WorldWideScience

Sample records for nanoscale science activities

  1. Rocket Science at the Nanoscale.

    Science.gov (United States)

    Li, Jinxing; Rozen, Isaac; Wang, Joseph

    2016-06-28

    Autonomous propulsion at the nanoscale represents one of the most challenging and demanding goals in nanotechnology. Over the past decade, numerous important advances in nanotechnology and material science have contributed to the creation of powerful self-propelled micro/nanomotors. In particular, micro- and nanoscale rockets (MNRs) offer impressive capabilities, including remarkable speeds, large cargo-towing forces, precise motion controls, and dynamic self-assembly, which have paved the way for designing multifunctional and intelligent nanoscale machines. These multipurpose nanoscale shuttles can propel and function in complex real-life media, actively transporting and releasing therapeutic payloads and remediation agents for diverse biomedical and environmental applications. This review discusses the challenges of designing efficient MNRs and presents an overview of their propulsion behavior, fabrication methods, potential rocket fuels, navigation strategies, practical applications, and the future prospects of rocket science and technology at the nanoscale.

  2. Nanoscale Science and Engineering in Romania

    International Nuclear Information System (INIS)

    Dascalu, Dan; Topa, Vladimir; Kleps, Irina

    2001-01-01

    In spite of difficult working conditions and with very low financial support, many groups from Romania are involved in emerging fields, such as the nanoscale science and technology. Until the last years, this activity was developed without a central coordination and without many interactions between these research groups. In the year 2000, some of the institutes and universities active in the nanotechnology field in Romania founded the MICRONANOTECH network. The aim of this paper is to emphasize the main activities and results of the Romanian groups working in this novel domain. Most of the groups are deal with the nanomaterial technology and only few of them have activities in nanostructure science and engineering, in new concepts and device modeling and technology. This paper describes the nanotechnology research development in two of the most significant institutes from Romania: Centre for Nanotechnologies from National Institute for Research and Development in Microtehnologies (IMT-Bucharest) and from National Institute for Research and Development in Materials Physics (INCD-FM), Magurele. The Romanian research results in nanotechnology field were presented in numerous papers presented in international conferences or published in national and international journals. They are also presented in patents, international awards and fellowships. The research effort and financial support are outlined. Some future trends of the Romanian nanoscale science and technology research are also described

  3. 78 FR 24241 - Nanoscale Science, Engineering, and Technology Subcommittee; Committee on Technology, National...

    Science.gov (United States)

    2013-04-24

    ... OFFICE OF SCIENCE AND TECHNOLOGY POLICY Nanoscale Science, Engineering, and Technology.... SUMMARY: The National Nanotechnology Coordination Office (NNCO), on behalf of the Nanoscale Science, Engineering, and Technology (NSET) Subcommittee of the Committee on Technology, National Science and...

  4. 77 FR 61448 - Nanoscale Science, Engineering and Technology Subcommittee Committee on Technology, National...

    Science.gov (United States)

    2012-10-09

    ... OFFICE OF SCIENCE AND TECHNOLOGY POLICY Nanoscale Science, Engineering and Technology Subcommittee...: The National Nanotechnology Coordination Office (NNCO), on behalf of the Nanoscale Science, Engineering, and Technology (NSET) Subcommittee of the Committee on Technology, National Science and...

  5. 77 FR 56681 - Nanoscale Science, Engineering, and Technology Subcommittee; Committee on Technology, National...

    Science.gov (United States)

    2012-09-13

    ... OFFICE OF SCIENCE AND TECHNOLOGY POLICY Nanoscale Science, Engineering, and Technology...: Notice of webinar. SUMMARY: The National Nanotechnology Coordination Office (NNCO), on behalf of the Nanoscale Science, Engineering, and Technology (NSET) Subcommittee of the Committee on Technology, National...

  6. Nanoscale science and nanotechnology education in Africa ...

    African Journals Online (AJOL)

    Nanoscale science and nanotechnology education in Africa: importance and ... field with its footing in chemistry, physics, molecular biology and engineering. ... career/business/development opportunities, risks and policy challenges that would ...

  7. 77 FR 13159 - Nanoscale Science, Engineering, and Technology Subcommittee of the Committee on Technology...

    Science.gov (United States)

    2012-03-05

    ... OFFICE OF SCIENCE AND TECHNOLOGY POLICY Nanoscale Science, Engineering, and Technology... public meeting. SUMMARY: The National Nanotechnology Coordination Office (NNCO), on behalf of the Nanoscale Science, Engineering, and Technology (NSET) Subcommittee of the Committee on Technology, National...

  8. 75 FR 30874 - National Nanotechnology Coordination Office, Nanoscale Science, Engineering and Technology...

    Science.gov (United States)

    2010-06-02

    ... OFFICE OF SCIENCE AND TECHNOLOGY POLICY National Nanotechnology Coordination Office, Nanoscale Science, Engineering and Technology Subcommittee, National Science and Technology Council, Committee on Technology; The National Nanotechnology Initiative (NNI) Strategic Planning Stakeholder Workshop: Public...

  9. DOE - BES Nanoscale Science Research Centers (NSRCs)

    Energy Technology Data Exchange (ETDEWEB)

    Beecher, Cathy Jo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-14

    These are slides from a powerpoint shown to guests during tours of Center for Integrated Nanotechnologies (CINT) at Los Alamos National Laboratory. It shows the five DOE-BES nanoscale science research centers (NSRCs), which are located at different national laboratories throughout the country. Then it goes into detail specifically about the Center for Integrated Nanotechnologies at LANL, including statistics on its user community and CINT's New Mexico industrial users.

  10. Nanoscale Science, Engineering and Technology Research Directions

    Energy Technology Data Exchange (ETDEWEB)

    Lowndes, D. H.; Alivisatos, A. P.; Alper, M.; Averback, R. S.; Jacob Barhen, J.; Eastman, J. A.; Imre, D.; Lowndes, D. H.; McNulty, I.; Michalske, T. A.; Ho, K-M; Nozik, A. J.; Russell, T. P.; Valentin, R. A.; Welch, D. O.; Barhen, J.; Agnew, S. R.; Bellon, P.; Blair, J.; Boatner, L. A.; Braiman, Y.; Budai, J. D.; Crabtree, G. W.; Feldman, L. C.; Flynn, C. P.; Geohegan, D. B.; George, E. P.; Greenbaum, E.; Grigoropoulos, C.; Haynes, T. E.; Heberlein, J.; Hichman, J.; Holland, O. W.; Honda, S.; Horton, J. A.; Hu, M. Z.-C.; Jesson, D. E.; Joy, D. C.; Krauss, A.; Kwok, W.-K.; Larson, B. C.; Larson, D. J.; Likharev, K.; Liu, C. T.; Majumdar, A.; Maziasz, P. J.; Meldrum, A.; Miller, J. C.; Modine, F. A.; Pennycook, S. J.; Pharr, G. M.; Phillpot, S.; Price, D. L.; Protopopescu, V.; Poker, D. B.; Pui, D.; Ramsey, J. M.; Rao, N.; Reichl, L.; Roberto, J.; Saboungi, M-L; Simpson, M.; Strieffer, S.; Thundat, T.; Wambsganss, M.; Wendleken, J.; White, C. W.; Wilemski, G.; Withrow, S. P.; Wolf, D.; Zhu, J. H.; Zuhr, R. A.; Zunger, A.; Lowe, S.

    1999-01-01

    This report describes important future research directions in nanoscale science, engineering and technology. It was prepared in connection with an anticipated national research initiative on nanotechnology for the twenty-first century. The research directions described are not expected to be inclusive but illustrate the wide range of research opportunities and challenges that could be undertaken through the national laboratories and their major national scientific user facilities with the support of universities and industry.

  11. Super-Resolution Molecular and Functional Imaging of Nanoscale Architectures in Life and Materials Science

    KAUST Repository

    Habuchi, Satoshi

    2014-06-12

    Super-resolution (SR) fluorescence microscopy has been revolutionizing the way in which we investigate the structures, dynamics, and functions of a wide range of nanoscale systems. In this review, I describe the current state of various SR fluorescence microscopy techniques along with the latest developments of fluorophores and labeling for the SR microscopy. I discuss the applications of SR microscopy in the fields of life science and materials science with a special emphasis on quantitative molecular imaging and nanoscale functional imaging. These studies open new opportunities for unraveling the physical, chemical, and optical properties of a wide range of nanoscale architectures together with their nanostructures and will enable the development of new (bio-)nanotechnology.

  12. EDITORIAL: Big science at the nanoscale Big science at the nanoscale

    Science.gov (United States)

    Reed, Mark

    2009-10-01

    In 1990, the journal Nanotechnology was the first academic publication dedicated to disseminating the results of research in what was then a new field of scientific endeavour. To celebrate the 20th volume of Nanotechnology, we are publishing a special issue of top research papers covering all aspects of this multidisciplinary science, including biology, electronics and photonics, quantum phenomena, sensing and actuating, patterning and fabrication, material synthesis and the properties of nanomaterials. In the early 1980s, scanning probe microscopes brought the concepts of matter and interactions at the nanoscale into visual reality, and hastened a flurry of activity in the burgeoning new field of nanoscience. Twenty years on and nanotechnology has truly come of age. The ramifications are pervasive throughout daily life in communication, health care and entertainment technology. For example, DVDs have now consigned videotapes to the ark and mobile phones are as prevalent as house keys, and these technologies already look set to be superseded by internet phones and Blu-Ray discs. Nanotechnology has been in the unique position of following the explosive growth of this discipline from its outset. The surge of activity in the field is notable in the number of papers published by the journal each year, which has skyrocketed. The journal is now published weekly, publishing over 1400 articles a year. What is more, the quality of these articles is also constantly improving; the average number of citations to articles within two years of publication, quantified by the ISI impact factor, continues to increase every year. The rate of activity in the field shows no signs of slowing down, as is evident from the wealth of great research published each week. The aim of the 20th volume special issue is to present some of the very best and most recent research in many of the wide-ranging fields covered by the journal, a celebration of the present state of play in nanotechnology and

  13. Nanotechnology and the public: Effectively communicating nanoscale science and engineering concepts

    International Nuclear Information System (INIS)

    Castellini, O. M.; Walejko, G. K.; Holladay, C. E.; Theim, T. J.; Zenner, G. M.; Crone, W. C.

    2007-01-01

    Researchers are faced with challenges when addressing the public on concepts and applications associated with nanotechnology. The goal of our work was to understand the public's knowledge of nanotechnology in order to identify appropriate starting points for dialog. Survey results showed that people lack true understanding of concepts associated with atoms and the size of the nanoscale regime. Such gaps in understanding lead to a disappointing lack of communication between researchers and the public concerning fundamental concepts in nanoscale science and engineering. Strategies are offered on how scientists should present their research when engaging the public on nanotechnology topics

  14. Nanoscale Ionic Liquids

    Science.gov (United States)

    2006-11-01

    Technical Report 11 December 2005 - 30 November 2006 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Nanoscale Ionic Liquids 5b. GRANT NUMBER FA9550-06-1-0012...Title: Nanoscale Ionic Liquids Principal Investigator: Emmanuel P. Giannelis Address: Materials Science and Engineering, Bard Hall, Cornell University...based fluids exhibit high ionic conductivity. The NFs are typically synthesized by grafting a charged, oligomeric corona onto the nanoparticle cores

  15. Social and ethical dimensions of nanoscale science and engineering research.

    Science.gov (United States)

    Sweeney, Aldrin E

    2006-07-01

    Continuing advances in human ability to manipulate matter at the atomic and molecular levels (i.e. nanoscale science and engineering) offer many previously unimagined possibilities for scientific discovery and technological development. Paralleling these advances in the various science and engineering sub-disciplines is the increasing realization that a number of associated social, ethical, environmental, economic and legal dimensions also need to be explored. An important component of such exploration entails the identification and analysis of the ways in which current and prospective researchers in these fields conceptualize these dimensions of their work. Within the context of a National Science Foundation funded Research Experiences for Undergraduates (REU) program in nanomaterials processing and characterization at the University of Central Florida (2002-2004), here I present for discussion (i) details of a "nanotechnology ethics" seminar series developed specifically for students participating in the program, and (ii) an analysis of students' and participating research faculty's perspectives concerning social and ethical issues associated with nanotechnology research. I conclude with a brief discussion of implications presented by these issues for general scientific literacy and public science education policy.

  16. EDITORIAL: Quantum science and technology at the nanoscale Quantum science and technology at the nanoscale

    Science.gov (United States)

    Demming, Anna

    2010-07-01

    correlated, and how they influence spin currents and their fluctuations, as well as the mechanisms behind current-induced spin polarizations in chaotic ballistic systems. In a theoretical report on current-induced spin polarization from the University of Arizona, progress is made in filling in some of these gaps, and a 'spin-probe' model is proposed [5]. Spin is also an important element in quantum information research. With electron spin coherence lifetimes exceeding 1 ms at room temperature, as well as the added benefit of being optically addressable, nitrogen-vacancy defects in diamond have been identified as having considerable potential for quantum information applications. Now researchers in the US describe the fabrication and low-temperature characterization of silica microdisk cavities coupled to diamond nanoparticles, and present theoretical and experimental studies of gallium phosphide structures coupled to nitrogen-vacancy centers in bulk diamond [6]. Double quantum dots have been considered as prospective candidates for charge qubits for quantum information processors. The application of a bias voltage can be used to control tunnelling between the double quantum dots, allowing the energy states to be tuned. Researchers in Switzerland investigate experimentally the effect of ohmic heating of the phonon bath on decoherence, and find that the system can be considered as a thermoelectric generator [7]. This progress has only been made possible by advances in our understanding of the fundamental science behind quantum mechanics, and work exploring this territory is still a hotbed of activity and progress. Increasingly sophisticated tools, both numerical and experimental, have facilitated engagement with quantum phenomena in nanoscale systems. Molecular spin clusters represent an ideal setting within solid-state systems to test concepts in quantum mechanics, as highlighted in this issue by researchers in Italy, who report their work on controlling entanglement between

  17. Art Advancing Science: Filmmaking Leads to Molecular Insights at the Nanoscale.

    Science.gov (United States)

    Reilly, Charles; Ingber, Donald E

    2017-12-26

    Many have recognized the potential value of facilitating activities that span the art-science interface for the benefit of society; however, there are few examples that demonstrate how pursuit of an artistic agenda can lead to scientific insights. Here, we describe how we set out to produce an entertaining short film depicting the fertilization of the egg by sperm as a parody of a preview for another Star Wars movie to excite the public about science, but ended up developing a simulation tool for multiscale modeling. To produce an aesthetic that communicates mechanical continuity across spatial scales, we developed custom strategies that integrate physics-based animation software from the entertainment industry with molecular dynamics simulation tools, using experimental data from research publications. Using this approach, we were able to depict biological physicality across multiple spatial scales, from how sperm tails move to collective molecular behavior within the axoneme to how the molecular motor, dynein, produces force at the nanometer scale. The dynein simulations, which were validated by replicating results of past simulations and cryo-electron microscopic studies, also predicted a potential mechanism for how ATP hydrolysis drives dynein motion along the microtubule as well as how dynein changes its conformation when it goes through the power stroke. Thus, pursuit of an artistic work led to insights into biology at the nanoscale as well as the development of a highly generalizable modeling and simulation technology that has utility for nanoscience and any other area of scientific investigation that involves analysis of complex multiscale systems.

  18. Frontier in nanoscale flows fractional calculus and analytical methods

    CERN Document Server

    Lewis, Roland; Liu, Hong-yan

    2014-01-01

    This ebook covers the basic properties of nanoscale flows, and various analytical and numerical methods for nanoscale flows and environmental flows. This ebook is a good reference not only for audience of the journal, but also for various communities in mathematics, nanotechnology and environmental science.

  19. Activity and Stability of Nanoscale Oxygen Reduction Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Shao-Horn, Yang

    2015-07-28

    Design of highly active and stable nanoscale catalysts for electro-oxidation of small organic molecules is of great importance to the development of efficient fuel cells. The amount and instability of Pt-based catalysts in the cathode limits the cost, efficiency and lifetime of proton exchange membrane fuel cells. We developed a microscopic understanding of the factors governing activity and stability in Pt and PtM alloys. Experimental efforts were focused on probing the size and shape dependence of ORR activity of Pt-based nanoparticles supported on carbon nanotubes. A microscopic understanding of the activity was achieved by correlating voltammetry and rotating ring disk electrodes to surface atomic and electronic structures, which were elucidated predominantly by high-resolution transmission electron microscopy (HRTEM), Scanning transmission electron microscopy energy dispersive X-ray Spectroscopy (STEM-EDS) and synchrotron X-ray absorption spectroscopy (XAS).

  20. Nanoscale thermal transport: Theoretical method and application

    Science.gov (United States)

    Zeng, Yu-Jia; Liu, Yue-Yang; Zhou, Wu-Xing; Chen, Ke-Qiu

    2018-03-01

    With the size reduction of nanoscale electronic devices, the heat generated by the unit area in integrated circuits will be increasing exponentially, and consequently the thermal management in these devices is a very important issue. In addition, the heat generated by the electronic devices mostly diffuses to the air in the form of waste heat, which makes the thermoelectric energy conversion also an important issue for nowadays. In recent years, the thermal transport properties in nanoscale systems have attracted increasing attention in both experiments and theoretical calculations. In this review, we will discuss various theoretical simulation methods for investigating thermal transport properties and take a glance at several interesting thermal transport phenomena in nanoscale systems. Our emphasizes will lie on the advantage and limitation of calculational method, and the application of nanoscale thermal transport and thermoelectric property. Project supported by the Nation Key Research and Development Program of China (Grant No. 2017YFB0701602) and the National Natural Science Foundation of China (Grant No. 11674092).

  1. Micro- and nanoscale phenomena in tribology

    CERN Document Server

    Chung, Yip-Wah

    2011-01-01

    Drawn from presentations at a recent National Science Foundation Summer Institute on Nanomechanics, Nanomaterials, and Micro/Nanomanufacturing, Micro- and Nanoscale Phenomena in Tribology explores the convergence of the multiple science and engineering disciplines involved in tribology and the connection from the macro to nano world. Written by specialists from computation, materials science, mechanical engineering, surface physics, and chemistry, each chapter provides up-to-date coverage of both basic and advanced topics and includes extensive references for further study.After discussing the

  2. Science and technology on the nanoscale with swift heavy ions in matter

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Reinhard, E-mail: r.neumann@gsi.de

    2013-11-01

    Swift heavy ions have stimulated developments of science and technology on the nanoscale due to the specific manner of transferring their kinetic energy in a solid successively in small portions along their trajectories. They thus create absolutely straight, almost cylindrical, and very narrow damage trails of diameter 5–10 nm. In various materials, such as polymers, a suitable etchant can transform these tracks into narrow channels of cylindrical, conical, or other desired shapes. These channels represent a starting point particularly for two major fields: they can be chemically modified to control small species and act, e.g., as sensors and transmitters of specific biomolecules. Irradiation of a sample with only one heavy ion allows the fabrication of single-nanochannel devices enabling measurements of enormous sensitivity. Filling nanochannels with a material provides nanowires. These objects of restricted dimensions exhibit finite-size and quantum behavior and give rise to a broad range of fundamental and applied research. This contribution briefly recollects microtechnological achievements with swift heavy ions that began already in the 1970s, preparing the ground for gradual size decrease down to the nanoscopic objects now under study. Various examples of material modifications on the nanoscale are presented, including recent results obtained with nanochannels and nanowires. Emerging developments are addressed, encompassing in situ recording of processes in biological cells stimulated by well-aimed ion irradiation, the fabrication of three-dimensional nanowire architectures, and plasmonic effects in nanowires.

  3. Nanoscale Characterization for the Classroom

    International Nuclear Information System (INIS)

    Carroll, D.L.

    1999-01-01

    This report describes the development of a semester course in 'nano-scale characterization'. The interdisciplinary course is opened to both advanced undergraduate and graduate students with a standard undergraduate preparation in Materials Science, Chemistry, or Physics. The approach is formal rather than the typical 'research seminar' and has a laboratory component

  4. Ellipsometry at the nanoscale

    CERN Document Server

    Hingerl, Kurt

    2013-01-01

    This book presents and introduces ellipsometry in nanoscience and nanotechnology making a bridge between the classical and nanoscale optical behaviour of materials. It delineates the role of the non-destructive and non-invasive optical diagnostics of ellipsometry in improving science and technology of nanomaterials and related processes by illustrating its exploitation, ranging from fundamental studies of the physics and chemistry of nanostructures to the ultimate goal of turnkey manufacturing control. This book is written for a broad readership: materials scientists, researchers, engineers, as well as students and nanotechnology operators who want to deepen their knowledge about both basics and applications of ellipsometry to nanoscale phenomena. It starts as a general introduction for people curious to enter the fields of ellipsometry and polarimetry applied to nanomaterials and progresses to articles by experts on specific fields that span from plasmonics, optics, to semiconductors and flexible electronics...

  5. Infochemistry Information Processing at the Nanoscale

    CERN Document Server

    Szacilowski, Konrad

    2012-01-01

    Infochemistry: Information Processing at the Nanoscale, defines a new field of science, and describes the processes, systems and devices at the interface between chemistry and information sciences. The book is devoted to the application of molecular species and nanostructures to advanced information processing. It includes the design and synthesis of suitable materials and nanostructures, their characterization, and finally applications of molecular species and nanostructures for information storage and processing purposes. Divided into twelve chapters; the first three chapters serve as an int

  6. Nanoscale control of energy and matter: challenges and opportunities for plasma science

    International Nuclear Information System (INIS)

    Ostrikov, Kostya

    2013-01-01

    Multidisciplinary challenges and opportunities in the ultimate ability to achieve nanoscale control of energy and matter are discussed using an example of the Plasma Nanoscience. This is an emerging multidisciplinary research field at the cutting edge of a large number of disciplines including but not limited to physics and chemistry of plasmas and gas discharges, materials science, surface science, nanoscience and nanotechnology, solid state physics, space physics and astrophysics, photonics, optics, plasmonics, spintronics, quantum information, physical chemistry, biomedical sciences and related engineering subjects. The origin, progress and future perspectives of this research field driven by the global scientific and societal challenges, is examined. The future potential of the Plasma Nanoscience to remain as a highly topical area in the global research and technological agenda in the Age of Fundamental-Level Control for a Sustainable Future is assessed using a framework of the five Grand Challenges for Basic Energy Sciences recently mapped by the US Department of Energy. It is concluded that the ongoing research is very relevant and is expected to substantially expand to competitively contribute to the solution of all of these Grand Challenges. The approach to control energy and matter at nano- and subnanoscales is based on identifying the prevailing carriers and transfer mechanisms of the energy and matter at the spatial and temporal scales that are most relevant to any particular nanofabrication process. Strong accent is made on the competitive edge of the plasma-based nanotechnology in applications related to the major socio-economic issues (energy, food, water, health and environment) that are crucial for a sustainable development of humankind. Several important emerging topics, opportunities and multidisciplinary synergies for the Plasma Nanoscience are highlighted. The main nanosafety issues are also discussed and the environment- and human health

  7. Nanoscale zero-valent iron impregnation of covalent organic polymer grafted activated carbon for water treatment

    DEFF Research Database (Denmark)

    Mines, Paul D.; Uthuppu, Basil; Thirion, Damien

    2016-01-01

    The use of nanoscale zero valent iron (nZVI) has quickly become a leading research material for the treatment of typically hard to degrade contaminants found in groundwater. These contaminants include antibiotics, pesticides, halogenated organics, heavy metals, among others. However, the effectiv......The use of nanoscale zero valent iron (nZVI) has quickly become a leading research material for the treatment of typically hard to degrade contaminants found in groundwater. These contaminants include antibiotics, pesticides, halogenated organics, heavy metals, among others. However...... polymeric network already previously proven to stabilize nZVI and a long-standing water treatment material,1 activated carbon; we have developed an advanced material that allows for the not only the stabilization of nZVI, but also the improved degradation of various water contaminants. This was done...... by performing a series of surface modification techniques to the surface of the activated carbon, then physically grafting the covalent organic polymer to the carbon in a shell-like manner, and ultimately synthesizing nZVI in situ within the pores of both the activated carbon and the polymeric network. Not only...

  8. Traceable nanoscale measurement at NML-SIRIM

    International Nuclear Information System (INIS)

    Dahlan, Ahmad M.; Abdul Hapip, A. I.

    2012-01-01

    The role of national metrology institute (NMI) has always been very crucial in national technology development. One of the key activities of the NMI is to provide traceable measurement in all parameters under the International System of Units (SI). Dimensional measurement where size and shape are two important features investigated, is one of the important area covered by NMIs. To support the national technology development, particularly in manufacturing sectors and emerging technology such nanotechnology, the National Metrology Laboratory, SIRIM Berhad (NML-SIRIM), has embarked on a project to equip Malaysia with state-of-the-art nanoscale measurement facility with the aims of providing traceability of measurement at nanoscale. This paper will look into some of the results from current activities at NML-SIRIM related to measurement at nanoscale particularly on application of atomic force microscope (AFM) and laser based sensor in dimensional measurement. Step height standards of different sizes were measured using AFM and laser-based sensors. These probes are integrated into a long-range nanoscale measuring machine traceable to the international definition of the meter thus ensuring their traceability. Consistency of results obtained by these two methods will be discussed and presented. Factors affecting their measurements as well as their related uncertainty of measurements will also be presented.

  9. Traceable nanoscale measurement at NML-SIRIM

    Science.gov (United States)

    Dahlan, Ahmad M.; Abdul Hapip, A. I.

    2012-06-01

    The role of national metrology institute (NMI) has always been very crucial in national technology development. One of the key activities of the NMI is to provide traceable measurement in all parameters under the International System of Units (SI). Dimensional measurement where size and shape are two important features investigated, is one of the important area covered by NMIs. To support the national technology development, particularly in manufacturing sectors and emerging technology such nanotechnology, the National Metrology Laboratory, SIRIM Berhad (NML-SIRIM), has embarked on a project to equip Malaysia with state-of-the-art nanoscale measurement facility with the aims of providing traceability of measurement at nanoscale. This paper will look into some of the results from current activities at NML-SIRIM related to measurement at nanoscale particularly on application of atomic force microscope (AFM) and laser based sensor in dimensional measurement. Step height standards of different sizes were measured using AFM and laser-based sensors. These probes are integrated into a long-range nanoscale measuring machine traceable to the international definition of the meter thus ensuring their traceability. Consistency of results obtained by these two methods will be discussed and presented. Factors affecting their measurements as well as their related uncertainty of measurements will also be presented.

  10. Traceable nanoscale measurement at NML-SIRIM

    Energy Technology Data Exchange (ETDEWEB)

    Dahlan, Ahmad M.; Abdul Hapip, A. I. [National Metrology Laboratory SIRIM Berhad (NML-SIRIM), Lot PT 4803, Bandar Baru Salak Tinggi, 43900 Sepang (Malaysia)

    2012-06-29

    The role of national metrology institute (NMI) has always been very crucial in national technology development. One of the key activities of the NMI is to provide traceable measurement in all parameters under the International System of Units (SI). Dimensional measurement where size and shape are two important features investigated, is one of the important area covered by NMIs. To support the national technology development, particularly in manufacturing sectors and emerging technology such nanotechnology, the National Metrology Laboratory, SIRIM Berhad (NML-SIRIM), has embarked on a project to equip Malaysia with state-of-the-art nanoscale measurement facility with the aims of providing traceability of measurement at nanoscale. This paper will look into some of the results from current activities at NML-SIRIM related to measurement at nanoscale particularly on application of atomic force microscope (AFM) and laser based sensor in dimensional measurement. Step height standards of different sizes were measured using AFM and laser-based sensors. These probes are integrated into a long-range nanoscale measuring machine traceable to the international definition of the meter thus ensuring their traceability. Consistency of results obtained by these two methods will be discussed and presented. Factors affecting their measurements as well as their related uncertainty of measurements will also be presented.

  11. Fourth International Conference on Nanoscale Magnetism

    CERN Document Server

    Aktas, Bekir; Advances in Nanoscale Magnetism

    2009-01-01

    The book aims to provide an overview of recent progress in the understanding of magnetic properties in nanoscale through recent results of various theoretical and experimental investigations. The papers describe a wide range of physical aspects, together with theoretical and experimental methods. It is of central interest to researchers and specialists in magnetism and magnetic materials science, both in academic and industrial research, as well as advanced students.

  12. Catalytic wet oxidation of ammonia solution: Activity of the nanoscale platinum-palladium-rhodium composite oxide catalyst

    International Nuclear Information System (INIS)

    Hung, C.-M.

    2009-01-01

    Aqueous solutions of 400-1000 mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H 2 PtCl 6 , Pd(NO 3 ) 3 and Rh(NO 3 ) 3 . Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503 K in an oxygen partial pressure of 2.0 MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9 h -1 in the wet catalytic processes

  13. Catalytic wet oxidation of ammonia solution: Activity of the nanoscale platinum-palladium-rhodium composite oxide catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Hung, C.-M. [Department of Industry Engineering and Management, Yung-Ta Institute of Technology and Commerce, 316 Chung-shan Road, Linlo, Pingtung 909, Taiwan (China)], E-mail: hungcm1031@gmail.com

    2009-04-15

    Aqueous solutions of 400-1000 mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H{sub 2}PtCl{sub 6}, Pd(NO{sub 3}){sub 3} and Rh(NO{sub 3}){sub 3}. Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503 K in an oxygen partial pressure of 2.0 MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9 h{sup -1} in the wet catalytic processes.

  14. Catalytic wet oxidation of ammonia solution: activity of the nanoscale platinum-palladium-rhodium composite oxide catalyst.

    Science.gov (United States)

    Hung, Chang-Mao

    2009-04-15

    Aqueous solutions of 400-1000 mg/L of ammonia were oxidized in a trickle-bed reactor (TBR) in this study of nanoscale platinum-palladium-rhodium composite oxide catalysts, which were prepared by the co-precipitation of H(2)PtCl(6), Pd(NO(3))(3) and Rh(NO(3))(3). Hardly any of the dissolved ammonia was removed by wet oxidation in the absence of any catalyst, whereas about 99% of the ammonia was reduced during wet oxidation over nanoscale platinum-palladium-rhodium composite oxide catalysts at 503 K in an oxygen partial pressure of 2.0 MPa. A synergistic effect exists in the nanoscale platinum-palladium-rhodium composite structure, which is the material with the highest ammonia reduction activity. The nanometer-sized particles were characterized by TEM, XRD and FTIR. The effect of the initial concentration and reaction temperature on the removal of ammonia from the effluent streams was also studied at a liquid hourly space velocity of under 9 h(-1) in the wet catalytic processes.

  15. Granular activated carbon with grafted nanoporous polymer enhances nanoscale zero-valent iron impregnation and water contaminant removal

    DEFF Research Database (Denmark)

    Mines, Paul D.; Uthuppu, Basil; Thirion, Damien

    2018-01-01

    Granular activated carbon was customized with a chemical grafting procedure of a nanoporous polymeric network for the purpose of nanoscale zero-valent iron impregnation and subsequent water contaminant remediation. Characterization of the prepared composite material revealed that not only was the...

  16. DOE A9024 Final Report Functional and Nanoscale Materials Systems: Frontier Programs of Science at the Frederick Seitz Materials Research Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Jennifer A.

    2009-03-24

    The scientific programs of the FSMRL supported under the DOE A9024 Grant consisted of four interdisciplinary research clusters, as described. The clusters were led by Professors Tai Chiang (Physics), Jeffrey Moore (Chemistry), Paul Goldbart (Physics), and Steven Granick (Materials Science and Engineering). The completed work followed a dominant theme--Nanoscale Materials Systems--and emphasized studies of complex phenomena involving surfaces, interfaces, complex materials, dynamics, energetics, and structures and their transformations. A summary of our key accomplishments is provided for each cluster.

  17. Longitudinal Patent Analysis for Nanoscale Science and Engineering: Country, Institution and Technology Field

    International Nuclear Information System (INIS)

    Huang Zan; Chen Hsinchun; Yip, Alan; Ng, Gavin; Guo Fei; Chen Zhikai; Roco, Mihail C.

    2003-01-01

    Nanoscale science and engineering (NSE) and related areas have seen rapid growth in recent years. The speed and scope of development in the field have made it essential for researchers to be informed on the progress across different laboratories, companies, industries and countries. In this project, we experimented with several analysis and visualization techniques on NSE-related United States patent documents to support various knowledge tasks. This paper presents results on the basic analysis of nanotechnology patents between 1976 and 2002, content map analysis and citation network analysis. The data have been obtained on individual countries, institutions and technology fields. The top 10 countries with the largest number of nanotechnology patents are the United States, Japan, France, the United Kingdom, Taiwan, Korea, the Netherlands, Switzerland, Italy and Australia. The fastest growth in the last 5 years has been in chemical and pharmaceutical fields, followed by semiconductor devices. The results demonstrate potential of information-based discovery and visualization technologies to capture knowledge regarding nanotechnology performance, transfer of knowledge and trends of development through analyzing the patent documents

  18. Longitudinal Patent Analysis for Nanoscale Science and Engineering: Country, Institution and Technology Field

    Science.gov (United States)

    Huang, Zan; Chen, Hsinchun; Yip, Alan; Ng, Gavin; Guo, Fei; Chen, Zhi-Kai; Roco, Mihail C.

    2003-08-01

    Nanoscale science and engineering (NSE) and related areas have seen rapid growth in recent years. The speed and scope of development in the field have made it essential for researchers to be informed on the progress across different laboratories, companies, industries and countries. In this project, we experimented with several analysis and visualization techniques on NSE-related United States patent documents to support various knowledge tasks. This paper presents results on the basic analysis of nanotechnology patents between 1976 and 2002, content map analysis and citation network analysis. The data have been obtained on individual countries, institutions and technology fields. The top 10 countries with the largest number of nanotechnology patents are the United States, Japan, France, the United Kingdom, Taiwan, Korea, the Netherlands, Switzerland, Italy and Australia. The fastest growth in the last 5 years has been in chemical and pharmaceutical fields, followed by semiconductor devices. The results demonstrate potential of information-based discovery and visualization technologies to capture knowledge regarding nanotechnology performance, transfer of knowledge and trends of development through analyzing the patent documents.

  19. Nanoscale ferroelectrics and multiferroics key processes and characterization issues, and nanoscale effects

    CERN Document Server

    Alguero, Miguel

    2016-01-01

    This book reviews the key issues in processing and characterization of nanoscale ferroelectrics and multiferroics, and provides a comprehensive description of their properties, with an emphasis in differentiating size effects of extrinsic ones like boundary or interface effects. Recently described nanoscale novel phenomena are also addressed. Organized into three parts it addresses key issues in processing (nanostructuring), characterization (of the nanostructured materials) and nanoscale effects. Taking full advantage of the synergies between nanoscale ferroelectrics and multiferroics, it covers materials nanostructured at all levels, from ceramic technologies like ferroelectric nanopowders, bulk nanostructured ceramics and thick films, and magnetoelectric nanocomposites, to thin films, either polycrystalline layer heterostructures or epitaxial systems, and to nanoscale free standing objects with specific geometries, such as nanowires and tubes at different levels of development. The book is developed from t...

  20. Investigating Nanoscale Electrochemistry with Surface- and Tip-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    Zaleski, Stephanie; Wilson, Andrew J; Mattei, Michael; Chen, Xu; Goubert, Guillaume; Cardinal, M Fernanda; Willets, Katherine A; Van Duyne, Richard P

    2016-09-20

    events: single-molecule SERS (SMSERS), superlocalization SERS imaging, and tip-enhanced Raman spectroscopy (TERS). While all of the studies we discuss probe model redox dye systems, the experiments described herein push the study of nanoscale electrochemistry toward the fundamental limit, in terms of both chemical sensitivity and spatial resolution. The second half of this Account discusses current experimental strategies for studying nanoelectrochemistry with SERS techniques, which includes relevant electrochemically and optically active molecules, substrates, and substrate functionalization methods. In particular, we highlight the wide variety of SERS-active substrates and optically active molecules that can be implemented for EC-SERS, as well as the need to carefully characterize both the electrochemistry and resultant EC-SERS response of each new redox-active molecule studied. Finally, we conclude this Account with our perspective on the future directions of studying nanoscale electrochemistry with SERS/TERS, which includes the integration of SECM with TERS and the use of theoretical methods to further describe the fundamental intricacies of single-molecule, single-site electrochemistry at the nanoscale.

  1. Nanoscale and single-molecule interfacial electron transfer

    DEFF Research Database (Denmark)

    Hansen, Allan Glargaard; Wackerbarth, Hainer; Nielsen, Jens Ulrik

    2003-01-01

    for comprehensive later theoretical work and data interpretation in many areas of chemistry, electrochemistry, and biology. We discuss here some new areas of theoretical electrochemical ET science, with focus on nanoscale electrochemical and bioelectrochemical sciences. Particular attention is given to in situ...... scanning tunneling microscopy (STM) and single-electron tunneling (SET, or Coulomb blockade) in electrochemical. systems directly in aqueous electrolyte solution and at room temperature. We illustrate the new theoretical formalism and its perspectives by recent cases of electrochemical SET, negative...... differential resistance patterns, and by ET dynamics of organized assemblies of biological macromolecules, such as redox metalloproteins and oligonucleotides on single-crystal Au(III)-electrode surfaces....

  2. Neuromorphic computing with nanoscale spintronic oscillators.

    Science.gov (United States)

    Torrejon, Jacob; Riou, Mathieu; Araujo, Flavio Abreu; Tsunegi, Sumito; Khalsa, Guru; Querlioz, Damien; Bortolotti, Paolo; Cros, Vincent; Yakushiji, Kay; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Stiles, Mark D; Grollier, Julie

    2017-07-26

    Neurons in the brain behave as nonlinear oscillators, which develop rhythmic activity and interact to process information. Taking inspiration from this behaviour to realize high-density, low-power neuromorphic computing will require very large numbers of nanoscale nonlinear oscillators. A simple estimation indicates that to fit 10 8 oscillators organized in a two-dimensional array inside a chip the size of a thumb, the lateral dimension of each oscillator must be smaller than one micrometre. However, nanoscale devices tend to be noisy and to lack the stability that is required to process data in a reliable way. For this reason, despite multiple theoretical proposals and several candidates, including memristive and superconducting oscillators, a proof of concept of neuromorphic computing using nanoscale oscillators has yet to be demonstrated. Here we show experimentally that a nanoscale spintronic oscillator (a magnetic tunnel junction) can be used to achieve spoken-digit recognition with an accuracy similar to that of state-of-the-art neural networks. We also determine the regime of magnetization dynamics that leads to the greatest performance. These results, combined with the ability of the spintronic oscillators to interact with each other, and their long lifetime and low energy consumption, open up a path to fast, parallel, on-chip computation based on networks of oscillators.

  3. Dynamics at the nanoscale

    International Nuclear Information System (INIS)

    Stoneham, A.M.; Gavartin, J.L.

    2007-01-01

    However fascinating structures may be at the nanoscale, time-dependent behaviour at the nanoscale has far greater importance. Some of the dynamics is random, with fluctuations controlling rate processes and making thermal ratchets possible. Some of the dynamics causes the transfer of energy, of signals, or of charge. Such transfers are especially efficiently controlled in biological systems. Other dynamical processes occur when we wish to control the nanoscale, e.g., to avoid local failures of gate dielectrics, or to manipulate structures by electronic excitation, to use spin manipulation in quantum information processing. Our prime purpose is to make clear the enormous range and variety of time-dependent nanoscale phenomena

  4. Exposure, Health and Ecological Effects Review of Engineered Nanoscale Cerium and Cerium Oxide Associated with its Use as a Fuel Additive

    Science.gov (United States)

    Advances of nanoscale science have produced nanomaterials with unique physical and chemical properties at commercial levels which are now incorporated into over 1000 products. Nanoscale cerium (di) oxide (CeO(2)) has recently gained a wide range of applications which includes coa...

  5. Nanoscale device physics science and engineering fundamentals

    CERN Document Server

    Tiwari, Sandip

    2017-01-01

    Nanoscale devices are distinguishable from the larger microscale devices in their specific dependence on physical phenomena and effects that are central to their operation. The size change manifests itself through changes in importance of the phenomena and effects that become dominant and the changes in scale of underlying energetics and response. Examples of these include classical effects such as single electron effects, quantum effects such as the states accessible as well as their properties; ensemble effects ranging from consequences of the laws of numbers to changes in properties arising from different magnitudes of the inter-actions, and others. These interactions, with the limits placed on size, make not just electronic, but also magnetic, optical and mechanical behavior interesting, important and useful. Connecting these properties to the behavior of devices is the focus of this textbook. Description of the book series: This collection of four textbooks in the Electroscience series span the undergrad...

  6. Nanoscale visualization of redox activity at lithium-ion battery cathodes.

    Science.gov (United States)

    Takahashi, Yasufumi; Kumatani, Akichika; Munakata, Hirokazu; Inomata, Hirotaka; Ito, Komachi; Ino, Kosuke; Shiku, Hitoshi; Unwin, Patrick R; Korchev, Yuri E; Kanamura, Kiyoshi; Matsue, Tomokazu

    2014-11-17

    Intercalation and deintercalation of lithium ions at electrode surfaces are central to the operation of lithium-ion batteries. Yet, on the most important composite cathode surfaces, this is a rather complex process involving spatially heterogeneous reactions that have proved difficult to resolve with existing techniques. Here we report a scanning electrochemical cell microscope based approach to define a mobile electrochemical cell that is used to quantitatively visualize electrochemical phenomena at the battery cathode material LiFePO4, with resolution of ~100 nm. The technique measures electrode topography and different electrochemical properties simultaneously, and the information can be combined with complementary microscopic techniques to reveal new perspectives on structure and activity. These electrodes exhibit highly spatially heterogeneous electrochemistry at the nanoscale, both within secondary particles and at individual primary nanoparticles, which is highly dependent on the local structure and composition.

  7. Vortex pinning in superconductors laterally modulated by nanoscale self-assembled arrays

    DEFF Research Database (Denmark)

    Vanacken, J.; Vinckx, W.; Moshchalkov, V.V.

    2008-01-01

    Being the exponent of the so-called "bottom-up" approach, self-assembled structures are now-a-days attracting a lot of attention in the fields of science and technology. In this work, we show that nanoscale self-assembled arrays used as templates can provide periodic modulation in superconducting...

  8. Engineering Platinum Alloy Electrocatalysts in Nanoscale for PEMFC Application

    Energy Technology Data Exchange (ETDEWEB)

    He, Ting [Idaho National Laboratory

    2016-03-01

    Fuel cells are expected to be a key next-generation energy source used for vehicles and homes, offering high energy conversion efficiency and minimal pollutant emissions. However, due to large overpotentials on anode and cathode, the efficiency is still much lower than theoretically predicted. During the past decades, considerable efforts have been made to investigate synergy effect of platinum alloyed with base metals. But, engineering the alloy particles in nanoscale has been a challenge. Most important challenges in developing nanostructured materials are the abilities to control size, monodispersity, microcomposition, and even morphology or self-assembly capability, so called Nanomaterials-by-Design, which requires interdisciplinary collaborations among computational modeling, chemical synthesis, nanoscale characterization as well as manufacturing processing. Electrocatalysts, particularly fuel cell catalysts, are dramatically different from heterogeneous catalysts because the surface area in micropores cannot be electrochemically controlled on the same time scale as more transport accessible surfaces. Therefore, electrocatalytic architectures need minimal microporous surface area while maximizing surfaces accessible through mesopores or macropores, and to "pin" the most active, highest performance physicochemical state of the materials even when exposed to thermodynamic forces, which would otherwise drive restructuring, crystallization, or densification of the nanoscale materials. In this presentation, results of engineering nanoscale platinum alloy particles down to 2 ~ 4 nm will be discussed. Based on nature of alloyed base metals, various synthesis technologies have been studied and developed to achieve capabilities of controlling particle size and particle microcomposition, namely, core-shell synthesis, microemulsion technique, thermal decomposition process, surface organometallic chemical method, etc. The results show that by careful engineering the

  9. Dynamic structural disorder in supported nanoscale catalysts

    International Nuclear Information System (INIS)

    Rehr, J. J.; Vila, F. D.

    2014-01-01

    We investigate the origin and physical effects of “dynamic structural disorder” (DSD) in supported nano-scale catalysts. DSD refers to the intrinsic fluctuating, inhomogeneous structure of such nano-scale systems. In contrast to bulk materials, nano-scale systems exhibit substantial fluctuations in structure, charge, temperature, and other quantities, as well as large surface effects. The DSD is driven largely by the stochastic librational motion of the center of mass and fluxional bonding at the nanoparticle surface due to thermal coupling with the substrate. Our approach for calculating and understanding DSD is based on a combination of real-time density functional theory/molecular dynamics simulations, transient coupled-oscillator models, and statistical mechanics. This approach treats thermal and dynamic effects over multiple time-scales, and includes bond-stretching and -bending vibrations, and transient tethering to the substrate at longer ps time-scales. Potential effects on the catalytic properties of these clusters are briefly explored. Model calculations of molecule-cluster interactions and molecular dissociation reaction paths are presented in which the reactant molecules are adsorbed on the surface of dynamically sampled clusters. This model suggests that DSD can affect both the prefactors and distribution of energy barriers in reaction rates, and thus can significantly affect catalytic activity at the nano-scale

  10. Dynamic structural disorder in supported nanoscale catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Rehr, J. J.; Vila, F. D. [Department of Physics, University of Washington, Seattle, Washington 98195 (United States)

    2014-04-07

    We investigate the origin and physical effects of “dynamic structural disorder” (DSD) in supported nano-scale catalysts. DSD refers to the intrinsic fluctuating, inhomogeneous structure of such nano-scale systems. In contrast to bulk materials, nano-scale systems exhibit substantial fluctuations in structure, charge, temperature, and other quantities, as well as large surface effects. The DSD is driven largely by the stochastic librational motion of the center of mass and fluxional bonding at the nanoparticle surface due to thermal coupling with the substrate. Our approach for calculating and understanding DSD is based on a combination of real-time density functional theory/molecular dynamics simulations, transient coupled-oscillator models, and statistical mechanics. This approach treats thermal and dynamic effects over multiple time-scales, and includes bond-stretching and -bending vibrations, and transient tethering to the substrate at longer ps time-scales. Potential effects on the catalytic properties of these clusters are briefly explored. Model calculations of molecule-cluster interactions and molecular dissociation reaction paths are presented in which the reactant molecules are adsorbed on the surface of dynamically sampled clusters. This model suggests that DSD can affect both the prefactors and distribution of energy barriers in reaction rates, and thus can significantly affect catalytic activity at the nano-scale.

  11. Nanoscale thermal transport. II. 2003-2012

    Science.gov (United States)

    Cahill, David G.; Braun, Paul V.; Chen, Gang; Clarke, David R.; Fan, Shanhui; Goodson, Kenneth E.; Keblinski, Pawel; King, William P.; Mahan, Gerald D.; Majumdar, Arun; Maris, Humphrey J.; Phillpot, Simon R.; Pop, Eric; Shi, Li

    2014-03-01

    A diverse spectrum of technology drivers such as improved thermal barriers, higher efficiency thermoelectric energy conversion, phase-change memory, heat-assisted magnetic recording, thermal management of nanoscale electronics, and nanoparticles for thermal medical therapies are motivating studies of the applied physics of thermal transport at the nanoscale. This review emphasizes developments in experiment, theory, and computation in the past ten years and summarizes the present status of the field. Interfaces become increasingly important on small length scales. Research during the past decade has extended studies of interfaces between simple metals and inorganic crystals to interfaces with molecular materials and liquids with systematic control of interface chemistry and physics. At separations on the order of ˜ 1 nm , the science of radiative transport through nanoscale gaps overlaps with thermal conduction by the coupling of electronic and vibrational excitations across weakly bonded or rough interfaces between materials. Major advances in the physics of phonons include first principles calculation of the phonon lifetimes of simple crystals and application of the predicted scattering rates in parameter-free calculations of the thermal conductivity. Progress in the control of thermal transport at the nanoscale is critical to continued advances in the density of information that can be stored in phase change memory devices and new generations of magnetic storage that will use highly localized heat sources to reduce the coercivity of magnetic media. Ultralow thermal conductivity—thermal conductivity below the conventionally predicted minimum thermal conductivity—has been observed in nanolaminates and disordered crystals with strong anisotropy. Advances in metrology by time-domain thermoreflectance have made measurements of the thermal conductivity of a thin layer with micron-scale spatial resolution relatively routine. Scanning thermal microscopy and thermal

  12. Nanoscale biophysics of the cell

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2018-01-01

    Macroscopic cellular structures and functions are generally investigated using biological and biochemical approaches. But these methods are no longer adequate when one needs to penetrate deep into the small-scale structures and understand their functions. The cell is found to hold various physical structures, molecular machines, and processes that require physical and mathematical approaches to understand and indeed manipulate them. Disorders in general cellular compartments, perturbations in single molecular structures, drug distribution therein, and target specific drug-binding, etc. are mostly physical phenomena. This book will show how biophysics has revolutionized our way of addressing the science and technology of nanoscale structures of cells, and also describes the potential for manipulating the events that occur in them.

  13. Friction laws at the nanoscale.

    Science.gov (United States)

    Mo, Yifei; Turner, Kevin T; Szlufarska, Izabela

    2009-02-26

    Macroscopic laws of friction do not generally apply to nanoscale contacts. Although continuum mechanics models have been predicted to break down at the nanoscale, they continue to be applied for lack of a better theory. An understanding of how friction force depends on applied load and contact area at these scales is essential for the design of miniaturized devices with optimal mechanical performance. Here we use large-scale molecular dynamics simulations with realistic force fields to establish friction laws in dry nanoscale contacts. We show that friction force depends linearly on the number of atoms that chemically interact across the contact. By defining the contact area as being proportional to this number of interacting atoms, we show that the macroscopically observed linear relationship between friction force and contact area can be extended to the nanoscale. Our model predicts that as the adhesion between the contacting surfaces is reduced, a transition takes place from nonlinear to linear dependence of friction force on load. This transition is consistent with the results of several nanoscale friction experiments. We demonstrate that the breakdown of continuum mechanics can be understood as a result of the rough (multi-asperity) nature of the contact, and show that roughness theories of friction can be applied at the nanoscale.

  14. Emotionally Intense Science Activities

    Science.gov (United States)

    King, Donna; Ritchie, Stephen; Sandhu, Maryam; Henderson, Senka

    2015-01-01

    Science activities that evoke positive emotional responses make a difference to students' emotional experience of science. In this study, we explored 8th Grade students' discrete emotions expressed during science activities in a unit on Energy. Multiple data sources including classroom videos, interviews and emotion diaries completed at the end of…

  15. Exposure and Health Effects Review of Engineered Nanoscale Cerium and Cerium Dioxide Associated with its Use as a Fuel Additive - NOW IN PRINT IN THE JOURNAL

    Science.gov (United States)

    Advances of nanoscale science have produced nanomaterials with unique physical and chemical properties at commercial levels that are now incorporated into over 1000 products. Nanoscale cerium (di) oxide (Ce02) has recently gained a wide range of applications which includes coatin...

  16. Rate and State Friction Relation for Nanoscale Contacts: Thermally Activated Prandtl-Tomlinson Model with Chemical Aging

    Science.gov (United States)

    Tian, Kaiwen; Goldsby, David L.; Carpick, Robert W.

    2018-05-01

    Rate and state friction (RSF) laws are widely used empirical relationships that describe macroscale to microscale frictional behavior. They entail a linear combination of the direct effect (the increase of friction with sliding velocity due to the reduced influence of thermal excitations) and the evolution effect (the change in friction with changes in contact "state," such as the real contact area or the degree of interfacial chemical bonds). Recent atomic force microscope (AFM) experiments and simulations found that nanoscale single-asperity amorphous silica-silica contacts exhibit logarithmic aging (increasing friction with time) over several decades of contact time, due to the formation of interfacial chemical bonds. Here we establish a physically based RSF relation for such contacts by combining the thermally activated Prandtl-Tomlinson (PTT) model with an evolution effect based on the physics of chemical aging. This thermally activated Prandtl-Tomlinson model with chemical aging (PTTCA), like the PTT model, uses the loading point velocity for describing the direct effect, not the tip velocity (as in conventional RSF laws). Also, in the PTTCA model, the combination of the evolution and direct effects may be nonlinear. We present AFM data consistent with the PTTCA model whereby in aging tests, for a given hold time, static friction increases with the logarithm of the loading point velocity. Kinetic friction also increases with the logarithm of the loading point velocity at sufficiently high velocities, but at a different increasing rate. The discrepancy between the rates of increase of static and kinetic friction with velocity arises from the fact that appreciable aging during static contact changes the energy landscape. Our approach extends the PTT model, originally used for crystalline substrates, to amorphous materials. It also establishes how conventional RSF laws can be modified for nanoscale single-asperity contacts to provide a physically based friction

  17. Everyday science & science every day: Science-related talk & activities across settings

    Science.gov (United States)

    Zimmerman, Heather

    To understand the development of science-related thinking, acting, and learning in middle childhood, I studied youth in schools, homes, and other neighborhood settings over a three-year period. The research goal was to analyze how multiple everyday experiences influence children's participation in science-related practices and their thinking about science and scientists. Ethnographic and interaction analysis methodologies were to study the cognition and social interactions of the children as they participated in activities with peers, family, and teachers (n=128). Interviews and participant self-documentation protocols elucidated the participants' understandings of science. An Everyday Expertise (Bell et al., 2006) theoretical framework was employed to study the development of science understandings on three analytical planes: individual learner, social groups, and societal/community resources. Findings came from a cross-case analysis of urban science learners and from two within-case analyses of girls' science-related practices as they transitioned from elementary to middle school. Results included: (1) children participated actively in science across settings---including in their homes as well as in schools, (2) children's interests in science were not always aligned to the school science content, pedagogy, or school structures for participation, yet children found ways to engage with science despite these differences through crafting multiple pathways into science, (3) urban parents were active supporters of STEM-related learning environments through brokering access to social and material resources, (4) the youth often found science in their daily activities that formal education did not make use of, and (5) children's involvement with science-related practices can be developed into design principles to reach youth in culturally relevant ways.

  18. Nanoscale thermal transport. II. 2003–2012

    International Nuclear Information System (INIS)

    Cahill, David G.; Braun, Paul V.; Chen, Gang; Clarke, David R.; Fan, Shanhui; Goodson, Kenneth E.; Keblinski, Pawel; King, William P.; Mahan, Gerald D.; Majumdar, Arun; Maris, Humphrey J.; Phillpot, Simon R.; Pop, Eric; Shi, Li

    2014-01-01

    A diverse spectrum of technology drivers such as improved thermal barriers, higher efficiency thermoelectric energy conversion, phase-change memory, heat-assisted magnetic recording, thermal management of nanoscale electronics, and nanoparticles for thermal medical therapies are motivating studies of the applied physics of thermal transport at the nanoscale. This review emphasizes developments in experiment, theory, and computation in the past ten years and summarizes the present status of the field. Interfaces become increasingly important on small length scales. Research during the past decade has extended studies of interfaces between simple metals and inorganic crystals to interfaces with molecular materials and liquids with systematic control of interface chemistry and physics. At separations on the order of ∼1 nm, the science of radiative transport through nanoscale gaps overlaps with thermal conduction by the coupling of electronic and vibrational excitations across weakly bonded or rough interfaces between materials. Major advances in the physics of phonons include first principles calculation of the phonon lifetimes of simple crystals and application of the predicted scattering rates in parameter-free calculations of the thermal conductivity. Progress in the control of thermal transport at the nanoscale is critical to continued advances in the density of information that can be stored in phase change memory devices and new generations of magnetic storage that will use highly localized heat sources to reduce the coercivity of magnetic media. Ultralow thermal conductivity—thermal conductivity below the conventionally predicted minimum thermal conductivity—has been observed in nanolaminates and disordered crystals with strong anisotropy. Advances in metrology by time-domain thermoreflectance have made measurements of the thermal conductivity of a thin layer with micron-scale spatial resolution relatively routine. Scanning thermal microscopy and

  19. Nanoscale microwave microscopy using shielded cantilever probes

    KAUST Repository

    Lai, Keji; Kundhikanjana, Worasom; Kelly, Michael A.; Shen, Zhi-Xun

    2011-01-01

    Quantitative dielectric and conductivity mapping in the nanoscale is highly desirable for many research disciplines, but difficult to achieve through conventional transport or established microscopy techniques. Taking advantage of the micro-fabrication technology, we have developed cantilever-based near-field microwave probes with shielded structures. Sensitive microwave electronics and finite-element analysis modeling are also utilized for quantitative electrical imaging. The system is fully compatible with atomic force microscope platforms for convenient operation and easy integration of other modes and functions. The microscope is ideal for interdisciplinary research, with demonstrated examples in nano electronics, physics, material science, and biology.

  20. Nanoscale microwave microscopy using shielded cantilever probes

    KAUST Repository

    Lai, Keji

    2011-04-21

    Quantitative dielectric and conductivity mapping in the nanoscale is highly desirable for many research disciplines, but difficult to achieve through conventional transport or established microscopy techniques. Taking advantage of the micro-fabrication technology, we have developed cantilever-based near-field microwave probes with shielded structures. Sensitive microwave electronics and finite-element analysis modeling are also utilized for quantitative electrical imaging. The system is fully compatible with atomic force microscope platforms for convenient operation and easy integration of other modes and functions. The microscope is ideal for interdisciplinary research, with demonstrated examples in nano electronics, physics, material science, and biology.

  1. Manufacturing at Nanoscale: Top-Down, Bottom-up and System Engineering

    International Nuclear Information System (INIS)

    Zhang Xiang; Sun Cheng; Fang, Nicholas

    2004-01-01

    The current nano-technology revolution is facing several major challenges: to manufacture nanodevices below 20 nm, to fabricate three-dimensional complex nano-structures, and to heterogeneously integrate multiple functionalities. To tackle these grand challenges, the Center for Scalable and Integrated NAno-Manufacturing (SINAM), a NSF Nanoscale Science and Engineering Center, set its goal to establish a new manufacturing paradigm that integrates an array of new nano-manufacturing technologies, including the plasmonic imaging lithography and ultramolding imprint lithography aiming toward critical resolution of 1-10 nm and the hybrid top-down and bottom-up technologies to achieve massively parallel integration of heterogeneous nanoscale components into higher-order structures and devices. Furthermore, SINAM will develop system engineering strategies to scale-up the nano-manufacturing technologies. SINAMs integrated research and education platform will shed light to a broad range of potential applications in computing, telecommunication, photonics, biotechnology, health care, and national security

  2. The Role of Membrane Curvature in Nanoscale Topography-Induced Intracellular Signaling.

    Science.gov (United States)

    Lou, Hsin-Ya; Zhao, Wenting; Zeng, Yongpeng; Cui, Bianxiao

    2018-05-15

    Over the past decade, there has been growing interest in developing biosensors and devices with nanoscale and vertical topography. Vertical nanostructures induce spontaneous cell engulfment, which enhances the cell-probe coupling efficiency and the sensitivity of biosensors. Although local membranes in contact with the nanostructures are found to be fully fluidic for lipid and membrane protein diffusions, cells appear to actively sense and respond to the surface topography presented by vertical nanostructures. For future development of biodevices, it is important to understand how cells interact with these nanostructures and how their presence modulates cellular function and activities. How cells recognize nanoscale surface topography has been an area of active research for two decades before the recent biosensor works. Extensive studies show that surface topographies in the range of tens to hundreds of nanometers can significantly affect cell functions, behaviors, and ultimately the cell fate. For example, titanium implants having rough surfaces are better for osteoblast attachment and host-implant integration than those with smooth surfaces. At the cellular level, nanoscale surface topography has been shown by a large number of studies to modulate cell attachment, activity, and differentiation. However, a mechanistic understanding of how cells interact and respond to nanoscale topographic features is still lacking. In this Account, we focus on some recent studies that support a new mechanism that local membrane curvature induced by nanoscale topography directly acts as a biochemical signal to induce intracellular signaling, which we refer to as the curvature hypothesis. The curvature hypothesis proposes that some intracellular proteins can recognize membrane curvatures of a certain range at the cell-to-material interface. These proteins then recruit and activate downstream components to modulate cell signaling and behavior. We discuss current technologies

  3. Nanoscale thermal transport

    Science.gov (United States)

    Cahill, David G.; Ford, Wayne K.; Goodson, Kenneth E.; Mahan, Gerald D.; Majumdar, Arun; Maris, Humphrey J.; Merlin, Roberto; Phillpot, Simon R.

