planifolia with confirmation purposes. The reliability of the proposed methodology was demonstrated in the confirmation the natural or non-natural origin of vanilla in samples using V. planifolia extracts and other selected food samples containing this flavor.

Application of Carbon-Microsphere-Modified Electrodes for Electrochemistry of Hemoglobin and Electrocatalytic Sensing of Trichloroacetic Acid

PubMed Central

Wang, Wen-Cheng; Yan, Li-Jun; Shi, Fan; Niu, Xue-Liang; Huang, Guo-Lei; Zheng, Cai-Juan; Sun, Wei

2015-01-01

By using the hydrothermal method, carbon microspheres (CMS) were fabricated and used for electrode modification. The characteristics of CMS were investigated using various techniques. The biocompatible sensing platform was built by immobilizing hemoglobin (Hb) on the micrometer-sized CMS-modified electrode with a layer of chitosan membrane. On the cyclic voltammogram, a couple of quasi-reversible cathodic and anodic peaks appeared, showing that direct electrochemistry of Hb with the working electrode was achieved. The catalytic reduction peak currents of the bioelectrode to trichloroacetic acid was established in the linear range of 2.0~70.0 mmol·L−1 accompanied by a detection limit of 0.30 mmol·L−1 (3σ). The modified electrode displayed favorable sensitivity, good reproducibility and stability, which suggests that CMS is promising for fabricating third-generation bioelectrochemical sensors. PMID:26703621

High Performance Computing Modeling Advances Accelerator Science for High-Energy Physics

DOE PAGES

Amundson, James; Macridin, Alexandru; Spentzouris, Panagiotis

2014-07-28

The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space, and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing are essential for accurately modeling them. In the past decade, the US Department of Energy's SciDAC program has produced accelerator-modeling tools that have been employed to tackle some of the most difficult accelerator science problems. The authors discuss the Synergia framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation package capable ofmore » handling the entire spectrum of beam dynamics simulations. Our authors present Synergia's design principles and its performance on HPC platforms.« less

Deconvolution of Composition and Crystallite Size of Silver Hollandite Nanorods: Influence on Electrochemistry

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

Durham, Jessica L.; Huang, Jianping; Zhang, Bingjie

In this paper, silver hollandite (Ag 1.4Mn 8O 16) has been synthesized by an aqueous, low-temperature co-precipitation technique to afford silver hollandite with distinct crystallite sizes (10 and 15 nm, identified as S-Ag 1.4Mn 8O 16 and L-Ag 1.4Mn 8O 16, respectively) and equivalent silver content (x), allowing for the deconvolution of electrochemical effects related to crystallite size and silver content. The as-prepared silver hollandite materials were confirmed to be structurally analogous. Notably, TEM imaging reveals a high degree of bundling of S-Ag 1.4Mn 8O 16 nanorods compared to L-Ag 1.4Mn 8O 16 which facilitates more intimate connection of themore » S-Ag 1.4Mn 8O 16 material with enhanced interparticle contact. The electrochemical behavior and lithium diffusion properties were investigated by galvanostatic cycling, CV, electrochemical impedance, pulsed-discharge experiments, and ex-situ XAS analysis of cycled cathodes. Lithium based electrochemical cells containing S-Ag 1.4Mn 8O 16 delivered a capacity 15X higher than L-Ag 1.4Mn 8O 16 on cycle 1. Ex-situ XAS demonstrated structural change for S-Ag 1.4Mn 8O 16 and formation of Ag 0 on insertion of 3.8 Li + intercalation. However, the samples of L-Ag 1.4Mn 8O 16 were lithiated by a more limited 0.25 molar equivalents, where no significant structural changes were observed. Finally, the findings affirm crystallite size significantly impacts electrochemistry independent of cation occupancy of the α-MnO 2 type structure.« less

Deconvolution of Composition and Crystallite Size of Silver Hollandite Nanorods: Influence on Electrochemistry

DOE PAGES

Durham, Jessica L.; Huang, Jianping; Zhang, Bingjie; ...

2017-12-16

In this paper, silver hollandite (Ag 1.4Mn 8O 16) has been synthesized by an aqueous, low-temperature co-precipitation technique to afford silver hollandite with distinct crystallite sizes (10 and 15 nm, identified as S-Ag 1.4Mn 8O 16 and L-Ag 1.4Mn 8O 16, respectively) and equivalent silver content (x), allowing for the deconvolution of electrochemical effects related to crystallite size and silver content. The as-prepared silver hollandite materials were confirmed to be structurally analogous. Notably, TEM imaging reveals a high degree of bundling of S-Ag 1.4Mn 8O 16 nanorods compared to L-Ag 1.4Mn 8O 16 which facilitates more intimate connection of themore » S-Ag 1.4Mn 8O 16 material with enhanced interparticle contact. The electrochemical behavior and lithium diffusion properties were investigated by galvanostatic cycling, CV, electrochemical impedance, pulsed-discharge experiments, and ex-situ XAS analysis of cycled cathodes. Lithium based electrochemical cells containing S-Ag 1.4Mn 8O 16 delivered a capacity 15X higher than L-Ag 1.4Mn 8O 16 on cycle 1. Ex-situ XAS demonstrated structural change for S-Ag 1.4Mn 8O 16 and formation of Ag 0 on insertion of 3.8 Li + intercalation. However, the samples of L-Ag 1.4Mn 8O 16 were lithiated by a more limited 0.25 molar equivalents, where no significant structural changes were observed. Finally, the findings affirm crystallite size significantly impacts electrochemistry independent of cation occupancy of the α-MnO 2 type structure.« less

Preparing prospective physics teachers to teach integrated science in junior high school

NASA Astrophysics Data System (ADS)

Wiyanto; Hartono; Nugroho, S. E.

2018-03-01

The physics education study program especially prepares its students to teach physics in senior high school, however in reality many its graduates have become science teachers in junior high school. Therefore introducing integrated science to prospective physics teachers is important, because based on the curriculum, science in the junior high school should be taught integratedly. This study analyzed integrated science teaching materials that developed by prospective physics teachers. Results from this study showed that majority of the integration materials that developed by the prospective physics teachers focused on topic with an overlapping concept or theme as connecting between two or three subjects.

Experimental And Theoretical High Energy Physics Research At UCLA

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

Cousins, Robert D.

2013-07-22

This is the final report of the UCLA High Energy Physics DOE Grant No. DE-FG02- 91ER40662. This report covers the last grant project period, namely the three years beginning January 15, 2010, plus extensions through April 30, 2013. The report describes the broad range of our experimental research spanning direct dark matter detection searches using both liquid xenon (XENON) and liquid argon (DARKSIDE); present (ICARUS) and R&D for future (LBNE) neutrino physics; ultra-high-energy neutrino and cosmic ray detection (ANITA); and the highest-energy accelerator-based physics with the CMS experiment and CERN’s Large Hadron Collider. For our theory group, the report describesmore » frontier activities including particle astrophysics and cosmology; neutrino physics; LHC interaction cross section calculations now feasible due to breakthroughs in theoretical techniques; and advances in the formal theory of supergravity.« less

Participation in High Energy Physics at the University of Chicago

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

Martinec, Emil J.

2013-06-27

This report covers research at the University of Chicago in theoretical high energy physics and its connections to cosmology, over the period Nov. 1, 2009 to April 30, 2013. This research is divided broadly into two tasks: Task A, which covers a broad array of topics in high energy physics; and task C, primarily concerned with cosmology.

Gender Differences in Introductory University Physics Performance: The Influence of High School Physics Preparation and Affective Factors

ERIC Educational Resources Information Center

Hazari, Zahra; Tai, Robert H.; Sadler, Philip M.

2007-01-01

The attrition of females studying physics after high school is a growing concern to the science education community. Most undergraduate science programs require introductory physics coursework. Thus, success in introductory physics is usually necessary for students to progress to higher levels of science study. Success also influences attitudes;…

Oklahoma Center for High Energy Physics (OCHEP)

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

Nandi, S; Strauss, M J; Snow, J

2012-02-29

The DOE EPSCoR implementation grant, with the support from the State of Oklahoma and from the three universities, Oklahoma State University, University of Oklahoma and Langston University, resulted in establishing of the Oklahoma Center for High Energy Physics (OCHEP) in 2004. Currently, OCHEP continues to flourish as a vibrant hub for research in experimental and theoretical particle physics and an educational center in the State of Oklahoma. All goals of the original proposal were successfully accomplished. These include foun- dation of a new experimental particle physics group at OSU, the establishment of a Tier 2 computing facility for the Largemore » Hadron Collider (LHC) and Tevatron data analysis at OU and organization of a vital particle physics research center in Oklahoma based on resources of the three universities. OSU has hired two tenure-track faculty members with initial support from the grant funds. Now both positions are supported through OSU budget. This new HEP Experimental Group at OSU has established itself as a full member of the Fermilab D0 Collaboration and LHC ATLAS Experiment and has secured external funds from the DOE and the NSF. These funds currently support 2 graduate students, 1 postdoctoral fellow, and 1 part-time engineer. The grant initiated creation of a Tier 2 computing facility at OU as part of the Southwest Tier 2 facility, and a permanent Research Scientist was hired at OU to maintain and run the facility. Permanent support for this position has now been provided through the OU university budget. OCHEP represents a successful model of cooperation of several universities, providing the establishment of critical mass of manpower, computing and hardware resources. This led to increasing Oklahoma's impact in all areas of HEP, theory, experiment, and computation. The Center personnel are involved in cutting edge research in experimental, theoretical, and computational aspects of High Energy Physics with the research areas ranging

Physical education Teachers' and public health Nurses' perception of Norwegian high school Students' participation in physical education - a focus group study.

PubMed

Abildsnes, Eirik; Stea, Tonje H; Berntsen, Sveinung; Omfjord, Christina S; Rohde, Gudrun

2015-12-24

High quality physical education programs in high schools may facilitate adoption of sustainable healthy living among adolescents. Public health nurses often meet students who avoid taking part in physical education programs. We aimed to explore physical education teachers' and public health nurses' perceptions of high school students' attitudes towards physical education, and to explore physical education teachers' thoughts about how to facilitate and promote students' participation in class. Prior to an initiative from physical education teachers, introducing a new physical education model in two high schools in the South of Norway, we conducted focus groups with 6 physical education teachers and 8 public health nurses. After implementation of the new model, we conducted two additional focus group interviews with 10 physical education teachers. In analyses we used Systematic Text Condensation and an editing analysis style. In general, the students were experienced as engaged and appreciating physical education lessons. Those who seldom attended often strived with other subjects in school as well, had mental health problems, or were characterized as outsiders in several arenas. Some students were reported to be reluctant to expose their bodies in showers after class, and students who seldom attended physical education class frequently visited the school health services. Although the majority of students were engaged in class, several of the students lacked knowledge about physical fitness and motoric skills to be able to master daily activities. The participants related the students' competence and attitude towards participation in physical education class to previous experiences in junior high school, to the competence of physical education teachers, and to possibility for students to influence the content of physical education programs. The participants suggested that high school students' attitudes towards participation in physical education is heterogeneous

Studies In Theoretical High Energy Particle Physics

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

Keung, Wai Yee

2017-07-01

This is a final technical report for grant no. DE-SC0007948 describing research activities in theoretical high energy physics at University of Illinois at Chicago for the whole grant period from July 1, 2012 to March 31, 2017.

Physics at high energy photon photon colliders

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

Chanowitz, M.S.

I review the physic prospects for high energy photon photon colliders, emphasizing results presented at the LBL Gamma Gamma Collider Workshop. Advantages and difficulties are reported for studies of QCD, the electroweak gauge sector, supersymmetry, and electroweak symmetry breaking.

Polarized targets in high energy physics

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

Cates, G.D. Jr.

1994-12-01

Various approaches are discussed for producing polarized nuclear targets for high energy physics experiments. As a unifying theme, examples are drawn from experiments to measure spin dependent structure functions of nucleons in deep inelastic scattering. This single physics goal has, over roughly two decades, been a driving force in advances in target technology. Actual or planned approaches have included solid targets polarized by dynamic nuclear polarization (DNP), several types of internal targets for use in storage rings, and gaseous {sup 3}He targets polarized by spin-exchange optical pumping. This last approach is the type of target adopted for SLAC E-142, anmore » experiment to measure the spin structure function of the neutron, and is described in detail.« less

STM, SECPM, AFM and Electrochemistry on Single Crystalline Surfaces

PubMed Central

Wolfschmidt, Holger; Baier, Claudia; Gsell, Stefan; Fischer, Martin; Schreck, Matthias; Stimming, Ulrich

2010-01-01

Scanning probe microscopy (SPM) techniques have had a great impact on research fields of surface science and nanotechnology during the last decades. They are used to investigate surfaces with scanning ranges between several 100 μm down to atomic resolution. Depending on experimental conditions, and the interaction forces between probe and sample, different SPM techniques allow mapping of different surface properties. In this work, scanning tunneling microscopy (STM) in air and under electrochemical conditions (EC-STM), atomic force microscopy (AFM) in air and scanning electrochemical potential microscopy (SECPM) under electrochemical conditions, were used to study different single crystalline surfaces in electrochemistry. Especially SECPM offers potentially new insights into the solid-liquid interface by providing the possibility to image the potential distribution of the surface, with a resolution that is comparable to STM. In electrocatalysis, nanostructured catalysts supported on different electrode materials often show behavior different from their bulk electrodes. This was experimentally and theoretically shown for several combinations and recently on Pt on Au(111) towards fuel cell relevant reactions. For these investigations single crystals often provide accurate and well defined reference and support systems. We will show heteroepitaxially grown Ru, Ir and Rh single crystalline surface films and bulk Au single crystals with different orientations under electrochemical conditions. Image studies from all three different SPM methods will be presented and compared to electrochemical data obtained by cyclic voltammetry in acidic media. The quality of the single crystalline supports will be verified by the SPM images and the cyclic voltammograms. Furthermore, an outlook will be presented on how such supports can be used in electrocatalytic studies. PMID:28883327

HIGH ENERGY PHYSICS: Bulgarians Sue CERN for Leniency.

PubMed

Koenig, R

2000-10-13

In cash-strapped Bulgaria, scientists are wondering whether a ticket for a front-row seat in high-energy physics is worth the price: Membership dues in CERN, the European particle physics lab, nearly equal the country's entire budget for competitive research grants. Faced with that grim statistic and a plea for leniency from Bulgaria's government, CERN's governing council is considering slashing the country's membership dues for the next 2 years.

Problems with the rush toward advanced physics in high schools

NASA Astrophysics Data System (ADS)

Gollub, Jerry

2003-04-01

The Advanced Placement (AP) Program has a major impact on the physics experience of many high school students. It affects admission to college, course choices and performance in college, and subsequent career decisions. A study committee of the National Research Council published a review of these programs in 2002, and concluded that while the program has many positive features, important problems need to be addressed. [1] The programs are not currently consistent with what we have learned about student learning from cognitive research. Students are often poorly prepared for AP courses, because of lack of coordination within schools. The Physics AP-B (non-calculus) program is too broad to allow most high school students to achieve an adequate level of conceptual understanding. Participation by minority students in these programs is far below that of other students. The AP exams need to be re-evaluated to insure that they actually measure conceptual understanding and complex reasoning. The AP exams are sometimes used inappropriately to rate teachers or schools. College and high school courses are poorly coordinated, with the result that students often take an introductory physics survey as many as three times. Policies on college credit for AP courses differ widely. These problems cannot be fixed by the College Board alone. [1] Jerry P. Gollub and Robin Spital, "Advanced Physics in the High Schools", Physics Today, May 2002.

Sophisticated epistemologies of physics versus high-stakes tests: How do elite high school students respond to competing influences about how to learn physics?

NASA Astrophysics Data System (ADS)

Yerdelen-Damar, Sevda; Elby, Andrew

2016-06-01

This study investigates how elite Turkish high school physics students claim to approach learning physics when they are simultaneously (i) engaged in a curriculum that led to significant gains in their epistemological sophistication and (ii) subject to a high-stakes college entrance exam. Students reported taking surface (rote) approaches to learning physics, largely driven by college entrance exam preparation and therefore focused on algorithmic problem solving at the expense of exploring concepts and real-life examples more deeply. By contrast, in recommending study strategies to "Arzu," a hypothetical student who doesn't need to take a college entrance exam and just wants to understand physics deeply, the students focused more on linking concepts and real-life examples and on making sense of the formulas and concepts—deep approaches to learning that reflect somewhat sophisticated epistemologies. These results illustrate how students can epistemically compartmentalize, consciously taking different epistemic stances—different views of what counts as knowing and learning—in different contexts even within the same discipline.

Social Cognitive Theory and Physical Activity Among Korean Male High-School Students.

PubMed

Lee, Chung Gun; Park, Seiyeong; Lee, Seung Hwan; Kim, Hyunwoo; Park, Ji-Won

2018-02-01

The most critical step in developing and implementing effective physical activity interventions is to understand the determinants and correlates of physical activity, and it is strongly suggested that such effort should be based on theories. The purpose of this study is to test the direct, indirect, and total effect of social cognitive theory constructs on physical activity among Korean male high-school students. Three-hundred and forty-one 10th-grade male students were recruited from a private single-sex high school located in Seoul, South Korea. Structural equation modeling was used to test the expected relationships among the latent variables. The proposed model accounted for 42% of the variance in physical activity. Self-efficacy had the strongest total effect on physical activity. Self-efficacy for being physically active was positively associated with physical activity ( p < .01). Self-efficacy also had positive indirect effects on physical activity through perceived benefits ( p < .05) and goal setting ( p < .01). The results of this study indicated that the social cognitive theory is a useful framework to understand physical activity among Korean male adolescents. Physical activity interventions targeting Korean male high-school students should focus on the major sources of efficacy.

Research in Theoretical High-Energy Physics at Southern Methodist University

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

Olness, Fredrick; Nadolsky, Pavel

2016-08-05

The SMU Theory group has developed a strong expertise in QCD, PDFs, and incisive comparisons between collider data and theory. The group pursues realistic phenomenological calculations for high-energy processes, the highly demanded research area driven by the LHC physics. Our field has seen major discoveries in recent years from a variety of experiments, large and small, including a number recognized by Nobel Prizes. There is a wealth of novel QCD data to explore. The SMU theory group develops the most advanced and innovative tools for comprehensive analysis in applications ranging from Higgs physics and new physics searches to nuclear scattering.

High energy physics, past, present and future

NASA Astrophysics Data System (ADS)

Sugawara, Hirotaka

2017-03-01

At the beginning of last century we witnessed the emergence of new physics, quantum theory and gravitational theory, which gave us correct understanding of the world of atoms and deep insight into the structure of universe we live in. Towards the end of the century, string theory emerged as the most promising candidate to unify these two theories. In this talk, I would like to assert that the understanding of the origin of physical constants, ℏ (Planck constant) for quantum theory, and G (Newton’s gravitational constant) for gravitational theory within the framework of string theory is the key to understanding string theory. Then, I will shift to experimental high energy physics and discuss the necessity of world-wide collaboration in the area of superconducting technology which is essential in constructing the 100 TeV hadron collider.

"Why Do I Slog through the Physics?" Understanding High School Students' Difficulties in Learning Physics

ERIC Educational Resources Information Center

Ekici, Erhan

2016-01-01

The aim of this study is to develop a valid and reliable instrument to assess why physics courses are perceived as one of the most difficult courses among high school students and to investigate the reasons why students have difficulty in learning physics through this scale. This study includes the development and validation studies of the…

Who Teaches High School Physics? Results from the 2012-13 Nationwide Survey of High School Physics Teachers. Focus On

ERIC Educational Resources Information Center

White, Susan; Tyler, John

2014-01-01

During the 2012-13 academic year, the authors collected data from a representative national sample of over 3,500 public and private high schools across the U.S. to inquire about physics availabilities and offerings. This report describes their findings.

Application of experiential learning model using simple physical kit to increase attitude toward physics student senior high school in fluid

NASA Astrophysics Data System (ADS)

Johari, A. H.; Muslim

2018-05-01

Experiential learning model using simple physics kit has been implemented to get a picture of improving attitude toward physics senior high school students on Fluid. This study aims to obtain a description of the increase attitudes toward physics senior high school students. The research method used was quasi experiment with non-equivalent pretest -posttest control group design. Two class of tenth grade were involved in this research 28, 26 students respectively experiment class and control class. Increased Attitude toward physics of senior high school students is calculated using an attitude scale consisting of 18 questions. Based on the experimental class test average of 86.5% with the criteria of almost all students there is an increase and in the control class of 53.75% with the criteria of half students. This result shows that the influence of experiential learning model using simple physics kit can improve attitude toward physics compared to experiential learning without using simple physics kit.

A Comparison of the Fitness, Obesity, and Physical Activity Levels of High School Physical Education Students across Race and Gender

ERIC Educational Resources Information Center

Davis, Kathryn L.; Wojcik, Janet R.; DeWaele, Christi S.

2016-01-01

Introduction: Little is known about the physical fitness, obesity, and physical activity (PA) levels of high school students in physical education classes when comparing racial and gender groups. Purpose: To compare the fitness, obesity, and PA levels of female and male students of different racial groups in 6 high schools in the southeastern…

Success in Introductory College Physics: The Role of High School Preparation.

ERIC Educational Resources Information Center

Sadler, Philip M.; Tai, Robert H.

