WorldWideScience

Sample records for nanoscale physical properties

  1. Influence of strain on the physical properties of materials at the nanoscale

    Science.gov (United States)

    Manoharan, Mohan Prasad

    At the nanoscale, materials properties differ substantially from that at the bulk scale, opening new avenues for technological applications and basic science research. Such size effects arise from dimensional and microstructural constraints, especially when specimen size coincides with the critical fundamental length scales for various physical properties. While the state of the art practice is to investigate the size effects on 'individual' properties (mechanical or electrical or thermal and so on), the focus of this research is to explore the size effects on the 'coupling' among these domains. In particular, the effect of mechanical strain on various physical properties of materials at the nanoscale is studied. This is motivated by the hypothesis that very small elastic strain could be engineered in micro and nanoscale systems to 'tune' materials properties, which is not possible at the bulk scale using strain as a parameter. The objective of this research is to study the influence of strain on various material properties at the nanoscale, such as crystal structure, thermal and electrical conductivity, electronic bandgap and tribological properties through experimental characterization. While characterization of nanoscale materials in single domains remains the state of the art, coupled domain studies usher even stiffer challenges. This is because in addition to the difficulties in nanoscale specimen preparation, handling and properties measurement, meticulous attention has to be given to the boundary conditions for each of the domains. Another desired feature of the experimental setup is the capability for in situ high resolution microscopy so that microstructural details as well as experimental accuracy are achieved. A major contribution of this research is the development of microfabricated integrated systems to perform coupled domain characterization of small scale specimens in situ in thermal (infra-red), micro-Raman and electron microscopes. In addition

  2. Improving fundamental abilities of atomic force microscopy for investigating quantitative nanoscale physical properties of complex biological systems

    Science.gov (United States)

    Cartagena-Rivera, Alexander X.

    Measurements of local material properties of complex biological systems (e.g. live cells and viruses) in their respective physiological conditions are extremely important in the fields of biophysics, nanotechnology, material science, and nanomedicine. Yet, little is known about the structure-function-property relationship of live cells and viruses. In the case of live cells, the measurements of progressive variations in viscoelastic properties in vitro can provide insight to the mechanistic processes underpinning morphogenesis, mechano-transduction, motility, metastasis, and many more fundamental cellular processes. In the case of living viruses, the relationship between capsid structural framework and the role of the DNA molecule interaction within viruses influencing their stiffness, damping and electrostatic properties can shed light in virological processes like protein subunits assembly/dissassembly, maturation, and infection. The study of mechanics of live cells and viruses has been limited in part due to the lack of technology capable of acquiring high-resolution (nanoscale, subcellular) images of its heterogeneous material properties which vary widely depending on origin and physical interaction. The capabilities of the atomic force microscope (AFM) for measuring forces and topography with sub-nm precision have greatly contributed to research related to biophysics and biomechanics during the past two decades. AFM based biomechanical studies have the unique advantage of resolving/mapping spatially the local material properties over living cells and viruses. However, conventional AFM techniques such as force-volume and quasi-static force-distance curves are too low resolution and low speed to resolve interesting biophysical processes such as cytoskeletal dynamics for cells or assembly/dissasembly of viruses. To overcome this bottleneck, a novel atomic force microscopy mode is developed, that leads to sub-10-nm resolution and sub-15-minutes mapping of local

  3. Attosecond physics at the nanoscale.

    Science.gov (United States)

    Ciappina, M F; Pérez-Hernández, J A; Landsman, A S; Okell, W A; Zherebtsov, S; Förg, B; Schötz, J; Seiffert, L; Fennel, T; Shaaran, T; Zimmermann, T; Chacón, A; Guichard, R; Zaïr, A; Tisch, J W G; Marangos, J P; Witting, T; Braun, A; Maier, S A; Roso, L; Krüger, M; Hommelhoff, P; Kling, M F; Krausz, F; Lewenstein, M

    2017-05-01

    Recently two emerging areas of research, attosecond and nanoscale physics, have started to come together. Attosecond physics deals with phenomena occurring when ultrashort laser pulses, with duration on the femto- and sub-femtosecond time scales, interact with atoms, molecules or solids. The laser-induced electron dynamics occurs natively on a timescale down to a few hundred or even tens of attoseconds (1 attosecond  =  1 as  =  10 -18 s), which is comparable with the optical field. For comparison, the revolution of an electron on a 1s orbital of a hydrogen atom is  ∼152 as. On the other hand, the second branch involves the manipulation and engineering of mesoscopic systems, such as solids, metals and dielectrics, with nanometric precision. Although nano-engineering is a vast and well-established research field on its own, the merger with intense laser physics is relatively recent. In this report on progress we present a comprehensive experimental and theoretical overview of physics that takes place when short and intense laser pulses interact with nanosystems, such as metallic and dielectric nanostructures. In particular we elucidate how the spatially inhomogeneous laser induced fields at a nanometer scale modify the laser-driven electron dynamics. Consequently, this has important impact on pivotal processes such as above-threshold ionization and high-order harmonic generation. The deep understanding of the coupled dynamics between these spatially inhomogeneous fields and matter configures a promising way to new avenues of research and applications. Thanks to the maturity that attosecond physics has reached, together with the tremendous advance in material engineering and manipulation techniques, the age of atto-nanophysics has begun, but it is in the initial stage. We present thus some of the open questions, challenges and prospects for experimental confirmation of theoretical predictions, as well as experiments aimed at characterizing the

  4. Linking nanoscale mechanical behavior to bulk physical properties and phenomena of energetic materials

    Science.gov (United States)

    Taw, Matthew R.

    The hardness and reduced modulus of aspirin, RDX, HMX, TATB, FOX-7, ADAAF, and TNT/CL-20 were experimentally measured with nanoindentation. These values are reported for the first time using as-received micron sized crystals of energetic materials with no additional mechanical processing. The results for TATB, ADAAF, and TNT/CL-20 are the first of their kind, while comparisons to previous nanoindentation studies on large, carefully grown single crystals of the other energetic materials show that mechanical properties of the larger crystals are comparable to crystals in the condition they are practically used. Measurements on aspirin demonstrate the variation that can occur between nanoindentation indents based on the orientation of a Berkovich tip relative to the surface of the sample. The Hertzian elastic contact model was used to analyze the materials initial yield, or pop-in, behavior. The length, energy, indentation load, and shear stress at initial yielding were used to characterize each material. For the energetic materials the length and energy of the yield excursions were compared to the drop weight sensitivity. This comparison revealed a general trend that more impact sensitive materials have longer, more severe pop-in excursions. Hot spot initiation mechanisms involving crystal defects such as void collapses and dislocation pile-up followed by avalanche are supported by these trends. While this only takes one aspect of impact sensitivity into consideration, if this trend is observed in a larger range of energetics these methods could possibly be used to great advantage in the early stages of new explosives synthesis to obtain an estimation of drop weight sensitivity.

  5. Nanoscale device physics science and engineering fundamentals

    CERN Document Server

    Tiwari, Sandip

    2017-01-01

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

  6. Magnetic Properties of Molecular and Nanoscale Magnets

    OpenAIRE

    Krupskaya, Yulia

    2011-01-01

    The idea of miniaturizing devices down to the nanoscale where quantum ffeffects become relevant demands a detailed understanding of the interplay between classical and quantum properties. Therefore, characterization of newly produced nanoscale materials is a very important part of the research in this fifield. Studying structural and magnetic properties of nano- and molecular magnets and the interplay between these properties reveals new interesting effects and suggests ways to control and op...

  7. Properties of nanoscale metal hydrides.

    Science.gov (United States)

    Fichtner, Maximilian

    2009-05-20

    Nanoscale hydride particles may exhibit chemical stabilities which differ from those of a macroscopic system. The stabilities are mainly influenced by a surface energy term which contains size-dependent values of the surface tension, the molar volume and an additional term which takes into account a potential reduction of the excess surface energy. Thus, the equilibrium of a nanoparticular hydride system may be shifted to the hydrogenated or to the dehydrogenated side, depending on the size and on the prefix of the surface energy term of the hydrogenated and dehydrogenated material. Additional complexity appears when solid-state reactions of complex hydrides are considered and phase segregation has to be taken into account. In such a case the reversibility of complex hydrides may be reduced if the nanoparticles are free standing on a surface. However, it may be enhanced if the system is enclosed by a nanoscale void which prevents the reaction partners on the dehydrogenated side from diffusing away from each other. Moreover, the generally enhanced diffusivity in nanocrystalline systems may lower the kinetic barriers for the material's transformation and, thus, facilitate hydrogen absorption and desorption.

  8. Attosecond physics at the nanoscale

    Czech Academy of Sciences Publication Activity Database

    Ciappina, Marcelo F.; Perez-Hernandez, J.A.; Landsman, A.S.; Okell, W.A.; Zherebtsov, S.; Foerg, B.; Schoetz, J.; Seiffert, L.; Fennel, T.; Shaaran, T.; Zimmermann, T.; Chacon, A.; Guichard, R.; Zair, A.; Tisch, J.W.G.; Marangos, J.P.; Witting, T.; Braun, A.; Maier, S. A.; Roso, L.; Krueger, M.; Hommelhoff, P.; Kling, M.F.; Krausz, F.; Lewenstein, M.

    2017-01-01

    Roč. 80, č. 5 (2017), 1-50, č. článku 054401. ISSN 0034-4885 R&D Projects: GA MŠk EF15_008/0000162; GA MŠk LQ1606 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : attosecond physics * plasmonic fields * strong field physics Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 14.311, year: 2016

  9. Tuning functional properties: From nanoscale building blocks to ...

    Indian Academy of Sciences (India)

    ous nanoscale building blocks, metal and semiconductor nanoparticles and carbon nanotubes have gained much attention and a brief summary of their functional properties is discussed. Further- more, the functional properties of nanomaterials can be fine-tuned by a stepwise integration of these nanoscale building blocks ...

  10. Physical properties

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Research activities into the physical properties of metals and ceramics at Lawrence Berkeley Laboratory during 1976 are reported. Topics covered include: high field superconductivity; microstructure and mechanical behavior of ceramics, glass-metal, and ceramic-metal systems; high temperature reactions; relation of microstructure to properties in ceramics; and structure and properties of carbon materials and composite materials

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

    CERN Document Server

    Weiner, John

    2013-01-01

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

  12. Nanoscale theranostics for physical stimulus-responsive cancer therapies.

    Science.gov (United States)

    Chen, Qian; Ke, Hengte; Dai, Zhifei; Liu, Zhuang

    2015-12-01

    Physical stimulus-responsive therapies often employing multifunctional theranostic agents responsive to external physical stimuli such as light, magnetic field, ultra-sound, radiofrequency, X-ray, etc., have been widely explored as novel cancer therapy strategies, showing encouraging results in many pre-clinical animal experiments. Unlike conventional cancer chemotherapy which often accompanies with severe toxic side effects, physical stimulus-responsive agents usually are non-toxic by themselves and would destruct cancer cells only under specific external stimuli, and thus could offer greatly reduced toxicity and enhanced treatment specificity. In addition, physical stimulus-responsive therapies can also be combined with other traditional therapeutics to achieve synergistic anti-tumor effects via a variety of mechanisms. In this review, we will summarize the latest progress in the development of physical stimulus-responsive therapies, and discuss the important roles of nanoscale theranostic agents involved in those non-conventional therapeutic strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The synthesis and properties of nanoscale ionic materials

    KAUST Repository

    Rodriguez, Robert Salgado

    2010-02-17

    In this article we discuss the effect of constituents on structure, flow, and thermal properties of nanoscale ionic materials (NIMs). NIMs are a new class of nanohybrids consisting of a nanometer-sized core, a charged corona covalently attached to the core, and an oppositely charged canopy. The hybrid nature of NIMs allows for their properties to be engineered by selectively varying their components. The unique properties associated with these systems can help overcome some of the issues facing the implementation of nanohybrids to various commercial applications, including carbon dioxide capture,water desalinization and as lubricants. Copyright © 2010 John Wiley & Sons, Ltd.

  14. Nitrogen-vacancy centers in diamond: nanoscale sensors for physics and biology.

    Science.gov (United States)

    Schirhagl, Romana; Chang, Kevin; Loretz, Michael; Degen, Christian L

    2014-01-01

    Crystal defects in diamond have emerged as unique objects for a variety of applications, both because they are very stable and because they have interesting optical properties. Embedded in nanocrystals, they can serve, for example, as robust single-photon sources or as fluorescent biomarkers of unlimited photostability and low cytotoxicity. The most fascinating aspect, however, is the ability of some crystal defects, most prominently the nitrogen-vacancy (NV) center, to locally detect and measure a number of physical quantities, such as magnetic and electric fields. This metrology capacity is based on the quantum mechanical interactions of the defect's spin state. In this review, we introduce the new and rapidly evolving field of nanoscale sensing based on single NV centers in diamond. We give a concise overview of the basic properties of diamond, from synthesis to electronic and magnetic properties of embedded NV centers. We describe in detail how single NV centers can be harnessed for nanoscale sensing, including the physical quantities that may be detected, expected sensitivities, and the most common measurement protocols. We conclude by highlighting a number of the diverse and exciting applications that may be enabled by these novel sensors, ranging from measurements of ion concentrations and membrane potentials to nanoscale thermometry and single-spin nuclear magnetic resonance.

  15. Atomistic methodologies for material properties of 2D materials at the nanoscale

    Science.gov (United States)

    Zhang, Zhen

    Research on two dimensional (2D) materials, such as graphene and MoS2, now involves thousands of researchers worldwide cutting across physics, chemistry, engineering and biology. Due to the extraordinary properties of 2D materials, research extends from fundamental science to novel applications of 2D materials. From an engineering point of view, understanding the material properties of 2D materials under various conditions is crucial for tailoring the electrical and mechanical properties of 2D-material-based devices at the nanoscale. Even at the nanoscale, molecular systems typically consist of a vast number of atoms. Molecular dynamics (MD) simulations enable us to understand the properties of assemblies of molecules in terms of their structure and the microscopic interactions between them. From a continuum approach, mechanical properties and thermal properties, such as strain, stress, and heat capacity, are well defined and experimentally measurable. In MD simulations, material systems are considered to be discrete, and only interatomic potential, interatomic forces, and atom positions are directly obtainable. Besides, most of the fracture mechanics concepts, such as stress intensity factors, are not applicable since there is no singularity in MD simulations. However, energy release rate still remains to be a feasible and crucial physical quantity to characterize the fracture mechanical property of materials at the nanoscale. Therefore, equivalent definition of a physical quantity both in atomic scale and macroscopic scale is necessary in order to understand molecular and continuum scale phenomena concurrently. This work introduces atomistic simulation methodologies, based on interatomic potential and interatomic forces, as a tool to unveil the mechanical properties, thermal properties and fracture mechanical properties of 2D materials at the nanoscale. Among many 2D materials, graphene and MoS2 have attracted intense interest. Therefore, we applied our

  16. Biominerals at the nanoscale: transmission electron microscopy methods for studying the special properties of biominerals

    DEFF Research Database (Denmark)

    Posfai, Mihaly; Kasama, Takeshi; Dunin-Borkowski, Rafal E.

    2013-01-01

    textures, and magnetic properties of biominerals at the nanoscale. In this chapter, we review the state of the art in the application of TEM techniques to the study of these properties, both in biomineral crystals and at the inorganic-organic interface. Examples are taken primarily from studies of magnetic...... fields. In order to fulfill their roles in organisms, biominerals have strictly controlled physical and chemical properties. Transmission electron microscopy (TEM) is ideally suited for the study of the structures, arrangements, compositions, morphologies, crystallographic orientations, crystallographic...

  17. Physical controls on directed virus assembly at nanoscale chemical templates

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, C L; Chung, S; Chatterji, A; Lin, T; Johnson, J E; Hok, S; Perkins, J; De Yoreo, J

    2006-05-10

    Viruses are attractive building blocks for nanoscale heterostructures, but little is understood about the physical principles governing their directed assembly. In-situ force microscopy was used to investigate organization of Cowpea Mosaic Virus engineered to bind specifically and reversibly at nanoscale chemical templates with sub-30nm features. Morphological evolution and assembly kinetics were measured as virus flux and inter-viral potential were varied. The resulting morphologies were similar to those of atomic-scale epitaxial systems, but the underlying thermodynamics was analogous to that of colloidal systems in confined geometries. The 1D templates biased the location of initial cluster formation, introduced asymmetric sticking probabilities, and drove 1D and 2D condensation at subcritical volume fractions. The growth kinetics followed a t{sup 1/2} law controlled by the slow diffusion of viruses. The lateral expansion of virus clusters that initially form on the 1D templates following introduction of polyethylene glycol (PEG) into the solution suggests a significant role for weak interaction.

  18. Nanoscale diffusive memristor crossbars as physical unclonable functions.

    Science.gov (United States)

    Zhang, R; Jiang, H; Wang, Z R; Lin, P; Zhuo, Y; Holcomb, D; Zhang, D H; Yang, J J; Xia, Q

    2018-02-08

    Physical unclonable functions have emerged as promising hardware security primitives for device authentication and key generation in the era of the Internet of Things. Herein, we report novel physical unclonable functions built upon the crossbars of nanoscale diffusive memristors that translate the stochastic distribution of Ag clusters in a SiO 2 matrix into a random binary bitmap that serves as a device fingerprint. The random dispersion of Ag led to an uneven number of clusters at each cross-point, which in turn resulted in a stochastic ability to switch in the Ag:SiO 2 diffusive memristors in an array. The randomness of the dispersion was a barrier to fingerprint cloning and the unique fingerprints of each device were persistent after fabrication. Using an optimized fabrication procedure, we maximized the randomness and achieved an inter-class Hamming distance of 50.68%. We also discovered that the bits were not flipping after over 10 4 s at 400 K, suggesting superior reliability of our physical unclonable functions. In addition, our diffusive memristor-based physical unclonable functions were easy to fabricate and did not require complicated post-processing for digitization and thus, provide new opportunities in hardware security applications.

  19. TOPICAL REVIEW: Nanoscale transport properties at silicon carbide interfaces

    Science.gov (United States)

    Roccaforte, F.; Giannazzo, F.; Raineri, V.

    2010-06-01

    Wide bandgap semiconductors promise devices with performances not achievable using silicon technology. Among them, silicon carbide (SiC) is considered the top-notch material for a new generation of power electronic devices, ensuring the improved energy efficiency required in modern society. In spite of the significant progress achieved in the last decade in the material quality, there are still several scientific open issues related to the basic transport properties at SiC interfaces and ion-doped regions that can affect the devices' performances, keeping them still far from their theoretical limits. Hence, significant efforts in fundamental research at the nanoscale have become mandatory to better understand the carrier transport phenomena, both at surfaces and interfaces. In this paper, the most recent experiences on nanoscale transport properties will be addressed, reviewing the relevant key points for the basic devices' building blocks. The selected topics include the major concerns related to the electronic transport at metal/SiC interfaces, to the carrier concentration and mobility in ion-doped regions and to channel mobility in metal/oxide/SiC systems. Some aspects related to interfaces between different SiC polytypes are also presented. All these issues will be discussed considering the current status and the drawbacks of SiC devices.

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

    Science.gov (United States)

    Demming, Anna

    2013-06-01

    At the nanoscale physics follows familiar principles that lead to unfamiliar and even unlikely responses. The change in the balance of a range of physical features results in behaviour that can differ wildly from the same materials at the macroscale. In this issue Di Ventra and Pershin examine some of the memory effects that have attracted increasing interest in investigations of nanoscale electronic systems [1]. The work builds on the familiar premise that external perturbations cannot have an instantaneous effect on any condensed matter system. As they point out, 'This is even more so in systems of nanoscale dimensions where the dynamics of a few atoms may affect the whole structure dramatically'. In this way they explain that the response of these systems will always have some degree of memory present and that memristive, memcapacitive and meminductive systems are simply examples where this feature is particularly prominent. In the late 1990s investigations into the use of carbon nanotubes and SiC nanorods revealed that the moduli of these structures changes with diameter, highlighting the eccentricities of mechanical properties at the nanoscale. These results prompted Miller at the University of Saskatchewan and Shenoy at the Indian Institute of Technology to study the properties of nanotubes and nanorods in detail [2]. 'In the eyes of an engineer these structures are essentially little beams', they explained, 'Albeit they are "little" to a degree that challenges our traditional notions of continuum mechanics'. In their work they developed one of the first simple models for explaining the behaviour of the Young's modulus of nanostructures, verified by direct atomistic simulation of axial loading of these structures. Since then, consideration of different nanoscale structures and the dissipation of energy under stress and strain have also demystified the extraordinary mechanical properties of natural materials such as collagen [3] and spider's silk [4]. The

  1. Nanoscale defect architectures and their influence on material properties

    Science.gov (United States)

    Campbell, Branton

    2006-10-01

    Diffraction studies of long-range order often permit one to unambiguously determine the atomic structure of a crystalline material. Many interesting material properties, however, are dominated by nanoscale crystal defects that can't be characterized in this way. Fortunately, advances in x-ray detector technology, synchrotron x-ray source brightness, and computational power make it possible to apply new methods to old problems. Our research group uses multi-megapixel x-ray cameras to map out large contiguous volumes of reciprocal space, which can then be visually explored using graphics engines originally developed by the video-game industry. Here, I will highlight a few recent examples that include high-temperature superconductors, colossal magnetoresistors and piezoelectric materials.

  2. Nanoscale Device Properties of Tellurium-based Chalcogenide Compounds

    Science.gov (United States)

    Dahal, Bishnu R.

    The great progress achieved in miniaturization of microelectronic devices has now reached a distinct bottleneck, as devices are starting to approach the fundamental fabrication and performance limit. Even if a major breakthrough is made in the fabrication process, these scaled down electronic devices will not function properly since the quantum effects can no longer be neglected in the nanoscale regime. Advances in nanotechnology and new materials are driving novel technologies for future device applications. Current microelectronic devices have the smallest feature size, around 10 nm, and the industry is planning to switch away from silicon technology in the near future. The new technology will be fundamentally different. There are several leading technologies based on spintronics, tunneling transistors, and the newly discovered 2-dimensional material systems. All of these technologies are at the research level, and are far from ready for use in making devices in large volumes. This dissertation will focus on a very promising material system, Te-based chalcogenides, which have potential applications in spintronics, thermoelectricity and topological insulators that can lead to low-power-consumption electronics. Very recently it was predicted and experimentally observed that the spin-orbit interaction in certain materials can lead to a new electronic state called topological insulating phase. The topological insulator, like an ordinary insulator, has a bulk energy gap separating the highest occupied electronic band from the lowest empty band. However, the surface states in the case of a three-dimensional or edge states in a two-dimensional topological insulator allow electrons to conduct at the surface, due to the topological character of the bulk wavefunctions. These conducting states are protected by time-reversal symmetry, and cannot be eliminated by defects or chemical passivation. The edge/surface states satisfy Dirac dispersion relations, and hence the physics

  3. Physical properties and fisheries

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.

    The physical aspects influencing the different stages of behaviour of the marine fish can be divided into two categories (1) the physical properties of the ocean like temperature, salinity, oxygen, high penetration etc.; and (2) the physical...

  4. Thermophysical properties study of micro/nanoscale materials

    Science.gov (United States)

    Feng, Xuhui

    Thermal transport in low-dimensional structure has attracted tremendous attentions because micro/nanoscale materials play crucial roles in advancing micro/nanoelectronics industry. The thermal properties are essential for understanding of the energy conversion and thermal management. To better investigate micro/nanoscale materials and characterize the thermal transport, pulse laser-assisted thermal relaxation 2 (PLTR2) and transient electrothermal (TET) are both employed to determine thermal property of various forms of materials, including thin films and nanowires. As conducting polymer, Poly(3-hexylthiophene) (P3HT) thin film is studied to understand its thermal properties variation with P3HT weight percentage. 4 P3HT solutions of different weight percentages are compounded to fabricate thin films using spin-coating technique. Experimental results indicate that weight percentage exhibits impact on thermophysical properties. When percentage changes from 2% to 7%, thermal conductivity varies from 1.29 to 1.67 W/m·K and thermal diffusivity decreases from 10-6 to 5×10-7 m2/s. Moreover, PLTR2 technique is applied to characterize the three-dimensional anisotropic thermal properties in spin-coated P3HT thin films. Raman spectra verify that the thin films embrace partially orientated P3HT molecular chains, leading to anisotropic thermal transport. Among all three directions, lowest thermal property is observed along out-of-plane direction. For in-plane characterization, anisotropic ratio is around 2 to 3, indicating that the orientation of the molecular chains has strong impact on the thermal transport along different directions. Titanium dioxide (TiO2) thin film is synthesized by electrospinning features porous structure composed by TiO2 nanowires with random orientations. The porous structure caused significant degradation of thermal properties. Effective thermal diffusivity, conductivity, and density of the films are 1.35˜3.52 × 10-6 m2/s, 0.06˜0.36 W/m·K, and

  5. Lanthanide upconversion luminescence at the nanoscale: fundamentals and optical properties

    Science.gov (United States)

    Nadort, Annemarie; Zhao, Jiangbo; Goldys, Ewa M.

    2016-07-01

    Upconversion photoluminescence is a nonlinear effect where multiple lower energy excitation photons produce higher energy emission photons. This fundamentally interesting process has many applications in biomedical imaging, light source and display technology, and solar energy harvesting. In this review we discuss the underlying physical principles and their modelling using rate equations. We discuss how the understanding of photophysical processes enabled a strategic influence over the optical properties of upconversion especially in rationally designed materials. We subsequently present an overview of recent experimental strategies to control and optimize the optical properties of upconversion nanoparticles, focussing on their emission spectral properties and brightness.

  6. Physical properties of solids

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, M. K.; Young, Jr, F. W.

    1977-10-01

    Research at ORNL into the physical properties of solids is described. Topics covered include: optical, electrical, and magnetic properties of magnesium oxide; ionic conductivity and superconductivity; surface physics and catalysis; defects and impurities in insulating crystals; photovoltaic conversion of solar energy; and fracture studies. (GHT)

  7. Nanoscale luminescent lanthanide-based metal-organic frameworks: properties, synthesis, and applications

    Science.gov (United States)

    Hu, Dongqin; Song, Yonghai; Wang, Li

    2015-07-01

    Nanoscale luminescent lanthanide-based metal-organic frameworks (NLLn-MOFs) possess superior optical and physical properties such as higher luminescent lifetime, quantum yield, high stability, high surface area, high agent loading, and intrinsic biodegradability, and therefore are regarded as a novel generation of luminescent material compared with bulk lanthanide-based metal-organic frameworks (Ln-MOFs). Traditional luminescent Ln-MOFs have been well studied; however, NLLn-MOFs taking the advantages of nanomaterials have attracted extensive investigations for applications in optical imaging in living cells, light-harvesting, and sensing. In this review, we provide a survey of the latest progresses made in developing NLLn-MOFs, which contains the fundamental optical features, synthesis, and their potential applications. Finally, the future prospects and challenges of the rapidly growing field are summarized.

  8. The Properties of Confined Water and Fluid Flow at the Nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Schwegler, E; Reed, J; Lau, E; Prendergast, D; Galli, G; Grossman, J C; Cicero, G

    2009-03-09

    This project has been focused on the development of accurate computational tools to study fluids in confined, nanoscale geometries, and the application of these techniques to probe the structural and electronic properties of water confined between hydrophilic and hydrophobic substrates, including the presence of simple ions at the interfaces. In particular, we have used a series of ab-initio molecular dynamics simulations and quantum Monte Carlo calculations to build an understanding of how hydrogen bonding and solvation are modified at the nanoscale. The properties of confined water affect a wide range of scientific and technological problems - including protein folding, cell-membrane flow, materials properties in confined media and nanofluidic devices.

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

    CERN Document Server

    Weiner, John

    2017-01-01

    Light–matter interaction is pervasive throughout the disciplines of optical and atomic physics, condensedmatter physics, and electrical engineering with frequency and length scales extending over many orders of magnitude. The frequency range extends from a few tens of Hz for sea communications to hundreds of petaHz (1015 s–1) for X-ray imaging systems. Length scales range from thousands of kilometres to a few hundred picometres. Although the present work does not offer an exhaustive treatise on this vast subject, it does aim to provide advanced undergraduates, graduate students, and researchers from these diverse disciplines the principal tools required to understand and contribute to rapidly advancing developments in light–matter interaction centred at optical frequencies and length scales. Classical electrodynamics, with an emphasis on the macroscopic expressions of Maxwell’s equations, physical optics, and quantum mechanics provide unique perspectives to the interaction of light and matter at these...

  10. The mechanical properties modeling of nano-scale materials by molecular dynamics

    NARCIS (Netherlands)

    Yuan, C.; Driel, W.D. van; Poelma, R.; Zhang, G.Q.

    2012-01-01

    We propose a molecular modeling strategy which is capable of mod-eling the mechanical properties on nano-scale low-dielectric (low-k) materials. Such modeling strategy has been also validated by the bulking force of carbon nano tube (CNT). This modeling framework consists of model generation method,

  11. Nanoscale semiconductor hybrids: fundamental physics and advanced devices

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Binh-Minh [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-04-09

    Key summary: Low dimensional hybrids: more flexibility and better controllability of materials properties. Type-II Antimonide-based superlattice: system of interacting quantum wells, for infrared detection and imaging. Hetero-designs in core/multi-shell nanowires: promising candidate for high performance electronic and sensing applications. An interdisciplinary research plan could trigger interest and collaboration within RIT.

  12. Nanoscale Structural and Mechanical Properties of Nontypeable Haemophilus influenzae Biofilms▿

    Science.gov (United States)

    Arce, Fernando Terán; Carlson, Ross; Monds, James; Veeh, Richard; Hu, Fen Z.; Stewart, Philip S.; Lal, Ratnesh; Ehrlich, Garth D.; Avci, Recep

    2009-01-01

    Nontypeable Haemophilus influenzae (NTHI) bacteria are commensals in the human nasopharynx, as well as pathogens associated with a spectrum of acute and chronic infections. Two important factors that influence NTHI pathogenicity are their ability to adhere to human tissue and their ability to form biofilms. Extracellular polymeric substances (EPS) and bacterial appendages such as pili critically influence cell adhesion and intercellular cohesion during biofilm formation. Structural components in the outer cell membrane, such as lipopolysaccharides, also play a fundamental role in infection of the host organism. In spite of their importance, these pathogenic factors are not yet well characterized at the nanoscale. Here, atomic force microscopy (AFM) was used in aqueous environments to visualize structural details, including probable Hif-type pili, of live NTHI bacteria at the early stages of biofilm formation. Using single-molecule AFM-based spectroscopy, the molecular elasticities of lipooligosaccharides present on NTHI cell surfaces were analyzed and compared between two strains (PittEE and PittGG) with very different pathogenicity profiles. Furthermore, the stiffness of single cells of both strains was measured and subsequently their turgor pressure was estimated. PMID:19218382

  13. The science of tiny things: physics at the nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Copp, Stacy Marla [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-07

    Nanoscience is the study of tiny objects that are only a billionth of a meter in size, or about 1,000 to 10,000 times smaller than a human hair. From the electronics in your smartphone to the molecular motors that are in your body’s cells, nanoscientists study and design materials that span a huge range of subjects, from physics to chemistry to biology. I will talk about some of what we do at LANL’s Center for Integrated Technologies, as well as how I first got interested in nanoscience and how I became a nanoscientist at LANL.

  14. Effects of External Stimuli on Microstructure-Property Relationship at the Nanoscale

    Science.gov (United States)

    Wang, Baoming

    The technical contribution of this research is a unique nanofabricated experimental setup that integrates nanoscale specimens with tools for interrogating mechanical (stress-strain, fracture, and fatigue), thermal and electrical (conductivity) properties as function of external stimuli such as strain, temperature, electrical field and radiation. It addresses the shortcomings of the state of the art characterization techniques, which are yet to perform such simultaneous and multi-domain measurements. Our technique has virtually no restriction on specimen material type and thickness, which makes the setup versatile. It is demonstrated with 100 nm thick nickel, aluminum, zirconium; 25 nm thick molybdenum di-sulphide (MoS2), 10 nm hexagonal boron nitride (h-BN) specimens and 100nm carbon nanofiber, all in freestanding thin film form. The technique is compatible with transmission electron microscopy (TEM). In-situ TEM captures microstructural features, (defects, phases, precipitates and interfaces), diffraction patterns and chemical microanalysis in real time. 'Seeing the microstructure while measuring properties' is our unique capability. It helps identifying fundamental mechanisms behind thermo-electro-mechanical coupling and degradation, so that these mechanisms can be used to (i) explain the results obtained for mesoscale specimens of the same materials and experimental conditions and (ii) develop computational models to explain and predict properties at both nano and meso scales. The uniqueness of this contribution is therefore simultaneously quantitative and qualitative probing of length-scale dependent external stimuli effects on microstructures and physical properties of nanoscale materials. The scientific contribution of this research is the experimental validation of the fundamental hypothesis that, if the nanoscale size can cause significant deviation in a certain domain, e.g., mechanical, it can also make that domain more sensitive to external stimuli when

  15. A Nanoscale Simulation Study of Elastic Properties of Gaspeite

    Directory of Open Access Journals (Sweden)

    Benazzouz Brahim-Khalil

    2015-02-01

    Full Text Available The study of structural and mechanical properties of carbonate rock is an interesting subject in engineering and its different applications. In this paper, the crystal structure of gaspeite (NiCO3 is investigated by carrying out molecular dynamics simulations based on energy minimization technique using an interatomic interaction potential.

  16. Quantum Electrostatic Model for Optical Properties of Nanoscale Gold Films

    Directory of Open Access Journals (Sweden)

    Qian Haoliang

    2015-11-01

    Full Text Available The optical properties of thin gold films with thickness varying from 2.5 nm to 30 nm are investigated. Due to the quantum size effect, the optical constants of the thin gold film deviate from the Drude model for bulk material as film thickness decreases, especially around 2.5 nm, where the electron energy level becomes discrete. A theory based on the self-consistent solution of the Schrödinger equation and the Poisson equation is proposed and its predictions agree well with experimental results.

  17. Electrical Properties of Nanoscale ZnS Thin Film Transistor

    Directory of Open Access Journals (Sweden)

    Teresa Oh

    2015-01-01

    Full Text Available To understand the contact mechanism from electrical properties of the ZnS TFTs, ZnS was fabricated on SiOC as a gate insulator on a Si substrate. Ohmic contact without a potential barrier increased the leakage current, but Schottky contact decreased the leakage current because of a Schottky barrier (SB. The ZnS TFTs prepared on SiOC with a Schottky contact improved the stability with respect to the reduction of drain voltages. The structural matching between ZnS and SiOC increased the height of SB such as ZnS annealed at 200°C, which made ZnS become an amorphous structure. ZnS/SiOC films with a low SB increased the capacitance and leakage current. The crystallinity orientation of ZnS localized defect states and the drift current owing to the impurity charge carriers caused the leakage current through low SB near zero voltages. But the increment of diffusion currents in a depletion layer increased the SB and then decreased the leakage current. So the electrical properties of devices were improved by a tunneling effect of diffusion currents.

  18. Lattice Dynamical Properties of Ferroelectric Thin Films at the Nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Xiaoxing [Temple University

    2014-01-13

    In this project, we have successfully demonstrated atomic layer-by-layer growth by laser MBE from separate targets by depositing SrTiO3 films from SrO and TiO2 targets. The RHEED intensity oscillation was used to monitor and control the growth of each SrO and TiO2 layer. We have shown that by using separate oxide targets, laser MBE can achieve the same level of stoichiometry control as the reactive MBE. We have also studied strain relaxation in LaAlO3 films and its effect on the 2D electron gas at LaAlO3/SrTiO3 interface. We found that there are two layers of different in-plane lattice constants in the LaAlO3 films, one next to the SrTiO3 substrate nearly coherently strained, while the top part relaxed as the film thickness increases above 20 unit cells. This strain relaxation significantly affect the transport properties of the LaAlO3/SrTiO3 interface.

  19. Viscoelastic nanoscale properties of cuticle contribute to the high-pass properties of spider vibration receptor (Cupiennius salei Keys)

    OpenAIRE

    McConney, Michael E; Schaber, Clemens F; Julian, Michael D; Barth, Friedrich G; Tsukruk, Vladimir V

    2007-01-01

    Atomic force microscopy (AFM) and surface force spectroscopy were applied in live spiders to their joint pad material located distal of the metatarsal lyriform organs, which are highly sensitive vibration sensors. The surface topography of the material is sufficiently smooth to probe the local nanomechanical properties with nanometre elastic deflections. Nanoscale loads were applied in the proximad direction on the distal joint region simulating the natural stimulus situation. The force curve...

  20. Delivery of Functionality in Complex Food Systems: Physically inspired approaches from nanoscale to microscale, Paris 14 to 17 July, 2015.

    Science.gov (United States)

    Relkin, Perla

    2016-10-01

    The 6th international symposium in the series "Delivery of Functionality in Complex Food Systems: Physically inspired approaches from nanoscale to microscal" was held in the heart of Paris from 14 to 17 July, 2015. It brought together PhD students, academic food researchers and industrials from diversified food sectors. The scientific sessions of this meeting were constructed around important topics dealing with 1) Engineering of tailored-made structures in bio-based systems; 2) Complexity and emergent phenomena in the integrative food science; 3) Investigation of nano and microstructures in the bulk and at interfaces; 4) Modeling approaches from bio-molecules and matrix structures to functionality; 5) Tuning binding & release of bioactive compounds by matrix modulation, and finally; 6) Tuning the delivery of functionality to the body. These topics were selected to cover different scientific fields and to show the contribution of food physical structures to development of health- and plaisure-supporting food functions. The oral communications were all introduced by key note speakers and they were all illustrated by outstanding high quality short communications. One of the most original features of this symposium was the increasing number of presentations using multiscale and modeling approaches illustrating the concept of complexity and emergent phenomena integrative food science. These highlighted the importance of studies on interactions between structure properties of engineered delivery systems and human body (sensory properties, digestion, release, bioavailability and bioaccessibility). Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Non-equilibrium phenomena in confined soft matter irreversible adsorption, physical aging and glass transition at the nanoscale

    CERN Document Server

    2015-01-01

    This book presents cutting-edge experimental and computational results and provides comprehensive coverage on the impact of non-equilibrium structure and dynamics on the properties of soft matter confined to the nanoscale. The book is organized into three main sections: ·         Equilibration and physical aging: by treating non-equilibrium phenomena with the formal methodology of statistical physics in bulk, the analysis of the kinetics of equilibration sheds new light on the physical origin of the non-equilibrium character of thin polymer films. Both the impact of sample preparation and that of interfacial interactions are analyzed using a large set of experiments. A historical overview of the investigation of the non-equilibrium character of thin polymer films is also presented. Furthermore, the discussion focuses on how interfaces and geometrical confinement perturb the pathways and kinetics of equilibrations of soft glasses (a process of tremendous technological interest). ·         Irr...

  2. Mapping the mechanical properties of cholesterol-containing supported lipid bilayers with nanoscale spatial resolution.

    Science.gov (United States)

    Shamitko-Klingensmith, Nicole; Molchanoff, Kelley M; Burke, Kathleen A; Magnone, George J; Legleiter, Justin

    2012-09-18

    It has been demonstrated that many biological processes are influenced by mechanical changes in membranes comprised of a variety of lipid components. As a result, the ability to map physicomechanical properties of surfaces with high temporal and spatial resolution is desirable. Tapping mode atomic force microscopy (AFM) has proven to be a useful technique for imaging biological surfaces due to its ability to operate in solution; however, access to information concerning the mechanical properties of these surfaces can also be obtained by reconstructing the time-resolved tip/sample force interactions during the imaging process. An advantage of such an approach is the direct correlation of topographical features with mechanical properties. Reconstruction of the tip/sample force is achievable by a technique called scanning probe acceleration microscopy (SPAM), which treats the cantilever as an accelerometer. The acceleration, which is directly related to the tip/sample force, of the cantilever is obtained by taking the second derivative of the cantilever deflection signal during a tapping mode AFM experiment in solution with standard cantilevers. Herein, we describe the applicability of SPAM to study mechanical properties of supported lipid bilayers with nanoscale spatial resolution via numerical simulations and experiment. The maximum and minimum tapping forces respond to changes in specific surface mechanical properties. Furthermore, we demonstrate how these changes can be used to map relative changes in the Young's modulus and adhesive properties of supported total brain lipid extract bilayers containing exogenous cholesterol. Finally, the ability of SPAM to distinguish nanoscale lipid raft domains based on changes in local mechanical properties is demonstrated.

  3. Thermal transport in low dimensions from statistical physics to nanoscale heat transfer

    CERN Document Server

    2016-01-01

    Understanding non-equilibrium properties of classical and quantum many-particle systems is one of the goals of contemporary statistical mechanics. Besides its own interest for the theoretical foundations of irreversible thermodynamics(e.g. of the Fourier's law of heat conduction), this topic is also relevant to develop innovative ideas for nanoscale thermal management with possible future applications to nanotechnologies and effective energetic resources. The first part of the volume (Chapters 1-6) describes the basic models, the phenomenology and the various theoretical approaches to understand heat transport in low-dimensional lattices (1D e 2D). The methods described will include equilibrium and nonequilibrium molecular dynamics simulations, hydrodynamic and kinetic approaches and the solution of stochastic models. The second part (Chapters 7-10) deals with applications to nano and microscale heat transfer, as for instance phononic transport in carbon-based nanomaterials, including the prominent case of na...