    2003-01-01

    Rapid progress in the synthesis and processing of materials with structure on nanometer length scales has created a demand for greater scientific understanding of thermal transport in nanoscale devices, individual nanostructures, and nanostructured materials. This review emphasizes developments in experiment, theory, and computation that have occurred in the past ten years and summarizes the present status of the field. Interfaces between materials become increasingly important on small length scales. The thermal conductance of many solid-solid interfaces have been studied experimentally but the range of observed interface properties is much smaller than predicted by simple theory. Classical molecular dynamics simulations are emerging as a powerful tool for calculations of thermal conductance and phonon scattering, and may provide for a lively interplay of experiment and theory in the near term. Fundamental issues remain concerning the correct definitions of temperature in nonequilibrium nanoscale systems. Modern Si microelectronics are now firmly in the nanoscale regime—experiments have demonstrated that the close proximity of interfaces and the extremely small volume of heat dissipation strongly modifies thermal transport, thereby aggravating problems of thermal management. Microelectronic devices are too large to yield to atomic-level simulation in the foreseeable future and, therefore, calculations of thermal transport must rely on solutions of the Boltzmann transport equation; microscopic phonon scattering rates needed for predictive models are, even for Si, poorly known. Low-dimensional nanostructures, such as carbon nanotubes, are predicted to have novel transport properties; the first quantitative experiments of the thermal conductivity of nanotubes have recently been achieved using microfabricated measurement systems. Nanoscale porosity decreases the permittivity of amorphous dielectrics but porosity also strongly decreases the thermal conductivity. The

  4. Quantum Materials at the Nanoscale - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Stephen Lance [Univ. of Illinois, Urbana, IL (United States). Dept. of Physics

    2016-01-11

    The central aim of the Quantum Materials at the Nanoscale (QMN) cluster was to understand and control collective behavior involving the interplay of spins, orbitals, and charges, which governs many scientifically interesting and technologically important phenomena in numerous complex materials. Because these phenomena involve various competing interactions, and influence properties on many different length and energy scales in complex materials, tackling this important area of study motivated a collaborative effort that combined the diverse capabilities of QMN cluster experimentalists, the essential theoretical analysis provided by QMN cluster theorists, and the outstanding facilities and staff of the FSMRL. During the funding period 2007-2014, the DOE cluster grant for the Quantum Materials at the Nanoscale (QMN) cluster supported, at various times, 15 different faculty members (14 in Physics and 1 in Materials Science and Engineering), 7 postdoctoral research associates, and 57 physics and materials science PhD students. 41 of these PhD students have since graduated and have gone on to a variety of advanced technical positions at universities, industries, and national labs: 25 obtained postdoctoral positions at universities (14), industrial labs (2 at IBM), DOE national facilities (3 at Argonne National Laboratory, 1 at Brookhaven National Lab, 1 at Lawrence Berkeley National Lab, and 1 at Sandia National Lab), and other federal facilities (2 at NIST); 13 took various industrial positions, including positions at Intel (5), Quantum Design (1), Lasque Industries (1), Amazon (1), Bloomberg (1), and J.P. Morgan (1). Thus, the QMN grant provided the essential support for training a large number of technically advanced personnel who have now entered key national facilities, industries, and institutions. Additionally, during the period 2007-2015, the QMN cluster produced 159 publications (see pages 14-23), including 23 papers published in Physical Review Letters; 16

  5. Patterning high explosives at the nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Nafday, Omkar A.; Pitchimani, Rajasekar; Weeks, Brandon L. [Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409 (United States); Haaheim, Jason [NanoInk Inc., 8025 Lamon Ave., Skokie, IL 60077 (United States)

    2006-10-15

    For the first time, we have shown that spin coating and Dip pen nanolithography (DPN trademark) are simple methods of preparing energetic materials such as PETN and HMX on the nanoscale, requiring no heating of the energetic material. Nanoscale patterning has been demonstrated by the DPN method while continuous thin films were produced using the spin coating method. Results are presented for preparing continuous PETN thin films of nanometer thickness by the spin coating method and for controlling the architecture of arbitrary nanoscale patterns of PETN and HMX by the DPN method. These methods are simple for patterning energetic materials and can be extended beyond PETN and HMX, opening the door for fundamental studies at the nanoscale. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  6. 78 FR 45992 - National Science and Technology Council; Notice of Meeting: Open Meeting of the National Science...

    Science.gov (United States)

    2013-07-30

    ..., Engineering, and Technology Subcommittee National Nanotechnology Coordination Office ACTION: Notice of public meeting. SUMMARY: The National Nanotechnology Coordination Office (NNCO), on behalf of the Nanoscale Science, Engineering, and Technology (NSET) Subcommittee of the Committee on Technology, National Science...

  7. A hard X-ray nanoprobe beamline for nanoscale microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Winarski, Robert P., E-mail: winarski@anl.gov; Holt, Martin V. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States); Rose, Volker [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States); Fuesz, Peter; Carbaugh, Dean; Benson, Christa; Shu, Deming; Kline, David; Stephenson, G. Brian; McNulty, Ian [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States); Maser, Jörg [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States)

    2012-11-01

    The Hard X-ray Nanoprobe Beamline is a precision platform for scanning probe and full-field microscopy with 3–30 keV X-rays. A combination of high-stability X-ray optics and precision motion sensing and control enables detailed studies of the internal features of samples with resolutions approaching 30 nm. The Hard X-ray Nanoprobe Beamline (or Nanoprobe Beamline) is an X-ray microscopy facility incorporating diffraction, fluorescence and full-field imaging capabilities designed and operated by the Center for Nanoscale Materials and the Advanced Photon Source at Sector 26 of the Advanced Photon Source at Argonne National Laboratory. This facility was constructed to probe the nanoscale structure of biological, environmental and material sciences samples. The beamline provides intense focused X-rays to the Hard X-ray Nanoprobe (or Nanoprobe) which incorporates Fresnel zone plate optics and a precision laser sensing and control system. The beamline operates over X-ray energies from 3 to 30 keV, enabling studies of most elements in the periodic table, with a particular emphasis on imaging transition metals.

  8. Nanoscale drug delivery for targeted chemotherapy.

    Science.gov (United States)

    Xin, Yong; Huang, Qian; Tang, Jian-Qin; Hou, Xiao-Yang; Zhang, Pei; Zhang, Long Zhen; Jiang, Guan

    2016-08-28

    Despite significant improvements in diagnostic methods and innovations in therapies for specific cancers, effective treatments for neoplastic diseases still represent major challenges. Nanotechnology as an emerging technology has been widely used in many fields and also provides a new opportunity for the targeted delivery of cancer drugs. Nanoscale delivery of chemotherapy drugs to the tumor site is highly desirable. Recent studies have shown that nanoscale drug delivery systems not only have the ability to destroy cancer cells but may also be carriers for chemotherapy drugs. Some studies have demonstrated that delivery of chemotherapy via nanoscale carriers has greater therapeutic benefit than either treatment modality alone. In this review, novel approaches to nanoscale delivery of chemotherapy are described and recent progress in this field is discussed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Intelligent Design of Nano-Scale Molecular Imaging Agents

    Directory of Open Access Journals (Sweden)

    Takeaki Ozawa

    2012-12-01

    Full Text Available Visual representation and quantification of biological processes at the cellular and subcellular levels within living subjects are gaining great interest in life science to address frontier issues in pathology and physiology. As intact living subjects do not emit any optical signature, visual representation usually exploits nano-scale imaging agents as the source of image contrast. Many imaging agents have been developed for this purpose, some of which exert nonspecific, passive, and physical interaction with a target. Current research interest in molecular imaging has mainly shifted to fabrication of smartly integrated, specific, and versatile agents that emit fluorescence or luminescence as an optical readout. These agents include luminescent quantum dots (QDs, biofunctional antibodies, and multifunctional nanoparticles. Furthermore, genetically encoded nano-imaging agents embedding fluorescent proteins or luciferases are now gaining popularity. These agents are generated by integrative design of the components, such as luciferase, flexible linker, and receptor to exert a specific on–off switching in the complex context of living subjects. In the present review, we provide an overview of the basic concepts, smart design, and practical contribution of recent nano-scale imaging agents, especially with respect to genetically encoded imaging agents.

  10. NANOSCALE BIOSENSORS IN ECOSYSTEM EXPOSURE RESEARCH

    Science.gov (United States)

    This powerpoint presentation presented information on nanoscale biosensors in ecosystem exposure research. The outline of the presentation is as follows: nanomaterials environmental exposure research; US agencies involved in nanosensor research; nanoscale LEDs in biosensors; nano...

  11. The use of nanoscale fluorescence microscopic to decipher cell wall modifications during fungal penetration

    Directory of Open Access Journals (Sweden)

    Dorothea eEllinger

    2014-06-01

    Full Text Available Plant diseases are one of the most studied subjects in the field of plant science due to their impact on crop yield and food security. Our increased understanding of plant–pathogen interactions was mainly driven by the development of new techniques that facilitated analyses on a subcellular and molecular level. The development of labeling technologies, which allowed the visualization and localization of cellular structures and proteins in live cell imaging, promoted the use of fluorescence and laser-scanning microscopy in the field of plant–pathogen interactions. Recent advances in new microscopic technologies opened their application in plant science and in the investigation of plant diseases. In this regard, in planta Förster/Fluorescence resonance energy transfer has demonstrated to facilitate the measurement of protein-protein interactions within the living tissue, supporting the analysis of regulatory pathways involved in plant immunity and putative host-pathogen interactions on a nanoscale level. Localization microscopy, an emerging, non-invasive microscopic technology, will allow investigations with a nanoscale resolution leading to new possibilities in the understanding of molecular processes.

  12. Spintronics in nanoscale devices

    CERN Document Server

    Hedin, Eric R

    2013-01-01

    By exploiting the novel properties of quantum dots and nanoscale Aharonov-Bohm rings together with the electronic and magnetic properties of various semiconductor materials and graphene, researchers have conducted numerous theoretical and computational modeling studies and experimental tests that show promising behavior for spintronics applications. Spin polarization and spin-filtering capabilities and the ability to manipulate the electron spin state through external magnetic or electric fields have demonstrated the promise of workable nanoscale devices for computing and memory applications.

  13. Nanomaterial Case Studies: Nanoscale Titanium Dioxide (External Review Draft)

    Science.gov (United States)

    This draft document presents two case studies of nanoscale titanium dioxide (nano-TiO2) used (1) to remove arsenic from drinking water and (2) as an active ingredient in topical sunscreen. The draft case studies are organized around a comprehensive environmental asses...

  14. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Nanotechnology is an emerging field in science and technology, which can be applied to synthesize new materials at the nanoscale level. The present investigation aimed at comparing the synthesis, characterization andin vitro anticancer efficacy of synthesized silver and gold nanoparticles using leaves extract of Bauhinia ...

  15. Biochar supported nanoscale zerovalent iron composite used as persulfate activator for removing trichloroethylene.

    Science.gov (United States)

    Yan, Jingchun; Han, Lu; Gao, Weiguo; Xue, Song; Chen, Mengfang

    2015-01-01

    Biochar (BC) supported nanoscale zerovalent iron (nZVI) composite was synthesized and used as an activator for persulfate to enhance the trichloroethylene (TCE) removal in aqueous solutions. The degradation efficiency of TCE (0.15mmolL(-1)) was 99.4% in the presence of nZVI/BC (4.5mmolL(-1), nZVI to BC mass ratio was 1:5) and persulfate (4.5mmolL(-1)) within 5min, which was significantly higher than that (56.6%) in nZVI-persulfate system under the same conditions. Owing to large specific surface area and oxygen-containing functional groups of BC, nZVI/BC enhanced the SO4(-) generation and accelerated TCE degradation. On the basis of the characterization and analysis data, possible activation mechanisms of the Fe(2+)/Fe(3+) (Fe(II)/Fe(III)) redox action and the electron-transfer mediator of the BC oxygen functional groups promoting the generation of SO4(-) in nZVI/BC-persulfate system were clarified. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Nanoscale phase change memory materials.

    Science.gov (United States)

    Caldwell, Marissa A; Jeyasingh, Rakesh Gnana David; Wong, H-S Philip; Milliron, Delia J

    2012-08-07

    Phase change memory materials store information through their reversible transitions between crystalline and amorphous states. For typical metal chalcogenide compounds, their phase transition properties directly impact critical memory characteristics and the manipulation of these is a major focus in the field. Here, we discuss recent work that explores the tuning of such properties by scaling the materials to nanoscale dimensions, including fabrication and synthetic strategies used to produce nanoscale phase change memory materials. The trends that emerge are relevant to understanding how such memory technologies will function as they scale to ever smaller dimensions and also suggest new approaches to designing materials for phase change applications. Finally, the challenges and opportunities raised by integrating nanoscale phase change materials into switching devices are discussed.

  17. Educational activities for neutron sciences

    International Nuclear Information System (INIS)

    Hiraka, Haruhiro; Ohoyama, Kenji; Iwasa, Kazuaki

    2011-01-01

    Since now we have several world-leading neutron science facilities in Japan, enlightenment activities for introducing neutron sciences, for example, to young people is an indispensable issue. Hereafter, we will report present status of the activities based on collaborations between universities and neutron facilities. A few suggestions for future educational activity of JSNS are also shown. (author)

  18. Overview of nanoscale NEXAFS performed with soft X-ray microscopes

    Directory of Open Access Journals (Sweden)

    Peter Guttmann

    2015-02-01

    Full Text Available Today, in material science nanoscale structures are becoming more and more important. Not only for the further miniaturization of semiconductor devices like carbon nanotube based transistors, but also for newly developed efficient energy storage devices, gas sensors or catalytic systems nanoscale and functionalized materials have to be analysed. Therefore, analytical tools like near-edge X-ray absorption fine structure (NEXAFS spectroscopy has to be applied on single nanostructures. Scanning transmission X-ray microscopes (STXM as well as full-field transmission X-ray microscopes (TXM allow the required spatial resolution to study individual nanostructures. In the soft X-ray energy range only STXM was used so far for NEXAFS studies. Due to its unique setup, the TXM operated by the Helmholtz-Zentrum Berlin (HZB at the electron storage ring BESSY II is the first one in the soft X-ray range which can be used for NEXAFS spectroscopy studies which will be shown in this review. Here we will give an overview of the different microscopes used for NEXAFS studies and describe their advantages and disadvantages for different samples.

  19. Overview of nanoscale NEXAFS performed with soft X-ray microscopes.

    Science.gov (United States)

    Guttmann, Peter; Bittencourt, Carla

    2015-01-01

    Today, in material science nanoscale structures are becoming more and more important. Not only for the further miniaturization of semiconductor devices like carbon nanotube based transistors, but also for newly developed efficient energy storage devices, gas sensors or catalytic systems nanoscale and functionalized materials have to be analysed. Therefore, analytical tools like near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has to be applied on single nanostructures. Scanning transmission X-ray microscopes (STXM) as well as full-field transmission X-ray microscopes (TXM) allow the required spatial resolution to study individual nanostructures. In the soft X-ray energy range only STXM was used so far for NEXAFS studies. Due to its unique setup, the TXM operated by the Helmholtz-Zentrum Berlin (HZB) at the electron storage ring BESSY II is the first one in the soft X-ray range which can be used for NEXAFS spectroscopy studies which will be shown in this review. Here we will give an overview of the different microscopes used for NEXAFS studies and describe their advantages and disadvantages for different samples.

  20. Exploring Connections Between Earth Science and Biology - Interdisciplinary Science Activities for Schools

    Science.gov (United States)

    Vd Flier-Keller, E.; Carolsfeld, C.; Bullard, T.

    2009-05-01

    To increase teaching of Earth science in schools, and to reflect the interdisciplinary nature and interrelatedness of science disciplines in today's world, we are exploring opportunities for linking Earth science and Biology through engaging and innovative hands-on science activities for the classroom. Through the NSERC-funded Pacific CRYSTAL project based at the University of Victoria, scientists, science educators, and teachers at all levels in the school system are collaborating to research ways of enriching the preparation of students in math and science, and improving the quality of science education from Kindergarten to Grade 12. Our primary foci are building authentic, engaging science experiences for students, and fostering teacher leadership through teacher professional development and training. Interdisciplinary science activities represent an important way of making student science experiences real, engaging and relevant, and provide opportunities to highlight Earth science related topics within other disciplines, and to expand the Earth science taught in schools. The Earth science and Biology interdisciplinary project builds on results and experiences of existing Earth science education activities, and the Seaquaria project. We are developing curriculum-linked activities and resource materials, and hosting teacher workshops, around two initial areas; soils, and marine life and the fossil record. An example activity for the latter is the hands-on examination of organisms occupying the nearshore marine environment using a saltwater aquarium and touch tank or beach fieldtrip, and relating this to a suite of marine fossils to facilitate student thinking about representation of life in the fossil record e.g. which life forms are typically preserved, and how are they preserved? Literacy activities such as fossil obituaries encourage exploration of paleoenvironments and life habits of fossil organisms. Activities and resources are being tested with teachers

  1. Nano-Science-Engineering-Technology Applications to Food and Nutrition.

    Science.gov (United States)

    Nakajima, Mitsutoshi; Wang, Zheng; Chaudhry, Qasim; Park, Hyun Jin; Juneja, Lekh R

    2015-01-01

    Nanoscale Science, Engineering and Technology are applied to Food and Nutrition. Various delivery systems include nanoemulsions, microemulsions, solid lipid nanoparticles, micelles, and liposomes. The nanoscale systems have advantages, such as higher bioavailabitity, and other physicochemical properties. The symposium will provide an overview of the formulation, characterization, and utilization of nanotechnology-based food and nutrition.

  2. Nanoscale strontium titanate photocatalysts for overall water splitting.

    Science.gov (United States)

    Townsend, Troy K; Browning, Nigel D; Osterloh, Frank E

    2012-08-28

    SrTiO(3) (STO) is a large band gap (3.2 eV) semiconductor that catalyzes the overall water splitting reaction under UV light irradiation in the presence of a NiO cocatalyst. As we show here, the reactivity persists in nanoscale particles of the material, although the process is less effective at the nanoscale. To reach these conclusions, Bulk STO, 30 ± 5 nm STO, and 6.5 ± 1 nm STO were synthesized by three different methods, their crystal structures verified with XRD and their morphology observed with HRTEM before and after NiO deposition. In connection with NiO, all samples split water into stoichiometric mixtures of H(2) and O(2), but the activity is decreasing from 28 μmol H(2) g(-1) h(-1) (bulk STO), to 19.4 μmol H(2) g(-1) h(-1) (30 nm STO), and 3.0 μmol H(2) g(-1) h(-1) (6.5 nm STO). The reasons for this decrease are an increase of the water oxidation overpotential for the smaller particles and reduced light absorption due to a quantum size effect. Overall, these findings establish the first nanoscale titanate photocatalyst for overall water splitting.

  3. Nanotechnology: The Stuff of Science Fiction or Science Fact?

    Science.gov (United States)

    Aston, Diane

    2011-01-01

    This article discusses nanotechnology as a route to the production of new materials and provides a brief history of the evolution of this branch of materials science. Properties on the nanoscale are compared with those on the macroscale. The practical application of nanomaterials in industries such as communications, construction, cosmetics,…

  4. Enhanced nanoscale friction on fluorinated graphene.

    Science.gov (United States)

    Kwon, Sangku; Ko, Jae-Hyeon; Jeon, Ki-Joon; Kim, Yong-Hyun; Park, Jeong Young

    2012-12-12

    Atomically thin graphene is an ideal model system for studying nanoscale friction due to its intrinsic two-dimensional (2D) anisotropy. Furthermore, modulating its tribological properties could be an important milestone for graphene-based micro- and nanomechanical devices. Here, we report unexpectedly enhanced nanoscale friction on chemically modified graphene and a relevant theoretical analysis associated with flexural phonons. Ultrahigh vacuum friction force microscopy measurements show that nanoscale friction on the graphene surface increases by a factor of 6 after fluorination of the surface, while the adhesion force is slightly reduced. Density functional theory calculations show that the out-of-plane bending stiffness of graphene increases up to 4-fold after fluorination. Thus, the less compliant F-graphene exhibits more friction. This indicates that the mechanics of tip-to-graphene nanoscale friction would be characteristically different from that of conventional solid-on-solid contact and would be dominated by the out-of-plane bending stiffness of the chemically modified graphene. We propose that damping via flexural phonons could be a main source for frictional energy dissipation in 2D systems such as graphene.

  5. Nanoscale Electrochemical Sensing and Processing in Microreactors

    NARCIS (Netherlands)

    Odijk, Mathieu; van den Berg, Albert

    2018-01-01

    In this review, we summarize recent advances in nanoscale electrochemistry, including the use of nanoparticles, carbon nanomaterials, and nanowires. Exciting developments are reported for nanoscale redox cycling devices, which can chemically amplify signal readout. We also discuss promising

  6. WFIRST Project Science Activities

    Science.gov (United States)

    Gehrels, Neil

    2012-01-01

    The WFIRST Project is a joint effort between GSFC and JPL. The project scientists and engineers are working with the community Science Definition Team to define the requirements and initial design of the mission. The objective is to design an observatory that meets the WFIRST science goals of the Astr02010 Decadal Survey for minimum cost. This talk will be a report of recent project activities including requirements flowdown, detector array development, science simulations, mission costing and science outreach. Details of the interim mission design relevant to scientific capabilities will be presented.

  7. Nanoscale cryptography: opportunities and challenges.

    Science.gov (United States)

    Masoumi, Massoud; Shi, Weidong; Xu, Lei

    2015-01-01

    While most of the electronics industry is dependent on the ever-decreasing size of lithographic transistors, this scaling cannot continue indefinitely. To improve the performance of the integrated circuits, new emerging and paradigms are needed. In recent years, nanoelectronics has become one of the most important and exciting forefront in science and engineering. It shows a great promise for providing us in the near future with many breakthroughs that change the direction of technological advances in a wide range of applications. In this paper, we discuss the contribution that nanotechnology may offer to the evolution of cryptographic hardware and embedded systems and demonstrate how nanoscale devices can be used for constructing security primitives. Using a custom set of design automation tools, it is demonstrated that relative to a conventional 45-nm CMOS system, performance gains can be obtained up to two orders of magnitude reduction in area and up to 50 % improvement in speed.

  8. EDITORIAL: Physical behaviour at the nanoscale: a model for fertile research Physical behaviour at the nanoscale: a model for fertile research

    Science.gov (United States)

    Demming, Anna

    2013-06-01

    that allow new ideas and a deepening understanding to take root. Over the last few decades nanoscale research has matured into a science with generally well understood principles, allowing technology companies to develop next-generation devices with functions that dwarf some of the most creative fancies of science fiction. Yet some of the greatest leaps of inspiration have come where observations tax the limits of what current theory can explain, forcing researchers to question and examine historic reasoning. As Di Ventra and Pershin demonstrate in this issue, current memristor research is proving very fertile ground for such questioning and examining, ultimately leading to a deepening understanding of the physical properties of these nanoscale systems. References [1] Di Ventra M and Pershin Y V 2013 On the physical properties of memristive, memcapacitive, and meminductive systems Nanotechnology 24 255201 [2] Miller R E and Shenoy V B 2000 Size-dependent elastic properties of nanosized structural elements Nanotechnology 11 139-47 [3] Buehler M J 2006 Nature designs tough collagen: explaining the nanostructure of collagen fibrils Proc. Natl Acad. Sci. USA 103 12285-90 [4] Keten S, Xu Z, Ihle B and Buehler M J 2010 Nanoconfinement controls stiffness, strength and mechanical toughness of B-sheet crystals in silk Nature Mater. 9 359-67 [5] Misewich J A, Martel R, Avouris Ph, Tsang J C, Heinze S and Tersoff J 2003 Electrically induced optical emission from a carbon nanotube FET Science 300 783-6 [6]Jiang H, Hu J, Gu F and Li C 2009 Stable field emission performance from urchin-like ZnO nanostructures Nanotechnology 20 055706 [7] Forbes R G 2012 Extraction of emission parameters for large-area field emitters, using a technically complete Fowler-Nordheim-type equation Nanotechnology 23 095706 [8] Chua L O 1971 Memristor—the missing circuit element IEEE Trans. Circuit Theory 18 507-19 [9]Strukov D B, Snider G S, Stewart D R and Williams R S 2008 The missing memristor found

  9. Influence of Physical Activities to Science Performance

    Directory of Open Access Journals (Sweden)

    RS Wilson DR. Constantino

    2017-11-01

    Full Text Available This study explored the physical activities of fifth and sixth graders that projected correlations to science performance and how these physical activities may be utilized for classroom purposes in the context of science-related play activities. Descriptive survey correlational design directed the data collection and analysis of the physical activities of purposively selected 133 fifth and sixth graders. Primarily, the study used a researcher-developed and validated instrument (Physical Activity Questionnaire [PAQ], and standard instruments: Philippine National Physical Activity Guide (PNPAG and General Physical Activity Questionnaire (GPAQ. The latter classified the physical activities into five domains which directed the interpretation of the participants‟ responses. The Pearson-r Moment of Correlation described the level of correlation of the frequency of engagement to physical activities (limited to local and localized activities and the science grade of the respondents. Results show that each of the physical activity domains showed specific correlations to science performance of the respondents. For further research, enrichment of the relationship of the physical activities and the science performance may focus on possible moderating variables like economic status, and time allotment for physical activities.

  10. Design Optimization of Radionuclide Nano-Scale Batteries

    International Nuclear Information System (INIS)

    Schoenfeld, D.W.; Tulenko, J.S.; Wang, J.; Smith, B.

    2004-01-01

    Radioisotopes have been used for power sources in heart pacemakers and space applications dating back to the 50's. Two key properties of radioisotope power sources are high energy density and long half-life compared to chemical batteries. The tritium battery used in heart pacemakers exceeds 500 mW--hr, and is being evaluated by the University of Florida for feasibility as a MEMS (MicroElectroMechanical Systems) power source. Conversion of radioisotope sources into electrical power within the constraints of nano-scale dimensions requires cutting-edge technologies and novel approaches. Some advances evolving in the III-V and II-IV semiconductor families have led to a broader consideration of radioisotopes rather free of radiation damage limitations. Their properties can lead to novel battery configurations designed to convert externally located emissions from a highly radioactive environment. This paper presents results for the analytical computational assisted design and modeling of semiconductor prototype nano-scale radioisotope nuclear batteries from MCNP and EGS programs. The analysis evaluated proposed designs and was used to guide the selection of appropriate geometries, material properties, and specific activities to attain power requirements for the MEMS batteries. Plans utilizing high specific activity radioisotopes were assessed in the investigation of designs employing multiple conversion cells and graded junctions with varying band gap properties. Voltage increases sought by serial combination of VOC s are proposed to overcome some of the limitations of a low power density. The power density is directly dependent on the total active areas

  11. Nanoscale technology in biological systems

    CERN Document Server

    Greco, Ralph S; Smith, R Lane

    2004-01-01

    Reviewing recent accomplishments in the field of nanobiology Nanoscale Technology in Biological Systems introduces the application of nanoscale matrices to human biology. It focuses on the applications of nanotechnology fabrication to biomedical devices and discusses new physical methods for cell isolation and manipulation and intracellular communication at the molecular level. It also explores the application of nanobiology to cardiovascular diseases, oncology, transplantation, and a range of related disciplines. This book build a strong background in nanotechnology and nanobiology ideal for

  12. 77 FR 24228 - Proposal Review Panel for Social and Economic Sciences; Notice of Meeting

    Science.gov (United States)

    2012-04-23

    ... NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Social and Economic Sciences; Notice of...; Division of Social and Economic Sciences, Room 990, National Science Foundation, 4201 Wilson Boulevard... Science Foundation announces the following meeting: Name: Site visit review of the Nanoscale Science and...

  13. Creating nanoscale emulsions using condensation.

    Science.gov (United States)

    Guha, Ingrid F; Anand, Sushant; Varanasi, Kripa K

    2017-11-08

    Nanoscale emulsions are essential components in numerous products, ranging from processed foods to novel drug delivery systems. Existing emulsification methods rely either on the breakup of larger droplets or solvent exchange/inversion. Here we report a simple, scalable method of creating nanoscale water-in-oil emulsions by condensing water vapor onto a subcooled oil-surfactant solution. Our technique enables a bottom-up approach to forming small-scale emulsions. Nanoscale water droplets nucleate at the oil/air interface and spontaneously disperse within the oil, due to the spreading dynamics of oil on water. Oil-soluble surfactants stabilize the resulting emulsions. We find that the oil-surfactant concentration controls the spreading behavior of oil on water, as well as the peak size, polydispersity, and stability of the resulting emulsions. Using condensation, we form emulsions with peak radii around 100 nm and polydispersities around 10%. This emulsion formation technique may open different routes to creating emulsions, colloidal systems, and emulsion-based materials.

  14. EXAFS and XANES analysis of oxides at the nanoscale

    Directory of Open Access Journals (Sweden)

    Alexei Kuzmin

    2014-11-01

    Full Text Available Worldwide research activity at the nanoscale is triggering the appearance of new, and frequently surprising, materials properties in which the increasing importance of surface and interface effects plays a fundamental role. This opens further possibilities in the development of new multifunctional materials with tuned physical properties that do not arise together at the bulk scale. Unfortunately, the standard methods currently available for solving the atomic structure of bulk crystals fail for nanomaterials due to nanoscale effects (very small crystallite sizes, large surface-to-volume ratio, near-surface relaxation, local lattice distortions etc.. As a consequence, a critical reexamination of the available local-structure characterization methods is needed. This work discusses the real possibilities and limits of X-ray absorption spectroscopy (XAS analysis at the nanoscale. To this end, the present state of the art for the interpretation of extended X-ray absorption fine structure (EXAFS is described, including an advanced approach based on the use of classical molecular dynamics and its application to nickel oxide nanoparticles. The limits and possibilities of X-ray absorption near-edge spectroscopy (XANES to determine several effects associated with the nanocrystalline nature of materials are discussed in connection with the development of ZnO-based dilute magnetic semiconductors (DMSs and iron oxide nanoparticles.

  15. Using mathematical models to understand the effect of nanoscale roughness on protein adsorption for improving medical devices

    Directory of Open Access Journals (Sweden)

    Ercan B

    2013-09-01

    Full Text Available Batur Ercan,1 Dongwoo Khang,2 Joseph Carpenter,3 Thomas J Webster1 1Department of Chemical Engineering, Northeastern University, Boston, MA, USA; 2School of Materials Science and Engineering and Center for PRC and RIGET, Gyeongsang National University, Jinju, South Korea; 3School of Medicine, Stanford University, Stanford, CA, USA Abstract: Surface roughness and energy significantly influence protein adsorption on to biomaterials, which, in turn, controls select cellular adhesion to determine the success and longevity of an implant. To understand these relationships at a fundamental level, a model was originally proposed by Khang et al to correlate nanoscale surface properties (specifically, nanoscale roughness and energy to protein adsorption, which explained the greater cellular responses on nanostructured surfaces commonly reported in the literature today. To test this model for different surfaces from what was previously used to develop that model, in this study we synthesized highly ordered poly(lactic-co-glycolic acid surfaces of identical chemistry but altered nanoscale surface roughness and energy using poly(dimethylsiloxane molds of polystyrene beads. Fibronectin and collagen type IV adsorption studies showed a linear adsorption behavior as the surface nanoroughness increased. This supported the general trends observed by Khang et al. However, when fitting such data to the mathematical model established by Khang et al, a strong correlation did not result. Thus, this study demonstrated that the equation proposed by Khang et al to predict protein adsorption should be modified to accommodate for additional nanoscale surface property contributions (ie, surface charge to make the model more accurate. In summary, results from this study provided an important step in developing future mathematical models that can correlate surface properties (such as nanoscale roughness and surface energy to initial protein adsorption events important to

  16. Flexible nanoscale high-performance FinFETs

    KAUST Repository

    Sevilla, Galo T.

    2014-10-28

    With the emergence of the Internet of Things (IoT), flexible high-performance nanoscale electronics are more desired. At the moment, FinFET is the most advanced transistor architecture used in the state-of-the-art microprocessors. Therefore, we show a soft-etch based substrate thinning process to transform silicon-on-insulator (SOI) based nanoscale FinFET into flexible FinFET and then conduct comprehensive electrical characterization under various bending conditions to understand its electrical performance. Our study shows that back-etch based substrate thinning process is gentler than traditional abrasive back-grinding process; it can attain ultraflexibility and the electrical characteristics of the flexible nanoscale FinFET show no performance degradation compared to its rigid bulk counterpart indicating its readiness to be used for flexible high-performance electronics.

  17. Nanoscale tissue engineering: spatial control over cell-materials interactions

    Science.gov (United States)

    Wheeldon, Ian; Farhadi, Arash; Bick, Alexander G.; Jabbari, Esmaiel; Khademhosseini, Ali

    2011-01-01

    Cells interact with the surrounding environment by making tens to hundreds of thousands of nanoscale interactions with extracellular signals and features. The goal of nanoscale tissue engineering is to harness the interactions through nanoscale biomaterials engineering in order to study and direct cellular behaviors. Here, we review the nanoscale tissue engineering technologies for both two- and three-dimensional studies (2- and 3D), and provide a holistic overview of the field. Techniques that can control the average spacing and clustering of cell adhesion ligands are well established and have been highly successful in describing cell adhesion and migration in 2D. Extension of these engineering tools to 3D biomaterials has created many new hydrogel and nanofiber scaffolds technologies that are being used to design in vitro experiments with more physiologically relevant conditions. Researchers are beginning to study complex cell functions in 3D, however, there is a need for biomaterials systems that provide fine control over the nanoscale presentation of bioactive ligands in 3D. Additionally, there is a need for 2- and 3D techniques that can control the nanoscale presentation of multiple bioactive ligands and the temporal changes in cellular microenvironment. PMID:21451238

  18. Nanoscale tissue engineering: spatial control over cell-materials interactions

    International Nuclear Information System (INIS)

    Wheeldon, Ian; Farhadi, Arash; Bick, Alexander G; Khademhosseini, Ali; Jabbari, Esmaiel

    2011-01-01

    Cells interact with the surrounding environment by making tens to hundreds of thousands of nanoscale interactions with extracellular signals and features. The goal of nanoscale tissue engineering is to harness these interactions through nanoscale biomaterials engineering in order to study and direct cellular behavior. Here, we review two- and three-dimensional (2- and 3D) nanoscale tissue engineering technologies, and provide a holistic overview of the field. Techniques that can control the average spacing and clustering of cell adhesion ligands are well established and have been highly successful in describing cell adhesion and migration in 2D. Extension of these engineering tools to 3D biomaterials has created many new hydrogel and nanofiber scaffold technologies that are being used to design in vitro experiments with more physiologically relevant conditions. Researchers are beginning to study complex cell functions in 3D. However, there is a need for biomaterials systems that provide fine control over the nanoscale presentation of bioactive ligands in 3D. Additionally, there is a need for 2- and 3D techniques that can control the nanoscale presentation of multiple bioactive ligands and that can control the temporal changes in the cellular microenvironment. (topical review)

  19. The Effect of Physical Activity on Science Competence and Attitude towards Science Content

    Science.gov (United States)

    Klinkenborg, Ann Maria

    This study examines the effect of physical activity on science instruction. To combat the implications of physical inactivity, schools need to be willing to consider all possible opportunities for students to engage in moderate-to-vigorous physical activity (MVPA). Integrating physical activity with traditional classroom content is one instructional method to consider. Researchers have typically focused on integration with English/language arts (ELA) and mathematics. The purpose of this study was to determine the effect of physical activity on science competence and attitude towards science. Fifty-three third grade children participated in this investigation; one group received science instruction with a physical activity intervention while the other group received traditional science instruction. Participants in both groups completed a modified version of What I Really Think of Science attitude scale (Pell & Jarvis, 2001) and a physical science test of competence prior to and following the intervention. Children were videotaped during science instruction and their movement coded to measure the proportion of time spent in MVPA. Results revealed that children in the intervention group demonstrated greater MVPA during the instructional period. A moderate to large effect size (partial eta squared = .091) was seen in the intervention group science competence post-test indicating greater understanding of force, motion, work, and simple machines concepts than that of the control group who were less physically active. There was no statistically significant attitude difference between the intervention and control groups post-test, (F(1,51) = .375, p = .543). These results provide evidence that integration can effectively present physical science content and have a positive impact on the number of minutes of health-enhancing physical activity in a school day.

  20. Nanoscale Molecules Under Thermodynamic Control:" Digestive Ripening" or " Nanomachining"

    Energy Technology Data Exchange (ETDEWEB)

    Klabunde, Kenneth J. [Kansas State Univ., Manhattan, KS (United States)

    2015-06-04

    Overall Research Goals and Specific Objectives: Nanoscale materials are becoming ubiquitous in science and engineering, and are found widely in nature. However, their formation processes and uniquely high chemical reactivities are not understood well, indeed are often mysterious. Over recent years, a number of research teams have described nanoparticle synthesis, and aging, thermal treatment, or etching times have been mentioned. We have used the terms “digestive ripening” and “nanomachining” and have suggested that thermodynamics plays an important part in the size adjustment to monodisperse arrays being formed. Since there is scant theoretical understanding of digestive ripening, the overall goal in our research is to learn what experimental parameters (ligand used, temperature, solvent, time) are most important, how to control nanoparticle size and shape after initial crude nanoparticles have been synthesized, and gain better understanding of the chemical mechanism details. Specific objectives for the past twentynine months since the grant began have been to (1) Secure and train personnel;as of 2011, a postdoc Deepa Jose, female from the Indian Institute of Science in Bangalore, India; Yijun Sun, a second year graduate student, female from China; and Jessica Changstrom, female from the USA, GK12 fellow (program for enhancing teaching ability) are actively carrying out research. (2) Find out what happens to sulfur bound hydrogen of thiol when it interacts with gold nanoparticles. Our findings are discussed in detail later. (3) Determine the effect of particle size, shape, and temperature on dodecyl thiol assited digestive ripening of gold nanoparticles. See our discussions later. (4) To understand in detail the ligand interaction in molecular clusters and nanoparticles (5) Determine the effect of chain length of amines on Au nanoparticle size under digestive ripening conditions (carbon chain length varied from 4-18). (6) Determine the catalytic activity

  1. The Architectural Designs of a Nanoscale Computing Model

    Directory of Open Access Journals (Sweden)

    Mary M. Eshaghian-Wilner

    2004-08-01

    Full Text Available A generic nanoscale computing model is presented in this paper. The model consists of a collection of fully interconnected nanoscale computing modules, where each module is a cube of cells made out of quantum dots, spins, or molecules. The cells dynamically switch between two states by quantum interactions among their neighbors in all three dimensions. This paper includes a brief introduction to the field of nanotechnology from a computing point of view and presents a set of preliminary architectural designs for fabricating the nanoscale model studied.

  2. Monolithic integration of nanoscale tensile specimens and MEMS structures

    International Nuclear Information System (INIS)

    Yilmaz, Mehmet; Kysar, Jeffrey W

    2013-01-01

    Nanoscale materials often have stochastic material properties due to a random distribution of material defects and an insufficient number of defects to ensure a consistent average mechanical response. Current methods to measure the mechanical properties employ MEMS-based actuators. The nanoscale specimens are typically mounted manually onto the load platform, so the boundary conditions have random variations, complicating the experimental measurement of the intrinsic stochasticity of the material properties. Here we show methods for monolithic integration of a nanoscale specimen co-fabricated with the loading platform. The nanoscale specimen is gold with dimensions of ∼40 nm thickness, 350 ± 50 nm width, and 7 μm length and the loading platform is an interdigitated electrode electrostatic actuator. The experiment is performed in a scanning electron microscope and digital image correlation is employed to measure displacements to determine stress and strain. The ultimate tensile strength of the nanocrystalline nanoscale specimen approaches 1 GPa, consistent with measurements made by other nanometer scale sample characterization methods on other material samples at the nanometer scale, as well as gold samples at the nanometer scale. The batch-compatible microfabrication method can be used to create nominally identical nanoscale specimens and boundary conditions for a broad range of materials. (paper)

  3. Micro-electrolysis of Cr (VI) in the nanoscale zero-valent iron loaded activated carbon.

    Science.gov (United States)

    Wu, Limei; Liao, Libing; Lv, Guocheng; Qin, Faxiang; He, Yujuan; Wang, Xiaoyu

    2013-06-15

    In this paper we prepared a novel material of activated carbon/nanoscale zero-valent iron (C-Fe(0)) composite. The C-Fe(0) was proved to possess large specific surface area and outstanding reducibility that result in the rapid and stable reaction with Cr (VI). The prepared composite has been examined in detail in terms of the influence of solution pH, concentration and reaction time in the Cr (VI) removal experiments. The results showed that the C-Fe(0) formed a micro-electrolysis which dominated the reaction rate. The Micro-electrolysis reaches equilibrium is ten minutes. Its reaction rate is ten times higher than that of traditional adsorption reaction, and the removal rate of Cr reaches up to 99.5%. By analyzing the obtained profiles from the cyclic voltammetry, PXRD and XPS, we demonstrate that the Cr (VI) is reduced to insoluble Cr (III) compound in the reaction. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. FOREWORD Nanomaterials science Nanomaterials science

    Science.gov (United States)

    Rohrer, Heinrich

    2010-10-01

    . Interfaces gave them their functions, and shaping them into ever-smaller functional components made them indispensably omnipresent as transistors—produced in billions per person and per year—and they are no doubt the rulers of today's technical world. The semiconductor and transistor serve as an inspiring example of functionalizing materials. The developments of microelectronics profited very much from scalability, that is, the properties and functions do not change significantly with size. Therefore, every step toward smaller dimensions was a technical and commercial challenge with risks well under control. The transition to the nanoscale, however, is discontinuous. Examples of this transition are the local probe methods that exploit the mechanically controlled proximity to the object under consideration and that have become indispensable as microscopes and as measuring and modifying tools, the size of molecular components that are much smaller than the smallest possibly achievable transistor, the properties and functions of materials below a critical size as mentioned above, the continuum properties versus discrete ones, and novel concepts inspired by living nature. Those novel concepts include growing circuits first and building the active components at the nodes afterwards and measuring weak by weak, small by small, and many by many. It is these discontinuous steps that make the nanoscale different, not just smaller. They pose exciting challenges, open great opportunities and nearly unlimited possibilities, but they also carry serious technical, commercial, environmental, and health risks. The nanoscale is also a great opportunity for materials science in general. Materials science is interdisciplinary per se. A materials scientist should have a reasonable understanding of physics, chemistry, engineering, and more recently, also biology. Certainly one can always team up with representatives from other disciplines and forge collaborations. However, an effective team

  5. PREFACE: Nanoscale science and technology

    Science.gov (United States)

    Bellucci, Stefano

    2008-11-01

    optical throughput of the probe and scanning position accuracy. Prato showed a method to characterize force sensitivity of piezoelectric transducers and we've implemented a test system for off line characterization of probes. Recent improvements in aperture SNOM were also illustrated in this talk by some biological applications. H Stadler showed the development of a new instrumentation, combining optical and scanning probe microscopy (SPM) multimodal characterization, specifically designed for SPM based life science research and full integration with optical microscopy. The prerequisites and design of such equipment besides newer application examples in this area were discussed. Stadler also overviewed work on improving quantitative mechanical characterization on the nanoscale. This included hardware like SPM control electronics and probe development as theoretical aspects and software for data evaluation. Comparative field emission studies of as-produced CNTs vis á vis commercially obtained SWCNT were presented by A Tiberia. Carbon nanotubes synthesized at INFN-Laboratori Nazionali di Frascati in the nanotechnology group of S Bellucci by DC thermal plasma process were analyzed by electron microscope and studied for their field emission properties. These carbon nanotubes were deposited on a tungsten wire, which acted as the cathode. Care was taken to ensure complete covering of the wire. The emission studies were performed in a stainless steel chamber under a dynamic vacuum in the range of 10-8 Torr. The field emitted current was detected using a phosphorous coated ITO (indium tin oxide) glass plate. The phosphorous coat also helped in imaging the tips of the nanotubes. This was crucial in accurately estimating the emitting area and thus the field enhancement factor. The I-V curves for the field emission were recorded for various distances between the electrodes. Similar studies were performed for commercially obtained single walled carbon nanotubes and the results

  6. Elementary Science and Reading Activities for Teacher Educators.

    Science.gov (United States)

    Rezba, Richard J.

    The author suggests ways reading can be integrated with science and describes the reading activities in an elementary science methods course. The activities include: (1) selecting a science tradebook for children to review and for the teacher to analyze vocabulary; (2) helping children review science tradebooks; and (3) encouraging independent…

  7. Nanoscale heterogeneity at the aqueous electrolyte-electrode interface

    Science.gov (United States)

    Limmer, David T.; Willard, Adam P.

    2015-01-01

    Using molecular dynamics simulations, we reveal emergent properties of hydrated electrode interfaces that while molecular in origin are integral to the behavior of the system across long times scales and large length scales. Specifically, we describe the impact of a disordered and slowly evolving adsorbed layer of water on the molecular structure and dynamics of the electrolyte solution adjacent to it. Generically, we find that densities and mobilities of both water and dissolved ions are spatially heterogeneous in the plane parallel to the electrode over nanosecond timescales. These and other recent results are analyzed in the context of available experimental literature from surface science and electrochemistry. We speculate on the implications of this emerging microscopic picture on the catalytic proficiency of hydrated electrodes, offering a new direction for study in heterogeneous catalysis at the nanoscale.

  8. Passive film growth on carbon steel and its nanoscale features at various passivating potentials

    International Nuclear Information System (INIS)

    Li, Yuan; Cheng, Y. Frank

    2017-01-01

    Highlights: • Imaged the topography of passivated steel at various film-forming potentials. • Characterized the nanoscale features of passive films. • Determined the composition of passive films formed at various potentials. - Abstract: In this work, the passivation and topographic sub-structure of passive films on a carbon steel in a carbonate/bicarbonate solution was characterized by electrochemical measurements, atomic force microscopy and X-ray photoelectron spectroscopy. When passivating at a potential near the active-passive transition, the film contains the mixture of Fe_3O_4, Fe_2O_3 and FeOOH, with numerous nanoscale features. As the film-forming potential shifts positively, the passive film becomes more compact and the nanoscale features disappear. When the film is formed at a passive potential where the oxygen evolution is enabled, the content of FeOOH in the film increases, resulting in an amorphous topography and reduced corrosion resistance.

  9. Nanoscale heterostructures with molecular-scale single-crystal metal wires.

    Science.gov (United States)

    Kundu, Paromita; Halder, Aditi; Viswanath, B; Kundu, Dipan; Ramanath, Ganpati; Ravishankar, N

    2010-01-13

    Creating nanoscale heterostructures with molecular-scale (synthesis of nanoscale heterostructures with single-crystal molecular-scale Au nanowires attached to different nanostructure substrates. Our method involves the formation of Au nanoparticle seeds by the reduction of rocksalt AuCl nanocubes heterogeneously nucleated on the substrates and subsequent nanowire growth by oriented attachment of Au nanoparticles from the solution phase. Nanoscale heterostructures fabricated by such site-specific nucleation and growth are attractive for many applications including nanoelectronic device wiring, catalysis, and sensing.

  10. Bulletin of Materials Science | News

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 33; Issue 2 ... films deposited by rf magnetron sputtering using a high quality ceramic target ... Critical shear stress produced by interaction of edge dislocation with nanoscale inhomogeneity ... production cost limiting zircon usage as a raw material at an industrial scale.

  11. Nanoscale Mechanical Stimulation of Human Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    H Nikukar

    2014-05-01

    We observed significant responses after 1 and 2-week stimulations in cell number, cell shapes and phenotypical markers. Microarray was performed for all groups. Cell count showed normal cell growth with stimulation. However, cell surface area, cell perimeter, and arboration after 1-week stimulation showed significant increases. Immunofluorescent studies have showed significant increase in osteocalcin production after stimulation. Conclusions: Nanoscale mechanical vibration showed significant changes in human mesenchymal stem cell behaviours. Cell morphology changed to become more polygonal and increased expression of the osteoblast markers were noted. These findings with gene regulation changes suggesting nanoscale mechanostimulation has stimulated osteoblastogenesis.  Keywords:  Mesenchymal, Nanoscale, Stem Cells.

  12. Converging Technologies for Improving Human Performance: Integrating From the Nanoscale

    International Nuclear Information System (INIS)

    Roco, M.C.; Bainbridge, W.S.

    2002-01-01

    In the early decades of the twenty-first century, concentrated efforts can unify science based on the unity of nature, thereby advancing the combination of nanotechnology, biotechnology, information technology, and new humane technologies based in cognitive science. Converging technologies integrated from the nanoscale could determine a tremendous improvement in human abilities and societal outcomes. This is a broad, cross cutting, emerging, and timely opportunity of interest to individuals, society, and humanity in the long term.About eighty scientific leaders, industry experts, and policy makers across a range of fields have contributed to develop a vision for the potential to improve human physical, mental, and social capabilities through the convergence of the four technologies. Six major themes have emerged: (a) The broad potential of converging technologies; (b) Expanding human cognition and communication; (c) Improving human health and physical capabilities; (d) Enhancing group and societal outcomes; (e) National security, and (f) Unifying science and education. This article summarizes the observations, conclusions, and recommendations made in the report (Roco and Bainbridge, eds., 2002. Converging Technologies for Improving Human Performance, NSF-DOC Report, June 2002, Arlington VA, USA)

  13. Resonance – Journal of Science Education | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. Ashwin B R Kumar. Articles written in Resonance – Journal of Science Education. Volume 23 Issue 1 January 2018 pp 23-40 General Article. Chemistry at the Nanoscale: When Every Reaction is a Discrete Event · Ashwin B R Kumar Ram Ramaswamy.

  14. Modeling, methodologies and tools for molecular and nano-scale communications modeling, methodologies and tools

    CERN Document Server

    Nakano, Tadashi; Moore, Michael

    2017-01-01

    (Preliminary) The book presents the state of art in the emerging field of molecular and nanoscale communication. It gives special attention to fundamental models, and advanced methodologies and tools used in the field. It covers a wide range of applications, e.g. nanomedicine, nanorobot communication, bioremediation and environmental managements. It addresses advanced graduate students, academics and professionals working at the forefront in their fields and at the interfaces between different areas of research, such as engineering, computer science, biology and nanotechnology.

  15. Nanoscale thermal transport. II. 2003–2012

    OpenAIRE

    Cahill, David G.; Braun, Paul V.; Chen, Gang; Clarke, David R.; Fan, Shanhui; Goodson, Kenneth E.; Keblinski, Pawel; King, William P.; Mahan, Gerald D.; Majumdar, Arun; Maris, Humphrey J.; Phillpot, Simon R.; Pop, Eric; Shi, Li

    2013-01-01

    A diverse spectrum of technology drivers such as improved thermal barriers, higher efficiency thermoelectric energy conversion, phase-change memory, heat-assisted magnetic recording, thermal management of nanoscale electronics, and nanoparticles for thermal medical therapies are motivating studies of the applied physics of thermal transport at the nanoscale. This review emphasizes developments in experiment, theory, and computation in the past ten years and summarizes the present status of th...

  16. Passive film growth on carbon steel and its nanoscale features at various passivating potentials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuan; Cheng, Y. Frank, E-mail: fcheng@ucalgary.ca

    2017-02-28

    Highlights: • Imaged the topography of passivated steel at various film-forming potentials. • Characterized the nanoscale features of passive films. • Determined the composition of passive films formed at various potentials. - Abstract: In this work, the passivation and topographic sub-structure of passive films on a carbon steel in a carbonate/bicarbonate solution was characterized by electrochemical measurements, atomic force microscopy and X-ray photoelectron spectroscopy. When passivating at a potential near the active-passive transition, the film contains the mixture of Fe{sub 3}O{sub 4}, Fe{sub 2}O{sub 3} and FeOOH, with numerous nanoscale features. As the film-forming potential shifts positively, the passive film becomes more compact and the nanoscale features disappear. When the film is formed at a passive potential where the oxygen evolution is enabled, the content of FeOOH in the film increases, resulting in an amorphous topography and reduced corrosion resistance.

  17. Dopant atoms as quantum components in silicon nanoscale devices

    Science.gov (United States)

    Zhao, Xiaosong; Han, Weihua; Wang, Hao; Ma, Liuhong; Li, Xiaoming; Zhang, Wang; Yan, Wei; Yang, Fuhua

    2018-06-01

    Recent progress in nanoscale fabrication allows many fundamental studies of the few dopant atoms in various semiconductor nanostructures. Since the size of nanoscale devices has touched the limit of the nature, a single dopant atom may dominate the performance of the device. Besides, the quantum computing considered as a future choice beyond Moore's law also utilizes dopant atoms as functional units. Therefore, the dopant atoms will play a significant role in the future novel nanoscale devices. This review focuses on the study of few dopant atoms as quantum components in silicon nanoscale device. The control of the number of dopant atoms and unique quantum transport characteristics induced by dopant atoms are presented. It can be predicted that the development of nanoelectronics based on dopant atoms will pave the way for new possibilities in quantum electronics. Project supported by National Key R&D Program of China (No. 2016YFA0200503).

  18. Nanotechnology research: applications in nutritional sciences.

    Science.gov (United States)

    Srinivas, Pothur R; Philbert, Martin; Vu, Tania Q; Huang, Qingrong; Kokini, Josef L; Saltos, Etta; Saos, Etta; Chen, Hongda; Peterson, Charles M; Friedl, Karl E; McDade-Ngutter, Crystal; Hubbard, Van; Starke-Reed, Pamela; Miller, Nancy; Betz, Joseph M; Dwyer, Johanna; Milner, John; Ross, Sharon A

    2010-01-01

    The tantalizing potential of nanotechnology is to fabricate and combine nanoscale approaches and building blocks to make useful tools and, ultimately, interventions for medical science, including nutritional science, at the scale of approximately 1-100 nm. In the past few years, tools and techniques that facilitate studies and interventions in the nanoscale range have become widely available and have drawn widespread attention. Recently, investigators in the food and nutrition sciences have been applying the tools of nanotechnology in their research. The Experimental Biology 2009 symposium entitled "Nanotechnology Research: Applications in Nutritional Sciences" was organized to highlight emerging applications of nanotechnology to the food and nutrition sciences, as well as to suggest ways for further integration of these emerging technologies into nutrition research. Speakers focused on topics that included the problems and possibilities of introducing nanoparticles in clinical or nutrition settings, nanotechnology applications for increasing bioavailability of bioactive food components in new food products, nanotechnology opportunities in food science, as well as emerging safety and regulatory issues in this area, and the basic research applications such as the use of quantum dots to visualize cellular processes and protein-protein interactions. The session highlighted several emerging areas of potential utility in nutrition research. Nutrition scientists are encouraged to leverage ongoing efforts in nanomedicine through collaborations. These efforts could facilitate exploration of previously inaccessible cellular compartments and intracellular pathways and thus uncover strategies for new prevention and therapeutic modalities.

  19. Nanomaterial Case Studies: Nanoscale Titanium Dioxide in ...

    Science.gov (United States)

    EPA announced the availability of the final report, Nanomaterial Case Studies: Nanoscale Titanium Dioxide in Water Treatment and in Topical Sunscreen. This report is a starting point to determine what is known and what needs to be known about selected nanomaterials as part of a process to identify and prioritize research to inform future assessments of the potential ecological and health implications of these materials. Two specific applications of nanoscale titanium dioxide (nano-TiO2) are considered: (1) as an agent for removing arsenic from drinking water; and (2) as an active ingredient in topical sunscreen. These case studies are organized around a comprehensive environmental assessment (CEA) framework that combines a product life cycle perspective with the risk assessment paradigm. They are intended to help identify what may need to be known in order to conduct a comprehensive environmental assessment of the potential risks related to nano-TiO2. These “case studies” do not represent completed or even preliminary assessments, nor are they intended to serve as a basis for risk management decisions in the near term on these specific uses of nano TiO2. Rather, the intent is to use this document in developing the scientific and technical information needed for future assessment efforts.

  20. Fast heat flux modulation at the nanoscale

    OpenAIRE

    van Zwol, P. J.; Joulain, K.; Abdallah, P. Ben; Greffet, J. J.; Chevrier, J.

    2011-01-01

    We introduce a new concept for electrically controlled heat flux modulation. A flux contrast larger than 10 dB is expected with switching time on the order of tens of nanoseconds. Heat flux modulation is based on the interplay between radiative heat transfer at the nanoscale and phase change materials. Such large contrasts are not obtainable in solids, or in far field. As such this opens up new horizons for temperature modulation and actuation at the nanoscale.

  1. Nanoscale phase-change materials and devices

    International Nuclear Information System (INIS)

    Zheng, Qinghui; Wang, Yuxi; Zhu, Jia

    2017-01-01

    Phase-change materials (PCMs) that can reversibly transit between crystalline and amorphous phases have been widely used for data-storage and other functional devices. As PCMs scale down to nanoscale, the properties and transition procedures can vary, bringing both challenges and opportunities in scalability. This article describes the physical structures, properties and applications of nanoscale phase-change materials and devices. The limitations and performance of scaling properties in phase-change materials and the recent progress and challenges in phase-change devices are presented. At the end, some emerging applications related to phase-change materials are also introduced. (topical review)

  2. Nanoscale phase-change materials and devices

    Science.gov (United States)

    Zheng, Qinghui; Wang, Yuxi; Zhu, Jia

    2017-06-01

    Phase-change materials (PCMs) that can reversibly transit between crystalline and amorphous phases have been widely used for data-storage and other functional devices. As PCMs scale down to nanoscale, the properties and transition procedures can vary, bringing both challenges and opportunities in scalability. This article describes the physical structures, properties and applications of nanoscale phase-change materials and devices. The limitations and performance of scaling properties in phase-change materials and the recent progress and challenges in phase-change devices are presented. At the end, some emerging applications related to phase-change materials are also introduced.

  3. 78 FR 56952 - Notice of Meetings: Public Meetings of the National Science and Technology Council; Committee on...

    Science.gov (United States)

    2013-09-16

    ... Science and Technology Council; Committee on Technology; Nanoscale Science, Engineering, and Technology Subcommittee; National Nanotechnology Coordination Office AGENCY: Office of Science and Technology Policy. ACTION: Notice of public meetings. SUMMARY: The National Nanotechnology Coordination Office (NNCO), on...

  4. Mapping nanoscale effects of localized noise-source activities on photoconductive charge transports in polymer-blend films

    Science.gov (United States)

    Shekhar, Shashank; Cho, Duckhyung; Cho, Dong-Guk; Yang, Myungjae; Hong, Seunghun

    2018-05-01

    We develolped a method to directly image the nanoscale effects of localized noise-source activities on photoconducting charge transports in domain structures of phase-separated polymer-blend films of Poly(9,9-di-n-octylfluorenyl-2,7-diyl) and Poly(9,9-di-n-octylfluorene-alt-benzothiadiazole). For the imaging, current and noise maps of the polymer-blend were recorded using a conducting nanoprobe in contact with the surface, enabling the conductivity (σ) and noise-source density (N T) mappings under an external stimulus. The blend-films exhibited the phase-separation between the constituent polymers at domains level. Within a domain, high σ (low N T) and low σ (high N T) regions were observed, which could be associated with the ordered and disordered regions of a domain. In the N T maps, we observed that noise-sources strongly affected the conduction mechanism, resulting in a scaling behavior of σ ∝ {{N}{{T}}}-0.5 in both ordered and disordered regions. When a blend film was under an influence of an external stimulus such as a high bias or an illumination, an increase in the σ was observed, but that also resulted in increases in the N T as a trade-off. Interestingly, the Δσ versus ΔN T plot exhibited an unusual scaling behavior of Δσ ∝ {{Δ }}{{N}{{T}}}0.5, which is attributed to the de-trapping of carriers from deep traps by the external stimuli. In addition, we found that an external stimulus increased the conductivity at the interfaces without significantly increasing their N T, which can be the origin of the superior performances of polymer-blend based devices. These results provide valuable insight about the effects of noise-sources on nanoscale optoelectronic properties in polymer-blend films, which can be an important guideline for improving devices based on polymer-blend.

  5. Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons

    Science.gov (United States)

    Zecevic, Jovana; Vanbutsele, Gina; de Jong, Krijn P.; Martens, Johan A.

    2015-12-01

    The ability to control nanoscale features precisely is increasingly being exploited to develop and improve monofunctional catalysts. Striking effects might also be expected in the case of bifunctional catalysts, which are important in the hydrocracking of fossil and renewable hydrocarbon sources to provide high-quality diesel fuel. Such bifunctional hydrocracking catalysts contain metal sites and acid sites, and for more than 50 years the so-called intimacy criterion has dictated the maximum distance between the two types of site, beyond which catalytic activity decreases. A lack of synthesis and material-characterization methods with nanometre precision has long prevented in-depth exploration of the intimacy criterion, which has often been interpreted simply as ‘the closer the better’ for positioning metal and acid sites. Here we show for a bifunctional catalyst—comprising an intimate mixture of zeolite Y and alumina binder, and with platinum metal controllably deposited on either the zeolite or the binder—that closest proximity between metal and zeolite acid sites can be detrimental. Specifically, the selectivity when cracking large hydrocarbon feedstock molecules for high-quality diesel production is optimized with the catalyst that contains platinum on the binder, that is, with a nanoscale rather than closest intimacy of the metal and acid sites. Thus, cracking of the large and complex hydrocarbon molecules that are typically derived from alternative sources, such as gas-to-liquid technology, vegetable oil or algal oil, should benefit especially from bifunctional catalysts that avoid locating platinum on the zeolite (the traditionally assumed optimal location). More generally, we anticipate that the ability demonstrated here to spatially organize different active sites at the nanoscale will benefit the further development and optimization of the emerging generation of multifunctional catalysts.

  6. Trends in nanoscale mechanics mechanics of carbon nanotubes, graphene, nanocomposites and molecular dynamics

    CERN Document Server

    2014-01-01

    This book contains a collection of the state-of-the-art reviews written by the leading researchers in the areas of nanoscale mechanics, molecular dynamics, nanoscale modeling of nanocomposites and mechanics of carbon nanotubes. No other book has reviews of the recent discoveries such as a nanoscale analog of the Pauli’s principle, i.e., effect of the spatial exclusion of electrons or the SEE effect, a new Registry Matrix Analysis for the nanoscale interfacial sliding and new data on the effective viscosity of interfacial electrons in nanoscale stiction at the interfaces. This volume is also an exceptional resource on the well tested nanoscale modeling of carbon nanotubes and nanocomposites, new nanoscale effects, unique evaluations of the effective thickness of carbon nanotubes under different loads, new data on which size of carbon nanotubes is safer and many other topics. Extensive bibliography concerning all these topics is included along with the lucid short reviews. Numerous illustrations are provided...

  7. Democratization of Nanoscale Imaging and Sensing Tools Using Photonics.

    Science.gov (United States)

    McLeod, Euan; Wei, Qingshan; Ozcan, Aydogan

    2015-07-07

    Providing means for researchers and citizen scientists in the developing world to perform advanced measurements with nanoscale precision can help to accelerate the rate of discovery and invention as well as improve higher education and the training of the next generation of scientists and engineers worldwide. Here, we review some of the recent progress toward making optical nanoscale measurement tools more cost-effective, field-portable, and accessible to a significantly larger group of researchers and educators. We divide our review into two main sections: label-based nanoscale imaging and sensing tools, which primarily involve fluorescent approaches, and label-free nanoscale measurement tools, which include light scattering sensors, interferometric methods, photonic crystal sensors, and plasmonic sensors. For each of these areas, we have primarily focused on approaches that have either demonstrated operation outside of a traditional laboratory setting, including for example integration with mobile phones, or exhibited the potential for such operation in the near future.