2001-01-01

Examines the extent to which a high school physics course prepares students for college physics success. In this study of 1,933 introductory college physics students, demographic and schooling factors account for a large fraction of the variation in college physics grades at 18 colleges and universities from around the nation. (Author/SAH)

Methods for Probing New Physics at High Energies

NASA Astrophysics Data System (ADS)

Denton, Peter B.

This dissertation covers two broad topics. The title, " Methods for Probing New Physics at High Energies," hopefully encompasses both of them. The first topic is located in part I of this work and is about integral dispersion relations. This is a technique to probe for new physics at energy scales near to the machine energy of a collider. For example, a hadron collider taking data at a given energy is typically only sensitive to new physics occurring at energy scales about a factor of five to ten beneath the actual machine energy due to parton distribution functions. This technique is sensitive to physics happening directly beneath the machine energy in addition to the even more interesting case: directly above. Precisely where this technique is sensitive is one of the main topics of this area of research. The other topic is located in part II and is about cosmic ray anisotropy at the highest energies. The unanswered questions about cosmic rays at the highest energies are numerous and interconnected in complicated ways. What may be the first piece of the puzzle to fall into place is determining their sources. This work looks to determine if and when the use of spherical harmonics becomes sensitive enough to determine these sources. The completed papers for this work can be found online. For part I on integral dispersion relations see reference published in Physical Review D. For part II on cosmic ray anisotropy, there are conference proceedings published in the Journal of Physics: Conference Series. The analysis of the location of an experiment on anisotropy reconstruction is, and the comparison of different experiments' abilities to reconstruct anisotropies is published in The Astrophysical Journal and the Journal of High Energy Astrophysics respectively. While this dissertation is focused on three papers completed with Tom Weiler at Vanderbilt University, other papers were completed at the same time. The first was with Nicusor Arsene, Lauretiu Caramete, and

Physical activity and neighborhood resources in high school girls.

PubMed

Pate, Russell R; Colabianchi, Natalie; Porter, Dwayne; Almeida, Maria J; Lobelo, Felipe; Dowda, Marsha

2008-05-01

Physical activity behavior is influenced by a person's physical environment, but few studies have used objective measures to study the influences of the physical environment on physical activity behavior in youth. The purpose of this study was to examine the relationship between selected neighborhood physical activity resources and physical activity levels in high school girls. Participants were students in schools that had participated in a large physical activity intervention trial. The 3-Day Physical Activity Recall was completed by 1506 12th-grade girls. Data on physical activity facilities and resources in the participating communities were collected using a variety of methods. Physical activity resources within a 0.75-mile street-network buffer around each girl's home were counted using ArcGIS, version 9.1. Mixed-model regression models were used to determine if there was a relationship between three physical activity variables and the number of physical activity resources within the 0.75-mile buffer. Data were collected in 2002-2003 and analyzed in 2006-2007. On average, 3.5 physical activity resources (e.g., schools, parks, commercial facilities) were located within the 0.75-mile street-network buffer. Thirty-six percent of the girls had no physical activity resource within the buffer. When multiple physical activity resources were considered, the number of commercial physical activity facilities was significantly associated with reported vigorous physical activity, and the number of parks was associated with total METs in white girls. Multiple physical activity resources within a 0.75-mile street-network buffer around adolescent girls' homes are associated physical activity in those girls. Several types of resources are associated with vigorous physical activity and total activity in adolescent girls. Future studies should examine the temporal and causal relationships between the physical environment, physical activity, and health outcomes related to

The Survey and Analysis of Excellent Senior High School Physics Teachers' Professional Growth Actuality

ERIC Educational Resources Information Center

Sun, Haibin; Liu, Tingting

2010-01-01

Excellent senior high school physics teachers are the backbone power in the new course reform of physics in China. The excellent senior high school physics teachers' professional growth actuality in Shandong is surveyed in this article by the self-made "Questionnaire of Excellent Senior High School Physics Teachers' Professional Growth",…

High school physics enrollments by socioeconomic status and type of class

NASA Astrophysics Data System (ADS)

White, Susan C.

2016-01-01

Since September, we have been examining the relationship between high school physics enrollments by race/ethnicity and socioeconomic status. We have seen that the number of seniors and the number of physics teachers is roughly evenly divided into each type of school: those where students are typically better off economically than their peers at other schools in the area, those where students' economic status is typical for the area, and those where students are worse off. We have seen that even though the number of seniors and the number of physics teachers is roughly equal, the number of students taking physics is not. As we see in the figure, the enrollments in various types of physics classes are not equivalent either. While the total number of students taking Physics First or conceptual physics is about the same, the number of students in advanced classes—honors, AP, or second-year physics—is heavily skewed toward the better off schools. It is hard to know the direction of any cause and effect, but it is clear the students attending better off schools are more likely to take physics and are more likely to take more advanced physics classes in high school.

Towards a high quality high school workforce: A longitudinal, demographic analysis of U.S. public school physics teachers

NASA Astrophysics Data System (ADS)

Rushton, Gregory T.; Rosengrant, David; Dewar, Andrew; Shah, Lisa; Ray, Herman E.; Sheppard, Keith; Watanabe, Lynn

2017-12-01

Efforts to improve the number and quality of the high school physics teaching workforce have taken several forms, including those sponsored by professional organizations. Using a series of large-scale teacher demographic data sets from the National Center for Education Statistics (NCES), this study sought to investigate trends in teacher quality at the national level in the two and a half decades between 1987 and 2012. Specifically, we investigated (i) details about the degree backgrounds, main teaching assignments, and experience levels of those assigned to teach physics; (ii) whether the proportion of those with certifications in physics as a fraction of the entire physics teaching workforce had changed; and (iii) if workforce diversity (with respect to race and gender) had changed over time. Our data indicate that trends in these domains have generally been positive, but still fall short of having a highly qualified physics teacher in each classroom. Additionally, the population of physics teachers has more novices and fewer veterans than it did 10 years ago, although veteran physics teachers are not as rare as those in other branches of high school STEM fields. We also analyzed trends in physics teacher race and gender diversity and found them to lag behind other STEM and non-STEM teacher communities. High school physics is still mostly taught by white males with backgrounds from outside of physics. Implications for future policy decisions at the local and national levels are discussed, including attending to the specific needs of degree-holding and non-degree-holding physics teachers separately and localizing teacher recruitment and preparation efforts in regional centers.

Bringing Real Solar Physics to the High School Classroom

NASA Astrophysics Data System (ADS)

Seaton, Daniel

2006-06-01

UNH's Partnership for Research Opportunities to Benefit Education (PROBE) project sends graduate students into high school classrooms across New Hampshire in order to help introduce students to authentic scientific inquiry. As one of ten graduate fellows, I worked with students in in ninth through twelfth grades in physical science, physics, earth science, and astronomy classes; helping students carry out individual and class projects on physics and solar physics. Projects related to solar physics included the production and analysis of plasma using a microwave oven, measurement of the solar constant, measurement of the solar rotation rate, solar spectroscopy, analysis of data from TRACE and SOHO, and the construction of various solar-powered devices. This work was generously supported by a grant from the National Science Foundation's GK-12 initiative (NSF#0338277).

Final Report. Research in Theoretical High Energy Physics

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

Greensite, Jeffrey P.; Golterman, Maarten F.L.

Grant-supported research in theoretical high-energy physics, conducted in the period 1992-2015 is briefly described, and a full listing of published articles result from those research activities is supplied.

Energy peaks: A high energy physics outlook

NASA Astrophysics Data System (ADS)

Franceschini, Roberto

2017-12-01

Energy distributions of decay products carry information on the kinematics of the decay in ways that are at the same time straightforward and quite hidden. I will review these properties and discuss their early historical applications, as well as more recent ones in the context of (i) methods for the measurement of masses of new physics particle with semi-invisible decays, (ii) the characterization of Dark Matter particles produced at colliders, (iii) precision mass measurements of Standard Model particles, in particular of the top quark. Finally, I will give an outlook of further developments and applications of energy peak method for high energy physics at colliders and beyond.

Improving physics teaching materials on sound for visually impaired students in high school

NASA Astrophysics Data System (ADS)

Toenders, Frank G. C.; de Putter-Smits, Lesley G. A.; Sanders, Wendy T. M.; den Brok, Perry

2017-09-01

When visually impaired students attend regular high school, additional materials are necessary to help them understand physics concepts. The time for teachers to develop teaching materials for such students is scarce. Visually impaired students in regular high school physics classes often use a braille version of the physics textbook. Previously, we evaluated the physics learning environment of a blind high school student in a regular Dutch high school. In this research we evaluate the use of a revised braille textbook, relief drawings and 3D models. The research focussed on the topic of sound in grade 10.

The limitations of mathematical modeling in high school physics education

NASA Astrophysics Data System (ADS)

Forjan, Matej

The theme of the doctoral dissertation falls within the scope of didactics of physics. Theoretical analysis of the key constraints that occur in the transmission of mathematical modeling of dynamical systems into field of physics education in secondary schools is presented. In an effort to explore the extent to which current physics education promotes understanding of models and modeling, we analyze the curriculum and the three most commonly used textbooks for high school physics. We focus primarily on the representation of the various stages of modeling in the solved tasks in textbooks and on the presentation of certain simplifications and idealizations, which are in high school physics frequently used. We show that one of the textbooks in most cases fairly and reasonably presents the simplifications, while the other two half of the analyzed simplifications do not explain. It also turns out that the vast majority of solved tasks in all the textbooks do not explicitly represent model assumptions based on what we can conclude that in high school physics the students do not develop sufficiently a sense of simplification and idealizations, which is a key part of the conceptual phase of modeling. For the introduction of modeling of dynamical systems the knowledge of students is also important, therefore we performed an empirical study on the extent to which high school students are able to understand the time evolution of some dynamical systems in the field of physics. The research results show the students have a very weak understanding of the dynamics of systems in which the feedbacks are present. This is independent of the year or final grade in physics and mathematics. When modeling dynamical systems in high school physics we also encounter the limitations which result from the lack of mathematical knowledge of students, because they don't know how analytically solve the differential equations. We show that when dealing with one-dimensional dynamical systems

Electrochemistry of Prebiotic Early Earth Hydrothermal Chimney Systems

NASA Astrophysics Data System (ADS)

Hermis, N.; Barge, L. M.; Chin, K. B.; LeBlanc, G.; Cameron, R.

2017-12-01

Hydrothermal chimneys are self-organizing chemical garden precipitates generated from geochemical disequilibria within sea-vent environments, and have been proposed as a possible setting for the emergence of life because they contain mineral catalysts and transect ambient pH / Eh / chemical gradients [1]. We simulated the growth of hydrothermal chimneys in early Earth vent systems by using different hydrothermal simulants such as sodium sulfide (optionally doped with organic molecules) which were injected into an early Earth ocean simulant containing dissolved ferrous iron, nickel, and bicarbonate [2]. Chimneys on the early Earth would have constituted flow-through reactors, likely containing Fe/Ni-sulfide catalysts that could have driven proto-metabolic electrochemical reactions. The electrochemical activity of the chimney system was characterized non-invasively by placing electrodes at different locations across the chimney wall and in the ocean to analyze the bulk properties of surface charge potential in the chimney / ocean / hydrothermal fluid system. We performed in-situ characterization of the chimney using electrochemical impedance spectroscopy (EIS) which allowed us to observe the changes in physio-chemical behavior of the system through electrical spectra of capacitance and impedance over a wide range of frequencies during the metal sulfide chimney growth. The electrochemical properties of hydrothermal chimneys in natural systems persist due to the disequilibria maintained between the ocean and hydrothermal fluid. When the injection in our experiment (analogous to fluid flow in a vent) stopped, we observed a corresponding decline in open circuit voltage across the chimney wall, though the impedance of the precipitate remained lor. Further work is needed to characterize the electrochemistry of simulated chimney systems by controlling response factors such as electrode geometry and environmental conditions, in order to simulate electrochemical reactions

CERN and high energy physics, the grand picture

ScienceCinema

Heuer, Rolf-Dieter

2018-05-24

The lecture will touch on several topics, to illustrate the role of CERN in the present and future of high-energy physics: how does CERN work? What is the role of the scientific community, of bodies like Council and SPC, and of international cooperation, in the definition of CERN's scientific programme? What are the plans for the future of the LHC and of the non-LHC physics programme? What is the role of R&D; and technology transfer at CERN?

Nuclear Physics in High School: what are the previous knowledge?

NASA Astrophysics Data System (ADS)

Pombo, F. de O.

2017-11-01

Nuclear physics is a branch of physics that about a century occupies an important space in the theoretical, experimental and scientific fields. Currently, its relevance in application is concentrated in several areas such as energy production, diagnostic processes and medical treatment and nuclear bombs, high destructive power. Whereas, according to legal regulations, the teaching of physics must make the student competent in the understanding of the world and assuming the perspective of Paulo Freire (2011) that education is not done on the subject, but together with him, in dialogue with his point of departure, his prior knowledge, we established the general objective of raising students prior knowledge of the third year of high School at Nair Ferreira Neves school, in São Sebastião-SP, about nuclear physics. We concluded that the school has not fulfilled its role in relation to nuclear physics, because students have information from other means of information and these knowledge are stereotyped and mistaken, damaging the world's reading and exercising full citizenship.

Statistical issues in searches for new phenomena in High Energy Physics

NASA Astrophysics Data System (ADS)

Lyons, Louis; Wardle, Nicholas

2018-03-01

Many analyses of data in High Energy Physics are concerned with searches for New Physics. We review the statistical issues that arise in such searches, and then illustrate these using the specific example of the recent successful search for the Higgs boson, produced in collisions between high energy protons at CERN’s Large Hadron Collider.

Does school physical education really contribute to accelerometer-measured daily physical activity and non sedentary behaviour in high school students?

PubMed

Mayorga-Vega, Daniel; Martínez-Baena, Alejandro; Viciana, Jesús

2018-09-01

Physical education has been highlighted as an important environment for physical activity promotion, however, to our knowledge there are no previous studies examining the contribution of physical education to daily accelerometer-measured physical activity and non sedentary behaviour. The purpose was to compare the accelerometer-measured physical activity and sedentary behaviour between physical education, non-physical education and weekend days in adolescents. Of the 394 students from a Spanish high school that were invited to participate, 158 students (83 boys and 75 girls) aged 13-16 years were analyzed (wear time ≥ 600 min). Participants' physical activity and sedentary behaviour were objectively-measured by GT3X+ accelerometers during physical education (one session), non-physical education and weekend days. Results indicated that overall adolescents had statistically significant greater physical activity levels and lower values of sedentary behaviour on physical education days than on non-physical education and weekend days (e.g., moderate-to-vigorous physical activity = 71, 54 and 57 min; sedentary = 710, 740 and 723 min) (p < 0.05). Physical education contributes significantly to reducing students' daily physical inactivity and sedentary behaviour. Increasing the number of physical education classes seems to be an effective strategy to reduce the high current prevalence of physical inactivity and sedentary behaviour in adolescence.

Science Notes.

ERIC Educational Resources Information Center

School Science Review, 1990

1990-01-01

Included are 30 science activities that include computer monitoring, fieldwork, enzyme activity, pH, drugs, calorimeters, Raoult's Law, food content, solubility, electrochemistry, titration, physical properties of materials, gel filtration, energy, concepts in physics, and electricity. (KR)

Accelerator physics and technology challenges of very high energy hadron colliders

NASA Astrophysics Data System (ADS)

Shiltsev, Vladimir D.

2015-08-01

High energy hadron colliders have been in the forefront of particle physics for more than three decades. At present, international particle physics community considers several options for a 100 TeV proton-proton collider as a possible post-LHC energy frontier facility. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. This paper briefly reviews the accelerator physics and technology challenges of the future very high energy colliders and outlines the areas of required research and development towards their technical and financial feasibility.

Accelerator physics and technology challenges of very high energy hadron colliders

DOE PAGES

Shiltsev, Vladimir D.

2015-08-20

High energy hadron colliders have been in the forefront of particle physics for more than three decades. At present, international particle physics community considers several options for a 100 TeV proton–proton collider as a possible post-LHC energy frontier facility. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. This article briefly reviews the accelerator physics and technology challenges of the future very high energy colliders and outlines the areas of required research and development towards their technical and financial feasibility.

Gender Differences in the High School and Affective Experiences of Introductory College Physics Students

NASA Astrophysics Data System (ADS)

Hazari, Zahra; Sadler, Philip M.; Tai, Robert H.

2008-10-01

The disparity in persistence between males and females studying physics has been a topic of concern to physics educators for decades. Overall, while female students perform as well as or better than male students, they continue to lag considerably in terms of persistence. The most significant drop in females studying physics occurs between high school and college.2 Since most female physicists report that they became attracted to physics and decided to study it further while in high school, according to the International Study of Women in Physics,3 it is problematic that high school is also the stage at which females begin to opt out at much higher rates than males. Although half of the students taking one year of physics in high school are female, females are less likely than males to take a second or Advanced Placement (AP) physics course.4 In addition, the percentage of females taking the first physics course in college usually falls between 30% and 40%. In other words, although you may see gender parity in a first high school physics course, this parity does not usually persist to the next level of physics course. In addition, even if there is parity in a high school physics course, it does not mean that males and females experience the course in the same way. It is this difference in experience that may help to explain the drop in persistence of females.

Assessment of rechargeable batteries for high power applications.

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

Delnick, Frank M.; Ripple, Robert Eugene; Butler, Paul Charles

2004-05-01

This paper describes an assessment of a variety of battery technologies for high pulse power applications. Sandia National Laboratories (SNL) is performing the assessment activities in collaboration with NSWC-Dahlgren. After an initial study of specifications and manufacturers' data, the assessment team identified the following electrochemistries as promising for detailed evaluation: lead-acid (Pb-acid), nickel/metal hydride (Ni/MH), nickel/cadmium (Ni/Cd), and a recently released high power lithium-ion (Li-ion) technology. In the first three technology cases, test cells were obtained from at least two and in some instances several companies that specialize in the respective electrochemistry. In the case of the Li-ion technology, cellsmore » from a single company and are being tested. All cells were characterized in Sandia's battery test labs. After several characterization tests, the Pb-acid technology was identified as a backup technology for the demanding power levels of these tests. The other technologies showed varying degrees of promise. Following additional cell testing, the assessment team determined that the Ni/MH technology was suitable for scale-up and acquired 50-V Ni/MH modules from two suppliers for testing. Additional tests are underway to better characterize the Ni/Cd and the Li-ion technologies as well. This paper will present the testing methodology and results from these assessment activities.« less

Determination of psychostimulants and their metabolites by electrochemistry linked on-line to flowing atmospheric pressure afterglow mass spectrometry.

PubMed

Smoluch, Marek; Mielczarek, Przemyslaw; Reszke, Edward; Hieftje, Gary M; Silberring, Jerzy

2014-09-07

The flowing atmospheric pressure afterglow (FAPA) ion source operates in the ambient atmosphere and has been proven to be a promising tool for direct and rapid determination of numerous compounds. Here we linked a FAPA-MS system to an electrochemical flow cell for the identification of drug metabolites generated electrochemically in order to study simulated metabolic pathways. Psychostimulants and their metabolites produced by electrochemistry (EC) were detected on-line by FAPA-MS. The FAPA source has never been used before for an on-line connection with liquid flow, neither for identification of products generated in an electrochemical flow cell. The system was optimized to achieve the highest ionization efficiency by adjusting several parameters, including distances and angles between the ion source and the outlet of the EC system, the high voltage for plasma generation, flow-rates, and EC parameters. Simulated metabolites from tested compounds [methamphetamine (MAF), para-methoxy-N-methylamphetamine (PMMA), dextromethorphan (DXM), and benzydamine (BAM)] were formed in the EC cell at various pH levels. In all cases the main products were oxidized substrates and compounds after N-demethylation. Generation of such products and their thorough on-line identification confirm that the cytochrome P450 - driven metabolism of pharmaceuticals can be efficiently simulated in an electrochemical cell; this approach may serve as a step towards predictive pharmacology using a fast and robust design.

Peer Instruction at Japanese High School Physics

NASA Astrophysics Data System (ADS)

Takahashi, H.; Nitta, H.

2010-07-01

We report on our attempt to introduce the peer instruction (PI) into a Japanese high-school physics course. To evaluate the effectiveness of PI in the course, we define the PI-efficiency (PIE). It is shown that PIE is useful to find out students' reasoning difficulties as well as effective usages of PI.

Direct electrochemistry of dopamine on gold-Agaricus bisporus laccase enzyme electrode: characterization and quantitative detection.

PubMed

Shervedani, Reza Karimi; Amini, Akbar

2012-04-01

Direct electrochemistry of a new laccase enzyme immobilized on gold and its application as a biosensor for dopamine (DA) are investigated by voltammetry and electrochemical impedance spectroscopy. The sensor demonstrated a redox adsorption behavior with E(0') = + 180 mV vs. Ag/AgCl for immobilized Agaricus bisporus laccase (LacAB) enzyme. The MPA platform was assembled on Au with and without utilization of ultrasounds. Excellent results were obtained by using the enzyme electrode fabricated based on MPA assembled with sonication. The LacAB immobilized in this condition showed a large electrocatalytic activity for oxidation of DA. Accordingly, a third-generation (mediator free) biosensor was constructed for DA. The DA concentration could be measured in the linear range of 0.5 to 13.0 and 47.0 to 430.0 μmol L(-1) with correlation coefficients of 0.999 and 0.989, respectively, and a detection limit of 29.0 nmol L(-1). The biosensor was successfully tested for determination of DA in human blood plasma and pharmaceutical samples. Copyright © 2011 Elsevier B.V. All rights reserved.