  4. Nano-scale characterization of fracture surfaces of blended epoxy resins related to fracture properties

    Energy Technology Data Exchange (ETDEWEB)

    Haris, Andi [Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Adachi, Tadaharu [Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan)], E-mail: adachi@mech.titech.ac.jp; Araki, Wakako [Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2008-11-25

    The fracture surface morphologies of epoxy resins with different macromolecular structures created by blending two epoxy monomers with different molecular weights (Epikote 828 and Epikote 1001) were characterized using atomic force microscopy with different sampling intervals. A measured fracture surface parameter (roughness ratio, S{sub dr}) was quantitatively analyzed from the topographic images and then correlated to the measured fracture energy, G{sub IC}. The fracture energy increased with the content of Epikote 1001 monomer, {phi}. The nano-scale surface roughness strongly depended on {phi}, meaning that each epoxy resin can be considered to have a different material structure in several nano-scales; heterogeneity, network or crosslink, which can be observed at higher resolution, 6 nm for 3 x 3 {mu}m{sup 2} scanning area, and 2 nm for 1 x 1 {mu}m{sup 2} scanning area. The fracture property is thus sensitive to the observed nano-structure whereas the glassy modulus is not. Therefore, the combination of the viscoelastic and fracture properties can be tailored by changing the network or crosslink structure by blending monomers with different molecular weights.

  5. Thermal stability, swelling behavior and CO 2 absorption properties of Nanoscale Ionic Materials (NIMs)

    KAUST Repository

    Andrew Lin, Kun-Yi

    2014-11-11

    © The Royal Society of Chemistry 2015. Nanoscale Ionic Materials (NIMs) consist of a nanoscale core, a corona of charged brushes tethered on the surface of the core, and a canopy of the oppositely charged species linked to the corona. Unlike conventional polymeric nanocomposites, NIMs can display liquid-like behavior in the absence of solvents, have a negligible vapor pressure and exhibit unique solvation properties. These features enable NIMs to be a promising CO2 capture material. To optimize NIMs for CO2 capture, their structure-property relationships were examined by investigating the roles of the canopy and the core in their thermal stability, and thermally- and CO2-induced swelling behaviors. NIMs with different canopy sizes and core fractions were synthesized and their thermal stability as well as thermally- and CO2-induced swelling behaviors were determined using thermogravimetry, and ATR FT-IR and Raman spectroscopies. It was found that the ionic bonds between the canopy and the corona, as well as covalent bonds between the corona and the core significantly improved the thermal stability compared to pure polymer and polymer/nanofiller mixtures. A smaller canopy size and a larger core fraction led to a greater enhancement in thermal stability. This thermal stability enhancement was responsible for the long-term thermal stability of NIMs over 100 temperature swing cycles. Owing to their ordered structure, NIMs swelled less when heated or when they adsorbed CO2 compared to their corresponding polymers. This journal is

  6. Nanoscale determination of surface orientation and electrostatic properties of ZnO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga-Perez, J.; Munoz-Sanjose, V. [Universitat de Valencia, Departament de Fisica Aplicada i Electromagnetisme, Burjassot (Spain); Palacios-Lidon, E.; Colchero, J. [Universidad de Murcia, Departamento de Fisica, Facultad de Quimica, Campus Espinardo, Murcia (Spain)

    2007-07-15

    Scanning force microscopy related techniques are applied to study surface nanoscale properties. We show that nanogoniometry can be combined with local electrostatic measurements - electrostatic force microscopy and Kelvin probe microscopy - to identify surface planes families and to study their local electrical properties. The scanning force microscopy techniques employed are analyzed and the correct way of acquiring and interpreting data is discussed in detail. The experiments performed on ZnO films grown along the nonpolar [112 anti 0] direction show that these films completely facet into {l_brace}101 anti 11{r_brace} and {l_brace}10 anti 1 anti 1{r_brace} planes, which follow a well defined pattern of surface potential along the [0001 ] direction. This pattern is explained in terms of the different ionic termination - Zn or O ions - of the exposed facets. Finally, the presence of inversion domain boundaries is discussed. (orig.)

  7. The influence of nanoscale inorganic content over optical and surface properties of model composites.

    Science.gov (United States)

    Salgado, Vinícius Esteves; Cavalcante, Larissa Maria; Silikas, Nick; Schneider, Luis Felipe J

    2013-11-01

    To investigate the influence of nanoscale inorganic content over optical and surface properties of model composites before and after ageing. Three model composites were formulated with silica fillers in nanoscale of 7 nm (G1), 12 nm (G2) and 16 nm (G3), at 45.5% by weight in a matrix of BisGMA/TEGDMA 1:1. Color coordinates (CIE L*a*b* parameters), color difference (ΔE*), translucency parameter (TP), surface gloss (SG) and surface roughness (SR) were measured before and after ageing procedures of immersion in water and toothbrush abrasion. Surface hardness (SH) were evaluated before and after immersion in absolute ethanol. Results were submitted to two-way ANOVA followed by Tukey's post hoc test performed at a pre-set alpha of 0.05. Regarding CIE L*a*b* parameters, a darkening, a redness and a blueness effect, were respectively detected after water storage for all groups. Smaller filler sizes (G1) had the highest CIE b* values, whereas medium (G2) (p0.05), although a tendency towards lower values in smaller filler materials was observed. Ageing after immersion in absolute ethanol decreased SH for all model composites. Filler sizes and ageing procedures influenced the optical and surface properties of the nanostructured composites evaluated in this study. Filler size influenced optical and surface properties of resin composites. Materials containing smaller filler size offered improved optical stability and surface properties that can lead to longer maintenance of the restoration's appearance in the oral environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Nanoscale electromechanical properties of CaCu3Ti4O12 ceramics

    Science.gov (United States)

    Tararam, R.; Bdikin, I. K.; Panwar, N.; Varela, J. A.; Bueno, P. R.; Kholkin, A. L.

    2011-09-01

    Piezoresponse Force Microscopy (PFM) is used to characterize the nanoscale electromechanical properties of centrosymmetric CaCu3Ti4O12 ceramics with giant dielectric constant. Clear PFM contrast both in vertical (out-of-plane) and lateral (in-plane) modes is observed on the ceramic surface with varying magnitude and polarization direction depending on the grain crystalline orientation. Lateral signal changes its sign upon 180° rotation of the sample thus ruling out spurious electrostatic contribution and confirming piezoelectric nature of the effect. Piezoresponse could be locally reversed by suitable electrical bias (local poling) and induced polarization was quite stable showing long-time relaxation (˜3 hrs). The electromechanical contrast in unpoled ceramics is attributed to the surface flexoelectric effect (strain gradient induced polarization) while piezoresponse hysteresis and ferroelectric-like behavior are discussed in terms of structural instabilities due to Ti off-center displacements and structural defects in this material.

  9. A multi-physics modelling framework to describe the behaviour of nano-scale multilayer systems undergoing irradiation damage

    International Nuclear Information System (INIS)

    Villani, Aurelien

    2015-01-01

    Radiation damage is known to lead to material failure and thus is of critical importance to lifetime and safety within nuclear reactors. While mechanical behaviour of materials under irradiation has been the subject of numerous studies, the current predictive capabilities of such phenomena appear limited. The clustering of point defects such as vacancies and self interstitial atoms gives rise to creep, void swelling and material embrittlement. Nano-scale metallic multilayer systems have be shown to have the ability to evacuate such point defects, hence delaying the occurrence of critical damage. In addition, they exhibit outstanding mechanical properties. The objective of this work is to develop a thermodynamically consistent continuum framework at the meso and nano-scales, which accounts for the major physical processes encountered in such metallic multilayer systems and is able to predict their microstructural evolution and behavior under irradiation. Mainly three physical phenomena are addressed in the present work: stress-diffusion coupling and diffusion induced creep, the void nucleation and growth in multilayer systems under irradiation, and the interaction of dislocations with the multilayer interfaces. In this framework, the microstructure is explicitly modeled, in order to account accurately for their effects on the system behavior. The diffusion creep strain rate is related to the gradient of the vacancy flux. A Cahn-Hilliard approach is used to model void nucleation and growth, and the diffusion equations for vacancies and self interstitial atoms are complemented to take into account the production of point defects due to irradiation cascades, the mutual recombination of defects and their evacuation through grain boundaries. In metallic multilayers, an interface affected zone is defined, with an additional slip plane to model the interface shearable character, and where dislocations cores are able to spread. The model is then implemented numerically

  10. The physical properties of coal

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2015-01-01

    Full Text Available stream_source_info Van Schoor2_2015.pdf.txt stream_content_type text/plain stream_size 15563 Content-Encoding UTF-8 stream_name Van Schoor2_2015.pdf.txt Content-Type text/plain; charset=UTF-8 22 2 the physIcAl propert...Ies of coAl Michael van Schoor, Leonie Mare This chapter explains why geophysicists usually want to know as much as possible about the physical properties of the different lithological units in an area before embarking on a geophysical survey. We also...

  11. Physical properties of liquid sodium

    International Nuclear Information System (INIS)

    Alberdi Primicia, J.; Martinez Piquer, T.A.

    1977-01-01

    The molten sodium has been the more accepted coolant for the first generation of FBR, by this reason the knowledge of its technology is needed for the development of the next LMFBR. A series of necessary data for designing sodium liquid systems are given. Tables and graphics about the most important physical sodium properties between 1200-1400 degC are gathered. The results have been obtained from equations that relate the properties with temperature using a Fortran IV program. (author) [es

  12. Harnessing the extracellular bacterial production of nanoscale cobalt ferrite with exploitable magnetic properties.

    Science.gov (United States)

    Coker, Victoria S; Telling, Neil D; van der Laan, Gerrit; Pattrick, Richard A D; Pearce, Carolyn I; Arenholz, Elke; Tuna, Floriana; Winpenny, Richard E P; Lloyd, Jonathan R

    2009-07-28

    Nanoscale ferrimagnetic particles have a diverse range of uses from directed cancer therapy and drug delivery systems to magnetic recording media and transducers. Such applications require the production of monodisperse nanoparticles with well-controlled size, composition, and magnetic properties. To fabricate these materials purely using synthetic methods is costly in both environmental and economical terms. However, metal-reducing microorganisms offer an untapped resource to produce these materials. Here, the Fe(III)-reducing bacterium Geobacter sulfurreducens is used to synthesize magnetic iron oxide nanoparticles. A combination of electron microscopy, soft X-ray spectroscopy, and magnetometry techniques was employed to show that this method of biosynthesis results in high yields of crystalline nanoparticles with a narrow size distribution and magnetic properties equal to the best chemically synthesized materials. In particular, it is demonstrated here that cobalt ferrite (CoFe(2)O(4)) nanoparticles with low temperature coercivity approaching 8 kOe and an effective anisotropy constant of ∼10(6) erg cm(-3) can be manufactured through this biotechnological route. The dramatic enhancement in the magnetic properties of the nanoparticles by the introduction of high quantities of Co into the spinel structure represents a significant advance over previous biomineralization studies in this area using magnetotactic bacteria. The successful production of nanoparticulate ferrites achieved in this study at high yields could open up the way for the scaled-up industrial manufacture of nanoparticles using environmentally benign methodologies.

  13. Physical Properties of Liquid Crystals

    CERN Document Server

    Gray, George W; Spiess, Hans W

    1999-01-01

    This handbook is a unique compendium of knowledge on all aspects of the physics of liquid crystals. In over 500 pages it provides detailed information on the physical properties of liquid crystals as well as the recent theories and results on phase transitions, defects and textures of different types of liquid crystals. An in-depth understanding of the physical fundamentals is a prerequisite for everyone working in the field of liquid crystal research. With this book the experts as well as graduate students entering the field get all the information they need.

  14. The physical properties of glycerin

    International Nuclear Information System (INIS)

    Kimsanov, B.Kh.; Karimov, M.B.; Khuseynov, K.

    1998-01-01

    In this chapter of book authors describe physical properties of glycerin. The pure glycerin presents syrup-vivid insipid transparent solution odorless and sweet on taste. The glycerin is very hygroscopic and can absorb from air till 40% moisture against its mass

  15. Focused-ion-beam induced interfacial intermixing of magnetic bilayers for nanoscale control of magnetic properties

    International Nuclear Information System (INIS)

    Burn, D M; Atkinson, D; Hase, T P A

    2014-01-01

    Modification of the magnetic properties in a thin-film ferromagnetic/non-magnetic bilayer system by low-dose focused ion-beam (FIB) induced intermixing is demonstrated. The highly localized capability of FIB may be used to locally control magnetic behaviour at the nanoscale. The magnetic, electronic and structural properties of NiFe/Au bilayers were investigated as a function of the interfacial structure that was actively modified using focused Ga + ion irradiation. Experimental work used MOKE, SQUID, XMCD as well as magnetoresistance measurements to determine the magnetic behavior and grazing incidence x-ray reflectivity to elucidate the interfacial structure. Interfacial intermixing, induced by low-dose irradiation, is shown to lead to complex changes in the magnetic behavior that are associated with monotonic structural evolution of the interface. This behavior may be explained by changes in the local atomic environment within the interface region resulting in a combination of processes including the loss of moment on Ni and Fe, an induced moment on Au and modifications to the spin-orbit coupling between Au and NiFe. (paper)

  16. Physical properties of polymers handbook

    CERN Document Server

    2007-01-01

    This book offers concise information on the properties of polymeric materials, particularly those most relevant to physical chemistry and chemical physics. Extensive updates and revisions to each chapter include eleven new chapters on novel polymeric structures, reinforcing phases in polymers, and experiments on single polymer chains. The study of complex materials is highly interdisciplinary, and new findings are scattered among a large selection of scientific and engineering journals. This book brings together data from experts in the different disciplines contributing to the rapidly growing area of polymers and complex materials.

  17. Physical properties of europium sesquioxide

    International Nuclear Information System (INIS)

    Gilchrist, K.E.; Brown, R.G.; Preston, S.D.

    1977-01-01

    Europium sesquioxide (Eu 2 O 3 ) is a neutron-absorbing material of potential use in reactor control rods and is being evaluated for use in fast reactors. This paper presents the results of physical and mechanical property measurements performed on unirradiated europia. The material exists in two useful crystallographic forms. Both the monoclinic form and a cubic variety, stabilized by the addition of 17 wt% molybdenum trioxide (MoO 3 ), have been examined. The properties reported are density, specific heat, thermal diffusivity and conductivity, thermal expansivity, Young's modulus, and strength. The data are compared with similar information in the literature. (Auth.)

  18. Viscoelastic nanoscale properties of cuticle contribute to the high-pass properties of spider vibration receptor (Cupiennius salei Keys).

    Science.gov (United States)

    McConney, Michael E; Schaber, Clemens F; Julian, Michael D; Barth, Friedrich G; Tsukruk, Vladimir V

    2007-12-22

    Atomic force microscopy (AFM) and surface force spectroscopy were applied in live spiders to their joint pad material located distal of the metatarsal lyriform organs, which are highly sensitive vibration sensors. The surface topography of the material is sufficiently smooth to probe the local nanomechanical properties with nanometre elastic deflections. Nanoscale loads were applied in the proximad direction on the distal joint region simulating the natural stimulus situation. The force curves obtained indicate the presence of a soft, liquid-like epicuticular layer (20-40 nm thick) above the pad material, which has much higher stiffness. The Young modulus of the pad material is close to 15 MPa at low frequencies, but increases rapidly with increasing frequencies approximately above 30 Hz to approximately 70 MPa at 112 Hz. The adhesive forces drop sharply by about 40% in the same frequency range. The strong frequency dependence of the elastic modulus indicates the viscoelastic nature of the pad material, its glass transition temperature being close to room temperature (25 +/- 2 degrees C) and, therefore, to its maximized energy absorption from low-frequency mechanical stimuli. These viscoelastic properties of the cuticular pad are suggested to be at least partly responsible for the high-pass characteristics of the vibration sensor's physiological properties demonstrated earlier.

  19. Nanoscale phase-change materials and devices

    Science.gov (United States)

    Zheng, Qinghui; Wang, Yuxi; Zhu, Jia

    2017-06-01

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

  20. Nanoscale phase-change materials and devices

    International Nuclear Information System (INIS)

    Zheng, Qinghui; Wang, Yuxi; Zhu, Jia

    2017-01-01

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

  1. Nanoscale biophysical properties of the cell surface galactosaminogalactan from the fungal pathogen Aspergillus fumigatus

    Science.gov (United States)

    Beaussart, Audrey; El-Kirat-Chatel, Sofiane; Fontaine, Thierry; Latgé, Jean-Paul; Dufrêne, Yves F.

    2015-09-01

    Many fungal pathogens produce cell surface polysaccharides that play essential roles in host-pathogen interactions. In Aspergillus fumigatus, the newly discovered polysaccharide galactosaminogalactan (GAG) mediates adherence to a variety of substrates through molecular mechanisms that are poorly understood. Here we use atomic force microscopy to unravel the localization and adhesion of GAG on living fungal cells. Using single-molecule imaging with tips bearing anti-GAG antibodies, we found that GAG is massively exposed on wild-type (WT) germ tubes, consistent with the notion that this glycopolymer is secreted by the mycelium of A. fumigatus, while it is lacking on WT resting conidia and on germ tubes from a mutant (Δuge3) deficient in GAG. Imaging germ tubes with tips bearing anti-β-glucan antibodies shows that exposure of β-glucan is strongly increased in the Δuge3 mutant, indicating that this polysaccharide is masked by GAG during hyphal growth. Single-cell force measurements show that expression of GAG on germ tubes promotes specific adhesion to pneumocytes and non-specific adhesion to hydrophobic substrates. These results provide a molecular foundation for the multifunctional adhesion properties of GAG, thus suggesting it could be used as a potential target in anti-adhesion therapy and immunotherapy. Our methodology represents a powerful approach for characterizing the nanoscale organization and adhesion of cell wall polysaccharides during fungal morphogenesis, thereby contributing to increase our understanding of their role in biofilm formation and immune responses.

  2. Controlling mechanical properties of bio-inspired hydrogels by modulating nano-scale, inter-polymeric junctions

    Directory of Open Access Journals (Sweden)

    Seonki Hong

    2014-06-01

    Full Text Available Quinone tanning is a well-characterized biochemical process found in invertebrates, which produce diverse materials from extremely hard tissues to soft water-resistant adhesives. Herein, we report new types of catecholamine PEG derivatives, PEG-NH-catechols that can utilize an expanded spectrum of catecholamine chemistry. The PEGs enable simultaneous participation of amine and catechol in quinone tanning crosslinking. The intermolecular reaction between PEG-NH-catechols forms a dramatic nano-scale junction resulting in enhancement of gelation kinetics and mechanical properties of PEG hydrogels compared to results obtained by using PEGs in the absence of amine groups. Therefore, the study provides new insight into designing new crosslinking chemistry for controlling nano-scale chemical reactions that can broaden unique properties of bulk hydrogels.

  3. John H. Dillon Medal Talk: Protein Fibrils, Polymer Physics: Encounter at the Nanoscale

    Science.gov (United States)

    Mezzenga, Raffaele

    2011-03-01

    Aggregation of proteins is central to many aspects of daily life, ranging from blood coagulation, to eye cataract formation disease, food processing, or neurodegenerative infections. In particular, the physical mechanisms responsible for amyloidosis, the irreversible fibril formation of various proteins implicated in protein misfolding disorders such as Alzheimer, Creutzfeldt-Jakob or Huntington's diseases, have not yet been fully elucidated. In this talk I will discuss how polymer physics and colloidal science concepts can be used to reveal very useful information on the formation, structure and properties of amyloid protein fibrils. I will discuss their physical properties at various length scales, from their collective liquid crystalline behavior in solution to their structural features at the single molecule length scale and show how polymer science notions can shed a new light on these interesting systems. 1) ``Understanding amyloid aggregation by statistical analysis of atomic force microscopy images'' J. Adamcik, J.-M. Jung, J. Flakowski, P. De Los Rios, G. Dietler and R. Mezzenga, Nature nanotechnology, 5, 423 (2010)

  4. Material properties and applications of blended organic thin films with nanoscale domains deposited by RIR-MAPLE

    Science.gov (United States)

    Stiff-Roberts, Adrienne D.; McCormick, Ryan D.; Ge, Wangyao

    2015-03-01

    Resonant-infrared, matrix-assisted pulsed laser evaporation (RIR-MAPLE) has been used to deposit blended, organic thin-films with nanoscale domain sizes of constituent polymers, small molecules, or colloidal nanoparticles. In the emulsion-based RIR-MAPLE process, the target contains a nonpolar, organic solvent phase and a polar, water phase. The emulsion properties have a direct impact on the nanoscale morphology of single-component organic thin films, while the morphology of blended, organic thin films also depends on the RIR-MAPLE deposition mode. In addition to these fundamental aspects, applications of blended organic films (organic solar cells, anti-reflection coatings, and multi-functional surfaces) deposited by emulsion-based RIR-MAPLE are presented. Importantly, domain sizes in the blended films are critical to thin-film functionality.

  5. Harnessing microbial subsurface metal reduction activities to synthesise nanoscale cobalt ferrite with enhanced magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Coker, Victoria S.; Telling, Neil D.; van der Laan, Gerrit; Pattrick, Richard A.D.; Pearce, Carolyn I.; Arenholz, Elke; Tuna, Floriana; Winpenny, Richard E.P.; Lloyd, Jonathan R.

    2009-03-24

    Nanoscale ferrimagnetic particles have a diverse range of uses from directed cancer therapy and drug delivery systems to magnetic recording media and transducers. Such applications require the production of monodisperse nanoparticles with well-controlled size, composition, and magnetic properties. To fabricate these materials purely using synthetic methods is costly in both environmental and economical terms. However, metal-reducing microorganisms offer an untapped resource to produce these materials. Here, the Fe(III)-reducing bacterium Geobacter sulfurreducens is used to synthesize magnetic iron oxide nanoparticles. A combination of electron microscopy, soft X-ray spectroscopy, and magnetometry techniques was employed to show that this method of biosynthesis results in high yields of crystalline nanoparticles with a narrow size distribution and magnetic properties equal to the best chemically synthesized materials. In particular, it is demonstrated here that cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles with low temperature coercivity approaching 8 kOe and an effective anisotropy constant of {approx} 10{sup 6} erg cm{sup -3} can be manufactured through this biotechnological route. The dramatic enhancement in the magnetic properties of the nanoparticles by the introduction of high quantities of Co into the spinel structure represents a significant advance over previous biomineralization studies in this area using magnetotactic bacteria. The successful production of nanoparticulate ferrites achieved in this study at high yields could open up the way for the scaled-up industrial manufacture of nanoparticles using environmentally benign methodologies. Production of ferromagnetic nanoparticles for pioneering cancer therapy, drug delivery, chemical sensors, catalytic activity, photoconductive materials, as well as more traditional uses in data storage embodies a large area of inorganic synthesis research. In particular, the addition of transition metals other than

  6. Harnessing microbial subsurface metal reduction activities to synthesize nanoscale cobalt ferrite with enhanced magnetic properties

    International Nuclear Information System (INIS)

    Coker, Victoria S.; Telling, Neil D.; van der Laan, Gerrit; Pattrick, Richard A.D.; Pearce, Carolyn I.; Arenholz, Elke; Tuna, Floriana; Winpenny, Richard E.P.; Lloyd, Jonathan R.

    2009-01-01

    Nanoscale ferrimagnetic particles have a diverse range of uses from directed cancer therapy and drug delivery systems to magnetic recording media and transducers. Such applications require the production of monodisperse nanoparticles with well-controlled size, composition, and magnetic properties. To fabricate these materials purely using synthetic methods is costly in both environmental and economical terms. However, metal-reducing microorganisms offer an untapped resource to produce these materials. Here, the Fe(III)-reducing bacterium Geobacter sulfurreducens is used to synthesize magnetic iron oxide nanoparticles. A combination of electron microscopy, soft X-ray spectroscopy, and magnetometry techniques was employed to show that this method of biosynthesis results in high yields of crystalline nanoparticles with a narrow size distribution and magnetic properties equal to the best chemically synthesized materials. In particular, it is demonstrated here that cobalt ferrite (CoFe 2 O 4 ) nanoparticles with low temperature coercivity approaching 8 kOe and an effective anisotropy constant of ∼ 10 6 erg cm -3 can be manufactured through this biotechnological route. The dramatic enhancement in the magnetic properties of the nanoparticles by the introduction of high quantities of Co into the spinel structure represents a significant advance over previous biomineralization studies in this area using magnetotactic bacteria. The successful production of nanoparticulate ferrites achieved in this study at high yields could open up the way for the scaled-up industrial manufacture of nanoparticles using environmentally benign methodologies. Production of ferromagnetic nanoparticles for pioneering cancer therapy, drug delivery, chemical sensors, catalytic activity, photoconductive materials, as well as more traditional uses in data storage embodies a large area of inorganic synthesis research. In particular, the addition of transition metals other than Fe into the structure

  7. Spintronics in nanoscale devices

    CERN Document Server

    Hedin, Eric R

    2013-01-01

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

  8. Microscale and nanoscale hierarchical structured mesh films with superhydrophobic and superoleophilic properties induced by long-chain fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Wang Shutao [Center for Molecular Science, Institute of Chemistry, Beijing 100080 (China); Song Yanlin [Center for Molecular Science, Institute of Chemistry, Beijing 100080 (China); Jiang Lei [Center for Molecular Science, Institute of Chemistry, Beijing 100080 (China)

    2007-01-10

    Inspired by the lotus effect, we fabricate new microscale and nanoscale hierarchical structured copper mesh films by a simple electrochemical deposition. After modification of the long-chain fatty acid monolayer, these films show superhydrophobic and superoleophilic properties, which could be used for the effective separation of oil and water. The length of the fatty acid chain strongly influences the surface wettability of as-prepared films. It is confirmed that the cooperative effect of the hierarchical structure of the copper film and the nature of the long-chain fatty acid contribute to this unique surface wettability.

  9. Microscale and nanoscale hierarchical structured mesh films with superhydrophobic and superoleophilic properties induced by long-chain fatty acids

    Science.gov (United States)

    Wang, Shutao; Song, Yanlin; Jiang, Lei

    2007-01-01

    Inspired by the lotus effect, we fabricate new microscale and nanoscale hierarchical structured copper mesh films by a simple electrochemical deposition. After modification of the long-chain fatty acid monolayer, these films show superhydrophobic and superoleophilic properties, which could be used for the effective separation of oil and water. The length of the fatty acid chain strongly influences the surface wettability of as-prepared films. It is confirmed that the cooperative effect of the hierarchical structure of the copper film and the nature of the long-chain fatty acid contribute to this unique surface wettability.

  10. Nanoscale flexoelectricity.

    Science.gov (United States)

    Nguyen, Thanh D; Mao, Sheng; Yeh, Yao-Wen; Purohit, Prashant K; McAlpine, Michael C

    2013-02-20

    Electromechanical effects are ubiquitous in biological and materials systems. Understanding the fundamentals of these coupling phenomena is critical to devising next-generation electromechanical transducers. Piezoelectricity has been studied in detail, in both the bulk and at mesoscopic scales. Recently, an increasing amount of attention has been paid to flexoelectricity: electrical polarization induced by a strain gradient. While piezoelectricity requires crystalline structures with no inversion symmetry, flexoelectricity does not carry this requirement, since the effect is caused by inhomogeneous strains. Flexoelectricity explains many interesting electromechanical behaviors in hard crystalline materials and underpins core mechanoelectric transduction phenomena in soft biomaterials. Most excitingly, flexoelectricity is a size-dependent effect which becomes more significant in nanoscale systems. With increasing interest in nanoscale and nano-bio hybrid materials, flexoelectricity will continue to gain prominence. This Review summarizes work in this area. First, methods to amplify or manipulate the flexoelectric effect to enhance material properties will be investigated, particularly at nanometer scales. Next, the nature and history of these effects in soft biomaterials will be explored. Finally, some theoretical interpretations for the effect will be presented. Overall, flexoelectricity represents an exciting phenomenon which is expected to become more considerable as materials continue to shrink. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Surface Chemistry in Nanoscale Materials

    Science.gov (United States)

    Biener, Jürgen; Wittstock, Arne; Baumann, Theodore F.; Weissmüller, Jörg; Bäumer, Marcus; Hamza, Alex V.

    2009-01-01

    Although surfaces or, more precisely, the surface atomic and electronic structure, determine the way materials interact with their environment, the influence of surface chemistry on the bulk of the material is generally considered to be small. However, in the case of high surface area materials such as nanoporous solids, surface properties can start to dominate the overall material behavior. This allows one to create new materials with physical and chemical properties that are no longer determined by the bulk material, but by their nanoscale architectures. Here, we discuss several examples, ranging from nanoporous gold to surface engineered carbon aerogels that demonstrate the tuneability of nanoporous solids for sustainable energy applications.

  12. Surface Chemistry in Nanoscale Materials

    Directory of Open Access Journals (Sweden)

    Alex V. Hamza

    2009-12-01

    Full Text Available Although surfaces or, more precisely, the surface atomic and electronic structure, determine the way materials interact with their environment, the influence of surface chemistry on the bulk of the material is generally considered to be small. However, in the case of high surface area materials such as nanoporous solids, surface properties can start to dominate the overall material behavior. This allows one to create new materials with physical and chemical properties that are no longer determined by the bulk material, but by their nanoscale architectures. Here, we discuss several examples, ranging from nanoporous gold to surface engineered carbon aerogels that demonstrate the tuneability of nanoporous solids for sustainable energy applications.

  13. Physical properties and mantle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Shankland, T.J.; Johnson, P.A.; McCall, K.R. [Los Alamos National Lab., NM (United States). Earth and Environmental Sciences Div.] [and others

    1997-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Because planetary interiors are remote, laboratory methods and associated theory are an essential step for interpreting geophysical measurements in terms of quantities that are needed for understanding Earth--temperature, composition, stress state, history, and hazards. One objective is the study of minerals and rocks as materials using experimental methods; another is to develop new methods, as in high pressure research, codes for computation in rock/soil physics, or nuclear-based analysis. Accomplishments include developing a single-crystal x-ray diffraction apparatus with application to materials at extremely high pressure and temperature; P-V-T equations of state and seismic velocity measurements for understanding the composition of Earth`s outer 1,000 km; creating computational tools to explain complex stress-strain histories of rocks; and measuring tungsten/thorium ratios W/Th that agree with the hypothesis that Earth accreted heterogeneously. Work performed in this project applies to geosciences, geothermal energy, mineral and rock properties, seismic detection, and isotope dating.

  14. Physical properties of organic coolants

    International Nuclear Information System (INIS)

    Debbage, A.G.; Garton, D.A.; Kinneir, J.H.

    1963-03-01

    Density, viscosity, specific heat, vapour pressure and calorific value were measured within the temperature range 100 - 400 deg C for mixtures of Santowax R with pyrolytic high boiler and Santowax R with O.M.R.E. radiolytic high boiler; in addition measurements were made on Santowax OM, X-7 standard, X-7 loop coolant and O.M.R.E. coolant supplied by Atomic Energy of Canada Ltd. The accuracy of the measurements made were density (± 1/4%), viscosity (± 2%), specific heat (± 2%), vapour pressure (± 2%) and calorific value (± 1/2%). Thermal conductivity was calculated from an improved form of the Smiths equation with an accuracy within ± 6%. Equations fitted to the vapour pressure results were used to provide data outside the experimental range for burnout correlation purposes. The general effect of high boiler content on the specific heat and calorific values was small. The differences in physical property values for corresponding values of either pyrolytic or radiolytic high boiler were small for density (0.3%) and specific heat (2%), but quite large for viscosity (70%) with the pyrolytic high boiler mixture giving the higher value. The chemical analysis of all materials was based on gas chromatography and the relationship between this and an earlier distillation method established. (author)

  15. Fundamentals of semiconductors physics and materials properties

    CERN Document Server

    Yu, Peter Y

    2005-01-01

    Provides detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors. This textbook emphasizes understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors and features an extensive collection of tables of material parameters, figures, and problems.

  16. Temporal characteristics of aerosol physical properties at ...

    Indian Academy of Sciences (India)

    Realizing the importance of aerosol physical properties at the adjoining continental and coastal locations in the airmass pathways onto the oceanic region, extensive measurements of aerosol physical properties were made at Visakhapatnam (17.7°N, 83.3°E), an eastern coastal location in peninsular India during the ICARB ...

  17. Physical properties of organic soils. Chapter 5.

    Science.gov (United States)

    Elon S. Verry; Don H. Boelter; Juhani Paivanen; Dale S. Nichols; Tom Malterer; Avi Gafni

    2011-01-01

    Compared with research on mineral soils, the study of the physical properties of organic soils in the United States is relatively new. A comprehensive series of studies on peat physical properties were conducted by Don Boelter (1959-1975), first at the Marcell Experimental Forest (MEF) and later throughout the northern Lakes States to investigate how to express bulk...

  18. Electroweak properties of particle physics. Volume 2

    International Nuclear Information System (INIS)

    Aleksan, R.; Ellis, N.; Falvard, A.; Fayard, L.; Frere, J.M.; Kuehn, J.H.; Le Yaouanc, A.; Roudeau, P.; Wormser, G.

    1991-01-01

    The 23th GIf school was held at Ecole Polytechnique, Palaiseau, France from 16 to 20 September 1991. The subject was large: Electroweak properties of heavy quarks. The second part has been devoted to B physics at hadron machines, search for Top, Charm particle physics and Quarkonium physics

  19. Physical properties and moisture relations of wood

    Science.gov (United States)

    William Simpson; Anton TenWolde

    1999-01-01

    The versatility of wood is demonstrated by a wide variety of products. This variety is a result of a spectrum of desirable physical characteristics or properties among the many species of wood. In many cases, more than one property of wood is important to the end product. For example, to select a wood species for a product, the value of appearance- type properties,...

  20. Physical properties of thorium fluoride

    International Nuclear Information System (INIS)

    Van Uitert, L.G.; Guggenheim, H.J.; O'Bryan, H.M.; Warner, A.W. Jr.; Brownlow, D.; Bernstein, J.L.; Pasteur, G.A.; Johnson, L.F.

    1976-01-01

    Thorium fluoride has many properties that make it of interest for infrared windows. It is transparent to about eleven microns, is unaffected by moisture, has a moderate hardness, and suffers little dimensional change upon heating

  1. Nanoscale effects on the thermal and mechanical properties of AlGaAs/GaAs quantum well laser diodes: influence on the catastrophic optical damage

    Science.gov (United States)

    Souto, Jorge; Pura, José Luis; Jiménez, Juan

    2017-06-01

    In this work we study the catastrophic optical damage (COD) of graded-index separate confinement heterostructure quantum well (QW) laser diodes based on AlGaAs/GaAs. The emphasis is placed on the impact that the nanoscale physical properties have on the operation and degradation of the active layers of these devices. When these laser diodes run in continuous-wave mode with high internal optical power densities, the QW and guide layers can experiment very intense local heating phenomena that lead to device failure. A thermo-mechanical model has been set up to study the mechanism of degradation. This model has been solved by applying finite element methods. A variety of physical factors related to the materials properties, which play a paramount role in the laser degradation process, have been considered. Among these, the reduced thicknesses of the QW and the guides lead to thermal conductivities smaller than the bulk figures, which are further reduced as extended defects develop in these layers. This results in a progressively deteriorating thermal management in the device. To the best of our knowledge, this model for laser diodes is the first one to have taken into account low scale mechanical effects that result in enhanced strengths in the structural layers. Moreover, the consequences of these conflicting size-dependent properties on the thermo-mechanical behaviour on the route to COD are examined. Subsequently, this approach opens the possibility of taking advantage of these properties in order to design robust diode lasers (or other types of power devices) in a controlled manner.

  2. Physically unclonable functions constructions, properties and applications

    CERN Document Server

    Maes, Roel

    2013-01-01

    Physically unclonable functions (PUFs) are innovative physical security primitives that produce unclonable and inherent instance-specific measurements of physical objects; in many ways they are the inanimate equivalent of biometrics for human beings. Since they are able to securely generate and store secrets, they allow us to bootstrap the physical implementation of an information security system. In this book the author discusses PUFs in all their facets: the multitude of their physical constructions, the algorithmic and physical properties which describe them, and the techniques required to

  3. Thermal and physical properties of bakery products.

    Science.gov (United States)

    Baik, O D; Marcotte, M; Sablani, S S; Castaigne, F

    2001-07-01

    This article reviews the measurement techniques, prediction models, and data on thermo-physical properties of bakery products: specific heat, thermal conductivity, thermal diffusivity, and density. Over the last decade, investigation has focused more on thermo-physical properties of nonbread bakery products. Both commonly used and new measurement techniques for thermo-physical properties reported in the publication are presented with directions for their proper use. Data and prediction models are tabulated for the range of moisture content and temperature of the bakery products.

  4. Magnetic properties of nano-scale hematite, α-Fe2O3, studied by time-of-flight inelastic neutron spectroscopy

    DEFF Research Database (Denmark)

    Hill, Adrian H.; Jacobsen, Henrik Skåret; Stewart, J. Ross

    2014-01-01

    Samples of nanoscale hematite, α-Fe2O3, with different surface geometries and properties have been studied with inelastic time-of-flight neutron scattering. The 15 nm diameter nanoparticles previously shown to have two collective magnetic excitation modes in separate triple-axis neutron scatterin...

  5. Investigation of Plant Cell Wall Properties: A Study of Contributions from the Nanoscale to the Macroscale Impacting Cell Wall Recalcitrance

    Science.gov (United States)

    Crowe, Jacob Dillon

    , alkaline hydrogen peroxide and liquid hot water pretreatments were shown to alter structural properties impacting nanoscale porosity in corn stover. Delignification by alkaline hydrogen peroxide pretreatment decreased cell wall rigidity, with subsequent cell wall swelling resulting in increased nanoscale porosity and improved enzymatic hydrolysis compared to limited swelling and increased accessible surface areas observed in liquid hot water pretreated biomass. The volume accessible to a 90 A dextran probe within the cell wall was found to be positively correlated to both enzyme binding and glucose hydrolysis yields, indicating cell wall porosity is a key contributor to effective hydrolysis yields. In the third study, the effect of altered xylan content and structure was investigated in irregular xylem (irx) Arabidopsis thaliana mutants to understand the role xylan plays in secondary cell wall development and organization. Higher xylan extractability and lower cellulose crystallinity observed in irx9 and irx15 irx15-L mutants compared to wild type indicated altered xylan integration into the secondary cell wall. Nanoscale cell wall organization observed using multiple microscopy techniques was impacted to some extent in all irx mutants, with disorganized cellulose microfibril layers in sclerenchyma secondary cell walls likely resulting from irregular xylan structure and content. Irregular secondary cell wall microfibril layers showed heterogeneous nanomechanical properties compared to wild type, which translated to mechanical deficiencies observed in stem tensile tests. These results suggest nanoscale defects in cell wall strength can correspond to macroscale phenotypes.

  6. A physics-based potential and electric field model of a nanoscale ...

    Indian Academy of Sciences (India)

    In this paper, we have developed a physics-based model for surface potential, channel potential, electric field and drain current for AlGaN/GaN high electron mobility transistor with high-K gate dielectric using two-dimensional Poisson equation under full depletion approximation with the inclusion of effect of polarization ...

  7. A physics-based potential and electric field model of a nanoscale ...

    Indian Academy of Sciences (India)

    ... paper, we have developed a physics-based model for surface potential, channel potential, electric field and drain current for AlGaN/GaN high electron mobility transistor with high-K gate dielectric using two-dimensional Poisson equation under full depletion approximation with the inclusion of effect of polarization charges.

  8. Treatments that enhance physical properties of wood

    Science.gov (United States)

    Roger M. Rowell; Peggy Konkol

    1987-01-01

    This paper was prepared for anyone who wants to know more about enhancing wood’s physical properties, from the amateur wood carver to the president of a forest products company. The authors describe chemical and physical treatments of wood that enhance the strength, stiffness, water repellency, and stability of wood. Five types of treatments are described: 1. water-...

  9. Important physical properties of peat materials

    Science.gov (United States)

    D.H. Boelter

    1968-01-01

    Peat materials from 12 bogs in northern Minnesota, U.S.A., showed significant differences in physical properties. It is pointed out that 1) these properties can be related to the hydrology of organic soils only if the soils represent undisturbed field conditions, and 2) volumetric expressions of water content are necessary to correctly evaluate the amount of water in a...

  10. Structure and physical properties of silkworm cocoons

    Science.gov (United States)

    Chen, Fujia; Porter, David; Vollrath, Fritz

    2012-01-01

    Silkworm cocoons have evolved a wide range of different structures and combinations of physical and chemical properties in order to cope with different threats and environmental conditions. We present our observations and measurements on 25 diverse types of cocoons in a first attempt to correlate physical properties with the structure and morphology of the cocoons. These two architectural parameters appear to be far more important than the material properties of the silk fibres themselves. We consider tensile and compressive mechanical properties and gas permeation of the cocoon walls, and in each case identify mechanisms or models that relate these properties to cocoon structure, usually based upon non-woven fibre composites. These properties are of relevance also for synthetic non-woven composite materials and our studies will help formulate bio-inspired design principles for new materials. PMID:22552916

  11. Fourth International Conference on Nanoscale Magnetism

    CERN Document Server

    Aktas, Bekir; Advances in Nanoscale Magnetism

    2009-01-01

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

  12. Wettability of natural root mucilage studied by atomic force microscopy and contact angle: Links between nanoscale and macroscale surface properties

    Science.gov (United States)

    Kaltenbach, Robin; Diehl, Dörte; Schaumann, Gabriele E.