  8. Nanoscale-Agglomerate-Mediated Heterogeneous Nucleation.

    Science.gov (United States)

    Cha, Hyeongyun; Wu, Alex; Kim, Moon-Kyung; Saigusa, Kosuke; Liu, Aihua; Miljkovic, Nenad

    2017-12-13

    Water vapor condensation on hydrophobic surfaces has received much attention due to its ability to rapidly shed water droplets and enhance heat transfer, anti-icing, water harvesting, energy harvesting, and self-cleaning performance. However, the mechanism of heterogeneous nucleation on hydrophobic surfaces remains poorly understood and is attributed to defects in the hydrophobic coating exposing the high surface energy substrate. Here, we observe the formation of high surface energy nanoscale agglomerates on hydrophobic coatings after condensation/evaporation cycles in ambient conditions. To investigate the deposition dynamics, we studied the nanoscale agglomerates as a function of condensation/evaporation cycles via optical and field emission scanning electron microscopy (FESEM), microgoniometric contact angle measurements, nucleation statistics, and energy dispersive X-ray spectroscopy (EDS). The FESEM and EDS results indicated that the nanoscale agglomerates stem from absorption of sulfuric acid based aerosol particles inside the droplet and adsorption of volatile organic compounds such as methanethiol (CH 3 SH), dimethyl disulfide (CH 3 SSCH), and dimethyl trisulfide (CH 3 SSSCH 3 ) on the liquid-vapor interface during water vapor condensation, which act as preferential sites for heterogeneous nucleation after evaporation. The insights gained from this study elucidate fundamental aspects governing the behavior of both short- and long-term heterogeneous nucleation on hydrophobic surfaces, suggest previously unexplored microfabrication and air purification techniques, and present insights into the challenges facing the development of durable dropwise condensing surfaces.

  9. Progress in nanoscale dry processes for fabrication of high-aspect-ratio features: How can we control critical dimension uniformity at the bottom?

    Science.gov (United States)

    Ishikawa, Kenji; Karahashi, Kazuhiro; Ishijima, Tatsuo; Cho, Sung Il; Elliott, Simon; Hausmann, Dennis; Mocuta, Dan; Wilson, Aaron; Kinoshita, Keizo

    2018-06-01

    In this review, we discuss the progress of emerging dry processes for nanoscale fabrication of high-aspect-ratio features, including emerging design technology for manufacturability. Experts in the fields of plasma processing have contributed to addressing the increasingly challenging demands of nanoscale deposition and etching technologies for high-aspect-ratio features. The discussion of our atomic-scale understanding of physicochemical reactions involving ion bombardment and neutral transport presents the major challenges shared across the plasma science and technology community. Focus is placed on advances in fabrication technology that control surface reactions on three-dimensional features, as well as state-of-the-art techniques used in semiconductor manufacturing with a brief summary of future challenges.

  10. Nanoscale shape-memory alloys for ultrahigh mechanical damping.

    Science.gov (United States)

    San Juan, Jose; Nó, Maria L; Schuh, Christopher A

    2009-07-01

    Shape memory alloys undergo reversible transformations between two distinct phases in response to changes in temperature or applied stress. The creation and motion of the internal interfaces between these phases during such transformations dissipates energy, making these alloys effective mechanical damping materials. Although it has been shown that reversible phase transformations can occur in nanoscale volumes, it is not known whether these transformations have a sample size dependence. Here, we demonstrate that the two phases responsible for shape memory in Cu-Al-Ni alloys are more stable in nanoscale pillars than they are in the bulk. As a result, the pillars show a damping figure of merit that is substantially higher than any previously reported value for a bulk material, making them attractive for damping applications in nanoscale and microscale devices.

  11. Atomic nanoscale technology in the nuclear industry

    CERN Document Server

    Woo, Taeho

    2011-01-01

    Developments at the nanoscale are leading to new possibilities and challenges for nuclear applications in areas ranging from medicine to international commerce to atomic power production/waste treatment. Progress in nanotech is helping the nuclear industry slash the cost of energy production. It also continues to improve application reliability and safety measures, which remain a critical concern, especially since the reactor disasters in Japan. Exploring the new wide-ranging landscape of nuclear function, Atomic Nanoscale Technology in the Nuclear Industry details the breakthroughs in nanosca

  12. Heat transfer across the interface between nanoscale solids and gas.

    Science.gov (United States)

    Cheng, Chun; Fan, Wen; Cao, Jinbo; Ryu, Sang-Gil; Ji, Jie; Grigoropoulos, Costas P; Wu, Junqiao

    2011-12-27

    When solid materials and devices scale down in size, heat transfer from the active region to the gas environment becomes increasingly significant. We show that the heat transfer coefficient across the solid-gas interface behaves very differently when the size of the solid is reduced to the nanoscale, such as that of a single nanowire. Unlike for macroscopic solids, the coefficient is strongly pressure dependent above ∼10 Torr, and at lower pressures it is much higher than predictions of the kinetic gas theory. The heat transfer coefficient was measured between a single, free-standing VO(2) nanowire and surrounding air using laser thermography, where the temperature distribution along the VO(2) nanowire was determined by imaging its domain structure of metal-insulator phase transition. The one-dimensional domain structure along the nanowire results from the balance between heat generation by the focused laser and heat dissipation to the substrate as well as to the surrounding gas, and thus serves as a nanoscale power-meter and thermometer. We quantified the heat loss rate across the nanowire-air interface, and found that it dominates over all other heat dissipation channels for small-diameter nanowires near ambient pressure. As the heat transfer across the solid-gas interface is nearly independent of the chemical identity of the solid, the results reveal a general scaling relationship for gaseous heat dissipation from nanostructures of all solid materials, which is applicable to nanoscale electronic and thermal devices exposed to gaseous environments.

  13. Investigation of Short Channel Effect on Vertical Structures in Nanoscale MOSFET

    Directory of Open Access Journals (Sweden)

    Munawar A. Riyadi

    2009-12-01

    Full Text Available The recent development of MOSFET demands innovative approach to maintain the scaling into nanoscale dimension. This paper focuses on the physical nature of vertical MOSFET in nanoscale regime. Vertical structure is one of the promising devices in further scaling, with relaxed-lithography feature in the manufacture. The comparison of vertical and lateral MOSFET performance for nanoscale channel length (Lch is demonstrated with the help of numerical tools. The evaluation of short channel effect (SCE parameters, i.e. threshold voltage roll-off, subthreshold swing (SS, drain induced barrier lowering (DIBL and leakage current shows the considerable advantages as well as its thread-off in implementing the structure, in particular for nanoscale regime.

  14. Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto

    Science.gov (United States)

    Bond, Tiziana C; Miles, Robin; Davidson, James; Liu, Gang Logan

    2015-11-03

    Methods for fabricating nanoscale array structures suitable for surface enhanced Raman scattering, structures thus obtained, and methods to characterize the nanoscale array structures suitable for surface enhanced Raman scattering. Nanoscale array structures may comprise nanotrees, nanorecesses and tapered nanopillars.

  15. Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto

    Science.gov (United States)

    Bond, Tiziana C.; Miles, Robin; Davidson, James C.; Liu, Gang Logan

    2014-07-22

    Methods for fabricating nanoscale array structures suitable for surface enhanced Raman scattering, structures thus obtained, and methods to characterize the nanoscale array structures suitable for surface enhanced Raman scattering. Nanoscale array structures may comprise nanotrees, nanorecesses and tapered nanopillars.

  16. Nanoscale array structures suitable for surface enhanced raman scattering and methods related thereto

    Science.gov (United States)

    Bond, Tiziana C.; Miles, Robin; Davidson, James C.; Liu, Gang Logan

    2015-07-14

    Methods for fabricating nanoscale array structures suitable for surface enhanced Raman scattering, structures thus obtained, and methods to characterize the nanoscale array structures suitable for surface enhanced Raman scattering. Nanoscale array structures may comprise nanotrees, nanorecesses and tapered nanopillars.

  17. Active material, optical mode and cavity impact on nanoscale electro-optic modulation performance

    Science.gov (United States)

    Amin, Rubab; Suer, Can; Ma, Zhizhen; Sarpkaya, Ibrahim; Khurgin, Jacob B.; Agarwal, Ritesh; Sorger, Volker J.

    2017-10-01

    Electro-optic modulation is a key function in optical data communication and possible future optical compute engines. The performance of modulators intricately depends on the interaction between the actively modulated material and the propagating waveguide mode. While a variety of high-performance modulators have been demonstrated, no comprehensive picture of what factors are most responsible for high performance has emerged so far. Here we report the first systematic and comprehensive analytical and computational investigation for high-performance compact on-chip electro-optic modulators by considering emerging active materials, model considerations and cavity feedback at the nanoscale. We discover that the delicate interplay between the material characteristics and the optical mode properties plays a key role in defining the modulator performance. Based on physical tradeoffs between index modulation, loss, optical confinement factors and slow-light effects, we find that there exist combinations of bias, material and optical mode that yield efficient phase or amplitude modulation with acceptable insertion loss. Furthermore, we show how material properties in the epsilon near zero regime enable reduction of length by as much as by 15 times. Lastly, we introduce and apply a cavity-based electro-optic modulator figure of merit, Δλ/Δα, relating obtainable resonance tuning via phase shifting relative to the incurred losses due to the fundamental Kramers-Kronig relations suggesting optimized device operating regions with optimized modulation-to-loss tradeoffs. This work paves the way for a holistic design rule of electro-optic modulators for high-density on-chip integration.

  18. Nanoscale conductive pattern of the homoepitaxial AlGaN/GaN transistor.

    Science.gov (United States)

    Pérez-Tomás, A; Catalàn, G; Fontserè, A; Iglesias, V; Chen, H; Gammon, P M; Jennings, M R; Thomas, M; Fisher, C A; Sharma, Y K; Placidi, M; Chmielowska, M; Chenot, S; Porti, M; Nafría, M; Cordier, Y

    2015-03-20

    The gallium nitride (GaN)-based buffer/barrier mode of growth and morphology, the transistor electrical response (25-310 °C) and the nanoscale pattern of a homoepitaxial AlGaN/GaN high electron mobility transistor (HEMT) have been investigated at the micro and nanoscale. The low channel sheet resistance and the enhanced heat dissipation allow a highly conductive HEMT transistor (Ids > 1 A mm(-1)) to be defined (0.5 A mm(-1) at 300 °C). The vertical breakdown voltage has been determined to be ∼850 V with the vertical drain-bulk (or gate-bulk) current following the hopping mechanism, with an activation energy of 350 meV. The conductive atomic force microscopy nanoscale current pattern does not unequivocally follow the molecular beam epitaxy AlGaN/GaN morphology but it suggests that the FS-GaN substrate presents a series of preferential conductive spots (conductive patches). Both the estimated patches density and the apparent random distribution appear to correlate with the edge-pit dislocations observed via cathodoluminescence. The sub-surface edge-pit dislocations originating in the FS-GaN substrate result in barrier height inhomogeneity within the HEMT Schottky gate producing a subthreshold current.

  19. Phonon Transport through Nanoscale Contact in Tip-Based Thermal Analysis of Nanomaterials.

    Science.gov (United States)

    Dulhani, Jay; Lee, Bong Jae

    2017-07-28

    Nanomaterials have been actively employed in various applications for energy and sustainability, such as biosensing, gas sensing, solar thermal energy conversion, passive radiative cooling, etc. Understanding thermal transports inside such nanomaterials is crucial for optimizing their performance for different applications. In order to probe the thermal transport inside nanomaterials or nanostructures, tip-based nanoscale thermometry has often been employed. It has been well known that phonon transport in nanometer scale is fundamentally different from that occurred in macroscale. Therefore, Fourier's law that relies on the diffusion approximation is not ideally suitable for describing the phonon transport occurred in nanostructures and/or through nanoscale contact. In the present study, the gray Boltzmann transport equation (BTE) is numerically solved using finite volume method. Based on the gray BTE, phonon transport through the constriction formed by a probe itself as well as the nanoscale contact between the probe tip and the specimen is investigated. The interaction of a probe and a specimen (i.e., treated as a substrate) is explored qualitatively by analyzing the temperature variation in the tip-substrate configuration. Besides, each contribution of a probe tip, tip-substrate interface, and a substrate to the thermal resistance are analyzed for wide ranges of the constriction ratio of the probe.

  20. Topology optimization for nano-scale heat transfer

    DEFF Research Database (Denmark)

    Evgrafov, Anton; Maute, Kurt; Yang, Ronggui

    2009-01-01

    We consider the problem of optimal design of nano-scale heat conducting systems using topology optimization techniques. At such small scales the empirical Fourier's law of heat conduction no longer captures the underlying physical phenomena because the mean-free path of the heat carriers, phonons...... in our case, becomes comparable with, or even larger than, the feature sizes of considered material distributions. A more accurate model at nano-scales is given by kinetic theory, which provides a compromise between the inaccurate Fourier's law and precise, but too computationally expensive, atomistic...

  1. Direct Probing of Polarization Charge at Nanoscale Level

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Owoong [Sungkyunkwan Univ., Suwon (Republic of Korea). School of Advanced Materials and Engineering; Seol, Daehee [Sungkyunkwan Univ., Suwon (Republic of Korea). School of Advanced Materials and Engineering; Lee, Dongkyu [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Han, Hee [Korea Research Inst. of Standards and Science (KRISS), Daejeon (South Korea); Lindfors-Vrejoiu, Ionela [Univ. of Cologne (Germany). Physics Inst.; Lee, Woo [Korea Research Inst. of Standards and Science (KRISS), Daejeon (South Korea); Jesse, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences; Lee, Ho Nyung [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Kalinin, Sergei V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences; Alexe, Marin [Univ. of Warwick, Coventry (United Kingdom). Dept. of Physics; Kim, Yunseok [Sungkyunkwan Univ., Suwon (Republic of Korea). School of Advanced Materials and Engineering

    2017-11-14

    Ferroelectric materials possess spontaneous polarization that can be used for multiple applications. Owing to a long-term development of reducing the sizes of devices, the preparation of ferroelectric materials and devices is entering the nanometer-scale regime. In order to evaluate the ferroelectricity, there is a need to investigate the polarization charge at the nanoscale. Nonetheless, it is generally accepted that the detection of polarization charges using a conventional conductive atomic force microscopy (CAFM) without a top electrode is not feasible because the nanometer-scale radius of an atomic force microscopy (AFM) tip yields a very low signal-to-noise ratio. But, the detection is unrelated to the radius of an AFM tip and, in fact, a matter of the switched area. In this work, the direct probing of the polarization charge at the nanoscale is demonstrated using the positive-up-negative-down method based on the conventional CAFM approach without additional corrections or circuits to reduce the parasitic capacitance. The polarization charge densities of 73.7 and 119.0 µC cm-2 are successfully probed in ferroelectric nanocapacitors and thin films, respectively. The results we obtained show the feasibility of the evaluation of polarization charge at the nanoscale and provide a new guideline for evaluating the ferroelectricity at the nanoscale.

  2. Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray (Final Report)

    Science.gov (United States)

    EPA announced the release of the final report, Nanomaterial Case Study: Nanoscale Silver in Disinfectant Spray. This report represents a case study of engineered nanoscale silver (nano-Ag), focusing on the specific example of nano-Ag as possibly used in disinfectant spr...

  3. Nanoscale hotspots due to nonequilibrium thermal transport

    International Nuclear Information System (INIS)

    Sinha, Sanjiv; Goodson, Kenneth E.

    2004-01-01

    Recent experimental and modeling efforts have been directed towards the issue of temperature localization and hotspot formation in the vicinity of nanoscale heat generating devices. The nonequilibrium transport conditions which develop around these nanoscale devices results in elevated temperatures near the heat source which can not be predicted by continuum diffusion theory. Efforts to determine the severity of this temperature localization phenomena in silicon devices near and above room temperature are of technological importance to the development of microelectronics and other nanotechnologies. In this work, we have developed a new modeling tool in order to explore the magnitude of the additional thermal resistance which forms around nanoscale hotspots from temperatures of 100-1000K. The models are based on a two fluid approximation in which thermal energy is transferred between ''stationary'' optical phonons and fast propagating acoustic phonon modes. The results of the model have shown excellent agreement with experimental results of localized hotspots in silicon at lower temperatures. The model predicts that the effect of added thermal resistance due to the nonequilibrium phonon distribution is greatest at lower temperatures, but is maintained out to temperatures of 1000K. The resistance predicted by the numerical code can be easily integrated with continuum models in order to predict the temperature distribution around nanoscale heat sources with improved accuracy. Additional research efforts also focused on the measurements of the thermal resistance of silicon thin films at higher temperatures, with a focus on polycrystalline silicon. This work was intended to provide much needed experimental data on the thermal transport properties for micro and nanoscale devices built with this material. Initial experiments have shown that the exposure of polycrystalline silicon to high temperatures may induce recrystallization and radically increase the thermal

  4. Science Activities in Energy: Electrical Energy.

    Science.gov (United States)

    Oak Ridge Associated Universities, TN.

    Presented is a science activities in energy package which includes 16 activities relating to electrical energy. Activities are simple, concrete experiments for fourth, fifth and sixth grades which illustrate principles and problems relating to energy. Each activity is outlined in a single card which is introduced by a question. A teacher's…

  5. 77 FR 5282 - National Science and Technology Council

    Science.gov (United States)

    2012-02-02

    ... Public Meeting. SUMMARY: The National Nanotechnology Coordination Office (NNCO), on behalf of the Nanoscale Science, Engineering, and Technology (NSET) Subcommittee of the Committee on Technology, National... Impact of Nanotechnology'' on March 27-28, 2012. This symposium will bring together key policy makers...

  6. Nanomaterials science

    Directory of Open Access Journals (Sweden)

    Heinrich Rohrer

    2010-01-01

    technology revolution. Interfaces gave them their functions, and shaping them into ever-smaller functional components made them indispensably omnipresent as transistors—produced in billions per person and per year—and they are no doubt the rulers of today's technical world.The semiconductor and transistor serve as an inspiring example of functionalizing materials. The developments of microelectronics profited very much from scalability, that is, the properties and functions do not change significantly with size. Therefore, every step toward smaller dimensions was a technical and commercial challenge with risks well under control. The transition to the nanoscale, however, is discontinuous. Examples of this transition are the local probe methods that exploit the mechanically controlled proximity to the object under consideration and that have become indispensable as microscopes and as measuring and modifying tools, the size of molecular components that are much smaller than the smallest possibly achievable transistor, the properties and functions of materials below a critical size as mentioned above, the continuum properties versus discrete ones, and novel concepts inspired by living nature. Those novel concepts include growing circuits first and building the active components at the nodes afterwards and measuring weak by weak, small by small, and many by many. It is these discontinuous steps that make the nanoscale different, not just smaller. They pose exciting challenges, open great opportunities and nearly unlimited possibilities, but they also carry serious technical, commercial, environmental, and health risks.The nanoscale is also a great opportunity for materials science in general. Materials science is interdisciplinary per se. A materials scientist should have a reasonable understanding of physics, chemistry, engineering, and more recently, also biology. Certainly one can always team up with representatives from other disciplines and forge collaborations. However

  7. Coherence and Divergence of Megatrends in Science and Engineering

    Science.gov (United States)

    Roco, M. C.

    2002-04-01

    Scientific discoveries and technological innovations are at the core of human endeavor, and it is estimated that their role will only increase in time. Such advancements evolve in coherence, with areas of confluence and temporary divergences, which bring synergism and that stimulate further developments following in average an exponential growth. Six increasingly interconnected megatrends are perceived as dominating the scene for the next decades: (a) information and computing, (b) nanoscale science and engineering (S&E), (c) biology and bio-environmental approaches, (d) medical sciences and enhancing human physical capabilities, (e) cognitive sciences and enhancing intellectual abilities, and (f) collective behavior and system approach. This paper presents a perspective on the process of identification, planning and program implementation of S&E megatrends, with illustration for the US research initiative on nanoscale science, engineering, and technology. The interplay between coherence and divergence, leading to unifying science and converging technologies, does not develop only among simultaneous scientific trends but also along time and across geopolitical boundaries. There is no single way of development of S&E, and here is the role of taking visionary measures. Societal implication scientists need to be involved from the conceptual phase of a program responding to a S&E megatrend.

  8. Coherence and Divergence of Megatrends in Science and Engineering

    International Nuclear Information System (INIS)

    Roco, M.C.

    2002-01-01

    Scientific discoveries and technological innovations are at the core of human endeavor, and it is estimated that their role will only increase in time. Such advancements evolve in coherence, with areas of confluence and temporary divergences, which bring synergism and that stimulate further developments following in average an exponential growth. Six increasingly interconnected megatrends are perceived as dominating the scene for the next decades: (a) information and computing, (b) nanoscale science and engineering (S and E), (c) biology and bio-environmental approaches, (d) medical sciences and enhancing human physical capabilities, (e) cognitive sciences and enhancing intellectual abilities, and (f) collective behavior and system approach.This paper presents a perspective on the process of identification, planning and program implementation of S and E megatrends, with illustration for the US research initiative on nanoscale science, engineering, and technology. The interplay between coherence and divergence, leading to unifying science and converging technologies, does not develop only among simultaneous scientific trends but also along time and across geopolitical boundaries. There is no single way of development of S and E, and here is the role of taking visionary measures. Societal implication scientists need to be involved from the conceptual phase of a program responding to a S and E megatrend

  9. Applying Nanotechnology to Human Health: Revolution in Biomedical Sciences

    Directory of Open Access Journals (Sweden)

    Siddhartha Shrivastava

    2009-01-01

    Full Text Available Recent research on biosystems at the nanoscale has created one of the most dynamic science and technology domains at the confluence of physical sciences, molecular engineering, biology, biotechnology, and medicine. This domain includes better understanding of living and thinking systems, revolutionary biotechnology processes, synthesis of new drugs and their targeted delivery, regenerative medicine, neuromorphic engineering, and developing a sustainable environment. Nanobiosystems research is a priority in many countries and its relevance within nanotechnology is expected to increase in the future. The realisation that the nanoscale has certain properties needed to solve important medical challenges and cater to unmet medical needs is driving nanomedical research. The present review explores the significance of nanoscience and latest nanotechnologies for human health. Addressing the associated opportunities, the review also suggests how to manage far-reaching developments in these areas.

  10. Nanoscale capacitance: A quantum tight-binding model

    Science.gov (United States)

    Zhai, Feng; Wu, Jian; Li, Yang; Lu, Jun-Qiang

    2017-01-01

    Landauer-Buttiker formalism with the assumption of semi-infinite electrodes as reservoirs has been the standard approach in modeling steady electron transport through nanoscale devices. However, modeling dynamic electron transport properties, especially nanoscale capacitance, is a challenging problem because of dynamic contributions from electrodes, which is neglectable in modeling macroscopic capacitance and mesoscopic conductance. We implement a self-consistent quantum tight-binding model to calculate capacitance of a nano-gap system consisting of an electrode capacitance C‧ and an effective capacitance Cd of the middle device. From the calculations on a nano-gap made of carbon nanotube with a buckyball therein, we show that when the electrode length increases, the electrode capacitance C‧ moves up while the effective capacitance Cd converges to a value which is much smaller than the electrode capacitance C‧. Our results reveal the importance of electrodes in modeling nanoscale ac circuits, and indicate that the concepts of semi-infinite electrodes and reservoirs well-accepted in the steady electron transport theory may be not applicable in modeling dynamic transport properties.

  11. Nanoscale form dictates mesoscale function in plasmonic DNA–nanoparticle superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Michael B.; Ku, Jessie C.; Vaccarezza, Victoria M.; Schatz, George C.; Mirkin , Chad A. (NWU)

    2016-06-15

    The nanoscale manipulation of matter allows properties to be created in a material that would be difficult or even impossible to achieve in the bulk state. Progress towards such functional nanoscale architectures requires the development of methods to precisely locate nanoscale objects in three dimensions and for the formation of rigorous structure–function relationships across multiple size regimes (beginning from the nanoscale). Here, we use DNA as a programmable ligand to show that two- and three-dimensional mesoscale superlattice crystals with precisely engineered optical properties can be assembled from the bottom up. The superlattices can transition from exhibiting the properties of the constituent plasmonic nanoparticles to adopting the photonic properties defined by the mesoscale crystal (here a rhombic dodecahedron) by controlling the spacing between the gold nanoparticle building blocks. Furthermore, we develop a generally applicable theoretical framework that illustrates how crystal habit can be a design consideration for controlling far-field extinction and light confinement in plasmonic metamaterial superlattices.

  12. Nanoscale RRAM-based synaptic electronics: toward a neuromorphic computing device.

    Science.gov (United States)

    Park, Sangsu; Noh, Jinwoo; Choo, Myung-Lae; Sheri, Ahmad Muqeem; Chang, Man; Kim, Young-Bae; Kim, Chang Jung; Jeon, Moongu; Lee, Byung-Geun; Lee, Byoung Hun; Hwang, Hyunsang

    2013-09-27

    Efforts to develop scalable learning algorithms for implementation of networks of spiking neurons in silicon have been hindered by the considerable footprints of learning circuits, which grow as the number of synapses increases. Recent developments in nanotechnologies provide an extremely compact device with low-power consumption.In particular, nanoscale resistive switching devices (resistive random-access memory (RRAM)) are regarded as a promising solution for implementation of biological synapses due to their nanoscale dimensions, capacity to store multiple bits and the low energy required to operate distinct states. In this paper, we report the fabrication, modeling and implementation of nanoscale RRAM with multi-level storage capability for an electronic synapse device. In addition, we first experimentally demonstrate the learning capabilities and predictable performance by a neuromorphic circuit composed of a nanoscale 1 kbit RRAM cross-point array of synapses and complementary metal-oxide-semiconductor neuron circuits. These developments open up possibilities for the development of ubiquitous ultra-dense, ultra-low-power cognitive computers.

  13. Nanoscale RRAM-based synaptic electronics: toward a neuromorphic computing device

    International Nuclear Information System (INIS)

    Park, Sangsu; Noh, Jinwoo; Choo, Myung-lae; Sheri, Ahmad Muqeem; Jeon, Moongu; Lee, Byung-Geun; Lee, Byoung Hun; Chang, Man; Kim, Young-Bae; Kim, Chang Jung; Hwang, Hyunsang

    2013-01-01

    Efforts to develop scalable learning algorithms for implementation of networks of spiking neurons in silicon have been hindered by the considerable footprints of learning circuits, which grow as the number of synapses increases. Recent developments in nanotechnologies provide an extremely compact device with low-power consumption. In particular, nanoscale resistive switching devices (resistive random-access memory (RRAM)) are regarded as a promising solution for implementation of biological synapses due to their nanoscale dimensions, capacity to store multiple bits and the low energy required to operate distinct states. In this paper, we report the fabrication, modeling and implementation of nanoscale RRAM with multi-level storage capability for an electronic synapse device. In addition, we first experimentally demonstrate the learning capabilities and predictable performance by a neuromorphic circuit composed of a nanoscale 1 kbit RRAM cross-point array of synapses and complementary metal–oxide–semiconductor neuron circuits. These developments open up possibilities for the development of ubiquitous ultra-dense, ultra-low-power cognitive computers. (paper)

  14. Effects of particle composition and environmental parameters on catalytic hydrodechlorination of trichloroethylene by nanoscale bimetallic Ni-Fe.

    Science.gov (United States)

    Wei, Jianjun; Qian, Yajing; Liu, Wenjuan; Wang, Lutao; Ge, Yijie; Zhang, Jianghao; Yu, Jiang; Ma, Xingmao

    2014-05-01

    Catalytic nickel was successfully incorporated into nanoscale iron to enhance its dechlorination efficiency for trichloroethylene (TCE), one of the most commonly detected chlorinated organic compounds in groundwater. Ethane was the predominant product. The greatest dechlorination efficiency was achieved at 22 molar percent of nickel. This nanoscale Ni-Fe is poorly ordered and inhomogeneous; iron dissolution occurred whereas nickel was relatively stable during the 24-hr reaction. The morphological characterization provided significant new insights on the mechanism of catalytic hydrodechlorination by bimetallic nanoparticles. TCE degradation and ethane production rates were greatly affected by environmental parameters such as solution pH, temperature and common groundwater ions. Both rate constants decreased and then increased over the pH range of 6.5 to 8.0, with the minimum value occurring at pH 7.5. TCE degradation rate constant showed an increasing trend over the temperature range of 10 to 25°C. However, ethane production rate constant increased and then decreased over the range, with the maximum value occurring at 20°C. Most salts in the solution appeared to enhance the reaction in the first half hour but overall they displayed an inhibitory effect. Combined ions showed a similar effect as individual salts. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  15. A nanoscale perspective on the effects of transverse microprestress on drying creep of nanoporous solids

    Science.gov (United States)

    Sinko, Robert; Bažant, Zdeněk P.; Keten, Sinan

    2018-01-01

    The Pickett effect describes the excess non-additive strain developed during drying of a nanoporous solid material under creep. One explanation for its origins, developed using micromechanical models, is the progressive relaxation of internally developed microprestress. However, these models have not explicitly considered the effects of this microprestress on nanoscale energy barriers that govern the relative motion and displacement between nanopore walls during deformation. Here, we evaluate the nanoscale effects of transverse microprestresses on the drying creep behaviour of a nanoscale slit pore using coarse-grained molecular dynamics. We find that the underlying energy barrier depends exponentially on the transverse microprestress, which is attributed to changes in the effective viscosity and degree of nanoconfinement of molecules in the water interlayer. Specifically, as the transverse microprestress is relaxed (i.e. its magnitude decreases), the activation energy barrier is reduced, thereby leading to an acceleration of the creep behaviour and a stronger Pickett effect. Based on our simulation results, we introduce a new microprestress-dependent energy term into our existing Arrhenius model, which describes the relative displacement of pore walls as a function of the underlying activation energy barriers. Our findings further verify the existing micromechanical theories for the origin of the Pickett effect and establish a quantitative relationship between the transverse microprestress and the intensity of the Pickett effect.

  16. A nanoscale perspective on the effects of transverse microprestress on drying creep of nanoporous solids.

    Science.gov (United States)

    Sinko, Robert; Bažant, Zdeněk P; Keten, Sinan

    2018-01-01

    The Pickett effect describes the excess non-additive strain developed during drying of a nanoporous solid material under creep. One explanation for its origins, developed using micromechanical models, is the progressive relaxation of internally developed microprestress. However, these models have not explicitly considered the effects of this microprestress on nanoscale energy barriers that govern the relative motion and displacement between nanopore walls during deformation. Here, we evaluate the nanoscale effects of transverse microprestresses on the drying creep behaviour of a nanoscale slit pore using coarse-grained molecular dynamics. We find that the underlying energy barrier depends exponentially on the transverse microprestress, which is attributed to changes in the effective viscosity and degree of nanoconfinement of molecules in the water interlayer. Specifically, as the transverse microprestress is relaxed (i.e. its magnitude decreases), the activation energy barrier is reduced, thereby leading to an acceleration of the creep behaviour and a stronger Pickett effect. Based on our simulation results, we introduce a new microprestress-dependent energy term into our existing Arrhenius model, which describes the relative displacement of pore walls as a function of the underlying activation energy barriers. Our findings further verify the existing micromechanical theories for the origin of the Pickett effect and establish a quantitative relationship between the transverse microprestress and the intensity of the Pickett effect.

  17. Resonance – Journal of Science Education | Indian Academy of ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 2. DNA's New Avatar as Nanoscale Construction Material. Yamuna Krishnan. Research News Volume 13 Issue 2 February 2008 pp 195-197. Fulltext. Click here to view fulltext PDF. Permanent link:

  18. Factors affecting implementation of practical activities in science ...

    African Journals Online (AJOL)

    Absence of separate and well equipped laboratory for each science, absence of efforts made by science teacher to use local material for practice of basic activities and less attention of local government and school administrative to existing problem results in less student motivation to practical activity which have influence ...

  19. Nanoscale organic ferroelectric resistive switches

    NARCIS (Netherlands)

    Khikhlovskyi, V.; Wang, R.; Breemen, A.J.J.M. van; Gelinck, G.H.; Janssen, R.A.J.; Kemerink, M.

    2014-01-01

    Organic ferroelectric resistive switches function by grace of nanoscale phase separation in a blend of a semiconducting and a ferroelectric polymer that is sandwiched between metallic electrodes. In this work, various scanning probe techniques are combined with numerical modeling to unravel their

  20. Bio-Conjugates for Nanoscale Applications

    DEFF Research Database (Denmark)

    Villadsen, Klaus

    Bio-conjugates for Nanoscale Applications is the title of this thesis, which covers three different projects in chemical bio-conjugation research, namely synthesis and applications of: Lipidated fluorescent peptides, carbohydrate oxime-azide linkers and N-aryl O-R2 oxyamine derivatives. Lipidated...

  1. Learning Activities That Combine Science Magic Activities with the 5E Instructional Model to Influence Secondary-School Students' Attitudes to Science

    Science.gov (United States)

    Lin, Jang-Long; Cheng, Meng-Fei; Chang, Ying-Chi; Li, Hsiao-Wen; Chang, Jih-Yuan; Lin, Deng-Min

    2014-01-01

    The purpose of this study was to investigate how learning materials based on Science Magic activities affect student attitudes to science. A quasi-experimental design was conducted to explore the combination of Science Magic with the 5E Instructional Model to develop learning materials for teaching a science unit about friction. The participants…

  2. Systems engineering at the nanoscale

    Science.gov (United States)

    Benkoski, Jason J.; Breidenich, Jennifer L.; Wei, Michael C.; Clatterbaughi, Guy V.; Keng, Pei Yuin; Pyun, Jeffrey

    2012-06-01

    Nanomaterials have provided some of the greatest leaps in technology over the past twenty years, but their relatively early stage of maturity presents challenges for their incorporation into engineered systems. Perhaps even more challenging is the fact that the underlying physics at the nanoscale often run counter to our physical intuition. The current state of nanotechnology today includes nanoscale materials and devices developed to function as components of systems, as well as theoretical visions for "nanosystems," which are systems in which all components are based on nanotechnology. Although examples will be given to show that nanomaterials have indeed matured into applications in medical, space, and military systems, no complete nanosystem has yet been realized. This discussion will therefore focus on systems in which nanotechnology plays a central role. Using self-assembled magnetic artificial cilia as an example, we will discuss how systems engineering concepts apply to nanotechnology.

  3. Creative scientific research international session of 2nd meeting on advanced pulsed-neutron research on quantum functions in nano-scale materials

    International Nuclear Information System (INIS)

    Itoh, Shinichi

    2005-06-01

    1 MW-class pulsed-neutron sources will be constructed in Japan, United State and United Kingdom in a few years. Now is the time for a challenge to innovate on neutron science and extend new science fields. Toward the new era, we develop new pulsed-neutron technologies as well as new neutron devices under the international collaborations with existing pulsed-neutron facilities, such as the UK-Japan collaboration program on neutron scattering. At the same time, the new era will bring international competitions to neutron researchers. We aim to create new neutron science toward the new pulsed-neutron era by introducing the new technologies developed here. For this purpose, we have started the research project, 'Advanced pulsed-neutron research on quantum functions in nano-scale materials,' in the duration between JFY2004 and JFY2008. The 2nd meeting of this project was held on 22-24 February 2005 to summarize activities in FY2004 and to propose research projects in the coming new fiscal year. In this international session as a part of this meeting, the scientific results and research plans on the UK-Japan collaboration program, the research plans on the collaboration between IPNS (Intense Pulsed Neutron Source, Argonne National Laboratory) and KENS (Neutron Science Laboratory, KEK), also the recent scientific results arisen form this project were presented. (author)

  4. Scanning nanoscale multiprobes for conductivity measurements

    DEFF Research Database (Denmark)

    Bøggild, Peter; Hansen, Torben Mikael; Kuhn, Oliver

    2000-01-01

    We report fabrication and measurements with two- and four-point probes with nanoscale dimensions, for high spatial resolution conductivity measurements on surfaces and thin films. By combination of conventional microfabrication and additive three-dimensional nanolithography, we have obtained...... electrode spacings down to 200 nm. At the tips of four silicon oxide microcantilevers, narrow carbon tips are grown in converging directions and subsequently coated with a conducting layer. The probe is placed in contact with a conducting surface, whereby the electrode resistance can be determined....... The nanoelectrodes withstand considerable contact force before breaking. The probe offers a unique possibility to position the voltage sensors, as well as the source and drain electrodes in areas of nanoscale dimensions. ©2000 American Institute of Physics....

  5. Isolation of nanoscale exosomes using viscoelastic effect

    Science.gov (United States)

    Hu, Guoqing; Liu, Chao

    2017-11-01

    Exosomes, molecular cargos secreted by almost all mammalian cells, are considered as promising biomarkers to identify many diseases including cancers. However, the small size of exosomes (30-200 nm) poses serious challenges on their isolation from the complex media containing a variety of extracellular vesicles (EVs) of different sizes, especially in small sample volumes. Here we develop a viscoelasticity-based microfluidic system to directly separate exosomes from cell culture media or serum in a continuous, size-dependent, and label-free manner. Using a small amount of biocompatible polymer as the additive into the media to control the viscoelastic forces exerted on EVs, we are able to achieve a high separation purity (>90%) and recovery (>80%) of exosomes. The size cutoff in viscoelasticity-based microfluidics can be easily controlled using different PEO concentrations. Based on this size-dependent viscoelastic separation strategy, we envision the handling of diverse nanoscale objects, such as gold nanoparticles, DNA origami structures, and quantum dots. This work was supported financially by National Natural Science Foundation of China (11572334, 91543125).

  6. Charge separation at nanoscale interfaces: energy-level alignment including two-quasiparticle interactions.

    Science.gov (United States)

    Li, Huashan; Lin, Zhibin; Lusk, Mark T; Wu, Zhigang

    2014-10-21

    The universal and fundamental criteria for charge separation at interfaces involving nanoscale materials are investigated. In addition to the single-quasiparticle excitation, all the two-quasiparticle effects including exciton binding, Coulomb stabilization, and exciton transfer are considered, which play critical roles on nanoscale interfaces for optoelectronic applications. We propose a scheme allowing adding these two-quasiparticle interactions on top of the single-quasiparticle energy level alignment for determining and illuminating charge separation at nanoscale interfaces. Employing the many-body perturbation theory based on Green's functions, we quantitatively demonstrate that neglecting or simplifying these crucial two-quasiparticle interactions using less accurate methods is likely to predict qualitatively incorrect charge separation behaviors at nanoscale interfaces where quantum confinement dominates.

  7. Nanotechnology Research: Applications in Nutritional Sciences12

    Science.gov (United States)

    Srinivas, Pothur R.; Philbert, Martin; Vu, Tania Q.; Huang, Qingrong; Kokini, Josef L.; Saos, Etta; Chen, Hongda; Peterson, Charles M.; Friedl, Karl E.; McDade-Ngutter, Crystal; Hubbard, Van; Starke-Reed, Pamela; Miller, Nancy; Betz, Joseph M.; Dwyer, Johanna; Milner, John; Ross, Sharon A.

    2010-01-01

    The tantalizing potential of nanotechnology is to fabricate and combine nanoscale approaches and building blocks to make useful tools and, ultimately, interventions for medical science, including nutritional science, at the scale of ∼1–100 nm. In the past few years, tools and techniques that facilitate studies and interventions in the nanoscale range have become widely available and have drawn widespread attention. Recently, investigators in the food and nutrition sciences have been applying the tools of nanotechnology in their research. The Experimental Biology 2009 symposium entitled “Nanotechnology Research: Applications in Nutritional Sciences” was organized to highlight emerging applications of nanotechnology to the food and nutrition sciences, as well as to suggest ways for further integration of these emerging technologies into nutrition research. Speakers focused on topics that included the problems and possibilities of introducing nanoparticles in clinical or nutrition settings, nanotechnology applications for increasing bioavailability of bioactive food components in new food products, nanotechnology opportunities in food science, as well as emerging safety and regulatory issues in this area, and the basic research applications such as the use of quantum dots to visualize cellular processes and protein-protein interactions. The session highlighted several emerging areas of potential utility in nutrition research. Nutrition scientists are encouraged to leverage ongoing efforts in nanomedicine through collaborations. These efforts could facilitate exploration of previously inaccessible cellular compartments and intracellular pathways and thus uncover strategies for new prevention and therapeutic modalities. PMID:19939997

  8. Exploring Ultimate Water Capillary Evaporation in Nanoscale Conduits.

    Science.gov (United States)

    Li, Yinxiao; Alibakhshi, Mohammad Amin; Zhao, Yihong; Duan, Chuanhua

    2017-08-09

    Capillary evaporation in nanoscale conduits is an efficient heat/mass transfer strategy that has been widely utilized by both nature and mankind. Despite its broad impact, the ultimate transport limits of capillary evaporation in nanoscale conduits, governed by the evaporation/condensation kinetics at the liquid-vapor interface, have remained poorly understood. Here we report experimental study of the kinetic limits of water capillary evaporation in two dimensional nanochannels using a novel hybrid channel design. Our results show that the kinetic-limited evaporation fluxes break down the limits predicated by the classical Hertz-Knudsen equation by an order of magnitude, reaching values up to 37.5 mm/s with corresponding heat fluxes up to 8500 W/cm 2 . The measured evaporation flux increases with decreasing channel height and relative humidity but decreases as the channel temperature decreases. Our findings have implications for further understanding evaporation at the nanoscale and developing capillary evaporation-based technologies for both energy- and bio-related applications.

  9. Activation analysis in the environment: Science and technology

    International Nuclear Information System (INIS)

    Lenihan, J.

    1989-01-01

    Science is disciplined curiosity. Activation analysis was created more than 50 yr ago by Hevesy's curiosity and Levi's experimental skill. Technology is the exploitation of machines and materials for the fulfillment of human needs or wants. The early history of neutron activation analysis (NAA) was greatly influenced by military requirements. Since then the technique has found applications in many disciplines, including materials science, medicine, archaeology, geochemistry, agriculture, and forensic science. More recently, neutron activation analysts, responding to increasing public interest and concern, have made distinctive contributions to the study of environmental problems. Activation analysis, though it uses some procedures derived from physics, is essentially a chemical technique. The chemical study of the environment may be reviewed under many headings; three are discussed here: 1. occupational medicine 2. health of the general public 3. environmental pollution

  10. Imaging nanoscale spatial modulation of a relativistic electron beam with a MeV ultrafast electron microscope

    Science.gov (United States)

    Lu, Chao; Jiang, Tao; Liu, Shengguang; Wang, Rui; Zhao, Lingrong; Zhu, Pengfei; Liu, Yaqi; Xu, Jun; Yu, Dapeng; Wan, Weishi; Zhu, Yimei; Xiang, Dao; Zhang, Jie

    2018-03-01

    An accelerator-based MeV ultrafast electron microscope (MUEM) has been proposed as a promising tool to the study structural dynamics at the nanometer spatial scale and the picosecond temporal scale. Here, we report experimental tests of a prototype MUEM where high quality images with nanoscale fine structures were recorded with a pulsed ˜3 MeV picosecond electron beam. The temporal and spatial resolutions of the MUEM operating in the single-shot mode are about 4 ps (FWHM) and 100 nm (FWHM), corresponding to a temporal-spatial resolution of 4 × 10-19 s m, about 2 orders of magnitude higher than that achieved with state-of-the-art single-shot keV UEM. Using this instrument, we offer the demonstration of visualizing the nanoscale periodic spatial modulation of an electron beam, which may be converted into longitudinal density modulation through emittance exchange to enable production of high-power coherent radiation at short wavelengths. Our results mark a great step towards single-shot nanometer-resolution MUEMs and compact intense x-ray sources that may have widespread applications in many areas of science.

  11. University/Science Center Collaborations (A Science Center Perspective): Developing an Infrastructure of Partnerships with Science Centers to Support the Engagement of Scientists and Engineers in Education and Outreach for Broad Impact

    Science.gov (United States)

    Marshall, Eric

    2009-03-01

    Science centers, professional associations, corporations and university research centers share the same mission of education and outreach, yet come from ``different worlds.'' This gap may be bridged by working together to leverage unique strengths in partnership. Front-end evaluation results for the development of new resources to support these (mostly volunteer-based) partnerships elucidate the factors which lead to a successful relationship. Maintaining a science museum-scientific community partnership requires that all partners devote adequate resources (time, money, etc.). In general, scientists/engineers and science museum professionals often approach relationships with different assumptions and expectations. The culture of science centers is distinctly different from the culture of science. Scientists/engineers prefer to select how they will ultimately share their expertise from an array of choices. Successful partnerships stem from clearly defined roles and responsibilities. Scientists/engineers are somewhat resistant to the idea of traditional, formal training. Instead of developing new expertise, many prefer to offer their existing strengths and expertise. Maintaining a healthy relationship requires the routine recognition of the contributions of scientists/engineers. As professional societies, university research centers and corporations increasingly engage in education and outreach, a need for a supportive infrastructure becomes evident. Work of TryScience.org/VolTS (Volunteers TryScience), the MRS NISE Net (Nanoscale Informal Science Education Network) subcommittee, NRCEN (NSF Research Center Education Network), the IBM On Demand Community, and IEEE Educational Activities exemplify some of the pieces of this evolving infrastructure.

  12. Nano-Scale Positioning Design with Piezoelectric Materials

    Directory of Open Access Journals (Sweden)

    Yung Yue Chen

    2017-12-01

    Full Text Available Piezoelectric materials naturally possess high potential to deliver nano-scale positioning resolution; hence, they are adopted in a variety of engineering applications widely. Unfortunately, unacceptable positioning errors always appear because of the natural hysteresis effect of the piezoelectric materials. This natural property must be mitigated in practical applications. For solving this drawback, a nonlinear positioning design is proposed in this article. This nonlinear positioning design of piezoelectric materials is realized by the following four steps: 1. The famous Bouc–Wen model is utilized to present the input and output behaviors of piezoelectric materials; 2. System parameters of the Bouc–Wen model that describe the characteristics of piezoelectric materials are simultaneously identified with the particle swam optimization method; 3. Stability verification for the identified Bouc–Wen model; 4. A nonlinear feedback linearization control design is derived for the nano-scale positioning design of the piezoelectric material, mathematically. One important contribution of this investigation is that the positioning error between the output displacement of the controlled piezoelectric materials and the desired trajectory in nano-scale level can be proven to converge to zero asymptotically, under the effect of the hysteresis.

  13. Static electric field enhancement in nanoscale structures

    Energy Technology Data Exchange (ETDEWEB)

    Lepetit, Bruno, E-mail: bruno.lepetit@irsamc.ups-tlse.fr; Lemoine, Didier, E-mail: didier.lemoine@irsamc.ups-tlse.fr [Université de Toulouse, UPS, Laboratoire Collisions Agrégats Réactivité, IRSAMC, F-31062 Toulouse (France); CNRS, UMR 5589, F-31062 Toulouse (France); Márquez-Mijares, Maykel, E-mail: mmarquez@instec.cu [Université de Toulouse, UPS, Laboratoire Collisions Agrégats Réactivité, IRSAMC, F-31062 Toulouse (France); CNRS, UMR 5589, F-31062 Toulouse (France); Instituto Superior de Tecnologías y Ciencias Aplicadas, Avenida Salvador Allende 1110, Quinta de los Molinos, La Habana (Cuba)

    2016-08-28

    We study the effect of local atomic- and nano-scale protrusions on field emission and, in particular, on the local field enhancement which plays a key role as known from the Fowler-Nordheim model of electronic emission. We study atomic size defects which consist of right angle steps forming an infinite length staircase on a tungsten surface. This structure is embedded in a 1 GV/m ambient electrostatic field. We perform calculations based upon density functional theory in order to characterize the total and induced electronic densities as well as the local electrostatic fields taking into account the detailed atomic structure of the metal. We show how the results must be processed to become comparable with those of a simple homogeneous tungsten sheet electrostatic model. We also describe an innovative procedure to extrapolate our results to nanoscale defects of larger sizes, which relies on the microscopic findings to guide, tune, and improve the homogeneous metal model, thus gaining predictive power. Furthermore, we evidence analytical power laws for the field enhancement characterization. The main physics-wise outcome of this analysis is that limited field enhancement is to be expected from atomic- and nano-scale defects.

  14. Science Activities in Energy: Wind Energy.

    Science.gov (United States)

    Oak Ridge Associated Universities, TN.

    Included in this science activities energy package are 12 activities related to wind energy for elementary students. Each activity is outlined on a single card and is introduced by a question. Topics include: (1) At what time of day is there enough wind to make electricity where you live?; (2) Where is the windiest spot on your schoolground?; and…

  15. Nanoscale chirality in metal and semiconductor nanoparticles.

    Science.gov (United States)

    Kumar, Jatish; Thomas, K George; Liz-Marzán, Luis M

    2016-10-18

    The field of chirality has recently seen a rejuvenation due to the observation of chirality in inorganic nanomaterials. The advancements in understanding the origin of nanoscale chirality and the potential applications of chiroptical nanomaterials in the areas of optics, catalysis and biosensing, among others, have opened up new avenues toward new concepts and design of novel materials. In this article, we review the concept of nanoscale chirality in metal nanoclusters and semiconductor quantum dots, then focus on recent experimental and theoretical advances in chiral metal nanoparticles and plasmonic chirality. Selected examples of potential applications and an outlook on the research on chiral nanomaterials are additionally provided.

  16. From established science to class room science, or how to take into account didactic activity in the history of science

    Directory of Open Access Journals (Sweden)

    Bruno Belhoste

    2012-02-01

    Full Text Available This paper deals with the relationship between science and education in historiography, questioning the separation between the two activities, and highlighting the role of education to scientific activity. First, it distinguishes the largely accepted needs of historical contextualization from the epistemological problem, related to the place of history education in the history of science. It defends that the history of science education is not foreign to the history of science. It criticizes Chevallard’s notion of didactic transposition for reinforcing the gap between scientific knowledge and teaching knowledge. Finally, it argues that the sciences are in permanent reconstruction and that scientific knowledge is not tied to socio-cultural contexts from which it emerged.

  17. Nanoscale volcanoes: accretion of matter at ion-sculpted nanopores.

    Science.gov (United States)

    Mitsui, Toshiyuki; Stein, Derek; Kim, Young-Rok; Hoogerheide, David; Golovchenko, J A

    2006-01-27

    We demonstrate the formation of nanoscale volcano-like structures induced by ion-beam irradiation of nanoscale pores in freestanding silicon nitride membranes. Accreted matter is delivered to the volcanoes from micrometer distances along the surface. Volcano formation accompanies nanopore shrinking and depends on geometrical factors and the presence of a conducting layer on the membrane's back surface. We argue that surface electric fields play an important role in accounting for the experimental observations.

  18. Chemistry and Materials Science progress report, first half FY 1992

    International Nuclear Information System (INIS)

    1992-07-01

    This report contains sections on: Fundamentals of the physics and processing of metals; interfaces, adhesion, and bonding; energetic materials; plutonium research; synchrotron radiation-based materials science; atomistic approach to the interaction of surfaces with the environment: actinide studies; properties of carbon fibers; buried layer formation using ion implantation; active coherent control of chemical reaction dynamics; inorganic and organic aerogels; synthesis and characterization of melamine-formaldehyde aerogels; structural transformation and precursor phenomena in advanced materials; magnetic ultrathin films, surfaces, and overlayers; ductile-phase toughening of refractory-metal intermetallics; particle-solid interactions; electronic structure evolution of metal clusters; and nanoscale lithography induced chemically or physically by modified scanned probe microscopy

  19. Assessment report on research and development activities. Activity: 'Advanced science research' (Interim report)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-15

    Japan Atomic Energy Agency (hereinafter referred to as 'JAEA') consulted an assessment committee, 'Evaluation Committee of Research Activities for Advanced Science Research' (hereinafter referred to as 'Committee') for interim assessment of 'Advanced Science Research,' in accordance with 'General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by JAEA. In response to the JAEA's request, the Committee assessed the research programs and activities of the Advanced Science Research Center (hereinafter referred to as 'ASRC') for the period of two years from April 2010. The Committee evaluated the management and the research programs of the ASRC based on the explanatory documents prepared by the ASRC and the oral presentations with questions-and-answers by the Director and the research group leaders. This report summarizes the result of the assessment by the Committee with the Committee report attached from page 7. (author)

  20. Assessment report of research and development activities. Activity: advanced science research' (Interim report)

    International Nuclear Information System (INIS)

    2008-08-01

    Japan Atomic Energy Agency (hereinafter referred to as 'JAEA') consults an assessment committee, 'Evaluation Committee of Research Activities for Advanced Science Research' (hereinafter referred to as 'Committee') for interim assessment of 'Advanced Science Research,' in accordance with General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by JAEA. In response to the JAEA's request, the Committee assessed the research program of the Advanced Science Research Center (hereinafter referred to as 'ASRC') during the period of two years from October 2005 to September 2007. The Committee evaluated the management and research activities of the ASRC based on the explanatory documents prepared by the ASRC, the oral presentations with questions-and-answers by the Director and the research group leaders, and interviews from group members through on-site visits by the Committee members. One CD-ROM is attached as an appendix. (J.P.N.)

  1. Prioritizing Active Learning: An Exploration of Gateway Courses in Political Science

    Science.gov (United States)

    Archer, Candace C.; Miller, Melissa K.

    2011-01-01

    Prior research in political science and other disciplines demonstrates the pedagogical and practical benefits of active learning. Less is known, however, about the extent to which active learning is used in political science classrooms. This study assesses the prioritization of active learning in "gateway" political science courses, paying…

  2. Phototoxicity and Dosimetry of Nano-scale Titanium Dioxide in Aquatic Organisms

    Science.gov (United States)

    We have been testing nanoscale TiO2 (primarily Evonik P25) in acute exposures to identify and quantify its phototoxicity under solar simulated radiation (SSR), and to develop dose metrics reflective of both nano-scale properties and the photon component of its potency. Several e...

  3. Nanoscale footprints of self-running gallium droplets on GaAs surface.

    Directory of Open Access Journals (Sweden)

    Jiang Wu

    Full Text Available In this work, the nanoscale footprints of self-driven liquid gallium droplet movement on a GaAs (001 surface will be presented and analyzed. The nanoscale footprints of a primary droplet trail and ordered secondary droplets along primary droplet trails are observed on the GaAs surface. A well ordered nanoterrace from the trail is left behind by a running droplet. In addition, collision events between two running droplets are investigated. The exposed fresh surface after a collision demonstrates a superior evaporation property. Based on the observation of droplet evolution at different stages as well as nanoscale footprints, a schematic diagram of droplet evolution is outlined in an attempt to understand the phenomenon of stick-slip droplet motion on the GaAs surface. The present study adds another piece of work to obtain the physical picture of a stick-slip self-driven mechanism in nanoscale, bridging nano and micro systems.

  4. Conceptual strategies and inter-theory relations: The case of nanoscale cracks

    Science.gov (United States)

    Bursten, Julia R.

    2018-05-01

    This paper introduces a new account of inter-theory relations in physics, which I call the conceptual strategies account. Using the example of a multiscale computer simulation model of nanoscale crack propagation in silicon, I illustrate this account and contrast it with existing reductive, emergent, and handshaking approaches. The conceptual strategies account develops the notion that relations among physical theories, and among their models, are constrained but not dictated by limitations from physics, mathematics, and computation, and that conceptual reasoning within those limits is required both to generate and to understand the relations between theories. Conceptual strategies result in a variety of types of relations between theories and models. These relations are themselves epistemic objects, like theories and models, and as such are an under-recognized part of the epistemic landscape of science.

  5. Quantum Transport Simulations of Nanoscale Materials

    KAUST Repository

    Obodo, Tobechukwu Joshua

    2016-01-01

    -performance supercomputers allow us to control and exploit their microscopic properties at the atomic scale, hence making it possible to design novel nanoscale molecular devices with interesting features (e.g switches, rectifiers, negative differential conductance, and high

  6. The nanoscale organization of the B lymphocyte membrane☆

    Science.gov (United States)

    Maity, Palash Chandra; Yang, Jianying; Klaesener, Kathrin; Reth, Michael

    2015-01-01

    The fluid mosaic model of Singer and Nicolson correctly predicted that the plasma membrane (PM) forms a lipid bi-layer containing many integral trans-membrane proteins. This model also suggested that most of these proteins were randomly dispersed and freely diffusing moieties. Initially, this view of a dynamic and rather unorganized membrane was supported by early observations of the cell surfaces using the light microscope. However, recent studies on the PM below the diffraction limit of visible light (~ 250 nm) revealed that, at nanoscale dimensions, membranes are highly organized and compartmentalized structures. Lymphocytes are particularly useful to study this nanoscale membrane organization because they grow as single cells and are not permanently engaged in cell:cell contacts within a tissue that can influence membrane organization. In this review, we describe the methods that can be used to better study the protein:protein interaction and nanoscale organization of lymphocyte membrane proteins, with a focus on the B cell antigen receptor (BCR). Furthermore, we discuss the factors that may generate and maintain these membrane structures. PMID:25450974

  7. Cell-specific STORM superresolution imaging reveals nanoscale organization of cannabinoid signaling

    Science.gov (United States)

    Szabó, Szilárd I.; Szabadits, Eszter; Pintér, Balázs; Woodhams, Stephen G.; Henstridge, Christopher M.; Balla, Gyula Y.; Nyilas, Rita; Varga, Csaba; Lee, Sang-Hun; Matolcsi, Máté; Cervenak, Judit; Kacskovics, Imre; Watanabe, Masahiko; Sagheddu, Claudia; Melis, Miriam; Pistis, Marco; Soltesz, Ivan; Katona, István

    2014-01-01

    A major challenge in neuroscience is to determine the nanoscale position and quantity of signaling molecules in a cell-type-, and subcellular compartment-specific manner. We therefore developed a novel approach combining cell-specific physiological and anatomical characterization with superresolution imaging, and studied the molecular and structural parameters shaping the physiological properties of synaptic endocannabinoid signaling in the mouse hippocampus. We found that axon terminals of perisomatically-projecting GABAergic interneurons possess increased CB1 receptor number, active-zone complexity, and receptor/effector ratio compared to dendritically-projecting interneurons, in agreement with higher efficiency of cannabinoid signaling at somatic versus dendritic synapses. Furthermore, chronic Δ9-tetrahydrocannabinol administration, which reduces cannabinoid efficacy on GABA release, evoked dramatic CB1-downregulation in a dose-dependent manner. Full receptor recovery required several weeks after cessation of Δ9-tetrahydrocannabinol treatment. These findings demonstrate that cell-type-specific nanoscale analysis of endogenous protein distribution is possible in brain circuits, and identify novel molecular properties controlling endocannabinoid signaling and cannabis-induced cognitive dysfunction. PMID:25485758

  8. Fast nanoscale heat-flux modulation with phase-change materials

    OpenAIRE

    Van Zwol , Pieter; Joulain , Karl; Ben-Abdallah , Philippe; Greffet , Jean-Jacques; Chevrier , Joël

    2011-01-01

    International audience; We introduce a new concept for electrically controlled heat flux modulation. A flux contrast larger than 10 dB is expected with switching time on the order of tens of nanoseconds. Heat flux modulation is based on the interplay between radiative heat transfer at the nanoscale and phase change materials. Such large contrasts are not obtainable in solids, or in far field. As such this opens up new horizons for temperature modulation and actuation at the nanoscale.

  9. Enabling complex nanoscale pattern customization using directed self-assembly.

    Science.gov (United States)

    Doerk, Gregory S; Cheng, Joy Y; Singh, Gurpreet; Rettner, Charles T; Pitera, Jed W; Balakrishnan, Srinivasan; Arellano, Noel; Sanders, Daniel P

    2014-12-16

    Block copolymer directed self-assembly is an attractive method to fabricate highly uniform nanoscale features for various technological applications, but the dense periodicity of block copolymer features limits the complexity of the resulting patterns and their potential utility. Therefore, customizability of nanoscale patterns has been a long-standing goal for using directed self-assembly in device fabrication. Here we show that a hybrid organic/inorganic chemical pattern serves as a guiding pattern for self-assembly as well as a self-aligned mask for pattern customization through cotransfer of aligned block copolymer features and an inorganic prepattern. As informed by a phenomenological model, deliberate process engineering is implemented to maintain global alignment of block copolymer features over arbitrarily shaped, 'masking' features incorporated into the chemical patterns. These hybrid chemical patterns with embedded customization information enable deterministic, complex two-dimensional nanoscale pattern customization through directed self-assembly.

  10. Thermoelectric efficiency of nanoscale devices in the linear regime

    Science.gov (United States)

    Bevilacqua, G.; Grosso, G.; Menichetti, G.; Pastori Parravicini, G.

    2016-12-01

    We study quantum transport through two-terminal nanoscale devices in contact with two particle reservoirs at different temperatures and chemical potentials. We discuss the general expressions controlling the electric charge current, heat currents, and the efficiency of energy transmutation in steady conditions in the linear regime. With focus in the parameter domain where the electron system acts as a power generator, we elaborate workable expressions for optimal efficiency and thermoelectric parameters of nanoscale devices. The general concepts are set at work in the paradigmatic cases of Lorentzian resonances and antiresonances, and the encompassing Fano transmission function: the treatments are fully analytic, in terms of the trigamma functions and Bernoulli numbers. From the general curves here reported describing transport through the above model transmission functions, useful guidelines for optimal efficiency and thermopower can be inferred for engineering nanoscale devices in energy regions where they show similar transmission functions.

  11. Nanoscale piezoelectric vibration energy harvester design

    Science.gov (United States)

    Foruzande, Hamid Reza; Hajnayeb, Ali; Yaghootian, Amin

    2017-09-01

    Development of new nanoscale devices has increased the demand for new types of small-scale energy resources such as ambient vibrations energy harvesters. Among the vibration energy harvesters, piezoelectric energy harvesters (PEHs) can be easily miniaturized and fabricated in micro and nano scales. This change in the dimensions of a PEH leads to a change in its governing equations of motion, and consequently, the predicted harvested energy comparing to a macroscale PEH. In this research, effects of small scale dimensions on the nonlinear vibration and harvested voltage of a nanoscale PEH is studied. The PEH is modeled as a cantilever piezoelectric bimorph nanobeam with a tip mass, using the Euler-Bernoulli beam theory in conjunction with Hamilton's principle. A harmonic base excitation is applied as a model of the ambient vibrations. The nonlocal elasticity theory is used to consider the size effects in the developed model. The derived equations of motion are discretized using the assumed-modes method and solved using the method of multiple scales. Sensitivity analysis for the effect of different parameters of the system in addition to size effects is conducted. The results show the significance of nonlocal elasticity theory in the prediction of system dynamic nonlinear behavior. It is also observed that neglecting the size effects results in lower estimates of the PEH vibration amplitudes. The results pave the way for designing new nanoscale sensors in addition to PEHs.