Constraining Data Mining with Physical Models: Voltage- and Oxygen Pressure-Dependent Transport in Multiferroic Nanostructures

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

Strelcov, Evgheni; Belianinov, Alexei; Hsieh, Ying-Hui

Development of new generation electronic devices requires understanding and controlling the electronic transport in ferroic, magnetic, and optical materials, which is hampered by two factors. First, the complications of working at the nanoscale, where interfaces, grain boundaries, defects, and so forth, dictate the macroscopic characteristics. Second, the convolution of the response signals stemming from the fact that several physical processes may be activated simultaneously. Here, we present a method of solving these challenges via a combination of atomic force microscopy and data mining analysis techniques. Rational selection of the latter allows application of physical constraints and enables direct interpretation ofmore » the statistically significant behaviors in the framework of the chosen physical model, thus distilling physical meaning out of raw data. We demonstrate our approach with an example of deconvolution of complex transport behavior in a bismuth ferrite–cobalt ferrite nanocomposite in ambient and ultrahigh vacuum environments. Measured signal is apportioned into four electronic transport patterns, showing different dependence on partial oxygen and water vapor pressure. These patterns are described in terms of Ohmic conductance and Schottky emission models in the light of surface electrochemistry. Finally and furthermore, deep data analysis allows extraction of local dopant concentrations and barrier heights empowering our understanding of the underlying dynamic mechanisms of resistive switching.« less

Constraining Data Mining with Physical Models: Voltage- and Oxygen Pressure-Dependent Transport in Multiferroic Nanostructures

DOE PAGES

Strelcov, Evgheni; Belianinov, Alexei; Hsieh, Ying-Hui; ...

2015-08-27

Development of new generation electronic devices requires understanding and controlling the electronic transport in ferroic, magnetic, and optical materials, which is hampered by two factors. First, the complications of working at the nanoscale, where interfaces, grain boundaries, defects, and so forth, dictate the macroscopic characteristics. Second, the convolution of the response signals stemming from the fact that several physical processes may be activated simultaneously. Here, we present a method of solving these challenges via a combination of atomic force microscopy and data mining analysis techniques. Rational selection of the latter allows application of physical constraints and enables direct interpretation ofmore » the statistically significant behaviors in the framework of the chosen physical model, thus distilling physical meaning out of raw data. We demonstrate our approach with an example of deconvolution of complex transport behavior in a bismuth ferrite–cobalt ferrite nanocomposite in ambient and ultrahigh vacuum environments. Measured signal is apportioned into four electronic transport patterns, showing different dependence on partial oxygen and water vapor pressure. These patterns are described in terms of Ohmic conductance and Schottky emission models in the light of surface electrochemistry. Finally and furthermore, deep data analysis allows extraction of local dopant concentrations and barrier heights empowering our understanding of the underlying dynamic mechanisms of resistive switching.« less

Fighting for physics and Earth science in Florida's high schools

NASA Astrophysics Data System (ADS)

Cottle, Paul

2009-11-01

During its Spring 2009 session, the Florida Legislature considered a bill that would have suspended its comprehensive standardized test in high school science and substituted an end-of-course test in biology to satisfy the requirements of the No Child Left Behind (NCLB) Act. By doing so, the bill would have further deemphasized high school physics and Earth science in a state where physics courses are sometimes not available in high schools (even in International Baccalaureate programs) and where the state's own statistics say that only 16% of high school graduates have taken a physics course. A group of about one hundred science faculty from thirteen colleges and universities in Florida responded with a letter to Governor Crist and visits to legislators asking that the biology-only provisions be defeated (and they were). The group has now produced a white paper on high school science requirements that has been distributed to government and business leaders and been publicized via op-ed pieces and news items in several media outlets statewide. This poster will describe the situation in Florida and the faculty group's efforts. It will also compare Florida's high school requirements in science with those in the other SESAPS states.

Where the girls aren't: High school girls and advanced placement physics enrollment

NASA Astrophysics Data System (ADS)

Barton, Susan O'brien

During the high school years, when many students first have some choice in course selection, research indicates that girls choose to enroll in more math and science courses, take more advanced placement courses, and take more honors courses in English, biology, chemistry, mathematics, and foreign languages than ever before. Yet, not only are boys more likely to take all of the three core science courses (biology, chemistry, and physics), boys enroll in advanced placement physics approximately three times as often as do girls. This study examines the perceptions, attitudes, and aspirations of thirty high school girls enrolled in senior-level science electives in an attempt to understand their high school science course choices, and what factors were influencing them. This is a qualitative investigation employing constructivist grounded theory methods. There are two main contributions of this study. First, it presents a new conceptual and analytical framework to investigate the problem of why some high school girls do not enroll in physics coursework. This framework is grounded in the data and is comprised of three existing feminist perspectives along the liberal/radical continuum of feminist thought. Second, this study illuminates a complex set of reasons why participants avoided high school physics (particularly advanced placement physics) coursework. These reasons emerged as three broad categories related to: (a) a lack of connectedness with physics curriculum and instruction; (b) prior negative experiences with physics and math classroom climates; and (c) future academic goals and career aspirations. Taken together, the findings of this study indicate that the problem of high school girls and physics enrollment---particularly advanced placement physics enrollment---is a problem that cannot be evaluated or considered from one perspective.

Effects of Music on Physical Activity Rates of Junior High School Physical Education Students

ERIC Educational Resources Information Center

Brewer, Lindsey; Barney, David C.; Prusak, Keven A.; Pennington, Todd

2016-01-01

Music is an everyday occurrence in a person's life. Music is heard in the workplace, in homes, and in the mall. Music can also be heard as a person exercises. Therefore, the purpose of this study was to examine the effects of music on junior high students (n = 305) step counts and time in activity in junior high school physical education classes.…

Improving Physics Teaching Materials on Sound for Visually Impaired Students in High School

ERIC Educational Resources Information Center

Toenders, Frank G. C.; de Putter-Smits, Lesley G. A.; Sanders, Wendy T. M.; den Brok, Perry

2017-01-01

When visually impaired students attend regular high school, additional materials are necessary to help them understand physics concepts. The time for teachers to develop teaching materials for such students is scarce. Visually impaired students in regular high school physics classes often use a braille version of the physics textbook. Previously,…

High-energy Physics with Hydrogen Bubble Chambers

DOE R&D Accomplishments Database

Alvarez, L. W.

1958-03-07

Recent experience with liquid hydrogen bubble chambers of 25 and 40 cm dia. in high-energy physics experiments is discussed. Experiments described are: interactions of K{sup -} mesons with protons, interactions of antiprotons with protons, catalysis of nuclear fusion reactions by muons, and production and decay of hyperons from negative pions. (W.D.M.)

Simulation of the oxidative metabolism of diclofenac by electrochemistry/(liquid chromatography/)mass spectrometry.

PubMed

Faber, Helene; Melles, Daniel; Brauckmann, Christine; Wehe, Christoph Alexander; Wentker, Kristina; Karst, Uwe

2012-04-01

Diclofenac is a frequently prescribed drug for rheumatic diseases and muscle pain. In rare cases, it may be associated with a severe hepatotoxicity. In literature, it is discussed whether this toxicity is related to the oxidative phase I metabolism, resulting in electrophilic quinone imines, which can subsequently react with nucleophiles present in the liver in form of glutathione or proteins. In this work, electrochemistry coupled to mass spectrometry is used as a tool for the simulation of the oxidative pathway of diclofenac. Using this purely instrumental approach, diclofenac was oxidized in a thin layer cell equipped with a boron doped diamond working electrode. Sum formulae of generated oxidation products were calculated based on accurate mass measurements with deviations below 2 ppm. Quinone imines from diclofenac were detected using this approach. It could be shown for the first time that these quinone imines do not react with glutathione exclusively but also with larger molecules such as the model protein β-lactoglobulin A. A tryptic digest of the generated drug-protein adduct confirms that the protein is modified at the only free thiol-containing peptide. This simple and purely instrumental set-up offers the possibility of generating reactive metabolites of diclofenac and to assess their reactivity rapidly and easily.

Alternative High School Students' Physical Activity: Role of Self-Efficacy

ERIC Educational Resources Information Center

Kenyon, Denyelle Baete; Kubik, Martha Y.; Davey, Cynthia; Sirard, John; Fulkerson, Jayne A.

2012-01-01

Objective: To examine physical activity self-efficacy as a mediator of the association between perceived barriers to PA and moderate-to-vigorous physical activity (MVPA) among alternative high school (AHS) students. Methods: Students (N = 145) from 6 AHS completed self-report questionnaires. Results: Mediation analyses revealed partial mediation…

The effects of modeling instruction on high school physics academic achievement

NASA Astrophysics Data System (ADS)

Wright, Tiffanie L.

The purpose of this study was to explore whether Modeling Instruction, compared to traditional lecturing, is an effective instructional method to promote academic achievement in selected high school physics classes at a rural middle Tennessee high school. This study used an ex post facto , quasi-experimental research methodology. The independent variables in this study were the instructional methods of teaching. The treatment variable was Modeling Instruction and the control variable was traditional lecture instruction. The Treatment Group consisted of participants in Physical World Concepts who received Modeling Instruction. The Control Group consisted of participants in Physical Science who received traditional lecture instruction. The dependent variable was gains scores on the Force Concepts Inventory (FCI). The participants for this study were 133 students each in both the Treatment and Control Groups (n = 266), who attended a public, high school in rural middle Tennessee. The participants were administered the Force Concepts Inventory (FCI) prior to being taught the mechanics of physics. The FCI data were entered into the computer-based Statistical Package for the Social Science (SPSS). Two independent samples t-tests were conducted to answer the research questions. There was a statistically significant difference between the treatment and control groups concerning the instructional method. Modeling Instructional methods were found to be effective in increasing the academic achievement of students in high school physics. There was no statistically significant difference between FCI gains scores for gender. Gender was found to have no effect on the academic achievement of students in high school physics classes. However, even though there was not a statistically significant difference, female students' gains scores were higher than male students' gains scores when Modeling Instructional methods of teaching were used. Based on these findings, it is recommended

Radiation Physics for Space and High Altitude Air Travel

NASA Technical Reports Server (NTRS)

Cucinotta, F. A.; Wilson, J. W.; Goldhagen, P.; Saganti, P.; Shavers, M. R.; McKay, Gordon A. (Technical Monitor)

2000-01-01

Galactic cosmic rays (GCR) are of extra-solar origin consisting of high-energy hydrogen, helium, and heavy ions. The GCR are modified by physical processes as they traverse through the solar system, spacecraft shielding, atmospheres, and tissues producing copious amounts of secondary radiation including fragmentation products, neutrons, mesons, and muons. We discuss physical models and measurements relevant for estimating biological risks in space and high-altitude air travel. Ambient and internal spacecraft computational models for the International Space Station and a Mars mission are discussed. Risk assessment is traditionally based on linear addition of components. We discuss alternative models that include stochastic treatments of columnar damage by heavy ion tracks and multi-cellular damage following nuclear fragmentation in tissue.

High-precision arithmetic in mathematical physics

DOE PAGES

Bailey, David H.; Borwein, Jonathan M.

2015-05-12

For many scientific calculations, particularly those involving empirical data, IEEE 32-bit floating-point arithmetic produces results of sufficient accuracy, while for other applications IEEE 64-bit floating-point is more appropriate. But for some very demanding applications, even higher levels of precision are often required. Furthermore, this article discusses the challenge of high-precision computation, in the context of mathematical physics, and highlights what facilities are required to support future computation, in light of emerging developments in computer architecture.

Physical Activity Levels in Coeducational and Single-Gender High School Physical Education Settings

ERIC Educational Resources Information Center

Hannon, James; Ratliffe, Thomas

2005-01-01

The purpose of this study was to investigate the effects of coeducational (coed) and single-gender game-play settings on the activity levels of Caucasian and African American high school physical education students. Students participated in flag football, ultimate Frisbee, and soccer units. Classes were as follows: there were two coed classes, two…

Interconnection of Key Microbial Functional Genes for Enhanced Benzo[a]pyrene Biodegradation in Sediments by Microbial Electrochemistry.

PubMed

Yan, Zaisheng; He, Yuhong; Cai, Haiyuan; Van Nostrand, Joy D; He, Zhili; Zhou, Jizhong; Krumholz, Lee R; Jiang, He-Long

2017-08-01

Sediment microbial fuel cells (SMFCs) can stimulate the degradation of polycyclic aromatic hydrocarbons in sediments, but the mechanism of this process is poorly understood at the microbial functional gene level. Here, the use of SMFC resulted in 92% benzo[a]pyrene (BaP) removal over 970 days relative to 54% in the controls. Sediment functions, microbial community structure, and network interactions were dramatically altered by the SMFC employment. Functional gene analysis showed that c-type cytochrome genes for electron transfer, aromatic degradation genes, and extracellular ligninolytic enzymes involved in lignin degradation were significantly enriched in bulk sediments during SMFC operation. Correspondingly, chemical analysis of the system showed that these genetic changes resulted in increases in the levels of easily oxidizable organic carbon and humic acids which may have resulted in increased BaP bioavailability and increased degradation rates. Tracking microbial functional genes and corresponding organic matter responses should aid mechanistic understanding of BaP enhanced biodegradation by microbial electrochemistry and development of sustainable bioremediation strategies.

An experimental investigation of the flow physics of high-lift systems

NASA Technical Reports Server (NTRS)

Thomas, Flint O.; Nelson, R. C.

1995-01-01

This progress report is a series of overviews outlining experiments on the flow physics of confluent boundary layers for high-lift systems. The research objectives include establishing the role of confluent boundary layer flow physics in high-lift production; contrasting confluent boundary layer structures for optimum and non-optimum C(sub L) cases; forming a high quality, detailed archival data base for CFD/modelling; and examining the role of relaminarization and streamline curvature. Goals of this research include completing LDV study of an optimum C(sub L) case; performing detailed LDV confluent boundary layer surveys for multiple non-optimum C(sub L) cases; obtaining skin friction distributions for both optimum and non-optimum C(sub L) cases for scaling purposes; data analysis and inner and outer variable scaling; setting-up and performing relaminarization experiments; and a final report establishing the role of leading edge confluent boundary layer flow physics on high-lift performance.

Resource Letter AFHEP-1: Accelerators for the Future of High-Energy Physics

NASA Astrophysics Data System (ADS)

Barletta, William A.

2012-02-01

This Resource Letter provides a guide to literature concerning the development of accelerators for the future of high-energy physics. Research articles, books, and Internet resources are cited for the following topics: motivation for future accelerators, present accelerators for high-energy physics, possible future machine, and laboratory and collaboration websites.

Graphene electrochemistry: an overview of potential applications.

PubMed

Brownson, Dale A C; Banks, Craig E

2010-11-01

Graphene, a 2D nanomaterial that possesses spectacular physical, chemical and thermal properties, has caused immense excitement amongst scientists since its freestanding form was isolated in 2004. With research into graphene rife, it promises enhancements and vast applicability within many industrial aspects. Furthermore, graphene possesses a vast array of unique and highly desirable electrochemical properties, and it is this application that offers the most enthralling and spectacular journey. We present a review of the current literature concerning the electrochemical applications and advancements of graphene, starting with its use as a sensor substrate through to applications in energy production and storage, depicting the truly remarkable journey of a material that has just come of age.

High energy expenditure masks low physical activity in obesity.

PubMed

DeLany, J P; Kelley, D E; Hames, K C; Jakicic, J M; Goodpaster, B H

2013-07-01

To investigate energy expenditure in lean and obese individuals, focusing particularly on physical activity and severely obese individuals. Total daily energy expenditure (TDEE) was assessed using doubly labeled water, resting metabolic rate (RMR) by indirect calorimetry, activity energy expenditure (AEE) by difference and time spent in physical activity by multisensor activity monitors. In all, 177 lean, Class I and severely obese individuals (age 31-56 years, body mass index 20-64 kg m(-2)) were analyzed. All components of energy expenditure were elevated in obese individuals. For example, TDEE was 2404±95 kcal per day in lean and 3244±48 kcal per day in Class III obese individuals. After appropriate adjustment, RMR was similar in all groups. Analysis of AEE by body weight and obesity class indicated a lower AEE in obese individuals. Confirming lower physical activity, obese individuals spent less time engaged in moderate-to-vigorous physical activity (2.7±1.3, 1.8±0.6, 2.0±1.4 and 1.2±1.0 h per day in lean, Class I, Class II and Class III individuals) and more time in sedentary behaviors. There was no indication of metabolic efficiency in even the severely obese, as adjusted RMR was similar across all groups. The higher AEE observed in the obese is consistent with a higher cost of activities due to higher body weight. However, the magnitude of the higher AEE (20-25% higher in obese individuals) is lower than expected (weight approximately 100% higher in Class III individuals). Confirming a lower volume of physical activity in the obese, the total time spent in moderate-to-vigorous physical activity and average daily metabolic equivalent of task level were lower with increasing obesity. These findings demonstrate that high body weight in obese individuals leads to a high TDEE and AEE, which masks the fact that they are less physically active, which can be influenced by duration or intensity of activity, than in lean individuals.

High school students' physical education conceptual knowledge.

PubMed

Ayers, Suzan F

2004-09-01

The value of conceptual physical education knowledge has long been acknowledged (American Alliance for Health, Physical Education, and Recreation, 1969; Kneer, 1981; NASPE, 1995) yet has not been formally measured or assessed. Seven multiple choice tests with established validity and reliability (Ayers, 2001b) were used to assess the concepts identified in Mohnsen's text (1998). Tests were administered to 3,263 high school students at the schools of 17 NASPE Teachers of the Year in 16 states. On all tests, girls outscored boys, and Caucasians outscored all other racial groups. Examinees' average performance on each test was: motor development (65%), exercise physiology (62%), social psychology (60%), biomechanics (57%), aesthetic experiences (56%), motor learning (53%), and historical perspectives (49%). Analyses of each area determined concepts students knew and did not know.

Physics-Based Modeling and Measurement of High-Flux Condensation Heat Transfer

DTIC Science & Technology

2011-09-01

TRANSFER (Contract No. N000140811139) by Prof. Issam Mudawar Sung-Min Kim Joseph Kim Boiling and Two-Phase Flow Laboratory School of...Final 01-10-2008 to 30-09-2011 Physics-Based Modeling and Measurement of High-Flux Condensation Heat Transfer NA N00014-08-1-1139 NA NA NA NA Mudawar ...respectively. phase change, condensation, electronics cooling, micro-channel, high-flux U U U UU 107 Mudawar , Issam 765-494-5705 Reset PHYSICS-BASED

Compilation of current high energy physics experiments - Sept. 1978

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

Addis, L.; Odian, A.; Row, G. M.

1978-09-01

This compilation of current high-energy physics experiments is a collaborative effort of the Berkeley Particle Data Group, the SLAC library, and the nine participating laboratories: Argonne (ANL), Brookhaven (BNL), CERN, DESY, Fermilab (FNAL), KEK, Rutherford (RHEL), Serpukhov (SERP), and SLAC. Nominally, the compilation includes summaries of all high-energy physics experiments at the above laboratories that were approved (and not subsequently withdrawn) before about June 1978, and had not completed taking of data by 1 January 1975. The experimental summaries are supplemented with three indexes to the compilation, several vocabulary lists giving names or abbreviations used, and a short summary ofmore » the beams at each of the laboratories (except Rutherford). The summaries themselves are included on microfiche. (RWR)« less

What High School Physics Teachers Teach: Results from the 2012-13 Nationwide Survey of High School Physics Teachers. Focus On

ERIC Educational Resources Information Center

Tyler, John; White, Susan

2014-01-01

During the 2012-13 academic year, the Statistic Research Center (SRC) collected data from a representative national sample of over 3,500 public and private high schools across the U.S. to inquire about physics availabilities and offerings. This report describes their findings. SRC takes two different approaches to describe the characteristics of…

Android-assisted physics mobile learning to improve senior high school students' divergent thinking skills and physics HOTS

NASA Astrophysics Data System (ADS)

Mardiana, Nana; Kuswanto, Heru

2017-08-01

The aims of the research concerned here were to reveal (1) the characteristics of Android-assisted PML (physics mobile learning) to improve SMA (sekolah menengah atas, Indonesian senior high school) students' divergent thinking skills and physics HOTS (higher order thinking skills); (2) the feasibility of the Android-assisted PML; and (3) the influence of using the Android-assisted PML on improvement in SMA students' divergent thinking skills and physics HOTS. The7 research was of the R&D (research and development) type, adapted from theBorg-&-Gall development model. The research data were analyzed by means of MANOVA with the significance level of 5%. The results are as follows. (1) The product of the development, a learning media in software form with the android package(apk) format, is named PML (to refer to Physics Mobile Learning), which has such characterictics as being operable with use of Android devicesand being very good in quality in the aspect oflearning, material, software technology, and audiovisual appearance. 2) The developed learning media referred to as PML is appropriate for learning activity according to evaluation by a material expert, a media expert, peer reviewers, and physics teachers as well as according to results of students' tryouts. (3) The use of the Android-assisted PML media product could improve SMA students' divergent thinking skillsand physics HOTS with the respective high-category gain scores of 0.701 and 0.759.

Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications

NASA Astrophysics Data System (ADS)

Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W.; Dokmeci, Mehmet Remzi; Boyden, Edward S.; Khademhosseini, Ali

2016-03-01

To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such “hybrid microscopy” methods—combining physical and optical magnifications—can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes (“mini-microscopes”), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics—a process we refer to as Expansion Mini-Microscopy (ExMM)—is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places.

Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications.

PubMed

Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W; Dokmeci, Mehmet Remzi; Boyden, Edward S; Khademhosseini, Ali

2016-03-15

To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such "hybrid microscopy" methods--combining physical and optical magnifications--can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes ("mini-microscopes"), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics--a process we refer to as Expansion Mini-Microscopy (ExMM)--is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places.

HEPDOOP: High-Energy Physics Analysis using Hadoop

NASA Astrophysics Data System (ADS)

Bhimji, W.; Bristow, T.; Washbrook, A.

2014-06-01

We perform a LHC data analysis workflow using tools and data formats that are commonly used in the "Big Data" community outside High Energy Physics (HEP). These include Apache Avro for serialisation to binary files, Pig and Hadoop for mass data processing and Python Scikit-Learn for multi-variate analysis. Comparison is made with the same analysis performed with current HEP tools in ROOT.

Electrochemistry at a Metal Nanoparticle on a Tunneling Film: A Steady-State Model of Current Densities at a Tunneling Ultramicroelectrode.

PubMed

Hill, Caleb M; Kim, Jiyeon; Bard, Allen J

2015-09-09

Here, a new methodology is proposed for treating electrochemical current densities in metal-insulator-metal nanoparticle (M-I-MNP) systems. The described model provides broad, practical insights about MNP-mediated electron transfer to redox species in solution, where electron transfer from the underlying electrode to a MNP via tunneling and heterogeneous electron transfer from the MNP to redox species in solution are treated as sequential steps. Tunneling is treated through an adaptation of the Simmons model of tunneling in metal-insulator-metal structures, and explicit equations are provided for tunneling currents, which demonstrate the effect of various experimental parameters, such as insulator thickness and MNP size. Overall, a general approach is demonstrated for determining experimental conditions where tunneling will have a measurable impact on the electrochemistry of M-I-MNP systems.

Comparing high and low acculturated mothers and physical activity in Hispanic children.

PubMed

Olvera, Norma; Smith, Dennis W; Lee, Chanam; Liu, Jian; Lee, Jay; Kim, Jun-Hyun; Kellam, Stephanie F

2011-09-01

Parents represent a key ecological component in influencing their child's physical activity. The aim of this exploratory study was to assess the relationship between maternal acculturation and physical activity in Hispanic children. 102 Hispanic mothers (mean age 36.2 yrs; +SD 7.3 yrs) and their children (mean age 10.0 yrs, +SD 0.8 yrs) participated. Most of the mothers (74%) were foreign-born, with 62% classified as low acculturated and 38% high acculturated. Demographic, acculturation, and anthropometric measures were completed by mothers and children. Physical activity was measured using accelerometers. Relationships between maternal acculturation and demographic variables and children's physical activity were examined using chi-square, Analysis of Variance, and simple regression. Children had higher physical activity levels than their mothers (t(49) = -7.87, P < .0001). Significant correlations between maternal and child's physical activity levels were observed in moderate (r2 = 0.13, P = .001), vigorous (r2 = 0.08, P = .05), and moderate-to-vigorous physical activity (r2 = 0.17, P = .002). Low acculturated mothers were more likely to have active children compared with high acculturated mothers. Maternal BMI and other demographic characteristics were not significantly associated with child's physical activity. Findings from this study revealed an association among maternal acculturation, role modeling, and child's physical activity.

Applications of physical methods in high-frequency futures markets

NASA Astrophysics Data System (ADS)

Bartolozzi, M.; Mellen, C.; Chan, F.; Oliver, D.; Di Matteo, T.; Aste, T.

2007-12-01

In the present work we demonstrate the application of different physical methods to high-frequency or tick-bytick financial time series data. In particular, we calculate the Hurst exponent and inverse statistics for the price time series taken from a range of futures indices. Additionally, we show that in a limit order book the relaxation times of an imbalanced book state with more demand or supply can be described by stretched exponential laws analogous to those seen in many physical systems.

Gender Differences in High School Students' Interests in Physics

ERIC Educational Resources Information Center

Baran, Medine

2016-01-01

The aim of this research was to determine the interests of high school students in Physics and variable of how the influential factors on their interests depending on gender. The research sample included 154 (F:78 M:76) high school students. A structured interview form was used as the data collection tool in the study. The research data were…

Electrochemistry of poly(3,4-ethylenedioxythiophene)-polyaniline/ Prussian blue electrochromic devices containing an ionic liquid based gel electrolyte film.

PubMed

Deepa, Melepurath; Awadhia, Arvind; Bhandari, Shweta

2009-07-21

Electrochromic devices based on poly(3,4-ethylenedioxythiophene) (PEDOT) as the cathodic coloring electrode and polyaniline (PANI) or Prussian blue (PB) as the counter electrode containing a highly conductive, self-supporting, distensible and transparent polymer-gel electrolyte film encapsulating an ionic liquid, 1-butyl-1-methylpyrrolidiniumbis-(trifluoromethylsulfonyl)imide, have been fabricated. Polarization, charge transfer and diffusion processes control the electrochemistry of the functional electrodes during coloration and bleaching and these phenomena differ when PEDOT and PANI/PB were employed alternately as working electrodes. While the electrochemical impedance response shows good similitude for PEDOT and PANI electrodes, the responses of PEDOT and PB were significantly different in the PEDOT-PB device, especially during reduction of PB, wherein the overall amplitude of the impedance response is enormous. Large values of the coloration efficiency maxima of 281 cm2 C(-1) (lambda = 583 nm) and 274 cm2 C(-1) (lambda = 602 nm), achieved at -1.0 and -1.5 V for the PEDOT PANI and PEDOT-PB devices have been correlated to the particularly low magnitude of charge transfer resistance and high polarization capacitance operative at the PEDOT ionic liquid based electrolyte interface at these dc potentials, thus allowing facile ion-transport and consequently resulting in enhanced absorption modulation. Moderately fast switching kinetics and the ability of these devices to sustain about 2500 cycles of clear-to-dark and dark-to-clear without incurring major losses in the optical contrast, along with the ease of construction of these cells in terms of high scalability and reproducibility of the synthetic procedure for fabrication of the electrochromic films and the ionic liquid based gel electrolyte film, are indicators of the promise these devices hold for practical applications like electrochromic windows and displays.

Back pain in physically inactive students compared to physical education students with a high and average level of physical activity studying in Poland.

PubMed

Kędra, Agnieszka; Kolwicz-Gańko, Aleksandra; Kędra, Przemysław; Bochenek, Anna; Czaprowski, Dariusz

2017-11-28

The aim of the study was (1) to characterise back pain in physically inactive students as well as in trained (with a high level of physical activity) and untrained (with an average level of physical activity) physical education (PE) students and (2) to find out whether there exist differences regarding the declared incidence of back pain (within the last 12 months) between physically inactive students and PE students as well as between trained (with a high level of physical activity) and untrained (with an average level of physical activity) PE students. The study included 1321 1st-, 2nd- and 3rd-year students (full-time bachelor degree course) of Physical Education, Physiotherapy, Pedagogy as well as Tourism and Recreation from 4 universities in Poland. A questionnaire prepared by the authors was applied as a research tool. The 10-point Visual Analogue Scale (VAS) was used to assess pain intensity. Prior to the study, the reliability of the questionnaire was assessed by conducting it on the group of 20 participants twice with a shorter interval. No significant differences between the results obtained in the two surveys were revealed (p < 0.05). In the group of 1311 study participants, 927 (70.7%) respondents declared having experienced back pain within the last 12 months. Physically inactive students declared back pain frequency similar to the frequency declared by their counterparts studying physical education (p > 0.05). Back pain was more common in the group of trained students than among untrained individuals (p < 0.05). Back pain was mainly located in the lumbar spine. A frequent occurrence of back pain (70.7%) was noted in the examined groups of students. The percentage of students declaring back pain increased in the course of studies (p < 0.05) and, according to the students' declarations, it was located mainly in the lumbar spine. No significant differences regarding the incidence of back pain were found between physically inactive

University of Oklahoma - High Energy Physics

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

Skubic, Patrick L.

2013-07-31

The High Energy Physics program at the University of Oklahoma, Pat Skubic, Principal Investigator, is attempting to understand nature at the deepest level using the most advanced experimental and theoretical tools. The four experimental faculty, Brad Abbott, Phil Gutierrez, Pat Skubic, and Mike Strauss, together with post-doctoral associates and graduate students, are finishing their work as part of the D0 collaboration at Fermilab, and increasingly focusing their investigations at the Large Hadron Collidor (LHC) as part of the ATLAS Collaboration. Work at the LHC has become even more exciting with the recent discovery by ATLAS and the other collaboration, CMS,more » of the long-sought Higgs boson, which plays a key role in generating masses for the elementary constituents of matter. Work of the OUHEP group has been in the three areas of hardware, software, and analysis. Now that the Higgs boson has been discovered, completing the Standard Model of fundamental physics, new efforts will focus on finding hints of physics beyond the standard model, such as supersymmetry. The OUHEP theory group (Kim Milton, PI) also consists of four faculty members, Howie Baer, Chung Kao, Kim Milton, and Yun Wang, and associated students and postdocs. They are involved in understanding fundamental issues in formulating theories of the microworld, and in proposing models that carry us past the Standard Model, which is an incomplete description of nature. They therefore work in close concert with their experimental colleagues. One also can study fundamental physics by looking at the large scale structure of the universe; in particular the ``dark energy'' that seems to be causing the universe to expand at an accelerating rate, effectively makes up about 3/4 of the energy in the universe, and yet is totally unidentified. Dark energy and dark matter, which together account for nearly all of the energy in the universe, are an important probe of fundamental physics at the very shortest

High School Physical Education Teachers' Beliefs about Teaching Students with Mild to Severe Disabilities

ERIC Educational Resources Information Center

Casebolt, Kevin M.; Hodge, Samuel R.

2010-01-01

The purpose of this study was to analyze high school physical education teachers' beliefs about teaching students with disabilities in inclusive physical education. The participants (3 men, 2 women) were certified physical education teachers at four suburban high schools. The research method was descriptive-qualitative using a case study approach…

An experimental investigation of the flow physics of high-lift systems

NASA Technical Reports Server (NTRS)

Thomas, Flint O.; Nelson, R. C.

1995-01-01

This progress report, a series of viewgraphs, outlines experiments on the flow physics of confluent boundary layers for high lift systems. The design objective is to design high lift systems with improved C(sub Lmax) for landing approach and improved take-off L/D and simultaneously reduce acquisition and maintenance costs. In effect, achieve improved performance with simpler designs. The research objectives include: establish the role of confluent boundary layer flow physics in high-lift production; contrast confluent boundary layer structure for optimum and non-optimum C(sub L) cases; formation of a high quality, detailed archival data base for CFD/modeling; and examination of the role of relaminarization and streamline curvature.

Special Colloquium : Looking at High Energy Physics from a gender studies perspective

ScienceCinema

Goetschel, Helene

2018-01-23

Human actors, workplace cultures and knowledge production: Gender studies analyse the social constructions and cultural representations of gender. Using methods and tools from the humanities and social science, we look at all areas, including the natural sciences and technology, science education and research labs. After a short introduction to gender studies, the main focus of my talk will be the presentation of selected research findings on gender and high energy physics. You will hear about an ongoing research project on women in neutrino physics and learn about a study on the world of high energy physicists characterised by "rites of passage" and "male tales" told during a life in physics. I will also present a study on how the HEP community communicates, and research findings on the naming culture in HEP. Getting to know findings from another field on your own might contribute to create a high energy physics culture that is fair and welcoming to all genders.

Special Colloquium : Looking at High Energy Physics from a gender studies perspective

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

Goetschel, Helene

Human actors, workplace cultures and knowledge production: Gender studies analyse the social constructions and cultural representations of gender. Using methods and tools from the humanities and social science, we look at all areas, including the natural sciences and technology, science education and research labs. After a short introduction to gender studies, the main focus of my talk will be the presentation of selected research findings on gender and high energy physics. You will hear about an ongoing research project on women in neutrino physics and learn about a study on the world of high energy physicists characterised by "rites ofmore » passage" and "male tales" told during a life in physics. I will also present a study on how the HEP community communicates, and research findings on the naming culture in HEP. Getting to know findings from another field on your own might contribute to create a high energy physics culture that is fair and welcoming to all genders.« less

Worksite interventions for preventing physical deterioration among employees in job-groups with high physical work demands: background, design and conceptual model of FINALE.

PubMed

Holtermann, Andreas; Jørgensen, Marie B; Gram, Bibi; Christensen, Jeanette R; Faber, Anne; Overgaard, Kristian; Ektor-Andersen, John; Mortensen, Ole S; Sjøgaard, Gisela; Søgaard, Karen

2010-03-09

A mismatch between individual physical capacities and physical work demands enhance the risk for musculoskeletal disorders, poor work ability and sickness absence, termed physical deterioration. However, effective intervention strategies for preventing physical deterioration in job groups with high physical demands remains to be established. This paper describes the background, design and conceptual model of the FINALE programme, a framework for health promoting interventions at 4 Danish job groups (i.e. cleaners, health-care workers, construction workers and industrial workers) characterized by high physical work demands, musculoskeletal disorders, poor work ability and sickness absence. A novel approach of the FINALE programme is that the interventions, i.e. 3 randomized controlled trials (RCT) and 1 exploratory case-control study are tailored to the physical work demands, physical capacities and health profile of workers in each job-group. The RCT among cleaners, characterized by repetitive work tasks and musculoskeletal disorders, aims at making the cleaners less susceptible to musculoskeletal disorders by physical coordination training or cognitive behavioral theory based training (CBTr). Because health-care workers are reported to have high prevalence of overweight and heavy lifts, the aim of the RCT is long-term weight-loss by combined physical exercise training, CBTr and diet. Construction work, characterized by heavy lifting, pushing and pulling, the RCT aims at improving physical capacity and promoting musculoskeletal and cardiovascular health. At the industrial work-place characterized by repetitive work tasks, the intervention aims at reducing physical exertion and musculoskeletal disorders by combined physical exercise training, CBTr and participatory ergonomics. The overall aim of the FINALE programme is to improve the safety margin between individual resources (i.e. physical capacities, and cognitive and behavioral skills) and physical work demands

Is the Physical Being Taken out of Physical Education? On the Possible Effects of High-Stakes Testing on an Embattled Profession's Curriculum Goals

ERIC Educational Resources Information Center

Seymour, Clancy; Garrison, Mark

2015-01-01

Building on recent discussions regarding how current national standards for physical education promote cognitive outcomes over physical outcomes, the authors explore how a new era in high-stakes testing is also contributing to an emphasis on the cognitive, over the physical. While high-stakes testing has been linked to reducing the amount of…

Neutrinos, ultra-high-energy cosmic rays and fundamental physics

NASA Astrophysics Data System (ADS)

Ellis, John

2001-05-01

In the first lecture, aspects of neutrino physics beyond the Standard Model are emphasized, including the emerging default options for atmospheric and solar neutrino oscillations, namely νμ-->ντ and νe-->νμ,τ respectively, and the need to check them, the prospects opened up by the successful starts of SNO and K2K and the opportunities for future long-baseline neutrino experiments. In the second lecture, it is discussed how cosmic rays may provide opportunities for probing fundamental physics. For example, ultra-high-energy cosmic rays might originate from the decays of metastable heavy particles, and astrophysical γ rays can be used to test models of quantum gravity. Both scenarios offer ways to avoid the GZK cut-off, and might best be probed using high-energy astrophysical neutrinos. .

Water as a promoter and catalyst for dioxygen electrochemistry in aqueous and organic media.

DOE PAGES

Staszak-Jirkovsky, Jakub; Subbaraman, Ram; Strmcnik, Dusan; ...

2015-11-01

Water and oxygen electrochemistry lies at the heart of interfacial processes controlling energy transformations in fuel cells, electrolyzers, and batteries. Here, by comparing results for the ORR obtained in alkaline aqueous media to those obtained in ultradry organic electrolytes with known amounts of H2O added intentionally, we propose a new rationale in which water itself plays an important role in determining the reaction kinetics. This effect derives from the formation of HOad center dot center dot center dot H2O (aqueous solutions) and LiO2 center dot center dot center dot H2O (organic solvents) complexes that place water in a configurationally favorablemore » position for proton transfer to weakly adsorbed intermediates. We also find that, even at low concentrations (<10 ppm), water acts simultaneously as a promoter and as a catalyst in the production of Li2O2, regenerating itself through a sequence of steps that include the formation and recombination of H+ and OH-. We conclude that, although the binding energy between metal surfaces and oxygen intermediates is an important descriptor in electrocatalysis, understanding the role of water as a proton-donor reactant may explain many anomalous features in electrocatalysis at metal-liquid interfaces.« less

Electrochemistry and Spectroelectrochemistry of Lead Halide Perovskite Films: Materials Science Aspects and Boundary Conditions.

PubMed

Samu, Gergely F; Scheidt, Rebecca A; Kamat, Prashant V; Janáky, Csaba

2018-02-13

The unique optoelectronic properties of lead halide perovskites have triggered a new wave of excitement in materials chemistry during the past five years. Electrochemistry, spectroelectrochemistry, and photoelectrochemistry could be viable tools both for analyzing the optoelectronic features of these materials and for assembling them into hybrid architectures (e.g., solar cells). At the same time, the instability of these materials limits the pool of solvents and electrolytes that can be employed in such experiments. The focus of our study is to establish a stability window for electrochemical tests for all-inorganic CsPbBr 3 and hybrid organic-inorganic MAPbI 3 perovskites. In addition, we aimed to understand the reduction and oxidation events that occur and to assess the damage done during these processes at extreme electrochemical conditions. In this vein, we demonstrated the chemical, structural, and morphological changes of the films in both reductive and oxidative environments. Taking all these results together as a whole, we propose a set of boundary conditions and protocols for how electrochemical experiments with lead halide perovskites should be carried out and interpreted. The presented results will contribute to the understanding of the electrochemical response of these materials and lead to a standardization of results in the literature so that comparisons can more easily be made.

Assessment of electrochemical concepts: a comparative study involving senior high-school students in Indonesia and Japan

NASA Astrophysics Data System (ADS)

Rahayu, Sri; Treagust, David F.; Chandrasegaran, A. L.; Kita, Masakazu; Ibnu, Suhadi

2011-07-01

Background and purpose: This study investigated Indonesian and Japanese senior high-school students' understanding of electrochemistry concepts. Sample The questionnaire was administered to 244 Indonesian and 189 Japanese public senior high-school students. Design and methods An 18-item multiple-choice questionnaire relating to five conceptual categories (reactions occurring during electrolysis, differences between electrolytic and voltaic cells, movement of ions in voltaic cells, poles in voltaic cells, voltaic cell reactions) was administered. Results The findings of this study show that difficulties and alternative conceptions previously reported in the literature are held equally by students from a developing and developed country, Indonesian and Japan respectively. Conclusions Collectively, the findings suggest that students' understanding of electrochemistry concepts is relatively weak. Students from both samples shared common difficulties and displayed several alternative conceptions dealing with electrolysis, electricity flow, the voltaic cell and the electrode reactions. Not surprisingly, the students displayed limited consistency in understanding of the concepts in the five categories. This study has implications for teaching and learning, particularly in classroom discussions using models and computer animations in order to reinforce understanding at the sub-microscopic level.

Objectively assessed recess physical activity in girls and boys from high and low socioeconomic backgrounds.

PubMed

Baquet, Georges; Ridgers, Nicola D; Blaes, Aurélie; Aucouturier, Julien; Van Praagh, Emmanuel; Berthoin, Serge

2014-02-21

The school environment influences children's opportunities for physical activity participation. The aim of the present study was to assess objectively measured school recess physical activity in children from high and low socioeconomic backgrounds. Four hundred and seven children (6-11 years old) from 4 primary schools located in high socioeconomic status (high-SES) and low socioeconomic status (low-SES) areas participated in the study. Children's physical activity was measured using accelerometry during morning and afternoon recess during a 4-day school week. The percentage of time spent in light, moderate, vigorous, very high and in moderate- to very high-intensity physical activity were calculated using age-dependent cut-points. Sedentary time was defined as 100 counts per minute. Boys were significantly (p < 0.001) more active than girls. No difference in sedentary time between socioeconomic backgrounds was observed. The low-SES group spent significantly more time in light (p < 0.001) and very high (p < 0.05) intensity physical activity compared to the high-SES group. High-SES boys and girls spent significantly more time in moderate (p < 0.001 and p < 0.05, respectively) and vigorous (p < 0.001) physical activity than low-SES boys. Differences were observed in recess physical activity levels according to socioeconomic background and sex. These results indicate that recess interventions should target children in low-SES schools.

Current Status of Women in Physics in Korea—and the New Physics Camp Initiative for High School Girls

NASA Astrophysics Data System (ADS)

Kim, Hyunjung; Song, Sanghoon; Park, Hyunjeong; Park, Jiseon; An, Jihye; Park, Joyoung; Yim, Haein; Song, Jeonghyeon; Yoon, Jin-Hee; Park, Youngah

2009-04-01

The Korean Physical Society (KPS) Women Committee has organized a series of the physics camps for high school girl students to give them an opportunity to work together and interact with professional physicists. Although the KPS Women Committee has successfully set the KPS's face toward women's issues, it still needs more systematic support for helping and promoting the activities of women physicists. We describe the physics camp initiative and present the current status of women in physics in Korea, comparing female ratios in undergraduate and graduate school and faculty for the last ten years (1998-2007). The employment rate for females is compared with that for males according to education level. The total number of female students in physics in Korea has increased; however, it is still a very small portion of females who stay in physics with professional positions.