    2017-04-01

    Organic coatings are considered as main cause of soil water repellency (SWR). This phenomenon plays a crucial role in the rhizosphere, at the interface of plant water uptake and soil hydraulics. Still, there is little knowledge about the nanoscale properties of natural soil compounds such as root-mucilage and its mechanistic effect on wettability. In this study, dried films of natural root-mucilage from Sorghum (Sorghum sp., MOENCH) on glass substrates were studied in order to explore experimental and evaluation methods that allow to link between macroscopic wettability and nano-/microscopic surface properties in this model soil system. SWR was assessed by optical contact angle (CA) measurements. The nanostructure of topography and adhesion forces of the mucilage surfaces was revealed by atomic force microscopy (AFM) measurements in ambient air, using PeakForce Quantitative Nanomechanical Mapping (PFQNM). Undiluted mucilage formed hydrophobic films on the substrate with CA > 90° and rather homogeneous nanostructure. Contact angles showed reduced water repellency of surfaces, when concentration of mucilage was decreased by dilution. AFM height and adhesion images displayed incomplete mucilage surface coverage for diluted samples. Hole-like structures in the film frequently exhibited increased adhesion forces. Spatial analysis of the AFM data via variograms enabled a numerical description of such 'adhesion holes'. The use of geostatistical approaches in AFM studies of the complex surface structure of soil compounds was considered meaningful in view of the need of comprehensive analysis of large AFM image data sets that exceed the capability of comparative visual inspection. Furthermore, force curves measured with the AFM showed increased break-free distances and pull-off forces inside the observed 'adhesion holes', indicating enhanced capillary forces due to adsorbed water films at hydrophilic domains for ambient RH (40 ± 2 %). This offers the possibility of

  13. Structural, electronic, optical and vibrational properties of nanoscale carbons and nanowires: a colloquial review

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Milton W [Department of Physics, Penn State University, 104 Davey Lab MB123, University Park, PA 16802-6300 (United States); Crespi, Vincent H [Department of Physics and Department of Material Science and Engineering, 104 Davey Lab MB193, University Park, PA 16802-6300 (United States); Dresselhaus, Mildred S [Department of Electrical Engineering and Computer Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02138 (United States); Dresselhaus, Gene [Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02138 (United States); Fischer, John E [Department of Materials Science and Engineering, University of Pennsylvania, 3231 Walnut St, Philadelphia, PA 19104-6272 (United States); Gutierrez, Humberto R [Department of Physics, Penn State University, 104 Davey Lab MB060, University Park, PA 16802-6300 (United States); Kojima, K; Wako, K [Department of Information Science, Yokohama Soei Junior College, Miho-cho 1, Midori-ku, Yokohama 226-0015 (Japan); Mahan, Gerald D [Department of Physics, Penn State University, 104 Davey Lab MB169, University Park, PA 16802-6300 (United States); Rao, Apparao M [Department of Physics and Astronomy and Center for Optical Materials Science and Engineering Technologies, Clemson University, Clemson, SC 29634 (United States); Sofo, Jorge O [Department of Physics, Penn State University, 104 Davey Lab MB172, University Park, PA 16802-6300 (United States); Tachibana, M [Graduate School of Integrated Science, Yokohama City University, Seto 22-2, Kanazawa-ku, Yokohama 236-0027 (Japan); Xiong Qihua, E-mail: mwc@psu.ed, E-mail: millie@mgm.mit.ed, E-mail: gene@mgm.mit.ed, E-mail: fischer@seas.upenn.ed, E-mail: hur3@psu.ed, E-mail: gdm12@psu.ed, E-mail: arao@clemson.ed [School of Physical and Mathematical Sciences, Division of Physics and Applied Physics, Nanyang Technological University, 21 Nanyang Link, SPMS-PAP-04-14 (Singapore)

    2010-08-25

    This review addresses the field of nanoscience as viewed through the lens of the scientific career of Peter Eklund, thus with a special focus on nanocarbons and nanowires. Peter brought to his research an intense focus, imagination, tenacity, breadth and ingenuity rarely seen in modern science. His goal was to capture the essential physics of natural phenomena. This attitude also guides our writing: we focus on basic principles, without sacrificing accuracy, while hoping to convey an enthusiasm for the science commensurate with Peter's. The term 'colloquial review' is intended to capture this style of presentation. The diverse phenomena of condensed matter physics involve electrons, phonons and the structures within which excitations reside. The 'nano' regime presents particularly interesting and challenging science. Finite size effects play a key role, exemplified by the discrete electronic and phonon spectra of C{sub 60} and other fullerenes. The beauty of such molecules (as well as nanotubes and graphene) is reflected by the theoretical principles that govern their behavior. As to the challenge, 'nano' requires special care in materials preparation and treatment, since the surface-to-volume ratio is so high; they also often present difficulties of acquiring an experimental signal, since the samples can be quite small. All of the atoms participate in the various phenomena, without any genuinely 'bulk' properties. Peter was a master of overcoming such challenges. The primary activity of Eklund's research was to measure and understand the vibrations of atoms in carbon materials. Raman spectroscopy was very dear to Peter. He published several papers on the theory of phonons (Eklund et al 1995a Carbon 33 959-72, Eklund et al 1995b Thin Solid Films 257 211-32, Eklund et al 1992 J. Phys. Chem. Solids 53 1391-413, Dresselhaus and Eklund 2000 Adv. Phys. 49 705-814) and many more papers on measuring phonons (Pimenta et al

  14. Structural, electronic, optical and vibrational properties of nanoscale carbons and nanowires: a colloquial review

    Science.gov (United States)

    Cole, Milton W.; Crespi, Vincent H.; Dresselhaus, Mildred S.; Dresselhaus, Gene; Fischer, John E.; Gutierrez, Humberto R.; Kojima, K.; Mahan, Gerald D.; Rao, Apparao M.; Sofo, Jorge O.; Tachibana, M.; Wako, K.; Xiong, Qihua

    2010-08-01

    This review addresses the field of nanoscience as viewed through the lens of the scientific career of Peter Eklund, thus with a special focus on nanocarbons and nanowires. Peter brought to his research an intense focus, imagination, tenacity, breadth and ingenuity rarely seen in modern science. His goal was to capture the essential physics of natural phenomena. This attitude also guides our writing: we focus on basic principles, without sacrificing accuracy, while hoping to convey an enthusiasm for the science commensurate with Peter's. The term 'colloquial review' is intended to capture this style of presentation. The diverse phenomena of condensed matter physics involve electrons, phonons and the structures within which excitations reside. The 'nano' regime presents particularly interesting and challenging science. Finite size effects play a key role, exemplified by the discrete electronic and phonon spectra of C60 and other fullerenes. The beauty of such molecules (as well as nanotubes and graphene) is reflected by the theoretical principles that govern their behavior. As to the challenge, 'nano' requires special care in materials preparation and treatment, since the surface-to-volume ratio is so high; they also often present difficulties of acquiring an experimental signal, since the samples can be quite small. All of the atoms participate in the various phenomena, without any genuinely 'bulk' properties. Peter was a master of overcoming such challenges. The primary activity of Eklund's research was to measure and understand the vibrations of atoms in carbon materials. Raman spectroscopy was very dear to Peter. He published several papers on the theory of phonons (Eklund et al 1995a Carbon 33 959-72, Eklund et al 1995b Thin Solid Films 257 211-32, Eklund et al 1992 J. Phys. Chem. Solids 53 1391-413, Dresselhaus and Eklund 2000 Adv. Phys. 49 705-814) and many more papers on measuring phonons (Pimenta et al 1998b Phys. Rev. B 58 16016-9, Rao et al 1997a Nature

  15. Quantitative Imaging of Nanoscale Mechanical Properties Using Hybrid Nanoindentation and Force Modulation

    National Research Council Canada - National Science Library

    Asif, S. A; Wahl, K. J; Colton, R. J; Warren, O. L

    2001-01-01

    In this article, we present a quantitative stiffness imaging technique and demonstrate its use to directly map the dynamic mechanical properties of materials with nanometer-scale lateral resolution...

  16. Fundamentals of semiconductors physics and materials properties

    CERN Document Server

    Yu, Peter Y

    2010-01-01

    This fourth edition of the well-established Fundamentals of Semiconductors serves to fill the gap between a general solid-state physics textbook and research articles by providing detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors. The approach is physical and intuitive rather than formal and pedantic. Theories are presented to explain experimental results. This textbook has been written with both students and researchers in mind. Its emphasis is on understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors. The explanations are based on physical insights. Each chapter is enriched by an extensive collection of tables of material parameters, figures, and problems. Many of these problems "lead the student by the hand" to arrive at the results. The major changes made in the fourth edition include: an extensive appendix about the important and by now well-established deep center known as the DX center, additional problems...

  17. Fundamentals of semiconductors physics and materials properties

    CERN Document Server

    Yu, Peter Y

    1996-01-01

    Fundamentals of Semiconductors attempts to fill the gap between a general solid-state physics textbook and research articles by providing detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors The approach is physical and intuitive rather than formal and pedantic Theories are presented to explain experimental results This textbook has been written with both students and researchers in mind Its emphasis is on understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors The explanations are based on physical insights Each chapter is enriched by an extensive collection of tables of material parameters, figures and problems Many of these problems 'lead the student by the hand' to arrive at the results

  18. Ion-damage-free planarization or shallow angle sectioning of solar cells for mapping grain orientation and nanoscale photovoltaic properties.

    Science.gov (United States)

    Kutes, Yasemin; Luria, Justin; Sun, Yu; Moore, Andrew; Aguirre, Brandon A; Cruz-Campa, Jose L; Aindow, Mark; Zubia, David; Huey, Bryan D

    2017-05-05

    Ion beam milling is the most common modern method for preparing specific features for microscopic analysis, even though concomitant ion implantation and amorphization remain persistent challenges, particularly as they often modify materials properties of interest. Atomic force microscopy (AFM), on the other hand, can mechanically mill specific nanoscale regions in plan-view without chemical or high energy ion damage, due to its resolution, directionality, and fine load control. As an example, AFM-nanomilling (AFM-NM) is implemented for top-down planarization of polycrystalline CdTe thin film solar cells, with a resulting decrease in the root mean square (RMS) roughness by an order of magnitude, even better than for a low incidence FIB polished surface. Subsequent AFM-based property maps reveal a substantially stronger contrast, in this case of the short-circuit current or open circuit voltage during light exposure. Electron back scattering diffraction (EBSD) imaging also becomes possible upon AFM-NM, enabling direct correlations between the local materials properties and the polycrystalline microstructure. Smooth shallow-angle cross-sections are demonstrated as well, based on targeted oblique milling. As expected, this reveals a gradual decrease in the average short-circuit current and maximum power as the underlying CdS and electrode layers are approached, but a relatively consistent open-circuit voltage through the diminishing thickness of the CdTe absorber. AFM-based nanomilling is therefore a powerful tool for material characterization, uniquely providing ion-damage free, selective area, planar smoothing or low-angle sectioning of specimens while preserving their functionality. This enables novel, co-located advanced AFM measurements, EBSD analysis, and investigations by related techniques that are otherwise hindered by surface morphology or surface damage.

  19. Ion-damage-free planarization or shallow angle sectioning of solar cells for mapping grain orientation and nanoscale photovoltaic properties

    Science.gov (United States)

    Kutes, Yasemin; Luria, Justin; Sun, Yu; Moore, Andrew; Aguirre, Brandon A.; Cruz-Campa, Jose L.; Aindow, Mark; Zubia, David; Huey, Bryan D.

    2017-05-01

    Ion beam milling is the most common modern method for preparing specific features for microscopic analysis, even though concomitant ion implantation and amorphization remain persistent challenges, particularly as they often modify materials properties of interest. Atomic force microscopy (AFM), on the other hand, can mechanically mill specific nanoscale regions in plan-view without chemical or high energy ion damage, due to its resolution, directionality, and fine load control. As an example, AFM-nanomilling (AFM-NM) is implemented for top-down planarization of polycrystalline CdTe thin film solar cells, with a resulting decrease in the root mean square (RMS) roughness by an order of magnitude, even better than for a low incidence FIB polished surface. Subsequent AFM-based property maps reveal a substantially stronger contrast, in this case of the short-circuit current or open circuit voltage during light exposure. Electron back scattering diffraction (EBSD) imaging also becomes possible upon AFM-NM, enabling direct correlations between the local materials properties and the polycrystalline microstructure. Smooth shallow-angle cross-sections are demonstrated as well, based on targeted oblique milling. As expected, this reveals a gradual decrease in the average short-circuit current and maximum power as the underlying CdS and electrode layers are approached, but a relatively consistent open-circuit voltage through the diminishing thickness of the CdTe absorber. AFM-based nanomilling is therefore a powerful tool for material characterization, uniquely providing ion-damage free, selective area, planar smoothing or low-angle sectioning of specimens while preserving their functionality. This enables novel, co-located advanced AFM measurements, EBSD analysis, and investigations by related techniques that are otherwise hindered by surface morphology or surface damage.

  20. Analysis of the magnetic properties nanoscale barium hexaferrite (BHF) prepared by milling and ultrasonic method

    International Nuclear Information System (INIS)

    Novizal; Edie, Sasito; Manawan, Mykel T.E.

    2016-01-01

    Barium hexaferrite (BHF) is well established material which widely used respectively as permanent magnets. In this research, we report our recent investigation on magnetic properties analysis of barium hexaferrite (BHF) compounds with a ratio of Fe/Ba: 11 prepared by a mechanical alloying process and high power ultrasonic destruction to promote the soft magnetic properties. The investigation carried out by Scanning Electron Microscope (SEM) shows the grain size between 500-1500 nm, it indicates that each grain is composed of several crystallites or polycrystalline. By mean of X-ray diff raction revealed the phase composition and the mean crystallite size <70 nm. The Characterization of the magnetic properties of the effects of downsizing the particle size of ∼ 200 nm to ∼ 50 nm by the ultasonik method provide saturation value of 0.35 T, remanent 0.24 T and the coercivity is 115 kA / m. (paper)

  1. Thermo-Physical Properties of Selected Inconel

    Directory of Open Access Journals (Sweden)

    Krajewski P.K.

    2014-10-01

    Full Text Available The paper brings results of examinations of main thermo-physical properties of selected Inconel alloys, i.e. their heat diffusivity, thermal conductivity and heat capacity, measured in wide temperature range of 20 – 900 oC. Themathematical relationships of the above properties vs. temperature were obtained for the IN 100 and IN 713C alloys. These data can be used when modelling the IN alloys solidification processes aimed at obtaining required structure and properties as well as when designing optimal work temperature parameters.

  2. In Vitro Evaluation of Nanoscale Hydroxyapatite-Based Bone Reconstructive Materials with Antimicrobial Properties.

    Science.gov (United States)

    Ajduković, Zorica R; Mihajilov-Krstev, Tatjana M; Ignjatović, Nenad L; Stojanović, Zoran; Mladenović-Antić, Snezana B; Kocić, Branislava D; Najman, Stevo; Petrović, Nenad D; Uskoković, Dragan P

    2016-02-01

    In the field of oral implantology the loss of bone tissue prevents adequate patient care, and calls for the use of synthetic biomaterials with properties that resemble natural bone. Special attention is paid to the risk of infection after the implantation of these materials. Studies have suggested that some nanocontructs containing metal ions have antimicrobial properties. The aim of this study was to examine the antimicrobial and hemolytic activity of cobalt-substituted hydroxyapatite nanoparticles, compared to hydroxyapatite and hydroxyapatite/poly-lactide-co-glycolide. The antibacterial effects of these powders were tested against two pathogenic bacterial strains: Escherichia coi (ATCC 25922) and Staphylococcus aureus (ATCC 25923), using the disc diffusion method and the quantitative antimicrobial test in a liquid medium. The quantitative antimicrobial test showed that all of the tested biomaterials have some antibacterial properties. The effects of both tests were more prominent in case of S. aureus than in E coli. A higher percentage of cobalt in the crystal structure of cobalt-substituted hydroxyapatite nanoparticles led to an increased antimicrobial activity. All of the presented biomaterial samples were found to be non-hemolytic. Having in mind that the tested of cobalt-substituted hydroxyapatite (Ca/Co-HAp) material in given concentrations shows good hemocompatibility and antimicrobial effects, along with its previously studied biological properties, the conclusion can be reached that it is a potential candidate that could substitute calcium hydroxyapatite as the material of choice for use in bone tissue engineering and clinical practices in orthopedic, oral and maxillofacial surgery.

  3. Physical and Release Properties of Metronidazole Suppositories ...

    African Journals Online (AJOL)

    Purpose: A study was made of the effects of some bases and adjuvants on the physical and release properties of metronidazole suppositories with a view to providing more information for the optimization of the rectal formulation of metronidazole. Method: Suppositories (1g) containing 200mg of metronidazole each were ...

  4. Electronic and structural properties of TiB2: Bulk, surface, and nanoscale effects

    International Nuclear Information System (INIS)

    Volonakis, George; Tsetseris, Leonidas; Logothetidis, Stergios

    2011-01-01

    Titanium diboride (TiB 2 ), is a widely used hard material that comprises graphene-like layers of B and intercalated Ti atoms. Here we report the results of extensive first-principles calculations on key properties of bulk TiB 2 , TiB 2 surfaces, and TiB 2 nanocrystals (NCs). The computational approach is first validated based on the agreement between calculated structural and electronic properties of bulk TiB 2 and available experimental and theoretical data. We then obtain the formation energies for several surface cuts and use these values to construct TiB 2 NCs based on the Wulff theorem. Finally, we demonstrate by studying the adsorption of small molecules that hydrogen and oxygen adatoms can be attached through strongly exothermic chemisorption reactions on TiB 2 surfaces. Likewise, water molecules bind on various TiB 2 surfaces and NC facets, with an energetic preference for the latter. The results are relevant to applications that depend on reactivity-related TiB 2 properties, for example resistance to corrosion and interactions with water-based solutions.

  5. Relation of nanoscale and macroscopic properties of mixed-phase silicon thin films

    Czech Academy of Sciences Publication Activity Database

    Fejfar, Antonín; Vetushka, Aliaksi; Kalusová, V.; Čertík, Ondřej; Ledinský, Martin; Rezek, Bohuslav; Stuchlík, Jiří; Kočka, Jan

    2010-01-01

    Roč. 207, č. 3 (2010), s. 582-586 ISSN 1862-6300 R&D Projects: GA MŠk(CZ) LC06040; GA AV ČR KAN400100701; GA MŠk LC510; GA AV ČR(CZ) IAA100100902 Institutional research plan: CEZ:AV0Z10100521 Keywords : conductive atomic force microscopy (C-AFM) * mixed phase silicon thin films Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.458, year: 2010 http://dx.doi.org/10.1002/pssa.200982907

  6. Synthesis, structure, and opto-electronic properties of organic-based nanoscale heterojunctions

    Czech Academy of Sciences Publication Activity Database

    Rezek, Bohuslav; Čermák, Jan; Kromka, Alexander; Ledinský, Martin; Hubík, Pavel; Mareš, Jiří J.; Purkrt, Adam; Cimrová, Věra; Fejfar, Antonín; Kočka, Jan

    2011-01-01

    Roč. 6, March (2011), 238/1-238/12 ISSN 1931-7573 R&D Projects: GA ČR GD202/09/H041; GA MŠk(CZ) LC06040; GA AV ČR KAN400100701; GA MŠk LC510; GA AV ČR(CZ) IAAX00100902; GA MŠk(CZ) 1M06031 Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z40500505 Keywords : nanocrystalline diamond * hydrogen-terminated diamond * oxygen-terminated diamond * diamond transistor * proteins * fetal bovine serum (FBS) Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.726, year: 2011

  7. Dynamic structural disorder in supported nanoscale catalysts

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  8. Structure, microstructure and magnetic properties of electrodeposited Co and Co-Pt in different nanoscale geometries

    Energy Technology Data Exchange (ETDEWEB)

    Khatri, Manvendra Singh

    2010-07-09

    Thin films and nanowires of Co-Pt have been prepared by means of electrodeposition. Composition, structure, microstructure and magnetic properties have been intensively studied using X-ray diffraction, scanning electron microscopy and vibrating sample magnetometry and correlated to the deposition parameters such as electrolyte composition, deposition current and/or potential. Co rich Co-Pt films have been deposited at various current densities. A nearly constant composition of Co{sub 70}Pt{sub 30} was achieved for current densities between 18 and 32 mA/cm{sup 2}. Detailed texture measurements confirmed an increasing fraction of the hexagonal phase with its c-axis aligned perpendicular to the film plane with increasing current density. Accordingly, magnetic properties are strongly affected by the magnetocrystalline anisotropy of the hexagonal phase that competes with the shape anisotropy of the thin film geometry. Co-Pt nanowires have been prepared within alumina templates at different deposition potentials between -0.6 and -0.9 V{sub SCE} changing the composition from nearly pure Pt to Co. The composition Co{sub 80}Pt{sub 20} was observed at a deposition potential of -0.7 V{sub SCE}. Co-Pt nanowires are nanocrystalline in the as-deposited state. Magnetic measurements reveal changing fcc and hcp phase fractions within the wires as the effective anisotropy significantly differs from the expected shape anisotropy for nanowires with high aspect ratio. This change in effective anisotropy is attributed to the preferential alignment of the c-axis of hcp Co-Pt phase perpendicular to the nanowires axis. A promising alternative with much smaller feature sizes is the diblock copolymer template. Electrodeposition of Co and Co-Pt into these templates has been carried out. Inhomogeneities in the template thickness as well as a certain substrate roughness have been identified to be the reasons for inhomogeneous template filling. Thus magnetic properties are dominated by large

  9. Nanoscale Piezoelectric Properties of Self-Assembled Fmoc-FF Peptide Fibrous Networks.

    Science.gov (United States)

    Ryan, Kate; Beirne, Jason; Redmond, Gareth; Kilpatrick, Jason I; Guyonnet, Jill; Buchete, Nicolae-Viorel; Kholkin, Andrei L; Rodriguez, Brian J

    2015-06-17

    Fibrous peptide networks, such as the structural framework of self-assembled fluorenylmethyloxycarbonyl diphenylalanine (Fmoc-FF) nanofibrils, have mechanical properties that could successfully mimic natural tissues, making them promising materials for tissue engineering scaffolds. These nanomaterials have been determined to exhibit shear piezoelectricity using piezoresponse force microscopy, as previously reported for FF nanotubes. Structural analyses of Fmoc-FF nanofibrils suggest that the observed piezoelectric response may result from the noncentrosymmetric nature of an underlying β-sheet topology. The observed piezoelectricity of Fmoc-FF fibrous networks is advantageous for a range of biomedical applications where electrical or mechanical stimuli are required.

  10. Dissolved organic matter adsorption to model surfaces: adlayer formation, properties, and dynamics at the nanoscale.

    Science.gov (United States)

    Armanious, Antonius; Aeppli, Meret; Sander, Michael

    2014-08-19

    Adlayers of dissolved organic matter (DOM) form on many surfaces in natural and engineered systems and affect a number of important processes in these systems. Yet, the nanoscalar properties and dynamics of DOM adlayers remain poorly investigated. This work provides a systematic analysis of the properties and dynamics of adlayers formed from a diverse set of eight humic and fulvic acids, used as DOM models, on surfaces of self-assembled monolayers (SAMs) of different alkylthiols covalently bound to gold supports. DOM adsorption to positively charged amine-terminated SAMs resulted in the formation of water-rich adlayers with nanometer thicknesses that were relatively rigid, irreversibly adsorbed, and collapsed upon air drying, as demonstrated by combined quartz crystal microbalance and ellipsometry measurements. DOM adlayer thicknesses varied only slightly with solution pH from 5 to 8 but increased markedly with increasing ionic strength. Contact angle measurements revealed that the DOM adlayers were relatively polar, likely due to the high water contents of the adlayers. Comparing DOM adsorption to SAM-coated sensors that systematically differed in surface charge and polarity characteristics showed that electrostatics dominated DOM-surface interactions. Laccase adsorption to DOM adlayers on amine-terminated SAMs served to demonstrate the applicability of the presented experimental approach to study the interactions of (bio)macromolecules and (nano)particles with DOM.

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

    Science.gov (United States)

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

  12. Physical properties of sunflower grains after drying

    Directory of Open Access Journals (Sweden)

    Paulo Carteri Coradi

    2015-12-01

    Full Text Available The knowledge of the physical properties of the grains is important for the optimization of post-harvest operations. This study aimed to evaluate the effects of convective drying with different air temperatures (45, 55, 65 and 75 °C the physical properties of sunflower seeds. The drying sunflower grains was performed in convection oven with forced air. In natural conditions, samples of 5 kg of pellets were used for each repetition drying. During the drying process, the grains samples were weighed periodically until they reach 10% (wet basis, w.b., then were subjected to evaluations of physical properties. According to the results it was observed that the porosity, apparent density, thousand kernel weight to the drag coefficient, roundness, sphericity and width of sunflower seed did not change with increasing temperature drying air. It was concluded that the drying air temperatures of 45 °C and 55 retained the initial physical characteristics of sunflower seeds. The temperature of the drying air of 75 °C had greater influence on changes in volumetric shrinkage of the grains.

  13. Physical Properties of Hanford Transuranic Waste

    Energy Technology Data Exchange (ETDEWEB)

    Berg, John C.

    2010-03-25

    The research described herein was undertaken to provide needed physical property descriptions of the Hanford transuranic tank sludges under conditions that might exist during retrieval, treatment, packaging and transportation for disposal. The work addressed the development of a fundamental understanding of the types of systems represented by these sludge suspensions through correlation of the macroscopic rheological properties with particle interactions occurring at the colloidal scale in the various liquid media. The results of the work have advanced existing understanding of the sedimentation and aggregation properties of complex colloidal suspensions. Bench scale models were investigated with respect to their structural, colloidal and rheological properties that should be useful for the development and optimization of techniques to process the wastes at various DOE sites.

  14. Correlating the nanoscale mechanical and chemical properties of knockout mice bones

    Science.gov (United States)

    Kavukcuoglu, Nadire Beril

    Bone is a mineral-organic composite where the organic matrix is mainly type I collagen plus small amounts of non-collagenous proteins including osteopontin (OPN), osteocalcin (OC) and fibrillin 2 (Fbn2). Mature bone undergoes remodeling continually so new bone is formed and old bone resorbed. Uncoupling between the bone resorption and bone formation causes an overall loss of bone mass and leads to diseases like osteoporosis and osteopenia. These are characterized by structural deterioration of the bone tissue and an increased risk of fracture. The non-collagenous bone proteins are known to have a role in regulating bone turnover and to affect the structural integrity of bone. OPN and OC play a key role in bone resorption and formation, while absence of Fbn-2 causes a connective tissue disorder (congenital contractural arachnodactyly) and has been associated with decreased bone mass. In this thesis nanoindentation and Raman-microspectroscopy techniques were used to investigate and correlate the mechanical and chemical properties of cortical femoral bones from OPN deficient (OPN-/-), OC deficient (OC-/-) and Fbn-2 deficient (Fbn2-/-) mice and their age, sex and background matched wild-type controls (OPN+/+, OC+/+ and Fbn2+/+). For OPN the hardness (H) and elastic modulus (E) of under 12 week OPN-/- bones were significantly lower than for OPN+/+ bones, but Raman showed no significant difference. Mechanical properties of bones from mice older than 12 weeks were not significantly different with genotype. However, mineralization and crystallinity from >50 week OPN-/- bones were significantly higher than for OPN+/+ bones. Mechanical properties of OPN-/- bones showed no variation with age, but mineralization, crystallinity and type-B carbonate substitution increased for both genotypes. For OC-/- intra-bone analyses showed that the hardness and crystallinity of the bones were significantly higher, especially in the mid-cortical sections, compared to OC+/+ bones. Fbn2

  15. Nanoscale deformation mechanisms and yield properties of hydrated bone extracellular matrix.

    Science.gov (United States)

    Schwiedrzik, Jakob; Taylor, Aidan; Casari, Daniele; Wolfram, Uwe; Zysset, Philippe; Michler, Johann

    2017-09-15

    Bone features a hierarchical architecture combining antagonistic properties like toughness and strength. In order to better understand the mechanisms leading to this advantageous combination, its postyield and failure behaviour was analyzed on the length scale of a single lamella. Micropillars were compressed to large strains under hydrated conditions to measure their anisotropic yield and post-yield behaviour. An increase in strength compared to the macroscale by a factor of 1.55 and a strong influence of hydration with a decrease by 60% in yield stress compared to vacuum conditions were observed. Post-compression transmission electron microscopic analysis revealed anisotropic deformation mechanisms. In axial pillars, where fibrils were oriented along the loading axis, kink bands were observed and shear cracks emerged at the interface of ordered and disordered regions. Micromechanical analysis of fibril kinking allowed an estimate of the extrafibrillar matrix shear strength to be made: 120±40MPa. When two opposing shear planes met a wedge was formed, splitting the micropillar axially in a mode 1 crack. Making use of an analytical solution, the mode 1 fracture toughness of bone extracellular matrix for splitting along the fibril direction was estimated to be 0.07MPam. This is 1-2 orders of magnitude smaller than on the macroscale, which may be explained by the absence of extrinsic toughening mechanisms. In transverse pillars, where fibrils were oriented perpendicular to the loading axis, cracks formed in regions where adverse fibril orientation reduced the local fracture resistance. This study underlines the importance of bone's hierarchical microstructure for its macroscopic strength and fracture resistance and the need to study structure-property relationships as well as failure mechanisms under hydrated conditions on all length scales. Bone's hierarchical architecture combines toughness and strength. To understand the governing deformation mechanisms, its

  16. Iron Oxide Nanoradiomaterials: Combining Nanoscale Properties with Radioisotopes for Enhanced Molecular Imaging.

    Science.gov (United States)

    Pellico, Juan; Llop, Jordi; Fernández-Barahona, Irene; Bhavesh, Riju; Ruiz-Cabello, Jesús; Herranz, Fernando

    2017-01-01

    The combination of the size-dependent properties of nanomaterials with radioisotopes is emerging as a novel tool for molecular imaging. There are numerous examples already showing how the controlled synthesis of nanoparticles and the incorporation of a radioisotope in the nanostructure offer new features beyond the simple addition of different components. Among the different nanomaterials, iron oxide-based nanoparticles are the most used in imaging because of their versatility. In this review, we will study the different radioisotopes for biomedical imaging, how to incorporate them within the nanoparticles, and what applications they can be used for. Our focus is directed towards what is new in this field, what the nanoparticles can offer to the field of nuclear imaging, and the radioisotopes hybridized with nanomaterials for use in molecular imaging.

  17. Iron Oxide Nanoradiomaterials: Combining Nanoscale Properties with Radioisotopes for Enhanced Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Juan Pellico

    2017-01-01

    Full Text Available The combination of the size-dependent properties of nanomaterials with radioisotopes is emerging as a novel tool for molecular imaging. There are numerous examples already showing how the controlled synthesis of nanoparticles and the incorporation of a radioisotope in the nanostructure offer new features beyond the simple addition of different components. Among the different nanomaterials, iron oxide-based nanoparticles are the most used in imaging because of their versatility. In this review, we will study the different radioisotopes for biomedical imaging, how to incorporate them within the nanoparticles, and what applications they can be used for. Our focus is directed towards what is new in this field, what the nanoparticles can offer to the field of nuclear imaging, and the radioisotopes hybridized with nanomaterials for use in molecular imaging.

  18. MAGNETIC WOVEN FABRICS - PHYSICAL AND MAGNETIC PROPERTIES

    Directory of Open Access Journals (Sweden)

    GROSU Marian C

    2015-05-01

    Full Text Available A coated material is a composite structure that consists of at least two components: base material and coating layer. The purpose of coating is to provide special properties to base material, with potential to be applied in EMI shielding and diverse smart technical fields. This paper reports the results of a study about some physical and magnetic properties of coated woven fabrics made from cotton yarns with fineness of 17 metric count. For this aim, a plain woven fabric was coated with a solution hard magnetic polymer based. As hard magnetic powder, barium hexaferrite (BaFe12O19 was selected. The plain woven fabric used as base has been coated with five solutions having different amounts of hard magnetic powder (15% - 45% in order to obtain five different magnetic woven fabrics. A comparison of physical properties regarding weight (g/m2, thickness (mm, degree of charging (% and magnetic properties of magnetic woven samples were presented. Saturation magnetizing (emu/g, residual magnetizing (emu/g and coercive force (kA/m of pure hard magnetic powder and woven fabrics have been studied as hysteresis characteristics. The magnetic properties of the woven fabrics depend on the mass percentage of magnetic powder from coating solution. Also, the residual magnetism and coercive field of woven fabrics represents only a part of bulk barium hexafferite residual magnetism and coercive field.

  19. Physical properties of the planet Mercury

    Science.gov (United States)

    Clark, Pamela E.

    1988-01-01

    The global physical properties of Mercury are summarized with attention given to its figure and orbital parameters. The combination of properties suggests that Mercury has an extensive iron-rich core, possibly with a still-functioning dynamo, which is 42 percent of the interior by volume. Mercury's three major axes are comparable in size, indicating that the planet is a triaxial ellipsoid rather than an oblate spheroid. In terms of the domination of its surface by an intermediate plains terrane, it is more Venus- or Mars-like; however, due to the presence of a large metallic magnetic core, its interior may be more earth-like.

  20. Double-edged effect of electric field on the mechanical property of water-filled carbon nanotubes with an application to nanoscale trigger.

    Science.gov (United States)

    Ye, Hongfei; Zheng, Yonggang; Zhou, Lili; Zhao, Junfei; Zhang, Hong Wu; Chen, Zhen

    2017-11-08

    Polar water molecules would exhibit extraordinary phenomena under nanoscale confinement. By means of electric field, the water-filled carbon nanotube (CNT) that has been successfully fabricated in laboratory is expected to make distinct responses to the external electricity. Here, we examine the effect of electric field direction on the mechanical property of water-filled CNTs. It is found that the longitudinal electric field enhances but the transversal electric field reduces the elastic modulus and critical buckling stress of water-filled CNTs. The double-edged effect of electric field is attributed to the competition between the axial and circumferential pressures induced by polar water molecules. Furthermore, it is notable that the transversal electric field could result in an internal pressure with elliptical distribution, which is an effective and convenient approach to apply the nonuniform pressure on nanochannels. Based on a pre-strained water-filled CNTs, we design a nanoscale trigger with the evident and rapid height change started through switching the direction of electric field. The reported finding lays a foundation for the electricity-controlled property of nanochannels filled with polar molecules and provides an insight into the design of nanoscale functional devices. © 2017 IOP Publishing Ltd.

  1. Divergent effect of electric fields on the mechanical property of water-filled carbon nanotubes with an application as a nanoscale trigger

    Science.gov (United States)

    Ye, Hongfei; Zheng, Yonggang; Zhou, Lili; Zhao, Junfei; Zhang, Hongwu; Chen, Zhen

    2018-01-01

    Polar water molecules exhibit extraordinary phenomena under nanoscale confinement. Through the application of an electric field, a water-filled carbon nanotube (CNT) that has been successfully fabricated in the laboratory is expected to have distinct responses to the external electricity. Here, we examine the effect of electric field direction on the mechanical property of water-filled CNTs. It is observed that a longitudinal electric field enhances, but the transverse electric field reduces the elastic modulus and critical buckling stress of water-filled CNTs. The divergent effect of the electric field is attributed to the competition between the axial and circumferential pressures induced by polar water molecules. Furthermore, it is notable that the transverse electric field could result in an internal pressure with elliptical distribution, which is an effective and convenient approach to apply nonuniform pressure on nanochannels. Based on pre-strained water-filled CNTs, we designed a nanoscale trigger with an evident and rapid height change initiated by switching the direction of the electric field. The reported finding provides a foundation for an electricity-controlled property of nanochannels filled with polar molecules and provides an insight into the design of nanoscale functional devices.

  2. Nanoscale Topography on Black Titanium Imparts Multi-biofunctional Properties for Orthopedic Applications

    Science.gov (United States)

    Hasan, Jafar; Jain, Shubham; Chatterjee, Kaushik

    2017-01-01

    We have developed a chlorine based reactive ion etching process to yield randomly oriented anisotropic nanostructures that render the titanium metal surface ‘black’ similar to that of black silicon. The surface appears black due to the nanostructures in contrast to the conventional shiny surface of titanium. The nanostructures were found to kill bacteria on contact by mechanically rupturing the cells as has been observed previously on wings of certain insects. The etching was optimized to yield nanostructures of ≈1 μm height for maximal bactericidal efficiency without compromising cytocompatibility. Within 4 hours of contact with the black titanium surface, 95% ± 5% of E. coli, 98% ± 2% of P. aeruginosa, 92% ± 5% of M. smegmatis and 22% ± 8% of S. aureus cells that had attached were killed. The killing efficiency for the S. aureus increased to 76% ± 4% when the cells were allowed to adhere up to 24 hours. The black titanium supported the attachment and proliferation of human mesenchymal stem cells and augmented osteogenic lineage commitment in vitro. Thus, the bioinspired nanostructures on black titanium impart multi-biofunctional properties toward engineering the next-generation biomaterials for orthopedic implants.

  3. Magnetic properties of nanoscale crystalline maghemite obtained by a new synthetic route

    Energy Technology Data Exchange (ETDEWEB)

    Mercante, L.A. [Instituto de Quimica, Universidade Federal Fluminense, Niteroi, RJ (Brazil); Melo, W.W.M. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Granada, M.; Troiani, H.E. [Centro Atomico Bariloche and Instituto Balseiro, Comision Nacional de Energia Atomica, 8400 S.C. de Bariloche, RN (Argentina); Macedo, W.A.A.; Ardison, J.D. [Laboratorio de Fisica Aplicada, CDTN/CNEN, Belo Horizonte, MG (Brazil); Vaz, M.G.F. [Instituto de Quimica, Universidade Federal Fluminense, Niteroi, RJ (Brazil); Novak, M.A., E-mail: mnovak@if.ufrj.br [Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

    2012-09-15

    In this work we describe the synthesis and characterization of maghemite nanoparticles obtained by a new synthetic route. The material was synthesized using triethylamine as a coprecipitation agent in the presence of the organic ligand N,N Prime -bis(3,5-di-tert-butyl-catechol)-2,4-diaminotoluene (LCH{sub 3}). Moessbauer spectrum at 4 K shows typical hyperfine parameters of maghemite and Transmission Electron Microscopy images reveal that the nanoparticles have a mean diameter of 3.9 nm and a narrow size distribution. AC magnetic susceptibility in zero field presents an Arrhenius behavior with unreasonable relaxation parameters due to the strong influence of dipolar interaction. In contrast when the measurements are performed in a 1 kOe field, the effect of dipolar interactions becomes negligible and the obtained parameters are in good agreement with the static magnetic properties. The dynamic energy barrier obtained from the AC susceptibility results is larger than the expected from the average size observed by HRTEM results, evidencing the strong influence of the surface contribution to the anisotropy. - Highlights: Black-Right-Pointing-Pointer Maghemite nanoparticles obtained by a new synthetic route. Black-Right-Pointing-Pointer TEM images shown crystalline nanoparticles with average 3.9 nm diameter. Black-Right-Pointing-Pointer Normal Arrhenius behavior restored with applied DC fields.

  4. Nanoscale characterization and local piezoelectric properties of lead-free KNN-LT-LS thin films

    Science.gov (United States)

    Abazari, M.; Choi, T.; Cheong, S.-W.; Safari, A.

    2010-01-01

    We report the observation of domain structure and piezoelectric properties of pure and Mn-doped (K0.44,Na0.52,Li0.04)(Nb0.84,Ta0.1,Sb0.06)O3 (KNN-LT-LS) thin films on SrTiO3 substrates. It is revealed that, using piezoresponse force microscopy, ferroelectric domain structure in such 500 nm thin films comprised of primarily 180° domains. This was in accordance with the tetragonal structure of the films, confirmed by relative permittivity measurements and x-ray diffraction patterns. Effective piezoelectric coefficient (d33) of the films were calculated using piezoelectric displacement curves and shown to be ~53 pm V-1 for pure KNN-LT-LS thin films. This value is among the highest values reported for an epitaxial lead-free thin film and shows a great potential for KNN-LT-LS to serve as an alternative to PZT thin films in future applications.

  5. F-Canyon Sludge Physical Properties

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, M. R.; Hansen, P. R.; Fink, S. D.

    2005-08-22

    The Site Deactivation and Decommissioning (SDD) Organization is evaluating options to disposition the 800 underground tanks (including removal of the sludge heels from these tanks). To support this effort, D&D requested assistance from Savannah River National Laboratory (SRNL) personnel to determine the pertinent physical properties to effectively mobilize the sludge from these tanks (Tanks 804, 808, and 809). SDD provided SRNL with samples of the sludge from Tanks 804, 808, and 809. The authors measured the following physical properties for each tank: particle settling rate, shear strength (i.e., settled solids yield stress), slurry rheology (i.e., yield stress and consistency), total solids concentration in the sludge, soluble solids concentration of the sludge, sludge density, and particle size distribution.

  6. IMPROVING PHYSICAL PROPERTIES OF RAPE BIOFUELS

    Directory of Open Access Journals (Sweden)

    Zbigniew Kiernicki

    2012-12-01

    Full Text Available The researches on the use of biodiesel and fuel derived from waste plastics are presented in the paper. Biodiesel and fuel obtained from waste plastics were both used as fuel components. FAME is a bio-admixture in the fuel. The catalytic cracking of polyolefin was the source of second fuel admixture. The physical properties of the analyzed components of fuel have been presented. The operational parameters of direct injection in diesel engines fuelled by tested fuel blends was set out. The preparation of the fuel mixture was also described. The concept of the diesel fuel which is made from the components of opposite physical properties could have a positive practical effect and could improve the use of biofuels.

