Detecting Upward Directed Charged Particle Fluxes in the Mars Science Laboratory Radiation Assessment Detector

NASA Astrophysics Data System (ADS)

Appel, J. K.; Köehler, J.; Guo, J.; Ehresmann, B.; Zeitlin, C.; Matthiä, D.; Lohf, H.; Wimmer-Schweingruber, R. F.; Hassler, D.; Brinza, D. E.; Böhm, E.; Böttcher, S.; Martin, C.; Burmeister, S.; Reitz, G.; Rafkin, S.; Posner, A.; Peterson, J.; Weigle, G.

2018-01-01

The Mars Science Laboratory rover Curiosity, operating on the surface of Mars, is exposed to radiation fluxes from above and below. Galactic Cosmic Rays travel through the Martian atmosphere, producing a modified spectrum consisting of both primary and secondary particles at ground level. These particles produce an upward directed secondary particle spectrum as they interact with the Martian soil. Here we develop a method to distinguish the upward and downward directed particle fluxes in the Radiation Assessment Detector (RAD) instrument, verify it using data taken during the cruise to Mars, and apply it to data taken on the Martian surface. We use a combination of Geant4 and Planetocosmics modeling to find discrimination criteria for the flux directions. After developing models of the cruise phase and surface shielding conditions, we compare model-predicted values for the ratio of upward to downward flux with those found in RAD observation data. Given the quality of available information on Mars Science Laboratory spacecraft and rover composition, we find generally reasonable agreement between our models and RAD observation data. This demonstrates the feasibility of the method developed and tested here. We additionally note that the method can also be used to extend the measurement range and capabilities of the RAD instrument to higher energies.

Science and Technology Highlights | NREL

Science.gov Websites

Leads to Enhanced Upgrading Methods NREL's efforts to standardize techniques for bio-oil analysis inform enhanced modeling capability and affordable methods to increase energy efficiency. December 2012 NREL Meets Performance Demands of Advanced Lithium-ion Batteries Novel surface modification methods are

EDITORIAL: Focus on Advances in Surface and Interface Science 2008 FOCUS ON ADVANCES IN SURFACE AND INTERFACE SCIENCE 2008

NASA Astrophysics Data System (ADS)

Scheffler, Matthias; Schneider, Wolf-Dieter

2008-12-01

Basic research in surface and interface science is highly interdisciplinary, covering the fields of physics, chemistry, biophysics, geo-, atmospheric and environmental sciences, material science, chemical engineering, and more. The various phenomena are interesting by themselves, and they are most important in nearly all modern technologies, as for example electronic, magnetic, and optical devices, sensors, catalysts, lubricants, hard and thermal-barrier coatings, protection against corrosion and crack formation under harsh environments. In fact, detailed understanding of the elementary processes at surfaces is necessary to support and to advance the high technology that very much founds the prosperity and lifestyle of our society. Current state-of-the-art experimental studies of elementary processes at surfaces, of surface properties and functions employ a variety of sophisticated tools. Some are capable of revealing the location and motion of individual atoms. Others measure excitations (electronic, magnetic and vibronic), employing, for example, special light sources such as synchrotrons, high magnetic fields, or free electron lasers. The surprising variety of intriguing physical phenomena at surfaces, interfaces, and nanostructures also pose a persistent challenge for the development of theoretical descriptions, methods, and even basic physical concepts. This second focus issue on the topic of 'Advances in Surface and Interface Science' in New Journal of Physics, following on from last year's successful collection, provides an exciting synoptic view on the latest pertinent developments in the field. Focus on Advances in Surface and Interface Science 2008 Contents Organic layers at metal/electrolyte interfaces: molecular structure and reactivity of viologen monolayers Stephan Breuer, Duc T Pham, Sascha Huemann, Knud Gentz, Caroline Zoerlein, Ralf Hunger, Klaus Wandelt and Peter Broekmann Spin polarized d surface resonance state of fcc Co/Cu(001) K Miyamoto, K Iori, K Sakamoto, H Narita, A Kimura, M Taniguchi, S Qiao, K Hasegawa, K Shimada, H Namatame and S Blügel Activated associative desorption of C + O → CO from Ru(001) induced by femtosecond laser pulses S Wagner, H Öström, A Kaebe, M Krenz, M Wolf, A C Luntz and C Frischkorn Surface structure of Sn-doped In2O3 (111) thin films by STM Erie H Morales, Yunbin He, Mykola Vinnichenko, Bernard Delley and Ulrike Diebold Coulomb oscillations in three-layer graphene nanostructures J Güttinger, C Stampfer, F Molitor, D Graf, T Ihn and K Ensslin Adsorption processes of hydrogen molecules on SiC(001), Si(001) and C(001) surfaces Xiangyang Peng, Peter Krüger and Johannes Pollmann Fermi surface nesting in several transition metal dichalcogenides D S Inosov, V B Zabolotnyy, D V Evtushinsky, A A Kordyuk, B Büchner, R Follath, H Berger and S V Borisenko Probing molecule-surface interactions through ultra-fast adsorbate dynamics: propane/Pt(111) A P Jardine, H Hedgeland, D Ward, Y Xiaoqing, W Allison, J Ellis and G Alexandrowicz A novel method achieving ultra-high geometrical resolution in scanning tunnelling microscopy R Temirov, S Soubatch, O Neucheva, A C Lassise and F S Tautz

Adsorption and self-assembly of bio-organic molecules at model surfaces: A route towards increased complexity

NASA Astrophysics Data System (ADS)

Costa, Dominique; Pradier, Claire-Marie; Tielens, Frederik; Savio, Letizia

2015-12-01

Understanding the bio-physical-chemical interactions at nanostructured biointerfaces and the assembly mechanisms of so-called hybrid nano-composites is nowadays a key issue for nanoscience in view of the many possible applications foreseen. The contribution of surface science in this field is noteworthy since, using a bottom-up approach, it allows the investigation of the fundamental processes at the basis of complex interfacial phenomena and thus it helps to unravel the elementary mechanisms governing them. Nowadays it is well demonstrated that a wide variety of different molecular assemblies can form upon adsorption of small biomolecules at surfaces. The geometry of such self-organized structures can often be tuned by a careful control of the experimental conditions during the deposition process. Indeed an impressive number of studies exists (both experimental and - to a lesser extent - theoretical), which demonstrates the ability of molecular self-assembly to create different structural motifs in a more or less predictable manner, by tuning the molecular building blocks as well as the metallic substrate. In this frame, amino acids and small peptides at surfaces are key, basic, systems to be studied. The amino acids structure is simple enough to serve as a model for the chemisorption of biofunctional molecules, but their adsorption at surfaces has applications in surface functionalization, in enantiospecific catalysis, biosensing, shape control of nanoparticles or in emerging fields such as "green" corrosion inhibition. In this paper we review the most recent advances in this field. We shall start from the adsorption of amino acids at metal surfaces and we will evolve then in the direction of more complex systems, in the light of the latest improvements of surface science techniques and of computational methods. On one side, we will focus on amino acids adsorption at oxide surfaces, on the other on peptide adsorption both at metal and oxide substrates. Particular attention will be drawn to the added value provided by the combination of several experimental surface science techniques and to the precious contribution of advanced complementary computational methods to resolve the details of systems of increased complexity. Finally, some hints on experiments performed in presence of water and then characterized in UHV and on the related theoretical work will be presented. This is a further step towards a better approximation of real biological systems. However, since the methods employed are often not typical of surface science, this topic is not developed in detail.

Computational techniques in tribology and material science at the atomic level

NASA Technical Reports Server (NTRS)

Ferrante, J.; Bozzolo, G. H.

1992-01-01

Computations in tribology and material science at the atomic level present considerable difficulties. Computational techniques ranging from first-principles to semi-empirical and their limitations are discussed. Example calculations of metallic surface energies using semi-empirical techniques are presented. Finally, application of the methods to calculation of adhesion and friction are presented.

Decoupled Method for Reconstruction of Surface Conditions From Internal Temperatures On Ablative Materials With Uncertain Recession Model

NASA Technical Reports Server (NTRS)

Oliver, A. Brandon

2017-01-01

Obtaining measurements of flight environments on ablative heat shields is both critical for spacecraft development and extremely challenging due to the harsh heating environment and surface recession. Thermocouples installed several millimeters below the surface are commonly used to measure the heat shield temperature response, but an ill-posed inverse heat conduction problem must be solved to reconstruct the surface heating environment from these measurements. Ablation can contribute substantially to the measurement response making solutions to the inverse problem strongly dependent on the recession model, which is often poorly characterized. To enable efficient surface reconstruction for recession model sensitivity analysis, a method for decoupling the surface recession evaluation from the inverse heat conduction problem is presented. The decoupled method is shown to provide reconstructions of equivalent accuracy to the traditional coupled method but with substantially reduced computational effort. These methods are applied to reconstruct the environments on the Mars Science Laboratory heat shield using diffusion limit and kinetically limited recession models.

Method and System for Producing Full Motion Media to Display on a Spherical Surface

NASA Technical Reports Server (NTRS)

Starobin, Michael A. (Inventor)

2015-01-01

A method and system for producing full motion media for display on a spherical surface is described. The method may include selecting a subject of full motion media for display on a spherical surface. The method may then include capturing the selected subject as full motion media (e.g., full motion video) in a rectilinear domain. The method may then include processing the full motion media in the rectilinear domain for display on a spherical surface, such as by orienting the full motion media, adding rotation to the full motion media, processing edges of the full motion media, and/or distorting the full motion media in the rectilinear domain for instance. After processing the full motion media, the method may additionally include providing the processed full motion media to a spherical projection system, such as a Science on a Sphere system.

Mass Spectrometry as a Preparative Tool for the Surface Science of Large Molecules

NASA Astrophysics Data System (ADS)

Rauschenbach, Stephan; Ternes, Markus; Harnau, Ludger; Kern, Klaus

2016-06-01

Measuring and understanding the complexity that arises when nanostructures interact with their environment are one of the major current challenges of nanoscale science and technology. High-resolution microscopy methods such as scanning probe microscopy have the capacity to investigate nanoscale systems with ultimate precision, for which, however, atomic scale precise preparation methods of surface science are a necessity. Preparative mass spectrometry (pMS), defined as the controlled deposition of m/z filtered ion beams, with soft ionization sources links the world of large, biological molecules and surface science, enabling atomic scale chemical control of molecular deposition in ultrahigh vacuum (UHV). Here we explore the application of high-resolution scanning probe microscopy and spectroscopy to the characterization of structure and properties of large molecules. We introduce the fundamental principles of the combined experiments electrospray ion beam deposition and scanning tunneling microscopy. Examples for the deposition and investigation of single particles, for layer and film growth, and for the investigation of electronic properties of individual nonvolatile molecules show that state-of-the-art pMS technology provides a platform analog to thermal evaporation in conventional molecular beam epitaxy. Additionally, it offers additional, unique features due to the use of charged polyatomic particles. This new field is an enormous sandbox for novel molecular materials research and demands the development of advanced molecular ion beam technology.

Earth Systems Science in an Integrated Science Content and Methods Course for Elementary Education Majors

NASA Astrophysics Data System (ADS)

Madsen, J. A.; Allen, D. E.; Donham, R. S.; Fifield, S. J.; Shipman, H. L.; Ford, D. J.; Dagher, Z. R.

2004-12-01

With funding from the National Science Foundation, we have designed an integrated science content and methods course for sophomore-level elementary teacher education (ETE) majors. This course, the Science Semester, is a 15-credit sequence that consists of three science content courses (Earth, Life, and Physical Science) and a science teaching methods course. The goal of this integrated science and education methods curriculum is to foster holistic understandings of science and pedagogy that future elementary teachers need to effectively use inquiry-based approaches in teaching science in their classrooms. During the Science Semester, traditional subject matter boundaries are crossed to stress shared themes that teachers must understand to teach standards-based elementary science. Exemplary approaches that support both learning science and learning how to teach science are used. In the science courses, students work collaboratively on multidisciplinary problem-based learning (PBL) activities that place science concepts in authentic contexts and build learning skills. In the methods course, students critically explore the theory and practice of elementary science teaching, drawing on their shared experiences of inquiry learning in the science courses. An earth system science approach is ideally adapted for the integrated, inquiry-based learning that takes place during the Science Semester. The PBL investigations that are the hallmark of the Science Semester provide the backdrop through which fundamental earth system interactions can be studied. For example in the PBL investigation that focuses on energy, the carbon cycle is examined as it relates to fossil fuels. In another PBL investigation centered on kids, cancer, and the environment, the hydrologic cycle with emphasis on surface runoff and ground water contamination is studied. In a PBL investigation that has students learning about the Delaware Bay ecosystem through the story of the horseshoe crab and the biome that swirls around this remarkable arthropod, students are exposed to interactions between the hydrosphere, atmosphere, and geosphere and they examine ways in which climate change can affect this ecosystem.

From 'just the facts' to 'more theory and methods, please': The evolution of the research article in Administrative Science Quarterly, 1956-2008.

PubMed

Strang, David; Siler, Kyle

2017-08-01

This paper analyzes the surface structure of research articles published in Administrative Science Quarterly between 1956 and 2008. The period is marked by a shift from essays that interweave theory, methods and results to experimental reports that separate them. There is dramatic growth in the size of theory, methods and discussion sections, accompanied by a shrinking results section. Bibliographic references and hypotheses expand in number and become concentrated in theory sections. Article structure varies primarily with historical time and also with research design (broadly, quantitative vs. qualitative) and the author's background. We link trends in article structure to the disciplinary development of organization studies and consider its distinctive trajectory relative to physical science.

Ultra-short wavelength x-ray system

DOEpatents

Umstadter, Donald [Ann Arbor, MI; He, Fei [Ann Arbor, MI; Lau, Yue-Ying [Potomac, MD

2008-01-22

A method and apparatus to generate a beam of coherent light including x-rays or XUV by colliding a high-intensity laser pulse with an electron beam that is accelerated by a synchronized laser pulse. Applications include x-ray and EUV lithography, protein structural analysis, plasma diagnostics, x-ray diffraction, crack analysis, non-destructive testing, surface science and ultrafast science.

Optical Field Confinement Enhanced Single ZnO Microrod UV Photodetector

NASA Astrophysics Data System (ADS)

Wei, Ming; Xu, Chun-Xiang; Qin, Fei-Fei; Gowri Manohari, Arumugam; Lu, Jun-Feng; Zhu, Qiu-Xiang

2017-07-01

ZnO microrods are synthesized using the vapor phase transport method, and the magnetron sputtering is used to decorate the Al nanoparticles (NPs) on a single ZnO microrod. The micro-PL and I-V responses are measured before and after the decoration of Al NPs. The FDTD stimulation is also carried out to demonstrate the optical field distribution around the decoration of Al NPs on the surface of a ZnO microrod. Due to an implementation of Al NPs, the ZnO microrod exhibits an improved photoresponse behavior. In addition, Al NPs induced localized surface plasmons (LSPs) as well as improved optical field confinement can be ascribed to an enhancement of ultraviolet (UV) response. This research provides a method for improving the responsivity of photodetectors. Supported by the National Natural Science Foundation of China under Grant Nos 61475035 and 61275054, the Science and Technology Support Program of Jiangsu Province under Grant No BE2016177, and the Collaborative Innovation Center of Suzhou Nano Science and Technology.

An RBF-FD closest point method for solving PDEs on surfaces

NASA Astrophysics Data System (ADS)

Petras, A.; Ling, L.; Ruuth, S. J.

2018-10-01

Partial differential equations (PDEs) on surfaces appear in many applications throughout the natural and applied sciences. The classical closest point method (Ruuth and Merriman (2008) [17]) is an embedding method for solving PDEs on surfaces using standard finite difference schemes. In this paper, we formulate an explicit closest point method using finite difference schemes derived from radial basis functions (RBF-FD). Unlike the orthogonal gradients method (Piret (2012) [22]), our proposed method uses RBF centers on regular grid nodes. This formulation not only reduces the computational cost but also avoids the ill-conditioning from point clustering on the surface and is more natural to couple with a grid based manifold evolution algorithm (Leung and Zhao (2009) [26]). When compared to the standard finite difference discretization of the closest point method, the proposed method requires a smaller computational domain surrounding the surface, resulting in a decrease in the number of sampling points on the surface. In addition, higher-order schemes can easily be constructed by increasing the number of points in the RBF-FD stencil. Applications to a variety of examples are provided to illustrate the numerical convergence of the method.

Depositing aluminum as sacrificial metal to reduce metal-graphene contact resistance

NASA Astrophysics Data System (ADS)

Da-cheng, Mao; Zhi, Jin; Shao-qing, Wang; Da-yong, Zhang; Jing-yuan, Shi; Song-ang, Peng; Xuan-yun, Wang

2016-07-01

Reducing the contact resistance without degrading the mobility property is crucial to achieve high-performance graphene field effect transistors. Also, the idea of modifying the graphene surface by etching away the deposited metal provides a new angle to achieve this goal. We exploit this idea by providing a new process method which reduces the contact resistance from 597 Ω·μm to sub 200 Ω·μm while no degradation of mobility is observed in the devices. This simple process method avoids the drawbacks of uncontrollability, ineffectiveness, and trade-off with mobility which often exist in the previously proposed methods. Project by the National Science and Technology Major Project, China (Grant No. 2011ZX02707.3), the National Natural Science Foundation of China (Grant No. 61136005), the Chinese Academy of Sciences (Grant No. KGZD-EW-303), and the Project of Beijing Municipal Science and Technology Commission, China (Grant No. Z151100003515003).

Neuston Trawl and Whole Water Samples: A Comparison of Microplastic Sampling Techniques in The Gulf of Maine and Their Application to Citizen-Driven Science

NASA Astrophysics Data System (ADS)

Kautz, M.

2016-12-01

Microplastic research in aquatic environments has quickly evolved over the last decade. To have meaningful inter-study comparisons, it is necessary to define methodological criteria for both the sampling and sorting of microplastics. The most common sampling method used for sea surface samples has traditionally been a neuston net (NN) tow. Originally designed for plankton collection, neuston tows allow for a large volume of water to be sampled and can be coupled with phytoplankton monitoring. The widespread use of surface nets allows for easy comparison between data sets, but the units of measurement for calculating microplastic concentration vary, from surface area m2 and Km2, to volume of water sampled, m3. Contamination by the air, equipment, or sampler is a constant concern in microplastic research. Significant in-field contamination concerns for neuston tow sampling include air exposure time, microplastics in rinse water, sampler contact, and plastic net material. Seeking to overcome the lack of contamination control and the intrinsic instrumental size limitation associated with surface tow nets, we developed an alternative sampling method. The whole water (WW) method is a one-liter grab sample of surface water adapted from College of the Atlantic and Sea Education Association (SEA) student, Marina Garland. This is the only WW method that we are aware of being used to sample microplastic. The method addresses the increasing need to explore smaller size domains, to reduce potential contamination and to incorporate citizen scientists into data collection. Less water is analyzed using the WW method, but it allows for targeted sampling of point-source pollution, intertidal, and shallow areas. The WW methodology can easily be integrated into long-term or citizen science monitoring initiatives due to its simplicity and low equipment demands. The aim of our study was to demonstrate a practical and economically feasible method for sampling microplastic abundance at the micro (10-6m) and nano (10-8m) scale that can be used in a wide variety of environments, and for assessing spatial and temporal distributions. The method has been employed in a multi-year citizen science collaboration with Adventurers and Scientists for Conservation to study microplastic worldwide.

An Efficient Ray-Tracing Method for Determining Terrain Intercepts in EDL Simulations

NASA Technical Reports Server (NTRS)

Shidner, Jeremy D.

2016-01-01

The calculation of a ray's intercept from an arbitrary point in space to a prescribed surface is a common task in computer simulations. The arbitrary point often represents an object that is moving according to the simulation, while the prescribed surface is fixed in a defined frame. For detailed simulations, this surface becomes complex, taking the form of real-world objects such as mountains, craters or valleys which require more advanced methods to accurately calculate a ray's intercept location. Incorporation of these complex surfaces has commonly been implemented in graphics systems that utilize highly optimized graphics processing units to analyze such features. This paper proposes a simplified method that does not require computationally intensive graphics solutions, but rather an optimized ray-tracing method for an assumed terrain dataset. This approach was developed for the Mars Science Laboratory mission which landed on the complex terrain of Gale Crater. First, this paper begins with a discussion of the simulation used to implement the model and the applicability of finding surface intercepts with respect to atmosphere modeling, altitude determination, radar modeling, and contact forces influencing vehicle dynamics. Next, the derivation and assumptions of the intercept finding method are presented. Key assumptions are noted making the routines specific to only certain types of surface data sets that are equidistantly spaced in longitude and latitude. The derivation of the method relies on ray-tracing, requiring discussion on the formulation of the ray with respect to the terrain datasets. Further discussion includes techniques for ray initialization in order to optimize the intercept search. Then, the model implementation for various new applications in the simulation are demonstrated. Finally, a validation of the accuracy is presented along with the corresponding data sets used in the validation. A performance summary of the method will be shown using the analysis from the Mars Science Laboratory's terminal descent sensing model. Alternate uses will also be shown for determining horizon maps and orbiter set times.

Emerging surface characterization techniques for carbon steel corrosion: a critical brief review.

PubMed

Dwivedi, D; Lepkova, K; Becker, T

2017-03-01

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The reviewed methods include time of flight-secondary ion mass spectrometry, X-ray absorption spectroscopy methods, particle-induced X-ray emission, Rutherford backscatter spectroscopy, Auger electron spectroscopy, electron probe microanalysis, near-edge X-ray absorption fine structure spectroscopy, X-ray photoemission electron microscopy, low-energy electron diffraction, small-angle neutron scattering and neutron reflectometry, and conversion electron Moessbauer spectrometry. Advantages and limitations of the analytical methods in thin-film surface investigations are discussed. Technical parameters of nominated analytical methods are provided to assist in the selection of suitable methods for analysis of metallic substrates deposited with surface films. The challenges associated with the applications of the emerging analytical methods in corrosion science are also addressed.

Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

NASA Astrophysics Data System (ADS)

Dwivedi, D.; Lepkova, K.; Becker, T.

2017-03-01

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The reviewed methods include time of flight-secondary ion mass spectrometry, X-ray absorption spectroscopy methods, particle-induced X-ray emission, Rutherford backscatter spectroscopy, Auger electron spectroscopy, electron probe microanalysis, near-edge X-ray absorption fine structure spectroscopy, X-ray photoemission electron microscopy, low-energy electron diffraction, small-angle neutron scattering and neutron reflectometry, and conversion electron Moessbauer spectrometry. Advantages and limitations of the analytical methods in thin-film surface investigations are discussed. Technical parameters of nominated analytical methods are provided to assist in the selection of suitable methods for analysis of metallic substrates deposited with surface films. The challenges associated with the applications of the emerging analytical methods in corrosion science are also addressed.

Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

PubMed Central

Dwivedi, D.; Becker, T.

2017-01-01

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The reviewed methods include time of flight-secondary ion mass spectrometry, X-ray absorption spectroscopy methods, particle-induced X-ray emission, Rutherford backscatter spectroscopy, Auger electron spectroscopy, electron probe microanalysis, near-edge X-ray absorption fine structure spectroscopy, X-ray photoemission electron microscopy, low-energy electron diffraction, small-angle neutron scattering and neutron reflectometry, and conversion electron Moessbauer spectrometry. Advantages and limitations of the analytical methods in thin-film surface investigations are discussed. Technical parameters of nominated analytical methods are provided to assist in the selection of suitable methods for analysis of metallic substrates deposited with surface films. The challenges associated with the applications of the emerging analytical methods in corrosion science are also addressed. PMID:28413351

A nano-scale mirror-like surface of Ti-6Al-4V attained by chemical mechanical polishing

NASA Astrophysics Data System (ADS)

Chenliang, Liang; Weili, Liu; Shasha, Li; Hui, Kong; Zefang, Zhang; Zhitang, Song

2016-05-01

Metal Ti and its alloys have been widely utilized in the fields of aviation, medical science, and micro-electro-mechanical systems, for its excellent specific strength, resistance to corrosion, and biological compatibility. As the application of Ti moves to the micro or nano scale, however, traditional methods of planarization have shown their short slabs. Thus, we introduce the method of chemical mechanical polishing (CMP) to provide a new way for the nano-scale planarization method of Ti alloys. We obtain a mirror-like surface, whose flatness is of nano-scale, via the CMP method. We test the basic mechanical behavior of Ti-6Al-4V (Ti64) in the CMP process, and optimize the composition of CMP slurry. Furthermore, the possible reactions that may take place in the CMP process have been studied by electrochemical methods combined with x-ray photoelectron spectroscopy (XPS). An equivalent circuit has been built to interpret the dynamic of oxidation. Finally, a model has been established to explain the synergy of chemical and mechanical effects in the CMP of Ti-6Al-4V. Project supported by the National Major Scientific and Technological Special Project during the Twelfth Five-year Plan Period of China (Grant No. 2009ZX02030-1), the National Natural Science Foundation of China (Grant No. 51205387), the Support by Science and Technology Commission of Shanghai City, China (Grant No. 11nm0500300), and the Science and Technology Commission of Shanghai City, China (Grant No. 14XD1425300).

A facile method to modify bentonite nanoclay with silane

NASA Astrophysics Data System (ADS)

Abeywardena, Sujani B. Y.; Perera, Srimala; Nalin de Silva, K. M.; Tissera, Nadeeka P.

2017-07-01

Immobilization of smectite clay onto a desirable surface has received much attention, since its nanospace can be utilized for many applications in material science. Here, we present an efficient method to functionalize surface of bentonite nanoclay (BNC) through the grafting of 3-aminotriethoxysilane (APTES). Infrared spectroscopy and elemental analysis confirmed the presence of organic chains and amine groups in modified nanoclay. XRD analysis confirmed grafting of APTES on the surface of bentonite nanoclay without intercalation. The accomplishment of the surface modification was quantitatively proved by TGA analysis. Modified BNC can covalently couple with different material surfaces, allowing its nanospace to be utilized for intercalation of cations, bio-molecules, and polymeric materials, to be used in advanced military aerospace, pharmaceuticals, and many other commercial applications.

A Novel Method of Recording Motion

ERIC Educational Resources Information Center

Ben-Shalom, Amir; Gluck, Paul

2013-01-01

By attaching LEDs and lasers to moving objects, and shining their light on photochromic surfaces below them, we can display traces of many motions of interest in introductory physics courses and science museums.

A novel method of recording motion

NASA Astrophysics Data System (ADS)

Ben-Shalom, Amir; Gluck, Paul

2013-05-01

By attaching LEDs and lasers to moving objects, and shining their light on photochromic surfaces below them, we can display traces of many motions of interest in introductory physics courses and science museums.

Attosecond time-resolved streaked photoemission from Mg-covered W(110) surfaces

NASA Astrophysics Data System (ADS)

Liao, Qing; Thumm, Uwe

2015-05-01

We formulate a quantum-mechanical model for infrared-streaked photoelectron emission by an ultrashort extreme ultraviolet pulse from adsorbate-covered metal surfaces. Applying this numerical model to ultrathin Mg adsorbates on W(110) substrates, we analyze streaked photoelectron spectra and attosecond streaking time delays for photoemission from the Mg/W(110) conduction band and Mg(2p) and W(4f) core levels. Based on this analysis, we propose the use of attosecond streaking spectroscopy on adsorbate-covered surfaces with variable adsorbate thickness as a method for investigating (a) electron transport in condensed-matter systems and (b) metal-adsorbate-interface properties at subatomic length and time scales. Our calculated streaked photoemission spectra and time delays agree with recently obtained experimental data. Supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy under Grant No. DE-FG02-86ER13491 and NSF Grant PHY-1068752.

Polyphosphates as inorganic polyelectrolytes interacting with oppositely charged ions, polymers and deposited on surfaces: fundamentals and applications.

PubMed

Cini, N; Ball, V

2014-07-01

Polyphosphates are important but neglected polyelectrolytes that play a major role in biology and in surface science for the stabilization of colloids against flocculation and for the preservation of food. They are also known as "Calgon" ® and intensively used as additives in washing powders. This review aims to review recent developments in which linear polyphosphates are used for the design of new functional coatings using sol-gel processes and layer-by-layer deposition methods. All these methods rely on the high charge density of polyphosphates as inorganic polyelectrolytes, therefore the structure and properties of these molecules are also reviewed. New perspectives will also been given for the design of stimuli responsive coatings at the tiny frontier between biology and materials science. Copyright © 2014 Elsevier B.V. All rights reserved.

Multichannel analysis of surface wave method with the autojuggie

USGS Publications Warehouse

Tian, G.; Steeples, D.W.; Xia, J.; Miller, R.D.; Spikes, K.T.; Ralston, M.D.

2003-01-01

The shear (S)-wave velocity of near-surface materials and its effect on seismic-wave propagation are of fundamental interest in many engineering, environmental, and groundwater studies. The multichannel analysis of surface wave (MASW) method provides a robust, efficient, and accurate tool to observe near-surface S-wave velocity. A recently developed device used to place large numbers of closely spaced geophones simultaneously and automatically (the 'autojuggie') is shown here to be applicable to the collection of MASW data. In order to demonstrate the use of the autojuggie in the MASW method, we compared high-frequency surface-wave data acquired from conventionally planted geophones (control line) to data collected in parallel with the automatically planted geophones attached to steel bars (test line). The results demonstrate that the autojuggie can be applied in the MASW method. Implementation of the autojuggie in very shallow MASW surveys could drastically reduce the time required and costs incurred in such surveys. ?? 2003 Elsevier Science Ltd. All rights reserved.

Electronic structure of O-doped SiGe calculated by DFT + U method

NASA Astrophysics Data System (ADS)

Zhao, Zong-Yan; Yang, Wen; Yang, Pei-Zhi

2016-12-01

To more in depth understand the doping effects of oxygen on SiGe alloys, both the micro-structure and properties of O-doped SiGe (including: bulk, (001) surface, and (110) surface) are calculated by DFT + U method in the present work. The calculated results are as follows. (i) The (110) surface is the main exposing surface of SiGe, in which O impurity prefers to occupy the surface vacancy sites. (ii) For O interstitial doping on SiGe (110) surface, the existences of energy states caused by O doping in the band gap not only enhance the infrared light absorption, but also improve the behaviors of photo-generated carriers. (iii) The finding about decreased surface work function of O-doped SiGe (110) surface can confirm previous experimental observations. (iv) In all cases, O doing mainly induces the electronic structures near the band gap to vary, but is not directly involved in these variations. Therefore, these findings in the present work not only can provide further explanation and analysis for the corresponding underlying mechanism for some of the experimental findings reported in the literature, but also conduce to the development of μc-SiGe-based solar cells in the future. Project supported by the Natural Science Foundation of Yunnan Province, China (Grant No. 2015FB123), the 18th Yunnan Province Young Academic and Technical Leaders Reserve Talent Project, China (Grant No. 2015HB015), and the National Natural Science Foundation of China (Grant No. U1037604).

Tribology. LC Science Tracer Bullet.

ERIC Educational Resources Information Center

Havas, George D., Comp.

Tribology is the science and technology of interacting surfaces in relative motion. It incorporates a number of scientific fields, including friction, wear, lubrication, materials science, and various branches of surface physics and surface chemistry. Tribology forms a vital part of engineering science. The interacting surfaces may be on machinery…

Proposal of a taste evaluating method of the sponge cake by using 3D range sensor

NASA Astrophysics Data System (ADS)

Kato, Kunihito; Yamamoto, Kazuhiko; Ogawa, Noriko

2002-10-01

Nowadays, the image processing techniques are while applying to the food industry in many situations. The most of these researches are applications for the quality control in plants, and there are hardly any cases of measuring the 'taste'. We are developing the measuring system of the deliciousness by using the image sensing. In this paper, we propose the estimation method of the deliciousness of a sponge cake. Considering about the deliciousness of the sponge cake, if the size of the bubbles on the surface is small and the number of them is large, then it is defined that the deliciousness of the sponge cake is better in the field of the food science. We proposed a method of detection bubbles in the surface of the sectional sponge cake automatically by using 3-D image processing. By the statistical information of these detected bubbles based on the food science, the deliciousness is estimated.

Progress in Preparation of Monodisperse Polymer Microspheres

NASA Astrophysics Data System (ADS)

Zhang, Hongyan

2017-12-01

The monodisperse crosslinked polymer microspheres have attracted much attention because of their superior thermal and solvent resistance, mechanical strength, surface activity and adsorption properties. They are of wide prospects for using in many fields such as biomedicine, electronic science, information technology, analytical chemistry, standard measurement and environment protection etc. Functional polymer microspheres prepared by different methods have the outstanding surface property, quantum size effect and good potential future in applications with its designable structure, controlled size and large ratio of surface to volume. Scholars of all over the world have focused on this hot topic. The preparation method and research progress in functional polymer microspheres are addressed in the paper.

Migration of Carbon Adatoms on the Surface of Charged SWCNT

NASA Astrophysics Data System (ADS)

Han, Longtao; Krstic, Predrag; Kaganovich, Igor

2016-10-01

In volume plasma, the growth of SWCNT from a transition metal catalyst could be enhanced by incoming carbon flux on SWCNT surface, which is generated by the adsorption and migration of carbon adatoms on SWCNT surface. In addition, the nanotube can be charged by the irradiation of plasma particles. How this charging effect will influence the adsorption and migration behavior of carbon atom has not been revealed. Using Density Functional Theory, Nudged Elastic Band and Kinetic Monte Carlo method, we found equilibrium sites, vibrational frequency, adsorption energy, most probable pathways for migration of adatoms, and the barrier sizes along these pathways. The metallic (5,5) SWCNT can support a fast migration of the carbon adatom along a straight path with low barriers, which is further enhanced by the presence of negative charge on SWCNT. The enhancement is contributed by the higher adsorption energy and thence longer lifetime of adatom on the charged SWCNT surface. The lifetime and migration distance of adatom increase by three and two orders of magnitude, respectively, as shown by Kinetic Monte Carlo simulation. These results support the surface migration mechanism of SWCNT growth in plasma environment. This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Material Sciences and Engineering Division.

Current issues and problems in welding science

NASA Astrophysics Data System (ADS)

David, S. A.; Debroy, T.

1992-07-01

Recent advances in welding science are examined with consideration given to the progress made in understanding physical processes of welding and in understanding weldment microstructure and properties and the correlation between microstructure and properties of the welds. Particular attention is given to the methods used for intelligent control and automation of welding. Also discussed are issues and problems that were brought to the surface by technological advances and interdisciplinary research on welding.

Self-Cleaning Surfaces Prepared By Microstructuring System

NASA Astrophysics Data System (ADS)

Sabbah, Abbas; Vandeparre, H.; Brau, F.; Damman, P.

The wettability of materials is a very important aspect of surface science governed by the chemical composition of the surface and its morphology. In this context, materials replicating nature's superhydrophobic surfaces, such as lotus leafs, rose petals and butterfly wings, have widely attracted attention of physicists and material engineers [1-3]. Despite of considerable efforts during the last decade, superhydrophobic surfaces are still expensive and usually involved microfabrication processes, such as photolithography technique. In this study, we propose an original and simple method to create superhydrophobic surfaces by controling elastic instabilities [4-8]. Indeed, we demonstrate that the self-organization of wrinkles on top of non-wettable polymer surfaces leads to surperhydrophobic surfaces.

Imaging of surface spin textures on bulk crystals by scanning electron microscopy

NASA Astrophysics Data System (ADS)

Akamine, Hiroshi; Okumura, So; Farjami, Sahar; Murakami, Yasukazu; Nishida, Minoru

2016-11-01

Direct observation of magnetic microstructures is vital for advancing spintronics and other technologies. Here we report a method for imaging surface domain structures on bulk samples by scanning electron microscopy (SEM). Complex magnetic domains, referred to as the maze state in CoPt/FePt alloys, were observed at a spatial resolution of less than 100 nm by using an in-lens annular detector. The method allows for imaging almost all the domain walls in the mazy structure, whereas the visualisation of the domain walls with the classical SEM method was limited. Our method provides a simple way to analyse surface domain structures in the bulk state that can be used in combination with SEM functions such as orientation or composition analysis. Thus, the method extends applications of SEM-based magnetic imaging, and is promising for resolving various problems at the forefront of fields including physics, magnetics, materials science, engineering, and chemistry.

Knowledge Production at Industrial Research Institutes: Institutional Logics and Struggles for Relevance in the Swedish Institute for Surface Chemistry, 1980-2005

ERIC Educational Resources Information Center

Bruno, Karl; Larsen, Katarina; van Leeuwen, Thed N.

2017-01-01

This article examines dynamics of knowledge production and discourses of basic-applied science and relevance at the Swedish Institute for Surface Chemistry, a semi-public industrially oriented research institute, from 1980 to 2005. We employ a three-pronged method, consisting of (1) an analysis of how the institute articulated its research…

Student Solution Manual for Essential Mathematical Methods for the Physical Sciences

NASA Astrophysics Data System (ADS)

Riley, K. F.; Hobson, M. P.

2011-02-01

1. Matrices and vector spaces; 2. Vector calculus; 3. Line, surface and volume integrals; 4. Fourier series; 5. Integral transforms; 6. Higher-order ODEs; 7. Series solutions of ODEs; 8. Eigenfunction methods; 9. Special functions; 10. Partial differential equations; 11. Solution methods for PDEs; 12. Calculus of variations; 13. Integral equations; 14. Complex variables; 15. Applications of complex variables; 16. Probability; 17. Statistics.

Essential Mathematical Methods for the Physical Sciences

NASA Astrophysics Data System (ADS)

Riley, K. F.; Hobson, M. P.

2011-02-01

1. Matrices and vector spaces; 2. Vector calculus; 3. Line, surface and volume integrals; 4. Fourier series; 5. Integral transforms; 6. Higher-order ODEs; 7. Series solutions of ODEs; 8. Eigenfunction methods; 9. Special functions; 10. Partial differential equations; 11. Solution methods for PDEs; 12. Calculus of variations; 13. Integral equations; 14. Complex variables; 15. Applications of complex variables; 16. Probability; 17. Statistics; Appendices; Index.

Plasmon-mediated chemical surface functionalization at the nanoscale

NASA Astrophysics Data System (ADS)

Nguyen, Mai; Lamouri, Aazdine; Salameh, Chrystelle; Lévi, Georges; Grand, Johan; Boubekeur-Lecaque, Leïla; Mangeney, Claire; Félidj, Nordin

2016-04-01

Controlling the surface grafting of species at the nanoscale remains a major challenge, likely to generate many opportunities in materials science. In this work, we propose an original strategy for chemical surface functionalization at the nanoscale, taking advantage of localized surface plasmon (LSP) excitation. The surface functionalization is demonstrated through aryl film grafting (derived from a diazonium salt), covalently bonded at the surface of gold lithographic nanostripes. The aryl film is specifically grafted in areas of maximum near field enhancement, as confirmed by numerical calculation based on the discrete dipole approximation method. The energy of the incident light and the LSP wavelength are shown to be crucial parameters to monitor the aryl film thickness of up to ~30 nm. This robust and versatile strategy opens up exciting prospects for the nanoscale confinement of functional layers on surfaces, which should be particularly interesting for molecular sensing or nanooptics.Controlling the surface grafting of species at the nanoscale remains a major challenge, likely to generate many opportunities in materials science. In this work, we propose an original strategy for chemical surface functionalization at the nanoscale, taking advantage of localized surface plasmon (LSP) excitation. The surface functionalization is demonstrated through aryl film grafting (derived from a diazonium salt), covalently bonded at the surface of gold lithographic nanostripes. The aryl film is specifically grafted in areas of maximum near field enhancement, as confirmed by numerical calculation based on the discrete dipole approximation method. The energy of the incident light and the LSP wavelength are shown to be crucial parameters to monitor the aryl film thickness of up to ~30 nm. This robust and versatile strategy opens up exciting prospects for the nanoscale confinement of functional layers on surfaces, which should be particularly interesting for molecular sensing or nanooptics. Electronic supplementary information (ESI) available: Additional figures are displayed (from Fig. SI1-SI6) to illustrate the content of the paper, including the proposed mechanisms of diazonium-derived aryl film grafting, the AFM measurements of the aryl film thickness and the calculation by the DDA method. See DOI: 10.1039/C6NR00744A

Using the Earth as an Effective Model for Integrating Space Science Into Education Outreach Programs

NASA Astrophysics Data System (ADS)

Morris, P. A.; Allen, J.; Galindo, C.; McKay, G.; Obot, V.; Reiff, P.

2005-05-01

Our methods of teaching Earth and space science as two disciplines do not represent the spirit of earlier scientists such as Aristotle, da Vinci, and Galileo. We need to re-evaluate these methods and take advantage of the excitement created in the general public over the recent space science exploration programs. The information that we are obtaining from both the Mars missions and Cassini-Huygens focuses on interpreting geomorphology, mineral compositions and gas identification based on Earth as a baseline for data evaluation. This type of evaluation is an extension of Hutton's 18th century principle of Uniformitarianism, the present is the key to the past, or Earth is the key for understanding extraterrestrial bodies. Geomorphological examples are volcanic activity, meteoritic impacts, and evidence of water altering surface features. The Hawaiian, or shield, type volcanoes are analogues for Olympus Mons and the other volcanoes on Mars. Other examples include comparing sand dunes on Earth with possible Martian dunes, known stream patterns on Earth with potential stream patterns on Mars, and even comparing meteoritic impact features on Mars, the Earth, Moon and Mercury. All of these comparisons have been developed into inquiry-based activities and are available through NASA publications. Each of these activities is easily adapted to emphasize either Earth science or space science or both. Beyond geomorphology, solar storms are an excellent topic for integrating Earth and space science. Solar storms are traditionally part of space science studies, but most students do not understand their effect on Earth or the intense effects they could have on humans, whether traveling through space or exploring the surfaces of the Moon or Mars. Effects are not only limited to space travel and other planetary surfaces but also include Earth's magnetosphere, which in turn, affect radio transmission and potentially climate. Like geomorphology courses, there are extensive NASA programs available via either the Internet or CD (e.g., those distributed by P. Reiff, Rice University) that provide inquiry-based activities for students. There is great potential to share the connections of Earth and space science by using NASA developed education materials. The materials can be adapted for the classroom, after school programs, family outreach events, and summer science enrichment programs.

Monitoring surface water quality using social media in the context of citizen science

NASA Astrophysics Data System (ADS)

Zheng, Hang; Hong, Yang; Long, Di; Jing, Hua

2017-02-01

Surface water quality monitoring (SWQM) provides essential information for water environmental protection. However, SWQM is costly and limited in terms of equipment and sites. The global popularity of social media and intelligent mobile devices with GPS and photography functions allows citizens to monitor surface water quality. This study aims to propose a method for SWQM using social media platforms. Specifically, a WeChat-based application platform is built to collect water quality reports from volunteers, which have been proven valuable for water quality monitoring. The methods for data screening and volunteer recruitment are discussed based on the collected reports. The proposed methods provide a framework for collecting water quality data from citizens and offer a primary foundation for big data analysis in future research.

A synthesis of fluorescent starch based on carbon nanoparticles for fingerprints detection

NASA Astrophysics Data System (ADS)

Li, Hongren; Guo, Xingjia; Liu, Jun; Li, Feng

2016-10-01

A pyrolysis method for synthesizing carbon nanoparticles (CNPs) were developed by using malic acid and ammonium oxalate as raw materials. The incorporation of a minor amount of carbon nanoparticles into starch powder imparts remarkable color-tunability. Based on this phenomenon, an environment friendly fluorescent starch powder for detecting latent fingerprints in non-porous surfaces was prepared. The fingerprints on different non-porous surfaces developed with this powder showed very good fluorescent images under ultraviolet excitation. The method using fluorescent starch powder as fluorescent marks is simple, rapid and green. Experimental results illustrated the effectiveness of proposed methods, enabling its practical applications in forensic sciences.

Investigating Arsenic Contents in Surface and Drinking Water by Voltammetry and the Method of Standard Additions

ERIC Educational Resources Information Center

Cheng, Anran; Tyne, Rebecca; Kwok, Yu Ting; Rees, Louis; Craig, Lorraine; Lapinee, Chaipat; D'Arcy, Mitch; Weiss, Dominik J.; Salau¨n, Pascal

2016-01-01

Testing water samples for arsenic contamination has become an important water quality issue worldwide. Arsenic usually occurs in very small concentrations, and a sensitive analytical method is needed. We present here a 1-day laboratory module developed to introduce Earth Sciences and/or Chemistry student undergraduates to key aspects of this…

Accurate double many-body expansion potential energy surface of HS2A2A‧) by scaling the external correlation

NASA Astrophysics Data System (ADS)

Lu-Lu, Zhang; Yu-Zhi, Song; Shou-Bao, Gao; Yuan, Zhang; Qing-Tian, Meng

2016-05-01

A globally accurate single-sheeted double many-body expansion potential energy surface is reported for the first excited state of HS2 by fitting the accurate ab initio energies, which are calculated at the multireference configuration interaction level with the aug-cc-pVQZ basis set. By using the double many-body expansion-scaled external correlation method, such calculated ab initio energies are then slightly corrected by scaling their dynamical correlation. A grid of 2767 ab initio energies is used in the least-square fitting procedure with the total root-mean square deviation being 1.406 kcal·mol-1. The topographical features of the HS2(A2A‧) global potential energy surface are examined in detail. The attributes of the stationary points are presented and compared with the corresponding ab initio results as well as experimental and other theoretical data, showing good agreement. The resulting potential energy surface of HS2(A2A‧) can be used as a building block for constructing the global potential energy surfaces of larger S/H molecular systems and recommended for dynamic studies on the title molecular system. Project supported by the National Natural Science Foundation of China (Grant No. 11304185), the Taishan Scholar Project of Shandong Province, China, the Shandong Provincial Natural Science Foundation, China (Grant No. ZR2014AM022), the Shandong Province Higher Educational Science and Technology Program, China (Grant No. J15LJ03), the China Postdoctoral Science Foundation (Grant No. 2014M561957), and the Post-doctoral Innovation Project of Shandong Province, China (Grant No. 201402013).

Bayesian inversion analysis of nonlinear dynamics in surface heterogeneous reactions.

PubMed

Omori, Toshiaki; Kuwatani, Tatsu; Okamoto, Atsushi; Hukushima, Koji

2016-09-01

It is essential to extract nonlinear dynamics from time-series data as an inverse problem in natural sciences. We propose a Bayesian statistical framework for extracting nonlinear dynamics of surface heterogeneous reactions from sparse and noisy observable data. Surface heterogeneous reactions are chemical reactions with conjugation of multiple phases, and they have the intrinsic nonlinearity of their dynamics caused by the effect of surface-area between different phases. We adapt a belief propagation method and an expectation-maximization (EM) algorithm to partial observation problem, in order to simultaneously estimate the time course of hidden variables and the kinetic parameters underlying dynamics. The proposed belief propagation method is performed by using sequential Monte Carlo algorithm in order to estimate nonlinear dynamical system. Using our proposed method, we show that the rate constants of dissolution and precipitation reactions, which are typical examples of surface heterogeneous reactions, as well as the temporal changes of solid reactants and products, were successfully estimated only from the observable temporal changes in the concentration of the dissolved intermediate product.

Free energy of steps using atomistic simulations

NASA Astrophysics Data System (ADS)

Freitas, Rodrigo; Frolov, Timofey; Asta, Mark

The properties of solid-liquid interfaces are known to play critical roles in solidification processes. Particularly special importance is given to thermodynamic quantities that describe the equilibrium state of these surfaces. For example, on the solid-liquid-vapor heteroepitaxial growth of semiconductor nanowires the crystal nucleation process on the faceted solid-liquid interface is influenced by the solid-liquid and vapor-solid interfacial free energies, and also by the free energies of associated steps at these faceted interfaces. Crystal-growth theories and mesoscale simulation methods depend on quantitative information about these properties, which are often poorly characterized from experimental measurements. In this work we propose an extension of the capillary fluctuation method for calculation of the free energy of steps on faceted crystal surfaces. From equilibrium atomistic simulations of steps on (111) surfaces of Copper we computed accurately the step free energy for different step orientations. We show that the step free energy remains finite at all temperature up to the melting point and that the results obtained agree with the more well established method of thermodynamic integration if finite size effects are taken into account. The research of RF and MA at UC Berkeley were supported by the US National Science Foundation (Grant No. DMR-1105409). TF acknowledges support through a postdoctoral fellowship from the Miller Institute for Basic Research in Science.

Optical metrology at the Optical Sciences Center: an historical review

NASA Astrophysics Data System (ADS)

Creath, Katherine; Parks, Robert E.

2014-10-01

The Optical Sciences Center (OSC) begun as a graduate-level applied optics teaching institution to support the US space effort. The making of optics representative of those used in other space programs was deemed essential. This led to the need for optical metrology: at first Hartmann tests, but almost immediately to interferometric tests using the newly invented HeNe laser. Not only were new types of interferometers needed, but the whole infrastructure that went with testing, fringe location methods, aberration removal software and contour map generation to aid the opticians during polishing needed to be developed. Over the last half century more rapid and precise methods of interferogram data reduction, surface roughness measurement, and methods of instrument calibration to separate errors from those in the optic have been pioneered at OSC. Other areas of research included null lens design and the writing of lens design software that led into the design of computer generated holograms for asphere testing. More recently work has been done on the reduction of speckle noise in interferograms, methods to test large convex aspheres, and a return to slope measuring tests to increase the dynamic range of the types of aspheric surfaces amenable to optical testing including free-form surfaces. This paper documents the history of the development of optical testing projects at OSC and highlights the contributions some of the individuals associated with new methods of testing and the infrastructure needed to support the testing. We conclude with comments about the future trends optical metrology.

Acoustic imaging in application to reconstruction of rough rigid surface with airborne ultrasound waves

NASA Astrophysics Data System (ADS)

Krynkin, A.; Dolcetti, G.; Hunting, S.

2017-02-01

Accurate reconstruction of the surface roughness is of high importance to various areas of science and engineering. One important application of this technology is for remote monitoring of open channel flows through observing its dynamic surface roughness. In this paper a novel airborne acoustic method of roughness reconstruction is proposed and tested with a static rigid rough surface. This method is based on the acoustic holography principle and Kirchhoff approximation which make use of acoustic pressure data collected at multiple receiver points spread along an arch. The Tikhonov regularisation and generalised cross validation technique are used to solve the underdetermined system of equations for the acoustic pressures. The experimental data are collected above a roughness created with a 3D printer. For the given surface, it is shown that the proposed method works well with the various number of receiver positions. In this paper, the tested ratios between the number of surface points at which the surface elevation can be reconstructed and number of receiver positions are 2.5, 5, and 7.5. It is shown that, in a region comparable with the projected size of the main directivity lobe, the method is able to reconstruct the spatial spectrum density of the actual surface elevation with the accuracy of 20%.

Acoustic imaging in application to reconstruction of rough rigid surface with airborne ultrasound waves.

PubMed

Krynkin, A; Dolcetti, G; Hunting, S

2017-02-01

Accurate reconstruction of the surface roughness is of high importance to various areas of science and engineering. One important application of this technology is for remote monitoring of open channel flows through observing its dynamic surface roughness. In this paper a novel airborne acoustic method of roughness reconstruction is proposed and tested with a static rigid rough surface. This method is based on the acoustic holography principle and Kirchhoff approximation which make use of acoustic pressure data collected at multiple receiver points spread along an arch. The Tikhonov regularisation and generalised cross validation technique are used to solve the underdetermined system of equations for the acoustic pressures. The experimental data are collected above a roughness created with a 3D printer. For the given surface, it is shown that the proposed method works well with the various number of receiver positions. In this paper, the tested ratios between the number of surface points at which the surface elevation can be reconstructed and number of receiver positions are 2.5, 5, and 7.5. It is shown that, in a region comparable with the projected size of the main directivity lobe, the method is able to reconstruct the spatial spectrum density of the actual surface elevation with the accuracy of 20%.

Reversible Immobilization of Proteins in Sensors and Solid-State Nanopores.

PubMed

Ananth, Adithya; Genua, María; Aissaoui, Nesrine; Díaz, Leire; Eisele, Nico B; Frey, Steffen; Dekker, Cees; Richter, Ralf P; Görlich, Dirk

2018-05-01

The controlled functionalization of surfaces with proteins is crucial for many analytical methods in life science research and biomedical applications. Here, a coating for silica-based surfaces is established which enables stable and selective immobilization of proteins with controlled orientation and tunable surface density. The coating is reusable, retains functionality upon long-term storage in air, and is applicable to surfaces of complex geometry. The protein anchoring method is validated on planar surfaces, and then a method is developed to measure the anchoring process in real time using silicon nitride solid-state nanopores. For surface attachment, polyhistidine tags that are site specifically introduced into recombinant proteins are exploited, and the yeast nucleoporin Nsp1 is used as model protein. Contrary to the commonly used covalent thiol chemistry, the anchoring of proteins via polyhistidine tag is reversible, permitting to take proteins off and replace them by other ones. Such switching in real time in experiments on individual nanopores is monitored using ion conductivity. Finally, it is demonstrated that silica and gold surfaces can be orthogonally functionalized to accommodate polyhistidine-tagged proteins on silica but prevent protein binding to gold, which extends the applicability of this surface functionalization method to even more complex sensor devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controlling the physics and chemistry of binary and ternary praseodymium and cerium oxide systems.

PubMed

Niu, Gang; Zoellner, Marvin Hartwig; Schroeder, Thomas; Schaefer, Andreas; Jhang, Jin-Hao; Zielasek, Volkmar; Bäumer, Marcus; Wilkens, Henrik; Wollschläger, Joachim; Olbrich, Reinhard; Lammers, Christian; Reichling, Michael

2015-10-14

Rare earth praseodymium and cerium oxides have attracted intense research interest in the last few decades, due to their intriguing chemical and physical characteristics. An understanding of the correlation between structure and properties, in particular the surface chemistry, is urgently required for their application in microelectronics, catalysis, optics and other fields. Such an understanding is, however, hampered by the complexity of rare earth oxide materials and experimental methods for their characterisation. Here, we report recent progress in studying high-quality, single crystalline, praseodymium and cerium oxide films as well as ternary alloys grown on Si(111) substrates. Using these well-defined systems and based on a systematic multi-technique surface science approach, the corresponding physical and chemical properties, such as the surface structure, the surface morphology, the bulk-surface interaction and the oxygen storage/release capability, are explored in detail. We show that specifically the crystalline structure and the oxygen stoichiometry of the oxide thin films can be well controlled by the film preparation method. This work leads to a comprehensive understanding of the properties of rare earth oxides and highlights the applications of these versatile materials. Furthermore, methanol adsorption studies are performed on binary and ternary rare earth oxide thin films, demonstrating the feasibility of employing such systems for model catalytic studies. Specifically for ceria systems, we find considerable stability against normal environmental conditions so that they can be considered as a "materials bridge" between surface science models and real catalysts.

A novel method for the photographic recovery of fingermark impressions from ammunition cases using digital imaging.

PubMed

Porter, Glenn; Ebeyan, Robert; Crumlish, Charles; Renshaw, Adrian

2015-03-01

The photographic preservation of fingermark impression evidence found on ammunition cases remains problematic due to the cylindrical shape of the deposition substrate preventing complete capture of the impression in a single image. A novel method was developed for the photographic recovery of fingermarks from curved surfaces using digital imaging. The process involves the digital construction of a complete impression image made from several different images captured from multiple camera perspectives. Fingermark impressions deposited onto 9-mm and 0.22-caliber brass cartridge cases and a plastic 12-gauge shotgun shell were tested using various image parameters, including digital stitching method, number of images per 360° rotation of shell, image cropping, and overlap. The results suggest that this method may be successfully used to recover fingermark impression evidence from the surfaces of ammunition cases or other similar cylindrical surfaces. © 2014 American Academy of Forensic Sciences.

Restoring the magnetism of ultrathin LaMn O3 films by surface symmetry engineering

NASA Astrophysics Data System (ADS)

Peng, J. J.; Song, C.; Li, F.; Gu, Y. D.; Wang, G. Y.; Pan, F.

2016-12-01

The frustration of magnetization and conductivity properties of ultrathin manganite is detrimental to their device performance, preventing their scaling down process. Here we demonstrate that the magnetism of ultrathin LaMn O3 films can be restored by a SrTi O3 capping layer, which engineers the surface from a symmetry breaking induced out-of-plane orbital occupancy to the recovered in-plane orbital occupancy. The stabilized in-plane orbital occupancy would strengthen the intralayer double exchange and thus recovers the robust magnetism. This method is proved to be effective for films as thin as 2 unit cells, greatly shrinking the critical thickness of 6 unit cells for ferromagnetic LaMn O3 as demonstrated previously [Wang et al., Science 349, 716 (2015), 10.1126/science.aaa5198]. The achievement made in this work opens up new perspectives to an active control of surface states and thereby tailors the surface functional properties of transition metal oxides.

The Art and Science of Polymer Brushes: Recent Developments in Patterning and Characterization Approaches.

PubMed

Panzarasa, Guido

2017-06-28

Polymer brushes are dense arrays of macromolecular chains tethered by one end at a surface. They are at the cutting edge of polymer nanotechnology since the dawn of controlled surface-initiated polymerization techniques unlocked new prospects for the synthesis of polymer brushes with tailorable properties. More recently, thanks to the growing interest in the use of brushes for the generation of functional surfaces, the need for advanced patterning and characterization approaches rapidly increased. Meeting these needs requires the contribution of experts from different disciplines: polymer chemistry, surface science, electrochemistry and particle physics. The focus of this review is to highlight recent developments in the field of polymer brushes, specifically the application of photocatalytic lithography as a versatile patterning strategy, the study of grafted-from polymer brushes by electrochemical methods and, most importantly, the introduction of positron annihilation spectroscopy as a powerful technique for the investigation of the structure of polymer brushes and of their composites with nanoparticles.

Aerial Refueling Simulator Validation Using Operational Experimentation and Response Surface Methods with Time Series Responses

DTIC Science & Technology

2013-03-21

10 2.3 Time Series Response Data ................................................................................. 12 2.4 Comparison of Response...to 12 evaluating the efficiency of the parameter estimates. In the past, the most popular form of response surface design used the D-optimality...as well. A model can refer to almost anything in math , statistics, or computer science. It can be any “physical, mathematical, or logical

Preparation of atomically flat TiO2(001) surfaces

NASA Astrophysics Data System (ADS)

Wang, Yang; Weitering, Hanno H.; Snijders, Paul C.

2015-03-01

Transition metal oxides with the rutile structure (MO2, M = e.g. Ti, V, or Nb) have highly directional partially occupied t2g orbitals. Some of these orbitals form quasi-1D electronic bands along the rutile c-axis, and Peierls-like ordering phenomena have been observed in VO2 and NbO2. Tailoring the electronic properties of these materials via quantum confinement requires epitaxial growth on suitable substrates such as low index TiO2 surfaces. Because of the high surface energy of rutile TiO2(001), the standard approach of sputtering and annealing usually introduces faceting. Here we demonstrate a facile method to create atomically flat, non-faceted TiO2(001) surfaces. Using scanning tunneling microscopy we observe terraces with a width of approximately 150 nm. Step heights of approximately 0.3 nm are observed, consistent with the c lattice parameter of rutile TiO2. Low energy electron diffraction patterns reveal sharp diffraction spots with an in-plane lattice constant of 0.358 nm which is consistent with a (1x1) ordering of the (001) plane. These TiO2(001) single crystal surfaces can serve as an ideal substrate for further growth of rutile heterostructures. Research sponsored by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

Assessment of environments for Mars Science Laboratory entry, descent, and surface operations

USGS Publications Warehouse

Vasavada, Ashwin R.; Chen, Allen; Barnes, Jeffrey R.; Burkhart, P. Daniel; Cantor, Bruce A.; Dwyer-Cianciolo, Alicia M.; Fergason, Robini L.; Hinson, David P.; Justh, Hilary L.; Kass, David M.; Lewis, Stephen R.; Mischna, Michael A.; Murphy, James R.; Rafkin, Scot C.R.; Tyler, Daniel; Withers, Paul G.

2012-01-01

The Mars Science Laboratory mission aims to land a car-sized rover on Mars' surface and operate it for at least one Mars year in order to assess whether its field area was ever capable of supporting microbial life. Here we describe the approach used to identify, characterize, and assess environmental risks to the landing and rover surface operations. Novel entry, descent, and landing approaches will be used to accurately deliver the 900-kg rover, including the ability to sense and "fly out" deviations from a best-estimate atmospheric state. A joint engineering and science team developed methods to estimate the range of potential atmospheric states at the time of arrival and to quantitatively assess the spacecraft's performance and risk given its particular sensitivities to atmospheric conditions. Numerical models are used to calculate the atmospheric parameters, with observations used to define model cases, tune model parameters, and validate results. This joint program has resulted in a spacecraft capable of accessing, with minimal risk, the four finalist sites chosen for their scientific merit. The capability to operate the landed rover over the latitude range of candidate landing sites, and for all seasons, was verified against an analysis of surface environmental conditions described here. These results, from orbital and model data sets, also drive engineering simulations of the rover's thermal state that are used to plan surface operations.

Nutrient Runoff Losses from Liquid Dairy Manure Applied with Low-Disturbance Methods.

PubMed

Jokela, William; Sherman, Jessica; Cavadini, Jason

2016-09-01

Manure applied to cropland is a source of phosphorus (P) and nitrogen (N) in surface runoff and can contribute to impairment of surface waters. Tillage immediately after application incorporates manure into the soil, which may reduce nutrient loss in runoff as well as N loss via NH volatilization. However, tillage also incorporates crop residue, which reduces surface cover and may increase erosion potential. We applied liquid dairy manure in a silage corn ( L.)-cereal rye ( L.) cover crop system in late October using methods designed to incorporate manure with minimal soil and residue disturbance. These include strip-till injection and tine aerator-band manure application, which were compared with standard broadcast application, either incorporated with a disk or left on the surface. Runoff was generated with a portable rainfall simulator (42 mm h for 30 min) three separate times: (i) 2 to 5 d after the October manure application, (ii) in early spring, and (iii) after tillage and planting. In the postmanure application runoff, the highest losses of total P and dissolved reactive P were from surface-applied manure. Dissolved P loss was reduced 98% by strip-till injection; this result was not statistically different from the no-manure control. Reductions from the aerator band method and disk incorporation were 53 and 80%, respectively. Total P losses followed a similar pattern, with 87% reduction from injected manure. Runoff losses of N had generally similar patterns to those of P. Losses of P and N were, in most cases, lower in the spring rain simulations with fewer significant treatment effects. Overall, results show that low-disturbance manure application methods can significantly reduce nutrient runoff losses compared with surface application while maintaining residue cover better than incorporation by tillage. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Ethers on Si(001): A Prime Example for the Common Ground between Surface Science and Molecular Organic Chemistry.

PubMed

Pecher, Lisa; Laref, Slimane; Raupach, Marc; Tonner, Ralf

2017-11-20

By using computational chemistry it has been shown that the adsorption of ether molecules on Si(001) under ultrahigh vacuum conditions can be understood with classical concepts of organic chemistry. Detailed analysis of the two-step reaction mechanism-1) formation of a dative bond between the ether oxygen atom and a Lewis acidic surface atom and 2) nucleophilic attack of a nearby Lewis basic surface atom-shows that it mirrors acid-catalyzed ether cleavage in solution. The O-Si dative bond is the strongest of its kind, and the reactivity in step 2 defies the Bell-Evans-Polanyi principle. Electron rearrangement during C-O bond cleavage has been visualized with a newly developed method for analyzing bonding, which shows that the mechanism of nucleophilic substitutions on semiconductor surfaces is identical to molecular S N 2 reactions. Our findings illustrate how surface science and molecular chemistry can mutually benefit from each other and unexpected insight can be gained. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isoelectric points and points of zero charge of metal (hydr)oxides: 50years after Parks' review.

PubMed

Kosmulski, Marek

2016-12-01

The pH-dependent surface charging of metal (hydr)oxides is reviewed on the occasion of the 50th anniversary of the publication by G.A. Parks: "Isoelectric points of solid oxides, solid hydroxides, and aqueous hydroxo complex systems" in Chemical Reviews. The point of zero charge (PZC) and isoelectric point (IEP) became standard parameters to characterize metal oxides in aqueous dispersions, and they define adsorption (surface excess) of ions, stability against coagulation, rheological properties of dispersions, etc. They are commonly used in many branches of science including mineral processing, soil science, materials science, geochemistry, environmental engineering, and corrosion science. Parks established standard procedures and experimental conditions which are required to obtain reliable and reproducible values of PZC and IEP. The field is very active, and the number of related papers exceeds 300 a year, and the standards established by Parks remain still valid. Relevant experimental techniques improved over the years, especially the measurements of electrophoretic mobility became easier and more reliable, are the numerical values of PZC and IEP compiled by Parks were confirmed by contemporary publications with a few exceptions. The present paper is an up-to-date compilation of the values of PZC and IEP of metal oxides. Unlike in former reviews by the same author, which were more comprehensive, only limited number of selected results are presented and discussed here. On top of the results obtained by means of classical methods (titration and electrokinetic methods), new methods and correlations found over the recent 50years are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

Science Operations on the Lunar Surface - Understanding the Past, Testing in the Present, Considering the Future

NASA Technical Reports Server (NTRS)

Eppler, Dean B.

2013-01-01

The scientific success of any future human lunar exploration mission will be strongly dependent on design of both the systems and operations practices that underpin crew operations on the lunar surface. Inept surface mission preparation and design will either ensure poor science return, or will make achieving quality science operation unacceptably difficult for the crew and the mission operations and science teams. In particular, ensuring a robust system for managing real-time science information flow during surface operations, and ensuring the crews receive extensive field training in geological sciences, are as critical to mission success as reliable spacecraft and a competent operations team.

Surface nanocrystalline and hardening effects of Ti-Al-V alloy by electropulsing ultrasonic shock

NASA Astrophysics Data System (ADS)

Ye, Xiaoxin; Tang, Guoyi

2015-03-01

The effect of electropulsing ultrasonic shock (EUS) on the surface hardening and microstructure of Ti6Al4V alloy was studied. It was found that electropulsing improved the microhardness dramatically both in the influential depth and maximum value, compared with the only ultrasonic-shocked sample. It's indicated that refined surface layer with nanocrystalline and improved microhardness were obtained on account of surface severe plastic deformation, dynamic recrystallization (DRX) and phase change, which was implemented at relative low temperature and high strain rate/capacity due to the coupling of the thermal and athermal effects of EUS. It's different from conventional experiments and theory. It's discussed that the positive contributions of EPT in the thermodynamics and kinetics of microstructure and properties change were attributed to the reduction of nucleation energy barrier and acceleration of atomic diffusion. Therefore, it's supposed that EUS is an energy-saving and high-efficiency method of surface treatment technique with the help of high-energy electropulses, which is promising in cost reduction of the surface engineering and energy management. The work is supported by National Natural Science Foundation of China (No. 50571048) and Shenzhen science and technology research funding project of China (No. SGLH20121008144756946).

InP Transferred Electron Cathodes: Basic to Manufacturing Methods

DTIC Science & Technology

2007-08-29

Source: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films ; January/February 2003; v.21, no.1, p.219-225 Optimization and...Vacuum, Surfaces and Films ; Sept/Oct 2007 V. 25, No. 5 List of papers submitted or published that acknowledge ARO support during this reporting period...technologies. Night vision devices gather existing ambient light (starlight, moonlight or infra-red light) through a front lens. This light goes into a

SERS as an analytical tool in environmental science: The detection of sulfamethoxazole in the nanomolar range by applying a microfluidic cartridge setup.

PubMed

Patze, Sophie; Huebner, Uwe; Liebold, Falk; Weber, Karina; Cialla-May, Dana; Popp, Juergen

2017-01-01

Sulfamethoxazole (SMX) is a commonly applied antibiotic for treating urinary tract infections; however, allergic reactions and skin eczema are known side effects that are observed for all sulfonamides. Today, this molecule is present in drinking and surface water sources. The allowed concentration in tap water is 2·10 -7  mol L -1 . SMX could unintentionally be ingested by healthy people when drinking contaminated tap water, representing unnecessary drug intake. To assess the quality of tap water, fast, specific and sensitive detection methods are required, in which consequence measures for improving the purification of water might be initiated in the short term. Herein, the quantitative detection of SMX down to environmentally and physiologically relevant concentrations in the nanomolar range by employing surface-enhanced Raman spectroscopy (SERS) and a microfluidic cartridge system is presented. By applying surface-water samples as matrices, the detection of SMX down to 2.2·10 -9  mol L -1 is achieved, which illustrates the great potential of our proposed method in environmental science. Copyright © 2016 Elsevier B.V. All rights reserved.

Agnes Pockels: Life, Letters and Papers

NASA Astrophysics Data System (ADS)

Helm, Christiane A.