  12. Bulk nanoscale materials in steel products

    International Nuclear Information System (INIS)

    Chehab, B; Wang, X; Masse, J-P; Zurob, H; Embury, D; Bouaziz, O

    2010-01-01

    Although a number of nanoscale metallic materials exhibit interesting mechanical properties the fabrication paths are often complex and difficult to apply to bulk structural materials. However a number of steels which exhibit combinations of plasticity and phase transitions can be deformed to produce ultra high strength levels in the range 1 to 3 GPa. The resultant high stored energy and complex microstructures allow new nanoscale structures to be produced by combinations of recovery and recrystallisation. The resultant structures exhibit totally new combinations of strength and ductility to be achieved. In specific cases this also enables both the nature of the grain boundary structure and the spatial variation in structure to be controlled. In this presentation both the detailed microstructural features and their relation to the strength, work-hardening capacity and ductility will be discussed for a number of martensitic and austenitic steels.

  13. Potential of silicon nanowires structures as nanoscale piezoresistors in mechanical sensors

    International Nuclear Information System (INIS)

    Messina, M; Njuguna, J

    2012-01-01

    This paper presents the design of a single square millimeter 3-axial accelerometer for bio-mechanics measurements that exploit the potential of silicon nanowires structures as nanoscale piezoresistors. The main requirements of this application are miniaturization and high measurement accuracy. Nanowires as nanoscale piezoresistive devices have been chosen as sensing element, due to their high sensitivity and miniaturization achievable. By exploiting the electro-mechanical features of nanowires as nanoscale piezoresistors, the nominal sensor sensitivity is overall boosted by more than 30 times. This approach allows significant higher accuracy and resolution with smaller sensing element in comparison with conventional devices without the need of signal amplification.

  14. Humidity effects on the electronic transport properties in carbon based nanoscale device

    International Nuclear Information System (INIS)

    He, Jun; Chen, Ke-Qiu

    2012-01-01

    By applying nonequilibrium Green's functions in combination with the density functional theory, we investigate the effect of humidity on the electronic transport properties in carbon based nanoscale device. The results show that different humidity may form varied localized potential barrier, which is a very important factor to affect the stability of electronic transport in the nanoscale system. A mechanism for the humidity effect is suggested. -- Highlights: ► Electronic transport in carbon based nanoscale device. ► Humidity affects the stability of electronic transport. ► Different humidity may form varied localized potential barrier.

  15. Inelastic transport theory for nanoscale systems

    DEFF Research Database (Denmark)

    Frederiksen, Thomas

    2007-01-01

    This thesis describes theoretical and numerical investigations of inelastic scat- tering and energy dissipation in electron transport through nanoscale sys- tems. A computational scheme, based on a combination of density functional theory (DFT) and nonequilibrium Green’s functions (NEGF), has been...

  16. Flexible nanoscale high-performance FinFETs

    KAUST Repository

    Sevilla, Galo T.; Ghoneim, Mohamed T.; Fahad, Hossain M.; Rojas, Jhonathan Prieto; Hussain, Aftab M.; Hussain, Muhammad Mustafa

    2014-01-01

    With the emergence of the Internet of Things (IoT), flexible high-performance nanoscale electronics are more desired. At the moment, FinFET is the most advanced transistor architecture used in the state-of-the-art microprocessors. Therefore, we show

  17. Catalysis at the nanoscale may change selectivity.

    Science.gov (United States)

    Costentin, Cyrille; Savéant, Jean-Michel

    2016-10-18

    Among the many virtues ascribed to catalytic nanoparticles, the prospect that the passage from the macro- to the nanoscale may change product selectivity attracts increasing attention. To date, why such effects may exist lacks explanation. Guided by recent experimental reports, we propose that the effects may result from the coupling between the chemical steps in which the reactant, intermediates, and products are involved and transport of these species toward the catalytic surface. Considering as a thought experiment the competitive formation of hydrogen and formate upon reduction of hydrogenocarbonate ions on metals like palladium or platinum, a model is developed that allows one to identify the governing parameters and predict the effect of nanoscaling on selectivity. The model leads to a master equation relating product selectivity and thickness of the diffusion layer. The latter parameter varies considerably upon passing from the macro- to the nanoscale, thus predicting considerable variations of product selectivity. These are subtle effects in the sense that the same mechanism might exhibit a reverse variation of the selectivity if the set of parameter values were different. An expression is given that allows one to predict the direction of the effect. There has been a tendency to assign the catalytic effects of nanoscaling to chemical reactivity changes of the active surface. Such factors might be important in some circumstances. We, however, insist on the likely role of short-distance transport on product selectivity, which could have been thought, at first sight, as the exclusive domain of chemical factors.

  18. MD Simulation on Collision Behavior Between Nano-Scale TiO₂ Particles During Vacuum Cold Spraying.

    Science.gov (United States)

    Yao, Hai-Long; Yang, Guan-Jun; Li, Chang-Jiu

    2018-04-01

    Particle collision behavior influences significantly inter-nano particle bonding formation during the nano-ceramic coating deposition by vacuum cold spraying (or aerosol deposition method). In order to illuminate the collision behavior between nano-scale ceramic particles, molecular dynamic simulation was applied to explore impact process between nano-scale TiO2 particles through controlling impact velocities. Results show that the recoil efficiency of the nano-scale TiO2 particle is decreased with the increase of the impact velocity. Nano-scale TiO2 particle exhibits localized plastic deformation during collision at low velocities, while it is intensively deformed by collision at high velocities. This intensive deformation promotes the nano-particle adhesion rather than rebounding off. A relationship between the adhesion energy and the rebound energy is established for the bonding formation of the nano-scale TiO2 particle. The adhesion energy required to the bonding formation between nano-scale ceramic particles can be produced by high velocity collision.

  19. Design exploration of emerging nano-scale non-volatile memory

    CERN Document Server

    Yu, Hao

    2014-01-01

    This book presents the latest techniques for characterization, modeling and design for nano-scale non-volatile memory (NVM) devices.  Coverage focuses on fundamental NVM device fabrication and characterization, internal state identification of memristic dynamics with physics modeling, NVM circuit design, and hybrid NVM memory system design-space optimization. The authors discuss design methodologies for nano-scale NVM devices from a circuits/systems perspective, including the general foundations for the fundamental memristic dynamics in NVM devices.  Coverage includes physical modeling, as well as the development of a platform to explore novel hybrid CMOS and NVM circuit and system design.   • Offers readers a systematic and comprehensive treatment of emerging nano-scale non-volatile memory (NVM) devices; • Focuses on the internal state of NVM memristic dynamics, novel NVM readout and memory cell circuit design, and hybrid NVM memory system optimization; • Provides both theoretical analysis and pr...

  20. Promoting Female Students' Learning Motivation towards Science by Exercising Hands-On Activities

    Science.gov (United States)

    Wen-jin, Kuo; Chia-ju, Liu; Shi-an, Leou

    2012-01-01

    The purpose of this study is to design different hands-on science activities and investigate which activities could better promote female students' learning motivation towards science. This study conducted three types of science activities which contains nine hands-on activities, an experience scale and a learning motivation scale for data…

  1. Effects of nanoscale contacts to graphene

    NARCIS (Netherlands)

    Franklin, A.D.; Han, S.-J.; Bol, A.A.; Haensch, W.

    2011-01-01

    Understanding and optimizing transport between metal contacts and graphene is one of the foremost challenges for graphene devices. In this letter, we present the first results on the effects of reducing contact dimensions to the nanoscale in single-layer graphene transistors. Using noninvasive

  2. Nanoscale Nutrient Delivery Systems for Food Applications: Improving Bioactive Dispersibility, Stability, and Bioavailability.

    Science.gov (United States)

    McClements, David Julian

    2015-07-01

    There has been a surge of interest in the development of nanoscale systems for the encapsulation, protection, and delivery of lipophilic nutrients, vitamins, and nutraceuticals. This review article highlights the challenges associated with incorporating these lipophilic bioactive components into foods, and then discusses potential nanoscale delivery systems that can be used to overcome these challenges. In particular, the desirable characteristics required for any nanoscale delivery system are presented, as well as methods of fabricating them and of characterizing them. An overview of different delivery systems is given, such as microemulsions, nanoemulsions, emulsions, microgels, and biopolymer nanoparticles, and their potential applications are discussed. Nanoscale delivery systems have considerable potential within the food industry, but they must be carefully formulated to ensure that they are safe, economically viable, and effective. Nanoscale delivery systems have numerous potential applications in the food industry for encapsulating, protecting, and releasing bioactive agents, such as nutraceuticals and vitamins. This review article highlights methods for designing, fabricating, characterizing, and utilizing edible nanoparticles from a variety of different food-grade ingredients. © 2015 Institute of Food Technologists®

  3. Nanoscale Organic Hybrid Electrolytes

    KAUST Repository

    Nugent, Jennifer L.

    2010-08-20

    Nanoscale organic hybrid electrolytes are composed of organic-inorganic hybrid nanostructures, each with a metal oxide or metallic nanoparticle core densely grafted with an ion-conducting polyethylene glycol corona - doped with lithium salt. These materials form novel solvent-free hybrid electrolytes that are particle-rich, soft glasses at room temperature; yet manifest high ionic conductivity and good electrochemical stability above 5V. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Nanoscale Organic Hybrid Electrolytes

    KAUST Repository

    Nugent, Jennifer L.; Moganty, Surya S.; Archer, Lynden A.

    2010-01-01

    Nanoscale organic hybrid electrolytes are composed of organic-inorganic hybrid nanostructures, each with a metal oxide or metallic nanoparticle core densely grafted with an ion-conducting polyethylene glycol corona - doped with lithium salt. These materials form novel solvent-free hybrid electrolytes that are particle-rich, soft glasses at room temperature; yet manifest high ionic conductivity and good electrochemical stability above 5V. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Sample classroom activities based on climate science

    Science.gov (United States)

    Miler, T.

    2009-09-01

    We present several activities developed for the middle school education based on a climate science. The first activity was designed to teach about the ocean acidification. A simple experiment can prove that absorption of CO2 in water increases its acidity. A liquid pH indicator is suitable for the demonstration in a classroom. The second activity uses data containing coordinates of a hurricane position. Pupils draw a path of a hurricane eye in a tracking chart (map of the Atlantic ocean). They calculate an average speed of the hurricane, investigate its direction and intensity development. The third activity uses pictures of the Arctic ocean on September when ice extend is usually the lowest. Students measure the ice extend for several years using a square grid printed on a plastic foil. Then they plot a graph and discuss the results. All these activities can be used to improve the natural science education and increase the climate change literacy.

  6. Science Shop and NGO activities related to air pollution

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard; Brodersen, Søsser

    2005-01-01

    The paper describes activities, which these organisations and science shops carry out within the field of air pollution and its analysis, abatement and prevention. The activities have been mapped and analysed through dialogue with a number of these organisations. The activities include activities...... with focus on development of citizens' capacity for measurement and assessment of air pollution and strategies for abatement and prevention of air pollution. The paper discusses also possibilities for further development of dialogue and co-operation between civil society, science shops and ACCENT researchers....

  7. Nanoscale superconducting memory based on the kinetic inductance of asymmetric nanowire loops

    Science.gov (United States)

    Murphy, Andrew; Averin, Dmitri V.; Bezryadin, Alexey

    2017-06-01

    The demand for low-dissipation nanoscale memory devices is as strong as ever. As Moore’s law is staggering, and the demand for a low-power-consuming supercomputer is high, the goal of making information processing circuits out of superconductors is one of the central goals of modern technology and physics. So far, digital superconducting circuits could not demonstrate their immense potential. One important reason for this is that a dense superconducting memory technology is not yet available. Miniaturization of traditional superconducting quantum interference devices is difficult below a few micrometers because their operation relies on the geometric inductance of the superconducting loop. Magnetic memories do allow nanometer-scale miniaturization, but they are not purely superconducting (Baek et al 2014 Nat. Commun. 5 3888). Our approach is to make nanometer scale memory cells based on the kinetic inductance (and not geometric inductance) of superconducting nanowire loops, which have already shown many fascinating properties (Aprili 2006 Nat. Nanotechnol. 1 15; Hopkins et al 2005 Science 308 1762). This allows much smaller devices and naturally eliminates magnetic-field cross-talk. We demonstrate that the vorticity, i.e., the winding number of the order parameter, of a closed superconducting loop can be used for realizing a nanoscale nonvolatile memory device. We demonstrate how to alter the vorticity in a controlled fashion by applying calibrated current pulses. A reliable read-out of the memory is also demonstrated. We present arguments that such memory can be developed to operate without energy dissipation.

  8. Assessment report of research and development activities. Activity: 'Advanced science research' (Pre-review report)

    International Nuclear Information System (INIS)

    2010-11-01

    Japan Atomic Energy Agency (hereinafter referred to as 'JAEA') consulted an assessment committee, 'Evaluation Committee of Research Activities for Advanced Science Research' (hereinafter referred to as 'Committee') for prior assessment of 'Advanced Science Research,' in accordance with 'General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by JAEA. In response to the JAEA's request, the Committee assessed the research program and activities of the Advanced Science Research Center (hereinafter referred to as 'ASRC') for the period of five years from April 2010. The Committee evaluated the management and the research program of the ASRC based on the explanatory documents prepared by the ASRC and the oral presentations with questions-and-answers by the Director and the research group leaders. This report summarizes the result of the assessment by the Committee with the Committee report attached from page 7. (author)

  9. Tuning the Friction of Silicon Surfaces Using Nanopatterns at the Nanoscale

    Directory of Open Access Journals (Sweden)

    Jing Han

    2017-12-01

    Full Text Available Friction and wear become significant at small scale lengths, particularly in MEMS/NEMS. Nanopatterns are regarded as a potential approach to solve these problems. In this paper, we investigated the friction behavior of nanopatterned silicon surfaces with a periodical rectangular groove array in dry and wear-less single-asperity contact at the nanoscale using molecular dynamics simulations. The synchronous and periodic oscillations of the normal load and friction force with the sliding distance were determined at frequencies defined by the nanopattern period. The linear load dependence of the friction force is always observed for the nanopatterned surface and is independent of the nanopattern geometry. We show that the linear friction law is a formal Amontons’ friction law, while the significant linear dependence of the friction force-versus-real contact area and real contact area-versus-normal load captures the general features of the nanoscale friction for the nanopatterned surface. Interestingly, the nanopattern increases the friction force at the nanoscale, and the desired friction reduction is also observed. The enlargement and reduction of the friction critically depended on the nanopattern period rather than the area ratio. Our simulation results reveal that the nanopattern can modulate the friction behavior at the nanoscale from the friction signal to the friction law and to the value of the friction force. Thus, elaborate nanopatterning is an effective strategy for tuning the friction behavior at the nanoscale.

  10. Computational optimization of catalyst distributions at the nano-scale

    International Nuclear Information System (INIS)

    Ström, Henrik

    2017-01-01

    Highlights: • Macroscopic data sampled from a DSMC simulation contain statistical scatter. • Simulated annealing is evaluated as an optimization algorithm with DSMC. • Proposed method is more robust than a gradient search method. • Objective function uses the mass transfer rate instead of the reaction rate. • Combined algorithm is more efficient than a macroscopic overlay method. - Abstract: Catalysis is a key phenomenon in a great number of energy processes, including feedstock conversion, tar cracking, emission abatement and optimizations of energy use. Within heterogeneous, catalytic nano-scale systems, the chemical reactions typically proceed at very high rates at a gas–solid interface. However, the statistical uncertainties characteristic of molecular processes pose efficiency problems for computational optimizations of such nano-scale systems. The present work investigates the performance of a Direct Simulation Monte Carlo (DSMC) code with a stochastic optimization heuristic for evaluations of an optimal catalyst distribution. The DSMC code treats molecular motion with homogeneous and heterogeneous chemical reactions in wall-bounded systems and algorithms have been devised that allow optimization of the distribution of a catalytically active material within a three-dimensional duct (e.g. a pore). The objective function is the outlet concentration of computational molecules that have interacted with the catalytically active surface, and the optimization method used is simulated annealing. The application of a stochastic optimization heuristic is shown to be more efficient within the present DSMC framework than using a macroscopic overlay method. Furthermore, it is shown that the performance of the developed method is superior to that of a gradient search method for the current class of problems. Finally, the advantages and disadvantages of different types of objective functions are discussed.

  11. Multiple simultaneous fabrication of molecular nanowires using nanoscale electrocrystallization

    International Nuclear Information System (INIS)

    Hasegawa, Hiroyuki; Ueda, Rieko; Kubota, Tohru; Mashiko, Shinro

    2006-01-01

    We carried out a multiple simultaneous fabrication based on the nanoscale electrocrystallization to simultaneously construct molecular nanowires at two or more positions. This substrate-independent nanoscale electrocrystallization process enables nanowires fabrication at specific positions using AC. We also succeeded in multiple fabrications only at each gap between the electrode tips. We found that π-stack was formed along the long axis of the nanowires obtained by analyzing the selected-area electron diffraction. We believe this technique has the potential for expansion to the novel low-cost and energy-saving fabrication of high-performance nanodevices

  12. Rockets: Physical science teacher's guide with activities

    Science.gov (United States)

    Vogt, Gregory L.; Rosenberg, Carla R. (Editor)

    1993-01-01

    This guide begins with background information sections on the history of rocketry, scientific principles, and practical rocketry. The sections on scientific principles and practical rocketry are based on Isaac Newton's three laws of motion. These laws explain why rockets work and how to make them more efficient. The background sections are followed with a series of physical science activities that demonstrate the basic science of rocketry. Each activity is designed to be simple and take advantage of inexpensive materials. Construction diagrams, materials and tools lists, and instructions are included. A brief discussion elaborates on the concepts covered in the activities and is followed with teaching notes and discussion questions. The guide concludes with a glossary of terms, suggested reading list, NASA educational resources, and an evaluation questionnaire with a mailer.

  13. Cell-specific STORM super-resolution imaging reveals nanoscale organization of cannabinoid signaling.

    Science.gov (United States)

    Dudok, Barna; Barna, László; Ledri, Marco; Szabó, Szilárd I; Szabadits, Eszter; Pintér, Balázs; Woodhams, Stephen G; Henstridge, Christopher M; Balla, Gyula Y; Nyilas, Rita; Varga, Csaba; Lee, Sang-Hun; Matolcsi, Máté; Cervenak, Judit; Kacskovics, Imre; Watanabe, Masahiko; Sagheddu, Claudia; Melis, Miriam; Pistis, Marco; Soltesz, Ivan; Katona, István

    2015-01-01

    A major challenge in neuroscience is to determine the nanoscale position and quantity of signaling molecules in a cell type- and subcellular compartment-specific manner. We developed a new approach to this problem by combining cell-specific physiological and anatomical characterization with super-resolution imaging and studied the molecular and structural parameters shaping the physiological properties of synaptic endocannabinoid signaling in the mouse hippocampus. We found that axon terminals of perisomatically projecting GABAergic interneurons possessed increased CB1 receptor number, active-zone complexity and receptor/effector ratio compared with dendritically projecting interneurons, consistent with higher efficiency of cannabinoid signaling at somatic versus dendritic synapses. Furthermore, chronic Δ(9)-tetrahydrocannabinol administration, which reduces cannabinoid efficacy on GABA release, evoked marked CB1 downregulation in a dose-dependent manner. Full receptor recovery required several weeks after the cessation of Δ(9)-tetrahydrocannabinol treatment. These findings indicate that cell type-specific nanoscale analysis of endogenous protein distribution is possible in brain circuits and identify previously unknown molecular properties controlling endocannabinoid signaling and cannabis-induced cognitive dysfunction.

  14. The significant role of plasmonic effects in femtosecond laser-induced grating fabrication on the nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Min; Zhao, Fuli [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou, 510275 (China); Cheng, Ya; Xu, Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai, 201800 (China)

    2013-02-15

    Nowadays, plasmonics aiming at manipulating light beyond the diffraction limit has aroused great interest on account of the promise of nanoscale optical devices. Generally, the ability to break diffraction barrier is achieved via controlling surface plasmons (SPs) on artificial structures as products of human ingenuity. Here, nevertheless, it is demonstrated that in short-pulse laser ablation ultrafast active plasmonic structures spontaneously generate by virtue of plasmonic effects rather than human will. First, with the experimental results on ZnO, Si, and GaAs, explicit evidence is provided for the grating-splitting phenomenon that acts as a direct route for the formation of laser-induced deep-subwavelength gratings. The splitting mechanism can break through the diffraction limit and push laser-induced structures towards the nanoscale. Then, through comprehensive numerical studies based on the viewpoint of plasmonics, it can be confirmed that the grating-splitting phenomenon originates in the conversion of SP modes from the resonant to the nonresonant mode and further to the inphase or antiphase asymmetric mode. In short, plasmonic effects play an important role in ultrafast laser-induced grating splitting towards the nanoscale, which will provide new insights into the mechanisms of ultrafast laser-induced nanostructures. (copyright 2012 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. The significant role of plasmonic effects in femtosecond laser-induced grating fabrication on the nanoscale

    International Nuclear Information System (INIS)

    Huang, Min; Zhao, Fuli; Cheng, Ya; Xu, Zhizhan

    2013-01-01

    Nowadays, plasmonics aiming at manipulating light beyond the diffraction limit has aroused great interest on account of the promise of nanoscale optical devices. Generally, the ability to break diffraction barrier is achieved via controlling surface plasmons (SPs) on artificial structures as products of human ingenuity. Here, nevertheless, it is demonstrated that in short-pulse laser ablation ultrafast active plasmonic structures spontaneously generate by virtue of plasmonic effects rather than human will. First, with the experimental results on ZnO, Si, and GaAs, explicit evidence is provided for the grating-splitting phenomenon that acts as a direct route for the formation of laser-induced deep-subwavelength gratings. The splitting mechanism can break through the diffraction limit and push laser-induced structures towards the nanoscale. Then, through comprehensive numerical studies based on the viewpoint of plasmonics, it can be confirmed that the grating-splitting phenomenon originates in the conversion of SP modes from the resonant to the nonresonant mode and further to the inphase or antiphase asymmetric mode. In short, plasmonic effects play an important role in ultrafast laser-induced grating splitting towards the nanoscale, which will provide new insights into the mechanisms of ultrafast laser-induced nanostructures. (copyright 2012 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Benchtop Nanoscale Patterning Using Soft Lithography

    Science.gov (United States)

    Meenakshi, Viswanathan; Babayan, Yelizaveta; Odom, Teri W.

    2007-01-01

    This paper outlines several benchtop nanoscale patterning experiments that can be incorporated into undergraduate laboratories or advanced high school chemistry curricula. The experiments, supplemented by an online video lab manual, are based on soft lithographic techniques such as replica molding, micro-molding in capillaries, and micro-contact…

  17. A Scale to Assess Science Activity Videos (SASAV): The Study of Validity and Reliability

    Science.gov (United States)

    Kara, Yilmaz; Bakirci, Hasan

    2018-01-01

    The purpose of the study was to develop an assessment scale for science activity videos that can be used to determine qualified science activity videos that can fulfill the objectives of activity based science education, help teachers to evaluate any science activity videos and decide whether to include into science learning process. The subjects…

  18. Programmed assembly of nanoscale structures using peptoids.

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Jianhua (University of the Pacific, Stockton, CA); Russell, Scott (California State University, Stanislaus, Turlock, CA); Morishetti, Kiran (University of the Pacific, Stockton, CA); Robinson, David B.; Zuckermann, Ronald N. (Lawrence Berkeley National Laboratory, Berkeley, CA); Buffleben, George M.; Hjelm, Rex P. (Los Alamos National Laboratory, Los Alamos, NM); Kent, Michael Stuart (Sandia National Laboratories, Albuquerque, NM)

    2011-02-01

    Sequence-specific polymers are the basis of the most promising approaches to bottom-up programmed assembly of nanoscale materials. Examples include artificial peptides and nucleic acids. Another class is oligo(N-functional glycine)s, also known as peptoids, which permit greater sidegroup diversity and conformational control, and can be easier to synthesize and purify. We have developed a set of peptoids that can be used to make inorganic nanoparticles more compatible with biological sequence-specific polymers so that they can be incorporated into nucleic acid or other biologically based nanostructures. Peptoids offer degrees of modularity, versatility, and predictability that equal or exceed other sequence-specific polymers, allowing for rational design of oligomers for a specific purpose. This degree of control will be essential to the development of arbitrarily designed nanoscale structures.

  19. Hybrid, Nanoscale Phospholipid/Block Copolymer Vesicles

    Directory of Open Access Journals (Sweden)

    Bo Liedberg

    2013-09-01

    Full Text Available Hybrid phospholipid/block copolymer vesicles, in which the polymeric membrane is blended with phospholipids, display interesting self-assembly behavior, incorporating the robustness and chemical versatility of polymersomes with the softness and biocompatibility of liposomes. Such structures can be conveniently characterized by preparing giant unilamellar vesicles (GUVs via electroformation. Here, we are interested in exploring the self-assembly and properties of the analogous nanoscale hybrid vesicles (ca. 100 nm in diameter of the same composition prepared by film-hydration and extrusion. We show that the self-assembly and content-release behavior of nanoscale polybutadiene-b-poly(ethylene oxide (PB-PEO/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC hybrid phospholipid/block copolymer vesicles can be tuned by the mixing ratio of the amphiphiles. In brief, these hybrids may provide alternative tools for drug delivery purposes and molecular imaging/sensing applications and clearly open up new avenues for further investigation.

  20. Molecular dynamics investigation of nanoscale substrate topography and its interaction with liquids

    Science.gov (United States)

    Cordeiro Rodrigues, Jhonatam

    Nanotechnology has been presenting successful applications in several areas. However, experimentation with nanoscale materials is costly and limited in analysis capability. This research investigates the use of molecular dynamics (MD) simulations to model and study nanomaterials and manufacturing processes. MD simulations are employed to reduce cost, optimize design, increase productivity and allow for the investigation of material interactions not yet observable through experimentation. This work investigates the interaction of water with substrates at the nanoscale. The effect of temperature, droplet impingement velocities and size, as well as substrate material, are investigated at the nanoscale. Several substrate topography designs were modeled to reveal their influence on the wettability of the substrate. Nanoscale gold and silicon substrates are more hydrophilic at higher temperatures than at room temperature. The reduction in droplet diameter increases its wettability. High impingement velocity of droplets does not influence final wettability of substrates but induces higher diffusion rates of droplets in a heated environment. Droplets deposited over a gradient of surface exposure presents spontaneous movement. The Leidenfrost effect was investigated at the nanoscale. Droplets of 4 and 10nm in diameter presented behaviors pertinent to the Leidenfrost effect at 373K, significantly lower than at micro scale and of potential impact to the field. Topographical features were manipulated using superhydrophobic coating resulting in micro whiskers. Nanoimprint lithography (NIL) was used to manufacture substrate topographies at the nanoscale. Water droplets were deposited on the substrates and their wettability was measured using droplet contact angles. Lower surface area exposure resulted in higher contact angles. The experimental relationships between surface topography and substrate wettability were used to validate the insights gained from MD simulations for

  1. Where Young People See Science: Everyday Activities Connected to Science

    Science.gov (United States)

    Zimmerman, Heather Toomey; Bell, Philip

    2014-01-01

    This project analyses the prevalence and social construction of science in the everyday activities of multicultural, multilingual children in one urban community. Using cross-setting ethnographic fieldwork (i.e. home, museum, school, community), we developed an ecologically grounded interview protocol and analytical scheme for gauging students'…

  2. Geometrical tuning of nanoscale split-ring resonators

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Kristensen, Anders; Xiao, Sanshui

    2010-01-01

    We investigate the capacitance tuning of nanoscale split-ring resonators. An LC-model predicts a simple dependence of resonance frequency on slit aspect ratio. Experimental and numerical data follow the predictions of the LC-model....

  3. Assessment report of research and development activities. Activity: 'Nuclear science and engineering research' (Interim report)

    International Nuclear Information System (INIS)

    2013-11-01

    Japan Atomic Energy Agency (hereinafter referred to as 'JAEA') consults an assessment committee, 'Evaluation Committee of Research Activities for Nuclear Science and Engineering' (hereinafter referred to as 'Committee') for interim assessment of 'Nuclear Science and Engineering,' in accordance with 'General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by the JAEA. In response to the JAEA's request, the Committee assessed the research program of the Nuclear Science and Engineering Directorate (hereinafter referred to as 'NSED') and Center for Computational Science and e-Systems (hereinafter referred to as 'CCSE') during the period of about four years from September 2008 to September 2012. The Committee evaluated the management and research activities of the NSED and the CCSE based on explanatory documents prepared by the NSED and the CCSE, and oral presentations with questions-and-answers by unit managers etc. A CD-ROM is attached as an appendix. (J.P.N.)

  4. Single molecules and single nanoparticles as windows to the nanoscale

    Science.gov (United States)

    Caldarola, Martín; Orrit, Michel

    2018-05-01

    Since the first optical detection of single molecules, they have been used as nanometersized optical sensors to explore the physical properties of materials and light-matter interaction at the nanoscale. Understanding nanoscale properties of materials is fundamental for the development of new technology that requires precise control of atoms and molecules when the quantum nature of matter cannot be ignored. In the following lines, we illustrate this journey into nanoscience with some experiments from our group.

  5. Nanofluidics: A New Arena for Materials Science.

    Science.gov (United States)

    Xu, Yan

    2018-01-01

    A significant growth of research in nanofluidics is achieved over the past decade, but the field is still facing considerable challenges toward the transition from the current physics-centered stage to the next application-oriented stage. Many of these challenges are associated with materials science, so the field of nanofluidics offers great opportunities for materials scientists to exploit. In addition, the use of unusual effects and ultrasmall confined spaces of well-defined nanofluidic environments would offer new mechanisms and technologies to manipulate nanoscale objects as well as to synthesize novel nanomaterials in the liquid phase. Therefore, nanofluidics will be a new arena for materials science. In the past few years, burgeoning progress has been made toward this trend, as overviewed in this article, including materials and methods for fabricating nanofluidic devices, nanofluidics with functionalized surfaces and functional material components, as well as nanofluidics for manipulating nanoscale materials and fabricating new nanomaterials. Many critical challenges as well as fantastic opportunities in this arena lie ahead. Some of those, which are of particular interest, are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Brillouin gain enhancement in nano-scale photonic waveguide

    Science.gov (United States)

    Nouri Jouybari, Soodabeh

    2018-05-01

    The enhancement of stimulated Brillouin scattering in nano-scale waveguides has a great contribution in the improvement of the photonic devices technology. The key factors in Brillouin gain are the electrostriction force and radiation pressure generated by optical waves in the waveguide. In this article, we have proposed a new scheme of nano-scale waveguide in which the Brillouin gain is considerably improved compared to the previously-reported schemes. The role of radiation pressure in the Brillouin gain was much higher than the role of the electrostriction force. The Brillouin gain strongly depends on the structural parameters of the waveguide and the maximum value of 12127 W-1 m-1 is obtained for the Brillouin gain.

  7. Nanoscale roughness contact in a slider-disk interface.

    Science.gov (United States)

    Hua, Wei; Liu, Bo; Yu, Shengkai; Zhou, Weidong

    2009-07-15

    The nanoscale roughness contact between molecularly smooth surfaces of a slider-disk interface in a hard disk drive is analyzed, and the lubricant behavior at very high shear rate is presented. A new contact model is developed to study the nanoscale roughness contact behavior by classifying various forms of contact into slider-lubricant contact, slider-disk elastic contact and plastic contact. The contact pressure and the contact probabilities of the three types of contact are investigated. The new contact model is employed to explain and provide insight to an interesting experimental result found in a thermal protrusion slider. The protrusion budget for head surfing in the lubricant, which is the ideal state for contact recording, is also discussed.

  8. Nanoscale roughness contact in a slider-disk interface

    International Nuclear Information System (INIS)

    Hua Wei; Liu Bo; Yu Shengkai; Zhou Weidong

    2009-01-01

    The nanoscale roughness contact between molecularly smooth surfaces of a slider-disk interface in a hard disk drive is analyzed, and the lubricant behavior at very high shear rate is presented. A new contact model is developed to study the nanoscale roughness contact behavior by classifying various forms of contact into slider-lubricant contact, slider-disk elastic contact and plastic contact. The contact pressure and the contact probabilities of the three types of contact are investigated. The new contact model is employed to explain and provide insight to an interesting experimental result found in a thermal protrusion slider. The protrusion budget for head surfing in the lubricant, which is the ideal state for contact recording, is also discussed.

  9. Cationic nanoparticles induce nanoscale disruption in living cell plasma membranes.

    Science.gov (United States)

    Chen, Jiumei; Hessler, Jessica A; Putchakayala, Krishna; Panama, Brian K; Khan, Damian P; Hong, Seungpyo; Mullen, Douglas G; Dimaggio, Stassi C; Som, Abhigyan; Tew, Gregory N; Lopatin, Anatoli N; Baker, James R; Holl, Mark M Banaszak; Orr, Bradford G

    2009-08-13

    It has long been recognized that cationic nanoparticles induce cell membrane permeability. Recently, it has been found that cationic nanoparticles induce the formation and/or growth of nanoscale holes in supported lipid bilayers. In this paper, we show that noncytotoxic concentrations of cationic nanoparticles induce 30-2000 pA currents in 293A (human embryonic kidney) and KB (human epidermoid carcinoma) cells, consistent with a nanoscale defect such as a single hole or group of holes in the cell membrane ranging from 1 to 350 nm(2) in total area. Other forms of nanoscale defects, including the nanoparticle porating agents adsorbing onto or intercalating into the lipid bilayer, are also consistent; although the size of the defect must increase to account for any reduction in ion conduction, as compared to a water channel. An individual defect forming event takes 1-100 ms, while membrane resealing may occur over tens of seconds. Patch-clamp data provide direct evidence for the formation of nanoscale defects in living cell membranes. The cationic polymer data are compared and contrasted with patch-clamp data obtained for an amphiphilic phenylene ethynylene antimicrobial oligomer (AMO-3), a small molecule that is proposed to make well-defined 3.4 nm holes in lipid bilayers. Here, we observe data that are consistent with AMO-3 making approximately 3 nm holes in living cell membranes.

  10. Nanoscale Correlated Disorder in Out-of-Equilibrium Myelin Ultrastructure.

    Science.gov (United States)

    Campi, Gaetano; Di Gioacchino, Michael; Poccia, Nicola; Ricci, Alessandro; Burghammer, Manfred; Ciasca, Gabriele; Bianconi, Antonio

    2018-01-23

    Ultrastructural fluctuations at nanoscale are fundamental to assess properties and functionalities of advanced out-of-equilibrium materials. We have taken myelin as a model of supramolecular assembly in out-of-equilibrium living matter. Myelin sheath is a simple stable multilamellar structure of high relevance and impact in biomedicine. Although it is known that myelin has a quasi-crystalline ultrastructure, there is no information on its fluctuations at nanoscale in different states due to limitations of the available standard techniques. To overcome these limitations, we have used scanning micro X-ray diffraction, which is a unique non-invasive probe of both reciprocal and real space to visualize statistical fluctuations of myelin order of the sciatic nerve of Xenopus laevis. The results show that the ultrastructure period of the myelin is stabilized by large anticorrelated fluctuations at nanoscale, between hydrophobic and hydrophilic layers. The ratio between the total thickness of hydrophilic and hydrophobic layers defines the conformational parameter, which describes the different states of myelin. Our key result is that myelin in its out-of-equilibrium functional state fluctuates point-to-point between different conformations showing a correlated disorder described by a Levy distribution. As the system approaches the thermodynamic equilibrium in an aged state, the disorder loses its correlation degree and the structural fluctuation distribution changes to Gaussian. In a denatured state at low pH, it changes to a completely disordered stage. Our results aim to clarify the degradation mechanism in biological systems by associating these states with ultrastructural dynamic fluctuations at nanoscale.

  11. VLSI micro- and nanophotonics science, technology, and applications

    CERN Document Server

    Lee, El-Hang; Razeghi, Manijeh; Jagadish, Chennupati

    2011-01-01

    Addressing the growing demand for larger capacity in information technology, VLSI Micro- and Nanophotonics: Science, Technology, and Applications explores issues of science and technology of micro/nano-scale photonics and integration for broad-scale and chip-scale Very Large Scale Integration photonics. This book is a game-changer in the sense that it is quite possibly the first to focus on ""VLSI Photonics"". Very little effort has been made to develop integration technologies for micro/nanoscale photonic devices and applications, so this reference is an important and necessary early-stage pe

  12. Simple Methods for Production of Nanoscale Metal Oxide Films from Household Sources

    Science.gov (United States)

    Campbell, Dean J.; Baliss, Michelle S.; Hinman, Jordan J.; Ziegenhorn, John W.; Andrews, Mark J.; Stevenson, Keith J.

    2013-01-01

    Production of thin metal oxide films was recently explored as part of an outreach program with a goal of producing nanoscale structures with household items. Household items coated with various metals or titanium compounds can be heated to produce colorful films with nanoscale thicknesses. As part of a materials chemistry laboratory experiment…

  13. Light-matter interaction physics and engineering at the nanoscale

    CERN Document Server

    Weiner, John

    2013-01-01

    This book draws together the essential elements of classical electrodynamics, surface wave physics, plasmonic materials, and circuit theory of electrical engineering to provide insight into the essential physics of nanoscale light-matter interaction and to provide design methodology for practical nanoscale plasmonic devices. A chapter on classical and quantal radiation also highlights the similarities (and differences) between the classical fields of Maxwell's equations and the wave functions of Schrodinger's equation. The aim of this chapter is to provide a semiclassical picture of atomic absorption and emission of radiation, lending credence and physical plausibility to the "rules" of standard wave-mechanical calculations.

  14. COMPUTATIONAL SCIENCE CENTER

    International Nuclear Information System (INIS)

    DAVENPORT, J.

    2006-01-01

    Computational Science is an integral component of Brookhaven's multi science mission, and is a reflection of the increased role of computation across all of science. Brookhaven currently has major efforts in data storage and analysis for the Relativistic Heavy Ion Collider (RHIC) and the ATLAS detector at CERN, and in quantum chromodynamics. The Laboratory is host for the QCDOC machines (quantum chromodynamics on a chip), 10 teraflop/s computers which boast 12,288 processors each. There are two here, one for the Riken/BNL Research Center and the other supported by DOE for the US Lattice Gauge Community and other scientific users. A 100 teraflop/s supercomputer will be installed at Brookhaven in the coming year, managed jointly by Brookhaven and Stony Brook, and funded by a grant from New York State. This machine will be used for computational science across Brookhaven's entire research program, and also by researchers at Stony Brook and across New York State. With Stony Brook, Brookhaven has formed the New York Center for Computational Science (NYCCS) as a focal point for interdisciplinary computational science, which is closely linked to Brookhaven's Computational Science Center (CSC). The CSC has established a strong program in computational science, with an emphasis on nanoscale electronic structure and molecular dynamics, accelerator design, computational fluid dynamics, medical imaging, parallel computing and numerical algorithms. We have been an active participant in DOES SciDAC program (Scientific Discovery through Advanced Computing). We are also planning a major expansion in computational biology in keeping with Laboratory initiatives. Additional laboratory initiatives with a dependence on a high level of computation include the development of hydrodynamics models for the interpretation of RHIC data, computational models for the atmospheric transport of aerosols, and models for combustion and for energy utilization. The CSC was formed to bring together

  15. Study of nanoscale structural biology using advanced particle beam microscopy

    Science.gov (United States)

    Boseman, Adam J.

    This work investigates developmental and structural biology at the nanoscale using current advancements in particle beam microscopy. Typically the examination of micro- and nanoscale features is performed using scanning electron microscopy (SEM), but in order to decrease surface charging, and increase resolution, an obscuring conductive layer is applied to the sample surface. As magnification increases, this layer begins to limit the ability to identify nanoscale surface structures. A new technology, Helium Ion Microscopy (HIM), is used to examine uncoated surface structures on the cuticle of wild type and mutant fruit flies. Corneal nanostructures observed with HIM are further investigated by FIB/SEM to provide detailed three dimensional information about internal events occurring during early structural development. These techniques are also used to reconstruct a mosquito germarium in order to characterize unknown events in early oogenesis. Findings from these studies, and many more like them, will soon unravel many of the mysteries surrounding the world of developmental biology.

  16. In-situ X-ray absorption spectroscopy analysis of capacity fade in nanoscale-LiCoO2

    International Nuclear Information System (INIS)

    Patridge, Christopher J.; Love, Corey T.; Swider-Lyons, Karen E.; Twigg, Mark E.; Ramaker, David E.

    2013-01-01

    The local structure of nanoscale (∼10–40 nm) LiCoO 2 is monitored during electrochemical cycling utilizing in-situ X-ray absorption spectroscopy (XAS). The high surface area of the LiCoO 2 nanoparticles not only enhances capacity fade, but also provides a large signal from the particle surface relative to the bulk. Changes in the nanoscale LiCoO 2 metal-oxide bond lengths, structural disorder, and chemical state are tracked during cycling by adapting the delta mu (Δμ) technique in complement with comprehensive extended X-ray absorption fine structure (EXAFS) modeling. For the first time, we use a Δμ EXAFS method, and by comparison of the difference EXAFS spectra, extrapolate significant coordination changes and reduction of cobalt species with cycling. This combined approach suggests Li–Co site exchange at the surface of the nanoscale LiCoO 2 as a likely factor in the capacity fade and irreversible losses in practical, microscale LiCoO 2 . - Graphical abstract: Electrochemical cycling of Li-ion batteries has strong impact on the structure and integrity of the cathode active material particularly near the surface/electrolyte interface. In developing a new method, we have used in-situ X-ray absorption spectroscopy during electrochemical cycling of nanoscale LiCoO 2 to track changes during charge and discharge and between subsequent cycles. Using difference spectra, several small changes in Co-O bond length, Co-O and Co-Co coordination, and site exchange between Co and Li sites can be tracked. These methods show promise as a new technique to better understand processes which lead to capacity fade and loss in Li-ion batteries. - Highlights: • A new method is developed to understand capacity fade in Li-ion battery cathodes. • Structural changes are tracked during Li intercalation/deintercalation of LiCoO 2 . • Surface structural changes are emphasized using nanoscale-LiCoO 2 and difference spectra. • Full multiple scattering calculations are used to

  17. Materials Science Division activity report 1991-1993

    International Nuclear Information System (INIS)

    Amarendra, G.; Tiwari, A.M.; Subramanian, N.; Venugopal Rao, G.

    1995-01-01

    This progress report gives an account of the various research and developmental activities carried out at the Materials Science Division of the Indira Gandhi Centre for Atomic Research, Kalpakkam during 1991-93. It also gives a summary of the results of the research activities, describes the experimental facilities and also list the publications

  18. Energy Storage. Teachers Guide. Science Activities in Energy.

    Science.gov (United States)

    Jacobs, Mary Lynn, Ed.

    Included in this science activities energy package for students in grades 4-10 are 12 activities related to energy storage. Each activity is outlined on the front and back of a single sheet and is introduced by a key question. Most of the activities can be completed in the classroom with materials readily available in any community. Among the…

  19. The influence of extracurricular activities on middle school students' science learning in China

    Science.gov (United States)

    Zhang, Danhui; Tang, Xing

    2017-07-01

    Informal science learning has been found to have effects on students' science learning. Through the use of secondary data from a national assessment of 7410 middle school students in China, this study explores the relationship among five types of extracurricular science activities, learning interests, academic self-concept, and science achievement. Structural equation modelling was used to investigate the influence of students' self-chosen and school-organised extracurricular activities on science achievement through mediating interests and the academic self-concept. Chi-square tests were used to determine whether there was an opportunity gap in the student's engagement in extracurricular activities. The students' volunteer and school-organised participation in extracurricular science activities had a positive and indirect influence on their science achievement through the mediating variables of their learning interests and academic self-concept. However, there were opportunity gaps between different groups of students in terms of school location, family background, and especially the mother's education level. Students from urban areas with better-educated mothers or higher socioeconomic status are more likely to access diverse science-related extracurricular activities.

  20. Nanoscale superconducting memory based on the kinetic inductance of asymmetric nanowire loops

    International Nuclear Information System (INIS)

    Murphy, Andrew; Bezryadin, Alexey; Averin, Dmitri V

    2017-01-01

    The demand for low-dissipation nanoscale memory devices is as strong as ever. As Moore’s law is staggering, and the demand for a low-power-consuming supercomputer is high, the goal of making information processing circuits out of superconductors is one of the central goals of modern technology and physics. So far, digital superconducting circuits could not demonstrate their immense potential. One important reason for this is that a dense superconducting memory technology is not yet available. Miniaturization of traditional superconducting quantum interference devices is difficult below a few micrometers because their operation relies on the geometric inductance of the superconducting loop. Magnetic memories do allow nanometer-scale miniaturization, but they are not purely superconducting (Baek et al 2014 Nat. Commun. 5 3888). Our approach is to make nanometer scale memory cells based on the kinetic inductance (and not geometric inductance) of superconducting nanowire loops, which have already shown many fascinating properties (Aprili 2006 Nat. Nanotechnol. 1 15; Hopkins et al 2005 Science 308 1762). This allows much smaller devices and naturally eliminates magnetic-field cross-talk. We demonstrate that the vorticity, i.e., the winding number of the order parameter, of a closed superconducting loop can be used for realizing a nanoscale nonvolatile memory device. We demonstrate how to alter the vorticity in a controlled fashion by applying calibrated current pulses. A reliable read-out of the memory is also demonstrated. We present arguments that such memory can be developed to operate without energy dissipation. (paper)

  1. Energy efficiency in nanoscale synthesis using nanosecond plasmas.

    Science.gov (United States)

    Pai, David Z; Ken Ostrikov, Kostya; Kumar, Shailesh; Lacoste, Deanna A; Levchenko, Igor; Laux, Christophe O

    2013-01-01

    We report a nanoscale synthesis technique using nanosecond-duration plasma discharges. Voltage pulses 12.5 kV in amplitude and 40 ns in duration were applied repetitively at 30 kHz across molybdenum electrodes in open ambient air, generating a nanosecond spark discharge that synthesized well-defined MoO₃ nanoscale architectures (i.e. flakes, dots, walls, porous networks) upon polyamide and copper substrates. No nitrides were formed. The energy cost was as low as 75 eV per atom incorporated into a nanostructure, suggesting a dramatic reduction compared to other techniques using atmospheric pressure plasmas. These findings show that highly efficient synthesis at atmospheric pressure without catalysts or external substrate heating can be achieved in a simple fashion using nanosecond discharges.

  2. Nanoscopy—imaging life at the nanoscale: a Nobel Prize achievement with a bright future

    International Nuclear Information System (INIS)

    Blom, Hans; Bates, Mark

    2015-01-01

    A grand scientific prize was awarded last year to three pioneering scientists, for their discovery and development of molecular ‘ON–OFF’ switching which, when combined with optical imaging, can be used to see the previously invisible with light microscopy. The Royal Swedish Academy of Science announced on October 8th their decision and explained that this achievement—rooted in physics and applied in biology and medicine—was awarded with the Nobel Prize in Chemistry for controlling fluorescent molecules to create images of specimens smaller than anything previously observed with light. The story of how this noble switch in optical microscopy was achieved and how it was engineered to visualize life at the nanoscale is highlighted in this invited comment. (invited comment)

  3. Synthesis, dynamics and photophysics of nanoscale systems

    Science.gov (United States)

    Mirkovic, Tihana

    The emerging field of nanotechnology, which spans diverse areas such as nanoelectronics, medicine, chemical and pharmaceutical industries, biotechnology and computation, focuses on the development of devices whose improved performance is based on the utilization of self-assembled nanoscale components exhibiting unique properties owing to their miniaturized dimensions. The first phase in the conception of such multifunctional devices based on integrated technologies requires the study of basic principles behind the functional mechanism of nanoscale components, which could originate from individual nanoobjects or result as a collective behaviour of miniaturized unit structures. The comprehensive studies presented in this thesis encompass the mechanical, dynamical and photophysical aspects of three nanoscale systems. A newly developed europium sulfide nanocrystalline material is introduced. Advances in synthetic methods allowed for shape control of surface-functionalized EuS nanocrystals and the fabrication of multifunctional EuS-CdSe hybrid particles, whose unique structural and optical properties hold promise as useful attributes of integrated materials in developing technologies. A comprehensive study based on a new class of multifunctional nanomaterials, derived from the basic unit of barcoded metal nanorods is presented. Their chemical composition affords them the ability to undergo autonomous motion in the presence of a suitable fuel. The nature of their chemically powered self-propulsion locomotion was investigated, and plausible mechanisms for various motility modes were presented. Furthermore functionalization of striped metallic nanorods has been realized through the incorporation of chemically controlled flexible hinges displaying bendable properties. The structural aspect of the light harvesting machinery of a photosynthetic cryptophyte alga, Rhodomonas CS24, and the mobility of the antenna protein, PE545, in vivo were investigated. Information obtained

  4. Molecular Building Blocks for Nanotechnology From Diamondoids to Nanoscale Materials and Applications

    CERN Document Server

    Mansoori, G. Ali; Assoufid, Lahsen; Zhang, Guoping

    2007-01-01

    This book is a result of the research and educational activities of a group of outstanding scientists worldwide who have authored the chapters of this book dealing with the behavior of nanoscale building blocks. It contains a variety of subjects covering computational, dry and wet nanotechnology. The state-of-the-art subject matters presented here provide the reader with the latest developments on ongoing nanoscience and nanotechnology research from the bottom-up approach, which starts with with atoms and molecules as molecular building blocks.

  5. Nanoscale wide-band semiconductors for photocatalytic remediation of aquatic pollution.

    Science.gov (United States)

    Sarkar, Biplab; Daware, Akshay Vishnu; Gupta, Priya; Krishnani, Kishore Kumar; Baruah, Sunandan; Bhattacharjee, Surajit

    2017-11-01

    Water pollution is a serious challenge to the public health. Among different forms of aquatic pollutants, chemical and biological agents create paramount threat to water quality when the safety standards are surpassed. There are many conventional remediatory strategies that are practiced such as resin-based exchanger and activated charcoal/carbon andreverse osmosis. Newer technologies using plants, microorganisms, genetic engineering, and enzyme-based approaches are also proposed for aquatic pollution management. However, the conventional technologies have shown impending inadequacies. On the other hand, new bio-based techniques have failed to exhibit reproducibility, wide specificity, and fidelity in field conditions. Hence, to solve these shortcomings, nanotechnology ushered a ray of hope by applying nanoscale zinc oxide (ZnO), titanium dioxide (TiO 2 ), and tungsten oxide (WO 3 ) particles for the remediation of water pollution. These nanophotocatalysts are active, cost-effective, quicker in action, and can be implemented at a larger scale. These nanoparticles are climate-independent, assist in complete mineralization of pollutants, and can act non-specifically against chemically and biologically based aquatic pollutants. Photocatalysis for environmental remediation depends on the availability of solar light. The mechanism of photocatalysis involves the formation of electron-hole pairs upon light irradiations at intensities higher than their band gap energies. In the present review, different methods of synthesis of nanoscale ZnO, TiO 2 , and WO 3 as well as their structural characterizations have been discussed. Photodegradation of organic pollutants through mentioned nanoparticles has been reviewed with recent advancements. Enhancing the efficacy of photocatalysis through doping of TiO 2 and ZnO nanoparticles with non-metals, metals, and metal ions has also been documented in this report.

  6. Quantitative nanoscale surface voltage measurement on organic semiconductor blends

    International Nuclear Information System (INIS)

    Cuenat, Alexandre; Muñiz-Piniella, Andrés; Muñoz-Rojo, Miguel; Murphy, Craig E; Tsoi, Wing C

    2012-01-01

    We report on the validation of a method based on Kelvin probe force microscopy (KPFM) able to measure the different phases and the relative work function of polymer blend heterojunctions at the nanoscale. The method does not necessitate complex ultra-high vacuum setup. The quantitative information that can be extracted from the topography and the Kelvin probe measurements is critically analysed. Surface voltage difference can be observed at the nanoscale on poly(3-hexyl-thiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) blends and dependence on the annealing condition and the regio-regularity of P3HT is observed. (paper)

  7. 75 FR 9007 - National Science and Technology Council, Committee on Technology Capstone Workshop Risk...

    Science.gov (United States)

    2010-02-26

    ... Nanotechnology: Public Meeting ACTION: Notice of public meeting. SUMMARY: The National Nanotechnology Coordination Office (NNCO), on behalf of the Nanoscale Science, Engineering, and Technology (NSET) Subcommittee... and Ethical, Legal, and Societal Implications (ELSI) of Nanotechnology. Risk Management Methods is one...

  8. Elementary school science teachers' reflection for nature of science: Workshop of NOS explicit and reflective on force and motion learning activity

    Science.gov (United States)

    Patho, Khanittha; Yuenyong, Chokchai; Chamrat, Suthida

    2018-01-01

    The nature of science has been part of Thailand's science education curriculum since 2008. However, teachers lack of understanding about the nature of science (NOS) and its teaching, particularly element school science teachers. In 2012, the Science Institute of Thailand MOE, started a project of Elementary Science Teacher Professional Development to enhance their thinking about the Nature of Science. The project aimed to enhance teachers' understanding of NOS, science teaching for explicit and reflective NOS, with the aim of extending their understanding of NOS to other teachers. This project selected 366 educational persons. The group was made up of a teacher and a teacher supervisor from 183 educational areas in 74 provinces all Thailand. The project provided a one week workshop and a year's follow up. The week-long workshop consisted of 11 activities of science teaching for explicit reflection on 8 aspects of NOS. Workshop of NOS explicit and reflective on force and motion learning activity is one of eight activities. This activity provided participants to learn force and motion and NOS from the traditional toy "Bang-Poh". The activity tried to enhance participants to explicit NOS for 5 aspects including empirical basis, subjectivity, creativity, observation and inference, and sociocultural embeddedness. The explicit NOS worksheet provided questions to ask participants to reflect their existing ideas about NOS. The paper examines elementary school science teachers' understanding of NOS from the force and motion learning activity which provided explicit reflection on 5 NOS aspects. An interpretive paradigm was used to analyse the teachers' reflections in a NOS worksheet. The findings indicated that majority of them could reflect about the empirical basis of science and creativity but few reflected on observation and inference, or sociocultural embeddedness. The paper will explain the teachers' NOS thinking and discuss the further enhancing of their understanding

  9. The effect of science demonstrations as a community service activity on pre-service science teachers' teaching practices

    Science.gov (United States)

    Gurel, Derya Kaltakci

    2016-03-01

    In the scope of this study, pre-service science teachers (PSST) developed and carried out science demonstrations with everyday materials for elementary school students as a community service activity. 17 PSST enrolled in the community services practices course at Kocaeli University comprised the sample of the present study. Community service practices aim to develop consciousness of social responsibility and professional skills, as well as to gain awareness of social and community problems and find solutions for pre-service teachers. With this aim, each PSST developed five science demonstration activities and their brochures during a semester. At the end of the semester, a total of 85 demonstrations were carried out at public elementary schools, which are especially located in socioeconomically poor districts of Kocaeli, Turkey. In the present case study, the effect of developing and carrying out science demonstrations for elementary school students on six of the PSST' teaching practices on density and buoyancy concept was investigated. 30-minute interviews conducted with each PSST, videos recorded during their demonstration performances, brochures they prepared for their demonstration activities, and reflection papers were used as data collection tools of the study. The results showed that community service practices with science demonstrations had positive effects on PSST' science content knowledge and pedagogical content knowledge.

  10. Neutron activation analysis - an aid to forensic science

    International Nuclear Information System (INIS)

    Chattopadhyay, N.; Basu, A.K.; Tripathi, A.B.R.; Bhadkambekar, C.A.; Shukla, S.K.

    2006-01-01

    Forensic Science is oriented towards the examination of evidence specimens, collected from a scene of crime in order to establish the link between the criminal and the crime. This science therefore has a profound role to play in criminal justice delivery system. The importance of neutron activation analysis (NAA) as a specialised technique to aid crime investigation has emerged and has been recognised

  11. The influence of thermal and conductive temperatures in a nanoscale resonator

    Science.gov (United States)

    Hobiny, Aatef; Abbas, Ibrahim A.

    2018-06-01

    In this work, the thermoelastic interaction in a nano-scale resonator based on two-temperature Green-Naghdi model is established. The nanoscale resonator ends were simply supported. In the Laplace's domain, the analytical solution of conductivity temperature and thermodynamic temperature, the displacement and the stress components are obtained. The eigenvalue approach resorted to for solutions. In the vector-matrix differential equations form, the essential equations were written. The numerical results for all variables are presented and are illustrated graphically.

  12. Simultaneous topographical, electrical and optical microscopy of optoelectronic devices at the nanoscale

    KAUST Repository

    Kumar, Naresh

    2017-01-12

    Novel optoelectronic devices rely on complex nanomaterial systems where the nanoscale morphology and local chemical composition are critical to performance. However, the lack of analytical techniques that can directly probe these structure-property relationships at the nanoscale presents a major obstacle to device development. In this work, we present a novel method for non-destructive, simultaneous mapping of the morphology, chemical composition and photoelectrical properties with <20 nm spatial resolution by combining plasmonic optical signal enhancement with electrical-mode scanning probe microscopy. We demonstrate that this combined approach offers subsurface sensitivity that can be exploited to provide molecular information with a nanoscale resolution in all three spatial dimensions. By applying the technique to an organic solar cell device, we show that the inferred surface and subsurface composition distribution correlates strongly with the local photocurrent generation and explains macroscopic device performance. For instance, the direct measurement of fullerene phase purity can distinguish between high purity aggregates that lead to poor performance and lower purity aggregates (fullerene intercalated with polymer) that result in strong photocurrent generation and collection. We show that the reliable determination of the structure-property relationship at the nanoscale can remove ambiguity from macroscopic device data and support the identification of the best routes for device optimisation. The multi-parameter measurement approach demonstrated herein is expected to play a significant role in guiding the rational design of nanomaterial-based optoelectronic devices, by opening a new realm of possibilities for advanced investigation via the combination of nanoscale optical spectroscopy with a whole range of scanning probe microscopy modes.

  13. Nanoscale mechanical stimulation method for quantifying C. elegans mechanosensory behavior and memory

    OpenAIRE

    Kiso, Kaori; Sugi, Takuma; Okumura, Etsuko; Igarashi, Ryuji

    2016-01-01

    Here, we establish a novel economic system to quantify C. elegans mechanosensory behavior and memory by a controllable nanoscale mechanical stimulation. Using piezoelectric sheet speaker, we can flexibly change the vibration properties at a nanoscale displacement level and quantify behavioral responses and memory under the control of each vibration property. This system will facilitate understanding of physiological aspects of C. elegans mechanosensory behavior and memory.

  14. Common Principles of Molecular Electronics and Nanoscale Electrochemistry.

    Science.gov (United States)

    Bueno, Paulo Roberto

    2018-05-24

    The merging of nanoscale electronics and electrochemistry can potentially modernize the way electronic devices are currently engineered or constructed. It is well known that the greatest challenges will involve not only miniaturizing and improving the performance of mobile devices, but also manufacturing reliable electrical vehicles, and engineering more efficient solar panels and energy storage systems. These are just a few examples of how technological innovation is dependent on both electrochemical and electronic elements. This paper offers a conceptual discussion of this central topic, with particular focus on the impact that uniting physical and chemical concepts at a nanoscale could have on the future development of electroanalytical devices. The specific example to which this article refers pertains to molecular diagnostics, i.e., devices that employ physical and electrochemical concepts to diagnose diseases.

  15. Nanoscale synthesis and characterization of graphene-based objects

    Directory of Open Access Journals (Sweden)

    Daisuke Fujita

    2011-01-01

    Full Text Available Graphene-based nano-objects such as nanotrenches, nanowires, nanobelts and nanoscale superstructures have been grown by surface segregation and precipitation on carbon-doped mono- and polycrystalline nickel substrates in ultrahigh vacuum. The dominant morphologies of the nano-objects were nanowire and nanosheet. Nucleation of graphene sheets occurred at surface defects such as step edges and resulted in the directional growth of nanowires. Surface analysis by scanning tunneling microscopy (STM has clarified the structure and functionality of the novel nano-objects at atomic resolution. Nanobelts were detected consisting of bilayer graphene sheets with a nanoscale width and a length of several microns. Moiré patterns and one-dimensional reconstruction were observed on multilayer graphite terraces. As a useful functionality, application to repairable high-resolution STM probes is demonstrated.

  16. Ion concentration in micro and nanoscale electrospray emitters.

    Science.gov (United States)

    Yuill, Elizabeth M; Baker, Lane A

    2018-06-01

    Solution-phase ion transport during electrospray has been characterized for nanopipettes, or glass capillaries pulled to nanoscale tip dimensions, and micron-sized electrospray ionization emitters. Direct visualization of charged fluorophores during the electrospray process is used to evaluate impacts of emitter size, ionic strength, analyte size, and pressure-driven flow on heterogeneous ion transport during electrospray. Mass spectrometric measurements of positively- and negatively-charged proteins were taken for micron-sized and nanopipette emitters under low ionic strength conditions to further illustrate a discrepancy in solution-driven transport of charged analytes. A fundamental understanding of analyte electromigration during electrospray, which is not always considered, is expected to provide control over selective analyte depletion and enrichment, and can be harnessed for sample cleanup. Graphical abstract Fluorescence micrographs of ion migration in nanoscale pipettes while solution is electrosprayed.