  7. Electrochemical properties of CuO hollow nanopowders prepared from formless Cu–C composite via nanoscale Kirkendall diffusion process

    Energy Technology Data Exchange (ETDEWEB)

    Won, Jong Min [Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of); Kim, Jong Hwa [Daegu Center, Korea Basic Science Institute, 80 Daehakro Bukgu, Daegu 702-701 (Korea, Republic of); Choi, Yun Ju [Suncheon Center, Korea Basic Science Institute, Suncheon 540-742 (Korea, Republic of); Cho, Jung Sang [Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of); Kang, Yun Chan, E-mail: yckang@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Anam-Dong, Seongbuk-Gu, Seoul 136-713 (Korea, Republic of)

    2016-06-25

    Hollow CuO nanopowders are prepared using a simple spray drying process that relied on nanoscale Kirkendall diffusion; these nanopowders have potential applications in lithium-ion batteries. Citric acid is used as both the carbon source material and chelating agent and plays a key role in the preparation of the hollow nanopowders. The formless Cu–C composite that formed as an intermediate product transforms into slightly aggregated CuO hollow nanopowders after post-treatment at 300 and 400 °C under an air atmosphere. The CuO hollow nanopowders exhibit higher initial discharge capacities and better cycling performances than those of the filled-structured CuO nanopowders, which are prepared at a post-treatment temperature of 500 °C under an air atmosphere. The discharge capacities of the CuO nanopowders post-treated at 300, 400, and 500 °C for the 150{sup th} cycle at a current density of 1 A g{sup −1} are 793, 632, and 464 mA h g{sup −1}, respectively, and their capacity retentions calculated from the maximum discharge capacities are 88, 80, and 73%, respectively. The CuO nanopowders with hollow structures exhibit better structural stability for repeated lithium insertion and desertion processes than those with filled structures. - Highlights: • Hollow CuO nanopowders are prepared using a simple spray drying process. • Cu–C composite transforms into CuO hollow nanopowders by Kirkendall diffusion. • Hollow CuO nanopowders show good electrochemical properties for lithium-ion storage.

  8. Nanoscale Structure-Property Relationships of Polyacrylonitrile/CNT Composites as a Function of Polymer Crystallinity and CNT Diameter.

    Science.gov (United States)

    Gissinger, Jacob R; Pramanik, Chandrani; Newcomb, Bradley; Kumar, Satish; Heinz, Hendrik

    2018-01-10

    Polyacrylonitrile (PAN)/carbon nanotube (CNT) composites are used as precursors for ultrastrong and lightweight carbon fibers. However, insights into the structure at the nanoscale and the relationships to mechanical and thermal properties have remained difficult to obtain. In this study, molecular dynamics simulation with accurate potentials and available experimental data were used to describe the influence of different degrees of PAN preorientation and CNT diameter on the atomic-scale structure and properties of the composites. The inclusion of CNTs in the polymer matrix is favored for an intermediate degree of PAN orientation and small CNT diameter whereas high PAN crystallinity and larger CNT diameter disfavor CNT inclusion. The glass transition at the CNT/PAN interface involves the release of rotational degrees of freedom of the polymer backbone and increased mobility of the protruding nitrile side groups in contact with the carbon nanotubes. The glass-transition temperature of the composite increases in correlation with the amount of CNT/polymer interfacial area per unit volume, i.e., in the presence of CNTs, for higher CNT volume fraction,  and inversely with CNT diameter. The increase in glass-transition temperature upon CNT addition is larger for PAN of lower crystallinity than for PAN of higher crystallinity. Interfacial shear strengths of the composites are higher for CNTs of smaller diameter and for PAN with preorientation, in correlation with more favorable CNT inclusion energies. The lowest interfacial shear strength was observed in amorphous PAN for the same CNT diameter. PAN with ∼75% crystallinity exhibited hexagonal patterns of nitrile groups near and far from the CNT interface which could influence carbonization into regular graphitic structures. The results illustrate the feasibility of near-quantitative insights into macroscale properties of polymer/CNT composites from simulations of nanometer-scale composite domains. Guidance is most

  9. PHYSICAL PROPERTIES OF SOYBEAN (A RESEARCH REPORT ...

    African Journals Online (AJOL)

    NIJOTECH

    ABSTRACT. Physical properties of linear dimensions, sphericity and solid density of four different varieties of dry mature soybean were determined in this study. For the varieties - TGX1768-6F,. TGX-1681-3F, TGX-536-02D, and TGX-1740-3F, the mean sphericity are 0.745, 0.857, 0.830, and 0.829 respectively. It is shown ...

  10. Nanoscale cellulose films with different crystallinities and mesostructures--their surface properties and interaction with water.

    Science.gov (United States)

    Aulin, Christian; Ahola, Susanna; Josefsson, Peter; Nishino, Takashi; Hirose, Yasuo; Osterberg, Monika; Wågberg, Lars

    2009-07-07

    the films was studied using a quartz crystal microbalance with dissipation. To understand the swelling properties of the films, it was necessary to consider both the difference in crystalline ordering and the difference in mesostructure of the films.

  11. Fabrication and properties of nanoscale multiferroic heterostructures for application in magneto-electric random access memory (MERAM) devices

    Science.gov (United States)

    Kim, Gunwoo

    Magnetoelectric random access memory (MERAM) has emerged as a promising new class of non-volatile solid-state memory device. It offers nondestructive reading along with low power consumption during the write operation. A common implementation of MERAM involves use of multiferroic tunneling junctions (MFTJs), which besides offering non-volatility are both electrically and magnetically tunable. Fundamentally, a MFTJ consists of a heterostructure of an ultrathin multiferroic or ferroelectric material as the active tunneling barrier sandwiched between ferromagnetic electrodes. Thereby, the MFTJ exhibits both tunnel electroresistance (TER) and tunnel magnetoresistance (TMR) effects with application of an electric and magnetic field, respectively. In this thesis work, we have developed two-dimensional (2D) thin-film multiferroic heterostructure METJ prototypes consisting of ultrathin ferroelectric BaTiO3 (BTO) layer and a conducting ferromagnetic La0.67Sr 0.33MnO3 (LSMO) electrode. The heteroepitaxial films are grown using the pulsed laser deposition (PLD) technique. This oxide heterostructure offers the opportunity to study the nano-scale details of the tunnel electroresistance (TER) effect using scanning probe microscopy techniques. We performed the measurements using the MFP-3D (Asylum Research) scanning probe microscope. The ultrathin BTO films (1.2-2.0 nm) grown on LSMO electrodes display both ferro- and piezo-electric properties and exhibit large tunnel resistance effect. We have explored the growth and properties of one-dimensional (1D) heterostructures, referred to as multiferoric nanowire (NW) heterostructures. The ferromagnetic/ferroelectric composite heterostructures are grown as sheath layers using PLD on lattice-matched template NWs, e.g. MgO, that are deposited by chemical vapor deposition utilizing the vapor-liquid-solid (VLS) mechanism. The one-dimensional geometry can substantially overcome the clamping effect of the substrate present in two

  12. Physical and Frictional Properties of NERICA

    Directory of Open Access Journals (Sweden)

    2016-11-01

    Full Text Available Some physical and frictional properties of the seeds and husks of New Rice for Africa (NERICA were studied at varying moisture contents of 13%, 17%, and 20% (w.b. In the study, four varieties of NERICA namely; FARO 44, FARO 51, FARO 52 and FARO 57 were selected to represent the different size ranges common to NERICA. The physical properties of NERICA such as shape, size, volume, moisture contents, density, weights, surface area, aspect ratio and sphericity were obtained through physical measurement of the grains samples of each of the four varieties. Results of the physical measurements indicate that the size ranges for the varieties are as follows: FARO 44; 3.653mm to 3.858mm, FARO 51; 3.685mm to 3.916mm, FARO 52; 3.674mm to 3.863mm and FARO 57; 3.924mm to 4.019mm. Results of the frictional properties, shows that plywood material has the highest value of 28.4(1.36 = 33.0(1.41, 29.9(1.38 = 35.2(1.45 and 30.4(1.28 = 37.6(1.51 at 13%, 17% and 20% (w.b respectively, while plastic material has the lowest coefficient of friction value of 20.8(1.21 = 17.7(1.14, 19.4(1.17 = 21.8(1.24 and 21.3(1.24 = 22.9(1.26 at 13%, 17% and 20% (w.b respectively.

  13. Nanoscale friction and wear maps.

    Science.gov (United States)

    Tambe, Nikhil S; Bhushan, Bharat

    2008-04-28

    Friction and wear are part and parcel of all walks of life, and for interfaces that are in close or near contact, tribology and mechanics are supremely important. They can critically influence the efficient functioning of devices and components. Nanoscale friction force follows a complex nonlinear dependence on multiple, often interdependent, interfacial and material properties. Various studies indicate that nanoscale devices may behave in ways that cannot be predicted from their larger counterparts. Nanoscale friction and wear mapping can help identify some 'sweet spots' that would give ultralow friction and near-zero wear. Mapping nanoscale friction and wear as a function of operating conditions and interface properties is a valuable tool and has the potential to impact the very way in which we design and select materials for nanotechnology applications.

  14. Nanoscale technology in biological systems

    CERN Document Server

    Greco, Ralph S; Smith, R Lane

    2004-01-01

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

  15. 31 CFR 544.204 - Expenses of maintaining blocked physical property; liquidation of blocked property.

    Science.gov (United States)

    2010-07-01

    ... physical property; liquidation of blocked property. 544.204 Section 544.204 Money and Finance: Treasury... maintaining blocked physical property; liquidation of blocked property. (a) Except as otherwise authorized..., all expenses incident to the maintenance of physical property blocked pursuant to § 544.201(a) shall...

  16. 31 CFR 543.204 - Expenses of maintaining blocked physical property; liquidation of blocked property.

    Science.gov (United States)

    2010-07-01

    ... physical property; liquidation of blocked property. 543.204 Section 543.204 Money and Finance: Treasury... physical property; liquidation of blocked property. (a) Except as otherwise authorized, and notwithstanding... to the maintenance of physical property blocked pursuant to § 543.201(a) shall be the responsibility...

  17. 31 CFR 547.204 - Expenses of maintaining blocked physical property; liquidation of blocked property.

    Science.gov (United States)

    2010-07-01

    ... physical property; liquidation of blocked property. 547.204 Section 547.204 Money and Finance: Treasury... maintaining blocked physical property; liquidation of blocked property. (a) Except as otherwise authorized..., all expenses incident to the maintenance of physical property blocked pursuant to § 547.201(a) shall...

  18. Physical Properties of Synthetic Resin Materials

    Science.gov (United States)

    Fishbein, Meyer

    1939-01-01

    A study was made to determine the physical properties of synthetic resins having paper, canvas, and linen reinforcements, and of laminated wood impregnated with a resin varnish. The results show that commercial resins have moduli of elasticity that are too low for structural considerations. Nevertheless, there do exist plastics that have favorable mechanical properties and, with further development, it should be possible to produce resin products that compare favorably with the light-metal alloys. The results obtained from tests on Compound 1840, resin-impregnated wood, show that this material can stand on its own merit by virtue of a compressive strength four times that of the natural wood. This increase in compressive strength was accomplished with an increase of density to a value slightly below three times the normal value and corrected one of the most serious defects of the natural product.

  19. Corrosion and physical properties of microalloyed rebar

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, L. [Univ. Autonoma de Campeche, Cuernavaca, Morelos (Mexico). Programa de Corrosion del Golfo de Mexico]|[UNAM, Cuernavaca, Morelos (Mexico). Inst. de Fisica; Hernandez, G.; Carpio, J.J. [Univ. Autonoma de Campeche, Cuernavaca, Morelos (Mexico). Programa de Corrosion del Golfo de Mexico; Arganis, C. [Inst. Nacional de Investigaciones Nucleares, Salazar (Mexico)

    1995-06-01

    The modifications of the Construction Code of Mexico City after the 1985 earthquakes included a recommendation to use low-alloy rebar as a first option for the reinforced-concrete buildings; main structural components. The first Mexican specification of low-alloy concrete rebar of weldable grade and optimal mechanical response during plastic deformation caused by earthquakes was issued in 1987. Reported here are the results of a comparative study of features of standard and microalloyed rebar considering physical and electrochemical properties of these materials embedded in plain and chloride-contaminated concrete.

  20. Physical Properties of the Glycoprotein Mucin

    Science.gov (United States)

    Matthews, Garrett; Davis, William; Superfine, Richard; Boucher, Richard

    2003-03-01

    Epithelial cell surfaces are covered by a protective gel known as mucus. The physiological function of this gel depends on its rheological properties, and these properties are largely derived from the secreted glycoprotein mucin. The genetic disease Cystic Fibrosis (CF) is characterized by the adhesion of thick, viscous mucus on these tissues. In the lungs, this results in the interruption of mucus transport thus compromising the first line of defense against pathogens in these tissues. In order to restore the flow of tracheobronchial mucus out of the body, knowledge of the molecular and physical properties of mucin and mucin solutions would be greatly beneficial. The present model for these molecules is that of a long linear strand consisting of highly glycosylated regions linked by cystein-rich globular regions. It is thought that the globular regions may interact either through intermolecular disulfide bonds or through hydrophobic interactions. It has also been speculated that the glycosylated regions may have lectin-like interactions. In the present work, single mucin molecules were imaged at high resolution using atomic force microscopy (AFM). Phase mode imaging was used to map the interactions between functionalized AFM tips and the molecular topography. Additionally, using force-distance curves with the AFM, the adhesion between mucin bound tips and cell surface glycocalyx and glycocalyx-like model surfaces, was measured. And, finally, the viscoelastic properties of mucin solutions were measured using the recently developed technique, single particle tracking microrheology. A model is being developed that will incorporate the properties of mucins beginning at the single molecule and ending with the bulk viscoelastic properties.

  1. Symmetry and physical properties of crystals

    CERN Document Server

    Malgrange, Cécile; Schlenker, Michel

    2014-01-01

    Crystals are everywhere, from natural crystals (minerals) through the semiconductors and magnetic materials in electronic devices and computers or piezoelectric resonators at the heart of our quartz watches to electro-optical devices. Understanding them in depth is essential both for pure research and for their applications. This book provides a clear, thorough presentation of their symmetry, both at the microscopic space-group level and the macroscopic point-group level. The implications of the symmetry of crystals for their physical properties are then presented, together with their mathematical description in terms of tensors. The conditions on the symmetry of a crystal for a given property to exist then become clear, as does the symmetry of the property. The geometrical representation of tensor quantities or properties is presented, and its use in determining important relationships emphasized. An original feature of this book is that most chapters include exercises with complete solutions. This all...

  2. Chemistry and physical properties of estolides

    International Nuclear Information System (INIS)

    Isbell, T.A.

    2011-01-01

    Estolides are a developing class of natural and synthetic compounds that have been synthesized from hydroxy oils like castor and lesquerella or by the condensation of fatty acids across the olefin of a second fatty acid. Castor and lesquerella estolides are derived from either their triglycerides or their free fatty acids utilizing their hydroxyl moiety to establish the estolide bond. The triglyceride estolides have pour points of 9 to -36 degrees centigrade but suffer poor oxidative stability with RPVOT times of 29 - 52 minutes even with 1% of an anti-oxidant package incorporated into the samples. In contrast to the triglyceride estolides of castor and lesquerella, the estolides from lesquerolic and ricinoleic acids have very good pour points of -36 to - 54 degrees centigrade. Estolides derived from the acid catalyzed condensation of oleic acid with a variety of fatty acids can be made in good yield and posses a wide range of physical properties. Of particular interest are the saturated capped estolides of oleic that have both good low temperature properties (pour point -5 to -39 degrees centigrade) and good oxidative stability. Estolides from meadow foam fatty acids do not have good low temperature properties but have been extensively used in cosmetics where they provide good moisturizing properties. (Author).

  3. Selected physical properties of various diesel blends

    Science.gov (United States)

    Hlaváčová, Zuzana; Božiková, Monika; Hlaváč, Peter; Regrut, Tomáš; Ardonová, Veronika

    2018-01-01

    The quality determination of biofuels requires identifying the chemical and physical parameters. The key physical parameters are rheological, thermal and electrical properties. In our study, we investigated samples of diesel blends with rape-seed methyl esters content in the range from 3 to 100%. In these, we measured basic thermophysical properties, including thermal conductivity and thermal diffusivity, using two different transient methods - the hot-wire method and the dynamic plane source. Every thermophysical parameter was measured 100 times using both methods for all samples. Dynamic viscosity was measured during the heating process under the temperature range 20-80°C. A digital rotational viscometer (Brookfield DV 2T) was used for dynamic viscosity detection. Electrical conductivity was measured using digital conductivity meter (Model 1152) in a temperature range from -5 to 30°C. The highest values of thermal parameters were reached in the diesel sample with the highest biofuel content. The dynamic viscosity of samples increased with higher concentration of bio-component rapeseed methyl esters. The electrical conductivity of blends also increased with rapeseed methyl esters content.

  4. HYDRAULIC AND PHYSICAL PROPERTIES OF MCU SALTSTONE

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, K; Mark Phifer, M

    2008-03-19

    The Saltstone Disposal Facility (SDF), located in the Z-Area of the Savannah River Site (SRS), is used for the disposal of low-level radioactive salt solution. The SDF currently contains two vaults: Vault 1 (6 cells) and Vault 4 (12 cells). Additional disposal cells are currently in the design phase. The individual cells of the saltstone facility are filled with saltstone., Saltstone is produced by mixing the low-level radioactive salt solution, with blast furnace slag, fly ash, and cement or lime to form a dense, micro-porous, monolithic, low-level radioactive waste form. The saltstone is pumped into the disposal cells where it subsequently solidifies. Significant effort has been undertaken to accurately model the movement of water and contaminants through the facility. Key to this effort is an accurate understanding of the hydraulic and physical properties of the solidified saltstone. To date, limited testing has been conducted to characterize the saltstone. The primary focus of this task was to estimate the hydraulic and physical properties of MCU (Modular Caustic Side Solvent Extraction Unit) saltstone relative to two permeating fluids. These fluids included simulated groundwater equilibrated with vault concrete and simulated saltstone pore fluid. Samples of the MCU saltstone were prepared by the Savannah River National Laboratory (SRNL) and allowed to cure for twenty eight days prior to testing. These samples included two three-inch diameter by six inch long mold samples and three one-inch diameter by twelve inch long mold samples.

  5. Ellipsometry at the nanoscale

    CERN Document Server

    Hingerl, Kurt

    2013-01-01

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

  6. Physical Properties of Silicone Gel Breast Implants.

    Science.gov (United States)

    Jewell, Mark L; Bengtson, Bradley P; Smither, Kate; Nuti, Gina; Perry, TracyAnn

    2018-04-28

    Surgical applications using breast implants are individualized operations to fill and shape the breast. Physical properties beyond shape, size, and surface texture are important considerations during implant selection. Compare form stability, gel material properties, and shell thickness of textured shaped, textured round, and smooth round breast implants from 4 manufacturers: Allergan, Mentor, Sientra, and Establishment Labs through bench testing. Using a mandrel height gauge, form stability was measured by retention of dimensions on device movement from a horizontal to vertical supported orientation. Dynamic response of gel material (gel cohesivity, resistance to gel deformation, energy absorption) was measured using a synchronized target laser following application of graded negative pressure. Shell thickness was measured using digital thickness gauge calipers. Form stability, gel material properties, and shell thickness differed across breast implants. Of textured shaped devices, Allergan Natrelle 410 exhibited greater form stability than Mentor MemoryShape and Sientra Shaped implants. Allergan Inspira round implants containing TruForm 3 gel had greater form stability, higher gel cohesivity, greater resistance to gel deformation, and lower energy absorption than those containing TruForm 2 gel and in turn, implants containing TruForm 1 gel. Shell thickness was greater for textured versus smooth devices, and differed across styles. Gel cohesivity, resistance to gel deformation, and energy absorption are directly related to form stability, which in turn determines shape retention. These characteristics provide information to aid surgeons choosing an implant based on surgical application, patient tissue characteristics, and desired outcome.

  7. Physical properties of beryllium oxide - Irradiation effects

    International Nuclear Information System (INIS)

    Elston, J.; Caillat, R.

    1958-01-01

    This work has been carried out in view of determining several physical properties of hot-pressed beryllium oxide under various conditions and the change of these properties after irradiation. Special attention has been paid on to the measurement of the thermal conductivity coefficient and thermal diffusivity coefficient. Several designs for the measurement of the thermal conductivity coefficient have been achieved. They permit its determination between 50 and 300 deg. C, between 400 and 800 deg. C. Some measurements have been made above 1000 deg. C. In order to measure the thermal diffusivity coefficient, we heat a perfectly flat surface of a sample in such a way that the heat flux is modulated (amplitude and frequency being adjustable). The thermal diffusivity coefficient is deduced from the variations of temperature observed on several spots. Tensile strength; compressive strength; expansion coefficient; sound velocity and crystal parameters have been also measured. Some of the measurements have been carried out after neutron irradiation. Some data have been obtained on the change of the properties of beryllium oxide depending on the integrated neutron flux. (author) [fr

  8. Synthesis, microstructure, and physical properties of metallic barcode nanowires

    Science.gov (United States)

    Park, Bum Chul; Kim, Young Keun

    2017-05-01

    With rapid progress in nanotechnology, nanostructured materials have come closer to our life. Single-component nanowires are actively investigated because of their novel properties, attributed to their nanoscale dimensions and adjustable aspect ratio, but their technical limitations cannot be resolved easily. Heterostructured nanomaterials gained attention as alternatives because they can improve the existing single-component structure or add new functions to it. Among them, barcode nanowires (BNWs), comprising at least two different functional segments, can perform multiple functions for use in biomedical sensors, information encoding and security, and catalysts. BNW applications require reliable response to the external field. Hence, researchers have been attempting to improve the reliability of synthesis and regulate the properties precisely. This article highlights the recent progress and prospects for the synthesis, properties, and applications of metallic BNWs with focus on the dependence of the magnetic, optical, and mechanical properties on material, composition, shape, and microstructure.

  9. Investigation of the Structural, Electrical, and Optical Properties of the Nano-Scale GZO Thin Films on Glass and Flexible Polyimide Substrates

    Directory of Open Access Journals (Sweden)

    Fang-Hsing Wang

    2016-05-01

    Full Text Available In this study, Ga2O3-doped ZnO (GZO thin films were deposited on glass and flexible polyimide (PI substrates at room temperature (300 K, 373 K, and 473 K by the radio frequency (RF magnetron sputtering method. After finding the deposition rate, all the GZO thin films with a nano-scale thickness of about 150 ± 10 nm were controlled by the deposition time. X-ray diffraction patterns indicated that the GZO thin films were not amorphous and all exhibited the (002 peak, and field emission scanning electron microscopy showed that only nano-scale particles were observed. The dependences of the structural, electrical, and optical properties of the GZO thin films on different deposition temperatures and substrates were investigated. X-ray photoemission spectroscopy (XPS was used to measure the elemental composition at the chemical and electronic states of the GZO thin films deposited on different substrates, which could be used to clarify the mechanism of difference in electrical properties of the GZO thin films. In this study, the XPS binding energy spectra of Ga2p3/2 and Ga2p1/2 peaks, Zn2p3/2 and Zn2p1/2 peaks, the Ga3d peak, and O1s peaks for GZO thin films on glass and PI substrates were well compared.

  10. Glycolic acid physical properties and impurities assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pickenheim, B. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hay, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); BIBLER, N. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-08-09

    This document has been revised to add analytical data for fresh, 1 year old, and 4 year old glycolic acid as recommended in Revision 2 of this document. This was needed to understand the concentration of formaldehyde and methoxyacetic acid, impurities present in the glycolic acid used in Savannah River National Laboratory (SRNL) experiments. Based on this information, the concentration of these impurities did not change during storage. These impurities were in the glycolic acid used in the testing included in this report and in subsequent testing using DuPont (now called Chemours) supplied Technical Grade 70 wt% glycolic acid. However, these impurities were not reported in the first two versions of this report. The Defense Waste Processing Facility (DWPF) is planning to implement a nitric-glycolic acid flowsheets to increase attainment to meet closure commitment dates during Sludge Batch 9. In fiscal year 2009, SRNL was requested to determine the physical properties of formic and glycolic acid blends.

  11. Physical properties of Al-R melts

    International Nuclear Information System (INIS)

    Sidorov, V.; Gornov, O.; Bykov, V.; Son, L.; Ryltsev, R.; Uporov, S.; Shevchenko, V.; Kononenko, V.; Shunyaev, K.; Ilynykh, N.; Moiseev, G.; Kulikova, T.; Sordelet, D.

    2007-01-01

    In this work, we present experimental data of physical properties (viscosity, surface tension, magnetic susceptibility and electroresistivity) studies for Al-R (R = Ce, Pr, Sm, Gd, Dy, Ho, Yb and Y) alloys and first intermetallic compounds from aluminum side, Al 11 R 3 (Al 3 R). All properties were measured during heating up to 2000 K and the following cooling down under helium atmosphere. The main results are: (1) the electronic characteristics of the objects are in good correlation with R positions in the periodic table, but rather lower than for pure elements. The conclusion is that through all investigated temperature range, the rare-earth elements have partly covalent but not only metallic states; (2) all the melts remain strongly microheterogeneous even at high overheatings above liquidus. The existence of associations with Al 2 R type is highly probable here. Some destruction of these associations takes place with increasing temperature above melting point at the composition of Al 2 R compound. However, the transformation into true solution state is somewhere above 1900 K. To check the idea, the thermodynamic modeling of the melts was performed. It was shown that associates with Al 2 R type are stable up to 2000 K

  12. 31 CFR 548.204 - Expenses of maintaining blocked physical property; liquidation of blocked property.

    Science.gov (United States)

    2010-07-01

    ... physical property; liquidation of blocked property. 548.204 Section 548.204 Money and Finance: Treasury... property; liquidation of blocked property. (a) Except as otherwise authorized, and notwithstanding the... maintenance of physical property blocked pursuant to § 548.201(a) shall be the responsibility of the owners or...

  13. 31 CFR 546.204 - Expenses of maintaining blocked physical property; liquidation of blocked property.

    Science.gov (United States)

    2010-07-01

    ... physical property; liquidation of blocked property. 546.204 Section 546.204 Money and Finance: Treasury... property; liquidation of blocked property. (a) Except as otherwise authorized, and notwithstanding the... maintenance of physical property blocked pursuant to § 546.201(a) shall be the responsibility of the owners or...

  14. Glycolic acid physical properties and impurities assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D. P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pickenheim, B. R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bibler, N. E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hay, M. S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-06-08

    This document has been revised due to recent information that the glycolic acid used in Savannah River National Laboratory (SRNL) experiments contains both formaldehyde and methoxyacetic acid. These impurities were in the glycolic acid used in the testing included in this report and in subsequent testing using DuPont (now called Chemours) supplied Technical Grade 70 wt% glycolic acid. However, these impurities were not reported in earlier revisions. Additional data concerning the properties of glycolic acid have also been added to this report. The Defense Waste Processing Facility (DWPF) is planning to implement a nitric-glycolic acid flowsheets to increase attainment to meet closure commitment dates during Sludge Batch 9. In fiscal year 2009, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in Technical Grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.033 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H2 and cause an adverse effect in the Slurry Receipt and Adjustment Tank (SRAT) or Slurry Mix Evaporator (SME) process. It has been cited that glycolic acid

  15. Physical Properties of Moringa ( Moringa oleifera ) Seeds in relation ...

    African Journals Online (AJOL)

    Physical properties are very important in the design and manufacturing of processing machines. In this research work, the physical properties of Moringa were determined as design parameters for the development of an oil expeller for the crop. The properties were: length, width, thickness, arithmetic and geometric ...

  16. Changes in some physical properties of a typic haplorthox in ...

    African Journals Online (AJOL)

    The assessment of the impacts of different crop rotations on soil physical properties is needed to identify those with the potential to improve such properties which enhance crops´ responses to soil nutrients. The effects of eight crop rotations on physical properties of a Rhodic Ferralsol (Typic Haplorthox) were assessed in ...

  17. 40 CFR 716.50 - Reporting physical and chemical properties.

    Science.gov (United States)

    2010-07-01

    ... chemical properties. Studies of physical and chemical properties must be reported under this subpart if... they investigated one or more of the following properties: (a) Water solubility. (b) Adsorption... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reporting physical and chemical...

  18. Nanoscale thermal transport

    Science.gov (United States)

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

    2003-01-01

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

  19. Spectra and physical properties of Taurid meteoroids

    Science.gov (United States)

    Matlovič, Pavol; Tóth, Juraj; Rudawska, Regina; Kornoš, Leonard

    2017-09-01

    Taurids are an extensive stream of particles produced by comet 2P/Encke, which can be observed mainly in October and November as a series of meteor showers rich in bright fireballs. Several near-Earth asteroids have also been linked with the meteoroid complex, and recently the orbits of two carbonaceous meteorites were proposed to be related to the stream, raising interesting questions about the origin of the complex and the composition of 2P/Encke. Our aim is to investigate the nature and diversity of Taurid meteoroids by studying their spectral, orbital, and physical properties determined from video meteor observations. Here we analyze 33 Taurid meteor spectra captured during the predicted outburst in November 2015 by stations in Slovakia and Chile, including 14 multi-station observations for which the orbital elements, material strength parameters, dynamic pressures, and mineralogical densities were determined. It was found that while orbits of the 2015 Taurids show similarities with several associated asteroids, the obtained spectral and physical characteristics point towards cometary origin with highly heterogeneous content. Observed spectra exhibited large dispersion of iron content and significant Na intensity in all cases. The determined material strengths are typically cometary in the KB classification, while PE criterion is on average close to values characteristic for carbonaceous bodies. The studied meteoroids were found to break up under low dynamic pressures of 0.02-0.10 MPa, and were characterized by low mineralogical densities of 1.3-2.5 g cm-3. The widest spectral classification of Taurid meteors to date is presented.

  20. Nanoscale phase change memory materials.

    Science.gov (United States)

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

    2012-08-07

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

  1. Structure and Electrochemical Properties of a Mechanochemically Processed Silicon and Oxide-Based Nanoscale Composite as an Active Material for Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Norihiro Shimoi

    2017-01-01

    Full Text Available Si is essential as an active material in Li-ion batteries because it provides both high charge and optimal cycling characteristics. A composite of Si particles, Cu particles, and pure H2O was realized to serve as an anode active material and optimize the charge–discharge characteristics of Li-ion batteries. The composite was produced by grinding using a planetary ball mill machine, which allowed for homogenous dispersion of nanoscale Cu3Si as Si–Cu alloy grains and nanoscale Si grains in each poly-Si particle produced. Furthermore, some Si particles were oxidized by H2O, and oxidized Si was distributed throughout the composite, mainly as silicon monoxide. As a result, each Si particle included silicon monoxide and conductive Cu3Si materials, allowing for effective optimization of the recharging and charge-discharge characteristics. Thus, a new and simple process was realized for synthesizing a Si active material composited with silicon oxides, including silicon monoxide. This Si-rich conductive material is suitable as an anode for Li-ion batteries with high charge and optimized cycling properties.

  2. Diffraction phase microscopy imaging and multi-physics modeling of the nanoscale thermal expansion of a suspended resistor.

    Science.gov (United States)

    Wang, Xiaozhen; Lu, Tianjian; Yu, Xin; Jin, Jian-Ming; Goddard, Lynford L

    2017-07-04

    We studied the nanoscale thermal expansion of a suspended resistor both theoretically and experimentally and obtained consistent results. In the theoretical analysis, we used a three-dimensional coupled electrical-thermal-mechanical simulation and obtained the temperature and displacement field of the suspended resistor under a direct current (DC) input voltage. In the experiment, we recorded a sequence of images of the axial thermal expansion of the central bridge region of the suspended resistor at a rate of 1.8 frames/s by using epi-illumination diffraction phase microscopy (epi-DPM). This method accurately measured nanometer level relative height changes of the resistor in a temporally and spatially resolved manner. Upon application of a 2 V step in voltage, the resistor exhibited a steady-state increase in resistance of 1.14 Ω and in relative height of 3.5 nm, which agreed reasonably well with the predicted values of 1.08 Ω and 4.4 nm, respectively.

  3. Physical properties of molten carbonate electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, T.; Yanagida, M.; Tanimoto, K. [Osaka National Research Institute (Japan)] [and others

    1996-12-31

    Recently many kinds of compositions of molten carbonate electrolyte have been applied to molten carbonate fuel cell in order to avoid the several problems such as corrosion of separator plate and NiO cathode dissolution. Many researchers recognize that the addition of alkaline earth (Ca, Sr, and Ba) carbonate to Li{sub 2}CO{sub 3}-Na{sub 2}CO{sub 3} and Li{sub 2}CO{sub 3}-K{sub 2}CO{sub 3} eutectic electrolytes is effective to avoid these problems. On the other hand, one of the corrosion products, CrO{sub 4}{sup 2-} ion is found to dissolve into electrolyte and accumulated during the long-term MCFC operations. This would affect the performance of MCFC. There, however, are little known data of physical properties of molten carbonate containing alkaline earth carbonates and CrO{sub 4}{sup 2-}. We report the measured and accumulated data for these molten carbonate of electrical conductivity and surface tension to select favorable composition of molten carbonate electrolytes.

  4. Chemistry and physical properties of estolides

    Directory of Open Access Journals (Sweden)

    Isbell, Terry A.

    2011-03-01

    Full Text Available Estolides are a developing class of natural and synthetic compounds that have been synthesized from hydroxy oils like castor and lesquerella or by the condensation of fatty acids across the olefin of a second fatty acid. Castor and lesquerella estolides are derived from either their triglycerides or their free fatty acids utilizing their hydroxyl moiety to establish the estolide bond. The triglyceride estolides have pour points of 9 to –36ºC but suffer poor oxidative stability with RPVOT times of 29 – 52 minutes even with 1% of an anti-oxidant package incorporated into the samples. In contrast to the triglyceride estolides of castor and lesquerella, the estolides from lesquerolic and ricinoleic acids have very good pour points of –36 to –54ºC. Estolides derived from the acid catalyzed condensation of oleic acid with a variety of fatty acids can be made in good yield and posses a wide range of physical properties. Of particular interest are the saturated capped estolides of oleic that have both good low temperature properties (pour point –5 to – 39ºC and good oxidative stability. Estolides from meadowfoam fatty acids do not have good low temperature properties but have been extensively used in cosmetics where they provide good moisturizing properties.

    Los estólidos son una familia de compuestos sintetizados a partir de aceites hidroxilados como los de ricino o lesquerella o mediante la condensación de ácidos grasos sobre el doble enlace de un segundo ácido graso insaturado. Los estólidos de ricino y lesquerela se derivan tanto de sus triglicéridos como de sus ácidos grasos libres empleándose el residuo hidroxilo para formar los ésteres estólidos de los mismos. Los triglicéridos estólidos tienen puntos de fluidez crítica de entre 9 y -36ºC y baja estabilidad, con tiempos de oxidación en recipiente vacío a presión (RPVOT de entre 29 y 52 minutos incluso con la adición de un 1% de una mezcla antioxidante a las

  5. Recombinant protein-based nanoscale biomemory devices.

    Science.gov (United States)

    Yagati, A K; Min, J; Choi, J W

    2014-01-01

    Biomolecular computing devices that are based on the properties of biomolecular activities offer a unique possibility for constructing new computing structures. A new concept of using various biomolecules has been proposed in order to develop a protein-based memory device that is capable of switching physical properties when electrical input signals are applied to perform memory switching. To clarify the proposed concept, redox protein is immobilized on Au nanoelectrodes to catalyze reversible reactions of redox-active molecules, which is controlled electrochemically and reversibly converted between its ON/OFF states. In this review, we summarize recent research towards developing nanoscale biomemory devices including design, synthesis, fabrication, and functionalization based on the proposed concept. At first we analyze the memory function properties of the proposed device at bulk material level and then explain the WORM (write-once-read-many times) nature of the device, later we extend the analysis to multi-bit and multi-level storage functions, and then we focus the developments in nanoscale biomemory devices based on the electron transport of redox molecules to the underlying Au patterned surface. The developed device operates at very low voltages and has good stability and excellent reversibility, proving to be a promising platform for future memory devices.

  6. The effect of cycling on the nanoscale morphology and redox properties of poly[2,2′-bithiophene

    International Nuclear Information System (INIS)

    O’Neil, K.D.; Smith, A.; Forristal, T.A.; Semenikhin, O.A.

    2013-01-01

    The changes in the redox behavior and nanoscale morphology of poly[2,2′-bithiophene] deposited onto highly oriented pyrolytic graphite substrates upon repeated doping–undoping were studied. It was shown that repeated cycling resulted in very particular changes in the voltammetric response of the polymer films as well as their nanoscale morphology. Specifically, when the cycling was performed to relatively low anodic potentials, the overall doping–undoping charge did not change; however, the shape of voltammograms was consistently changing showing broadening of the voltammograms and reducing of the doping peak height in the anodic scan, as well as broadening and deterioration of the undoping peak in the reverse scan. Furthermore, a remarkable feature was observed that all voltammogram traces intersected at several characteristic potentials producing quasi-isosbestic points. With an increase in the anodic scan potential limit, the overall doping–undoping charge starts to decrease showing irreversible degradation of the polymer; however, the general pattern of the peak broadening could be still observed. Atomic force microscopic (AFM) studies of the polymer films cycled to various anodic limits showed that repeated cycling resulted in a gradual decrease in the degree of crystallinity, as revealed by AFM phase imaging, and an increase in the degree of disorder. Coupled with the changes in the redox behavior, these findings suggested the formation of more flexible and open polymer nanostructure that enables easier penetration of the dopant ions and solvent. However, at the same time, an increase in the degree of disorder reduced the interchain interactions and inhibited the formation of extended electronic states delocalized across neighboring polymer chains. This occurred at first without irreversible degradation of the polymer and a decrease in the overall doping–undoping charge. Cycling to higher anodic potentials resulted in irreversible degradation

  7. Physical properties of 5 root canal sealers.

    Science.gov (United States)

    Zhou, Hui-min; Shen, Ya; Zheng, Wei; Li, Li; Zheng, Yu-feng; Haapasalo, Markus

    2013-10-01

    The aim of this study was to evaluate the pH change, viscosity and other physical properties of 2 novel root canal sealers (MTA Fillapex and Endosequence BC) in comparison with 2 epoxy resin-based sealers (AH Plus and ThermaSeal), a silicone-based sealer (GuttaFlow), and a zinc oxide-eugenol-based sealer (Pulp Canal Sealer). ISO 6876/2001 specifications were followed. The pH change of freshly mixed and set sealers was evaluated during periods of 1 day and 5 weeks, respectively. The viscosity was investigated at different injection rates (72, 10, and 5 mm/min) at room temperature by using a syringe-based system that was based on the Instron 3360 series universal testing system. The flow, dimensional change, solubility, and film thickness of all the tested sealers were in agreement with ISO 6876/2001 recommendations. The MTA Fillapex sealer exhibited a higher flow than the Endosequence BC sealer (P pH at all times. The pH of fresh samples of the AH Plus and ThermaSeal sealers was alkaline at first but decreased significantly after 24 hours. The viscosity of the tested sealers increased with the decreased injection rates. The tested sealers were pseudoplastic according to their viscosities as determined in this study. The MTA Fillapex and Endosequence BC sealers each possessed comparable flow and dimensional stability but higher film thickness and solubility than the other sealers tested. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Piezoelectric effects and electromechanical theories at the nanoscale.

    Science.gov (United States)

    Zhang, Jin; Wang, Chengyuan; Bowen, Chris

    2014-11-21

    Considerable effort has been made to study the piezoelectric effect on the nanoscale, which serves as a physical basis for a wide range of smart nanodevices and nanoelectronics. This paper reviews recent progress in the research on the piezoelectric properties and electromechanical effects of piezoelectric nanomaterials (PNs). The review begins with an introduction to existing PNs which exhibit a diverse range of atomic structures and configurations. The nanoscale measurement of their effective piezoelectric coefficients (EPCs) is summarised with an emphasis on the major factors determining the piezoelectric properties of PNs. The paper concludes with a review of the electromechanical theories that are able to capture the small-scale effects on PNs, which include the surface piezoelectricity, flexoelectricity and Eringen's nonlocal theory. In contrast to the classical theories, two types of EPCs are defined, which were found to be size-dependent and loading condition-selective.

  9. 2D or not 2D? The impact of nanoscale roughness and substrate interactions on the tribological properties of graphene and MoS2

    International Nuclear Information System (INIS)

    Elinski, Meagan B; Liu, Zhuotong; Spear, Jessica C; Batteas, James D

    2017-01-01

    The use of 2D nanomaterials for controlling friction and wear at interfaces has received increased attention over the past few years due to their unique structural, thermal, electrical and mechanical properties. These materials proffer potential critical solutions to challenges in boundary lubrication across numerous platforms ranging from engines, to biomedical implants and micro- and nano-scaled machines that will play a major role in the Internet of Things. There has been significant work on a range of 2D nanomaterials, such as graphene and molybdenum disulfide (MoS 2 ). From these studies, their frictional properties have been shown to be highly dependent on numerous factors, such as substrate structure, strain, and competing chemical interactions between the interfaces in sliding contact. Moreover, when considering real contacts in machined interfaces, these surfaces are often composed of nanoscaled asperities, whose intermittent contact dominates the tribochemical processes that result in wear. In this review we aim to capture recent work on the tribological properties of graphene and MoS 2 and to discuss the impacts of surface roughness (from the atomic scale to the nanoscale) and chemical interactions at interfaces on their frictional properties, and their use in designing advanced boundary lubrication schemes. (topical review)

  10. Effect of ozone gas processing on physical and chemical properties ...

    African Journals Online (AJOL)

    Purpose: To investigate the effects of ozone treatment on chemical and physical properties of wheat (Triticum aestivum L.) gluten, glutenin and gliadin. Methods: Wheat proteins isolated from wheat flour were treated with ozone gas. The physical and chemical properties of gluten proteins were investigated after treatment ...