2004-03-01

Agnes Pockels (1862 - 1935) was a German woman, whose studies pioneered surface science. She was born in malaria infected North Italy while her father served in the Austrian army. Because he suffered adverse health effects, the family moved in1871 to Braunschweig (North Germany). There, Pockels went to high school. She was interested in science, but formal training was not available for girls. She took on the role of household manager and nurse as her parents' health deteriorated further. Her diary illustrates the difficulties she faced in trying to maintain her own health, the health of her parents and her scientific research at the same time. When Pockels was 18 or 19, she designed a ring tensiometer. Additionally, she found a new method to introduce water-insoluble compounds to the water surface by dissolving them in an organic solvent, and applying drops of the solution. Her surface film balance technique from 1882 is the basis for the method later developed by Langmuir. Since her experimental work was highly original and in a new field, she failed to get it recognized in her own country. When she was 28, she wrote to Lord Rayleigh, since she had read about his recent experiments in surface physics. Rayleigh was so impressed with her experimental methods and results that he had her letter translated from German and published it in Nature (1891). She continued her research on surface films, interactions of solutions and contact angles (more papers, 3 in Nature). Still, she did all experiments at home. With the death of her brother in 1913 and the onset of the war, she retired into private life. Thus she was surprised when she was awarded in her late 60ies with a honorary doctorate by the TU Braunschweig (1932) and the annual prize of the German Colloid Society (1931).

Contact-free calibration of an asymmetric multi-layer interferometer for the surface force balance

NASA Astrophysics Data System (ADS)

Balabajew, Marco; van Engers, Christian D.; Perkin, Susan

2017-12-01

The Surface Force Balance (SFB, also known as Surface Force Apparatus, SFA) has provided important insights into many phenomena within the field of colloid and interface science. The technique relies on using white light interferometry to measure the distance between surfaces with sub-nanometer resolution. Up until now, the determination of the distance between the surfaces required a so-called "contact calibration," an invasive procedure during which the surfaces are brought into mechanical contact. This requirement for a contact calibration limits the range of experimental systems that can be investigated with SFB, for example, it precludes experiments with substrates that would be irreversibly modified or damaged by mechanical contact. Here we present a non-invasive method to measure absolute distances without performing a contact calibration. The method can be used for both "symmetric" and "asymmetric" systems. We foresee many applications for this general approach including, most immediately, experiments using single layer graphene electrodes in the SFB which may be damaged when brought into mechanical contact.

Surface capillary currents: Rediscovery of fluid-structure interaction by forced evolving boundary theory

NASA Astrophysics Data System (ADS)

Wang, Chunbai; Mitra, Ambar K.

2016-01-01

Any boundary surface evolving in viscous fluid is driven with surface capillary currents. By step function defined for the fluid-structure interface, surface currents are found near a flat wall in a logarithmic form. The general flat-plate boundary layer is demonstrated through the interface kinematics. The dynamics analysis elucidates the relationship of the surface currents with the adhering region as well as the no-slip boundary condition. The wall skin friction coefficient, displacement thickness, and the logarithmic velocity-defect law of the smooth flat-plate boundary-layer flow are derived with the advent of the forced evolving boundary method. This fundamental theory has wide applications in applied science and engineering.

Non-invasive imaging methods applied to neo- and paleo-ontological cephalopod research

NASA Astrophysics Data System (ADS)

Hoffmann, R.; Schultz, J. A.; Schellhorn, R.; Rybacki, E.; Keupp, H.; Gerden, S. R.; Lemanis, R.; Zachow, S.

2014-05-01

Several non-invasive methods are common practice in natural sciences today. Here we present how they can be applied and contribute to current topics in cephalopod (paleo-) biology. Different methods will be compared in terms of time necessary to acquire the data, amount of data, accuracy/resolution, minimum/maximum size of objects that can be studied, the degree of post-processing needed and availability. The main application of the methods is seen in morphometry and volumetry of cephalopod shells. In particular we present a method for precise buoyancy calculation. Therefore, cephalopod shells were scanned together with different reference bodies, an approach developed in medical sciences. It is necessary to know the volume of the reference bodies, which should have similar absorption properties like the object of interest. Exact volumes can be obtained from surface scanning. Depending on the dimensions of the study object different computed tomography techniques were applied.

Sensing surface mechanical deformation using active probes driven by motor proteins

PubMed Central

Inoue, Daisuke; Nitta, Takahiro; Kabir, Arif Md. Rashedul; Sada, Kazuki; Gong, Jian Ping; Konagaya, Akihiko; Kakugo, Akira

2016-01-01

Studying mechanical deformation at the surface of soft materials has been challenging due to the difficulty in separating surface deformation from the bulk elasticity of the materials. Here, we introduce a new approach for studying the surface mechanical deformation of a soft material by utilizing a large number of self-propelled microprobes driven by motor proteins on the surface of the material. Information about the surface mechanical deformation of the soft material is obtained through changes in mobility of the microprobes wandering across the surface of the soft material. The active microprobes respond to mechanical deformation of the surface and readily change their velocity and direction depending on the extent and mode of surface deformation. This highly parallel and reliable method of sensing mechanical deformation at the surface of soft materials is expected to find applications that explore surface mechanics of soft materials and consequently would greatly benefit the surface science. PMID:27694937

A method for establishing a long duration, stratospheric platform for astronomical research

NASA Astrophysics Data System (ADS)

Fesen, Robert; Brown, Yorke

2015-10-01

During certain times of the year at middle and low latitudes, winds in the upper stratosphere move in nearly the opposite direction than the wind in the lower stratosphere. Here we present a method for maintaining a high-altitude balloon platform in near station-keeping mode that utilizes this stratospheric wind shear. The proposed method places a balloon-borne science platform high in the stratosphere connected by a lightweight, high-strength tether to a tug vehicle located in the lower or middle stratosphere. Using aerodynamic control surfaces, wind-induced aerodynamic forces on the tug can be manipulated to counter the wind drag acting on the higher altitude science vehicle, thus controlling the upper vehicle's geographic location. We describe the general framework of this station-keeping method, some important properties required for the upper stratospheric science payload and lower tug platforms, and compare this station-keeping approach with the capabilities of a high altitude airship and conventional tethered aerostat approaches. We conclude by discussing the advantages of such a platform for a variety of missions with emphasis on astrophysical research.

Reaction Mechanisms on Multiwell Potential Energy Surfaces in Combustion (and Atmospheric) Chemistry

DOE PAGES

Osborn, David L.

2017-03-15

Chemical reactions occurring on a potential energy surface with multiple wells are ubiquitous in low temperature combustion and the oxidation of volatile organic compounds in earth’s atmosphere. The rich variety of structural isomerizations that compete with collisional stabilization make characterizing such complex-forming reactions challenging. This review describes recent experimental and theoretical advances that deliver increasingly complete views of their reaction mechanisms. New methods for creating reactive intermediates coupled with multiplexed measurements provide many experimental observables simultaneously. Automated methods to explore potential energy surfaces can uncover hidden reactive pathways, while master equation methods enable a holistic treatment of both sequential andmore » well-skipping pathways. Our ability to probe and understand nonequilibrium effects and reaction sequences is increasing. These advances provide the fundamental science base for predictive models of combustion and the atmosphere that are crucial to address global challenges.« less

Reaction Mechanisms on Multiwell Potential Energy Surfaces in Combustion (and Atmospheric) Chemistry

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

Osborn, David L.

Chemical reactions occurring on a potential energy surface with multiple wells are ubiquitous in low temperature combustion and the oxidation of volatile organic compounds in earth’s atmosphere. The rich variety of structural isomerizations that compete with collisional stabilization make characterizing such complex-forming reactions challenging. This review describes recent experimental and theoretical advances that deliver increasingly complete views of their reaction mechanisms. New methods for creating reactive intermediates coupled with multiplexed measurements provide many experimental observables simultaneously. Automated methods to explore potential energy surfaces can uncover hidden reactive pathways, while master equation methods enable a holistic treatment of both sequential andmore » well-skipping pathways. Our ability to probe and understand nonequilibrium effects and reaction sequences is increasing. These advances provide the fundamental science base for predictive models of combustion and the atmosphere that are crucial to address global challenges.« less

A Modified Electrostatic Adsorption Apparatus for Latent Fingerprint Development on Unfired Cartridge Cases.

PubMed

Xu, Jingyang; Zhang, Ziyuan; Zheng, Xiaochun; Bond, John W

2017-05-01

Visualization of latent fingerprints on metallic surfaces by the method of applying electrostatic charging and adsorption is considered as a promising chemical-free method, which has the merit of nondestruction, and is considered to be effective for some difficult situations such as aged fingerprint deposits or those exposed to environmental extremes. In fact, a portable electrostatic generator can be easily accessible in a local forensic technology laboratory, which is already widely used in the visualization of footwear impressions. In this study, a modified version of this electrostatic apparatus is proposed for latent fingerprint development and has shown great potential in visualizing fingerprints on metallic surfaces such as cartridge cases. Results indicate that this experimental arrangement can successfully develop aged latent fingerprints on metal surfaces, and we demonstrate its effectiveness compared with existing conventional fingerprint recovery methods. © 2016 American Academy of Forensic Sciences.

Phonon dispersion on Ag (100) surface: A modified analytic embedded atom method study

NASA Astrophysics Data System (ADS)

Xiao-Jun, Zhang; Chang-Le, Chen

2016-01-01

Within the harmonic approximation, the analytic expression of the dynamical matrix is derived based on the modified analytic embedded atom method (MAEAM) and the dynamics theory of surface lattice. The surface phonon dispersions along three major symmetry directions , and X¯M¯ are calculated for the clean Ag (100) surface by using our derived formulas. We then discuss the polarization and localization of surface modes at points X¯ and M¯ by plotting the squared polarization vectors as a function of the layer index. The phonon frequencies of the surface modes calculated by MAEAM are compared with the available experimental and other theoretical data. It is found that the present results are generally in agreement with the referenced experimental or theoretical results, with a maximum deviation of 10.4%. The agreement shows that the modified analytic embedded atom method is a reasonable many-body potential model to quickly describe the surface lattice vibration. It also lays a significant foundation for studying the surface lattice vibration in other metals. Project supported by the National Natural Science Foundation of China (Grant Nos. 61471301 and 61078057), the Scientific Research Program Funded by Shaanxi Provincial Education Department, China (Grant No. 14JK1301), and the Specialized Research Fund for the Doctoral Program of Higher Education, China (Grant No. 20126102110045).

Consideration of sample return and the exploration strategy for Mars

NASA Technical Reports Server (NTRS)

Bogard, D. C.; Duke, M. B.; Gibson, E. K.; Minear, J. W.; Nyquist, L. E.; Phinney, W. C.

1979-01-01

The scientific rationale and requirements for a Mars surface sample return were examined and the experience gained from the analysis and study of the returned lunar samples were incorporated into the science requirements and engineering design for the Mars sample return mission. The necessary data sets for characterizing Mars are presented. If further analyses of surface samples are to be made, the best available method is for the analysis to be conducted in terrestrial laboratories.

Possible Mg intercalation mechanism at the Mo6 S8 cathode surface proposed by first-principles methods

NASA Astrophysics Data System (ADS)

Wan, Liwen; Prendergast, David

2015-03-01

In recent years, great attention has been paid to the development of divalent Mg-ion batteries, which can potentially double the energy density and volumetric capacity compared to monovalent Li-ion batteries. The prototype Mg-ion battery, comprising Mg(anode)/Mg(AlCl2BuEt)2.THF(electrolyte)/Mo6S8(cathode), was established in 2000 by Aurbach et al. Despite the remarkable success of this prototype system, we still lack a clear understanding of the fundamental Mg intercalation/deposition mechanism at the electrolyte/electrode interfaces that perhaps results in the observed sluggish Mg transport process. Our previous work has shown that Mg-ions are strongly coordinated in the bulk electrolyte by a combination of counterion, Cl-, and organic aprotic solvent, THF. In this work, we use first-principles methods to study Mg intercalation behavior at the Mo6S8 cathode surface with the presence of solvent molecules. It is found that the image charge, formed on this metallic cathode surface, can effectively weaken the solvent-surface interactions and facilitate Mg intercalation. A detailed Mg intercalation mechanism is proposed and the unique role of Mo6S8 as the cathode material is emphasized. This work is supported as part of the Joint Center for Energy Storage Research (JCESR), an Energy Innovation Hub funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences.

Special Issue: European Conference on Surface Science 2014

NASA Astrophysics Data System (ADS)

Opila, Robert L.; Ertas, Gulay

2015-11-01

The present Special Issue of Applied Surface Science is intended to provide a collection of peer-reviewed contributions presented at the Symposium "European Conference on Surface Science" held in Antalya (Turkey), August 31-September 5, 2014. This conference is organized annually through the joint efforts of the Surface Science Division of IUVSTA and the Surface and Interface Section of the European Physical Society (EPS). The ECOSS conference series started in 1978 in Amsterdam, Netherlands, and has been held in various cities throughout Europe during the past years. This is the first time that an ECOSS conference was held in Turkey, with the chairmanship of Prof. Sefik Suzer of Bilkent University, Ankara.

A multi-residue method for the analysis of pesticides and pesticide degradates in water using HLB solid-phase extraction and gas chromatography-ion trap mass spectrometry

USGS Publications Warehouse

Hladik, M.L.; Smalling, K.L.; Kuivila, K.M.

2008-01-01

A method was developed for the analysis of over 60 pesticides and degradates in water by HLB solid-phase extraction and gas-chromatography/mass spectrometry. Method recoveries and detection limits were determined using two surface waters with different dissolved organic carbon (DOC) concentrations. In the lower DOC water, recoveries and detection limits were 80%-108% and 1-12 ng/L, respectively. In the higher DOC water, the detection limits were slightly higher (1-15 ng/L). Additionally, surface water samples from four sites were analyzed and 14 pesticides were detected with concentrations ranging from 4 to 1,200 ng/L. ?? 2008 Springer Science+Business Media, LLC.

Software for pest-management science: computer models and databases from the United States Department of Agriculture-Agricultural Research Service.

PubMed

Wauchope, R Don; Ahuja, Lajpat R; Arnold, Jeffrey G; Bingner, Ron; Lowrance, Richard; van Genuchten, Martinus T; Adams, Larry D

2003-01-01

We present an overview of USDA Agricultural Research Service (ARS) computer models and databases related to pest-management science, emphasizing current developments in environmental risk assessment and management simulation models. The ARS has a unique national interdisciplinary team of researchers in surface and sub-surface hydrology, soil and plant science, systems analysis and pesticide science, who have networked to develop empirical and mechanistic computer models describing the behavior of pests, pest responses to controls and the environmental impact of pest-control methods. Historically, much of this work has been in support of production agriculture and in support of the conservation programs of our 'action agency' sister, the Natural Resources Conservation Service (formerly the Soil Conservation Service). Because we are a public agency, our software/database products are generally offered without cost, unless they are developed in cooperation with a private-sector cooperator. Because ARS is a basic and applied research organization, with development of new science as our highest priority, these products tend to be offered on an 'as-is' basis with limited user support except for cooperating R&D relationship with other scientists. However, rapid changes in the technology for information analysis and communication continually challenge our way of doing business.

Surface effects on the thermal conductivity of silicon nanowires

NASA Astrophysics Data System (ADS)

Li, Hai-Peng; Zhang, Rui-Qin

2018-03-01

Thermal transport in silicon nanowires (SiNWs) has recently attracted considerable attention due to their potential applications in energy harvesting and generation and thermal management. The adjustment of the thermal conductivity of SiNWs through surface effects is a topic worthy of focus. In this paper, we briefly review the recent progress made in this field through theoretical calculations and experiments. We come to the conclusion that surface engineering methods are feasible and effective methods for adjusting nanoscale thermal transport and may foster further advancements in this field. Project supported by the National Natural Science Foundation ofChina (Grant No. 11504418), China Scholarship Council (Grant No. 201706425053), Basic Research Program in Shenzhen, China (Grant No. JCYJ20160229165210666), and the Fundamental Research Funds for the Central Universities of China (Grant No. 2015XKMS075).

CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Novel Route to Fabrication of Metal-Sandwiched Nanoscale Tapered Structures

NASA Astrophysics Data System (ADS)

Zhang, Yang; Yu, Da-Peng

2009-08-01

Tapered dielectric structures in metal have exhibited extraordinary performance in both surface plasmon polariton (SPP) waveguiding and SPP focusing. This is crucial to plasmonic research and industrial plasmonic device integration. We present a method that facilitates easy fabrication of smooth-surfaced sub-micron tapered structures in large scale simply with electron beam lithography (EBL). When a PMMA layer is spin-coated on previously-EBL-defined PMMA structures, steep edges can be transformed into a declining slope to form tapered PMMA structures, scaled from 10 nm to 1000 nm. Despite the simplicity of our method, patterns with PMMA surface smoothness can be well-positioned and replicated in large numbers, which therefore gives scientists easy access to research on the properties of tapered structures.

Coherent Control About a Conical Intersection

NASA Astrophysics Data System (ADS)

Liekhus-Schmaltz, Chelsea; McCracken, Gregory; Kaldun, Andreas; Cryan, James P.; Bucksbaum, Philip H.

2017-04-01

Conical intersections (CIs) are degeneracies between molecular potential energy surfaces that occur in essentially all molecules with more than three atoms. Many studies have established that CIs allow for non-Born-Oppenheimer (non-adiabatic) molecular dynamics. In addition, CIs have many useful attributes for coherent control that have not been fully studied. Here we demonstrate two modes of control around a CI that make use of these properties. The first method uses a continuous light field, resonant absorption, and stimulated emission to control the population on two intersecting electronic states. The second method uses a pulsed light field and the geometric phase accumulated by a wavepacket traversing a CI to control the shape of the wavepacket. This work was supported by the National Science Foundation under Grant No. PHY-0649578, the DOE SCGSR fellowship program, and the DOE, Office of Science, BES, Chemical Sciences, Geosciences, and Biosciences Division.

Suborbital Science Program: Dryden Flight Research Center

NASA Technical Reports Server (NTRS)

DelFrate, John

2008-01-01

This viewgraph presentation reviews the suborbital science program at NASA Dryden Flight Research Center. The Program Objectives are given in various areas: (1) Satellite Calibration and Validation (Cal/val)--Provide methods to perform the cal/val requirements for Earth Observing System satellites; (2) New Sensor Development -- Provide methods to reduce risk for new sensor concepts and algorithm development prior to committing sensors to operations; (3) Process Studies -- Facilitate the acquisition of high spatial/temporal resolution focused measurements that are required to understand small atmospheric and surface structures which generate powerful Earth system effects; and (4) Airborne Networking -- Develop disruption-tolerant networking to enable integrated multiple scale measurements of critical environmental features. Dryden supports the NASA Airborne Science Program and the nation in several elements: ER-2, G-3, DC-8, Ikhana (Predator B) & Global Hawk and Reveal. These are reviewed in detail in the presentation.

Using Analog Field Tests To Link and Prepare Science and In-Situ Resource Utilization for Future Space Missions

NASA Technical Reports Server (NTRS)

Sanders, Gerald B.

2010-01-01

A major goal of NASA s human exploration program is to learn how to use the resources of space, known as In-Situ Resource Utilization (ISRU), to lower the cost and risk of human space exploration. Successful implementation of ISRU requires detailed knowledge of surface and subsurface materials, minerals, and volatiles that may be present. This same information is required to better understand the physical and geologic composition, structure, origin, and evolution of the Moon, Mars, and other extraterrestrial bodies of interest. It is also important to recognize that while ISRU and science objectives may be similar, the desired method or hardware to achieve the information desired may be drastically different. One method to promote understanding, coordination, and joint development of instruments and operations between Science and ISRU is the use of analog field demonstrations.

The Gender Subtext of Organizational Learning

ERIC Educational Resources Information Center

Raaijmakers, Stephan; Bleijenbergh, Inge; Fokkinga, Brigit; Visser, Max

2018-01-01

Purpose: This paper aims to challenge the alleged gender-neutral character of Argyris and Schön's theory of organizational learning (1978). While theories in organizational science seem gender neutral at the surface, a closer analysis reveals they are often based on men's experiences. Design/methodology/approach: This paper uses the method of…

Autonomous Surface Sample Acquisition for Planetary and Lunar Exploration

NASA Astrophysics Data System (ADS)

Barnes, D. P.

2007-08-01

Surface science sample acquisition is a critical activity within any planetary and lunar exploration mission, and our research is focused upon the design, implementation, experimentation and demonstration of an onboard autonomous surface sample acquisition capability for a rover equipped with a robotic arm upon which are mounted appropriate science instruments. Images captured by a rover stereo camera system can be processed using shape from stereo methods and a digital elevation model (DEM) generated. We have developed a terrain feature identification algorithm that can determine autonomously from DEM data suitable regions for instrument placement and/or surface sample acquisition. Once identified, surface normal data can be generated autonomously which are then used to calculate an arm trajectory for instrument placement and sample acquisition. Once an instrument placement and sample acquisition trajectory has been calculated, a collision detection algorithm is required to ensure the safe operation of the arm during sample acquisition.We have developed a novel adaptive 'bounding spheres' approach to this problem. Once potential science targets have been identified, and these are within the reach of the arm and will not cause any undesired collision, then the 'cost' of executing the sample acquisition activity is required. Such information which includes power expenditure and duration can be used to select the 'best' target from a set of potential targets. We have developed a science sample acquisition resource requirements calculation that utilises differential inverse kinematics methods to yield a high fidelity result, thus improving upon simple 1st order approximations. To test our algorithms a new Planetary Analogue Terrain (PAT) Laboratory has been created that has a terrain region composed of Mars Soil Simulant-D from DLR Germany, and rocks that have been fully characterised in the laboratory. These have been donated by the UK Planetary Analogue Field Study network, and constitute the science targets for our autonomous sample acquisition work. Our PAT Lab. terrain has been designed to support our new rover chassis which is based upon the ExoMars rover Concept-E mechanics which were investigated during the ESA ExoMars Phase A study. The rover has 6 wheel drives, 6 wheels steering, and a 6 wheel walking capability. Mounted on the rover chassis is the UWA robotic arm and mast. We have designed and built a PanCam system complete with a computer controlled pan and tilt mechanism. The UWA PanCam is based upon the ExoMars PanCam (Phase A study) and hence supports two Wide Angle Cameras (WAC - 64 degree FOV), and a High Resolution Camera (HRC - 5 degree FOV). WAC separation is 500 mm. Software has been developed to capture images which form the data input into our on-board autonomous surface sample acquisition algorithms.

A Surface Science Perspective on TiO2 Photocatalysis

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

Henderson, Michael A.

2011-06-15

The field of surface science provides a unique approach to understanding bulk, surface and interfacial phenomena occurring during TiO2 photochemistry and photocatalysis. This review highlights, from a surface science perspective, recent literature providing molecular-level insights into phonon-initiated events on TiO2 surfaces obtained in seven key scientific issues: (1) photon absorption, (2) charge transport and trapping, (3) electron transfer dynamics, (4) the adsorbed state, (5) mechanisms, (6) poisons and promoters, and (7) phase and form.

Evolution of vortex-surface fields in transitional boundary layers

NASA Astrophysics Data System (ADS)

Yang, Yue; Zhao, Yaomin; Xiong, Shiying

2016-11-01

We apply the vortex-surface field (VSF), a Lagrangian-based structure-identification method, to the DNS database of transitional boundary layers. The VSFs are constructed from the vorticity fields within a sliding window at different times and locations using a recently developed boundary-constraint method. The isosurfaces of VSF, representing vortex surfaces consisting of vortex lines with different wall distances in the laminar stage, show different evolutionary geometries in transition. We observe that the vortex surfaces with significant deformation evolve from wall-parallel planar sheets through hairpin-like structures and packets into a turbulent spot with regeneration of small-scale hairpins. From quantitative analysis, we show that a small number of representative or influential vortex surfaces can contribute significantly to the increase of the drag coefficient in transition, which implies a reduced-order model based on VSF. This work has been supported in part by the National Natural Science Foundation of China (Grant Nos. 11472015, 11522215 and 11521091), and the Thousand Young Talents Program of China.

Surface Tension and Viscosity Measurements in Microgravity: Some Results and Fluid Flow Observations during MSL-1

NASA Technical Reports Server (NTRS)

Hyer, Robert W.; Trapaga, G.; Flemings, M. C.

1999-01-01

The viscosity of a liquid metal was successfully measured for the first time by a containerless method, the oscillating drop technique. This method also provides a means to obtain a precise, non-contact measurement of the surface tension of the droplet. This technique involves exciting the surface of the molten sample and then measuring the resulting oscillations; the natural frequency of the oscillating sample is determined by its surface tension, and the damping of the oscillations by the viscosity. These measurements were performed in TEMPUS, a microgravity electromagnetic levitator (EML), on the Space Shuttle as a part of the First Microgravity Science Laboratory (MSL-1), which flew in April and July 1997 (STS-83 and STS-94). Some results of the surface tension and viscosity measurements are presented for Pd82Si18. Some observations of the fluid dynamic characteristics (dominant flow patterns, turbulent transition, cavitation, etc.) of levitated droplets are presented and discussed together with magnetohydrodynamic calculations, which were performed to justify these findings.

Catalysis in the Diels-Alder Cycloaddition of Biomass-Derived Furan and Methyl Acrylate by Transition Metal Oxide Surfaces.

NASA Astrophysics Data System (ADS)

Salavati-Fard, Taha; Jenness, Glen; Caratzoulas, Stavros; Doren, Douglas

Using computational methods, the catalytic effects of oxide surfaces on the Diels-Alder reaction between biomass-derived furan and methyl acrylate are investigated. The cycloadduct can be dehydrated later to produce methyl benzoic which is an important step toward benzoic acid production. Different systems such as clean, partially hydroxylated and fully hydroxylated ZrO2 are considered. The Langmuir and Eley-Rideal mechanisms are studied, as well. Our calculations show that the oxide surfaces catalyze the reaction significantly through the interaction of metal sites with the electron-poor reactant. The calculations are interpreted by making use of the total and projected electronic density of states and band structure of the catalyst. This material is based on work supported as part of the Catalysis Center for Energy Innovation, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001004.

Elementary Chemical Reactions in Surface Photocatalysis

NASA Astrophysics Data System (ADS)

Guo, Qing; Zhou, Chuanyao; Ma, Zhibo; Ren, Zefeng; Fan, Hongjun; Yang, Xueming

2018-04-01

Photocatalytic hydrogen evolution and organic degradation on oxide materials have been extensively investigated in the last two decades. Great efforts have been dedicated to the study of photocatalytic reaction mechanisms of a variety of molecules on TiO2 surfaces by using surface science methods under ultra-high vacuum (UHV) conditions, providing fundamental understanding of surface chemical reactions in photocatalysis. In this review, we summarize the recent progress in the study of photocatalysis of several important species (water, methanol, and aldehydes) on different TiO2 surfaces. The results of these studies have provided us deep insights into the elementary processes of surface photocatalysis and stimulated a new frontier of research in this area. Based on the results of these studies, a new dynamics-based photocatalysis model is also discussed.

Parallel Study of HEND, RAD, and DAN Instrument Response to Martian Radiation and Surface Conditions

NASA Technical Reports Server (NTRS)

Martiniez Sierra, Luz Maria; Jun, Insoo; Litvak, Maxim; Sanin, Anton; Mitrofanov, Igor; Zeitlin, Cary

2015-01-01

Nuclear detection methods are being used to understand the radiation environment at Mars. JPL (Jet Propulsion Laboratory) assets on Mars include: Orbiter -2001 Mars Odyssey [High Energy Neutron Detector (HEND)]; Mars Science Laboratory Rover -Curiosity [(Radiation Assessment Detector (RAD); Dynamic Albedo Neutron (DAN))]. Spacecraft have instruments able to detect ionizing and non-ionizing radiation. Instrument response on orbit and on the surface of Mars to space weather and local conditions [is discussed] - Data available at NASA-PDS (Planetary Data System).

Workshop on Surface Science and Technology Held in Ann Arbor, Michigan on 7-9 November 1990

DTIC Science & Technology

1992-03-01

assess the state of the art of surface science and technology as well as to identify new research opportunities essential for the understanding and control...The objective of this workshop was to review and assess the state of the art of surface science and technology as well as to identify new research...AD-A253 566 ’ # 4 - m~~i n~nl lInIir ~~ na Ri1 ?epoi’rt: EN 1Workshop on Surface Science and Technology DTIC ft , L-CTE I OUG0 3192 Ann Arbor

Shape optimization of self-avoiding curves

NASA Astrophysics Data System (ADS)

Walker, Shawn W.

2016-04-01

This paper presents a softened notion of proximity (or self-avoidance) for curves. We then derive a sensitivity result, based on shape differential calculus, for the proximity. This is combined with a gradient-based optimization approach to compute three-dimensional, parameterized curves that minimize the sum of an elastic (bending) energy and a proximity energy that maintains self-avoidance by a penalization technique. Minimizers are computed by a sequential-quadratic-programming (SQP) method where the bending energy and proximity energy are approximated by a finite element method. We then apply this method to two problems. First, we simulate adsorbed polymer strands that are constrained to be bound to a surface and be (locally) inextensible. This is a basic model of semi-flexible polymers adsorbed onto a surface (a current topic in material science). Several examples of minimizing curve shapes on a variety of surfaces are shown. An advantage of the method is that it can be much faster than using molecular dynamics for simulating polymer strands on surfaces. Second, we apply our proximity penalization to the computation of ideal knots. We present a heuristic scheme, utilizing the SQP method above, for minimizing rope-length and apply it in the case of the trefoil knot. Applications of this method could be for generating good initial guesses to a more accurate (but expensive) knot-tightening algorithm.

Study of Vibrational Energy Transfer at a Surface by a Time-of-Flight Method.

DTIC Science & Technology

1983-07-31

82174* - *-. L7 .i.&. I- I OD(D SOI x O 1 6/81 INIT DISTRIBUTION LIST July 31, 1983 No. Copies No. Copies Dr. L.V. Schmidt 1 Dr. F. Roberto 1 Assistant...of Scientific Dr. A.L. Slafkosky 1Research Scientific Advisor Directorate of Aerospace Sciences Commandant of the Marine Corps Bolling Air Force Base...Research Research Code 432 Directorate of Chemical Sciences Arlington, VA 22217 Bolling Air Force Base Washington, D.C. 20332Mr. David SiegelI Office of

The birth and evolution of surface science: child of the union of science and technology.

PubMed

Duke, C B

2003-04-01

This article is an account of the birth and evolution of surface science as an interdisciplinary research area. Surface science emanated from the confluence of concepts and tools in physics and chemistry with technological innovations that made it possible to determine the structure and properties of surfaces and interfaces and the dynamics of chemical reactions at surfaces. The combination in the 1960s and 1970s of ultra-high-vacuum (i.e., P < 10(-7) Pascal or 10(-9) Torr) technology with the recognition that electrons in the energy range from 50 to 500 eV exhibited inelastic collision mean free paths of the order of a few angstroms fostered an explosion of activity. The results were a reformulation of the theory of electron solid scattering, the nearly universal use of electron spectroscopies for surface characterization, the rise of surface science as an independent interdisciplinary research area, and the emergence of the American Vacuum Society (AVS) as a major international scientific society. The rise of microelectronics in the 1970s and 1980s resulted in huge increases in computational power. These increases enabled more complex experiments and the utilization of density functional theory for the quantitative prediction of surface structure and dynamics. Development of scanning-probe microscopies in the 1990s led to atomic-resolution images of macroscopic surfaces and interfaces as well as videos of atoms moving about on surfaces during growth and diffusion. Scanning probes have since brought solid-liquid interfaces into the realm of atomic-level surface science, expanding its scope to more complex systems, including fragile biological materials and processes.

Titan Lifting Entry & Atmospheric Flight (T-LEAF) Science Mission

NASA Astrophysics Data System (ADS)

Lee, G.; Sen, B.; Ross, F.; Sokol, D.

2016-12-01

Northrop Grumman has been developing the Titan Lifting Entry & Atmospheric Flight (T-LEAF) sky rover to roam the lower atmosphere and observe at close quarters the lakes and plains of Saturn's ocean moon, Titan. T-LEAF also supports surface exploration and science by providing precision delivery of in-situ instruments to the surface of Titan. T-LEAF is a highly maneuverable sky rover and its aerodynamic shape (i.e., a flying wing) does not restrict it to following prevailing wind patterns on Titan, but allows mission operators to chart its course. This freedom of mobility allows T-LEAF to follow the shorelines of Titan's methane lakes, for example, or to target very specific surface locations. We will present a straw man concept of T-LEAF, including size, mass, power, on-board science payloads and measurement, and surface science dropsonde deployment CONOPS. We will discuss the various science instruments and their vehicle level impacts, such as meteorological and electric field sensors, acoustic sensors for measuring shallow depths, multi-spectral imagers, high definition cameras and surface science dropsondes. The stability of T-LEAF and its long residence time on Titan will provide for time to perform a large aerial survey of select prime surface targets deployment of dropsondes at selected locations surface measurements that are coordinated with on-board remote measurements communication relay capabilities to orbiter (or Earth). In this context, we will specifically focus upon key factors impacting the design and performance of T-LEAF science: science payload accommodation, constraints and opportunities characteristics of flight, payload deployment and measurement CONOPS in the Titan atmosphere. This presentation will show how these factors provide constraints as well as enable opportunities for novel long duration scientific studies of Titan's surface.

A KNOWLEDGE DISCOVERY STRATEGY FOR RELATING SEA SURFACE TEMPERATURES TO FREQUENCIES OF TROPICAL STORMS AND GENERATING PREDICTIONS OF HURRICANES UNDER 21ST-CENTURY GLOBAL WARMING SCENARIOS

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

Race, Caitlin; Steinbach, Michael; Ganguly, Auroop R

2010-01-01

The connections among greenhouse-gas emissions scenarios, global warming, and frequencies of hurricanes or tropical cyclones are among the least understood in climate science but among the most fiercely debated in the context of adaptation decisions or mitigation policies. Here we show that a knowledge discovery strategy, which leverages observations and climate model simulations, offers the promise of developing credible projections of tropical cyclones based on sea surface temperatures (SST) in a warming environment. While this study motivates the development of new methodologies in statistics and data mining, the ability to solve challenging climate science problems with innovative combinations of traditionalmore » and state-of-the-art methods is demonstrated. Here we develop new insights, albeit in a proof-of-concept sense, on the relationship between sea surface temperatures and hurricane frequencies, and generate the most likely projections with uncertainty bounds for storm counts in the 21st-century warming environment based in turn on the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios. Our preliminary insights point to the benefits that can be achieved for climate science and impacts analysis, as well as adaptation and mitigation policies, by a solution strategy that remains tailored to the climate domain and complements physics-based climate model simulations with a combination of existing and new computational and data science approaches.« less

Surface area-volume ratios in insects.

PubMed

Kühsel, Sara; Brückner, Adrian; Schmelzle, Sebastian; Heethoff, Michael; Blüthgen, Nico

2017-10-01

Body mass, volume and surface area are important for many aspects of the physiology and performance of species. Whereas body mass scaling received a lot of attention in the literature, surface areas of animals have not been measured explicitly in this context. We quantified surface area-volume (SA/V) ratios for the first time using 3D surface models based on a structured light scanning method for 126 species of pollinating insects from 4 orders (Diptera, Hymenoptera, Lepidoptera, and Coleoptera). Water loss of 67 species was measured gravimetrically at very dry conditions for 2 h at 15 and 30 °C to demonstrate the applicability of the new 3D surface measurements and relevance for predicting the performance of insects. Quantified SA/V ratios significantly explained the variation in water loss across species, both directly or after accounting for isometric scaling (residuals of the SA/V ∼ mass 2/3 relationship). Small insects with a proportionally larger surface area had the highest water loss rates. Surface scans of insects to quantify allometric SA/V ratios thus provide a promising method to predict physiological responses, improving the potential of body mass isometry alone that assume geometric similarity. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Gaussian process based intelligent sampling for measuring nano-structure surfaces

NASA Astrophysics Data System (ADS)

Sun, L. J.; Ren, M. J.; Yin, Y. H.

2016-09-01

Nanotechnology is the science and engineering that manipulate matters at nano scale, which can be used to create many new materials and devices with a vast range of applications. As the nanotech product increasingly enters the commercial marketplace, nanometrology becomes a stringent and enabling technology for the manipulation and the quality control of the nanotechnology. However, many measuring instruments, for instance scanning probe microscopy, are limited to relatively small area of hundreds of micrometers with very low efficiency. Therefore some intelligent sampling strategies should be required to improve the scanning efficiency for measuring large area. This paper presents a Gaussian process based intelligent sampling method to address this problem. The method makes use of Gaussian process based Bayesian regression as a mathematical foundation to represent the surface geometry, and the posterior estimation of Gaussian process is computed by combining the prior probability distribution with the maximum likelihood function. Then each sampling point is adaptively selected by determining the position which is the most likely outside of the required tolerance zone among the candidates and then inserted to update the model iteratively. Both simulationson the nominal surface and manufactured surface have been conducted on nano-structure surfaces to verify the validity of the proposed method. The results imply that the proposed method significantly improves the measurement efficiency in measuring large area structured surfaces.

Correlation between average tissue depth data and quantitative accuracy of forensic craniofacial reconstructions measured by geometric surface comparison method.

PubMed

Lee, Won-Joon; Wilkinson, Caroline M; Hwang, Hyeon-Shik; Lee, Sang-Mi

2015-05-01

Accuracy is the most important factor supporting the reliability of forensic facial reconstruction (FFR) comparing to the corresponding actual face. A number of methods have been employed to evaluate objective accuracy of FFR. Recently, it has been attempted that the degree of resemblance between computer-generated FFR and actual face is measured by geometric surface comparison method. In this study, three FFRs were produced employing live adult Korean subjects and three-dimensional computerized modeling software. The deviations of the facial surfaces between the FFR and the head scan CT of the corresponding subject were analyzed in reverse modeling software. The results were compared with those from a previous study which applied the same methodology as this study except average facial soft tissue depth dataset. Three FFRs of this study that applied updated dataset demonstrated lesser deviation errors between the facial surfaces of the FFR and corresponding subject than those from the previous study. The results proposed that appropriate average tissue depth data are important to increase quantitative accuracy of FFR. © 2015 American Academy of Forensic Sciences.

Experts workshop on the ecotoxicological risk assessment of ionizable organic chemicals: Towards a science-based framework for chemical assessment

EPA Science Inventory

There is a growing need to develop analytical methods and tools that can be applied to assess the environmental risks associated with charged, polar, and ionisable organic chemicals, such as those used as active pharmaceutical ingredients, biocides, and surface active chemicals. ...

Molecular metal catalysts on supports: organometallic chemistry meets surface science.

PubMed

Serna, Pedro; Gates, Bruce C

2014-08-19

Recent advances in the synthesis and characterization of small, essentially molecular metal complexes and metal clusters on support surfaces have brought new insights to catalysis and point the way to systematic catalyst design. We summarize recent work unraveling effects of key design variables of site-isolated catalysts: the metal, metal nuclearity, support, and other ligands on the metals, also considering catalysts with separate, complementary functions on supports. The catalysts were synthesized with the goal of structural simplicity and uniformity to facilitate incisive characterization. Thus, they are essentially molecular species bonded to porous supports chosen for their high degree of uniformity; the supports are crystalline aluminosilicates (zeolites) and MgO. The catalytic species are synthesized in reactions of organometallic precursors with the support surfaces; the precursors include M(L)2(acetylacetonate)1-2, with M = Ru, Rh, Ir, or Au and the ligands L = C2H4, CO, or CH3. Os3(CO)12 and Ir4(CO)12 are used as precursors of supported metal clusters, and some such catalysts are made by ship-in-a-bottle syntheses to trap the clusters in zeolite cages. The simplicity and uniformity of the supported catalysts facilitate precise structure determinations, even in reactive atmospheres and during catalysis. The methods of characterizing catalysts in reactive atmospheres include infrared (IR), extended X-ray absorption fine structure (EXAFS), X-ray absorption near edge structure (XANES), and nuclear magnetic resonance (NMR) spectroscopies, and complementary methods include density functional theory and atomic-resolution aberration-corrected scanning transmission electron microscopy for imaging of individual metal atoms. IR, NMR, XANES, and microscopy data demonstrate the high degrees of uniformity of well-prepared supported species. The characterizations determine the compositions of surface metal complexes and clusters, including the ligands and the metal-support bonding and structure, which identify the supports as ligands with electron-donor properties that influence reactivity and catalysis. Each of the catalyst design variables has been varied independently, illustrated by mononuclear and tetranuclear iridium on zeolite HY and on MgO and by isostructural rhodium and iridium (diethylene or dicarbonyl) complexes on these supports. The data provide examples resolving the roles of the catalyst design variables and place the catalysis science on a firm foundation of organometallic chemistry linked with surface science. Supported molecular catalysts offer the advantages of characterization in the absence of solvents and with surface-science methods that do not require ultrahigh vacuum. Families of supported metal complexes have been made by replacement of ligands with others from the gas phase. Spectroscopically identified catalytic reaction intermediates help to elucidate catalyst performance and guide design. The methods are illustrated for supported complexes and clusters of rhodium, iridium, osmium, and gold used to catalyze reactions of small molecules that facilitate identification of the ligands present during catalysis: alkene dimerization and hydrogenation, H-D exchange in the reaction of H2 with D2, and CO oxidation. The approach is illustrated with the discovery of a highly active and selective MgO-supported rhodium carbonyl dimer catalyst for hydrogenation of 1,3-butadiene to give butenes.

Surface chemistry at Swiss Universities of Applied Sciences.

PubMed

Brodard, Pierre; Pfeifer, Marc E; Adlhart, Christian D; Pieles, Uwe; Shahgaldian, Patrick

2014-01-01

In the Swiss Universities of Applied Sciences, a number of research groups are involved in surface science, with different methodological approaches and a broad range of sophisticated characterization techniques. A snapshot of the current research going on in different groups from the University of Applied Sciences and Arts Western Switzerland (HES-SO), the Zurich University of Applied Sciences (ZHAW) and the University of Applied Sciences and Arts Northwestern Switzerland (FHNW) is given.

Developing the Cleanliness Requirements for an Organic-detection Instrument MOMA-MS

NASA Technical Reports Server (NTRS)

Perry, Radford; Canham, John; Lalime, Erin

2015-01-01

The cleanliness requirements for an organic-detection instrument, like the Mars Organic Molecule Analyzer Mass Spectrometer (MOMA-MS), on a Planetary Protection Class IVb mission can be extremely stringent. These include surface molecular and particulate, outgassing, and bioburden. The prime contractor for the European Space Agencys ExoMars 2018 project, Thales Alenia Space Italy, provided requirements based on a standard, conservative approach of defining limits which yielded levels that are unverifiable by standard cleanliness verification methods. Additionally, the conservative method for determining contamination surface area uses underestimation while conservative bioburden surface area relies on overestimation, which results in inconsistencies for the normalized reporting. This presentation will provide a survey of the challenge to define requirements that can be reasonably verified and still remain appropriate to the core science of the ExoMars mission.

Science Syllabus for Middle and Junior High Schools. Block D, The Earth's Changing Surface.

ERIC Educational Resources Information Center

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

This syllabus begins with a list of program objectives and performance criteria for the study of three general topic areas in earth science and a list of 22 science processes. Following this information is a listing of concepts and understandings for subtopics within the general topic areas: (1) the earth's surface--surface features, rock…

A Surface Science Paradigm for a Post-Huygens Titan Mission

NASA Technical Reports Server (NTRS)

Zimmerman, Wayne F.; Lunine, Jonathan; Lorenz, Ralph

2005-01-01

With the Cassini-Huygens atmospheric probe drop-off mission fast approaching, it is essential that scientists and engineers start scoping potential follow-on surface science missions. This paper provides a summary of the first year of a two year design study which examines in detail the desired surface science measurements and resolution, potential instrument suite, and complete payload delivery system. Also provided are design concepts for both an aerial inflatable mobility platform and deployable instrument sonde. The tethered deployable sonde provides the capability to sample near surface atmosphere, sub-surface liquid (if it exists), and surface solid material. Actual laboratory tests of the amphibious sonde prototype are also presented.

3D reconstruction of SEM images by use of optical photogrammetry software.

PubMed

Eulitz, Mona; Reiss, Gebhard

2015-08-01

Reconstruction of the three-dimensional (3D) surface of an object to be examined is widely used for structure analysis in science and many biological questions require information about their true 3D structure. For Scanning Electron Microscopy (SEM) there has been no efficient non-destructive solution for reconstruction of the surface morphology to date. The well-known method of recording stereo pair images generates a 3D stereoscope reconstruction of a section, but not of the complete sample surface. We present a simple and non-destructive method of 3D surface reconstruction from SEM samples based on the principles of optical close range photogrammetry. In optical close range photogrammetry a series of overlapping photos is used to generate a 3D model of the surface of an object. We adapted this method to the special SEM requirements. Instead of moving a detector around the object, the object itself was rotated. A series of overlapping photos was stitched and converted into a 3D model using the software commonly used for optical photogrammetry. A rabbit kidney glomerulus was used to demonstrate the workflow of this adaption. The reconstruction produced a realistic and high-resolution 3D mesh model of the glomerular surface. The study showed that SEM micrographs are suitable for 3D reconstruction by optical photogrammetry. This new approach is a simple and useful method of 3D surface reconstruction and suitable for various applications in research and teaching. Copyright © 2015 Elsevier Inc. All rights reserved.

Theoretical Models for Surface Forces and Adhesion and Their Measurement Using Atomic Force Microscopy

PubMed Central

Leite, Fabio L.; Bueno, Carolina C.; Da Róz, Alessandra L.; Ziemath, Ervino C.; Oliveira, Osvaldo N.

2012-01-01

The increasing importance of studies on soft matter and their impact on new technologies, including those associated with nanotechnology, has brought intermolecular and surface forces to the forefront of physics and materials science, for these are the prevailing forces in micro and nanosystems. With experimental methods such as the atomic force spectroscopy (AFS), it is now possible to measure these forces accurately, in addition to providing information on local material properties such as elasticity, hardness and adhesion. This review provides the theoretical and experimental background of AFS, adhesion forces, intermolecular interactions and surface forces in air, vacuum and in solution. PMID:23202925

The birth and evolution of surface science: Child of the union of science and technology

PubMed Central

Duke, C. B.

2003-01-01

This article is an account of the birth and evolution of surface science as an interdisciplinary research area. Surface science emanated from the confluence of concepts and tools in physics and chemistry with technological innovations that made it possible to determine the structure and properties of surfaces and interfaces and the dynamics of chemical reactions at surfaces. The combination in the 1960s and 1970s of ultra-high-vacuum (i.e., P < 10−7 Pascal or 10−9 Torr) technology with the recognition that electrons in the energy range from 50 to 500 eV exhibited inelastic collision mean free paths of the order of a few angstroms fostered an explosion of activity. The results were a reformulation of the theory of electron solid scattering, the nearly universal use of electron spectroscopies for surface characterization, the rise of surface science as an independent interdisciplinary research area, and the emergence of the American Vacuum Society (AVS) as a major international scientific society. The rise of microelectronics in the 1970s and 1980s resulted in huge increases in computational power. These increases enabled more complex experiments and the utilization of density functional theory for the quantitative prediction of surface structure and dynamics. Development of scanning-probe microscopies in the 1990s led to atomic-resolution images of macroscopic surfaces and interfaces as well as videos of atoms moving about on surfaces during growth and diffusion. Scanning probes have since brought solid–liquid interfaces into the realm of atomic-level surface science, expanding its scope to more complex systems, including fragile biological materials and processes. PMID:12651946

Modeling for free surface flow with phase change and its application to fusion technology

NASA Astrophysics Data System (ADS)

Luo, Xiaoyong

The development of predictive capabilities for free surface flow with phase change is essential to evaluate liquid wall protection schemes for various fusion chambers. With inertial fusion energy (IFE) concepts such as HYLIFE-II, rapid condensation into cold liquid surfaces is required when using liquid curtains for protecting reactor walls from blasts and intense neutron radiation. With magnetic fusion energy (MFE) concepts, droplets are injected onto the free surface of the liquid to minimize evaporation by minimizing the surface temperature. This dissertation presents a numerical methodology for free surface flow with phase change to help resolve feasibility issues encountered in the aforementioned fusion engineering fields, especially spray droplet condensation efficiency in IFE and droplet heat transfer enhancement on free surface liquid divertors in MFE. The numerical methodology is being conducted within the framework of the incompressible flow with the phase change model. A new second-order projection method is presented in conjunction with Approximate-Factorization techniques (AF method) for incompressible Navier-Stokes equations. A sub-cell conception is introduced and the Ghost Fluid Method in extended in a modified mass transfer model to accurately calculate the mass transfer across the interface. The Crank-Nicholson method is used for the diffusion term to eliminate the numerical viscous stability restriction. The third-order ENO scheme is used for the convective term to guarantee the accuracy of the method. The level set method is used to capture accurately the free surface of the flow and the deformation of the droplets. This numerical investigation identifies the physics characterizing transient heat and mass transfer of the droplet and the free surface flow. The results show that the numerical methodology is quite successful in modeling the free surface with phase change even though some severe deformations such as breaking and merging occur. The versatility of the numerical methodology shows that the work can easily handle complex physical conditions that occur in the fusion science and engineering.

Simultaneous Retrieval of Aerosol and Surface Optical Properties from Combined Airborne- and Ground-Based Direct and Diffuse Radiometric Measurements

NASA Technical Reports Server (NTRS)

Gatebe, C. K.; Dubovik, O.; King, M. D.; Sinyuk, A.

2010-01-01

This paper presents a new method for simultaneously retrieving aerosol and surface reflectance properties from combined airborne and ground-based direct and diffuse radiometric measurements. The method is based on the standard Aerosol Robotic Network (AERONET) method for retrieving aerosol size distribution, complex index of refraction, and single scattering albedo, but modified to retrieve aerosol properties in two layers, below and above the aircraft, and parameters on surface optical properties from combined datasets (Cloud Absorption Radiometer (CAR) and AERONET data). A key advantage of this method is the inversion of all available spectral and angular data at the same time, while accounting for the influence of noise in the inversion procedure using statistical optimization. The wide spectral (0.34-2.30 m) and angular range (180 ) of the CAR instrument, combined with observations from an AERONET sunphotometer, provide sufficient measurement constraints for characterizing aerosol and surface properties with minimal assumptions. The robustness of the method was tested on observations made during four different field campaigns: (a) the Southern African Regional Science Initiative 2000 over Mongu, Zambia, (b) the Intercontinental Transport Experiment-Phase B over Mexico City, Mexico (c) Cloud and Land Surface Interaction Campaign over the Atmospheric Radiation Measurement (ARM) Central Facility, Oklahoma, USA, and (d) the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) over Elson Lagoon in Barrow, Alaska, USA. The four areas are dominated by different surface characteristics and aerosol types, and therefore provide good test cases for the new inversion method.

Human Mars Surface Science Operations

NASA Technical Reports Server (NTRS)

Bobskill, Marianne R.; Lupisella, Mark L.

2014-01-01

Human missions to the surface of Mars will have challenging science operations. This paper will explore some of those challenges, based on science operations considerations as part of more general operational concepts being developed by NASA's Human Spaceflight Architecture (HAT) Mars Destination Operations Team (DOT). The HAT Mars DOT has been developing comprehensive surface operations concepts with an initial emphasis on a multi-phased mission that includes a 500-day surface stay. This paper will address crew science activities, operational details and potential architectural and system implications in the areas of (a) traverse planning and execution, (b) sample acquisition and sample handling, (c) in-situ science analysis, and (d) planetary protection. Three cross-cutting themes will also be explored in this paper: (a) contamination control, (b) low-latency telerobotic science, and (c) crew autonomy. The present traverses under consideration are based on the report, Planning for the Scientific Exploration of Mars by Humans1, by the Mars Exploration Planning and Analysis Group (MEPAG) Human Exploration of Mars-Science Analysis Group (HEM-SAG). The traverses are ambitious and the role of science in those traverses is a key component that will be discussed in this paper. The process of obtaining, handling, and analyzing samples will be an important part of ensuring acceptable science return. Meeting planetary protection protocols will be a key challenge and this paper will explore operational strategies and system designs to meet the challenges of planetary protection, particularly with respect to the exploration of "special regions." A significant challenge for Mars surface science operations with crew is preserving science sample integrity in what will likely be an uncertain environment. Crewed mission surface assets -- such as habitats, spacesuits, and pressurized rovers -- could be a significant source of contamination due to venting, out-gassing and cleanliness levels associated with crew presence. Low-latency telerobotic science operations has the potential to address a number of contamination control and planetary protection issues and will be explored in this paper. Crew autonomy is another key cross-cutting challenge regarding Mars surface science operations, because the communications delay between earth and Mars could as high as 20 minutes one way, likely requiring the crew to perform many science tasks without direct timely intervention from ground support on earth. Striking the operational balance between crew autonomy and earth support will be a key challenge that this paper will address.

Dental Implant Systems

PubMed Central

Oshida, Yoshiki; Tuna, Elif B.; Aktören, Oya; Gençay, Koray

2010-01-01

Among various dental materials and their successful applications, a dental implant is a good example of the integrated system of science and technology involved in multiple disciplines including surface chemistry and physics, biomechanics, from macro-scale to nano-scale manufacturing technologies and surface engineering. As many other dental materials and devices, there are crucial requirements taken upon on dental implants systems, since surface of dental implants is directly in contact with vital hard/soft tissue and is subjected to chemical as well as mechanical bio-environments. Such requirements should, at least, include biological compatibility, mechanical compatibility, and morphological compatibility to surrounding vital tissues. In this review, based on carefully selected about 500 published articles, these requirements plus MRI compatibility are firstly reviewed, followed by surface texturing methods in details. Normally dental implants are placed to lost tooth/teeth location(s) in adult patients whose skeleton and bony growth have already completed. However, there are some controversial issues for placing dental implants in growing patients. This point has been, in most of dental articles, overlooked. This review, therefore, throws a deliberate sight on this point. Concluding this review, we are proposing a novel implant system that integrates materials science and up-dated surface technology to improve dental implant systems exhibiting bio- and mechano-functionalities. PMID:20480036

Nomad rover field experiment, Atacama Desert, Chile 1. Science results overview

NASA Astrophysics Data System (ADS)

Cabrol, N. A.; Thomas, G.; Witzke, B.

2001-04-01

Nomad was deployed for a 45 day traverse in the Atacama Desert, Chile, during the summer of 1997. During this traverse, 1 week was devoted to science experiments. The goal of the science experiments was to test different planetary surface exploration strategies that included (1) a Mars mission simulation, (2) a science on the fly experiment, where the rover was kept moving 75% of the operation time. (The goal of this operation was to determine whether or not successful interpretation of the environment is related to the time spent on a target. The role of mobility in helping the interpretation was also assessed.) (3) a meteorite search using visual and instrumental methods to remotely identify meteorites in extreme environments, and (4) a time-delay experiment with and without using the panospheric camera. The results were as follow: the remote science team positively identified the main characteristics of the test site geological environment. The science on the fly experiment showed that the selection of appropriate targets might be even more critical than the time spent on a study area to reconstruct the history of a site. During the same operation the science team members identified and sampled a rock from a Jurassic outcrop that they proposed to be a fossil. The presence of paleolife indicators in this rock was confirmed later by laboratory analysis. Both visual and instrumental modes demonstrated the feasibility, in at least some conditions, of carrying out a field search for meteorites by using remote-controlled vehicles. Finally, metrics collected from the observation of the science team operations, and the use team members made of mission data, provided critical information on what operation sequences could be automated on board rovers in future planetary surface explorations.

Aryl diazonium salts: a new class of coupling agents for bonding polymers, biomacromolecules and nanoparticles to surfaces.

PubMed

Mahouche-Chergui, Samia; Gam-Derouich, Sarra; Mangeney, Claire; Chehimi, Mohamed M

2011-07-01

This critical review summarizes existing knowledge on the use of diazonium salts as a new generation of surface modifiers and coupling agents for binding synthetic polymers, biomacromolecules, and nanoparticles to surfaces. Polymer grafts can be directly grown at surfaces through the so-called grafting from approaches based on several polymerization methods but can also be pre-formed in solution and then grafted to surfaces through grafting onto strategies including "click" reactions. Several routes are also described for binding biomacromolecules through aryl layers in view of developing biosensors and protein arrays, while the use of aryl diazonium coupling agents is extended to the attachment of nanoparticles. Patents and industrial applications of the surface chemistry of diazonium compounds are covered. This review stresses the paramount role of aryl diazonium coupling agents in adhesion, surface and materials sciences (114 references).

Applying the Coupled-Cluster Ansatz to Solids and Surfaces in the Thermodynamic Limit

NASA Astrophysics Data System (ADS)

Gruber, Thomas; Liao, Ke; Tsatsoulis, Theodoros; Hummel, Felix; Grüneis, Andreas

2018-04-01

Modern electronic structure theories can predict and simulate a wealth of phenomena in surface science and solid-state physics. In order to allow for a direct comparison with experiment, such ab initio predictions have to be made in the thermodynamic limit, substantially increasing the computational cost of many-electron wave-function theories. Here, we present a method that achieves thermodynamic limit results for solids and surfaces using the "gold standard" coupled cluster ansatz of quantum chemistry with unprecedented efficiency. We study the energy difference between carbon diamond and graphite crystals, adsorption energies of water on h -BN, as well as the cohesive energy of the Ne solid, demonstrating the increased efficiency and accuracy of coupled cluster theory for solids and surfaces.

A Course in Colloid and Surface Science.

ERIC Educational Resources Information Center

Scamehorn, John F.

1984-01-01

Describes a course for chemical engineers, chemists, and petroleum engineers that focuses on colloid and surface science. Major topic areas in the course include capillarity, surface thermodynamics, adsorption contact angle, micelle formation, solubilization in micelles, emulsions, foams, and applications. (JN)

Predicting Catalytic Activity of Nanoparticles by a DFT-Aided Machine-Learning Algorithm.

PubMed

Jinnouchi, Ryosuke; Asahi, Ryoji

2017-09-07

Catalytic activities are often dominated by a few specific surface sites, and designing active sites is the key to realize high-performance heterogeneous catalysts. The great triumphs of modern surface science lead to reproduce catalytic reaction rates by modeling the arrangement of surface atoms with well-defined single-crystal surfaces. However, this method has limitations in the case for highly inhomogeneous atomic configurations such as on alloy nanoparticles with atomic-scale defects, where the arrangement cannot be decomposed into single crystals. Here, we propose a universal machine-learning scheme using a local similarity kernel, which allows interrogation of catalytic activities based on local atomic configurations. We then apply it to direct NO decomposition on RhAu alloy nanoparticles. The proposed method can efficiently predict energetics of catalytic reactions on nanoparticles using DFT data on single crystals, and its combination with kinetic analysis can provide detailed information on structures of active sites and size- and composition-dependent catalytic activities.

Synthesis, characterization, applications, and challenges of iron oxide nanoparticles

PubMed Central

Ali, Attarad; Zafar, Hira; Zia, Muhammad; ul Haq, Ihsan; Phull, Abdul Rehman; Ali, Joham Sarfraz; Hussain, Altaf

2016-01-01

Recently, iron oxide nanoparticles (NPs) have attracted much consideration due to their unique properties, such as superparamagnetism, surface-to-volume ratio, greater surface area, and easy separation methodology. Various physical, chemical, and biological methods have been adopted to synthesize magnetic NPs with suitable surface chemistry. This review summarizes the methods for the preparation of iron oxide NPs, size and morphology control, and magnetic properties with recent bioengineering, commercial, and industrial applications. Iron oxides exhibit great potential in the fields of life sciences such as biomedicine, agriculture, and environment. Nontoxic conduct and biocompatible applications of magnetic NPs can be enriched further by special surface coating with organic or inorganic molecules, including surfactants, drugs, proteins, starches, enzymes, antibodies, nucleotides, nonionic detergents, and polyelectrolytes. Magnetic NPs can also be directed to an organ, tissue, or tumor using an external magnetic field for hyperthermic treatment of patients. Keeping in mind the current interest in iron NPs, this review is designed to report recent information from synthesis to characterization, and applications of iron NPs. PMID:27578966

Cutaneous exposure scenarios for engineered nanoparticles used in semiconductor fabrication: a preliminary investigation of workplace surface contamination

PubMed Central

Shepard, Michele; Brenner, Sara

2014-01-01

Background: Numerous studies are ongoing in the fields of nanotoxicology and exposure science; however, gaps remain in identifying and evaluating potential exposures from skin contact with engineered nanoparticles in occupational settings. Objectives: The aim of this study was to identify potential cutaneous exposure scenarios at a workplace using engineered nanoparticles (alumina, ceria, amorphous silica) and evaluate the presence of these materials on workplace surfaces. Methods: Process review, workplace observations, and preliminary surface sampling were conducted using microvacuum and wipe sample collection methods and transmission electron microscopy with elemental analysis. Results: Exposure scenarios were identified with potential for incidental contact. Nanoparticles of silica or silica and/or alumina agglomerates (or aggregates) were identified in surface samples from work areas where engineered nanoparticles were used or handled. Conclusions: Additional data are needed to evaluate occupational exposures from skin contact with engineered nanoparticles; precautionary measures should be used to minimize potential cutaneous exposures in the workplace. PMID:25000112

Lunar Science Enabled by the Deep Space Gateway and PHASR Rover

NASA Astrophysics Data System (ADS)

Bakambu, J. N.; Shaw, A.; Fulford, P.; Osinski, G.; Bourassa, M.; Rehmatullah, F.; Zanetti, M.; Rembala, R.

2018-02-01

The Deep Space Gateway will be a tremendous boon to lunar surface science. It will enable the PHASR Rover, a concept for a Canadian rover system, with international contributions and the goal of sample acquisition and lunar surface science.

Developing Science Operations Concepts for the Future of Planetary Surface Exploration

NASA Astrophysics Data System (ADS)

Young, K. E.; Bleacher, J. E.; Rogers, A. D.; McAdam, A.; Evans, C. A.; Graff, T. G.; Garry, W. B.; Whelley, P. L.; Scheidt, S.; Carter, L.; Coan, D.; Reagan, M.; Glotch, T.; Lewis, R.

2017-02-01

Human exploration of other planetary bodies is crucial in answering critical science questions about our solar system. As we seek to put humans on other surfaces by 2050, we must understand the science operations concepts needed for planetary EVA.

Planar regions of GaAs (001) prepared by Ga droplet motion

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

Zheng, Changxi, E-mail: changxi.zheng@monash.edu; Tang, Wen-Xin; Jesson, David E., E-mail: jessonDE@cardiff.ac.uk

2016-07-15

The authors describe a simple method for obtaining planar regions of GaAs (001) suitable for surface science studies. The technique, which requires no buffer layer growth, atomic hydrogen source, or the introduction of As flux, employs controllable Ga droplet motion to create planar trail regions during Langmuir evaporation. Low-energy electron microscopy/diffraction techniques are applied to monitor the droplet motion and characterize the morphology and the surface reconstruction. It is found that the planar regions exhibit atomic flatness at the level of a high-quality buffer layer.

Decontaminating Solar Wind Samples with the Genesis Ultra-Pure Water Megasonic Wafer Spin Cleaner

NASA Technical Reports Server (NTRS)

Calaway, Michael J.; Rodriquez, M. C.; Allton, J. H.; Stansbery, E. K.

2009-01-01

The Genesis sample return capsule, though broken during the landing impact, contained most of the shattered ultra-pure solar wind collectors comprised of silicon and other semiconductor wafers materials. Post-flight analysis revealed that all wafer fragments were littered with surface particle contamination from spacecraft debris as well as soil from the impact site. This particulate contamination interferes with some analyses of solar wind. In early 2005, the Genesis science team decided to investigate methods for removing the surface particle contamination prior to solar wind analysis.

Mars Network: Strategies for Deploying Enabling Telecommunications Capabilities in Support of Mars Exploration

NASA Technical Reports Server (NTRS)

Edwards, C. D.; Adams, J. T.; Agre, J. R.; Bell, D. J.; Clare, L. P.; Durning, J. F.; Ely, T. A.; Hemmati, H.; Leung, R. Y.; McGraw, C. A.

2000-01-01

The coming decade of Mars exploration will involve a diverse set of robotic science missions, including in situ and sample return investigations, and ultimately moving towards sustained robotic presence on the Martian surface. In supporting this mission set, NASA must establish a robust telecommunications architecture that meets the specific science needs of near-term missions while enabling new methods of future exploration. This paper will assess the anticipated telecommunications needs of future Mars exploration, examine specific options for deploying capabilities, and quantify the performance of these options in terms of key figures of merit.

Functional Interfaces Constructed by Controlled/Living Radical Polymerization for Analytical Chemistry.

PubMed

Wang, Huai-Song; Song, Min; Hang, Tai-Jun

2016-02-10

The high-value applications of functional polymers in analytical science generally require well-defined interfaces, including precisely synthesized molecular architectures and compositions. Controlled/living radical polymerization (CRP) has been developed as a versatile and powerful tool for the preparation of polymers with narrow molecular weight distributions and predetermined molecular weights. Among the CRP system, atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) are well-used to develop new materials for analytical science, such as surface-modified core-shell particles, monoliths, MIP micro- or nanospheres, fluorescent nanoparticles, and multifunctional materials. In this review, we summarize the emerging functional interfaces constructed by RAFT and ATRP for applications in analytical science. Various polymers with precisely controlled architectures including homopolymers, block copolymers, molecular imprinted copolymers, and grafted copolymers were synthesized by CRP methods for molecular separation, retention, or sensing. We expect that the CRP methods will become the most popular technique for preparing functional polymers that can be broadly applied in analytical chemistry.

An improved pyrite pretreatment protocol for kinetic and isotopic studies

NASA Astrophysics Data System (ADS)

Mirzoyan, Natella; Kamyshny, Alexey; Halevy, Itay

2014-05-01

An improved pyrite pretreatment protocol for kinetic and isotopic studies Natella Mirzoyan1, Alexey Kamyshny Jr.2, Itay Halevy1 1Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel 2Geological and Environmental Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel Pyrite is one of the most abundant and widespread of the sulfide minerals with a central role in biogeochemical cycles of iron and sulfur. Due to its diverse roles in the natural and anthropogenic sulfur cycle, pyrite has been extensively studied in various experimental investigations of the kinetics of its dissolution and oxidation, the isotopic fractionations associated with these reactions, and the microbiological processes involved. Pretreatment of pyrite for removal of oxidation impurities to prevent experimental artifacts and inaccuracies is often practiced. While numerous pyrite-cleaning methods have been used in experiments, a common pyrite pretreatment method, often used to investigate pyrite chemistry by the isotopic fractionations associated with it, includes several rinses by HCl, acetone and deionized water. Elemental sulfur (S0) is a common product of incomplete pyrite oxidation. Removal of S0 is desirable to avoid experimental biases associated with its participation in pyrite transformations, but is more complicated than the removal of sulfate. Although rinsing with an organic solvent is in part aimed at removing S0, to the best of our knowledge, the extraction efficiency of S0 in existing protocols has not been assessed. We have developed and tested a new protocol for elemental sulfur removal from the surface of pyrite by ultrasonication with warm acetone. Our data demonstrate the presence of large fractions of S0 on untreated pyrite particle surfaces, of which only approximately 60% was removed by the commonly used pretreatment method. The new protocol described here was found to be more efficient at S0 removal than the commonly used method, and was capable of removing virtually all S0 from the pyrite grains. As pyrite oxidation and dissolution processes are surface-dependent, and even the slightest coating by Fe2+ or sulfide oxidation products can sharply decrease pyrite reactivity, the improved removal of S0 prevents such decreases and allows clearer insights into pyrite reaction mechanisms to be gained from experimental studies. In addition to S0 removal, the suggested method was shown not to introduce any biases in the particle size distribution. The main difference observed between the two protocols is the removal of larger amounts of surface-attached fine particles in the proposed method along with S0. This also removes a potential bias, associated with the surface area of pyrite available for chemical reaction. The suggested pyrite pretreatment protocol is more efficient in removal of S0 contamination from pyrite grains and provides multiple advantages for both kinetic and isotopic investigations of pyrite transformations under various environmental conditions.

A study on the distribution of adsorbed nanoparticles

NASA Astrophysics Data System (ADS)

Li, Ding

2008-02-01

We use Monte Carlo simulation to calculate the distributions of particles under adsorption force near planar and cylindrical surfaces, respectively. Both hard sphere interaction and repulsive Yukawa (screened coulomb) interaction are employed in our simulations. We study the influence of the inter-particle potentials. The difference between the MC simulation results and the analytical results of ideal gas model shows that the interaction between particles plays an important role in the density distribution under external fields. Moreover, the 2-dimensional constructions of particles close to the surface are studied and show relations of the interaction between particles. These results may indicate us how to improve the methods of building nanoparticle coatings and nano-scale patterns. Supported by 100 Persons Project of Chinese Academy of Sciences, National Natural Science Foundation of China (10474109, 10674146) and Major State Research Development Programme of China (2006CB933000, 2006CB708612)

Laser ablation surface-enhanced Raman microspectroscopy.