Analysing the physics learning environment of visually impaired students in high schools

NASA Astrophysics Data System (ADS)

Toenders, Frank G. C.; de Putter-Smits, Lesley G. A.; Sanders, Wendy T. M.; den Brok, Perry

2017-07-01

Although visually impaired students attend regular high school, their enrolment in advanced science classes is dramatically low. In our research we evaluated the physics learning environment of a blind high school student in a regular Dutch high school. For visually impaired students to grasp physics concepts, time and additional materials to support the learning process are key. Time for teachers to develop teaching methods for such students is scarce. Suggestions for changes to the learning environment and of materials used are given.

Teaching High School Physics with a Story-Line

ERIC Educational Resources Information Center

Dagenais, Andre

2010-01-01

High school physics curricula are designed to meet a number of goals, all of which compete for classroom and homework time. The process-oriented goals include the development of skills in problem solving, measurement, analyzing data, and research, particularly in this world of internet based, unfiltered information. Content goals, on the other…

Direct electrochemistry and electrocatalysis of glucose oxidase immobilized on reduced graphene oxide and silver nanoparticles nanocomposite modified electrode.

PubMed

Palanisamy, Selvakumar; Karuppiah, Chelladurai; Chen, Shen-Ming

2014-02-01

The direct electrochemistry of glucose oxidase (GOx) was successfully realized on electrochemically reduced graphene oxide and silver nanoparticles (RGO/Ag) nanocomposite modified electrode. The fabricated nanocomposite was characterized by field emission scanning electron microscope and energy dispersive spectroscopy. The GOx immobilized nanocomposite modified electrode showed a pair of well-defined redox peaks with a formal potential (E°) of -0.422 V, indicating that the bioactivity of GOx was retained. The heterogeneous electron transfer rate constant (Ks) of GOx at the nanocomposite was calculated to be 5.27 s(-1), revealing a fast direct electron transfer of GOx. The GOx immobilized RGO/Ag nanocomposite electrode exhibited a good electrocatalytic activity toward glucose over a linear concentration range from 0.5 to 12.5 mM with a detection limit of 0.16 mM. Besides, the fabricated biosensor showed an acceptable sensitivity and selectivity for glucose. Copyright © 2013 Elsevier B.V. All rights reserved.

HEPData: a repository for high energy physics data

NASA Astrophysics Data System (ADS)

Maguire, Eamonn; Heinrich, Lukas; Watt, Graeme

2017-10-01

The Durham High Energy Physics Database (HEPData) has been built up over the past four decades as a unique open-access repository for scattering data from experimental particle physics papers. It comprises data points underlying several thousand publications. Over the last two years, the HEPData software has been completely rewritten using modern computing technologies as an overlay on the Invenio v3 digital library framework. The software is open source with the new site available at https://hepdata.net now replacing the previous site at http://hepdata.cedar.ac.uk. In this write-up, we describe the development of the new site and explain some of the advantages it offers over the previous platform.

Large-x connections of nuclear and high-energy physics

DOE PAGES

Accardi, Alberto

2013-11-20

I discuss how global QCD fits of parton distribution functions can make the somewhat separated fields of high-energy particle physics and lower energy hadronic and nuclear physics interact to the benefit of both. I review specific examples of this interplay from recent works of the CTEQ-Jefferson Lab collaboration, including hadron structure at large parton momentum and gauge boson production at colliders. Particular attention is devoted to quantifying theoretical uncertainties arising in the treatment of large partonic momentum contributions to deep inelastic scattering observables, and to discussing the experimental progress needed to reduce these.

Synthesis, electrochemistry, and electrogenerated chemiluminescence of two BODIPY-appended bipyridine homologues.

PubMed

Qi, Honglan; Teesdale, Justin J; Pupillo, Rachel C; Rosenthal, Joel; Bard, Allen J

2013-09-11

Two new 2,2'-bipyridine (bpy) derivatives containing ancillary BODIPY chromophores attached at the 5- and 5'-positions (BB3) or 6- and 6'-positions (BB4) were prepared and characterized. In this work, the basic photophysics, electrochemistry, and electrogenerated chemiluminescence (ECL) of BB3 and BB4 are compared with those previously reported for a related bpy-BODIPY derivative (BB2) (J. Phys. Chem. C 2011, 115, 17993-18001). Cyclic voltammetry revealed that BB3 and BB4 display reversible 2e(-) oxidation and reduction waves, which consist of two closely spaced (50-70 mV) 1e(-) events. This redox behavior is consistent with the frontier molecular orbitals calculated for BB3 and BB4 and indicates that the 2,2'-bipyridine spacer of each bpy-BODIPY homologue does not facilitate efficient electronic communication between the tethered indacene units. In the presence of a coreactant such as tri-n-propylamine (TPA) or benzoyl peroxide (BPO), BB3 and BB4 exhibit strong ECL and produce spectra that are very similar to their corresponding photoluminescence profiles. The ECL signal obtained under annihilation conditions, however, is significantly different and is characterized by two distinct bands. One of these bands is centered at ∼570 nm and is attributed to emission via an S- or T-route. The second band occurs at longer wavelengths and is centered around ∼740 nm. The shape and concentration dependence of this long-wavelength ECL signal is not indicative of emission from an excimer or aggregate, but rather it suggests that a new emissive species is formed from the bpy-BODIPY luminophores during the annihilation process.

Synthesis, Electrochemistry and Electrogenerated Chemiluminesce of two BODIPY-Appended Bipyridine Homologues

PubMed Central

Qi, Honglan; Teesdale, Justin J.; Pupillo, Rachel C.

2014-01-01

Two new 2,2’-bipyridine (bpy) derivatives containing ancillary BODIPY chromophores attached at the 5- and 5’-positions (BB3) or 6- and 6’-positions (BB4) were prepared and characterized. In this work, the basic photophysics, electrochemistry and electrogenerated chemiluminescence (ECL) of BB3 and BB4 are compared with those previously reported for a related bpy-BODIPY derivative (BB2) (J. Phys. Chem. C 2011, 115, 17993–18001). Cyclic voltammetry revealed that BB3 and BB4 display reversible 2e− oxidation and reduction waves, which consist of two closely spaced (50 – 70 mV) 1e− events. This redox behavior is consistent with the frontier molecular orbitals calculated for BB3 and BB4 and indicates that the 2,2’-bipyridine spacer of each bpy- BODIPY homologue does not facilitate efficient electronic communication between the tethered indacene units. In the presence of a coreactant such as tri-n-propylamine (TPA) or benzoyl peroxide (BPO), BB3 and BB4 exhibit strong ECL and produce spectra that are very similar to their corresponding photoluminescence profiles. The ECL signal obtained under annihilation conditions, however, is significantly different and is characterized by two distinct bands. One of these bands is centered at ~570 nm and is attributed to emission via an S- or T-route. The second band, occurs at longer wavelengths and is centered around ~740 nm. The shape and concentration dependence of this long-wavelength ECL signal is not indicative of emission from an excimer or aggregate, but rather is suggests that a new emissive species is formed from the bpy-BODIPY luminophores during the annihilation process. PMID:23980850

Synthesis and electrochemistry of heterobimetallic ruthenium/platinum and molybdenum/platinum complexes

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

Orth, S.D.; Terry, M.R.; Abboud, K.A.

1996-02-14

As starting materials for heterobimetallic complexes, [RuCp(PPh{sub 3})CO(PPh{sub 2}H)]PF{sub 6} and [RuCp(PPh{sub 3})CO({eta}-dppm)]-PF{sub 6} were prepared from RuCp(PPh{sub 3})(CO)Cl. In the course of preparing [RuCp({eta}{sup 2}-dppm)({eta}-dppm)]Cl from RuCp(Ph{sub 3}P)({eta}-dppm)Cl, the monomer RuCpCl({eta}-dppm){sub 2} was isolated. The uncommon coordination mode of the two monodentatebis(phosphines) was confirmed by X-ray crystallography [a = 11.490(1) {angstrom}, b = 14.869(2) {angstrom}, c = 15.447(2) {angstrom}, {alpha} = 84.63(1){degrees}, {beta} = 70.55(1){degrees}, {gamma} = 72.92(1){degrees}, V = 2378.7(5) {angstrom}{sup 3}, d{sub calc} = 1.355 g cm{sup -3} (298 K), triclinic, P1, Z = 2]. The dppm-bridged bimetallic complexes RuCp(PPh{sub 3})Cl({mu}-dppm)PtCl{sub 2}, RuCpCl({mu}-dppm){sub 2}PtCl{sub 2}, and [RuCp(PPh{submore » 3})CO({mu}-dppm)PtCl{sub 2}]PF{sub 6} each exhibit electrochemistry consistent with varying degrees of metal-metal interaction. The cationic heterobimetallic complexes [Mo(CO){sub 3}({mu}-dppm){sub 2}Pt(H)]PF{sub 6} and [MoCp-(CO){sub 2}-({mu}-PPh{sub 2})({mu}-H)Pt(PPh{sub 3})(MeCN)]PF{sub 6} were prepared by chloride abstraction from the corresponding neutral bimetallic species and show electrochemical behavior similar to the analogous Ru/Pt complexes.« less

Ability Group Configuration for the High School Physics Classroom

NASA Astrophysics Data System (ADS)

Zitnik, Scott

This research project looks to investigate the effectiveness of different ability grouping arrangements for the high school physics classroom. Students were first organized based on their academic aptitude in physics into three general groups of high, medium, and low achieving students. They were then divided into both groups of four and dyads that were constructed in one of four arrangements, namely: random, homogeneous, heterogeneous, or student choice. Data was collected based on their academic performance as well as survey responses regarding the group and dyad performance. Students worked in a rotation of these groups and dyads for a unit to measure student preference and introduce collaborative work formally to the classes. At this point it was evident that students preferred the student choice arrangement based on survey responses, yet the student choice survey responses also resulted in the lowest level of reliability when compared to all other grouping methods. For the next unit students were kept in either the random, homogeneous, or heterogeneous grouping arrangement for the entirety of the unit. At the conclusion of the second unit student achievement as well as survey responses were analyzed. As a result of this research there appears to be a slight student preference as well as academic benefit to homogeneous group and dyad arrangements for each of the three ability groups of students in the high school physics classroom when compared to random and heterogeneous grouping methods of academic group arrangement.

Success of students in a college physics course with and without experiencing a high school course

NASA Astrophysics Data System (ADS)

Yager, Robert E.; Krajcik, Joseph S.

High school students with high ability were enrolled in a standard college physics course for each of two summers with the same professor, same course outline, same textbook, same laboratories, and the same examinations. Half of each group had completed a high school physics course; half had not. Dormitory counselors were available for assistance and support. In addition, tutors were available in the laboratories to provide any help necessary with interpretation of lectures and performances in the laboratory, and with mathematical computation. Pre- and posttest measures concerning course content and attitude were given. After the eight-week summer instruction, the students who had not completed high school physics performed as well on the final course examination; there were no differences with respect to course grade or attitude toward physics. The group that had not completed high school physics used the tutors provided far more frequently than did students who had completed the high school course. When high-ability students are enrolled in college physics with tutors made available for needed assistance, there appears to be no advantage for students to complete the standard high school physics course.

Emotion recognition in fathers and mothers at high-risk for child physical abuse.

PubMed

Asla, Nagore; de Paúl, Joaquín; Pérez-Albéniz, Alicia

2011-09-01

The present study was designed to determine whether parents at high risk for physical child abuse, in comparison with parents at low risk, show deficits in emotion recognition, as well as to examine the moderator effect of gender and stress on the relationship between risk for physical child abuse and emotion recognition. Based on their scores on the Abuse Scale of the CAP Inventory (Milner, 1986), 64 parents at high risk (24 fathers and 40 mothers) and 80 parents at low risk (40 fathers and 40 mothers) for physical child abuse were selected. The Subtle Expression Training Tool/Micro Expression Training Tool (Ekman, 2004a, 2004b) and the Diagnostic Analysis of Nonverbal Accuracy II (Nowicki & Carton, 1993) were used to assess emotion recognition. As expected, parents at high risk, in contrast to parents at low risk, showed deficits in emotion recognition. However, differences between high- and low-risk participants were observed only for fathers, but not for mothers. Whereas fathers at high risk for physical child abuse made more errors than mothers at high risk, no differences between mothers at low risk and fathers at low risk were found. No interaction between stress, gender, and risk status was observed for errors in emotion recognition. The present findings, if confirmed with physical abusers, could be helpful to further our understanding of deficits in processing information of physically abusive parents and to develop treatment strategies specifically focused on emotion recognition. Moreover, if gender differences can be confirmed, the findings could be helpful to develop specific treatment programs for abusive fathers. Copyright © 2011 Elsevier Ltd. All rights reserved.

Parallel Computing:. Some Activities in High Energy Physics

NASA Astrophysics Data System (ADS)

Willers, Ian

This paper examines some activities in High Energy Physics that utilise parallel computing. The topic includes all computing from the proposed SIMD front end detectors, the farming applications, high-powered RISC processors and the large machines in the computer centers. We start by looking at the motivation behind using parallelism for general purpose computing. The developments around farming are then described from its simplest form to the more complex system in Fermilab. Finally, there is a list of some developments that are happening close to the experiments.

Environmental Learning Experiences: Bio-Physical, Senior High School.

ERIC Educational Resources Information Center

Junglas, Mary R.; And Others

This environmental education curriculum guide was developed for teacher use at the senior high school level. Although the guide deals with the bio-physical aspects of the environment, it is designed to encourage an integration of the disciplines into an inter-disciplinary approach. The volume consists of a set of ideas, activities, and opinions…

High occupational physical activity and risk of ischaemic heart disease in women: the interplay with physical activity during leisure time.

PubMed

Allesøe, Karen; Holtermann, Andreas; Aadahl, Mette; Thomsen, Jane F; Hundrup, Yrsa A; Søgaard, Karen

2015-12-01

Recent studies indicate that physically demanding work is a risk factor for heart disease among men, especially those with low or moderate physical activity during leisure time. Among women, present evidence is inconclusive. The design was a prospective cohort study. This investigation in the Danish Nurse Cohort Study included 12,093 female nurses aged 45-64 years, who answered a self-report questionnaire on physical activity at work and during leisure time, known risk factors for ischaemic heart disease (IHD) and occupational factors at baseline in 1993. Information on the 15-year incidence of IHD was obtained by individual linkage in the National Register of Hospital Discharges to 2008. During follow-up 580 participants were hospitalised with IHD. A significant interaction between occupational and leisure time physical activity was found with the lowest risk of IHD among nurses with the combination of moderate physical activity at work and vigorous physical activity during leisure time. Compared to this group high physical activity at work was associated with a higher risk of IHD at all levels of physical activity during leisure time increasing from hazard ratio 1.75 (95% confidence interval (CI) 1.10-2.80) among nurses with vigorous physical activity during leisure time to 2.65 (95% CI 1.44-4.88) among nurses being sedentary during leisure time. This study among Danish nurses suggests that high physical activity at work is a risk factor for IHD among women. Vigorous physical activity during leisure time lowered but did not completely counteract the adverse effect of occupational physical activity on risk of IHD. © The European Society of Cardiology 2014.

Worksite interventions for preventing physical deterioration among employees in job-groups with high physical work demands: Background, design and conceptual model of FINALE

PubMed Central

2010-01-01

Background A mismatch between individual physical capacities and physical work demands enhance the risk for musculoskeletal disorders, poor work ability and sickness absence, termed physical deterioration. However, effective intervention strategies for preventing physical deterioration in job groups with high physical demands remains to be established. This paper describes the background, design and conceptual model of the FINALE programme, a framework for health promoting interventions at 4 Danish job groups (i.e. cleaners, health-care workers, construction workers and industrial workers) characterized by high physical work demands, musculoskeletal disorders, poor work ability and sickness absence. Methods/Design A novel approach of the FINALE programme is that the interventions, i.e. 3 randomized controlled trials (RCT) and 1 exploratory case-control study are tailored to the physical work demands, physical capacities and health profile of workers in each job-group. The RCT among cleaners, characterized by repetitive work tasks and musculoskeletal disorders, aims at making the cleaners less susceptible to musculoskeletal disorders by physical coordination training or cognitive behavioral theory based training (CBTr). Because health-care workers are reported to have high prevalence of overweight and heavy lifts, the aim of the RCT is long-term weight-loss by combined physical exercise training, CBTr and diet. Construction work, characterized by heavy lifting, pushing and pulling, the RCT aims at improving physical capacity and promoting musculoskeletal and cardiovascular health. At the industrial work-place characterized by repetitive work tasks, the intervention aims at reducing physical exertion and musculoskeletal disorders by combined physical exercise training, CBTr and participatory ergonomics. The overall aim of the FINALE programme is to improve the safety margin between individual resources (i.e. physical capacities, and cognitive and behavioral skills

High Performance Liquid Chromatography Experiments to Undergraduate Laboratories

ERIC Educational Resources Information Center

Kissinger, Peter T.; And Others

1977-01-01

Reviews the principles of liquid chromatography with electrochemical detection (LCEC), an analytical technique that incorporates the advantages of both liquids chromatography and electrochemistry. Also suggests laboratory experiments using this technique. (MLH)

High school student physics research experience yields positive results

NASA Astrophysics Data System (ADS)

Podolak, K. R.; Walters, M. J.

2016-03-01

All high school students that wish to continue onto college are seeking opportunities to be competitive in the college market. They participate in extra-curricular activities which are seen to foster creativity and the skills necessary to do well in the college environment. In the case of students with an interest in physics, participating in a small scale research project while in high school gives them the hands on experience and ultimately prepares them more for the college experience. SUNY Plattsburgh’s Physics department started a five-week summer program for high school students in 2012. This program has proved not only beneficial for students while in the program, but also as they continue on in their development as scientists/engineers. Independent research, such as that offered by SUNY Plattsburgh’s five-week summer program, offers students a feel and taste of the culture of doing research, and life as a scientist. It is a short-term, risk free way to investigate whether a career in research or a particular scientific field is a good fit.

One-step synthesis of large-scale graphene film doped with gold nanoparticles at liquid-air interface for electrochemistry and Raman detection applications.

PubMed

Zhang, Panpan; Huang, Ying; Lu, Xin; Zhang, Siyu; Li, Jingfeng; Wei, Gang; Su, Zhiqiang

2014-07-29

We demonstrated a facile one-step synthesis strategy for the preparation of a large-scale reduced graphene oxide multilayered film doped with gold nanoparticles (RGO/AuNP film) and applied this film as functional nanomaterials for electrochemistry and Raman detection applications. The related applications of the fabricated RGO/AuNP film in electrochemical nonenzymatic H2O2 biosensor, electrochemical oxygen reduction reaction (ORR), and surface-enhanced Raman scattering (SERS) detection were investigated. Electrochemical data indicate that the H2O2 biosensor fabricated by RGO/AuNP film shows a wide linear range, low limitation of detection, high selectivity, and long-term stability. In addition, it was proved that the created RGO/AuNP film also exhibits excellent ORR electrochemical catalysis performance. The created RGO/AuNP film, when serving as SERS biodetection platform, presents outstanding performances in detecting 4-aminothiophenol with an enhancement factor of approximately 5.6 × 10(5) as well as 2-thiouracil sensing with a low concentration to 1 μM. It is expected that this facile strategy for fabricating large-scale graphene film doped with metallic nanoparticles will spark inspirations in preparing functional nanomaterials and further extend their applications in drug delivery, wastewater purification, and bioenergy.

HIAF: New opportunities for atomic physics with highly charged heavy ions

NASA Astrophysics Data System (ADS)

Ma, X.; Wen, W. Q.; Zhang, S. F.; Yu, D. Y.; Cheng, R.; Yang, J.; Huang, Z. K.; Wang, H. B.; Zhu, X. L.; Cai, X.; Zhao, Y. T.; Mao, L. J.; Yang, J. C.; Zhou, X. H.; Xu, H. S.; Yuan, Y. J.; Xia, J. W.; Zhao, H. W.; Xiao, G. Q.; Zhan, W. L.

2017-10-01

A new project, High Intensity heavy ion Accelerator Facility (HIAF), is currently being under design and construction in China. HIAF will provide beams of stable and unstable heavy ions with high energies, high intensities and high quality. An overview of new opportunities for atomic physics using highly charged ions and radioactive heavy ions at HIAF is given.

The HESP (High Energy Solar Physics) project

NASA Technical Reports Server (NTRS)

Kai, K.

1986-01-01

A project for space observations of solar flares for the coming solar maximum phase is briefly described. The main objective is to make a comprehensive study of high energy phenomena of flares through simultaneous imagings in both hard and soft X-rays. The project will be performed with collaboration from US scientists. The HESP (High Energy Solar Physics) WG of ISAS (Institute of Space and Astronautical Sciences) has extensively discussed future aspects of space observations of high energy phenomena of solar flares based on successful results of the Hinotori mission, and proposed a comprehensive research program for the next solar maximum, called the HESP (SOLAR-A) project. The objective of the HESP project is to make a comprehensive study of both high energy phenomena of flares and quiet structures including pre-flare states, which have been left uncovered by SMM and Hinotori. For such a study simultaneous imagings with better resolutions in space and time in a wide range of energy will be extremely important.