  11. Structural and physical properties of Sm doped magnesium zinc ...

    Indian Academy of Sciences (India)

    2017-09-22

    Sep 22, 2017 ... and physical properties of prepared glass samples were characterized. The X-ray diffraction pattern verified their amorphous nature. The physical properties such as density, refractive index, molar volume, rare earth ion concentration, etc. were ..... We are grateful to UTM and Ministry of Education for the.

  12. Atomic structure and physical properties of liquid Pb Bi alloys

    Science.gov (United States)

    Kaban, I.; Hoyer, W.; Plevachuk, Yu; Sklyarchuk, V.

    2004-09-01

    The atomic structure and physical properties (dynamic viscosity, electrical conductivity, and thermopower) of liquid Pb-Bi alloys have been investigated in a wide temperature range. Gradual and reversible changes of the physical properties during heating and cooling of the Pb-Bi liquid alloys have been observed. No drastic structural transformations or atomic rearrangement with temperature variation have been found.

  13. Influence of substrate temperature on certain physical properties ...

    Indian Academy of Sciences (India)

    Influence of substrate temperature on certain physical properties and antibacterial activity of nanocrystalline Ag-doped In 2 O 3 thin films ... films were subjected to various characterization studies, to explore certain features like the influence of various deposition temperatures on physical and antibacterial properties.

  14. A Comparative Evaluation of the Physical and Chemical Properties ...

    African Journals Online (AJOL)

    The physical and chemical properties of tamarind seeds (Tamarindus indica L.) in Nigeria were investigated. Tamarind fruits were randomly collected from 18 towns in the savannah region of Nigeria. The seeds were manually separated from the pulp and membranes, sun-dried and the physical properties determined.

  15. Proximate, Physical And Sensory Properties Of Soy-Sweet Potato ...

    African Journals Online (AJOL)

    Flour mixtures consisting of full-fat soy flour and sweet potato flour at 25-75% levels were used in cookie production. Proximate, physical and sensory properties of the cookies were determined. Physical and sensory properties investigated included thickness, diameter, spread factor, spread ratio, fragility, appearance, ...

  16. Universal size dependence of the physical properties of nanomaterials

    Science.gov (United States)

    Eremin, E. N.; Yurov, V. M.; Guchenko, S. A.; Laurynas, V. Ch

    2017-06-01

    Dimensional analysis of the experimentally observed dependence of the physical properties of nanoparticles, nanofilms and nanomaterials showed that there is a universal equation that accurately describes the observed size effects. It is shown that the size factor is also a universal value and is determined only by the atomic structure of the nanomaterial. Discovered universal relationships enable us to calculate the physical properties (mechanical, electrical, magnetic, thermal, etc.) of small particles and thin films based on knowledge of the properties of bulk materials.

  17. Mechanical and physical properties of plasma-sprayed stabilized zirconia

    Science.gov (United States)

    Siemers, P. A.; Mehan, R. L.

    1983-01-01

    Physical and mechanical properties were determined for plasma-sprayed MgO- or Y2O3-stabilized ZrO2 thermal barrier coatings. Properties were determined for the ceramic coating in both the freestanding condition and as-bonded to a metal substrate. The properties of the NiCrAlY bond coating were also investigated.

  18. Complexity and the Emergence of Physical Properties

    Directory of Open Access Journals (Sweden)

    Miguel Angel Fuentes

    2014-08-01

    Full Text Available Using the effective complexity measure, proposed by M. Gell-Mann and S. Lloyd, we give a quantitative definition of an emergent property. We use several previous results and properties of this particular information measure closely related to the random features of the entity and its regularities.

  19. Physical properties of organic fullerene cocrystals

    Science.gov (United States)

    Macovez, Roberto

    2017-12-01

    The basic facts and fundamental properties of binary fullerene cocrystals are reviewed, focusing especially on solvates and salts of Buckminsterfullerene (C60), and hydrates of hydrophilic C60 derivatives. The examined properties include the lattice structure and the presence of orientational disorder and/or rotational dynamics (of both fullerenes and cocrystallizing moieties), thermodynamic properties such as decomposition enthalpies, and charge transport properties. Both thermodynamic properties and molecular orientational disorder shed light on the extent of intermolecular interactions in these binary solid-state systems. Comparison is carried out also with pristine fullerite and with the solid phases of functionalized C60. Interesting experimental findings on binary fullerene cocrystals include the simultaneous occurrence of rotations of both constituent molecular species, crystal morphologies reminiscent of quasi-crystalline behaviour, the observation of proton conduction in hydrate solids of hydrophilic fullerene derivatives, and the production of super-hard carbon materials by application of high pressures on solvated fullerene crystals.

  20. Flexoelectricity in Nanoscale Ferroelectrics

    Science.gov (United States)

    Catalan, Gustau

    2012-02-01

    All ferroelectrics are piezoelectric and thus have an intrinsic coupling between polarization and strain. There exists an additional electromechanical coupling, however, between polarization and strain gradients. Strain gradients are intrinsically vectorial fields and, therefore, they can in principle be used to modify both the orientation and the sign of the polarization, thanks to the coupling known as flexoelectricity. Flexoelectricity is possible even in paraelectric materials, but is generally stronger in ferroelectrics on account of their high permittivity (the flexoelectric coefficient is proportional to the dielectric constant). Moreover, strain gradients can be large at the nanoscale due to the smallness of the relaxation length and, accordingly, strong flexoelectric effects can be expected in nanoscale ferroelectrics. In this talk we will present two recent results that highlight the above features. In the first part, I will show how polarization tilting can be achieved in a nominally tetragonal ferroelectric (PbTiO3) thanks to the internal flexoelectric fields generated in nano-twinned epitaxial thin films. Flexoelectricity thus offers a purely physical means of achieving rotated polarizations, which are thought to be useful for enhanced piezoelectricity. In the second part, we will show how the large strain gradients generated by pushing the sharp tip of an atomic force microscope against the surface of a thin ferroelectric film can be used to actively switch its polarity by 180^o. This enables a new concept for ``multiferroic'' memory operation in which the memory bits are written mechanically and read electrically.

  1. WE-DE-202-01: Connecting Nanoscale Physics to Initial DNA Damage Through Track Structure Simulations

    International Nuclear Information System (INIS)

    Schuemann, J.

    2016-01-01

    Radiation therapy for the treatment of cancer has been established as a highly precise and effective way to eradicate a localized region of diseased tissue. To achieve further significant gains in the therapeutic ratio, we need to move towards biologically optimized treatment planning. To achieve this goal, we need to understand how the radiation-type dependent patterns of induced energy depositions within the cell (physics) connect via molecular, cellular and tissue reactions to treatment outcome such as tumor control and undesirable effects on normal tissue. Several computational biology approaches have been developed connecting physics to biology. Monte Carlo simulations are the most accurate method to calculate physical dose distributions at the nanometer scale, however simulations at the DNA scale are slow and repair processes are generally not simulated. Alternative models that rely on the random formation of individual DNA lesions within one or two turns of the DNA have been shown to reproduce the clusters of DNA lesions, including single strand breaks (SSBs), double strand breaks (DSBs) without the need for detailed track structure simulations. Efficient computational simulations of initial DNA damage induction facilitate computational modeling of DNA repair and other molecular and cellular processes. Mechanistic, multiscale models provide a useful conceptual framework to test biological hypotheses and help connect fundamental information about track structure and dosimetry at the sub-cellular level to dose-response effects on larger scales. In this symposium we will learn about the current state of the art of computational approaches estimating radiation damage at the cellular and sub-cellular scale. How can understanding the physics interactions at the DNA level be used to predict biological outcome? We will discuss if and how such calculations are relevant to advance our understanding of radiation damage and its repair, or, if the underlying biological

  2. Modelling of physical properties - databases, uncertainties and predictive power

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    Physical and thermodynamic property in the form of raw data or estimated values for pure compounds and mixtures are important pre-requisites for performing tasks such as, process design, simulation and optimization; computer aided molecular/mixture (product) design; and, product-process analysis...... in the estimated/predicted property values, how to assess the quality and reliability of the estimated/predicted property values? The paper will review a class of models for prediction of physical and thermodynamic properties of organic chemicals and their mixtures based on the combined group contribution – atom...

  3. Micro/nanoscale continuous printing: direct-writing of wavy micro/nano structures via electrospinning

    International Nuclear Information System (INIS)

    Fang, Feiyu; Du, Zefeng; Zeng, Jun; Zhu, Ziming; Chen, Xin; Chen, Xindu; Lv, Yuanjun; Wang, Han

    2015-01-01

    Micro/nanofibers that are created by direct-writing using an electrospinning (ES) technique have aroused much recent attention, owing to their intriguing physical properties and great potential as building blocks for micro/nanoscale devices. In this work, a wavy direct-writing (WDW) process was developed to directly write wavy micro/nanostructures suitable for the fabrication of micro/nanoscale devices. The low voltage WDW technique is anticipated to be useful for a broad range of applications including flexible/stretchable electronics, micro optoelectronics, nano-antennas, microelectromechanical systems (MEMS), and biomedical engineering. (paper)

  4. 10428 PHYSICAL, CHEMICAL AND SENSORY PROPERTIES OF ...

    African Journals Online (AJOL)

    user

    beta carotene contents increased significantly (p < 0.05) as the level of substitution increased. The standard recorded ... Key words: Cookies, sweet potato, mango mesocarp, physical, Chemical, Sensory, Beta carotene ... baking powder and eggs were purchased from Wurukum Market, Makurdi, Benue State. Preparation of ...

  5. Moisture relations and physical properties of wood

    Science.gov (United States)

    Samuel V. Glass; Samuel L. Zelinka

    2010-01-01

    Wood, like many natural materials, is hygroscopic; it takes on moisture from the surrounding environment. Moisture exchange between wood and air depends on the relative humidity and temperature of the air and the current amount of water in the wood. This moisture relationship has an important influence on wood properties and performance. Many of the challenges of using...

  6. A Nanoscale Tale

    Science.gov (United States)

    Serrano, Elba

    2008-10-01

    Experimentalists constantly seek to overcome technical limitations. This is especially true in the world of biophysics, where the drive to study molecular targets such as ion channels, a type of membrane transport protein, has resulted in methodological breakthroughs that have merited the Nobel Prize (Hodgkin and Huxley, 1963; Neher and Sakmann, 1991). In this presentation I will explain how nanoscale phenomena that are essential for sensory perception underlie the ability of dancers, gymnasts, and musicians to excel at their artistic endeavors. I will describe how our investigations of sensory mechanotransduction and the quest for improved signal amplification inspired a scientific journey that has culminated in an exciting new line of collaborative NIH-funded research with nanomaterials (quantum dots). I will conclude with a general discussion of how training in physics offers an ideal foundation for interdisciplinary research in health related fields, such as those that deal with neuroscience and disorders of the nervous system.

  7. Highly repeatable nanoscale phase coexistence in vanadium dioxide films

    Science.gov (United States)

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

    2018-02-01

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

  8. Impacts of land leveling on lowland soil physical properties

    OpenAIRE

    Parfitt, José Maria Barbat; Timm, Luís Carlos; Reichardt, Klaus; Pauletto, Eloy Antonio

    2014-01-01

    The practice of land leveling alters the soil surface to create a uniform slope to improve land conditions for the application of all agricultural practices. The aims of this study were to evaluate the impacts of land leveling through the magnitudes, variances and spatial distributions of selected soil physical properties of a lowland area in the State of Rio Grande do Sul, Brazil; the relationships between the magnitude of cuts and/or fills and soil physical properties after the leveling pro...

  9. Synthesis and Physical Properties of Liquid Crystals: An Interdisciplinary Experiment

    Science.gov (United States)

    Van Hecke, Gerald R.; Karukstis, Kerry K.; Hanhan Li; Hendargo, Hansford C.; Cosand, Andrew J.; Fox, Marja M.

    2005-01-01

    A study involves multiple chemistry and physics concepts applied to a state of matter that has biological relevance. An experiment involving the synthesis and physical properties of liquid crystals illustrates the interdisciplinary nature of liquid crystal research and the practical devices derived from such research.

  10. Let Students Discover an Important Physical Property of a Slinky

    Science.gov (United States)

    Gash, Philip

    2016-01-01

    This paper describes a simple experiment that lets first-year physics and engineering students discover an important physical property of a Slinky. The restoring force for the fundamental oscillation frequency is provided only by those coils between the support and the Slinky center of mass.

  11. Evaluation of anatomical and physical properties of Khaya nthotheca

    African Journals Online (AJOL)

    The anatomical and physical properties of Khaya anthotheca (Welw.) C. DC wood from the transition forest of middle altitude (zone 1) and the humid dense forest of low altitude (zone 2) in the East of the Democratic Republic of Congo were evaluated to ascertain the effect of growth area on the anatomical and physical ...

  12. Changes in Physical Properties of Graphene Oxide with Thermal Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Pandit, Bhishma; Jo, Chang Hee; Joo, Kwan Seon; Cho, Jaehee [Chonbuk National University, Jeonju (Korea, Republic of)

    2017-08-15

    Reduced graphene oxide (rGO) has attracted significant attention as an easily fabricable two dimensional material. Depending on the oxygen-containing functional groups (OFGs) in an rGO specimen, the optical and electrical properties can vary significantly, directly affecting the performance of devices in which rGO is implemented. Here, we investigated the optical and electrical properties of GO treated with various annealing (reduction) temperatures from 350 to 950 ℃ in H2 ambient. Using diverse characteristic tools, we found that the transmittance, nanoscale domain size, OFGs in GO and rGO, and Schottky barrier height (SBH) measured on n-type GaN are significantly influenced by the annealing temperature. The relative intensity of the defect-induced band in Raman spectroscopy showed a minimum at the annealing temperature of approximately 350 ℃, before the OFGs in rGO showed vigorous changes in relative content. When the domain size of rGO reached a minimum at the annealing temperature of 650 ℃, the SBH of rGO/GaN showed the maximum value of 1.07 eV.

  13. Physical Properties of Climbing Black Pepper ( Piper nigrum ) and ...

    African Journals Online (AJOL)

    Mass, density and moisture loss of climbing pepper were significantly affected by drying temperature and duration at 5% level of significance. Other climbing pepper physical properties under study were not influenced significantly. All alligator pepper properties considered were not significant (p > 0.05). Climbing pepper ...

  14. Physical, Chemical and Sensory Properties of Baked Products from ...

    African Journals Online (AJOL)

    AYBWEP) were processed into bread and cookies in the following ratios: 100: 0; 95: 5; 90: 10; 85: 15; 80: 20. The proximate composition, physical, chemical properties and sensory properties of bread and cookies samples from the blends were ...

  15. Impact of UV radiation on the physical properties of polypropylene ...

    African Journals Online (AJOL)

    The purpose of this study was to analyse the influence of simulated sun light radiation (xenon lamp) on physical properties of polypropylene (PP) nonwoven material, which is used for the production of agrotextiles. The research showed that the properties of row cover change when radiated with UV light. Tensile, tearing ...

  16. Physical and Chemical Properties of Soils under Contrasting Land ...

    African Journals Online (AJOL)

    The soil chemical properties studied were soil pH, organic carbon, total nitrogen, available P, exchangeable base (Ca2+, Mg2+, K+ and Na+) and exchangeable acidity (H+ and Al3+). The physical properties were aggregate stability, mean weight diameter, water dispersible clay and clay flocculation index. Two fractions of ...

  17. Prediction of thermo-physical properties of liquid formulated products

    DEFF Research Database (Denmark)

    Mattei, Michele; Conte, Elisa; Kontogeorgis, Georgios

    2013-01-01

    The objective of this chapter is to give an overview of the models, methods and tools that may be used for the estimation of liquid formulated products. First a classification of the products is given and the thermo-physical properties needed to represent their functions are listed. For each...... property, a collection of the available models are presented according to the property type and the model type. It should be noted, however, that the property models considered or highlighted in this chapter are only examples and are not necessarily the best and most accurate for the corresponding property....

  18. Nanoscale magnetism and novel electronic properties of a bilayer bismuth(111) film with vacancies and chemical doping.

    Science.gov (United States)

    Sahoo, M P K; Zhang, Yajun; Wang, Jie

    2016-07-27

    Magnetically doped topological insulators (TIs) exhibit several exotic phenomena including the magnetoelectric effect and quantum anomalous Hall effect. However, from an experimental perspective, incorporation of spin moment into 3D TIs is still challenging. Thus, instead of 3D TIs, the 2D form of TIs may open up new opportunities to induce magnetism. Based on first principles calculations, we demonstrate a novel strategy to realize robust magnetism and exotic electronic properties in a 2D TI [bilayer Bi(111) film: abbreviated as Bi(111)]. We examine the magnetic and electronic properties of Bi(111) with defects such as bismuth monovacancies (MVs) and divacancies (DVs), and these defects decorated with 3d transition metals (TMs). It has been observed that the MV in Bi(111) can induce novel half metallicity with a net magnetic moment of 1 μB. The origin of half metallicity and magnetism in MV/Bi(111) is further explained by the passivation of the σ-dangling bonds near the defect site. Furthermore, in spite of the nonmagnetic nature of DVs, the TMs (V, Cr, Mn, and Fe) trapped at the 5/8/5 defect structure of DVs can not only yield a much higher spin moment than those trapped at the MVs but also display intriguing electronic properties such as metallic, semiconducting and spin gapless semiconducting properties. The predicted magnetic and electronic properties of TM/DV/Bi(111) systems are explained through density of states, spin density distribution and Bader charge analysis.

  19. Development of Ultra-high Mechanical Damping Structures Based on Nano-scale Properties of Shape Memory Alloys

    Science.gov (United States)

    2011-07-27

    Alloys Jose San Juan Universidad del Pais Vasco Department of Physics of Condensed Matter Facultd de Ciencia y Tecnologia Bilbao...Facultd de Ciencia y Tecnologia Bilbao, Spain 48080 8. PERFORMING ORGANIZATION REPORT NUMBER N/A 9. SPONSORING/MONITORING AGENCY NAME(S

  20. Chalk: composition, diagenesis and physical properties

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    2007-01-01

    entry pressure, and elastic moduli are consequences of primary sediment composition and of subsequent diagenetic history as caused by microbial action, burial stress, temperature, and pore pressure. Porosity is a main determining factor for other properties. For a given porosity, the specific surface...... of burial, and over-pressuring. These factors cause the stress, temperature and pore-pressure to increase at different rates during burial in different localities....... of the sediment controls permeability and capillary entry pressure. As diagenesis progresses, the specific surface is less and less due to the calcite component and more and more due to the fine-grained silicates, as a reflection of the coarsening and cementation of the calcite crystals. The elastic moduli, which...

  1. EXAFS and XANES analysis of oxides at the nanoscale

    Directory of Open Access Journals (Sweden)

    Alexei Kuzmin

    2014-11-01

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

  2. Dynamics at the nanoscale

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  3. Nanoscale thermal probing

    Directory of Open Access Journals (Sweden)

    Yanan Yue

    2012-03-01

    Full Text Available Nanoscale novel devices have raised the demand for nanoscale thermal characterization that is critical for evaluating the device performance and durability. Achieving nanoscale spatial resolution and high accuracy in temperature measurement is very challenging due to the limitation of measurement pathways. In this review, we discuss four methodologies currently developed in nanoscale surface imaging and temperature measurement. To overcome the restriction of the conventional methods, the scanning thermal microscopy technique is widely used. From the perspective of measuring target, the optical feature size method can be applied by using either Raman or fluorescence thermometry. The near-field optical method that measures nanoscale temperature by focusing the optical field to a nano-sized region provides a non-contact and non-destructive way for nanoscale thermal probing. Although the resistance thermometry based on nano-sized thermal sensors is possible for nanoscale thermal probing, significant effort is still needed to reduce the size of the current sensors by using advanced fabrication techniques. At the same time, the development of nanoscale imaging techniques, such as fluorescence imaging, provides a great potential solution to resolve the nanoscale thermal probing problem.

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

    Science.gov (United States)

    Habuchi, Satoshi

    2014-01-01

    Super-resolution (SR) fluorescence microscopy has been revolutionizing the way in which we investigate the structures, dynamics, and functions of a wide range of nanoscale systems. In this review, I describe the current state of various SR fluorescence microscopy techniques along with the latest developments of fluorophores and labeling for the SR microscopy. I discuss the applications of SR microscopy in the fields of life science and materials science with a special emphasis on quantitative molecular imaging and nanoscale functional imaging. These studies open new opportunities for unraveling the physical, chemical, and optical properties of a wide range of nanoscale architectures together with their nanostructures and will enable the development of new (bio-)nanotechnology. PMID:25152893

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

    KAUST Repository

    Habuchi, Satoshi

    2014-06-12

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

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

    CERN Document Server

    Alguero, Miguel

    2016-01-01

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

  7. Construction of Hydrophobic Wood Surface and Mechanical Property of Wood Cell Wall on Nanoscale Modified by Dimethyldichlorosilane

    Science.gov (United States)

    Yang, Rui; Wang, Siqun; Zhou, Dingguo; Zhang, Jie; Lan, Ping; Jia, Chong

    2018-01-01

    Dimethyldichlorosilane was used to improve the hydrophobicity of wood surface. The water contact angle of the treated wood surface increased from 85° to 143°, which indicated increased hydrophobicity. The nanomechanical properties of the wood cell wall were evaluated using a nanoindentation test to analyse the hydrophobic mechanism on the nano scale. The elastic modulus of the cell wall was significantly affected by the concentration but the influence of treatment time is insignificant. The hardness of the cell wall for treated samples was significantly affected by both treatment time and concentration. The interaction between treatment time and concentration was extremely significant for the elastic modulus of the wood cell wall.

  8. Investigating correlation between legal and physical property: possibilities and constraints

    Science.gov (United States)

    Dimopoulou, E.; Kitsakis, D.; Tsiliakou, E.

    2015-06-01

    Contemporary urban environment is characterized by complexity and mixed use of space, in which overlapping land parcels and different RRRs (Rights, Restrictions and Responsibilities) are frequent phenomena. Internationally, real property legislation either focuses on surface property or has introduced individual 3D real property units. The former approach merely accommodates issues related to subdivision, expropriation and transactions on part of the real property above or below surface, while the latter provides for defining and registering 3D real property units. National laws require two-dimensional real property descriptions and only a limited number of jurisdictions provide for threedimensional data presentation and recording. International awareness on 3D Cadastre may be apparent through the proposals for transition of existing cadastral systems to 3D along with legal amendments improving national 3D Cadastre legislation. Concurrently the use of appropriate data sources and the correct depiction of 3D property units' boundaries and spatial relationships need to be addressed. Spatial relations and constraints amongst real world objects could be modeled geometrically and topologically utilizing numerous modeling tools, e.g. CityGML, BIM and further sophisticated 3D software or by adapting international standards, e.g. LADM. A direct correlation between legal and physical property should be based on consistent geometry between physical and legal space, improving the accuracy that legal spaces' volumes or locations are defined. To address these issues, this paper investigates correlation possibilities and constraints between legal and physical space of typical 3D property cases. These cases comprise buildings or their interior spaces with mixed use, as well as complex structures described by explicit facade patterns, generated by procedural or by BIM ready 3D models. The 3D models presented are evaluated, regarding compliancy to physical or legal reality.

  9. Physical properties of Aten, Apollo and Amor asteroids

    Science.gov (United States)

    Mcfadden, Lucy-Ann; Tholen, David J.; Veeder, Glenn J.

    1989-01-01

    Data available on the physical properties of a group of planet-crossing asteroids, the Aten, Apollo, and Amor objects (AAAO) (include data on the taxonomy, mineralogical surface composition, diameter, rotation rate, shape, and surface texture) are presented together with the type of observations used for obtaining these data. These data show that the population of the AAAO is diverse in all of their physical characteristics. This diversity implies that the AAAO come from multiple sources and had different evolutionary histories.

  10. Physical properties of sidewall cores from Decatur, Illinois

    Science.gov (United States)

    Morrow, Carolyn A.; Kaven, Joern; Moore, Diane E.; Lockner, David A.

    2017-10-18

    To better assess the reservoir conditions influencing the induced seismicity hazard near a carbon dioxide sequestration demonstration site in Decatur, Ill., core samples from three deep drill holes were tested to determine a suite of physical properties including bulk density, porosity, permeability, Young’s modulus, Poisson’s ratio, and failure strength. Representative samples of the shale cap rock, the sandstone reservoir, and the Precambrian basement were selected for comparison. Physical properties were strongly dependent on lithology. Bulk density was inversely related to porosity, with the cap rock and basement samples being both least porous (

  11. Prediction of transport and other physical properties of fluids

    CERN Document Server

    Bretsznajder, S

    1971-01-01

    Prediction of Transport and Other Physical Properties of Fluids reviews general methods for predicting the transport and other physical properties of fluids such as gases and liquids. Topics covered range from the theory of corresponding states and methods for estimating the surface tension of liquids to some basic concepts of the kinetic theory of gases. Methods of estimating liquid viscosity based on the principle of additivity are also described. This volume is comprised of eight chapters and opens by presenting basic information on gases and liquids as well as intermolecular forces and con

  12. Physical Properties of Low-Molecular Weight Polydimethylsiloxane Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Christine Cardinal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Graham, Alan [Univ. of Colorado, Denver, CO (United States); Nemer, Martin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Phinney, Leslie M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Garcia, Robert M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Soehnel, Melissa Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stirrup, Emily Kate [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    Physical property measurements including viscosity, density, thermal conductivity, and heat capacity of low-molecular weight polydimethylsiloxane (PDMS) fluids were measured over a wide temperature range (-50°C to 150°C when possible). Properties of blends of 1 cSt and 20 cSt PDMS fluids were also investigated. Uncertainties in the measurements are cited. These measurements will provide greater fidelity predictions of environmental sensing device behavior in hot and cold environments.

  13. Novel Dilute Bismide, Epitaxy, Physical Properties and Device Application

    Directory of Open Access Journals (Sweden)

    Lijuan Wang

    2017-02-01

    Full Text Available Dilute bismide in which a small amount of bismuth is incorporated to host III-Vs is the least studied III-V compound semiconductor and has received steadily increasing attention since 2000. In this paper, we review theoretical predictions of physical properties of bismide alloys, epitaxial growth of bismide thin films and nanostructures, surface, structural, electric, transport and optic properties of various binaries and bismide alloys, and device applications.

  14. Physical properties of charged particle beams for use in radiotherapy

    International Nuclear Information System (INIS)

    Knapp, E.A.

    1975-01-01

    The physical properties of the possible charged particle beams used for cancer radiotherapy are reviewed. Each property is discussed for all interesting particles (π, p, α, Ne ion) and the differences are emphasized. This is followed by a short discussion of the several beam delivery systems used in particle therapy today, emphasizing the differences in the problems for the several different radiations, particularly the differences between the accelerated particle beams and those of a secondary nature. Dose calculation techniques are described

  15. First evidence on phloem transport of nanoscale calcium oxide in groundnut using solution culture technique

    Science.gov (United States)

    Deepa, Manchala; Sudhakar, Palagiri; Nagamadhuri, Kandula Venkata; Balakrishna Reddy, Kota; Giridhara Krishna, Thimmavajjula; Prasad, Tollamadugu Naga Venkata Krishna Vara

    2015-06-01

    Nanoscale materials, whose size typically falls below 100 nm, exhibit novel chemical, physical and biological properties which are different from their bulk counterparts. In the present investigation, we demonstrated that nanoscale calcium oxide particles (n-CaO) could transport through phloem tissue of groundnut unlike the corresponding bulk materials. n-CaO particles are prepared using sol-gel method. The size of the as prepared n-CaO measured (69.9 nm) using transmission electron microscopic technique (TEM). Results of the hydroponics experiment using solution culture technique revealed that foliar application of n-CaO at different concentrations (10, 50, 100, 500, 1,000 ppm) on groundnut plants confirmed the entry of calcium into leaves and stems through phloem compared to bulk source of calcium sprayed (CaO and CaNO3). After spraying of n-CaO, calcium content in roots, shoots and leaves significantly increased. Based on visual scoring of calcium deficiency correction and calcium content in plant parts, we may establish the fact that nanoscale calcium oxide particles (size 69.9 nm) could move through phloem tissue in groundnut. This is the first report on phloem transport of nanoscale calcium oxide particles in plants and this result points to the use of nanoscale calcium oxide particles as calcium source to the plants through foliar application, agricultural crops in particular, as bulk calcium application through foliar nutrition is restricted due to its non-mobility in phloem.

  16. Co-current Doping Effect of Nanoscale Carbon and Aluminum Nitride on Critical Current Density and Flux Pinning Properties of Bulk MgB2 Superconductors

    Science.gov (United States)

    Tripathi, D.; Dey, T. K.

    2018-01-01

    The effect of nanoscale aluminum nitride (n-AlN) and carbon (n-C) co-doping on superconducting properties of polycrystalline bulk MgB2 superconductor has been investigated. Polycrystalline pellets of MgB2 , MgB2 + 0.5 wt% AlN (nano), MgB_{1.99}C_{0.01} and MgB_{1.99}C_{0.01} + 0.5 wt% AlN (nano) have been synthesized by a solid reaction process under inert atmosphere. The transition temperature (TC) estimated from resistivity measurement indicates only a small decrease for C (nano) and co-doped MgB2 samples. The magnetic field response of investigated samples has been measured at 4, 10, and 20 K in the field range ± 6 T. MgB2 pellets co-doped with 0.5 wt% n-AlN and 1 wt% n-C display appreciable enhancement in critical current density (J_C ) of MgB2 in both low (≥ 3 times), as well as, high-field region (≥ 15 times). J_C versus H behavior of both pristine and doped MgB2 pellets is well explained in the light of the collective pinning model. Further, the normalized pinning force density f_p(= F_p/F_{pmax}) displays a fair correspondence with the scaling procedure proposed by Eisterer et al. Moreover, the scaled data of the pinning force density (i.e., f_p{-}h data) of the investigated pellets at different temperature are well interpreted by a modified Dew-Hughes expression reported by Sandu and Chee.

  17. Manipulation of nanoscale phase separation and optical properties of P3HT/PMMA polymer blends for photoluminescent electron beam resist.

    Science.gov (United States)

    Wu, Ming-Chung; Liao, Hsueh-Chung; Chou, Yi; Hsu, Che-Pu; Yen, Wei-Che; Chuang, Chih-Min; Lin, Yun-Yue; Chen, Chun-Wei; Chen, Yang-Fang; Su, Wei-Fang

    2010-08-19

    A novel photoluminescence electron beam resist made from the blend of poly(3-hexylthiophene) (P3HT) and poly(methyl methacrylate) (PMMA) has been successfully developed in this study. In order to optimize the resolution of the electron beam resist, the variations of nanophase separated morphology produced by differing blending ratios were examined carefully. Concave P3HT-rich island-like domains were observed in the thin film of the resist. The size of concave island-like domains decreased from 350 to 100 nm when decreasing the blending ratio of P3HT/PMMA from 1:5 to 1:50 or lower, concurrently accompanied by significant changes in optical properties and morphological behaviors. The lambda(max) of the film absorption is blue-shifted from 520 to 470 nm, and its lambda(max) of photoluminescence (PL) is also shifted from 660 to 550 nm. The radiative lifetime is shorter while the luminescence efficiency is higher when the P3HT/PMMA ratio decreases. These results are attributed to the quantum confinement effect of single P3HT chain isolated in PMMA matrix, which effectively suppresses the energy transfer between the well-separated polymer chains of P3HT. The factors affecting the resolution of the P3HT/PMMA electron beam resists were systematically investigated, including blending ratios and molecular weight. The photoluminescence resist with the best resolution was fabricated by using a molecular weight of 13 500 Da of P3HT and a blending ratio of 1:1000. Furthermore, high-resolution patterns can be obtained on both flat silicon wafers and rough substrates made from 20 nm Au nanoparticles self-assembled on APTMS (3-aminopropyltrimethoxysilane)-coated silicon wafers. Our newly developed electron beam resist provides a simple and convenient approach for the fabrication of nanoscale photoluminescent periodic arrays, which can underpin many optoelectronic applications awaiting future exploration.

  18. Synthesis, characterization, and physical properties of 1D nanostructures

    Science.gov (United States)

    Marley, Peter Mchael

    framework is facilitated by the nanometer-sized dimensions of the materials, which leads to accommodation of strain without amorphization. The topotactic approach demonstrated here indicates not just novel intercalation chemistry accessible at nanoscale dimensions but also suggests a facile synthetic route to ternary vanadium oxide bronzes (MxV2O 5) exhibiting intriguing physical properties that range from electronic phase transitions to charge ordering and superconductivity.

  19. Impacts of land leveling on lowland soil physical properties

    Directory of Open Access Journals (Sweden)

    José Maria Barbat Parfitt

    2014-02-01

    Full Text Available The practice of land leveling alters the soil surface to create a uniform slope to improve land conditions for the application of all agricultural practices. The aims of this study were to evaluate the impacts of land leveling through the magnitudes, variances and spatial distributions of selected soil physical properties of a lowland area in the State of Rio Grande do Sul, Brazil; the relationships between the magnitude of cuts and/or fills and soil physical properties after the leveling process; and evaluation of the effect of leveling on the spatial distribution of the top of the B horizon in relation to the soil surface. In the 0-0.20 m layer, a 100-point geo-referenced grid covering two taxonomic soil classes was used in assessment of the following soil properties: soil particle density (Pd and bulk density (Bd; total porosity (Tp, macroporosity (Macro and microporosity (Micro; available water capacity (AWC; sand, silt, clay, and dispersed clay in water (Disp clay contents; electrical conductivity (EC; and weighted average diameter of aggregates (WAD. Soil depth to the top of the B horizon was also measured before leveling. The overall effect of leveling on selected soil physical properties was evaluated by paired "t" tests. The effect on the variability of each property was evaluated through the homogeneity of variance test. The thematic maps constructed by kriging or by the inverse of the square of the distances were visually analyzed to evaluate the effect of leveling on the spatial distribution of the properties and of the top of the B horizon in relation to the soil surface. Linear regression models were fitted with the aim of evaluating the relationship between soil properties and the magnitude of cuts and fills. Leveling altered the mean value of several soil properties and the agronomic effect was negative. The mean values of Bd and Disp clay increased and Tp, Macro and Micro, WAD, AWC and EC decreased. Spatial distributions of all

  20. Fat properties during homogenization, spray-drying, and storage affect the physical properties of dairy powders.

    Science.gov (United States)

    Vignolles, M L; Lopez, C; Madec, M N; Ehrhardt, J J; Méjean, S; Schuck, P; Jeantet, R

    2009-01-01

    Changes in fat properties were studied before, during, and after the drying process (including during storage) to determine the consequences on powder physical properties. Several methods were combined to characterize changes in fat structure and thermal properties as well as the physical properties of powders. Emulsion droplet size and droplet aggregation depended on the homogenizing pressures and were also affected by spray atomization. Aggregation was usually greater after spray atomization, resulting in greater viscosities. These processes did not have the same consequences on the stability of fat in the powders. The quantification of free fat is a pertinent indicator of fat instability in the powders. Confocal laser scanning microscopy permitted the characterization of the structure of fat in situ in the powders. Powders from unhomogenized emulsions showed greater free fat content. Surface fat was always overrepresented, regardless of the composition and process parameters. Differential scanning calorimetry melting experiments showed that fat was partially crystallized in situ in the powders stored at 20 degrees C, and that it was unstable on a molecular scale. Thermal profiles were also related to the supramolecular structure of fat in the powder particle matrix. Powder physical properties depended on both composition and process conditions. The free fat content seemed to have a greater influence than surface fat on powder physical properties, except for wettability. This study clearly showed that an understanding of fat behavior is essential for controlling and improving the physical properties of fat-filled dairy powders and their overall quality.

  1. Influence of substrate temperature on certain physical properties ...

    Indian Academy of Sciences (India)

    The deposited films were subjected to various characterization studies, to explore certain features like the influence of various deposition temperatures on physical and antibacterial properties. XRD results showed that all the samples exhibited preferential orientation along the (2 2 2) plane. The variation in the crystalline ...

  2. A comparative study of the physical and mechanical properties of ...

    African Journals Online (AJOL)

    This study investigates the compliance of the physical and mechanical properties of granites produced in some parts of Ogun State to relevant codes and standards. The desire to carry out the study was borne by personal on – site experience that single size aggregates produced in some parts of Ogun State do not conform ...

  3. The physical fibre properties of Gonometa postica after degumming ...

    African Journals Online (AJOL)

    The physical properties of the silk fibres that were evaluated in this study included weight loss determination, degumming efficiency and scanning electron microscopy. The results indicated that the weight loss of G. postica fibres ranged from 27 to 41% over a time period of 10 days for the different methods evaluated.

  4. Tillage and manure effect on soil physical and chemical properties ...

    African Journals Online (AJOL)

    ... tillage and liquid manure applications on some physical and chemical properties and also on the carbon and nitrogen mineralization potential from a meadow soil. Our results indicated that tillage and manure applications had no effect on the concentration of Cu, Mn, total N and organic C in the 0 - 15 cm layer of soil after ...

  5. Physical and mechanical properties of saligna eucalyptus grown in Hawaii

    Science.gov (United States)

    C.C. Gerhards

    1965-01-01

    Physical and mechanical properties were determined for saligna eucalyptus (Eucalyptus saligna, Smith) grown in Hawaii. In comparison with wood of the same species grown in Australia, saligna eucalyptus grown in Hawaii was lower in density, shrinkage, and compressive strength parallel to grain; it was about equal in strength in bending and shear; and it was stiffer....

  6. Some Physical And Mechanical Properties Of Uapaca Kirkiana, A ...

    African Journals Online (AJOL)

    Preparation of test samples and laboratory procedure to determine some physical and mechanical properties followed standard methods. Analysis of variance was used to determine the variation between and within trees and regression analysis was used to determine relationship between wood basic density and ...

  7. Effect of Tillage and Mulch Combination on Soil Physical Properties ...

    African Journals Online (AJOL)

    The effect of tillage method and mulching on selected soil physical properties and performance of sorghum (Sorghum bicolor) was studied in rainforest zone of South West Nigeria. Treatments were 4 x 2 factorial combination of tillage methods (zero tillage, manual clearing, heap, ridge), 12t/ha dry plant residue mulch, and ...

  8. Physical, chemical and sensory properties of cookies produced from ...

    African Journals Online (AJOL)

    This study was a result of the need for utilization of local raw materials for food production and diversification as well as an attempt to reduce the rising cost of wheat imports. The objective of this study was to investigate the physical, chemical and sensory properties of cookies produced from sweet potato and mango ...

  9. Molecular clips based on propanediurea : synthesis and physical properties

    NARCIS (Netherlands)

    Jansen, Robertus Johannes

    2002-01-01

    This thesis describes the synthesis and physical properties of a series of molecular clips derived from the concave molecule propanediurea. These molecular clips are cavity-containing receptors that can bind a variety of aromatic guests. This binding is a result of hydrogen bonding and pi-pi

  10. Some physical and mechanical properties of African birch ...

    African Journals Online (AJOL)

    The use of locally manufactured or waste materials in structural buildings without loss of performance is very crucial to the growth of developing countries. This report provides the results of some physical and mechanical property tests carried out on air dried African birch (Anogeissus leiocarpus) timber grown in Nigeria.

  11. Moisture dependent of some physical and morphological properties ...

    African Journals Online (AJOL)

    The static coefficients for friction of dent corn seeds were determined steel, plywood, wood, glass and galvanized sheet at various moisture contents. The highest static coefficient of friction was found on the wood and the lowest on the glass sheet among the materials tested. Key words: Dent corn, physical properties, ...

  12. determination of some physical properties of three groundnut varieties

    African Journals Online (AJOL)

    Dr Obe

    groundnuts. Three varieties of groundnuts namely ICGV-SM-93523, RMP-9 and RMP- 12 were collected and some of the physical properties, such as weight, angle of repose, coefficient of friction, bulk density, size, shape and moisture content were determined. The angle of repose for the three varieties was found to range ...

  13. Physical properties of peats as related to degree of decomposition

    Science.gov (United States)

    D.H. Boelter

    1969-01-01

    Important physical characteristics, such as water retention, water yield coefficient, and hydraulic conductivity, vary greatly for representative northern Minnesota peat materials. The differences are related to the degree of decomposition, which largely determines the porosity and pore size distribution. Fiber content (> 0.1 mm) and bulk density are properties...

  14. Evaluation of the mechanical and physical properties of a posterior ...

    African Journals Online (AJOL)

    To evaluate the mechanical and physical properties of a micro-hybrid resin composite used in adult posterior restorations A micro-hybrid, light curing resin composite Unolux BCS Composite Restorative, (UnoDent, England) was used to restore 74 carious classes I and II cavities on posterior teeth of 62 adult patients.

  15. Tillage Effects on Maize Performance and Physical Properties of a ...

    African Journals Online (AJOL)

    The effects of six tillage methods on soil physical properties maize (Zea mays L.) germination, growth and yield were evaluated in field experiments during 1995 and 1996 cropping seasons. The selected treatments represented both conventional and conservation tillage practices common within the study area. The soil ...