PubMed

Londero, Pablo S; Lombardi, John R; Leona, Marco

2013-06-04

Improved identification of trace organic compounds in complex matrixes is critical for a variety of fields such as material science, heritage science, and forensics. Surface-enhanced Raman scattering (SERS) is a vibrational spectroscopy technique that can attain single-molecule sensitivity and has been shown to complement mass spectrometry, but lacks widespread application without a robust method that utilizes the effect. We demonstrate a new, highly sensitive, and widely applicable approach to SERS analysis based on laser ablation in the presence of a tailored plasmonic substrate. We analyze several challenging compounds, including non-water-soluble pigments and dyed leather from an ancient Egyptian chariot, achieving sensitivity as high as 120 amol for a 1:1 signal-to-noise ratio and 5 μm spatial resolution. This represents orders of magnitude improvement in spatial resolution and sensitivity compared to those of other SERS approaches intended for widespread application, greatly increasing the applicability of SERS.

A Surface Science Paradigm for a Post-Huygens Titan Mission

NASA Technical Reports Server (NTRS)

Zimmerman, Wayne; Lunine, Jonathan; Lorenz, Ralph

2004-01-01

With the Cassini-Huygens atmospheric probe drop-off mission fast approaching, it is essential that scientists and engineers start scoping potential follow-on surface science missions. This paper provides a summary of the first year of a two year design study which examines in detail the desired surface science measurements and resolution, potential instrument suite, and complete payload delivery system. Also provided are design concepts for both an aerial inflatable mobility platform and deployable instrument sonde. The tethered deployable sonde provides the capability to sample nearsurface atmosphere, sub-surface liquid (if it exists), and surface solid material. Actual laboratory tests of the amphibious sonde prototype are also presented.

Learning approaches as predictors of academic performance in first year health and science students.

PubMed

Salamonson, Yenna; Weaver, Roslyn; Chang, Sungwon; Koch, Jane; Bhathal, Ragbir; Khoo, Cheang; Wilson, Ian

2013-07-01

To compare health and science students' demographic characteristics and learning approaches across different disciplines, and to examine the relationship between learning approaches and academic performance. While there is increasing recognition of a need to foster learning approaches that improve the quality of student learning, little is known about students' learning approaches across different disciplines, and their relationships with academic performance. Prospective, correlational design. Using a survey design, a total of 919 first year health and science students studying in a university located in the western region of Sydney from the following disciplines were recruited to participate in the study - i) Nursing: n = 476, ii) Engineering: n = 75, iii) Medicine: n = 77, iv) Health Sciences: n = 204, and v) Medicinal Chemistry: n = 87. Although there was no statistically significant difference in the use of surface learning among the five discipline groups, there were wide variations in the use of deep learning approach. Furthermore, older students and those with English as an additional language were more likely to use deep learning approach. Controlling for hours spent in paid work during term-time and English language usage, both surface learning approach (β = -0.13, p = 0.001) and deep learning approach (β = 0.11, p = 0.009) emerged as independent and significant predictors of academic performance. Findings from this study provide further empirical evidence that underscore the importance for faculty to use teaching methods that foster deep instead of surface learning approaches, to improve the quality of student learning and academic performance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Optimal Reorganization of NASA Earth Science Data for Enhanced Accessibility and Usability for the Hydrology Community

NASA Technical Reports Server (NTRS)

Teng, William; Rui, Hualan; Strub, Richard; Vollmer, Bruce

2016-01-01

A long-standing "Digital Divide" in data representation exists between the preferred way of data access by the hydrology community and the common way of data archival by earth science data centers. Typically, in hydrology, earth surface features are expressed as discrete spatial objects (e.g., watersheds), and time-varying data are contained in associated time series. Data in earth science archives, although stored as discrete values (of satellite swath pixels or geographical grids), represent continuous spatial fields, one file per time step. This Divide has been an obstacle, specifically, between the Consortium of Universities for the Advancement of Hydrologic Science, Inc. and NASA earth science data systems. In essence, the way data are archived is conceptually orthogonal to the desired method of access. Our recent work has shown an optimal method of bridging the Divide, by enabling operational access to long-time series (e.g., 36 years of hourly data) of selected NASA datasets. These time series, which we have termed "data rods," are pre-generated or generated on-the-fly. This optimal solution was arrived at after extensive investigations of various approaches, including one based on "data curtains." The on-the-fly generation of data rods uses "data cubes," NASA Giovanni, and parallel processing. The optimal reorganization of NASA earth science data has significantly enhanced the access to and use of the data for the hydrology user community.

Preparation of MgO/B₂O₃ coatings by plasma spraying on SUS304 surface and effects of heat-resistant.

PubMed

Song, Bo; Zhou, Ningning; Ju, Dongying

2013-12-01

This study mainly deals with the preparation of MgO/B2O3 coatings by plasma spraying on the SUS304 surface and the effects of heat-resistant. The power materials of low thermal conductivity were selected to control the heat divergent performance of high temperature parts. The reticular micro-structure between the cover thermal layer and the substrate was prepared by using the plasma spraying method. The powder mixture of MgO and B2O3 were selected as spraying materials and the SUS304 was used as the substrate material. The MgO/B2O3 coating was prepared on the surface of the SUS304 to provide better cover thermal performance. The properties of the microstructures and the morphologies were studied by Optical Microscope, Scanning Electron Microscope, Electron Probe Microanalyzer, and X-ray Diffraction. The results showed that the cover thermal performance has been improved. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Combining inkjet printing and sol-gel chemistry for making pH-sensitive surfaces.

PubMed

Orsi, Gianni; De Maria, Carmelo; Montemurro, Francesca; Chauhan, Veeren M; Aylott, Jonathan W; Vozzi, Giovanni

2015-01-01

Today biomedical sciences are experiencing the importance of imaging biological parameters with luminescence methods. Studying 2D pH distribution with those methods allows building knowledge about complex cellular processes. Immobilizing pH sensitive nanoparticles inside hydrogel matrixes, in order to guarantee a proper SNR, could easily make stable and biocompatible 2D sensors. Inkjet printing is also well known as tool for printing images onto porous surfaces. Recently it has been used as a free-form fabrication method for building three-dimensional parts, and now is being explored as a way of printing electrical and optical devices. Inkjet printing was used either as a rapid prototyping method for custom biosensors. Sol-gel method is naturally bound with inkjet, because the picoliter-sized ink droplets evaporate quickly, thus allowing quick sol-gel transitions on the printed surface. In this work will be shown how to merge those technologies, in order to make a nanoparticles doped printable hydrogel, which could be used for making 2D/3D smart scaffolds able to monitor cell activities. An automated image analysis system was developed in order to quickly have the pH measurements from pH nanosensors fluorescence images.

Enhancing Return from Lunar Surface Missions via the Deep Space Gateway

NASA Astrophysics Data System (ADS)

Chavers, D. G.; Whitley, R. J.; Percy, T. K.; Needham, D. H.; Polsgrove, T. T.

2018-02-01

The Deep Space Gateway (DSG) will facilitate access to and communication with lunar surface assets. With a science airlock, docking port, and refueling capability in an accessible orbit, the DSG will enable high priority science across the lunar surface.

Nanostructured Metal Oxides for Stoichiometric Degradation of Chemical Warfare Agents.

PubMed

Štengl, Václav; Henych, Jiří; Janoš, Pavel; Skoumal, Miroslav

2016-01-01

Metal oxides have very important applications in many areas of chemistry, physics and materials science; their properties are dependent on the method of preparation, the morphology and texture. Nanostructured metal oxides can exhibit unique characteristics unlike those of the bulk form depending on their morphology, with a high density of edges, corners and defect surfaces. In recent years, methods have been developed for the preparation of metal oxide powders with tunable control of the primary particle size as well as of a secondary particle size: the size of agglomerates of crystallites. One of the many ways to take advantage of unique properties of nanostructured oxide materials is stoichiometric degradation of chemical warfare agents (CWAs) and volatile organic compounds (VOC) pollutants on their surfaces.

Surface-Water Quality-Assurance Plan for the USGS Wisconsin Water Science Center

USGS Publications Warehouse

Garn, H.S.

2007-01-01

This surface-water quality-assurance plan documents the standards, policies, and procedures used by the Wisconsin Water Science Center of the U.S. Geological Survey, Water Resources Discipline, for activities related to the collection, processing, storage, analysis, management, and publication of surface-water data. The roles and responsibilities of Water Science Center personnel in following these policies and procedures including those related to safety and training are presented.

A microelectronics approach for the ROSETTA surface science package

NASA Technical Reports Server (NTRS)

Sandau, Rainer (Editor); Alkalaj, Leon

1996-01-01

In relation to the Rosetta surface science package, the benefits of the application of advanced microelectronics packaging technologies and other output from the Mars environmental survey (MESUR) integrated microelectronics study are reported on. The surface science package will be designed to operate for tens of hours. Its limited mass and power consumption make necessary a highly integrated design with all the instruments and subunits operated from a centralized control and information management subsystem.

Software Package Completed for Alloy Design at the Atomic Level

NASA Technical Reports Server (NTRS)

Bozzolo, Guillermo H.; Noebe, Ronald D.; Abel, Phillip B.; Good, Brian S.

2001-01-01

As a result of a multidisciplinary effort involving solid-state physics, quantum mechanics, and materials and surface science, the first version of a software package dedicated to the atomistic analysis of multicomponent systems was recently completed. Based on the BFS (Bozzolo, Ferrante, and Smith) method for the calculation of alloy and surface energetics, this package includes modules devoted to the analysis of many essential features that characterize any given alloy or surface system, including (1) surface structure analysis, (2) surface segregation, (3) surface alloying, (4) bulk crystalline material properties and atomic defect structures, and (5) thermal processes that allow us to perform phase diagram calculations. All the modules of this Alloy Design Workbench 1.0 (ADW 1.0) are designed to run in PC and workstation environments, and their operation and performance are substantially linked to the needs of the user and the specific application.

Complex technology of vacuum-arc processing of structural material surface

NASA Astrophysics Data System (ADS)

Arustamov, V. N.; Ashurov, Kh. B.; Kadyrov, Kh. Kh.; Khudoikulov, I. Kh.

2015-08-01

The development of environmentally friendly and energy-resource-saving technologies based on vacuum arc discharge is a topical problem in science and engineering. In view of their unique properties, cathode spots of a vacuum arc induce cleaning of the surface of an article (cathode) from various contaminations and pulsed thermal action on the surface layers. These processes occur in complex with vacuum-arc deposition of coatings in the same technological cycle, which makes it possible to considerably increase the efficiency of methods for changing physical, mechanical, and chemical properties of the surface of steel articles, which considerably increase their service life. Analysis of the formation of the temperature regime of the surface during vacuum arc action and of the parameters of the deposited coating will make it possible to optimize the regimes of complex treatment of the surfaces of articles and is of considerable theoretical and practical importance.

A Preliminary Examination of Science Backroom Roles and Activities for Robotic Lunar Surface Science

NASA Astrophysics Data System (ADS)

Fong, T.; Deans, M.; Smith, T.; Lee, P.; Heldmann, J.; Pacis, E.; Schreckenghost, D.; Landis, R.; Osborn, J.; Kring, D.; Heggy, E.; Mishkin, A.; Snook, K.; Stoker, C.

2008-07-01

To understand the utility of a science backroom for the current lunar architecture, we are developing a new ground control structure for human and robot surface activity. In June 2008, we began examining this structure through a series of analog field tests.

The effect of grinding and/or airborne-particle abrasion on the bond strength between zirconia and veneering porcelain: a systematic review

PubMed Central

Lundberg, Karin; Wu, Lindsey; Papia, Evaggelia

2017-01-01

Abstract Objective: The aim of the study was to make an inventory of current literature on the bond strength between zirconia and veneering porcelain after surface treatment of zirconia by grinding with diamond bur and/or with airborne-particle abrasion. Material and methods: The literature search for the present review was made following recommended guidelines using acknowledged methodology on how to do a systematic review. The electronic databases PubMed, Cochrane Library, and Science Direct were used in the present study. Results: Twelve studies were selected. Test methods used in the original studies included shear bond strength (SBS) test, tensile bond strength test, and micro-tensile bond strength test. The majority of studies used SBS. Results showed a large variation within each surface treatment of zirconia, using different grain size, blasting time, and pressure. Conclusions: Airborne-particle abrasion might improve the bond strength and can therefore be considered a feasible surface treatment for zirconia that is to be bonded. Grinding has been recommended as a surface treatment for zirconia to improve the bond strength; however, this recommendation cannot be verified. A standardized test method and surface treatment are required to be able to compare the results from different studies and draw further conclusions. PMID:28642927

Nanophotonics of biomaterials and inorganic nanostructures

NASA Astrophysics Data System (ADS)

Petrik, P.; Agocs, E.; Kalas, B.; Fodor, B.; Lohner, T.; Nador, J.; Saftics, A.; Kurunczi, S.; Novotny, T.; Perez-Feró, E.; Nagy, R.; Hamori, A.; Horvath, R.; Hózer, Z.; Fried, M.

2017-01-01

Optical methods have been used for the sensitive characterization of surfaces and thin films for more than a century. The first ellipsometric measurement was conducted on metal surfaces by Paul Drude in 1889. The word ‘ellipsometer’ was first used by Rothen in a study of antigen-antibody interactions on polished metal surfaces in 1945. The ‘bible’ of ellipsometry has been published in the second half of the ‘70s. The publications in the topic of ellipsometry started to increase rapidly by the end of the ‘80s, together with concepts like surface plasmon resonance, later new topics like photonic crystals emerged. These techniques find applications in many fields, including sensorics or photovoltaics. In optical sensorics, the highest sensitivities were achieved by waveguide interferometry and plasmon resonance configurations. The instrumentation of ellipsometry is also being developed intensively towards higher sensitivity and performance by combinations with plasmonics, scatterometry, imaging or waveguide methods, utilizing the high sensitivity, high speed, non-destructive nature and mapping capabilities. Not only the instrumentation but also the methods of evaluation show a significant development, which leads to the characterization of structures with increasing complexity, including photonic, porous or metal surfaces. This article discusses a selection of interesting applications of photonics in the Centre for Energy Research of the Hungarian Academy of Sciences.

A fluorescent-photochrome method for the quantitative characterization of solid phase antibody orientation.

PubMed

Ahluwalia, Arti; De Rossi, Danilo; Giusto, Giuseppe; Chen, Oren; Papper, Vladislav; Likhtenshtein, Gertz I

2002-06-15

A fluorescent-photochrome method of quantifying the orientation and surface density of solid phase antibodies is described. The method is based on measurements of quenching and rates of cis-trans photoisomerization and photodestruction of a stilbene-labeled hapten by a quencher in solution. These experimental parameters enable a quantitative description of the order of binding sites of antibodies immobilized on a surface and can be used to characterize the microviscosity and steric hindrance in the vicinity of the binding site. Furthermore, a theoretical method for the determination of the depth of immersion of the fluorescent label in a two-phase system was developed. The model exploits the concept of dynamic interactions and is based on the empirical dependence of parameters of static exchange interactions on distances between exchangeable centers. In the present work, anti-dinitrophenyl (DNP) antibodies and stilbene-labeled DNP were used to investigate three different protein immobilization methods: physical adsorption, covalent binding, and the Langmuir-Blodgett technique. Copyright 2002 Elsevier Science (USA).

Geologic Traverse Planning for Apollo Missions

NASA Technical Reports Server (NTRS)

Lofgren, Gary

2012-01-01

The science on Apollo missions was overseen by the Science Working Panel (SWP), but done by multiple PIs. There were two types of science, packages like the Apollo Lunar Surface Experiment Package (ALSEP) and traverse science. Traverses were designed on Earth for the astronauts to execute. These were under direction of the Lunar Surface PI, but the agreed traverse was a cooperation between the PI and SWP. The landing sites were selected by a different designated committee, not the SWP, and were based on science and safety.

Magnetic Field Measurements on the Lunar Surface: Lessons Learned from Apollo and Science Enabled by Future Missions

NASA Astrophysics Data System (ADS)

Chi, P. J.

2017-10-01

We discuss the science to be enabled by new magnetometer measurements on the lunar surface, based on results from Apollo and other lunar missions. Also discussed are approaches to deploying magnetometers on the lunar surface with today's technology.

Philae Descent and Science of the Surface

NASA Image and Video Library

2014-11-07

This artist concept of the Rosetta mission Philae lander on the surface of comet 67P/Churyumov-Gerasimenko, is from an animation showing the upcoming deployment of Philae and its subsequent science operations on the surface of the comet. http://photojournal.jpl.nasa.gov/catalog/PIA18891

Early-stage detection of VE-cadherin during endothelial differentiation of human mesenchymal stem cells using SPR biosensor.

PubMed

Fathi, Farzaneh; Rezabakhsh, Aysa; Rahbarghazi, Reza; Rashidi, Mohammad-Reza

2017-10-15

Surface plasmon resonance (SPR) biosensors are most commonly applied for real-time dynamic analysis and measurement of interactions in bio-molecular studies and cell-surface analysis without the need for labeling processes. Up to present, SPR application in stem cell biology and biomedical sciences was underused. Herein, a very simple and sensitive method was developed to evaluate human mesenchymal stem cells trans-differentiation to endothelial lineage of over a period of 14 days based on VE-cadherin biomarker. The SPR signals increased with the increase of the amount of VE-cadherin expression on the cell surface during cell differentiation process. The method was able to detect ≈27 cells permm 2 . No significant effect was observed on the cell viability during the cell attachment to the surface of immune-reactive biochips and during the SPR analysis. Using this highly sensitive SPR method, it was possible to sense the early stage of endothelial differentiation on day 3 in label-free form, whereas flow cytometry and fluorescent microscopy methods were found unable to detect the cell differentiation at the same time. Therefore, the proposed method can rapidly and accurately detect cell differentiation in live cells and label-free manner without any need of cell breakage and has great potential for both diagnostic and experimental approaches. Copyright © 2017. Published by Elsevier B.V.

Using terrestrial light detection and ranging (lidar) technology for land-surface analysis in the Southwest

USGS Publications Warehouse

Soulard, Christopher E.; Bogle, Rian

2011-01-01

Emerging technologies provide scientists with methods to measure Earth processes in new ways. One of these technologies--ultra-high-resolution, ground-based light detection and ranging (lidar)--is being used by USGS Western Geographic Science Center scientists to characterize the role of wind and fire processes in shaping desert landscapes of the Southwest United States.

An emerging platform for drug delivery: aerogel based systems.

PubMed

Ulker, Zeynep; Erkey, Can

2014-03-10

Over the past few decades, advances in "aerogel science" have provoked an increasing interest for these materials in pharmaceutical sciences for drug delivery applications. Because of their high surface areas, high porosities and open pore structures which can be tuned and controlled by manipulation of synthesis conditions, nanostructured aerogels represent a promising class of materials for delivery of various drugs as well as enzymes and proteins. Along with biocompatible inorganic aerogels and biodegradable organic aerogels, more complex systems such as surface functionalized aerogels, composite aerogels and layered aerogels have also been under development and possess huge potential. Emphasis is given to the details of the aerogel synthesis and drug loading methods as well as the influence of synthesis parameters and loading methods on the adsorption and release of the drugs. Owing to their ability to increase the bioavailability of low solubility drugs, to improve both their stability and their release kinetics, there are an increasing number of research articles concerning aerogels in different drug delivery applications. This review presents an up to date overview of the advances in all kinds of aerogel based drug delivery systems which are currently under investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

Estimating Global Impervious Surface based on Social-economic Data and Satellite Observations

NASA Astrophysics Data System (ADS)

Zeng, Z.; Zhang, K.; Xue, X.; Hong, Y.

2016-12-01

Impervious surface areas around the globe are expanding and significantly altering the surface energy balance, hydrology cycle and ecosystem services. Many studies have underlined the importance of impervious surface, r from hydrological modeling to contaminant transport monitoring and urban development estimation. Therefore accurate estimation of the global impervious surface is important for both physical and social sciences. Given the limited coverage of high spatial resolution imagery and ground survey, using satellite remote sensing and geospatial data to estimate global impervious areas is a practical approach. Based on the previous work of area-weighted imperviousness for north branch of the Chicago River provided by HDR, this study developed a method to determine the percentage of impervious surface using latest global land cover categories from multi-source satellite observations, population density and gross domestic product (GDP) data. Percent impervious surface at 30-meter resolution were mapped. We found that 1.33% of the CONUS (105,814 km2) and 0.475% of the land surface (640,370km2) are impervious surfaces. To test the utility and practicality of the proposed method, National Land Cover Database (NLCD) 2011 percent developed imperviousness for the conterminous United States was used to evaluate our results. The average difference between the derived imperviousness from our method and the NLCD data across CONUS is 1.14%, while difference between our results and the NLCD data are within ±1% over 81.63% of the CONUS. The distribution of global impervious surface map indicates that impervious surfaces are primarily concentrated in China, India, Japan, USA and Europe where are highly populated and/or developed. This study proposes a straightforward way of mapping global imperviousness, which can provide useful information for hydrologic modeling and other applications.

Surface Modification of Intraocular Lenses

PubMed Central

Huang, Qi; Cheng, George Pak-Man; Chiu, Kin; Wang, Gui-Qin

2016-01-01

Objective: This paper aimed to review the current literature on the surface modification of intraocular lenses (IOLs). Data Sources: All articles about surface modification of IOLs published up to 2015 were identified through a literature search on both PubMed and ScienceDirect. Study Selection: The articles on the surface modification of IOLs were included, but those on design modification and surface coating were excluded. Results: Technology of surface modification included plasma, ion beam, layer-by-layer self-assembly, ultraviolet radiation, and ozone. The main molecules introduced into IOLs surface were poly (ethylene glycol), polyhedral oligomeric silsesquioxane, 2-methacryloyloxyethyl phosphorylcholine, TiO2, heparin, F-heparin, titanium, titanium nitride, vinyl pyrrolidone, and inhibitors of cytokines. The surface modification either resulted in a more hydrophobic lens, a more hydrophilic lens, or a lens with a hydrophilic anterior and hydrophobic posterior surface. Advances in research regarding surface modification of IOLs had led to a better biocompatibility in both in vitro and animal experiments. Conclusion: The surface modification is an efficient, convenient, economic and promising method to improve the biocompatibility of IOLs. PMID:26830993

The survival and inactivation of enteric viruses on soft surfaces: A systematic review of the literature.

PubMed

Yeargin, Thomas; Buckley, David; Fraser, Angela; Jiang, Xiuping

2016-11-01

Worldwide, enteric viruses are the main cause of acute gastroenteritis. In humans, these viruses spread via person-to-person contact, food, water, and/or the environment. Their survival and inactivation on hard surfaces have been extensively studied; however, nonlaunderable soft surfaces, such as upholstery and carpet, have received little attention. The aim of this systematic review was to determine factors that influence the survival and inactivation of enteric viruses on nonlaunderable soft surfaces. EBSCO and Web of Science were searched for experimental studies published between 1965 and 2015 using Preferred Reporting Items for Systematic Reviews and Meta-Analyses methods. Titles and abstracts were screened using 3 eligibility criteria. The quality of all study methods was also assessed. Our search yielded 12 articles. Viruses survived between 0 hours and 140 days depending on surface and environment conditions. Virus survival was influenced by temperature, relative humidity, organic content, and deposition method. A variety of chemistries were tested across studies and were shown to have a varied effect on enteric viruses. Chlorine, glutaraldehyde, vaporous ozone, and hydrogen peroxide were the most efficacious against enteric viruses (> 3-log reduction). Environmental factors, such as temperature and relative humidity, can influence survival of enteric viruses on nonlaunderable soft surfaces. The efficacy of liquid and vaporous chemistries are associated with surface and virus type. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Laser surface texturing of polymers for biomedical applications

NASA Astrophysics Data System (ADS)

Riveiro, Antonio; Maçon, Anthony L. B.; del Val, Jesus; Comesaña, Rafael; Pou, Juan

2018-02-01

Polymers are materials widely used in biomedical science because of their biocompatibility, and good mechanical properties (which, in some cases, are similar to those of human tissues); however, these materials are, in general, chemically and biologically inert. Surface characteristics, such as topography (at the macro-, micro, and nanoscale), surface chemistry, surface energy, charge or wettability are interrelated properties, and they cooperatively influence the biological performance of materials when used for biomedical applications. They regulate the biological response at the implant/tissue interface (e.g., influencing the cell adhesion, cell orientation, cell motility, etc.). Several surface processing techniques have been explored to modulate these properties for biomedical applications. Despite their potentials, these methods have limitations that prevent their applicability. In this regard, laser-based methods, in particular laser surface texturing (LST), can be an interesting alternative. Different works have showed the potentiality of this technique to control the surface properties of biomedical polymers and enhance their biological performance; however, more research is needed to obtain the desired biological response. This work provides a general overview of the basics and applications of LST for the surface modification of polymers currently used in the clinical practice (e.g. PEEK, UHMWPE, PP, etc.). The modification of roughness, wettability, and their impact on the biological response is addressed to offer new insights on the surface modification of biomedical polymers.

Statistical contact angle analyses; "slow moving" drops on a horizontal silicon-oxide surface.

PubMed

Schmitt, M; Grub, J; Heib, F

2015-06-01

Sessile drop experiments on horizontal surfaces are commonly used to characterise surface properties in science and in industry. The advancing angle and the receding angle are measurable on every solid. Specially on horizontal surfaces even the notions themselves are critically questioned by some authors. Building a standard, reproducible and valid method of measuring and defining specific (advancing/receding) contact angles is an important challenge of surface science. Recently we have developed two/three approaches, by sigmoid fitting, by independent and by dependent statistical analyses, which are practicable for the determination of specific angles/slopes if inclining the sample surface. These approaches lead to contact angle data which are independent on "user-skills" and subjectivity of the operator which is also of urgent need to evaluate dynamic measurements of contact angles. We will show in this contribution that the slightly modified procedures are also applicable to find specific angles for experiments on horizontal surfaces. As an example droplets on a flat freshly cleaned silicon-oxide surface (wafer) are dynamically measured by sessile drop technique while the volume of the liquid is increased/decreased. The triple points, the time, the contact angles during the advancing and the receding of the drop obtained by high-precision drop shape analysis are statistically analysed. As stated in the previous contribution the procedure is called "slow movement" analysis due to the small covered distance and the dominance of data points with low velocity. Even smallest variations in velocity such as the minimal advancing motion during the withdrawing of the liquid are identifiable which confirms the flatness and the chemical homogeneity of the sample surface and the high sensitivity of the presented approaches. Copyright © 2014 Elsevier Inc. All rights reserved.

Surface oscillation of levitated liquid droplets under microgravity

NASA Astrophysics Data System (ADS)

Watanabe, Masahito; Hibiya, Taketoshi; Ozawa, Shumpei; Mizuno, Akitoshi

2012-07-01

Microgravity conditions have advantages of measurement of surface tension and viscosity of metallic liquids by the oscillating drop method with an electromagnetic levitation (EML) device. Thus, we are now planning the thermophysical properties, the surface tension, viscosity, density and etc., measurements of liquid alloys using the electromagnetic levitator named MSL-EML (Materials Science Laboratory Electromagnetic Levitator), which ahs been developed by the European Space Agency (ESA), installed in the International Space Station (ISS). The surface tension and the viscosity of liquid samples by the oscillating drop method are obtained from the surface oscillation frequency and damping time of surface oscillation respectively. However, analysis of oscillating drop method in EML must be improved even in the microgravity conditions, because on the EML conditions the electromagnetic force (EMF) cannot generate the surface oscillation with discretely oscillation mode. Since under microgravity the levitated droplet shape is completely spherical, the surface oscillation frequency with different oscillation modes degenerates into the single frequency. Therefore, surface tension will be not affected the EML condition under microgravity, but viscosity will be affected on the different oscillation mode of surface oscillations. Because dumping time of surface oscillation of liquid droplets depends on the oscillation modes, the case of surface oscillation including multi oscillation modes the viscosity values obtained from dumping time will be modified from the correct viscosity. Therefore, we investigate the dumping time of surface oscillation of levitated droplets with different oscillation modes and also with including multi oscillation modes using the electrostatic levitation (ESL) on ground and EML under microgravity conditions by the parabolic flight of airplane. The ESL can discretely generate the surface oscillation with different oscillation modes by the change of generation frequency of surface oscillation, so we can obtain dumping time of surface oscillation with discrete oscillation mode. We repot the results of the damping time of the surface oscillation of levitated liquid droplet by ESL and EML experiment with numerical simulation of the damped oscillation model.

Electronic materials high-T(sub c) superconductivity polymers and composites structural materials surface science and catalysts industry participation

NASA Technical Reports Server (NTRS)

1988-01-01

The fifth year of the Center for Advanced Materials was marked primarily by the significant scientific accomplishments of the research programs. The Electronics Materials program continued its work on the growth and characterization of gallium arsenide crystals, and the development of theories to understand the nature and distribution of defects in the crystals. The High Tc Superconductivity Program continued to make significant contributions to the field in theoretical and experimental work on both bulk materials and thin films and devices. The Ceramic Processing group developed a new technique for cladding YBCO superconductors for high current applications in work with the Electric Power Research Institute. The Polymers and Composites program published a number of important studies involving atomistic simulations of polymer surfaces with excellent correlations to experimental results. The new Enzymatic Synthesis of Materials project produced its first fluorinated polymers and successfully began engineering enzymes designed for materials synthesis. The structural Materials Program continued work on novel alloys, development of processing methods for advanced ceramics, and characterization of mechanical properties of these materials, including the newly documented characterization of cyclic fatigue crack propagation behavior in toughened ceramics. Finally, the Surface Science and Catalysis program made significant contributions to the understanding of microporous catalysts and the nature of surface structures and interface compounds.

Exploring the relationship between the engineering and physical sciences and the health and life sciences by advanced bibliometric methods.

PubMed

Waltman, Ludo; van Raan, Anthony F J; Smart, Sue

2014-01-01

We investigate the extent to which advances in the health and life sciences (HLS) are dependent on research in the engineering and physical sciences (EPS), particularly physics, chemistry, mathematics, and engineering. The analysis combines two different bibliometric approaches. The first approach to analyze the 'EPS-HLS interface' is based on term map visualizations of HLS research fields. We consider 16 clinical fields and five life science fields. On the basis of expert judgment, EPS research in these fields is studied by identifying EPS-related terms in the term maps. In the second approach, a large-scale citation-based network analysis is applied to publications from all fields of science. We work with about 22,000 clusters of publications, each representing a topic in the scientific literature. Citation relations are used to identify topics at the EPS-HLS interface. The two approaches complement each other. The advantages of working with textual data compensate for the limitations of working with citation relations and the other way around. An important advantage of working with textual data is in the in-depth qualitative insights it provides. Working with citation relations, on the other hand, yields many relevant quantitative statistics. We find that EPS research contributes to HLS developments mainly in the following five ways: new materials and their properties; chemical methods for analysis and molecular synthesis; imaging of parts of the body as well as of biomaterial surfaces; medical engineering mainly related to imaging, radiation therapy, signal processing technology, and other medical instrumentation; mathematical and statistical methods for data analysis. In our analysis, about 10% of all EPS and HLS publications are classified as being at the EPS-HLS interface. This percentage has remained more or less constant during the past decade.

Exploring the Relationship between the Engineering and Physical Sciences and the Health and Life Sciences by Advanced Bibliometric Methods

PubMed Central

Waltman, Ludo; van Raan, Anthony F. J.; Smart, Sue

2014-01-01

We investigate the extent to which advances in the health and life sciences (HLS) are dependent on research in the engineering and physical sciences (EPS), particularly physics, chemistry, mathematics, and engineering. The analysis combines two different bibliometric approaches. The first approach to analyze the ‘EPS-HLS interface’ is based on term map visualizations of HLS research fields. We consider 16 clinical fields and five life science fields. On the basis of expert judgment, EPS research in these fields is studied by identifying EPS-related terms in the term maps. In the second approach, a large-scale citation-based network analysis is applied to publications from all fields of science. We work with about 22,000 clusters of publications, each representing a topic in the scientific literature. Citation relations are used to identify topics at the EPS-HLS interface. The two approaches complement each other. The advantages of working with textual data compensate for the limitations of working with citation relations and the other way around. An important advantage of working with textual data is in the in-depth qualitative insights it provides. Working with citation relations, on the other hand, yields many relevant quantitative statistics. We find that EPS research contributes to HLS developments mainly in the following five ways: new materials and their properties; chemical methods for analysis and molecular synthesis; imaging of parts of the body as well as of biomaterial surfaces; medical engineering mainly related to imaging, radiation therapy, signal processing technology, and other medical instrumentation; mathematical and statistical methods for data analysis. In our analysis, about 10% of all EPS and HLS publications are classified as being at the EPS-HLS interface. This percentage has remained more or less constant during the past decade. PMID:25360616

Electron collisions with atoms, ions, molecules, and surfaces: Fundamental science empowering advances in technology

PubMed Central

Bartschat, Klaus; Kushner, Mark J.

2016-01-01

Electron collisions with atoms, ions, molecules, and surfaces are critically important to the understanding and modeling of low-temperature plasmas (LTPs), and so in the development of technologies based on LTPs. Recent progress in obtaining experimental benchmark data and the development of highly sophisticated computational methods is highlighted. With the cesium-based diode-pumped alkali laser and remote plasma etching of Si3N4 as examples, we demonstrate how accurate and comprehensive datasets for electron collisions enable complex modeling of plasma-using technologies that empower our high-technology–based society. PMID:27317740

Research on inverse, hybrid and optimization problems in engineering sciences with emphasis on turbomachine aerodynamics: Review of Chinese advances

NASA Technical Reports Server (NTRS)

Liu, Gao-Lian

1991-01-01

Advances in inverse design and optimization theory in engineering fields in China are presented. Two original approaches, the image-space approach and the variational approach, are discussed in terms of turbomachine aerodynamic inverse design. Other areas of research in turbomachine aerodynamic inverse design include the improved mean-streamline (stream surface) method and optimization theory based on optimal control. Among the additional engineering fields discussed are the following: the inverse problem of heat conduction, free-surface flow, variational cogeneration of optimal grid and flow field, and optimal meshing theory of gears.

The spectroscopy and chemical dynamics of microparticles explored using an ultrasonic trap.

PubMed

Mason, N J; Drage, E A; Webb, S M; Dawes, A; McPheat, R; Hayes, G

2008-01-01

Microsized particles play an important role in many diverse areas of science and technology, for example, surface reactions of micron-sized particles play a key role in astrochemistry, plasma reactors and atmospheric chemistry. To date much of our knowledge of such surface chemistry is derived from 'traditional' surface science-based research. However, the large surface area and morphology of surface material commonly used in such surface science techniques may not necessarily mimic that on the surface of micron/nano scale particles. Hence, a new generation of experiments in which the spectroscopy (e.g., albedo) and chemical reactivity of micron-sized particles can be studied directly must be developed. One, as yet underexploited, non-invasive technique is the use of ultrasonic levitation. In this article, we describe the operation of an 'ultrasonic trap' to store and study the physical and chemical properties of microparticles.

Atomic scale characterization and surface chemistry of metal modified titanate nanotubes and nanowires

NASA Astrophysics Data System (ADS)

Kukovecz, Ákos; Kordás, Krisztián; Kiss, János; Kónya, Zoltán

2016-10-01

Titanates are salts of polytitanic acid that can be synthesized as nanostructures in a great variety concerning crystallinity, morphology, size, metal content and surface chemistry. Titanate nanotubes (open-ended hollow cylinders measuring up to 200 nm in length and 15 nm in outer diameter) and nanowires (solid, elongated rectangular blocks with length up to 1500 nm and 30-60 nm diameter) are the most widespread representatives of the titanate nanomaterial family. This review covers the properties and applications of these two materials from the surface science point of view. Dielectric, vibrational, electron and X-ray spectroscopic results are comprehensively discussed first, then surface modification methods including covalent functionalization, ion exchange and metal loading are covered. The versatile surface chemistry of one-dimensional titanates renders them excellent candidates for heterogeneous catalytic, photocatalytic, photovoltaic and energy storage applications, therefore, these fields are also reviewed.

Automated calculation of surface energy fluxes with high-frequency lake buoy data

USGS Publications Warehouse

Woolway, R. Iestyn; Jones, Ian D; Hamilton, David P.; Maberly, Stephen C; Muroaka, Kohji; Read, Jordan S.; Smyth, Robyn L; Winslow, Luke A.

2015-01-01

Lake Heat Flux Analyzer is a program used for calculating the surface energy fluxes in lakes according to established literature methodologies. The program was developed in MATLAB for the rapid analysis of high-frequency data from instrumented lake buoys in support of the emerging field of aquatic sensor network science. To calculate the surface energy fluxes, the program requires a number of input variables, such as air and water temperature, relative humidity, wind speed, and short-wave radiation. Available outputs for Lake Heat Flux Analyzer include the surface fluxes of momentum, sensible heat and latent heat and their corresponding transfer coefficients, incoming and outgoing long-wave radiation. Lake Heat Flux Analyzer is open source and can be used to process data from multiple lakes rapidly. It provides a means of calculating the surface fluxes using a consistent method, thereby facilitating global comparisons of high-frequency data from lake buoys.

A digital photogrammetric method for measuring horizontal surficial movements on the slumgullion earthflow, Hinsdale county, Colorado

USGS Publications Warehouse

Powers, P.S.; Chiarle, M.; Savage, W.Z.

1996-01-01

The traditional approach to making aerial photographic measurements uses analog or analytic photogrammetric equipment. We have developed a digital method for making measurements from aerial photographs which uses geographic information system (GIS) software, and primarily DOS-based personal computers. This method, which is based on the concept that a direct visual comparison can be made between images derived from two sets of aerial photographs taken at different times, was applied to the surface of the active portion of the Slumgullion earthflow in Colorado to determine horizontal displacement vectors from the movements of visually identifiable objects, such as trees and large rocks. Using this method, more of the slide surface can be mapped in a shorter period of time than using the standard photogrammetric approach. More than 800 horizontal displacement vectors were determined on the active earthflow surface using images produced by our digital photogrammetric technique and 1985 (1:12,000-scale) and 1990 (1:6,000-scale) aerial photographs. The resulting displacement field shows, with a 2-m measurement error (??? 10%), that the fastest moving portion of the landslide underwent 15-29 m of horizontal displacement between 1985 and 1990. Copyright ?? 1996 Elsevier Science Ltd.

Proportional Reasoning Ability and Concepts of Scale: Surface Area to Volume Relationships in Science

ERIC Educational Resources Information Center

Taylor, Amy; Jones, Gail

2009-01-01

The "National Science Education Standards" emphasise teaching unifying concepts and processes such as basic functions of living organisms, the living environment, and scale. Scale influences science processes and phenomena across the domains. One of the big ideas of scale is that of surface area to volume. This study explored whether or not there…

Integrating Science Content and Pedagogy in the Earth, Life, and Physical Sciences: A K-8 Pre-Service Teacher Preparation Continuum at the University of Delaware

NASA Astrophysics Data System (ADS)

Madsen, J.; Allen, D.; Donham, R.; Fifield, S.; Ford, D.; Shipman, H.; Dagher, Z.

2007-12-01

University of Delaware faculty in the geological sciences, biological sciences, and the physics and astronomy departments have partnered with faculty and researchers from the school of education to form a continuum for K- 8 pre-service teacher preparation in science. The goal of the continuum is to develop integrated understandings of content and pedagogy so that these future teachers can effectively use inquiry-based approaches in teaching science in their classrooms. Throughout the continuum where earth science content appears an earth system science approach, with emphasis on inquiry-based activities, is employed. The continuum for K-8 pre-service teachers includes a gateway content course in the earth, life, or physical sciences taken during the freshman year followed by integrated science content and methods courses taken during the sophomore year. These integrated courses, called the Science Semester, were designed and implemented with funding from the National Science Foundation. During the Science Semester, traditional content and pedagogy subject matter boundaries are crossed to stress shared themes that teachers must understand to teach standards-based science. Students work collaboratively on multidisciplinary problem-based learning (PBL) activities that place science concepts in authentic contexts and build learning skills. They also critically explore the theory and practice of elementary science teaching, drawing on their shared experiences of inquiry learning during the Science Semester. The PBL activities that are the hallmark of the Science Semester provide the backdrop through which fundamental earth system interactions can be studied. For example in a PBL investigation that focuses on kids, cancer, and the environment, the hydrologic cycle with emphasis on surface runoff and ground water contamination is studied. Those students seeking secondary certification in science will enroll, as a bridge toward their student teaching experience, in an additional content course within a science discipline that is concurrently taught with a science methods course. Emphasizing inquiry-based activities, these bridge courses also focus on developing integrated understandings of the sciences. The continuum extends beyond the student teaching experience by tracking cohorts of science teachers during their in-service years. With funding from the National Science Foundation's Teacher Professional Continuum program, we are conducting research on this inquiry-based professional development approach for K-8 teachers across this continuum.

Study of sporadical properties of crosslinked polyelectrolyte multilayers

NASA Astrophysics Data System (ADS)

Balu, Deebika

Polyelectrolyte multilayers (PEM) have become a highly studied class of materials due to the range of their applicability in many areas of research, including biology, chemistry and materials science. Recent advances in surface coatings have enabled modification of PEM surfaces to provide desirable properties such as controlled release, super-hydrophobicity, biocompatibility, antifouling and antibacterial properties. In the past decade, antimicrobial PEM coatings have been investigated as a safer alternative to the traditional disinfection methods that usually involve application of hazardous chemicals onto the surface to be cleaned. These antimicrobial coatings could be applied to common surfaces prone to colonization of bacteria (such as bench tops, faucet handles, etc) to supplement routine sanitization protocols by providing sustained antimicrobial activity. Vegetative bacteria (such as Escherichia coli) are more susceptible to antimicrobial agents than bacterial species that form spores. Hence, the antimicrobial activity of PEM coatings fabricated using Layer by Layer (LbL) technique were assayed using Bacillus anthracis spores (Sterne strain). In this thesis, the sporicidal effect of various polyelectrolyte multilayer coatings containing cross-linked polymers immersed in bleach have been evaluated as potential augmentation to existing disinfection methods.

Estimating the Depth of Stratigraphic Units from Marine Seismic Profiles Using Nonstationary Geostatistics

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

Chihi, Hayet; Galli, Alain; Ravenne, Christian

2000-03-15

The object of this study is to build a three-dimensional (3D) geometric model of the stratigraphic units of the margin of the Rhone River on the basis of geophysical investigations by a network of seismic profiles at sea. The geometry of these units is described by depth charts of each surface identified by seismic profiling, which is done by geostatistics. The modeling starts by a statistical analysis by which we determine the parameters that enable us to calculate the variograms of the identified surfaces. After having determined the statistical parameters, we calculate the variograms of the variable Depth. By analyzingmore » the behavior of the variogram we then can deduce whether the situation is stationary and if the variable has an anisotropic behavior. We tried the following two nonstationary methods to obtain our estimates: (a) The method of universal kriging if the underlying variogram was directly accessible. (b) The method of increments if the underlying variogram was not directly accessible. After having modeled the variograms of the increments and of the variable itself, we calculated the surfaces by kriging the variable Depth on a small-mesh estimation grid. The two methods then are compared and their respective advantages and disadvantages are discussed, as well as their fields of application. These methods are capable of being used widely in earth sciences for automatic mapping of geometric surfaces or for variables such as a piezometric surface or a concentration, which are not 'stationary,' that is, essentially, possess a gradient or a tendency to develop systematically in space.« less

T-matrix method in plasmonics: An overview

NASA Astrophysics Data System (ADS)

Khlebtsov, Nikolai G.

2013-07-01

Optical properties of isolated and coupled plasmonic nanoparticles (NPs) are of great interest for many applications in nanophotonics, nanobiotechnology, and nanomedicine owing to rapid progress in fabrication, characterization, and surface functionalization technologies. To simulate optical responses from plasmonic nanostructures, various electromagnetic analytical and numerical methods have been adapted, tested, and used during the past two decades. Currently, the most popular numerical techniques are those that do not suffer from geometrical and composition limitations, e.g., the discrete dipole approximation (DDA), the boundary (finite) element method (BEM, FEM), the finite difference time domain method (FDTDM), and others. However, the T-matrix method still has its own niche in plasmonic science because of its great numerical efficiency, especially for systems with randomly oriented particles and clusters. In this review, I consider the application of the T-matrix method to various plasmonic problems, including dipolar, multipolar, and anisotropic properties of metal NPs; sensing applications; surface enhanced Raman scattering; optics of 1D-3D nanoparticle assemblies; plasmonic particles and clusters near and on substrates; and manipulation of plasmonic NPs with laser tweezers.

40 CFR Appendix G to Part 50 - Reference Method for the Determination of Lead in Suspended Particulate Matter Collected From...

Code of Federal Regulations, 2012 CFR

2012-07-01

... obtains filters with a lead content of 75 µg/filter. It is important that the variation in lead content... important to keep the sample covered so that corrosion products—formed on fume hood surfaces which may... National Science Foundation for publications, 1976. 3. Zdrojewski, A. et al. “The Accurate Measurement of...

40 CFR Appendix G to Part 50 - Reference Method for the Determination of Lead in Suspended Particulate Matter Collected From...

Code of Federal Regulations, 2011 CFR

2011-07-01

... obtains filters with a lead content of 75 µg/filter. It is important that the variation in lead content... important to keep the sample covered so that corrosion products—formed on fume hood surfaces which may... National Science Foundation for publications, 1976. 3. Zdrojewski, A. et al. “The Accurate Measurement of...

40 CFR Appendix G to Part 50 - Reference Method for the Determination of Lead in Suspended Particulate Matter Collected From...

Code of Federal Regulations, 2013 CFR

2013-07-01

... obtains filters with a lead content of 75 µg/filter. It is important that the variation in lead content... important to keep the sample covered so that corrosion products—formed on fume hood surfaces which may... National Science Foundation for publications, 1976. 3. Zdrojewski, A. et al. “The Accurate Measurement of...

Accurate Measurements of Refractive Indices for Dielectrics in an Undergraduate Optics Laboratory for Science and Engineering Students

ERIC Educational Resources Information Center

Hsu, Wei-Tai; Bahrim, Cristian

2009-01-01

Based on our novel method recently published in the "Am. J. Phys." 77 337-43 (2009) for finding precise values of the indices of refraction for dielectrics from measurements of the polarized light reflected by the surface, in this paper we propose an improved technique for finding Brewster angles with a better precision, of 0.001 degrees, using…

Synthesis and Free Radical Polymerization of Fluorinated Polyhedral Oligomeric Silsesquioxane (F-POSS) Macromers: Precursors for Low Surface Energy Materials and Devices

DTIC Science & Technology

2012-04-01

Methanol Octane Methylene Iodide Water Superhydrophobic /oleophilic dip-coated fabric Tuteja et al, Science, 2007, 318, 1618 Superamphiphobic...building block material for low surface energy materials • Applications – Mechanical robust superhydrophobic /oleophobic/omniphobic surfaces • Via...non-wetting polymeric surfaces 5 mm Methanol Octane Methylene Iodide Water Superhydrophobic /oleophilic dip-coated fabric Tuteja et al, Science, 2007

[Progress in the application of laser ablation ICP-MS to surface microanalysis in material science].

PubMed

Zhang, Yong; Jia, Yun-hai; Chen, Ji-wen; Shen, Xue-jing; Liu, Ying; Zhao, Leiz; Li, Dong-ling; Hang, Peng-cheng; Zhao, Zhen; Fan, Wan-lun; Wang, Hai-zhou

2014-08-01

In the present paper, apparatus and theory of surface analysis is introduced, and the progress in the application of laser ablation ICP-MS to microanalysis in ferrous, nonferrous and semiconductor field is reviewed in detail. Compared with traditional surface analytical tools, such as SEM/EDS (scanning electron microscopy/energy dispersive spectrum), EPMA (electron probe microanalysis analysis), AES (auger energy spectrum), etc. the advantage is little or no sample preparation, adjustable spatial resolution according to analytical demand, multi-element analysis and high sensitivity. It is now a powerful complementary method to traditional surface analytical tool. With the development of LA-ICP-MS technology maturing, more and more analytical workers will use this powerful tool in the future, and LA-ICP-MS will be a super star in elemental analysis field just like LIBS (Laser-induced breakdown spectroscopy).

Hummingbird Comet Nucleus Analysis Mission

NASA Technical Reports Server (NTRS)

Kojiro, Daniel; Carle, Glenn C.; Lasher, Larry E.

2000-01-01

Hummingbird is a highly focused scientific mission, proposed to NASA s Discovery Program, designed to address the highest priority questions in cometary science-that of the chemical composition of the cometary nucleus. After rendezvous with the comet, Hummingbird would first methodically image and map the comet, then collect and analyze dust, ice and gases from the cometary atmosphere to enrich characterization of the comet and support landing site selection. Then, like its namesake, Hummingbird would carefully descend to a pre-selected surface site obtaining a high-resolution image, gather a surface material sample, acquire surface temperature and then immediately return to orbit for detailed chemical and elemental analyses followed by a high resolution post-sampling image of the site. Hummingbird s analytical laboratory contains instrumentation for a comprehensive molecular and elemental analysis of the cometary nucleus as well as an innovative surface sample acquisition device.

Selection of pecan shell-based activated carbons for removal of organic and inorganic impurities from water.

PubMed

Niandou, Mohamed A S; Novak, Jeffrey M; Bansode, Rishipal R; Yu, Jianmei; Rehrah, Djaafar; Ahmedna, Mohamed

2013-01-01

Activated carbons are a byproduct from pyrolysis and have value as a purifying agent. The effectiveness of activated carbons is dependent on feedstock selection and pyrolysis conditions that modify their surface properties. Therefore, pecan shell-based activated carbons (PSACs) were prepared by soaking shells in 50% (v/v) HPO or 25 to 50% of KOH-NaHCO followed by pyrolysis at 400 to 700°C under a N atmosphere. Physically activated PSACs were produced by pyrolysis at 700°C under N followed by activation with steam or CO at 700 to 900°C. Physicochemical, surface, and adsorption properties of the PSACs were compared with two commercially available activated carbons. The average mass yield of PSACs with respect to the initial mass of the biomass was about 20 and 34% for physically activated and chemically activated carbons, respectively. Acid-activated carbons exhibited higher surface area, higher bulk density, and lower ash content compared with steam- or CO-activated carbons and the two commercial products. Base activation led to the development of biochar with moderate to high surface area with surface charges suitable for adsorption of anionic species. Regardless of the activation method, PSACs had high total surface area ranging from 400 to 1000 m g, better pore size distribution, and more surface charges than commercial samples. Our results also showed that PSACs were effective in removing inorganic contaminants such as Cu and NO as well as organic contaminants such as atrazine and metolachlor. This study showed that pyrolysis conditions and activation had a large influence on the PSAC's surface characteristics, which can limit its effectiveness as a custom sorbent for targeted water contaminants. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Pilot Scale Application of a Method for the Analysis of ...

EPA Pesticide Factsheets

A growing number of studies now indicate that perfluorinated compounds (PFCs) are globally distributed in the environment. Their widespread distribution and presence in remote locations has led to questions about the importance of atmospheric and oceanic transport. Describing their distribution in surface soils is also an essential but neglected element in developing a comprehensive understanding of their occurrence in the environment. Soils are the critical link between global atmospheric and hydrologic processes where both local and distant contaminants can accumulate and be released into aquatic and terrestrial communities. Because PFC concentrations in soils will influence ground and surface water, wildlife, and crops, methods to accurately measure PFCs in soil are clearly needed. To help answer this need, we developed a method for the analysis of nine perfluorinated carboxylic acids and four perfluorinated sulfonic acids in soil. Samples from six nations (n = 10 per nation) were analyzed by LC-MS/MS to demonstrate the method performance parameters and to make preliminary observations about the occurrence of the PFCs in soils in different parts of the world. The resulting method shows acceptable performance characteristics for the target compounds in most soils while documenting the widespread occurrence of PFCs in surface soils The National Exposure Research Laboratory′s (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in

Plasmon Resonance Methods in GPCR Signaling and Other Membrane Events

PubMed Central

Alves, I.D.; Park, C.K.; Hruby, V.J.

2005-01-01

The existence of surface guided electromagnetic waves has been theoretically predicted from Maxwell’s equations and investigated during the first decades of the 20th century. However, it is only since the late 1960’s that they have attracted the interest of surface physicists and earned the moniker of “surface plasmon”. With the advent of commercially available instruments and well established theories, the technique has been used to study a wide variety of biochemical and biotechnological phenomena. Spectral response of the resonance condition serves as a sensitive indicator of the optical properties of thin films immobilized within a wavelength of the surface. This enhanced surface sensitivity has provided a boon to the surface sciences, and fosters collaboration between surface chemistry, physics and the ongoing biological and biotechnological revolution. Since then, techniques based on surface plasmons such as Surface Plasmon Resonance (SPR), SPR Imaging, Plasmon Waveguide Resonance (PWR) and others, have been increasingly used to determine the affinity and kinetics of a wide variety of real time molecular interactions such as protein-protein, lipid-protein and ligand-protein, without the need for a molecular tag or label. The physical-chemical methodologies used to immobilize membranes at the surface of these optical devices are reviewed, pointing out advantages and limitations of each method. The paper serves to summarize both historical and more recent developments of these technologies for investigating structure-function aspects of these molecular interactions, and regulation of specific events in signal transduction by G-protein coupled receptors (GPCRs). PMID:16101432

Threshold Determination for Local Instantaneous Sea Surface Height Derivation with Icebridge Data in Beaufort Sea

NASA Astrophysics Data System (ADS)

Zhu, C.; Zhang, S.; Xiao, F.; Li, J.; Yuan, L.; Zhang, Y.; Zhu, T.

2018-05-01

The NASA Operation IceBridge (OIB) mission is the largest program in the Earth's polar remote sensing science observation project currently, initiated in 2009, which collects airborne remote sensing measurements to bridge the gap between NASA's ICESat and the upcoming ICESat-2 mission. This paper develop an improved method that optimizing the selection method of Digital Mapping System (DMS) image and using the optimal threshold obtained by experiments in Beaufort Sea to calculate the local instantaneous sea surface height in this area. The optimal threshold determined by comparing manual selection with the lowest (Airborne Topographic Mapper) ATM L1B elevation threshold of 2 %, 1 %, 0.5 %, 0.2 %, 0.1 % and 0.05 % in A, B, C sections, the mean of mean difference are 0.166 m, 0.124 m, 0.083 m, 0.018 m, 0.002 m and -0.034 m. Our study shows the lowest L1B data of 0.1 % is the optimal threshold. The optimal threshold and manual selections are also used to calculate the instantaneous sea surface height over images with leads, we find that improved methods has closer agreement with those from L1B manual selections. For these images without leads, the local instantaneous sea surface height estimated by using the linear equations between distance and sea surface height calculated over images with leads.

Surface and downhole shear wave seismic methods for thick soil site investigations

USGS Publications Warehouse

Hunter, J.A.; Benjumea, B.; Harris, J.B.; Miller, R.D.; Pullan, S.E.; Burns, R.A.; Good, R.L.

2002-01-01

Shear wave velocity-depth information is required for predicting the ground motion response to earthquakes in areas where significant soil cover exists over firm bedrock. Rather than estimating this critical parameter, it can be reliably measured using a suite of surface (non-invasive) and downhole (invasive) seismic methods. Shear wave velocities from surface measurements can be obtained using SH refraction techniques. Array lengths as large as 1000 m and depth of penetration to 250 m have been achieved in some areas. High resolution shear wave reflection techniques utilizing the common midpoint method can delineate the overburden-bedrock surface as well as reflecting boundaries within the overburden. Reflection data can also be used to obtain direct estimates of fundamental site periods from shear wave reflections without the requirement of measuring average shear wave velocity and total thickness of unconsolidated overburden above the bedrock surface. Accurate measurements of vertical shear wave velocities can be obtained using a seismic cone penetrometer in soft sediments, or with a well-locked geophone array in a borehole. Examples from thick soil sites in Canada demonstrate the type of shear wave velocity information that can be obtained with these geophysical techniques, and show how these data can be used to provide a first look at predicted ground motion response for thick soil sites. ?? 2002 Published by Elsevier Science Ltd.

Two-dimensional free-energy surface on the exchange reaction of alkyl chloride/chloride using the QM/MM-MC method

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

Ohisa, M.; Yamataka, H.; Dupuis, Michel

2007-12-05

Two-dimensional free-energy surfaces are calculated for alkyl chloride/chloride exchange/inversion reactions: Cl- + RCl (R = Me and t-Bu) surrounded by one hundred H2O molecules as a model of solvent. The methodology of free-energy calculation by perturbation theory based on a mixed-Hamiltonian model (QM/MM) combined with Monte Carlo sampling of the solvent configurations was used to obtain the changes in solvation free energy. We devised a special procedure to analyze the two-dimensional free-energy surfaces to gain unique insight into the differences in the reaction mechanisms between the two systems. The inversion reaction path for R = t-Bu on the free-energy surfacemore » is found to proceed in an asynchronous way within a concerted framework via the ion-pair region. This is in contrast to the R = Me system that proceeds as a typical SN2 reaction. This work was supported by the U.S. Department of Energy's (DOE) Office of Basic Energy Sciences, Chemical Sciences program. The Pacific Northwest National Laboratory is operated by Battelle for DOE.« less

Europa Science Platforms and Kinetic Energy Probes

NASA Technical Reports Server (NTRS)

Hays, C. C.; Klein, G. A.

2003-01-01

This presentation will outline a proposed mission for the Jupiter Icy Moons Orbiter (JIMO). The mission outlined will concentrate on an examination of Europa. Some of the primary science goals for the JIMO mission are: 1) to answer broad science questions, 2) improved knowledge of Jovian system; specifically, lunar geological and geophysical properties, 3) chemical composition of Jovian lunar surfaces and subterranean matter, and 4) the search for life. In order to address these issues, the experiment proposed here will deploy orbiting, surface, and subterranean science platforms.

Microwave selective thermal development of latent fingerprints on porous surfaces: potentialities of the method and preliminary experimental results.

PubMed

Rosa, Roberto; Veronesi, Paolo; Leonelli, Cristina

2013-09-01

The thermal development of latent fingerprints on paper surfaces is a simple, safe, and chemicals-free method, based on the faster heating of the substrate underlying the print residue. Microwave heating is proposed for the first time for the development of latent fingerprints on cellulose-based substrate, in order to add to the thermal development mechanism the further characteristic of being able to heat the fingerprint residues to a different extent with respect to the substrate, due to the intrinsic difference in their dielectric properties. Numerical simulation was performed to confirm and highlight the selectivity of microwaves, and preliminary experimental results point out the great potentialities of this technique, which allowed developing both latent sebaceous-rich and latent eccrine-rich fingerprints on different porous surfaces, in less than 30 sec time with an applied output power of 500 W. Microwaves demonstrated more effectiveness in the development of eccrine-rich residues, aged up to 12 weeks. © 2013 American Academy of Forensic Sciences.

Focus on advances in surface and interface science 2010 Focus on advances in surface and interface science 2010

NASA Astrophysics Data System (ADS)

Aeschlimann, Martin; Berndt, Richard

2013-02-01

While surface science has traditionally focused on catalytic processes at surfaces, more recent developments have seen it evolve into a broad research area encompassing issues as diverse as single-molecule experiments, preparation and analysis of nanostructures, studies of novel and exotic materials, and elementary excitations in solids to name but a few. The aim of this small, but very select, focus issue of New Journal of Physics is to present a snapshot of just some of the latest cutting-edge research now being carried out on these topics. As editors, we hope that you find the contributions of interest to you and your future research.

Lessons Learned in Science Operations for Planetary Surface Exploration

NASA Technical Reports Server (NTRS)

Young, K. E.; Graff, T. G.; Reagan, M.; Coan, D.; Evans, C. A.; Bleacher, J. E.; Glotch, T. D.

2017-01-01

The six Apollo lunar surface missions represent the only occasions where we have conducted scientific operations on another planetary surface. While these six missions were successful in bringing back valuable geologic samples, technology advances in the subsequent forty years have enabled much higher resolution scientific activity in situ. Regardless of where astronauts next visit (whether it be back to the Moon or to Mars or a Near Earth Object), the science operations procedures completed during this mission will need to be refined and updated to reflect these advances. We have undertaken a series of operational tests in relevant field environments to understand how best to develop the new generation of science operations procedures for planetary surface exploration.

Atomistic Modeling of Corrosion Events at the Interface between a Metal and Its Environment

DOE PAGES

Taylor, Christopher D.

2012-01-01

Atomistic simulation is a powerful tool for probing the structure and properties of materials and the nature of chemical reactions. Corrosion is a complex process that involves chemical reactions occurring at the interface between a material and its environment and is, therefore, highly suited to study by atomistic modeling techniques. In this paper, the complex nature of corrosion processes and mechanisms is briefly reviewed. Various atomistic methods for exploring corrosion mechanisms are then described, and recent applications in the literature surveyed. Several instances of the application of atomistic modeling to corrosion science are then reviewed in detail, including studies ofmore » the metal-water interface, the reaction of water on electrified metallic interfaces, the dissolution of metal atoms from metallic surfaces, and the role of competitive adsorption in controlling the chemical nature and structure of a metallic surface. Some perspectives are then given concerning the future of atomistic modeling in the field of corrosion science.« less

Surface texture measurement for dental wear applications

NASA Astrophysics Data System (ADS)

Austin, R. S.; Mullen, F.; Bartlett, D. W.

2015-06-01

The application of surface topography measurement and characterization within dental materials science is highly active and rapidly developing, in line with many modern industries. Surface measurement and structuring is used extensively within oral and dental science to optimize the optical, tribological and biological performance of natural and biomimetic dental materials. Although there has historically been little standardization in the use and reporting of surface metrology instrumentation and software, the dental industry is beginning to adopt modern areal measurement and characterization techniques, especially as the dental industry is increasingly adopting digital impressioning techniques in order to leverage CAD/CAM technologies for the design and construction of dental restorations. As dental treatment becomes increasingly digitized and reliant on advanced technologies such as dental implants, wider adoption of standardized surface topography and characterization techniques will become evermore essential. The dental research community welcomes the advances that are being made in surface topography measurement science towards realizing this ultimate goal.

Adsorption of pentacene on (100) vicinal surfaces: role of coordination, surface chemistry and vdWs effects

NASA Astrophysics Data System (ADS)

Matos, Jeronimo; Kara, Abdelkader

2015-03-01

In contrast to low miller index surfaces, vicinal surfaces are characterized by steps and step edges that not only present an interesting atomic landscape for the adsorption organic molecules, but also a unique electronic structure resulting in part from the low coordinated atoms at the step edges. The adsorption of pentacene on the stepped (511), (711), (911) surfaces (respectively 3, 4 and 5-atom wide terraces) of Cu and Ag (coinage transition metals); Pt (reactive transition metal); and Ni (reactive, magnetic transition metal) are studied using density functional theory, in order to investigate the support effects arising from differing surface chemistry. We compare the adsorption energy, adsorption geometry and electronic structure predicted by the PBE functional with those obtained from one of the optimized vdW-DF methods: optB88-vdW. Work supported by the U.S. Department of Energy Basic Energy Science under Contract No. DE-FG02-11ER16243.

Surface chemistry of carbon dioxide revisited

NASA Astrophysics Data System (ADS)

Taifan, William; Boily, Jean-François; Baltrusaitis, Jonas

2016-12-01

This review discusses modern developments in CO2 surface chemistry by focusing on the work published since the original review by H.J. Freund and M.W. Roberts two decades ago (Surface Science Reports 25 (1996) 225-273). It includes relevant fundamentals pertaining to the topics covered in that earlier review, such as conventional metal and metal oxide surfaces and CO2 interactions thereon. While UHV spectroscopy has routinely been applied for CO2 gas-solid interface analysis, the present work goes further by describing surface-CO2 interactions under elevated CO2 pressure on non-oxide surfaces, such as zeolites, sulfides, carbides and nitrides. Furthermore, it describes additional salient in situ techniques relevant to the resolution of the interfacial chemistry of CO2, notably infrared spectroscopy and state-of-the-art theoretical methods, currently used in the resolution of solid and soluble carbonate species in liquid-water vapor, liquid-solid and liquid-liquid interfaces. These techniques are directly relevant to fundamental, natural and technological settings, such as heterogeneous and environmental catalysis and CO2 sequestration.

Single-shot ultrafast tomographic imaging by spectral multiplexing

NASA Astrophysics Data System (ADS)

Matlis, N. H.; Axley, A.; Leemans, W. P.

2012-10-01

Computed tomography has profoundly impacted science, medicine and technology by using projection measurements scanned over multiple angles to permit cross-sectional imaging of an object. The application of computed tomography to moving or dynamically varying objects, however, has been limited by the temporal resolution of the technique, which is set by the time required to complete the scan. For objects that vary on ultrafast timescales, traditional scanning methods are not an option. Here we present a non-scanning method capable of resolving structure on femtosecond timescales by using spectral multiplexing of a single laser beam to perform tomographic imaging over a continuous range of angles simultaneously. We use this technique to demonstrate the first single-shot ultrafast computed tomography reconstructions and obtain previously inaccessible structure and position information for laser-induced plasma filaments. This development enables real-time tomographic imaging for ultrafast science, and offers a potential solution to the challenging problem of imaging through scattering surfaces.

Novel imaging analysis system to measure the spatial dimension of engineered tissue construct.

PubMed

Choi, Kyoung-Hwan; Yoo, Byung-Su; Park, So Ra; Choi, Byung Hyune; Min, Byoung-Hyun

2010-02-01

The measurement of the spatial dimensions of tissue-engineered constructs is very important for their clinical applications. In this study, a novel method to measure the volume of tissue-engineered constructs was developed using iterative mathematical computations. The method measures and analyzes three-dimensional (3D) parameters of a construct to estimate its actual volume using a sequence of software-based mathematical algorithms. The mathematical algorithm is composed of two stages: the shape extraction and the determination of volume. The shape extraction utilized 3D images of a construct: length, width, and thickness, captured by a high-quality camera with charge coupled device. The surface of the 3D images was then divided into fine sections. The area of each section was measured and combined to obtain the total surface area. The 3D volume of the target construct was then mathematically obtained using its total surface area and thickness. The accuracy of the measurement method was verified by comparing the results with those obtained from the hydrostatic weighing method (Korea Research Institute of Standards and Science [KRISS], Korea). The mean difference in volume between two methods was 0.0313 +/- 0.0003% (n = 5, P = 0.523) with no significant statistical difference. In conclusion, our image-based spatial measurement system is a reliable and easy method to obtain an accurate 3D volume of a tissue-engineered construct.

Light scattering and absorption by space weathered planetary bodies: Novel numerical solution

NASA Astrophysics Data System (ADS)

Markkanen, Johannes; Väisänen, Timo; Penttilä, Antti; Muinonen, Karri

2017-10-01

Airless planetary bodies are exposed to space weathering, i.e., energetic electromagnetic and particle radiation, implantation and sputtering from solar wind particles, and micrometeorite bombardment.Space weathering is known to alter the physical and chemical composition of the surface of an airless body (C. Pieters et al., J. Geophys. Res. Planets, 121, 2016). From the light scattering perspective, one of the key effects is the production of nanophase iron (npFe0) near the exposed surfaces (B. Hapke, J. Geophys. Res., 106, E5, 2001). At visible and ultraviolet wavelengths these particles have a strong electromagnetic response which has a major impact on scattering and absorption features. Thus, to interpret the spectroscopic observations of space-weathered asteroids, the model should treat the contributions of the npFe0 particles rigorously.Our numerical approach is based on the hierarchical geometric optics (GO) and radiative transfer (RT). The modelled asteroid is assumed to consist of densely packed silicate grains with npFe0 inclusions. We employ our recently developed RT method for dense random media (K. Muinonen, et al., Radio Science, submitted, 2017) to compute the contributions of the npFe0 particles embedded in silicate grains. The dense media RT method requires computing interactions of the npFe0 particles in the volume element for which we use the exact fast superposition T-matrix method (J. Markkanen, and A.J. Yuffa, JQSRT 189, 2017). Reflections and refractions on the grain surface and propagation in the grain are addressed by the GO. Finally, the standard RT is applied to compute scattering by the entire asteroid.Our numerical method allows for a quantitative interpretation of the spectroscopic observations of space-weathered asteroids. In addition, it may be an important step towards more rigorous a thermophysical model of asteroids when coupled with the radiative and conductive heat transfer techniques.Acknowledgments. Research supported by European Research Council with Advanced Grant No. 320773 SAEMPL. Computational resources provided by CSC- IT Centre for Science Ltd, Finland.