  17. Nanoscale biomemory composed of recombinant azurin on a nanogap electrode

    International Nuclear Information System (INIS)

    Chung, Yong-Ho; Lee, Taek; Choi, Jeong-Woo; Park, Hyung Ju; Yun, Wan Soo; Min, Junhong

    2013-01-01

    We fabricate a nanoscale biomemory device composed of recombinant azurin on nanogap electrodes. For this, size-controllable nanogap electrodes are fabricated by photolithography, electron beam lithography, and surface catalyzed chemical deposition. Moreover, we investigate the effect of gap distance to optimize the size of electrodes for a biomemory device and explore the mechanism of electron transfer from immobilized protein to a nanogap counter-electrode. As the distance of the nanogap electrode is decreased in the nanoscale, the absolute current intensity decreases according to the distance decrement between the electrodes due to direct electron transfer, in contrast with the diffusion phenomenon of a micro-electrode. The biomemory function is achieved on the optimized nanogap electrode. These results demonstrate that the fabricated nanodevice composed of a nanogap electrode and biomaterials provides various advantages such as quantitative control of signals and exclusion of environmental effects such as noise. The proposed bioelectronics device, which could be mass-produced easily, could be applied to construct a nanoscale bioelectronics system composed of a single biomolecule. (paper)

  18. Extremely flexible nanoscale ultrathin body silicon integrated circuits on plastic.

    Science.gov (United States)

    Shahrjerdi, Davood; Bedell, Stephen W

    2013-01-09

    In recent years, flexible devices based on nanoscale materials and structures have begun to emerge, exploiting semiconductor nanowires, graphene, and carbon nanotubes. This is primarily to circumvent the existing shortcomings of the conventional flexible electronics based on organic and amorphous semiconductors. The aim of this new class of flexible nanoelectronics is to attain high-performance devices with increased packing density. However, highly integrated flexible circuits with nanoscale transistors have not yet been demonstrated. Here, we show nanoscale flexible circuits on 60 Å thick silicon, including functional ring oscillators and memory cells. The 100-stage ring oscillators exhibit the stage delay of ~16 ps at a power supply voltage of 0.9 V, the best reported for any flexible circuits to date. The mechanical flexibility is achieved by employing the controlled spalling technology, enabling the large-area transfer of the ultrathin body silicon devices to a plastic substrate at room temperature. These results provide a simple and cost-effective pathway to enable ultralight flexible nanoelectronics with unprecedented level of system complexity based on mainstream silicon technology.

  19. Examination of Pre-Service Science Teachers' Activities Using Problem Based Learning Method

    Science.gov (United States)

    Ekici, Didem Inel

    2016-01-01

    In this study, both the activities prepared by pre-service science teachers regarding the Problem Based Learning method and the pre-service science teachers' views regarding the method were examined before and after applying their activities in a real class environment. 69 pre-service science teachers studying in the 4th grade of the science…

  20. In-situ X-ray absorption spectroscopy analysis of capacity fade in nanoscale-LiCoO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Patridge, Christopher J. [NRC/NRL Cooperative Research Associate, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Love, Corey T., E-mail: corey.love@nrl.navy.mil [Chemistry Division, Code 6113, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Swider-Lyons, Karen E. [Chemistry Division, Code 6113, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Twigg, Mark E. [Electronics Science and Technology Division, Code 6812, U.S. Naval Research Laboratory, Washington, DC 20375 (United States); Ramaker, David E. [Chemistry Division, Code 6189, U.S. Naval Research laboratory, Washington, DC 20375 (United States)

    2013-07-15

    The local structure of nanoscale (∼10–40 nm) LiCoO{sub 2} is monitored during electrochemical cycling utilizing in-situ X-ray absorption spectroscopy (XAS). The high surface area of the LiCoO{sub 2} nanoparticles not only enhances capacity fade, but also provides a large signal from the particle surface relative to the bulk. Changes in the nanoscale LiCoO{sub 2} metal-oxide bond lengths, structural disorder, and chemical state are tracked during cycling by adapting the delta mu (Δμ) technique in complement with comprehensive extended X-ray absorption fine structure (EXAFS) modeling. For the first time, we use a Δμ EXAFS method, and by comparison of the difference EXAFS spectra, extrapolate significant coordination changes and reduction of cobalt species with cycling. This combined approach suggests Li–Co site exchange at the surface of the nanoscale LiCoO{sub 2} as a likely factor in the capacity fade and irreversible losses in practical, microscale LiCoO{sub 2}. - Graphical abstract: Electrochemical cycling of Li-ion batteries has strong impact on the structure and integrity of the cathode active material particularly near the surface/electrolyte interface. In developing a new method, we have used in-situ X-ray absorption spectroscopy during electrochemical cycling of nanoscale LiCoO{sub 2} to track changes during charge and discharge and between subsequent cycles. Using difference spectra, several small changes in Co-O bond length, Co-O and Co-Co coordination, and site exchange between Co and Li sites can be tracked. These methods show promise as a new technique to better understand processes which lead to capacity fade and loss in Li-ion batteries. - Highlights: • A new method is developed to understand capacity fade in Li-ion battery cathodes. • Structural changes are tracked during Li intercalation/deintercalation of LiCoO{sub 2}. • Surface structural changes are emphasized using nanoscale-LiCoO{sub 2} and difference spectra. • Full multiple

  1. Nanoscale rectenna for broadband rectification of light from infrared to visible

    Science.gov (United States)

    Zimmerman, Darin; Chen, James; Phillips, Michael; Rager, Dennis; Sinisi, Zachary; Wambold, Raymond; Weisel, Gary; Weiss, Brock; Willis, Brian; Miskovsky, Nicholas

    2014-03-01

    We describe a novel approach to the efficient collection and rectification of solar radiation in a device designed to operate from the infrared through the visible. Here, a nanoscale, rectenna array acts both as an absorber of incident radiation and as a rectifier. Rectification derives not from temperature or material asymmetry, as with metal-insulator-metal or silicon-based, Schottky diodes. Instead, it derives from the geometric asymmetry of the rectenna, which is composed of a pointed tip and a flat collector anode. In this arrangement, the difference between the potential barriers for forward and reverse bias results in a rectified dc current. To achieve anode-cathode gap distances within the tunneling regime, we employ selective atomic-layer deposition of copper applied to palladium rectenna arrays produced by electron-beam lithography. We present details of device fabrication and preliminary results of computer simulation, optical characterization, and electro-optical response. This work supported in part by the National Science Foundation: ECCS-1231248 and ECCS-1231313.

  2. Nanoscale Dimples for Improved Absorption in and Efficiency of Organic Solar Cells

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr

    Organic solar cells (OSC’s) have attracted much attention in the past years due to their low costs, light weight and mechanical flexibility. A promising method for improving the power conversion efficiencies of the devices is by incorporating structured electrodes in the solar cell architecture....... That way light absorption in the active layers of the devices can be improved. A cheap and large-scale production compatible method for structuring the electrodes in OSC’s is by the use of Anodic Alumina Oxide (AAO) membranes. Here, nano-scale pores of controlled dimensions are formed through anodic...

  3. Investigating the status and barriers of science laboratory activities ...

    African Journals Online (AJOL)

    This study aims at investigating the barriers encountered by science teachers in laboratory activities in Rwandan teacher training colleges (TTCs) using questionnaires and interviews. The results confirmed that teachers face barriers like time limitation, material scarcity and lack of improvising skills in their everyday science ...

  4. Nanoscale microstructural characterization of a nanobainitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Timokhina, I.B., E-mail: ilana.timokhina@eng.monash.edu.au [Centre for Material and Fibre Innovation, Deakin University, Victoria 3216 (Australia); Beladi, H. [Centre for Material and Fibre Innovation, Deakin University, Victoria 3216 (Australia); Xiong, X.Y. [Monash Centre for Electron Microscopy, Monash University, Victoria 3800 (Australia); Adachi, Y. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Hodgson, P.D. [Centre for Material and Fibre Innovation, Deakin University, Victoria 3216 (Australia)

    2011-08-15

    A 0.79 C-1.5 Si-1.98 Mn-0.98 Cr-0.24 Mo-1.06 Al-1.58 Co (wt.%) steel was isothermally heat treated at 200 deg. C for 10 days and 350 deg. C for 1 day to form a nanoscale bainitic microstructure consisting of nanobainitic ferrite laths with high dislocation density and retained austenite films. The microstructures of the samples were characterized by transmission electron microscopy and atom probe tomography. Despite the formation of nanoscale bainite with a high volume fraction of retained austenite in both steels, the ductility of both steels was surprisingly low. It is believed that this was associated with the formation of carbon-depleted retained austenite after isothermal transformation at 200 deg. C due to the formation of high number of Fe-C clusters and particles in the bainitic ferrite laths and carbon-enriched austenite after isothermal transformation at 350 deg. C.

  5. A study of estimating cutting depth for multi-pass nanoscale cutting by using atomic force microscopy

    International Nuclear Information System (INIS)

    Lin, Zone-Ching; Hsu, Ying-Chih

    2012-01-01

    This paper studies two models for estimating cutting depth of multi-pass nanoscale cutting by using an atomic force microscopy (AFM) probe. One estimates cutting depth for multi-pass nanoscale cutting by using regression equations of nanoscale contact pressure factor (NCP factor) while the other uses equation of specific down force energy (SDFE). This paper proposes taking a diamond-coated probe of AFM as the cutting tool to carry out multi-pass nanoscale cutting experiments on the surface of sapphire substrate. In the process of experimentation, different down forces are set, and the probe shape of AFM is known, then using each down force to multi-pass cutting the sapphire substrate. From the measured experimental data of a central cutting depth of the machining groove by AFM, this paper calculates the specific down force energy of each down force. The experiment results reveal that the specific down force energy of each case of multi-pass nanoscale cutting for different down forces under a probe of AFM is close to a constant value. This paper also compares the nanoscale cutting results from estimating cutting depths for each pass of multi-pass among the experimental results and the calculating results obtained by the two theories models. It is found that the model of specific down force energy can calculate cutting depths for each nanoscale cutting pass by one equation. It is easier to use than the multi-regression equations of the nanoscale contact pressure factor. Besides, the estimations of cutting depth results obtained by the model of specific down force energy are closer to that of the experiment results. It shows that the proposed specific down force energy model in this paper is an acceptable model.

  6. Science Engagement Through Hands-On Activities that Promote Scientific Thinking and Generate Excitement and Awareness of NASA Assets, Missions, and Science

    Science.gov (United States)

    Graff, P. V.; Foxworth, S.; Miller, R.; Runco, S.; Luckey, M. K.; Maudlin, E.

    2018-01-01

    The public with hands-on activities that infuse content related to NASA assets, missions, and science and reflect authentic scientific practices promotes understanding and generates excitement about NASA science, research, and exploration. These types of activities expose our next generation of explorers to science they may be inspired to pursue as a future STEM career and expose people of all ages to unique, exciting, and authentic aspects of NASA exploration. The activities discussed here (Blue Marble Matches, Lunar Geologist Practice, Let's Discover New Frontiers, Target Asteroid, and Meteorite Bingo) have been developed by Astromaterials Research and Exploration Science (ARES) Science Engagement Specialists in conjunction with ARES Scientists at the NASA Johnson Space Center. Activities are designed to be usable across a variety of educational environments (formal and informal) and reflect authentic scientific content and practices.

  7. Quantification of nanoscale density fluctuations by electron microscopy: probing cellular alterations in early carcinogenesis

    International Nuclear Information System (INIS)

    Pradhan, Prabhakar; Damania, Dhwanil; Turzhitsky, Vladimir; Subramanian, Hariharan; Backman, Vadim; Joshi, Hrushikesh M; Dravid, Vinayak P; Roy, Hemant K; Taflove, Allen

    2011-01-01

    Most cancers are curable if they are diagnosed and treated at an early stage. Recent studies suggest that nanoarchitectural changes occur within cells during early carcinogenesis and that such changes precede microscopically evident tissue alterations. It follows that the ability to comprehensively interrogate cell nanoarchitecture (e.g., macromolecular complexes, DNA, RNA, proteins and lipid membranes) could be critical to the diagnosis of early carcinogenesis. We present a study of the nanoscale mass-density fluctuations of biological tissues by quantifying their degree of disorder at the nanoscale. Transmission electron microscopy images of human tissues are used to construct corresponding effective disordered optical lattices. The properties of nanoscale disorder are then studied by statistical analysis of the inverse participation ratio (IPR) of the spatially localized eigenfunctions of these optical lattices at the nanoscale. Our results show an increase in the disorder of human colonic epithelial cells in subjects harboring early stages of colon neoplasia. Furthermore, our findings strongly suggest that increased nanoscale disorder correlates with the degree of tumorigenicity. Therefore, the IPR technique provides a practicable tool for the detection of nanoarchitectural alterations in the earliest stages of carcinogenesis. Potential applications of the technique for early cancer screening and detection are also discussed

  8. Collaborative activities for improving the quality of science teaching and learning and learning to teach science

    Science.gov (United States)

    Tobin, Kenneth

    2012-03-01

    I have been involved in research on collaborative activities for improving the quality of teaching and learning high school science. Initially the collaborative activities we researched involved the uses of coteaching and cogenerative dialogue in urban middle and high schools in Philadelphia and New York (currently I have active research sites in New York and Brisbane, Australia). The research not only transformed practices but also produced theories that informed the development of additional collaborative activities and served as interventions for research and creation of heuristics for professional development programs and teacher certification courses. The presentation describes a collage of collaborative approaches to teaching and learning science, including coteaching, cogenerative dialogue, radical listening, critical reflection, and mindful action. For each activity in the collage I provide theoretical frameworks and empirical support, ongoing research, and priorities for the road ahead. I also address methodologies used in the research, illustrating how teachers and students collaborated as researchers in multilevel investigations of teaching and learning and learning to teach that included ethnography, video analysis, and sophisticated analyses of the voice, facial expression of emotion, eye gaze, and movement of the body during classroom interactions. I trace the evolution of studies of face-to-face interactions in science classes to the current focus on emotions and physiological aspects of teaching and learning (e.g., pulse rate, pulse strength, breathing patterns) that relate to science participation and achievement.

  9. Nanoscale effects in dendrimer-mediated targeting of neuroinflammation.

    Science.gov (United States)

    Nance, Elizabeth; Zhang, Fan; Mishra, Manoj K; Zhang, Zhi; Kambhampati, Siva P; Kannan, Rangaramanujam M; Kannan, Sujatha

    2016-09-01

    Neuroinflammation, mediated by activated microglia and astrocytes, plays a key role in the pathogenesis of many neurological disorders. Systemically-administered dendrimers target neuroinflammation and deliver drugs with significant efficacy, without the need for ligands. Elucidating the nanoscale aspects of targeting neuroinflammation will enable superior nanodevices for eventual translation. Using a rabbit model of cerebral palsy, we studied the in vivo contributions of dendrimer physicochemical properties and disease pathophysiology on dendrimer brain uptake, diffusion, and cell specific localization. Neutral dendrimers move efficiently within the brain parenchyma and rapidly localize in glial cells in regions of injury. Dendrimer uptake is also dependent on the extent of blood-brain-barrier breakdown, glial activation, and disease severity (mild, moderate, or severe), which can lend the dendrimer to be used as an imaging biomarker for disease phenotype. This new understanding of the in vivo mechanism of dendrimer-mediated delivery in a clinically-relevant rabbit model provides greater opportunity for clinical translation of targeted brain injury therapies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Self-assembly of nanoscale particles with biosurfactants and membrane scaffold proteins.

    Science.gov (United States)

    Faas, Ramona; Pohle, Annelie; Moß, Karin; Henkel, Marius; Hausmann, Rudolf

    2017-12-01

    Nanodiscs are membrane mimetics which may be used as tools for biochemical and biophysical studies of a variety of membrane proteins. These nanoscale structures are composed of a phospholipid bilayer held together by an amphipathic membrane scaffold protein (MSP). In the past, nanodiscs were successfully assembled with membrane scaffold protein 1D1 and 1,2-dipalmitoyl- sn -glycero-3-phosphorylcholine with a homogeneous diameter of ∼10 nm. In this study, the formation of nanoscale particles from MSP1D1 and rhamnolipid biosurfactants is investigated. Different protein to lipid ratios of 1:80, 1:90 and 1:100 were used for the assembly reaction, which were consecutively separated, purified and analyzed by size-exclusion chromatography (SEC) and dynamic light scattering (DLS). Size distributions were measured to determine homogeneity and confirm size dimensions. In this study, first evidence is presented on the formation of nanoscale particles with rhamnolipid biosurfactants and membrane scaffold proteins.

  11. Crystallization of high-strength nano-scale leucite glass-ceramics.

    Science.gov (United States)

    Theocharopoulos, A; Chen, X; Wilson, R M; Hill, R; Cattell, M J

    2013-11-01

    Fine-grained, high strength, translucent leucite dental glass-ceramics are synthesized via controlled crystallization of finely milled glass powders. The objectives of this study were to utilize high speed planetary milling of an aluminosilicate glass for controlled surface crystallization of nano-scale leucite glass-ceramics and to test the biaxial flexural strength. An aluminosilicate glass was synthesized, attritor or planetary milled and heat-treated. Glasses and glass-ceramics were characterized using particle size analysis, X-ray diffraction and scanning electron microscopy. Experimental (fine and nanoscale) and commercial (Ceramco-3, IPS Empress Esthetic) leucite glass-ceramics were tested using the biaxial flexural strength (BFS) test. Gaussian and Weibull statistics were applied. Experimental planetary milled glass-ceramics showed an increased leucite crystal number and nano-scale median crystal sizes (0.048-0.055 μm(2)) as a result of glass particle size reduction and heat treatments. Experimental materials had significantly (p0.05) strength difference. All other groups' mean BFS and characteristic strengths were found to be significantly different (pglass-ceramics with high flexural strength. These materials may help to reduce problems associated with brittle fracture of all-ceramic restorations and give reduced enamel wear. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  12. Using Random Numbers in Science Research Activities.

    Science.gov (United States)

    Schlenker, Richard M.; And Others

    1996-01-01

    Discusses the importance of science process skills and describes ways to select sets of random numbers for selection of subjects for a research study in an unbiased manner. Presents an activity appropriate for grades 5-12. (JRH)

  13. Nanoscale multireference quantum chemistry: full configuration interaction on graphical processing units.

    Science.gov (United States)

    Fales, B Scott; Levine, Benjamin G

    2015-10-13

    Methods based on a full configuration interaction (FCI) expansion in an active space of orbitals are widely used for modeling chemical phenomena such as bond breaking, multiply excited states, and conical intersections in small-to-medium-sized molecules, but these phenomena occur in systems of all sizes. To scale such calculations up to the nanoscale, we have developed an implementation of FCI in which electron repulsion integral transformation and several of the more expensive steps in σ vector formation are performed on graphical processing unit (GPU) hardware. When applied to a 1.7 × 1.4 × 1.4 nm silicon nanoparticle (Si72H64) described with the polarized, all-electron 6-31G** basis set, our implementation can solve for the ground state of the 16-active-electron/16-active-orbital CASCI Hamiltonian (more than 100,000,000 configurations) in 39 min on a single NVidia K40 GPU.

  14. Art as an Avenue to Science Literacy: Teaching Nanotechnology through Stained Glass

    Science.gov (United States)

    Duncan, Kimberly A.; Johnson, Chris; McElhinny, Kyle; Ng, Steve; Cadwell, Katie D.; Zenner Petersen, Greta M.; Johnson, Angela; Horoszewski, Dana; Gentry, Ken; Lisensky, George; Crone, Wendy C.

    2010-01-01

    Nanoscale science and engineering (NSE) and nanotechnology are emerging fields that have captured the attention of scientists and engineers, as well as mainstream media. However, the general public is relatively unaware of NSE, and schools (both K-12 and undergraduate institutions) rarely include nanotechnology as part of their curriculum. To help…

  15. Simulation of capillary bridges between nanoscale particles.

    Science.gov (United States)

    Dörmann, Michael; Schmid, Hans-Joachim

    2014-02-04

    Capillary forces are very important as they exceed in general other adhesion forces. But at the same time the exact calculation of these forces is very complex, so often assumptions and approximations are used. Previous research was done with regard to micrometer sized particles, but the behavior of nanoscale particles is different. Hence, the results for micrometer sized particles cannot be directly transferred when considering nanoscale particles. Therefore, a simulation method was developed to calculate numerically the shape of a rotationally symmetrical capillary bridge between two spherical particles or a particle and a plate. The capillary bridge in the gap between the particles is formed due to capillary condensation and is in thermodynamic equilibrium with the gas phase. Hence the Kelvin equation and the Young-Laplace equation can be used to calculate the profile of the capillary bridge, depending on the relative humidity of the surrounding air. The bridge profile consists of several elements that are determined consecutively and interpolated linearly. After the shape is determined, the volume and force, divided into capillary pressure force and surface tension force, can be calculated. The validation of this numerical model will be shown by comparison with several different analytical calculations for micrometer-sized particles. Furthermore, it is demonstrated that two often used approximations, (1) the toroidal approximation and (2) the use of an effective radius, cannot be used for nanoscale particles without remarkable mistake. It will be discussed how the capillary force and its components depend on different parameters, like particle size, relative humidity, contact angle, and distance, respectively. The rupture of a capillary bridge due to particle separation will also be presented.

  16. Development of Nanoscale Graphitic Devices and The Transport Characterization

    International Nuclear Information System (INIS)

    Gunasekaran, Venugopal

    2011-02-01

    This dissertation describes the development of graphitic based nanoscale devices with its fabrication and transport characterization results. It covers graphite nano-scale stacked-junctions fabricated using focused ion beam (FIB) 3-D etching technique, a single layer graphite layer (graphene) preparation and its electrical transport characterization results and the synthesis and investigation of electrical transport behavior of graphene oxide based thin film devices. The first chapter describes the basic information about the carbon family in detail in which the electronic properties and structure of graphite, graphene and graphene oxide are discussed. In addition, the necessity of developing nanoscale graphitic devices is given. The second chapter explains the experimental techniques used in this research for fabricating nanoscale devices which includes focused ion beam 3-D fabrication procedures, mechanical exfoliation technique and photolithographic methods. In third chapter, we have reported the results on temperature dependence of graphite planar-type structures fabricated along ab-plane. In the fourth and fifth chapters, the fabrication and electrical transport characteristics of large in-plane area graphite planar-type structures (fabricated along ab-plane and c-axis) were discussed and their transport anisotropy properties were investigated briefly. In the sixth chapter, we focused the fabrication of the submicron sized graphite stacked junctions and their electrical transport characterization studies. In which, FIB was used to fabricated the submicron junctions with various in-plane area (with same stack height) are and their transport characteristics were compared. The seventh chapter reports investigation of electrical transport results of nanoscale graphite stacked-junctions in which the temperature dependent transport (R-T) studies, current-voltage measurements for the various in-plane areas and for various stack height samples were analyzed. The

  17. Leveraging Citizen Science and Information Technology for Population Physical Activity Promotion

    Science.gov (United States)

    King, Abby C.; Winter, Sandra J.; Sheats, Jylana L.; Rosas, Lisa G.; Buman, Matthew P.; Salvo, Deborah; Rodriguez, Nicole M.; Seguin, Rebecca A.; Moran, Mika; Garber, Randi; Broderick, Bonnie; Zieff, Susan G.; Sarmiento, Olga Lucia; Gonzalez, Silvia A.; Banchoff, Ann; Dommarco, Juan Rivera

    2016-01-01

    PURPOSE While technology is a major driver of many of society’s comforts, conveniences, and advances, it has been responsible, in a significant way, for engineering regular physical activity and a number of other positive health behaviors out of people’s daily lives. A key question concerns how to harness information and communication technologies (ICT) to bring about positive changes in the health promotion field. One such approach involves community-engaged “citizen science,” in which local residents leverage the potential of ICT to foster data-driven consensus-building and mobilization efforts that advance physical activity at the individual, social, built environment, and policy levels. METHOD The history of citizen science in the research arena is briefly described and an evidence-based method that embeds citizen science in a multi-level, multi-sectoral community-based participatory research framework for physical activity promotion is presented. RESULTS Several examples of this citizen science-driven community engagement framework for promoting active lifestyles, called “Our Voice”, are discussed, including pilot projects from diverse communities in the U.S. as well as internationally. CONCLUSIONS The opportunities and challenges involved in leveraging citizen science activities as part of a broader population approach to promoting regular physical activity are explored. The strategic engagement of citizen scientists from socio-demographically diverse communities across the globe as both assessment as well as change agents provides a promising, potentially low-cost and scalable strategy for creating more active, healthful, and equitable neighborhoods and communities worldwide. PMID:27525309

  18. Nanoscale Chemical Processes Affecting Storage Capacities and Seals during Geologic CO2 Sequestration.

    Science.gov (United States)

    Jun, Young-Shin; Zhang, Lijie; Min, Yujia; Li, Qingyun

    2017-07-18

    Geologic CO 2 sequestration (GCS) is a promising strategy to mitigate anthropogenic CO 2 emission to the atmosphere. Suitable geologic storage sites should have a porous reservoir rock zone where injected CO 2 can displace brine and be stored in pores, and an impermeable zone on top of reservoir rocks to hinder upward movement of buoyant CO 2 . The injection wells (steel casings encased in concrete) pass through these geologic zones and lead CO 2 to the desired zones. In subsurface environments, CO 2 is reactive as both a supercritical (sc) phase and aqueous (aq) species. Its nanoscale chemical reactions with geomedia and wellbores are closely related to the safety and efficiency of CO 2 storage. For example, the injection pressure is determined by the wettability and permeability of geomedia, which can be sensitive to nanoscale mineral-fluid interactions; the sealing safety of the injection sites is affected by the opening and closing of fractures in caprocks and the alteration of wellbore integrity caused by nanoscale chemical reactions; and the time scale for CO 2 mineralization is also largely dependent on the chemical reactivities of the reservoir rocks. Therefore, nanoscale chemical processes can influence the hydrogeological and mechanical properties of geomedia, such as their wettability, permeability, mechanical strength, and fracturing. This Account reviews our group's work on nanoscale chemical reactions and their qualitative impacts on seal integrity and storage capacity at GCS sites from four points of view. First, studies on dissolution of feldspar, an important reservoir rock constituent, and subsequent secondary mineral precipitation are discussed, focusing on the effects of feldspar crystallography, cations, and sulfate anions. Second, interfacial reactions between caprock and brine are introduced using model clay minerals, with focuses on the effects of water chemistries (salinity and organic ligands) and water content on mineral dissolution and

  19. The synthesis and properties of nanoscale ionic materials

    KAUST Repository

    Rodriguez, Robert Salgado; Herrer, Rafael; Bourlinos, Athanasios B.; Li, Ruipeng; Amassian, Aram; Archer, Lynden A.; Giannelis, Emmanuel P.

    2010-01-01

    In this article we discuss the effect of constituents on structure, flow, and thermal properties of nanoscale ionic materials (NIMs). NIMs are a new class of nanohybrids consisting of a nanometer-sized core, a charged corona covalently attached

  20. Technical activities, 1990: Surface Science Division

    International Nuclear Information System (INIS)

    Powell, C.J.

    1991-05-01

    The report summarizes technical activities and accomplishments of the NIST Surface Science Division during Fiscal Year 1990. Overviews are presented of the Division and of its three constituent groups: Surface Dynamical Processes, Thin Films and Interfaces, and Surface Spectroscopies and Standards. These overviews are followed by reports of selected technical accomplishments during the year. A summary is given of Division outputs and interactions that includes lists of publications, talks, committee assignments, seminars (including both Division seminars and Interface Science seminars arranged through the Division), conferences organized, and a standard reference material certified. Finally, lists are given of Division staff and of guest scientists who have worked in the Division during the past year

  1. Nanoscale MOS devices: device parameter fluctuations and low-frequency noise (Invited Paper)

    Science.gov (United States)

    Wong, Hei; Iwai, Hiroshi; Liou, J. J.

    2005-05-01

    It is well-known in conventional MOS transistors that the low-frequency noise or flicker noise is mainly contributed by the trapping-detrapping events in the gate oxide and the mobility fluctuation in the surface channel. In nanoscale MOS transistors, the number of trapping-detrapping events becomes less important because of the large direct tunneling current through the ultrathin gate dielectric which reduces the probability of trapping-detrapping and the level of leakage current fluctuation. Other noise sources become more significant in nanoscale devices. The source and drain resistance noises have greater impact on the drain current noise. Significant contribution of the parasitic bipolar transistor noise in ultra-short channel and channel mobility fluctuation to the channel noise are observed. The channel mobility fluctuation in nanoscale devices could be due to the local composition fluctuation of the gate dielectric material which gives rise to the permittivity fluctuation along the channel and results in gigantic channel potential fluctuation. On the other hand, the statistical variations of the device parameters across the wafer would cause the noise measurements less accurate which will be a challenge for the applicability of analytical flicker noise model as a process or device evaluation tool for nanoscale devices. Some measures for circumventing these difficulties are proposed.

  2. Electrostatic potential fluctuation induced by charge discreteness in a nanoscale trench

    International Nuclear Information System (INIS)

    Lee, Taesang; Kim, S. S.; Jho, Y. S.; Park, Gunyoung; Chang, C. S.

    2007-01-01

    A simplified two-dimensional Monte Carlo simulation is performed to estimate the charging potential fluctuations caused by strong binary Coulomb interactions between discrete charged particles in nanometer scale trenches. It is found that the discrete charge effect can be an important part of the nanoscale trench research, inducing scattering of ion trajectories in a nanoscale trench by a fluctuating electric field. The effect can enhance the ion deposition on the side walls and disperse the material contact energy of the incident ions, among others

  3. Assessment report on research and development activities. Activity: 'Advanced science research' (Interim report)

    International Nuclear Information System (INIS)

    2012-11-01

    Japan Atomic Energy Agency (hereinafter referred to as “JAEA”) consulted an assessment committee, “Evaluation Committee of Research Activities for Advanced Science Research” (hereinafter referred to as “Committee”) for interim assessment of “Advanced Science Research,” in accordance with “General Guideline for the Evaluation of Government Research and Development (R and D) Activities” by Cabinet Office, Government of Japan, “Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology” and “Regulation on Conduct for Evaluation of R and D Activities” by JAEA. In response to the JAEA's request, the Committee assessed the research programs and activities of the Advanced Science Research Center (hereinafter referred to as “ASRC”) for the period of two years from April 2010. The Committee evaluated the management and the research programs of the ASRC based on the explanatory documents prepared by the ASRC and the oral presentations with questions-and-answers by the Director and the research group leaders. This report summarizes the result of the assessment by the Committee with the Committee report attached from page 7. (author)

  4. COMPUTATIONAL SCIENCE CENTER

    Energy Technology Data Exchange (ETDEWEB)

    DAVENPORT, J.

    2006-11-01

    Computational Science is an integral component of Brookhaven's multi science mission, and is a reflection of the increased role of computation across all of science. Brookhaven currently has major efforts in data storage and analysis for the Relativistic Heavy Ion Collider (RHIC) and the ATLAS detector at CERN, and in quantum chromodynamics. The Laboratory is host for the QCDOC machines (quantum chromodynamics on a chip), 10 teraflop/s computers which boast 12,288 processors each. There are two here, one for the Riken/BNL Research Center and the other supported by DOE for the US Lattice Gauge Community and other scientific users. A 100 teraflop/s supercomputer will be installed at Brookhaven in the coming year, managed jointly by Brookhaven and Stony Brook, and funded by a grant from New York State. This machine will be used for computational science across Brookhaven's entire research program, and also by researchers at Stony Brook and across New York State. With Stony Brook, Brookhaven has formed the New York Center for Computational Science (NYCCS) as a focal point for interdisciplinary computational science, which is closely linked to Brookhaven's Computational Science Center (CSC). The CSC has established a strong program in computational science, with an emphasis on nanoscale electronic structure and molecular dynamics, accelerator design, computational fluid dynamics, medical imaging, parallel computing and numerical algorithms. We have been an active participant in DOES SciDAC program (Scientific Discovery through Advanced Computing). We are also planning a major expansion in computational biology in keeping with Laboratory initiatives. Additional laboratory initiatives with a dependence on a high level of computation include the development of hydrodynamics models for the interpretation of RHIC data, computational models for the atmospheric transport of aerosols, and models for combustion and for energy utilization. The CSC was formed to

  5. 474 Science Activities for Young Children.

    Science.gov (United States)

    Green, Moira D.

    This book uses a child-initiated, whole language approach to help children have fun while exploring the world of science. The activities are divided into 23 units. Each unit begins with an "Attention Getter," the purpose of which is to introduce the unit to children in a way that grabs their attention, stimulates their interest, and creates…

  6. Quantum dynamics in nanoscale magnets in dissipative environments

    NARCIS (Netherlands)

    Miyashita, S; Saito, K; Kobayashi, H.; de Raedt, H.A.

    2000-01-01

    In discrete energy structure of nanoscale magnets, nonadiabatic transitions at avoided level crossings lead to fundamental processes of dynamics of magnetizations. The thermal environment causes dissipative effects on these processes. In this paper we review the features of the nonadiabatic

  7. Teaching Primary Science: Emotions, Identity and the Use of Practical Activities

    Science.gov (United States)

    Cripps Clark, John; Groves, Susie

    2012-01-01

    This paper uses cultural historical activity theory to examine the interactions between the choices primary teachers make in the use of practical activities in their teaching of science and the purposes they attribute to these; their emotions, background and beliefs; and the construction of their identities as teachers of science. It draws on four…

  8. High efficiency polymer solar cells with vertically modulated nanoscale morphology

    International Nuclear Information System (INIS)

    Kumar, Ankit; Hong Ziruo; Yang Yang; Li Gang

    2009-01-01

    Nanoscale morphology has been shown to be a critical parameter governing charge transport properties of polymer bulk heterojunction (BHJ) solar cells. Recent results on vertical phase separation have intensified the research on 3D morphology control. In this paper, we intend to modify the distribution of donors and acceptors in a classical BHJ polymer solar cell by making the active layer richer in donors and acceptors near the anode and cathode respectively. Here, we chose [6,6]-phenyl- C 61 -butyric acid methyl ester (PCBM) to be the acceptor material to be thermally deposited on top of [poly(3-hexylthiophene)] P3HT: the PCBM active layer to achieve a vertical composition gradient in the BHJ structure. Here we report on a solar cell with enhanced power conversion efficiency of 4.5% which can be directly correlated with the decrease in series resistance of the device.

  9. DNA-based construction at the nanoscale: emerging trends and applications

    Science.gov (United States)

    Lourdu Xavier, P.; Chandrasekaran, Arun Richard

    2018-02-01

    The field of structural DNA nanotechnology has evolved remarkably—from the creation of artificial immobile junctions to the recent DNA-protein hybrid nanoscale shapes—in a span of about 35 years. It is now possible to create complex DNA-based nanoscale shapes and large hierarchical assemblies with greater stability and predictability, thanks to the development of computational tools and advances in experimental techniques. Although it started with the original goal of DNA-assisted structure determination of difficult-to-crystallize molecules, DNA nanotechnology has found its applications in a myriad of fields. In this review, we cover some of the basic and emerging assembly principles: hybridization, base stacking/shape complementarity, and protein-mediated formation of nanoscale structures. We also review various applications of DNA nanostructures, with special emphasis on some of the biophysical applications that have been reported in recent years. In the outlook, we discuss further improvements in the assembly of such structures, and explore possible future applications involving super-resolved fluorescence, single-particle cryo-electron (cryo-EM) and x-ray free electron laser (XFEL) nanoscopic imaging techniques, and in creating new synergistic designer materials.

  10. Selective nanoscale growth of lattice mismatched materials

    Science.gov (United States)

    Lee, Seung-Chang; Brueck, Steven R. J.

    2017-06-20

    Exemplary embodiments provide materials and methods of forming high-quality semiconductor devices using lattice-mismatched materials. In one embodiment, a composite film including one or more substantially-single-particle-thick nanoparticle layers can be deposited over a substrate as a nanoscale selective growth mask for epitaxially growing lattice-mismatched materials over the substrate.

  11. Tunable all-optical plasmonic rectifier in nanoscale metal-insulator-metal waveguides.

    Science.gov (United States)

    Xu, Yi; Wang, Xiaomeng; Deng, Haidong; Guo, Kangxian

    2014-10-15

    We propose a tunable all-optical plasmonic rectifier based on the nonlinear Fano resonance in a metal-insulator-metal plasmonic waveguide and cavities coupling system. We develop a theoretical model based on the temporal coupled-mode theory to study the device physics of the nanoscale rectifier. We further demonstrate via the finite difference time domain numerical experiment that our idea can be realized in a plasmonic system with an ultracompact size of ~120×800  nm². The tunable plasmonic rectifier could facilitate the all-optical signal processing in nanoscale.

  12. On ripples and rafts: Curvature induced nanoscale structures in lipid membranes

    International Nuclear Information System (INIS)

    Schmid, Friederike; Dolezel, Stefan; Meinhardt, Sebastian; Lenz, Olaf

    2014-01-01

    We develop an elastic theory that predicts the spontaneous formation of nanoscale structures in lipid bilayers which locally phase separate between two phases with different spontaneous monolayer curvature. The theory rationalizes in a unified manner the observation of a variety of nanoscale structures in lipid membranes: Rippled states in one-component membranes, lipid rafts in multicomponent membranes. Furthermore, we report on recent observations of rippled states and rafts in simulations of a simple coarse-grained model for lipid bilayers, which are compatible with experimental observations and with our elastic model

  13. Engaging Youth in Climate Change Issues with Family Science Day Activities

    Science.gov (United States)

    Brevik, Corinne E.; Brevik, Eric C.; Steffan, Joshua J.

    2016-04-01

    Dickinson State University organizes four Family Science Day events each fall during the months of September, October, November, and December. Activities are geared toward elementary-aged children to increase student engagement in the sciences. Offered on Saturday afternoons, each event focuses on a different science-related theme. Families can attend these events free of charge, and the kids participate in a large variety of hands-on activities that center around the event's theme. This year, the November event focused on climate change, including an emphasis on the roles soil plays in the climate system. The timing of this topic was carefully chosen. 2015 has been declared the International Year of Soil by the United Nations, and the Soil Science Society of America theme for the month of November was Soils and Climate. This public outreach event was an amazing opportunity to help the youth in our community learn about climate change in a fun, interactive environment. Climate changes in the past, present, and future were emphasized. Activities including the Farming Game, painting with soils, taking Jello "cores", creating a cloud in a jar, and making a glacier in a bag helped children learn how science is a process of discovery that allows them to better understand the world they live in. In addition to the hands-on activities, a planetarium show focused on climate change was also offered during the event, surrounding the kids and their parents in a fully immersive, 360-degree show that allowed them to personally observe phenomena that are otherwise difficult to visualize. All of the activities at the Family Science Day event were staffed by university students, and this proved to be a very valuable experience for them as well. Some of the students who helped are majoring in a science field, and for them, the experience taught public communication. They learned to break complicated concepts down into simpler terms that young kids could understand. Education

  14. Incorporating Hot Topics in Ocean Sciences to Outreach Activities in Marine and Environmental Science Education

    Science.gov (United States)

    Bergondo, D. L.; Mrakovcich, K. L.; Vlietstra, L.; Tebeau, P.; Verlinden, C.; Allen, L. A.; James, R.

    2016-02-01

    The US Coast Guard Academy, an undergraduate military Academy, in New London CT, provides STEM education programs to the local community that engage the public on hot topics in ocean sciences. Outreach efforts include classroom, lab, and field-based activities at the Academy as well as at local schools. In one course, we partner with a STEM high school collecting fish and environmental data on board a research vessel and subsequently students present the results of their project. In another course, cadets develop and present interactive demonstrations of marine science to local school groups. In addition, the Academy develops In another course, cadets develop and present interactive demonstrations of marine science to local school groups. In addition, the Academy develops and/or participates in outreach programs including Science Partnership for Innovation in Learning (SPIL), Women in Science, Physics of the Sea, and the Ocean Exploration Trust Honors Research Program. As part of the programs, instructors and cadets create interactive and collaborative activities that focus on hot topics in ocean sciences such as oil spill clean-up, ocean exploration, tsunamis, marine biodiversity, and conservation of aquatic habitats. Innovative science demonstrations such as real-time interactions with the Exploration Vessel (E/V) Nautilus, rotating tank simulations of ocean circulation, wave tank demonstrations, and determining what materials work best to contain and clean-up oil, are used to enhance ocean literacy. Children's books, posters and videos are some creative ways students summarize their understanding of ocean sciences and marine conservation. Despite time limitations of students and faculty, and challenges associated with securing funding to keep these programs sustainable, the impact of the programs is overwhelmingly positive. We have built stronger relationships with local community, enhanced ocean literacy, facilitated communication and mentorship between young

  15. FDTD based model of ISOCT imaging for validation of nanoscale sensitivity (Conference Presentation)

    Science.gov (United States)

    Eid, Aya; Zhang, Di; Yi, Ji; Backman, Vadim

    2017-02-01

    Many of the earliest structural changes associated with neoplasia occur on the micro and nanometer scale, and thus appear histologically normal. Our group has established Inverse Spectroscopic OCT (ISOCT), a spectral based technique to extract nanoscale sensitive metrics derived from the OCT signal. Thus, there is a need to model light transport through relatively large volumes (< 50 um^3) of media with nanoscale level resolution. Finite Difference Time Domain (FDTD) is an iterative approach which directly solves Maxwell's equations to robustly estimate the electric and magnetic fields propagating through a sample. The sample's refractive index for every spatial voxel and wavelength are specified upon a grid with voxel sizes on the order of λ/20, making it an ideal modelling technique for nanoscale structure analysis. Here, we utilize the FDTD technique to validate the nanoscale sensing ability of ISOCT. The use of FDTD for OCT modelling requires three components: calculating the source beam as it propagates through the optical system, computing the sample's scattered field using FDTD, and finally propagating the scattered field back through the optical system. The principles of Fourier optics are employed to focus this interference field through a 4f optical system and onto the detector. Three-dimensional numerical samples are generated from a given refractive index correlation function with known parameters, and subsequent OCT images and mass density correlation function metrics are computed. We show that while the resolvability of the OCT image remains diffraction limited, spectral analysis allows nanoscale sensitive metrics to be extracted.

  16. Nanoscale semiconducting silicon as a nutritional food additive

    Energy Technology Data Exchange (ETDEWEB)

    Canham, L T [pSiNutria Ltd, Malvern Hills Science Park, Geraldine Road, Malvern, Worcestershire WR14 3SZ (United Kingdom)

    2007-05-09

    Very high surface area silicon powders can be realized by high energy milling or electrochemical etching techniques. Such nanoscale silicon structures, whilst biodegradable in the human gastrointestinal tract, are shown to be remarkably stable in most foodstuffs and beverages. The potential for using silicon to improve the shelf life and bioavailability of specific nutrients in functional foods is highlighted. Published drug delivery data implies that the nanoentrapment of hydrophobic nutrients will significantly improve their dissolution kinetics, through a combined effect of nanostructuring and solid state modification. Nutrients loaded to date include vitamins, fish oils, lycopene and coenzyme Q10. In addition, there is growing published evidence that optimized release of orthosilicic acid, the biodegradation product of semiconducting silicon in the gut, offers beneficial effects with regard bone health. The utility of nanoscale silicon in the nutritional field shows early promise and is worthy of much further study.

  17. Nanoscale semiconducting silicon as a nutritional food additive

    International Nuclear Information System (INIS)

    Canham, L T

    2007-01-01

    Very high surface area silicon powders can be realized by high energy milling or electrochemical etching techniques. Such nanoscale silicon structures, whilst biodegradable in the human gastrointestinal tract, are shown to be remarkably stable in most foodstuffs and beverages. The potential for using silicon to improve the shelf life and bioavailability of specific nutrients in functional foods is highlighted. Published drug delivery data implies that the nanoentrapment of hydrophobic nutrients will significantly improve their dissolution kinetics, through a combined effect of nanostructuring and solid state modification. Nutrients loaded to date include vitamins, fish oils, lycopene and coenzyme Q10. In addition, there is growing published evidence that optimized release of orthosilicic acid, the biodegradation product of semiconducting silicon in the gut, offers beneficial effects with regard bone health. The utility of nanoscale silicon in the nutritional field shows early promise and is worthy of much further study

  18. EDITORIAL: Mastering matter at the nanoscale Mastering matter at the nanoscale

    Science.gov (United States)

    Forchel, Alfred

    2009-10-01

    In the early 1980s, the development of scanning probe techniques gave scientists a titillating view of surfaces with nanometre resolution, igniting activity in research at the nanoscale. Images at unprecedented resolution were unveiled with the aid of various types of nanosized tips, including the scanning tunnelling (Binnig G, Rohrer H, Gerber C and Weibel E 1982 Appl. Phys. Lett. 40 178-80) the atomic force (Binnig G, Quate C F and Gerber C 1986 Phys. Rev. Lett. 56 930-3) and the near-field scanning microscopes (Dürig U, Pohl D W and Rohner F 1986 J. Appl. Phys. 59 3318-27). From the magnitude of tunnelling currents between conductive surfaces and van der Waals forces between dielectrics to the non-propagating evanescent fields at illuminated surfaces, a range of signal responses were harnessed enabling conductive, dielectric and even biological systems to be imaged. But it may be argued that it was the ability to manipulate matter at the nanoscale that really empowered nanotechnology. From the inception of the scanning probe revolution, these probes used to image nanostructures were also discovered to be remarkable tools for the manipulation of nanoparticles. Insights into the mechanism behind such processes were reported by a team of researchers at UCLA over ten years ago in 1998 (Baur C et al 1998 Nanotechnology 9 360-4). In addition, lithography and etching methods of patterning continue to evolve into ever more sophisticated techniques for exerting design over the structure of matter at the nanoscale. These so-called top-down methods, such as photolithography, electron-beam lithography and nanoimprint lithography, now provide control over features with a resolution of a few nanometres. Bottom-up fabrication techniques that exploit the self-assembly of constituents into desired structures have also stimulated extensive research. These techniques, such as the electrochemically assembled quantum-dot arrays reported by a team of US reasearchers over ten years

  19. Visualizing copper assisted graphene growth in nanoscale

    Science.gov (United States)

    Rosmi, Mohamad Saufi; Yusop, Mohd Zamri; Kalita, Golap; Yaakob, Yazid; Takahashi, Chisato; Tanemura, Masaki

    2014-01-01

    Control synthesis of high quality large-area graphene on transition metals (TMs) by chemical vapor deposition (CVD) is the most fascinating approach for practical device applications. Interaction of carbon atoms and TMs is quite critical to obtain graphene with precise layer number, crystal size and structure. Here, we reveal a solid phase reaction process to achieve Cu assisted graphene growth in nanoscale by in-situ transmission electron microscope (TEM). Significant structural transformation of amorphous carbon nanofiber (CNF) coated with Cu is observed with an applied potential in a two probe system. The coated Cu particle recrystallize and agglomerate toward the cathode with applied potential due to joule heating and large thermal gradient. Consequently, the amorphous carbon start crystallizing and forming sp2 hybridized carbon to form graphene sheet from the tip of Cu surface. We observed structural deformation and breaking of the graphene nanoribbon with a higher applied potential, attributing to saturated current flow and induced Joule heating. The observed graphene formation in nanoscale by the in-situ TEM process can be significant to understand carbon atoms and Cu interaction. PMID:25523645

  20. Improving Neural Recording Technology at the Nanoscale

    Science.gov (United States)

    Ferguson, John Eric

    Neural recording electrodes are widely used to study normal brain function (e.g., learning, memory, and sensation) and abnormal brain function (e.g., epilepsy, addiction, and depression) and to interface with the nervous system for neuroprosthetics. With a deep understanding of the electrode interface at the nanoscale and the use of novel nanofabrication processes, neural recording electrodes can be designed that surpass previous limits and enable new applications. In this thesis, I will discuss three projects. In the first project, we created an ultralow-impedance electrode coating by controlling the nanoscale texture of electrode surfaces. In the second project, we developed a novel nanowire electrode for long-term intracellular recordings. In the third project, we created a means of wirelessly communicating with ultra-miniature, implantable neural recording devices. The techniques developed for these projects offer significant improvements in the quality of neural recordings. They can also open the door to new types of experiments and medical devices, which can lead to a better understanding of the brain and can enable novel and improved tools for clinical applications.

  1. Learning about Science Graphs and Word Games. Superific Science Book V. A Good Apple Science Activity Book for Grades 5-8+.

    Science.gov (United States)

    Conway, Lorraine

    This packet of student materials contains a variety of worksheet activities dealing with science graphs and science word games. These reproducible materials deal with: (1) bar graphs; (2) line graphs; (3) circle graphs; (4) pictographs; (5) histograms; (6) artgraphs; (7) designing your own graphs; (8) medical prefixes; (9) color prefixes; (10)…

  2. Linear arrangement of nano-scale magnetic particles formed in Cu-Fe-Ni alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung, E-mail: k3201s@hotmail.co [Department of Materials Engineering (SEISAN), Yokohama National University, 79-5 Tokiwadai, Hodogayaku, Yokohama, 240-8501 (Japan); Takeda, Mahoto [Department of Materials Engineering (SEISAN), Yokohama National University, 79-5 Tokiwadai, Hodogayaku, Yokohama, 240-8501 (Japan); Takeguchi, Masaki [Advanced Electron Microscopy Group, National Institute for Materials Science (NIMS), Sakura 3-13, Tsukuba, 305-0047 (Japan); Bae, Dong-Sik [School of Nano and Advanced Materials Engineering, Changwon National University, Gyeongnam, 641-773 (Korea, Republic of)

    2010-04-30

    The structural evolution of nano-scale magnetic particles formed in Cu-Fe-Ni alloys on isothermal annealing at 878 K has been investigated by means of transmission electron microscopy (TEM), electron dispersive X-ray spectroscopy (EDS), electron energy-loss spectroscopy (EELS) and field-emission scanning electron microscopy (FE-SEM). Phase decomposition of Cu-Fe-Ni occurred after an as-quenched specimen received a short anneal, and nano-scale magnetic particles were formed randomly in the Cu-rich matrix. A striking feature that two or more nano-scale particles with a cubic shape were aligned linearly along <1,0,0> directions was observed, and the trend was more pronounced at later stages of the precipitation. Large numbers of <1,0,0> linear chains of precipitates extended in three dimensions in late stages of annealing.

  3. Nanoscale Test Strips for Multiplexed Blood Analysis, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of our nanoscale test strips, or nanostrips, is to provide rapid, low-cost, powerful multiplexed analyses in a diminutive form so that whole body health...

  4. NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity.

    Science.gov (United States)

    Al-Awami, Ali K; Beyer, Johanna; Strobelt, Hendrik; Kasthuri, Narayanan; Lichtman, Jeff W; Pfister, Hanspeter; Hadwiger, Markus

    2014-12-01

    We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

  5. An Indentation Technique for Nanoscale Dynamic Viscoelastic Measurements at Elevated Temperature

    Science.gov (United States)

    Ye, Jiping

    2012-08-01

    Determination of nano/micro-scale viscoelasticity is very important to understand the local rheological behavior and degradation phenomena of multifunctional polymer blend materials. This article reviews research results concerning the development of indentation techniques for making nanoscale dynamic viscoelastic measurements at elevated temperature. In the last decade, we have achieved breakthroughs in noise floor reduction in air and thermal load drift/noise reduction at high temperature before taking on the challenge of nanoscale viscoelastic measurements. A high-temperature indentation technique has been developed that facilitates viscoelastic measurements up to 200 °C in air and 500 °C in a vacuum. During the last year, two viscoelastic measurement methods have been developed by making a breakthrough in suppressing the contact area change at high temperature. One is a sharp-pointed time-dependent nanoindentation technique for microscale application and the other is a spherical time-dependent nanoindentation technique for nanoscale application. In the near future, we expect to lower the thermal load drift and load noise floor even more substantially.

  6. NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity

    KAUST Repository

    Al-Awami, Ali K.; Beyer, Johanna; Strobelt, Hendrik; Kasthuri, Narayanan; Lichtman, Jeff W.; Pfister, Hanspeter; Hadwiger, Markus

    2014-01-01

    We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

  7. NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity

    KAUST Repository

    Al-Awami, Ali K.

    2014-12-31

    We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

  8. TUTORIAL: Focused-ion-beam-based rapid prototyping of nanoscale magnetic devices

    Science.gov (United States)

    Khizroev, S.; Litvinov, D.

    2004-03-01

    In this tutorial, focused-ion-beam (FIB)-based fabrication is considered from a very unconventional angle. FIB is considered not as a fabrication tool that can be used for mass production of electronic devices, similar to optical and E-beam—based lithography, but rather as a powerful tool to rapidly fabricate individual nanoscale magnetic devices for prototyping future electronic applications. Among the effects of FIB-based fabrication of magnetic devices, the influence of Ga+-ion implantation on magnetic properties is presented. With help of magnetic force microscopy (MFM), it is shown that there is a critical doze of ions that a magnetic material can be exposed to without experiencing a change in the magnetic properties. Exploiting FIB from such an unconventional perspective is especially favourable today when the future of so many novel technologies depends on the ability to rapidly fabricate prototype nanoscale magnetic devices. As one of the most illustrative examples, the multi-billion-dollar data storage industry is analysed as the technology field that strongly benefited from implementing FIB in the above-described role. The essential role of FIB in the most recent trend of the industry towards perpendicular magnetic recording is presented. Moreover, other emerging and fast-growing technologies are considered as examples of nanoscale technologies whose future could strongly depend on the implementation of FIB in the role of a nanoscale fabrication tool for rapid prototyping. Among the other described technologies are 'ballistic' magnetoresistance, patterned magnetic media, magnetoresistive RAM (MRAM), and magnetic force microscopy.

  9. Nano-scale Materials and Nano-technology Processes in Environmental Protection

    International Nuclear Information System (INIS)

    Vissokov, Gh; Tzvetkoff, T.

    2003-01-01

    A number of environmental and energy technologies have benefited substantially from nano-scale technology: reduced waste and improved energy efficiency; environmentally friendly composite structures; waste remediation; energy conversion. In this report examples of current achievements and paradigm shifts are presented: from discovery to application; a nano structured materials; nanoparticles in the environment (plasma chemical preparation); nano-porous polymers and their applications in water purification; photo catalytic fluid purification; hierarchical self-assembled nano-structures for adsorption of heavy metals, etc. Several themes should be considered priorities in developing nano-scale processes related to environmental management: 1. To develop understanding and control of relevant processes, including protein precipitation and crystallisation, desorption of pollutants, stability of colloidal dispersion, micelle aggregation, microbe mobility, formation and mobility of nanoparticles, and tissue-nanoparticle interaction. Emphasis should be given to processes at phase boundaries (solid-liquid, solid-gas, liquid-gas) that involve mineral and organic soil components, aerosols, biomolecules (cells, microbes), bio tissues, derived components such as bio films and membranes, and anthropogenic additions (e.g. trace and heavy metals); 2. To carry out interdisciplinary research that initiates Noel approaches and adopts new methods for characterising surfaces and modelling complex systems to problems at interfaces and other nano-structures in the natural environment, including those involving biological or living systems. New technological advances such as optical traps, laser tweezers, and synchrotrons are extending examination of molecular and nano-scale processes to the single-molecule or single-cell level; 3. To integrate understanding of the roles of molecular and nano-scale phenomena and behaviour at the meso- and/or macro-scale over a period of time

  10. Oxide films at the nanoscale: new structures, new functions, and new materials.

    Science.gov (United States)

    Giordano, Livia; Pacchioni, Gianfranco

    2011-11-15

    We all make use of oxide ultrathin films, even if we are unaware of doing so. They are essential components of many common devices, such as mobile phones and laptops. The films in these ubiquitous electronics are composed of silicon dioxide, an unsurpassed material in the design of transistors. But oxide films at the nanoscale (typically just 10 nm or less in thickness) are integral to many other applications. In some cases, they form under normal reactive conditions and confer new properties to a material: one example is the corrosion protection of stainless steel, which is the result of a passive film. A new generation of devices for energy production and communications technology, such as ferroelectric ultrathin film capacitors, tunneling magnetoresistance sensors, solar energy materials, solid oxide fuel cells, and many others, are being specifically designed to exploit the unusual properties afforded by reduced oxide thickness. Oxide ultrathin films also have tremendous potential in chemistry, representing a rich new source of catalytic materials. About 20 years ago, researchers began to prepare model systems of truly heterogeneous catalysts based on thin oxide layers grown on single crystals of metal. Only recently, however, was it realized that these systems may behave quite differently from their corresponding bulk oxides. One of the phenomena uncovered is the occurrence of a spontaneous charge transfer from the metal support to an adsorbed species through the thin insulating layer (or vice versa). The importance of this property is clear: conceptually, the activation and bond breaking of adsorbed molecules begin with precisely the same process, electron transfer into an antibonding orbital. But electron transfer can also be harnessed to make a supported metal particle more chemically active, increase its adhesion energy, or change its shape. Most importantly, the basic principles underlying electron transfer and other phenomena (such as structural

  11. Nanoscale control of energy and matter in plasma-surface interactions: towards energy-efficient nanotech

    Science.gov (United States)

    Ostrikov, Kostya

    2010-11-01

    This presentation focuses on the plasma issues related to the solution of the grand challenge of directing energy and matter at nanoscales. This ability is critical for the renewable energy and energy-efficient technologies for sustainable future development. It will be discussed how to use environmentally and human health benign non-equilibrium plasma-solid systems and control the elementary processes of plasma-surface interactions to direct the fluxes of energy and matter at multiple temporal and spatial scales. In turn, this makes it possible to achieve the deterministic synthesis of self- organised arrays of metastable nanostructures in the size range beyond the reach of the present-day nanofabrication. Such structures have tantalising prospects to enhance performance of nanomaterials in virtually any area of human activity yet remain almost inaccessible because the Nature's energy minimisation rules allow only a small number of stable equilibrium states. By using precisely controlled and kinetically fast nanoscale transfer of energy and matter under non-equilibrium conditions and harnessing numerous plasma- specific controls of species creation, delivery to the surface, nucleation and large-scale self-organisation of nuclei and nanostructures, the arrays of metastable nanostructures can be created, arranged, stabilised, and further processed to meet the specific requirements of the envisaged applications. These approaches will eventually lead to faster, unprecedentedly- clean, human-health-friendly, and energy-efficient nanoscale synthesis and processing technologies for the next-generation renewable energy and light sources, biomedical devices, information and communication systems, as well as advanced functional materials for applications ranging from basic food, water, health and clean environment needs to national security and space missions.

  12. Nanoscale effects in interdiffusion

    International Nuclear Information System (INIS)

    Erdelyi, Z.; Langer, G.A.; Beke, D.L.; Csik, A.

    2007-01-01

    Complete text of publication follows. Diffusion on the nano/atomic scales in multilayers, thin films has many challenging features even if the role of structural defects can be neglected and 'only' the effects related to the nano/atomic scale raise. The most basic equations to describe the diffusion are Fick's equations. It is important to emphasize that the diffusion coefficient in Fick's equations is in general composition independent and Fick's classical equations do not include the stress effects, which can have important influence onto the diffusion especially on the nano/atomic scale. We illustrate that the continuum descriptions of the diffusion cannot be applied automatically on such short distances, the classical continuum approximations (Fick's laws) cannot describe correctly the atomic movements. They predict faster kinetics than the atomistic models and the interface shift is always proportional to the square root of the time. However, the kinetics can be even linear on the nano/atomic scale. We have shown from computer simulations that Fick's laws violate on the nanoscale either in completely or restricted miscible systems. This is strongly related to the discrete character of the system on the nanoscale and to the highly neglected fact in the literature that the diffusion coefficients depend on the composition. As will be seen the composition dependence of D is very important and has very significant influence on the diffusion kinetics on the nano/atomic scales. It originates from the fact that usually the diffusion coefficients are different in an A and in a B matrix. Consequently in case of a real interface, which is not atomically sharp, i.e. there is a more or less intermixed region between the pure A and B matrixes, the diffusion coefficient changes continuously while e.g. an A atom diffuses from the pure A matrix into the pure B. This feature can be also called diffusion asymmetry. We have also illustrated that in this case not only the

  13. Science Support: The Building Blocks of Active Data Curation

    Science.gov (United States)

    Guillory, A.

    2013-12-01

    While the scientific method is built on reproducibility and transparency, and results are published in peer reviewed literature, we have come to the digital age of very large datasets (now of the order of petabytes and soon exabytes) which cannot be published in the traditional way. To preserve reproducibility and transparency, active curation is necessary to keep and protect the information in the long term, and 'science support' activities provide the building blocks for active data curation. With the explosive growth of data in all fields in recent years, there is a pressing urge for data centres to now provide adequate services to ensure long-term preservation and digital curation of project data outputs, however complex those may be. Science support provides advice and support to science projects on data and information management, from file formats through to general data management awareness. Another purpose of science support is to raise awareness in the science community of data and metadata standards and best practice, engendering a culture where data outputs are seen as valued assets. At the heart of Science support is the Data Management Plan (DMP) which sets out a coherent approach to data issues pertaining to the data generating project. It provides an agreed record of the data management needs and issues within the project. The DMP is agreed upon with project investigators to ensure that a high quality documented data archive is created. It includes conditions of use and deposit to clearly express the ownership, responsibilities and rights associated with the data. Project specific needs are also identified for data processing, visualization tools and data sharing services. As part of the National Centre for Atmospheric Science (NCAS) and National Centre for Earth Observation (NCEO), the Centre for Environmental Data Archival (CEDA) fulfills this science support role of facilitating atmospheric and Earth observation data generating projects to ensure

  14. Super-Resolution Molecular and Functional Imaging of Nanoscale Architectures in Life and Materials Science

    KAUST Repository

    Habuchi, Satoshi

    2014-01-01

    fluorescence microscopy techniques along with the latest developments of fluorophores and labeling for the SR microscopy. I discuss the applications of SR microscopy in the fields of life science and materials science with a special emphasis on quantitative

  15. S.E.A. Lab. Science Experiments and Activities. Marine Science for High School Students in Chemistry, Biology and Physics.

    Science.gov (United States)

    Hart, Kathy, Ed.