  16. Materials used to simulate physical properties of human skin.

    Science.gov (United States)

    Dąbrowska, A K; Rotaru, G-M; Derler, S; Spano, F; Camenzind, M; Annaheim, S; Stämpfli, R; Schmid, M; Rossi, R M

    2016-02-01

    For many applications in research, material development and testing, physical skin models are preferable to the use of human skin, because more reliable and reproducible results can be obtained. This article gives an overview of materials applied to model physical properties of human skin to encourage multidisciplinary approaches for more realistic testing and improved understanding of skin-material interactions. The literature databases Web of Science, PubMed and Google Scholar were searched using the terms 'skin model', 'skin phantom', 'skin equivalent', 'synthetic skin', 'skin substitute', 'artificial skin', 'skin replica', and 'skin model substrate.' Articles addressing material developments or measurements that include the replication of skin properties or behaviour were analysed. It was found that the most common materials used to simulate skin are liquid suspensions, gelatinous substances, elastomers, epoxy resins, metals and textiles. Nano- and micro-fillers can be incorporated in the skin models to tune their physical properties. While numerous physical skin models have been reported, most developments are research field-specific and based on trial-and-error methods. As the complexity of advanced measurement techniques increases, new interdisciplinary approaches are needed in future to achieve refined models which realistically simulate multiple properties of human skin. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Influence of vermicompost on soil chemical and physical properties ...

    African Journals Online (AJOL)

    In this study, the effects of vermicompost on soil chemical and physical properties was evaluated in tomato (Lycopersicum esculentum var Super Beta) field. The experiment was arranged in a randomized complete block design with four replications. Different amounts of vermicompost (0, 5, 10, 15 t ha-1) were incorporated ...

  18. Physical, chemical and electrochemical properties of pure and doped ceria

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Sammes, N.M.; Tompsett, G.A.

    2000-01-01

    This paper gives an extract of available data on the physical, chemical, electrochemical and mechanical properties of pure and doped ceria, predominantly in the temperature range from 200 to 1000 degrees C. Several areas are pointed out where further research is needed in order to make a better...

  19. Some Physical and Mechanical Properties of Daniellia Ogea Harms ...

    African Journals Online (AJOL)

    Throughout the antediluvian and up to date, humans keep understanding the nature of wood which has been used to meet some bunches of human's demands such as in industry, in framing and in war. This paper presents some physical and mechanical properties of Daniellia ogea (Iya) green timber specie freshly felled ...

  20. Physical and Pasting Properties of 'Ofada' Rice ( Oryza sativa L ...

    African Journals Online (AJOL)

    In this study, grain physical and pasting properties of ofada rice cultivated in South-West Nigeria was evaluated using Standard Evaluation System (SES) for rice with the aim of providing basic information for brand development and utilization of ofada in the development of novel food products. Results showed that size and ...

  1. Proximate Composition, Physical and Sensory Properties of Non ...

    African Journals Online (AJOL)

    Objective: The objective of the study was to investigate the possibility of preparing non-wheat cakes using acha and Bambara nut flour blends and generate base line data on the chemical, physical and sensory properties of the cakes. Materials and methods: Acha grains and Bambara nut seeds were processed into flour ...

  2. Tillage effects on soil. Physical properties and sunflower ...

    African Journals Online (AJOL)

    Soil physical properties and sunflower (Helianthus annuus) yield under convectional tillage (CT) and zero-tillage (Z,TJ. was monitored for 3 consecutive years in Ilorin, Southern Guinea Savannah zone of Nigeria (SGSZN). While bulk density of CT increased slightly over the years, significant decrease of 12 and 8% were ...

  3. Evaluation of physical, functional and pasting properties of ...

    African Journals Online (AJOL)

    The physical, functional and pasting properties of fermented cassava (Manihot esculenta Crantz) flour (lafun) from 10 different sources in Southwest Nigeria were evaluated by standard methods. The fermented flour was collected in polyethylene bags (500 g) each from the processing centers and transferred to the ...

  4. Effects of soil physical properties on erodibility and infiltration ...

    African Journals Online (AJOL)

    This study looked at the physical properties of soil of selected areas of Gidan Kwano campus of Federal University of Technology Minna, Nigeria and their effects on erodibility and infiltration parameters. Infiltration rate of the selected areas were conducted using a double ring infiltrometer and soil samples collected at ...

  5. Tillage and manure effect on soil physical and chemical properties ...

    African Journals Online (AJOL)

    The objective of this work was to study the effects of tillage and liquid manure applications on some physical and chemical properties and also on the carbon and nitrogen mineralization potential from a meadow soil. Our results indicated that tillage and manure applications had no effect on the concentration of Cu, Mn, total ...

  6. Influence of substrate temperature on certain physical properties ...

    Indian Academy of Sciences (India)

    2016-11-12

    Nov 12, 2016 ... influence of various deposition temperatures on physical and antibacterial properties. ... terial agents include metal oxide semiconductors as they are ... This method is found to be simple, cost-effective and can be used to prepare dense films on large areas with better quality. 2. Experimental details for the ...

  7. Proximate Compositions and physical properties of selected maize ...

    African Journals Online (AJOL)

    Physical properties such as germination capacity, hydration capacity, floater test and thousand-grain weight differed significantly (P≤ 0.05) among the selected varieties. The suitability of the maize grain varieties to processing and production of different maize based food products were highlighted. Key words: Maize ...

  8. Investigation of the mechanical and physical properties of greywacke specimens

    Czech Academy of Sciences Publication Activity Database

    Holub, Karel; Konečný, Pavel; Knejzlík, Jaromír

    2009-01-01

    Roč. 46, č. 1 (2009), s. 188-193 ISSN 1365-1609 Institutional research plan: CEZ:AV0Z30860518 Keywords : greywacke * mechanical and physical properties Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.142, year: 2009 www.elsevier.com/locate ijrmms

  9. Tillage Effects on Maize Performance and Physical Properties of a ...

    African Journals Online (AJOL)

    Abstract. The effects of six tillage methods on soil physical properties maize (Zea mays L.) germination, growth and yield were evaluated in field experiments during 1995 and 1996 cropping seasons. The selected treatments represented both conventional and conservation tillage practices common within the study area.

  10. Physical Properties And Maize Production In A Spent Oil ...

    African Journals Online (AJOL)

    Information on the use of plant species and organic nutrients to improve the physical properties of oil-contaminated soil, with a view to making it conducive for crop production, is very important. Three legumes (Gliricidia sepium, Leucenae leucocephala and Calapogonium caeruleam) combined or not with poultry manure ...

  11. Characterization of physical and aerodynamic properties of walnuts

    Science.gov (United States)

    The objective of this research was to study the physical and aerodynamic properties of freshly harvested walnuts. Measurements were carried out for three walnut varieties, Tulare, Howard and Chandler cultivated in California, USA. The nuts treated with and without Ethephon were collected from mechan...

  12. Assessment of physical properties of foods commonly consumed by children

    Directory of Open Access Journals (Sweden)

    G Neeraja

    2018-01-01

    Conclusion: The physical properties and texture of food can be considered to be a risk factor for evaluating the relationship between food retention and dental caries. This information can further be used as an educative tool to parents and caregivers for effective modification of diet.

  13. The physical fibre properties of Gonometa postica after degumming

    African Journals Online (AJOL)

    user

    paste, which is currently in use as a chemical degumming agent. The physical properties of the silk fibres that were evaluated in this study included weight loss determination, degumming efficiency and scanning electron microscopy. The results indicated that the weight loss of G. postica fibres ranged from 27 to 41% over a.

  14. Terrestrial gamma dose rates and physical-chemical properties of ...

    African Journals Online (AJOL)

    It is the purpose of this study to provide a better perspective on the high radioactivity area in Jos Plateau and its implication on farm soil and would seek for any correlation between natural radioactivity and soil physical-chemical properties following the decades of mining activities in the area. To achieve this, soil samples ...

  15. Design, synthesis and physical properties of poly(styrene ...

    Indian Academy of Sciences (India)

    Administrator

    Keywords. Poly(thiourea-azo-sulfone); SBS; electrical conductivity; thermal stability; tensile strength. 1. Introduction. Elastomer blends have been recurrently exploited in various industries to obtain best compromised physical properties including processability. In this regard, styrene– butadiene block copolymers form an ...

  16. Some physical and strength properties of immature Pinus patula ...

    African Journals Online (AJOL)

    A study was conducted to determine physical and strength properties of immature Pinus patula grown in Iringa and Njombe regions of Tanzania. Sample trees aged 5 to 15 years were collected from farmers' woodlots. The trees were categorized into 5 age classes: 5 - 7, 8 - 10, 11 - 12, 13 - 14 and 15 years. Four trees from ...

  17. Physical property characterization of 183-H Basin sludge

    International Nuclear Information System (INIS)

    Biyani, R.K.; Delegard, C.H.

    1995-01-01

    This document describes the characterization of 183-H Basin sludge physical properties, e.g. bulk density of sludge and absorbent, and determination of free liquids. Calcination of crucible-size samples of sludge was also done and the resulting 'loss-on-ignition' was compared to the theoretical weight loss based on sludge analysis obtained from Weston Labs

  18. Investigation of the physical and mechanical properties of Shea Tree ...

    African Journals Online (AJOL)

    Investigation of the physical and mechanical properties of Shea Tree timber ( Vitellaria paradoxa ) used for structural applications in Kwara State, Nigeria. ... strength parallel to grain of 24.7 (N/mm2), compressive strength perpendicular to grain of 8.99 (N/mm2), shear strength of 2.01 (N/mm2), and tensile strength parallel to ...

  19. Using physical properties of molten glass to estimate glass composition

    International Nuclear Information System (INIS)

    Choi, Kwan Sik; Yang, Kyoung Hwa; Park, Jong Kil

    1997-01-01

    A vitrification process is under development in KEPRI for the treatment of low-and medium-level radioactive waste. Although the project is for developing and building Vitrification Pilot Plant in Korea, one of KEPRI's concerns is the quality control of the vitrified glass. This paper discusses a methodology for the estimation of glass composition by on-line measurement of molten glass properties, which could be applied to the plant for real-time quality control of the glass product. By remotely measuring viscosity and density of the molten glass, the glass characteristics such as composition can be estimated and eventually controlled. For this purpose, using the database of glass composition vs. physical properties in isothermal three-component system of SiO 2 -Na 2 O-B 2 O 3 , a software TERNARY has been developed which determines the glass composition by using two known physical properties (e.g. density and viscosity)

  20. Mechanical and physical properties of metakaolin based geopolymer paste

    Directory of Open Access Journals (Sweden)

    Risdanareni Puput

    2017-01-01

    Full Text Available This paper presents the result of studies on utilizing metakaolin obtained from Belitung as fly ash substitute material to produce geopolymer paste. Mechanical properties were assessed by compressive strength while physical properties were assessed by setting time, porosity, microstructure test and density test. The experiment was performed on geopolymer paste with 0, 25%, 50%, 75% and 100% fly ash replacement with metakaolin. Sodium Hidroxide (NaOH with concentration of 10 Molars and Sodium Silicate (Na2SiO3 were used as alkaline activator. In addition, activator ratio between sodium silicate to sodium hidroxide of 2 was applied. The result obtains that increasing metakaolin contain in mixture deliver longer setting time, higher open pore number, lower density and lower compressive strength of geopolymer paste. However, adding metakaolin up to 25 % into geopolymer paste mixture could increase mechanical and physical properties of geopolymer paste.

  1. Pulsed-laser-induced nanoscale island formation in thin metal-on-oxide films

    OpenAIRE

    Henley, SJ; Carey, JD; Silva, SRP

    2005-01-01

    he mechanisms controlling the nanostructuring of thin metal-on-oxide films by nanosecond pulsed excimer lasers are investigated. When permitted by the interfacial energetics, the breakup of the metal film into nanoscale islands is observed. A range of metals (Au, Ag, Mo, Ni, Ti, and Zn) with differing physical and thermodynamic properties, and differing tendencies for oxide formation, are investigated. The nature of the interfacial metal-substrate interaction, the thermal conductivity of the ...

  2. PhySIC: a veto supertree method with desirable properties.

    Science.gov (United States)

    Ranwez, Vincent; Berry, Vincent; Criscuolo, Alexis; Fabre, Pierre-Henri; Guillemot, Sylvain; Scornavacca, Celine; Douzery, Emmanuel J P

    2007-10-01

    This paper focuses on veto supertree methods; i.e., methods that aim at producing a conservative synthesis of the relationships agreed upon by all source trees. We propose desirable properties that a supertree should satisfy in this framework, namely the non-contradiction property (PC) and the induction property (PI). The former requires that the supertree does not contain relationships that contradict one or a combination of the source topologies, whereas the latter requires that all topological information contained in the supertree is present in a source tree or collectively induced by several source trees. We provide simple examples to illustrate their relevance and that allow a comparison with previously advocated properties. We show that these properties can be checked in polynomial time for any given rooted supertree. Moreover, we introduce the PhySIC method (PHYlogenetic Signal with Induction and non-Contradiction). For k input trees spanning a set of n taxa, this method produces a supertree that satisfies the above-mentioned properties in O(kn(3) + n(4)) computing time. The polytomies of the produced supertree are also tagged by labels indicating areas of conflict as well as those with insufficient overlap. As a whole, PhySIC enables the user to quickly summarize consensual information of a set of trees and localize groups of taxa for which the data require consolidation. Lastly, we illustrate the behaviour of PhySIC on primate data sets of various sizes, and propose a supertree covering 95% of all primate extant genera. The PhySIC algorithm is available at http://atgc.lirmm.fr/cgi-bin/PhySIC.

  3. The Effects of Montmorillonite and Cellulose Nanocrystals on Physical Properties of Carboxymethyl Cellulose/Polyvinyl Alcohol Blend Films

    Directory of Open Access Journals (Sweden)

    Leila Abolghasemi Fakhri

    2013-01-01

    Full Text Available Cellulose nanocrystal  CNC is a type of nanomaterial which is produced by  partial hydrolysis of cellulose and elimination of its amorphous regions. CNC has several advantages such as biodegradability and safety toward human health. In this study, CNC was produced from cotton linters and methods such as transmission electron microscopy and atomic force microscopy were used for confrmation of nanoscale  size production of cellulose crystals. Carboxymethyl cellulose  CMC/polyvinyl alcohol  PVA-nanoclay  MMT and CMC-PVA-CNC flms, containing 3-10% (wt/wt CMC nanofllers, were prepared by casting method and their physical properties were compared in order to approve the use of CNC instead of MMT for its contribution in improving the physical properties of carboxymethyl cellulose-based  flms.  The  X-ray  diffraction  results  indicated  the  formation  of  an exfoliated nanostructure at all nanoparticle concentrations. The results showed that there was no signifcant difference (p < 0.5 between the moisture absorption properties of flms containing the two types of nanofller. The flms containing nanoclay showed higher mechanical strength compared to those containing CNC. The ultimate tensile strengths of the flms containing 10% nanoclay and CNC were higher than the control flm (69.72% and 47.05%, respectively.

  4. Frontier in nanoscale flows fractional calculus and analytical methods

    CERN Document Server

    Lewis, Roland; Liu, Hong-yan

    2014-01-01

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

  5. Physical properties of biological entities: an introduction to the ontology of physics for biology.

    Directory of Open Access Journals (Sweden)

    Daniel L Cook

    Full Text Available As biomedical investigators strive to integrate data and analyses across spatiotemporal scales and biomedical domains, they have recognized the benefits of formalizing languages and terminologies via computational ontologies. Although ontologies for biological entities-molecules, cells, organs-are well-established, there are no principled ontologies of physical properties-energies, volumes, flow rates-of those entities. In this paper, we introduce the Ontology of Physics for Biology (OPB, a reference ontology of classical physics designed for annotating biophysical content of growing repositories of biomedical datasets and analytical models. The OPB's semantic framework, traceable to James Clerk Maxwell, encompasses modern theories of system dynamics and thermodynamics, and is implemented as a computational ontology that references available upper ontologies. In this paper we focus on the OPB classes that are designed for annotating physical properties encoded in biomedical datasets and computational models, and we discuss how the OPB framework will facilitate biomedical knowledge integration.

  6. Physical properties of sugar cookies containing chia-oat composites.

    Science.gov (United States)

    Inglett, George E; Chen, Diejun; Liu, Sean

    2014-12-01

    Omega-3 fatty acids of chia seeds (Salvia hispanica L.) and soluble β-glucan of oat products are known for lowering blood cholesterol and preventing coronary heart disease. Nutrim, oat bran concentrate (OBC), and whole oat flour (WOF) were composited with finely ground chia, and used in cookies at 20% replacement of wheat flour for improved nutritional and physical quality. The objective was to evaluate physical properties of chia-oat composites, dough, and cookies. These composites had improved water-holding capacities compared to the starting materials. The geometrical properties and texture properties of the cookies were not greatly influenced by a 20% flour replacement using chia-OBC or chia-WOF composites. There was a decrease in the cookie diameter, and increases in the height of cookies and dough hardness using 20% Chia- Nutrim composite. These fine-particle chia-oat composites were prepared by a feasible procedure for improved nutritional value and physical properties of foods. The cookies containing chia-oat composites can be considered a health-promoting functional food. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  7. Investigations of Physical and Rheological Properties of Aged Rubberised Bitumen

    Directory of Open Access Journals (Sweden)

    Asim Hassan Ali

    2013-01-01

    Full Text Available Several road pavement distresses are related to rheological bitumen properties. Rutting and fatigue cracking are the major distresses that lead to permanent failures in pavement construction. Influence of crumb rubber modifier (CRM on rheological properties of bitumen binder such as improvement of high and intermediate temperatures is investigated in the binder’s fatigue and rutting resistance through physical-rheological changes in this research. The bitumen binders were aged by rolling thin film oven (RTFOT to simulate short-term aging and pressure aging vessel (PAV to simulate long-term aging. The effects of aging on the rheological and physical properties of bitumen binders were studied conducting dynamic shear rheometer test (DSR, Brookfield viscometer test, softening point test, and penetration test. The results showed that the use of rubberised bitumen binder reduces the aging effect on physical and rheological properties of the bitumen binder as illustrated through lower aging index of viscosity, lower aging index of , and an increase in with crumb rubber modifier content increasing, indicating that the crumb rubber might improve the aging resistance of rubberised bitumen binder. In addition, the results showed that the softening point increment ( and penetration aging ratio (PAR of the rubberised bitumen binder decreased significantly due to crumb rubber modification. Furthermore, the higher crumb rubber content, the lower after PAV aging, which led to higher resistance to fatigue cracking bitumen.

  8. Physical Properties of Hanford Transuranic Waste. Final Report

    International Nuclear Information System (INIS)

    Berg, John C.

    2010-01-01

    The research described herein was undertaken to provide needed physical property descriptions of the Hanford transuranic tank sludges under conditions that might exist during retrieval, treatment, packaging and transportation for disposal. The work addressed the development of a fundamental understanding of the types of systems represented by these sludge suspensions through correlation of the macroscopic rheological properties with particle interactions occurring at the colloidal scale in the various liquid media. The results of the work have advanced existing understanding of the sedimentation and aggregation properties of complex colloidal suspensions. Bench scale models were investigated with respect to their structural, colloidal and rheological properties that should be useful for the development and optimization of techniques to process the wastes at various DOE sites.

  9. Physical and Acoustical Properties of Corn Husk Fiber Panels

    Directory of Open Access Journals (Sweden)

    Nasmi Herlina Sari

    2016-01-01

    Full Text Available This research focuses on the development of a sustainable acoustic material comprising natural fibers of corn husk that were alkali modified by 1%, 2%, 5%, and 8% NaOH. The morphology and the acoustical, physical, and mechanical properties of the resulting fibers were experimentally investigated. Five different types of sample were produced in panel form, the acoustical properties of which were studied using a two-microphone impedance tube test. The porosity, tortuosity, and airflow resistivity of each panel were investigated, tensile tests were conducted, and the morphological aspects were evaluated via scanning electron microscopy. The sound absorption and tensile properties of the treated panels were better than those of raw fiber panels; the treated panels were of high airflow resistivity and had low porosity. Scanning electron micrographs of the surfaces of the corn husk fibers revealed that the different sound absorption properties of these panels were due to roughness and the lumen structures.

  10. Ultrasonic evaluation of the physical and mechanical properties of granites.

    Science.gov (United States)

    Vasconcelos, G; Lourenço, P B; Alves, C A S; Pamplona, J

    2008-09-01

    Masonry is the oldest building material that survived until today, being used all over the world and being present in the most impressive historical structures as an evidence of spirit of enterprise of ancient cultures. Conservation, rehabilitation and strengthening of the built heritage and protection of human lives are clear demands of modern societies. In this process, the use of nondestructive methods has become much common in the diagnosis of structural integrity of masonry elements. With respect to the evaluation of the stone condition, the ultrasonic pulse velocity is a simple and economical tool. Thus, the central issue of the present paper concerns the evaluation of the suitability of the ultrasonic pulse velocity method for describing the mechanical and physical properties of granites (range size between 0.1-4.0 mm and 0.3-16.5 mm) and for the assessment of its weathering state. The mechanical properties encompass the compressive and tensile strength and modulus of elasticity, and the physical properties include the density and porosity. For this purpose, measurements of the longitudinal ultrasonic pulse velocity with distinct natural frequency of the transducers were carried out on specimens with different size and shape. A discussion of the factors that induce variations on the ultrasonic velocity is also provided. Additionally, statistical correlations between ultrasonic pulse velocity and mechanical and physical properties of granites are presented and discussed. The major output of the work is the confirmation that ultrasonic pulse velocity can be effectively used as a simple and economical nondestructive method for a preliminary prediction of mechanical and physical properties, as well as a tool for the assessment of the weathering changes of granites that occur during the serviceable life. This is of much interest due to the usual difficulties in removing specimens for mechanical characterization.

  11. Quantum Materials at the Nanoscale - Final Report

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-11

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

  12. Nuclear materials thermo-physical property database and property analysis using the database

    International Nuclear Information System (INIS)

    Jeong, Yeong Seok

    2002-02-01

    It is necessary that thermo-physical properties and understand of nuclear materials for evaluation and analysis to steady and accident states of commercial and research reactor. In this study, development of nuclear materials thermo-properties database and home page. In application of this database, it is analyzed of thermal conductivity, heat capacity, enthalpy, and linear thermal expansion of fuel and cladding material and compared thermo-properties model in nuclear fuel performance evaluation codes with experimental data in database. Results of compare thermo-property model of UO 2 fuel and cladding major performance evaluation code, both are similar

  13. THE PHYSICAL PROPERTIES OF HEARTWOOD AND SAPWOOD OF EUCALYPTUS GRANDIS

    Directory of Open Access Journals (Sweden)

    Bekir Cihad BAL

    2012-12-01

    Full Text Available In this study, some of the physical propertiesof heartwood and sapwood of Eucalyptus grandisgrown in Karabucak, Turkey were determined. Thephysical properties determined were air-drieddensity, oven-dried density, basic density, shrinkage,swelling, fiber saturation point, and maximummoisture content. According to the test results, thephysical properties of the heartwood samplesdiffered from those of the sapwood samples due tothe presence of high proportion of juvenile wood inthe heartwood. It can be said that the shrinkage andswelling percentages were better for heartwood thansapwood. Air-dried density, oven-dried density, andbasic density of sapwood were higher than those ofheartwood.

  14. Physical and performance properties of coal tar urethanes - pipe

    International Nuclear Information System (INIS)

    Hickney, J.; Hendry, M.

    1984-01-01

    The purpose of this paper is to review certain physical properties of coal tar extended urethane coatings designed specifically for use in the pipe coatings market. The blend of coal tar and urethane resins provides a novel finished product with properties cumulatively inherent in its constituents. Typically, coal tar and coal tar pitch offer exceptional water resistance and cathodic alkali resistance when blended with other resins. An example is the standard coal tar epoxies used for many years in the marine markets for shipbottoms

  15. Nanoscale Cobalt-Manganese Oxide Catalyst Supported on Shape-Controlled Cerium Oxide: Effect of Nanointerface Configuration on Structural, Redox, and Catalytic Properties.

    Science.gov (United States)

    Hillary, Brendan; Sudarsanam, Putla; Amin, Mohamad Hassan; Bhargava, Suresh K

    2017-02-28

    Understanding the role of nanointerface structures in supported bimetallic nanoparticles is vital for the rational design of novel high-performance catalysts. This study reports the synthesis, characterization, and the catalytic application of Co-Mn oxide nanoparticles supported on CeO 2 nanocubes with the specific aim of investigating the effect of nanointerfaces in tuning structure-activity properties. High-resolution transmission electron microscopy analysis reveals the formation of different types of Co-Mn nanoalloys with a range of 6 ± 0.5 to 14 ± 0.5 nm on the surface of CeO 2 nanocubes, which are in the range of 15 ± 1.5 to 25 ± 1.5 nm. High concentration of Ce 3+ species are found in Co-Mn/CeO 2 (23.34%) compared with that in Mn/CeO 2 (21.41%), Co/CeO 2 (15.63%), and CeO 2 (11.06%), as evidenced by X-ray photoelectron spectroscopy (XPS) analysis. Nanoscale electron energy loss spectroscopy analysis in combination with XPS studies shows the transformation of Co 2+ to Co 3+ and simultaneously Mn 4+/3+ to Mn 2+ . The Co-Mn/CeO 2 catalyst exhibits the best performance in solvent-free oxidation of benzylamine (89.7% benzylamine conversion) compared with the Co/CeO 2 (29.2% benzylamine conversion) and Mn/CeO 2 (82.6% benzylamine conversion) catalysts for 3 h at 120 °C using air as the oxidant. Irrespective of the catalysts employed, a high selectivity toward the dibenzylimine product (97-98%) was found compared with the benzonitrile product (2-3%). The interplay of redox chemistry of Mn and Co at the nanointerface sites between Co-Mn nanoparticles and CeO 2 nanocubes as well as the abundant structural defects in cerium oxide plays a key role in the efficiency of the Co-Mn/CeO 2 catalyst for the aerobic oxidation of benzylamine.

  16. The effect of water, various incorporations and substitutions on physical and chemical properties of bioapatite and mechanical properties of bone tissue

    Directory of Open Access Journals (Sweden)

    A. S. Avrunin

    2015-01-01

    Full Text Available Basing on scientific publications and original research the authors specified the effect of incorporation and adsorption of different ions and water molecules on physical, chemical and mechanical properties of bioapatite and determined new directions for investigations of intercrystallite interactions in nanoscale. Inner structure of the apatite crystallites more adaptable to chemical substitutions in comparison with other minerals controls their important characteristics such as a size, solubility, hardness, fragility, formability and thermal stability. The water molecules incorporated in crystallites and adsorbed on their surfaces stabilize them. In case the distances between crystallites become shorter than 10 nm the water molecules adsorbed on their surface play dominant role in bonding between the crystallites. This bond determines the main mechanical properties of bones. We bring forward a suggestion that theoretical model developed on the basis of near edge X-ray spectroscopic studies of bones using the contemporary high brilliant sources of X-ray radiation (synchrotrons and X-ray free electrons lasers will allow to receive new quantitative data on local electronic and atomic structure (coordination numbers, ionic charges, interatomic distances interatomic and intercrystallite forces of nanoelements in osseous tissue. The investigation results must bring to construction of new morphologically correct model providing deeper understanding of processes occurring in mineral matrix and mechanical properties of bones.

  17. Investigation of physical imaging properties in various digital radiography systems

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hoi Woun [Dept. of Radiological Science, Baekseok Culture University, Cheonan (Korea, Republic of); Min, Jung Hwan [Dept. of Radiological technology, Shingu University, Seongnam (Korea, Republic of); Yoon, Yong Su [Dept. of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Kyushu (Japan); Kim, Jung Min [Dept. of Health and Environmental Science, College of Health Science, Korea University, Seoul (Korea, Republic of)

    2017-09-15

    We aimed to evaluate the physical imaging properties in various digital radiography systems with charged coupled device (CCD), computed radiography (CR), and indirect flat panel detector (FPD). The imaging properties measured in this study were modulation transfer function (MTF) wiener spectrum (WS), and detective quantum efficiency (DQE) to compare the performance of each digital radiography system. The system response of CCD were in a linear relationship with exposure and that of CR and FPD were proportional to the logarithm of exposure. The MTF of both CR and FPD indicated a similar tendency but in case of CCD, it showed lower MTF than that of CR and FPD. FPD showed the lowest WS and also indicated the highest DQE among three systems. According to the results, digital radiography system with different type of image receptor had its own image characteristics. Therefore, it is important to know the physical imaging characteristics of the digital radiography system accurately to obtain proper image quality.

  18. Cesium Eluate Evaporation Solubility and Physical Property Behavior

    International Nuclear Information System (INIS)

    Pierce, R.A.

    2003-01-01

    The baseline flowsheet for low activity waste (LAW) in the Hanford River Protection Project (RPP) Waste Treatment Plant (WTP) includes pretreatment of supernatant by removing cesium using ion exchange. When the ion exchange column is loaded, the cesium will be eluted with a 0.5M nitric acid (HNO3) solution to allow the column to be conditioned for re-use. The cesium eluate solution will then be concentrated in a vacuum evaporator to minimize storage volume and recycle HNO3. To prevent the formation of solids during storage of the evaporator bottoms, criteria have been set for limiting the concentration of the evaporator product to 80 percent of saturation at 25 degrees C. A fundamental element of predicting evaporator product solubility is to collect data that can be used to estimate key operating parameters. The data must be able to predict evaporator behavior for a range of eluate concentrations that are evaporated to the point of precipitation. Parameters that were selected for modeling include solubility, density, viscosity, thermal conductivity, and heat capacity. Of central importance is identifying the effect of varying feed components on overall solubility. The point of solubility defines the upper limit for eluate evaporation operations and liquid storage. The solubility point also defines those chemical compounds that have the greatest effects on physical properties. Third, solubility behavior identifies intermediate points where physical property data should be measured for the database. Physical property data (density, viscosity, thermal conductivity, and heat capacity) may be an integral part of tracking evaporator operations as they progress toward their end point. Once the data have been collected, statistical design software can develop mathematical equations that estimate solubility and other physical properties

  19. Structural and physical properties of Sm 3 doped magnesium zinc ...

    Indian Academy of Sciences (India)

    Samarium (Sm 3 + ) doped magnesium zinc sulfophosphate glass system of composition ( 60 – x )P 2 O 5 –20MgO–20ZnSO 4 – x Sm 2 O 3 ( x = 0.0 , 0.5, 1.0, 1.5 and 2.0 mol%) were synthesized using melt-quenching technique. The structure and physical properties of prepared glass samples were characterized.

  20. Effects of moisture content on some physical properties of red ...

    African Journals Online (AJOL)

    The physical properties of red pepper seed were evaluated as a function of moisture content. The average length, width and thickness were 4.46, 3.66 and 0.79 mm, respectively, at 7.27% d.b. moisture content. In the moisture range of 7.27 to 20.69% dry basis (d.b.), studies on rewetted red pepper seed showed that the ...

  1. Generalized Spin Coherent States: Construction and Some Physical Properties

    International Nuclear Information System (INIS)

    Berrada, K.; El Baz, M.; Hassouni, Y.

    2009-12-01

    A generalized deformation of the su(2) algebra and a scheme for constructing associated spin coherent states is developed. The problem of resolving the unity operator in terms of these states is addressed and solved for some particular cases. The construction is carried using a deformation of Holstein-Primakoff realization of the su(2) algebra. The physical properties of these states is studied through the calculation of Mandel's parameter. (author)

  2. Physical and functional properties of breakfast cereals from maize ...

    African Journals Online (AJOL)

    The results revealed the following ranges of physical and functional properties; pH (4.70- 6.56), bulk density (0.29 - 0.71g/ml), water absorption capacity (68.31- 76.39%), oil absorption capacity (0.87- 1.32%), foam capacity (2.48- 3.49%), viscosity (19.73-31.08%), gelation temperature (121-157°C), emulsification capacity ...

  3. Some physical and mechanical properties of palm kernel shell (PKS ...

    African Journals Online (AJOL)

    In this study, some of the mechanical and physical properties of palm kernel shells (PKS) were evaluated. These are moisture content, 7.8325 ± 0.6672%; true density, 1.254 ± 5.292 x 10-3 g/cm3; bulk density, 1.1248g/cm3; mean rupture force along width, and thickness were 3174.52 ± 270.70N and 2806.94 ± 498.45N for ...

  4. Some physical properties of spinach ( Spinacia oleracea L.) seed ...

    African Journals Online (AJOL)

    The physical properties of spinach seed were evaluated as a function of moisture content. Average length, width and thickness were 4.03, 3.51 and 2.44 mm, respectively, at 11.93% dry basis (d.b). moisture content. In the moisture range from 11.93 to 21.52% d.b. studies on rewetted spinach seed showed that the thousand ...

  5. Physical Properties and Antibacterial Efficacy of Biodegradable Chitosan Films

    OpenAIRE

    中島, 照夫

    2009-01-01

    [Synopsis] Chitin, chitosan and quaternary chitosan films were prepared, and the physical properties and the antibacterial activities of chitosan and quaternary chitosan films were evaluated. The tensile strength of chitin films was 30~40% lower than that of chitosan films, but the crystallinity of chitin film was much higher than that of chitosan films. The crystallinity and orientation of crystallites were hardly affected by the four kinds of solvent chosen to cast chitosan films, but a de...

  6. Physical and Chemical Properties of Some Selected Rice Varieties ...

    African Journals Online (AJOL)

    Abstract. Physical and chemical properties of nine rice varieties grown and processed in Ebonyi State were studied. Average length and width of the tested varieties ranged between 6.31 and 7.63mm and 2.04 to 2.28mm respectively. All the grains are long grain but, Afikpo mars had the longest grain length of 7.63mm while ...

  7. Nanoscale biophysics of the cell

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2018-01-01

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

  8. Biochar Impacts on Soil Physical Properties and Greenhouse Gas Emissions

    Directory of Open Access Journals (Sweden)

    Rattan Lal

    2013-04-01

    Full Text Available Biochar, a co-product of a controlled pyrolysis process, can be used as a tool for sequestering C in soil to offset greenhouse gas (GHG emissions, and as a soil amendment. Whereas the impacts of biochar application on soil chemical properties are widely known, the research information on soil physical properties is scarce. The objectives of this review are to (i synthesize available data on soil physical properties and GHG emissions, (ii offer possible mechanisms related to the biochar-amended soil processes, and (iii identify researchable priorities. Application rates of 1%–2% (w/w of biochar can significantly improve soil physical quality in terms of bulk density (BD, and water holding capacity (WHC. However, little data are available on surface area (SA, aggregation stability, and penetration resistance (PR of biochar-amended soil. While biochar amendment can initially accentuate the flux of carbon dioxide (CO2, the emission of GHGs may be suppressed over time. A 2-phase complexation hypothesis is proposed regarding the mechanisms of the interaction between soil and biochar.

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

    African Journals Online (AJOL)

    Nanoscale science and nanotechnology is a rapidly growing and multidisciplinary field with its footing in chemistry, physics, molecular biology and engineering. It has led to breakthroughs in energy, environmental science, agriculture, biotechnology and several others. it is also capable of making a positive and significant ...

  10. IAEA NAPRO coordinated research project: physical properties of sodium - 15331

    International Nuclear Information System (INIS)

    Passerini, S.; Gerardi, C.; Grandy, C.; Azpitarte, O.E.; Chocron, M.; Japas, M.L.; Bubelis, E.; Perez-Martin, S.; Jayaraj, S.; Roelofs, F.; Latge, C.; Gerschenfeld, A.; Long, Bin; Selvaraj, P.; Marinenko, E.; Zagorulko, Y.; Ohira, H.; Monti, S.

    2015-01-01

    The International Atomic Energy Agency (IAEA) recently established a CRP on 'Sodium properties and safe operation of experimental facilities in support of the development and deployment of Sodium Cooled Fast Reactors - NAPRO', to be carried out in the period 2013-2017. The first phase of the CRP is focused on the collection and assessment of sodium properties, and it will lead to a consistent property data set which will be published in the form of a handbook. This work is carried out by the 11 participating organizations from 10 Member States through the review and evaluation of the existing available data, the identification of the data gaps and the development of recommendations for experimental programmes to support closing these data gaps. A specific work package (WP 1.1), under the leadership of Argonne National Laboratory, is focused on the analysis of physical properties of sodium: 19 thermodynamic properties (including gaseous state) and 12 transport properties. The expected outcome includes the improved understanding of the availability, accuracy and range of applications of sodium properties centered on fast reactors and other technological applications. The implemented methodology for WP 1.1 (including the division of work among participants and an overall overview of the collected references) is described and so the properties included in WP 1.1 and their classification. Major findings to date related to WP 1.1 are presented in this work, including detailed analysis of two selected properties. The availability of relevant data in principal and out-of-principal references is discussed. Finally, challenges encountered with the collection of references, uncertainty and lack of recent experimental investigation are also listed and adjustments to the methodological approach are proposed as future work. (authors)

  11. Force modulation for enhanced nanoscale electrical sensing

    NARCIS (Netherlands)

    Koelmans, W.W.; Sebastian, A.; Abelmann, Leon; Despont, M.; Pozidis, H.

    2011-01-01

    Scanning probe microscopy employing conductive probes is a powerful tool for the investigation and modification of electrical properties at the nanoscale. Application areas include semiconductor metrology, probe-based data storage and materials research. Conductive probes can also be used to emulate

  12. Nanolithography using nanoscale ridge apertures

    Science.gov (United States)

    Wang, Liang

    transmission enhancement and nanoscale light concentration. Lithographic holes as small as 40 nm x 50 nm and 50 nm x 60 nm for bowtie and C apertures, respectively, has been achieved. To study the properties of nanoscale bowtie apertures, a home-made near-field scanning optical microscope (NSOM) is developed. AFM images of standard calibration samples are used to calibrate the piezoelectric stage and topography resolution. NSOM results of bowtie apertures are also presented to study their transmission enhancement and field localization. Near-field scanning optical microscopy (NSOM) probe integrated with nanometer scale bowtie aperture for enhanced optical transmission is demonstrated. The bowtie-shape aperture allows waveguide propagating mode in the bowtie gap region, which enables simultaneous nanoscale optical resolution and enhanced optical transmission. These unique optical characteristics of bowtie aperture are demonstrated by measuring optical near fields produced by apertures in metal film. It is shown that bowtie aperture probes have one order of magnitude increase in transmission over probes with a regular shape aperture. The imaging results using bowtie aperture are in agreement with those obtained from numerical calculations. Spectroscopic measurements of transmitted field through bowtie shaped nanoscale apertures in visible wavelength region were used to further calibrate the aperture. Resonance in these apertures and its relation with the aperture geometry are investigated. The near-field spectral response is also investigated using Finite Difference Time Domain (FDTD) computation and compared with the spectroscopic measurements. The dependences of the peak wavelength and peak amplitude on the geometry of the bowtie aperture are illustrated. Design rules are proposed to optimize the bowtie aperture for producing a sub-wavelength, high transmission field.

  13. HYDRAULIC AND PHYSICAL PROPERTIES OF SALTSTONE GROUTS AND VAULT CONCRETES

    International Nuclear Information System (INIS)

    Dixon, K.; Harbour, J.; Phifer, M.

    2008-01-01

    The Saltstone Disposal Facility (SDF), located in the Z-Area of the Savannah River Site (SRS), is used for the disposal of low-level radioactive salt solution. The SDF currently contains two vaults: Vault 1 (6 cells) and Vault 4 (12 cells). Additional disposal cells are currently in the design phase. The individual cells of the saltstone facility are filled with saltstone. Saltstone is produced by mixing the low-level radioactive salt solution, with blast furnace slag, fly ash, and cement (dry premix) to form a dense, micro-porous, monolithic, low-level radioactive waste form. The saltstone is pumped into the disposal cells where it subsequently solidifies. Significant effort has been undertaken to accurately model the movement of water and contaminants through the facility. Key to this effort is an accurate understanding of the hydraulic and physical properties of the solidified saltstone. To date, limited testing has been conducted to characterize the saltstone. The primary focus of this task was to estimate the hydraulic and physical properties of three types of saltstone and two vault concretes. The saltstone formulations included saltstone premix batched with (1) Deliquification, Dissolution, and Adjustment (DDA) salt simulant (w/pm 0.60), (2) Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) salt simulant (w/pm 0.60), and (3) Salt Waste Processing Facility (SWPF) salt simulant (w/pm 0.60). The vault concrete formulations tested included the Vault 1/4 concrete and two variations of the Vault 2 concrete (Mix 1 and Mix 2). Wet properties measured for the saltstone formulations included yield stress, plastic viscosity, wet unit weight, bleed water volume, gel time, set time, and heat of hydration. Hydraulic and physical properties measured on the cured saltstone and concrete samples included saturated hydraulic conductivity, moisture retention, compressive strength, porosity, particle density, and dry bulk density. These properties

  14. Nanoscale hierarchical optical interactions for secure information

    Directory of Open Access Journals (Sweden)

    Tate Naoya

    2016-12-01

    Full Text Available There is increasing demand for novel physical security that can differentiate between real and false specific artifact that have been added to bank bills, certifications, and other vouchers. The most simple and effective method for improving the security level is to scale down the elemental structures so that they cannot be duplicated by attackers. While there is a paradox that the achieved fabrication resolution by a defender can also be realized by an attacker, further improvement in security is possible by the functional fusion of artifact metrics and nanophotonics. The fundamental advantages of this concept are the high-level clone resistance and individuality of nanoscale artifacts, which are based on the super-resolution fabrication and nanoscale hierarchical structure of optical near-field interactions, respectively. In this paper, the basis for the fabrication of nanoscale artifacts by utilizing random phenomena is described, and a quantitative evaluation of the security level is presented. An experimental demonstration using a nano-/macro-hierarchical hologram is presented to demonstrate the fundamental procedure for retrieving nanoscale features as hidden information. Finally, the concept and a simple demonstration of non-scanning probe microscopy are described as a practical application of the retrieval and authentication of nanoscale artifact metrics.