Building Surface Science Capacity to Serve the Automobile Industry in Southeastern Michigan, final report

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

Shen, Weidian

This project, “Building Surface Science Capacity to Serve the Automobile Industry in Southeastern Michigan” was carried out in two phases: (1) the 2009 – 2012 renovation of space in the new EMU Science Complex, which included the Surface Science Laboratory (SSL), a very vigorous research lab at EMU that carries on a variety of research projects to serve the auto and other industries in Michigan; and (2) the 2013 purchase of several pieces of equipment to further enhance the research capability of the SSL. The funding granted by the DoE was proposed to “renovate the space in the Science Complexmore » to include SSL and purchase equipment for tribological and electrochemical impedance measurements in the lab, thus SSL will serve the auto and other industries in Michigan better.” We believe we have fully accomplished the mission.« less

Planetary landing-zone reconnaissance using ice-penetrating radar data: Concept validation in Antarctica

NASA Astrophysics Data System (ADS)

Grima, Cyril; Schroeder, Dustin M.; Blankenship, Donald D.; Young, Duncan A.

2014-11-01

The potential for a nadir-looking radar sounder to retrieve significant surface roughness/permittivity information valuable for planetary landing site selection is demonstrated using data from an airborne survey of the Thwaites Glacier Catchment, West Antarctica using the High Capability Airborne Radar Sounder (HiCARS). The statistical method introduced by Grima et al. (2012. Icarus 220, 84-99. http://dx.doi.org/10.1007/s11214-012-9916-y) for surface characterization is applied systematically along the survey flights. The coherent and incoherent components of the surface signal, along with an internally generated confidence factor, are extracted and mapped in order to show how a radar sounder can be used as both a reflectometer and a scatterometer to identify regions of low surface roughness compatible with a planetary lander. These signal components are used with a backscattering model to produce a landing risk assessment map by considering the following surface properties: Root mean square (RMS) heights, RMS slopes, roughness homogeneity/stationarity over the landing ellipse, and soil porosity. Comparing these radar-derived surface properties with simultaneously acquired nadir-looking imagery and laser-altimetry validates this method. The ability to assess all of these parameters with an ice penetrating radar expands the demonstrated capability of a principle instrument in icy planet satellite science to include statistical reconnaissance of the surface roughness to identify suitable sites for a follow-on lander mission.

New Frontiers Science at Venus from Orbit plus Atmospheric Gas Sampling

NASA Astrophysics Data System (ADS)

Smrekar, Suzanne; Dyar, Melinda; Hensley, Scott; Helbert, Joern; VOX Science and Engineering Teams

2017-10-01

Venus remains the most Earth-like body in terms of size, composition, surface age, and insulation. Venus Origins Explorer (VOX) determines how Earth’s twin diverged, and enables breakthroughs in our understanding of rocky planet evolution and habitability. At the time of the Decadal Survey the ability to map mineralogy from orbit (Helbert et al.) and present-day radar techniques to detect active deformation were not fully appreciated. VOX leverages these methods and in-situ noble gases to answer New Frontiers science objectives:1. Atmospheric physics/chemistry: noble gases and isotopes to constrain atmospheric sources, escape processes, and integrated volcanic outgassing; global search for current volcanically outgassed water.2. Past hydrological cycles: global tessera composition to determine the role of volatiles in crustal formation.3. Crustal physics/chemistry: global crustal mineralogy/chemistry, tectonic processes, heat flow, resolve the catastrophic vs. equilibrium resurfacing debate, active geologic processes and possible crustal recycling.4. Crustal weathering: surface-atmosphere weathering reactions from redox state and the chemical equilibrium of the near-surface atmosphere.5. Atmospheric properties/winds: map cloud particle modes and their temporal variations, and track cloud-level winds in the polar vortices.6. Surface-atmosphere interactions: chemical reactions from mineralogy; weathering state between new, recent and older flows; possible volcanically outgassed water.VOX’s Atmosphere Sampling Vehicle (ASV) dips into and samples the well-mixed atmosphere, using Venus Original Constituents Experiment (VOCE) to measure noble gases. VOX’s orbiter carries the Venus Emissivity Mapper (VEM) and the Venus Interferometric Synthetic Aperture Radar (VISAR), and maps the gravity field using Ka-band tracking.VOX is the logical next mission to Venus because it delivers: 1) top priority atmosphere, surface, and interior science; 2) key global data for comparative planetology; 3) high-resolution topography, composition, and imaging to optimize future landers; 4) opportunities for revolutionary discoveries with a 3-year long mission, proven implementation and 44 Tb of data.

JPRS Report, Science & Technology. China: Stealth/Counter-Stealth Research.

DTIC Science & Technology

1992-11-19

Frequency-Selective Surfaces 92FE0801F Beijing DIANZIXUEBAO [ACTA ELECTRONICA SINICA] in Chinese Vol 20 No 6, Jun 92 pp 85-88 [Article by Shen...microwave devices and electromag- netic scattering. Motion Compensation Method in ISAR Imaging 92FE0801A Beijing DIANZIXUEBAO [ACTA ELECTRONICA ...Chinese Society of Electronics and an editor of DIANZI XUEBAO [ACTA ELECTRONICA SINICA]. Deng Wenbiao Born in February 1961, he graduated from the

Friction and Wear Sciences for a Highly Durable Railgun Weapon

DTIC Science & Technology

2007-10-01

FFT- Based Numerical Methods for Elasto-Plastic Contacts of Nominally Flat Surfaces,” to appear in Journal of Applied Mechanics. 20. Jin, X...is the fusion enthalpy per unit mass, C!"" ~ = and ! ~ is a dimensionless coefficient and 100 ~ !" . Listed in Table I are the material’s...searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments

Digital terrain modelling and industrial surface metrology - Converging crafts

USGS Publications Warehouse

Pike, R.J.

2001-01-01

Quantitative characterisation of surface form, increasingly from digital 3-D height data, is cross-disciplinary and can be applied at any scale. Thus, separation of industrial-surface metrology from its Earth-science counterpart, (digital) terrain modelling, is artificial. Their growing convergence presents an opportunity to develop in surface morphometry a unified approach to surface representation. This paper introduces terrain modelling and compares it with metrology, noting their differences and similarities. Examples of potential redundancy among parameters illustrate one of the many issues common to both disciplines. ?? 2001 Elsevier Science Ltd. All rights reserved.

Soft Lithography

NASA Astrophysics Data System (ADS)

Xia, Younan; Whitesides, George M.

1998-08-01

Soft lithography represents a non-photolithographic strategy based on selfassembly and replica molding for carrying out micro- and nanofabrication. It provides a convenient, effective, and low-cost method for the formation and manufacturing of micro- and nanostructures. In soft lithography, an elastomeric stamp with patterned relief structures on its surface is used to generate patterns and structures with feature sizes ranging from 30 nm to 100 mum. Five techniques have been demonstrated: microcontact printing (muCP), replica molding (REM), microtransfer molding (muTM), micromolding in capillaries (MIMIC), and solvent-assisted micromolding (SAMIM). In this chapter we discuss the procedures for these techniques and their applications in micro- and nanofabrication, surface chemistry, materials science, optics, MEMS, and microelectronics.

Acoustic tweezers: patterning cells and microparticles using standing surface acoustic waves (SSAW).

PubMed

Shi, Jinjie; Ahmed, Daniel; Mao, Xiaole; Lin, Sz-Chin Steven; Lawit, Aitan; Huang, Tony Jun

2009-10-21

Here we present an active patterning technique named "acoustic tweezers" that utilizes standing surface acoustic wave (SSAW) to manipulate and pattern cells and microparticles. This technique is capable of patterning cells and microparticles regardless of shape, size, charge or polarity. Its power intensity, approximately 5x10(5) times lower than that of optical tweezers, compares favorably with those of other active patterning methods. Flow cytometry studies have revealed it to be non-invasive. The aforementioned advantages, along with this technique's simple design and ability to be miniaturized, render the "acoustic tweezers" technique a promising tool for various applications in biology, chemistry, engineering, and materials science.

Electron-Scavenging Chemistry of Benzoquinone on TiO2(110)

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

Henderson, Michael A.; Shen, Mingmin

The chemistry of benzoquinone (BQ) on TiO2(110) was examined using temperature programmed desorption (TPD), electron energy loss spectroscopy (EELS) and Auger electron spectroscopy (AES). BQ adsorbs mostly molecularly on the clean surface, although EELS demonstrates that electrons from surface Ti3+ sites at oxygen vacancy sites (VO) are readily oxidized by the high electron scavenging ability of the molecule. In contrast, when the surface is covered with water, subsequently adsorbed BQ molecules that scavenge surface electrons also abstract H from surface OHbr groups to form hydroquinone (HQ), which desorbs at ~450 K. This work was supported by the US Department ofmore » Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. The research was performed using the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.« less

Space Weathering Impact on Solar System Surfaces and Planetary Mission Science

NASA Technical Reports Server (NTRS)

Cooper, John F.

2011-01-01

We often look "through a glass, darkly" at solar system bodies with tenuous atmospheres and direct surface exposure to the local space environment. Space weathering exposure acts via universal space-surface interaction processes to produce a thin patina of outer material covering, potentially obscuring endogenic surface materials of greatest interest for understanding origins and interior evolution. Examples of obscuring exogenic layers are radiation crusts on cometary nuclei and iogenic components of sulfate hydrate deposits on the trailing hemisphere of Europa. Weathering processes include plasma ion implantation into surfaces, sputtering by charged particles and solar ultraviolet photons, photolytic chemistry driven by UV irradiation, and radiolytic chemistry evolving from products of charged particle irradiation. Regolith structure from impacts, and underlying deeper structures from internal evolution, affects efficacy of certain surface interactions, e.g. sputtering as affected by porosity and surface irradiation dosage as partly attenuated by local topographic shielding. These processes should be regarded for mission science planning as potentially enabling, e.g. since direct surface sputtering, and resultant surface-bound exospheres, can provide in-situ samples of surface composition to ion and neutral mass spectrometers on orbital spacecraft. Sample return for highest sensitivity compOSitional and structural analyses at Earth will usually be precluded by limited range of surface sampling, long times for return, and high cost. Targeted advancements in instrument technology would be more cost efficient for local remote and in-situ sample analysis. More realistic laboratory simulations, e.g. for bulk samples, are needed to interpret mission science observations of weathered surfaces. Space environment effects on mission spacecraft and science operations must also be specified and mitigated from the hourly to monthly changes in space weather and from longer term (e.g., solar cycle) evolution of space climate. Capable instrumentation on planetary missions can and should be planned to contribute to knowledge of interplanetary space environments. Evolving data system technologies such as virtual observatories should be explored for more interdisciplinary application to the science of planetary surface, atmospheric, magnetospheric, and interplanetary interactions.

Multifarious applications of atomic force microscopy in forensic science investigations.

PubMed

Pandey, Gaurav; Tharmavaram, Maithri; Rawtani, Deepak; Kumar, Sumit; Agrawal, Y

2017-04-01

Forensic science is a wide field comprising of several subspecialties and uses methods derived from natural sciences for finding criminals and other evidence valid in a legal court. A relatively new area; Nano-forensics brings a new era of investigation in forensic science in which instantaneous results can be produced that determine various agents such as explosive gasses, biological agents and residues in different crime scenes and terrorist activity investigations. This can be achieved by applying Nanotechnology and its associated characterization techniques in forensic sciences. Several characterization techniques exist in Nanotechnology and nano-analysis is one such technique that is used in forensic science which includes Electron microscopes (EM) like Transmission (TEM) and Scanning (SEM), Raman microscopy (Micro -Raman) and Scanning Probe Microscopes (SPMs) like Atomic Force Microscope (AFM). Atomic force microscopy enables surface characterization of different materials by examining their morphology and mechanical properties. Materials that are immeasurable such as hair, body fluids, textile fibers, documents, polymers, pressure sensitive adhesives (PSAs), etc. are often encountered during forensic investigations. This review article will mainly focus on the use of AFM in the examination of different evidence such as blood stains, forged documents, human hair samples, ammunitions, explosives, and other such applications in the field of Forensic Science. Copyright © 2017 Elsevier B.V. All rights reserved.

Land and cryosphere products from Suomi NPP VIIRS: Overview and status

PubMed Central

Justice, Christopher O; Román, Miguel O; Csiszar, Ivan; Vermote, Eric F; Wolfe, Robert E; Hook, Simon J; Friedl, Mark; Wang, Zhuosen; Schaaf, Crystal B; Miura, Tomoaki; Tschudi, Mark; Riggs, George; Hall, Dorothy K; Lyapustin, Alexei I; Devadiga, Sadashiva; Davidson, Carol; Masuoka, Edward J

2013-01-01

[1] The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched in October 2011 as part of the Suomi National Polar-Orbiting Partnership (S-NPP). The VIIRS instrument was designed to improve upon the capabilities of the operational Advanced Very High Resolution Radiometer and provide observation continuity with NASA’s Earth Observing System’s Moderate Resolution Imaging Spectroradiometer (MODIS). Since the VIIRS first-light images were received in November 2011, NASA- and NOAA-funded scientists have been working to evaluate the instrument performance and generate land and cryosphere products to meet the needs of the NOAA operational users and the NASA science community. NOAA’s focus has been on refining a suite of operational products known as Environmental Data Records (EDRs), which were developed according to project specifications under the National Polar-Orbiting Environmental Satellite System. The NASA S-NPP Science Team has focused on evaluating the EDRs for science use, developing and testing additional products to meet science data needs, and providing MODIS data product continuity. This paper presents to-date findings of the NASA Science Team’s evaluation of the VIIRS land and cryosphere EDRs, specifically Surface Reflectance, Land Surface Temperature, Surface Albedo, Vegetation Indices, Surface Type, Active Fires, Snow Cover, Ice Surface Temperature, and Sea Ice Characterization. The study concludes that, for MODIS data product continuity and earth system science, an enhanced suite of land and cryosphere products and associated data system capabilities are needed beyond the EDRs currently available from the VIIRS. PMID:25821661

Land and cryosphere products from Suomi NPP VIIRS: Overview and status.

PubMed

Justice, Christopher O; Román, Miguel O; Csiszar, Ivan; Vermote, Eric F; Wolfe, Robert E; Hook, Simon J; Friedl, Mark; Wang, Zhuosen; Schaaf, Crystal B; Miura, Tomoaki; Tschudi, Mark; Riggs, George; Hall, Dorothy K; Lyapustin, Alexei I; Devadiga, Sadashiva; Davidson, Carol; Masuoka, Edward J

2013-09-16

[1] The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched in October 2011 as part of the Suomi National Polar-Orbiting Partnership (S-NPP). The VIIRS instrument was designed to improve upon the capabilities of the operational Advanced Very High Resolution Radiometer and provide observation continuity with NASA's Earth Observing System's Moderate Resolution Imaging Spectroradiometer (MODIS). Since the VIIRS first-light images were received in November 2011, NASA- and NOAA-funded scientists have been working to evaluate the instrument performance and generate land and cryosphere products to meet the needs of the NOAA operational users and the NASA science community. NOAA's focus has been on refining a suite of operational products known as Environmental Data Records (EDRs), which were developed according to project specifications under the National Polar-Orbiting Environmental Satellite System. The NASA S-NPP Science Team has focused on evaluating the EDRs for science use, developing and testing additional products to meet science data needs, and providing MODIS data product continuity. This paper presents to-date findings of the NASA Science Team's evaluation of the VIIRS land and cryosphere EDRs, specifically Surface Reflectance, Land Surface Temperature, Surface Albedo, Vegetation Indices, Surface Type, Active Fires, Snow Cover, Ice Surface Temperature, and Sea Ice Characterization. The study concludes that, for MODIS data product continuity and earth system science, an enhanced suite of land and cryosphere products and associated data system capabilities are needed beyond the EDRs currently available from the VIIRS.

Science and Reconnaissance from the Europa Clipper Mission Concept: Exploring Europa's Habitability

NASA Astrophysics Data System (ADS)

Pappalardo, Robert; Senske, David; Prockter, Louise; Paczkowski, Brian; Vance, Steve; Goldstein, Barry; Magner, Thomas; Cooke, Brian

2015-04-01

Europa is recognized by the Planetary Science De-cadal Survey as a prime candidate to search for a pre-sent-day habitable environment in our solar system. As such, NASA has pursued a series of studies, facilitated by a Europa Science Definition Team (SDT), to define a strategy to best advance our scientific understanding of this icy world with the science goal: Explore Europa to investigate its habitability. (In June of 2014, the SDT completed its task of identifying the overarching science objectives and investigations.) Working in concert with a technical team, a set of mission archi-tectures were evaluated to determine the best way to achieve the SDT defined science objectives. The fa-vored architecture would consist of a spacecraft in Ju-piter orbit making many close flybys of Europa, con-centrating on remote sensing to explore the moon. In-novative mission design would use gravitational per-turbations of the spacecraft trajectory to permit flybys at a wide variety of latitudes and longitudes, enabling globally distributed regional coverage of Europa's sur-face, with nominally 45 close flybys, typically at alti-tudes from 25 to 100 km. This concept has become known as the Europa Clipper. The Europa SDT recommended three science ob-jectives for the Europa Clipper: Ice Shell and Ocean: Characterize the ice shell and any subsurface water, including their heterogeneity, ocean properties, and the nature of surface-ice-ocean exchange; Composition: Understand the habitability of Europa's ocean through composition and chemistry; and Geology: Understand the formation of surface features, including sites of recent or current activity, and characterize high science interest localities. The Europa SDT also considered implications of the Hubble Space Telescope detection of possible plumes at Europa. To feed forward to potential subsequent future ex-ploration that could be enabled by a lander, it was deemed that the Europa Clipper mission concept should provide the capability to perform reconnais-sance for a future lander. In consultation with NASA Headquarters, the SDT developed a reconnaissance goal: Characterize Scientifically Compelling Sites, and Hazards, for a Potential Future Landed Mission to Europa. This leads to two reconnaissance objectives: Site Safety: Assess the distribution of surface hazards, the load-bearing capacity of the surface, the structure of the subsurface, and the regolith thickness; and Sci-ence Value: Assess the composition of surface materi-als, the geologic context of the surface, the potential for geological activity, the proximity of near surface water, and the potential for active upwelling of ocean material. The Europa Clipper mission concept provides an efficient means to explore Europa and investigate its habitability through understanding the satellite's ice shell and ocean, composition, and geology. It also provides for surface reconnaissance for potential future landed exploration of Europa. Development of the Eu-ropa Clipper mission concept is ongoing, with current studies focusing on spacecraft design trades and re-finements, launch vehicle options (EELV and SLS), and power source (MMRTG and solar), to name a few. We will provide an update on status of the science and reconnaissance effort, as well as the results of trade studies as relevant to the science and reconnaissance potential of the mission concept.

The surface science of nanocrystals

NASA Astrophysics Data System (ADS)

Boles, Michael A.; Ling, Daishun; Hyeon, Taeghwan; Talapin, Dmitri V.

2016-02-01

All nanomaterials share a common feature of large surface-to-volume ratio, making their surfaces the dominant player in many physical and chemical processes. Surface ligands -- molecules that bind to the surface -- are an essential component of nanomaterial synthesis, processing and application. Understanding the structure and properties of nanoscale interfaces requires an intricate mix of concepts and techniques borrowed from surface science and coordination chemistry. Our Review elaborates these connections and discusses the bonding, electronic structure and chemical transformations at nanomaterial surfaces. We specifically focus on the role of surface ligands in tuning and rationally designing properties of functional nanomaterials. Given their importance for biomedical (imaging, diagnostics and therapeutics) and optoelectronic (light-emitting devices, transistors, solar cells) applications, we end with an assessment of application-targeted surface engineering.

Surface Modeling and Grid Generation of Orbital Sciences X34 Vehicle. Phase 1

NASA Technical Reports Server (NTRS)

Alter, Stephen J.

1997-01-01

The surface modeling and grid generation requirements, motivations, and methods used to develop Computational Fluid Dynamic volume grids for the X34-Phase 1 are presented. The requirements set forth by the Aerothermodynamics Branch at the NASA Langley Research Center serve as the basis for the final techniques used in the construction of all volume grids, including grids for parametric studies of the X34. The Integrated Computer Engineering and Manufacturing code for Computational Fluid Dynamics (ICEM/CFD), the Grid Generation code (GRIDGEN), the Three-Dimensional Multi-block Advanced Grid Generation System (3DMAGGS) code, and Volume Grid Manipulator (VGM) code are used to enable the necessary surface modeling, surface grid generation, volume grid generation, and grid alterations, respectively. All volume grids generated for the X34, as outlined in this paper, were used for CFD simulations within the Aerothermodynamics Branch.

Laser writing of single-crystalline gold substrates for surface enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Singh, Astha; Sharma, Geeta; Ranjan, Neeraj; Mittholiya, Kshitij; Bhatnagar, Anuj; Singh, B. P.; Mathur, Deepak; Vasa, Parinda

2017-07-01

Surface enhanced Raman scattering (SERS) spectroscopy, a powerful contemporary tool for studying low-concentration analytes via surface plasmon induced enhancement of local electric field, is of utility in biochemistry, material science, threat detection, and environmental studies. We have developed a simple, fast, scalable, and relatively low-cost optical method of fabricating and characterizing large-area, reusable and broadband SERS substrates with long storage lifetime. We use tightly focused, intense infra-red laser pulses to write gratings on single-crystalline, Au (1 1 1) gold films on mica which act as SERS substrates. Our single-crystalline SERS substrates compare favourably, in terms of surface quality and roughness, to those fabricated in poly-crystalline Au films. Tests show that our SERS substrates have the potential of detecting urea and 1,10-phenantroline adulterants in milk and water, respectively, at 0.01 ppm (or lower) concentrations.

Quantitative Modeling of Earth Surface Processes

NASA Astrophysics Data System (ADS)

Pelletier, Jon D.

This textbook describes some of the most effective and straightforward quantitative techniques for modeling Earth surface processes. By emphasizing a core set of equations and solution techniques, the book presents state-of-the-art models currently employed in Earth surface process research, as well as a set of simple but practical research tools. Detailed case studies demonstrate application of the methods to a wide variety of processes including hillslope, fluvial, aeolian, glacial, tectonic, and climatic systems. Exercises at the end of each chapter begin with simple calculations and then progress to more sophisticated problems that require computer programming. All the necessary computer codes are available online at www.cambridge.org/9780521855976. Assuming some knowledge of calculus and basic programming experience, this quantitative textbook is designed for advanced geomorphology courses and as a reference book for professional researchers in Earth and planetary science looking for a quantitative approach to Earth surface processes.

Cutaneous exposure scenarios for engineered nanoparticles used in semiconductor fabrication: a preliminary investigation of workplace surface contamination.

PubMed

Shepard, Michele; Brenner, Sara

2014-01-01

Numerous studies are ongoing in the fields of nanotoxicology and exposure science; however, gaps remain in identifying and evaluating potential exposures from skin contact with engineered nanoparticles in occupational settings. The aim of this study was to identify potential cutaneous exposure scenarios at a workplace using engineered nanoparticles (alumina, ceria, amorphous silica) and evaluate the presence of these materials on workplace surfaces. Process review, workplace observations, and preliminary surface sampling were conducted using microvacuum and wipe sample collection methods and transmission electron microscopy with elemental analysis. Exposure scenarios were identified with potential for incidental contact. Nanoparticles of silica or silica and/or alumina agglomerates (or aggregates) were identified in surface samples from work areas where engineered nanoparticles were used or handled. Additional data are needed to evaluate occupational exposures from skin contact with engineered nanoparticles; precautionary measures should be used to minimize potential cutaneous exposures in the workplace.

Application of Relaxed Eddy Accumulation (REA) method to estimate CO2 and CH4 surface fluxes in the city of Krakow, southern Poland.

NASA Astrophysics Data System (ADS)

Zimnoch, Miroslaw; Gorczyca, Zbigniew; Pieniazek, Katarzyna; Jasek, Alina; Chmura, Lukasz; Rozanski, Kazimierz

2013-04-01

There is a growing interest in the recent years in studies aimed at quantifying carbon cycling in urban centres. Worldwide migration of human population from rural to urban areas and corresponding growth of extensive urban agglomerations and megacities leads to intensification of anthropogenic emissions of carbon and strong disruption of natural carbon cycle on these areas. Therefore, a deeper understanding of the carbon "metabolism" of such regions is required. Apart of better quantification of surface carbon fluxes, also a thorough understanding of the functioning of biosphere under strong anthropogenic influence is needed. Nowadays, covariance methods are widely applied for studying gas exchange between the atmosphere and the Earth's surface. Relaxed Eddy Accumulation method (REA), combined with the CO2 and CH4 CRDS analyser allows simultaneous measurements of surface fluxes of carbon dioxide and methane within the chosen footprint of the detection system, thus making possible thorough characterisation of the overall exchange of those gases between the atmosphere and the urban surface across diverse spatial and temporal scales. Here we present preliminary results of the study aimed at quantifying surface fluxes of CO2 and CH4 in Krakow, southern Poland. The REA system for CO2 and CH4 flux measurements has been installed on top of a 20m high tower mounted on the roof of the faculty building, close to the city centre of Krakow. The sensors were installed ca 42 m above the local ground. Gill Windmaster-Pro sonic anemometer was coupled with self-made system, designed by the Poznan University of Life Sciences, Poland, for collecting air samples in two pairs of 10-liter Tedlar bags, and with Picarro G2101-i CRDS analyser. The air was collected in 30-min intervals. The CO2 and CH4 mixing ratios in these cumulative downdraft and updraft air samples were determined by the CRDS analyser after each sampling interval. Based on the measured mixing ratios difference and the vertical wind component, the variability of the mean surface fluxes of CO2 and CH4 was quantified. In case of CO2 flux, a typical diurnal pattern with the maximum values of around 30 mmol m-2 h-1 occurring during night hours and the minimum values, around -40 mmol m-2 h-1, occurring early afternoon was observed during sunny days ("plus" and "minus" signs mark upward and downward fluxes, respectively). In addition, some events with much higher fluxes (up to 100 mmol m-2 h-1) were observed, mainly during rush hours. Temporal variability of methane flux turned out to be much higher than that observed for CO2. During summer, it varied from approximately -100 to +500 μmol m-2 h-1, with the mean value of around +100 μmol m-2 h-1 and maximum values occurring predominantly during daytime. In addition to flux measurements, an attempt was made to characterize also the isotopic signature of carbon in the CO2 flux components measured with the aid of REA method. The results showed that the precision of δ13CO2 measurements performed with Picarro analyser was not sufficient to differentiate the isotopic signatures of upward and downward CO2 fluxes. Acknowledgement: This work is supported by the Ministry of Science and Higher Education (project No. 817.N-COST/2010/0 and the statutory funds of the AGH University of Science and Technology, project no. 11.11.220.01).

Soil surface roughness: comparing old and new measuring methods and application in a soil erosion model

NASA Astrophysics Data System (ADS)

Thomsen, L. M.; Baartman, J. E. M.; Barneveld, R. J.; Starkloff, T.; Stolte, J.

2015-04-01

Quantification of soil roughness, i.e. the irregularities of the soil surface due to soil texture, aggregates, rock fragments and land management, is important as it affects surface storage, infiltration, overland flow, and ultimately sediment detachment and erosion. Roughness has been measured in the field using both contact methods (such as roller chain and pinboard) and sensor methods (such as stereophotogrammetry and terrestrial laser scanning (TLS)). A novel depth-sensing technique, originating in the gaming industry, has recently become available for earth sciences: the Xtion Pro method. Roughness data obtained using various methods are assumed to be similar; this assumption is tested in this study by comparing five different methods to measure roughness in the field on 1 m2 agricultural plots with different management (ploughing, harrowing, forest and direct seeding on stubble) in southern Norway. Subsequently, the values were used as input for the LISEM soil erosion model to test their effect on the simulated hydrograph at catchment scale. Results show that statistically significant differences between the methods were obtained only for the fields with direct seeding on stubble; for the other land management types the methods were in agreement. The spatial resolution of the contact methods was much lower than for the sensor methods (10 000 versus at least 57 000 points per square metre). In terms of costs and ease of use in the field, the Xtion Pro method is promising. Results from the LISEM model indicate that especially the roller chain overestimated the random roughness (RR) values and the model subsequently calculated less surface runoff than measured. In conclusion, the choice of measurement method for roughness data matters and depends on the required accuracy, resolution, mobility in the field and available budget. It is recommended to use only one method within one study.

Soil surface roughness: comparing old and new measuring methods and application in a soil erosion model

NASA Astrophysics Data System (ADS)

Thomsen, L. M.; Baartman, J. E. M.; Barneveld, R. J.; Starkloff, T.; Stolte, J.

2014-11-01

Quantification of soil roughness, i.e. the irregularities of the soil surface due to soil texture, aggregates, rock fragments and land management, is important as it affects surface storage, infiltration, overland flow and ultimately sediment detachment and erosion. Roughness has been measured in the field using both contact methods, such as roller chain and pinboard, and sensor methods, such as stereophotogrammetry and terrestrial laser scanning (TLS). A novel depth sensing technique, originating in the gaming industry, has recently become available for earth sciences; the Xtion Pro method. Roughness data obtained using various methods are assumed to be similar; this assumption is tested in this study by comparing five different methods to measure roughness in the field on 1 m2 agricultural plots with different management (ploughing, harrowing, forest and direct seeding on stubble) in southern Norway. Subsequently, the values were used as input for the LISEM soil erosion model to test their effect on the simulated hydrograph on catchment scale. Results show that statistically significant differences between the methods were obtained only for the fields with direct drilling on stubble; for the other land management types the methods were in agreement. The spatial resolution of the contact methods was much lower than for the sensor methods (10 000 versus at least 57 000 points per m2 respectively). In terms of costs and ease of handling in the field, the Xtion Pro method is promising. Results from the LISEM model indicate that especially the roller chain underestimated the RR values and the model thereby calculated less surface runoff than measured. In conclusion: the choice of measurement method for roughness data matters and depends on the required accuracy, resolution, mobility in the field and available budget. It is recommended to use only one method within one study.

Active Oxygen Vacancy Site for Methanol Synthesis from CO2 Hydrogenation on In2O3(110): A DFT Study

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

Ye, Jingyun; Liu, Changjun; Mei, Donghai

2013-06-03

Methanol synthesis from CO2 hydrogenation on the defective In2O3(110) surface with surface oxygen vacancies has been investigated using periodic density functional theory calculations. The relative stabilities of six possible surface oxygen vacancies numbered from Ov1 to Ov6 on the perfect In2O3(110) surface were examined. The calculated oxygen vacancy formation energies show that the D1 surface with the Ov1 defective site is the most thermodynamically favorable while the D4 surface with the Ov4 defective site is the least stable. Two different methanol synthesis routes from CO2 hydrogenation over both D1 and D4 surfaces were studied and the D4 surface was foundmore » to be more favorable for CO2 activation and hydrogenation. On the D4 surface, one of the O atoms of the CO2 molecule fills in the Ov4 site upon adsorption. Hydrogenation of CO2 to HCOO on the D4 surface is both thermodynamically and kinetically favorable. Further hydrogenation of HCOO involves both forming the C-H bond and breaking the C-O bond, resulting in H2CO and hydroxyl. The HCOO hydrogenation is slightly endothermic with an activation barrier of 0.57 eV. A high barrier of 1.14 eV for the hydrogenation of H2CO to H3CO indicates that this step is the rate-limiting step in the methanol synthesis on the defective In2O3(110) surface. We gratefully acknowledge the supports from the National Natural Science Foundation of China (#20990223) and from US Department of Energy, Basic Energy Science program (DE-FG02-05ER46231). D. Mei was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. The computations were performed in part using the Molecular Science Computing Facility in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), which is a U.S. Department of Energy national scientific user facility located at Pacific Northwest National Laboratory in Richland, Washington. PNNL is a multiprogram national laboratory operated for DOE by Battelle.« less

A Landscape Indicator Approach to the Identification and Articulation of the Ecological Consequences of Land Cover Change in the Chesapeake Bay Watershed, 1970-2000

USGS Publications Warehouse

Slonecker, Terrence

2008-01-01

The advancement of geographic science in the area of land surface status and trends and land cover change is at the core of the current geographic scientific research of the U.S. Geological Survey (USGS) (McMahon and others, 2005). Perhaps the least developed or articulated aspects of USGS land change science have been the identification and analysis of the ecological consequences of land cover change. Changes in land use and land cover significantly affect the ability of ecosystems to provide essential ecological goods and services, which, in turn, affect the economic, public health, and social benefits that these ecosystems provide. One of the great scientific challenges for geographic science is to understand and calibrate the effects of land use and land cover change and the complex interaction between human and biotic systems at a variety of natural, geographic, and political scales. Understanding the dynamics of land surface change requires an increased understanding of the complex nature of human-environmental systems and will require a suite of scientific tools that include traditional geographic data and analysis methods, such as remote sensing and geographic information systems (GIS), as well as innovative approaches to understanding the dynamics of complex systems. One such approach that has gained much recent scientific attention is the landscape indicator, or landscape assessment, approach, which has been developed with the emergence of the science of landscape ecology.

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

NASA Astrophysics Data System (ADS)

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

2016-08-01

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

Towards a long-term Science Exploitation Plan for the Sea and Land Surface Temperature Radiometer on Sentinel-3 and the Along-Track Scanning Radiometers

NASA Astrophysics Data System (ADS)

Remedios, John J.; Llewellyn-Jones, David

2014-05-01

The Sea and Land Surface Temperature Radiometer (SLSTR) on Sentinel-3 is the latest satellite instrument in a series of dual-angle optical and thermal sensors, the Along-Track Scanning Radiometers (ATSRs). Operating on Sentinel-3, the SLSTR has a number of significant improvements compared to the original ATSRs including wider swaths for nadir and dual angles, emphasis on all surface temperature domains, dedicated fire channels and additional cloud channels. The SLSTR therefore provides some excellent opportunities to extend science undertaken with the ATSRs whilst also providing long-term data sets to investigate climate change. The European Space Agency, together with the Department of Energy and Climate Change, sponsored the production of an Exploitation Plan for the ATSRs. In the last year, this been extended to cover the SLSTR also. The plan enables UK and European member states to plan activities related to SLSTR in a long-term context. Covering climate change, oceanography, land surface, atmosphere and cryosphere science, particular attention is paid to the exploitation of long-term data sets. In the case of SLSTR, relevant products include sea, land, lake and ice surface temperatures; aerosols and clouds; fires and gas flares; land surface reflectances. In this presentation, the SLSTR and ATSR science Exploitation Plan will be outlined with emphasis on SLSTR science opportunities, on appropriate co-ordinating mechanisms and on example implementation plans. Particular attention will be paid to the challenges of linking ATSR records with SLSTR to provide consistent long-term data sets, and on the international context of such data sets. The exploitation plan approach to science may prove relevant and useful for other Sentinel instruments.

Venus Aerobot Surface Science Imaging System (VASSIS)

NASA Technical Reports Server (NTRS)

Greeley, Ronald

1999-01-01

The VASSIS task was to design and develop an imaging system and container for operation above the surface of Venus in preparation for a Discovery-class mission involving a Venus aerobot balloon. The technical goals of the effort were to: a) evaluate the possible nadir-viewed surface image quality as a function of wavelength and altitude in the Venus lower atmosphere, b) design a pressure vessel to contain the imager and supporting electronics that will meet the environmental requirements of the VASSIS mission, c) design and build a prototype imaging system including an Active-Pixel Sensor camera head and VASSIS-like optics that will meet the science requirements. The VASSIS science team developed a set of science requirements for the imaging system upon which the development work of this task was based.

The ExoMars Rover Science Archive: Status and Plans

NASA Astrophysics Data System (ADS)

Heather, D.; Lim, T.; Metcalfe, L.

2017-09-01

The ExoMars program is a co-operation between ESA and Roscosmos comprising two missions: the first, launched on 14 March 2016, included the Trace Gas Orbiter and Schiaparelli lander; the second, due for launch in 2020, will be a Rover and Surface Platform (RSP). The ExoMars Rover and Surface Platform deliveries will be among the first data in the PSA to be formatted according to the new PDS4 Standards, and will be the first rover data to be hosted within the archive at all. The archiving and management of the science data to be returned from ExoMars will require a significant development effort for the new Planetary Science Archive (PSA). This presentation will outline the current plans for archiving of the ExoMars Rover and Surface Platform science data.

The 2010 Desert Rats Science Operations Test: Outcomes and Lessons Learned

NASA Technical Reports Server (NTRS)

Eppler, D. B.

2011-01-01

The Desert RATS 2010 Team tested a variety of science operations management techniques, applying experience gained during the manned Apollo missions and the robotic Mars missions. This test assessed integrated science operations management of human planetary exploration using real-time, tactical science operations to oversee daily crew science activities, and a night shift strategic science operations team to conduct strategic level assessment of science data and daily traverse results. In addition, an attempt was made to collect numerical metric data on the outcome of the science operations to assist test evaluation. The two most important outcomes were 1) the production of significant (almost overwhelming) volume of data produced during daily traverse operations with two rovers, advanced imaging systems and well trained, scientifically proficient crew-members, and 2) the degree to which the tactical team s interaction with the surface crew enhanced science return. This interaction depended on continuous real-time voice and data communications, and the quality of science return from any human planetary exploration mission will be based strongly on the aggregate interaction between a well trained surface crew and a dedicated science operations support team using voice and imaging data from a planet s surface. In addition, the scientific insight developed by both the science operations team and the crews could not be measurable by simple numerical quantities, and its value will be missed by a purely metric-based evaluation of test outcome. In particular, failure to recognize the critical importance of this qualitative type interaction may result in mission architecture choices that will reduce science return.

From an 'ice-see' perspective: The current use, potential and limitations of Structure-from-Motion photogrammetry for cryospheric applications

NASA Astrophysics Data System (ADS)

Westoby, Matthew; Dunning, Stuart; Allan, Mark; Smith, Mark; Quincey, Duncan; Carrivick, Jonathan; Watson, C. Scott

2016-04-01

Structure-from-Motion with Multi-View Stereo (SfM-MVS) methods are rapidly becoming the tool of choice for geoscientists who require a relatively low-cost and viable alternative to traditional surveying technologies for characterising the form and short-term evolution of Earth surface landforms and landscapes. Uptake of SfM-MVS methods by workers in the cryospheric science community has been particularly rapid. The choice to use SfM-MVS has many logistical benefits which promote its adoption in remote glacial environments, namely the requirement for little more than a digital camera and proprietary or open-source software for topographic reconstruction, and a surveyed network of ground control to transform the resultant 3D models into a real-world co-ordinate system, if desired. Optionally, a dedicated aerial photography platform (e.g. kite, blimp, multirotor or fixed-wing UAV) may be used for initial photograph acquisition, which can facilitate glacier-scale observation and analysis. To date, cryospheric applications of SfM-MVS have included: the monitoring of glacier, moraine, and rock glacier movement; the evolution of ice cliffs on debris-covered glaciers; the reconstruction of ice-marginal or deglaciated topography; patch- and moraine-scale sedimentological characterisation; and the characterisation of glacier surfaces to monitor supraglacial drainage development or to inform energy balance modelling. This contribution will showcase existing applications and original data and discuss exciting potential opportunities and current limitations of the SfM-MVS method for the cryospheric sciences.

Mapping Land and Water Surface Topography with instantaneous Structure from Motion

NASA Astrophysics Data System (ADS)

Dietrich, J.; Fonstad, M. A.

2012-12-01

Structure from Motion (SfM) has given researchers an invaluable tool for low-cost, high-resolution 3D mapping of the environment. These SfM 3D surface models are commonly constructed from many digital photographs collected with one digital camera (either handheld or attached to aerial platform). This method works for stationary or very slow moving objects. However, objects in motion are impossible to capture with one-camera SfM. With multiple simultaneously triggered cameras, it becomes possible to capture multiple photographs at the same time which allows for the construction 3D surface models of moving objects and surfaces, an instantaneous SfM (ISfM) surface model. In river science, ISfM provides a low-cost solution for measuring a number of river variables that researchers normally estimate or are unable to collect over large areas. With ISfM and sufficient coverage of the banks and RTK-GPS control it is possible to create a digital surface model of land and water surface elevations across an entire channel and water surface slopes at any point within the surface model. By setting the cameras to collect time-lapse photography of a scene it is possible to create multiple surfaces that can be compared using traditional digital surface model differencing. These water surface models could be combined the high-resolution bathymetry to create fully 3D cross sections that could be useful in hydrologic modeling. Multiple temporal image sets could also be used in 2D or 3D particle image velocimetry to create 3D surface velocity maps of a channel. Other applications in earth science include anything where researchers could benefit from temporal surface modeling like mass movements, lava flows, dam removal monitoring. The camera system that was used for this research consisted of ten pocket digital cameras (Canon A3300) equipped with wireless triggers. The triggers were constructed with an Arduino-style microcontroller and off-the-shelf handheld radios with a maximum range of several kilometers. The cameras are controlled from another microcontroller/radio combination that allows for manual or automatic triggering of the cameras. The total cost of the camera system was approximately 1500 USD.

Viking Mars encounter

NASA Technical Reports Server (NTRS)

1976-01-01

Various phases of planetary operations related to the Viking mission to Mars are described. Topics discussed include: approach phase, Mars orbit insertion, prelanding orbital activities, separation, descent and landing, surface operations, surface sampling and operations starting, orbiter science and radio science, Viking 2, Deep Space Network and data handling.

Exploring preservice teachers' interpretations of curricular experiences while learning to teach in an inquiry-oriented way: A phenomenology

NASA Astrophysics Data System (ADS)

Sander, Scott A.

Despite ubiquitous calls for school reform, the traditional transmission model of education continues to dominate our nation's science classrooms at all levels. How do these experiences impact those who enter formal teacher education programs and Methods courses that promote a more inquiry-oriented way of teaching science? The purpose of this foundational study was to explore the interpretations of five preservice science teachers' (PSTs) curricular experiences in order to gain a greater understanding directly from the participants about learning to teach in an inquiry-oriented way. Phenomenology was selected as a flexible methodology that enabled access to the "lifeworld" that PSTs had constructed of their experiences within a science Methods course. The inquiry-based methods used within the course also provided the data that ultimately became the bulk of the stories presented in Chapter 4. The methods were selected for their ability to make the PSTs' thinking visible. The use of "thinking routines" within the context of the Methods course supplied data from the PSTs as they were in the role of a student. The use of the virtual classroom TeachLivE(TM) supplied data from the PSTs as they were in the role of a teacher. The data generated by these unique methods helped to constitute the stories presented in Chapter 4. Instead of stories about the PSTs these are stories constructed from the data that represents the thinking of PSTs. The stories are presented as what PSTs see, believe, care about, and wonder with regards to learning to teach in an inquiry-oriented way. This data indicates that while PSTs have taken notice of the challenge to their existing ideas about teaching science there are still significant barriers that must be overcome to replace entrenched beliefs in order for them to implement inquiry-oriented practices in their future classrooms. As a beginning step in the inquiry process and aligned with constructivist theories of learning, thinking routines and TeachLivE have the potential to elicit the prior knowledge of PSTs regarding learning to teach. By providing a way to hear the voices of PSTs and make their thinking visible, I surface implications for science education and future research to shift the traditional discourse within classrooms.

Science Objectives and Mission Concepts for Europa Exploration

NASA Astrophysics Data System (ADS)

Tamppari, L. K.; Senske, D. A.; Johnson, T. V.; Oberto, R.; Zimmerman, W.; JPL's Team-X Team

2000-10-01

Since the arrival of the Galileo spacecraft to the Jovian system in 1995, evidence indicating a liquid water ocean beneath the icy Europan crust has become much stronger. This evidence combined with the fact that Europa is greater than 90 wt% water [1] makes it a candidate body to harbor extant or extinct life. The outstanding Europa science questions [2] are to determine whether or not there is or has been a liquid water layer under the ice and whether or not liquid water currently exists on the surface or has in the geologically recent past, what geological processes create the ice rafts and other ice-tectonic processes that affect the surface, the composition of the deep interior , geochemical sources of energy, the nature of the neutral atmosphere and ionosphere, and the nature of the radiation environment, especially with regard to its implications for organic and biotic chemistry. In addition, in situ studies of the surface of Europa would offer the opportunity to characterize the chemistry of the ice including organics, pH, salinity, and redox potential. In order to address these scientific objectives, a Europa program, involving multiple spacecraft, is envisioned. The JPL Outer Planets program has been helping to lay the groundwork for such a program. This effort is being conducted with particular emphasis on compiling and identifying science objectives which will flow down to a Europa mission architecture. This poster will show the tracability of observational methods from the science objectives. Also in support of developing a Europa mission architecture, JPL's Team-X has conducted a variety of Europa mission studies . A comparison of the studies done to date will be presented, highlighting science objectives accomplished, technological challenges, and cost. A more detailed presentation will be given on a Europa Lander concept study. First, the science objectives and instrumentation will be shown, including instrument mass, power usage, volume, and data rate. Second, the mission design will be discussed, including candidate launch and arrival dates and landing ellipse issues. Third, the technology developments required and other issues will be presented. This poster presentation will provide an opportunity for the science community to influence future work on developing a Europa architecture, including refinements to a Europa Lander , other mission concepts, and further science objective identification and prioritization. This work was carried out at Caltech's Jet Propulsion Laboratory under a contract from NASA. [1] Morrison, D., Introduction to the Satellites of Jupiter in Satellites of Jupiter, Morrison ed., 1982. [2] Space Studies Board, A Strategy for the Exploration of Europa, National Academy Press, Washington D. C., 1999.

A pitfall in shallow shear-wave refraction surveying

USGS Publications Warehouse

Xia, J.; Miller, R.D.; Park, C.B.; Wightman, E.; Nigbor, R.

2002-01-01

The shallow shear-wave refraction method works successfully in an area with a series of horizontal layers. However, complex near-surface geology may not fit into the assumption of a series of horizontal layers. That a plane SH-wave undergoes wave-type conversion along an interface in an area of nonhorizontal layers is theoretically inevitable. One real example shows that the shallow shear-wave refraction method provides velocities of a converted wave rather than an SH- wave. Moreover, it is impossible to identify the converted wave by refraction data itself. As most geophysical engineering firms have limited resources, an additional P-wave refraction survey is necessary to verify if velocities calculated from a shear-wave refraction survey are velocities of converted waves. The alternative at this time may be the surface wave method, which can provide reliable S-wave velocities, even in an area of velocity inversion (a higher velocity layer underlain by a lower velocity layer). ?? 2002 Elsevier Science B.V. All rights reserved.

The development of surface science in China: retrospect and prospects

NASA Astrophysics Data System (ADS)

Xide, Xie

1994-01-01

It is generally agreed that the year of 1977 marked the birth of surface science in China, therefore the length of its history of development is only half of that shown in the title of this volume. Since 1977 laboratories with modern facilities for surface studies have been established in various universities and research institutes. Three open laboratories better equipped than others have been set up in Beijing, Xiamen and Shanghai for surface physics, surface chemistry and applied surface physics, respectively. Five National Conferences on Physics of Surfaces and Interfaces were held in 1982, 1984, 1985, 1988 and 1991. In 1993 China is going to host the Fourth International Conference on the Structure of Surfaces in Shanghai August 16-19 which will serve as a milestone in the history of development of surface science in China. With the access to many overseas laboratories, quite a number of Chinese scientists and students have had opportunities to work and study abroad and have brought back with them experiences acquired. During the Conferences just mentioned, one could witness a number of steady progresses made over the years. In the present review, a brief description about the establishment of some major research facilities and progresses of some of the research is given with emphasis on work related to semiconductor surfaces, interfaces, superlattices, heterojunctions and quantum wells. Although the review nominally covers the development of research in surface science in China, due to the limitation of the capabilities of the author, mostly work done at Fudan University is included. For this the author would like to express her deep apology to many Chinese colleagues whose works have not been properly mentioned.

In Situ Preparation of Biomimetic Thin Films and Their Surface-Shielding Effect for Organisms in High Vacuum

PubMed Central

Muranaka, Yoshinori; Shimomura, Masatsugu; Hariyama, Takahiko

2013-01-01

Self-standing biocompatible films have yet to be prepared by physical or chemical vapor deposition assisted by plasma polymerization because gaseous monomers have thus far been used to create only polymer membranes. Using a nongaseous monomer, we previously found a simple fabrication method for a free-standing thin film prepared from solution by plasma polymerization, and a nano-suit made by polyoxyethylene (20) sorbitan monolaurate can render multicellular organisms highly tolerant to high vacuum. Here we report thin films prepared by plasma polymerization from various monomer solutions. The films had a flat surface at the irradiated site and were similar to films produced by vapor deposition of gaseous monomers. However, they also exhibited unique characteristics, such as a pinhole-free surface, transparency, solvent stability, flexibility, and a unique out-of-plane molecular density gradient from the irradiated to the unirradiated surface of the film. Additionally, covering mosquito larvae with the films protected the shape of the organism and kept them alive under the high vacuum conditions in a field emission-scanning electron microscope. Our method will be useful for numerous applications, particularly in the biological sciences. PMID:24236023

The OH + D2 --> HOD + D angle-velocity distribution: quasi-classical trajectory calculations on the YZCL2 and WSLFH potential energy surfaces and comparison with experiments at ET = 0.28 eV.

PubMed

Sierra, José Daniel; Martínez, Rodrigo; Hernando, Jordi; González, Miguel

2009-12-28

The angle-velocity distribution (HOD) of the OH + D(2) reaction at a relative translational energy of 0.28 eV has been calculated using the quasi-classical trajectory (QCT) method on the two most recent potential energy surfaces available (YZCL2 and WSLFH PESs), widely extending a previous investigation of our group. Comparison with the high resolution experiments of Davis and co-workers (Science, 2000, 290, 958) shows that the structures (peaks) found in the relative translational energy distributions of products could not be satisfactorily reproduced in the calculations, probably due to the classical nature of the QCT method and the importance of quantum effects. The calculations, however, worked quite well for other properties. Overall, both surfaces led to similar results, although the YZCL2 surface is more accurate to describe the H(3)O PES, as derived from comparison with high level ab initio results. The differences observed in the QCT calculations were interpreted considering the somewhat larger anisotropy of the YZCL2 PES when compared with the WSLFH PES.

EDITORIAL: Three decades of scanning tunnelling microscopy that changed the course of surface science Three decades of scanning tunnelling microscopy that changed the course of surface science

NASA Astrophysics Data System (ADS)

Ramachandra Rao, M. S.; Margaritondo, Giorgio

2011-11-01

Three decades ago, with a tiny tip of platinum, the scientific world saw the real space imaging of single atoms with unprecedented spatial resolution. This signalled the birth of one of the most versatile surface probes, based on the physics of quantum mechanical tunnelling: the scanning tunnelling microscope (STM). Invented in 1981 by Gerd Binnig and Heinrich Rohrer of IBM, Zurich, it led to their award of the 1986 Nobel Prize. Atoms, once speculated to be abstract entities used by theoreticians for mere calculations, can be seen to exist for real with the nano-eye of an STM tip that also gives real-space images of molecules and adsorbed complexes on surfaces. From a very fundamental perspective, the STM changed the course of surface science and engineering. STM also emerged as a powerful tool to study various fundamental phenomena relevant to the properties of surfaces in technological applications such as tribology, medical implants, catalysis, sensors and biology—besides elucidating the importance of local bonding geometries and defects, non-periodic structures and the co-existence of nano-scale phases. Atom-level probing, once considered a dream, has seen the light with the evolution of STM. An important off-shoot of STM was the atomic force microscope (AFM) for surface mapping of insulating samples. Then followed the development of a flurry of techniques under the general name of scanning probe microscopy (SPM). These techniques (STM, AFM, MFM, PFM etc) designed for atomic-scale-resolution imaging and spectroscopy, have led to brand new developments in surface analysis. All of these novel methods enabled researchers in recent years to image and analyse complex surfaces on microscopic and nanoscopic scales. All of them utilize a small probe for sensing the surface. The invention of AFM by Gerd Binnig, Calvin Quate and Christopher Gerber opened up new opportunities for characterization of a variety of materials, and various industrial applications could be envisaged. AFM observations of thin-film surfaces give us a picture of surface topography and morphology and any visible defects. The growing importance of ultra-thin films for magnetic recording in hard disk drive systems requires an in-depth understanding of the fundamental mechanisms occurring during growth. This special issue of Journal of Physics D: Applied Physics covers all of the different aspects of SPM that illustrate the achievements of this methodology: nanoscale imaging and mapping (Chiang, and Douillard and Charra), piezoresponse force microscopy (Soergel) and STM engineering (Okuyama and Hamada, and Huang et al). Chiang takes the reader on a journey along the STM imaging of atoms and molecules on surfaces. Jesse and Kalinin explore the band excitations that occur during the corresponding processes. Jia et al propose STM and molecular beam epitaxy as a winning experimental combination at the interface of science and technology. Douillard and Charra describe the high-resolution mapping of plasmonic modes using photoemission and scanning tunnelling microscopy. Cricenti et al demonstrate the importance of SPM in material science and biology. Wiebe et al have probed atomic scale magnetism, revealed by spin polarized scanning tunnelling microscopy. In addition, Simon et al present Fourier transform scanning tunnelling spectroscopy and the possibility to obtain constant energy maps and band dispersion using local measurements. Lackinger and Heckl give a perspective of the use of STM to study covalent intermolecular coupling reactions on surfaces. Okuyama and Hamada investigated hydrogen bond imaging and engineering with STM. Soergel describes the study of substrate-dependent self-assembled CuPc molecules using piezo force microscope (PFM). We are very grateful to the authors and reviewers for the papers in this special issue of Journal of Physics D: Applied Physics. Their contributions have provided a comprehensive picture of the evolution, status and potential of scanning probe microscopy, conveying to the readers the full excitement of this forefront domain of physics.

New configuration for efficient and durable copper coating on the outer surface of a tube

DOE PAGES

Ahmad, Irfan; Chapman, Steven F.; Velas, Katherine M.; ...

2017-03-27

A well-adhered copper coating on stainless steel power coupler parts is required in superconducting radio frequency (SRF) accelerators. Radio frequency power coupler parts are complex, tubelike stainless steel structures, which require copper coating on their outer and inner surfaces. Conventional copper electroplating sometimes produces films with inadequate adhesion strength for SRF applications. Electroplating also requires a thin nickel strike layer under the copper coating, whose magnetic properties can be detrimental to SRF applications. Coaxial energetic deposition (CED) and sputtering methods have demonstrated efficient conformal coating on the inner surfaces of tubes but coating the outer surface of a tube ismore » challenging because these coating methods are line of sight. When the substrate is off axis and the plasma source is on axis, only a small section of the substrate’s outer surface is exposed to the source cathode. The conventional approach is to rotate the tube to achieve uniformity across the outer surface. This method results in poor film thickness uniformity and wastes most of the source plasma. Alameda Applied Sciences Corporation (AASC) has developed a novel configuration called hollow external cathode CED (HEC-CED) to overcome these issues. HEC-CED produces a film with uniform thickness and efficiently uses all eroded source material. Furthermore, the Cu film deposited on the outside of a stainless steel tube using the new HEC-CED configuration survived a high pressure water rinse adhesion test. HEC-CED can be used to coat the outside of any cylindrical structure.« less

New configuration for efficient and durable copper coating on the outer surface of a tube

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

Ahmad, Irfan; Chapman, Steven F.; Velas, Katherine M.

A well-adhered copper coating on stainless steel power coupler parts is required in superconducting radio frequency (SRF) accelerators. Radio frequency power coupler parts are complex, tubelike stainless steel structures, which require copper coating on their outer and inner surfaces. Conventional copper electroplating sometimes produces films with inadequate adhesion strength for SRF applications. Electroplating also requires a thin nickel strike layer under the copper coating, whose magnetic properties can be detrimental to SRF applications. Coaxial energetic deposition (CED) and sputtering methods have demonstrated efficient conformal coating on the inner surfaces of tubes but coating the outer surface of a tube ismore » challenging because these coating methods are line of sight. When the substrate is off axis and the plasma source is on axis, only a small section of the substrate’s outer surface is exposed to the source cathode. The conventional approach is to rotate the tube to achieve uniformity across the outer surface. This method results in poor film thickness uniformity and wastes most of the source plasma. Alameda Applied Sciences Corporation (AASC) has developed a novel configuration called hollow external cathode CED (HEC-CED) to overcome these issues. HEC-CED produces a film with uniform thickness and efficiently uses all eroded source material. Furthermore, the Cu film deposited on the outside of a stainless steel tube using the new HEC-CED configuration survived a high pressure water rinse adhesion test. HEC-CED can be used to coat the outside of any cylindrical structure.« less

Cleaning and passivation of copper surfaces to remove surface radioactivity and prevent oxide formation

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

Hoppe, Eric W.; Seifert, Allen; Aalseth, Craig E.

High-purity copper is an attractive material for constructing ultra-low-background radiation measurement devices. Many low-background experiments using high-purity copper have indicated surface contamination emerges as the dominant background. Radon daughters plate out on exposed surfaces, leaving a residual 210Pb background that is difficult to avoid. Dust is also a problem; even under cleanroom conditions, the amount of U and Th deposited on surfaces can represent the largest remaining background. To control these backgrounds, a copper cleaning chemistry has been developed. Designed to replace an effective, but overly aggressive concentrated nitric acid etch, this peroxide-based solution allows for a more controlled cleaningmore » of surfaces. The acidified hydrogen peroxide solution will generally target the Cu+/Cu2+ species which are the predominant surface participants, leaving the bulk of copper metal intact. This preserves the critical tolerances of parts and eliminates significant waste disposal issues. Accompanying passivation chemistry has also been developed that protects copper surfaces from oxidation. Using a high-activity polonium surface spike, the most difficult-to-remove daughter isotope of radon, the performance of these methods are quantified. © 2001 Elsevier Science. All rights reserved« less

Fundamentals of affinity cell separations.

PubMed

Zhang, Ye; Lyons, Veronica; Pappas, Dimitri

2018-03-01

Cell separations using affinity methods continue to be an enabling science for a wide variety of applications. In this review, we discuss the fundamental aspects of affinity separation, including the competing forces for cell capture and elution, cell-surface interactions, and models for cell adhesion. Factors affecting separation performance such as bond affinity, contact area, and temperature are presented. We also discuss and demonstrate the effects of nonspecific binding on separation performance. Metrics for evaluating cell separations are presented, along with methods of comparing separation techniques for cell isolation using affinity capture. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mobile laser scanning applied to the earth sciences

USGS Publications Warehouse

Brooks, Benjamin A.; Glennie, Craig; Hudnut, Kenneth W.; Ericksen, Todd; Hauser, Darren

2013-01-01

Lidar (light detection and ranging), a method by which the precise time of flight of emitted pulses of laser energy is measured and converted to distance for reflective targets, has helped scientists make topographic maps of Earth's surface at scales as fine as centimeters. These maps have allowed the discovery and analysis of myriad otherwise unstudied features, such as fault scarps, river channels, and even ancient ruins [Glennie et al., 2013b].

Overview of GNSS-R Research Program for Ocean Observations at Japan

NASA Astrophysics Data System (ADS)

Ichikawa, Kaoru; Ebinuma, Takuji; Akiyama, Hiroaki; Kitazawa, Yukihito

2015-04-01

GNSS-R is a new remote-sensing method which uses reflected GNSS signals. Since no transmitters are required, it is suitable for small satellites. Constellations of GNSS-R small satellites have abilities on revolutionary progress on 'all-time observable' remote-sensing methods . We have started a research program for GNSS-R applications on oceanographic observations under a contract with MEXT (Ministry of Education Culture, Sports, Science and Technology, JAPAN) as a'Space science research base formation program'. The duration of research program is 3 years (2015-2017). The one of important focuses of this program is creation of a new community to merge space engineering and marine science through establishment on application plans of GNSS-R. Actual GNSS-R data acquisition experiments using multi-copters, ships, and/or towers are planned, together with in-situ sea truth data such as wave spectrum, wind speed profiles and sea surface height. These data are compared to determine the accuracy and resolution of the estimates based on GNSS-R observations. Meanwhile, preparation of a ground station for receiving GNSS-R satellite data will be also established. Whole those data obtained in this project will be distributed for public. This paper introduces the overview of research plan..

2011 Mars Science Laboratory Mission Design Overview

NASA Technical Reports Server (NTRS)

Abilleira, Fernando

2010-01-01

Scheduled to launch in the fall of 2011 with arrival at Mars occurring in the summer of 2012, NASA's Mars Science Laboratory will explore and assess whether Mars ever had conditions capable of supporting microbial life. In order to achieve its science objectives, the Mars Science Laboratory will be equipped with the most advanced suite of instruments ever sent to the surface of the Red Planet. Delivering the next mobile science laboratory safely to the surface of Mars has various key challenges derived from a strict set of requirements which include launch vehicle performance, spacecraft mass, communications coverage during Entry, Descent, and Landing, atmosphere-relative entry speeds, latitude accessibility, and dust storm season avoidance among others. The Mars Science Laboratory launch/arrival strategy selected after careful review satisfies all these mission requirements.

Nanoparticle-based biologic mimetics

PubMed Central

Cliffel, David E.; Turner, Brian N.; Huffman, Brian J.

2009-01-01

Centered on solid chemistry foundations, biology and materials science have reached a crossroad where bottom-up designs of new biologically important nanomaterials are a reality. The topics discussed here present the interdisciplinary field of creating biological mimics. Specifically, this discussion focuses on mimics that are developed using various types of metal nanoparticles (particularly gold) through facile synthetic methods. These methods conjugate biologically relevant molecules, e.g., small molecules, peptides, proteins, and carbohydrates, in conformationally favorable orientations on the particle surface. These new products provide stable, safe, and effective substitutes for working with potentially hazardous biologicals for applications such as drug targeting, immunological studies, biosensor development, and biocatalysis. Many standard bioanalytical techniques can be used to characterize and validate the efficacy of these new materials, including quartz crystal microbalance (QCM), surface plasmon resonance (SPR), and enzyme-linked immunosorbent assay (ELISA). Metal nanoparticle–based biomimetics continue to be developed as potential replacements for the native biomolecule in applications of immunoassays and catalysis. PMID:20049778

Experimental study on TiN coated racetrack-type ceramic pipe

NASA Astrophysics Data System (ADS)

Wang, Jie; Xu, Yan-Hui; Zhang, Bo; Wei, Wei; Fan, Le; Pei, Xiang-Tao; Hong, Yuan-Zhi; Wang, Yong

2015-11-01

TiN film was coated on the internal surface of a racetrack-type ceramic pipe by three different methods: radio-frequency sputtering, DC sputtering and DC magnetron sputtering. The deposition rates of TiN film under different coating methods were compared. The highest deposition rate was 156 nm/h, which was obtained by magnetron sputtering coating. Based on AFM, SEM and XPS test results, the properties of TiN film, such as film roughness and surface morphology, were analyzed. Furthermore, the deposition rates were studied with two different cathode types, Ti wires and Ti plate. According to the SEM test results, the deposition rate of TiN/Ti film was about 800 nm/h with Ti plate cathode by DC magnetron sputtering. Using Ti plate cathode rather than Ti wire cathode can greatly improve the film deposition rate. Supported by National Nature Science Foundation of China (11075157)

Mechatronical systems and experimental methods for investigations on tribology of electrical contacts

NASA Astrophysics Data System (ADS)

Franek, Friedrich; Neuhaus, Alexander; Reichart, Martin; Schrank, Clemens

2008-08-01

The investigation of electrical low power switching contacts, including dry-circuit, is characterized as a highly interdisciplinary research field. The knowledge of plasma physics, the influence of kinetics on contact phenomena, material science and metallurgy, as well as thermal aspects and tribology, is demanded. The methods usually used at the Austrian Center of Competence for Tribology are e.g. defined contact make and break along two-independent axis using model switches, high-resolution measurement of displacement and electrical values, including the detection of arcs, contact force measurement in the kHz and cN range (one-axis and two-axis systems), on-line optical investigations (especially time lapse movie systems), state of the art 3D surface topography measurement of eroded contact surfaces, and (electron-) microscopical evaluation of metallographic cross sections. Some aspects of this methodology are presented in this paper.

Validation of tool mark analysis of cut costal cartilage.

PubMed

Love, Jennifer C; Derrick, Sharon M; Wiersema, Jason M; Peters, Charles

2012-03-01

This study was designed to establish the potential error rate associated with the generally accepted method of tool mark analysis of cut marks in costal cartilage. Three knives with different blade types were used to make experimental cut marks in costal cartilage of pigs. Each cut surface was cast, and each cast was examined by three analysts working independently. The presence of striations, regularity of striations, and presence of a primary and secondary striation pattern were recorded for each cast. The distance between each striation was measured. The results showed that striations were not consistently impressed on the cut surface by the blade's cutting edge. Also, blade type classification by the presence or absence of striations led to a 65% misclassification rate. Use of the classification tree and cross-validation methods and inclusion of the mean interstriation distance decreased the error rate to c. 50%. © 2011 American Academy of Forensic Sciences.

Rapid Identification of Legionella Pathogenicity by Surface-Enhanced Raman Spectroscopy.

PubMed

Li, Jing; Qin, Tian; Jia, Xiao Xiao; Deng, Ai Hua; Zhang, Xu; Fan, Wen Hui; Huo, Shuai Dong; Wen, Ting Yi; Liu, Wen Jun

2015-06-01

To establish Surface-enhanced Raman Spectroscopy (SERS) can be used as a rapid and reliable method to distinguish virulent strain and mild strain of L. pneumophila. Mortality data were collected from company departments through administrative documents, death certificates, etc. Trend analyses of cancer mortality were performed on the basis of 925 cancer deaths between 2001 and 2010. Our results indicated that the peaks of high virulence strains reached ⋝4000. This criterion was verified by subsequent cell experiments. In addition, we also conducted SERS rapid identification on the virulence of several collected clinical strains and obtained accurate results. The present study indicates that the established SERS protocol can be used as a rapid and reliable method to distinguish virulent and mildly virulent strains of L. pneumophila, which can be further used in clinical samples. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

FOREWORD: The 12th International Workshop on Desorption Induced by Electronic Transitions (DIET XII) (Pine Mountain, Georgia, USA, 19-23 April 2009) The 12th International Workshop on Desorption Induced by Electronic Transitions (DIET XII) (Pine Mountain, Georgia, USA, 19-23 April 2009)

NASA Astrophysics Data System (ADS)

Orlando, Thomas M.; Diebold, Ulrike

2010-03-01

The 12th International Workshop on Desorption Induced by Electronic Transitions (DIET XII) took place from 19-23 April 2009 in Pine Mountain, Georgia, USA. This was the 12th conference in a strong and vibrant series, which dates back to the early 1980s. DIET XII continued the tradition of exceptional interdisciplinary science and focused on the study of desorption and dynamics induced by electronic excitations of surfaces and interfaces. The format involved invited lectures, contributed talks and a poster session on the most recent developments and advances in this area of surface physics. The Workshop International Steering Committee and attendees wish to dedicate DIET XII to the memory of the late Professor Theodore (Ted) Madey. Ted was one of the main pioneers of this field and was one of the primary individuals working to keep this area of science exciting and adventurous. His overall contributions to surface science were countless and his contributions to the DIET field and community were enormous. He is missed and remembered by many friends and colleagues throughout the world. The papers collected in this issue cover many of the highlights of DIET XII. Topics include ultrafast electron transfer at surfaces and interfaces, quantum and spatially resolved mapping of surface dynamics and desorption, photon-, electron- and ion-beam induced processes at complex interfaces, the role of non-thermal desorption in astrochemistry and astrophysics and laser-/ion-based methods of examining soft matter and biological media. Although the workshop attracted many scientists active in the general area of non-thermal surface processes, DIET XII also attracted many younger scientists (i.e., postdoctoral fellows, advanced graduate students, and a select number of advanced undergraduate students). This field has had an impact in a number of areas including nanoscience, device physics, astrophysics, and now biophysics. We believe that this special issue of Journal of Physics: Condensed Matter will help foster further progress in the study of DIET processes. Since the field remains vibrant and exciting, the workshop series will continue with DIET XIII. Professor Richard Palmer (University of Birmingham, UK) will chair DIET XIII in the UK in early summer 2012. We gratefully acknowledge financial support from SPECS, HIDEN Analytical, BRUKER, The United States National Science Foundation, Georgia Institute of Technology and The State University of New Jersey, Rutgers.

Interfacial and Surface Science | Materials Science | NREL

Science.gov Websites

-flight SIMS (TOF-SIMS) provides surface spectroscopy of both inorganic and organic materials, and is Chamber This tool enables deposition of inorganic chalcogenides and for basic material and device studies lead halide perovskites and semiconductor quantum dots. Contact: Craig Perkins | Email | 303-384-6659

Science Operations for the 2008 NASA Lunar Analog Field Test at Black Point Lava Flow, Arizona

NASA Technical Reports Server (NTRS)

Garry W. D.; Horz, F.; Lofgren, G. E.; Kring, D. A.; Chapman, M. G.; Eppler, D. B.; Rice, J. W., Jr.; Nelson, J.; Gernhardt, M. L.; Walheim, R. J.