A Proposal to Introduce a Topic of Contemporary Physics into High-School Teaching

ERIC Educational Resources Information Center

Santos, Wilma M.S.; Luiz, Adir M.; de Carvalho, Carlos R.

2009-01-01

This article presents an approach to integrate contemporary physics into high-school teaching. We present a simple way to understand mass spectroscopy using basic physics concepts, so that high-school students may have contact with recent topics of modern research. The main features of a time-of-flight (TOF) mass spectrometer using secondary…

35th International Conference of High Energy Physics

NASA Astrophysics Data System (ADS)

The French particle physics community is particularly proud to have been selected to host the 35th ICHEP conference in 2010 in Paris. This conference is the focal point of all our field since more than fifty years and is the reference event where all important results in particle physics cosmology and astroparticles are presented and discussed. This alone suffices to make this event very important. But in 2010, a coincidence of exceptional events will make this conference even more attractive! What is then so special about ICHEP 2010 conference? It will be the first ICHEP conference where physics results obtained at the LHC will be presented! New results about the elusive Higgs boson, or signals of physics beyond the standard model might therefore be announced at this conference! Major discoveries in other domains such as gravitational waves, neutrino telescopes, neutrino oscillations, dark matter or in the flavour sector are also possible, just to name a few. In addition , 2010 will be an important date to shape up the future of our field. Several major projects will present the status of their Conceptual or Engineering Design Reports during the conference. The International Linear Collider (ILC) Global Design Effort team will present the report corresponding to the end of their Technical Design Phase 1. The Compact Linear Collider (CLIC) will also report on its Conceptual Design Report. Other major projects such as Super B factories will also be presented. These reports together with LHC physics results will form the basis for key political decisions needed to be taken in the years to come. In summary, there can be no doubt that Paris is the place to be in summer 2010 for anyone interested in High Energy Physics and we will make every effort to make your stay as interesting and enjoyable as possible.

Composition-Graded MoWSx Hybrids with Tailored Catalytic Activity by Bipolar Electrochemistry.

PubMed

Tan, Shu Min; Pumera, Martin

2017-12-06

Among transition metal dichalcogenide (TMD)-based composites, TMD/graphene-related material and bichalcogen TMD composites have been widely studied for application toward energy production via the hydrogen evolution reaction (HER). However, scarcely any literature explored the possibility of bimetallic TMD hybrids as HER electrocatalysts. The use of harmful chemicals and harsh preparation conditions in conventional syntheses also detracts from the objective of sustainable energy production. Herein, we present the conservational alternative synthesis of MoWS x via one-step bipolar electrochemical deposition. Through bipolar electrochemistry, the simultaneous fabrication of composition-graded MoWS x hybrids, i.e., sulfur-deficient Mo x W (1-x) S 2 and Mo x W (1-x) S 3 (MoWS x /BPE cathodic and MoWS x /BPE anodic , respectively) under cathodic and anodic overpotentials, was achieved. The best-performing MoWS x /BPE cathodic and MoWS x /BPE anodic materials exhibited Tafel slopes of 45.7 and 50.5 mV dec -1 , together with corresponding HER overpotentials of 315 and 278 mV at -10 mA cm -2 . The remarkable HER activities of the composite materials were attributed to their small particle sizes, as well as the near-unity value of their surface Mo/W ratios, which resulted in increased exposed HER-active sites and differing active sites for the concurrent adsorption of protons and desorption of hydrogen gas. The excellent electrocatalytic performances achieved via the novel methodology adopted here encourage the empowerment of electrochemical deposition as the foremost fabrication approach toward functional electrocatalysts for sustainable energy generation.

Development of Nanostructure Materials and Architecture for High Performance Li-rechargeable Batteries with Ultrafast Charge Rate

DTIC Science & Technology

2011-04-22

overcome these difficulties extensive work has been done. Surface coatings with ZnO , SiO2, and Bi2O3 have been proposed to enhance stability of electrodes...Liu, G. Q.; Wen, L.; Liu, Y. M. Journal of Solid State Electrochemistry 2010, 14, 2191. (23) Myung, S. T.; Komaba, S.; Kumagai, N.; Yashiro, H.; Chung...Y. R.; Shu, J.; Zhu, R. S. Journal of Solid State Electrochemistry 2009, 13, 913. (29) Aklalouch, M.; Amarilla, J. M.; Rojas, R. M.; Saadoune, I

Prospective High School Physics Teachers' Beliefs about Teaching Practices: From Traditionalist to Constructivist

ERIC Educational Resources Information Center

Demirci, Neset

2015-01-01

The main aim of this study was to determine the teaching practices of prospective high school physics teachers with respect to their preference for teaching as a traditionalist or as a constructivist. To study the beliefs of prospective high school physics teachers on this subject, firstly, the Teacher Belief Survey was administered to 135…

A Useful Demonstration of Calculus in a Physics High School Laboratory

ERIC Educational Resources Information Center

Alvarez, Gustavo; Schulte, Jurgen; Stockton, Geoffrey; Wheeler, David

2018-01-01

The real power of calculus is revealed when it is applied to actual physical problems. In this paper, we present a calculus inspired physics experiment suitable for high school and undergraduate programs. A model for the theory of the terminal velocity of a falling body subject to a resistive force is developed and its validity tested in an…

Health-Related Fitness Knowledge and Physical Activity of High School Students

ERIC Educational Resources Information Center

Thompson, Angela; Hannon, James C.

2012-01-01

The purpose of this study was to determine if health-related fitness (HRF) knowledge is related to self-reported physical activity (PA) of high school students. Students (N=165) enrolled in physical education from two schools in the Southwestern U.S participated. A 100-point HRF knowledge test was assembled, focusing on the HRF concepts of…

High-pT Physics in the Heavy Ion Era

NASA Astrophysics Data System (ADS)

Rak, Jan; Tannenbaum, Michael J.

2013-04-01

1. Introduction and overview; 2. Basic observables; 3. Some experimental techniques; 4. The search for structure; 5. Origins of high pT physics - the search for the W boson; 6. Discovery of hard scattering in p-p collisions; 7. Direct single lepton production and the discovery of charm; 8. J/ ψ, u and Drell-Yan pair production; 9. Two particle correlations; 10. Direct photon production; 11. The search for jets; 12. QCD in hard scattering; 13. Heavy ion physics in the high pT era; 14. RHIC and LHC; Appendix A. Probability and statistics; Appendix B. Methods of Monte Carlo calculations; Appendix C. TAB and the Glauber Monte Carlo calculation; Appendix D. Fits including systematic errors; Appendix E. The shape of the xE distribution triggered by a jet fragment, for example, π0; Appendix F. kT phenomenology and Gaussian smearing; References; Index.

Low-Temperature Synthesis, Structural Characterization, and Electrochemistry of Ni-Rich Spinel-like LiNi 2–y Mn y O 4 (0.4 ≤ y ≤ 1)

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

Kan, Wang Hay; Huq, Ashfia; Manthiram, Arumugam

The thermal conversion of chemically delithiated layered Li 0.5Ni 1-yMn yO 2 (0.2 ≤ y ≤ 0.5) into spinel-like LiNi 2-yMn yO 4 (0.4 ≤ y ≤ 1) has been systematically investigated. The formed spinel-like phases are metastable and cannot be accessed by a conventional high-temperature solid-state method. The layered-to-spinel transformation mechanism has been studied by the Rietveld refinement of in situ neutron diffraction as a function of temperature (25–300 °C). In particular, the ionic diffusion of Li and M ions is quantified at different temperatures. Electrochemistry of the metastable spinel-like phases obtained has been studied in lithium-ion cells. Amore » bond valence sum map has been performed to understand the ionic diffusion of lithium ions in the Ni-rich layered, spinel, and rock-salt structures. The study can aid the understanding of the possible phases that could be formed during the cycling of Ni-rich layered oxide cathodes.« less

Low-Temperature Synthesis, Structural Characterization, and Electrochemistry of Ni-Rich Spinel-like LiNi 2–yMn yO 4 (0.4 ≤ y ≤ 1)

DOE PAGES

Kan, Wang Hay; Huq, Ashfia; Manthiram, Arumugam

2015-10-28

The thermal conversion of chemically delithiated layered Li 0.5Ni 1–yMn yO 2 (0.2 ≤ y ≤ 0.5) into spinel-like LiNi 2–yMn yO 4 (0.4 ≤ y ≤ 1) has been systematically investigated in this paper. The formed spinel-like phases are metastable and cannot be accessed by a conventional high-temperature solid-state method. The layered-to-spinel transformation mechanism has been studied by the Rietveld refinement of in situ neutron diffraction as a function of temperature (25–300 °C). In particular, the ionic diffusion of Li and M ions is quantified at different temperatures. Electrochemistry of the metastable spinel-like phases obtained has been studied inmore » lithium-ion cells. A bond valence sum map has been performed to understand the ionic diffusion of lithium ions in the Ni-rich layered, spinel, and rock-salt structures. Finally, the study can aid the understanding of the possible phases that could be formed during the cycling of Ni-rich layered oxide cathodes.« less

Low-Temperature Synthesis, Structural Characterization, and Electrochemistry of Ni-Rich Spinel-like LiNi 2–yMn yO 4 (0.4 ≤ y ≤ 1)

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

Kan, Wang Hay; Huq, Ashfia; Manthiram, Arumugam

The thermal conversion of chemically delithiated layered Li 0.5Ni 1–yMn yO 2 (0.2 ≤ y ≤ 0.5) into spinel-like LiNi 2–yMn yO 4 (0.4 ≤ y ≤ 1) has been systematically investigated in this paper. The formed spinel-like phases are metastable and cannot be accessed by a conventional high-temperature solid-state method. The layered-to-spinel transformation mechanism has been studied by the Rietveld refinement of in situ neutron diffraction as a function of temperature (25–300 °C). In particular, the ionic diffusion of Li and M ions is quantified at different temperatures. Electrochemistry of the metastable spinel-like phases obtained has been studied inmore » lithium-ion cells. A bond valence sum map has been performed to understand the ionic diffusion of lithium ions in the Ni-rich layered, spinel, and rock-salt structures. Finally, the study can aid the understanding of the possible phases that could be formed during the cycling of Ni-rich layered oxide cathodes.« less

Longitudinal association of suicidal ideation and physical dating violence among high school students.

PubMed

Nahapetyan, Lusine; Orpinas, Pamela; Song, Xiao; Holland, Kristin

2014-04-01

Two salient problems in adolescent development are dating violence and suicidal ideation. Theory and empirical research have supported their association in primarily cross-sectional studies. The purpose of this study is to examine the longitudinal association between physical dating violence and suicidal ideation (thoughts or plans) in a cohort of students evaluated annually from Grades 9 to 12. The sample consisted of 556 random-selected students (50.2 % males; 47.5 % White, 37.8 % Black, 11.2 % Latino) who reported dating at least once during the four assessments. Self-reported frequency of suicidal ideation, dating, and physical dating violence perpetration and victimization were assessed each spring from ninth to twelfth grade. We used generalized estimating equations modeling to predict the effects of sex, race, school grade, and physical dating perpetration and victimization on suicidal ideation. Cumulatively, one-fourth of the sample reported suicidal ideation at least once by the end of Grade 12, and approximately half reported physical dating violence. Female gender (OR = 1.7, p = 0.02), physical dating perpetration (OR = 1.54, p = 0.048), physical dating victimization (OR = 2.03, p < 0.001), and being in grades 9-11 versus 12 in high school (OR = 1.83, p = 0.004) were significant predictors of suicidal ideation. Race was not a significant predictor among adolescents in this sample. This longitudinal study highlights the detrimental emotional effect of physical dating violence perpetration and victimization among high school students. It is important that suicide prevention programs incorporate physical dating violence education and prevention strategies starting early in high school.

Research in High Energy Physics at Duke University

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

Kotwal, Ashutosh V.; Goshaw, Al; Kruse, Mark

2013-07-29

This is the Closeout Report for the research grant in experimental elementary particle physics, carried out by the Duke University High Energy Physics (HEP) group. We re- port on physics results and detector development carried out under this grant, focussing on the recent three-year grant period (2010 to 2013). The Duke HEP group consisted of seven faculty members, two senior scientists, ve postdocs and eight graduate students. There were three thrusts of the research program. Measurements at the energy frontier at CDF and ATLAS were used to test aspects of elementary particle theory described by the Stan- dard Model (SM)more » and to search for new forces and particles beyond those contained within the SM. The neutrino sector was explored using data obtained from a large neutrino detector located in Japan, and R & D was conducted on new experiments to be built in the US. The measurements provided information about neutrino masses and the manner in which neutri- nos change species in particle beams. Two years ago we have started a new research program in rare processes based on the Mu2E experiment at Fermilab. This research is motivated by the search for the ! e transition with unprecedented sensitivity, a transition forbidden in the standard model but allowed in supersymmetric and other models of new physics. The high energy research program used proton and antiproton colliding beams. The experiments were done at the Fermilab Tevatron (proton-antiproton collisions at a center of mass energy of 1.96 TeV) and at the CERN Large Hadron Collider (proton-proton collisions at 7-8 TeV). The neutrino program used data obtained from the Super-Kamiokande detec- tor. This water- lled Cherenkov counter was used to detect and measure the properties of neutrinos produced in cosmic ray showers, and from neutrino beams produced from acceler- ators in Japan. The Mu2E experiment will use a special stopped muon beam to be built at Fermilab.« less

Research in High Energy Physics at Duke University

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

Goshaw, Alfred; Kotwal, Ashutosh; Kruse, Mark

2013-07-29

This is the Closeout Report for the research grant in experimental elementary particle physics, carried out by the Duke University High Energy Physics (HEP) group. We re- port on physics results and detector development carried out under this grant, focussing on the recent three-year grant period (2010 to 2013). The Duke HEP group consisted of seven faculty members, two senior scientists, five postdocs and eight graduate students. There were three thrusts of the research program. Measurements at the energy frontier at CDF and ATLAS were used to test aspects of elementary particle theory described by the Stan- dard Model (SM)more » and to search for new forces and particles beyond those contained within the SM. The neutrino sector was explored using data obtained from a large neutrino detector located in Japan, and R & D was conducted on new experiments to be built in the US. The measurements provided information about neutrino masses and the manner in which neutri- nos change species in particle beams. Two years ago we have started a new research program in rare processes based on the Mu2E experiment at Fermilab. This research is motivated by the search for the {mu} {yields} e transition with unprecedented sensitivity, a transition forbidden in the standard model but allowed in supersymmetric and other models of new physics. The high energy research program used proton and antiproton colliding beams. The experiments were done at the Fermilab Tevatron (proton-antiproton collisions at a center of mass energy of 1.96 TeV) and at the CERN Large Hadron Collider (proton-proton collisions at 7-8 TeV). The neutrino program used data obtained from the Super-Kamiokande detector. This water-filled Cherenkov counter was used to detect and measure the properties of neutrinos produced in cosmic ray showers, and from neutrino beams produced from acceler- ators in Japan. The Mu2E experiment will use a special stopped muon beam to be built at Fermilab.« less

Grid-Enabled High Energy Physics Research using a Beowulf Cluster

NASA Astrophysics Data System (ADS)

Mahmood, Akhtar

2005-04-01

At Edinboro University of Pennsylvania, we have built a 8-node 25 Gflops Beowulf Cluster with 2.5 TB of disk storage space to carry out grid-enabled, data-intensive high energy physics research for the ATLAS experiment via Grid3. We will describe how we built and configured our Cluster, which we have named the Sphinx Beowulf Cluster. We will describe the results of our cluster benchmark studies and the run-time plots of several parallel application codes. Once fully functional, the Cluster will be part of Grid3[www.ivdgl.org/grid3]. The current ATLAS simulation grid application, models the entire physical processes from the proton anti-proton collisions and detector's response to the collision debri through the complete reconstruction of the event from analyses of these responses. The end result is a detailed set of data that simulates the real physical collision event inside a particle detector. Grid is the new IT infrastructure for the 21^st century science -- a new computing paradigm that is poised to transform the practice of large-scale data-intensive research in science and engineering. The Grid will allow scientist worldwide to view and analyze huge amounts of data flowing from the large-scale experiments in High Energy Physics. The Grid is expected to bring together geographically and organizationally dispersed computational resources, such as CPUs, storage systems, communication systems, and data sources.

Success in introductory college physics: The role of gender, high school preparation, and student learning perceptions

NASA Astrophysics Data System (ADS)

Chen, Jean Chi-Jen

Physics is fundamental for science, engineering, medicine, and for understanding many phenomena encountered in people's daily lives. The purpose of this study was to investigate the relationships between student success in college-level introductory physics courses and various educational and background characteristics. The primary variables of this study were gender, high school mathematics and science preparation, preference and perceptions of learning physics, and performance in introductory physics courses. Demographic characteristics considered were age, student grade level, parents' occupation and level of education, high school senior grade point average, and educational goals. A Survey of Learning Preference and Perceptions was developed to collect the information for this study. A total of 267 subjects enrolled in six introductory physics courses, four algebra-based and two calculus-based, participated in the study conducted during Spring Semester 2002. The findings from the algebra-based physics courses indicated that participant's educational goal, high school senior GPA, father's educational level, mother's educational level, and mother's occupation in the area of science, engineering, or computer technology were positively related to performance while participant age was negatively related. Biology preparation, mathematics preparation, and additional mathematics and science preparation in high school were also positively related to performance. The relationships between the primary variables and performance in calculus-based physics courses were limited to high school senior year GPA and high school physics preparation. Findings from all six courses indicated that participant's educational goal, high school senior GPA, father's educational level, and mother's occupation in the area of science, engineering, or computer technology, high school preparation in mathematics, biology, and the completion of additional mathematics and science courses were

Electrochemistry of cytochrome P450 17α-hydroxylase/17,20-lyase (P450c17).

PubMed

Martin, Lisandra L; Kubeil, Clemens; Simonov, Alexandr N; Kuznetsov, Vladimir L; Corbin, C Jo; Auchus, Richard J; Conley, Alan J; Bond, Alan M; Rodgers, Raymond J

2017-02-05

Within the superfamily of cytochrome P450 enzymes (P450s), there is a small class which is functionally employed for steroid biosynthesis. The enzymes in this class appear to have a small active site to accommodate the steroid substrates specifically and snuggly, prior to the redox transformation or hydroxylation to form a product. Cytochrome P450c17 is one of these and is also a multi-functional P450, with two activities, the first 17α-hydroxylation of pregnenolone is followed by a subsequent 17,20-lyase transformation to dehydroepiandrosterone (DHEA) as the dominant pathways to cortisol precursors or androgens in humans, respectively. How P450c17 regulates these two redox reactions is of special interest. There is a paucity of direct electrochemical studies on steroidogenic P450s, and in this mini-review we provide an overview of these studies with P450c17. Historical consideration as to the difficulties in obtaining reliable electrochemistry due to issues of handling proteins on an electrode, together with advances in the electrochemical techniques are addressed. Recent work using Fourier transformed alternating current voltammetry is highlighted as this technique can provide both catalytic information simultaneously with the underlying redox transfer with the P450 haem. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Three Redox States of Trypanosoma brucei Alternative Oxidase Identified by Infrared Spectroscopy and Electrochemistry

PubMed Central

Maréchal, Amandine; Kido, Yasutoshi; Kita, Kiyoshi; Moore, Anthony L.; Rich, Peter R.

2009-01-01

Electrochemistry coupled with Fourier transform infrared (IR) spectroscopy was used to investigate the redox properties of recombinant alternative ubiquinol oxidase from Trypanosoma brucei, the organism responsible for African sleeping sickness. Stepwise reduction of the fully oxidized resting state of recombinant alternative ubiquinol oxidase revealed two distinct IR redox difference spectra. The first of these, signal 1, titrates in the reductive direction as an n = 2 Nernstian component with an apparent midpoint potential of 80 mV at pH 7.0. However, reoxidation of signal 1 in the same potential range under anaerobic conditions did not occur and only began with potentials in excess of 500 mV. Reoxidation by introduction of oxygen was also unsuccessful. Signal 1 contained clear features that can be assigned to protonation of at least one carboxylate group, further perturbations of carboxylic and histidine residues, bound ubiquinone, and a negative band at 1554 cm−1 that might arise from a radical in the fully oxidized protein. A second distinct IR redox difference spectrum, signal 2, appeared more slowly once signal 1 had been reduced. This component could be reoxidized with potentials above 100 mV. In addition, when both signals 1 and 2 were reduced, introduction of oxygen caused rapid oxidation of both components. These data are interpreted in terms of the possible active site structure and mechanism of oxygen reduction to water. PMID:19767647

Tailoring the Ag + Content within the Tunnels and on the Exposed Surfaces of α-MnO 2 Nanowires: Impact on Impedance and Electrochemistry

DOE PAGES

Zhang, Bingjie; Smith, Paul F.; Lee, Seung-Yong; ...