    A series of science experiments and activities designed for secondary school students taking biology, chemistry, physics, physical science or marine science courses are outlined. Each of the three major sections--chemistry, biology, and physics--addresses concepts that are generally covered in those courses but incorporates aspects of marine…

  16. Nano-scale processes behind ion-beam cancer therapy

    Science.gov (United States)

    Surdutovich, Eugene; Garcia, Gustavo; Mason, Nigel; Solov'yov, Andrey V.

    2016-04-01

    This topical issue collates a series of papers based on new data reported at the third Nano-IBCT Conference of the COST Action MP1002: Nanoscale Insights into Ion Beam Cancer Therapy, held in Boppard, Germany, from October 27th to October 31st, 2014. The Nano-IBCT COST Action was launched in December 2010 and brought together more than 300 experts from different disciplines (physics, chemistry, biology) with specialists in radiation damage of biological matter from hadron-therapy centres, and medical institutions. This meeting followed the first and the second conferences of the Action held in October 2011 in Caen, France and in May 2013 in Sopot, Poland respectively. This conference series provided a focus for the European research community and has highlighted the pioneering research into the fundamental processes underpinning ion beam cancer therapy. Contribution to the Topical Issue "COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy", edited by Andrey V. Solov'yov, Nigel Mason, Gustavo Garcia and Eugene Surdutovich.

  17. 75 FR 14128 - Center for Nanoscale Science and Technology Postdoctoral Researcher and Visiting Fellow...

    Science.gov (United States)

    2010-03-24

    ... Measurement Science and Engineering Program; Availability of Funds AGENCY: National Institute of Standards and... Measurement Science and Engineering Program. This program is intended to promote research, training, and... mission to support the development of nanotechnology through research on measurement and fabrication...

  18. Exchange-coupled nanoscale SmCo/NdFeB hybrid magnets

    Energy Technology Data Exchange (ETDEWEB)

    Wang Dapeng; Poudyal, Narayan; Rong, Chuanbing [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States); Zhang Ying [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States); Materials Science and Engineering, Ames Laboratory, USDOE, Iowa State University, Ames, IA 50011 (United States); Kramer, M.J. [Materials Science and Engineering, Ames Laboratory, USDOE, Iowa State University, Ames, IA 50011 (United States); Liu, J. Ping, E-mail: pliu@uta.edu [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)

    2012-09-15

    Nanoscale hybrid magnets containing SmCo{sub 5} and Nd{sub 2}Fe{sub 14}B hard magnetic phases have been produced via a novel 'in-one-pot' processing route. The grain size of the processed bulk composite materials is controlled below 20 nm. The refinement of the nanoscale morphology leads to effective inter-phase exchange coupling that results in single-phase like magnetic properties. Energy product of 14 MGOe was obtained in the isotropic nanocomposite magnets at room temperature. At elevated temperatures, the hybrid magnets have greatly improved thermal stability compared to the Nd{sub 2}Fe{sub 14}B single-phase counterpart and have substantially increased magnetization and energy products compared to the single-phase SmCo{sub 5} counterpart. - Highlights: Black-Right-Pointing-Pointer We realize interphase exchange coupling in nanoscale SmCo{sub 5}/Nd{sub 2}Fe{sub 14}B magnets. Black-Right-Pointing-Pointer We observe homogenously distributed two-phase grains with size smaller than 20 nm. Black-Right-Pointing-Pointer We observe a common Curie temperature in the hybrid magnet. Black-Right-Pointing-Pointer High-temperature magnetic properties of the hybrid magnets greatly improved. Black-Right-Pointing-Pointer Plastic deformation of composite materials leads to self-nanoscaling of grains.

  19. Localized temperature and chemical reaction control in nanoscale space by nanowire array.

    Science.gov (United States)

    Jin, C Yan; Li, Zhiyong; Williams, R Stanley; Lee, K-Cheol; Park, Inkyu

    2011-11-09

    We introduce a novel method for chemical reaction control with nanoscale spatial resolution based on localized heating by using a well-aligned nanowire array. Numerical and experimental analysis shows that each individual nanowire could be selectively and rapidly Joule heated for local and ultrafast temperature modulation in nanoscale space (e.g., maximum temperature gradient 2.2 K/nm at the nanowire edge; heating/cooling time chemical reactions such as polymer decomposition/cross-linking and direct and localized hydrothermal synthesis of metal oxide nanowires were demonstrated.

  20. Coherent Femtosecond Spectroscopy and Nonlinear Optical Imaging on the Nanoscale

    Science.gov (United States)

    Kravtsov, Vasily

    Optical properties of many materials and macroscopic systems are defined by ultrafast dynamics of electronic, vibrational, and spin excitations localized on the nanoscale. Harnessing these excitations for material engineering, optical computing, and control of chemical reactions has been a long-standing goal in science and technology. However, it is challenging due to the lack of spectroscopic techniques that can resolve processes simultaneously on the nanometer spatial and femtosecond temporal scales. This thesis describes the fundamental principles, implementation, and experimental demonstration of a novel type of ultrafast microscopy based on the concept of adiabatic plasmonic nanofocusing. Simultaneous spatio-temporal resolution on a nanometer-femtosecond scale is achieved by using a near-field nonlinear optical response induced by ultrafast surface plasmon polaritons nanofocused on a metal tip. First, we study the surface plasmon response in metallic structures and evaluate its prospects and limitations for ultrafast near-field microscopy. Through plasmon emission-based spectroscopy, we investigate dephasing times and interplay between radiative and non-radiative decay rates of localized plasmons and their modification due to coupling. We identify a new regime of quantum plasmonic coupling, which limits the achievable spatial resolution to several angstroms but at the same time provides a potential channel for generating ultrafast electron currents at optical frequencies. Next, we study propagation of femtosecond wavepackets of surface plasmon polaritons on a metal tip. In time-domain interferometric measurements we detect group delays that correspond to slowing of the plasmon polaritons down to 20% of the speed of light at the tip apex. This provides direct experimental verification of the plasmonic nanofocusing mechanism and suggests enhanced nonlinear optical interactions at the tip apex. We then measure a plasmon-generated third-order nonlinear optical

  1. Abstractocyte: A Visual Tool for Exploring Nanoscale Astroglial Cells

    KAUST Repository

    Mohammed, Haneen

    2017-01-01

    This thesis presents the design and implementation of Abstractocyte, a system for the visual analysis of astrocytes, and their relation to neurons, in nanoscale volumes of brain tissue. Astrocytes are glial cells, i.e., non-neuronal cells

  2. Environmental, Health, and Safety Research Needs for Engineered Nanoscale Materials

    National Research Council Canada - National Science Library

    Alderson, Norris; Alexander, Catherine; Merzbacher, Celia; Chernicoff, William; Middendorf, Paul; Beck, Nancy; Chow, Flora; Poster, Dianne; Danello, Mary Ann; Barrera, Enriqueta

    2006-01-01

    ...) research and information needs related to understanding and management of potential risks of engineered nanoscale materials that may be used, for example, in commercial or consumer products, medical...

  3. Quantum Transport Simulations of Nanoscale Materials

    KAUST Repository

    Obodo, Tobechukwu Joshua

    2016-01-07

    Nanoscale materials have many potential advantages because of their quantum confinement, cost and producibility by low-temperature chemical methods. Advancement of theoretical methods as well as the availability of modern high-performance supercomputers allow us to control and exploit their microscopic properties at the atomic scale, hence making it possible to design novel nanoscale molecular devices with interesting features (e.g switches, rectifiers, negative differential conductance, and high magnetoresistance). In this thesis, state-of-the-art theoretical calculations have been performed for the quantum transport properties of nano-structured materials within the framework of Density Functional Theory (DFT) and the Nonequilibrium Green\\'s Function (NEGF) formalism. The switching behavior of a dithiolated phenylene-vinylene oligomer sandwiched between Au(111) electrodes is investigated. The molecule presents a configurational bistability, which can be exploited in constructing molecular memories, switches, and sensors. We find that protonation of the terminating thiol groups is at the origin of the change in conductance. H bonding at the thiol group weakens the S-Au bond, and thus lowers the conductance. Our results allow us to re-interpret the experimental data originally attributing the conductance reduction to H dissociation. Also examined is current-induced migration of atoms in nanoscale devices that plays an important role for device operation and breakdown. We studied the migration of adatoms and defects in graphene and carbon nanotubes under finite bias. We demonstrate that current-induced forces within DFT are non-conservative, which so far has only been shown for model systems, and can lower migration barrier heights. Further, we investigated the quantum transport behavior of an experimentally observed diblock molecule by varying the amounts of phenyl (donor) and pyrimidinyl (acceptor) rings under finite bias. We show that a tandem configuration of

  4. Electron Microscopy and Analytical X-ray Characterization of Compositional and Nanoscale Structural Changes in Fossil Bone

    Science.gov (United States)

    Boatman, Elizabeth Marie

    The nanoscale structure of compact bone contains several features that are direct indicators of bulk tissue mechanical properties. Fossil bone tissues represent unique opportunities to understand the compact bone structure/property relationships from a deep time perspective, offering a possible array of new insights into bone diseases, biomimicry of composite materials, and basic knowledge of bioapatite composition and nanoscale bone structure. To date, most work with fossil bone has employed microscale techniques and has counter-indicated the survival of bioapatite and other nanoscale structural features. The obvious disconnect between the use of microscale techniques and the discernment of nanoscale structure has prompted this work. The goal of this study was to characterize the nanoscale constituents of fossil compact bone by applying a suite of diffraction, microscopy, and spectrometry techniques, representing the highest levels of spatial and energy resolution available today, and capable of complementary structural and compositional characterization from the micro- to the nanoscale. Fossil dinosaur and crocodile long bone specimens, as well as modern ratite and crocodile femurs, were acquired from the UC Museum of Paleontology. Preserved physiological features of significance were documented with scanning electron microscopy back-scattered imaging. Electron microprobe wavelength-dispersive X-ray spectroscopy (WDS) revealed fossil bone compositions enriched in fluorine with a complementary loss of oxygen. X-ray diffraction analyses demonstrated that all specimens were composed of apatite. Transmission electron microscopy (TEM) imaging revealed preserved nanocrystallinity in the fossil bones and electron diffraction studies further identified these nanocrystallites as apatite. Tomographic analyses of nanoscale elements imaged by TEM and small angle X-ray scattering were performed, with the results of each analysis further indicating that nanoscale structure is

  5. The Effects of Aesthetic Science Activities on Improving At-Risk Families Children's Anxiety About Learning Science and Positive Thinking

    Science.gov (United States)

    Hong, Zuway-R.; Lin, Huann-shyang; Chen, Hsiang-Ting; Wang, Hsin-Hui; Lin, Chia-Jung

    2014-01-01

    The purpose of this study was to explore the effects of aesthetic science activities on improving elementary school at-risk families' children's positive thinking, attitudes toward science, and decreasing their anxiety about learning science. Thirty-six 4th-grade children from at-risk families volunteered to participate in a 12-week intervention and formed the experimental group; another 97 typical 4th graders were randomly selected to participant in the assessment and were used as the comparison group. The treatment for experimental group children emphasized scaffolding aesthetic science activities and inquiry strategies. The Elementary School Student Questionnaire was administered to assess all children's positive thinking, attitudes toward science, and anxiety about learning science. In addition, nine target children from the experimental group with the lowest scores on either positive thinking, or attitudes toward science, or with the highest scores on anxiety about learning science in the pre-test were recruited to be interviewed at the end of the intervention and observed weekly. Confirmatory factor analyses, analyses of covariance, and content theme analysis assessed the similarities and differences between groups. It was found that the at-risk families' children were motivated by the treatment and made significant progress on positive thinking and attitudes toward science, and also decreased their anxiety about learning science. The findings from interviews and classroom observations also revealed that the intervention made differences in children's affective perceptions of learning science. Implication and research recommendation are discussed.

  6. Nanomaterial Case Studies: Nanoscale Titanium Dioxide ...

    Science.gov (United States)

    This draft document presents two case studies of nanoscale titanium dioxide (nano-TiO2) used (1) to remove arsenic from drinking water and (2) as an active ingredient in topical sunscreen. The draft case studies are organized around a comprehensive environmental assessment approach that combines a product life cycle framework with the risk assessment paradigm. The document does not draw conclusions about potential risks. Rather, the case studies are intended to help identify what needs to be known in order to conduct a comprehensive environmental assessment of the potential risks related to nano-TiO2. This draft document is part of a process that will inform the development of EPA’s research strategy to support nanomaterial risk assessments. The complex properties of various nanomaterials make evaluating them in the abstract or with generalizations difficult if not impossible. Thus, this document focuses on two specific uses of nano-TiO2, as a drinking water treatment and as topical sunscreen. These case studies do not represent completed or even preliminary assessments; rather, they present the structure for identifying and prioritizing research needed to support future assessments.

  7. Classroom Activities: Simple Strategies to Incorporate Student-Centered Activities within Undergraduate Science Lectures

    Science.gov (United States)

    Lom, Barbara

    2012-01-01

    The traditional science lecture, where an instructor delivers a carefully crafted monolog to a large audience of students who passively receive the information, has been a popular mode of instruction for centuries. Recent evidence on the science of teaching and learning indicates that learner-centered, active teaching strategies can be more effective learning tools than traditional lectures. Yet most colleges and universities retain lectures as their central instructional method. This article highlights several simple collaborative teaching techniques that can be readily deployed within traditional lecture frameworks to promote active learning. Specifically, this article briefly introduces the techniques of: reader’s theatre, think-pair-share, roundtable, jigsaw, in-class quizzes, and minute papers. Each technique is broadly applicable well beyond neuroscience courses and easily modifiable to serve an instructor’s specific pedagogical goals. The benefits of each technique are described along with specific examples of how each technique might be deployed within a traditional lecture to create more active learning experiences. PMID:23494568

  8. Classroom Activities: Simple Strategies to Incorporate Student-Centered Activities within Undergraduate Science Lectures.

    Science.gov (United States)

    Lom, Barbara

    2012-01-01

    The traditional science lecture, where an instructor delivers a carefully crafted monolog to a large audience of students who passively receive the information, has been a popular mode of instruction for centuries. Recent evidence on the science of teaching and learning indicates that learner-centered, active teaching strategies can be more effective learning tools than traditional lectures. Yet most colleges and universities retain lectures as their central instructional method. This article highlights several simple collaborative teaching techniques that can be readily deployed within traditional lecture frameworks to promote active learning. Specifically, this article briefly introduces the techniques of: reader's theatre, think-pair-share, roundtable, jigsaw, in-class quizzes, and minute papers. Each technique is broadly applicable well beyond neuroscience courses and easily modifiable to serve an instructor's specific pedagogical goals. The benefits of each technique are described along with specific examples of how each technique might be deployed within a traditional lecture to create more active learning experiences.

  9. Nanoscale structural order from the atomic pair distribution function (PDF): There's plenty of room in the middle

    International Nuclear Information System (INIS)

    Billinge, Simon J.L.

    2008-01-01

    Emerging materials of scientific and technological interest are generally complex and often nanostructured: they have atomic orderings that extend on nanometer length-scales. These can be discrete nanoparticles; bulk crystals with nanoscale chemical or displacive order within them; mesoporous materials that are bulk materials containing nanoscale holes; and nanocomposites that are intimate heterogeneous mixtures of nano-sized constituents. As always, a quantitative knowledge of the atomic structure within these materials is a prerequisite to understanding and engineering their properties. Traditional crystallographic methods for obtaining this information break down at the nanoscale, sometimes referred to as 'the nanostructure problem'. We describe here some emerging methods for studying nanoscale structure. We present some examples of recent successes. Finally, we discuss future directions and opportunities and draw attention to limitations and potential problems. -

  10. Student Buy-In to Active Learning in a College Science Course.

    Science.gov (United States)

    Cavanagh, Andrew J; Aragón, Oriana R; Chen, Xinnian; Couch, Brian; Durham, Mary; Bobrownicki, Aiyana; Hanauer, David I; Graham, Mark J

    2016-01-01

    The benefits of introducing active learning in college science courses are well established, yet more needs to be understood about student buy-in to active learning and how that process of buy-in might relate to student outcomes. We test the exposure-persuasion-identification-commitment (EPIC) process model of buy-in, here applied to student (n = 245) engagement in an undergraduate science course featuring active learning. Student buy-in to active learning was positively associated with engagement in self-regulated learning and students' course performance. The positive associations among buy-in, self-regulated learning, and course performance suggest buy-in as a potentially important factor leading to student engagement and other student outcomes. These findings are particularly salient in course contexts featuring active learning, which encourage active student participation in the learning process. © 2016 A. J. Cavanagh et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  11. Nanoscale inhomogeneity and photoacid generation dynamics in extreme ultraviolet resist materials

    Science.gov (United States)

    Wu, Ping-Jui; Wang, Yu-Fu; Chen, Wei-Chi; Wang, Chien-Wei; Cheng, Joy; Chang, Vencent; Chang, Ching-Yu; Lin, John; Cheng, Yuan-Chung

    2018-03-01

    The development of extreme ultraviolet (EUV) lithography towards the 22 nm node and beyond depends critically on the availability of resist materials that meet stringent control requirements in resolution, line edge roughness, and sensitivity. However, the molecular mechanisms that govern the structure-function relationships in current EUV resist systems are not well understood. In particular, the nanoscale structures of the polymer base and the distributions of photoacid generators (PAGs) should play a critical roles in the performance of a resist system, yet currently available models for photochemical reactions in EUV resist systems are exclusively based on homogeneous bulk models that ignore molecular-level details of solid resist films. In this work, we investigate how microscopic molecular organizations in EUV resist affect photoacid generations in a bottom-up approach that describes structure-dependent electron-transfer dynamics in a solid film model. To this end, molecular dynamics simulations and stimulated annealing are used to obtain structures of a large simulation box containing poly(4-hydroxystyrene) (PHS) base polymers and triphenylsulfonium based PAGs. Our calculations reveal that ion-pair interactions govern the microscopic distributions of the polymer base and PAG molecules, resulting in a highly inhomogeneous system with nonuniform nanoscale chemical domains. Furthermore, the theoretical structures were used in combination of quantum chemical calculations and the Marcus theory to evaluate electron transfer rates between molecular sites, and then kinetic Monte Carlo simulations were carried out to model electron transfer dynamics with molecular structure details taken into consideration. As a result, the portion of thermalized electrons that are absorbed by the PAGs and the nanoscale spatial distribution of generated acids can be estimated. Our data reveal that the nanoscale inhomogeneous distributions of base polymers and PAGs strongly affect the

  12. Polaron Hopping in Nano-scale Poly(dA–Poly(dT DNA

    Directory of Open Access Journals (Sweden)

    Singh Mahi

    2010-01-01

    Full Text Available Abstract We investigate the current–voltage relationship and the temperature-dependent conductance of nano-scale samples of poly(dA–poly(dT DNA molecules. A polaron hopping model has been used to calculate the I–V characteristic of nano-scale samples of DNA. This model agrees with the data for current versus voltage at temperatures greater than 100 K. The quantities G 0 , i 0 , and T 1d are determined empirically, and the conductivity is estimated for samples of poly(dA–poly(dT.

  13. Place-Based Science Teaching and Learning: 40 Activities for K-8 Classrooms

    Science.gov (United States)

    Buxton, Cory A.; Provenzo, Eugene F., Jr.

    2011-01-01

    Grounded in theory and best-practices research, this practical text provides elementary and middle school teachers with 40 place-based activities that will help them to make science learning relevant to their students. This text provides teachers with both a rationale and a set of strategies and activities for teaching science in a local context…

  14. Elements of Design-Based Science Activities That Affect Students' Motivation

    Science.gov (United States)

    Jones, Brett D.; Chittum, Jessica R.; Akalin, Sehmuz; Schram, Asta B.; Fink, Jonathan; Schnittka, Christine; Evans, Michael A.; Brandt, Carol

    2015-01-01

    The primary purpose of this study was to examine the ways in which a 12-week after-school science and engineering program affected middle school students' motivation to engage in science and engineering activities. We used current motivation research and theory as a conceptual framework to assess 14 students' motivation through questionnaires,…

  15. Evaporation of nanoscale water on a uniformly complete wetting surface at different temperatures.

    Science.gov (United States)

    Guo, Yuwei; Wan, Rongzheng

    2018-05-03

    The evaporation of nanoscale water films on surfaces affects many processes in nature and industry. Using molecular dynamics (MD) simulations, we show the evaporation of a nanoscale water film on a uniformly complete wetting surface at different temperatures. With the increase in temperature, the growth of the water evaporation rate becomes slow. Analyses show that the hydrogen bond (H-bond) lifetimes and orientational autocorrelation times of the outermost water film decrease slowly with the increase in temperature. Compared to a thicker water film, the H-bond lifetimes and orientational autocorrelation times of a monolayer water film are much slower. This suggests that the lower evaporation rate of the monolayer water film on a uniformly complete wetting surface may be caused by the constriction of the water rotation due to the substrate. This finding may be helpful for controlling nanoscale water evaporation within a certain range of temperatures.

  16. Nano-scale characterization of the dynamics of the chloroplast Toc translocon.

    Science.gov (United States)

    Reddick, L Evan; Chotewutmontri, Prakitchai; Crenshaw, Will; Dave, Ashita; Vaughn, Michael; Bruce, Barry D

    2008-01-01

    Translocons are macromolecular nano-scale machines that facilitate the selective translocation of proteins across membranes. Although common in function, different translocons have evolved diverse molecular mechanisms for protein translocation. Subcellular organelles of endosymbiotic origin such as the chloroplast and mitochondria had to evolve/acquire translocons capable of importing proteins whose genes were transferred to the host genome. These gene products are expressed on cytosolic ribosomes as precursor proteins and targeted back to the organelle by an N-terminal extension called the transit peptide or presequence. In chloroplasts the transit peptide is specifically recognized by the Translocon of the Outer Chloroplast membrane (Toc) which is composed of receptor GTPases that potentially function as gate-like switches, where GTP binding and hydrolysis somehow facilitate preprotein binding and translocation. Compared to other translocons, the dynamics of the Toc translocon are probably more complex and certainly less understood. We have developed biochemical/biophysical, imaging, and computational techniques to probe the dynamics of the Toc translocon at the nanoscale. In this chapter we provide detailed protocols for kinetic and binding analysis of precursor interactions in organeller, measurement of the activity and nucleotide binding of the Toc GTPases, native electrophoretic analysis of the assembly/organization of the Toc complex, visualization of the distribution and mobility of Toc apparatus on the surface of chloroplasts, and conclude with the identification and molecular modeling Toc75 POTRA domains. With these new methodologies we discuss future directions of the field.

  17. Assessment report of research and development activities in FY2014. Activity: 'Quantum beam science research' (Result evaluation)

    International Nuclear Information System (INIS)

    2015-09-01

    Japan Atomic Energy Agency (hereafter referred to as 'JAEA') consulted an assessment committee, 'Evaluation Committee of Research Activities for Quantum Beam Science' (hereafter referred to as 'Committee') for result evaluation of 'Quantum Beam Science', in accordance with 'General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by JAEA. In response to the JAEA's request, the Committee assessed the research program of the Quantum Beam Science Center (hereafter referred to as 'QuBS') during the period from April 2010 to September 2014. The Committee evaluated the management and research activities of QuBS based on the explanatory documents and oral presentations. (author)

  18. Student Buy-In to Active Learning in a College Science Course

    Science.gov (United States)

    Cavanagh, Andrew J.; Aragón, Oriana R.; Chen, Xinnian; Couch, Brian; Durham, Mary; Bobrownicki, Aiyana; Hanauer, David I.; Graham, Mark J.

    2016-01-01

    The benefits of introducing active learning in college science courses are well established, yet more needs to be understood about student buy-in to active learning and how that process of buy-in might relate to student outcomes. We test the exposure–persuasion–identification–commitment (EPIC) process model of buy-in, here applied to student (n = 245) engagement in an undergraduate science course featuring active learning. Student buy-in to active learning was positively associated with engagement in self-regulated learning and students’ course performance. The positive associations among buy-in, self-regulated learning, and course performance suggest buy-in as a potentially important factor leading to student engagement and other student outcomes. These findings are particularly salient in course contexts featuring active learning, which encourage active student participation in the learning process. PMID:27909026

  19. Computer simulations for the nano-scale

    International Nuclear Information System (INIS)

    Stich, I.

    2007-01-01

    A review of methods for computations for the nano-scale is presented. The paper should provide a convenient starting point into computations for the nano-scale as well as a more in depth presentation for those already working in the field of atomic/molecular-scale modeling. The argument is divided in chapters covering the methods for description of the (i) electrons, (ii) ions, and (iii) techniques for efficient solving of the underlying equations. A fairly broad view is taken covering the Hartree-Fock approximation, density functional techniques and quantum Monte-Carlo techniques for electrons. The customary quantum chemistry methods, such as post Hartree-Fock techniques, are only briefly mentioned. Description of both classical and quantum ions is presented. The techniques cover Ehrenfest, Born-Oppenheimer, and Car-Parrinello dynamics. The strong and weak points of both principal and technical nature are analyzed. In the second part we introduce a number of applications to demonstrate the different approximations and techniques introduced in the first part. They cover a wide range of applications such as non-simple liquids, surfaces, molecule-surface interactions, applications in nano technology, etc. These more in depth presentations, while certainly not exhaustive, should provide information on technical aspects of the simulations, typical parameters used, and ways of analysis of the huge amounts of data generated in these large-scale supercomputer simulations. (author)

  20. Space Research, Education, and Related Activities In the Space Sciences

    Science.gov (United States)

    Black, David

    2002-01-01

    The mission of this activity, known as the Cooperative Program in Space Sciences (CPSS), is to conduct space science research and leading-edge instrumentation and technology development, enable research by the space sciences communities, and to expedite the effective dissemination of space science research, technology, data, and information to the educational community and the general public. To fulfill this mission, the Universities Space Research Association (USRA) recruits and maintains a staff of scientific researchers, operates a series of guest investigator facilities, organizes scientific meetings and workshops, and encourages various interactions with students and university faculty members. This paper is the final report from this now completed Cooperative Agreement.

  1. Nanoscale indent formation in shape memory polymers using a heated probe tip

    Energy Technology Data Exchange (ETDEWEB)

    Yang, F [Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801 (United States); Wornyo, E [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Gall, K [Department of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); King, W P [Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801 (United States)

    2007-07-18

    This paper presents experimental investigation of nanoscale indentation formation in shape memory polymers. The polymers were synthesized by photopolymerizing a tert-butyl acrylate (tBA) monomer with a poly(ethylene glycol dimethacrylate) (PEGDMA) crosslinker. The concentration and the molecular weight of the crosslinker were varied to produce five polymers with tailored properties. Nanoscale indentations were formed on the polymer surfaces by using a heated atomic force microscope (AFM) cantilever at various temperatures near or above the glass transition (between 84 and 215 deg. C) and a range of heating durations from 100 {mu}s to 8 ms. The images of the indents were obtained with the same probe tip at room temperature. The contact pressure, a measure of transient hardness, was derived from the indentation height data as a function of time and temperature for different polymers. With increasing crosslinker molecular weight and decreasing crosslinker concentration, the contact pressures decreased at a fixed maximum load due to increased crosslink spacing in the polymer system. The results provide insight into the nanoscale response of these novel materials.

  2. Assessment report of research and development activities FY2014. Activity: 'Advanced science research' (Final report)

    International Nuclear Information System (INIS)

    2015-09-01

    Japan Atomic Energy Agency (hereinafter referred to as 'JAEA') consulted an assessment committee, 'Evaluation Committee of Research Activities for Advanced Science Research' (hereinafter referred to as 'Committee') for final evaluation and prior assessment of 'Advanced Science Research,' in accordance with 'General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by JAEA. In response to the JAEA's request, the Committee assessed the research programs and activities of the Advanced Science Research Center (hereinafter referred to as 'ASRC') for the period of five years from April 2010 and the research programs from April 2015. The Committee evaluated the management and the research programs of the ASRC based on the explanatory documents prepared by the ASRC and the oral presentations with questions-and-answers by the Director and the research group leaders. This report summarizes the results of the assessment by the Committee with the Committee report attached. (author)

  3. Nanoscale measurements of proton tracks using fluorescent nuclear track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sawakuchi, Gabriel O., E-mail: gsawakuchi@mdanderson.org; Sahoo, Narayan [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and Graduate School of Biomedical Sciences, The University of Texas, Houston, Texas 77030 (United States); Ferreira, Felisberto A. [Department of Nuclear Physics, University of Sao Paulo, SP 05508-090 (Brazil); McFadden, Conor H. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Hallacy, Timothy M. [Biophysics Program, Harvard University, Cambridge, Massachusetts 02138 (United States); Granville, Dal A. [Department of Medical Physics, The Ottawa Hospital Cancer Centre, Ottawa, Ontario K1H 8L6 (Canada); Akselrod, Mark S. [Crystal Growth Division, Landauer, Inc., Stillwater, Oklahoma 74074 (United States)

    2016-05-15

    Purpose: The authors describe a method in which fluorescence nuclear track detectors (FNTDs), novel track detectors with nanoscale spatial resolution, are used to determine the linear energy transfer (LET) of individual proton tracks from proton therapy beams by allowing visualization and 3D reconstruction of such tracks. Methods: FNTDs were exposed to proton therapy beams with nominal energies ranging from 100 to 250 MeV. Proton track images were then recorded by confocal microscopy of the FNTDs. Proton tracks in the FNTD images were fit by using a Gaussian function to extract fluorescence amplitudes. Histograms of fluorescence amplitudes were then compared with LET spectra. Results: The authors successfully used FNTDs to register individual proton tracks from high-energy proton therapy beams, allowing reconstruction of 3D images of proton tracks along with delta rays. The track amplitudes from FNTDs could be used to parameterize LET spectra, allowing the LET of individual proton tracks from therapeutic proton beams to be determined. Conclusions: FNTDs can be used to directly visualize proton tracks and their delta rays at the nanoscale level. Because the track intensities in the FNTDs correlate with LET, they could be used further to measure LET of individual proton tracks. This method may be useful for measuring nanoscale radiation quantities and for measuring the LET of individual proton tracks in radiation biology experiments.

  4. Highly repeatable nanoscale phase coexistence in vanadium dioxide films

    Science.gov (United States)

    Huffman, T. J.; Lahneman, D. J.; Wang, S. L.; Slusar, T.; Kim, Bong-Jun; Kim, Hyun-Tak; Qazilbash, M. M.

    2018-02-01

    It is generally believed that in first-order phase transitions in materials with imperfections, the formation of phase domains must be affected to some extent by stochastic (probabilistic) processes. The stochasticity would lead to unreliable performance in nanoscale devices that have the potential to exploit the transformation of physical properties in a phase transition. Here we show that stochasticity at nanometer length scales is completely suppressed in the thermally driven metal-insulator transition (MIT) in sputtered vanadium dioxide (V O2 ) films. The nucleation and growth of domain patterns of metallic and insulating phases occur in a strikingly reproducible way. The completely deterministic nature of domain formation and growth in films with imperfections is a fundamental and unexpected finding about the kinetics of this material. Moreover, it opens the door for realizing reliable nanoscale devices based on the MIT in V O2 and similar phase-change materials.

  5. Negative pressure characteristics of an evaporating meniscus at nanoscale

    Directory of Open Access Journals (Sweden)

    Maroo Shalabh

    2011-01-01

    Full Text Available Abstract This study aims at understanding the characteristics of negative liquid pressures at the nanoscale using molecular dynamics simulation. A nano-meniscus is formed by placing liquid argon on a platinum wall between two nano-channels filled with the same liquid. Evaporation is simulated in the meniscus by increasing the temperature of the platinum wall for two different cases. Non-evaporating films are obtained at the center of the meniscus. The liquid film in the non-evaporating and adjacent regions is found to be under high absolute negative pressures. Cavitation cannot occur in these regions as the capillary height is smaller than the critical cavitation radius. Factors which determine the critical film thickness for rupture are discussed. Thus, high negative liquid pressures can be stable at the nanoscale, and utilized to create passive pumping devices as well as significantly enhance heat transfer rates.

  6. Nano Superconducting Quantum Interference device: A powerful tool for nanoscale investigations

    Energy Technology Data Exchange (ETDEWEB)

    Granata, Carmine, E-mail: carmine.granata@cnr.it; Vettoliere, Antonio

    2016-02-19

    The magnetic sensing at nanoscale level is a promising and interesting research topic of nanoscience. Indeed, magnetic imaging is a powerful tool for probing biological, chemical and physical systems. The study of small spin cluster, like magnetic molecules and nanoparticles, single electron, cold atom clouds, is one of the most stimulating challenges of applied and basic research of the next years. In particular, the magnetic nanoparticle investigation plays a fundamental role for the modern material science and its relative technological applications like ferrofluids, magnetic refrigeration and biomedical applications, including drug delivery, hyper-thermia cancer treatment and magnetic resonance imaging contrast-agent. Actually, one of the most ambitious goals of the high sensitivity magnetometry is the detection of elementary magnetic moment or spin. In this framework, several efforts have been devoted to the development of a high sensitivity magnetic nanosensor pushing sensing capability to the individual spin level. Among the different magnetic sensors, Superconducting QUantum Interference Devices (SQUIDs) exhibit an ultra high sensitivity and are widely employed in numerous applications. Basically, a SQUID consists of a superconducting ring (sensitive area) interrupted by two Josephson junctions. In the recent years, it has been proved that the magnetic response of nano-objects can be effectively measured by using a SQUID with a very small sensitive area (nanoSQUID). In fact, the sensor noise, expressed in terms of the elementary magnetic moment (spin or Bohr magneton), is linearly dependent on the SQUID loop side length. For this reason, SQUIDs have been progressively miniaturized in order to improve the sensitivity up to few spin per unit of bandwidth. With respect to other techniques, nanoSQUIDs offer the advantage of direct measurement of magnetization changes in small spin systems. In this review, we focus on nanoSQUIDs and its applications. In

  7. Quantitative FLIM-FRET Microscopy to Monitor Nanoscale Chromatin Compaction In Vivo Reveals Structural Roles of Condensin Complexes

    Directory of Open Access Journals (Sweden)

    David Llères

    2017-02-01

    Full Text Available How metazoan genomes are structured at the nanoscale in living cells and tissues remains unknown. Here, we adapted a quantitative FRET (Förster resonance energy transfer-based fluorescence lifetime imaging microscopy (FLIM approach to assay nanoscale chromatin compaction in living organisms. Caenorhabditis elegans was chosen as a model system. By measuring FRET between histone-tagged fluorescent proteins, we visualized distinct chromosomal regions and quantified the different levels of nanoscale compaction in meiotic cells. Using RNAi and repetitive extrachromosomal array approaches, we defined the heterochromatin state and showed that its architecture presents a nanoscale-compacted organization controlled by Heterochromatin Protein-1 (HP1 and SETDB1 H3-lysine-9 methyltransferase homologs in vivo. Next, we functionally explored condensin complexes. We found that condensin I and condensin II are essential for heterochromatin compaction and that condensin I additionally controls lowly compacted regions. Our data show that, in living animals, nanoscale chromatin compaction is controlled not only by histone modifiers and readers but also by condensin complexes.

  8. Developing Preservice Science Teachers' Self-Determined Motivation toward Environment through Environmental Activities

    Science.gov (United States)

    Karaarslan, Guliz; Sungur, Semra; Ertepinar, Hamide

    2014-01-01

    The aim of this study was to develop pre-service science teachers' self-determined motivation toward environment before, after and five months following the environmental course activities guided by self-determination theory. The sample of the study was 33 pre-service science teachers who participated in an environmental science course. This…

  9. Nanoscale structure and atomic disorder in the iron-based chalcogenides

    Directory of Open Access Journals (Sweden)

    Naurang Lal Saini

    2013-01-01

    Full Text Available The multiband iron-based superconductors have layered structure with a phase diagram characterized by a complex interplay of charge, spin and lattice excitations, with nanoscale atomic structure playing a key role in their fundamental electronic properties. In this paper, we briefly review nanoscale structure and atomic disorder in iron-based chalcogenide superconductors. We focus on the Fe(Se,S1−xTex (11-type and K0.8Fe1.6Se2 (122-type systems, discussing their local structure obtained by extended x-ray absorption fine structure. Local structure studies on the Fe(Se,S1−xTex system reveal clear nanoscale phase separation characterized by coexisting components of different atomic configurations, similar to the case of random alloys. In fact, the Fe–Se/S and Fe–Te distances in the ternary Fe(Se,S1−xTex are found to be closer to the respective distances in the binary FeSe/FeS and FeTe systems, showing significant divergence of the local structure from the average one. The observed features are characteristic of ternary random alloys, indicating breaking of the local symmetry in these materials. On the other hand, K0.8Fe1.6Se2 is known for phase separation in an iron-vacancy ordered phase and an in-plane compressed lattice phase. The local structure of these 122-type chalcogenides shows that this system is characterized by a large local disorder. Indeed, the experiments suggest a nanoscale glassy phase in K0.8Fe1.6Se2, with the superconductivity being similar to the granular materials. While the 11-type structure has no spacer layer, the 122-type structure contains intercalated atoms unlike the 1111-type REFeAsO (RE = rare earth oxypnictides, having well-defined REO spacer layers. It is clear that the interlayer atomic correlations in these iron-based superconducting structures play an important role in structural stability as well as superconductivity and magnetism.

  10. Graduated characterization method using a multi-well microplate for reducing reactivity of nanoscale zero valent iron materials

    DEFF Research Database (Denmark)

    Hwang, Yuhoon; Salatas, Apostolos; Mines, Paul D.

    2015-01-01

    Even though nanoscale zero valent iron (nZVI) has been intensively studied for the treatment of a plethora of pollutants through reductive reaction, quantification of nZVI reactivity has not yet been standardized. Here, we adapted colorimetric assays for determining reductive activity of n...... with different compounds, combined with the use of a multi-well microplate based color assay, promises to be a useful and simple tool in various nZVI related research topics....

  11. Biomass I. Science Activities in Energy [and] Teacher's Guide.

    Science.gov (United States)

    Oak Ridge Associated Universities, TN.

    Designed for science students in fourth, fifth, and sixth grades, the activities in this unit illustrate principles and problems related to biomass as a form of energy. (The word biomass is used to describe all solid material of animal or vegetable origin from which energy may be extracted.) Twelve student activities using art, economics,…

  12. NASA'S Earth Science Data Stewardship Activities

    Science.gov (United States)

    Lowe, Dawn R.; Murphy, Kevin J.; Ramapriyan, Hampapuram

    2015-01-01

    NASA has been collecting Earth observation data for over 50 years using instruments on board satellites, aircraft and ground-based systems. With the inception of the Earth Observing System (EOS) Program in 1990, NASA established the Earth Science Data and Information System (ESDIS) Project and initiated development of the Earth Observing System Data and Information System (EOSDIS). A set of Distributed Active Archive Centers (DAACs) was established at locations based on science discipline expertise. Today, EOSDIS consists of 12 DAACs and 12 Science Investigator-led Processing Systems (SIPS), processing data from the EOS missions, as well as the Suomi National Polar Orbiting Partnership mission, and other satellite and airborne missions. The DAACs archive and distribute the vast majority of data from NASA’s Earth science missions, with data holdings exceeding 12 petabytes The data held by EOSDIS are available to all users consistent with NASA’s free and open data policy, which has been in effect since 1990. The EOSDIS archives consist of raw instrument data counts (level 0 data), as well as higher level standard products (e.g., geophysical parameters, products mapped to standard spatio-temporal grids, results of Earth system models using multi-instrument observations, and long time series of Earth System Data Records resulting from multiple satellite observations of a given type of phenomenon). EOSDIS data stewardship responsibilities include ensuring that the data and information content are reliable, of high quality, easily accessible, and usable for as long as they are considered to be of value.

  13. Taking an active stance: How urban elementary students connect sociocultural experiences in learning science

    Science.gov (United States)

    Upadhyay, Bhaskar; Maruyama, Geoffrey; Albrecht, Nancy

    2017-12-01

    In this interpretive case study, we draw from sociocultural theory of learning and culturally relevant pedagogy to understand how urban students from nondominant groups leverage their sociocultural experiences. These experiences allow them to gain an empowering voice in influencing science content and activities and to work towards self-determining the sciences that are personally meaningful. Furthermore, tying sociocultural experiences with science learning helps generate sociopolitical awareness among students. We collected interview and observation data in an urban elementary classroom over one academic year to understand the value of urban students' sociocultural experiences in learning science and choosing science activities.

  14. Modeling of nanoscale liquid mixture transport by density functional hydrodynamics

    Science.gov (United States)

    Dinariev, Oleg Yu.; Evseev, Nikolay V.

    2017-06-01

    Modeling of multiphase compositional hydrodynamics at nanoscale is performed by means of density functional hydrodynamics (DFH). DFH is the method based on density functional theory and continuum mechanics. This method has been developed by the authors over 20 years and used for modeling in various multiphase hydrodynamic applications. In this paper, DFH was further extended to encompass phenomena inherent in liquids at nanoscale. The new DFH extension is based on the introduction of external potentials for chemical components. These potentials are localized in the vicinity of solid surfaces and take account of the van der Waals forces. A set of numerical examples, including disjoining pressure, film precursors, anomalous rheology, liquid in contact with heterogeneous surface, capillary condensation, and forward and reverse osmosis, is presented to demonstrate modeling capabilities.

  15. Charge transport in nanoscale vertical organic semiconductor pillar devices

    NARCIS (Netherlands)

    Wilbers, J.G.E.; Xu, B.; Bobbert, P.A.; de Jong, M.P.; van der Wiel, W.G.

    2017-01-01

    We report charge transport measurements in nanoscale vertical pillar structures incorporating ultrathin layers of the organic semiconductor poly(3-hexylthiophene) (P3HT). P3HT layers with thickness down to 5 nm are gently top-contacted using wedging transfer, yielding highly reproducible, robust

  16. The emergence and policy implications of converging new technologies integrated from the nanoscale

    International Nuclear Information System (INIS)

    Roco, M. C.

    2005-01-01

    Science based on the unified concepts on matter at the nanoscale provides a new foundation for knowledge creation, innovation, and technology integration. Convergent new technologies refers to the synergistic combination of nanotechnology, biotechnology, information technology and cognitive sciences (NBIC), each of which is currently progressing at a rapid rate, experiencing qualitative advancements, and interacting with the more established fields such as mathematics and environmental technologies (Roco and Bainbridge, 2002). It is expected that converging technologies will bring about tremendous improvements in transforming tools, new products and services, enable human personal abilities and social achievements, and reshape societal relationships.After a brief overview of the general implications of converging new technologies, this paper focuses on its effects on R and D policies and business models as part of changing societal relationships. These R and D policies will have implications on investments in research and industry, with the main goal of taking advantage of the transformative development of NBIC. Introduction of converging technologies must be done with respect of immediate concerns (privacy, toxicity of new materials, etc.) and longer-term concerns including human integrity, dignity and welfare. The efficient introduction and development of converging new technologies will require new organizations and business models, as well as solutions for preparing the economy, such as multifunctional research facilities, integrative technology platforms, and global risk governance

  17. The emergence and policy implications of converging new technologies integrated from the nanoscale

    Science.gov (United States)

    Roco, M. C.

    2005-06-01

    Science based on the unified concepts on matter at the nanoscale provides a new foundation for knowledge creation, innovation, and technology integration. Convergent new technologies refers to the synergistic combination of nanotechnology, biotechnology, information technology and cognitive sciences (NBIC), each of which is currently progressing at a rapid rate, experiencing qualitative advancements, and interacting with the more established fields such as mathematics and environmental technologies (Roco & Bainbridge, 2002). It is expected that converging technologies will bring about tremendous improvements in transforming tools, new products and services, enable human personal abilities and social achievements, and reshape societal relationships. After a brief overview of the general implications of converging new technologies, this paper focuses on its effects on R&D policies and business models as part of changing societal relationships. These R&D policies will have implications on investments in research and industry, with the main goal of taking advantage of the transformative development of NBIC. Introduction of converging technologies must be done with respect of immediate concerns (privacy, toxicity of new materials, etc.) and longer-term concerns including human integrity, dignity and welfare. The efficient introduction and development of converging new technologies will require new organizations and business models, as well as solutions for preparing the economy, such as multifunctional research facilities, integrative technology platforms, and global risk governance.

  18. The emergence and policy implications of converging new technologies integrated from the nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Roco, M. C. [National Science Foundation (United States)], E-mail: mroco@nsf.gov

    2005-06-15

    Science based on the unified concepts on matter at the nanoscale provides a new foundation for knowledge creation, innovation, and technology integration. Convergent new technologies refers to the synergistic combination of nanotechnology, biotechnology, information technology and cognitive sciences (NBIC), each of which is currently progressing at a rapid rate, experiencing qualitative advancements, and interacting with the more established fields such as mathematics and environmental technologies (Roco and Bainbridge, 2002). It is expected that converging technologies will bring about tremendous improvements in transforming tools, new products and services, enable human personal abilities and social achievements, and reshape societal relationships.After a brief overview of the general implications of converging new technologies, this paper focuses on its effects on R and D policies and business models as part of changing societal relationships. These R and D policies will have implications on investments in research and industry, with the main goal of taking advantage of the transformative development of NBIC. Introduction of converging technologies must be done with respect of immediate concerns (privacy, toxicity of new materials, etc.) and longer-term concerns including human integrity, dignity and welfare. The efficient introduction and development of converging new technologies will require new organizations and business models, as well as solutions for preparing the economy, such as multifunctional research facilities, integrative technology platforms, and global risk governance.

  19. Investigation the opinions of the primary science teachers toward practice of teaching and learning activities in science learning area

    Science.gov (United States)

    Chamnanwong, Pornpaka; Thathong, Kongsak

    2018-01-01

    In preparing a science lesson plan, teachers may deal with numerous difficulties. Having a deep understanding of their problems and their demands is extremely essential for the teachers in preparing themselves for the job. Moreover, it is also crucial for the stakeholders in planning suitable and in-need teachers' professional development programs, in school management, and in teaching aid. This study aimed to investigate the primary school science teachers' opinion toward practice of teaching and learning activities in science learning area. Target group was 292 primary science teachers who teach Grade 4 - 6 students in Khon Kaen Province, Thailand in the academic year of 2014. Data were collected using Questionnaire about Investigation the opinions of the primary science teachers toward practice of teaching and learning activities in science learning area. The questionnaires were consisted of closed questions scored on Likert scale and open-ended questions that invite a sentence response to cover from LS Process Ideas. Research findings were as follow. The primary science teachers' level of opinion toward teaching and learning science subject ranged from 3.19 - 3.93 (mean = 3.43) as "Moderate" level of practice. The primary school science teachers' needs to participate in a training workshop based on LS ranged from 3.66 - 4.22 (mean = 3.90) as "High" level. The result indicated that they were interested in attending a training course under the guidance of the Lesson Study by training on planning of management of science learning to solve teaching problems in science contents with the highest mean score 4.22. Open-ended questions questionnaire showed the needs of the implementation of the lesson plans to be actual classrooms, and supporting for learning Medias, innovations, and equipment for science experimentation.

  20. Corrosion chemistry closing comments: opportunities in corrosion science facilitated by operando experimental characterization combined with multi-scale computational modelling.

    Science.gov (United States)

    Scully, John R

    2015-01-01

    Recent advances in characterization tools, computational capabilities, and theories have created opportunities for advancement in understanding of solid-fluid interfaces at the nanoscale in corroding metallic systems. The Faraday Discussion on Corrosion Chemistry in 2015 highlighted some of the current needs, gaps and opportunities in corrosion science. Themes were organized into several hierarchical categories that provide an organizational framework for corrosion. Opportunities to develop fundamental physical and chemical data which will enable further progress in thermodynamic and kinetic modelling of corrosion were discussed. These will enable new and better understanding of unit processes that govern corrosion at the nanoscale. Additional topics discussed included scales, films and oxides, fluid-surface and molecular-surface interactions, selected topics in corrosion science and engineering as well as corrosion control. Corrosion science and engineering topics included complex alloy dissolution, local corrosion, and modelling of specific corrosion processes that are made up of collections of temporally and spatially varying unit processes such as oxidation, ion transport, and competitive adsorption. Corrosion control and mitigation topics covered some new insights on coatings and inhibitors. Further advances in operando or in situ experimental characterization strategies at the nanoscale combined with computational modelling will enhance progress in the field, especially if coupling across length and time scales can be achieved incorporating the various phenomena encountered in corrosion. Readers are encouraged to not only to use this ad hoc organizational scheme to guide their immersion into the current opportunities in corrosion chemistry, but also to find value in the information presented in their own ways.

  1. Characterization of NiSi nanowires as field emitters and limitations of Fowler-Nordheim model at the nanoscale

    Science.gov (United States)

    Belkadi, Amina B.; Gale, E.; Isakovic, A. F.

    2015-03-01

    Nanoscale field emitters are of technological interest because of the anticipated faster turn-on time, better sustainability and compactness. This report focuses on NiSi nanowires as field emitters for two reasons: (a) possible enhancement of field emission in nanoscale field emitters over bulk, and (b) achieving the same field emission properties as in bulk, but at a lower energy cost. To this end, we have grown, fabricated and characterized NiSi nanowires as field emitters. Depending on the geometry of the NiSi nanowires (aspect ratio, shape etc.), the relevant major field emission parameters, such as (1) the turn-on field, (2) the work function, and (3) the field enhancement factor, can be comparable or even superior to other recently explored nanoscale field emitters, such as CdS and ZnO. We also report on a comparative performance of various nanoscale field emitters and on the difficulties in the performance comparison in the light of relatively poor applicability of the standard Folwer-Nordheim model for field emission analysis for the case of the nanoscale field emitters. Proposed modifications are discussed. This work is supported through SRC-ATIC Grant 2011-KJ-2190. We also acknoweldge BNL-CFN and Cornell CNF facilities and staff.

  2. Radiolitically Synthesized Hybrid Nanosystems for Bio-Nanotechnologies

    Energy Technology Data Exchange (ETDEWEB)

    Kacarevic-Popovic, Z. [Vinča Institute of Nuclear Sciences, Laboratory for Radiation Chemistry and Physics - Gamma, Belgrade (Serbia)

    2009-07-01

    Laboratory for Radiation chemistry and Physics, Gamma, Vinca Institute of Nuclear Sciences, has 15 employed researchers with Ph.D. and 15 graduate students working on ongoing projects in experimental research in nanoscale science and modification of materials by irradiation. This Laboratory has excellence and long lasting tradition in scientific activities. Based on the outstanding results in radiation chemistry in the Laboratory for Radiation Chemistry and Physics exists radiation unit for industrial sterilization of medical devices. In years 2003 and 2004 Serbian Ministry of Science invested 500,000 € for equipment for developing nanosciences in Laboratory. Laboratory is well equipped for synthesis and characterization of nanoscale materials. (author)

  3. Radiolitically Synthesized Hybrid Nanosystems for Bio-Nanotechnologies

    International Nuclear Information System (INIS)

    Kacarevic-Popovic, Z.

    2009-01-01

    Laboratory for Radiation chemistry and Physics, Gamma, Vinca Institute of Nuclear Sciences, has 15 employed researchers with Ph.D. and 15 graduate students working on ongoing projects in experimental research in nanoscale science and modification of materials by irradiation. This Laboratory has excellence and long lasting tradition in scientific activities. Based on the outstanding results in radiation chemistry in the Laboratory for Radiation Chemistry and Physics exists radiation unit for industrial sterilization of medical devices. In years 2003 and 2004 Serbian Ministry of Science invested 500,000 € for equipment for developing nanosciences in Laboratory. Laboratory is well equipped for synthesis and characterization of nanoscale materials. (author)

  4. Nanoscale and submicron fatigue crack growth in nickel microbeams

    International Nuclear Information System (INIS)

    Yang, Y.; Yao, N.; Imasogie, B.; Soboyejo, W.O.

    2007-01-01

    This paper presents a novel edge-notched microbeam technique for the study of short fatigue crack growth. The technique is used to study submicron and nanoscale fatigue in LIGA Ni thin films with columnar microstructures. The edge-notched microbeams were fabricated within LIGA Ni thin films, using focused ion beam (FIB) techniques. The microbeams were then cyclically deformed to failure at a stress ratio of 0.1. Different slip-band structures were observed below the nanoscale notches. Cyclic deformation resulted in the formation of primary slip bands below the notch. Subsequent crack growth then occurred by the unzipping of fatigue cracks along intersecting slip bands. The effects of the primary slip bands were idealized using dislocation-based models. These were used to estimate the intrinsic fatigue threshold and the fatigue endurance limit. The estimates from the model are shown to be consistent with experimental data from prior stress-life experiments and current/prior fatigue threshold estimates

  5. Laser ablation of nanoscale particles with 193 nm light

    International Nuclear Information System (INIS)

    Choi, J H; Lucas, D; Koshland, C P

    2007-01-01

    Laser interaction with nanoscale particles is distinct and different from laser-bulk material interaction, where a hot plasma is normally created. Here, we review our studies on 193 nm laser ablation of various nanoscale particles including NaCl, soot, polystyrene, and gold. The 20 ns laser beam with fluences up to 0.3 J/cm 2 irradiates nanoparticles in a gas stream at laser repetition rates from 10 to 100 Hz. The particle size distributions before and after irradiation are measured with a scanning mobility particle sizer (SMPS), and particle morphology is examined with electron microscopy. All the nanomaterials studied exhibit a similar disintegration pattern and similar particle formation characteristics. No broadband emission associated with particle heating or optical breakdown is observed. The nanoparticles formed after irradiation have a smaller mean diameter and an order of magnitude higher number concentration with a more spherical shape compared to the original particles. We use the photon-atom ratio (PAR) to interpret the laser-particle interaction energetics

  6. Magnetization switching schemes for nanoscale three-terminal spintronics devices

    Science.gov (United States)

    Fukami, Shunsuke; Ohno, Hideo

    2017-08-01

    Utilizing spintronics-based nonvolatile memories in integrated circuits offers a promising approach to realize ultralow-power and high-performance electronics. While two-terminal devices with spin-transfer torque switching have been extensively developed nowadays, there has been a growing interest in devices with a three-terminal structure. Of primary importance for applications is the efficient manipulation of magnetization, corresponding to information writing, in nanoscale devices. Here we review the studies of current-induced domain wall motion and spin-orbit torque-induced switching, which can be applied to the write operation of nanoscale three-terminal spintronics devices. For domain wall motion, the size dependence of device properties down to less than 20 nm will be shown and the underlying mechanism behind the results will be discussed. For spin-orbit torque-induced switching, factors governing the threshold current density and strategies to reduce it will be discussed. A proof-of-concept demonstration of artificial intelligence using an analog spin-orbit torque device will also be reviewed.

  7. Assessment report of research and development activities in FY2014. Activity: 'Quantum beam science research' (In-advance evaluation)

    International Nuclear Information System (INIS)

    2015-09-01

    Japan Atomic Energy Agency (hereafter referred to as 'JAEA') consulted an assessment committee, 'Evaluation Committee of Research Activities for Quantum Beam Science' (hereafter referred to as 'Committee') for result evaluation of 'Quantum Beam Science', in accordance with 'General Guideline for the Evaluation of Government Research and Development (R and D) Activities' by Cabinet Office, Government of Japan, 'Guideline for Evaluation of R and D in Ministry of Education, Culture, Sports, Science and Technology' and 'Regulation on Conduct for Evaluation of R and D Activities' by JAEA. In response to the JAEA's request, the Committee assessed the research program of the Quantum Beam Science Center (hereafter referred to as 'QuBS') during the period from April 2015 to March 2022. The Committee evaluated the management and research activities of QuBS based on the explanatory documents and oral presentations. (author)

  8. An integrative review of in-class activities that enable active learning in college science classroom settings

    Science.gov (United States)

    Arthurs, Leilani A.; Kreager, Bailey Zo

    2017-10-01

    Engaging students in active learning is linked to positive learning outcomes. This study aims to synthesise the peer-reviewed literature about 'active learning' in college science classroom settings. Using the methodology of an integrative literature review, 337 articles archived in the Educational Resources Information Center (ERIC) are examined. Four categories of in-class activities emerge: (i) individual non-polling activities, (ii) in-class polling activities, (iii) whole-class discussion or activities, and (iv) in-class group activities. Examining the collection of identified in-class activities through the lens of a theoretical framework informed by constructivism and social interdependence theory, we synthesise the reviewed literature to propose the active learning strategies (ALSs) model and the instructional decisions to enable active learning (IDEAL) theory. The ALS model characterises in-class activities in terms of the degrees to which they are designed to promote (i) peer interaction and (ii) social interdependence. The IDEAL theory includes the ALS model and provides a framework for conceptualising different levels of the general concept 'active learning' and how these levels connect to instructional decision-making about using in-class activities. The proposed ALS model and IDEAL theory can be utilised to inform instructional decision-making and future research about active learning in college science courses.

  9. Nanoscale waveguiding methods

    Directory of Open Access Journals (Sweden)

    Wang Chia-Jean

    2007-01-01

    Full Text Available AbstractWhile 32 nm lithography technology is on the horizon for integrated circuit (IC fabrication, matching the pace for miniaturization with optics has been hampered by the diffraction limit. However, development of nanoscale components and guiding methods is burgeoning through advances in fabrication techniques and materials processing. As waveguiding presents the fundamental issue and cornerstone for ultra-high density photonic ICs, we examine the current state of methods in the field. Namely, plasmonic, metal slot and negative dielectric based waveguides as well as a few sub-micrometer techniques such as nanoribbons, high-index contrast and photonic crystals waveguides are investigated in terms of construction, transmission, and limitations. Furthermore, we discuss in detail quantum dot (QD arrays as a gain-enabled and flexible means to transmit energy through straight paths and sharp bends. Modeling, fabrication and test results are provided and show that the QD waveguide may be effective as an alternate means to transfer light on sub-diffraction dimensions.

  10. Formation and Characterization of Stacked Nanoscale Layers of Polymers and Silanes on Silicon Surfaces

    Science.gov (United States)

    Ochoa, Rosie; Davis, Brian; Conley, Hiram; Hurd, Katie; Linford, Matthew R.; Davis, Robert C.

    2008-10-01

    Chemical surface patterning at the nanoscale is a critical component of chemically directed assembly of nanoscale devices or sensitive biological molecules onto surfaces. Complete and consistent formation of nanoscale layers of silanes and polymers is a necessary first step for chemical patterning. We explored methods of silanizing silicon substrates for the purpose of functionalizing the surfaces. The chemical functionalization, stability, flatness, and repeatability of the process was characterized by use of ellipsometry, water contact angle, and Atomic Force Microscopy (AFM). We found that forming the highest quality functionalized surfaces was accomplished through use of chemical vapor deposition (CVD). Specifically, surfaces were plasma cleaned and hydrolyzed before the silane was applied. A polymer layer less then 2 nm in thickness was electrostatically bound to the silane layer. The chemical functionalization, stability, flatness, and repeatability of the process was also characterized for the polymer layer using ellipsometry, water contact angle, and AFM.

  11. Feasibility Study of Nanoscale Semiconductor Manufacture Using Thermal Dip Pen Nanolithography

    National Research Council Canada - National Science Library

    King, William P

    2006-01-01

    ...) for the purpose of nanoscale electronics manufacturing. In this project, we have demonstrated that using the thermal DPN technique that both indium metal, and semiconducting organic materials (PDDT, PVDF...

  12. APS SCIENCE 2016

    Energy Technology Data Exchange (ETDEWEB)

    Fenner, Richard B. [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

    2017-05-01

    The Advanced Photon Source (APS) occupies an 80-acre site on the Argonne national laboratory campus, about 25 miles from downtown chicago, illinois. it shares the site with the center for nanoscale materials and the Advanced Protein characterization facility. for directions to Argonne, see http://www.anl.gov/directions-and-visitor-information. The APS, a national synchrotron radiation research facility operated by Argonne for the u.S. department of energy (doe) office of Science, provides this nation’s brightest high-energy x-ray beams for science. research by APS users extends from the center of the earth to outer space, from new information on combustion engines and microcircuits to new drugs and nanotechnologies whose scale is measured in billionths of a meter. The APS helps researchers illuminate answers to the challenges of our high-tech world, from developing new forms of energy, to sustaining our nation’s technological and economic competitiveness, to pushing back against the ravages of disease. research at the APS promises to have far-reaching

  13. 77 FR 16846 - National Science Advisory Board for Biosecurity Meeting; Office of Biotechnology Activities...

    Science.gov (United States)

    2012-03-22

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Science Advisory Board for Biosecurity Meeting; Office of Biotechnology Activities, Office of Science Policy, Office of.... Contact Person: Ronna Hill, NSABB Program Assistant, NIH Office of Biotechnology Activities, 6705...

  14. A poly(vinyl alcohol)/sodium alginate blend monolith with nanoscale porous structure.

    Science.gov (United States)

    Sun, Xiaoxia; Uyama, Hiroshi

    2013-10-04

    A stimuli-responsive poly(vinyl alcohol) (PVA)/sodium alginate (SA) blend monolith with nanoscale porous (mesoporous) structure is successfully fabricated by thermally impacted non-solvent induced phase separation (TINIPS) method. The PVA/SA blend monolith with different SA contents is conveniently fabricated in an aqueous methanol without any templates. The solvent suitable for the fabrication of the present blend monolith by TINIPS is different with that of the PVA monolith. The nanostructural control of the blend monolith is readily achieved by optimizing the fabrication conditions. Brunauer Emmett Teller measurement shows that the obtained blend monolith has a large surface area. Pore size distribution plot for the blend monolith obtained by the non-local density functional theory method reveals the existence of the nanoscale porous structure. Fourier transform infrared analysis reveals the strong interactions between PVA and SA. The pH-responsive property of the blend monolith is investigated on the basis of swelling ratio in different pH solutions. The present blend monolith of biocompatible and biodegradable PVA and SA with nanoscale porous structure has large potential for applications in biomedical and environmental fields.

  15. Developing Science Communication in Africa: Undergraduate and Graduate Students should be Trained and Actively Involved in Outreach Activity Development and Implementation.