2009-01-01

Surface science operations on the Moon will require merging lessons from Apollo with new operation concepts that exploit the Constellation Lunar Architecture. Prototypes of lunar vehicles and robots are already under development and will change the way we conduct science operations compared to Apollo. To prepare for future surface operations on the Moon, NASA, along with several supporting agencies and institutions, conducted a high-fidelity lunar mission simulation with prototypes of the small pressurized rover (SPR) and unpressurized rover (UPR) (Fig. 1) at Black Point lava flow (Fig. 2), 40 km north of Flagstaff, Arizona from Oct. 19-31, 2008. This field test was primarily intended to evaluate and compare the surface mobility afforded by unpressurized and pressurized rovers, the latter critically depending on the innovative suit-port concept for efficient egress and ingress. The UPR vehicle transports two astronauts who remain in their EVA suits at all times, whereas the SPR concept enables astronauts to remain in a pressurized shirt-sleeve environment during long translations and while making contextual observations and enables rapid (less than or equal to 10 minutes) transfer to and from the surface via suit-ports. A team of field geologists provided realistic science scenarios for the simulations and served as crew members, field observers, and operators of a science backroom. Here, we present a description of the science team s operations and lessons learned.

The New Horizons Radio Science Experiment: Expected Performance in Measurements of Pluto's Atmospheric Structure, Surface Pressure, and Surface Temperature

NASA Astrophysics Data System (ADS)

Hinson, D. P.; Linscott, I.; Woods, W. W.; Tyler, G. L.; Bird, M. K.; Paetzold, M.; Strobel, D. F.

2014-12-01

The New Horizons (NH) payload includes a Radio Science Experiment (REX) for investigating key characteristics of Pluto and Charon during the upcoming flyby in July 2015. REX flight equipment augments the NH radio transceiver used for spacecraft communications and tracking. The REX hardware implementation requires 1.6 W and 160 g. This presentation will focus on the final design and the predicted performance of two high-priority observations. First, REX will receive signals from a pair of 70-m antennas on Earth - each transmitting 20 kW at 4.2-cm wavelength - during a diametric radio occultation by Pluto. The data recorded by REX will reveal the surface pressure, the temperature structure of the lower atmosphere, and the surface radius. Second, REX will measure the thermal emission from Pluto at 4.2-cm wavelength during two linear scans across the disk at close range when both the dayside and the nightside are visible, allowing the surface temperature and its spatial variations to be determined. Both scans extend from limb to limb with a resolution of about 10 pixels; one bisects Pluto whereas the second crosses the winter pole. We will illustrate the capabilities of REX by reviewing the method of analysis and the precision achieved in a lunar occultation observed by New Horizons in May 2011. Re-analysis of radio occultation measurements by Voyager 2 at Triton is also under way. More generally, REX objectives include a radio occultation search for Pluto's ionosphere; examination of Charon through both radio occultation and radiometry; a search for a radar echo from Pluto's surface; and improved knowledge of the Pluto system mass and the Pluto-Charon mass ratio from a combination of two-way and one-way Doppler frequency measurements.

A Novel Method to Reconstruct the Force Curve by Higher Harmonics of the First Two Flexural Modes in Frequency Modulation Atomic Force Microscope (FM-AFM).

PubMed

Zhang, Suoxin; Qian, Jianqiang; Li, Yingzi; Zhang, Yingxu; Wang, Zhenyu

2018-06-04

Atomic force microscope (AFM) is an idealized tool to measure the physical and chemical properties of the sample surfaces by reconstructing the force curve, which is of great significance to materials science, biology, and medicine science. Frequency modulation atomic force microscope (FM-AFM) collects the frequency shift as feedback thus having high force sensitivity and it accomplishes a true noncontact mode, which means great potential in biological sample detection field. However, it is a challenge to establish the relationship between the cantilever properties observed in practice and the tip-sample interaction theoretically. Moreover, there is no existing method to reconstruct the force curve in FM-AFM combining the higher harmonics and the higher flexural modes. This paper proposes a novel method that a full force curve can be reconstructed by any order higher harmonics of the first two flexural modes under any vibration amplitude in FM-AFM. Moreover, in the small amplitude regime, short range forces are reconstructed more accurately by higher harmonics analysis compared with fundamental harmonics using the Sader-Jarvis formula.

Spatial Modelling Tools to Integrate Public Health and Environmental Science, Illustrated with Infectious Cryptosporidiosis

PubMed Central

Lal, Aparna

2016-01-01

Contemporary spatial modelling tools can help examine how environmental exposures such as climate and land use together with socio-economic factors sustain infectious disease transmission in humans. Spatial methods can account for interactions across global and local scales, geographic clustering and continuity of the exposure surface, key characteristics of many environmental influences. Using cryptosporidiosis as an example, this review illustrates how, in resource rich settings, spatial tools have been used to inform targeted intervention strategies and forecast future disease risk with scenarios of environmental change. When used in conjunction with molecular studies, they have helped determine location-specific infection sources and environmental transmission pathways. There is considerable scope for such methods to be used to identify data/infrastructure gaps and establish a baseline of disease burden in resource-limited settings. Spatial methods can help integrate public health and environmental science by identifying the linkages between the physical and socio-economic environment and health outcomes. Understanding the environmental and social context for disease spread is important for assessing the public health implications of projected environmental change. PMID:26848669

Spatial Modelling Tools to Integrate Public Health and Environmental Science, Illustrated with Infectious Cryptosporidiosis.

PubMed

Lal, Aparna

2016-02-02

Contemporary spatial modelling tools can help examine how environmental exposures such as climate and land use together with socio-economic factors sustain infectious disease transmission in humans. Spatial methods can account for interactions across global and local scales, geographic clustering and continuity of the exposure surface, key characteristics of many environmental influences. Using cryptosporidiosis as an example, this review illustrates how, in resource rich settings, spatial tools have been used to inform targeted intervention strategies and forecast future disease risk with scenarios of environmental change. When used in conjunction with molecular studies, they have helped determine location-specific infection sources and environmental transmission pathways. There is considerable scope for such methods to be used to identify data/infrastructure gaps and establish a baseline of disease burden in resource-limited settings. Spatial methods can help integrate public health and environmental science by identifying the linkages between the physical and socio-economic environment and health outcomes. Understanding the environmental and social context for disease spread is important for assessing the public health implications of projected environmental change.

Applications of Electrical Impedance Tomography (EIT): A Short Review

NASA Astrophysics Data System (ADS)

Kanti Bera, Tushar

2018-03-01

Electrical Impedance Tomography (EIT) is a tomographic imaging method which solves an ill posed inverse problem using the boundary voltage-current data collected from the surface of the object under test. Though the spatial resolution is comparatively low compared to conventional tomographic imaging modalities, due to several advantages EIT has been studied for a number of applications such as medical imaging, material engineering, civil engineering, biotechnology, chemical engineering, MEMS and other fields of engineering and applied sciences. In this paper, the applications of EIT have been reviewed and presented as a short summary. The working principal, instrumentation and advantages are briefly discussed followed by a detail discussion on the applications of EIT technology in different areas of engineering, technology and applied sciences.

Restoration of neurological functions by neuroprosthetic technologies: future prospects and trends towards micro-, nano-, and biohybrid systems.

PubMed

Stieglitz, T

2007-01-01

Today applications of neural prostheses that successfully help patients to increase their activities of daily living and participate in social life again are quite simple implants that yield definite tissue response and are well recognized as foreign body. Latest developments in genetic engineering, nanotechnologies and materials sciences have paved the way to new scenarios towards highly complex systems to interface the human nervous system. Combinations of neural cells with microimplants promise stable biohybrid interfaces. Nanotechnology opens the door to macromolecular landscapes on implants that mimic the biologic topology and surface interaction of biologic cells. Computer sciences dream of technical cognitive systems that act and react due to knowledge-based conclusion mechanisms to a changing or adaptive environment. Different sciences start to interact and discuss the synergies when methods and paradigms from biology, computer sciences and engineering, neurosciences, psychology will be combined. They envision the era of "converging technologies" to completely change the understanding of science and postulate a new vision of humans. In this chapter, these research lines will be discussed on some examples as well as the societal implications and ethical questions that arise from these new opportunities.

Multifunctional Ultra-high Vacuum Apparatus for Studies of the Interactions of Chemical Warfare Agents on Complex Surfaces

DTIC Science & Technology

2014-01-02

of the formation of a hydrogen-bonded hydroxyl. Characteristic modes of the sarin molecule itself are also ob- served. These experimental results show...chemical warfare agent, surface science, uptake, decontamination, filtration , UHV, XPS, FTIR, TPD REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S...challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science

Changing Face of Wood Science in Modern Era: Contribution of Nanotechnology.

PubMed

Mishra, Pawan Kumar; Giagli, Kyriaki; Tsalagkas, Dimitrios; Mishra, Harshita; Talegaonkar, Sushma; Gryc, Vladimír; Wimmer, Rupert

2018-02-14

Wood science and nanomaterials science interact together in two different aspects; a) fabrication of lignocellulosic nanomaterials derived from wood and plant-based sources and b) surface or bulk wood modification by nanoparticles. In this review, we attempt to visualize the impact of nanoparticles on the wood coating and preservation treatments based on a thorough registration of the patent databases. The study was carried out as an overview of the scientifically most followed trends on nanoparticles utilization in wood science and wood protection depicted by recent universal filed patents. This review is exclusively targeted on the solid (timber) wood as a subject material. Utilization of mainly metal nanoparticles as photoprotection, antibacterial, antifungal, antiabrasive and functional component on wood modification treatments was found to be widely patented. Additionally, an apparent minimization in the emission of volatile organic compounds (VOCs) has been succeeded. Bulk wood preservation and more importantly, wood coating, splay the range of strengthening wood dimensional stability and biological degradation, against moisture absorption and fungi respectively. Nanoparticle materials have addressed various issues of wood science in a more efficient and environmental way than the traditional methods. Nevertheless, abundant tests and regulations are still needed before industrializing or recycling these products. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Plasmonic Films Can Easily Be Better: Rules and Recipes

PubMed Central

2015-01-01

High-quality materials are critical for advances in plasmonics, especially as researchers now investigate quantum effects at the limit of single surface plasmons or exploit ultraviolet- or CMOS-compatible metals such as aluminum or copper. Unfortunately, due to inexperience with deposition methods, many plasmonics researchers deposit metals under the wrong conditions, severely limiting performance unnecessarily. This is then compounded as others follow their published procedures. In this perspective, we describe simple rules collected from the surface-science literature that allow high-quality plasmonic films of aluminum, copper, gold, and silver to be easily deposited with commonly available equipment (a thermal evaporator). Recipes are also provided so that films with optimal optical properties can be routinely obtained. PMID:25950012

Experimental methods of molecular matter-wave optics.

PubMed

Juffmann, Thomas; Ulbricht, Hendrik; Arndt, Markus

2013-08-01

We describe the state of the art in preparing, manipulating and detecting coherent molecular matter. We focus on experimental methods for handling the quantum motion of compound systems from diatomic molecules to clusters or biomolecules.Molecular quantum optics offers many challenges and innovative prospects: already the combination of two atoms into one molecule takes several well-established methods from atomic physics, such as for instance laser cooling, to their limits. The enormous internal complexity that arises when hundreds or thousands of atoms are bound in a single organic molecule, cluster or nanocrystal provides a richness that can only be tackled by combining methods from atomic physics, chemistry, cluster physics, nanotechnology and the life sciences.We review various molecular beam sources and their suitability for matter-wave experiments. We discuss numerous molecular detection schemes and give an overview over diffraction and interference experiments that have already been performed with molecules or clusters.Applications of de Broglie studies with composite systems range from fundamental tests of physics up to quantum-enhanced metrology in physical chemistry, biophysics and the surface sciences.Nanoparticle quantum optics is a growing field, which will intrigue researchers still for many years to come. This review can, therefore, only be a snapshot of a very dynamical process.

Highly selective creation of hydrophilic micro-craters on super hydrophobic surface using electrohydrodynamic jet printing

NASA Astrophysics Data System (ADS)

Lee, Jaehyun; Hwang, Sangyeon; Prasetyo, Fariza Dian; Nguyen, Vu Dat; Hong, Jungwoo; Shin, Jennifer H.; Byun, Doyoung

2014-11-01

Selective surface modification is considered as an alternative to conventional printing techniques in high resolution patterning. Here, we present fabrication of hydrophilic patterns on the super hydrophobic surface, which makes structure on the hydrophilic region. The super hydrophobic surface is able to be chemically changed to hydrophilic with alcohols. As a consecutive process, electrohydrodynamic (EHD) jet printing was utilized to fabricate local hydrophilic craters with 30-200 μm sizes. 3 kinds of target liquids were deposited well on hydrophilic region; PEDOT (poly 3,4 ethylenediocythiophene), polystyrene nano-particles, and salmonella bacteria medium. Additionally, qualitative analysis were presented for modification mechanism and surface properties on super hydrophobic/hydrophilic by analysis of surface energy with contact angle, SEM (scanning electron microscopy) image, and SIMS (secondary ion mass spectroscopy) analysis. This new simple modification method provides possibility to be utilizing in bio-patterning engineering such as cell culturing microchip and lab on a chip. This research was supported by the Basi Science Research Program through the National Research Foundation of Korea (NRF) (Grand Number: 2014-023284).

Superhydrophobic Natural and Artificial Surfaces-A Structural Approach.

PubMed

Avrămescu, Roxana-Elena; Ghica, Mihaela Violeta; Dinu-Pîrvu, Cristina; Prisada, Răzvan; Popa, Lăcrămioara

2018-05-22

Since ancient times humans observed animal and plants features and tried to adapt them according to their own needs. Biomimetics represents the foundation of many inventions from various fields: From transportation devices (helicopter, airplane, submarine) and flying techniques, to sports' wear industry (swimming suits, scuba diving gear, Velcro closure system), bullet proof vests made from Kevlar etc. It is true that nature provides numerous noteworthy models (shark skin, spider web, lotus leaves), referring both to the plant and animal kingdom. This review paper summarizes a few of "nature's interventions" in human evolution, regarding understanding of surface wettability and development of innovative special surfaces. Empirical models are described in order to reveal the science behind special wettable surfaces (superhydrophobic /superhydrophilic). Materials and methods used in order to artificially obtain special wettable surfaces are described in correlation with plants' and animals' unique features. Emphasis is placed on joining superhydrophobic and superhydrophilic surfaces, with important applications in cell culturing, microorganism isolation/separation and molecule screening techniques. Bio-inspired wettability is presented as a constitutive part of traditional devices/systems, intended to improve their characteristics and extend performances.

HydroCrowd: a citizen science snapshot to assess the spatial control of nitrogen solutes in surface waters

PubMed Central

Breuer, Lutz; Hiery, Noreen; Kraft, Philipp; Bach, Martin; Aubert, Alice H.; Frede, Hans-Georg

2015-01-01

We organized a crowdsourcing experiment in the form of a snapshot sampling campaign to assess the spatial distribution of nitrogen solutes, namely, nitrate, ammonium and dissolved organic nitrogen (DON), in German surface waters. In particular, we investigated (i) whether crowdsourcing is a reasonable sampling method in hydrology and (ii) what the effects of population density, soil humus content and arable land were on actual nitrogen solute concentrations and surface water quality. The statistical analyses revealed a significant correlation between nitrate and arable land (0.46), as well as soil humus content (0.37) but a weak correlation with population density (0.12). DON correlations were weak but significant with humus content (0.14) and arable land (0.13). The mean contribution of DON to total dissolved nitrogen was 22%. Samples were classified as water quality class II or above, following the European Water Framework Directive for nitrate and ammonium (53% and 82%, respectively). Crowdsourcing turned out to be a useful method to assess the spatial distribution of stream solutes, as considerable amounts of samples were collected with comparatively little effort. PMID:26561200

Surface manifestations of internal waves investigated by a subsurface buoyant jet: 3. Surface manifestations of internal waves

NASA Astrophysics Data System (ADS)

Bondur, V. G.; Grebenyuk, Yu. V.; Ezhova, E. V.; Kazakov, V. I.; Sergeev, D. A.; Soustova, I. A.; Troitskaya, Yu. I.

2010-08-01

In a large test reservoir at the Institute of Applied Physics, Russian Academy of Sciences, a series of experiments were performed to investigate the surface manifestations of internal waves radiated by a subsurface buoyant jet. The field of currents on the water surface of the reservoir was studied through the distribution of temperature with shallow thermocline. Using Particle Tracking Velocimetry (PTV), the velocity field of surface currents was measured. A theoretical model was developed to calculate the rates of disturbances on the surface. A comparison with experimental data indicated that the calculated data of the surface rate value are overestimated. This discrepancy was explained by the presence of a film of surface-active substances (SASs) with experimentally obtained parameters. Using scale modeling coefficients, we estimated the parameters of internal waves radiated by the subsurface wastewater system and the values of their surface manifestations in field conditions. We estimated the hydrodynamic contrasts in the field of surface waves, which can be caused by these inhomogeneous currents on the surface. For a wind velocity of 5 m/s, the magnitude of the contrast in the field of short waves can reach up to 10-25%, which is detected with confidence by remote-sensing methods.

Asymptotic Parachute Performance Sensitivity

NASA Technical Reports Server (NTRS)

Way, David W.; Powell, Richard W.; Chen, Allen; Steltzner, Adam D.

2006-01-01

In 2010, the Mars Science Laboratory mission will pioneer the next generation of robotic Entry, Descent, and Landing systems by delivering the largest and most capable rover to date to the surface of Mars. In addition to landing more mass than any other mission to Mars, Mars Science Laboratory will also provide scientists with unprecedented access to regions of Mars that have been previously unreachable. By providing an Entry, Descent, and Landing system capable of landing at altitudes as high as 2 km above the reference gravitational equipotential surface, or areoid, as defined by the Mars Orbiting Laser Altimeter program, Mars Science Laboratory will demonstrate sufficient performance to land on 83% of the planet s surface. By contrast, the highest altitude landing to date on Mars has been the Mars Exploration Rover at 1.3 km below the areoid. The coupling of this improved altitude performance with latitude limits as large as 60 degrees off of the equator and a precise delivery to within 10 km of a surface target, will allow the science community to select the Mars Science Laboratory landing site from thousands of scientifically interesting possibilities. In meeting these requirements, Mars Science Laboratory is extending the limits of the Entry, Descent, and Landing technologies qualified by the Mars Viking, Mars Pathfinder, and Mars Exploration Rover missions. Specifically, the drag deceleration provided by a Viking-heritage 16.15 m supersonic Disk-Gap-Band parachute in the thin atmosphere of Mars is insufficient, at the altitudes and ballistic coefficients under consideration by the Mars Science Laboratory project, to maintain necessary altitude performance and timeline margin. This paper defines and discusses the asymptotic parachute performance observed in Monte Carlo simulation and performance analysis and its effect on the Mars Science Laboratory Entry, Descent, and Landing architecture.

IsoNose - Isotopic Tools as Novel Sensors of Earth Surfaces Resources - A new Marie Curie Initial Training Network

NASA Astrophysics Data System (ADS)

von Blanckenburg, Friedhelm; Bouchez, Julien; Bouman, Caludia; Kamber, Balz; Gaillardet, Jérôme; Gorbushina, Anna; James, Rachael; Oelkers, Eric; Tesmer, Maja; Ashton, John

2015-04-01

The Marie Curie Initial Training Network »Isotopic Tools as Novel Sensors of Earth Surfaces Resources - IsoNose« is an alliance of eight international partners and five associated partners from science and industry. The project is coordinated at the Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences and will run until February 2018. In the last 15 years advances in novel mass-spectrometric methods have opened opportunities to identify "isotopic fingerprints" of virtually all metals and to make use of the complete information contained in these fingerprints. The understanding developed with these new tools will ultimately guide the exploitation of Earth surface environments. However, progress in bringing these methods to end-users depends on a multi transfer of knowledge between (1) isotope Geochemistry and Microbiology, Environmental Sciences (2), Economic Geology and (3) instrument developers and users in the development of user-friendly and new mass spectrometric methods. IsoNose will focus on three major Earth surface resources: soil, water and metals. These resources are currently being exploited to an unprecedented extent and their efficient management is essential for future sustainable development. Novel stable isotope techniques will disclose the processes generating (e.g. weathering, mineral ore formation) and destroying (e.g. erosion, pollution) these resources. Within this field the following questions will be addressed and answered: - How do novel stable isotope signatures characterize weathering processes? - How do novel stable isotope signatures trace water transport? - How to use novel stable isotope as environmental tracers? - How to use novel stable isotope for detecting and exploring metal ores? - How to improve analytical capabilities and develop robust routine applications for novel stable isotopes? Starting from the central questions mentioned above the IsoNose activities are organized in five scientific work packages: 1. Making soil from rock 2. Dissolved metals in the global water cycle 3. Human influence on metal cycling 4. Innovations in metal ore exploration 5. New analytical tools Acknowledgement: The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007-2013/ under REA grant agreement n° [608069].

Advanced Tools for River Science: EAARL and MD_SWMS: Chapter 3

USGS Publications Warehouse

Kinzel, Paul J.

2009-01-01

Disruption of flow regimes and sediment supplies, induced by anthropogenic or climatic factors, can produce dramatic alterations in river form, vegetation patterns, and associated habitat conditions. To improve habitat in these fluvial systems, resource managers may choose from a variety of treatments including flow and/or sediment prescriptions, vegetation management, or engineered approaches. Monitoring protocols developed to assess the morphologic response of these treatments require techniques that can measure topographic changes above and below the water surface efficiently, accurately, and in a standardized, cost-effective manner. Similarly, modeling of flow, sediment transport, habitat, and channel evolution requires characterization of river morphology for model input and verification. Recent developments by the U.S. Geological Survey with regard to both remotely sensed methods (the Experimental Advanced Airborne Research LiDAR; EAARL) and computational modeling software (the Multi-Dimensional Surface-Water Modeling System; MD_SWMS) have produced advanced tools for spatially explicit monitoring and modeling in aquatic environments. In this paper, we present a pilot study conducted along the Platte River, Nebraska, that demonstrates the combined use of these river science tools.

Simulation, Analysis, and Design of the Princeton Adaptable Stellarator for Education and Outreach (PASEO)

NASA Astrophysics Data System (ADS)

Carlson, Jared; Dominguez, Arturo; N/A Collaboration

2017-10-01

The PPPL Science Education Department, in collaboration with IPP, is currently developing a versatile small scale Stellarator for education and outreach purposes. The Princeton Adaptable Stellarator for Education and Outreach (PASEO) will provide visual demonstrations of Stellarator physics and serve as a lab platform for undergraduate and graduate students. Based off the Columbia Non-Neutral Torus (CNT) (1), and mini-CNTs (2), PASEO will create pure electron plasmas to study magnetic surfaces. PASEO uses similar geometries to these, but has an adjustable coil configuration to increase its versatility and conform to a highly visible vacuum chamber geometry. To simulate the magnetic surfaces in these new configurations, a MATALB code utilizing the Biot Savart law and a Fourth Order Runge-Kutta method was developed, leading to new optimal current ratios. The design for PASEO and its predicted plasma confinement are presented. (1) T.S. Pedersen et al., Fusion Science and Technology Vol. 46 July 2004 (2) C. Dugan, et al., American Physical Society; 48th Annual Meeting of the Division of Plasma Physics, October 30-November 3, 2006

Nano-metrology and terrain modelling - convergent practice in surface characterisation

USGS Publications Warehouse

Pike, R.J.

2000-01-01

The quantification of magnetic-tape and disk topography has a macro-scale counterpart in the Earth sciences - terrain modelling, the numerical representation of relief and pattern of the ground surface. The two practices arose independently and continue to function separately. This methodological paper introduces terrain modelling, discusses its similarities to and differences from industrial surface metrology, and raises the possibility of a unified discipline of quantitative surface characterisation. A brief discussion of an Earth-science problem, subdividing a heterogeneous terrain surface from a set of sample measurements, exemplifies a multivariate statistical procedure that may transfer to tribological applications of 3-D metrological height data.

Exploring Antarctic Land Surface Temperature Extremes Using Condensed Anomaly Databases

NASA Astrophysics Data System (ADS)

Grant, Glenn Edwin

Satellite observations have revolutionized the Earth Sciences and climate studies. However, data and imagery continue to accumulate at an accelerating rate, and efficient tools for data discovery, analysis, and quality checking lag behind. In particular, studies of long-term, continental-scale processes at high spatiotemporal resolutions are especially problematic. The traditional technique of downloading an entire dataset and using customized analysis code is often impractical or consumes too many resources. The Condensate Database Project was envisioned as an alternative method for data exploration and quality checking. The project's premise was that much of the data in any satellite dataset is unneeded and can be eliminated, compacting massive datasets into more manageable sizes. Dataset sizes are further reduced by retaining only anomalous data of high interest. Hosting the resulting "condensed" datasets in high-speed databases enables immediate availability for queries and exploration. Proof of the project's success relied on demonstrating that the anomaly database methods can enhance and accelerate scientific investigations. The hypothesis of this dissertation is that the condensed datasets are effective tools for exploring many scientific questions, spurring further investigations and revealing important information that might otherwise remain undetected. This dissertation uses condensed databases containing 17 years of Antarctic land surface temperature anomalies as its primary data. The study demonstrates the utility of the condensate database methods by discovering new information. In particular, the process revealed critical quality problems in the source satellite data. The results are used as the starting point for four case studies, investigating Antarctic temperature extremes, cloud detection errors, and the teleconnections between Antarctic temperature anomalies and climate indices. The results confirm the hypothesis that the condensate databases are a highly useful tool for Earth Science analyses. Moreover, the quality checking capabilities provide an important method for independent evaluation of dataset veracity.

An Agenda for Land-Surface Hydrology Research and a Call for the Second International Hydrological Decade

NASA Technical Reports Server (NTRS)

Entekhabi, Dara; Bras, Rafael L.; McLaughlin, Dennis B.; Asrar, Ghassem R.; Wei, Ying; Betts, Alan K.; Beven, Keith J.; Duffy, Christopher J.; Dunne, Thomas; Koster, Randall D.;

TH-CD-207A-03: A Surface Deformation Driven Respiratory Model for Organ Motion Tracking in Lung Cancer Radiotherapy

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

Chen, H; Zhen, X; Zhou, L

Purpose: To propose and validate a novel real-time surface-mesh-based internal organ-external surface motion and deformation tracking method for lung cancer radiotherapy. Methods: Deformation vector fields (DVFs) which characterizes the internal and external motion are obtained by registering the internal organ and tumor contours and external surface meshes to a reference phase in the 4D CT images using a recent developed local topology preserved non-rigid point matching algorithm (TOP). A composite matrix is constructed by combing the estimated internal and external DVFs. Principle component analysis (PCA) is then applied on the composite matrix to extract principal motion characteristics and finally yieldmore » the respiratory motion model parameters which correlates the internal and external motion and deformation. The accuracy of the respiratory motion model is evaluated using a 4D NURBS-based cardiac-torso (NCAT) synthetic phantom and three lung cancer cases. The center of mass (COM) difference is used to measure the tumor motion tracking accuracy, and the Dice’s coefficient (DC), percent error (PE) and Housdourf’s distance (HD) are used to measure the agreement between the predicted and ground truth tumor shape. Results: The mean COM is 0.84±0.49mm and 0.50±0.47mm for the phantom and patient data respectively. The mean DC, PE and HD are 0.93±0.01, 0.13±0.03 and 1.24±0.34 voxels for the phantom, and 0.91±0.04, 0.17±0.07 and 3.93±2.12 voxels for the three lung cancer patients, respectively. Conclusions: We have proposed and validate a real-time surface-mesh-based organ motion and deformation tracking method with an internal-external motion modeling. The preliminary results conducted on a synthetic 4D NCAT phantom and 4D CT images from three lung cancer cases show that the proposed method is reliable and accurate in tracking both the tumor motion trajectory and deformation, which can serve as a potential tool for real-time organ motion and deformation monitoring in lung cancer radiotherapy. This work is supported in part by grant from VARIAN MEDICAL SYSTEMS INC, the National Natural Science Foundation of China (no 81428019 and no 81301940), the Guangdong Natural Science Foundation (2015A030313302)and the 2015 Pearl River S&T Nova Program of Guangzhou (201506010096).« less

Direct measurement of bull's-eye nanoantenna metal loss

NASA Astrophysics Data System (ADS)

Hassani Nia, Iman; Jang, Sung J.; Memis, Omer G.; Gelfand, Ryan; Mohseni, Hooman

2013-09-01

The loss in optical antennas can affect their performance for their practical use in many branches of science such as biological and solar cell applications. However the big question is that how much loss is due to the joule heating in the metals. This would affect the efficiency of solar cells and is very important for single photon detection and also for some applications where high heat generation in nanoantennas is desirable, for example, payload release for cancer treatment. There are few groups who have done temperature measurements by methods such as Raman spectroscopy or fluorescence polarization anisotropy. The latter method, which is more reliable than Raman spectroscopy, requires the deposition of fluorescent molecules on the antenna surface. The molecules and the polarization of radiation rotate depending upon the surface temperature. The reported temperature measurement accuracy in this method is about 0.1° C. Here we present a method based on thermo-reflectance that allows better temperature accuracy as well as spatial resolution of 500 nm. Moreover, this method does not require the addition of new materials to the nanoantenna. We present the measured heat dissipation from bull's-eye nanoantennas and compare them with 3D simulation results.

Instrumentation development for In Situ 40Ar/39Ar planetary geochronology

USGS Publications Warehouse

Morgan, Leah; Munk, Madicken; Davidheiser-Kroll, Brett; Warner, Nicholas H.; Gupta, Sanjeev; Slaybaugh, Rachel; Harkness, Patrick; Mark, Darren

2017-01-01

The chronology of the Solar System, particularly the timing of formation of extra-terrestrial bodies and their features, is an outstanding problem in planetary science. Although various chronological methods for in situ geochronology have been proposed (e.g., Rb-Sr, K-Ar), and even applied (K-Ar), the reliability, accuracy, and applicability of the 40Ar/39Ar method makes it by far the most desirable chronometer for dating extra-terrestrial bodies. The method however relies on the neutron irradiation of samples, and thus a neutron source. Herein, we discuss the challenges and feasibility of deploying a passive neutron source to planetary surfaces for the in situ application of the 40Ar/39Ar chronometer. Requirements in generating and shielding neutrons, as well as analysing samples are described, along with an exploration of limitations such as mass, power and cost. Two potential solutions for the in situ extra-terrestrial deployment of the 40Ar/39Ar method are presented. Although this represents a challenging task, developing the technology to apply the 40Ar/39Ar method on planetary surfaces would represent a major advance towards constraining the timescale of solar system formation and evolution.

Modelisation geometrique par NURBS pour le design aerodynamique des ailes d'avion

NASA Astrophysics Data System (ADS)

Bentamy, Anas

The constant evolution of the computer science gives rise to many research areas especially in computer aided design. This study is part, of the advancement of the numerical methods in engineering computer aided design, specifically in aerospace science. The geometric modeling based on NURBS has been applied successfully to generate a parametric wing surface for aerodynamic design while satisfying manufacturing constraints. The goal of providing a smooth geometry described with few parameters has been achieved. In that case, a wing design including ruled surfaces at the leading edge slat and at the flap, and, curved central surfaces with intrinsic geometric property coming from conic curves, necessitates 130 control points and 15 geometric design variables. The 3D character of the wing need to be analyzed by techniques of investigation of surfaces in order to judge conveniently the visual aspect and detect any sign inversion in both directions of parametrization u and nu. Color mapping of the Gaussian curvature appears to be a very effective tools in visualization. The automation of the construction has been attained using an heuristic optimization algorithm, simulated annealing. The relative high speed of convergence to the solutions confirms its practical interest in engineering problems nowadays. The robustness of the geometric model has been tested successfully with an academic inverse design problem. The results obtained allow to foresee multiple possible applications from an extension to a complete geometric description of an airplane to the interaction with others disciplines belonging to a preliminary aeronautical design process.

Geochemistry of Slow-Growing Corals: Reconstructing Sea Surface Temperature, Salinity and the North Atlantic Oscillation

DTIC Science & Technology

2007-06-01

foraminifera, gastropods , and scaphopods) has been expressed as [Grossman and Ku, 1986]: 21 60 - 60w = -0.23 * (SST) +4.75 Eqn. (1) Slow growing corals...along the southeastern edge of the platform off John Smith’s Bay at 16m depth. (Figure adapted from World Ocean Circulation Experiment Newsletter...Atlantic Oscillation - Regional Temperatures and Precipitation, Science, 269, 676-679, 1995. Huybers, P., Multi-taper method coherence using adaptive

Analysis of High Precision GPS Time Series and Strain Rates for the Geothermal Play Fairway Analysis of Washington State Prospects Project

DOE Data Explorer

Michael Swyer

2015-02-22

Global Positioning System (GPS) time series from the National Science Foundation (NSF) Earthscope’s Plate Boundary Observatory (PBO) and Central Washington University’s Pacific Northwest Geodetic Array (PANGA). GPS station velocities were used to infer strain rates using the ‘splines in tension’ method. Strain rates were derived separately for subduction zone locking at depth and block rotation near the surface within crustal block boundaries.

Investigating the interrelationships among conceptions of, approaches to, and self-efficacy in learning science

NASA Astrophysics Data System (ADS)

Zheng, Lanqin; Dong, Yan; Huang, Ronghuai; Chang, Chun-Yen; Bhagat, Kaushal Kumar

2018-01-01

The purpose of this study was to examine the relations between primary school students' conceptions of, approaches to, and self-efficacy in learning science in Mainland China. A total of 1049 primary school students from Mainland China participated in this study. Three instruments were adapted to measure students' conceptions of learning science, approaches to learning science, and self-efficacy. The exploratory factor analysis and confirmatory factor analysis were adopted to validate three instruments. The path analysis was employed to understand the relationships between conceptions of learning science, approaches to learning science, and self-efficacy. The findings indicated that students' lower level conceptions of learning science positively influenced their surface approaches in learning science. Higher level conceptions of learning science had a positive influence on deep approaches and a negative influence on surface approaches to learning science. Furthermore, self-efficacy was also a hierarchical construct and can be divided into the lower level and higher level. Only students' deep approaches to learning science had a positive influence on their lower and higher level of self-efficacy in learning science. The results were discussed in the context of the implications for teachers and future studies.

Change detection and classification of land cover in multispectral satellite imagery using clustering of sparse approximations (CoSA) over learned feature dictionaries

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

Moody, Daniela I.; Brumby, Steven P.; Rowland, Joel C.

Neuromimetic machine vision and pattern recognition algorithms are of great interest for landscape characterization and change detection in satellite imagery in support of global climate change science and modeling. We present results from an ongoing effort to extend machine vision methods to the environmental sciences, using adaptive sparse signal processing combined with machine learning. A Hebbian learning rule is used to build multispectral, multiresolution dictionaries from regional satellite normalized band difference index data. Land cover labels are automatically generated via our CoSA algorithm: Clustering of Sparse Approximations, using a clustering distance metric that combines spectral and spatial textural characteristics tomore » help separate geologic, vegetative, and hydrologie features. We demonstrate our method on example Worldview-2 satellite images of an Arctic region, and use CoSA labels to detect seasonal surface changes. In conclusion, our results suggest that neuroscience-based models are a promising approach to practical pattern recognition and change detection problems in remote sensing.« less

Change detection and classification of land cover in multispectral satellite imagery using clustering of sparse approximations (CoSA) over learned feature dictionaries

DOE PAGES

Moody, Daniela I.; Brumby, Steven P.; Rowland, Joel C.; ...

2014-10-01

Neuromimetic machine vision and pattern recognition algorithms are of great interest for landscape characterization and change detection in satellite imagery in support of global climate change science and modeling. We present results from an ongoing effort to extend machine vision methods to the environmental sciences, using adaptive sparse signal processing combined with machine learning. A Hebbian learning rule is used to build multispectral, multiresolution dictionaries from regional satellite normalized band difference index data. Land cover labels are automatically generated via our CoSA algorithm: Clustering of Sparse Approximations, using a clustering distance metric that combines spectral and spatial textural characteristics tomore » help separate geologic, vegetative, and hydrologie features. We demonstrate our method on example Worldview-2 satellite images of an Arctic region, and use CoSA labels to detect seasonal surface changes. In conclusion, our results suggest that neuroscience-based models are a promising approach to practical pattern recognition and change detection problems in remote sensing.« less

Terrain Model Registration for Single Cycle Instrument Placement

NASA Technical Reports Server (NTRS)

Deans, Matthew; Kunz, Clay; Sargent, Randy; Pedersen, Liam

2003-01-01

This paper presents an efficient and robust method for registration of terrain models created using stereo vision on a planetary rover. Our approach projects two surface models into a virtual depth map, rendering the models as they would be seen from a single range sensor. Correspondence is established based on which points project to the same location in the virtual range sensor. A robust norm of the deviations in observed depth is used as the objective function, and the algorithm searches for the rigid transformation which minimizes the norm. An initial coarse search is done using rover pose information from odometry and orientation sensing. A fine search is done using Levenberg-Marquardt. Our method enables a planetary rover to keep track of designated science targets as it moves, and to hand off targets from one set of stereo cameras to another. These capabilities are essential for the rover to autonomously approach a science target and place an instrument in contact in a single command cycle.

Landsat surface reflectance quality assurance extraction (version 1.7)

USGS Publications Warehouse

Jones, J.W.; Starbuck, M.J.; Jenkerson, Calli B.

2013-01-01

The U.S. Geological Survey (USGS) Land Remote Sensing Program is developing an operational capability to produce Climate Data Records (CDRs) and Essential Climate Variables (ECVs) from the Landsat Archive to support a wide variety of science and resource management activities from regional to global scale. The USGS Earth Resources Observation and Science (EROS) Center is charged with prototyping systems and software to generate these high-level data products. Various USGS Geographic Science Centers are charged with particular ECV algorithm development and (or) selection as well as the evaluation and application demonstration of various USGS CDRs and ECVs. Because it is a foundation for many other ECVs, the first CDR in development is the Landsat Surface Reflectance Product (LSRP). The LSRP incorporates data quality information in a bit-packed structure that is not readily accessible without postprocessing services performed by the user. This document describes two general methods of LSRP quality-data extraction for use in image processing systems. Helpful hints for the installation and use of software originally developed for manipulation of Hierarchical Data Format (HDF) produced through the National Aeronautics and Space Administration (NASA) Earth Observing System are first provided for users who wish to extract quality data into separate HDF files. Next, steps follow to incorporate these extracted data into an image processing system. Finally, an alternative example is illustrated in which the data are extracted within a particular image processing system.

The Proof of the Pudding?: A Case Study of an "At-Risk" Design-Based Inquiry Science Curriculum

NASA Astrophysics Data System (ADS)

Chue, Shien; Lee, Yew-Jin

2013-12-01

When students collaboratively design and build artifacts that require relevant understanding and application of science, many aspects of scientific literacy are developed. Design-based inquiry (DBI) is one such pedagogy that can serve these desired goals of science education well. Focusing on a Projectile Science curriculum previously found to be implemented with satisfactory fidelity, we investigate the many hidden challenges when using DBI with Grade 8 students from one school in Singapore. A case study method was used to analyze video recordings of DBI lessons conducted over 10 weeks, project presentations, and interviews to ascertain the opportunities for developing scientific literacy among participants. One critical factor that hindered learning was task selection by teachers, which emphasized generic scientific process skills over more important cognitive and epistemic learning goals. Teachers and students were also jointly engaged in forms of inquiry that underscored artifact completion over deeper conceptual and epistemic understanding of science. Our research surfaced two other confounding factors that undermined the curriculum; unanticipated teacher effects and the underestimation of the complexity of DBI and of inquiry science in general. Thus, even though motivated or experienced teachers can implement an inquiry science curriculum with good fidelity and enjoy school-wide support, these by themselves will not guarantee deep learning of scientific literacy in DBI. Recommendations are made for navigating the hands- and minds-on aspects of learning science that is an asset as well as inherent danger during DBI teaching.

A New Method for Qualitative Multi-scale Analysis of Bacterial Biofilms on Filamentous Fungal Colonies Using Confocal and Electron Microscopy

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

Miquel Guennoc, Cora; Rose, Christophe; Guinnet, Frédéric

Bacterial biofilms frequently form on fungal surfaces and can be involved in numerous bacterial-fungal interaction processes, such as metabolic cooperation, competition, or predation. The study of biofilms is important in many biological fields, including environmental science, food production, and medicine. However, few studies have focused on such bacterial biofilms, partially due to the difficulty of investigating them. Most of the methods for qualitative and quantitative biofilm analyses described in the literature are only suitable for biofilms forming on abiotic surfaces or on homogeneous and thin biotic surfaces, such as a monolayer of epithelial cells. While laser scanning confocal microscopy (LSCM)more » is often used to analyze in situ and in vivo biofilms, this technology becomes very challenging when applied to bacterial biofilms on fungal hyphae, due to the thickness and the three dimensions of the hyphal networks. To overcome this shortcoming, we developed a protocol combining microscopy with a method to limit the accumulation of hyphal layers in fungal colonies. Using this method, we were able to investigate the development of bacterial biofilms on fungal hyphae at multiple scales using both LSCM and scanning electron microscopy (SEM). Furthermore, this report describes the protocol, including microorganism cultures, bacterial biofilm formation conditions, biofilm staining, and LSCM and SEM visualizations.« less

A New Method for Qualitative Multi-scale Analysis of Bacterial Biofilms on Filamentous Fungal Colonies Using Confocal and Electron Microscopy

DOE PAGES

Miquel Guennoc, Cora; Rose, Christophe; Guinnet, Frédéric; ...

2017-01-01

Bacterial biofilms frequently form on fungal surfaces and can be involved in numerous bacterial-fungal interaction processes, such as metabolic cooperation, competition, or predation. The study of biofilms is important in many biological fields, including environmental science, food production, and medicine. However, few studies have focused on such bacterial biofilms, partially due to the difficulty of investigating them. Most of the methods for qualitative and quantitative biofilm analyses described in the literature are only suitable for biofilms forming on abiotic surfaces or on homogeneous and thin biotic surfaces, such as a monolayer of epithelial cells. While laser scanning confocal microscopy (LSCM)more » is often used to analyze in situ and in vivo biofilms, this technology becomes very challenging when applied to bacterial biofilms on fungal hyphae, due to the thickness and the three dimensions of the hyphal networks. To overcome this shortcoming, we developed a protocol combining microscopy with a method to limit the accumulation of hyphal layers in fungal colonies. Using this method, we were able to investigate the development of bacterial biofilms on fungal hyphae at multiple scales using both LSCM and scanning electron microscopy (SEM). Furthermore, this report describes the protocol, including microorganism cultures, bacterial biofilm formation conditions, biofilm staining, and LSCM and SEM visualizations.« less

VIRTOPSY--scientific documentation, reconstruction and animation in forensic: individual and real 3D data based geo-metric approach including optical body/object surface and radiological CT/MRI scanning.

PubMed

Thali, Michael J; Braun, Marcel; Buck, Ursula; Aghayev, Emin; Jackowski, Christian; Vock, Peter; Sonnenschein, Martin; Dirnhofer, Richard

2005-03-01

Until today, most of the documentation of forensic relevant medical findings is limited to traditional 2D photography, 2D conventional radiographs, sketches and verbal description. There are still some limitations of the classic documentation in forensic science especially if a 3D documentation is necessary. The goal of this paper is to demonstrate new 3D real data based geo-metric technology approaches. This paper present approaches to a 3D geo-metric documentation of injuries on the body surface and internal injuries in the living and deceased cases. Using modern imaging methods such as photogrammetry, optical surface and radiological CT/MRI scanning in combination it could be demonstrated that a real, full 3D data based individual documentation of the body surface and internal structures is possible in a non-invasive and non-destructive manner. Using the data merging/fusing and animation possibilities, it is possible to answer reconstructive questions of the dynamic development of patterned injuries (morphologic imprints) and to evaluate the possibility, that they are matchable or linkable to suspected injury-causing instruments. For the first time, to our knowledge, the method of optical and radiological 3D scanning was used to document the forensic relevant injuries of human body in combination with vehicle damages. By this complementary documentation approach, individual forensic real data based analysis and animation were possible linking body injuries to vehicle deformations or damages. These data allow conclusions to be drawn for automobile accident research, optimization of vehicle safety (pedestrian and passenger) and for further development of crash dummies. Real 3D data based documentation opens a new horizon for scientific reconstruction and animation by bringing added value and a real quality improvement in forensic science.

The Impact of Apollo-Era Microbiology on Human Space Flight

NASA Technical Reports Server (NTRS)

Elliott, T. F; Castro, V. A.; Bruce, R. J.; Pierson, D. L.

2014-01-01

The microbiota of crewmembers and the spacecraft environment contributes significant risk to crew health during space flight missions. NASA reduces microbial risk with various mitigation methods that originated during the Apollo Program and continued to evolve through subsequent programs: Skylab, Shuttle, and International Space Station (ISS). A quarantine of the crew and lunar surface samples, within the Lunar Receiving Laboratory following return from the Moon, was used to prevent contamination with unknown extraterrestrial organisms. The quarantine durations for the crew and lunar samples were 21 days and 50 days, respectively. A series of infections among Apollo crewmembers resulted in a quarantine before launch to limit exposure to infectious organisms. This Health Stabilization Program isolated the crew for 21 days before flight and was effective in reducing crew illness. After the program developed water recovery hardware for Apollo spacecraft, the 1967 National Academy of Science Space Science Board recommended the monitoring of potable water. NASA implemented acceptability limits of 10 colony forming units (CFU) per mL and the absence of viable E. coli, anaerobes, yeasts, and molds in three separate 150 mL aliquots. Microbiological investigations of the crew and spacecraft environment were conducted during the Apollo program, including the Apollo-Soyuz Test Project and Skylab. Subsequent space programs implemented microbial screening of the crew for pathogens and acceptability limits on spacecraft surfaces and air. Microbiology risk mitigation methods have evolved since the Apollo program. NASA cancelled the quarantine of the crew after return from the lunar surface, reduced the duration of the Health Stabilization Program; and implemented acceptability limits for spacecraft surfaces and air. While microbial risks were not a main focus of the early Mercury and Gemini programs, the extended duration of Apollo flights resulted in the increased scrutiny of impact of the space flight environment on crew health. The lessons learned during that era of space flight continue to impact microbiology risk mitigation in space programs today.

Separating Atmospheric and Surface Contributions in Hyperspectral Imager for the Coastal Ocean (HICO) Scenes using Informed Non-Negative Matrix Factorization

NASA Astrophysics Data System (ADS)

Wright, L.; Coddington, O.; Pilewskie, P.

2016-12-01

Hyperspectral instruments are a growing class of Earth observing sensors designed to improve remote sensing capabilities beyond discrete multi-band sensors by providing tens to hundreds of continuous spectral channels. Improved spectral resolution, range and radiometric accuracy allow the collection of large amounts of spectral data, facilitating thorough characterization of both atmospheric and surface properties. These new instruments require novel approaches for processing imagery and separating surface and atmospheric signals. One approach is numerical source separation, which allows the determination of the underlying physical causes of observed signals. Improved source separation will enable hyperspectral imagery to better address key science questions relevant to climate change, including land-use changes, trends in clouds and atmospheric water vapor, and aerosol characteristics. We developed an Informed Non-negative Matrix Factorization (INMF) method for separating atmospheric and surface sources. INMF offers marked benefits over other commonly employed techniques including non-negativity, which avoids physically impossible results; and adaptability, which tailors the method to hyperspectral source separation. The INMF algorithm is adapted to separate contributions from physically distinct sources using constraints on spectral and spatial variability, and library spectra to improve the initial guess. We also explore methods to produce an initial guess of the spatial separation patterns. Using this INMF algorithm we decompose hyperspectral imagery from the NASA Hyperspectral Imager for the Coastal Ocean (HICO) with a focus on separating surface and atmospheric signal contributions. HICO's coastal ocean focus provides a dataset with a wide range of atmospheric conditions, including high and low aerosol optical thickness and cloud cover, with only minor contributions from the ocean surfaces in order to isolate the contributions of the multiple atmospheric sources.

The Philae lander mission and science overview.

PubMed

Boehnhardt, Hermann; Bibring, Jean-Pierre; Apathy, Istvan; Auster, Hans Ulrich; Ercoli Finzi, Amalia; Goesmann, Fred; Klingelhöfer, Göstar; Knapmeyer, Martin; Kofman, Wlodek; Krüger, Harald; Mottola, Stefano; Schmidt, Walter; Seidensticker, Klaus; Spohn, Tilman; Wright, Ian

2017-07-13

The Philae lander accomplished the first soft landing and the first scientific experiments of a human-made spacecraft on the surface of a comet. Planned, expected and unexpected activities and events happened during the descent, the touch-downs, the hopping across and the stay and operations on the surface. The key results were obtained during 12-14 November 2014, at 3 AU from the Sun, during the 63 h long period of the descent and of the first science sequence on the surface. Thereafter, Philae went into hibernation, waking up again in late April 2015 with subsequent communication periods with Earth (via the orbiter), too short to enable new scientific activities. The science return of the mission comes from eight of the 10 instruments on-board and focuses on morphological, thermal, mechanical and electrical properties of the surface as well as on the surface composition. It allows a first characterization of the local environment of the touch-down and landing sites. Unique conclusions on the organics in the cometary material, the nucleus interior, the comet formation and evolution became available through measurements of the Philae lander in the context of the Rosetta mission.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Author(s).

Removal of sulfamethazine by hypercrosslinked adsorbents in aquatic systems.

PubMed

Grimmett, Maria E

2013-01-01

Four hundred tons of sulfamethazine are fed to livestock annually in North America to prevent disease and promote growth, but most of the drug is excreted unmetabolized into the environment. Because of slow degradation and high mobility, sulfamethazine contaminates groundwater supplies and causes aquatic ecosystem damage. Current water treatment methods to remove pharmaceuticals are not universally effective and have considerable limitations, which necessitate newer remediation techniques. Hypercrosslinked adsorbents, polystyrene polymers 100% crosslinked with methylene bridges, show promise because of high surface areas, high mechanical strength, and regenerable properties. This study screened four Purolite hypercrosslinked adsorbents (MN152, MN250, PAD400, and PAD600) to remove sulfamethazine from contaminated water and then characterized the most efficient resin, MN250, with batch adsorption and desorption experiments to optimize its use. Sulfamethazine adsorption onto MN250 displayed an L-class isotherm shape consistent with monolayer adsorption, negligible solute-solute interactions at the adsorbent surface, and decreasing activation energies of desorption with increasing surface coverage. MN250 had a maximum experimental adsorption capacity of 111 mg g, showing high correlation to the Langmuir and Freundlich models. Adsorption kinetics revealed prolonged adsorption over 59 h and were best described by Ho's pseudo-second-order model. There was minimal desorption from MN250 in distilled water, indicating an irreversible adsorption process. MN250's high capacity for sulfamethazine adsorption, minimal desorption in water, and ability to be regenerated make it a practical solution for sulfamethazine removal in areas that have contaminated groundwater supplies (e.g., areas near concentrated livestock operations), especially as current treatment methods have significant drawbacks. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Europa Small Lander Design Concepts

NASA Astrophysics Data System (ADS)

Zimmerman, W. F.

2005-12-01

Title: Europa Small Lander Design Concepts Authors: Wayne F. Zimmerman, James Shirley, Robert Carlson, Tom Rivellini, Mike Evans One of the primary goals of NASA's Outer Planets Program is to revisit the Jovian system. A new Europa Geophysical Explorer (EGE) Mission has been proposed and is under evaluation. There is in addition strong community interest in a surface science mission to Europa. A Europa Lander might be delivered to the Jovian system with the EGE orbiter. A Europa Astrobiology Lander (EAL) Mission has also been proposed; this would launch sometime after 2020. The primary science objectives for either of these would most likely include: Surface imaging (both microscopic and near-field), characterization of surface mechanical properties (temperature, hardness), assessment of surface and near-surface organic and inorganic chemistry (volatiles, mineralogy, and compounds), characterization of the radiation environment (total dose and particles), characterization of the planetary seismicity, and the measurement of Europa's magnetic field. The biggest challenges associated with getting to the surface and surviving to perform science investigations revolve around the difficulty of landing on an airless body, the ubiquitous extreme topography, the harsh radiation environment, and the extreme cold. This presentation reviews some the recent design work on drop-off probes, also called "hard landers". Hard lander designs have been developed for a range of science payload delivery systems spanning small impactors to multiple science pods tethered to a central hub. In addition to developing designs for these various payload delivery systems, significant work has been done in weighing the relative merits of standard power systems (i.e., batteries) against radioisotope power systems. A summary of the power option accommodation benefits and issues will be presented. This work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under a contract from NASA,

Topical, Yes, but It Dives beneath the Surface

ERIC Educational Resources Information Center

Tyler, Paul

2017-01-01

Topical science is about developing an awareness of science issues in the news and the importance of science stories that affect pupils' lives and the world around them. It is about making science relevant for pupils and engaging them in the subject. The author explores how children can be engaged and inspired through topical science. The idea of…

The interactions of atmospheric cosmogenic radionuclides with spacecraft surfaces

NASA Technical Reports Server (NTRS)

Gregory, John C.; Fishman, G. J.; Harmon, A.; Parnell, T. A.; Herzog, G.; Klein, J.; Jull, A. J. T.

1991-01-01

The discovery of the cosmogenic radionuclide Be-7 on the front surface of the Long Duration Exposure Facility (LDEF) has opened new opportunities to study several unexplored regions of space science. The experiments have shown that the Be-7 found was concentrated in a thin surface layer of spacecraft material. The only reasonable source of the isotope is the atmosphere through which the spacecraft passed. It is expected that the uptake of Be in such circumstances will depend on the chemical form of the Be and the chemical nature of the substrate. It was found that the observed concentration of Be-7 does differ between metal surfaces and organic surfaces such as PTFE (Teflon). It is noted however, that (1) organic surfaces are etched by the atomic oxygen found under these orbital conditions, and (2) the relative velocity of the species is 8 km/s relative to the surface and the interaction chemistry and physics may differ from the norm. Be-7 is formed by disintegration of O and N nuclei under cosmic ray proton bombardment. Many other isotopes are produced by cosmic ray reactions, and some of these are suited to measurement by the extremely sensitive methods of accelerator mass spectrometry.

Low temperature surface chemistry and nanostructures

NASA Astrophysics Data System (ADS)

Sergeev, G. B.; Shabatina, T. I.

2002-03-01

The new scientific field of low temperature surface chemistry, which combines the low temperature chemistry (cryochemistry) and surface chemistry approaches, is reviewed in this paper. One of the most exciting achievements in this field of science is the development of methods to create highly ordered hybrid nanosized structures on different organic and inorganic surfaces and to encapsulate nanosized metal particles in organic and polymer matrices. We consider physical and chemical behaviour for the systems obtained by co-condensation of the components vapours on the surfaces cooled down to 4-10 and 70-100 K. In particular the size effect of both types, the number of atoms in the reactive species structure and the thickness of growing co-condensate film, on the chemical activity of the system is analysed in detail. The effect of the internal mechanical stresses on the growing interfacial co-condensate film formation and on the generation of fast (explosive) spontaneous reactions at low temperatures is discussed. The examples of unusual chemical interactions of metal atoms, clusters and nanosized particles, obtained in co-condensate films on the cooled surfaces under different conditions, are presented. The examples of highly ordered surface and volume hybrid nanostructures formation are analysed.

Polarized Light Reflected and Transmitted by Thick Rayleigh Scattering Atmospheres

NASA Astrophysics Data System (ADS)

Natraj, Vijay; Hovenier, J. W.

2012-03-01

Accurate values for the intensity and polarization of light reflected and transmitted by optically thick Rayleigh scattering atmospheres with a Lambert surface underneath are presented. A recently reported new method for solving integral equations describing Chandrasekhar's X- and Y-functions is used. The results have been validated using various tests and techniques, including the doubling-adding method, and are accurate to within one unit in the eighth decimal place. Tables are stored electronically and expected to be useful as benchmark results for the (exo)planetary science and astrophysics communities. Asymptotic expressions to obtain Stokes parameters for a thick layer from those of a semi-infinite atmosphere are also provided.

Surface plasmon resonance enhanced light absorption and wavelength tuneable in gold-coated iron oxide spherical nanoparticle

NASA Astrophysics Data System (ADS)

Dasri, Thananchai; Chingsungnoen, Artit

2018-06-01

Surface plasmon in nano-sized particles, such as gold, silver, copper and their composites, has recently attracted a great deal of attention due to its possible uses in many applications, especially in life sciences. It is desirable for application devices with a tenability of surface plasmon wavelength and optical properties enhancement. This article presents enhanced optical light absorption and tunable wavelength in gold-coated magnetite (Fe3O4@Au core-shell) nanoparticles embedded in water using the theoretical method of discrete dipole approximation (DDA). The absorption spectra in the wavelengths from 350 to 900 nm were found to be the spectra obtained from Fe3O4@Au core-shell nanoparticles, and when compared with pure Fe3O4 nanoparticles, the surface plasmon resonance can be enhanced and tuned over the entire visible spectrum (viz. 350-800 nm) of the electromagnetic spectrum by varying the Au shell thickness (2-5 nm). Similarly, the Faraday rotation spectra can also be obtained.

Damage Resistant Optical Glasses for High Power Lasers: A Continuing Glass Science and Technology Challenge

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

Campbell, J H

2002-08-28

A major challenge in the development of optical glasses for high-power lasers is reducing or eliminating laser-induced damage to the interior (bulk) and the polished surface of the glass. Bulk laser damage in glass generally originates from inclusions. With the development of novel glass melting and forming processes it is now possible to make both fused silica and a suit of meta-phosphate laser glasses in large sizes ({approx}>0.5-lm diameter), free of inclusions and with high optical homogeneity ({approx} 10{sup -6}). Considerable attention also has been focused on improving the laser damage resistance to polished optical glass surfaces. Studies have shownmore » that laser-induced damage to surfaces grows exponentially with the number of shots when illuminated with nano-second pulses at 351-nm above a given fluence threshold. A new approach for reducing and eliminating laser-induced surface damage relies on a series of post-polishing treatment steps. This damage improvement method is briefly reviewed.« less

Air, water, and surface bacterial contamination in a university-hospital autopsy room.

PubMed

Maujean, Géraldine; Malicier, Daniel; Fanton, Laurent

2012-03-01

Today, little is known about the bacteriological environment of the autopsy room and its potential interest for medico-legal practices. Seven hundred fifty microbiological samples were taken from surface (n = 660), air (n = 48), and water (n = 42) to evaluate it in a French University Forensic Department. Median bacterial counts were compared before and during autopsy for air samples, and before and after autopsy for surface samples, using Wilcoxon matched pairs signed ranks test. Bacterial identification relied on traditional phenotypic methods. Bacterial counts in the air were low before autopsy, increased significantly during procedure, and seemed more linked to the number of people in the room than to an important production of aerosol-containing bacteria. Despite cleaning, human fecal flora was omnipresent on surfaces, which revealed insufficient disinfection. Bacteriological sampling is an easy way to monitor cleaning practices in postmortem rooms, but chiefly a way to improve the reliability of medico-legal proofs of infectious deaths. © 2012 American Academy of Forensic Sciences.

Colloidal CuInSe2 nanocrystals thin films of low surface roughness

NASA Astrophysics Data System (ADS)

de Kergommeaux, Antoine; Fiore, Angela; Faure-Vincent, Jérôme; Pron, Adam; Reiss, Peter

2013-03-01

Thin-film processing of colloidal semiconductor nanocrystals (NCs) is a prerequisite for their use in (opto-)electronic devices. The commonly used spin-coating is highly materials consuming as the overwhelming amount of deposited matter is ejected from the substrate during the spinning process. Also, the well-known dip-coating and drop-casting procedures present disadvantages in terms of the surface roughness and control of the film thickness. We show that the doctor blade technique is an efficient method for preparing nanocrystal films of controlled thickness and low surface roughness. In particular, by optimizing the deposition conditions, smooth and pinhole-free films of 11 nm CuInSe2 NCs have been obtained exhibiting a surface roughness of 13 nm root mean square (rms) for a 350 nm thick film, and less than 4 nm rms for a 75 nm thick film. Invited talk at the 6th International Workshop on Advanced Materials Science and Nanotechnology, 30 October-2 November 2012, Ha Long, Vietnam.

Analysis of Low Frequency Ground Motions Induced by Near-Surface and Atmospheric Explosions.

DTIC Science & Technology

1982-08-01

Library S-CUBED ATTN: J. Murphy Institute for Defense Analyses ATTN: Classified Library Science Applications, Inc ATTN: Technical Library Kaman...AviDyne ATTN: Library Science Applications, Inc ATTN: N. Hobbs ATTN: D. Maxwell ATTN: D. Bernstein Kaman Sciences Corp ATTN: Library Science Applications

High Surface Area Dendrite Nanoelectrodes for Electrochemistry

NASA Astrophysics Data System (ADS)

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

2014-03-01

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

Statistical characterization of surface features from tungsten-coated divertor inserts in the DIII-D Metal Rings Campaign

NASA Astrophysics Data System (ADS)

Adams, Jacob; Unterberg, Ezekial; Chrobak, Christopher; Stahl, Brian; Abrams, Tyler

2017-10-01

Continuing analysis of tungsten-coated inserts from the recent DIII-D Metal Rings Campaign utilizes a statistical approach to study carbon migration and deposition on W surfaces and to characterize the pre- versus post-exposure surface morphology. A TZM base was coated with W using both CVD and PVD and allowed for comparison between the two coating methods. The W inserts were positioned in the lower DIII-D divertor in both the upper (shelf) region and lower (floor) region and subjected to multiple plasma shots, primarily in H-mode. Currently, the post-exposure W inserts are being characterized using SEM/EDX to qualify the surface morphology and to quantify the surface chemical composition. In addition, profilometry is being used to measure the surface roughness of the inserts both before and after plasma exposure. Preliminary results suggest a correlation between the pre-exposure surface roughness and the level of carbon deposited on the surface. Furthermore, ongoing in-depth analysis may reveal insights into the formation mechanism of nanoscale bumps found in the carbon-rich regions of the W surfaces that have not yet been explained. Work supported in part by US DoE under the Science Undergraduate Laboratory Internship (SULI) program and under DE-FC02-04ER54698.

A Framework for Lunar Surface Science Exploration

NASA Astrophysics Data System (ADS)

Eppler, D.; Bleacher, J.; Bell, E.; Cohen, B.; Deans, M.; Evans, C.; Graff, T.; Head, J.; Helper, M.; Hodges, K.; Hurtado, J.; Klaus, K.; Kring, D.; Schmitt, H.; Skinner, J.; Spudis, P.; Tewksbury, B.; Young, K.; Yingst, A.

2017-05-01

Successful lunar science will be dependent on mission concept, mobility, robotic/human assets, crew training, field tools, and IT assets. To achieve good science return, element integration must be considered at the start of any exploration program.

The effect of bearing surface on risk of periprosthetic joint infection in total hip arthroplasty: a systematic review and meta-analysis.

PubMed

Hexter, A T; Hislop, S M; Blunn, G W; Liddle, A D

2018-02-01

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty (THA). Different bearing surface materials have different surface properties and it has been suggested that the choice of bearing surface may influence the risk of PJI after THA. The objective of this meta-analysis was to compare the rate of PJI between metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), and ceramic-on-ceramic (CoC) bearings. Electronic databases (Medline, Embase, Cochrane library, Web of Science, and Cumulative Index of Nursing and Allied Health Literature) were searched for comparative randomized and observational studies that reported the incidence of PJI for different bearing surfaces. Two investigators independently reviewed studies for eligibility, evaluated risk of bias, and performed data extraction. Meta-analysis was performed using the Mantel-Haenzel method and random-effects model in accordance with methods of the Cochrane group. Our search strategy revealed 2272 studies, of which 17 met the inclusion criteria and were analyzed. These comprised 11 randomized controlled trials and six observational studies. The overall quality of included studies was high but the observational studies were at high risk of bias due to inadequate adjustment for confounding factors. The overall cumulative incidence of PJI across all studies was 0.78% (1514/193 378). For each bearing combination, the overall incidence was as follows: MoP 0.85% (1353/158 430); CoP 0.38% (67/17 489); and CoC 0.53% (94/17 459). The meta-analysis showed no significant difference between the three bearing combinations in terms of risk of PJI. On the basis of the clinical studies available, there is no evidence that bearing choice influences the risk of PJI. Future research, including basic science studies and large, adequately controlled registry studies, may be helpful in determining whether implant materials play a role in determining the risk of PJI following arthroplasty surgery. Cite this article: Bone Joint J 2018;100-B:134-42. ©2018 The British Editorial Society of Bone & Joint Surgery.

Observation duration analysis for Earth surface features from a Moon-based platform

NASA Astrophysics Data System (ADS)

Ye, Hanlin; Guo, Huadong; Liu, Guang; Ren, Yuanzhen

2018-07-01

Earth System Science is a discipline that performs holistic and comprehensive research on various components of the Earth. One of a key issue for the Earth monitoring and observation is to enhance the observation duration, the time intervals during which the Earth surface features can be observed by sensors. In this work, we propose to utilise the Moon as an Earth observation platform. Thanks to the long distance between the Earth and the Moon, and the vast space on the lunar surface which is suitable for sensor installation, this Earth observation platform could have large spatial coverage, long temporal duration, and could perform multi-layer detection of the Earth. The line of sight between a proposed Moon-based platform and the Earth will change with different lunar surface positions; therefore, in this work, the position of the lunar surface was divided into four regions, including one full observation region and three incomplete observation regions. As existing methods are not able to perform global-scale observations, a Boolean matrix method was established to calculate the necessary observation durations from a Moon-based platform. Based on Jet Propulsion Laboratory (JPL) ephemerides and Earth Orientation Parameters (EOP), a formula was developed to describe the geometrical relationship between the Moon-based platform and Earth surface features in the unified spatial coordinate system and the unified time system. In addition, we compared the observation geometries at different positions on the lunar surface and two parameters that are vital to observation duration calculations were considered. Finally, an analysis method was developed. We found that the observation duration of a given Earth surface feature shows little difference regardless of sensor position within the full observation region. However, the observation duration for sensors in the incomplete observation regions is reduced by at least half. In summary, our results demonstrate the suitability of a Moon-based platform located in the full observation region.

Human Exploration of Phobos

NASA Technical Reports Server (NTRS)

Abercromby, Andrew F. J.; Chappell, Steven P.; Gernhardt, Michael L.; Lee, David E.; Howe, A. Scott

2015-01-01

This study developed, analyzed, and compared mission architectures for human exploration of Mars' Moons within the context of an Evolvable Mars Campaign. METHODS: All trades assumed conjunction class missions to Phobos (approximately 500 days in Mars system) as it was considered the driving case for the transportation architecture. All architectures assumed that the Mars Transit Habitat would remain in a High Mars Orbit with crewmembers transferring between HMO and Phobos in a small crew taxi vehicle. A reference science / exploration program was developed including performance of a standard set of tasks at 55 locations on the Phobos surface. Detailed EVA timelines were developed using realistic flight rules to accomplish the reference science tasks using exploration systems ranging from jetpacks to multi-person pressurized excursion vehicles combined with Phobos surface and orbital (L1, L4/L5, 20km Distant Retrograde Orbit) habitat options. Detailed models of propellant mass, crew time, science productivity, radiation exposure, systems and consumables masses, and other figures of merit were integrated to enable quantitative comparison of different architectural options. Options for pre-staging assets using solar electric propulsion (SEP) vs. delivering all systems with the crew were also evaluated. Seven discrete mission architectures were evaluated. RESULTS: The driving consideration for habitat location (Phobos surface vs. orbital) was radiation exposure, with an estimated reduction in cumulative mission radiation exposure of up to 34% (vs. Mars orbital mission) when the habitat is located on the Phobos surface, compared with only 3-6% reduction for a habitat in a 20km DRO. The exploration utility of lightweight unpressurized excursion vehicles was limited by the need to remain within 20 minutes of Solar Particle Event radiation protection combined with complex GN&C systems required by the non-intuitive and highly-variable gravitational environment. Two-person pressurized excursion vehicles as well as mobile surface habitats offer significant exploration capability and operational benefits compared with unpressurized EVA mobility systems at the cost of increased system and propellant mass. Mechanical surface translation modes (i.e. hopping) were modeled and offer potentially significant propellant savings and the possibility of extended exploration operations between crewed missions. Options for extending the utilization of the crew taxi vehicle were examined, including use as an exploration asset for Phobos surface exploration (when combined with an alternate mobility system) and as an EVA platform, both on Phobos and for contingency EVA on the Mars Transit Habitat. CONCLUSIONS: Human exploration of Phobos offers a scientifically meaningful first step towards human Mars surface missions that develops and validates transportation, habitation, and exploration systems and operations in advance of the Mars landing systems.