2016-12-01

Efficient conduction of both electrons and cations (e.g., Li +) has a profound effect on the current and capacity of lithium-based batteries. With this study, we focus on cathode effects, with the preparation of pure silver hollandite materials with variable silver ion content within (intra-tunnel) and on the surface of α-MnO 2 tunneled materials, followed by the measurement and analysis of impedance and electrochemistry data. Specifically, pure Ag xMn 8O 16-y materials with low (x = 1.13) and high (x = 1.54) intra-tunnel silver content are compared with Ag xMn 8O 16-y·aAg 2O (a = 0.25, 0.63, 1.43) composites preparedmore » via a new Ag 2O coating strategy. When the Ag 2O (a = 0, 0.25) content is low, the material with higher intra-tunnel silver (x = 1.53) content delivers up to ~5-fold higher capacity accounted for by a ~10-fold lower impedance than its lower intra-tunnel silver (x = 1.13) counterpart. In the presence of high Ag 2O content (a = 0.63, 1.43), both composites exhibit comparable impedance but the lower intra-tunnel silver (x = 1.13) composite delivers up to ~1.5-fold higher capacity than higher intra-tunnel silver composite, highlighting the key role of Li + transport under those conditions. Our results demonstrate material design strategies which can significantly increase electronic and ionic conductivities.« less

Tailoring the Ag + Content within the Tunnels and on the Exposed Surfaces of α-MnO 2 Nanowires: Impact on Impedance and Electrochemistry

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

Zhang, Bingjie; Smith, Paul F.; Lee, Seung-Yong

Efficient conduction of both electrons and cations (e.g., Li +) has a profound effect on the current and capacity of lithium-based batteries. With this study, we focus on cathode effects, with the preparation of pure silver hollandite materials with variable silver ion content within (intra-tunnel) and on the surface of α-MnO 2 tunneled materials, followed by the measurement and analysis of impedance and electrochemistry data. Specifically, pure Ag xMn 8O 16-y materials with low (x = 1.13) and high (x = 1.54) intra-tunnel silver content are compared with Ag xMn 8O 16-y·aAg 2O (a = 0.25, 0.63, 1.43) composites preparedmore » via a new Ag 2O coating strategy. When the Ag 2O (a = 0, 0.25) content is low, the material with higher intra-tunnel silver (x = 1.53) content delivers up to ~5-fold higher capacity accounted for by a ~10-fold lower impedance than its lower intra-tunnel silver (x = 1.13) counterpart. In the presence of high Ag 2O content (a = 0.63, 1.43), both composites exhibit comparable impedance but the lower intra-tunnel silver (x = 1.13) composite delivers up to ~1.5-fold higher capacity than higher intra-tunnel silver composite, highlighting the key role of Li + transport under those conditions. Our results demonstrate material design strategies which can significantly increase electronic and ionic conductivities.« less

Physics Contests for High School Students.

ERIC Educational Resources Information Center

Fox, Doug; Nelson, Jim

1983-01-01

Describes how the Ontario Section of the American Association of Physics Teachers started a "Grade Eleven Prize Physics Contest" to generate interest in physics and recognize outstanding students. Also describes outcomes of contests, adaptation of the contest by Southeastern Pennsylvania Section, and suggestions for others wanting to…

Achieving direct electrochemistry of glucose oxidase by one step electrochemical reduction of graphene oxide and its use in glucose sensing.

PubMed

Shamsipur, Mojtaba; Tabrizi, Mahmoud Amouzadeh

2014-12-01

In this paper, the direct electrochemistry of glucose oxidase (GOD) was accomplished at a glassy carbon electrode modified with electrochemically reduced graphene oxide/sodium dodecyl sulfate (GCE/ERGO/SDS). A pair of reversible peaks is exhibited on GCE/ERGO/SDS/GOD by cyclic voltammetry. The peak-to-peak potential separation of immobilized GOD is 28 mV in 0.1 M phosphate buffer solution (pH7.0) with a scan rate of 50 mV/s. The average surface coverage is 2.62×10(-10) mol cm(-2). The resulting biosensor exhibited a good response to glucose with linear range from 1 to 8 mM (R(2)=0.9878), good reproducibility and detection limit of 40.8 μM. The results from the biosensor were similar (±5%) to those obtained from the clinical analyzer. Copyright © 2014 Elsevier B.V. All rights reserved.

Projectile and Circular Motion: A Model Four-Week Unit of Study for a High School Physics Class Using Physics Courseware.

ERIC Educational Resources Information Center

Geigel, Joan; And Others

A self-paced program designed to integrate the use of computers and physics courseware into the regular classroom environment is offered for physics high school teachers in this module on projectile and circular motion. A diversity of instructional strategies including lectures, demonstrations, videotapes, computer simulations, laboratories, and…

A Comparison of High and Low Performing Secondary Physical Education Programs in South Carolina.

ERIC Educational Resources Information Center

Castelli, Darla M.

This study compared high and low performing schools in a state secondary physical education high stakes assessment and accountability program. The South Carolina Physical Education Assessment Program (SCPEAP) required teachers to assess samples of students on competency across four state mandated performance indicators. This study examined the…

International Physics Summer Camp for High School Students

NASA Astrophysics Data System (ADS)

Pope, Damian T.; Korsunsky, B.

2006-12-01

Each year for the past three years, Perimeter Institute for Theoretical Physics in Waterloo, Ontario, Canada, has staged an annual physics summer camp for high school students worldwide. Known as the International Summer School for Young Physicists (ISSYP), it attracts students from all corners of the globe and this year had attendees from 15 countries and 5 continents. The camp is aimed at motivated students around the age of 16 and is a two-week immersion into the exciting world of cutting-edge physics today. It covers topics such as dark matter, superstring theory and quantum computers, and exposes attendees to some of the very latest research results. It includes lectures, tutorials, laboratory visits and small-group projects and, in addition to teaching new material, strives to give students a deeper appreciation of the true nature of science. Throughout, attendees have a great deal of interaction with the institute's scientists. This presentation will give an overview of the camp including the material taught within it, its impact on students and the goals of the program. More information about the camp can be found at: http://www.youngphysicists.ca

Physical activity behavior and related characteristics of highly active eighth-grade girls.

PubMed

Taverno Ross, Sharon E; Dowda, Marsha; Beets, Michael W; Pate, Russell R

2013-06-01

Although girls are generally less physically active than boys, some girls regularly engage in high levels of physical activity (PA); however, very little is known about these girls and how they differ from those who are less physically active. This study examined the PA behavior and related characteristics of highly active adolescent girls and compared them with those who are less active. Data from 1,866 eighth-grade girls from six field centers across the United States participating in the Trial of Activity for Adolescent Girls (TAAG) were included in the present analysis. Mixed-model analysis of variance examined differences in sociodemographic, anthropometric, psychosocial, and physical activity (accelerometry and self-report) variables between high- and low-active girls; effect sizes were calculated for the differences. High-active girls were taller, had lower body mass indices and body fat, and were less sedentary. High-active girls scored higher on self-efficacy, enjoyment of PA, self-management strategies, outcome-expectancy value, and support from family and friends than low-active girls. Low-active girls participated in more leisure time and educational sedentary activities than high-active girls. High-active girls participated in more PA classes/lessons outside of school, team sports, and individual sports. They were also more likely to participate in sports in an organized setting in the community or at school than low-active girls. Health promotion efforts should focus on decreasing the amount of time girls spend in sedentary activities and replacing that time with organized PA opportunities; such efforts should seek to minimize perceived barriers and increase self-efficacy and support for PA. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Perceptions of Heart Rate Monitor Use in High School Physical Education Classes

ERIC Educational Resources Information Center

Partridge, Julie A.; King, Kristi McClary; Bian, Wei

2011-01-01

Incorporating technology into the physical education curriculum is becoming a popular strategy in which teachers can assess, motivate, and provide feedback to students regarding their physical activity participation during class. The purpose of this exploratory study was to gain a greater understanding of high school students' perceptions of using…

A useful demonstration of calculus in a physics high school laboratory

NASA Astrophysics Data System (ADS)

Alvarez, Gustavo; Schulte, Jurgen; Stockton, Geoffrey; Wheeler, David

2018-01-01

The real power of calculus is revealed when it is applied to actual physical problems. In this paper, we present a calculus inspired physics experiment suitable for high school and undergraduate programs. A model for the theory of the terminal velocity of a falling body subject to a resistive force is developed and its validity tested in an experiment of a falling magnet in a column of self-induced eddy currents. The presented method combines multiple physics concepts such as 1D kinematics, classical mechanics, electromagnetism and non-trivial mathematics. It offers the opportunity for lateral as well as project-based learning.

Interactive Online Physics Labs Increase High School Students' Interest

ERIC Educational Resources Information Center

Gryczka, Patrick; Klementowicz, Edward; Sharrock, Chappel; Montclare, Jin Kim

2016-01-01

Here we describe the incorporation of a web-based application focusing on circuits for the physics high school classroom as part of an outreach program. The program involves college mentors creating and implementing science lessons in collaboration with the classroom teacher. Focusing on the challenge of understanding circuit design, a technology…

Conceptual problem solving in high school physics

NASA Astrophysics Data System (ADS)

Docktor, Jennifer L.; Strand, Natalie E.; Mestre, José P.; Ross, Brian H.

2015-12-01

Problem solving is a critical element of learning physics. However, traditional instruction often emphasizes the quantitative aspects of problem solving such as equations and mathematical procedures rather than qualitative analysis for selecting appropriate concepts and principles. This study describes the development and evaluation of an instructional approach called Conceptual Problem Solving (CPS) which guides students to identify principles, justify their use, and plan their solution in writing before solving a problem. The CPS approach was implemented by high school physics teachers at three schools for major theorems and conservation laws in mechanics and CPS-taught classes were compared to control classes taught using traditional problem solving methods. Information about the teachers' implementation of the approach was gathered from classroom observations and interviews, and the effectiveness of the approach was evaluated from a series of written assessments. Results indicated that teachers found CPS easy to integrate into their curricula, students engaged in classroom discussions and produced problem solutions of a higher quality than before, and students scored higher on conceptual and problem solving measures.

Physics Teachers' Behavioral, Control and Normative Beliefs about Teaching Physics According to the National High School Physics Curriculum in Turkey

ERIC Educational Resources Information Center

Kapucu, Serkan; Yildirim, Ufuk

2014-01-01

In Turkey, a new Turkish High School Physics Curriculum (THSPC) was put into practice, starting initially with the Grade 9 in the 2008-2009 education-year. When compared with the previous ones, this curriculum emphasized the importance of students' active involvement in learning, use of real-life contexts and development of new skills. Even though…

Gbps wireless transceivers for high bandwidth interconnections in distributed cyber physical systems

NASA Astrophysics Data System (ADS)

Saponara, Sergio; Neri, Bruno

2015-05-01

In Cyber Physical Systems there is a growing use of high speed sensors like photo and video camera, radio and light detection and ranging (Radar/Lidar) sensors. Hence Cyber Physical Systems can benefit from the high communication data rate, several Gbps, that can be provided by mm-wave wireless transceivers. At such high frequency the wavelength is few mm and hence the whole transceiver including the antenna can be integrated in a single chip. To this aim this paper presents the design of 60 GHz transceiver architecture to ensure connection distances up to 10 m and data rate up to 4 Gbps. At 60 GHz there are more than 7 GHz of unlicensed bandwidth (available for free for development of new services). By using a CMOS SOI technology RF, analog and digital baseband circuitry can be integrated in the same chip minimizing noise coupling. Even the antenna is integrated on chip reducing cost and size vs. classic off-chip antenna solutions. Therefore the proposed transceiver can enable at physical layer the implementation of low cost nodes for a Cyber Physical System with data rates of several Gbps and with a communication distance suitable for home/office scenarios, or on-board vehicles such as cars, trains, ships, airplanes

Direct electrochemistry of cytochrome c immobilized on titanium nitride/multi-walled carbon nanotube composite for amperometric nitrite biosensor.

PubMed

Haldorai, Yuvaraj; Hwang, Seung-Kyu; Gopalan, Anantha-Iyengar; Huh, Yun Suk; Han, Young-Kyu; Voit, Walter; Sai-Anand, Gopalan; Lee, Kwang-Pill

2016-05-15

In this report, titanium nitride (TiN) nanoparticles decorated multi-walled carbon nanotube (MWCNTs) nanocomposite is fabricated via a two-step process. These two steps involve the decoration of titanium dioxide nanoparticles onto the MWCNTs surface and a subsequent thermal nitridation. Transmission electron microscopy shows that TiN nanoparticles with a mean diameter of ≤ 20 nm are homogeneously dispersed onto the MWCNTs surface. Direct electrochemistry and electrocatalysis of cytochrome c immobilized on the MWCNTs-TiN composite modified on a glassy carbon electrode for nitrite sensing are investigated. Under optimum conditions, the current response is linear to its concentration from 1 µM to 2000 µM with a sensitivity of 121.5 µA µM(-1)cm(-2) and a low detection limit of 0.0014 µM. The proposed electrode shows good reproducibility and long-term stability. The applicability of the as-prepared biosensor is validated by the successful detection of nitrite in tap and sea water samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Teaching RLC Parallel Circuits in High-School Physics Class

ERIC Educational Resources Information Center

Simon, Alpár

2015-01-01

This paper will try to give an alternative treatment of the subject "parallel RLC circuits" and "resonance in parallel RLC circuits" from the Physics curricula for the XIth grade from Romanian high-schools, with an emphasis on practical type circuits and their possible applications, and intends to be an aid for both Physics…

Theoretical Problems in High Resolution Solar Physics, 2

NASA Technical Reports Server (NTRS)

Athay, G. (Editor); Spicer, D. S. (Editor)

1987-01-01

The Science Working Group for the High Resolution Solar Observatory (HRSO) laid plans beginning in 1984 for a series of workshops designed to stimulate a broadbased input from the scientific community to the HRSO mission. These workshops have the dual objectives of encouraging an early start on the difficult theoretical problems in radiative transfer, magnetohydrodynamics, and plasma physics that will be posed by the HRSO data, and maintaining current discussions of results in high resolution solar studies. This workshop was the second in the series. The workshop format presented invited review papers during the formal sessions and contributed poster papers for discussions during open periods. Both are presented.

Goals and design of public physics lectures: perspectives of high-school students, physics teachers and lecturers

NASA Astrophysics Data System (ADS)

Kapon, S.; Ganiel, U.; Eylon, B.

2009-09-01

Many large scientific projects and scientific centres incorporate some kind of outreach programme. Almost all of these outreach programmes include public scientific lectures delivered by practising scientists. In this article, we examine such lectures from the perspectives of: (i) lecturers (7) who are practising scientists acknowledged to be good public lecturers and (ii) audiences composed of high-school students (169) and high-school physics teachers (80) who attended these lectures. We identify and discuss the main goals as expressed by the lecturers and the audiences, and the correspondence between these goals. We also discuss how the lecturers' goals impact on the design of their lectures and examine how the lecture affects audiences with different attitudes towards (and interests in) physics. Our findings suggest that the goals of the participating lecturers and the expectations of their audiences were highly congruent. Both believe that a good public scientific lecture must successfully communicate state-of-the-art scientific knowledge to the public, while inspiring interest in and appreciation of science. Our findings also suggest that exemplary public scientific lectures incorporate content, structure and explanatory means that explicitly adhere to the lecturers' goals. We identify and list several design principles.

Education of Social Skills among Senior High School Age Students in Physical Education Classes

ERIC Educational Resources Information Center

Akelaitis, Arturas V.; Malinauskas, Romualdas K.

2016-01-01

Research aim was to reveal peculiarities of the education of social skills among senior high school age students in physical education classes. We hypothesized that after the end of the educational experiment the senior high school age students will have more developed social skills in physical education classes. Participants in the study were 51…

Variation by Gender in Abu Dhabi High School Students' Interests in Physics

ERIC Educational Resources Information Center

Badri, Masood; Mazroui, Karima Al; Al Rashedi, Asma; Yang, Guang

2016-01-01

Abu Dhabi high school students' interest in physics in different contexts was investigated with a survey conducted in connection with the international project, The Relevance of Science Education (ROSE). The sample consisted of 2248 students in public and private schools. Means of most items that belong to the school physics context for both girls…

Materials research at Stanford University

NASA Technical Reports Server (NTRS)

1976-01-01

Information briefly describing the total research activity related to the science of materials is reported. Emphasis is placed on physical and mechanical properties of composite materials, energy transportation, superconductors, microwave electronics, and solid state electrochemistry.

Final Report for Research in High Energy Physics (University of Hawaii)

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

Browder, Thomas E.

2013-08-31

Here we present a final report for the DOE award for the University of Hawaii High Energy Physics Group (UHHEPG) for the period from December 1, 2009 to May 31, 2013 (including a period of no-cost extension). The high energy physics (HEP) group at the University of Hawaii (UH) has been engaged in experiments at the intensity frontier studying flavor physics (Task A: Belle, Belle-II and Task B: BES) and neutrinos (Task C: SuperK, LBNE, Double Chooz, DarkSide, and neutrino R\\&D). On the energy frontier, new types of pixel detectors were developed for upgrades of the ATLAS experiment at themore » LHC (Task D). On the cosmic frontier, there were investigations of ultra high-energy neutrino astrophysics and the highest energy cosmic rays using special radio detection techniques (Task E: AMBER, ANITA R\\&D) and results of the analysis of ANITA data. In addition, we have developed new types of sophisticated and cutting edge instrumentation based on novel ``oscilloscope on a chip'' electronics (Task F). Theoretical physics research (Task G) is phenomenologically oriented and has studied experimental consequences of existing and proposed new theories relevant to the energy, cosmic and intensity frontiers. The senior investigators for proposal were T. E. Browder (Task A), F. A. Harris (Task B), P. Gorham (Task E), J. Kumar (Task G), J. Maricic (Task C), J. G. Learned (Task C), S. Pakvasa (Task G), S. Parker (Task D), S. Matsuno (Task C), X. Tata (Task G) and G. S. Varner (Tasks F, A, E).« less

Final Report: High Energy Physics at the Energy Frontier at Louisiana Tech

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

Sawyer, Lee; Wobisch, Markus; Greenwood, Zeno D.

The Louisiana Tech University High Energy Physics group has developed a research program aimed at experimentally testing the Standard Model of particle physics and searching for new phenomena through a focused set of analyses in collaboration with the ATLAS experiment at the Large Hadron Collider (LHC) at the CERN laboratory in Geneva. This research program includes involvement in the current operation and maintenance of the ATLAS experiment and full involvement in Phase 1 and Phase 2 upgrades in preparation for future high luminosity (HL-LHC) operation of the LHC. Our focus is solely on the ATLAS experiment at the LHC, withmore » some related detector development and software efforts. We have established important service roles on ATLAS in five major areas: Triggers, especially jet triggers; Data Quality monitoring; grid computing; GPU applications for upgrades; and radiation testing for upgrades. Our physics research is focused on multijet measurements and top quark physics in final states containing tau leptons, which we propose to extend into related searches for new phenomena. Focusing on closely related topics in the jet and top analyses and coordinating these analyses in our group has led to high efficiency and increased visibility inside the ATLAS collaboration and beyond. Based on our work in the DØ experiment in Run II of the Fermilab Tevatron Collider, Louisiana Tech has developed a reputation as one of the leading institutions pursuing jet physics studies. Currently we are applying this expertise to the ATLAS experiment, with several multijet analyses in progress.« less

Prevalence of physical inactivity and associated factors among high school students from state's public schools.

PubMed

Ceschini, Fabio L; Andrade, Douglas R; Oliveira, Luis C; Araújo Júnior, Jorge F; Matsudo, Victor K R

2009-01-01

To describe the prevalence of physical inactivity and associated factors among high school students from state's public schools in the city of São Paulo, state of São Paulo, Brazil. Sixteen state's public schools were randomly selected according to the geographic areas of the city (North, South, East, and West). The sample consisted of 3,845 high school students in 2006. Physical inactivity was measured using the International Physical Activity Questionnaire (short IPAQ) and was defined as practicing moderate and/or vigorous physical activity for a period of less than 300 minutes per week. The independent variables analyzed were: gender, age, socioeconomic level, geographic area of the city, awareness of the Agita São Paulo program, participation in physical education classes, smoking, alcohol intake and time spent per day watching television. Three-level Poisson regression was used for assessing the variables, with a significance level of p < 0.05. The general prevalence of physical inactivity among adolescents in São Paulo was 62.5% (95%CI 60.5-64.1). The factors associated with physical inactivity were gender, age, socioeconomic level, geographic area of the city, awareness of the Agita São Paulo program, non-participation in physical education classes, smoking, alcohol intake and time spent per day watching television. It was concluded that the prevalence of physical inactivity among adolescents in São Paulo was high in all the geographic areas evaluated, and that sociodemographic and behavioral factors contributed significantly to physical inactivity.

High School Physical Education: What Contributes to the Experience of Flow?

ERIC Educational Resources Information Center

Stormoen, Sidsel; Urke, Helga Bjørnøy; Tjomsland, Hege Eikeland; Wold, Bente; Diseth, Åge

2016-01-01

This study seeks to identify factors that promote positive experiences in high school physical education (PE). The study combines elements of Self-determination Theory (SDT) with the theory of "flow". Special attention is given to gender differences. The study sample consisted of 167 Norwegian senior high school students (78 females and…

An Event to Encourage High School Students to Pursue College Degrees in Physics and Math

NASA Astrophysics Data System (ADS)

Bukiet, Bruce; Thomas, Gordon

2003-04-01

We discuss a Math and Physics Day for high school students and teachers, with hands-on activities and seminars involving mathematics and physics. Participants also learn about careers for those who go on to major in physics and mathematics in college. The New York State Section of the APS has provided generous support for this workshop through its Outreach grant program. Approximately a dozen high schools and 100 students attend each year. The program, which runs from 9:15 AM until 2:15 PM, includes an introduction to undergraduate degree programs in Mathematics, Statistics, Optics, Actuarial Science and Applied Physics, a group physics experiment/contest, brief talks over lunch by speakers from industry who have degrees in Math or Physics, and an afternoon seminar. Teachers earn Professional Development credit.