  15. Chemical and physical properties of opencast lignite minesoils

    Energy Technology Data Exchange (ETDEWEB)

    Varela, C.; Vazquez, C.; Gonzalez-Sangregorio, M.V.; Leiros, M.C.; Gil-Sotres, F. (Facultad de Farmacia de Santiago de Compostela, Santiago de Compostela (Spain). Dept. de Edafologia y Quimica Agricola)

    1993-09-01

    The evolution of chemical and physical properties in a series of mine soils aged between 0 and 5 years, developed from spoil materials of the Meirama opencast lignite mine in Galicia (NW Spain), was studied. The soils are recovered without use of topsoil and are subject to identical management. In the surface horizon (0-7 cm), total C and N, CEC, and pyrophosphate-extracted Al[sub 2]O[sub 3] and Fe[sub 2]O[sub 3] increased with soil age. Oxalic-oxalate-extracted Al[sub 2]O[sub 3] and Fe[sub 2]O[sub 3] on the other hand, increased with soil age in all the horizons studied. Rapid recovery in terms of physical properties was also observed: bulk density dropped, while total porosity, percentage of macropores, and hydraulic conductivity increased, and aggregates showed greater stability on immersion in water. The results indicate that mineral weathering and organometallic complexation are the dominant processes at these early stages of edaphogenesis and that properties associated with gas exchange showed more rapid development than those associated with water movement. In spite of the above rapid modifications, the characteristics of the oldest soils in the series were still very different from those of native Galician soils.

  16. Variability in soil physical properties in landslide-prone areas

    Directory of Open Access Journals (Sweden)

    Leticia d’Agosto Miguel Fonseca

    2017-01-01

    Full Text Available The present study aimed to evaluate the relationship between the physical properties of the soil and relief in areas that are susceptible to landslides in the sub-basin of the Córrego do Yung, a creek in the urban district Três Moinhos of Juiz de Fora, Minas Gerais. Depth measurements of the solum were made at the soil sampling points, and the subsurface material was collected and analyzed for the two factors of particle size and type of horizon. In the laboratory, we determined the hydraulic conductivity, bulk and particle density, and total porosity, macroporosity and microporosity. The values of the physical properties throughout the sub-basin were predicted and mapped. Thematic maps were generated and showed a relation to each other: the clay was related to a higher hydraulic conductivity, higher porosity and lower soil density. In the steeper areas, the greater silt contents were mapped in the deeper layers and indicated the thin thickness of horizon B in these areas. A close relation of the curvature with the soil thickness was detected and was greater in the flat areas with less slope. The geostatistical analysis showed that the range of values for the properties of macroporosity, microporosity and silt was the lowest in the deeper layers, indicating low structural continuity in potentially erodible areas.

  17. Physical and rheological properties of Titanium Dioxide modified asphalt

    Science.gov (United States)

    Buhari, Rosnawati; Ezree Abdullah, Mohd; Khairul Ahmad, Mohd; Chong, Ai Ling; Haini, Rosli; Khatijah Abu Bakar, Siti

    2018-03-01

    Titanium Dioxide (TiO2) has been known as a useful photocatalytic material that is attributed to the several characteristics includes high photocatalytic activity compared with other metal oxide photocatalysts, compatible with traditional construction materials without changing any original performance. This study investigates the physical and rheological properties of modified asphalt with TiO2. Five samples of asphalt with different concentration of TiO2 were studied, namely asphalt 2%, 4%, 6% 8% and 10% TiO2. The tests includes are penetration, softening point, ductility, rotational viscosity and dynamic shear rheometer (DSR) test. From the results of this study, it is noted that addition of TiO2 has significant effect on the physical properties of asphalt. The viscosity tests revealed that asphalt 10% TiO2 has good workability among with reducing approximately 15°C compared to base asphalt. Based on the results from DSR measurements, asphalt 10% TiO2 has reduced temperature susceptibility and increase stiffness and elastic behaviour in comparison to base asphalt. As a result, TiO2 can be considered to be an additive to modify the properties of asphalt.

  18. Light Emission and Energy Transfer in Nanoscale Semiconductor Photonic Devices

    National Research Council Canada - National Science Library

    Kolbas, Robert

    1997-01-01

    The overall objective of this experimental program is to control the light emission properties and energy transfer mechanisms in nanoscale semiconductor structures in order to realize new or improved photonic devices...

  19. Nanoscale thermal transport: Theoretical method and application

    Science.gov (United States)

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

    2018-03-01

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

  20. Phonon hydrodynamics and its applications in nanoscale heat transport

    Science.gov (United States)

    Guo, Yangyu; Wang, Moran

    2015-09-01

    Phonon hydrodynamics is an effective macroscopic method to study heat transport in dielectric solid and semiconductor. It has a clear and intuitive physical picture, transforming the abstract and ambiguous heat transport process into a concrete and evident process of phonon gas flow. Furthermore, with the aid of the abundant models and methods developed in classical hydrodynamics, phonon hydrodynamics becomes much easier to implement in comparison to the current popular approaches based on the first-principle method and kinetic theories involving complicated computations. Therefore, it is a promising tool for studying micro- and nanoscale heat transport in rapidly developing micro and nano science and technology. However, there still lacks a comprehensive account of the theoretical foundations, development and implementation of this approach. This work represents such an attempt in providing a full landscape, from physical fundamental and kinetic theory of phonons to phonon hydrodynamics in view of descriptions of phonon systems at microscopic, mesoscopic and macroscopic levels. Thus a systematical kinetic framework, summing up so far scattered theoretical models and methods in phonon hydrodynamics as individual cases, is established through a frame of a Chapman-Enskog solution to phonon Boltzmann equation. Then the basic tenets and procedures in implementing phonon hydrodynamics in nanoscale heat transport are presented through a review of its recent wide applications in modeling thermal transport properties of nanostructures. Finally, we discuss some pending questions and perspectives highlighted by a novel concept of generalized phonon hydrodynamics and possible applications in micro/nano phononics, which will shed more light on more profound understanding and credible applications of this new approach in micro- and nanoscale heat transport science.

  1. Nuclear Magnetic Resonance Study of Nanoscale Ionic Materials

    KAUST Repository

    Oommen, Joanna Mary

    2010-08-13

    Nanoscale ionic materials (NIMs) are a new class of nanomaterials that exhibit interesting properties including negligible vapor pressures and tunable physical states, among others. In this study, we analyzed the temperature-wise performance of NIMs using nuclear magnetic resonance (NMR) spectroscopy. NIMs are relatively stable over a temperature range from 300 to 383 K, rendering them usable in high temperature applications. We confirmed the presence of covalent bonds between the SiO2 core and the sulfonate group and determined relative concentrations of aromatic and aliphatic hydrocarbons. These findings serve as first hand proof-of-concept for the usefulness of NMR analyses in further studies on the diffusive properties of NIMs. © 2010 The Electrochemical Society.

  2. PHYSICAL AND MECHANICAL PROPERTIES OF FOUR SALIX SPECIES

    Directory of Open Access Journals (Sweden)

    Silvana Nisgoski

    2012-11-01

    Full Text Available The increasing use of Salix species in the manufacture of various products has been attracting interest towards the Salicaceae family in South America. This paper reports the physical and mechanical parameters of Salix viminalis L. (purple osier, Salix x rubens Schrank (basket willow, Salix purpurea Linné (purple willow and Salix sp., cultivated in the Canoas River Valley, in the Serra Catarinense region of the state of Santa Catarina, Brazil. The evaluations were conducted with raw material, the most commonly used format in handcrafts, and the results indicate there are differences in physical and mechanical properties among the species. Salix viminalis and Salix purpurea were similar in density and in their modulus of elasticity, and had higher values of tensile and strength modulus than Salix x rubens and Salix sp.

  3. Improvement of physical properties of soyabeans by gamma irradiation

    International Nuclear Information System (INIS)

    Byun, M.-W.; Kwon, J.-H.; Mori, Tomohiko

    1993-01-01

    Physical properties of gamma-irradiated soybeans were evaluated at different temperatures by determining water absorption pattern and cooking characteristics of the sample. Irradiation at 2.5-10 kGy caused the reduction of soaking time in soybeans by 2-5 hours and the increase of hydration capacity by 10-20%, respectively, compared to the non-irradiated control at 20 o C. The activation energy for water absorption was lower in irradiated soybeans than in the non-irradiated control. Irradiation at 2.5-10 kGy caused the reduction of cooking time in soybeans by 30-60% compared to the non-irradiated control and the cooking rate constant of irradiated samples was higher about 2 times than that of the non-irradiated control. The irradiation efficacy on physical quality improvement was also recognized in the stored soybeans for one year at room temperature. (author)

  4. Physical properties of W gravities and W strings

    International Nuclear Information System (INIS)

    Das, S.R.; Dhar, A.; Rama, S.K.

    1991-01-01

    This paper investigates some basic physical properties of W gravities and W strings, using a free field realization. The authors argue that the configuration space of W gravities have global characteristics in addition to the Euler characteristic. The authors identify one such global quantity to be a monopole charge and show how this charge appears in the exponents. The free energy would then involve a θ parameter. Using a BRST procedure the authors find all the physical states of W 3 and W 4 gravities, and show that physical operators are nonsingular composites of the screening charge operators. (The latter are not physical operators for N ≥ 3.) For W strings we show how the W constraints lead to the emergence of a single (and not many) extra dimension coming from the W-gravity sector. By analyzing the resulting dispersion relations the authors find that both the lower and upper critical dimensions are lowered compared to ordinary two-dimensional gravity. The pure W gravity spectrum reveals an intriguing numerological connection with unitary minimal models coupled to ordinary gravity

  5. Chemical and physical properties of bone cement for vertebroplasty

    Directory of Open Access Journals (Sweden)

    Po-Liang Lai

    2013-08-01

    Full Text Available Vertebral compression fracture is the most common complication of osteoporosis. It may result in persistent severe pain and limited mobility, and significantly impacts the quality of life. Vertebroplasty involves a percutaneous injection of bone cement into the collapsed vertebrae by fluorescent guide. The most commonly used bone cement in percutaneous vertebroplasty is based on the polymerization of methylmethacrylate monomers to polymethylmethacrylate (PMMA polymers. However, information on the properties of bone cement is mostly published in the biomaterial sciences literature, a source with which the clinical community is generally unfamiliar. This review focuses on the chemistry of bone cement polymerization and the physical properties of PMMA. The effects of altering the portions and contents of monomer liquid and polymer powders on the setting time, polymerization temperature, and compressive strength of the cement are also discussed. This information will allow spine surgeons to manipulate bone cement characteristics for specific clinical applications and improve safety.

  6. Physical properties of coriander seeds at different moisture content

    Science.gov (United States)

    Balasubramanian, S.; Singh, K. K.; Kumar, R.

    2012-10-01

    Physical properties of coriander seeds were determined at moisture content of 3.5-17.7%, d.b. The major axis and 1 000 seeds mass were found to decrease nonlinearly with increase in seed moisture. The medium and minor axes, geometric mean diameter, sphericity, unit volume, surface area and angle of repose increased linearly. Bulk density decreased linearly, however the true density increased non-linearly. The coefficient of static friction increased nonlinearly for different surfaces with increase in moisture level and its maximum was found for plywood surface. The rupture force and energy absorbed decreased linearly with increasing moisture content.

  7. Vanadium Doped Tungsten Oxide Material - Electrical Physical and Sensing Properties

    Directory of Open Access Journals (Sweden)

    Shishkin N. Y.

    2008-05-01

    Full Text Available The electrical physical and sensing (to VOCs and inorganic gases properties of vanadium doped tungsten oxide in the regions of phase transition temperature were investigated. Vanadium oxide (II dimerization was observed in the doped material, corresponding to new phase transition. The extreme sensitivity and selectivity to chemically active gases and vapors in small concentrations: CO, NOx, NH3 acetone, ethanol near phase transitions temperature was found. Sensor elements were manufactured for the quantitative detection (close to 1 ppm of alcohol and ammonia.

  8. Physical and chemical properties of wami tilapia skin gelatin

    Directory of Open Access Journals (Sweden)

    Alexandre Da Trindade Alfaro

    2013-09-01

    Full Text Available Gelatin was extracted from the skin of tilapia (Oreochromis urolepis hornorum and characterized according to its physical and chemical properties. It had pH 4.66, which is slightly higher than the values reported for gelatins processed by acid solubilization. In general, the ionic content was low, and the average yield of the process was 5.10 g/100 g. The proximal composition of the gelatin was similar to that of the commercial gelatins, with slightly higher moisture content. The tilapia skin gelatin had whitish-yellow color and average turbidity of 67 NTU.

  9. Physical and chemical properties of wami tilapia skin gelatin

    OpenAIRE

    Alfaro, Alexandre Da Trindade; Fonseca, Gustavo Graciano; Balbinot, Evellin; Machado, Alessandra; Prentice, Carlos

    2013-01-01

    Gelatin was extracted from the skin of tilapia (Oreochromis urolepis hornorum) and characterized according to its physical and chemical properties. It had pH 4.66, which is slightly higher than the values reported for gelatins processed by acid solubilization. In general, the ionic content was low, and the average yield of the process was 5.10 g/100 g. The proximal composition of the gelatin was similar to that of the commercial gelatins, with slightly higher moisture content. The tilapia ski...

  10. Expressions of the radius and the surface tension of surface of tension in terms of the pressure distribution for nanoscale liquid threads

    International Nuclear Information System (INIS)

    Yan Hong; Wei Jiu-An; Cui Shu-Wen; Zhu Ru-Zeng

    2013-01-01

    The expressions of the radius and the surface tension of surface of tension R s and γ s in terms of the pressure distribution for nanoscale liquid threads are of great importance for molecular dynamics (MD) simulations of the interfacial phenomena of nanoscale fluids; these two basic expressions are derived in this paper. Although these expressions were derived first in the literature [Kim B G, Lee J S, Han M H, and Park S, 2006 Nanoscale and Microscale Thermophysical Engineering, 10, 283] and used widely thereafter, the derivation is wrong both in logical structure and physical thought. In view of the importance of these basic expressions, the logic and physical mistakes appearing in that derivation are pointed out. (condensed matter: structural, mechanical, and thermal properties)

  11. 41 CFR 109-1.5110 - Physical inventories of personal property.

    Science.gov (United States)

    2010-07-01

    ... property records, and with applicable financial control accounts. (j) The results of physical inventories... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Physical inventories of...-INTRODUCTION 1.51-Personal Property Management Standards and Practices § 109-1.5110 Physical inventories of...

  12. 31 CFR 593.204 - Expenses of maintaining blocked physical property; liquidation of blocked account.

    Science.gov (United States)

    2010-07-01

    ... physical property; liquidation of blocked account. 593.204 Section 593.204 Money and Finance: Treasury... maintaining blocked physical property; liquidation of blocked account. (a) Except as otherwise authorized, and... to the maintenance of physical property blocked pursuant to § 593.201(a) shall be the responsibility...

  13. Physical-chemical property based sequence motifs and methods regarding same

    Science.gov (United States)

    Braun, Werner [Friendswood, TX; Mathura, Venkatarajan S [Sarasota, FL; Schein, Catherine H [Friendswood, TX

    2008-09-09

    A data analysis system, program, and/or method, e.g., a data mining/data exploration method, using physical-chemical property motifs. For example, a sequence database may be searched for identifying segments thereof having physical-chemical properties similar to the physical-chemical property motifs.

  14. SIFAT FISIK, KIMIA, DAN FUNGSIONAL DAMAR [Brief Review on: Physical, Chemical and Functional Properties of Dammar

    OpenAIRE

    Noryawati Mulyono1); Anton Apriyantono2)

    2004-01-01

    Dammar is one of Indonesian forestry products which is abundant. It has unique physical, chemical and functional properties. The important physical properties of dammar include its solubility in some organic solvents, softening temperature, viscosity and its absorbance. The important chemical properties reviewed here include its properties as resin, composition of terpenoid compounds present in dammar, and essential oil yielded from distillation of fresh dammar. Physical and chemical properti...

  15. Correlation between some mechanical and physical properties of polycrystalline graphites

    International Nuclear Information System (INIS)

    Yoda, Shinichi; Fujisaki, Katsuo

    1982-01-01

    Mechanical and physical properties of polycrystalline graphites, tensile strength, compressive strength, flexural strength, Young's modulus, thermal expansion coefficient, electrical resistivity, volume fraction of porosity, and graphitisation were measured for ten brand graphites. Correlation between the mechanical and physical properties of the graphites were studied. Young's modulus and thermal expansion coefficient of the graphites depend on volume fraction of porosity. The Young's modulus of the graphites tended to increase with increasing the thermal expansion coefficient. For an anisotropic graphite, an interesting relationship between the Young's modulus E and the thermal expansion coefficient al pha was found in any specimen orientations; alpha E=constant. The value of alphah E was dependent upon the volume fraction of porosity. It should be noted here that the electrical resistivity increased with decreasing grain size. The flexural and the compressive strength were related with the volume fraction of porosity while the tensile strength was not, The relationships between the tensile, the compressive and the flexural strength can be approximately expressed as linear functions over a wide range of the stresses. (author)

  16. Hypoxia alters the physical properties of the tumor microenvironment

    Science.gov (United States)

    Gilkes, Daniele

    Of all the deaths attributed to cancer, 90% are due to metastasis, or the spread of cancer cells from a primary tumor to distant organs, and treatments that prevent or cure metastasis remain elusive. Emerging data indicate that low oxygen states within a tumor, termed hypoxia, can alter the chemical and physical parameters of the extracellular matrix (ECM), or scaffold of the tumor tissue. These changes generate a microenvironment that may be more conducive for promoting metastasis. During tumor evolution, changes in the composition and the overall content of the ECM reflect both its biophysical and biological properties and these strongly influence the cells properties, such as cellular proliferation and cell motility. The talk will cover how hypoxia arises within normal tissue and also in tumors. We will cover the role of hypoxia in collagen biogenesis which influences compositional changes to the tumor microenvironment and discuss how these changes lead to a stiffer tumor stroma. The challenges in determining the influence of chemical versus physical cues on cancer progression will also be considered.

  17. Measuring (bio)physical tree properties using accelerometers

    Science.gov (United States)

    van Emmerik, Tim; Steele-Dunne, Susan; Hut, Rolf; Gentine, Pierre; Selker, John; van de Giesen, Nick

    2017-04-01

    Trees play a crucial role in the water, carbon and nitrogen cycle on local, regional and global scales. Understanding the exchange of heat, water, and CO2 between trees and the atmosphere is important to assess the impact of drought, deforestation and climate change. Unfortunately, ground measurements of tree dynamics are often expensive, or difficult due to challenging environments. We demonstrate the potential of measuring (bio)physical properties of trees using robust and affordable acceleration sensors. Tree sway is dependent on e.g. mass and wind energy absorption of the tree. By measuring tree acceleration we can relate the tree motion to external loads (e.g. precipitation), and tree (bio)physical properties (e.g. mass). Using five months of acceleration data of 19 trees in the Brazilian Amazon, we show that the frequency spectrum of tree sway is related to mass, precipitation, and canopy drag. This presentation aims to show the concept of using accelerometers to measure tree dynamics, and we acknowledge that the presented example applications is not an exhaustive list. Further analyses are the scope of current research, and we hope to inspire others to explore additional applications.

  18. Understanding the physical properties of hybrid perovskites for photovoltaic applications

    Science.gov (United States)

    Huang, Jinsong; Yuan, Yongbo; Shao, Yuchuan; Yan, Yanfa

    2017-07-01

    New photovoltaic materials have been searched for in the past decades for clean and renewable solar energy conversion with an objective of reducing the levelized cost of electricity (that is, the unit price of electricity over the course of the device lifetime). An emerging family of semiconductor materials — organic-inorganic halide perovskites (OIHPs) — are the focus of the photovoltaic research community owing to their use of low cost, nature-abundant raw materials, low-temperature and scalable solution fabrication processes, and, in particular, the very high power conversion efficiencies that have been achieved within the short time of their development. In this Review, we summarize and critically assess the most recent advances in understanding the physical properties of both 3D and low-dimensional OIHPs that favour a small open-circuit voltage deficit and high power conversion efficiency. Several prominent topics in this field on the unique properties of OIHPs are surveyed, including defect physics, ferroelectricity, exciton dissociation processes, carrier recombination lifetime and photon recycling. The impact of ion migration on solar cell efficiency and stability are also critically analysed. Finally, we discuss the remaining challenges in the commercialization of OIHP photovoltaics.

  19. Physical properties of heat-treated rattan waste binderless particleboard

    Science.gov (United States)

    Tajuddin, Maisarah; Ahmad, Zuraida; Halim, Zahurin; Maleque, Md Abd; Ismail, Hanafi; Sarifuddin, Norshahida

    2017-07-01

    The objective of this study is to investigate the effects of heat treatment on the properties of binderless particleboard (BPB) fabricated via hot-pressing process with pressing temperature, pressing time and pressing pressure of 180°C, 5 minutes and 1 MPa, respectively. The fabricated BPB with density in the range of 0.8-0.95g cm-3 was heated in a temperature-controlled laboratory chamber at 80°C, 120°C and 160°C for period of 2 and 8 hours before underwent physical observation, mass loss measurement and thickness swelling test. The samples had remarkable color changes, mainly with samples of treatment temperature of 160˚C, where the color differences were 9.5 and 20.3. This changed the fabricated BPB samples from yellowish brown to dark brown color when treatment conditions increased. Darker color indicates greater mass loss due to severity of chemical component in the powder. Dimensional stability of fabricated BPB was improved with higher treatment temperature as more cellulose cross-linked and hemicellulose degraded that removed the hygroscopicity behavior of powder. These results revealed that heat treatment helped in improving the BPB physical properties, particularly in dimensional stability of boards.

  20. PHYSICAL PROPERTY MEASUREMENTS OF LABORATORY PREPARED SALTSTONE GROUT

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, E.; Cozzi, A.; Edwards, T.

    2014-05-05

    The Saltstone Production Facility (SPF) built two new Saltstone Disposal Units (SDU), SDU 3 and SDU 5, in 2013. The variable frequency drive (VFD) for the grout transfer hose pump tripped due to high current demand by the motor during the initial radioactive saltstone transfer to SDU 5B on 12/5/2013. This was not observed during clean cap processing on July 5, 2013 to SDU 3A, which is a slightly longer distance from the SPF than is SDU 5B. Saltstone Design Authority (SDA) is evaluating the grout pump performance and capabilities to transfer the grout processed in SPF to SDU 3/5. To assist in this evaluation, grout physical properties are required. At this time, there are no rheological data from the actual SPF so the properties of laboratory prepared samples using simulated salt solution or Tank 50 salt solution will be measured. The physical properties of grout prepared in the laboratory with de-ionized water (DI) and salt solutions were obtained at 0.60 and 0.59 water to premix (W/P) ratios, respectively. The yield stress of the DI grout was greater than any salt grout. The plastic viscosity of the DI grout was lower than all of the salt grouts (including salt grout with admixture). When these physical data were used to determine the pressure drop and fluid horsepower for steady state conditions, the salt grouts without admixture addition required a higher pressure drop and higher fluid horsepower to transport. When 0.00076 g Daratard 17/g premix was added, both the pressure drop and fluid horsepower were below that of the DI grout. Higher concentrations of Daratard 17 further reduced the pressure drop and fluid horsepower. The uncertainty in the single point Bingham Plastic parameters is + 4% of the reported values and is the bounding uncertainty. Two different mechanical agitator mixing protocols were followed for the simulant salt grout, one having a total mixing time of three minutes and the other having a time of 10 minutes. The Bingham Plastic parameters

  1. Sensing at the nanoscale

    Science.gov (United States)

    Demming, Anna; Hierold, Christofer

    2013-11-01

    The merits of nanostructures in sensing may seem obvious, yet playing these attributes to their maximum advantage can be a work of genius. As fast as sensing technology is improving, expectations are growing, with demands for cheaper devices with higher sensitivities and an ever increasing range of functionalities and compatibilities. At the same time tough scientific challenges like low power operation, noise and low selectivity are keeping researchers busy. This special issue on sensing at the nanoscale with guest editor Christofer Hierold from ETH Zurich features some of the latest developments in sensing research pushing at the limits of current capabilities. Cheap and easy fabrication is a top priority. Among the most popular nanomaterials in sensing are ZnO nanowires and in this issue Dario Zappa and colleagues at Brescia University in Italy simplify an already cheap and efficient synthesis method, demonstrating ZnO nanowire fabrication directly onto silicon substrates [1]. Meanwhile Nicolae Barson and colleagues in Germany point out the advantages of flame spray pyrolysis fabrication in a topical review [2] and, maximizing on existing resources, researchers in Denmark and Taiwan report cantilever sensing using a US20 commercial DVD-ROM optical pickup unit as the readout source [3]. The sensor is designed to detect physiological concentrations of soluble urokinase plasminogen activator receptor, a protein associated with inflammation due to HIV, cancer and other infectious diseases. With their extreme properties carbon nanostructures feature prominently in the issue, including the demonstration of a versatile and flexible carbon nanotube strain sensor [4] and a graphene charge sensor with sensitivities of the order of 1.3 × 10-3 e Hz-1/2 [5]. The issue of patterning for sensing devices is also tackled by researchers in the US who demonstrate a novel approach for multicomponent pattering metal/metal oxide nanoparticles on graphene [6]. Changes in electrical

  2. Aerosols physical properties at Hada Al Sham, western Saudi Arabia

    Science.gov (United States)

    Lihavainen, H.; Alghamdi, M. A.; Hyvärinen, A.-P.; Hussein, T.; Aaltonen, V.; Abdelmaksoud, A. S.; Al-Jeelani, H.; Almazroui, M.; Almehmadi, F. M.; Al Zawad, F. M.; Hakala, J.; Khoder, M.; Neitola, K.; Petäjä, T.; Shabbaj, I. I.; Hämeri, K.

    2016-06-01

    This is the first time to clearly derive the comprehensive physical properties of aerosols at a rural background area in Saudi Arabia. Aerosol measurements station was established at a rural background area in the Western Saudi Arabia to study the aerosol properties. This study gives overview of the aerosol physical properties (PM10, PM2.5, black carbon and total number concentration) over the measurement period from November 2012 to February 2015. The average PM10 and PM2.5 concentrations were 95 ± 78 μg m-3 (mean ± STD, at ambient conditions) and 33 ± 68 μg m-3 (at ambient conditions), respectively. As expected PM10 concentration was dominated by coarse mode particles (PM10-PM2.5), most probably desert dust. Especially from February to June the coarse mode concentrations were high because of dust storm season. Aerosol mass concentrations had clear diurnal cycle. Lower values were observed around noon. This behavior is caused by wind direction and speed, during night time very calm easterly winds are dominating whereas during daytime the stronger westerly winds are dominating (sea breeze). During the day time the boundary layer is evolving, causing enhanced mixing and dilution leading to lower concentration. PM10 and PM2.5 concentrations were comparable to values measured at close by city of Jeddah. Black carbon concentration was about 2% and 6% of PM10 and PM2.5 mass, respectively. Total number concentration was dominated by frequent new particle formation and particle growth events. The typical diurnal cycle in particle total number concentration was clearly different from PM10 and PM2.5.

  3. Optical and Physical Properties of ONP Deinked Pulp

    Directory of Open Access Journals (Sweden)

    Iman Akbarpoor

    2012-01-01

    Full Text Available Enzymes are protein molecules with complex structures that accelerate the biochemical reactions. Activity of these chemical compounds is accomplished at limited range of pH, temperature and concentration. In this study, the effects of different concentrations of cellulose enzyme were investigated on deinking of old newsprint. Old newsprint (ONP was repulped at 5% consistency for 10 minutes in disintegrator with total revolution number of 26500. Enzymatic treatments of recycled ONP pulp were done under constant conditions (10% consistency,treatment time of 15 minutes, pH range of 5-5.5 at different cellulose concentrations of 0.025, 0.05, 0.1 and 0.2% (based on oven-dry waste paper. The optical and physical properties of the standard paper (60g/m2 made at different concentrations of cellulose were evaluated in comparison with control pulp (untreated ONP pulp with cellulase. Overall, the results achieved by comparison the optical properties of the paper produced indicated that using cellulase in deinking of ONP led to increase the brightness and the yellowness and decrease the opacity. The brightness was improved to a maximum level of 47.5 ISO %, but the yellowness was decreased to a minimum level of 11.3 ISO %, while the brightness reduced and the yellowness increased at higher concentrations than 0.05% cellulase. The highest opacity of 99.3 ISO % was achieved using 0.1% cellulase even higher than control pulp. The results gained by comparison the physical properties of the paper showed that using cellulase resulted in decrease of paper calliper, air resistance and density and improve the freeness of pulp

  4. Physical Properties of Ethyl Methacrylate as a Bolus in Radiotherapy

    Directory of Open Access Journals (Sweden)

    Atousa Montaseri

    2012-03-01

    Full Text Available Introduction Bolus is a soft and resilient material which is used for increasing skin dose or to even out the irregular patient contour. The main property of various materials used presently as bolus is the water-equivalent electron density. Ethyl methacrylate is used as a soft-liner in dentistry and its physical and chemical properties are proved to be nontoxic for human body. The goal of this study was to assess the feasibility of using this material as bolus in radiotherapy and also evaluating some parameters such as mass, electron densities, and transmission factors. Materials and Methods Computed tomography data from the sample material were acquired to assess mass and electron densities with various techniques (mA and kVp. Circular ROIs were delineated on CT DICOM images and densities were calculated using CT numbers. Transmission factors were calculated for 6 and 18 MV. Results Evaluation of our results are evident that showed that mass and electron densities of ethyl methacrylate are similar to those of water and soft tissue. Furthermore, transmission factors are close to those of water. Conclusion According to the results of this study and other properties such as flexibility and harmlessness, it seems that ethyl methacrylate is a suitable material to be used as bolus in radiotherapy.

  5. Physical, chemical, and biological properties of wonder kelp--Laminaria.

    Science.gov (United States)

    Kim, Se-Kwon; Bhatnagar, Ira

    2011-01-01

    Laminaria is a kelp that finds its place in the brown algae family. It has been an area of study for past many years, and its wonderful biological properties have always attracted medical professionals and researchers to explore more and more from this wonder kelp. The constituents of Laminaria include iodine, potassium, magnesium, calcium and iron. Iodine compounds, TEA-hydroiodide in particular, are great lipolytic agents as they stimulate lipase activity. Laminarins on the other hand are used as a tumor angiogenic blocker. This genus of the kelps is also rich in algin, a high molecular weight polysaccharide that forms viscous colloidal solutions or gels in water leading to the use of kelp derivatives as bulk laxatives. It has great applications in cosmeceutical science, as well as some antibacterial properties have also been assigned to Laminaria. A deeper insight into the physical, biological, and chemical properties of this wonder kelp would lead to further exploitation of Laminaria for medicinal and cosmeceutical purpose. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Gamma irradiation influence on physical properties of milk proteins

    International Nuclear Information System (INIS)

    Ciesla, K.; Salmieri, S.; Lacroix, M.; Le Tien, C.

    2004-01-01

    Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and β-sheets, in particular from increase of β-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling

  7. Physical and Mechanical Properties of Briquettes Produced from Energy Plants

    Directory of Open Access Journals (Sweden)

    Oľga Urbanovičová

    2017-01-01

    Full Text Available The study deals with the use of energy crops for the production of thermal energy in the form of briquettes and devising appropriate parameters for their production. Briquettes were produced from seven kinds of energy crops, Salix viminalis, Miscanthus sinensis, Rosa multiflora, Polygonum sachalinensis, Helianthus tuberosus, Sida hermaphrodita and Spartina pectinata, specifically. In the production of briquettes, moisture is the most important properties of material to be pressed, which ranges from 8 to 15 % as it was observed. At a higher humidity it has not been possible to produce briquettes farther in the study conditions. Another important condition for the successful production of briquettes was the particle size of chopped mass. The optimum particle size range from 8 to 20 %. The briquettes were pressed at a pressure of 21 MPa and with diameter of 50 %. Subsequently, physical and mechanical properties (density, moisture, mechanical resistance and chemical properties (chlorine, iron, nitrogen, calcium, ash, lignin content were measured. The briquettes density reached from 800 to 900 kg.m−3 with calorific value from 14 to 19 MJ.kg−1 which refers to fact that energy crops are competitive to fossil fuels by their calorific value.

  8. Computational Studies of Physical Properties of Boron Carbide

    Energy Technology Data Exchange (ETDEWEB)

    Lizhi Ouyang

    2011-09-30

    The overall goal is to provide valuable insight in to the mechanisms and processes that could lead to better engineering the widely used boron carbide which could play an important role in current plight towards greener energy. Carbon distribution in boron carbide, which has been difficult to retrieve from experimental methods, is critical to our understanding of its structure-properties relation. For modeling disorders in boron carbide, we implemented a first principles method based on supercell approach within our G(P,T) package. The supercell approach was applied to boron carbide to determine its carbon distribution. Our results reveal that carbon prefers to occupy the end sites of the 3-atom chain in boron carbide and further carbon atoms will distribute mainly on the equatorial sites with a small percentage on the 3-atom chains and the apex sites. Supercell approach was also applied to study mechanical properties of boron carbide under uniaxial load. We found that uniaxial load can lead to amorphization. Other physical properties of boron carbide were calculated using the G(P,T) package.

  9. Photothermoelastic contrast in nanoscale infrared spectroscopy

    Science.gov (United States)

    Morozovska, Anna N.; Eliseev, Eugene A.; Borodinov, Nikolay; Ovchinnikova, Olga S.; Morozovsky, Nicholas V.; Kalinin, Sergei V.

    2018-01-01

    The contrast formation mechanism in nanoscale Infrared (IR) Spectroscopy is analyzed. The temperature distribution and elastic displacement across the illuminated T-shape boundary between two materials with different IR-radiation absorption coefficients and thermo-physical and elastic properties located on a rigid substrate are calculated self-consistently for different frequencies f ˜ (1 kHz-1 MHz) of IR-radiation modulation (fully coupled problem). Analytical expressions for the temperature and displacement profiles across the "thermo-elastic step" are derived in the decoupling approximation for f = 0 ("static limit"), and conditions for approximation validity at low frequencies of IR-modulation are established. The step height was found to be thickness-independent for thick layers and proportional to the square of the thickness for very thin films. The theoretical results will be of potential interest for applications in the scanning thermo-ionic and thermal infrared microscopies for relatively long sample thermalization times and possibly for photothermal induced resonance microscopy using optomechanical probes.

  10. Investigation of Titanium Sesquioxide Ti2O3: Synthesis and Physical Properties

    KAUST Repository

    Li, Yangyang

    2016-11-08

    Titanium is one of the earth-abundant elements, and its oxides including titanium dioxide (TiO2) and strontium titanium oxide (SrTiO3) are widely used in technologies of electronics, energy conversion, catalysis, sensing, and so on. Generally, the Ti ions in these compounds have a valence of 4+ with the outer shell electron configuration of 3d0. In this thesis, we explore interface and titanite containing Ti3+ ions with 3d1 itinerate electrons, which we believe open new doors towards some new titanite-based technologies. In the first part of this thesis (Chapter 3), we will discuss the nanoscale chemical and valence evolution at a metal/oxide interface: Ti/SrTiO3. In many devices, metal-oxide interfaces are ubiquitous and play important roles in the performance of a wide range of electronic and optoelectronic devices. This motivated us to examine the microscopic structure of the interfaces between strontium titanium oxide and metals. In this work, one unit cell of cubic perovskite Ti2O3 was observed at the Ti/SrTiO3 interface, and oxygen diffusion depth of ~3.2 nm was observed in the sample fabricated at room temperature. Meanwhile, oxygen vacancy domains in the SrTiO3 substrates was observed and characterized by low angle annular dark field (LAADF) imaging and electron energy loss spectra (EELS). In the main part of this thesis, we will focus on the structure and physical properties of Ti2O3, a titanite which has received less attention so far in the research community. Different from TiO2 and SrTiO3, Ti2O3 has a much narrower band-gap (~0.1 eV), and we will discuss some preliminary results of its physical properties and potential applications. In Chapter 4, we will discuss the photothermal application and mid-infrared photodetectors using Ti2O3 nanoparticles based on its ultra-narrow bandgap. Photo-thermal effect via a Ti2O3/membrane structure is further applied to seawater desalination. A high temperature of 70 °C was achieved when this Ti2O3/membrane double

  11. Psychometric properties of the PROMIS Physical Function item bank in patients receiving physical therapy.

    Directory of Open Access Journals (Sweden)

    Martine H P Crins

    Full Text Available The Patient-Reported Outcomes Measurement Information System (PROMIS is a universally applicable set of instruments, including item banks, short forms and computer adaptive tests (CATs, measuring patient-reported health across different patient populations. PROMIS CATs are highly efficient and the use in practice is considered feasible with little administration time, offering standardized and routine patient monitoring. Before an item bank can be used as CAT, the psychometric properties of the item bank have to be examined. Therefore, the objective was to assess the psychometric properties of the Dutch-Flemish PROMIS Physical Function item bank (DF-PROMIS-PF in Dutch patients receiving physical therapy.Cross-sectional study.805 patients >18 years, who received any kind of physical therapy in primary care in the past year, completed the full DF-PROMIS-PF (121 items.Unidimensionality was examined by Confirmatory Factor Analysis and local dependence and monotonicity were evaluated. A Graded Response Model was fitted. Construct validity was examined with correlations between DF-PROMIS-PF T-scores and scores on two legacy instruments (SF-36 Health Survey Physical Functioning scale [SF36-PF10] and the Health Assessment Questionnaire Disability-Index [HAQ-DI]. Reliability (standard errors of theta was assessed.The results for unidimensionality were mixed (scaled CFI = 0.924, TLI = 0.923, RMSEA = 0.045, 1th factor explained 61.5% of variance. Some local dependence was found (8.2% of item pairs. The item bank showed a broad coverage of the physical function construct (threshold-parameters range: -4.28-2.33 and good construct validity (correlation with SF36-PF10 = 0.84 and HAQ-DI = -0.85. Furthermore, the DF-PROMIS-PF showed greater reliability over a broader score-range than the SF36-PF10 and HAQ-DI.The psychometric properties of the DF-PROMIS-PF item bank are sufficient. The DF-PROMIS-PF can now be used as short forms or CAT to measure the level of

  12. CHANGES IN THE PHYSICAL PROPERTIES OF BREAD DURING STORAGE

    Directory of Open Access Journals (Sweden)

    Teresa Fortuna

    2012-04-01

    Full Text Available The aim of this work was to compare the physical properties of breadcrumb during five days of storage in vacuum containers and polyethylene bags. On the basis of result it was stated, that storage of baguettes in vacuum condition and in polyethylene foil did not prevent the staling of breadcrumb. Hardness of breadcrumb stored in plastic bags on the fifth day was higher than hardness of bread stored in vacuum containers. The others texture values did not differ significantly on the fifth day of storage between packaging methods. The changes in water activity values both in vacuum containers and polyethylene bags were negligible during storage. Increase in lightness and decrease in yellowness were observed over the storage period, regardless of packaging method, while the values of a* remained essentially unchanged.doi:10.5219/194

  13. Dynamic simulation of flash drums using rigorous physical property calculations

    Directory of Open Access Journals (Sweden)

    F. M. Gonçalves

    2007-06-01

    Full Text Available The dynamics of flash drums is simulated using a formulation adequate for phase modeling with equations of state (EOS. The energy and mass balances are written as differential equations for the internal energy and the number of moles of each species. The algebraic equations of the model, solved at each time step, are those of a flash with specified internal energy, volume and mole numbers (UVN flash. A new aspect of our dynamic simulations is the use of direct iterations in phase volumes (instead of pressure for solving the algebraic equations. It was also found that an iterative procedure previously suggested in the literature for UVN flashes becomes unreliable close to phase boundaries and a new alternative is proposed. Another unusual aspect of this work is that the model expressions, including the physical properties and their analytical derivatives, were quickly implemented using computer algebra.

  14. Regional dust deposits on Mars: Physical properties, age, and history

    International Nuclear Information System (INIS)

    Christensen, P.R.

    1986-01-01

    Major dust storms on Mars play an important role in the deposition and removal of fine dust material. Thermal, radar, and visual remote sensing observations provide important constraints on the Martian regolith which have been used to determine the location and physical properties of regional dust deposits. These deposits are located in three northern equatorial regions, Tharsis (-20 0 S to 50 0 N, 60 0 to 190 0 W), Arabia (-5 0 S to 30 0 N, 300 0 to 360 0 W), and Elysium (10 0 to 30 0 N, 210 0 to 225 0 W). They are covered by fine (approx.2--40 μm), bright (albedo >0.27) particles, with fewer exposed rocks and coarse deposits than found elsewhere. Dust is currently deposited uniformly throughout the equatorial region at a rate of approx.40 μm/global storm

  15. Physical properties of wild mango fruit and nut

    Science.gov (United States)

    Ehiem, J. C.; Simonyan, K. J.

    2012-02-01

    Physical properties of two wild mango varieties were studied at 81.9 and 24.5% moisture (w.b.) for the fruits and nuts, respectively. The shape and size of the fruit are the same while that of nuts differs at P = 0.05. The mass, density and bulk density of the fruits are statistically different at P = 0.05 but the volume is the same. The shape and size, volume and bulk density of the nuts are statistically the same at P = 0.05. The nuts of both varieties are also the same at P = 0.05 in terms of mass and density. The packing factor for both fruits and nut of the two varieties are the same at 0.95. The relevant data obtained for the two varieties would be useful for design and development of machines and equipment for processing and handling operations.