Direct Functionalization of an Acid-Terminated Nanodiamond with Azide: Enabling Access to 4-Substituted-1,2,3-Triazole-Functionalized Particles

DOE PAGES

Kennedy, Zachary C.; Barrett, Christopher A.; Warner, Marvin G.

2017-03-01

Azides on the periphery of nanodiamond materials (ND) are of great utility because they have been shown to undergo Cu-catalyzed and Cu-free cycloaddition reactions with structurally diverse alkynes, affording particles tailored for applications in biology and materials science. However, current methods employed to access ND featuring azide groups typically require either harsh pretreatment procedures or multiple synthesis steps and use surface linking groups that may be susceptible to undesirable cleavage. Here in this paper we demonstrate an alternative single-step approach to producing linker-free, azide-functionalized ND. Our method was applied to low-cost, detonation-derived ND powders where surface carbonyl groups undergo silver-mediatedmore » decarboxylation and radical substitution with azide. ND with directly grafted azide groups were then treated with a variety of aliphatic, aromatic, and fluorescent alkynes to afford 1-(ND)-4-substituted-1,2,3-triazole materials under standard copper-catalyzed cycloaddition conditions. Surface modification steps were verified by characteristic infrared absorptions and elemental analyses. High loadings of triazole surface groups (up to 0.85 mmol g –1) were obtained as determined from thermogravimetric analysis. The azidation procedure disclosed is envisioned to become a valuable initial transformation in numerous future applications of ND.« less

Computational fluid dynamics - An introduction for engineers

NASA Astrophysics Data System (ADS)

Abbott, Michael Barry; Basco, David R.

An introduction to the fundamentals of CFD for engineers and physical scientists is presented. The principal definitions, basic ideas, and most common methods used in CFD are presented, and the application of these methods to the description of free surface, unsteady, and turbulent flow is shown. Emphasis is on the numerical treatment of incompressible unsteady fluid flow with primary applications to water problems using the finite difference method. While traditional areas of application like hydrology, hydraulic and coastal engineering and oceanography get the main emphasis, newer areas of application such as medical fluid dynamics, bioengineering, and soil physics and chemistry are also addressed. The possibilities and limitations of CFD are pointed out along with the relations of CFD to other branches of science.

Transforming Elementary Science Teacher Education by Bridging Formal and Informal Science Education in an Innovative Science Methods Course

ERIC Educational Resources Information Center

Riedinger, Kelly; Marbach-Ad, Gili; McGinnis, J. Randy; Hestness, Emily; Pease, Rebecca

2011-01-01

We investigated curricular and pedagogical innovations in an undergraduate science methods course for elementary education majors at the University of Maryland. The goals of the innovative elementary science methods course included: improving students' attitudes toward and views of science and science teaching, to model innovative science teaching…

BIOMECHANICS. Jumping on water: Surface tension-dominated jumping of water striders and robotic insects.

PubMed

Koh, Je-Sung; Yang, Eunjin; Jung, Gwang-Pil; Jung, Sun-Pill; Son, Jae Hak; Lee, Sang-Im; Jablonski, Piotr G; Wood, Robert J; Kim, Ho-Young; Cho, Kyu-Jin

2015-07-31

Jumping on water is a unique locomotion mode found in semi-aquatic arthropods, such as water striders. To reproduce this feat in a surface tension-dominant jumping robot, we elucidated the hydrodynamics involved and applied them to develop a bio-inspired impulsive mechanism that maximizes momentum transfer to water. We found that water striders rotate the curved tips of their legs inward at a relatively low descending velocity with a force just below that required to break the water surface (144 millinewtons/meter). We built a 68-milligram at-scale jumping robotic insect and verified that it jumps on water with maximum momentum transfer. The results suggest an understanding of the hydrodynamic phenomena used by semi-aquatic arthropods during water jumping and prescribe a method for reproducing these capabilities in artificial systems. Copyright © 2015, American Association for the Advancement of Science.

Crystalline Bacterial Surface Layer (S-Layer) Opens Golden Opportunities for Nanobiotechnology in Textiles.

PubMed

Asadi, Narges; Chand, Nima; Rassa, Mehdi

2015-12-01

This study focuses on the successful recrystallization of bacterial S-layer arrays of the Lactobacillus acidophilus ATCC 4356 at textile surfaces to create a novel method and material. Optimum bacterial growth was obtained at approximately 45 °C, pH 5.0, and 14 h pi. The cells were resuspended in guanidine hydrochloride and the 43 kDa S-protein was dialyzed and purified. The optimum reassembly on the polypropylene fabric surface in terms of scanning electron microscopy (SEM), reflectance, and uniformity (spectrophotometry) was obtained at 30 °C, pH 5.0 for 30 minutes in the presence of 2 gr/l (liquor ratio; 1:40) of the S-protein. Overall, our data showed that the functional aspects and specialty applications of the fabric would be very attractive for the textile and related sciences, and result in advanced technical textiles.

NASA flight electronics environmental stress screening survey

NASA Technical Reports Server (NTRS)

Marian, E. J. (Compiler)

1983-01-01

Data compiled by the Institute of Environmental Sciences were used to establish guidelines for identifying defective, abnormal, or marginal parts as well as manufacturing defects. These data are augmented with other available sources of similar information in conjunction with NASA centers' data and presented in a form that may be useful to all NASA centers in planning and developing effective environmental stress screens. Information relative to thermal and vibration screens as the most effective methods for surfacing latent failures in electronic equipment at the component level is considered.

Luminescent nanodiamonds for biomedical applications.

PubMed

Say, Jana M; van Vreden, Caryn; Reilly, David J; Brown, Louise J; Rabeau, James R; King, Nicholas J C

2011-12-01

In recent years, nanodiamonds have emerged from primarily an industrial and mechanical applications base, to potentially underpinning sophisticated new technologies in biomedical and quantum science. Nanodiamonds are relatively inexpensive, biocompatible, easy to surface functionalise and optically stable. This combination of physical properties are ideally suited to biological applications, including intracellular labelling and tracking, extracellular drug delivery and adsorptive detection of bioactive molecules. Here we describe some of the methods and challenges for processing nanodiamond materials, detection schemes and some of the leading applications currently under investigation.

Next Generation LOCAD-PTS Cartridge Development

NASA Technical Reports Server (NTRS)

Morris, H.; Nutter, D.; Weite, E.; Wells, M.; Maule, J.; Damon, M.; Monaco, L.; Steele, A.; Wainwright, N.

2008-01-01

Future astrobiology exploration missions will require rapid, point-of-use techniques for surface science experiments and contamination monitoring. The Lab-On-a-Chip Application Development (LOCAD) team is developing operational instruments that advance spaceflight technologies to molecular-based methods. Currently, LOCAD-Portable Test System (PTS) is quantifying levels of the bacterial molecule endotoxin onboard the Internatioal Space Station. Future research and development will focus on more sensitive molecular techniques that expand the number of compounds detected to include beta-glucan from fungal cell walls.

Water Column Variability in Coastal Regions

DTIC Science & Technology

1998-01-01

Bay off the HKUST campus. Endeco/YSI sondes were placed at 0.4 m depth below the surface and at 1 m off the bottom in 6 m of water to make...with colleagues at the Hong Kong University of Science and Technology ( HKUST ) using these methods to examine coastal variability in southern China due...the University of Rhode Island in order to devote the year to an intensive set of field measurements at HKUST . Wendy Woods also spent the past year

Basic approaches to and tasks of space technology

NASA Technical Reports Server (NTRS)

Okhotin, A. S.

1978-01-01

The high vacuum and weightlessness of outer space offer great possibilities for the new field of space technology. To take advantage of this, it is necessary to study such physical and chemical phenomena as diffusion, surface tension, heat exchange, and crystallization. The research shows the possibility of obtaining materials with a more perfect structure. Methods of treating materials can be used in space which are impossible on earth. Achievements in material science in outer space will have a large impact on the national economy.

Superhydrophobic Natural and Artificial Surfaces—A Structural Approach

PubMed Central

Avrămescu, Roxana-Elena; Ghica, Mihaela Violeta; Dinu-Pîrvu, Cristina; Prisada, Răzvan; Popa, Lăcrămioara

2018-01-01

Since ancient times humans observed animal and plants features and tried to adapt them according to their own needs. Biomimetics represents the foundation of many inventions from various fields: From transportation devices (helicopter, airplane, submarine) and flying techniques, to sports’ wear industry (swimming suits, scuba diving gear, Velcro closure system), bullet proof vests made from Kevlar etc. It is true that nature provides numerous noteworthy models (shark skin, spider web, lotus leaves), referring both to the plant and animal kingdom. This review paper summarizes a few of “nature’s interventions” in human evolution, regarding understanding of surface wettability and development of innovative special surfaces. Empirical models are described in order to reveal the science behind special wettable surfaces (superhydrophobic /superhydrophilic). Materials and methods used in order to artificially obtain special wettable surfaces are described in correlation with plants’ and animals’ unique features. Emphasis is placed on joining superhydrophobic and superhydrophilic surfaces, with important applications in cell culturing, microorganism isolation/separation and molecule screening techniques. Bio-inspired wettability is presented as a constitutive part of traditional devices/systems, intended to improve their characteristics and extend performances. PMID:29789488

Utilizing Radioisotope Power Systems for Human Lunar Exploration

NASA Technical Reports Server (NTRS)

Schreiner, Timothy M.

2005-01-01

The Vision for Space Exploration has a goal of sending crewed missions to the lunar surface as early as 2015 and no later than 2020. The use of nuclear power sources could aid in assisting crews in exploring the surface and performing In-Situ Resource Utilization (ISRU) activities. Radioisotope Power Systems (RPS) provide constant sources of electrical power and thermal energy for space applications. RPSs were carried on six of the crewed Apollo missions to power surface science packages, five of which still remain on the lunar surface. Future RPS designs may be able to play a more active role in supporting a long-term human presence. Due to its lower thermal and radiation output, the planned Stirling Radioisotope Generator (SRG) appears particularly attractive for manned applications. The MCNPX particle transport code has been used to model the current SRG design to assess its use in proximity with astronauts operating on the surface. Concepts of mobility and ISRU infrastructure were modeled using MCNPX to analyze the impact of RPSs on crewed mobility systems. Strategies for lowering the radiation dose were studied to determine methods of shielding the crew from the RPSs.

Identification of the Structure Model of the Si(111)-(5×2)-Au Surface

NASA Astrophysics Data System (ADS)

Shirasawa, Tetsuroh; Voegeli, Wolfgang; Nojima, Takehiro; Iwasawa, Yusaku; Yamaguchi, Yudai; Takahashi, Toshio

2014-10-01

The atomic structure of the Si(111)-(5×2)-Au surface, a periodic gold chain on the silicon surface, has been a long-debated issue in surface science. The recent three candidates, the so-called Erwin-Barke-Himpsel (EBH) model [S. C. Erwin, I. Barke, and F. J. Himpsel, Phys. Rev. B 80, 155409 (2009)], the Abukawa-Nishigaya (AN) model [T. Abukawa and Y. Nishigaya, Phys. Rev. Lett. 110, 036102 (2013)], and the Kwon-Kang (KK) model [S. G. Kwon and M. H. Kang, Phys. Rev. Lett. 113, 086101 (2014)] that has one additional Au atom than the EBH model are tested by surface x-ray diffraction data. A two-dimensional Patterson map constructed from the in-plane diffraction intensities rejects the AN model and prefers the KK model over the EBH model. On the basis of the arrangement of Au obtained from the Patterson map, all the reconstructed Si atoms, such as the so-called honeycomb chain structure, are directly imaged out by utilizing a holographic method. The KK model reproduces out-of-plane diffraction data as well.

Shell-isolated nanoparticle-enhanced Raman spectroscopy: principle and applications (Presentation Recording)

NASA Astrophysics Data System (ADS)

Li, Jian-Feng; Tian, Zhong-Qun

2015-08-01

Surface-enhanced Raman spectroscopy (SERS) is a powerful technique that yields fingerprint vibrational information with ultra-high sensitivity. However, only roughened Ag, Au and Cu surfaces can generate strong SERS effect. The lack of materials and morphology generality has severely limited the breadth of SERS practical applications on surface science, electrochemistry and catalysis. Shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) was therefore invented to break the long-standing limitation of SERS. In SHINERS, Au@SiO2 core-shell nanoparticles were rationally designed. The gold core acts as plasmonic antenna and encapsulated by an ultra-thin, uniform and pinhole-free silica shell, can provide high electromagnetic field to enhance the Raman signals of probed molecules. The inert silica shell acts as tunneling barrier prevents the core from interacting with the environment. SHINERS has already been applied to a number of challenging systems, such as hydrogen and CO on Pt(hkl) and Rh(hkl), which can't be realized by traditional SERS. Combining with electrochemical methods, we has investigated the adsorption processes of pyridine at the Au(hkl) single crystal/solution interface, and in-situ monitored the surface electro-oxidation at Au(hkl) electrodes. These pioneering studies demonstrate convincingly the ability of SHINERS in exploring correlations between structure and reactivity as well as in monitoring intermediates at the interfaces. SHINERS was also explored from semiconductor surface for industry, to living bacteria for life science, and to pesticide residue detection for food safety. The concept of shell-isolated nanoparticle-enhancement is being applied to other spectroscopies such as infrared absorption, sum frequency generation and fluorescence. Jian-Feng Li et al., Nature, 2010, 464, 392-395.

Runoff losses of excreted chlortetracycline, sulfamethazine, and tylosin from surface-applied and soil-incorporated beef cattle feedlot manure.

PubMed

Amarakoon, Inoka D; Zvomuya, Francis; Cessna, Allan J; Degenhardt, Dani; Larney, Francis J; McAllister, Tim A

2014-03-01

Veterinary antimicrobials in land-applied manure can move to surface waters via rain or snowmelt runoff, thus increasing their dispersion in agro-environments. This study quantified losses of excreted chlortetracycline, sulfamethazine, and tylosin in simulated rain runoff from surface-applied and soil-incorporated beef cattle ( L.) feedlot manure (60 Mg ha, wet wt.). Antimicrobial concentrations in runoff generally reflected the corresponding concentrations in the manure. Soil incorporation of manure reduced the concentrations of chlortetracycline (from 75 to 12 μg L for a 1:1 mixture of chlortetracycline and sulfamethazine and from 43 to 17 μg L for chlortetracycline alone) and sulfamethazine (from 3.9 to 2.6 μg L) in runoff compared with surface application. However, there was no significant effect of manure application method on tylosin concentration (range, 0.02-0.06 μg L) in runoff. Mass losses, as a percent of the amount applied, for chlortetracycline and sulfamethazine appeared to be independent of their respective soil sorption coefficients. Mass losses of chlortetracycline were significantly reduced with soil incorporation of manure (from 6.5 to 1.7% when applied with sulfamethazine and from 6.5 to 3.5% when applied alone). Mass losses of sulfamethazine (4.8%) and tylosin (0.24%) in runoff were not affected by manure incorporation. Although our results confirm that cattle-excreted veterinary antimicrobials can be removed via surface runoff after field application, the magnitudes of chlortetracycline and sulfamethazine losses were reduced by soil incorporation of manure immediately after application. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

A Series of MATLAB Learning Modules to Enhance Numerical Competency in Applied Marine Sciences

NASA Astrophysics Data System (ADS)

Fischer, A. M.; Lucieer, V.; Burke, C.

2016-12-01

Enhanced numerical competency to navigate the massive data landscapes are critical skills students need to effectively explore, analyse and visualize complex patterns in high-dimensional data for addressing the complexity of many of the world's problems. This is especially the case for interdisciplinary, undergraduate applied marine science programs, where students are required to demonstrate competency in methods and ideas across multiple disciplines. In response to this challenge, we have developed a series of repository-based data exploration, analysis and visualization modules in MATLAB for integration across various attending and online classes within the University of Tasmania. The primary focus of these modules is to teach students to collect, aggregate and interpret data from large on-line marine scientific data repositories to, 1) gain technical skills in discovering, accessing, managing and visualising large, numerous data sources, 2) interpret, analyse and design approaches to visualise these data, and 3) to address, through numerical approaches, complex, real-world problems, that the traditional scientific methods cannot address. All modules, implemented through a MATLAB live script, include a short recorded lecture to introduce the topic, a handout that gives an overview of the activities, an instructor's manual with a detailed methodology and discussion points, a student assessment (quiz and level-specific challenge task), and a survey. The marine science themes addressed through these modules include biodiversity, habitat mapping, algal blooms and sea surface temperature change and utilize a series of marine science and oceanographic data portals. Through these modules students, with minimal experience in MATLAB or numerical methods are introduced to array indexing, concatenation, sorting, and reshaping, principal component analysis, spectral analysis and unsupervised classification within the context of oceanographic processes, marine geology and marine community ecology.

The effects of cloud inhomogeneities upon radiative fluxes, and the supply of a cloud truth validation dataset

NASA Technical Reports Server (NTRS)

Welch, Ronald M.

1993-01-01

A series of cloud and sea ice retrieval algorithms are being developed in support of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Science Team objectives. These retrievals include the following: cloud fractional area, cloud optical thickness, cloud phase (water or ice), cloud particle effective radius, cloud top heights, cloud base height, cloud top temperature, cloud emissivity, cloud 3-D structure, cloud field scales of organization, sea ice fractional area, sea ice temperature, sea ice albedo, and sea surface temperature. Due to the problems of accurately retrieving cloud properties over bright surfaces, an advanced cloud classification method was developed which is based upon spectral and textural features and artificial intelligence classifiers.

Aeroheating Thermal Analysis Methods for Aerobraking Mars Missions

NASA Technical Reports Server (NTRS)

Amundsen, Ruth M.; Dec, John A.; George, Benjamin E.

2002-01-01

Mars missions often employ aerobraking upon arrival at Mars as a low-mass method to gradually reduce the orbit period from a high-altitude, highly elliptical insertion orbit to the final science orbit. Two recent missions that made use of aerobraking were Mars Global Surveyor (MGS) and Mars Odyssey. Both spacecraft had solar arrays as the main aerobraking surface area. Aerobraking produces a high heat load on the solar arrays, which have a large surface area exposed to the airflow and relatively low mass. To accurately model the complex behavior during aerobraking, the thermal analysis must be tightly coupled to the flight mechanics, aerodynamics, and atmospheric modeling efforts being performed during operations. To properly represent the temperatures prior to and during the drag pass, the model must include the orbital solar and planetary heat fluxes. The correlation of the thermal model to flight data allows a validation of the modeling process, as well as information on what processes dominate the thermal behavior. This paper describes the thermal modeling method that was developed for this purpose, as well as correlation for two flight missions, and a discussion of improvements to the methodology.

On-Orbit Planetary Science Laboratories for Simulating Surface Conditions of Planets and Small Bodies

NASA Astrophysics Data System (ADS)

Thangavelautham, J.; Asphaug, E.; Schwartz, S.

2017-02-01

Our work has identified the use of on-orbit centrifuge science laboratories as a key enabler towards low-cost, fast-track physical simulation of off-world environments for future planetary science missions.

Chemistry and Materials Science progress report, FY 1994. Revision 2

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

NONE

1996-01-01

Thrust areas of the weapons-supporting research include surface science, fundamentals of the physics and processing of metals, energetic materials, etc. The laboratory directed R and D include director`s initiatives, individual projects, and transactinium science studies.

Inquiring into Three Approaches to Hands-On Learning in Elementary and Secondary Science Methods Courses.

ERIC Educational Resources Information Center

Barnes, Marianne B.; Foley, Kathleen R.

1999-01-01

Investigates three approaches to hands-on science learning in two contexts, an elementary science methods class and a secondary science methods class. Focused on an activity on foam. Concludes that when developing models for teaching science methods courses, methods instructors need to share power with prospective teachers. (Author/MM)

The Cryospheres of Mars and Ceres - What thermal observations tell us about near surface ice.

NASA Astrophysics Data System (ADS)

Titus, T. N.; Li, J. Y.; Moullet, A.

2017-12-01

Mars and Ceres both have near surface water ice that forms a cryosphere at polar latitudes. Gamma ray and neutron observations have provided important constraints on the location and depths of the cryosphere for both planetary bodies, but these observations have very low spatial resolution [e.g. 1, 2]. Thermal observations, which are also sensitive to the presence of a near-surface cryosphere as demonstrated by several studies of Mars [e.g. 3, 4], provide additional constraints. Thermal observations can identify depth to the cryosphere (as long as it is within a few thermal skin depths) and water-ice stability. This presentation will compare both the similarities and the differences of these two planetary cryospheres, as well as the thermal observations from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) [5], the Atacama Large Millimeter/submillimeter Array (ALMA) [6], and publically available Dawn Visible Infrared spectrometer (VIR) [7]. The KRC thermal model [8] will use these observed surface temperatures to constrain depths to near surface ice (i.e. the cyropshere). References: [1] Feldman et al., 2002, Science, 297(5578), 75-78. [2] Prettyman et al., 2017, Science, 355(6320), 55-59. [3] Titus et al., 2003, Science, 299(5609), 1048-1051 [4] Mellon et al., 2008, JGR, 113(E12), CiteID E00A25. [5] Christensen et al., 1998, Science, 279(5357), 1692. [6] Wootten A. et al. (2015) IAU General Assembly, Meeting #29, #2237199 [7] de Santis et al., 2011, Space Science Reviews, 163(1-4), 329-369. [8] Kieffer, 2013, JGR, 118, Issue 3, pp. 451-470.

Land, Cryosphere, and Nighttime Environmental Products from Suomi NPP VIIRS: Overview and Status

NASA Technical Reports Server (NTRS)

Roman, Miguel O.; Justice, Chris; Csiszar, Ivan

2014-01-01

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched in October 2011 as part of the Suomi National Polar-orbiting Partnership (S-NPP: http://npp.gsfc.nasa.gov/). VIIRS was designed to improve upon the capabilities of the operational Advanced Very High Resolution Radiometer (AVHRR) and provide observation continuity with NASA's Earth Observing System's (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS). Since the VIIRS first-light images were received in November 2011, NASA and NOAA funded scientists have been working to evaluate the instrument performance and derived products to meet the needs of the NOAA operational users and the NASA science community. NOAA's focus has been on refining a suite of operational products known as Environmental Data Records (EDRs), which were developed according to project specifications under the former National Polar-orbiting Environmental Satellite System (NPOESS). The NASA S-NPP Science Team has focused on evaluating the EDRs for science use, developing and testing additional products to meet science data needs and providing MODIS data product continuity. This paper will present to-date findings of the NASA Science Team's evaluation of the VIIRS Land and Cryosphere EDRs, specifically Surface Reflectance, Land Surface Temperature, Surface Albedo, Vegetation Indices, Surface Type, Active Fires, Snow Cover, Ice Surface Temperature, and Sea Ice Characterization (http://viirsland.gsfc.nasa.gov/index.html). The paper will also discuss new capabilities being developed at NASA's Land Product Evaluation and Test Element (http://landweb.nascom.nasa.gov/NPP_QA/); including downstream data and products derived from the VIIRS Day/Night Band (DNB).

Colorimetric detection of DNA damage by using hemin-graphene nanocomposites

NASA Astrophysics Data System (ADS)

Wei, W.; Zhang, D. M.; Yin, L. H.; Pu, Y. P.; Liu, S. Q.

2013-04-01

A colorimetric method for detection of DNA damage was developed by using hemin-graphene nanosheets (H-GNs). H-GNs were skillfully synthesized by adsorping of hemin on graphene through π-π interactions. The as-prepared H-GNs possessed both the ability of graphene to differentiate the damage DNA from intact DNA and the catalytic action of hemin. The damaged DNA made H-GNs coagulated to different degrees from the intact DNA because there were different amount of negative charge exposed on their surface, which made a great impact on the solubility of H-GNs. As a result, the corresponding centrifugal supernatant of H-GNs solution showed different color in the presence of 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2, which could be discriminated by naked eyes or by ultraviolet (UV)-visible spectrometer. Based on this, the damaged effects of styrene oxide (SO), NaAsO2 and UV radiation on DNA were studied. Results showed that SO exerted most serious damage effect on DNA although all of them damaged DNA seriously. The new method for detection of DNA damage showed good prospect in the evaluation of genotoxicity of new compounds, the maximum limit of pesticide residue, food additives, and so on, which is important in the fields of food science, pharmaceutical science and pesticide science.

Global OpenSearch

NASA Astrophysics Data System (ADS)

Newman, D. J.; Mitchell, A. E.

2015-12-01

At AGU 2014, NASA EOSDIS demonstrated a case-study of an OpenSearch framework for Earth science data discovery. That framework leverages the IDN and CWIC OpenSearch API implementations to provide seamless discovery of data through the 'two-step' discovery process as outlined by the Federation for Earth Sciences (ESIP) OpenSearch Best Practices. But how would an Earth Scientist leverage this framework and what are the benefits? Using a client that understands the OpenSearch specification and, for further clarity, the various best practices and extensions, a scientist can discovery a plethora of data not normally accessible either by traditional methods (NASA Earth Data Search, Reverb, etc) or direct methods (going to the source of the data) We will demonstrate, via the CWICSmart web client, how an earth scientist can access regional data on a regional phenomena in a uniform and aggregated manner. We will demonstrate how an earth scientist can 'globalize' their discovery. You want to find local data on 'sea surface temperature of the Indian Ocean'? We can help you with that. 'European meteorological data'? Yes. 'Brazilian rainforest satellite imagery'? That too. CWIC allows you to get earth science data in a uniform fashion from a large number of disparate, world-wide agencies. This is what we mean by Global OpenSearch.

Folding to Curved Surfaces: A Generalized Design Method and Mechanics of Origami-based Cylindrical Structures.

PubMed

Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C Q

2016-09-14

Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson's ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering.

Folding to Curved Surfaces: A Generalized Design Method and Mechanics of Origami-based Cylindrical Structures

NASA Astrophysics Data System (ADS)

Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C. Q.

2016-09-01

Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson’s ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering.

Folding to Curved Surfaces: A Generalized Design Method and Mechanics of Origami-based Cylindrical Structures

PubMed Central

Wang, Fei; Gong, Haoran; Chen, Xi; Chen, C. Q.

2016-01-01

Origami structures enrich the field of mechanical metamaterials with the ability to convert morphologically and systematically between two-dimensional (2D) thin sheets and three-dimensional (3D) spatial structures. In this study, an in-plane design method is proposed to approximate curved surfaces of interest with generalized Miura-ori units. Using this method, two combination types of crease lines are unified in one reprogrammable procedure, generating multiple types of cylindrical structures. Structural completeness conditions of the finite-thickness counterparts to the two types are also proposed. As an example of the design method, the kinematics and elastic properties of an origami-based circular cylindrical shell are analysed. The concept of Poisson’s ratio is extended to the cylindrical structures, demonstrating their auxetic property. An analytical model of rigid plates linked by elastic hinges, consistent with numerical simulations, is employed to describe the mechanical response of the structures. Under particular load patterns, the circular shells display novel mechanical behaviour such as snap-through and limiting folding positions. By analysing the geometry and mechanics of the origami structures, we extend the design space of mechanical metamaterials and provide a basis for their practical applications in science and engineering. PMID:27624892

Adsorption of Potassium on the MoS2(100) Surface: A First-Principles Investigation

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

Andersen, Amity; Kathmann, Shawn M.; Lilga, Michael A.

2011-04-15

Periodic density functional theory calculations were performed to investigate the interaction that potassium with the Mo and S edges of the MoS2(100) surface. Both neutral and cationic (+1) charged potassium-promoted systems at different sulfur coverages were considered. Our calculations indicate that the potassium atom readily donates its single 4s valence electron to the MoS2 structure for the neutral potassium-promoted system, and the neutral and cationic potassium-promoted systems demonstrate a similar adsorption behavior. Moreover, potassium changes the magnetic properties known to occur at the metallic edge surface, which have implications for electron spin dependent surface characterization methods (i.e., electron spin/paramagnetic spectroscopy).more » Potassium in both the neutral and cationic systems tends to maximize its interactions with the available sulfur atoms at the edge surface, preferring sites over four-fold S hollows on fully sulfided Mo and S edges and over the interstitial gap where two to four edge surface S atoms are available for coordination. As the potassium coverage increases, the adsorption energy per potassium atom, surface work function, and transfer of the K 4s electron to the MoS2(100) surface decreases, which is in line with an increased metallization of the potassium adlayer. The potassium adlayer tends to form chains along the interstitial with K-K distances ~1 Å, which is notably less than those of bulk bcc K metal (4.61 Å). Density of states for the potassium-saturated surface suggests enhanced involvement of broad K 3d states beginning just above the Fermi level. Potassium-promotion of MoS2(100) has implications for alcohol catalysis: increasing the surface basicity by increasing the electron charge of the surface, providing hydrogenation-promoting CO site, blocking edge surface that dissociate CO and lead to methanation, and limiting H2 dissociative adsorption to the edge surface and possibly inhibiting the H2 dissociative adsorption via s character electron repulsion. This research was performed in part using the Molecular Science Computing Facility in the William R. Wiley Environmental Molecular Sciences Laboratory, a U.S. Department of Energy (DOE) national scientific user facility located at the Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for DOE.« less

Science Hybrid Orbiter and Lunar Relay (SCHOLR) Architecture and Design

NASA Technical Reports Server (NTRS)

Trase, Kathryn K.; Barch, Rachel A.; Chaney, Ryan E.; Coulter, Rachel A.; Gao, Hui; Huynh, David P.; Iaconis, Nicholas A.; MacMillan, Todd S.; Pitner, Gregory M.; Schwab, Devin T.

2011-01-01

Considered both a stepping-stone to deep space and a key to unlocking the mysteries of planetary formation, the Moon offers a unique opportunity for scientific study. Robotic precursor missions are being developed to improve technology and enable new approaches to exploration. Robots, lunar landers, and satellites play significant roles in advancing science and technologies, offering close range and in-situ observations. Science and exploration data gathered from these nodes and a lunar science satellite is intended to support future human expeditions and facilitate future utilization of lunar resources. To attain a global view of lunar science, the nodes will be distributed over the lunar surface, including locations on the far side of the Moon. Given that nodes on the lunar far side do not have direct line-of-sight for Earth communications, the planned presence of such nodes creates the need for a lunar communications relay satellite. Since the communications relay capability would only be required for a small portion of the satellite s orbit, it may be possible to include communication relay components on a science spacecraft. Furthermore, an integrated satellite has the potential to reduce lunar surface mission costs. A SCience Hybrid Orbiter and Lunar Relay (SCHOLR) is proposed to accomplish scientific goals while also supporting the communications needs of landers on the far side of the Moon. User needs and design drivers for the system were derived from the anticipated needs of future robotic and lander missions. Based on these drivers and user requirements, accommodations for communications payload aboard a science spacecraft were developed. A team of interns identified and compared possible SCHOLR architectures. The final SCHOLR architecture was analyzed in terms of orbiter lifetime, lunar surface coverage, size, mass, power, and communications data rates. This paper presents the driving requirements, operational concept, and architecture views for SCHOLR within a lunar surface nodal network. Orbital and bidirectional link analysis, between lunar nodes, orbiter, and Earth, as well as a conceptual design for the spacecraft are also presented

Lubricant retention in liquid-infused microgrooves exposed to turbulent flow

NASA Astrophysics Data System (ADS)

Fu, Matthew; Chen, Ting-Hsuan; Arnold, Craig; Hultmark, Marcus

2017-11-01

Liquid infused surfaces are a promising method of passive drag reduction for turbulent flows. These surfaces rely on functionalized roughness elements to trap a liquid lubricant that is immiscible with external fluids. The presence of the lubricant creates a collection of fluid-fluid interfaces which can support a finite slip velocity at the effective surface. Generating a streamwise slip at the surface has been demonstrated as an effective mechanism for drag reduction; however, sustained drag reduction is predicated on the retention of the lubricating layer. Here, a turbulent channel-flow facility is used to characterize the robustness of liquid-infused surfaces and evaluate criteria for ensuring retention of the lubricant. Microscale grooved surfaces infused with alkane lubricants are mounted flush in the channel and exposed to turbulent flows. The retention of lubricants and pressure drop are monitored to characterize the effects of surface geometry and lubricant properties. To improve the retention of lubricant within grooved structures, a novel laser patterning technique is used to scribe chemical barriers onto grooved surfaces and evaluated. Supported under ONR Grants N00014-12-1-0875 and N00014-12-1-0962 (program manager Ki-Han Kim) and by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.

Recent Progress on Stability and Passivation of Black Phosphorus.

PubMed

Abate, Yohannes; Akinwande, Deji; Gamage, Sampath; Wang, Han; Snure, Michael; Poudel, Nirakar; Cronin, Stephen B

2018-05-11

From a fundamental science perspective, black phosphorus (BP) is a canonical example of a material that possesses fascinating surface and electronic properties. It has extraordinary in-plane anisotropic electrical, optical, and vibrational states, as well as a tunable band gap. However, instability of the surface due to chemical degradation in ambient conditions remains a major impediment to its prospective applications. Early studies were limited by the degradation of black phosphorous surfaces in air. Recently, several robust strategies have been developed to mitigate these issues, and these novel developments can potentially allow researchers to exploit the extraordinary properties of this material and devices made out of it. Here, the fundamental chemistry of BP degradation and the tremendous progress made to address this issue are extensively reviewed. Device performances of encapsulated BP are also compared with nonencapsulated BP. In addition, BP possesses sensitive anisotropic photophysical surface properties such as excitons, surface plasmons/phonons, and topologically protected and Dirac semi-metallic surface states. Ambient degradation as well as any passivation method used to protect the surface could affect the intrinsic surface properties of BP. These properties and the extent of their modifications by both the degradation and passivation are reviewed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Status of the ExoMars Project

NASA Astrophysics Data System (ADS)

Kminek, Gerhard; Vago, Jorge; Gianfiglio, Giacinto; Haldemann, Albert; Elfving, Anders; Pinel, Jacques; McCoy, Don

The ExoMars mission will deploy two science elements on the Martian surface: a rover and a small, fixed package. The fixed Humboldt science package, will measure planetary geophysics parameters important for understanding Mars's evolution and habitability, identify possible surface hazards to future human missions, and study the environment. The Rover Pasteur science package will search for signs of past and present life on Mars, and characterise the water and geochemical environment with depth by collecting and analysing subsurface samples down to 2 meters. The very powerful combination of surface mobility and subsurface access to locations where organic molecules may be well-preserved is unique to this mission. ExoMars is currently in Phase B prior to PDR. This presentation will provide an update on the project status, including instrument and technology developments.

Earth System Science at NASA: Teleconnections Between Sea Surface Temperature and Epidemics in Africa

NASA Technical Reports Server (NTRS)

Meeson, Blanche W.

2000-01-01

The research carried out in the Earth Sciences in NASA and at NASA's Goddard Space Flight Center will be the focus of the presentations. In addition, one research project that links sea surface temperature to epidemics in Africa will be highlighted. At GSFC research interests span the full breath of disciplines in Earth Science. Branches and research groups focus on areas as diverse as planetary geomagnetics and atmospheric chemistry. These organizations focus on atmospheric sciences (atmospheric chemistry, climate and radiation, regional processes, atmospheric modeling), hydrological sciences (snow, ice, oceans, and seasonal-to-interannual prediction), terrestrial physics (geology, terrestrial biology, land-atmosphere interactions, geophysics), climate modeling (global warming, greenhouse gases, climate change), on sensor development especially using lidar and microwave technologies, and on information technologies, that enable support of scientific and technical research.

Detecting Fermi-level shifts by Auger electron spectroscopy in Si and GaAs

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

Debehets, J.; Homm, P.; Menghini, M.

In this paper, changes in surface Fermi-level of Si and GaAs, caused by doping and cleaning, are investigated by Auger electron spectroscopy. Based on the Auger voltage contrast, we compared the Auger transition peak energy but with higher accuracy by using a more accurate detector and an improved peak position determination method. For silicon, a peak shift as large as 0.46 eV was detected when comparing a cleaned p-type and n-type wafer, which corresponds rather well with the theoretical difference in Fermi-level. If no cleaning was applied, the peak position did not differ significantly for both wafer types, indicating Fermi-levelmore » pinning in the band gap. For GaAs, peak shifts were detected after cleaning with HF and (NH4)2S-solutions in an inert atmosphere (N2-gas). Although the (NH4)2S-cleaning in N2 is very efficient in removing the oxygen from the surface, the observed Ga- and As-peak shifts are smaller than those obtained after the HF-cleaning. It is shown that the magnitude of the shift is related to the surface composition. After Si-deposition on the (NH4)2S-cleaned surface, the Fermi-level shifts back to a similar position as observed for an as-received wafer, indicating that this combination is not successful in unpinning the Fermi-level of GaAs. This work has been funded by J.D.'s PhD fellowship of the Fund of Scientific Research-Flanders (FWO-V) (Dossier No. 11U4516N). P.H. acknowledges support from Becas Chile-CONICYT. This research was also supported by the FWO Odysseus Program, the Belgian Hercules Stichting with the Project No. Her/08/25 and AKUL/13/19 and the KU Leuven project GOA "Fundamental challenges in Semiconductor Research". The authors would also like to thank Bastiaan Opperdoes and Ludwig Henderix for technical support. The work was supported by the U.S. Department of Energy (USDOE), Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, and performed in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). Battelle operates PNNL for the USDOE under contract DE-AC05-76RL01830.« less

Surface-water quality-assurance plan for the U.S. Geological Survey Washington Water Science Center

USGS Publications Warehouse

Mastin, Mark C.

2016-02-19

This Surface-Water Quality-Assurance Plan documents the standards, policies, and procedures used by the U.S. Geological Survey Washington Water Science Center (WAWSC) for activities related to the collection, processing, storage, analysis, and publication of surface-water data. This plan serves as a guide to all WAWSC personnel involved in surface-water data activities, and changes as the needs and requirements of the WAWSC change. Regular updates to this plan represent an integral part of the quality-assurance process. In the WAWSC, direct oversight and responsibility by the hydrographer(s) assigned to a surface-water station, combined with team approaches in all work efforts, assure highquality data, analyses, reviews, and reports for cooperating agencies and the public.

Science and Reconnaissance from the Europa Clipper Mission Concept: Exploring Europa's Habitability

NASA Astrophysics Data System (ADS)

Senske, D.; Pappalardo, R. T.; Prockter, L. M.; Paczkowski, B.; Vance, S.; Goldstein, B.; Magner, T. J.; Cooke, B.

2014-12-01

Europa is a prime candidate to search for a present-day habitable environment in our solar system. As such, NASA has engaged a Science Definition Team (SDT) to define a strategy to advance our scientific understanding of this icy world with the goal: Explore Europa to investigate its habitability. A mission architecture is defined where a spacecraft in Jupiter orbit would make many close flybys of Europa, concentrating on remote sensing to explore the moon. The spacecraft trajectory would permit ~45 flybys at a variety of latitudes and longitudes, enabling globally distributed regional coverage of Europa's surface. This concept is known as the Europa Clipper. The SDT recommended three science objectives for the Europa Clipper: Ice Shell and Ocean--Characterize the ice shell and any subsurface water, including their heterogeneity, ocean properties, and the nature of surface-ice-ocean exchange; Composition--Understand the habitability of Europa's ocean through composition and chemistry; Geology--Understand the formation of surface features, including sites of recent or current activity, and characterize high science interest localities. The SDT also considered implications of the recent HST detection of plumes at Europa. To feed forward to potential future exploration that could be enabled by a lander, it was deemed that the Clipper should provide the capability to perform reconnaissance. In consultation with NASA Headquarters, the SDT developed a reconnaissance goal: Characterize Scientifically Compelling Sites, and Hazards, for a Potential Future Landed Mission to Europa. This leads to two objectives: Site Safety--Assess the distribution of surface hazards, the load-bearing capacity of the surface, the structure of the subsurface, and the regolith thickness; Science Value--Assess the composition of surface materials, the geologic context of the surface, the potential for geological activity, the proximity of near surface water, and the potential for active upwelling of ocean material. The Clipper concept provides an efficient means to explore Europa and investigate its habitability. Development of the mission concept is ongoing with current studies focusing on spacecraft design trades and refinements, launch vehicle options (EELV and SLS), and power source (MMRTG and solar), to name a few.

Obtaining Magnetic Properties of Meteorites Using Magnetic Scanner

NASA Astrophysics Data System (ADS)

Kletetschka, G.; Nabelek, L.; Mazanec, M.; Simon, K.; Hruba, J.

2015-12-01

Magnetic images of Murchison meteorite's and Chelyabinsk meteorite's thin section have been obtained from magnetic scanning system from Youngwood Science and Engineering (YSE) capable of resolving magnetic anomalies down to 10-3 mT range from about 0.3 mm distance between the probe and meteorite surface (resolution about 0.15 mm). Anomalies were produced repeatedly, each time after application of magnetic field pulse of varying amplitude and constant, normal or reversed, direction. This process resulted in both magnetizing and demagnetizing of the meteorite thin section, while keeping the magnetization vector in the plane of the thin section. Analysis of the magnetic data allows determination of coercivity of remanence (Bcr) for the magnetic sources in situ. Value of Bcr is critical for calculating magnetic forces applicable during missions to asteroids where gravity is compromised. Bcr was estimated by two methods. First method measured varying dipole magnetic field strength produced by each anomaly in the direction of magnetic pulses. Second method measured deflections of the dipole direction from the direction of magnetic pulses (Nabelek et al., 2015). Nabelek, L., Mazanec, M., Kdyr, S., and Kletetschka, G., 2015, Magnetic, in situ, mineral characterization of Chelyabinsk meteorite thin section: Meteoritics & Planetary Science.

Mars Science and Telecommunications Orbiter: Report of the Science Analysis Group, March 2006

NASA Technical Reports Server (NTRS)

Farmer, Crofton Barney; Calvin, Wendy M.; Campbell, Bruce; Fox, Jane; Haberle, Bob; Kasting, Jim; Luhmann, Janet; Nagy, Andy; Allen, Mark; Winterhalter, Daniel

2006-01-01

This document reports the findings of the Mars Science and Telecommunications Orbiter (MSTO) Science Advocacy Group (SAG), which was convened by the Mars Exploration Program Analysis Group (MEPAG) and the Mars Exploration Office at JPL to identify and prioritize areas of Mars atmospheric and surface science objectives for Mars that can be accomplished from orbit on a MSTO like mission.

3DSEM++: Adaptive and intelligent 3D SEM surface reconstruction.

PubMed

Tafti, Ahmad P; Holz, Jessica D; Baghaie, Ahmadreza; Owen, Heather A; He, Max M; Yu, Zeyun

2016-08-01

Structural analysis of microscopic objects is a longstanding topic in several scientific disciplines, such as biological, mechanical, and materials sciences. The scanning electron microscope (SEM), as a promising imaging equipment has been around for decades to determine the surface properties (e.g., compositions or geometries) of specimens by achieving increased magnification, contrast, and resolution greater than one nanometer. Whereas SEM micrographs still remain two-dimensional (2D), many research and educational questions truly require knowledge and facts about their three-dimensional (3D) structures. 3D surface reconstruction from SEM images leads to remarkable understanding of microscopic surfaces, allowing informative and qualitative visualization of the samples being investigated. In this contribution, we integrate several computational technologies including machine learning, contrario methodology, and epipolar geometry to design and develop a novel and efficient method called 3DSEM++ for multi-view 3D SEM surface reconstruction in an adaptive and intelligent fashion. The experiments which have been performed on real and synthetic data assert the approach is able to reach a significant precision to both SEM extrinsic calibration and its 3D surface modeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measurements of the Charged and Neutral Particle Spectra on the Martian Surface with MSL/RAD

NASA Astrophysics Data System (ADS)

Koehler, Jan

The Radiation Assessment Detector (RAD) onboard Mars Science Laboratory’s rover Curiosity is the first ever instrument to measure the energetic particle radiation environment on the surface of Mars. Charged particles are a major component of this environment, both galactic cosmic rays propagating to the Martian surface and secondary particles created by interactions of these cosmic rays with the atoms of the Martian atmosphere and soil. Another important factor for determining the biological impact of the Martian surface radiation is the specific contribution of neutrons, which possess a high biological effectiveness. In contrast to charged particles, neutrons and gamma rays are generally only measured indirectly. Their measurement is the result of a complex convolution of the incident particle spectrum with the measurement process. We apply an inversion method to calculate the gamma/neutron spectra from the RAD neutral particle measurements. Here we show first surface measurements of the Martian particle spectra and compare them to theoretical predictions. Measuring the Martian particle spectra is an essential step for determining the mutagenic influences to past or present life at or beneath the Martian surface as well as the radiation hazard for future human exploration, including the shielding design of a potential habitat.

Incorporating Formative Assessment and Science Content into Elementary Science Methods--A Case Study

ERIC Educational Resources Information Center

Brower, Derek John

2012-01-01

Just as elementary students enter the science classroom with prior knowledge and experiences, so do preservice elementary teachers who enter the science methods classroom. Elementary science methods instructors recognize the challenges associated with preparing teachers for the science classroom. Two of these challenges include overcoming limited…

Lunar Surface Architecture Utilization and Logistics Support Assessment

NASA Astrophysics Data System (ADS)

Bienhoff, Dallas; Findiesen, William; Bayer, Martin; Born, Andrew; McCormick, David

2008-01-01

Crew and equipment utilization and logistics support needs for the point of departure lunar outpost as presented by the NASA Lunar Architecture Team (LAT) and alternative surface architectures were assessed for the first ten years of operation. The lunar surface architectures were evaluated and manifests created for each mission. Distances between Lunar Surface Access Module (LSAM) landing sites and emplacement locations were estimated. Physical characteristics were assigned to each surface element and operational characteristics were assigned to each surface mobility element. Stochastic analysis was conducted to assess probable times to deploy surface elements, conduct exploration excursions, and perform defined crew activities. Crew time is divided into Outpost-related, exploration and science, overhead, and personal activities. Outpost-related time includes element deployment, EVA maintenance, IVA maintenance, and logistics resupply. Exploration and science activities include mapping, geological surveys, science experiment deployment, sample analysis and categorizing, and physiological and biological tests in the lunar environment. Personal activities include sleeping, eating, hygiene, exercising, and time off. Overhead activities include precursor or close-out tasks that must be accomplished but don't fit into the other three categories such as: suit donning and doffing, airlock cycle time, suit cleaning, suit maintenance, post-landing safing actions, and pre-departure preparations. Equipment usage time, spares, maintenance actions, and Outpost consumables are also estimated to provide input into logistics support planning. Results are normalized relative to the NASA LAT point of departure lunar surface architecture.

Science Support Room Operations During Desert RATS 2009

NASA Technical Reports Server (NTRS)

Lofgren, G. E.; Horz, F.; Bell, M. S.; Cohen, B. A.; Eppler,D. B.; Evans, C. a.; Hodges, K. V.; Hynek, B. M.; Gruener, J. E.; Kring, D. A.;

Planetary science: A 5-micron-bright spot on Titan: Evidence for surface diversity

USGS Publications Warehouse

Barnes, J.W.; Brown, R.H.; Turtle, E.P.; McEwen, A.S.; Lorenz, R.D.; Janssen, M.; Schaller, E.L.; Brown, M.E.; Buratti, B.J.; Sotin, Christophe; Griffith, C.; Clark, R.; Perry, J.; Fussner, S.; Barbara, J.; West, R.; Elachi, C.; Bouchez, A.H.; Roe, H.G.; Baines, K.H.; Bellucci, G.; Bibring, J.-P.; Capaccioni, F.; Cerroni, P.; Combes, M.; Coradini, A.; Cruikshank, D.P.; Drossart, P.; Formisano, V.; Jaumann, R.; Langevin, Y.; Matson, D.L.; McCord, T.B.; Nicholson, P.D.; Sicardy, B.

2005-01-01

Observations from the Cassini Visual and Infrared Mapping Spectrometer show an anomalously bright spot on Titan located at 80??W and 20??S. This area is bright in reflected tight at all observed wavelengths, but is most noticeable at 5 microns. The spot is associated with a surface albedo feature identified in images taken by the Cassini Imaging Science Subsystem. We discuss various hypotheses about the source of the spot, reaching the conclusion that the spot is probably due to variation in surface composition, perhaps associated with recent geophysical phenomena.

Barium as a potential indicator of phosphorus in agricultural runoff.

PubMed

Ahlgren, Joakim; Djodjic, Faruk; Wallin, Mats

2012-01-01

In many catchments, anthropogenic input of contaminants, and in particular phosphorus (P), into surface water is a mixture of agricultural and sewage runoff. Knowledge about the relative contribution from each of these sources is vital for mitigation of major environmental problems such as eutrophication. In this study, we investigated whether the distribution of trace elements in surface waters can be used to trace the contamination source. Water from three groups of streams was investigated: streams influenced only by agricultural runoff, streams influenced mainly by sewage runoff, and reference streams. Samples were collected at different flow regimes and times of year and analyzed for 62 elements using ICP-MS. Our results show that there are significant differences between the anthropogenic sources affecting the streams in terms of total element composition and individual elements, indicating that the method has the potential to trace anthropogenic impact on surface waters. The elements that show significant differences between sources are strontium (p < 0.001), calcium (p < 0.004), potassium (p < 0.001), magnesium (p < 0.001), boron (p < 0.001), rhodium (p = 0.001), and barium (p < 0.001). According to this study, barium shows the greatest potential as a tracer for an individual source of anthropogenic input to surface waters. We observed a strong relationship between barium and total P in the investigated samples (R(2) = 0.78), which could potentially be used to apportion anthropogenic sources of P and thereby facilitate targeting of mitigation practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Lunar and Planetary Science XXXV: Outer Solar System

NASA Technical Reports Server (NTRS)

2004-01-01

The session 'Outer Solar System" inlcuded:Monte Carlo Modeling of [O I] 630 nm Auroral Emission on Io; The Detection of Iron Sulfide on Io; Io and Loki in 2003 as Seen from the Infrared Telescope Facility Using Mutual Satellite and Jupiter Occultations; Mapping of the Zamama-Thor Region of Io; First Solar System Results of the Spitzer Space Telescope; Mapping the Surface of Pluto with the Hubble Space Telescope; Experimental Study on Fischer-Tropsch Catalysis in the Circum-Saturnian Subnebula; New High-Pressure Phases of Ammonia Dihydrate; Gas Hydrate Stability at Low Temperatures and High Pressures with Applications to Mars and Europa; Laboratory UV Photolysis of Planetary Ice Analogs Containing H2O + CO2 (1:1); The OH Stretch Infrared Band of Water Ice and Its Temperature and Radiation Dependence; Band Position Variations in Reflectance Spectra of the Jovian Satellite Ganymede; Comparison of Porosity and Radar Models for Europa s Near Surface; Combined Effects of Diurnal and Nonsynchronous Surface Stresses on Europa; Europa s Northern Trailing Hemisphere: Lineament Stratigraphic Framework; Europa at the Highest Resolution: Implications for Surface Processes and Landing Sites; Comparison of Methods to Determine Furrow System Centers on Ganymede and Callisto; Resurfacing of Ganymede by Liquid-Water Volcanism; Layered Ejecta Craters on Ganymede: Comparisons with Martian Analogs; Evaluation of the Possible Presence of CO2-Clathrates in Europa s Icy Shell or Seafloor; Geosciences at Jupiter s Icy Moons: The Midas Touch; Planetary Remote Sensing Science Enabled by MIDAS (Multiple Instrument Distributed Aperture Sensor); and In Situ Surveying of Saturn s Rings.

A surface science compatible epifluorescence microscope for inspection of samples under ultra high vacuum and cryogenic conditions.

PubMed

Marquardt, Christian; Paulheim, Alexander; Rohbohm, Nils; Merkel, Rudolf; Sokolowski, Moritz

2017-08-01

We modified an epi-illumination light microscope and mounted it on an ultra high vacuum chamber for investigating samples used in a surface science experiment. For easy access and bake out, all optical components are placed outside the vacuum and the sample is imaged through a glass window. The microscope can be operated in reflection brightfield or epifluorescence mode to image the sample surface or fluorescent dye molecules adsorbed on it. The homemade sample mounting was made compatible for the use under the microscope; sample temperatures as low as 6 K can be achieved. The performance of the microscope is demonstrated on two model samples: Brightfield-images of a well-prepared Ag(100) surface show a macroscopic corrugation of the surface, although low energy electron diffraction data indicate a highly ordered crystalline surface. The surface shows macroscopic protrusions with flat regions, about 20-200 μm in diameter, in between. Fluorescence images of diluted 3,4,9,10-perylene tetracarboxylicacid dianhydride (PTCDA) molecules adsorbed on an ultrathin epitaxial KCl film on the Ag(100) surface show a shading effect at surface protrusions due to an inclined angle of incidence of the PTCDA beam during deposition. For some preparations, the distribution of the fluorescence intensity is inhomogeneous and shows a dense network of bright patches about 5 μm in diameter related to the macroscopic corrugation of the surface. We propose that such a light microscope can aid many surface science experiments, especially those dealing with epitaxial growth or fluorescent materials.

A dynamic subgrid-scale parameterization of the effective wall stress in atmospheric boundary layer flows over multiscale, fractal-like surfaces

NASA Astrophysics Data System (ADS)

Anderson, William; Meneveau, Charles

2010-05-01

A dynamic subgrid-scale (SGS) parameterization for hydrodynamic surface roughness is developed for large-eddy simulation (LES) of atmospheric boundary layer (ABL) flow over multiscale, fractal-like surfaces. The model consists of two parts. First, a baseline model represents surface roughness at horizontal length-scales that can be resolved in the LES. This model takes the form of a force using a prescribed drag coefficient. This approach is tested in LES of flow over cubes, wavy surfaces, and ellipsoidal roughness elements for which there are detailed experimental data available. Secondly, a dynamic roughness model is built, accounting for SGS surface details of finer resolution than the LES grid width. The SGS boundary condition is based on the logarithmic law of the wall, where the unresolved roughness of the surface is modeled as the product of local root-mean-square (RMS) of the unresolved surface height and an unknown dimensionless model coefficient. This coefficient is evaluated dynamically by comparing the plane-average hydrodynamic drag at two resolutions (grid- and test-filter scale, Germano et al., 1991). The new model is tested on surfaces generated through superposition of random-phase Fourier modes with prescribed, power-law surface-height spectra. The results show that the method yields convergent results and correct trends. Limitations and further challenges are highlighted. Supported by the US National Science Foundation (EAR-0609690).

Automatic Detection of Changes on Mars Surface from High-Resolution Orbital Images

NASA Astrophysics Data System (ADS)

Sidiropoulos, Panagiotis; Muller, Jan-Peter

2017-04-01

Over the last 40 years Mars has been extensively mapped by several NASA and ESA orbital missions, generating a large image dataset comprised of approximately 500,000 high-resolution images (of <100m resolution). The overall area mapped from orbital imagery is approximately 6 times the overall surface of Mars [1]. The multi-temporal coverage of Martian surface allows a visual inspection of the surface to identify dynamic phenomena, i.e. surface features that change over time, such as slope streaks [2], recurring slope lineae [3], new impact craters [4], etc. However, visual inspection for change detection is a limited approach, since it requires extensive use of human resources, which is very difficult to achieve when dealing with a rapidly increasing volume of data. Although citizen science can be employed for training and verification it is unsuitable for planetwide systematic change detection. In this work, we introduce a novel approach in planetary image change detection, which involves a batch-mode automatic change detection pipeline that identifies regions that have changed. This is tested in anger, on tens of thousands of high-resolution images over the MC11 quadrangle [5], acquired by CTX, HRSC, THEMIS-VIS and MOC-NA instruments [1]. We will present results which indicate a substantial level of activity in this region of Mars, including instances of dynamic natural phenomena that haven't been cataloged in the planetary science literature before. We will demonstrate the potential and usefulness of such an automatic approach in planetary science change detection. Acknowledgments: The research leading to these results has received funding from the STFC "MSSL Consolidated Grant" ST/K000977/1 and partial support from the European Union's Seventh Framework Programme (FP7/2007-2013) under iMars grant agreement n° 607379. References: [1] P. Sidiropoulos and J. - P. Muller (2015) On the status of orbital high-resolution repeat imaging of Mars for the observation of dynamic surface processes. Planetary and Space Science, 117: 207-222. [2] O. Aharonson, et al. (2003) Slope streak formation and dust deposition rates on Mars. Journal of Geophysical Research: Planets, 108(E12):5138 [3] A. McEwen, et al. (2011) Seasonal flows on warm martian slopes. Science, 333 (6043): 740-743. [4] S. Byrne, et al. (2009) Distribution of mid-latitude ground ice on mars from new impact craters. Science, 325(5948):1674-1676. [5] K. Gwinner, et al (2016) The High Resolution Stereo Camera (HRSC) of Mars Express and its approach to science analysis and mapping for Mars and its satellites. Planetary and Space Science, 126: 93-138.

Label-Enhanced Surface Plasmon Resonance: A New Concept for Improved Performance in Optical Biosensor Analysis

PubMed Central

Granqvist, Niko; Hanning, Anders; Eng, Lars; Tuppurainen, Jussi; Viitala, Tapani

2013-01-01

Surface plasmon resonance (SPR) is a well-established optical biosensor technology with many proven applications in the study of molecular interactions as well as in surface and material science. SPR is usually applied in the label-free mode which may be advantageous in cases where the presence of a label may potentially interfere with the studied interactions per se. However, the fundamental challenges of label-free SPR in terms of limited sensitivity and specificity are well known. Here we present a new concept called label-enhanced SPR, which is based on utilizing strongly absorbing dye molecules in combination with the evaluation of the full shape of the SPR curve, whereby the sensitivity as well as the specificity of SPR is significantly improved. The performance of the new label-enhanced SPR method was demonstrated by two simple model assays: a small molecule assay and a DNA hybridization assay. The small molecule assay was used to demonstrate the sensitivity enhancement of the method, and how competitive assays can be used for relative affinity determination. The DNA assay was used to demonstrate the selectivity of the assay, and the capabilities in eliminating noise from bulk liquid composition variations. PMID:24217357

Methods for Automating Analysis of Glacier Morphology for Regional Modelling: Centerlines, Extensions, and Elevation Bands

NASA Astrophysics Data System (ADS)

Viger, R. J.; Van Beusekom, A. E.

2016-12-01

The treatment of glaciers in modeling requires information about their shape and extent. This presentation discusses new methods and their application in a new glacier-capable variant of the USGS PRMS model, a physically-based, spatially distributed daily time-step model designed to simulate the runoff and evolution of glaciers through time. In addition to developing parameters describing PRMS land surfaces (hydrologic response units, HRUs), several of the analyses and products are likely of interest to cryospheric science community in general. The first method is a (fully automated) variation of logic previously presented in the literature for definition of the glacier centerline. Given that the surface of a glacier might be convex, using traditional topographic analyses based on a DEM to trace a path down the glacier is not reliable. Instead a path is derived based on a cost function. Although only a single path is presented in our results, the method can be easily modified to delineate a branched network of centerlines for each glacier. The second method extends the glacier terminus downslope by an arbitrary distance, according to local surface topography. This product is can be used to explore possible, if unlikely, scenarios under which glacier area grows. More usefully, this method can be used to approximate glacier extents from previous years without needing historical imagery. The final method presents an approach for segmenting the glacier into altitude-based HRUs. Successful integration of this information with traditional approaches for discretizing the non-glacierized portions of a basin requires several additional steps. These include synthesizing the glacier centerline network with one developed with a traditional DEM analysis, ensuring that flow can be routed under and beyond glaciers to a basin outlet. Results are presented based on analysis of the Copper River Basin, Alaska.

Research methods from social science can contribute much to the health sciences.

PubMed

Wensing, Michel

2008-06-01

Research methods from social science, such as social network analysis, random coefficient modeling, and advanced measurement techniques, can contribute much to the health sciences. There is, however, a slow rate of transmission of social science methodology into the health sciences. This paper identifies some of the barriers for adoption and proposes ideas for the future. Commentary. Contributions of social science to the health sciences are not always recognized as such. It may help if the professional profile of social science in the health sciences would be higher and if its focus would be more on making useful predictions. Clinical epidemiologists may assume that their discipline includes all relevant methods and that social science is largely based on qualitative research. These perceptions need to be challenged in order to widen the scope of clinical epidemiology and include relevant methods from other sciences. New methods help to ask new research questions and to provide better to old questions. This paper has sketched challenges for both social science researchers and clinical epidemiologists.

Urban heat island research from 1991 to 2015: a bibliometric analysis

NASA Astrophysics Data System (ADS)

Huang, Qunfang; Lu, Yuqi

2018-02-01

A bibliometric analysis based on the Science Citation Index-Expanded (SCI-Expanded) database from the Web of Science was performed to review urban heat island (UHI) research from 1991 to 2015 and statistically assess its developments, trends, and directions. In total, 1822 papers published in 352 journals over the past 25 years were analyzed for scientific output; citations; subject categories; major journals; outstanding keywords; and leading countries, institutions, authors, and research collaborations. The number of UHI-related publications has continuously increased since 1991. Meteorology atmospheric sciences, environmental sciences, and construction building technology were the three most frequent subject categories. Building and Environment, International Journal of Climatology, and Theoretical and Applied Climatology were the three most popular publishing journals. The USA and China were the two leading countries in UHI research, contributing 49.56% of the total articles. Chinese Academy of Science, Arizona State University, and China Meteorological Administration published the most UHI articles. Weng QH and Santamouris M were the two most prolific authors. Author keywords were classified into four major groups: (1) research methods and indicators, e.g., remote sensing, field measurement, and models; (2) generation factors, e.g., impervious urban surfaces, urban geometry, waste heat, vegetation, and pollutants; (3) environmental effects, e.g., urban climate, heat wave, ecology, and pollution; and (4) mitigation and adaption strategies, e.g., roof technology cooling, reflective cooling, vegetation cooling, and urban geometry cooling. A comparative analysis of popular issues revealed that UHI determination (intensity, heat source, supporting techniques) remains the central topic, whereas UHI impacts and mitigation strategies are becoming the popular issues that will receive increasing scientific attention in the future. Modeling will continue to be the leading research method, and remote sensing will be used more widely. Additionally, a combination of remote sensing and field measurements with models is expected.

Quality-assurance plan for groundwater activities, U.S. Geological Survey, Washington Water Science Center

USGS Publications Warehouse

Kozar, Mark D.; Kahle, Sue C.

2013-01-01

This report documents the standard procedures, policies, and field methods used by the U.S. Geological Survey’s (USGS) Washington Water Science Center staff for activities related to the collection, processing, analysis, storage, and publication of groundwater data. This groundwater quality-assurance plan changes through time to accommodate new methods and requirements developed by the Washington Water Science Center and the USGS Office of Groundwater. The plan is based largely on requirements and guidelines provided by the USGS Office of Groundwater, or the USGS Water Mission Area. Regular updates to this plan represent an integral part of the quality-assurance process. Because numerous policy memoranda have been issued by the Office of Groundwater since the previous groundwater quality assurance plan was written, this report is a substantial revision of the previous report, supplants it, and contains significant additional policies not covered in the previous report. This updated plan includes information related to the organization and responsibilities of USGS Washington Water Science Center staff, training, safety, project proposal development, project review procedures, data collection activities, data processing activities, report review procedures, and archiving of field data and interpretative information pertaining to groundwater flow models, borehole aquifer tests, and aquifer tests. Important updates from the previous groundwater quality assurance plan include: (1) procedures for documenting and archiving of groundwater flow models; (2) revisions to procedures and policies for the creation of sites in the Groundwater Site Inventory database; (3) adoption of new water-level forms to be used within the USGS Washington Water Science Center; (4) procedures for future creation of borehole geophysics, surface geophysics, and aquifer-test archives; and (5) use of the USGS Multi Optional Network Key Entry System software for entry of routine water-level data collected as part of long-term water-level monitoring networks.

Physics-Based Imaging Methods for Terahertz Nondestructive Evaluation Applications

NASA Astrophysics Data System (ADS)

Kniffin, Gabriel Paul

Lying between the microwave and far infrared (IR) regions, the "terahertz gap" is a relatively unexplored frequency band in the electromagnetic spectrum that exhibits a unique combination of properties from its neighbors. Like in IR, many materials have characteristic absorption spectra in the terahertz (THz) band, facilitating the spectroscopic "fingerprinting" of compounds such as drugs and explosives. In addition, non-polar dielectric materials such as clothing, paper, and plastic are transparent to THz, just as they are to microwaves and millimeter waves. These factors, combined with sub-millimeter wavelengths and non-ionizing energy levels, makes sensing in the THz band uniquely suited for many NDE applications. In a typical nondestructive test, the objective is to detect a feature of interest within the object and provide an accurate estimate of some geometrical property of the feature. Notable examples include the thickness of a pharmaceutical tablet coating layer or the 3D location, size, and shape of a flaw or defect in an integrated circuit. While the material properties of the object under test are often tightly controlled and are generally known a priori, many objects of interest exhibit irregular surface topographies such as varying degrees of curvature over the extent of their surfaces. Common THz pulsed imaging (TPI) methods originally developed for objects with planar surfaces have been adapted for objects with curved surfaces through use of mechanical scanning procedures in which measurements are taken at normal incidence over the extent of the surface. While effective, these methods often require expensive robotic arm assemblies, the cost and complexity of which would likely be prohibitive should a large volume of tests be needed to be carried out on a production line. This work presents a robust and efficient physics-based image processing approach based on the mature field of parabolic equation methods, common to undersea acoustics, seismology, and other areas of science and engineering. The method allows the generation of accurate 3D THz tomographic images of objects with irregular, non-planar surfaces using a simple planar scan geometry, thereby facilitating the integration of 3D THz imaging into mainstream NDE use.

Screening Test for Shed Skin Cells by Measuring the Ratio of Human DNA to Staphylococcus epidermidis DNA.

PubMed

Nakanishi, Hiroaki; Ohmori, Takeshi; Hara, Masaaki; Takahashi, Shirushi; Kurosu, Akira; Takada, Aya; Saito, Kazuyuki

2016-05-01

A novel screening method for shed skin cells by detecting Staphylococcus epidermidis (S. epidermidis), which is a resident bacterium on skin, was developed. Staphylococcus epidermidis was detected using real-time PCR. Staphylococcus epidermidis was detected in all 20 human skin surface samples. Although not present in blood and urine samples, S. epidermidis was detected in 6 of 20 saliva samples, and 5 of 18 semen samples. The ratio of human DNA to S. epidermidisDNA was significantly smaller in human skin surface samples than in saliva and semen samples in which S. epidermidis was detected. Therefore, although skin cells could not be identified by detecting only S. epidermidis, they could be distinguished by measuring the S. epidermidis to human DNA ratio. This method could be applied to casework touch samples, which suggests that it is useful for screening whether skin cells and human DNA are present on potential evidentiary touch samples. © 2016 American Academy of Forensic Sciences.

Revisiting 30 years of biofunctionalization and surface chemistry of inorganic nanoparticles for nanomedicine

PubMed Central

Conde, João; Dias, Jorge T.; Grazú, Valeria; Moros, Maria; Baptista, Pedro V.; de la Fuente, Jesus M.

2014-01-01

In the last 30 years we have assisted to a massive advance of nanomaterials in material science. Nanomaterials and structures, in addition to their small size, have properties that differ from those of larger bulk materials, making them ideal for a host of novel applications. The spread of nanotechnology in the last years has been due to the improvement of synthesis and characterization methods on the nanoscale, a field rich in new physical phenomena and synthetic opportunities. In fact, the development of functional nanoparticles has progressed exponentially over the past two decades. This work aims to extensively review 30 years of different strategies of surface modification and functionalization of noble metal (gold) nanoparticles, magnetic nanocrystals and semiconductor nanoparticles, such as quantum dots. The aim of this review is not only to provide in-depth insights into the different biofunctionalization and characterization methods, but also to give an overview of possibilities and limitations of the available nanoparticles. PMID:25077142

Plasma-assisted interface engineering of boron nitride nanostructure films.

PubMed

Pakdel, Amir; Bando, Yoshio; Golberg, Dmitri

2014-10-28

Today many aspects of science and technology are progressing into the nanoscale realm where surfaces and interfaces are intrinsically important in determining properties and performances of materials and devices. One familiar phenomenon in which interfacial interactions play a major role is the wetting of solids. In this work we use a facile one-step plasma method to control the wettability of boron nitride (BN) nanostructure films via covalent chemical functionalization, while their surface morphology remains intact. By tailoring the concentration of grafted hydroxyl groups, superhydrophilic, hydrophilic, and hydrophobic patterns are created on the initially superhydrophobic BN nanosheet and nanotube films. Moreover, by introducing a gradient of the functional groups, directional liquid spreading toward increasing [OH] content is achieved on the films. The resulting insights are meant to illustrate great potentials of this method to tailor wettability of ceramic films, control liquid flow patterns for engineering applications such as microfluidics and biosensing, and improve the interfacial contact and adhesion in nanocomposite materials.