Results of Using the Take-Away Technique on Students' Achievements and Attitudes in High School Physics and Physical Science Courses

ERIC Educational Resources Information Center

Carifio, James; Doherty, Michael

2012-01-01

The Take-away Technique was used in High School Physics and Physical Science courses for the unit on Newtonian mechanics in a teacher (6) by grade level (4) partially crossed design (N = 272). All classes received the same IE instructional treatment. The experimental group (classrooms) did a short Take-away after each class summarizing the key…

High School Student Physics Research Experience Yields Positive Results

ERIC Educational Resources Information Center

Podolak, K. R.; Walters, M. J.

2016-01-01

All high school students that wish to continue onto college are seeking opportunities to be competitive in the college market. They participate in extra-curricular activities which are seen to foster creativity and the skills necessary to do well in the college environment. In the case of students with an interest in physics, participating in a…

The application of electrochemistry to pharmaceutical stability testing--comparison with in silico prediction and chemical forced degradation approaches.

PubMed

Torres, Susana; Brown, Roland; Szucs, Roman; Hawkins, Joel M; Zelesky, Todd; Scrivens, Garry; Pettman, Alan; Taylor, Mark R

2015-11-10

The aim of this study was to evaluate the use of electrochemistry to generate oxidative degradation products of a model pharmaceutical compound. The compound was oxidized at different potentials using an electrochemical flow-cell fitted with a glassy carbon working electrode, a Pd/H2 reference electrode and a titanium auxiliary electrode. The oxidative products formed were identified and structurally characterized by LC-ESI-MS/MS using a high resolution Q-TOF mass spectrometer. Results from electrochemical oxidation using electrolytes of different pH were compared to those from chemical oxidation and from accelerated stability studies. Additionally, oxidative degradation products predicted using an in silico commercially available software were compared to those obtained from the various experimental methods. The electrochemical approach proved to be useful as an oxidative stress test as all of the final oxidation products observed under accelerated stability studies could be generated; previously reported reactive intermediate species were not observed most likely because the electrochemical mechanism differs from the oxidative pathway followed under accelerated stability conditions. In comparison to chemical degradation tests electrochemical degradation has the advantage of being much faster and does not require the use of strong oxidizing agents. Moreover, it enables the study of different operating parameters in short periods of time and optimisation of the reaction conditions (pH and applied potential) to achieve different oxidative products mixtures. This technique may prove useful as a stress test condition for the generation of oxidative degradation products and may help accelerate structure elucidation and development of stability indicating analytical methods. Copyright © 2015 Elsevier B.V. All rights reserved.

Student Engagement in High-Performing Schools: Relationships to Mental and Physical Health

ERIC Educational Resources Information Center

Conner, Jerusha O.; Pope, Denise

2014-01-01

This chapter examines how the three most common types of engagement found among adolescents attending high-performing high schools relate to indicators of mental and physical health. [This article originally appeared as NSSE Yearbook Vol. 113, No. 1.

Networking for High Energy and Nuclear Physics

NASA Astrophysics Data System (ADS)

Newman, Harvey B.

2007-07-01

This report gives an overview of the status and outlook for the world's research networks and major international links used by the high energy physics and other scientific communities, network technology advances on which our community depends and in which we have an increasingly important role, and the problem of the Digital Divide, which is a primary focus of ICFA's Standing Committee on Inter-regional Connectivity (SCIC). Wide area networks of sufficient, and rapidly increasing end-to-end capability are vital for every phase of high energy physicists' work. Our bandwidth usage, and the typical capacity of the major national backbones and intercontinental links used by our field have progressed by a factor of more than 1000 over the past decade, and the outlook is for a similar increase over the next decade. This striking exponential growth trend, outstripping the growth rates in other areas of information technology, has continued in the past year, with many of the major national, continental and transoceanic networks supporting research and education progressing from a 10 Gigabits/sec (Gbps) backbone to multiple 10 Gbps links in their core. This is complemented by the use of point-to-point "light paths" to support the most demanding applications, including high energy physics, in a growing list of cases. As we approach the era of LHC physics, the growing need to access and transport Terabyte-scale and later 10 to 100 Terabyte datasets among more than 100 "Tier1" and "Tier2" centers at universities and laboratories spread throughout the world has brought the key role of networks, and the ongoing need for their development, sharply into focus. Bandwidth itself on an increasing scale is not enough. Realizing the scientific wealth of the LHC and our other major scientific programs depends crucially on our ability to use the bandwidth efficiently and reliably, with reliable high rates of data throughput, and effectively, where many parallel large-scale data

The World in Slow Motion: Using a High-Speed Camera in a Physics Workshop

ERIC Educational Resources Information Center

Dewanto, Andreas; Lim, Geok Quee; Kuang, Jianhong; Zhang, Jinfeng; Yeo, Ye

2012-01-01

We present a physics workshop for college students to investigate various physical phenomena using high-speed cameras. The technical specifications required, the step-by-step instructions, as well as the practical limitations of the workshop, are discussed. This workshop is also intended to be a novel way to promote physics to Generation-Y…

Sol-gel derived silica/chitosan/Fe3O4 nanocomposite for direct electrochemistry and hydrogen peroxide biosensing

NASA Astrophysics Data System (ADS)

Satvekar, R. K.; Rohiwal, S. S.; Tiwari, A. P.; Raut, A. V.; Tiwale, B. M.; Pawar, S. H.

2015-01-01

A novel strategy to fabricate hydrogen peroxide third generation biosensor has been developed from sol-gel of silica/chitosan (SC) organic-inorganic hybrid material assimilated with iron oxide magnetic nanoparticles (Fe3O4). The large surface area of Fe3O4 and porous morphology of the SC composite facilitates a high loading of horseradish peroxidase (HRP). Moreover, the entrapped enzyme preserves its conformation and biofunctionality. The fabrication of hydrogen peroxide biosensor has been carried out by drop casting of the SC/F/HRP nanocomposite on glassy carbon electrode (GCE) for study of direct electrochemistry. The x-ray diffraction (XRD) pattern and transmission electron microscopy (TEM) confirms the phase purity and particle size of as-synthesized Fe3O4 nanoparticles, respectively. The nanocomposite was characterized by UV-vis spectroscopy, fluorescence spectroscopy and Fourier transform infrared (FTIR) for the characteristic structure and conformation of enzyme. The surface topographies of the nanocomposite thin films were investigated by scanning electron microscopy (SEM). Dynamic light scattering (DLS) was used to determine the particle size distribution. The electrostatic interactions of the SC composite with Fe3O4 nanoparticles were studied by the zeta potential measurement. Electrochemical impedance spectroscopy (EIS) of the SC/F/HRP/GCE electrode displays Fe3O4 nanoparticles as an excellent candidate for electron transfer. The SC/F/HRP/GCE exhibited a pair of well-defined quasi reversible cyclic voltammetry peaks due to the redox couple of HRP-heme Fe (III)/Fe (II) in pH 7.0 potassium phosphate buffer. The biosensor was employed to detect H2O2 with linear range of 5 μM to 40 μM and detection limit of 5 μM. The sensor displays excellent selectivity, sensitivity, good reproducibility and long term stability.

The Challenges of Designing and Implementing Effective Professional Development for Out-of-Field High School Physics Teachers

NASA Astrophysics Data System (ADS)

Escalada, Lawrence T.; Moeller, Julia K.

2006-02-01

With the existing shortage of qualified high school physics teachers and the current mandate of the No Child Left Behind Act requiring teachers to be "highly qualified" in all subjects they teach, university physics departments must offer content courses and programs that would allow out-of-field high school physics teachers to meet this requirement. This paper will identify how the University of Northern Iowa Physics Department is attempting to address the needs of the high school physics teacher through its course offerings and professional development programs for teachers. The effectiveness of one such physics professional development program, the UNI Physics Institute (UNI-PI), on secondary science teachers' and their students' conceptual understanding of Newtonian mechanics, and the teachers' instructional practices was investigated. Twenty-one Iowa out-of-field high school physics teachers participating in the program were able to complete the physics coursework required to obtain the State of Iowa 7-12 Grade Physics Teaching endorsement. Twelve of the participants completed a two-year program during the 2002 and 2003 summers. Background information, pre- and post-test physics conceptual assessments and other data was collected from participants throughout the Institute. Participants collected pre and post-test conceptual assessment data from their students during the 2002-2003 and 2003-2004 academic years. This comprehensive assessment data revealed the Institute's influence on participants' and students' conceptual understanding of Newtonian Mechanics. The results of this investigation, the insights we have gained, and possible future directions for professional development will be shared.

Goals and intentions mediate efficacy beliefs and declining physical activity in high school girls.

PubMed

Dishman, Rod K; Saunders, Ruth P; Felton, Gwen; Ward, Dianne S; Dowda, Marsha; Pate, Russ R

2006-12-01

According to theory, girls who set goals about increasing their physical activity and who are dissatisfied with their current activity level are likely to form intentions to be active and to carry out those intentions, especially if they have high efficacy and control beliefs about being physically active. We tested those ideas while observing naturally occurring change during high school. A cohort of 431 black and white girls was tested at the end of their 9th- and 12th-grade academic years. Confirmatory factor analysis established the structural invariance of the measures across the 3-year study period. Structural equation modeling and panel analysis were used to determine whether changes in goal setting and satisfaction would mediate relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. Testing occurred between February and May in 1999 and 2004. Data were analyzed in 2006. Goal setting and intention mediated the indirect relation between self-efficacy and change in physical activity. Perceived behavioral control and physical activity change were related directly and also indirectly by a path mediated through satisfaction and intention. Black girls had lower self-efficacy, but changes in other variables were unrelated to race. These observations of longitudinal relations elaborate application of self-efficacy theory and the theory of planned behavior to physical activity by showing that goal setting and satisfaction mediate the relations of self-efficacy and perceived behavioral control with changes in intention and physical activity. The results encourage additional research to identify the sources and development of physical activity goals, and their attainment, among girls, and whether experimental manipulation of goals and intentions can mitigate the decline in girls' physical activity during high school.

News Quantum physics: German Physical Society spring meeting Journal access: American Physical Society's online journals will be available for free in all US high schools Award: High-school physics teacher receives American award for excellence Teacher training: Fobinet offers coordination of teacher-training activities Astronomy: Astronomy fans see stars at Astrofest Conference: Delegates enjoy the workshops and activities at CPD conference Forthcoming events

NASA Astrophysics Data System (ADS)

2011-05-01

Quantum physics: German Physical Society spring meeting Journal access: American Physical Society's online journals will be available for free in all US high schools Award: High-school physics teacher receives American award for excellence Teacher training: Fobinet offers coordination of teacher-training activities Astronomy: Astronomy fans see stars at Astrofest Conference: Delegates enjoy the workshops and activities at CPD conference Forthcoming events

Multiple Teaching Approaches, Teaching Sequence and Concept Retention in High School Physics Education

ERIC Educational Resources Information Center

Fogarty, Ian; Geelan, David

2013-01-01

Students in 4 Canadian high school physics classes completed instructional sequences in two key physics topics related to motion--Straight Line Motion and Newton's First Law. Different sequences of laboratory investigation, teacher explanation (lecture) and the use of computer-based scientific visualizations (animations and simulations) were…

Physical Activity in High School during "Free-Time" Periods

ERIC Educational Resources Information Center

Silva, Pedro; Sousa, Michael; Sá, Carla; Ribeiro, José; Mota, Jorge

2015-01-01

The purpose of this study was to examine youth physical activity (PA) in free-time periods during high school days and their contribution to total PA. Differences in terms of sex, age, body mass index and school level were assessed in a sample of Portuguese adolescents. Participants totalled 213 (135 girls), aged 14.6 ± 1.7, from two different…

Oxygen-participated electrochemistry of new lithium-rich layered oxides Li3MRuO5 (M = Mn, Fe).

PubMed

Laha, S; Natarajan, S; Gopalakrishnan, J; Morán, E; Sáez-Puche, R; Alario-Franco, M Á; Dos Santos-Garcia, A J; Pérez-Flores, J C; Kuhn, A; García-Alvarado, F

2015-02-07

We describe the synthesis, crystal structure and lithium deinsertion-insertion electrochemistry of two new lithium-rich layered oxides, Li3MRuO5 (M = Mn, Fe), related to rock salt based Li2MnO3 and LiCoO2. The Li3MnRuO5 oxide adopts a structure related to Li2MnO3 (C2/m) where Li and (Li0.2Mn0.4Ru0.4) layers alternate along the c-axis, while the Li3FeRuO5 oxide adopts a near-perfect LiCoO2 (R3[combining macron]m) structure where Li and (Li0.2Fe0.4Ru0.4) layers are stacked alternately. Magnetic measurements indicate for Li3MnRuO5 the presence of Mn(3+) and low spin configuration for Ru(4+) where the itinerant electrons occupy a π*-band. The onset of a net maximum in the χ vs. T plot at 9.5 K and the negative value of the Weiss constant (θ) of -31.4 K indicate the presence of antiferromagnetic superexchange interactions according to different pathways. Lithium electrochemistry shows a similar behaviour for both oxides and related to the typical behaviour of Li-rich layered oxides where participation of oxide ions in the electrochemical processes is usually found. A long first charge process with capacities of 240 mA h g(-1) (2.3 Li per f.u.) and 144 mA h g(-1) (1.38 Li per f.u.) is observed for Li3MnRuO5 and Li3FeRuO5, respectively. An initial sloping region (OCV to ca. 4.1 V) is followed by a long plateau (ca. 4.3 V). Further discharge-charge cycling points to partial reversibility (ca. 160 mA h g(-1) and 45 mA h g(-1) for Mn and Fe, respectively). Nevertheless, just after a few cycles, cell failure is observed. X-ray photoelectron spectroscopy (XPS) characterisation of both pristine and electrochemically oxidized Li3MRuO5 reveals that in the Li3MnRuO5 oxide, Mn(3+) and Ru(4+) are partially oxidized to Mn(4+) and Ru(5+) in the sloping region at low voltage, while in the long plateau, O(2-) is also oxidized. Oxygen release likely occurs which may be the cause for failure of cells upon cycling. Interestingly, some other Li-rich layered oxides have been reported to

High Energy Physics and Nuclear Physics Network Requirements

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

Dart, Eli; Bauerdick, Lothar; Bell, Greg

The Energy Sciences Network (ESnet) is the primary provider of network connectivity for the U.S. Department of Energy (DOE) Office of Science (SC), the single largest supporter of basic research in the physical sciences in the United States. In support of SC programs, ESnet regularly updates and refreshes its understanding of the networking requirements needed by instruments, facilities, scientists, and science programs that it serves. This focus has helped ESnet to be a highly successful enabler of scientific discovery for over 25 years. In August 2013, ESnet and the DOE SC Offices of High Energy Physics (HEP) and Nuclear Physicsmore » (NP) organized a review to characterize the networking requirements of the programs funded by the HEP and NP program offices. Several key findings resulted from the review. Among them: 1. The Large Hadron Collider?s ATLAS (A Toroidal LHC Apparatus) and CMS (Compact Muon Solenoid) experiments are adopting remote input/output (I/O) as a core component of their data analysis infrastructure. This will significantly increase their demands on the network from both a reliability perspective and a performance perspective. 2. The Large Hadron Collider (LHC) experiments (particularly ATLAS and CMS) are working to integrate network awareness into the workflow systems that manage the large number of daily analysis jobs (1 million analysis jobs per day for ATLAS), which are an integral part of the experiments. Collaboration with networking organizations such as ESnet, and the consumption of performance data (e.g., from perfSONAR [PERformance Service Oriented Network monitoring Architecture]) are critical to the success of these efforts. 3. The international aspects of HEP and NP collaborations continue to expand. This includes the LHC experiments, the Relativistic Heavy Ion Collider (RHIC) experiments, the Belle II Collaboration, the Large Synoptic Survey Telescope (LSST), and others. The international nature of these collaborations makes them

Medium and high-energy neutrino physics from a lunar base

NASA Technical Reports Server (NTRS)

Wilson, Thomas L.

1990-01-01

Neutrino astronomy at high energy levels conducted from the moon is treated by considering 'particle astronomy' as a part of physics and the moon as a neutrino detector. The ability to observe the Galactic center is described by means of a 1-1000 TeV 'window' related to the drop in flux of atmospheric neutrinos from the earth. The long-baseline particle physics which are described in terms of a lunar observatory are found to be possible exclusively from a lunar station. The earth's neutrinos can be eliminated for the observations of astrophysical sources, and other potential areas of investigation include neutrino oscillation and the moon's interior. Neutrino exploration of the earth-moon and antineutrino radionuclide imaging are also considered. The moon is concluded to be a significantly more effective orbital platform for the study of neutrino physics than orbiting satellites developed on earth.

What Attracts High-Achieving Socioeconomically Disadvantaged Students to the Physical Sciences and Engineering?

ERIC Educational Resources Information Center

Conrad, Sarah; Canetto, Silvia Sara; MacPhee, David; Farro, Samantha

2009-01-01

Socioeconomically disadvantaged (SED) students are less likely to major in physical sciences or engineering. To guide recruitment and retention of a diversity of talent, this study examined what attracts high-achieving SED students to these fields. Participants were 50 undergraduates majoring in physical sciences or engineering enrolled in the…

Analyzing high energy physics data using database computing: Preliminary report

NASA Technical Reports Server (NTRS)

Baden, Andrew; Day, Chris; Grossman, Robert; Lifka, Dave; Lusk, Ewing; May, Edward; Price, Larry

1991-01-01

A proof of concept system is described for analyzing high energy physics (HEP) data using data base computing. The system is designed to scale up to the size required for HEP experiments at the Superconducting SuperCollider (SSC) lab. These experiments will require collecting and analyzing approximately 10 to 100 million 'events' per year during proton colliding beam collisions. Each 'event' consists of a set of vectors with a total length of approx. one megabyte. This represents an increase of approx. 2 to 3 orders of magnitude in the amount of data accumulated by present HEP experiments. The system is called the HEPDBC System (High Energy Physics Database Computing System). At present, the Mark 0 HEPDBC System is completed, and can produce analysis of HEP experimental data approx. an order of magnitude faster than current production software on data sets of approx. 1 GB. The Mark 1 HEPDBC System is currently undergoing testing and is designed to analyze data sets 10 to 100 times larger.

Contributing to Meaning Making: Facilitating Discourse in the High School Physics Classroom

NASA Astrophysics Data System (ADS)

Hovan, Scot Alan

The Next Generation Science Standards (NGSS) identify eight practices as essential to science and engineering, and these practices include asking students to construct explanations, to engage in argumentation, and to communicate scientific information. However, few teacher-training programs instruct teachers how to facilitate such discourse in the classroom. Modeling Instruction is one movement in physics education that organizes high school physics content around a small number of student-derived scientific models, and it relies on student discourse for the design, development, and deployment of these models. This research is a self-study of one high school physics teacher's experience facilitating large group discourse in the high school modeling physics classroom. Whiteboard meetings and graded discussions were examined by applying the analytical framework created by Mortimer and Scott (2003) to characterize the classroom talk and the discourse facilitation moves that I employed. In addition, elements of discourse analysis were used to examine some of the tensions that I experienced in the facilitation of this discourse. The findings suggest that deliberate identification of the teaching purposes for the discussion can help determine the scaffolding needed for students to enter the Discourse (Gee, 2011) of being a participant in these large group conversations. In addition, connecting the dialogic dimension of exploring student ideas with the authoritative dimension of introducing the scientific view and supporting the internalization of that view is necessary to contribute to meaning making in the science classroom.

Analysis of Motivational Profiles of Satisfaction and Importance of Physical Education in High School Adolescents

PubMed Central

Granero-Gallegos, Antonio; Baena-Extremera, Antonio; Pérez-Quero, Francisco J.; Ortiz-Camacho, Maria M.; Bracho-Amador, Clara

2012-01-01

The purpose of this study was to analyze the motivational profiles of satisfaction with and importance of physical education in high school students and its relation with gender and the practice of sport. The sample comprised 2002 students aged from 12 to 19 who completed the Sport Motivation Scale (Núñez et al., 2006), the Sport Satisfaction Instrument (Baena-Extremera et al., 2012) and the Importance of Physical Education Scale (Moreno et al., 2009). Descriptive analyzes, correlations between the scales, a cluster analysis for profiles, and a MANOVA were conducted to examine differences by gender. Three clusters (profiles) were identified. The first profile identified was "moderate" motivation (n = 463) and was associated with boys who practice physical activity for less than 3 hours per week. The second profile identified was "low" motivation (n = 545) and was associated mainly with girls who practice physical activity for less than 3 hours per week. And lastly the third profile identified was "high" motivation (n = 910), which was found to be greater in boys who practiced physical exercise for more than 3 hours a week. Key points High school students’ motivation was mainly intrinsic, scoring very low on a motivation and high on satisfaction/fun; equally, these students were task-oriented. There appears to be a positive relationship between intrinsic motivation and task-orientation in high school students. The subject of PE is considered very highly by the students, and hence it obtains high values on satisfaction/fun and is positively associated with the importance given to PE. PMID:24150070