    Science.gov (United States)

    Karikari, Thomas K; Yawson, Nat Ato; Quansah, Emmanuel

    2016-01-01

    Despite recent improvements in scientific research output from Africa, public understanding of science in many parts of the continent remains low. Science communication there is faced with challenges such as (i) lack of interest among some scientists, (ii) low availability of training programs for scientists, (iii) low literacy rates among the public, and (iv) multiplicity of languages. To address these challenges, new ways of training and motivating scientists to dialogue with non-scientists are essential. Developing communication skills early in researchers' scientific career would be a good way to enhance their public engagement abilities. Therefore, a potentially effective means to develop science communication in Africa would be to actively involve trainee scientists (i.e., undergraduate and graduate students) in outreach activity development and delivery. These students are often enthusiastic about science, eager to develop their teaching and communication skills, and can be good mentors to younger students. Involving them in all aspects of outreach activity is, therefore, likely to be a productive implementation strategy. However, science communication training specifically for students and the involvement of these students in outreach activity design and delivery are lacking in Africa. Here, we argue that improving the training and involvement of budding scientists in science communication activities would be a good way to bridge the wide gap between scientists and the African public.

  16. Why Change to Active Learning? Pre-Service and In-Service Science Teachers' Perceptions

    Science.gov (United States)

    O'Grady, Audrey; Simmie, Geraldine Mooney; Kennedy, Therese

    2014-01-01

    This article explores pre-service and in-service science teachers' perceptions on active learning, and examines the effectiveness of active learning by pre-service science teachers in the Irish second level classroom through a two-phase study. In the first phase, data on perceptions were gathered from final year pre-service teachers and in-service…

  17. Application of exergetic sustainability index to a nano-scale irreversible Brayton cycle operating with ideal Bose and Fermi gasses

    Energy Technology Data Exchange (ETDEWEB)

    Açıkkalp, Emin, E-mail: eacikkalp@gmail.com [Department of Mechanical and Manufacturing Engineering, Engineering Faculty, Bilecik S.E. University, Bilecik (Turkey); Caner, Necmettin [Department of Chemistry, Faculty of Arts and Sciences, Eskisehir Osmangazi University, Eskisehir (Turkey)

    2015-09-25

    Highlights: • An irreversible Brayton cycle operating quantum gasses is considered. • Exergetic sustainability index is derived for nano-scale cycles. • Nano-scale effects are considered. • Calculation are conducted for irreversible cycles. • Numerical results are presented and discussed. - Abstract: In this study, a nano-scale irreversible Brayton cycle operating with quantum gasses including Bose and Fermi gasses is researched. Developments in the nano-technology cause searching the nano-scale machines including thermal systems to be unavoidable. Thermodynamic analysis of a nano-scale irreversible Brayton cycle operating with Bose and Fermi gasses was performed (especially using exergetic sustainability index). In addition, thermodynamic analysis involving classical evaluation parameters such as work output, exergy output, entropy generation, energy and exergy efficiencies were conducted. Results are submitted numerically and finally some useful recommendations were conducted. Some important results are: entropy generation and exergetic sustainability index are affected mostly for Bose gas and power output and exergy output are affected mostly for the Fermi gas by x. At the high temperature conditions, work output and entropy generation have high values comparing with other degeneracy conditions.

  18. Overview of OECD-NEA Nuclear Science and Data Bank Activities

    International Nuclear Information System (INIS)

    Gulliford, Jim

    2012-01-01

    Overview: • NEA Areas of Work, Standing Committees; • Nuclear Science & the Data Bank: – Working Parties & Expert Groups; – integral experiments databases; – linked Data Bank/Nuclear Science products. • Reactor Physics and Criticality Integral Experiments: – ICSBEP& IRPhE evaluations; – Database tools (DICE, IDAT, SFCOMPO-X). • Other Activities related to Fast Reactors: – WPRS SFR Task Force; – Nuclear Data, WPEC sub-group on data adjustment; – Fuel Cycle and Materials. • Looking Ahead: – Uncertainty Analysis for transient modelling; – Russian Accession to the NEA and Data Bank; – Impact of Fukushima on Nuclear Science Programmes of Work

  19. Capturing citation activity in three health sciences departments: a comparison study of Scopus and Web of Science.

    Science.gov (United States)

    Sarkozy, Alexandra; Slyman, Alison; Wu, Wendy

    2015-01-01

    Scopus and Web of Science are the two major citation databases that collect and disseminate bibliometric statistics about research articles, journals, institutions, and individual authors. Liaison librarians are now regularly called upon to utilize these databases to assist faculty in finding citation activity on their published works for tenure and promotion, grant applications, and more. But questions about the accuracy, scope, and coverage of these tools deserve closer scrutiny. Discrepancies in citation capture led to a systematic study on how Scopus and Web of Science compared in a real-life situation encountered by liaisons: comparing three different disciplines at a medical school and nursing program. How many articles would each database retrieve for each faculty member using the author-searching tools provided? How many cited references for each faculty member would each tool generate? Results demonstrated troubling differences in publication and citation activity capture between Scopus and Web of Science. Implications for librarians are discussed.

  20. Development of a Large-Format Science-Grade CMOS Active Pixel Sensor, for Extreme Ultra Violet Spectroscopy and Imaging in Space Science

    National Research Council Canada - National Science Library

    Waltham, N. R; Prydderch, M; Mapson-Menard, H; Morrissey, Q; Turchetta, R; Pool, P; Harris, A

    2005-01-01

    We describe our programme to develop a large-format science-grade CMOS active pixel sensor for future space science missions, and in particular an extreme ultra-violet spectrograph for solar physics...

  1. The Influence of Extracurricular Activities on Middle School Students' Science Learning in China

    Science.gov (United States)

    Zhang, Danhui; Tang, Xing

    2017-01-01

    Informal science learning has been found to have effects on students' science learning. Through the use of secondary data from a national assessment of 7410 middle school students in China, this study explores the relationship among five types of extracurricular science activities, learning interests, academic self-concept, and science…

  2. Ultrafast phenomena at the nanoscale: science opportunities at the SwissFEL X-ray laser

    International Nuclear Information System (INIS)

    Abela, R.; Braun, H.; Ming, P.; Pedrozzi, M.; Quitmann, Ch.; Reiche, S.; Daalen, M. van; Veen, J.F. van der; Mesot, J.; Mesot, J.; Shiroka, T.; Veen, J.F. van der; Mesot, J.

    2009-09-01

    consultation with individual leading scientists. The scientific case presented here is the result of hard and dedicated work by about 20 research groups from Swiss universities and research institutes, as well as by PSI staff. It shows that Switzerland has an active scientific community eager to use the unique properties of SwissFEL, be it for optimizing catalytic processes, identifying polluting molecules, designing new pharmaceutical drugs or studying defects in engineering materials. As is usual with new facilities, new applications will emerge that no-one had ever imagined before. This is science and technology at its best, and PSI will be proud and honoured to make SwissFEL a reality. (authors)

  3. Ferroelectric crystals for photonic applications including nanoscale fabrication and characterization techniques

    CERN Document Server

    Ferraro, Pietro; De Natale, Paolo

    2015-01-01

    This book details the latest achievements in ferroelectric domain engineering and characterization at micro- and nano-scale dimensions and periods. It combines basic research of magnetic materials with device and production orientation.

  4. Abandoning evolution. The forgotten history of antievolution activism and the transformation of American social science.

    Science.gov (United States)

    Lienesch, Michael

    2012-12-01

    From its inception, antievolution activism has been aimed not only at the natural sciences but also, and almost as often, at the social sciences. Although almost entirely overlooked by scholars, this activism played a significant part in the development of American social science in the early twentieth century. Analyzing public writings and private papers of antievolution activists, academic social scientists, and university officials from the 1920s, this essay recalls this forgotten history, showing how antievolution activism contributed to the abandonment of evolutionary theory and the adoption of a set of secular, scientific, and professional characteristics that have come to define much of modern social science.

  5. Ion beam modification of biological materials in nanoscale

    Science.gov (United States)

    Yu, L. D.; Anuntalabhochai, S.

    2012-07-01

    Ion interaction with biological objects in nanoscale is a novel research area stemming from applications of low-energy ion beams in biotechnology and biomedicine. Although the ion beam applications in biotechnology and biomedicine have achieved great successes, many mechanisms remain unclear and many new applications are to be explored. We have carried out some research on exploring the mechanisms and new applications besides attaining ion beam induction of mutation breeding and gene transformation. In the studies on the mechanisms, we focused our investigations on the direct interaction in nanoscale between ions and biological living materials. Our research topics have included the low-energy ion range in DNA, low-energy ion or neutral beam bombardment effect on DNA topological form change and mutation, low-energy ion or neutral beam bombardment effect on the cell envelope and gene transformation, and molecular dynamics simulation of ultra-low-energy ion irradiation of DNA. In the exploration of new applications, we have started experiments on ion irradiation or bombardment, in the nanoscaled depth or area, of human cells for biomedical research. This paper introduces our experiments and reports interesting results.

  6. Ion beam modification of biological materials in nanoscale

    International Nuclear Information System (INIS)

    Yu, L.D.; Anuntalabhochai, S.

    2012-01-01

    Ion interaction with biological objects in nanoscale is a novel research area stemming from applications of low-energy ion beams in biotechnology and biomedicine. Although the ion beam applications in biotechnology and biomedicine have achieved great successes, many mechanisms remain unclear and many new applications are to be explored. We have carried out some research on exploring the mechanisms and new applications besides attaining ion beam induction of mutation breeding and gene transformation. In the studies on the mechanisms, we focused our investigations on the direct interaction in nanoscale between ions and biological living materials. Our research topics have included the low-energy ion range in DNA, low-energy ion or neutral beam bombardment effect on DNA topological form change and mutation, low-energy ion or neutral beam bombardment effect on the cell envelope and gene transformation, and molecular dynamics simulation of ultra-low-energy ion irradiation of DNA. In the exploration of new applications, we have started experiments on ion irradiation or bombardment, in the nanoscaled depth or area, of human cells for biomedical research. This paper introduces our experiments and reports interesting results.

  7. THE CENTER FOR ENVIRONMENTAL IMPLICATIONS OF NANOTECHNOLOGY (CEINT)

    Science.gov (United States)

    In the future CEIN will collaborate with the NC Museum of Life and Science (NCMLS) in an educational effort spanning G8-12 to adults. Our partnership will leverage NCMLS’s activities in the Nanoscale Informal Science Education Network (NISE Net) program and create materials...

  8. Capillary-induced crack healing between surfaces of nanoscale roughness.

    Science.gov (United States)

    Soylemez, Emrecan; de Boer, Maarten P

    2014-10-07

    Capillary forces are important in nature (granular materials, insect locomotion) and in technology (disk drives, adhesion). Although well studied in equilibrium state, the dynamics of capillary formation merit further investigation. Here, we show that microcantilever crack healing experiments are a viable experimental technique for investigating the influence of capillary nucleation on crack healing between rough surfaces. The average crack healing velocity, v̅, between clean hydrophilic polycrystalline silicon surfaces of nanoscale roughness is measured. A plot of v̅ versus energy release rate, G, reveals log-linear behavior, while the slope |d[log(v̅)]/dG| decreases with increasing relative humidity. A simplified interface model that accounts for the nucleation time of water bridges by an activated process is developed to gain insight into the crack healing trends. This methodology enables us to gain insight into capillary bridge dynamics, with a goal of attaining a predictive capability for this important microelectromechanical systems (MEMS) reliability failure mechanism.

  9. In vitro toxicity analysis of nanoscale aluminum: Particle size and shape effects

    Science.gov (United States)

    Palazuelos Jorganes, Maria

    2007-12-01

    Nanostructured materials promise to revolutionize many key areas of science and technology. As our ability to manipulate matter at the nanoscale increases, there is a need to assess the effects of these materials on human health and the environment. Materials at the nanoscale are interesting and useful because they possess properties that are different from the equivalent bulk or molecular scale. These same properties can make toxicological profiles very different from those of the same materials on a different scale. There is a rising consensus that toxicity analysis of nanomaterials should start from a thorough physicochemical characterization of the materials under investigation in order to be able to establish a proper correlation between the nanoparticles characteristics and their effects and behavior in physiological environments. This research is a clear example of the necessity of comprehensive studies when investigating the toxicity of nanomaterials. Aluminum nanoparticles are being extensively used for their very unique energetic properties. These materials offer a very promising market that is fostering many startup companies which are expected to consolidate on strong technological positions. Aluminum is generally recognized as a non-toxic material to humans and it is widely used for applications which imply direct human contact. The effect of aluminum nanoparticles in human health is still an unknown. My research consisted of an in vitro toxicity screening of aluminum materials from nano to micron size, including spherical irregularly shaped particles. Several issues relating to size, shape, detection and characterization of nanoparticles in the different environments relevant to in vitro toxicity analysis were addressed and suitable protocols were developed. Lung human epithelial cells were exposed to different concentrations of these materials and the effects were analyzed by means of various toxicity tests. Some of the materials investigated caused

  10. Radiation synthesis of the nano-scale materials

    Energy Technology Data Exchange (ETDEWEB)

    Yonghong, Ni; Zhicheng, Zhang; Xuewu, Ge; Xiangling, Xu [Department of Applied Chemistry, Univ. of Science and Technology of China, Hefei (China)

    2000-03-01

    Some recent research jobs on fabricating the nano-scale materials via {gamma}-irradiation in our laboratory are simply summarized in this paper. The main contents contain four aspects: (1) the preparation of metal alloy - powders; (2) the fabrication of polymer -metal nano-composites in aqueous solution, micro-emulsion and emulsion systems; (3) the synthesis of metal sulfide nano-particles and (4) the preparation of the ordered nano-structure materials. The corresponding preparation processes are also simply described. (author)

  11. Radiation synthesis of the nano-scale materials

    International Nuclear Information System (INIS)

    Ni Yonghong; Zhang Zhicheng; Ge Xuewu; Xu Xiangling

    2000-01-01

    Some recent research jobs on fabricating the nano-scale materials via γ-irradiation in our laboratory are simply summarized in this paper. The main contents contain four aspects: (1) the preparation of metal alloy - powders; (2) the fabrication of polymer -metal nano-composites in aqueous solution, micro-emulsion and emulsion systems; (3) the synthesis of metal sulfide nano-particles and (4) the preparation of the ordered nano-structure materials. The corresponding preparation processes are also simply described. (author)

  12. Activities, productivity, and compensation of men and women in the life sciences.

    Science.gov (United States)

    DesRoches, Catherine M; Zinner, Darren E; Rao, Sowmya R; Iezzoni, Lisa I; Campbell, Eric G

    2010-04-01

    To determine whether professional activities, professional productivity, and salaries of life sciences faculty differ by gender. The authors undertook this study because previous studies found differences in the academic experiences of women and men. In 2007, the authors conducted a mailed survey of 3,080 life sciences faculty at the 50 universities whose medical schools received the greatest amount of National Institutes of Health funding in 2004. The response rate was 74% (n = 2,168). The main outcome measures were a faculty member's total number of publications; number of publications in the past three years; average impact score of the journals in which he or she had published; professional activities; work hours per week; the numbers of hours spent specifically in teaching, patient care, research, professional activities, and administrative activities; and annual income. Among professors, the women reported greater numbers of hours worked per week and greater numbers of administrative and professional activities than did the men. Female faculty members reported fewer publications across all ranks. After control for professional characteristics and productivity, female researchers in the life sciences earned, on average, approximately $13,226 less annually than did their male counterparts. Men and women in the academic life sciences take on different roles as they advance through their careers. A substantial salary gap still exists between men and women that cannot be explained by productivity or other professional factors. Compensation and advancement policies should recognize the full scope of the roles that female researchers play.

  13. Analyzing Science Activities in Force and Motion Concepts: A Design of an Immersion Unit

    Science.gov (United States)

    Ayar, Mehmet C.; Aydeniz, Mehmet; Yalvac, Bugrahan

    2015-01-01

    In this paper, we analyze the science activities offered at 7th grade in the Turkish science and technology curriculum along with addressing the curriculum's original intent. We refer to several science education researchers' ideas, including Chinn & Malhotra's (Science Education, 86:175--218, 2002) theoretical framework and Edelson's (1998)…

  14. Nanoscale aluminum concaves for light-trapping in organic thin-films

    DEFF Research Database (Denmark)

    Goszczak, Arkadiusz Jaroslaw; Adam, Jost; Cielecki, Pawel Piotr

    2016-01-01

    Anodic aluminum oxide (AAO) templates, fabricated from oxalic acid and phosphoric acid, lead to non-periodic nanoscale concave structures in their underlying aluminum layer, which are investigated for their field-enhancement properties by applying a thin-film polymer coating based laser ablation...

  15. Spain: Marine sciences information activity report for 1999/2000

    OpenAIRE

    Wulff, Enrique

    2002-01-01

    This 99/00 marine sciences-relevant activities report is a portrait of research information available within Spain. From the least available electronic information on such subjects as vaccines to a flood of information on thematics like Spanish Antartic research.

  16. Adhesion Dynamics in Probing Micro- and Nanoscale Thin Solid Films

    Directory of Open Access Journals (Sweden)

    Xiaoling He

    2008-01-01

    Full Text Available This study focuses on modeling the probe dynamics in scratching and indenting thin solid films at micro- and nanoscales. The model identifies bifurcation conditions that define the stick-slip oscillation patterns of the tip. It is found that the local energy fluctuations as a function of the inelastic deformation, defect formation, material properties, and contact parameters determine the oscillation behavior. The transient variation of the localized function makes the response nonlinear at the adhesion junction. By quantifying the relation between the bifurcation parameters and the oscillation behavior, this model gives a realistic representation of the complex adhesion dynamics. Specifically, the model establishes the link between the stick-slip behavior and the inelastic deformation and the local potentials. This model justifies the experimental observations and the molecular dynamics simulation of the adhesion and friction dynamics in both the micro- and nanoscale contact.

  17. Imaging the Nanoscale Band Structure of Topological Sb

    OpenAIRE

    Soumyanarayanan, Anjan; Yee, Michael M.; He, Yang; Lin, Hsin; Gardner, Dillon R.; Bansil, Arun; Lee, Young S.; Hoffman, Jennifer E.

    2013-01-01

    Many promising building blocks of future electronic technology - including non-stoichiometric compounds, strongly correlated oxides, and strained or patterned films - are inhomogeneous on the nanometer length scale. Exploiting the inhomogeneity of such materials to design next-generation nanodevices requires a band structure probe with nanoscale spatial resolution. To address this demand, we report the first simultaneous observation and quantitative reconciliation of two candidate probes - La...

  18. Direct nanoscale imaging of evolving electric field domains in quantum structures.

    Science.gov (United States)

    Dhar, Rudra Sankar; Razavipour, Seyed Ghasem; Dupont, Emmanuel; Xu, Chao; Laframboise, Sylvain; Wasilewski, Zbig; Hu, Qing; Ban, Dayan

    2014-11-28

    The external performance of quantum optoelectronic devices is governed by the spatial profiles of electrons and potentials within the active regions of these devices. For example, in quantum cascade lasers (QCLs), the electric field domain (EFD) hypothesis posits that the potential distribution might be simultaneously spatially nonuniform and temporally unstable. Unfortunately, there exists no prior means of probing the inner potential profile directly. Here we report the nanoscale measured electric potential distribution inside operating QCLs by using scanning voltage microscopy at a cryogenic temperature. We prove that, per the EFD hypothesis, the multi-quantum-well active region is indeed divided into multiple sections having distinctly different electric fields. The electric field across these serially-stacked quantum cascade modules does not continuously increase in proportion to gradual increases in the applied device bias, but rather hops between discrete values that are related to tunneling resonances. We also report the evolution of EFDs, finding that an incremental change in device bias leads to a hopping-style shift in the EFD boundary--the higher electric field domain expands at least one module each step at the expense of the lower field domain within the active region.

  19. Mesoporous Ruthenium/Ruthenium Oxide Thin Films: Active Electrocatalysts for the Oxygen Evolution Reaction

    DEFF Research Database (Denmark)

    Kibsgaard, Jakob; Hellstern, Thomas R.; Choi, Shin-Jung

    2017-01-01

    We report the first synthesis of a fully contiguous large area supported thin film of highly ordered mesoporous Ru and RuO2 and investigate the electrocatalytic properties towards the oxygen evolution reaction (OER). We find that the nanoscale porous network of these catalysts provides significant...... enhancements in geometric OER activity without any loss in specific activity. This work demonstrates a strategy for engineering materials at the nanoscale that can simultaneously decrease precious metal loading and increase electrode activity....

  20. Local climate activities in co-operation between municipality, civil society and science shop

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard

    The Science Shop at DTU co-operates with the local municipal administration and the local branch of an environmental NGO about climate change. The co-operation was initiated by a proposal to the Science Shop from the municipal administration. Since the Science Shop requests civil society...... involvement in projects it was proposed to involve the local branch of the environmental NGO. The starting point was topics developed by the administration and the NGO together and announced to students as part of the Science Shop project supply. The focus is climate impact of local activities and strategies...... are initiated and co-ordinated by a group with members from municipal administration, the local NGO and the Science Shop. All projects have involved student projects, but most projects have also contributed to ongoing research activities. The projects up till now have focused on the municipal food supply...

  1. Alternative chemical-based synthesis routes and characterization of nano-scale particles

    International Nuclear Information System (INIS)

    Brocchi, E.A.; Motta, M.S.; Solorzano, I.G.; Jena, P.K.; Moura, F.J.

    2004-01-01

    Different nano-scale particles have been synthesized by alternative routes: nitrates dehydratation and oxide, or co-formed oxides, reduction by hydrogen. Chemical-based synthesis routes are described and thermodynamics studies and kinetics data are presented to support the feasibility for obtaining single-phase oxides and co-formed two-phase oxides. In addition, the reduction reaction has been applied to successfully produce metal/ceramic nanocomposites. Structural characterization has been carried out by means of X-ray diffraction and, more extensively, transmission electron microscopy operating in conventional diffraction contrast mode (CTEM) and high-resolution mode (HRTEM). Nano-scale size distribution of oxide particles is well demonstrated together with their defect-free structure in the lower range, around 20 nm, size. Structural features related to the synthesized nano-composites are also presented

  2. Computational Study on Atomic Structures, Electronic Properties, and Chemical Reactions at Surfaces and Interfaces and in Biomaterials

    Science.gov (United States)

    Takano, Yu; Kobayashi, Nobuhiko; Morikawa, Yoshitada

    2018-06-01

    Through computer simulations using atomistic models, it is becoming possible to calculate the atomic structures of localized defects or dopants in semiconductors, chemically active sites in heterogeneous catalysts, nanoscale structures, and active sites in biological systems precisely. Furthermore, it is also possible to clarify physical and chemical properties possessed by these nanoscale structures such as electronic states, electronic and atomic transport properties, optical properties, and chemical reactivity. It is sometimes quite difficult to clarify these nanoscale structure-function relations experimentally and, therefore, accurate computational studies are indispensable in materials science. In this paper, we review recent studies on the relation between local structures and functions for inorganic, organic, and biological systems by using atomistic computer simulations.

  3. 76 FR 57762 - Agency Information Collection Activities: Proposed New Collection-Social Science Assessment and...

    Science.gov (United States)

    2011-09-16

    ... Information Collection Activities: Proposed New Collection--Social Science Assessment and Geographic Analysis...: OMB Control Number: 1024-NEW. Title: Social Science Assessment and Geographic Analysis of Marine... for Coastal Science and Policy, Mail Stop 250, Flanagan, East Carolina University, Greenville, NC...

  4. An Integrative Review of In-Class Activities That Enable Active Learning in College Science Classroom Settings

    Science.gov (United States)

    Arthurs, Leilani A.; Kreager, Bailey Zo

    2017-01-01

    Engaging students in active learning is linked to positive learning outcomes. This study aims to synthesise the peer-reviewed literature about "active learning" in college science classroom settings. Using the methodology of an integrative literature review, 337 articles archived in the Educational Resources Information Center (ERIC) are…

  5. Enhancing Diversity in Undergraduate Science: Self-Efficacy Drives Performance Gains with Active Learning

    OpenAIRE

    Ballen, Cissy J.; Wieman, Carl; Salehi, Shima; Searle, Jeremy B.; Zamudio, Kelly R.

    2017-01-01

    Efforts to retain underrepresented minority (URM) students in science, technology, engineering, and mathematics (STEM) have shown only limited success in higher education, due in part to a persistent achievement gap between students from historically underrepresented and well-represented backgrounds. To test the hypothesis that active learning disproportionately benefits URM students, we quantified the effects of traditional versus active learning on student academic performance, science self...

  6. Destructive impact of molecular noise on nanoscale electrochemical oscillators

    Science.gov (United States)

    Cosi, Filippo G.; Krischer, Katharina

    2017-06-01

    We study the loss of coherence of electrochemical oscillations on meso- and nanosized electrodes with numeric simulations of the electrochemical master equation for a prototypical electrochemical oscillator, the hydrogen peroxide reduction on Pt electrodes in the presence of halides. On nanoelectrodes, the electrode potential changes whenever a stochastic electron-transfer event takes place. Electrochemical reaction rate coefficients depend exponentially on the electrode potential and become thus fluctuating quantities as well. Therefore, also the transition rates between system states become time-dependent which constitutes a fundamental difference to purely chemical nanoscale oscillators. Three implications are demonstrated: (a) oscillations and steady states shift in phase space with decreasing system size, thereby also decreasing considerably the oscillating parameter regions; (b) the minimal number of molecules necessary to support correlated oscillations is more than 10 times as large as for nanoscale chemical oscillators; (c) the relation between correlation time and variance of the period of the oscillations predicted for chemical oscillators in the weak noise limit is only fulfilled in a very restricted parameter range for the electrochemical nano-oscillator.

  7. Addressing the Recalcitrance of Cellulose Degradation through Cellulase Discovery, Nano-scale Elucidation of Molecular Mechanisms, and Kinetic Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Larry P., Bergstrom, Gary; Corgie, Stephane; Craighead, Harold; Gibson, Donna; Wilson, David

    2011-06-13

    This research project was designed to play a vital role in the development of low cost sugars from cellulosic biomass and contributing to the national effort to displace fossil fuel usage in the USA transportation sector. The goal was to expand the portfolio of cell wall degrading enzymes through innovative research at the nano-scale level, prospecting for novel cellulases and building a kinetic framework for the development of more effective enzymatic conversion processes. More precisely, the goal was to elucidate the molecular mechanisms for some cellulases that are very familiar to members of our research team and to investigate what we hope are novel cellulases or new enzyme combinations from the world of plant pathogenic fungi and bacteria. Hydrolytic activities of various cellulases and cellulase cocktails were monitored at the nanoscale of cellulose fibrils and the microscale of pretreated cellulose particles, and we integrated this insight into a heterogeneous reaction framework. The over-riding approach for this research program was the application of innovative and cutting edge optical and high-throughput screening and analysis techniques for observing how cellulases hydrolyze real substrates.

  8. In situ observations of crack arrest and bridging by nanoscale twins in copper thin films

    International Nuclear Information System (INIS)

    Kim, Seong-Woong; Li Xiaoyan; Gao Huajian; Kumar, Sharvan

    2012-01-01

    In situ tensile experiments in a transmission electron microscope revealed that micro-cracks in ultrafine grained, free-standing, thin copper foils containing nanoscale twins initiated in matrix domains separated by the twins and then arrested at twin boundaries as twin boundary sliding proceeded. The adjacent microcracks eventually coalesced through shear failure of the bridging twins. To investigate the atomic mechanism of this rarely seen nanoscale crack bridging behavior, molecular dynamics simulations were performed to show that during crack propagation twin boundaries are impinged upon by numerous dislocations from the plastically deforming matrix. These dislocations react at the interface and evolve into substantially impenetrable dislocation walls that strongly confine crack nucleation and resist crack propagation, leading to the experimentally observed crack bridging behavior. The present results raise an approach to significantly toughening polycrystalline thin films by incorporating nanoscale twin structures into individual grains that serve as crack bridging ligaments.

  9. Experimental Study of Electron and Phonon Dynamics in Nanoscale Materials by Ultrafast Laser Time-Domain Spectroscopy

    Science.gov (United States)

    Shen, Xiaohan

    With the rapid advances in the development of nanotechnology, nowadays, the sizes of elementary unit, i.e. transistor, of micro- and nanoelectronic devices are well deep into nanoscale. For the pursuit of cheaper and faster nanoscale electronic devices, the size of transistors keeps scaling down. As the miniaturization of the nanoelectronic devices, the electrical resistivity increases dramatically, resulting rapid growth in the heat generation. The heat generation and limited thermal dissipation in nanoscale materials have become a critical problem in the development of the next generation nanoelectronic devices. Copper (Cu) is widely used conducting material in nanoelectronic devices, and the electron-phonon scattering is the dominant contributor to the resistivity in Cu nanowires at room temperature. Meanwhile, phonons are the main carriers of heat in insulators, intrinsic and lightly doped semiconductors. The thermal transport is an ensemble of phonon transport, which strongly depends on the phonon frequency. In addition, the phonon transport in nanoscale materials can behave fundamentally different than in bulk materials, because of the spatial confinement. However, the size effect on electron-phonon scattering and frequency dependent phonon transport in nanoscale materials remain largely unexplored, due to the lack of suitable experimental techniques. This thesis is mainly focusing on the study of carrier dynamics and acoustic phonon transport in nanoscale materials. The weak photothermal interaction in Cu makes thermoreflectance measurement difficult, we rather measured the reflectivity change of Cu induced by absorption variation. We have developed a method to separately measure the processes of electron-electron scattering and electron-phonon scattering in epitaxial Cu films by monitoring the transient reflectivity signal using the resonant probe with particular wavelengths. The enhancement on electron-phonon scattering in epitaxial Cu films with thickness

  10. Laboratory micro- and nanoscale X-ray tomographic investigation of Al–7 at.%Cu solidification structures

    International Nuclear Information System (INIS)

    Patterson, B.M.; Henderson, K.C.; Gibbs, P.J.; Imhoff, S.D.; Clarke, A.J.

    2014-01-01

    X-ray computed tomography across multiple length scales provides an opportunity to non-destructively visualize and quantify the micro- to nano-scale microstructural features of solidification structures in three dimensions. Aluminum–7 at.%copper samples were directionally solidified at three cooling rates (0.44, 0.67, and 1.33 °C/s), resulting in systematic changes in the as-solidified microstructure, which are difficult to quantify using traditional microscopic techniques. The cooling rate of a material affects its ultimate microstructure, and characterizing that microstructure is key to predicting and understanding its bulk properties. Here, two different laboratory X-ray computed tomography instruments were used to characterize as-solidified microstructures, including micro-scale computed tomography with approximately 1 mm field-of-view, ∼ 1.7 μm resolution, and nano-scale X-ray computed tomography ∼ 65 μm FOV, 150 nm resolution. Micro-scale X-ray radiography and computed tomography enabled a quantitative investigation of changes in the primary dendritic solidification structure with increasing cooling rate. Nano-scale absorption contrast X-ray computed tomography resolved the distinct phases of the lamellar eutectic structure and three dimensional measurements of the ∼ 1 μm interlamellar spacing. It is found that the lamella eutectic structure thickness is inversely proportional to the cooling rate. Nano-scale Zernike phase contrast was also used to image voids at eutectic colony boundaries. The application and resolution of these two instruments are discussed with respect to the resolvable features of the solidification structures. - Highlights: • Al–Cu eutectic is a model system for studying solidification microstructure. • X-ray computed tomography provides a 3D picture of these complex structures. • Micro-scale tomography images the primary and secondary dendritic structures. • Nano-scale tomography images the eutectic lamella and

  11. Laboratory micro- and nanoscale X-ray tomographic investigation of Al–7 at.%Cu solidification structures

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, B.M., E-mail: bpatterson@lanl.gov; Henderson, K.C.; Gibbs, P.J.; Imhoff, S.D.; Clarke, A.J.

    2014-09-15

    X-ray computed tomography across multiple length scales provides an opportunity to non-destructively visualize and quantify the micro- to nano-scale microstructural features of solidification structures in three dimensions. Aluminum–7 at.%copper samples were directionally solidified at three cooling rates (0.44, 0.67, and 1.33 °C/s), resulting in systematic changes in the as-solidified microstructure, which are difficult to quantify using traditional microscopic techniques. The cooling rate of a material affects its ultimate microstructure, and characterizing that microstructure is key to predicting and understanding its bulk properties. Here, two different laboratory X-ray computed tomography instruments were used to characterize as-solidified microstructures, including micro-scale computed tomography with approximately 1 mm field-of-view, ∼ 1.7 μm resolution, and nano-scale X-ray computed tomography ∼ 65 μm FOV, 150 nm resolution. Micro-scale X-ray radiography and computed tomography enabled a quantitative investigation of changes in the primary dendritic solidification structure with increasing cooling rate. Nano-scale absorption contrast X-ray computed tomography resolved the distinct phases of the lamellar eutectic structure and three dimensional measurements of the ∼ 1 μm interlamellar spacing. It is found that the lamella eutectic structure thickness is inversely proportional to the cooling rate. Nano-scale Zernike phase contrast was also used to image voids at eutectic colony boundaries. The application and resolution of these two instruments are discussed with respect to the resolvable features of the solidification structures. - Highlights: • Al–Cu eutectic is a model system for studying solidification microstructure. • X-ray computed tomography provides a 3D picture of these complex structures. • Micro-scale tomography images the primary and secondary dendritic structures. • Nano-scale tomography images the eutectic lamella and

  12. Fabrication of Single, Vertically Aligned Carbon Nanotubes in 3D Nanoscale Architectures

    Science.gov (United States)

    Kaul, Anupama B.; Megerian, Krikor G.; Von Allmen, Paul A.; Baron, Richard L.

    2010-01-01

    Plasma-enhanced chemical vapor deposition (PECVD) and high-throughput manufacturing techniques for integrating single, aligned carbon nanotubes (CNTs) into novel 3D nanoscale architectures have been developed. First, the PECVD growth technique ensures excellent alignment of the tubes, since the tubes align in the direction of the electric field in the plasma as they are growing. Second, the tubes generated with this technique are all metallic, so their chirality is predetermined, which is important for electronic applications. Third, a wafer-scale manufacturing process was developed that is high-throughput and low-cost, and yet enables the integration of just single, aligned tubes with nanoscale 3D architectures with unprecedented placement accuracy and does not rely on e-beam lithography. Such techniques should lend themselves to the integration of PECVD grown tubes for applications ranging from interconnects, nanoelectromechanical systems (NEMS), sensors, bioprobes, or other 3D electronic devices. Chemically amplified polyhydroxystyrene-resin-based deep UV resists were used in conjunction with excimer laser-based (lambda = 248 nm) step-and-repeat lithography to form Ni catalyst dots = 300 nm in diameter that nucleated single, vertically aligned tubes with high yield using dc PECVD growth. This is the first time such chemically amplified resists have been used, resulting in the nucleation of single, vertically aligned tubes. In addition, novel 3D nanoscale architectures have been created using topdown techniques that integrate single, vertically aligned tubes. These were enabled by implementing techniques that use deep-UV chemically amplified resists for small-feature-size resolution; optical lithography units that allow unprecedented control over layer-to-layer registration; and ICP (inductively coupled plasma) etching techniques that result in near-vertical, high-aspect-ratio, 3D nanoscale architectures, in conjunction with the use of materials that are

  13. Special Issue on the Second International Workshop on Micro- and Nano-Scale Thermal Radiation

    Science.gov (United States)

    Zhang, Zhuomin; Liu, Linhua; Zhu, Qunzhi; Mengüç, M. Pinar

    2015-06-01

    Micro- and nano-scale thermal radiation has become one of the fastest growing research areas because of advances in nanotechnology and the development of novel materials. The related research and development includes near-field radiation transfer, spectral and directional selective emitters and receivers, plasmonics, metamaterials, and novel nano-scale fabrication techniques. With the advances in these areas, important applications in energy harvesting such as solar cells and thermophotovoltaics, nanomanufacturing, biomedical sensing, thermal imaging as well as data storage with the localized heating/cooling have been pushed to higher levels.

  14. Atomic layer deposition: an enabling technology for the growth of functional nanoscale semiconductors

    Science.gov (United States)

    Biyikli, Necmi; Haider, Ali

    2017-09-01

    In this paper, we present the progress in the growth of nanoscale semiconductors grown via atomic layer deposition (ALD). After the adoption by semiconductor chip industry, ALD became a widespread tool to grow functional films and conformal ultra-thin coatings for various applications. Based on self-limiting and ligand-exchange-based surface reactions, ALD enabled the low-temperature growth of nanoscale dielectric, metal, and semiconductor materials. Being able to deposit wafer-scale uniform semiconductor films at relatively low-temperatures, with sub-monolayer thickness control and ultimate conformality, makes ALD attractive for semiconductor device applications. Towards this end, precursors and low-temperature growth recipes are developed to deposit crystalline thin films for compound and elemental semiconductors. Conventional thermal ALD as well as plasma-assisted and radical-enhanced techniques have been exploited to achieve device-compatible film quality. Metal-oxides, III-nitrides, sulfides, and selenides are among the most popular semiconductor material families studied via ALD technology. Besides thin films, ALD can grow nanostructured semiconductors as well using either template-assisted growth methods or bottom-up controlled nucleation mechanisms. Among the demonstrated semiconductor nanostructures are nanoparticles, nano/quantum-dots, nanowires, nanotubes, nanofibers, nanopillars, hollow and core-shell versions of the afore-mentioned nanostructures, and 2D materials including transition metal dichalcogenides and graphene. ALD-grown nanoscale semiconductor materials find applications in a vast amount of applications including functional coatings, catalysis and photocatalysis, renewable energy conversion and storage, chemical sensing, opto-electronics, and flexible electronics. In this review, we give an overview of the current state-of-the-art in ALD-based nanoscale semiconductor research including the already demonstrated and future applications.

  15. Facilitation of Nanoscale Thermal Transport by Hydrogen Bonds

    OpenAIRE

    Zhang, Lin

    2017-01-01

    Thermal transport performance at the nanoscale and/or of biomaterials is essential to the success of many new technologies including nanoelectronics, biomedical devices, and various nanocomposites. Due to complicated microstructures and chemical bonding, thermal transport process in these materials has not been well understood yet. In terms of chemical bonding, it is well known that the strength of atomic bonding can significantly affect thermal transport across materials or across interfaces...

  16. Nanoscale examination of microdamage in sheep cortical bone using synchrotron radiation transmission x-ray microscopy.

    Directory of Open Access Journals (Sweden)

    Garry R Brock

    Full Text Available Microdamage occurs in bone through repeated and excessive loading. Accumulation of microdamage weakens bone, leading to a loss of strength, stiffness and energy dissipation in the tissue. Imaging techniques used to examine microdamage have typically been limited to the microscale. In the current study microdamage was examined at the nanoscale using transmission x-ray microscopy with an x-ray negative stain, lead-uranyl acetate. Microdamage was generated in notched and unnotched beams of sheep cortical bone (2×2×20 mm, with monotonic and fatigue loading. Bulk sections were removed from beams and stained with lead-uranyl acetate to identify microdamage. Samples were sectioned to 50 microns and imaged using transmission x-ray microscopy producing projection images of microdamage with nanoscale resolution. Staining indicated microdamage occurred in both the tensile and compressive regions. A comparison between monotonic and fatigue loading indicated a statistically significant greater amount of stain present in fatigue loaded sections. Microdamage occurred in three forms: staining to existing bone structures, cross hatch damage and a single crack extending from the notch tip. Comparison to microcomputed tomography demonstrated differences in damage morphology and total damage between the microscale and nanoscale. This method has future applications for understanding the underlying mechanisms for microdamage formation as well as three-dimensional nanoscale examination of microdamage.

  17. Innovative Project Activities in Science [From the NSTA Study of Innovative Project Activities

    Science.gov (United States)

    Science Teacher, 1975

    1975-01-01

    Describes four projects chosen as innovative project activities in science which exhibited identification of unique or novel problems and creative approaches to their solutions. Projects included a study of fish in Lake Erie, a goat raising project, an analysis of terrestrial plant ecology and soil composition, and a study of marine and wetlands…

  18. Nanoscale Rheology and Anisotropic Diffusion Using Single Gold Nanorod Probes

    Science.gov (United States)

    Molaei, Mehdi; Atefi, Ehsan; Crocker, John C.

    2018-03-01

    The complex rotational and translational Brownian motion of anisotropic particles depends on their shape and the viscoelasticity of their surroundings. Because of their strong optical scattering and chemical versatility, gold nanorods would seem to provide the ultimate probes of rheology at the nanoscale, but the suitably accurate orientational tracking required to compute rheology has not been demonstrated. Here we image single gold nanorods with a laser-illuminated dark-field microscope and use optical polarization to determine their three-dimensional orientation to better than one degree. We convert the rotational diffusion of single nanorods in viscoelastic polyethylene glycol solutions to rheology and obtain excellent agreement with bulk measurements. Extensions of earlier models of anisotropic translational diffusion to three dimensions and viscoelastic fluids give excellent agreement with the observed motion of single nanorods. We find that nanorod tracking provides a uniquely capable approach to microrheology and provides a powerful tool for probing nanoscale dynamics and structure in a range of soft materials.

  19. Physical controls on directed virus assembly at nanoscale chemical templates

    International Nuclear Information System (INIS)

    Cheung, C L; Chung, S; Chatterji, A; Lin, T; Johnson, J E; Hok, S; Perkins, J; De Yoreo, J

    2006-01-01

    Viruses are attractive building blocks for nanoscale heterostructures, but little is understood about the physical principles governing their directed assembly. In-situ force microscopy was used to investigate organization of Cowpea Mosaic Virus engineered to bind specifically and reversibly at nanoscale chemical templates with sub-30nm features. Morphological evolution and assembly kinetics were measured as virus flux and inter-viral potential were varied. The resulting morphologies were similar to those of atomic-scale epitaxial systems, but the underlying thermodynamics was analogous to that of colloidal systems in confined geometries. The 1D templates biased the location of initial cluster formation, introduced asymmetric sticking probabilities, and drove 1D and 2D condensation at subcritical volume fractions. The growth kinetics followed a t 1/2 law controlled by the slow diffusion of viruses. The lateral expansion of virus clusters that initially form on the 1D templates following introduction of polyethylene glycol (PEG) into the solution suggests a significant role for weak interaction

  20. Activities in KURRI. Aim to realize the concept of 'Kumatori science park'

    International Nuclear Information System (INIS)

    Shiroya, S.

    2007-01-01

    In Kyoto University Research Reactor Institute (KURRI), activities for the dissemination of knowledge on radiation and atomic energy are considered to be important to realize the future plan based on the conception of Kumatori science park', which will open to the world with roots in the neighboring area. Activities include technical tours of facilities in KURRI, science experiments for kids, lectures on fruits of research for public, courses of reactor physics experiments for the graduate and under-graduate students majoring nuclear engineering, and so on. (author)

  1. Ultrafast phenomena at the nanoscale: science opportunities at the SwissFEL X-ray laser

    Energy Technology Data Exchange (ETDEWEB)

    Abela, R.; Braun, H.; Ming, P.; Pedrozzi, M.; Quitmann, Ch.; Reiche, S.; Daalen, M. van; Veen, J.F. van der; Mesot, J. [Paul Scherrer Intitute (PSI), Villigen (Switzerland); Mesot, J.; Shiroka, T.; Veen, J.F. van der [Swiss Federal Institute of Technology (ETHZ), Zuerich (Switzerland); Mesot, J. [Swiss Federal Institute of Technology (EPFL), Lausanne (Switzerland)

    2009-09-15

    the past few years and by consultation with individual leading scientists. The scientific case presented here is the result of hard and dedicated work by about 20 research groups from Swiss universities and research institutes, as well as by PSI staff. It shows that Switzerland has an active scientific community eager to use the unique properties of SwissFEL, be it for optimizing catalytic processes, identifying polluting molecules, designing new pharmaceutical drugs or studying defects in engineering materials. As is usual with new facilities, new applications will emerge that no-one had ever imagined before. This is science and technology at its best, and PSI will be proud and honoured to make SwissFEL a reality. (authors)

  2. Brain-like associative learning using a nanoscale non-volatile phase change synaptic device array

    Directory of Open Access Journals (Sweden)

    Sukru Burc Eryilmaz

    2014-07-01

    Full Text Available Recent advances in neuroscience together with nanoscale electronic device technology have resulted in huge interests in realizing brain-like computing hardwares using emerging nanoscale memory devices as synaptic elements. Although there has been experimental work that demonstrated the operation of nanoscale synaptic element at the single device level, network level studies have been limited to simulations. In this work, we demonstrate, using experiments, array level associative learning using phase change synaptic devices connected in a grid like configuration similar to the organization of the biological brain. Implementing Hebbian learning with phase change memory cells, the synaptic grid was able to store presented patterns and recall missing patterns in an associative brain-like fashion. We found that the system is robust to device variations, and large variations in cell resistance states can be accommodated by increasing the number of training epochs. We illustrated the tradeoff between variation tolerance of the network and the overall energy consumption, and found that energy consumption is decreased significantly for lower variation tolerance.

  3. Processing used nuclear fuel with nanoscale control of uranium and ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Wylie, Ernest M.; Peruski, Kathryn M.; Prizio, Sarah E. [Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Bridges, Andrea N.A.; Rudisill, Tracy S.; Hobbs, David T. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Phillip, William A. [Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556 (United States); Burns, Peter C., E-mail: pburns@nd.edu [Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2016-05-15

    Current separation and purification technologies utilized in the nuclear fuel cycle rely primarily on liquid–liquid extraction and ion-exchange processes. Here, we report a laboratory-scale aqueous process that demonstrates nanoscale control for the recovery of uranium from simulated used nuclear fuel (SIMFUEL). The selective, hydrogen peroxide induced oxidative dissolution of SIMFUEL material results in the rapid assembly of persistent uranyl peroxide nanocluster species that can be separated and recovered at moderate to high yield from other process-soluble constituents using sequestration-assisted ultrafiltration. Implementation of size-selective physical processes like filtration could results in an overall simplification of nuclear fuel cycle technology, improving the environmental consequences of nuclear energy and reducing costs of processing. - Highlights: • Nanoscale control in irradiated fuel reprocessing. • Ultrafiltration to recover uranyl cage clusters. • Alternative to solvent extraction for uranium purification.

  4. Inherent wettability of different rock surfaces at nanoscale: a theoretical study

    Science.gov (United States)

    Chang, Xiao; Xue, Qingzhong; Li, Xiaofang; Zhang, Jianqiang; Zhu, Lei; He, Daliang; Zheng, Haixia; Lu, Shuangfang; Liu, Zilong

    2018-03-01

    Investigating the inherent wettability of rock surfaces at nanoscale is of great importance in ore floatation and oil recovery field. Using molecular dynamics simulations, we systematically study the wetting behavior of water on different rock surfaces (silica, calcite, gypsum, halite and graphite) at nanoscale. It is demonstrated that the inherent rock wettability follows the order of gypsum > calcite > halite > silica > graphite. Remarkably, we also manifest that the polarity of oil molecules can affect the water contact angles on silica surface. For example, the water contact angles on silica surface in hexane, dodecane, thiophene and toluene are 58 ± 2°, 63 ± 3°, 90 ± 1°, 118 ± 1°, respectively. Furthermore, we investigate the wetting behavior of water on heterogeneous rock surfaces and find that water molecules can move from hydrophobic surface to hydrophilic surface.

  5. Materials Science with Ion Beams

    CERN Document Server

    Bernas, Harry

    2010-01-01

    This book introduces materials scientists and designers, physicists and chemists to the properties of materials that can be modified by ion irradiation or implantation. These techniques can help design new materials or to test modified properties; novel applications already show that ion-beam techniques are complementary to others, yielding previously unattainable properties. Also, ion-beam interactions modify materials at the nanoscale, avoiding the often detrimental results of lithographic or chemical techniques. Here, the effects are related to better-known quasi-equilibrium thermodynamics, and the consequences to materials are discussed with concepts that are familiar to materials science. Examples addressed concern semiconductor physics, crystal and nanocluster growth, optics, magnetism, and applications to geology and biology.

  6. Nanoscale characterization of isolated individual type I collagen fibrils: polarization and piezoelectricity.

    Science.gov (United States)

    Minary-Jolandan, Majid; Yu, Min-Feng

    2009-02-25

    Piezoresponse force microscopy was applied to directly study individual type I collagen fibrils with diameters of approximately 100 nm isolated from bovine Achilles tendon. It was revealed that single collagen fibrils behave predominantly as shear piezoelectric materials with a piezoelectric coefficient on the order of 1 pm V(-1), and have unipolar axial polarization throughout their entire length. It was estimated that, under reasonable shear load conditions, the fibrils were capable of generating an electric potential up to tens of millivolts. The result substantiates the nanoscale origin of piezoelectricity in bone and tendons, and implies also the potential importance of the shear load-transfer mechanism, which has been the principle basis of the nanoscale mechanics model of collagen, in mechanoelectric transduction in bone.

  7. NASA SMD STEM Activation: Enabling NASA Science Experts and Content into the Learning Environment

    Science.gov (United States)

    Hasan, Hashima; Erickson, Kristen

    2018-01-01

    The NASA Science Mission Directorate (SMD) restructured its efforts to enhance learning in science, technology, engineering, and mathematics (STEM) content areas through a cooperative agreement notice issued in 2015. This effort resulted in the competitive selection of 27 organizations to implement a strategic approach that leverages SMD’s unique assets. Three of these are exclusively directed towards Astrophysics. These unique assets include SMD’s science and engineering content and Science Discipline Subject Matter Experts. Awardees began their work during 2016 and span all areas of Earth and space science and the audiences NASA SMD intends to reach. The goal of the restructured STEM Activation program is to further enable NASA science experts and content into the learning environment more effectively and efficiently with learners of all ages. The objectives are to enable STEM education, improve US scientific literacy, advance national educational goals, and leverage efforts through partnerships. This presentation will provide an overview of the NASA SMD STEM Activation landscape and its commitment to meeting user needs.

  8. Anomalous electromagnetic coupling via entanglement at the nanoscale

    International Nuclear Information System (INIS)

    Slepyan, Gregory; Boag, Amir; Mordachev, Vladimir; Sinkevich, Eugene; Maksimenko, Sergey; Kuzhir, Polina; Miano, Giovanni; Portnoi, Mikhail E; Maffucci, Antonio

    2017-01-01

    Understanding unwanted mutual interactions between devices at the nanoscale is crucial for the study of the electromagnetic compatibility in nanoelectronic and nanophotonic systems. Anomalous electromagnetic coupling (crosstalk) between nanodevices may arise from the combination of electromagnetic interaction and quantum entanglement. In this paper we study in detail the crosstalk between two identical nanodevices, each consisting of a quantum emitter (atom, quantum dot, etc), capacitively coupled to a pair of nanoelectrodes. Using the generalized susceptibility concept, the overall system is modeled as a two-port within the framework of the electrical circuit theory and it is characterized by the admittance matrix. We show that the entanglement changes dramatically the physical picture of the electromagnetic crosstalk. In particular, the excitation produced in one of the ports may be redistributed in equal parts between both the ports, in spite of the rather small electromagnetic interactions. Such an anomalous crosstalk is expected to appear at optical frequencies in lateral GaAs double quantum dots. A possible experimental set up is also discussed. The classical concepts of interference in the operation of electronic devices, which have been known since the early days of radio-communications and are associated with electromagnetic compatibility, should then be reconsidered at the nanoscale. (paper)

  9. Micro and Nano-Scale Technologies for Cell Mechanics

    Directory of Open Access Journals (Sweden)

    Mustafa Unal

    2014-10-01

    Full Text Available Cell mechanics is a multidisciplinary field that bridges cell biology, fundamental mechanics, and micro and nanotechnology, which synergize to help us better understand the intricacies and the complex nature of cells in their native environment. With recent advances in nanotechnology, microfabrication methods and micro-electro-mechanical-systems (MEMS, we are now well situated to tap into the complex micro world of cells. The field that brings biology and MEMS together is known as Biological MEMS (BioMEMS. BioMEMS take advantage of systematic design and fabrication methods to create platforms that allow us to study cells like never before. These new technologies have been rapidly advancing the study of cell mechanics. This review article provides a succinct overview of cell mechanics and comprehensively surveys micro and nano-scale technologies that have been specifically developed for and are relevant to the mechanics of cells. Here we focus on micro and nano-scale technologies, and their applications in biology and medicine, including imaging, single cell analysis, cancer cell mechanics, organ-on-a-chip systems, pathogen detection, implantable devices, neuroscience and neurophysiology. We also provide a perspective on the future directions and challenges of technologies that relate to the mechanics of cells.

  10. Daily practical activities and science teaching at EJA: Teacher and students' perception

    Directory of Open Access Journals (Sweden)

    Denise Westphal Merazzi

    2007-06-01

    Full Text Available The main theme of this paper is the science teaching in Adults and Youth Education. It was investigated the students' perceptions of adult and youth education (elementary school and their teachers, from science content's development through the works involving practical activities of everyday life. In this context, the methodology used in the research process was based on a survey of qualitative and quantitative approach, with hermeneutic content analysis' methodology and technique. In quantitative terms, we used the average ranking and statistical tests of Wilcoxon. Analyzing the data obtained, it was observed that the use of practical activities in science teaching in adult education is a satisfactory strategy for teaching and learning process and that there is a need to instill these practices in young and adults' education

  11. Towards Realization of Intelligent Medical Treatment at Nanoscale by Artificial Microscopic Swarm Control Systems

    Directory of Open Access Journals (Sweden)

    Alireza Rowhanimanesh

    2017-07-01

    Full Text Available Background: In this paper, the novel concept of artificial microscopic swarm control systems is proposed as a promising approach towards realization of intelligent medical treatment at nanoscale. In this new paradigm, treatment is done autonomously at nanoscale within the patient’s body by the proposed swarm control systems.Methods: From control engineering perspective, medical treatment can be considered as a control problem, in which the ultimate goal is to find the best feasible way to change the state of diseased tissue from unhealthy to healthy in presence of uncertainty. Although a living tissue is a huge swarm of microscopic cells, nearly all of the common treatment methods are based on macroscopic centralized control paradigm. Inspired by natural microscopic swarm control systems such as nervous, endocrine and immune systems that work based on swarm control paradigm, medical treatment needs a paradigm shift from macroscopic centralized control to microscopic swarm control. An artificial microscopic swarm control system consists of a huge number of very simple autonomous microscopic agents that exploit swarm intelligence to realize sense, control (computing and actuation at nanoscale in local, distributed and decentralized manner. This control system can be designed based on mathematical analysis and computer simulation.Results: The proposed approach is used for treatment of atherosclerosis and cancer based on mathematical analysis and in-silico study.Conclusion: The notion of artificial microscopic swarm control systems opens new doors towards realization of autonomous and intelligent medical treatment at nanoscale within the patient’s body.

  12. White paper on science and technology, 1996. Striving to become a front-runner in research activity

    International Nuclear Information System (INIS)

    1996-01-01

    This is the first report on policy measures implemented with regard to the promotion of science and technology, in accordance with Article 8 of the Science and Technology Basic Law, which was enacted in November 1995. Parts 1 and 2 of this report discuss trends in a wide range of scientific and technological activities to help the reader understand the policy measures implemented to promote science and technology. Part 1, titled 'Striving to become a front-runner in research activity', attempts and analysis of the public's expectations and demands concerning science and technology; of the state of affairs at institutions engaged in R and D; and of the issues that require attention in the pursuit of future of research activity. In Part 2, various types of data are used to compare Japan's scientific and technological activities with those in other major nations. And, Part 3 contains Policies implemented for the promotion of science and technology. (G.K.)

  13. Higher concentrations of nanoscale zero-valent iron (nZVI) in soil induced rice chlorosis due to inhibited active iron transportation

    International Nuclear Information System (INIS)

    Wang, Jie; Fang, Zhanqiang; Cheng, Wen; Yan, Xiaomin; Tsang, Pokeung Eric; Zhao, Dongye

    2016-01-01

    In this study, the effects of concentrations 0, 100, 250, 500, 750 and 1000 mg kg"−"1 of nanoscale zero-valent iron (nZVI) on germination, seedlings growth, physiology and toxicity mechanisms were investigated. The results showed that nZVI had no effect on germination, but inhibited the rice seedlings growth in higher concentrations (>500 mg kg"−"1 nZVI). The highest suppression rate of the length of roots and shoots reached 46.9% and 57.5%, respectively. The 1000mg kg"−"1 nZVI caused the highest suppression rates for chlorophyll and carotenoids, at 91.6% and 85.2%, respectively. In addition, the activity of antioxidant enzymes was altered by the translocation of nanoparticles and changes in active iron content. Visible symptoms of iron deficiency were observed at higher concentrations, at which the active iron content decreased 61.02% in the shoots, but the active iron content not decreased in roots. Interestingly, the total and available amounts of iron in the soil were not less than those in the control. Therefore, the plants iron deficiency was not caused by (i) deficiency of available iron in the soil and (ii) restraint of the absorption that plant takes in the available iron, while induced by (ⅲ) the transport of active iron from the root to the shoot was blocked. The cortex tissues were seriously damaged by nZVI which was transported from soil to the root, these were proved by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). This current study shows that the mechanism of iron deficiency in rice seedling was due to transport of active iron from the root to the shoot blocked, which was caused by the uptake of nZVI. - Highlights: • Higher concentrations of nZVI induced iron deficiency in rice seedlings visibly. • nZVI was taken in rice seedlings and transported form root to shoot. • The pathway of active iron transport from root to shoot was inhibited. • The cortex tissues

  14. Edible Earth and Space Science Activities

    Science.gov (United States)

    Lubowich, D.; Shupla, C.

    2014-07-01

    In this workshop we describe using Earth and Space Science demonstrations with edible ingredients to increase student interest. We show how to use chocolate, candy, cookies, popcorn, bagels, pastries, Pringles, marshmallows, whipped cream, and Starburst candy for activities such as: plate tectonics, the interior structure of the Earth and Mars, radioactivity/radioactive dating of rocks and stars, formation of the planets, lunar phases, convection, comets, black holes, curvature of space, dark energy, and the expansion of the Universe. In addition to creating an experience that will help students remember specific concepts, edible activities can be used as a formative assessment, providing students with the opportunity to create something that demonstrates their understanding of the model. The students often eat the demonstrations. These demonstrations are an effective teaching tool for all ages, and can be adapted for cultural, culinary, and ethnic differences among the students.

  15. Developing a Repertoire of Activities for Teaching Physical Science.

    Science.gov (United States)

    Cain, Peggy W.

    This activity manual is divided into 15 units which focus on: the nature of science; metric measurements; properties of matter; energy; atomic structure; chemical reactions; acids, bases, and salts; temperature and heat; readioactivity; mechanics; wave motion, sound, and light; static charges and current electricity magnetism and electromagnetism;…

  16. A Cultural Historical Activity Theory Approach in Natural Sciences Education Laboratory Lessons towards Reforming Teachers Training

    Science.gov (United States)

    Kolokouri, Eleni; Theodoraki, Xarikleia; Plakitsi, Katerina

    2012-01-01

    This paper focuses on connecting natural sciences education with Cultural Historical Activity Theory (CHAT). In this sense, natural sciences education is considered as a lifelong learning procedure, not seen as an individual but as a collective activity. Moreover, learning becomes a human activity in which theory and praxis are strongly connected…

  17. Enhancing Diversity in Undergraduate Science: Self-Efficacy Drives Performance Gains with Active Learning.

    Science.gov (United States)

    Ballen, Cissy J; Wieman, Carl; Salehi, Shima; Searle, Jeremy B; Zamudio, Kelly R

    2017-01-01

    Efforts to retain underrepresented minority (URM) students in science, technology, engineering, and mathematics (STEM) have shown only limited success in higher education, due in part to a persistent achievement gap between students from historically underrepresented and well-represented backgrounds. To test the hypothesis that active learning disproportionately benefits URM students, we quantified the effects of traditional versus active learning on student academic performance, science self-efficacy, and sense of social belonging in a large (more than 250 students) introductory STEM course. A transition to active learning closed the gap in learning gains between non-URM and URM students and led to an increase in science self-efficacy for all students. Sense of social belonging also increased significantly with active learning, but only for non-URM students. Through structural equation modeling, we demonstrate that, for URM students, the increase in self-efficacy mediated the positive effect of active-learning pedagogy on two metrics of student performance. Our results add to a growing body of research that supports varied and inclusive teaching as one pathway to a diversified STEM workforce. © 2017 C. J. Ballen et al. CBE—Life Sciences Education © 2017 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  18. Comparison of Micro- and Nanoscale Fe+3-Containing (Hematite) Particles for Their Toxicological Properties in Human Lung Cells In Vitro

    NARCIS (Netherlands)

    Bhattacharya, K.; Hoffmann, E.; Schins, R.F.P.; Boertz, J.; Prantl, E.M.; Alink, G.M.; Byrne, H.J.; Kuhlbusch, T.A.J.; Rahman, Q.; Wiggers, H.; Schulz, C.; Dopp, E.

    2012-01-01

    The specific properties of nanoscale particles, large surface-to-mass ratios and highly reactive surfaces, have increased their commercial application in many fields. However, the same properties are also important for the interaction and bioaccumulation of the nonbiodegradable nanoscale particles

  19. Simultaneous topographical, electrical and optical microscopy of optoelectronic devices at the nanoscale

    KAUST Repository

    Kumar, Naresh; Zoladek-Lemanczyk, Alina; Guilbert, Anne A. Y.; Su, Weitao; Tuladhar, Sachetan M.; Kirchartz, Thomas; Schroeder, Bob C.; McCulloch, Iain; Nelson, Jenny; Roy, Debdulal; Castro, Fernando A.