Direct analyte-probed nanoextraction coupled to nanospray ionization-mass spectrometry of drug residues from latent fingerprints.

PubMed

Clemons, Kristina; Wiley, Rachel; Waverka, Kristin; Fox, James; Dziekonski, Eric; Verbeck, Guido F

2013-07-01

Here, we present a method of extracting drug residues from fingerprints via Direct Analyte-Probed Nanoextraction coupled to nanospray ionization-mass spectrometry (DAPNe-NSI-MS). This instrumental technique provides higher selectivity and lower detection limits over current methods, greatly reducing sample preparation, and does not compromise the integrity of latent fingerprints. This coupled to Raman microscopy is an advantageous supplement for location and identification of trace particles. DAPNe uses a nanomanipulator for extraction and differing microscopies for localization of chemicals of interest. A capillary tip with solvent of choice is placed in a nanopositioner. The surface to be analyzed is placed under a microscope, and a particle of interest is located. Using a pressure injector, the solvent is injected onto the surface where it dissolves the analyte, and then extracted back into the capillary tip. The solution is then directly analyzed via NSI-MS. Analyses of caffeine, cocaine, crystal methamphetamine, and ecstasy have been performed successfully. © 2013 American Academy of Forensic Sciences.

Surface Chemistry of CWAs for Decon Enabling Sciences

DTIC Science & Technology

2014-11-04

representing the formation of a hydrogen-bonded mode. Characteristic modes of the sarin molecule itself are also observed. These experimental results show...Triangle Park, NC 27709-2211 surface science, CWA, uptake, decomposition, decontamination, filtration , XPS, FTIR, TPD, MS, UHV REPORT DOCUMENTATION PAGE 11...Karwacki, Team Leader CBR Filtration Research and Technology Directorate at ECBC. Through this collaboration, we have established a facility for the study

JPRS Report, Science & Technology, USSR: Life Sciences.

DTIC Science & Technology

1988-02-12

polypeptide chain frag- ments inside protein membranes or on their surfaces using bacteriorhodopsin as the test object. Purple membranes, partially...outside the membrane or close to its surface . A model was developed from these data which involved folding of certain regions of bacteriorhodopsin...into hepatic endothelial and Kupffer cells. These findings point to the putative usefulness of the PLP approach in gene therapy. Figures h

Applications of surface analytical techniques in Earth Sciences

NASA Astrophysics Data System (ADS)

Qian, Gujie; Li, Yubiao; Gerson, Andrea R.

2015-03-01

This review covers a wide range of surface analytical techniques: X-ray photoelectron spectroscopy (XPS), scanning photoelectron microscopy (SPEM), photoemission electron microscopy (PEEM), dynamic and static secondary ion mass spectroscopy (SIMS), electron backscatter diffraction (EBSD), atomic force microscopy (AFM). Others that are relatively less widely used but are also important to the Earth Sciences are also included: Auger electron spectroscopy (AES), low energy electron diffraction (LEED) and scanning tunnelling microscopy (STM). All these techniques probe only the very top sample surface layers (sub-nm to several tens of nm). In addition, we also present several other techniques i.e. Raman microspectroscopy, reflection infrared (IR) microspectroscopy and quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN) that penetrate deeper into the sample, up to several μm, as all of them are fundamental analytical tools for the Earth Sciences. Grazing incidence synchrotron techniques, sensitive to surface measurements, are also briefly introduced at the end of this review. (Scanning) transmission electron microscopy (TEM/STEM) is a special case that can be applied to characterisation of mineralogical and geological sample surfaces. Since TEM/STEM is such an important technique for Earth Scientists, we have also included it to draw attention to the capability of TEM/STEM applied as a surface-equivalent tool. While this review presents most of the important techniques for the Earth Sciences, it is not an all-inclusive bibliography of those analytical techniques. Instead, for each technique that is discussed, we first give a very brief introduction about its principle and background, followed by a short section on approaches to sample preparation that are important for researchers to appreciate prior to the actual sample analysis. We then use examples from publications (and also some of our known unpublished results) within the Earth Sciences to show how each technique is applied and used to obtain specific information and to resolve real problems, which forms the central theme of this review. Although this review focuses on applications of these techniques to study mineralogical and geological samples, we also anticipate that researchers from other research areas such as Material and Environmental Sciences may benefit from this review.

Overview of Mars Science Laboratory (MSL) Environmental Program

NASA Technical Reports Server (NTRS)

Forgave, John C.; Man, Kin F.; Hoffman, Alan R.

2006-01-01

This viewgraph presentation is an overview of the Mars Science Laboratory (MSL) program. The engineering objectives of the program are to create a Mobile Science Laboratory capable of one Mars Year surface operational lifetime (670 Martian sols = 687 Earth days). It will be able to land and operation over wide range of latitudes, altitudes and seasons It must have controlled propulsive landing and demonstrate improved landing precision via guided entry The general science objectives are to perform science that will focus on Mars habitability, perform next generation analytical laboratory science investigations, perform remote sensing/contact investigations and carry a suite of environmental monitoring instruments. Specific scientific objectives of the MSL are: (1) Characterization of geological features, contributing to deciphering geological history and the processes that have modified rocks and regolith, including the role of water. (2) Determination of the mineralogy and chemical composition (including an inventory of elements such as C, H, N, O, P, S, etc. known to be building blocks for life) of surface and near-surface materials. (3) Determination of energy sources that could be used to sustain biological processes. (4) Characterization of organic compounds and potential biomarkers in representative regolith, rocks, and ices. (5) Determination the stable isotopic and noble gas composition of the present-day bulk atmosphere. (6) Identification potential bio-signatures (chemical, textural, isotopic) in rocks and regolith. (7) Characterization of the broad spectrum of surface radiation, including galactic cosmic radiation, solar proton events, and secondary neutrons. (8) Characterization of the local environment, including basic meteorology, the state and cycling of water and C02, and the near-surface distribution of hydrogen. Several views of the planned MSL and the rover are shown. The MSL environmental program is to: (1) Ensure the flight hardware design is capable of surviving all the environments throughout its mission life time, including ground, transportation, launch, cruise, entry decent and landing (EDL) and surface operation environments. (2) Verify environmental testing and analysis have adequately validated the flight hardware's ability to withstand all natural, self-induced, and mission-activity-induced environments. The planned tests to ascertain the capability of the MSL to perform as desired are reviewed.

Surface Phonons and Polaritons.

DTIC Science & Technology

1976-01-01

by M. Balkaneki ( Flammarion Sciences , Paris , 1978) , p. 298 . —-——.——~~~~~~~~‘-,--—-—— - r r ~~~~~~~~~~~~~~ ~~-~r - wwr~~~~~~~~~~~ wr...inivasan, in Lattice Dynamics Edited by K. -~ Balkanski ( Flammarion Sciences , Paris , 1978), p. 305. 46. I. K. Lifshitz and L. U. Rosenzweig , Zh. Ekap...Lattice Dynamics,” Ed. M. Balkanski ( Flammarion Sciences, Paris, 1978), p. 280. 7. L. Dobrzynski and J . Friedel, Surface Sc 12, 469 (1968). 8. L

Response Surface Methodology Using a Fullest Balanced Model: A Re-Analysis of a Dataset in the Korean Journal for Food Science of Animal Resources.

PubMed

Rheem, Sungsue; Rheem, Insoo; Oh, Sejong

2017-01-01

Response surface methodology (RSM) is a useful set of statistical techniques for modeling and optimizing responses in research studies of food science. In the analysis of response surface data, a second-order polynomial regression model is usually used. However, sometimes we encounter situations where the fit of the second-order model is poor. If the model fitted to the data has a poor fit including a lack of fit, the modeling and optimization results might not be accurate. In such a case, using a fullest balanced model, which has no lack of fit, can fix such problem, enhancing the accuracy of the response surface modeling and optimization. This article presents how to develop and use such a model for the better modeling and optimizing of the response through an illustrative re-analysis of a dataset in Park et al. (2014) published in the Korean Journal for Food Science of Animal Resources .

Lunar BRDF Correction of Suomi-NPP VIIRS Day/Night Band Time Series Product

NASA Astrophysics Data System (ADS)

Wang, Z.; Roman, M. O.; Kalb, V.; Stokes, E.; Miller, S. D.

2015-12-01

Since the first-light images from the Suomi-NPP VIIRS low-light visible Day/Night Band (DNB) sensor were received in November 2011, the NASA Suomi-NPP Land Science Investigator Processing System (SIPS) has focused on evaluating this new capability for quantitative science applications, as well as developing and testing refined algorithms to meet operational and Land science research needs. While many promising DNB applications have been developed since the Suomi-NPP launch, most studies to-date have been limited by the traditional qualitative image display and spatial-temporal aggregated statistical analysis methods inherent in current heritage algorithms. This has resulted in strong interest for a new generation of science-quality products that can be used to monitor both the magnitude and signature of nighttime phenomena and anthropogenic sources of light emissions. In one particular case study, Román and Stokes (2015) demonstrated that tracking daily dynamic DNB radiances can provide valuable information about the character of the human activities and behaviors that influence energy, consumption, and vulnerability. Here we develop and evaluate a new suite of DNB science-quality algorithms that can exclude a primary source of background noise: i.e., the Lunar BRDF (Bidirectional Reflectance Distribution Function) effect. Every day, the operational NASA Land SIPS DNB algorithm makes use of 16 days worth of DNB-derived surface reflectances (SR) (based on the heritage MODIS SR algorithm) and a semiempirical kernel-driven bidirectional reflectance model to determine a global set of parameters describing the BRDF of the land surface. The nighttime period of interest is heavily weighted as a function of observation coverage. These gridded parameters, combined with Miller and Turner's [2009] top-of-atmosphere spectral irradiance model, are then used to determine the DNB's lunar radiance contribution at any point in time and under specific illumination conditions.

Thermodynamic forces in coarse-grained simulations

NASA Astrophysics Data System (ADS)

Noid, William

Atomically detailed molecular dynamics simulations have profoundly advanced our understanding of the structure and interactions in soft condensed phases. Nevertheless, despite dramatic advances in the methodology and resources for simulating atomically detailed models, low-resolution coarse-grained (CG) models play a central and rapidly growing role in science. CG models not only empower researchers to investigate phenomena beyond the scope of atomically detailed simulations, but also to precisely tailor models for specific phenomena. However, in contrast to atomically detailed simulations, which evolve on a potential energy surface, CG simulations should evolve on a free energy surface. Therefore, the forces in CG models should reflect the thermodynamic information that has been eliminated from the CG configuration space. As a consequence of these thermodynamic forces, CG models often demonstrate limited transferability and, moreover, rarely provide an accurate description of both structural and thermodynamic properties. In this talk, I will present a framework that clarifies the origin and impact of these thermodynamic forces. Additionally, I will present computational methods for quantifying these forces and incorporating their effects into CG MD simulations. As time allows, I will demonstrate applications of this framework for liquids, polymers, and interfaces. We gratefully acknowledge the support of the National Science Foundation via CHE 1565631.

Europa Geophysical Explorer Mission Concept Studies

NASA Astrophysics Data System (ADS)

Green, J. R.; Abelson, R. D.; Smythe, W.; Spilker, T. R.; Shirley, J. H.

2005-12-01

The Strategic Road Map for Solar System Exploration recommended in May 2005 that NASA implement the Europa Geophysical Explorer (EGE) as a Flagship mission early in the next decade. This supported the recommendations of the National Research Council's Solar System Decadal Survey and the priorities of the Outer Planets Assessment Group (OPAG). The Europa Geophysical Explorer would: (1) Characterize tidal deformations of the surface of Europa and surface geology, to confirm the presence of a subsurface ocean; (2) Measure the three-dimensional structure and distribution of subsurface water; and (3) Determine surface composition from orbit, and potentially, prebiotic chemistry, in situ. As the next step in Europa exploration, EGE would build on previous Europa Orbiter concepts, for example, the original Europa Orbiter and the Jupiter Icy Moons Orbiter (JIMO). As well, a new set of draft Level One Requirements, provided by NASA sponsors, guided the concept development. These requirements included: (1) Earliest Launch: 2012; (2) Launch Vehicle: Delta IV Heavy or Atlas V; (3) Primary Propulsion: Chemical; (4) Power: Radioisotope Power System (RPS); (4) Orbital Mission: 30 days minimum to meet orbital science objectives; and (5) Earth Gravity Assists: Allowed. The previous studies and the new requirements contributed to the development of several scientifically capable and relatively mass-rich mission options. In particular, Earth-gravity assists (EGA) were allowed, resulting in an increased delivered mass. As well, there have been advances in radiation-hardened components and subsystems, due to the investments from the X-2000 technology program and JIMO. Finally, developments in radioisotope power systems (RPS) have added to the capability and reliability of the mission. Several potential mission options were explored using a variety of trade study methods, ranging from the work of the JPL EGE Team of scientists and engineers in partnership with the OPAG Europa Sub-Group Advisory Team, JPL's Team X, and parametric modeling and simulation tools. We explored the system impacts of selecting different science payloads, power systems, mission durations, Deep Space Network (DSN) architectures, trajectory types, and launch vehicles. The comparisons show that there are feasible mission options that provide potentially available mass for enhanced spacecraft margins and science return, in addition to a 150-kg orbiter science instrument payload mass. This presentation describes high-priority science objectives for an EGE mission, results of the recent studies, and implementation options.

Teaching climate science within the transdisciplinary framework of Critical Zone science

NASA Astrophysics Data System (ADS)

White, T. S.; Wymore, A.; Dere, A. L. D.; Washburne, J. C.; Hoffman, A.; Conklin, M. H.

2017-12-01

During the past decade a new realm of Earth surface and environmental science has evolved, Critical Zone (CZ) science. The CZ is the outermost layer of the continents spanning from the top of the vegetation canopy down to the bottom of the fresh groundwater zone. CZ science integrates across many disciplines and cross cutting concepts, including climate science, and much progress has been made by the CZ community to develop educational curricula - descriptions of the climate science aspects of two of those follows. An interdisciplinary team of CZ scientists developed an undergraduate course entitled "Introduction to CZ science". The semester-long course is modular, has been tested in multiple university settings, and the content is available online. A primary tenet of the course is that to achieve environmental sustainability, society must understand the CZ system, the natural processes and services of the CZ that are of value to society, and how those processes operate with and without the presence of humanity. A fundamental concept in the course is that the fluxes of water, C, energy, reactive gases, particulates and nutrients throughout the CZ are directly and indirectly related to climatic phenomenon and processes. Units on land-atmosphere interactions, weathering, and water budgets highlight the connection between CZ science and climate science, and are augmented by learning activities that consider climate links to soil development and landscape evolution. An online open-source course entitled "Earth 530: Earth Surface Processes in the Critical Zone'" is offered as part of The Pennsylvania State University's Masters of Education in Earth Sciences program. The course is designed to educate teachers interested in incorporating CZ science into their classrooms, though it is usable by anyone with a basic understanding of Earth surface and environmental science. Earth 530 introduces students to knowledge needed to understand the CZ through integration of transdisciplinary science. The course structure is organized into seven units; those covering the atmosphere and climate, water, and landforms, are of particular interest to this session. Earth 530 is unique from the introductory course discussed previously in that students also consider paleoclimate and future climate predictions as part of this curriculum.

Synthetic river valleys: Creating prescribed topography for form-process inquiry and river rehabilitation design

NASA Astrophysics Data System (ADS)

Brown, R. A.; Pasternack, G. B.; Wallender, W. W.

2014-06-01

The synthesis of artificial landforms is complementary to geomorphic analysis because it affords a reflection on both the characteristics and intrinsic formative processes of real world conditions. Moreover, the applied terminus of geomorphic theory is commonly manifested in the engineering and rehabilitation of riverine landforms where the goal is to create specific processes associated with specific morphology. To date, the synthesis of river topography has been explored outside of geomorphology through artistic renderings, computer science applications, and river rehabilitation design; while within geomorphology it has been explored using morphodynamic modeling, such as one-dimensional simulation of river reach profiles, two-dimensional simulation of river networks, and three-dimensional simulation of subreach scale river morphology. To date, no approach allows geomorphologists, engineers, or river rehabilitation practitioners to create landforms of prescribed conditions. In this paper a method for creating topography of synthetic river valleys is introduced that utilizes a theoretical framework that draws from fluvial geomorphology, computer science, and geometric modeling. Such a method would be valuable to geomorphologists in understanding form-process linkages as well as to engineers and river rehabilitation practitioners in developing design surfaces that can be rapidly iterated. The method introduced herein relies on the discretization of river valley topography into geometric elements associated with overlapping and orthogonal two-dimensional planes such as the planform, profile, and cross section that are represented by mathematical functions, termed geometric element equations. Topographic surfaces can be parameterized independently or dependently using a geomorphic covariance structure between the spatial series of geometric element equations. To illustrate the approach and overall model flexibility examples are provided that are associated with mountain, lowland, and hybrid synthetic river valleys. To conclude, recommended advances such as multithread channels are discussed along with potential applications.

Science potential from a Europa lander.

PubMed

Pappalardo, R T; Vance, S; Bagenal, F; Bills, B G; Blaney, D L; Blankenship, D D; Brinckerhoff, W B; Connerney, J E P; Hand, K P; Hoehler, T M; Leisner, J S; Kurth, W S; McGrath, M A; Mellon, M T; Moore, J M; Patterson, G W; Prockter, L M; Senske, D A; Schmidt, B E; Shock, E L; Smith, D E; Soderlund, K M

2013-08-01

The prospect of a future soft landing on the surface of Europa is enticing, as it would create science opportunities that could not be achieved through flyby or orbital remote sensing, with direct relevance to Europa's potential habitability. Here, we summarize the science of a Europa lander concept, as developed by our NASA-commissioned Science Definition Team. The science concept concentrates on observations that can best be achieved by in situ examination of Europa from its surface. We discuss the suggested science objectives and investigations for a Europa lander mission, along with a model planning payload of instruments that could address these objectives. The highest priority is active sampling of Europa's non-ice material from at least two different depths (0.5-2 cm and 5-10 cm) to understand its detailed composition and chemistry and the specific nature of salts, any organic materials, and other contaminants. A secondary focus is geophysical prospecting of Europa, through seismology and magnetometry, to probe the satellite's ice shell and ocean. Finally, the surface geology can be characterized in situ at a human scale. A Europa lander could take advantage of the complex radiation environment of the satellite, landing where modeling suggests that radiation is about an order of magnitude less intense than in other regions. However, to choose a landing site that is safe and would yield the maximum science return, thorough reconnaissance of Europa would be required prior to selecting a scientifically optimized landing site.

Modeling and simulation of protein-surface interactions: achievements and challenges.

PubMed

Ozboyaci, Musa; Kokh, Daria B; Corni, Stefano; Wade, Rebecca C

2016-01-01

Understanding protein-inorganic surface interactions is central to the rational design of new tools in biomaterial sciences, nanobiotechnology and nanomedicine. Although a significant amount of experimental research on protein adsorption onto solid substrates has been reported, many aspects of the recognition and interaction mechanisms of biomolecules and inorganic surfaces are still unclear. Theoretical modeling and simulations provide complementary approaches for experimental studies, and they have been applied for exploring protein-surface binding mechanisms, the determinants of binding specificity towards different surfaces, as well as the thermodynamics and kinetics of adsorption. Although the general computational approaches employed to study the dynamics of proteins and materials are similar, the models and force-fields (FFs) used for describing the physical properties and interactions of material surfaces and biological molecules differ. In particular, FF and water models designed for use in biomolecular simulations are often not directly transferable to surface simulations and vice versa. The adsorption events span a wide range of time- and length-scales that vary from nanoseconds to days, and from nanometers to micrometers, respectively, rendering the use of multi-scale approaches unavoidable. Further, changes in the atomic structure of material surfaces that can lead to surface reconstruction, and in the structure of proteins that can result in complete denaturation of the adsorbed molecules, can create many intermediate structural and energetic states that complicate sampling. In this review, we address the challenges posed to theoretical and computational methods in achieving accurate descriptions of the physical, chemical and mechanical properties of protein-surface systems. In this context, we discuss the applicability of different modeling and simulation techniques ranging from quantum mechanics through all-atom molecular mechanics to coarse-grained approaches. We examine uses of different sampling methods, as well as free energy calculations. Furthermore, we review computational studies of protein-surface interactions and discuss the successes and limitations of current approaches.

A new multiresolution method applied to the 3D reconstruction of small bodies

NASA Astrophysics Data System (ADS)

Capanna, C.; Jorda, L.; Lamy, P. L.; Gesquiere, G.

2012-12-01

The knowledge of the three-dimensional (3D) shape of small solar system bodies, such as asteroids and comets, is essential in determining their global physical properties (volume, density, rotational parameters). It also allows performing geomorphological studies of their surface through the characterization of topographic features, such as craters, faults, landslides, grooves, hills, etc.. In the case of small bodies, the shape is often only constrained by images obtained by interplanetary spacecrafts. Several techniques are available to retrieve 3D global shapes from these images. Stereography which relies on control points has been extensively used in the past, most recently to reconstruct the nucleus of comet 9P/Tempel 1 [Thomas (2007)]. The most accurate methods are however photogrammetry and photoclinometry, often used in conjunction with stereography. Stereophotogrammetry (SPG) has been used to reconstruct the shapes of the nucleus of comet 19P/Borrelly [Oberst (2004)] and of the asteroid (21) Lutetia [Preusker (2012)]. Stereophotoclinometry (SPC) has allowed retrieving an accurate shape of the asteroids (25143) Itokawa [Gaskell (2008)] and (2867) Steins [Jorda (2012)]. We present a new photoclinometry method based on the deformation of a 3D triangular mesh [Capanna (2012)] using a multi-resolution scheme which starts from a sphere of 300 facets and yields a shape model with 100; 000 facets. Our strategy is inspired by the "Full Multigrid" method [Botsch (2007)] and consists in going alternatively between two resolutions in order to obtain an optimized shape model at a given resolution before going to the higher resolution. In order to improve the robustness of our method, we use a set of control points obtained by stereography. Our method has been tested on images acquired by the OSIRIS visible camera, aboard the Rosetta spacecraft of the European Space Agency, during the fly-by of asteroid (21) Lutetia in July 2010. We present the corresponding 3D shape model of its surface and compare it with models obtained with the SPG and SPC methods. We finally illustrate the practical interest of our approach in geomorphological studies through an analysis of depth to diameter ratio of several craters and topographic properties of other features. Botsch, M., et al., "Geometric modeling based on polygonal meshes," Proc. ACM SIGGRAPH Course Notes, 2007 Capanna, C., et al.: 3D Reconstruction of small solar system bodies using photoclinometry by deformation, IADIS International Journal on Computer Science and Information Systems, in press, 2012. Gaskell, R. W., et al.: Characterizing and navigating small bodies with imaging data, Meteoritics and Planetary Science, vol 43, p. 1049, 2008. Jorda, L., et al: Asteroid (2867) Steins: Shape, Topography and Global Physical Properties from OSIRIS observations, Icarus, in press, 2012. Oberst, J., et al.: The nucleus of Comet Borrelly: a study of morphology and surface brightness, Icarus, vol. 167, 2004. Preusker, F., et al.: The northern hemisphere of asteroid 21 Lutetia topography and orthoimages from Rosetta OSIRIS NAC image data, Planetary and Space Science, vol. 66, p. 54-63, 2012. Thomas, P. C., et al.: The shape, topography, and geology of Tempel 1 from Deep Impact observations, Icarus, vol. 187, Issue 1, p. 4-15, 2007

Collaboration in teacher workshops and citizen science

NASA Astrophysics Data System (ADS)

Gibbs, M. G.; Buxner, S.; Gay, P.; Crown, D. A.; Bracey, G.; Gugliucci, N.; Costello, K.; Reilly, E.

2013-12-01

The Moon and Earth system is an important topic for elementary and middle school science classrooms. Elementary and middle school teachers are challenged to keep current in science. The Planetary Science Institute created a program titled Workshops in Science Education and Resources (WISER): Planetary Perspectives to assist in-service K-12 teachers with their knowledge in earth and space science, using up-to-date science and inquiry activities to assist them in engaging their students. To augment the science and add a new aspect for teacher professional development, PSI is working in a new partnership collaborating with the Cosmoquest project in engaging teachers in authentic inquiry of the Moon. Teachers now learn about the Moon from PSI scientists and education staff and then engage in inquiry of the Moon using CosmoQuest's online citizen science project MoonMappers and its accompanying classroom curriculum TerraLuna. Through MoonMappers, teachers and students explore the lunar surface by viewing high-resolution pictures from the Lunar Reconnaissance Orbiter and marking craters and other interesting features. In addition, TerraLuna provides a unit of inquiry-based activities that bring MoonMappers and its science content into the classroom. This program addresses standards teachers need to teach and helps them not only teach about the Moon but also engage their students in authentic inquiry of the lunar surface.

Revolution in Field Science: Apollo Approach to Inaccessible Surface Exploration

NASA Astrophysics Data System (ADS)

Clark, P. E.

2010-07-01

The extraordinary challenge mission designers, scientists, and engineers, faced in planning the first human expeditions to the surface of another solar system body led to the development of a distinctive and even revolutionary approach to field work. Not only were those involved required to deal effectively with the extreme limitation in resources available for and access to a target as remote as the lunar surface; they were required to developed a rigorous approach to science activities ranging from geological field work to deploying field instruments. Principal aspects and keys to the success of the field work are discussed here, including the highly integrated, intensive, and lengthy science planning, simulation, and astronaut training; the development of a systematic scheme for description and documentation of geological sites and samples; and a flexible yet disciplined methodology for site documentation and sample collection. The capability for constant communication with a ‘backroom’ of geological experts who make requests and weigh in on surface operations was innovative and very useful in encouraging rapid dissemination of information to the greater community in general. An extensive archive of the Apollo era science activity related documents provides evidence of the principal aspects and keys to the success of the field work. The Apollo Surface Journal allows analysis of the astronaut’s performance in terms of capability for traveling on foot, documentation and sampling of field stations, and manual operation of tools and instruments, all as a function of time. The application of these analysis as ‘lessons learned’ for planning the next generation of human or robotic field science activities on the Moon and elsewhere are considered here as well.

General Dialdehyde Click Chemistry for Amine Bioconjugation.

PubMed

Elahipanah, Sina; O'Brien, Paul J; Rogozhnikov, Dmitry; Yousaf, Muhammad N

2017-05-17

The development of methods for conjugating a range of molecules to primary amine functional groups has revolutionized the fields of chemistry, biology, and material science. The primary amine is a key functional group and one of the most important nucleophiles and bases used in all of synthetic chemistry. Therefore, tremendous interest in the synthesis of molecules containing primary amines and strategies to devise chemical reactions to react with primary amines has been at the core of chemical research. In particular, primary amines are a ubiquitous functional group found in biological systems as free amino acids, as key side chain lysines in proteins, and in signaling molecules and metabolites and are also present in many natural product classes. Due to its abundance, the primary amine is the most convenient functional group handle in molecules for ligation to other molecules for a broad range of applications that impact all scientific fields. Because of the primary amine's central importance in synthetic chemistry, acid-base chemistry, redox chemistry, and biology, many methods have been developed to efficiently react with primary amines, including activated carboxylic acids, isothiocyanates, Michael addition type systems, and reaction with ketones or aldehydes followed by in situ reductive amination. Herein, we introduce a new traceless, high-yield, fast click-chemistry method based on the rapid and efficient trapping of amine groups via a functionalized dialdehyde group. The click reaction occurs in mild conditions in organic solvents or aqueous media and proceeds in high yield, and the starting dialdehyde reagent and resulting dialdehyde click conjugates are stable. Moreover, no catalyst or dialdehyde-activating group is required, and the only byproduct is water. The initial dialdehyde and the resulting conjugate are both straightforward to characterize, and the reaction proceeds with high atom economy. To demonstrate the broad scope of this new click-conjugation strategy, we designed a straightforward scheme to synthesize a suite of dialdehyde reagents. The dialdehyde molecules were used for applications in cell-surface engineering and for tailoring surfaces for material science applications. We anticipate the broad utility of the general dialdehyde click chemistry to primary amines in all areas of chemical research, ranging from polymers and bioconjugation to material science and nanoscience.

Transforming Elementary Science Teacher Education by Bridging Formal and Informal Science Education in an Innovative Science Methods Course

NASA Astrophysics Data System (ADS)

Riedinger, Kelly; Marbach-Ad, Gili; Randy McGinnis, J.; Hestness, Emily; Pease, Rebecca

2011-02-01

We investigated curricular and pedagogical innovations in an undergraduate science methods course for elementary education majors at the University of Maryland. The goals of the innovative elementary science methods course included: improving students' attitudes toward and views of science and science teaching, to model innovative science teaching methods and to encourage students to continue in teacher education. We redesigned the elementary science methods course to include aspects of informal science education. The informal science education course features included informal science educator guest speakers, a live animal demonstration and a virtual field trip. We compared data from a treatment course ( n = 72) and a comparison course ( n = 26). Data collection included: researchers' observations, instructors' reflections, and teacher candidates' feedback. Teacher candidate feedback involved interviews and results on a reliable and valid Attitudes and Beliefs about the Nature of and the Teaching of Science instrument. We used complementary methods to analyze the data collected. A key finding of the study was that while benefits were found in both types of courses, the difference in results underscores the need of identifying the primary purpose for innovation as a vital component of consideration.

Solvothermal synthesis of Bi2O3/BiVO4 heterojunction with enhanced visible-light photocatalytic performances

NASA Astrophysics Data System (ADS)

Ying, Wu; Jing, Wang; Yunfang, Huang; Yuelin, Wei; Zhixian, Sun; Xuanqing, Zheng; Chengkun, Zhang; Ningling, Zhou; Leqing, Fan; Jihuai, Wu

2016-08-01

Novel, three-dimensional, flower-like Bi2O3/BiVO4 heterojunction photocatalysts have been prepared by the combination of homogeneous precipitation and two-step solvothermal method followed by thermal solution of NaOH etching process. The as-obtained samples were fully characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, Brunauer-Emmett-Teller surface area, and UV—vis diffuse-reflectance spectroscopy in detail. The crystallinity, microstructure, specific surface area, optical property and photocatalytic activity of samples greatly changed depending on solvothermal reaction time. The photocatalytic activities of samples were evaluated on the degradation of methyl orange (MO) under visible-light irradiation. The Bi2O3/BiVO4 exhibited much higher photocatalytic activities than pure BiVO4 and conventional TiO2 (P25). The result revealed that the three-dimensional heterojunction played a critical role in the separation of the electron and hole pairs and enhancement of the interfacial charge transfer efficiency, which was responsible for the enhanced photocatalytic activity. Project supported by the National Natural Science Foundation of China (Nos. 61306077, 21301060), the Fundamental Research Funds for the Central Universities (Nos. JB-ZR1109, JB-ZR1212), the National Science Foundation of Quanzhou City (No. 2014Z108), the Promotion Program for Young and Middle-aged Teachers in Science and Technology Research of Huaqiao University (No. ZQN-PY207), Discipline Innovation Team Project of Huaqiao University (No. 201320), and the Instrumental Analysis Center Huaqiao University.

Seismic refraction analysis: the path forward

USGS Publications Warehouse

Haines, Seth S.; Zelt, Colin; Doll, William

2012-01-01

Seismic Refraction Methods: Unleashing the Potential and Understanding the Limitations; Tucson, Arizona, 29 March 2012 A workshop focused on seismic refraction methods took place on 29 May 2012, associated with the 2012 Symposium on the Application of Geophysics to Engineering and Environmental Problems. This workshop was convened to assess the current state of the science and discuss paths forward, with a primary focus on near-surface problems but with an eye on all applications. The agenda included talks on these topics from a number of experts interspersed with discussion and a dedicated discussion period to finish the day. Discussion proved lively at times, and workshop participants delved into many topics central to seismic refraction work.

Superposition-free comparison and clustering of antibody binding sites: implications for the prediction of the nature of their antigen

PubMed Central

Di Rienzo, Lorenzo; Milanetti, Edoardo; Lepore, Rosalba; Olimpieri, Pier Paolo; Tramontano, Anna

2017-01-01

We describe here a superposition free method for comparing the surfaces of antibody binding sites based on the Zernike moments and show that they can be used to quickly compare and cluster sets of antibodies. The clusters provide information about the nature of the bound antigen that, when combined with a method for predicting the number of direct antibody antigen contacts, allows the discrimination between protein and non-protein binding antibodies with an accuracy of 76%. This is of relevance in several aspects of antibody science, for example to select the framework to be used for a combinatorial antibody library. PMID:28338016

Teaching for Conceptual Change in Elementary and Secondary Science Methods Courses.

ERIC Educational Resources Information Center

Marion, Robin; Hewson, Peter W.; Tabachnick, B. Robert; Blomker, Kathryn B.

1999-01-01

Describes and analyzes two science methods courses at the elementary and secondary levels for how they addressed four ideas: (1) how students learn science; (2) how teachers teach science to students; (3) how prospective science teachers learn about the first two ideas; and (4) how methods instructors teach prospective science teachers about the…

The Ganymede Interior Structure, and Magnetosphere Observer (GISMO) Mission Concept

NASA Technical Reports Server (NTRS)

Lynch, K. L.; Smith, I. B.; Singer, K. N.; Vogt, M. F.; Blackburn, D. G.; Chaffin, M.; Choukroun, M.; Ehsan, N.; DiBraccio, G. A.; Gibbons, L. J.;

Recent advances in engineering science; Proceedings of the A. Cemal Eringen Symposium, University of California, Berkeley, June 20-22, 1988

NASA Technical Reports Server (NTRS)

Koh, Severino L. (Editor); Speziale, Charles G. (Editor)

1989-01-01

Various papers on recent advances in engineering science are presented. Some individual topics addressed include: advances in adaptive methods in computational fluid mechanics, mixtures of two medicomorphic materials, computer tests of rubber elasticity, shear bands in isotropic micropolar elastic materials, nonlinear surface wave and resonator effects in magnetostrictive crystals, simulation of electrically enhanced fibrous filtration, plasticity theory of granular materials, dynamics of viscoelastic media with internal oscillators, postcritical behavior of a cantilever bar, boundary value problems in nonlocal elasticity, stability of flexible structures with random parameters, electromagnetic tornadoes in earth's ionosphere and magnetosphere, helicity fluctuations and the energy cascade in turbulence, mechanics of interfacial zones in bonded materials, propagation of a normal shock in a varying area duct, analytical mechanics of fracture and fatigue.

Surface structure evolution in a homologous series of ionic liquids.

PubMed

Haddad, Julia; Pontoni, Diego; Murphy, Bridget M; Festersen, Sven; Runge, Benjamin; Magnussen, Olaf M; Steinrück, Hans-Georg; Reichert, Harald; Ocko, Benjamin M; Deutsch, Moshe

2018-02-06

Interfaces of room temperature ionic liquids (RTILs) are important for both applications and basic science and are therefore intensely studied. However, the evolution of their interface structure with the cation's alkyl chain length [Formula: see text] from Coulomb to van der Waals interaction domination has not yet been studied for even a single broad homologous RTIL series. We present here such a study of the liquid-air interface for [Formula: see text], using angstrom-resolution X-ray methods. For [Formula: see text], a typical "simple liquid" monotonic surface-normal electron density profile [Formula: see text] is obtained, like those of water and organic solvents. For [Formula: see text], increasingly more pronounced nanoscale self-segregation of the molecules' charged moieties and apolar chains yields surface layering with alternating regions of headgroups and chains. The layering decays into the bulk over a few, to a few tens, of nanometers. The layering periods and decay lengths, their linear [Formula: see text] dependence, and slopes are discussed within two models, one with partial-chain interdigitation and the other with liquid-like chains. No surface-parallel long-range order is found within the surface layer. For [Formula: see text], a different surface phase is observed above melting. Our results also impact general liquid-phase issues like supramolecular self-aggregation and bulk-surface structure relations.

The effectiveness of constructivist science instructional methods on middle school students' student achievement and motivation

NASA Astrophysics Data System (ADS)

Brooks, John

A problem facing science educators is determining the most effective means of science instruction so that students will meet or exceed the new rigorous standards. The theoretical framework for this study was based on reform and research efforts that have informed science teachers that using constructivism is the best method of science instruction. The purpose of this study was to investigate how the constructivist method of science instruction affected student achievement and student motivation in a sixth grade science classroom. The guiding research question involved understanding which method of science instruction would be most effective at improving student achievement in science. Other sub-questions included the factors that contribute to student motivation in science and the method of science instruction students receive that affects motivation to learn science. Quantitative data were collected using a pre-test and post-test single group design. T-test and ANCOVA were used to test quantitative hypotheses. Qualitative data were collected using student reflective journals and classroom discussions. Students' perspectives were transcribed, coded and used to further inform quantitative findings. The findings of this study supported the recommendations made by science reformists that the best method of science instruction was a constructivist method. This study also found that participant comments favored constructivist taught classes. The implications for social change at the local level included potential increases in student achievement in science and possibly increased understanding that can facilitate similar changes at other schools. From a global perspective, constructivist-oriented methods might result in students becoming more interested in majoring in science at the college level and in becoming part of a scientifically literate work force.

GN and C Subsystem Concept for Safe Precision Landing of the Proposed Lunar MARE Robotic Science Mission

NASA Technical Reports Server (NTRS)

Carson, John M., III; Johnson, Andrew E.; Anderson, F. Scott; Condon, Gerald L.; Nguyen, Louis H.; Olansen, Jon B.; Devolites, Jennifer L.; Harris, William J.; Hines, Glenn D.; Lee, David E.;

Analysis of selected herbicide metabolites in surface and ground water of the United States

USGS Publications Warehouse

Scribner, E.A.; Thurman, E.M.; Zimmerman, L.R.

2000-01-01

One of the primary goals of the US Geological Survey (USGS) Laboratory in Lawrence, Kansas, is to develop analytical methods for the analysis of herbicide metabolites in surface and ground water that are vital to the study of herbicide fate and degradation pathways in the environment. Methods to measure metabolite concentrations from three major classes of herbicides - triazine, chloroacetanilide and phenyl-urea - have been developed. Methods for triazine metabolite detection cover nine compounds: six compounds are detected by gas chromatography/mass spectrometry; one is detected by high-performance liquid chromatography with diode-array detection; and eight are detected by liquid chromatography/mass spectrometry. Two metabolites of the chloroacetanilide herbicides - ethane sulfonic acid and oxanilic acid - are detected by high-performance liquid chromatography with diode-array detection and liquid chromatography/mass spectrometry. Alachlor ethane sulfonic acid also has been detected by solid-phase extraction and enzyme-linked immunosorbent assay. Six phenylurea metabolites are all detected by liquid chromatography/mass spectrometry; four of the six metabolites also are detected by gas chromatography/mass spectrometry. Additionally, surveys of herbicides and their metabolites in surface water, ground water, lakes, reservoirs, and rainfall have been conducted through the USGS laboratory in Lawrence. These surveys have been useful in determining herbicide and metabolite occurrence and temporal distribution and have shown that metabolites may be useful in evaluation of non-point-source contamination. Copyright (C) 2000 Elsevier Science B.V.

European Science Notes Information Bulletin. Report on Current European and Middle Eastern Science

DTIC Science & Technology

1992-10-01

oceanographers. This has occurred at a time of current radar systems . The independent develop- rapidly increasing government interest in and fund...over each area in which surface current is ment of the waves (some motions caused by wave determined (for HF systems , averaging time spans action and...Ocean Observing System ; high-resolution model capabilities; ocean- atmosphere interface; Surface Density Depression Pool; forecasting INTRODUCTION tion

“Groundwater hydrology” is redundant

NASA Astrophysics Data System (ADS)

While in the Netherlands a few months ago, I mentioned “groundwater hydrology” to a very well-educated, very literary, and non-hydrologic old friend. She shuddered and told me in no uncertain words that this was a horrible term, completely redundant like a round circle, or as the linguists call it, a pleonasm. This is, of course, because hydrology already means water science (from the Greek words udor, or hydor for water, and logos for science), so that groundwater hydrology really stands for groundwater water science, and surface water hydrology for surface water science.These are pleonasms of the first kind and insults to any language purist, which all of us should strive to be! So I propose that henceforth groundwater hydrology be called subterranean hydrology. Other possibilities would be subsurface hydrology, but this sounds too shallow, or underground hydrology, which, however, could give the impression of some clandestine activity. Besides, subterranean hydrology would be in keeping with the words for groundwater in Latin-based languages (eau souterrain in French, acqua sotierranea in Italian, and aguas subterraneas in Spanish). Also, subterranean hydrology includes the vadose zone, which, of course, groundwater hydrology as such does not. Surface water hydrology would simply be called surface hydrology, and anything above that atmospheric hydrology.

Snapshots of Proton Accommodation at a Microscopic Water Surface: Understanding the Vibrational Spectral Signatures of the Charge Defect in Cryogenically Cooled H+(H2O)n=2 – 28 Clusters

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

Fournier, Joseph A.; Wolke, Conrad T.; Johnson, Mark A.

In this Article, we review the role of gas-phase, size-selected protonated water clusters, H+(H2O)n, in the analysis of the microscopic mechanics responsible for the behavior of the excess proton in bulk water. We extend upon previous studies of the smaller, two-dimensional sheet-like structures to larger (n≥10) assemblies with three-dimensional cage morphologies which better mimic the bulk environment. Indeed, clusters in which a complete second solvation shell forms around a surface-embedded hydronium ion yield vibrational spectra where the signatures of the proton defect display strikingly similar positions and breadth to those observed in dilute acids. We investigate effects of the localmore » structure and intermolecular interactions on the large red shifts observed in the proton vibrational signature upon cluster growth using various theoretical methods. We show that, in addition to sizeable anharmonic couplings, the position of the excess proton vibration can be traced to large increases in the electric field exerted on the embedded hydronium ion upon formation of the first and second solvation shells. MAJ acknowledges support from the U.S. Department of Energy under Grant No. DE-FG02- 06ER15800 as well as the facilities and staff of the Yale University Faculty of Arts and Sciences High Performance Computing Center, and by the National Science Foundation under Grant No. CNS 08-21132 that partially funded acquisition of the facilities. SMK and SSX acknowledge support from the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.« less

Planetary geomorphology: Some historical/analytical perspectives

NASA Astrophysics Data System (ADS)

Baker, V. R.

2015-07-01

Three broad themes from the history of planetary geomorphology provide lessons in regard to the logic (valid reasoning processes) for the doing of that science. The long controversy over the origin of lunar craters, which was dominated for three centuries by the volcanic hypothesis, provides examples of reasoning on the basis of authority and a priori presumptions. Percival Lowell's controversy with geologists over the nature of linear markings on the surface of Mars illustrates the role of tenacity in regard to the beliefs of some individual scientists. Finally, modern controversies over the role of water in shaping the surface of Mars illustrate how the a priori method, i.e., belief produced according to reason, can seductively cloud the scientific openness to the importance of brute facts that deviate from a prevailing paradigm.

Effects of Zn-In-Sn elements on the electric properties of magnesium alloy anode materials.

PubMed

Yu, Zhan; Ju, Dongying; Zhao, Hongyang; Hu, Xiaodong

2011-06-01

A new magnesium alloy anode is based on an environmentally friendly electrode that contains none of mercury, lead and chromate, but it can enhance the electric properties of alloy significantly. Magnesium alloy adding eco-friendly elements Zn-In-Sn which was developed by orthogonal design were obtained by two casting methods. The effect of additive elements on performance of electrode material was studied. The effects of elements addition and casting method on electric properties and corrosive properties of Mg-Zn-In-Sn alloys were investigated by using electrochemical measurements, corrosive tests and observation of surface structure. The results show that Mg-Zn-In-Sn alloy anode has higher electromotive force and more stable work potential than that commercial magnesium alloy AZ91. It is suitable for anode material of magnesium battery for its small hydrogen evolution, less self-corrosion rate and easy to shed corrosive offspring off. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

The Lunar Reconnaissance Orbiter Mission: Seven Years at the Moon - Accomplishments, Data, and Future Prospects

NASA Astrophysics Data System (ADS)

Petro, Noah; Keller, John

2016-07-01

The LRO Spacecraft has been orbiting the Moon for over 7 years (~91 lunations), and in that time data from the seven instruments has contributed to a revolution in our understanding of the Moon. Since launch the mission goals and instruments science questions have evolved, from the initial characterization of the lunar surface and its environment to studying the variability of surface hydration and measuring the flux of new craters that have formed during LRO's time in lunar orbit. The growing LRO dataset in the PDS presents a unique archive that allows for an unprecedented opportunity to study how an airless body changes over time. The LRO instrument suite [1] is performing nominally, with no significant performance issues since the mission entered the current extended mission. The Mini-RF instrument team is investigating new methods for collecting bistatic data using an Earth-based X-band transmitter [2] during a possible upcoming extended mission starting in September 2016, pending NASA approval. The LRO spacecraft has been in an elliptical, polar orbit with a low perilune over the South Pole since December 2011. This orbit minimizes annual fuel consumption, enabling LRO to use fuel to maximize opportunities for obtaining unique science (e.g., lunar eclipse measurements from Diviner, measuring spacecraft impacts by GRAIL and LADEE). The LRO instrument teams deliver data to the PDS every three months, data that includes raw, calibrated, and gridded/map products [3]. As of January, over 681TB has been archived. These higher-level data products include a number of resources that are useful for mission planners, in addition to planetary scientists. A focus of the mission has been on the South Pole, therefore a number of special products (e.g., illumination maps, high resolution topography, hydration maps) are available. Beyond the poles, high-resolution (~1-2 m spatial resolution) topographic products are available for select areas, as well as maps of rock abundance and surface slopes. It is important to note that LRO data has also vastly improved our understanding of the location of surface features across the entire Moon, thus enabling the accurate geolocation of any spot on the Moon. LRO will participate in the Planetary Science Division Senior Review to propose for two years of operations (FY17-18). As part of the senior review process the LRO instrument teams and project are defining exciting new science questions and instrument modes. We are also evaluating new orbits for the spacecraft in order to maximize the science return, as well as put us in a position to leverage possible future opportunities (e.g., observe future landings by commercial/private/international missions, upcoming eclipses). [1] Vondrak, R., et al., (2010) Space Science Reviews, 150, 7-22. [2] Patterson, G. W., et al., (2016) LPSC. [3] LRO PDS Archive, (http://pds-geosciences.wustl.edu/missions/lro/).

Proceedings of the 5th Symposium on applied surface analysis

NASA Astrophysics Data System (ADS)

Grant, J. T.

1984-04-01

The 5th Symposium on Applied Surface Analysis was held at the University of Dayton, 8-10 June 1983. This Symposium was held to meet a need, namely to show the transition between basic surface science research and applications of this research to areas of Department of Defense interest. Areas receiving special attention at this Symposium were chemical bonding and reactions at metal-semiconductors interfaces, surface analysis and the tribological processes of ion implanted materials, microbeam analysis and laser ionization of sputtered neutrals. Other topics discussed included adsorption, adhesion, corrosion, wear and thin films. Approximately 110 scientists active in the field of surface analysis participated in the Symposium. Four scientists presented invited papers at the Symposium. There were 29 contributed presentations. The proceedings of the Symposium are being published in a special issue of the journal, Applications of Surface Science, by North-Holland Publishing Company.

Traverse Planning Experiments for Future Planetary Surface Exploration

NASA Technical Reports Server (NTRS)

Hoffman, Stephen J.; Voels, Stephen A.; Mueller, Robert P.; Lee, Pascal C.

2012-01-01

The purpose of the investigation is to evaluate methodology and data requirements for remotely-assisted robotic traverse of extraterrestrial planetary surface to support human exploration program, assess opportunities for in-transit science operations, and validate landing site survey and selection techniques during planetary surface exploration mission analog demonstration at Haughton Crater on Devon Island, Nunavut, Canada. Additionally, 1) identify quality of remote observation data sets (i.e., surface imagery from orbit) required for effective pre-traverse route planning and determine if surface level data (i.e., onboard robotic imagery or other sensor data) is required for a successful traverse, and if additional surface level data can improve traverse efficiency or probability of success (TRPF Experiment). 2) Evaluate feasibility and techniques for conducting opportunistic science investigations during this type of traverse. (OSP Experiment). 3) Assess utility of remotely-assisted robotic vehicle for landing site validation survey. (LSV Experiment).

The EUSTACE project: delivering global, daily information on surface air temperature

NASA Astrophysics Data System (ADS)

Ghent, D.; Rayner, N. A.

2017-12-01

Day-to-day variations in surface air temperature affect society in many ways; however, daily surface air temperature measurements are not available everywhere. A global daily analysis cannot be achieved with measurements made in situ alone, so incorporation of satellite retrievals is needed. To achieve this, in the EUSTACE project (2015-2018, https://www.eustaceproject.eu) we have developed an understanding of the relationships between traditional (land and marine) surface air temperature measurements and retrievals of surface skin temperature from satellite measurements, i.e. Land Surface Temperature, Ice Surface Temperature, Sea Surface Temperature and Lake Surface Water Temperature. Here we discuss the science needed to produce a fully-global daily analysis (or ensemble of analyses) of surface air temperature on the centennial scale, integrating different ground-based and satellite-borne data types. Information contained in the satellite retrievals is used to create globally-complete fields in the past, using statistical models of how surface air temperature varies in a connected way from place to place. This includes developing new "Big Data" analysis methods as the data volumes involved are considerable. We will present recent progress along this road in the EUSTACE project, i.e.: • identifying inhomogeneities in daily surface air temperature measurement series from weather stations and correcting for these over Europe; • estimating surface air temperature over all surfaces of Earth from surface skin temperature retrievals; • using new statistical techniques to provide information on higher spatial and temporal scales than currently available, making optimum use of information in data-rich eras. Information will also be given on how interested users can become involved.

Nanoplasmonic sensors for biointerfacial science.

PubMed

Jackman, Joshua A; Rahim Ferhan, Abdul; Cho, Nam-Joon

2017-06-19

In recent years, nanoplasmonic sensors have become widely used for the label-free detection of biomolecules across medical, biotechnology, and environmental science applications. To date, many nanoplasmonic sensing strategies have been developed with outstanding measurement capabilities, enabling detection down to the single-molecule level. One of the most promising directions has been surface-based nanoplasmonic sensors, and the potential of such technologies is still emerging. Going beyond detection, surface-based nanoplasmonic sensors open the door to enhanced, quantitative measurement capabilities across the biointerfacial sciences by taking advantage of high surface sensitivity that pairs well with the size of medically important biomacromolecules and biological particulates such as viruses and exosomes. The goal of this review is to introduce the latest advances in nanoplasmonic sensors for the biointerfacial sciences, including ongoing development of nanoparticle and nanohole arrays for exploring different classes of biomacromolecules interacting at solid-liquid interfaces. The measurement principles for nanoplasmonic sensors based on utilizing the localized surface plasmon resonance (LSPR) and extraordinary optical transmission (EOT) phenomena are first introduced. The following sections are then categorized around different themes within the biointerfacial sciences, specifically protein binding and conformational changes, lipid membrane fabrication, membrane-protein interactions, exosome and virus detection and analysis, and probing nucleic acid conformations and binding interactions. Across these themes, we discuss the growing trend to utilize nanoplasmonic sensors for advanced measurement capabilities, including positional sensing, biomacromolecular conformation analysis, and real-time kinetic monitoring of complex biological interactions. Altogether, these advances highlight the rich potential of nanoplasmonic sensors and the future growth prospects of the community as a whole. With ongoing development of commercial nanoplasmonic sensors and analytical models to interpret corresponding measurement data in the context of biologically relevant interactions, there is significant opportunity to utilize nanoplasmonic sensing strategies for not only fundamental biointerfacial science, but also translational science applications related to clinical medicine and pharmaceutical drug development among countless possibilities.

Wide-field surface plasmon microscopy of nano- and microparticles: features, benchmarking, limitations, and bioanalytical applications

NASA Astrophysics Data System (ADS)

Nizamov, Shavkat; Scherbahn, Vitali; Mirsky, Vladimir M.

2017-05-01

Detection of nano- and micro-particles is an important task for chemical analytics, food industry, biotechnology, environmental monitoring and many other fields of science and industry. For this purpose, a method based on the detection and analysis of minute signals in surface plasmon resonance images due to adsorption of single nanopartciles was developed. This new technology allows one a real-time detection of interaction of single nano- and micro-particles with sensor surface. Adsorption of each nanoparticle leads to characteristic diffraction image whose intensity depends on the size and chemical composition of the particle. The adsorption rate characterizes volume concentration of nano- and micro-particles. Large monitored surface area of sensor enables a high dynamic range of counting and to a correspondingly high dynamic range in concentration scale. Depending on the type of particles and experimental conditions, the detection limit for aqueous samples can be below 1000 particles per microliter. For application of method in complex media, nanoparticle images are discriminated from image perturbations due to matrix components. First, the characteristic SPRM images of nanoparticles (templates) are collected in aqueous suspensions or spiked real samples. Then, the detection of nanoparticles in complex media using template matching is performed. The detection of various NPs in consumer products like cosmetics, mineral water, juices, and wines was shown at sub-ppb level. The method can be applied for ultrasensitive detection and analysis of nano- and micro-particles of biological (bacteria, viruses, endosomes), biotechnological (liposomes, protein nanoparticles for drug delivery) or technical origin.

Enhanced chiral response from the Fabry-Perot cavity coupled meta-surfaces

NASA Astrophysics Data System (ADS)

Yang, Ze-Jian; Hu, De-Jiao; Gao, Fu-Hua; Hou, Yi-Dong

2016-08-01

The circular dichroism (CD) signal of a two-dimensional (2D) chiral meta-surface is usually weak, where the difference between the transmitted (or reflected) right and left circular polarization is barely small. We present a general method to enhance the reflective CD spectrum, by adding a layer of reflective film behind the meta-surface. The light passes through the chiral meta-surface and propagates towards the reflector, where it is reflected back and further interacts with the chiral meta-surface. The light is reflected back and forth between these two layers, forming a Fabry-Perot type resonance, which interacts with the localized surface plasmonic resonance (LSPR) mode and greatly enhances the CD signal of the light wave leaving the meta-surface. We numerically calculate the CD enhancing effect of an L-shaped chiral meta-surface on a gold film in the visible range. Compared with the single layer meta-surface, the L-shaped chiral meta-surface has a CD maximum that is dramatically increased to 1. The analysis of reflection efficiency reveals that our design can be used to realize a reflective circular polarizer. Corresponding mode analysis shows that the huge CD originates from the hybrid mode comprised of FP mode and LSPR. Our results provide a general approach to enhancing the CD signal of a chiral meta-surface and can be used in areas like biosensing, circular polarizer, integrated photonics, etc. Project supported by the National Natural Science Foundation of China (Grant No. 61377054).

Fast Voronoi Diagrams and Offsets on Triangulated Surfaces

DTIC Science & Technology

2000-01-01

118 (1996), 499-508. 14. Malladi , R ., and J. A. Sethian, An O(N log N) algorithm for shape mod- eling, Proceedings of National Academy of Sciences...rights of reproduction in any form reserved. 194 R . Kimmel and J. A. Sethian the Osher-Sethian level set method [16,20], which grew out of Sethian’s...where .F(x, y) : R 2 -* R + is a function that defines a weight for each point in the domain. The distance map T(x, y) from a given point Po assigns

Recent advances on polyoxometalate-based molecular and composite materials.

PubMed

Song, Yu-Fei; Tsunashima, Ryo

2012-11-21

Polyoxometalates (POMs) are a subset of metal oxides with unique physical and chemical properties, which can be reliably modified through various techniques and methods to develop sophisticated materials and devices. In parallel with the large number of new crystal structures reported in the literature, the application of these POMs towards multifunctional materials has attracted considerable attention. This critical review summarizes recent progress on POM-based molecular and composite materials, and particularly highlights the emerging areas that are closely related to surface, electronic, energy, environment, life science, etc. (171 references).

Continued Development of in Situ Geochronology for Planetary Missions

NASA Technical Reports Server (NTRS)

Devismes, D.; Cohen, B. A.

2015-01-01

The instrument 'Potassium (K) Argon Laser Experiment' (KArLE) is developed and designed for in situ absolute dating of rocks on planetary surfaces. It is based on the K-Ar dating method and uses the Laser Induced Breakdown Spectroscopy - Laser Ablation - Quadrupole Mass Spectrometry (LIBSLA- QMS) technique. We use a dedicated interface to combine two instruments similar to SAM of Mars Science Laboratory (for the QMS) and ChemCam (for the LA and LIBS). The prototype has demonstrated that KArLE is a suitable and promising instrument for in situ absolute dating.

A novel strategy towards designing a CdSe quantum dot-metallohydrogel composite material.

PubMed

Chatterjee, Sayantan; Maitra, Uday

2016-08-11

We have described here an efficient method to disperse hydrophobic CdSe quantum dots (QDs) in an aqueous phase using cetyltrimethylammonium bromide (CTAB) micelles without any surface ligand exchange. The water soluble QDs were then embedded in 3D self assembled fibrillar networks (SAFINs) of a hydrogel showing homogeneous dispersibility as evidenced from optical and electron microscopic techniques. The photophysical studies of the hydrogel-QD composite are reported for the first time. These composite materials may have potential applications in biology, optoelectronics, sensors, non-linear optics and materials science.

2013 Chemical reactions at surfaces. Surfaces in Energy and the Environment. Gordon Research Conference and Gordon Research Seminar (April 28 - May 3, 2013 - Les Diablerets, Switzerland)

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

Stair, Peter C.

presentations on chemistry at solid and liquid surfaces of relevance to catalysis, synthesis, photochemistry, environmental science, and tribology. Topics include: Fundamental Surface Chemistry; Catalysis; Solid Liquid and Aerosol Interfaces; Surface Photochemistry; Synthesis of Surfaces; Environmental Interfaces; Hot Topics in Surface Chemical Reactions; Tribology; Gas-Surface Scattering and Reactions; Novel Materials and Environments.

Polar Resources: The Key To Development of Cis-Lunar Space

NASA Technical Reports Server (NTRS)

Larson, William E.

2017-01-01

There are plenty of unanswered science questions regarding the Moon that justify surface missions: (1) However the rate of science missions launched remains painfully slow: (a) Google X-Prize Landers may offer more opportunities, but the jury is still out: (2) Science alone will not be enough to sustain long term interest in the Moon by the Congress (or the Public) nor will it generate a frequent mission rate. We need something that drives a frequent and continual reason to go to the Moon: (1) Lunar tourism not practical in the near term; (2) Lunar Resources can be the economic driver that enables regular access to the lunar surface.

Detection of aniline oligomers on polyaniline-gold interface using resonance Raman scattering.

PubMed

Trchová, Miroslava; Morávková, Zuzana; Dybal, Jiří; Stejskal, Jaroslav

2014-01-22

In situ deposited conducting polyaniline films prepared by the oxidation of aniline with ammonium peroxydisulfate in aqueous media of various acidities on gold and silicon supports were characterized by Raman spectroscopy. Enhanced Raman bands were found in the spectra of polyaniline films produced in the solutions of weak acids or in water on gold surface. These bands were weak for the films prepared in solutions of a strong acid on a gold support. The same bands are present in the Raman spectra of the reaction intermediates deposited during aniline oxidation in water or aqueous solutions of weak or strong acids on silicon removed from the reaction mixture at the beginning of the reaction. Such films are formed by aniline oligomers adsorbed on the surface. They were detected on the polyaniline-gold interface using resonance Raman scattering on the final films deposited on gold. The surface resonance Raman spectroscopy of the monolayer of oligomers found in the bulk polyaniline film makes this method advantageous in surface science, with many applications in electrochemistry, catalysis, and biophysical, polymer, or analytical chemistry.

Label-Free in Situ Discrimination of Live and Dead Bacteria by Surface-Enhanced Raman Scattering.

PubMed

Zhou, Haibo; Yang, Danting; Ivleva, Natalia P; Mircescu, Nicoleta E; Schubert, Sören; Niessner, Reinhard; Wieser, Andreas; Haisch, Christoph

2015-07-07

Techniques to distinguish between live and dead bacteria in a quantitative manner are in high demand in numerous fields including medical care, food safety, and public security as well as basic science research. This work demonstrates new nanostructures (silver nanoparticles coating bacteria structure, Bacteria@AgNPs) and their utility for rapid counting of live and dead bacteria by surface-enhanced Raman scattering (SERS). We found that suspensions containing Gram-negative organisms as well as AgNPs give strong SERS signals of live bacteria when generated selectively on the particle surface. However, almost no SERS signals can be detected from Bacteria@AgNPs suspensions containing dead bacteria. We demonstrate successful quantification of different percentages of dead bacteria both in bulk liquid and on glass surfaces by using SERS mapping on a single cell basis. Furthermore, different chemicals have been used to elucidate the mechanism involved in this observation. Finally, we used the Bacteria@AgNPs method to detect antibiotic resistance of E. coli strains against several antibiotics used in human medicine.

Applications, Surface Modification and Functionalization of Nickel Nanorods

PubMed Central

Schrittwieser, Stefan; Reichinger, Daniela; Schotter, Joerg

2017-01-01

The growing number of nanoparticle applications in science and industry is leading to increasingly complex nanostructures that fulfill certain tasks in a specific environment. Nickel nanorods already possess promising properties due to their magnetic behavior and their elongated shape. The relevance of this kind of nanorod in a complex measurement setting can be further improved by suitable surface modification and functionalization procedures, so that customized nanostructures for a specific application become available. In this review, we focus on nickel nanorods that are synthesized by electrodeposition into porous templates, as this is the most common type of nickel nanorod fabrication method. Moreover, it is a facile synthesis approach that can be easily established in a laboratory environment. Firstly, we will discuss possible applications of nickel nanorods ranging from data storage to catalysis, biosensing and cancer treatment. Secondly, we will focus on nickel nanorod surface modification strategies, which represent a crucial step for the successful application of nanorods in all medical and biological settings. Here, the immobilization of antibodies or peptides onto the nanorod surface adds another functionality in order to yield highly promising nanostructures. PMID:29283415

Middle School Science Notes.

ERIC Educational Resources Information Center

School Science Review, 1981

1981-01-01

Describes activities, demonstrations, and materials suitable for middle school science, including investigations on solar energy, surface tension, exploding cottages, worms and light, airplanes, depolarizing simple cells, and the thermal expansion of metals. (JN)

Rethinking the Elementary Science Methods Course: A Case for Content, Pedagogy, and Informal Science Education.

ERIC Educational Resources Information Center

Kelly, Janet

2000-01-01

Indicates the importance of preparing prospective teachers who will be elementary science teachers with different methods. Presents the theoretical and practical rationale for developing a constructivist-based elementary science methods course. Discusses the impact student knowledge and understanding of science and student attitudes has on…

Visualization of Sources in the Universe

NASA Astrophysics Data System (ADS)

Kafatos, M.; Cebral, J. R.

1993-12-01

We have begun to develop a series of visualization tools of importance to the display of astronomical data and have applied these to the visualization of cosmological sources in the recently formed Institute for Computational Sciences and Informatics at GMU. One can use a three-dimensional perspective plot of the density surface for three dimensional data and in this case the iso-level contours are three- dimensional surfaces. Sophisticated rendering algorithms combined with multiple source lighting allow us to look carefully at such density contours and to see fine structure on the surface of the density contours. Stereoscopic and transparent rendering can give an even more sophisticated approach with multi-layered surfaces providing information at different levels. We have applied these methods to looking at density surfaces of 3-D data such as 100 clusters of galaxies and 2500 galaxies in the CfA redshift survey. Our plots presented are based on three variables, right ascension, declination and redshift. We have also obtained density structures in 2-D for the distribution of gamma-ray bursts (where distances are unknown) and the distribution of a variety of sources such as clusters of galaxies. Our techniques allow for correlations to be done visually.

Special Issue: 14th International Symposium on Novel and Nano Materials

NASA Astrophysics Data System (ADS)

Kim, Woo-Byoung; Choa, Yong-Ho; Ahn, Hyo-Jin; Park, Il-Kyu

2017-09-01

This Special Issue of Applied Surface Science is intended to provide a collection of peer-reviewed contributions presented at the 14th International Symposium on Novel Nano Materials (ISNNM) held in Budapest, Hungary as one of the most beautiful cities in Europe from July 3 to July 8, 2016. All selected papers underwent the regular peer review process as set by the journal of Applied Surface Science and its publisher (Elsevier).

European Science Notes Information Bulletin. Reports on Current European and Middle Eastern Science

DTIC Science & Technology

1992-01-01

ACTIVITIES IN THE ICE AND "l’lcsc conditions occur because of the relatively high CLIMATE DIVISION amount of radiation cooling from the ice surface...variant of dependent but space-inidepcndcnt noise seems to the Brusselator with diffusion. induce spatial correlations in a simple one -dimen- sional...that are designed to detect This report provides a background as to how objects on or near the sea surface.

Recent Advances in Hyporheic Zone Science

NASA Astrophysics Data System (ADS)

Hester, E. T.

2017-12-01

The hyporheic zone exists beneath and adjacent to streams and rivers where surface water and groundwater interact. It provides unique habitat for aquatic organisms, can buffer surface water temperatures, and can be highly reactive, processing nutrients and improving water quality. The hyporheic zone is the subject of considerable research and the past year in WRR witnessed important conceptual advances. A key focus was rigorous evaluation of mixing between surface water and groundwater that occurs within hyporheic sediments. Field observations indicate that greater mixing occurs in the hyporheic zone than in deeper groundwater, and this distinction has been explored by recent numerical modeling studies, but more research is needed to fully understand the causes. A commentary this year in WRR proposed that hyporheic mixing is enhanced by a combination of fluctuating boundary conditions and multiscale physical and chemical spatial heterogeneity but confirmation is left to future research. This year also witnessed the boundaries of knowledge pushed back in a number of other key areas. Field quantification of hyporheic exchange and reactions benefited from advances including the use and interpretation of high frequency nutrient sensors, actively heater fiber optic sensors, isotope tracers, and geophysical methods such as electrical resistivity imaging. Conceptual advances were made in understanding the effects of unsteady environmental conditions (e.g., tides and storms) and preferential flow on hyporheic processes. Finally, hyporheic science is being brought increasingly to bear on applied issues such as informing nutrient removal crediting for stream restoration practices, for example in the Chesapeake Bay watershed.

Mars Science with Small Aircraft

NASA Technical Reports Server (NTRS)

Calvin, W. M.; Miralles, C.; Clark, B. C.; Wilson, G. R.

2000-01-01

The Mars program has articulated a strategy to answer the question "Could Life have arisen on Mars?" by pursuing an in depth understanding of the location, persistence and expression of water in the surface and sub-surface environments. In addition to the need to understand the role of water in climate and climate history, detailed understanding of the surface and interior of the planet is required as well. Return of samples from the Martian surface is expected to provide key answers and site selection to maximize the science gleaned from samples becomes critical. Current and past orbital platforms have revealed a surface and planetary history of surprising complexity. While these remote views significantly advance our understanding of the planet it is clear that detailed regional surveys can both answer specific open questions as well as provide initial reconnaissance for subsequent landed operations.

Nanofluidics: A New Arena for Materials Science.

PubMed

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.

Structural characteristics of surface-functionalized nitrogen-doped diamond-like carbon films and effective adjustment to cell attachment

NASA Astrophysics Data System (ADS)

Liu, Ai-Ping; Liu, Min; Yu, Jian-Can; Qian, Guo-Dong; Tang, Wei-Hua

2015-05-01

Nitrogen-doped diamond-like carbon (DLC:N) films prepared by the filtered cathodic vacuum arc technology are functionalized with various chemical molecules including dopamine (DA), 3-Aminobenzeneboronic acid (APBA), and adenosine triphosphate (ATP), and the impacts of surface functionalities on the surface morphologies, compositions, microstructures, and cell compatibility of the DLC:N films are systematically investigated. We demonstrate that the surface groups of DLC:N have a significant effect on the surface and structural properties of the film. The activity of PC12 cells depends on the particular type of surface functional groups of DLC:N films regardless of surface roughness and wettability. Our research offers a novel way for designing functionalized carbon films as tailorable substrates for biosensors and biomedical engineering applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 51272237, 51272231, and 51010002) and the China Postdoctoral Science Foundation (Grant Nos. 2012M520063, 2013T60587, and Bsh1201016).

Autonomous Aerobraking Using Thermal Response Surface Analysis

NASA Technical Reports Server (NTRS)

Prince, Jill L.; Dec, John A.; Tolson, Robert H.

2007-01-01

Aerobraking is a proven method of significantly increasing the science payload that can be placed into low Mars orbits when compared to an all propulsive capture. However, the aerobraking phase is long and has mission cost and risk implications. The main cost benefit is that aerobraking permits the use of a smaller and cheaper launch vehicle, but additional operational costs are incurred during the long aerobraking phase. Risk is increased due to the repeated thermal loading of spacecraft components and the multiple attitude and propulsive maneuvers required for successful aerobraking. Both the cost and risk burdens can be significantly reduced by automating the aerobraking operations phase. All of the previous Mars orbiter missions that have utilized aerobraking have increasingly relied on onboard calculations during aerobraking. Even though the temperature of spacecraft components has been the limiting factor, operational methods have relied on using a surrogate variable for mission control. This paper describes several methods, based directly on spacecraft component maximum temperature, for autonomously predicting the subsequent aerobraking orbits and prescribing apoapsis propulsive maneuvers to maintain the spacecraft within specified temperature limits. Specifically, this paper describes the use of thermal response surface analysis in predicting the temperature of the spacecraft components and the corresponding uncertainty in this temperature prediction.

A method to evaluate utility for architectural comparisons for a campaign to explore the surface of Mars

NASA Astrophysics Data System (ADS)

Ward, Eric D.; Webb, Ryan R.; deWeck, Olivier L.

2016-11-01

There is a general consensus that Mars is the next high priority destination for human space exploration. There has been no lack of analysis and recommendations for human missions to Mars, including, for example, the NASA Design Reference Architectures and the Mars Direct proposal. These studies and others usually employ the traditional approach of selecting a baseline mission architecture and running individual trade studies. However, this can cause blind spots, as not all combinations are explored. An alternative approach is to holistically analyze the entire architectural trade-space such that all of the possible system interactions are identified and measured. In such a framework, an optimal design is sought by minimizing cost for maximal value. While cost is relatively easy to model for manned spaceflight, value is more difficult to define. In our efforts to develop a surface base architecture for the MIT Mars 2040 project, we explored several methods for quantifying value, including technology development benefits, challenge, and various metrics for measuring scientific return. We developed a science multi-score method that combines astrobiology and geologic research goals, which is weighted by the crew-member hours that can be used for scientific research rather than other activities.

Real-time specific surface area measurements via laser-induced breakdown spectroscopy

USGS Publications Warehouse

Washburn, Kathryn E.; Birdwell, Justin E.; Howard, James E.

2017-01-01

From healthcare to cosmetics to environmental science, the specific surface area (SSA) of micro- and mesoporous materials or products can greatly affect their chemical and physical properties. SSA results are also widely used to examine source rocks in conventional and unconventional petroleum resource plays. Despite its importance, current methods to measure SSA are often cumbersome, time-consuming, or require cryogenic consumables (e.g., liquid nitrogen). These methods are not amenable to high-throughput environments, have stringent sample preparation requirements, and are not practical for use in the field. We present a new application of laser-induced breakdown spectroscopy for rapid measurement of SSA. This study evaluates geological samples, specifically organic-rich oil shales, but the approach is expected to be applicable to many other types of materials. The method uses optical emission spectroscopy to examine laser-generated plasma and quantify the amount of argon adsorbed to a sample during an inert gas purge. The technique can accommodate a wide range of sample sizes and geometries and has the potential for field use. These advantages for SSA measurement combined with the simultaneous acquisition of composition information make this a promising new approach for characterizing geologic samples and other materials.

Chemistry and materials science progress report, FY 1994

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

NONE

1995-07-01

Research is reported in the areas of surface science, fundamentals of the physics and processing of metals, energetic materials, transactinide materials and properties and other indirectly related areas of weapons research.

Improvement of PET surface hydrophilicity and roughness through blending

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

Kolahchi, Ahmad Rezaei; Ajji, Abdellah; Carreau, Pierre J.

Controlling the adhesion of the polymer surface is a key issue in surface science, since polymers have been a commonly used material for many years. The surface modification in this study includes two different aspects. One is to enhance the hydrophilicity and the other is to create the roughness on the PET film surface. In this study we developed a novel and simple approach to modify polyethylene terephthalate (PET) film surface through polymer blending in twin-screw extruder. One example described in the study uses polyethylene glycol (PEG) in polyethylene terephthalate (PET) host to modify a PET film surface. Low contentmore » of polystyrene (PS) as a third component was used in the system to increase the rate of migration of PEG to the surface of the film. Surface enrichment of PEG was observed at the polymer/air interface of the polymer film containing PET-PEG-PS whereas for the PET-PEG binary blend more PEG was distributed within the bulk of the sample. Furthermore, a novel method to create roughness at the PET film surface was proposed. In order to roughen the surface of PET film, a small amount of PKHH phenoxy resin to change PS/PET interfacial tension was used. The compatibility effect of PKHH causes the formation of smaller PS droplets, which were able to migrate more easily through PET matrix. Consequently, resulting in a locally elevated concentration of PS near the surface of the film. The local concentration of PS eventually reached a level where a co-continuous morphology occurred, resulting in theinstabilities on the surface of the film.« less

Scientific Investigations Associated with the Human Exploration of Mars in the Next 35 Years

NASA Technical Reports Server (NTRS)

Niles, P. B.; Beaty, David; Hays, Lindsay; Bass, Deborah; Bell, Mary Sue; Bleacher, Jake; Cabrol, Nathalie A.; Conrad, Pan; Eppler, Dean; Hamilton, Vicky;

An Ab Initio Full Potential Fully Relativistic Study of the (0001) Surface of Double Hexagonal Close Packed Americium*

NASA Astrophysics Data System (ADS)

Gao, Da; Ray, Asok

2007-03-01

The electronic and geometric properties of bulk dhcp Am as well as quantum size effects in the surface energies and the work functions of the dhcp Am (0001) ultra thin films up to seven layers have been examined at nonmagnetic, ferromagnetic, and anti-ferromagnetic configurations via full-potential all-electron density-functional calculations with a mixed APW+lo/LAPW basis. The anti-ferromagnetic state including spin-orbit coupling is found to be the ground state of both bulk and the (0001) surface of dhcp Am with the 5f electrons primarily localized. Our results show that magnetic configurations and spin-orbit coupling play important roles in determining the equilibrium lattice constant, the bulk modulus as well as the localized feature of 5f electrons for dhcp Am. Quantum size effects are found to be more pronounced in work functions than in surface energies. *This work is supported by the Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U. S. Department of Energy and the Welch Foundation, Houston, Texas.

Managing Science Operations during Planetary Surface Operations at Long Light Delay-Time Targets: The 2011 Desert RATS Test

NASA Technical Reports Server (NTRS)

Eppler, D. B.

2012-01-01

Desert Research and Technology Studies (Desert RATS) is a multi-year series of hardware and operations tests carried out annually in the high desert of Arizona in the San Francisco Volcanic Field. Conducted since 1997, these activities are designed to exercise planetary surface hardware and operations in conditions where multi-day tests are achievable. Desert RATS 2011 Science Operations Test simulated the management of crewed science operations at targets that were beyond the light delay time experienced during Low-Earth Orbit (LEO) and lunar surface missions, such as a mission to a Near-Earth Object (NEO) or the martian surface. Operations at targets at these distances are likely to be the norm as humans move out of the Earth-Moon system. Operating at these distances places significant challenges on mission operations, as the imposed light-delay time makes normal, two-way conversations extremely inefficient. Consequently, the operations approach for space missions that has been exercised during the first half-century of human space operations is no longer viable, and new approaches must be devised.

Comparing wind directions inferred from Martian dust devil tracks analysis with those predicted by the Mars Climate Database

NASA Astrophysics Data System (ADS)

Statella, T.; Pina, P.; Silva, E. A.; Nervis Frigeri, Ary Vinicius; Neto, Frederico Gallon

2016-10-01

We have calculated the prevailing dust devil tracks direction as a means of verifying the Mars Climate Database (MCD) predicted wind directions accuracy. For that purpose we have applied an automatic method based on morphological openings for inferring the prevailing tracks direction in a dataset comprising 200 Mars Orbiter Camera (MOC) Narrow Angle (NA) and High Resolution Imaging Science Experiment (HiRISE) images of the Martian surface, depicting regions in the Aeolis, Eridania, Noachis, Argyre and Hellas quadrangles. The prevailing local wind directions were calculated from the MCD predicted speeds for the WE and SN wind components. The results showed that the MCD may not be able to predict accurately the locally dominant wind direction near the surface. In adittion, we confirm that the surface wind stress alone cannot produce dust lifting in the studied sites, since it never exceeds the threshold value of 0.0225 Nm-2 in the MCD.

The effect of impurities and incident angle on the secondary electron emission of Ni(110)

NASA Astrophysics Data System (ADS)

Lazar, Hadar; Patino, Marlene; Raitses, Yevgeny; Koel, Bruce E.; Gentile, Charles; Feibush, Eliot

2015-11-01

The investigation of secondary electron emission (SEE) of conducting materials used for magnetic fusion devices and plasma thrusters is important for determining device lifetime and performance. Methods to quantify the secondary electron emission from conducting materials and to characterize the effects that impurities and incident angles have on secondary electron emission were developed using 4-grid low energy electron diffraction (LEED) optics. The total secondary electron yield from a Ni(110) surface was continuously measured from the sample current as surface contamination increased from reactions with background gases in the ultrahigh vacuum chamber. Auger electron spectroscopy (AES) and temperature programmed desorption (TPD) were used to examine the composition and impurity levels on the Ni(110) surface. The total secondary electron yield was also measured at different incident angles. Thank you to the Princeton Plasma Physics Laboratory and the Department of Energy for the opportunity to work on this project through the Science Undergraduate Laboratory Internships.

Evaluation of Skin Surface as an Alternative Source of Reference DNA Samples: A Pilot Study.

PubMed

Albujja, Mohammed H; Bin Dukhyil, Abdul Aziz; Chaudhary, Abdul Rauf; Kassab, Ahmed Ch; Refaat, Ahmed M; Babu, Saranya Ramesh; Okla, Mohammad K; Kumar, Sachil

2018-01-01

An acceptable area for collecting DNA reference sample is a part of the forensic DNA analysis development. The aim of this study was to evaluate skin surface cells (SSC) as an alternate source of reference DNA sample. From each volunteer (n = 10), six samples from skin surface areas (forearm and fingertips) and two traditional samples (blood and buccal cells) were collected. Genomic DNA was extracted and quantified then genotyped using standard techniques. The highest DNA concentration of SSC samples was collected using the tape/forearm method of collection (2.1 ng/μL). Cotton swabs moistened with ethanol yielded higher quantities of DNA than swabs moistened with salicylic acid, and it gave the highest percentage of full STR profiles (97%). This study supports the use of SSC as a noninvasive sampling technique and as a extremely useful source of DNA reference samples among certain cultures where the use of buccal swabs can be considered socially unacceptable. © 2017 American Academy of Forensic Sciences.

Electronic and total energy properties of ternary and quaternary semiconductor compounds, alloys, and superlattices: Theoretical study of Cu/graphite bonding

NASA Technical Reports Server (NTRS)

Lambrecht, Walter R. L.

1992-01-01

The goals of the research were to provide a fundamental science basis for why the bonding of Cu to graphite is weak, to critically evaluate the previous analysis of the wetting studies with particular regard to the values used for the surface energies of Cu and graphite, and to make recommendations for future experiments or other studies which could advance the understanding and solution of this technological problem. First principles electronic structure calculations were used to study the problem. These are based on density functional theory in the local density approximation and the use of the linear muffin-tin orbital band structure method. Calculations were performed for graphite monolayers, single crystal graphite with the hexagonal AB stacking, bulk Cu, Cu(111) surface, and Cu/graphite superlattices. The study is limited to the basal plane of graphite because this is the graphite plane exposed to Cu and graphite surface energies and combined with the measured contact angles to evaluate the experimental adhesion energy.

Theoretical Foundations of Study of Cartography

NASA Astrophysics Data System (ADS)

Talhofer, Václav; Hošková-Mayerová, Šárka

2018-05-01

Cartography and geoinformatics are technical-based fields which deal with modelling and visualization of landscape in the form of a map. The theoretical foundation is necessary to obtain during study of cartography and geoinformatics based mainly on mathematics. For the given subjects, mathematics is necessary for understanding of many procedures that are connected to modelling of the Earth as a celestial body, to ways of its projection into a plane, to methods and procedures of modelling of landscape and phenomena in society and visualization of these models in the form of electronic as well as classic paper maps. Not only general mathematics, but also its extension of differential geometry of curves and surfaces, ways of approximation of lines and surfaces of functional surfaces, mathematical statistics and multi-criterial analyses seem to be suitable and necessary. Underestimation of the significance of mathematical education in cartography and geoinformatics is inappropriate and lowers competence of cartographers and professionals in geographic information science and technology to solve problems.

Composite Fermi surface in the half-filled Landau level with anisotropic electron mass

NASA Astrophysics Data System (ADS)

Ippoliti, Matteo; Geraedts, Scott; Bhatt, Ravindra

We study the problem of interacting electrons in the lowest Landau level at half filling in the quantum Hall regime, when the electron dispersion is given by an anisotropic mass tensor. Based on experimental observations and theoretical arguments, the ground state of the system is expected to consist of composite Fermions filling an elliptical Fermi sea, with the anisotropy of the ellipse determined by the competing effects of the isotropic Coulomb interaction and anisotropic electron mass tensor. We test this idea quantitatively by using a numerical density matrix renormalization group method for quantum Hall systems on an infinitely long cylinder. Singularities in the structure factor allow us to map the Fermi surface of the composite Fermions. We compute the composite Fermi surface anisotropy for several values of the electron mass anisotropy which allow us to deduce the functional dependence of the former on the latter. This research was supported by Department of Energy Office of Basic Energy Sciences through Grant No. DE-SC0002140.

Dopamine-assisted co-deposition: An emerging and promising strategy for surface modification.

PubMed

Qiu, Wen-Ze; Yang, Hao-Cheng; Xu, Zhi-Kang

2018-04-27

Mussel-inspired chemistry based on polydopamine (PDA) deposition has been developed as a facile and universal method for the surface modification of various materials. However, the inherent shortcomings of PDA coatings still impede their practical applications in the development of functional materials. In this review, we introduce the recent progress in the emerging dopamine-assisted co-deposition as a one-step strategy for functionalizing PDA-based coatings, and improving them in the aspects of deposition rate, morphology uniformity, surface wettability and chemical stability. The co-deposition mechanisms are categorized and discussed according to the interactions of dopamine or PDA with the introduced co-component. We also emphasize the influence of these interactions on the properties of the resultant PDA-based coatings. Meanwhile, we conclude the representative potential applications of those dopamine-assisted co-deposited coatings in material science, especially including separation membranes and biomaterials. Finally, some important issues and perspectives for theoretical study and applications are briefly discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Surface plasmon resonance near-infrared spectroscopy.

PubMed

Ikehata, Akifumi; Itoh, Tamitake; Ozaki, Yukihiro

2004-11-01

Near-infrared (NIR) spectroscopy is ill-suited to microanalysis because of its low absorptivity. We have developed a highly sensitive detection method for NIR spectroscopy based on absorption-sensitive surface plasmon resonance (SPR). The newly named SPR-NIR spectroscopy, which may open the way for NIR spectroscopy in microanalysis and surface science, is realized by an attachment of the Kretschmann configuration equipped with a mechanism for fine angular adjustment of incident light. The angular sweep of incident light enables us to make a tuning of a SPR peak for an absorption band of sample medium. From the dependences of wavelength, incident angle, and thickness of a gold film on the intensity of the SPR peak, it has been found that the absorbance can be enhanced by approximately 100 times compared with the absorbance obtained without the gold film under optimum conditions. This article reports the details of the experimental setup and the characteristics of absorption-sensitive SPR in the NIR region, together with some experimental results obtained by using it.

The effects of impurities and incidence angle on the secondary electron emission of Ni(110)

NASA Astrophysics Data System (ADS)

Lazar, Hadar; Patino, Marlene; Raitses, Yevgeny; Koel, Bruce; Gentile, Charles; Feibush, Eliot

The investigation of secondary electron emission (SEE) of conducting materials used for magnetic fusion devices and plasma thrusters is important for determining device lifetime and performance. Methods to quantify the secondary electron emission from conducting materials and to characterize the effects that impurities and incidence angles have on secondary electron emission were developed using 4-grid low energy electron diffraction (LEED) optics. The total secondary electron yield from a Ni(110) surface was continuously measured from the sample current as surface contamination increased from reactions with background gases in the ultrahigh vacuum chamber. Auger electron spectroscopy (AES) and temperature programmed desorption (TPD) were used to examine the composition and impurity levels on the Ni(110) surface. The total secondary electron yield was also measured at different incidence angles. Thank you to the Princeton Plasma Physics Laboratory (PPPL) and the Department of Energy (DOE) for the opportunity to work on this project through the Science Undergraduate Laboratory Internships (SULI).

TOPEX/POSEIDON - Mapping the ocean surface

NASA Technical Reports Server (NTRS)

Yamarone, C. A.; Rosell, S.; Farless, D. L.

1986-01-01

Global efforts are under way to model the earth as a complete planet so that weather patterns may be predicted on time scales of months and years. A major limitation in developing models of global weather is the inability to model the circulation of the oceans including the geostrophic surface currents. NASA will soon be initiating a satellite program to correct this deficiency by directly measuring these currents using the science of radar altimetry. Measurement of the ocean topography with broad, frequent coverage of all ocean basins for a long period of time will allow the derivation of the spatial and temporal behavior of surface ocean currents. The TOPEX/POSEIDON mission is a cooperative effort between NASA and the French Centre National d'Etudes Spatiales. This paper describes the goals of this research mission, the data type to be acquired, the satellite and sensors to be used to acquire the data, and the methods by which the data are to be processed and utilized.

Enhancing forensic science with spectroscopic imaging

NASA Astrophysics Data System (ADS)

Ricci, Camilla; Kazarian, Sergei G.

2006-09-01

This presentation outlines the research we are developing in the area of Fourier Transform Infrared (FTIR) spectroscopic imaging with the focus on materials of forensic interest. FTIR spectroscopic imaging has recently emerged as a powerful tool for characterisation of heterogeneous materials. FTIR imaging relies on the ability of the military-developed infrared array detector to simultaneously measure spectra from thousands of different locations in a sample. Recently developed application of FTIR imaging using an ATR (Attenuated Total Reflection) mode has demonstrated the ability of this method to achieve spatial resolution beyond the diffraction limit of infrared light in air. Chemical visualisation with enhanced spatial resolution in micro-ATR mode broadens the range of materials studied with FTIR imaging with applications to pharmaceutical formulations or biological samples. Macro-ATR imaging has also been developed for chemical imaging analysis of large surface area samples and was applied to analyse the surface of human skin (e.g. finger), counterfeit tablets, textile materials (clothing), etc. This approach demonstrated the ability of this imaging method to detect trace materials attached to the surface of the skin. This may also prove as a valuable tool in detection of traces of explosives left or trapped on the surfaces of different materials. This FTIR imaging method is substantially superior to many of the other imaging methods due to inherent chemical specificity of infrared spectroscopy and fast acquisition times of this technique. Our preliminary data demonstrated that this methodology will provide the means to non-destructive detection method that could relate evidence to its source. This will be important in a wider crime prevention programme. In summary, intrinsic chemical specificity and enhanced visualising capability of FTIR spectroscopic imaging open a window of opportunities for counter-terrorism and crime-fighting, with applications ranging from analysis of trace evidence (e.g. in soil), tablets, drugs, fibres, tape explosives, biological samples to detection of gunshot residues and imaging of fingerprints.

Dynamic Cooperation of Hydrogen Binding and π Stacking in ssDNA Adsorption on Graphene Oxide.

PubMed

Xu, Zhen; Lei, Xiaoling; Tu, Yusong; Tan, Zhi-Jie; Song, Bo; Fang, Haiping

2017-09-21

Functional nanoscale structures consisting of a DNA molecule coupled to graphene or graphene oxide (GO) have great potential for applications in biosensors, biomedicine, nanotechnology, and materials science. Extensive studies using the most sophisticated experimental techniques and theoretical methods have still not clarified the dynamic process of single-stranded DNA (ssDNA) adsorbed on GO surfaces. Based on a molecular dynamics simulation, this work shows that an ssDNA segment could be stably adsorbed on a GO surface through hydrogen bonding and π-π stacking interactions, with preferential binding to the oxidized rather than to the unoxidized region of the GO surface. The adsorption process shows a dynamic cooperation adsorption behavior; the ssDNA segment first captures the oxidized groups of the GO surface by hydrogen bonding interaction, and then the configuration relaxes to maximize the π-π stacking interactions between the aromatic rings of the nucleobases and those of the GO surface. We attributed this behavior to the faster forming hydrogen bonding interaction compared to π-π stacking; the π-π stacking interaction needs more relaxation time to regulate the configuration of the ssDNA segment to fit the aromatic rings on the GO surface. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Probing Interfacial Processes on Graphene Surface by Mass Detection

NASA Astrophysics Data System (ADS)

Kakenov, Nurbek; Kocabas, Coskun

2013-03-01

In this work we studied the mass density of graphene, probed interfacial processes on graphene surface and examined the formation of graphene oxide by mass detection. The graphene layers were synthesized by chemical vapor deposition method on copper foils and transfer-printed on a quartz crystal microbalance (QCM). The mass density of single layer graphene was measured by investigating the mechanical resonance of the QCM. Moreover, we extended the developed technique to probe the binding dynamics of proteins on the surface of graphene, were able to obtain nonspecific binding constant of BSA protein of graphene surface in aqueous solution. The time trace of resonance signal showed that the BSA molecules rapidly saturated by filling the available binding sites on graphene surface. Furthermore, we monitored oxidation of graphene surface under oxygen plasma by tracing the changes of interfacial mass of the graphene controlled by the shifts in Raman spectra. Three regimes were observed the formation of graphene oxide which increases the interfacial mass, the release of carbon dioxide and the removal of small graphene/graphene oxide flakes. Scientific and Technological Research Council of Turkey (TUBITAK) grant no. 110T304, 109T209, Marie Curie International Reintegration Grant (IRG) grant no 256458, Turkish Academy of Science (TUBA-Gebip).

Wavelet analysis of hemispheroid flow separation toward understanding human vocal fold pathologies

NASA Astrophysics Data System (ADS)

Plesniak, Daniel H.; Carr, Ian A.; Bulusu, Kartik V.; Plesniak, Michael W.

2014-11-01

Physiological flows observed in human vocal fold pathologies, such as polyps and nodules, can be modeled by flow over a wall-mounted protuberance. The experimental investigation of flow separation over a surface-mounted hemispheroid was performed using particle image velocimetry (PIV) and measurements of surface pressure in a low-speed wind tunnel. This study builds on the hypothesis that the signatures of vortical structures associated with flow separation are imprinted on the surface pressure distributions. Wavelet decomposition methods in one- and two-dimensions were utilized to elucidate the flow behavior. First, a complex Gaussian wavelet was used for the reconstruction of surface pressure time series from static pressure measurements acquired from ports upstream, downstream, and on the surface of the hemispheroid. This was followed by the application of a novel continuous wavelet transform algorithm (PIVlet 1.2) using a 2D-Ricker wavelet for coherent structure detection on instantaneous PIV-data. The goal of this study is to correlate phase shifts in surface pressure with Strouhal numbers associated with the vortex shedding. Ultimately, the wavelet-based analytical framework will be aimed at addressing pulsatile flows. This material is based in part upon work supported by the National Science Foundation under Grant Number CBET-1236351, and GW Center for Biomimetics and Bioinspired Engineering (COBRE).

GNSS as a sea ice sensor - detecting coastal freeze states with ground-based GNSS-R

NASA Astrophysics Data System (ADS)

Strandberg, Joakim; Hobiger, Thomas; Haas, Rüdiger

2017-04-01

Based on the idea of using freely available signals for remote sensing, ground-based GNSS-reflectometry (GNSS-R) has found more and more applications in hydrology, oceanography, agriculture and other Earth sciences. GNSS-R is based on analysing the elevation dependent SNR patterns of GNSS signals, and traditionally only the oscillation frequency and phase have been studied to retrieve parameters from the reflecting surfaces. However, recently Strandberg et al. (2016) developed an inversion algorithm that has changed the paradigms of ground-based GNSS-R as it enables direct access to the radiometric properties of the reflector. Using the signal envelope and the rate at which the magnitude of the SNR oscillations are damped w.r.t. satellite elevation, the algorithm retrieves the roughness of the reflector surface amongst other parameters. Based on this idea, we demonstrate for the first time that a GNSS installation situated close to the coastline can detect the presence of sea-ice unambiguously. Using data from the GTGU antenna at the Onsala Space Observatory, Sweden, the time series of the derived damping parameter clearly matches the occurrence of ice in the bay where the antenna is situated. Our results were validated against visual inspection logs as well as with the help of ice charts from the Swedish Meteorological and Hydrological Institute. Our method is even sensitive to partial and intermediate ice formation stages, with clear difference in response between frazil ice and both open and solidly frozen water surfaces. As the GTGU installation is entirely built with standard geodetic equipment, the method can be applied directly to any coastal GNSS site, allowing analysis of both new and historical data. One can use the method as an automatic way of retrieving independent ground truth data for ice extent measurements for use in hydrology, cryosphere studies, and even societal interest fields such as sea transportation. Finally, the new method opens up for further studies in the response of GNSS-R to ice-related parameters, as periods of ice can easily be detected in both historical and new GNSS data. Strandberg J., T. Hobiger, and Rüdiger Haas (2016), Improving GNSS-R sea level determination through inverse modeling of SNR data, Radio Science, 51(8), 1286-1296, doi:10.1002/2016RS006057.

Initial development of an NIR strain measurement technique in brittle geo-materials

NASA Astrophysics Data System (ADS)

Butcher, Emily; Gibson, Andrew; Benson, Philip

2016-04-01

Visible-Near Infrared Spectroscopy (VIS-NIR) is a technique developed for the non-contact measurement of compositional characteristics of surfaces. The technique is rapid, sensitive to change in surface topology and has found applications ranging from planetary geology, soil science, pharmacy to materials testing. The technique has also been used in a limited fashion to measure strain changes in rocks and minerals (Ord and Hobbs 1986). However, there have been few quantitative studies linking such changes in material strains (and other rock physics parameters) to the resulting VIS-NIT signature. This research seeks to determine whether improvements in VIS-NIR equipment means that such a technique is a viable method to measure strains in rock via this remote (non-contact) method. We report new experiments carried out using 40 mm Brazilian Tensile discs of Carrera Marble and Darley Dale Sandstone using an Instron 600LX in the University of Portsmouth Rock Mechanics Laboratory. The tensile test was selected for this experiment as the sample shape and sensor arrangements allow access to a 'flat' surface area throughout the test, allowing surface measurements to be continuously taken whilst the discs are strained to failure. An ASD Labspec 5000 with 25 mm foreoptic was used to collect reflectance spectra in the range 350-2500 nm during each tensile test. Results from Carrera Marble experiments show that reflectance at 2050 nm negatively correlates (by polynomial regression) with axial strain between 0.05-0.5%, with r2 of 0.99. Results from Darley Dale Sandstone data show that reflectance at 1970 nm positively correlates with axial deformation between 0.05-0.5%, with r2 of 0.98. Initial analyses suggests that the VIS-NIR possesses an output that scales in a quantifiable manner with rock strain, and shows promise as a technique for strain measurement. The method has particular application for allowing our laboratory measurements to "ground truth" data taken from drone and other remote sensing techniques that could employ this method. However, further work is underway to understand the exact nature of the correlations - for instance, whether reflectance is related to deformation to the mineral lattice, macro-surface or micro-surface.

Agile Science Operations: A New Approach for Primitive Exploration Bodies

NASA Technical Reports Server (NTRS)

Chien, Steve A.; Thompson, David R.; Castillo-Rogez, Julie C.; Doyle, Richard; Estlin, Tara; Mclaren, David

2012-01-01

Primitive body exploration missions such as potential Comet Surface Sample Return or Trojan Tour and Rendezvous would challenge traditional operations practices. Earth-based observations would provide only basic understanding before arrival and many science goals would be defined during the initial rendezvous. It could be necessary to revise trajectories and observation plans to quickly characterize the target for safe, effective observations. Detection of outgassing activity and monitoring of comet surface activity are even more time constrained, with events occurring faster than round-trip light time. "Agile science operations" address these challenges with contingency plans that recognize the intrinsic uncertainty in the operating environment and science objectives. Planning for multiple alternatives can significantly improve the time required to repair and validate spacecraft command sequences. When appropriate, time-critical decisions can be automated and shifted to the spacecraft for immediate access to instrument data. Mirrored planning systems on both sides of the light-time gap permit transfer of authority back and forth as needed. We survey relevant science objectives, identifying time bottlenecks and the techniques that could be used to speed missions' reaction to new science data. Finally, we discuss the results of a trade study simulating agile observations during flyby and comet rendezvous scenarios. These experiments quantify instrument coverage of key surface features as a function of planning turnaround time. Careful application of agile operations techniques can play a significant role in realizing the Decadal Survey plan for primitive body exploration

Dilemmas of Teaching Inquiry in Elementary Science Methods

ERIC Educational Resources Information Center

Newman, William J., Jr.; Abell, Sandra K.; Hubbard, Paula D.; McDonald, James; Otaala, Justine; Martini, Mariana

2004-01-01

Because various definitions of inquiry exist in the science education literature and in classroom practice, elementary science methods students and instructors face dilemmas during the study of inquiry. Using field notes, instructor anecdotal notes, student products, and course artifacts, science methods course instructors created fictional…

SeisCube Instrument and Environment Considerations for the Didymos System Geophysical Exploration

NASA Astrophysics Data System (ADS)

Cadu, Alexandre; Murdoch, Naomi; Mimoun, David; Karatekin, Ozgur; Garica, Raphaël F.; Carrasco, Jose A.; De Quiros, Francisco G.; Vasseur, Hugues; Eubanks, Marshall; Radley, Charles; Ritter, Birgit; Dehant, Veronique

2016-04-01

In the context of the Asteroid Impact & Deviation Assessment (AIDA) mission proposed by ESA and NASA, the Asteroid Geophysical Explorer (AGEX) mission concept has been selected for a preliminary study phase. Two 3-Unit CubeSats are embedded into the AIM probe and released into the asteroid binary system [1]. SeisCube will be deployed close to the secondary to reach its surface at a low relative velocity in order to stay on the ground after several rebounds, in a similar way that is foreseen for Mascot-2. The purpose of SeisCube is to provide information about the surface, the sub-surface and the internal structure of the asteroid, by analyzing rebound acceleration profile and seismic activity [2]. We describe the considered instrumentation necessary to fulfill the science objectives (gravimeters, accelerometers, geophones, etc.) in terms of measurement dynamics, frequency ranges, acquisition methods and other common budgets for space equipment. We also present the environment considerations which have to be taken into account for the platform and payload designs. The thermal aspect will be particularly discussed since it is a major issue in the airless body exploration [3] [4]. It implies some modifications in the CubeSat structure, integration and thermal regulation to ensure survival and operations under extreme conditions at the asteroid surface. We then describe the platform subsystems needed to ensure the operations after the deployment and the associated budgets and accommodation. As a direct consequence of the previous topics, we will finally discuss the possible trades-off to satisfy the main science requirements and the associated concept of operations. [1] O. Karatekin, D. Mimoun, J. A. Carrasco, N. Murdoch, A. Cadu, R. F. Garcia, F. G. De Quiros, H. Vasseur, B. Ritter, M. Eubanks, C. Radley and V. Dehant, "The Asteroid Geophysical Explorer (AGEX): Proposal to explore Didymos system using Cubsats," in European Geophysical Union, 2016. [2] N. Murdoch, A. Cadu, D. Mimoun, O. Karatekin, R. F. Garcia, J. A. Carrasco, F. G. De Guiros, H. Vasseur, B. Ritter, M. Eubanks, C. Radley and V. Dehart, "Invertigating the surface and subsurface properties of the Didymos binary asteroid with a landed CubeSat," in European Geophysical Union, 2016. [3] J. De Lafontaine and D. Kassing, "Technologies and Concepts for Lunar Surface Exploration," Acta Astronautica, vol. 38, no. 2, pp. 125-129, 1996. [4] S. Ulamec, J. Biele and E. Trollope, "How to survive a Lunar night," Planetary and Space Science, vol. 58, no. 14-15, pp. 1985-1995, 2010.

Optical properties of medium size noble and transition metal nanoparticles

NASA Astrophysics Data System (ADS)

Idrobo, Juan C.; Pantelides, Sokrates T.

2009-03-01

Using first-principles methods within time dependent density functional theory and the local density approximation (TDLDA) the absorption spectra of medium size (˜20-80 atoms) silver, gold and copper nanoparticles have been calculated. The nanoparticles are fcc fragments with different aspect ratios. We find that in the case of Ag nanoparticles is well reproduced by classical electrodynamics theory based in Mie's formalism, using the dielectric function of bulk Ag and taking into account the nanoparticle shape. For the case of Cu and Au, there is a similarity in the overall features of the quantum mechanical and classical spectra, but no detailed agreement. We will discuss the role that the d-electrons among all the different elements and the surface states play in controlling the optical properties of the nanoparticles. This work was supported by GOALI NSF grant (DMR-0513048), DOE, the Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, and Alcoa Inc.

MSL Chemistry and Mineralogy X-Ray Diffraction X-Ray Fluorescence (CheMin) Instrument

NASA Technical Reports Server (NTRS)

Zimmerman, Wayne; Blake, Dave; Harris, William; Morookian, John Michael; Randall, Dave; Reder, Leonard J.; Sarrazin, Phillipe

2013-01-01

This paper provides an overview of the Mars Science Laboratory (MSL) Chemistry and Mineralogy Xray Diffraction (XRD), X-ray Fluorescence (XRF) (CheMin) Instrument, an element of the landed Curiosity rover payload, which landed on Mars in August of 2012. The scientific goal of the MSL mission is to explore and quantitatively assess regions in Gale Crater as a potential habitat for life - past or present. The CheMin instrument will receive Martian rock and soil samples from the MSL Sample Acquisition/Sample Processing and Handling (SA/SPaH) system, and process it utilizing X-Ray spectroscopy methods to determine mineral composition. The Chemin instrument will analyze Martian soil and rocks to enable scientists to investigate geophysical processes occurring on Mars. The CheMin science objectives and proposed surface operations are described along with the CheMin hardware with an emphasis on the system engineering challenges associated with developing such a complex instrument.

Application of atomic force microscopy as a nanotechnology tool in food science.

PubMed

Yang, Hongshun; Wang, Yifen; Lai, Shaojuan; An, Hongjie; Li, Yunfei; Chen, Fusheng

2007-05-01

Atomic force microscopy (AFM) provides a method for detecting nanoscale structural information. First, this review explains the fundamentals of AFM, including principle, manipulation, and analysis. Applications of AFM are then reported in food science and technology research, including qualitative macromolecule and polymer imaging, complicated or quantitative structure analysis, molecular interaction, molecular manipulation, surface topography, and nanofood characterization. The results suggested that AFM could bring insightful knowledge on food properties, and the AFM analysis could be used to illustrate some mechanisms of property changes during processing and storage. However, the current difficulty in applying AFM to food research is lacking appropriate methodology for different food systems. Better understanding of AFM technology and developing corresponding methodology for complicated food systems would lead to a more in-depth understanding of food properties at macromolecular levels and enlarge their applications. The AFM results could greatly improve the food processing and storage technologies.

High-resolution Surface Analysis by Microarea Auger Spectroscopy: Computerization and Characterization

NASA Technical Reports Server (NTRS)

Browning, R.

1986-01-01

A custom scanning Auger electron microscope (SAM) capable of introducing a 3-5 keV electron beam of several nA into a 30 nm diameter sample area was fitted with a sample introduction system and was fully computerized to be used for materials science research. The method of multispectral Auger imaging was devised and implemented. The instrument was applied to various problems in materials science, including the study of the fiber/matrix interface in a SiC reinforced titanium alloy, the study of SiC whiskers in Al alloy 2124 (in cooperation with NASA-Langley), the study of NiCrAl superalloys (in collaboration with NASA-Lewis), the study of zircalloy specimens (in collaboration with Stanford University), and the microstructure of sintered SiC specimens (in collaboration with NASA-Lewis). The report contains a number of manuscripts submitted for publication on these subjects.

Immobilizing Highly Catalytically Active Pt Nanoparticles inside the Pores of Metal-Organic Framework: A Double Solvents Approach

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

Aijaz, Arshad; Karkamkar, Abhijeet J.; Choi, Young Joon

2012-08-29

Ultrafine Pt nanoparticles were successfully immobilized inside the pores of a metal-organic framework MIL-101 without deposition of Pt nanoparticles on the external surfaces of framework by using a 'double solvents' method. The resulting Pt@MIL-101 composites with different Pt loadings represent the first highly active MOF-immobilized metal nanocatalysts for catalytic reactions in all three phases: liquid-phase ammonia borane hydrolysis; solid-phase ammonia borane thermal dehy-drogenation and gas-phase CO oxidation. The observed excellent catalytic performances are at-tributed to the small Pt nanoparticles within the pores of MIL-101. 'We are thankful to AIST and METI for financial support. TA & AK are thankful formore » support from the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. PNNL is operated by Battelle.'« less

Digital database architecture and delineation methodology for deriving drainage basins, and a comparison of digitally and non-digitally derived numeric drainage areas

USGS Publications Warehouse

Dupree, Jean A.; Crowfoot, Richard M.

2012-01-01

The drainage basin is a fundamental hydrologic entity used for studies of surface-water resources and during planning of water-related projects. Numeric drainage areas published by the U.S. Geological Survey water science centers in Annual Water Data Reports and on the National Water Information Systems (NWIS) Web site are still primarily derived from hard-copy sources and by manual delineation of polygonal basin areas on paper topographic map sheets. To expedite numeric drainage area determinations, the Colorado Water Science Center developed a digital database structure and a delineation methodology based on the hydrologic unit boundaries in the National Watershed Boundary Dataset. This report describes the digital database architecture and delineation methodology and also presents the results of a comparison of the numeric drainage areas derived using this digital methodology with those derived using traditional, non-digital methods. (Please see report for full Abstract)

A new method for the characterization of the degree of fire damage to gypsum wallboard for use in fire investigations.

PubMed

Gorbett, Gregory E; Morris, Sarah M; Meacham, Brian J; Wood, Christopher B

2015-01-01

A new method to characterize the degree of fire damage to gypsum wallboard is introduced, implemented, and tested to determine the efficacy of its application among novices. The method was evaluated by comparing degree of fire damage assessments of novices with and without the method. Thirty-nine "novice" raters assessed damage to a gypsum wallboard surface, completing 66 ratings, first without the method, and then again using the method. The inter-rater reliability was evaluated for ratings of damage without and with the method. For novice fire investigators rating degree of damage without the aid of the method, ICC(1,2) = 0.277 with 95% CI (0.211, 0.365), and with the method, ICC(2,1) = 0.593 with 95% CI (0.509, 0.684). Results indicate that the raters were more reliable in their analysis of the degree of fire damage when using the method, which support the use of standardized processes to decrease the variability in data collection and interpretation. © 2014 American Academy of Forensic Sciences.

Wavelet Filter Banks for Super-Resolution SAR Imaging

NASA Technical Reports Server (NTRS)

Sheybani, Ehsan O.; Deshpande, Manohar; Memarsadeghi, Nargess

2011-01-01

This paper discusses Innovative wavelet-based filter banks designed to enhance the analysis of super resolution Synthetic Aperture Radar (SAR) images using parametric spectral methods and signal classification algorithms, SAR finds applications In many of NASA's earth science fields such as deformation, ecosystem structure, and dynamics of Ice, snow and cold land processes, and surface water and ocean topography. Traditionally, standard methods such as Fast-Fourier Transform (FFT) and Inverse Fast-Fourier Transform (IFFT) have been used to extract Images from SAR radar data, Due to non-parametric features of these methods and their resolution limitations and observation time dependence, use of spectral estimation and signal pre- and post-processing techniques based on wavelets to process SAR radar data has been proposed. Multi-resolution wavelet transforms and advanced spectral estimation techniques have proven to offer efficient solutions to this problem.

Shape control VO2 nanorods prepared by soft chemistry and electrochemical method

NASA Astrophysics Data System (ADS)

Simo, A.; Sibanyoni, J.; Fuku, X.; Numan, N.; Omorogbe, S.; Maaza, M.

2018-07-01

"Bottom up" approach is of primary interest for chemistry and materials science because the fundamental building blocks are atoms. Thus colloidal chemical synthetic methods can be utilized to prepare uniform nanocrystals with controlled particle size. In the following work of study, thermochromic VO2 nanostructures were prepared by hydrothermal technique soft chemistry. We concentrate on solution phase synthetic methods that enable a proper shape and size control of metal oxide nanocrystals. Their structural properties were studied by Scanning Electron Microscopy (SEM), Fourier Transform IR (FTIR) and Differential Scanning Calorimetry (DSC). It is demonstrated that the surfactant assistance (NaOH) has great influence on the morphology-control of the material. Electrochemical properties of the nanospheres show good stability after 20 cycles and the surface diffusion coefficient was calculated to be 5 × 10-6 cm2 s-1.

The EUSTACE project: delivering global, daily information on surface air temperature

NASA Astrophysics Data System (ADS)

Rayner, Nick

2017-04-01

Day-to-day variations in surface air temperature affect society in many ways; however, daily surface air temperature measurements are not available everywhere. A global daily analysis cannot be achieved with measurements made in situ alone, so incorporation of satellite retrievals is needed. To achieve this, in the EUSTACE project (2015-June 2018, https://www.eustaceproject.eu) we are developing an understanding of the relationships between traditional (land and marine) surface air temperature measurements and retrievals of surface skin temperature from satellite measurements, i.e. Land Surface Temperature, Ice Surface Temperature, Sea Surface Temperature and Lake Surface Water Temperature. Here we discuss the science needed to produce a fully-global daily analysis (or ensemble of analyses) of surface air temperature on the centennial scale, integrating different ground-based and satellite-borne data types. Information contained in the satellite retrievals is used to create globally-complete fields in the past, using statistical models of how surface air temperature varies in a connected way from place to place. As the data volumes involved are considerable, such work needs to include development of new "Big Data" analysis methods. We will present recent progress along this road in the EUSTACE project: 1. providing new, consistent, multi-component estimates of uncertainty in surface skin temperature retrievals from satellites; 2. identifying inhomogeneities in daily surface air temperature measurement series from weather stations and correcting for these over Europe; 3. estimating surface air temperature over all surfaces of Earth from surface skin temperature retrievals; 4. using new statistical techniques to provide information on higher spatial and temporal scales than currently available, making optimum use of information in data-rich eras. Information will also be given on how interested users can become involved.

The EUSTACE project: delivering global, daily information on surface air temperature

NASA Astrophysics Data System (ADS)

Ghent, D.; Rayner, N. A.

2016-12-01

Day-to-day variations in surface air temperature affect society in many ways; however, daily surface air temperature measurements are not available everywhere. A global daily analysis cannot be achieved with measurements made in situ alone, so incorporation of satellite retrievals is needed. To achieve this, in the EUSTACE project (2015-June 2018, https://www.eustaceproject.eu) we are developing an understanding of the relationships between traditional (land and marine) surface air temperature measurements and retrievals of surface skin temperature from satellite measurements, i.e. Land Surface Temperature, Ice Surface Temperature, Sea Surface Temperature and Lake Surface Water Temperature. Here we discuss the science needed to produce a fully-global daily analysis (or ensemble of analyses) of surface air temperature on the centennial scale, integrating different ground-based and satellite-borne data types. Information contained in the satellite retrievals is used to create globally-complete fields in the past, using statistical models of how surface air temperature varies in a connected way from place to place. As the data volumes involved are considerable, such work needs to include development of new "Big Data" analysis methods. We will present recent progress along this road in the EUSTACE project, i.e.: • providing new, consistent, multi-component estimates of uncertainty in surface skin temperature retrievals from satellites; • identifying inhomogeneities in daily surface air temperature measurement series from weather stations and correcting for these over Europe; • estimating surface air temperature over all surfaces of Earth from surface skin temperature retrievals; • using new statistical techniques to provide information on higher spatial and temporal scales than currently available, making optimum use of information in data-rich eras. Information will also be given on how interested users can become involved.

Unmanned surface traverses of Mars and Moon: Science objectives, payloads, operations

NASA Technical Reports Server (NTRS)

Jaffe, L. D.; Choate, R.

1973-01-01

Science objectives and properties to be measured are outlined for long surface traverse missions on Mars and the Moon, with remotely-controlled roving vehicles. A series of candidate rover payloads is proposed for each planet, varying in weight, cost, purpose, and development needed. The smallest weighs 35 kg; the largest almost 300 kg. A high degree of internal control will be needed on the Mars rover, including the ability to carry out complex science sequences. Decision-making by humans in the Mars mission includes supervisory control of rover operations and selection of features and samples of geological and biological interest. For the lunar mission, less control on the rover and more on earth is appropriate. Science portions of the rover mission profile are outlined, with timelines and mileage breakdowns. Operational problem areas for Mars include control, communications, data storage, night operations, and the mission operations system. For the moon, science data storage on the rover would be unnecessary and control much simpler.

The OSIRIS-REx Radio Science Experiment at Bennu

NASA Astrophysics Data System (ADS)

McMahon, J. W.; Scheeres, D. J.; Hesar, S. G.; Farnocchia, D.; Chesley, S.; Lauretta, D.

2018-02-01

The OSIRIS-REx mission will conduct a Radio Science investigation of the asteroid Bennu with a primary goal of estimating the mass and gravity field of the asteroid. The spacecraft will conduct proximity operations around Bennu for over 1 year, during which time radiometric tracking data, optical landmark tracking images, and altimetry data will be obtained that can be used to make these estimates. Most significantly, the main Radio Science experiment will be a 9-day arc of quiescent operations in a 1-km nominally circular terminator orbit. The pristine data from this arc will allow the Radio Science team to determine the significant components of the gravity field up to the fourth spherical harmonic degree. The Radio Science team will also be responsible for estimating the surface accelerations, surface slopes, constraints on the internal density distribution of Bennu, the rotational state of Bennu to confirm YORP estimates, and the ephemeris of Bennu that incorporates a detailed model of the Yarkovsky effect.

Spoof surface plasmons resonance effect and tunable electric response of improved metamaterial in the terahertz regime

NASA Astrophysics Data System (ADS)

Wang, Yue; Zhang, Li-Ying; Mei, Jin-Shuo; Zhang, Wen-Chao; Tong, Yi-Jing

2015-12-01

We propose an improved design and numerical study of an optimized tunable plasmonics artificial material resonator in the terahertz regime. We demonstrate that tunability can be realized with a transmission intensity as much as ˜61% in the lower frequency resonance, which is implemented through the effect of photoconductive switching under photoexcitation. In the higher frequency resonance, we show that spoof surface plasmons along the interface of metal/dielectric provide new types of electromagnetic resonances. Our approach opens up possibilities for the interface of metamaterial and plasmonics to be applied to optically tunable THz switching. Project supported by the National Natural Science Foundation of China (Grant No. 61201075), the Natural Science Foundation of Heilongjiang Province, China (Grant No. F2015039), the Young Scholar Project of Heilongjiang Provincial Education Bureau, China (Grant No. 1254G021), the China Postdoctoral Science Foundation (Grant No. 2012M511507), and the Science Funds for the Young Innovative Talents of Harbin University of Science and Technology, China (Grant No. 201302).

Use of radiation in biomaterials science

NASA Astrophysics Data System (ADS)

Benson, Roberto S.

2002-05-01

Radiation is widely used in the biomaterials science for surface modification, sterilization and to improve bulk properties. Radiation is also used to design of biochips, and in situ photopolymerizable of bioadhesives. The energy sources most commonly used in the irradiation of biomaterials are high-energy electrons, gamma radiation, ultraviolet (UV) and visible light. Surface modification involves placement of selective chemical moieties on the surface of a material by chemical reactions to improve biointeraction for cell adhesion and proliferation, hemocompatibility and water absorption. The exposure of a polymer to radiation, especially ionizing radiation, can lead to chain scission or crosslinking with changes in bulk and surface properties. Sterilization by irradiation is designed to inactivate most pathogens from the surface of biomedical devices. An overview of the use of gamma and UV radiation to improve surface tissue compatibility, bulk properties and surface properties for wear resistance, formation of hydrogels and curing dental sealants and bone adhesives is presented. Gamma and vacuum ultraviolet (VUV) irradiated ultrahigh molecular weight polyethylene (UHMWPE) exhibit improvement in surface modulus and hardness. The surface modulus and hardness of UHMWPE showed a dependence on type of radiation, dosage and processing. VUV surface modified e-PTFE vascular grafts exhibit increases in hydrophilicity and improvement towards adhesion of fibrin glue.

Elemental analysis by IBA and NAA — A critical comparison

NASA Astrophysics Data System (ADS)

Watterson, J. I. W.

1988-12-01

In this review neutron activation analysis (NAA) and ion beam analysis (IBA) have been compared in the context of the entire field of analytical science using the discipline of scientometrics, as developed by Braun and Lyon. This perspective on the relative achievements of the two methods is modified by considering and comparing their particular attributes and characteristics, particularly in relation to their differing degree of maturity. This assessment shows that NAA, as the more mature method, is the most widely applied nuclear technique, but the special capabilities of IBA give it the ability to provide information about surface composition and elemental distribution that is unique, while it is still relatively immature and it is not yet possible to define its ultimate role with any confidence.

A general scientific information system to support the study of climate-related data

NASA Technical Reports Server (NTRS)

Treinish, L. A.

1984-01-01

The development and use of NASA's Pilot Climate Data System (PCDS) are discussed. The PCDS is used as a focal point for managing and providing access to a large collection of actively used data for the Earth, ocean and atmospheric sciences. The PCDS provides uniform data catalogs, inventories, and access methods for selected NASA and non-NASA data sets. Scientific users can preview the data sets using graphical and statistical methods. The system has evolved from its original purpose as a climate data base management system in response to a national climate program, into an extensive package of capabilities to support many types of data sets from both spaceborne and surface based measurements with flexible data selection and analysis functions.

Pair-Wise, Deformable Mirror, Image Plane-Based Diversity Electric Field Estimation for High Contrast Coronagraphy

NASA Technical Reports Server (NTRS)

Give'on, Amir; Kern, Brian D.; Shaklan, Stuart

2011-01-01

In this paper we describe the complex electric field reconstruction from image plane intensity measurements for high contrast coronagraphic imaging. A deformable mirror (DM) surface is modied with pairs of complementary shapes to create diversity in the image plane of the science camera where the intensity of the light is measured. Along with the Electric Field Conjugation correction algorithm, this estimation method has been used in various high contrast imaging testbeds to achieve the best contrasts to date both in narrow and in broad band light. We present the basic methodology of estimation in easy to follow list of steps, present results from HCIT and raise several open quations we are confronted with using this method.

Inversion method applied to the rotation curves of galaxies

NASA Astrophysics Data System (ADS)

Márquez-Caicedo, L. A.; Lora-Clavijo, F. D.; Sanabria-Gómez, J. D.

2017-07-01

We used simulated annealing, Montecarlo and genetic algorithm methods for matching both numerical data of density and velocity profiles in some low surface brigthness galaxies with theoretical models of Boehmer-Harko, Navarro-Frenk-White and Pseudo Isothermal Profiles for galaxies with dark matter halos. We found that Navarro-Frenk-White model does not fit at all in contrast with the other two models which fit very well. Inversion methods have been widely used in various branches of science including astrophysics (Charbonneau 1995, ApJS, 101, 309). In this work we have used three different parametric inversion methods (MonteCarlo, Genetic Algorithm and Simmulated Annealing) in order to determine the best fit of the observed data of the density and velocity profiles of a set of low surface brigthness galaxies (De Block et al. 2001, ApJ, 122, 2396) with three models of galaxies containing dark mattter. The parameters adjusted by the inversion methods were the central density and a characteristic distance in the Boehmer-Harko BH (Boehmer & Harko 2007, JCAP, 6, 25), Navarro-Frenk-White NFW (Navarro et al. 2007, ApJ, 490, 493) and Pseudo Isothermal Profile PI (Robles & Matos 2012, MNRAS, 422, 282). The results obtained showed that the BH and PI Profile dark matter galaxies fit very well for both the density and the velocity profiles, in contrast the NFW model did not make good adjustments to the profiles in any analized galaxy.

Telling a Compelling Tale, Scientifically Speaking

NASA Astrophysics Data System (ADS)

Unger, M.; Hauser, R.; Backlund, P.

2009-12-01

We will examine three strategies for conveying science effectively to a broad audience: making science relevant, accessible, and intriguing. Through an analysis of the dissemination strategy for three research-related stories at the National Center for Atmospheric Research, we explore methods for successful communication of societally relevant science. We will discuss both time-honored and new means of conveying authentic science in a rapidly changing media landscape. This visualization from the Hayden Planetarium's Journey to the Stars shows the generation of magnetic field in the solar convection zone and its connection to a sunspot at the visible surface of the Sun. Note that the sunspot (with a size slightly larger than Earth) is enlarged for better visibility and not in proper scale relative to the Sun. (© 2009, American Museum of Natural History) New research shows that the Arctic reversed a long-term cooling trend and began warming rapidly in recent decades. The graph shows estimates of Arctic temperatures over the last 2,000 years, based on proxy records, the long-term cooling trend, and the recent warming based on actual observations. A 2000-year transient climate simulation with NCAR's Community Climate System Model shows the same overall temperature decrease as does the proxy temperature reconstruction, which gives scientists confidence that their estimates are accurate.

Low-Pressure Testing of the Mars Science Laboratory’s Solid Sampling System: Test Methods and Preliminary Results

NASA Astrophysics Data System (ADS)

Mukherjee, S.; von der Heydt, M.; Hanson, C.; Jandura, L.

2009-12-01

The Mars Science Laboratory mission is scheduled to launch in 2011 with an extensive suite of in situ science instruments. Acquiring, processing and delivering appropriate samples of rock and martian regolith to the instruments is a critical component in realizing the science capability of these payload elements. However, there are a number of challenges in validating the design of these systems. In particular, differences in the environment (atmospheric pressure and composition, temperature, gravity), target materials (variation in rock and soil properties), and state of the hardware (electrical potential, particulate coatings) may effect sampling performance. To better understand the end-to-end system and allow development of mitigation strategies if necessary, early testing of high-fidelity engineering models of the hardware in the solid sample chain is being conducted. The components of the sample acquisition, processing & delivery chain that will be tested are the drill, scoop, sieves, portioners, and instrument inlet funnels. An evaluation of the environmental parameter space was conducted to identify a subset that may have significant effects on sampling performance and cannot be well bounded by analysis. Accordingly, support equipment to enable testing at Mars surface pressures (5-10 Torr), with carbon dioxide was designed and built. A description of the testing set-up, investigations, and preliminary results will be presented.

Thermophysical modelling for high-resolution digital terrain models

NASA Astrophysics Data System (ADS)

Pelivan, I.

2018-07-01

A method is presented for efficiently calculating surface temperatures for highly resolved celestial body shapes. A thorough investigation of the necessary conditions leading to reach model convergence shows that the speed of surface temperature convergence depends on factors such as the quality of initial boundary conditions, thermal inertia, illumination conditions, and resolution of the numerical depth grid. The optimization process to shorten the simulation time while increasing or maintaining the accuracy of model results includes the introduction of facet-specific boundary conditions such as pre-computed temperature estimates and pre-evaluated simulation times. The individual facet treatment also allows for assigning other facet-specific properties such as local thermal inertia. The approach outlined in this paper is particularly useful for very detailed digital terrain models in combination with unfavourable illumination conditions such as little-to-no sunlight at all for a period of time as experienced locally on comet 67P/Churyumov-Gerasimenko. Possible science applications include thermal analysis of highly resolved local (landing) sites experiencing seasonal, environment, and lander shadowing. In combination with an appropriate roughness model, the method is very suitable for application to disc-integrated and disc-resolved data. Further applications are seen where the complexity of the task has led to severe shape or thermophysical model simplifications such as in studying surface activity or thermal cracking.

Single cells for forensic DNA analysis--from evidence material to test tube.

PubMed

Brück, Simon; Evers, Heidrun; Heidorn, Frank; Müller, Ute; Kilper, Roland; Verhoff, Marcel A

2011-01-01

The purpose of this project was to develop a method that, while providing morphological quality control, allows single cells to be obtained from the surfaces of various evidence materials and be made available for DNA analysis in cases where only small amounts of cell material are present or where only mixed traces are found. With the SteREO Lumar.V12 stereomicroscope and UV unit from Zeiss, it was possible to detect and assess single epithelial cells on the surfaces of various objects (e.g., glass, plastic, metal). A digitally operated micromanipulator developed by aura optik was used to lift a single cell from the surface of evidence material and to transfer it to a conventional PCR tube or to an AmpliGrid(®) from Advalytix. The actual lifting of the cells was performed with microglobes that acted as carriers. The microglobes were held with microtweezers and were transferred to the DNA analysis receptacles along with the adhering cells. In a next step, the PCR can be carried out in this receptacle without removing the microglobe. Our method allows a single cell to be isolated directly from evidence material and be made available for forensic DNA analysis. © 2010 American Academy of Forensic Sciences.

Thermophysical modeling for high-resolution digital terrain models

NASA Astrophysics Data System (ADS)

Pelivan, I.

2018-04-01

A method is presented for efficiently calculating surface temperatures for highly resolved celestial body shapes. A thorough investigation of the necessary conditions leading to reach model convergence shows that the speed of surface temperature convergence depends on factors such as the quality of initial boundary conditions, thermal inertia, illumination conditions, and resolution of the numerical depth grid. The optimization process to shorten the simulation time while increasing or maintaining the accuracy of model results includes the introduction of facet-specific boundary conditions such as pre-computed temperature estimates and pre-evaluated simulation times. The individual facet treatment also allows for assigning other facet-specific properties such as local thermal inertia. The approach outlined in this paper is particularly useful for very detailed digital terrain models in combination with unfavorable illumination conditions such as little to no sunlight at all for a period of time as experienced locally on comet 67P/Churyumov-Gerasimenko. Possible science applications include thermal analysis of highly resolved local (landing) sites experiencing seasonal, environment and lander shadowing. In combination with an appropriate roughness model, the method is very suitable for application to disk-integrated and disk-resolved data. Further applications are seen where the complexity of the task has led to severe shape or thermophysical model simplifications such as in studying surface activity or thermal cracking.

An instrument design for non-contact detection of biomolecules and minerals on Mars using fluorescence.

PubMed

Smith, Heather D; McKay, Christopher P; Duncan, Andrew G; Sims, Ronald C; Anderson, Anne J; Grossl, Paul R

2014-01-01

We discuss fluorescence as a method to detect polycyclic aromatic hydrocarbons and other organic molecules, as well as minerals on the surface of Mars. We present an instrument design that is adapted from the ChemCam instrument which is currently on the Mars Science Lander Rover Curiosity and thus most of the primary components are currently flight qualified for Mars surface operations, significantly reducing development costs. The major change compared to ChemCam is the frequency multipliers of the 1064 nm laser to wavelengths suitable for fluorescence excitation (266 nm, 355 nm, and 532 nm). We present fluorescence spectrum for a variety of organics and minerals relevant to the surface of Mars. Preliminary results show minerals already known on Mars, such as perchlorate, fluoresce strongest when excited by 355 nm. Also we demonstrate that polycyclic aromatic hydrocarbons, such as those present in Martian meteorites, are highly fluorescent at wavelengths in the ultraviolet (266 nm, 355 nm), but not as much in the visible (532 nm). We conclude that fluorescence can be an important method for Mars applications and standoff detection of organics and minerals. The instrument approach described in this paper builds on existing hardware and offers high scientific return for minimal cost for future missions.

An instrument design for non-contact detection of biomolecules and minerals on Mars using fluorescence

PubMed Central

2014-01-01

We discuss fluorescence as a method to detect polycyclic aromatic hydrocarbons and other organic molecules, as well as minerals on the surface of Mars. We present an instrument design that is adapted from the ChemCam instrument which is currently on the Mars Science Lander Rover Curiosity and thus most of the primary components are currently flight qualified for Mars surface operations, significantly reducing development costs. The major change compared to ChemCam is the frequency multipliers of the 1064 nm laser to wavelengths suitable for fluorescence excitation (266 nm, 355 nm, and 532 nm). We present fluorescence spectrum for a variety of organics and minerals relevant to the surface of Mars. Preliminary results show minerals already known on Mars, such as perchlorate, fluoresce strongest when excited by 355 nm. Also we demonstrate that polycyclic aromatic hydrocarbons, such as those present in Martian meteorites, are highly fluorescent at wavelengths in the ultraviolet (266 nm, 355 nm), but not as much in the visible (532 nm). We conclude that fluorescence can be an important method for Mars applications and standoff detection of organics and minerals. The instrument approach described in this paper builds on existing hardware and offers high scientific return for minimal cost for future missions. PMID:25057291

An analysis of K--5 teachers' beliefs regarding the uses of direct instruction, the discovery method, and the inquiry method in elementary science education

NASA Astrophysics Data System (ADS)

Kowalczyk, Donna Lee

The purpose of this study was to examine K--5 elementary teachers' reported beliefs about the use, function, and importance of Direct Instruction, the Discovery Method, and the Inquiry Method in the instruction of science in their classrooms. Eighty-two teachers completed questionnaires about their beliefs, opinions, uses, and ideas about each of the three instructional methods. Data were collected and analyzed using the Statistical Package of the Social Sciences (SPSS). Descriptive statistics and Chi-Square analyses indicated that the majority of teachers reported using all three methods to varying degrees in their classrooms. Guided Discovery was reported by the teachers as being the most frequently used method to teach science, while Pure Discovery was reportedly used the least frequently. The majority of teachers expressed the belief that a blend of all three instructional methods is the most effective strategy for teaching science at the elementary level. The teachers also reported a moderate level of confidence in teaching science. Students' ability levels, learning styles, and time/class schedule were identified as factors that most influence teachers' instructional choice. Student participation in hands-on activities, creative thinking ability, and developing an understanding of scientific concepts were reported as the learning behaviors most associated with student success in science. Data obtained from this study provide information about the nature and uses of Direct Instruction, the Discovery Method, and the Inquiry Method and teachers' perceptions and beliefs about each method's use in science education. Learning more about the science teaching and learning environment may help teachers, administrators, curriculum developers, and researchers gain greater insights about student learning, instructional effectiveness, and science curriculum development at the elementary level.

Stratigraphy and Surface Ages of Dwarf Planet (1) Ceres: Results from Geologic and Topographic Mapping in Survey, HAMO and LAMO Data of the Dawn Framing Camera Images

NASA Astrophysics Data System (ADS)

Wagner, R. J.; Schmedemann, N.; Stephan, K.; Jaumann, R.; Neesemann, A.; Preusker, F.; Kersten, E.; Roatsch, T.; Hiesinger, H.; Williams, D. A.; Yingst, R. A.; Crown, D. A.; Mest, S. C.; Raymond, C. A.; Russell, C. T.

2017-12-01

Since March 6, 2015, the surface of dwarf planet (1) Ceres is being imaged by the FC framing camera aboard the Dawn spacecraft from orbit at various altitudes [1]. For this study we focus on images from the Survey orbit phase (4424 km altitude) with spatial resolutions of 400 m/pxl and use images and topographic data from DTMs (digital terrain models) for global geologic mapping. On Ceres' surface cratered plains are ubiquitous, with variations in superimposed crater frequency indicating different ages and processes. Here, we take the topography into account for geologic mapping and discriminate cratered plains units according to their topographic level - high-standing, medium, or low-lying - in order to examine a possible correlation between topography and surface age. Absolute model ages (AMAs) are derived from two impact cratering chronology models discussed in detail by [2] (henceforth termed LDM: lunar-derived model, and ADM: asteroid-derived model). We also apply an improved method to obtain relative ages and AMAs from crater frequency measurements termed Poisson timing analysis [3]. Our ongoing analysis shows no trend that the topographic level has an influence on the age of the geologic units. Both high-standing and low-lying cratered plains have AMAs ranging from 3.5 to 1.5 Ga (LDM), versus 4.2 to 0.5 Ga (ADM). Some areas of measurement within these units, however, show effects of resurfacing processes in their crater distributions and feature an older and a younger age. We use LAMO data (altitude: 375 km; resolution 30 m/pxl) and/or HAMO data (altitude: 1475 km; resolution 140 m/pxl) to study local geologic units and their ages, e.g., smaller impact craters, especially those not dated so far with crater measurements and/or those with specific spectral properties [4], deposits of mass wasting (e.g., landslides), and mountains, such as Ahuna Mons. Crater frequencies are used to set these geologic units into the context of Ceres' time-stratigraphic system and chronologic periods [5]. References: [1] Russell C. T., et al. (2016), Science 353, doi:10.1126/science.aaf4219. [2] Hiesinger H. H. et al. (2016), Science 353, doi:10.1126/science.aaf4759. [3] Michael G. G. et al. (2016), Icarus 277, 279-285. [4] Stephan K. et al. (2017), submitted to Icarus. [5] Mest S. C. et al. (2017), LPSC XLVIII, abstr. No. 2512.

Using a Science/Technology/Society Approach to Prepare Reform-Oriented Science Teachers: The Case of a Secondary Science Methods Course

ERIC Educational Resources Information Center

Dass, Pradeep M.

2005-01-01

Reformed preparation of science teachers is indeed vital for the vision of science teaching reform to be accomplished. Typically, a critical component of a preservice science teacher preparation program is the science teaching methods course. The usual intent of this course is to help preservice science students develop an understanding of various…

On the sensitivity of some common metallographic reagents to restoring obliterated marks on medium carbon (0.31% C) steel surfaces.

PubMed

Yin, Siaw Hui; Kuppuswamy, R

2009-01-10

Chemical etching, which is the most sensitive method to recover obliterated serial numbers on metal surfaces, has been practised quite successfully in forensic science laboratories all over the world. A large number of etchants suitable for particular metal surfaces based on empirical studies is available in the literature. This article reviews the sensitivity and efficacy of some popular etchants for recovering obliterated marks on medium carbon steel (0.31% C with ferrite-pearlite microstructure) used in automobile parts. The experiments involved engraving these carbon steel plates with some alphanumeric characters using a computer controlled machine "Gravograph" and erasing them to several depths below the bottom of their engraving depth. Seven metallographic reagents of which most of them were copper containing compounds were chosen for etching. The erased plates were etched with every one of these etchants using swabbing method. The results have revealed that Fry's reagent comprising cupric chloride 90 g, hydrochloric acid 120 mL and water 100mL provided the necessary contrast and was concluded to be the most sensitive. The same reagent was recommended by earlier workers for revealing strain lines in steel surfaces. Earlier, another reagent containing 5 g copper sulphate, 60 mL water, 30 mL (conc.) ammonium hydroxide, and 60 mL (conc.) hydrochloric acid was proved to be more sensitive to restore erased marks on low carbon steel (0.1% C with ferrite-pearlite structure) [M.A.M. Zaili, R. Kuppuswamy, H. Harun, Restoration of engraved marks on steel surfaces by etching technique, Forensic Sci. Int. 171 (2007) 27-32]. Thus the sensitivity of the etching reagent on steel surfaces appeared to be dependent on the content of carbon in the steel.

Investigation of Surface Treatments to Improve the Friction and Wear of Titanium Alloys for Diesel Engine Components

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

Blau, Peter J.; Cooley, Kevin M.; Kirkham, Melanie J.

This final report summarizes experimental and analytical work performed under an agreement between the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Office of Transportation Technologies, and UT-Battelle LLC. The project was directed by Jerry Gibbs, of the U.S. Department of Energy’s Propulsion Materials Program, with management by D. P. Stinton and J. A. Haynes of ORNL. Participants included Peter J. Blau (Principal Investigator), Kevin M. Cooley (senior technician), Melanie J. Kirkham (materials scientist) of the Materials Science and Technology Division or ORNL, and Dinesh G. Bansal, a post doctoral fellow employed by Oak Ridge Associated Universitiesmore » (ORAU) and who, at the time of this writing, is an engineer with Cummins, Inc. This report covers a three-year effort that involved two stages. In the first stage, and after a review of the literature and discussions with surface treatment experts, a series of candidate alloys and surface treatments for titanium alloy (Ti-6Al-4V) was selected for initial screening. After pre-screening using an ASTM standard test method, the more promising surface treatments were tested in Phase 2 using a variable loading apparatus that was designed and built to simulate the changing load patterns in a typical connecting rod bearing. Information on load profiles from the literature was supplemented with the help of T.C. Chen and Howard Savage of Cummins, Inc. Considering the dynamic and evolving nature of materials technology, this report presents a snapshot of commercial and experimental bearing surface technologies for titanium alloys that were available during the period of this work. Undoubtedly, further improvements in surface engineering methods for titanium will evolve.« less