    2017-01-01

    resolution by combining plasmonic optical signal enhancement with electrical-mode scanning probe microscopy. We demonstrate that this combined approach offers subsurface sensitivity that can be exploited to provide molecular information with a nanoscale

  20. Nanoscale elasticity mappings of micro-constituents of abalone shell by band excitation-contact resonance force microscopy

    Science.gov (United States)

    Li, Tao; Zeng, Kaiyang

    2014-01-01

    The macroscopic mechanical properties of the abalone shell have been studied extensively in the literature, but the in situ nanoscale elasticity of various micro-constituents in the shell have not been characterized and reported yet. In this study, the nanoscale elasticity mappings including different micro-constituents in abalone shell were observed by using the Contact Resonance Force Microscopy (CR-FM) technique. CR-FM is one of the advanced scanning probe microscopy techniques that is able to quantify the local elastic moduli of various materials in a non-destructive manner. Instead of an average value, an elasticity mapping that reveals the nanoscale variations of elastic moduli with location can be extracted and correlated with the topography of the structure. Therefore in this study, by adopting the CR-FM technique that is incorporated with the band excitation technique, the elasticity variations of the abalone shell caused by different micro-constituents and crystal orientations are reported, and the elasticity values of the aragonite and calcite nanograins are quantified.The macroscopic mechanical properties of the abalone shell have been studied extensively in the literature, but the in situ nanoscale elasticity of various micro-constituents in the shell have not been characterized and reported yet. In this study, the nanoscale elasticity mappings including different micro-constituents in abalone shell were observed by using the Contact Resonance Force Microscopy (CR-FM) technique. CR-FM is one of the advanced scanning probe microscopy techniques that is able to quantify the local elastic moduli of various materials in a non-destructive manner. Instead of an average value, an elasticity mapping that reveals the nanoscale variations of elastic moduli with location can be extracted and correlated with the topography of the structure. Therefore in this study, by adopting the CR-FM technique that is incorporated with the band excitation technique, the

  1. Evaluation of Changes in Ghanaian Students' Attitudes Towards Science Following Neuroscience Outreach Activities: A Means to Identify Effective Ways to Inspire Interest in Science Careers.

    Science.gov (United States)

    Yawson, Nat Ato; Amankwaa, Aaron Opoku; Tali, Bernice; Shang, Velma Owusua; Batu, Emmanuella Nsenbah; Asiemoah, Kwame; Fuseini, Ahmed Denkeri; Tene, Louis Nana; Angaandi, Leticia; Blewusi, Isaac; Borbi, Makafui; Aduku, Linda Nana Esi; Badu, Pheonah; Abbey, Henrietta; Karikari, Thomas K

    2016-01-01

    The scientific capacity in many African countries is low. Ghana, for example, is estimated to have approximately twenty-three researchers per a million inhabitants. In order to improve interest in science among future professionals, appropriate techniques should be developed and employed to identify barriers and correlates of science education among pre-university students. Young students' attitudes towards science may affect their future career choices. However, these attitudes may change with new experiences. It is, therefore, important to evaluate potential changes in students' attitudes towards science after their exposure to experiences such as science outreach activities. Through this, more effective means of inspiring and mentoring young students to choose science subjects can be developed. This approach would be particularly beneficial in countries such as Ghana, where: (i) documented impacts of outreach activities are lacking; and (ii) effective means to develop scientist-school educational partnerships are needed. We have established an outreach scheme, aimed at helping to improve interaction between scientists and pre-university students (and their teachers). Outreach activities are designed and implemented by undergraduate students and graduate teaching assistants, with support from faculty members and technical staff. Through this, we aim to build a team of trainee scientists and graduates who will become ambassadors of science in their future professional endeavors. Here, we describe an approach for assessing changes in junior high school students' attitudes towards science following classroom neuroscience outreach activities. We show that while students tended to agree more with questions concerning their perceptions about science learning after the delivery of outreach activities, significant improvements were obtained for only two questions, namely "I enjoy science lessons" and "I want to be a scientist in the future." Furthermore, there was a

  2. Nanoscale protein arrays of rich morphologies via self-assembly on chemically treated diblock copolymer surfaces

    International Nuclear Information System (INIS)

    Song Sheng; Milchak, Marissa; Zhou Hebing; Lee, Thomas; Hanscom, Mark; Hahm, Jong-in

    2013-01-01

    Well-controlled assembly of proteins on supramolecular templates of block copolymers can be extremely useful for high-throughput biodetection. We report the adsorption and assembly characteristics of a model antibody protein to various polystyrene-block-poly(4-vinylpyridine) templates whose distinctive nanoscale structures are obtained through time-regulated exposure to chloroform vapor. The strong adsorption preference of the protein to the polystyrene segment in the diblock copolymer templates leads to an easily predictable, controllable, rich set of nanoscale protein morphologies through self-assembly. We also demonstrate that the chemical identities of various subareas within individual nanostructures can be readily elucidated by investigating the corresponding protein adsorption behavior on each chemically distinct area of the template. In our approach, a rich set of intricate nanoscale morphologies of protein arrays that cannot be easily attained through other means can be generated straightforwardly via self-assembly of proteins on chemically treated diblock copolymer surfaces, without the use of clean-room-based fabrication tools. Our approach provides much-needed flexibility and versatility for the use of block copolymer-based protein arrays in biodetection. The ease of fabrication in producing well-defined and self-assembled templates can contribute to a high degree of versatility and simplicity in acquiring an intricate nanoscale geometry and spatial distribution of proteins in arrays. These advantages can be extremely beneficial both for fundamental research and biomedical detection, especially in the areas of solid-state-based, high-throughput protein sensing. (paper)

  3. Nanoscale size effect in in situ titanium based composites with cell viability and cytocompatibility studies

    Energy Technology Data Exchange (ETDEWEB)

    Miklaszewski, Andrzej, E-mail: andrzej.miklaszewski@put.poznan.pl [Institute of Materials Science and Engineering, Poznan University of Technology, Jana Pawla II 24, 61-138 Poznan (Poland); Jurczyk, Mieczysława U. [Division Mother' s and Child' s Health, Poznan University of Medical Sciences, Polna 33, 60-535 Poznan (Poland); Kaczmarek, Mariusz [Department of Immunology, Chair of Clinical Immunology, Poznan University of Medical Sciences, Rokietnicka 5D, 60-806 Poznan (Poland); Paszel-Jaworska, Anna; Romaniuk, Aleksandra; Lipińska, Natalia [Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, Przybyszewskiego 49, 60-355 Poznan (Poland); Żurawski, Jakub [Department of Immunobiochemistry, Chair of Biology and Environmental Sciences, Poznan University of Medical Sciences, Rokietnicka 8, 60-806 Poznan (Poland); Urbaniak, Paulina [Department of Cell Biology, Poznan University of Medical Sciences, Rokietnicka 5D, 60-806 Poznan (Poland); Jurczyk, Mieczyslaw [Institute of Materials Science and Engineering, Poznan University of Technology, Jana Pawla II 24, 61-138 Poznan (Poland)

    2017-04-01

    Novel in situ Metal Matrix Nanocomposite (MMNC) materials based on titanium and boron, revealed their new properties in the nanoscale range. In situ nanocomposites, obtained through mechanical alloying and traditional powder metallurgy compaction and sintering, show obvious differences to their microstructural analogue. A unique microstructure connected with good mechanical properties reliant on the processing conditions favour the nanoscale range of results of the Ti-TiB in situ MMNC example. The data summarised in this work, support and extend the knowledge boundaries of the nanoscale size effect that influence not only the mechanical properties but also the studies on the cell viability and cytocompatibility. Prepared in the same bulk, in situ MMNC, based on titanium and boron, could be considered as a possible candidate for dental implants and other medical applications. The observed relations and research conclusions are transferable to the in situ MMNC material group. Aside from all the discussed relations, the increasing share of these composites in the ever-growing material markets, heavily depends on the attractiveness and a possible wider application of these composites as well as their operational simplicity presented in this work. - Highlights: • Nano and microscale size precursor influence the final composite microstructure and properties. • Obtained from the nanoscale precursor sinters, characterise with a uniform and highly dispersed microstructure • Mechanical properties favoured Nano scale size precursor • Boron addition could be significantly reduced for moderate properties range. • A possible candidate for dental implants and other medical applications.

  4. Friction and Surface Dynamics of Polymers on the Nanoscale by AFM

    NARCIS (Netherlands)

    Schönherr, Holger; Schónherr, Holger; Samori, Paolo; Tocha, E.; Vancso, Gyula J.

    2008-01-01

    In this article the measurement and understanding of friction forces and surface dynamics of polymers on the one hand and the importance of molecular relaxation processes and viscoelasticity in polymers for advanced micro- and nanoscale applications on the other hand are discussed. Particular

  5. In-situ Liquid Electron Microscopy Setups for Investigation of Nanoscale Electrochemistry

    DEFF Research Database (Denmark)

    Jensen, Eric; Møller-Nilsen, Rolf Erling Robberstad; Canepa, Silvia

    2014-01-01

    -situ electrochemistry and has achieved ~10 nm resolution. Such systems are important tools for developing sustainable technology and for understanding nanoscale phenomena. However, both systems suffer from interacting with theelectron beam, which is a high-voltage radiation source, and therefore initial experiments...

  6. Symposium GC: Nanoscale Charge Transport in Excitonic Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Bommisetty, Venkat [Univ. of South Dakota, Vermillion, SD (United States)

    2011-06-23

    This paper provides a summary only and table of contents of the sessions. Excitonic solar cells, including all-organic, hybrid organic-inorganic and dye-sensitized solar cells (DSSCs), offer strong potential for inexpensive and large-area solar energy conversion. Unlike traditional inorganic semiconductor solar cells, where all the charge generation and collection processes are well understood, these excitonic solar cells contain extremely disordered structures with complex interfaces which results in large variations in nanoscale electronic properties and has a strong influence on carrier generation, transport, dissociation and collection. Detailed understanding of these processes is important for fabrication of highly efficient solar cells. Efforts to improve efficiency are underway at a large number of research groups throughout the world focused on inorganic and organic semiconductors, photonics, photophysics, charge transport, nanoscience, ultrafast spectroscopy, photonics, semiconductor processing, device physics, device structures, interface structure etc. Rapid progress in this multidisciplinary area requires strong synergetic efforts among researchers from diverse backgrounds. Such effort can lead to novel methods for development of new materials with improved photon harvesting and interfacial treatments for improved carrier transport, process optimization to yield ordered nanoscale morphologies with well defined electronic structures.

  7. Interfibrillar stiffening of echinoderm mutable collagenous tissue demonstrated at the nanoscale.

    Science.gov (United States)

    Mo, Jingyi; Prévost, Sylvain F; Blowes, Liisa M; Egertová, Michaela; Terrill, Nicholas J; Wang, Wen; Elphick, Maurice R; Gupta, Himadri S

    2016-10-18

    The mutable collagenous tissue (MCT) of echinoderms (e.g., sea cucumbers and starfish) is a remarkable example of a biological material that has the unique attribute, among collagenous tissues, of being able to rapidly change its stiffness and extensibility under neural control. However, the mechanisms of MCT have not been characterized at the nanoscale. Using synchrotron small-angle X-ray diffraction to probe time-dependent changes in fibrillar structure during in situ tensile testing of sea cucumber dermis, we investigate the ultrastructural mechanics of MCT by measuring fibril strain at different chemically induced mechanical states. By measuring a variable interfibrillar stiffness (E IF ), the mechanism of mutability at the nanoscale can be demonstrated directly. A model of stiffness modulation via enhanced fibrillar recruitment is developed to explain the biophysical mechanisms of MCT. Understanding the mechanisms of MCT quantitatively may have applications in development of new types of mechanically tunable biomaterials.

  8. Controllable nanoscale rotating actuator system based on carbon nanotube and graphene

    International Nuclear Information System (INIS)

    Huang, Jianzhang; Han, Qiang

    2016-01-01

    A controllable nanoscale rotating actuator system consisting of a double carbon nanotube and graphene driven by a temperature gradient is proposed, and its rotating dynamics performance and driving mechanism are investigated through molecular dynamics simulations. The outer tube exhibits stable pure rotation with certain orientation under temperature gradient and the steady rotational speed rises as the temperature gradient increases. It reveals that the driving torque is caused by the difference of atomic van der Waals potentials due to the temperature gradient and geometrical features of carbon nanotube. A theoretical model for driving torque is established based on lattice dynamics theory and its predicted results agree well with molecular dynamics simulations. Further discussion is taken according to the theoretical model. The work in this study would be a guide for design and application of controllable nanoscale rotating devices based on carbon nanotubes and graphene. (paper)

  9. Sonochemical Synthesis of Photoluminescent Nanoscale Eu(III-Containing Metal-Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Cheng-an TAO

    2015-11-01

    Full Text Available Nanoscale lanthanide-containing metal-organic frameworks (MOFs have more and more interest due to their great properties and potential applications, but how to construct them easily is still challenging. Here, we present a facile and rapid synthesis of Eu(III-containing Nanoscale MOF (denoted as NMOF under ultrasonic irradiation. The effect of the ratio and the addition order of metal ions and linkers on the morphology and size of MOFs was investigated. It is found that both of the ratio and the addition order can affect the morphology and size of 1.4-benzenedicarboxylic acid(H2BDC -based MOFs, but they show no evident influence on that of H2aBDC-based MOFs. The former exhibit typical emission bands of Eu(III ions, while the latter only show the photoluminescent properties of ligands.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9695

  10. Probing Structural and Catalytic Characteristics of Galactose Oxidase Confined in Nanoscale Chemical Environments

    DEFF Research Database (Denmark)

    Ikemoto, Hideki; Mossin, Susanne; Ulstrup, Jens

    2014-01-01

    Galactose oxidase (GAOX) is a special metalloenzyme in terms of its active site structure and catalytic mechanisms. This work reports a study where the enzyme confined in a nanoscale chemical environment provided by mesoporous silicas (MPS) is probed. Two types of MPS, i.e. SBA-15 and MCF, were...... synthesized and used to accommodate GAOX. SBA-15-ROD is rod-shaped particles with periodically ordered nanopores (9.5 nm), while MCF has a mesocellular foam-like structure with randomly distributed pores (23 nm) interconnected by smaller windows (8.8 nm). GAOX is non-covalently confined in SBA-15- ROD, while...... it is covalently immobilized in MCF. Relatively high loadings in the range of 50–60 mg g1 are achieved. Electron spin resonance (ESR) spectroscopy is used to probe the active site structures of the enzyme. The similar ESR spectra observed for GAOX in the free and immobilized states support that the electronic...

  11. Nano-Scale Interpenetrating Phase Composites (IPC S) for Industrial and Vehicle Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, James Gordon [ORNL; Hu, Michael Z. [ORNL

    2010-06-01

    A one-year project was completed at Oak Ridge National Laboratory (ORNL) to explore the technical and economic feasibility of producing nano-scale Interpenetrating Phase Composite (IPC) components of a usable size for actual testing/implementation in a real applications such as high wear/corrosion resistant refractory shapes for industrial applications, lightweight vehicle braking system components, or lower cost/higher performance military body and vehicle armor. Nano-scale IPC s with improved mechanical, electrical, and thermal properties have previously been demonstrated at the lab scale, but have been limited in size. The work performed under this project was focused on investigating the ability to take the current traditional lab scale processes to a manufacturing scale through scaling of these processes or through the utilization of an alternative high-temperature process.

  12. Field Training Activities for Hydrologic Science in West Java, Indonesia

    Science.gov (United States)

    Agustina, C.; Fajri, P. N.; Fathoni, F.; Gusti, T. P.; Harifa, A. C.; Hendra, Y.; Hertanti, D. R.; Lusiana, N.; Rohmat, F. I.; Agouridis, C.; Fryar, A. E.; Milewski, A.; Pandjaitan, N.; Santoso, R.; Suharyanto, A.

    2013-12-01

    In hydrologic science and engineering, one challenge is establishing a common framework for discussion among workers from different disciplines. As part of the 'Building Opportunity Out of Science and Technology: Helping Hydrologic Outreach (BOOST H2O)' project, which is supported by the U.S. Department of State, nine current or recent graduate students from four Indonesian universities participated in a week of training activities during June 2013. Students had backgrounds in agricultural engineering, civil and environmental engineering, water resources engineering, natural resources management, and soil science. Professors leading the training, which was based at Bogor Agricultural University (IPB) in west Java, included an agricultural engineer, civil engineers, and geologists. Activities in surface-water hydrology included geomorphic assessment of streams (measuring slope, cross-section, and bed-clast size) and gauging stream flow (wading with top-setting rods and a current meter for a large stream, and using a bucket and stopwatch for a small stream). Groundwater-hydrology activities included measuring depth to water in wells, conducting a pumping test with an observation well, and performing vertical electrical soundings to infer hydrostratigraphy. Students also performed relatively simple water-quality measurements (temperature, electrical conductivity, pH, and alkalinity) in streams, wells, and springs. The group analyzed data with commercially-available software such as AQTESOLV for well hydraulics, freeware such as the U.S. Geological Survey alkalinity calculator, and Excel spreadsheets. Results were discussed in the context of landscape position, lithology, and land use.

  13. African Journal for Physical Activity and Health Sciences - Vol 21 ...

    African Journals Online (AJOL)

    African Journal for Physical Activity and Health Sciences - Vol 21, No 3 (2015) ... Factors Influencing the Health of Men in Polygynous Relationship · EMAIL FULL ... Views of HIV Positive Pregnant Women on Accessibility of the Prevention of ...

  14. Probing defect and magnetic structures on the nanoscale

    OpenAIRE

    Kallis, Alexis

    2010-01-01

    This thesis reports on experimental research on structural defects and magnetic species on the nanoscale. The latter project involved considerable development work on the production of a spin-polarised mono-energetic positron beam. The construction of the system is described through various trial steps with emphasis on the methods of maximum practical polarization of the positron beam and of electrons in the sample with the smallest possible loss of beam intensity. A new sodium-22 source caps...

  15. Noticeable red emission and Raman active modes in nanoscale gadolinium oxyfluoride (Gd4O3F6) systems with Eu3+ inclusion

    International Nuclear Information System (INIS)

    Hazarika, Samiran; Mohanta, Dambarudhar

    2017-01-01

    Eu 3+ doped gadolinium oxyfluoride (Gd 4 O 3 F 6 , GOF) nanoscale systems have been synthesized following a modified Pechini method. While exhibiting a tetragonal crystal structure, the GOF nanosystem gave an average crystallite size (d) of ∝21-26 nm. The Lotgering factor (L F ), which is a measure of orientation of crystallites along the preferred direction was found to vary between 0.22 and 0.48. In the photoluminescence spectra, ∝595 and ∝613 nm peaks were identified as magnetically driven ( 5 D 0 → 7 F 1 ) and electrically driven ( 5 D 0 → 7 F 2 ) transitions with latter (red emission) being strongly manifested with Eu 3+ doping concentration and intrinsic defects. Moreover, several Raman active modes have been probed in the Raman spectra with low frequency peaks (<300 cm -1 ) and moderate frequency peaks (∝481 and 567 cm -1 ) assigned to observable vibration of heavy atom Gd-Gd pairs and Gd-O groups, respectively. Apart from manifestation of phononic features, inclusion of Eu 3+ in the host lattice would bring new insight on improving the red emission response prior to concentration quenching. (orig.)

  16. Merging science, engineering, and data with FUN: Recreational Drones in STEaM Education Activities and Science Fair Projects

    Science.gov (United States)

    Olds, S. E.; Mooney, M. E.; Dahlman, L. E.

    2016-12-01

    Recreational drones, also known as unmanned aerial vehicles (UAVs), provide an ideal platform for engaging students in science, technology, engineering, and math (STEM) investigations for science fair projects, after-school clubs, and in-class activities. UAVs are very popular (estimate of >1 million received as gifts this past year), relatively inexpensive (Arduino board. This presentation will elaborate upon the year-long process of working with educators via webinars and a 1-day workshop at the 2016 ESIP summer meeting and beyond. It will also provide examples of student-led investigations, instructions for building the SABEL sensor package, insights gleaned from workshop feedback - and - the status of the new e-book compilation of student-focused activities using recreational drones to pursue STEM investigations!

  17. Visualizing nanoscale phase morphology for understanding photovoltaic performance of PTB7: PC71BM solar cell

    Science.gov (United States)

    Supasai, Thidarat; Amornkitbamrung, Vittaya; Thanachayanont, Chanchana; Tang, I.-Ming; Sutthibutpong, Thana; Rujisamphan, Nopporn

    2017-11-01

    Visualizing and controlling the phase separation of the donor and acceptor domains in organic bulk-hetero-junction (BHJ) solar devices made with poly([4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethyl-hexyl)carbon-yl]thieno[3,4-bthiophenediyl]) (PTB7) and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) are needed to achieve high power conversion efficiency (PCE). Traditional bright-field (BF) imaging, especially of polymeric materials, produces images of poor contrast when done at the nanoscale level. Clear nanoscale morphologies of the PTB7:PC71BM blends prepared with different 1,8-diiodooctane (DIO) concentrations were seen when using the energy-filtered transmission electron microscopy (EFTEM). The electron energy loss (EELS) spectra of the pure PTB7 and PC71BM samples are centered at 22.7 eV and 24.5 eV, respectively. Using the electrons whose energy losses are in the range of 16-30 eV, detail information of the phase morphology at the nanoscale was obtained. Correlations between the improvement in the photovoltaic performances and the increased electron mobility were seen. These correlations are discussed in terms of the changes (at the nanoscale level) in blending phase morphology when different DIO concentrations are added.

  18. Interplay of Peltier and Seebeck Effects in Nanoscale Nonlocal Spin Valves

    NARCIS (Netherlands)

    Bakker, F. L.; Slachter, A.; Adam, J-P; van Wees, B. J.

    2010-01-01

    We have experimentally studied the role of thermoelectric effects in nanoscale nonlocal spin valve devices. A finite element thermoelectric model is developed to calculate the generated Seebeck voltages due to Peltier and Joule heating in the devices. By measuring the first, second, and third

  19. Exploring the Solar System Activities Outline: Hands-On Planetary Science for Formal Education K-14 and Informal Settings

    Science.gov (United States)

    Allen, J. S.; Tobola, K. W.; Lindstrom, M. L.

    2003-01-01

    Activities by NASA scientists and teachers focus on integrating Planetary Science activities with existing Earth science, math, and language arts curriculum. The wealth of activities that highlight missions and research pertaining to the exploring the solar system allows educators to choose activities that fit a particular concept or theme within their curriculum. Most of the activities use simple, inexpensive techniques that help students understand the how and why of what scientists are learning about comets, asteroids, meteorites, moons and planets. With these NASA developed activities students experience recent mission information about our solar system such as Mars geology and the search for life using Mars meteorites and robotic data. The Johnson Space Center ARES Education team has compiled a variety of NASA solar system activities to produce an annotated thematic outline useful to classroom educators and informal educators as they teach space science. An important aspect of the outline annotation is that it highlights appropriate science content information and key science and math concepts so educators can easily identify activities that will enhance curriculum development. The outline contains URLs for the activities and NASA educator guides as well as links to NASA mission science and technology. In the informal setting educators can use solar system exploration activities to reinforce learning in association with thematic displays, planetarium programs, youth group gatherings, or community events. Within formal education at the primary level some of the activities are appropriately designed to excite interest and arouse curiosity. Middle school educators will find activities that enhance thematic science and encourage students to think about the scientific process of investigation. Some of the activities offered are appropriate for the upper levels of high school and early college in that they require students to use and analyze data.

  20. In-situ realtime monitoring of nanoscale gold electroplating using micro-electro-mechanical systems liquid cell operating in transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Egawa, Minoru; Fujita, Hiroyuki [Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505 (Japan); Ishida, Tadashi, E-mail: ishida.t.ai@m.titech.ac.jp [Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505 (Japan); Graduate School of Science and Technology, Tokyo Institute of Technology, Yokohama, Kanagawa 225-8503 (Japan); Jalabert, Laurent [LIMMS/CNRS-IIS (UMI 2820), Institute of Industrial Science, University of Tokyo, Meguro, Tokyo 153-8505 (Japan); CNRS, LAAS, 7 Avenue du Colonel Roche, F-31400 Toulouse, France and University of Toulouse, LAAS, F-31400 Toulouse (France)

    2016-01-11

    The dynamics of nanoscale electroplating between gold electrodes was investigated using a microfabricated liquid cell mounted on a scanning transmission electron microscope. The electroplating was recorded in-situ for 10 min with a spatial resolution higher than 6 nm. At the beginning of the electroplating, gold spike-like structures of about 50 nm in size grew from an electrode, connected gold nanoclusters around them, and form three dimensional nanoscale structures. We visualized the elementary process of the gold electroplating, and believe that the results lead to the deeper understanding of electroplating at the nanoscale.

  1. In-situ realtime monitoring of nanoscale gold electroplating using micro-electro-mechanical systems liquid cell operating in transmission electron microscopy

    International Nuclear Information System (INIS)

    Egawa, Minoru; Fujita, Hiroyuki; Ishida, Tadashi; Jalabert, Laurent

    2016-01-01

    The dynamics of nanoscale electroplating between gold electrodes was investigated using a microfabricated liquid cell mounted on a scanning transmission electron microscope. The electroplating was recorded in-situ for 10 min with a spatial resolution higher than 6 nm. At the beginning of the electroplating, gold spike-like structures of about 50 nm in size grew from an electrode, connected gold nanoclusters around them, and form three dimensional nanoscale structures. We visualized the elementary process of the gold electroplating, and believe that the results lead to the deeper understanding of electroplating at the nanoscale

  2. Strengthening effect of nano-scale precipitates in a die-cast Mg–4Al–5.6Sm–0.3Mn alloy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qiang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Bu, Fanqiang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Qiu, Xin [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yangzhou Hongfu Aluminium Co. Ltd, Yangzhou 100049 (China); Li, Yangde; Li, Weirong [E-ande Scientific & Technology Co. Ltd, Dongguan 523000 (China); Sun, Wei [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Liu, Xiaojuan, E-mail: lxjuan@ciac.ac.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Meng, Jian, E-mail: jmeng@ciac.jl.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2016-04-25

    In this paper we report a quantitative study of the age-hardening in the high-pressure die-cast Mg–4Al−5.6Sm−0.3Mn alloy. The results indicate that a number of nano-scale spherical precipitates identified as Al{sub 3}Sm using high-angle annular dark-field scanning transmission electron microscopy, precipitated in Mg matrix after aging at 150–225 °C, with no obvious changes on grain sizes, intermetallic phases formed during solidification, and dislocation densities. From the existing strengthening theory equations in which some lacking parameters were taken from the first-principles density functional theory (DFT) calculations, a quantitative insight into the strengthening mechanisms of the nano-scale precipitate was formulated. The results are in reasonable agreement with the experimental values, and the operative mechanism of precipitation strengthening was revealed as Orowan dislocation bypassing. - Highlights: • The yield strength of Mg–Al–Sm alloy was improved by aging treatment. • A number of nano-scale precipitates formed in matrix after aging treatments. • The nanoscale precipitate was confirmed as Al{sub 3}Sm based on the data of HAADF-STEM study. • The strengthening mechanisms of the nano-scale precipitate were quantitatively formulated. • The operative mechanism of precipitate strengthening is Orowan dislocation bypassing.

  3. On the relationship between the dynamic behavior and nanoscale staggered structure of the bone

    Science.gov (United States)

    Qwamizadeh, Mahan; Zhang, Zuoqi; Zhou, Kun; Zhang, Yong Wei

    2015-05-01

    Bone, a typical load-bearing biological material, composed of ordinary base materials such as organic protein and inorganic mineral arranged in a hierarchical architecture, exhibits extraordinary mechanical properties. Up to now, most of previous studies focused on its mechanical properties under static loading. However, failure of the bone occurs often under dynamic loading. An interesting question is: Are the structural sizes and layouts of the bone related or even adapted to the functionalities demanded by its dynamic performance? In the present work, systematic finite element analysis was performed on the dynamic response of nanoscale bone structures under dynamic loading. It was found that for a fixed mineral volume fraction and unit cell area, there exists a nanoscale staggered structure at some specific feature size and layout which exhibits the fastest attenuation of stress waves. Remarkably, these specific feature sizes and layouts are in excellent agreement with those experimentally observed in the bone at the same scale, indicating that the structural size and layout of the bone at the nanoscale are evolutionarily adapted to its dynamic behavior. The present work points out the importance of dynamic effect on the biological evolution of load-bearing biological materials.

  4. Student Motivation from and Resistance to Active Learning Rooted in Essential Science Practices

    Science.gov (United States)

    Owens, David C.; Sadler, Troy D.; Barlow, Angela T.; Smith-Walters, Cindi

    2017-12-01

    Several studies have found active learning to enhance students' motivation and attitudes. Yet, faculty indicate that students resist active learning and censure them on evaluations after incorporating active learning into their instruction, resulting in an apparent paradox. We argue that the disparity in findings across previous studies is the result of variation in the active learning instruction that was implemented. The purpose of this study was to illuminate sources of motivation from and resistance to active learning that resulted from a novel, exemplary active-learning approach rooted in essential science practices and supported by science education literature. This approach was enacted over the course of 4 weeks in eight sections of an introductory undergraduate biology laboratory course. A plant concept inventory, administered to students as a pre-, post-, and delayed-posttest indicated significant proximal and distal learning gains. Qualitative analysis of open-response questionnaires and interviews elucidated sources of motivation and resistance that resulted from this active-learning approach. Several participants indicated this approach enhanced interest, creativity, and motivation to prepare, and resulted in a challenging learning environment that facilitated the sharing of diverse perspectives and the development of a community of learners. Sources of resistance to active learning included participants' unfamiliarity with essential science practices, having to struggle with uncertainty in the absence of authoritative information, and the extra effort required to actively construct knowledge as compared to learning via traditional, teacher-centered instruction. Implications for implementation, including tips for reducing student resistance to active learning, are discussed.

  5. Active and Dynamic Nanomaterials Based on Active Biomolecules

    Science.gov (United States)

    Koch, Steven J.; Rivera, Susan B.; Boal, Andrew K.; Edwards, J. Matthew; Bauer, Joseph M.; Manginell, Ronald P.; Liu, Jun; Bunker, Bruce C.; Bachand, George D.

    2004-03-01

    Living organisms have evolved dynamic and adaptable materials that fundamentally differ from synthetic materials. These biomaterials use chemical energy to drive non-equilibrium assembly processes, and to reconfigure in response to external stimuli or life cycle changes. Two striking examples are the diatom's active assembly of silica into a patterned cytoskeleton, and the chameleon's active transport of pigment particles to rapidly change skin color. Advances in molecular biology and nanoscale materials synthesis now present the opportunity for integrating biomolecules with synthetic components to produce new types of materials with novel assembly and adaptation capabilities. Our group has begun utilizing kinesin motor proteins and microtubules (MTs) to explore the construction of biomimetic materials. Initial work has focused on characterizing and engineering the properties of the biomolecules for robust performance in artificial systems. We have characterized the biochemical and biophysical properties of a kinesin motor protein from a thermostable fungus, and have evaluated strategies for stabilizing and functionalizing the MTs. We also have developed strategies for directed transport of MT shuttles, and for controlling the loading and unloading of nanoscale cargo.

  6. Cluster-assembled cubic zirconia films with tunable and stable nanoscale morphology against thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Borghi, F.; Lenardi, C.; Podestà, A.; Milani, P., E-mail: pmilani@mi.infn.it [CIMAINA and Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy); Sogne, E. [CIMAINA and Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy); European School of Molecular Medicine (SEMM), IFOM-IEO, Milano (Italy); Merlini, M. [Dipartimento di Scienze della Terra “Ardito Desio”, Università degli Studi di Milano, via Mangiagalli 32, 20133 Milano (Italy); Ducati, C. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)

    2016-08-07

    Nanostructured zirconium dioxide (zirconia) films are very promising for catalysis and biotechnological applications: a precise control of the interfacial properties of the material at different length scales and, in particular, at the nanoscale, is therefore necessary. Here, we present the characterization of cluster-assembled zirconia films produced by supersonic cluster beam deposition possessing cubic structure at room temperature and controlled nanoscale morphology. We characterized the effect of thermal annealing in reducing and oxidizing conditions on the crystalline structure, grain dimensions, and topography. We highlight the mechanisms of film growth and phase transitions, which determine the observed interfacial morphological properties and their resilience against thermal treatments.

  7. Cluster-assembled cubic zirconia films with tunable and stable nanoscale morphology against thermal annealing

    International Nuclear Information System (INIS)

    Borghi, F.; Lenardi, C.; Podestà, A.; Milani, P.; Sogne, E.; Merlini, M.; Ducati, C.

    2016-01-01

    Nanostructured zirconium dioxide (zirconia) films are very promising for catalysis and biotechnological applications: a precise control of the interfacial properties of the material at different length scales and, in particular, at the nanoscale, is therefore necessary. Here, we present the characterization of cluster-assembled zirconia films produced by supersonic cluster beam deposition possessing cubic structure at room temperature and controlled nanoscale morphology. We characterized the effect of thermal annealing in reducing and oxidizing conditions on the crystalline structure, grain dimensions, and topography. We highlight the mechanisms of film growth and phase transitions, which determine the observed interfacial morphological properties and their resilience against thermal treatments.

  8. Cluster-assembled cubic zirconia films with tunable and stable nanoscale morphology against thermal annealing

    KAUST Repository

    Borghi, F.

    2016-08-05

    Nanostructured zirconium dioxide (zirconia) films are very promising for catalysis and biotechnological applications: a precise control of the interfacial properties of the material at different length scales and, in particular, at the nanoscale, is therefore necessary. Here, we present the characterization of cluster-assembled zirconia films produced by supersonic cluster beam deposition possessing cubic structure at room temperature and controlled nanoscale morphology. We characterized the effect of thermal annealing in reducing and oxidizing conditions on the crystalline structure, grain dimensions, and topography. We highlight the mechanisms of film growth and phase transitions, which determine the observed interfacial morphological properties and their resilience against thermal treatments. Published by AIP Publishing.

  9. Non-oxidic nanoscale composites: single-crystalline titanium carbide nanocubes in hierarchical porous carbon monoliths.

    Science.gov (United States)

    Sonnenburg, Kirstin; Smarsly, Bernd M; Brezesinski, Torsten

    2009-05-07

    We report the preparation of nanoscale carbon-titanium carbide composites with carbide contents of up to 80 wt%. The synthesis yields single-crystalline TiC nanocubes 20-30 nm in diameter embedded in a hierarchical porous carbon matrix. These composites were generated in the form of cylindrical monoliths but can be produced in various shapes using modern sol-gel and nanocasting methods in conjunction with carbothermal reduction. The monolithic material is characterized by a combination of microscopy, diffraction and physisorption. Overall, the results presented in this work represent a concrete design template for the synthesis of non-oxidic nanoscale composites with high surface areas.

  10. Cluster-assembled cubic zirconia films with tunable and stable nanoscale morphology against thermal annealing

    KAUST Repository

    Borghi, F.; Sogne, Elisa; Lenardi, C.; Podestà , A.; Merlini, M.; Ducati, C.; Milani, P.

    2016-01-01

    Nanostructured zirconium dioxide (zirconia) films are very promising for catalysis and biotechnological applications: a precise control of the interfacial properties of the material at different length scales and, in particular, at the nanoscale, is therefore necessary. Here, we present the characterization of cluster-assembled zirconia films produced by supersonic cluster beam deposition possessing cubic structure at room temperature and controlled nanoscale morphology. We characterized the effect of thermal annealing in reducing and oxidizing conditions on the crystalline structure, grain dimensions, and topography. We highlight the mechanisms of film growth and phase transitions, which determine the observed interfacial morphological properties and their resilience against thermal treatments. Published by AIP Publishing.

  11. Perspectives on the Contribution of Social Science to Adapted Physical Activity: Looking Forward, Looking Back

    Science.gov (United States)

    Causgrove Dunn, Janice; Cairney, John; Zimmer, Chantelle

    2016-01-01

    In this article, we reflect on the contributions of the social sciences to the field of adapted physical activity by examining the theories and methods that have been adopted from the social science disciplines. To broaden our perspective on adapted physical activity and provide new avenues for theoretical and empirical exploration, we discuss and…

  12. An analysis of laboratory activities found in "Applications In Biology/Chemistry: A Contextual Approach to Laboratory Science"

    Science.gov (United States)

    Haskins, Sandra Sue

    The purpose of this study was to quantitatively determine whether the material found in ABC promotes scientific inquiry through the inclusion of science process skills, and to quantitatively determine the type (experimental, comparative, or descriptive) and character (wet-lab, paper and pencil, model, or computer) of laboratory activities. The research design allowed for an examination of the frequency and type of science process skills required of students in 79 laboratory activities sampled from all 12 units utilizing a modified 33-item laboratory analysis inventory (LAI) (Germane et al, 1996). Interrater reliability for the science process skills was completed on 19 of the laboratory activities with a mean score of 86.1%. Interrater reliability for the type and character of the laboratory, on the same 19 laboratory activities, was completed with mean scores of 79.0% and 96.5%, respectively. It was found that all laboratory activities provide a prelaboratory activity. In addition, the science process skill category of student performance is required most often of students with the skill of learning techniques or manipulating apparatus occurring 99% of the time. The science process skill category observed the least was student planning and design, occurring only 3% of the time. Students were rarely given the opportunity to practice science process skills such as developing and testing hypotheses through experiments they have designed. Chi-square tests, applied at the .05 level of significance, revealed that there was a significant difference in the type of laboratory activities; comparative laboratory activities appeared more often (59%). In addition the character of laboratory activities, "wet-lab" activities appeared more often (90%) than any of the others.

  13. Low Dose X-Ray Speckle Visibility Spectroscopy Reveals Nanoscale Dynamics in Radiation Sensitive Ionic Liquids

    Science.gov (United States)

    Verwohlt, Jan; Reiser, Mario; Randolph, Lisa; Matic, Aleksandar; Medina, Luis Aguilera; Madsen, Anders; Sprung, Michael; Zozulya, Alexey; Gutt, Christian

    2018-04-01

    X-ray radiation damage provides a serious bottleneck for investigating microsecond to second dynamics on nanometer length scales employing x-ray photon correlation spectroscopy. This limitation hinders the investigation of real time dynamics in most soft matter and biological materials which can tolerate only x-ray doses of kGy and below. Here, we show that this bottleneck can be overcome by low dose x-ray speckle visibility spectroscopy. Employing x-ray doses of 22-438 kGy and analyzing the sparse speckle pattern of count rates as low as 6.7 ×10-3 per pixel, we follow the slow nanoscale dynamics of an ionic liquid (IL) at the glass transition. At the prepeak of nanoscale order in the IL, we observe complex dynamics upon approaching the glass transition temperature TG with a freezing in of the alpha relaxation and a multitude of millisecond local relaxations existing well below TG . We identify this fast relaxation as being responsible for the increasing development of nanoscale order observed in ILs at temperatures below TG .

  14. A luminescent ratiometric pH sensor based on a nanoscale and biocompatible Eu/Tb-mixed MOF.

    Science.gov (United States)

    Xia, Tifeng; Zhu, Fengliang; Jiang, Ke; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2017-06-13

    The precise and real-time monitoring of localized pH changes is of great importance in many engineering and environmental fields, especially for monitoring small pH changes in biological environments and living cells. Metal-organic frameworks (MOFs) with their nanoscale processability show very promising applications in bioimaging and biomonitoring, but the fabrication of nanoscale MOFs is still a challenge. In this study, we synthesized a nanoscale mixed-lanthanide metal-organic framework by a microemulsion method. The morphology and size of the NMOF can be simply adjusted by the addition of different amounts of the CTAB surfactant. This NMOF exhibits significant pH-dependent luminescence emission, which can act as a self-referenced pH sensor based on two emissions of Tb 3+ at 545 nm and Eu 3+ at 618 nm in the pH range from 3.00 to 7.00. The MTT assay and optical microscopy assay demonstrate the low cytotoxicity and good biocompatibility of the nanosensor.

  15. Nanoscale transformation of sp2 to sp3 of graphite by slow highly charged ion irradiation

    International Nuclear Information System (INIS)

    Meguro, T.; Hida, A.; Koguchi, Y.; Miyamoto, S.; Yamamoto, Y.; Takai, H.; Maeda, K.; Aoyagi, Y.

    2003-01-01

    Nanoscale transformation of electronic states by highly charged ion (HCI) impact on graphite surfaces is described. The high potential energy of slow HCI, which induces multiple emission of electrons from the surface, provides a strong modification of the electronic states of the local area upon graphite surfaces. The HCI impact and the subsequent surface treatment either by electron injection from a scanning tunneling microscopy tip or by He-Cd laser irradiation induce a localized transition from sp 2 to sp 3 hybridization in graphite, resulting in the formation of nanoscale diamond-like structures (nanodiamond) at the impact region. From Raman spectroscopic measurements on sp 2 related peaks, it is found that the HCI irradiation creates vacancy complexes in contrast to ions having a lower charge state, which generate single vacancies. It is of interest that a single impact of HCI creates one nanodiamond structure, suggesting potential applications of HCI in nanoscale material processing

  16. Nanoscale layer-selective readout of magnetization direction from a magnetic multilayer using a spin-torque oscillator

    International Nuclear Information System (INIS)

    Suto, Hirofumi; Nagasawa, Tazumi; Kudo, Kiwamu; Mizushima, Koichi; Sato, Rie

    2014-01-01

    Technology for detecting the magnetization direction of nanoscale magnetic material is crucial for realizing high-density magnetic recording devices. Conventionally, a magnetoresistive device is used that changes its resistivity in accordance with the direction of the stray field from an objective magnet. However, when several magnets are near such a device, the superposition of stray fields from all the magnets acts on the sensor, preventing selective recognition of their individual magnetization directions. Here we introduce a novel readout method for detecting the magnetization direction of a nanoscale magnet by use of a spin-torque oscillator (STO). The principles behind this method are dynamic dipolar coupling between an STO and a nanoscale magnet, and detection of ferromagnetic resonance (FMR) of this coupled system from the STO signal. Because the STO couples with a specific magnet by tuning the STO oscillation frequency to match its FMR frequency, this readout method can selectively determine the magnetization direction of the magnet. (papers)

  17. The mechanical properties modeling of nano-scale materials by molecular dynamics

    NARCIS (Netherlands)

    Yuan, C.; Driel, W.D. van; Poelma, R.; Zhang, G.Q.

    2012-01-01

    We propose a molecular modeling strategy which is capable of mod-eling the mechanical properties on nano-scale low-dielectric (low-k) materials. Such modeling strategy has been also validated by the bulking force of carbon nano tube (CNT). This modeling framework consists of model generation method,

  18. Science Serving the Nation: The Impact of Basic Research

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-01-01

    Impacts: The BES program supports basic research that underpins a broad range of energy technologies. Research in materials sciences and engineering leads to the development of materials that improve the efficiency, economy, environmental acceptability, and safety of energy generation, conversion, transmission, storage, and use. For example, advances in superconductivity have been introduced commercially in a number of demonstration projects around the country. Improvements in alloy design for high temperature applications are used in commercial furnaces and in green technologies such as lead-free solder. Research in chemistry has led to advances such as efficient combustion systems with reduced emissions of pollutants; new solar photoconversion processes; improved catalysts for the production of fuels and chemicals; and better separations and analytical methods for applications in energy processes, environmental remediation, and waste management. Research in geosciences results in advanced monitoring and measurement techniques for reservoir definition and an understanding of the fluid dynamics of complex fluids through porous and fractured subsurface rock. Research in the molecular and biochemical nature of photosynthesis aids the development of solar photo-energy conversion. The BES program also plays a major role in enabling the nanoscale revolution. The importance of nanoscience to future energy technologies is clearly reflected by the fact that all of the elementary steps of energy conversion (e.g., charge transfer, molecular rearrangement, and chemical reactions) take place on the nanoscale. The development of new nanoscale materials, as well as the methods to characterize, manipulate, and assemble them, create an entirely new paradigm for developing new and revolutionary energy technologies.

  19. Suited for spacewalking: Teacher's guide with activities for physical and life science

    Science.gov (United States)

    Vogt, Gregory L.; Manning, Cheryl A.; Rosenberg, Carla B.

    1994-01-01

    Space walking has captured the imagination of generations of children and adults since science-fiction authors first placed their characters on the Moon. This publication is an activity guide for teachers interested in using the intense interest many children have in space exploration as a launching point for exciting hands-on learning opportunities. The guide begins with brief discussions of the space environment, the history of space walking, the Space Shuttle spacesuit, and working in space. These are followed by a series of activities that enable children to explore the space environment as well as the science and technology behind the functions of spacesuits. The activities are not rated for specific grade levels because they can be adapted for students of many ages. The chart on curriculum application at the back of the book is designed to help teachers incorporate activities into various subject areas.

  20. Nanoscale Dewetting Transition in Protein Complex Folding

    Science.gov (United States)

    Hua, Lan; Huang, Xuhui; Liu, Pu; Zhou, Ruhong; Berne, Bruce J.

    2011-01-01

    In a previous study, a surprising drying transition was observed to take place inside the nanoscale hydrophobic channel in the tetramer of the protein melittin. The goal of this paper is to determine if there are other protein complexes capable of displaying a dewetting transition during their final stage of folding. We searched the entire protein data bank (PDB) for all possible candidates, including protein tetramers, dimers, and two-domain proteins, and then performed the molecular dynamics (MD) simulations on the top candidates identified by a simple hydrophobic scoring function based on aligned hydrophobic surface areas. Our large scale MD simulations found several more proteins, including three tetramers, six dimers, and two two-domain proteins, which display a nanoscale dewetting transition in their final stage of folding. Even though the scoring function alone is not sufficient (i.e., a high score is necessary but not sufficient) in identifying the dewetting candidates, it does provide useful insights into the features of complex interfaces needed for dewetting. All top candidates have two features in common: (1) large aligned (matched) hydrophobic areas between two corresponding surfaces, and (2) large connected hydrophobic areas on the same surface. We have also studied the effect on dewetting of different water models and different treatments of the long-range electrostatic interactions (cutoff vs PME), and found the dewetting phenomena is fairly robust. This work presents a few proteins other than melittin tetramer for further experimental studies of the role of dewetting in the end stages of protein folding. PMID:17608515

  1. J-ACTINET activities of training and education for actinide science research

    International Nuclear Information System (INIS)

    Miato, Kazuo; Konashi, Kenji; Yamana, Hajimu; Yamanaka, Shinsuke; Nagasaki, Shinya; Ikeda, Yasuhisa; Sato, Seichi; Arita, Yuji; Idemitsu, Kazuya; Koyama, Tadafumi

    2011-01-01

    Actinide science research is indispensable to maintain sustainable development of innovative nuclear technology, especially advanced fuels, partitioning/reprocessing, and waste management. For actinide science research, special facilities with containment and radiation shields are needed to handle actinide materials since actinide elements are γ-, α- and neutron-emitters. The number of facilities for actinide science research has been decreased, especially in universities, due to the high maintenance cost. J-ACTINET was established in 2008 to promote and facilitate actinide science research in close cooperation with the facilities and to foster many of young scientists and engineers to be actively engaged in the fields of actinide science. The research program was carried out, through which young researchers were expected to learn how to make experiments with advanced experimental tools and to broaden their horizons. The summer schools and computational science school were held to provide students, graduate students, and young researchers with the opportunities to come into contact with actinide science research. In these schools, not only the lectures, but also the practical exercises were made as essential part. The overseas dispatch program was also carried out, where graduate students and young researchers were sent to the international summer schools and conferences. (author)

  2. Facile approach to the fabrication of a micropattern possessing nanoscale substructure.

    Science.gov (United States)

    Ji, Qiang; Jiang, Xuesong; Yin, Jie

    2007-12-04

    On the basis of the combined technologies of photolithography and reaction-induced phase separation (RIPS), a facile approach has been successfully developed for the fabrication of a micropattern possessing nanoscale substructure on the thin film surface. This approach involves three steps. In the first step, a thin film was prepared by spin coating from a solution of a commercial random copolymer, polystyrene-r-poly(methyl methacrylate) (PS-r-PMMA) and a commercial crosslinker, trimethylolpropane triacrylate (TMPTA). In the second step, photolithograph was performed with the thin film using a 250 W high-pressure mercury lamp to produce the micropattern. Finally, the resulting micropattern was annealed at 200 degrees C for a certain time, and reaction-induced phase separation occurred. After soaking in chloroform for 4 h, nanoscale substructure was obtained. The whole processes were traced by atomic force microscopy (AFM), X-ray photoelectron spectrometry (XPS), and Fourier transform infrared (FTIR) spectroscopy, and the results supported the proposed structure.

  3. Gifted and Talented Students' Views about Biology Activities in a Science and Art Center

    Science.gov (United States)

    Özarslan, Murat; Çetin, Gülcan

    2018-01-01

    The aim of the study was to determine gifted and talented students' views about biology activities in a science and art center. The study was conducted with 26 gifted and talented students who studied at a science and art center in southwestern Turkey. Students studied animal and plant genus and species in biology activities. Data were collected…

  4. Nanoscale capacitance imaging with attofarad resolution using ac current sensing atomic force microscopy

    International Nuclear Information System (INIS)

    Fumagalli, L; Ferrari, G; Sampietro, M; Casuso, I; MartInez, E; Samitier, J; Gomila, G

    2006-01-01

    Nanoscale capacitance imaging with attofarad resolution (∼1 aF) of a nano-structured oxide thin film, using ac current sensing atomic force microscopy, is reported. Capacitance images are shown to follow the topographic profile of the oxide closely, with nanometre vertical resolution. A comparison between experimental data and theoretical models shows that the capacitance variations observed in the measurements can be mainly associated with the capacitance probed by the tip apex and not with positional changes of stray capacitance contributions. Capacitance versus distance measurements further support this conclusion. The application of this technique to the characterization of samples with non-voltage-dependent capacitance, such as very thin dielectric films, self-assembled monolayers and biological membranes, can provide new insight into the dielectric properties at the nanoscale

  5. Nanoscale capacitance imaging with attofarad resolution using ac current sensing atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fumagalli, L [Dipartimento di Elettronica e Informazione, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 (Italy); Ferrari, G [Dipartimento di Elettronica e Informazione, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 (Italy); Sampietro, M [Dipartimento di Elettronica e Informazione, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 (Italy); Casuso, I [Departament d' Electronica, Universitat de Barcelona, C/MartIi Franques 1, 08028 Barcelona (Spain); MartInez, E [Plataforma de Nanotecnologia, Parc Cientific de Barcelona, C/ Josep Samitier 1-5, 08028-Barcelona (Spain); Samitier, J [Departament d' Electronica, Universitat de Barcelona, C/MartIi Franques 1, 08028 Barcelona (Spain); Gomila, G [Departament d' Electronica, Universitat de Barcelona, C/MartIi Franques 1, 08028 Barcelona (Spain)

    2006-09-28

    Nanoscale capacitance imaging with attofarad resolution ({approx}1 aF) of a nano-structured oxide thin film, using ac current sensing atomic force microscopy, is reported. Capacitance images are shown to follow the topographic profile of the oxide closely, with nanometre vertical resolution. A comparison between experimental data and theoretical models shows that the capacitance variations observed in the measurements can be mainly associated with the capacitance probed by the tip apex and not with positional changes of stray capacitance contributions. Capacitance versus distance measurements further support this conclusion. The application of this technique to the characterization of samples with non-voltage-dependent capacitance, such as very thin dielectric films, self-assembled monolayers and biological membranes, can provide new insight into the dielectric properties at the nanoscale.

  6. Removal of 4-chlorophenol from aqueous solution by granular activated carbon/nanoscale zero valent iron based on Response Surface Modeling

    Directory of Open Access Journals (Sweden)

    Majlesi Monireh

    2017-12-01

    Full Text Available The phenolic compounds are known as priority pollutants, even in low concentrations, as a result of their toxicity and non-biodegradability. For this reason, strict standards have been established for them. In addition, chlorophenols are placed in the 38th to 43th in highest priority order of toxic pollutants. As a consequence, contaminated water or wastewaters with phenolic compounds have to be treated before discharging into the receiving water. In this study, Response Surface Methodology (RSM has been used in order to optimize the effect of main operational variables responsible for the higher 4-chlorophenol removal by Activated Carbon-Supported Nanoscale Zero Valent Iron (AC/NZVI. A Box-Behnken factorial Design (BBD with three levels was applied to optimize the initial concentration, time, pH, and adsorbent dose. The characterization of adsorbents was conducted by using SEM-EDS and XRD analyses. Furthermore, the adsorption isotherm and kinetics of 4-chlorophenol on AC and AC/NZVI under various conditions were studied. The model anticipated 100% removal efficiency for AC/NZVI at the optimum concentration (5.48 mg 4-chlorophenol/L, pH (5.44, contact time (44.7 min and dose (0.65g/L. Analysis of the response surface quadratic model signified that the experiments are accurate and the model is highly significant. Moreover, the synthetic adsorbent is highly efficient in removing of 4-chlorophenol.

  7. Student Buy-In to Active Learning in a College Science Course

    Science.gov (United States)

    Cavanagh, Andrew J.; Aragón, Oriana R.; Chen, Xinnian; Couch, Brian; Durham, Mary; Bobrownicki, Aiyana; Hanauer, David I.; Graham, Mark J.

    2016-01-01

    The benefits of introducing active learning in college science courses are well established, yet more needs to be understood about student buy-in to active learning and how that process of buy-in might relate to student outcomes. We test the exposure-persuasion-identification-commitment (EPIC) process model of buy-in, here applied to student (n =…

  8. Uncovering Students' Environmental Identity: An Exploration of Activities in an Environmental Science Course

    Science.gov (United States)

    Blatt, Erica

    2014-01-01

    This study at a public high school in the Northeastern United States explores how students' environmental identities are affected by various activities in an Environmental Science course. Data was collected as part of an ethnographic study involving an Environmental Science teacher and her tenth-twelfth grade students. The results focus on…

  9. Magneto-optics of nanoscale Bi:YIG films.

    Science.gov (United States)

    Berzhansky, Vladimir; Mikhailova, Tatyana; Shaposhnikov, Alexander; Prokopov, Anatoly; Karavainikov, Andrey; Kotov, Viacheslav; Balabanov, Dmitry; Burkov, Vladimir

    2013-09-10

    Magnetic circular dichroism in the spectral region from 270 to 850 nm and Faraday rotation at the wavelength of 655 nm in ultrathin (1.5-92.8 nm) films prepared by reactive ion beam sputtering of target of nominal composition Bi2.8Y0.2Fe5O12 were studied. The observed effects of the "blue shift," inversion of the signs and change in the intensity of magneto-optical transitions, are discussed. It is demonstrated that all studied nanoscale films reveal magnetic properties-and their composition depends on the method of substrate surface pretreatment.

  10. Integrating Micro- or Nanoscale Encapsulation Technology with Vitreous Cryopreservation: A New Strategy to Improve Biopreservation.

    Science.gov (United States)

    Zheng, Y Y; Zhao, G

      BACKGROUND: None-uniform distributions of temperatures, limited freezing and thawing rates, and thermal stresses are three main hindering factors for successful vitreous cryopreservation of mass volume of biosamples. Micro- and nanoscale encapsulation, owning the intrinsic features to avoid those limitations introduced by the traditional approaches, has been opened up a new way for effective and high-efficiency biopreservation. This short review article summarizes recent advances in cell encapsulation technology for biopreservation by manipulating cells and biological agents in micro- or nanoscale volume droplets and microgels, and discusses its promising applications for future vitreous cryopreservation.

  11. Primary Science Interview: Science Sparks

    Science.gov (United States)

    Bianchi, Lynne

    2016-01-01

    In this "Primary Science" interview, Lynne Bianchi talks with Emma Vanstone about "Science Sparks," which is a website full of creative, fun, and exciting science activity ideas for children of primary-school age. "Science Sparks" started with the aim of inspiring more parents to do science at home with their…

  12. Incorporating nanoscale science and technology into secondary school curriculum: Views of nano-trained science teachers

    Directory of Open Access Journals (Sweden)

    Antti Laherto

    2011-09-01

    Full Text Available The growing societal significance of nanoscience and nanotechnology (NST entails needs for addressing these topics in school curricula. This study lays groundwork for responding to those needs in Finland. The purpose was to analyse the appropriateness of NST for secondary school curriculum contents. First, a week-long in-service teacher training course was arranged on content knowledge of NST. After attending the course, 23 experienced science teachers were surveyed regarding their views on the educational significance of these issues, and on prospects for including them into the curriculum. A questionnaire with open-ended questions was used. Qualitative content analysis of the responses revealed that the respondents considered NST as desirable contents for secondary school, but arranging instruction is problematic. The teachers emphasised the educational significance of many applications, scientific principles and ethical issues related to NST. The outcomes are discussed with reference to recent studies on teachers’ barriers and educational concerns regarding NST.

  13. Optical tracking of nanoscale particles in microscale environments

    Science.gov (United States)

    Mathai, P. P.; Liddle, J. A.; Stavis, S. M.

    2016-03-01

    The trajectories of nanoscale particles through microscale environments record useful information about both the particles and the environments. Optical microscopes provide efficient access to this information through measurements of light in the far field from nanoparticles. Such measurements necessarily involve trade-offs in tracking capabilities. This article presents a measurement framework, based on information theory, that facilitates a more systematic understanding of such trade-offs to rationally design tracking systems for diverse applications. This framework includes the degrees of freedom of optical microscopes, which determine the limitations of tracking measurements in theory. In the laboratory, tracking systems are assemblies of sources and sensors, optics and stages, and nanoparticle emitters. The combined characteristics of such systems determine the limitations of tracking measurements in practice. This article reviews this tracking hardware with a focus on the essential functions of nanoparticles as optical emitters and microenvironmental probes. Within these theoretical and practical limitations, experimentalists have implemented a variety of tracking systems with different capabilities. This article reviews a selection of apparatuses and techniques for tracking multiple and single particles by tuning illumination and detection, and by using feedback and confinement to improve the measurements. Prior information is also useful in many tracking systems and measurements, which apply across a broad spectrum of science and technology. In the context of the framework and review of apparatuses and techniques, this article reviews a selection of applications, with particle diffusion serving as a prelude to tracking measurements in biological, fluid, and material systems, fabrication and assembly processes, and engineered devices. In so doing, this review identifies trends and gaps in particle tracking that might influence future research.

  14. Nanoscale Cross-Point Resistive Switching Memory Comprising p-Type SnO Bilayers

    KAUST Repository

    Hota, Mrinal Kanti; Hedhili, Mohamed N.; Wang, Qingxiao; Melnikov, Vasily; Mohammed, Omar F.; Alshareef, Husam N.

    2015-01-01

    Reproducible low-voltage bipolar resistive switching is reported in bilayer structures of p-type SnO films. Specifically, a bilayer homojunction comprising SnOx (oxygen-rich) and SnOy (oxygen-deficient) in nanoscale cross-point (300 × 300 nm2

  15. Informing, involving or engaging? Science communication, in the ages of atom-, bio- and nanotechnology.

    Science.gov (United States)

    Kurath, Monika; Gisler, Priska

    2009-09-01

    Science communication has shifted considerably in Europe over the last decades. Three technology controversies on atoms, genes, and nanoscale sciences and nanotechnologies (NST) turned the style of communication from one-way information, participation and dialogues to the idea of an early and more democratic engagement of the public. Analyzing science communication developing over the three controversies, this article shows that what happened in one technology field fed forward to and contributed to shaping the subsequent field and that communication was initiated at a progressively earlier stage of technology development. The article concludes with an empirical analysis of six public engagement projects in NST, saying that the shift towards more democratic engagement of the public hasn't been as profound and complete as has been thought. This is particularly due to the continuing adoption of a simplistic contrast structure that opposes science and the public as two self-contained, antagonistic social entities.

  16. Invitations to Life's Diversity. Teacher-Friendly Science Activities with Reproducible Handouts in English and Spanish. Grades 3-5. Living Things Science Series.

    Science.gov (United States)

    Camp, Carole Ann, Ed.

    This booklet, one of six in the Living Things Science series, presents activities about diversity and classification of living things which address basic "Benchmarks" suggested by the American Association for the Advancement of Science for the Living Environment for grades 3-5. Contents include background information, vocabulary (in…

  17. Science Hobbyists: Active Users of the Science-Learning Ecosystem

    Science.gov (United States)

    Corin, Elysa N.; Jones, M. Gail; Andre, Thomas; Childers, Gina M.; Stevens, Vanessa

    2017-01-01

    Science hobbyists engage in self-directed, free-choice science learning and many have considerable expertise in their hobby area. This study focused on astronomy and birding hobbyists and examined how they used organizations to support their hobby engagement. Interviews were conducted with 58 amateur astronomers and 49 birders from the midwestern…

  18. Science Fiction and Science Education.

    Science.gov (United States)

    Cavanaugh, Terence

    2002-01-01

    Uses science fiction films such as "Jurassic Park" or "Anaconda" to teach science concepts while fostering student interest. Advocates science fiction as a teaching tool to improve learning and motivation. Describes how to use science fiction in the classroom with the sample activity Twister. (YDS)

  19. On the role of weak interface in crack blunting process in nanoscale layered composites

    Science.gov (United States)

    Li, Yi; Zhou, Qing; Zhang, Shuang; Huang, Ping; Xu, Kewei; Wang, Fei; Lu, Tianjian

    2018-03-01

    Heterointerface in a nanoscale metallic layered composite could improve its crack resistance. However, the influence of metallic interface structures on crack propagation has not been well understood at atomic scale. By using the method of molecular dynamics (MD) simulation, the crack propagation behavior in Cu-Nb bilayer is compared with that in Cu-Ni bilayer. We find that the weak Cu-Nb interface plays an important role in hindering crack propagation in two ways: (i) dislocation nucleation at the interface releases stress concentration for the crack to propagate; (ii) the easily sheared weak incoherent interface blunts the crack tip. The results are helpful for understanding the interface structure dependent crack resistance of nanoscale bicrystal interfaces.

  20. Fabrication of nanoscale speckle using broad ion beam milling on polymers for deformation analysis

    Directory of Open Access Journals (Sweden)

    Qinghua Wang

    2016-07-01

    Full Text Available We first report a fabrication technique of nanoscale speckle patterns on polymers using broad ion beam milling. The proposed technique is simple and low-cost to produce speckles ranging from dozens of nanometers to less than three micrometers in a large area of several millimeters. Random patterns were successfully produced with an argon (Ar ion beam on the surfaces of four kinds of polymers: the epoxy matrix of carbon fiber reinforced plastic, polyester, polyvinyl formal-acetal, and polyimide. The speckle morphologies slightly vary with different polymers. The fabricated speckle patterns have good time stability and are promising to be used to measure the nanoscale deformations of polymers using the digital image correlation method.