  16. Study of physical properties of the dynamic filter

    International Nuclear Information System (INIS)

    Souza, Roberto Salomon

    2004-02-01

    This paper presents a characterization of the physical properties of the dynamic filter of Clinac 2300 CD linear accelerator of Varian Medical Systems, installed at the Cancer National Institute (INCA), Rio de Janeiro. The 'dynamic filter factors' were measured for the 6 and 15 MV photons, in squared and rectangular fields, and compared with factors furnished at the accelerator manual and used by the planning system, IN and OUT positions, at the maximum dose depths, 5 cm, 10 cm and 29 cm, for the 6 and 15 MV photons energies. The results demonstrated that the 'dynamic filter factors' does not changes with depth and the PDP for the opened field are the same for the fields with dynamic filters. Last but not least the dynamic filters were measured and compared with the nominal angles of the accelerator and the planning system, where some discrepancies were reported

  17. Influence of physical properties of soil on 137 Cs mobility

    International Nuclear Information System (INIS)

    Kanapickas, A.; Paulaitiene, I.; Mazeika, J.; Bauziene, I.

    2005-01-01

    A model to account for the mobility of radiocesium in soil is presented. The model requires a minimal set of coefficients that describe radiocesium migration and fixation rates, which can be related to physical soil properties. The peculiarities of experimental radiocesium profiles in soil are explained by the composition of soil, which affects the radiocesium fixation rate. It is shown that the migration of radiocesium in soil is governed by vertical convection of a mobile form, whereas diffusion is a slower process due to strong fixation. The results show that the velocity of vertical migration downward of mobile radiocesium can be set constant, because the overall migration rate depends on fixation. Modeling of experimental radiocesium soil profiles suggests that organic (humic) layers with reduced mineral content and humidity have a high radiocesium fixation rate. Soil structure that maintains high soil humidity and mineral content has an increased cesium exchangeability and. consequently, higher radiocesium mobility. (author)

  18. Maximum Likelihood Blood Velocity Estimator Incorporating Properties of Flow Physics

    DEFF Research Database (Denmark)

    Schlaikjer, Malene; Jensen, Jørgen Arendt

    2004-01-01

    )-data under investigation. The flow physic properties are exploited in the second term, as the range of velocity values investigated in the cross-correlation analysis are compared to the velocity estimates in the temporal and spatial neighborhood of the signal segment under investigation. The new estimator...... has been compared to the cross-correlation (CC) estimator and the previously developed maximum likelihood estimator (MLE). The results show that the CMLE can handle a larger velocity search range and is capable of estimating even low velocity levels from tissue motion. The CC and the MLE produce...... for the CC and the MLE. When the velocity search range is set to twice the limit of the CC and the MLE, the number of incorrect velocity estimates are 0, 19.1, and 7.2% for the CMLE, CC, and MLE, respectively. The ability to handle a larger search range and estimating low velocity levels was confirmed...

  19. Study of chemical and physical properties of synthetic carbonaceous materials

    Energy Technology Data Exchange (ETDEWEB)

    Kaloc, M.; Lesko, J.; Martineg, P.; Rojak, A.; Roubicek, V.; Weiss, Z.

    1980-01-01

    Results are presented of studying the chemical and physical properties of 17 samples of synthetic carbonaceous materials (''carbons'') of different origin and with different degree of thermal treatment, and for comparison two samples of natural graphite were tested. For all the samples an analysis was made of the element composition and they were studied by the methods DTA, TGA, IR-spectrometry, x-ray analysis and electron screen microscopy. The studies indicated that proper combination of these methods can provide a high quality evaluation of the initial materials and the processes of their processing, and also the attained carbonaceous materials from the viewpoint of using them in the modern sectors of technology: electrical metallurgy, electrical chemistry and electrothermal production, nuclear technology, production of semiconductor materials, etc.

  20. Nanoscale surface photovoltage of organic semiconductors with two pass Kelvin probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Escasain, E; Colchero, J; Palacios-Lidon, E [Departamento Fisica, Facultad de Quimica (Campus Espinardo), Universidad de Murcia, E-30100 Murcia (Spain); Lopez-Elvira, E; Baro, A M, E-mail: elisapl@um.es [Instituto de Ciencia de Materiales de Madrid-CSIC, Campus de Cantoblanco, E-28049, Madrid (Spain)

    2011-09-16

    Kelvin probe microscopy implemented with controlled sample illumination is used to study nanoscale surface photovoltage effects. With this objective a two trace method, where each scanning line is measured with and without external illumination, is proposed. This methodology allows a direct comparison of the contact potential images acquired in darkness and under illumination and, therefore, the surface photovoltage is simply inferred. Combined with an appropriate data analysis, the temporal and spatial evolution of reversible and irreversible photo-induced processes can be obtained. The potential and versatility of this technique is applied to MEH-PPV thin films. Photo-physical phenomena such as the mesoscale polymer electronic light-induced response as well as the local nanoscale electro-optical properties are studied.

  1. Introduction to the physics of nanoelectronics

    CERN Document Server

    Jalil, M B A

    2012-01-01

    Offers an introduction to the physics of nanoelectronics, that encompasses spintronics, electronics, Hall effects, single electronics, carbon and graphene electronics. In this title, the spin hall effect is explained and its application to the emerging field of spintronics, where an electron's spin as well as its charge is utilised, is discussed.$bThis book provides an introduction to the physics of nanoelectronics, with a focus on the theoretical aspects of nanoscale devices. The book begins with an overview of the mathematics and quantum mechanics pertaining to nanoscale electronics, to facilitate the understanding of subsequent chapters. It goes on to encompass quantum electronics, spintronics, Hall effects, carbon and graphene electronics, and topological physics in nanoscale devices. Theoretical methodology is developed using quantum mechanical and non-equilibrium Green's function (NEGF) techniques to calculate electronic currents and elucidate their transport properties at the atomic scale. The spin Hal...

  2. Nanoscale Vacuum Channel Transistor.

    Science.gov (United States)

    Han, Jin-Woo; Moon, Dong-Il; Meyyappan, M

    2017-04-12

    Vacuum tubes that sparked the electronics era had given way to semiconductor transistors. Despite their faster operation and better immunity to noise and radiation compared to the transistors, the vacuum device technology became extinct due to the high power consumption, integration difficulties, and short lifetime of the vacuum tubes. We combine the best of vacuum tubes and modern silicon nanofabrication technology here. The surround gate nanoscale vacuum channel transistor consists of sharp source and drain electrodes separated by sub-50 nm vacuum channel with a source to gate distance of 10 nm. This transistor performs at a low voltage (3 microamperes). The nanoscale vacuum channel transistor can be a possible alternative to semiconductor transistors beyond Moore's law.

  3. Nanoscale hotspots due to nonequilibrium thermal transport

    International Nuclear Information System (INIS)

    Sinha, Sanjiv; Goodson, Kenneth E.

    2004-01-01

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

  4. Nanoscale Organic Hybrid Electrolytes

    KAUST Repository

    Nugent, Jennifer L.

    2010-08-20

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

  5. Physical properties and chemical composition of Segamat Kaolin, Johor, Malaysia

    International Nuclear Information System (INIS)

    Umar Hamzah; Learn, K.K.; Sahibin Rahim

    2010-01-01

    Kaolin is a source of secondary mineral as a product of a weathering process of primary minerals. Its main component is fine grain kaolinite (< 2 μm) and it also contains other elements such as aluminium and iron phyllosilicate as the pigment. Aluminium rich kaolin is light in colour with high plasticity and is normally used in the ceramic, plastic, paint, paper, pesticide, pharmacology and cosmetic industries. The physical and chemical characteristics of kaolins are important for its potential application. In this study, about 25 kaolin samples were hand-augered from depths of 1-2 m at Buloh Kasap Segamat, Johor, Malaysia. Chemical analysis carried out included determination of oxides and types of minerals by X-ray diffraction and X-ray fluorescence. Shrinkage rate, rupture modulus and water absorption rate tests were carried out in the physical properties analysis. Plastic and liquid limits of the kaolin were also measured for plastic index. The Segamat kaolin was light in colour due to its high silicate composition. The highest mineral content in the kaolin was kaolinite and quartz occurred as impurities. The low shrinkage rate showed that the kaolin was dense with little voids, hence very suitable for use in the ceramic industry. This kaolin has low water absorption, plasticity and durable according to the rupture modulus test. (author)

  6. Measurement of the physical properties of the snowpack

    Science.gov (United States)

    Kinar, N. J.; Pomeroy, J. W.

    2015-06-01

    This paper reviews measurement techniques and corresponding devices used to determine the physical properties of the seasonal snowpack from distances close to the ground surface. The review is placed in the context of the need for scientific observations of snowpack variables that provide inputs for predictive hydrological models that help to advance scientific understanding of geophysical processes related to snow in the near-surface cryosphere. Many of these devices used to measure snow are invasive and require the snowpack to be disrupted, thereby precluding the possibility for multiple measurements to be made at the same sampling location. Moreover, many devices rely on the use of empirical calibration equations that may not be valid at all geographic locations. The spatial density of observations with most snow measurement devices is often inadequate. There is a need for improved automation of snowpack measurement instrumentation with an emphasis on field-based feedback of measurement validity in lieu of postprocessing of samples or data at a lab or office location. The scientific future of snow measurement instrumentation thereby requires a synthesis between science and engineering principles that takes into consideration geophysics and the physics of device operation.

  7. Physical Properties of Intermetallic FE2VA1

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ye [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Fe2VAl has recently been discovered to have a negative temperature coefficient of resistivity, moderately enhanced specific heat coefficient, and a large DOS at the Fermi level by photoemission. This triggered a round of heated research to understand the ground state of this material, both theoretically and experimentally. here they report a comprehensive characterization of Fe2VAl. X-ray diffraction exhibited appreciable antisite disorder in all of our samples. FTIR spectroscopy measurements showed that the carrier density and scattering time had little sample-to-sample variation or temperature dependence for near-stoichiometric samples. FTIR and DC resistivity suggest that the transport properties of Fe2VAl are influenced by both localized and delocalized carriers, with the former primarily responsible for the negative temperature coefficient of resistivity. Magnetization measurements reveal that near-stoichiometric samples have superparamagnetic clusters with at least two sizes of moments. X-ray photoemission from Fe core level showed localized magnetic moments on site-exchanged Fe. They conclude that in Fe2VAl, antisite disorder causes significant modification to the semi-metallic band structure proposed by LDA calculations. With antisite disorder considered, they are now able to explain most of the physical properties of Fe2VAl.

  8. Influence of the Soil Genesis on Physical and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Marian Marschalko

    2013-01-01

    Full Text Available The paper deals with the influence of soil genesis on the physical-mechanical properties. The presented case study was conducted in the region of the Ostrava Basin where there is a varied genetic composition of the Quaternary geological structure on the underlying Neogeneous sediments which are sediments of analogous granulometry but different genesis. In this study, 7827 soil samples of an eolian, fluvial, glacial, and deluvial origin and their laboratory analyses results were used. The study identified different values in certain cases, mostly in coarser-grained foundation soils, such as sandy loam S4 (MS and clayey sand F4 (CS. The soils of the fluvial origin manifest different values than other genetic types. Next, based on regression analyses, dependence was proved neither on the deposition depth (depth of samples nor from the point of view of the individual foundation soil classes or the genetic types. The contribution of the paper is to point at the influence of genesis on the foundation soil properties so that engineering geologists and geotechnicians pay more attention to the genesis during engineering-geological and geotechnical investigations.

  9. Physical Properties of Intermetallic FE2VA1

    International Nuclear Information System (INIS)

    Ye Feng

    2002-01-01

    Fe 2 VAl has recently been discovered to have a negative temperature coefficient of resistivity, moderately enhanced specific heat coefficient, and a large DOS at the Fermi level by photoemission. This triggered a round of heated research to understand the ground state of this material, both theoretically and experimentally. here they report a comprehensive characterization of Fe 2 VAl. X-ray diffraction exhibited appreciable antisite disorder in all of our samples. FTIR spectroscopy measurements showed that the carrier density and scattering time had little sample-to-sample variation or temperature dependence for near-stoichiometric samples. FTIR and DC resistivity suggest that the transport properties of Fe 2 VAl are influenced by both localized and delocalized carriers, with the former primarily responsible for the negative temperature coefficient of resistivity. Magnetization measurements reveal that near-stoichiometric samples have superparamagnetic clusters with at least two sizes of moments. X-ray photoemission from Fe core level showed localized magnetic moments on site-exchanged Fe. They conclude that in Fe 2 VAl, antisite disorder causes significant modification to the semi-metallic band structure proposed by LDA calculations. With antisite disorder considered, they are now able to explain most of the physical properties of Fe 2 VAl

  10. Effect of Ultrasonication on Physical Properties of Mineral Trioxide Aggregate

    Directory of Open Access Journals (Sweden)

    Peter Parashos

    2014-01-01

    Full Text Available Aim. To evaluate the effect on physical properties of Mineral Trioxide Aggregate (MTA of using direct hand compaction during placement and when using hand compaction with indirect ultrasonic activation with different application times. Methods. One hundred acrylic canals were obturated in 3 increments with MTA in sample sizes of 10. One group was obturated by hand with an endodontic plugger and the remainder obturated with indirect ultrasonic application, with times ranging from 2 seconds to 18 seconds per increment. Microhardness values, dye penetration depths, and radiographs of the samples were evaluated. Results. As ultrasonic application time per increment increased, microhardness values fell significantly (P<0.001 while dye penetration values increased (P<0.001. Microhardness of MTA ultrasonicated for 2 seconds was significantly higher than hand compaction (P=0.03. Most radiographic voids were visible in the hand-compacted group (P<0.001, which also had higher dye penetration depths than the 2-second ultrasonicated samples. Ultrasonication of MTA for 10–18 seconds resulted in significantly more voids than 2–8 seconds of ultrasonication (P=0.02. Conclusion. The use of ultrasonics with MTA improved the compaction and flow of MTA, but excessive ultrasonication adversely affected MTA properties. A time of 2 seconds of ultrasonication per increment presented the best compromise between microhardness values, dye penetration depths, and lack of radiographic voids.

  11. Structural and Physical Properties of Ionic Liquid Mixtures

    Science.gov (United States)

    Cha, Seoncheol; Kim, Doseok

    Ionic liquids are the materials consisting of only cations and anions and existing at liquid phase below 100 °C. They are called designer solven as the physical properties of the materials can be tuned by changing their constituent ions. Mixing ionic liquids is a new way of maximizing this advantage because the material properties can be changed continuously in the mixture. The excess molar volumes, a difference between the molar volumes of the mixtures and a linear interpolation between the volumes of pure components, have been found to differ significantly for some ionic liquid mixtures, but the origin of this difference is not well understood. The different microstructures of the mixtures, which can range from a simple mixture of two different consisting ionic liquids to a different structure from those of pure materials, have been suggested as the origin of this difference. We investigated ionic liquid mixture systems by IR spectroscopy by utilizing a particular peak in the IR spectrum for the moiety participating in the hydrogen bonding (νC(2)-H) that changes sensitively with the change of the anion in the ionic liquid. The absorbance of νC(2)-H changed proportionally to the composition for the mixtures consisting of halide anion. By contrast, the absorbance changed nonlinearly for the mixtures of which one of the anion had multiple interaction sites

  12. Physical and structural properties of polyaniline/microcrystalline cellulose nanocomposite

    Science.gov (United States)

    Abdi, Mahnaz M.; Liyana, Rawaida; Tahir, Paridah Md; Heng, Lee Yook; Sulaiman, Yusran; Waheeda, Nur Farhana; Hassan, Nabihah Abu

    2017-12-01

    A composite of Polyaniline/Microcrystalline Cellulose (PAni/MCC) was prepared via a chemical polymerization method in the presence of ammonium persulfate (NH4)2S2O8 as oxidant and cetyltrimethylammonium bromide (CTAB) as a cationic surfactant. The results of FESEM showed that the morphology of nanocomposite depends on the monomer concentration. Wire-like and porous nanostructure was observed for PAni/MCC/CTAB composite that could be suitable for enzyme immobilization and sensor applications. The electrochemical properties of the composites were studied using Cyclic Voltammetry (CV) and it was shown that PAni/MCC/CTAB composite generated a higher current response compared to the pure PAni. The synergy effect of MCC and CTAB on the physical and electrochemical properties of composite resulted in higher electron transferring in PAni/MCC/CTAB. The presence of significant peaks of PAni and MCC in FT-IR spectrum of nanocomposite indicating polymerization of aniline on the surface of MCC. Characteristic peaks of crystalline cellulose were observed at 22.8 and 14.7 2theta in XRD pattern.

  13. Enhanced nanoscale friction on fluorinated graphene.

    Science.gov (United States)

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

    2012-12-12

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

  14. Recovering physical properties from narrow-band photometry

    Science.gov (United States)

    Schoenell, W.; Cid Fernandes, R.; Benítez, N.; Vale Asari, N.

    2013-05-01

    Our aim in this work is to answer, using simulated narrow-band photometry data, the following general question: What can we learn about galaxies from these new generation cosmological surveys? For instance, can we estimate stellar age and metallicity distributions? Can we separate star-forming galaxies from AGN? Can we measure emission lines, nebular abundances and extinction? With what precision? To accomplish this, we selected a sample of about 300k galaxies with good S/N from the SDSS and divided them in two groups: 200k objects and a template library of 100k. We corrected the spectra to z = 0 and converted them to filter fluxes. Using a statistical approach, we calculated a Probability Distribution Function (PDF) for each property of each object and the library. Since we have the properties of all the data from the STARLIGHT-SDSS database, we could compare them with the results obtained from summaries of the PDF (mean, median, etc). Our results shows that we retrieve the weighted average of the log of the galaxy age with a good error margin (σ ≈ 0.1 - 0.2 dex), and similarly for the physical properties such as mass-to-light ratio, mean stellar metallicity, etc. Furthermore, our main result is that we can derive emission line intensities and ratios with similar precision. This makes this method unique in comparison to the other methods on the market to analyze photometry data and shows that, from the point of view of galaxy studies, future photometric surveys will be much more useful than anticipated.

  15. Symposium GC: Nanoscale Charge Transport in Excitonic Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Bommisetty, Venkat [Univ. of South Dakota, Vermillion, SD (United States)

    2011-06-23

    This paper provides a summary only and table of contents of the sessions. Excitonic solar cells, including all-organic, hybrid organic-inorganic and dye-sensitized solar cells (DSSCs), offer strong potential for inexpensive and large-area solar energy conversion. Unlike traditional inorganic semiconductor solar cells, where all the charge generation and collection processes are well understood, these excitonic solar cells contain extremely disordered structures with complex interfaces which results in large variations in nanoscale electronic properties and has a strong influence on carrier generation, transport, dissociation and collection. Detailed understanding of these processes is important for fabrication of highly efficient solar cells. Efforts to improve efficiency are underway at a large number of research groups throughout the world focused on inorganic and organic semiconductors, photonics, photophysics, charge transport, nanoscience, ultrafast spectroscopy, photonics, semiconductor processing, device physics, device structures, interface structure etc. Rapid progress in this multidisciplinary area requires strong synergetic efforts among researchers from diverse backgrounds. Such effort can lead to novel methods for development of new materials with improved photon harvesting and interfacial treatments for improved carrier transport, process optimization to yield ordered nanoscale morphologies with well defined electronic structures.

  16. Physical properties of dense, low-temperature plasmas

    International Nuclear Information System (INIS)

    Redmer, R.

    1997-01-01

    Plasmas occur in a wide range of the density-temperature plane. The physical quantities can be expressed by Green's functions which are evaluated by means of standard quantum statistical methods. The influences of many-particle effects such as dynamic screening and self-energy, structure factor and local-field corrections, formation and decay of bound states, degeneracy and Pauli exclusion principle are studied. As a basic concept for partially ionized plasmas, a cluster decomposition is performed for the self-energy as well as for the polarization function. The general model of a partially ionized plasma interpolates between low-density, nonmetallic systems such as atomic vapors and high-density, conducting systems such as metals or fully ionized plasmas. The equations of state, including the location of the critical point and the shape of the coexistence curve, are determined for expanded alkali-atom and mercury fluids. The occurrence of a metal-nonmetal transition near the critical point of the liquid-vapor phase transition leads in these materials to characteristic deviations from the behavior of nonconducting fluids such as the inert gases. Therefore, a unified approach is needed to describe the drastic changes of the electronic properties as well as the variation of the physical properties with the density. Similar results are obtained for the hypothetical plasma phase transition in hydrogen plasma. The transport coefficients (electrical and thermal conductivity, thermopower) are studied wthin linear response theory given here in the formulation of Zubarev which is valid for arbitrary degeneracy and yields the transport coefficients for the limiting cases of nondegenerate, weakly coupled plasmas (Spitzer theory) as well as degenerate, strongly coupled plasmas (Ziman theory). mercury within the MHNC scheme via effective ion-ion potentials which are derived from the polarization function within an extended RPA. The optical properties of dense plasmas, the shift

  17. Physical characterization of functionalized spider silk: electronic and sensing properties

    Directory of Open Access Journals (Sweden)

    Eden Steven, Jin Gyu Park, Anant Paravastu, Elsa Branco Lopes, James S Brooks, Ongi Englander, Theo Siegrist, Papatya Kaner and Rufina G Alamo

    2011-01-01

    Full Text Available This work explores functional, fundamental and applied aspects of naturally harvested spider silk fibers. Natural silk is a protein polymer where different amino acids control the physical properties of fibroin bundles, producing, for example, combinations of β-sheet (crystalline and amorphous (helical structural regions. This complexity presents opportunities for functional modification to obtain new types of material properties. Electrical conductivity is the starting point of this investigation, where the insulating nature of neat silk under ambient conditions is described first. Modification of the conductivity by humidity, exposure to polar solvents, iodine doping, pyrolization and deposition of a thin metallic film are explored next. The conductivity increases exponentially with relative humidity and/or solvent, whereas only an incremental increase occurs after iodine doping. In contrast, iodine doping, optimal at 70 °C, has a strong effect on the morphology of silk bundles (increasing their size, on the process of pyrolization (suppressing mass loss rates and on the resulting carbonized fiber structure (that becomes more robust against bending and strain. The effects of iodine doping and other functional parameters (vacuum and thin film coating motivated an investigation with magic angle spinning nuclear magnetic resonance (MAS-NMR to monitor doping-induced changes in the amino acid-protein backbone signature. MAS-NMR revealed a moderate effect of iodine on the helical and β-sheet structures, and a lesser effect of gold sputtering. The effects of iodine doping were further probed by Fourier transform infrared (FTIR spectroscopy, revealing a partial transformation of β-sheet-to-amorphous constituency. A model is proposed, based on the findings from the MAS-NMR and FTIR, which involves iodine-induced changes in the silk fibroin bundle environment that can account for the altered physical properties. Finally, proof

  18. Effect of film properties for non-linear DPL model in a nanoscale MOSFET with high-k material: ZrO2/HfO2/La2O3

    Science.gov (United States)

    Shomali, Zahra; Ghazanfarian, Jafar; Abbassi, Abbas

    2015-07-01

    Numerical simulation of non-linear non-Fourier heat conduction within a nano-scale metal-oxide-semiconductor field-effect transistor (MOSFET) is presented under the framework of Dual-Phase-Lag model including the boundary phonon scattering. The MOSFET is modeled in four cases of: (I) thin silicon slab, (II) including uniform heat generation, (III) double-layered buried oxide MOSFET with uniform heat generation in silicon-dioxide layer, and (IV) high-k/metal gate transistor. First, four cases are studied under four conditions of (a) constant bulk and (b) constant film thermal properties, (c) temperature-dependent properties of bulk silicon, and (d) temperature-dependent thermal properties of film silicon. The heat source and boundary conditions are similar to what existed in a real MOSFET. It is concluded that in all cases, considering the film properties lowers the temperature jump due to the reduction of the Knudsen number. Furthermore, the speed of heat flux penetration for film properties is less than that of the cases concerning bulk properties. Also, considering the temperature-dependent properties drastically changes the temperature and heat flux distributions within the transistor, which increases the diffusion speed and more, decreases the steady state time. Calculations for case (III) presents that all previous studies have underestimated the value of the peak temperature rise by considering the constant bulk properties of silicon. Also, it is found that among the high-k dielectrics investigated in case (IV), zirconium dioxide shows the least peak temperature rise. This presents that zirconium dioxide is a good candidate as far as the thermal issues are concerned.

  19. Physical properties of organic and biomaterials: Fundamentals and applications

    Science.gov (United States)

    Steven, Eden

    Silk materials are natural protein-based materials with an exceptional toughness. In addition to their toughness, silk materials also possess complex physical properties and functions resulting from a particular set of amino-acid arrangement that produces structures with crystalline beta-sheets connected by amorphous chains. Extensive studies have been performed to study their structure-function relationship leading to recent advancements in bio-integrated devices. Applications to fields other than textiles and biomedicine, however, have been scarce. In this dissertation, an investigation of the electronic properties, functionalization, and role of silk materials (spider silk and Bombyx mori cocoon silk) in the field of organic materials research is presented. The investigation is conducted from an experimental physics point of view where correlations with charge transport mechanisms in disordered, semiconducting, and insulating materials are made when appropriate. First, I present the electronic properties of spider silk fibers under ambient, humidified, iodized, polar solvent exposure, and pyrolized conditions. The conductivity is exponentially dependent on relative humidity changes and the solvent polarity. Iodine doping increases the conductivity only slightly but has pronounced effects on the pyrolization process, increasing the yield and flexibility of the pyrolized silk fibers. The iodized samples were further studied using magic angle spinning nuclear magnetic resonance (MAS-NMR) and Fourier transform infrared spectroscopy (FTIR) revealing non-homogenous iodine doping and I2 induced hydrogenation that are responsible for the minimal conductivity improvement and the pyrolization effects, respectively. Next, I present the investigation of silk fiber functionalization with gold and its role in electrical measurements. The gold functionalized silk fiber (Au-SS) is metallic down to cryogenic temperatures, has a certain amount of flexibility, and possesses

  20. Thermo-physical Properties and Mechanical Properties of Burn-resistant Titanium Alloy Ti40

    Directory of Open Access Journals (Sweden)

    LAI Yunjin

    2017-10-01

    Full Text Available As a functional material of burn-resistant titanium alloy, the physical properties of Ti40 alloy were first reported. The chemical compositions of Ti40 alloy ingots by VAR were uniform. The microstructures of Ti40 alloy slab manufactured by HEFF+WPF were uniform. The results show that the room temperature tensile strength of Ti40 alloy is 950 MPa degree. The properties of high temperature heat exposure, creep resistance and lasting time are good at 500 ℃. In the range from room temperature to 600 ℃, Young's modulus and shear modulus are decreased linearly with increasing the temperature, Poisson's ratio is increases slowly as the temperature rises, and linear thermal expansion coefficient and average linear expansion coefficient is increase as the temperature rises.

  1. Glycolic Acid Physical Properties, Impurities, And Radiation Effects Assessment

    International Nuclear Information System (INIS)

    Pickenheim, B.; Bibler, N.

    2010-01-01

    The DWPF is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H 2 and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O 2 when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and pumping of the solution may be hindered. A

  2. GLYCOLIC ACID PHYSICAL PROPERTIES, IMPURITIES, AND RADIATION EFFECTS ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, D.; Pickenheim, B.; Hay, M.

    2011-06-20

    The Defense Waste Processing Facility (DWPF) is pursuing alternative reductants/flowsheets to increase attainment to meet closure commitment dates. In fiscal year 2009, SRNL evaluated several options and recommended the further assessment of the nitric/formic/glycolic acid flowsheet. SRNL is currently performing testing with this flowsheet to support the DWPF down-select of alternate reductants. As part of the evaluation, SRNL was requested to determine the physical properties of formic and glycolic acid blends. Blends of formic acid in glycolic acid were prepared and their physical properties tested. Increasing amounts of glycolic acid led to increases in blend density, viscosity and surface tension as compared to the 90 wt% formic acid that is currently used at DWPF. These increases are small, however, and are not expected to present any difficulties in terms of processing. The effect of sulfur impurities in technical grade glycolic acid was studied for its impact on DWPF glass quality. While the glycolic acid specification allows for more sulfate than the current formic acid specification, the ultimate impact is expected to be on the order of 0.03 wt% sulfur in glass. Note that lower sulfur content glycolic acid could likely be procured at some increased cost if deemed necessary. A paper study on the effects of radiation on glycolic acid was performed. The analysis indicates that substitution of glycolic acid for formic acid would not increase the radiolytic production rate of H{sub 2} and cause an adverse effect in the SRAT or SME process. It has been cited that glycolic acid solutions that are depleted of O{sub 2} when subjected to large radiation doses produced considerable quantities of a non-diffusive polymeric material. Considering a constant air purge is maintained in the SRAT and the solution is continuously mixed, oxygen depletion seems unlikely, however, if this polymer is formed in the SRAT solution, the rheology of the solution may be affected and

  3. Physical property characterization of a damage zone in granitic rock - Implications for geothermal reservoir properties

    Science.gov (United States)

    Wenning, Quinn; Madonna, Claudio; Amann, Florian; Gischig, Valentin; Burg, Jean-Pierre

    2016-04-01

    Geothermal energy offers a viable alternative to mitigate greenhouse gas emitting energy production. A tradeoff between less expensive drilling costs and increased permeability at shallow depths versus increased heat production at deeper depths stipulates the economic energy potential of a given reservoir. From a geological perspective, successful retrieval of geothermal energy from the subsurface requires sufficient knowledge of the structural and stratigraphic relationship of the target formations, which govern the thermal conditions, physical properties, and fluid flow properties of reservoir rocks. In Switzerland, deep basement rocks (~5 km) with fluid conducting damage zones and enhanced fractured systems stimulated by hydraulic shearing are seen as a potential geothermal reservoir system. Damage zones, both natural and induced, provide permeability enhancement that is especially important for creating fluid conductivity where the matrix permeability is low. This study concentrates on characterizing the elastic and transport properties entering into a natural damage zone penetrated by a borehole at the Grimsel underground research laboratory. The borehole drilled from a cavern at 480 m below ground surface penetrates approximately 20 m of mostly intact Grimsel granodiorite before entering the first phyllosilicate-rich shear zone (~0.2 m thick). The borehole intersects a second shear zone at approximately 23.8m. Between the two shear zones the Grimsel granodiorite is heavily fractured. The minimum principle stress magnitude from in-situ measurements decreases along the borehole into the first shear zone. Two mutually perpendicular core samples of Grimsel granodiorite were taken every 0.1 m from 19.5 to 20.1 m to characterize the physical properties and anisotropy changes as a gradient away from the damage zone. Measurements of ultrasonic compressional (Vp) and shear (Vs) velocities at 1 MHz frequency are conducted at room temperature and hydrostatic pressures

  4. Accelerator physics and radiometric properties of superconducting wavelength shifters

    International Nuclear Information System (INIS)

    Scheer, Michael

    2008-01-01

    Subject of this thesis is the operation of wave-length shifters at electron storage rings and their use in radiometry. The basic aspects of the radiometry, the technical requirements, the influence of wave-length shifters on the storage ring, and results of first measurements are presented for a device installed at BESSY. Most of the calculations are carried out by the program WAVE, which has been developed within this thesis. WAVE allows to calculate the synchrotron radiation spectra of wavelength shifters within an relative uncertainty of 1/100000. The properties of wave-length shifters in terms of accelerator physics as well as a generating function for symplectic tracking calculations can also be calculated by WAVE. The later was implemented in the tracking code BETA to investigate the influence of insertion devices on the dynamic aperture and emittance of the storage ring. These studies led to the concept of alternating low- and high-beta-sections at BESSY-II, which allow to operate superconducting insertion devices without a significant distortion of the magnetic optics. To investigate the experimental aspects of the radiometry at wave-length shifters, a program based on the Monte-Carlo-code GEANT4 has been developed. It allows to simulate the radiometrical measurements and the absorption properties of detectors. With the developed codes first radiometrical measurements by the PTB have been analysed. A comparison of measurements and calculations show a reasonable agreement with deviations of about five percent in the spectral range of 40-60 keV behind a 1-mm-Cu filter. A better agreement was found between 20 keV and 80 keV without Cu filter. In this case the measured data agreed within a systematic uncertainty of two percent with the results of the calculations. (orig.)

  5. Nanoscale thermal transport. II. 2003–2012

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  6. Determination of composition and physical properties of partially ionized plasmas in the function of temperature

    International Nuclear Information System (INIS)

    Zaporowski, B.

    1992-01-01

    The investigations of various kinds of partially ionized plasma were conducted for the pressure of 0.1 MPa and in the range of temperature of 298.15 K to 24000 K. The physical properties of various kinds of partially ionized plasma depend mainly of their composition and temperature. The composition of particular kinds of partially ionized plasmas varies also in the function of temperature. Simultaneous going on of physical and chemical processes in plasma is the reason of difficulties in the calculations of plasma's physical properties. The use of the laws of macroscopic thermodynamics for the calculations of physical properties of partially ionized plasma is impossible. There are enough exact methods for measuring of physical properties of partially ionized plasma. For these reasons the theoretical method using the base of statistic physics was used to calculate the composition and physical properties of various kinds of partially ionized plasma. (author) 2 refs., 2 figs

  7. Preface: Friction at the nanoscale

    Science.gov (United States)

    Fusc, Claudio; Smith, Roger; Urbakh, Michael; Vanossi, Andrea

    2008-09-01

    Interfacial friction is one of the oldest problems in physics and chemistry, and certainly one of the most important from a practical point of view. Everyday operations on a broad range of scales, from nanometer and up, depend upon the smooth and satisfactory functioning of countless tribological systems. Friction imposes serious constraints and limitations on the performance and lifetime of micro-machines and, undoubtedly, will impose even more severe constraints on the emerging technology of nano-machines. Standard lubrication techniques used for large objects are expected to be less effective in the nano-world. Novel methods for control and manipulation are therefore needed. What has been missing is a molecular level understanding of processes occurring between and close to interacting surfaces to help understand, and later manipulate friction. Friction is intimately related to both adhesion and wear, and all three require an understanding of highly non-equilibrium processes occurring at the molecular level to determine what happens at the macroscopic level. Due to its practical importance and the relevance to basic scientific questions there has been major increase in activity in the study of interfacial friction on the microscopic level during the last decade. Intriguing structural and dynamical features have been observed experimentally. These observations have motivated theoretical efforts, both numerical and analytical. This special issue focusses primarily on discussion of microscopic mechanisms of friction and adhesion at the nanoscale level. The contributions cover many important aspects of frictional behaviour, including the origin of stick-slip motion, the dependence of measured forces on the material properties, effects of thermal fluctuations, surface roughness and instabilities in boundary lubricants on both static and kinetic friction. An important problem that has been raised in this issue, and which has still to be resolved, concerns the

  8. Quantifying the impact of livestock grazing on soil physical properties

    Science.gov (United States)

    Fučík, Petr; Zajíček, Antonín; Holubík, Ondřej

    2014-05-01

    Livestock grazing is considered to have a noticeable influence on soil properties, when pedocompaction / soil pore reduction induced either by cattle or sheeps may curtail water residence time and accelerate the beginning and volume of overland flow. However, direct measurements of soil physical parameters and their changes under different pastoral management are seldom reported in central European conditions. Knowledge about these alterations are indispensable for setting the proper, soil and water conservative grazing management in the view of increasing areas of pastures, not only in the Czech Republic. Impact of cattle grazing on changes of soil properties was studied in three experimental upland catchments in the Czech Republic, differing in soil characteristics and grazing management. Values of soil saturated hydraulic conductivity (Ks), assessed three times a year in-situ during 2012 - 2013 with pressure infiltrometers, were compared for grazed and ungrazed cambisols, pseudogleys and gleysols, for grazing intensity ranging from 0.5 to 2 Livestock units / ha. Soil bulk density (BD) and macroporosity (MP) were determined before and after grazing season every year with ring 100 cm3 steel cyllinders. These parameters were measured also on heavily treaded plots by cattle - hotspots - in each catchment. Ks values on grazed plots were significantly lower (on average by 39 - 66 %) than on ungrazed sites, BD values were reduced on average by 15 % and MP values were lower roughly about 22 % on grazed plots. Ks values on hotspots were lower by 50 - 90 %, BD values by 5 - 18 % and MP values by 8 - 28 % comparing to the rest of grazed areas. Decrease of soil infiltration capacity was influenced by grazing intensity and soil characteristics. The greatest reductions concerning infiltration capacity were manifested in soils being periodically waterlogged (either by surface or by groundwater). A profound influence on the infiltration process was revealed in pasture soils

  9. Changes in microstructure and physical properties of skutterudites after severe plastic deformation

    Czech Academy of Sciences Publication Activity Database

    Rogl, G.; Grytsiv, A.; Buršík, Jiří; Horky, J.; Anbalagan, R.; Bauer, E.; Mallik, R.Ch.; Rogl, P.; Zehetbauer, M.

    2015-01-01

    Roč. 17, č. 5 (2015), s. 3715-3722 ISSN 1463-9076 Institutional support: RVO:68081723 Keywords : physical properties * plastic deformation * TEM, SEM Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.449, year: 2015

  10. Structural and photo-physical properties of spin-coated poly (3-hexylthiophene) thin films

    CSIR Research Space (South Africa)

    Motaung, DE

    2009-07-01

    Full Text Available Regioregular poly(3-hexylthiophenes) (P3HTs) and its blends were studied regarding their structural and photo-physical properties using fullerene as an electron acceptor material. Photo-physical and structural characteristics of the polymer blends...

  11. Dependence of Nanoparticle Toxicity on Their Physical and Chemical Properties

    Science.gov (United States)

    Sukhanova, Alyona; Bozrova, Svetlana; Sokolov, Pavel; Berestovoy, Mikhail; Karaulov, Alexander; Nabiev, Igor

    2018-02-01

    Studies on the methods of nanoparticle (NP) synthesis, analysis of their characteristics, and exploration of new fields of their applications are at the forefront of modern nanotechnology. The possibility of engineering water-soluble NPs has paved the way to their use in various basic and applied biomedical researches. At present, NPs are used in diagnosis for imaging of numerous molecular markers of genetic and autoimmune diseases, malignant tumors, and many other disorders. NPs are also used for targeted delivery of drugs to tissues and organs, with controllable parameters of drug release and accumulation. In addition, there are examples of the use of NPs as active components, e.g., photosensitizers in photodynamic therapy and in hyperthermic tumor destruction through NP incorporation and heating. However, a high toxicity of NPs for living organisms is a strong limiting factor that hinders their use in vivo. Current studies on toxic effects of NPs aimed at identifying the targets and mechanisms of their harmful effects are carried out in cell culture models; studies on the patterns of NP transport, accumulation, degradation, and elimination, in animal models. This review systematizes and summarizes available data on how the mechanisms of NP toxicity for living systems are related to their physical and chemical properties.

  12. Physical and mechanical properties of Chrysophyllum marginatum wood

    Directory of Open Access Journals (Sweden)

    Jussan Albarello de Cezaro

    2016-06-01

    Full Text Available This study aimed to evaluate the physical and mechanical properties of the wood of Chrysophyllum marginatum (Hook. And Arn. Radlk. We used three trees with 20.3 ± 6 cm of diameter. It was determined by regression analysis the variation bottom-up of shrinkage, anisotropic coefficient, saturate moisture content and basic density. To characterize the static bending in the first log, in saturate and air dried conditions, it was performed variance analysis using Tukey›s test. It was observed a decrease in radial and tangential contractions and basic density on bottom-up direction. Saturate moisture content increased, considering the same direction. Anisotropic coefficient presented increase tendency up to 1.30 m height followed by stabilization from that position to the top. It was observed decreasing tendency of longitudinal contraction to approximately 40% of total height, followed by increasing up to the insertion of the first living branch. Mean anisotropic coefficient and basic density were 2.3kg m-³ and 594 kg m-³, respectively. Air dry condition showed greater static bending resistance than when saturate. Values of rupture and elasticity modulus were similar to those found in studies with Eucalyptus saligna and Carya illinoinensis.

  13. Avian magnetic compass: Its functional properties and physical basis

    Directory of Open Access Journals (Sweden)

    Roswitha WILTSCHKO, Wolfgang WILTSCHKO

    2010-06-01

    Full Text Available The avian magnetic compass was analyzed in bird species of three different orders – Passeriforms, Columbiforms and Galliforms – and in three different behavioral contexts, namely migratory orientation, homing and directional conditioning. The respective findings indicate similar functional properties: it is an inclination compass that works only within a functional window around the ambient magnetic field intensity; it tends to be lateralized in favor of the right eye, and it is wavelength-dependent, requiring light from the short-wavelength range of the spectrum. The underlying physical mechanisms have been identified as radical pair processes, spin-chemical reactions in specialized photopigments. The iron-based receptors in the upper beak do not seem to be involved. The existence of the same type of magnetic compass in only very distantly related bird species suggests that it may have been present already in the common ancestors of all modern birds, where it evolved as an all-purpose compass mechanism for orientation within the home range [Current Zoology 56 (3: 265–276, 2010].

  14. Chemical, Mineralogical, and Physical Properties of Martian Dust and Soil

    Science.gov (United States)

    Ming, D. W.; Morris, R. V.

    2017-01-01

    Global and regional dust storms on Mars have been observed from Earth-based telescopes, Mars orbiters, and surface rovers and landers. Dust storms can be global and regional. Dust is material that is suspended into the atmosphere by winds and has a particle size of 1-3 micrometer. Planetary scientist refer to loose unconsolidated materials at the surface as "soil." The term ''soil'' is used here to denote any loose, unconsolidated material that can be distinguished from rocks, bedrock, or strongly cohesive sediments. No implication for the presence or absence of organic materials or living matter is intended. Soil contains local and regional materials mixed with the globally distributed dust by aeolian processes. Loose, unconsolidated surface materials (dust and soil) may pose challenges for human exploration on Mars. Dust will no doubt adhere to spacesuits, vehicles, habitats, and other surface systems. What will be the impacts on human activity? The objective of this paper is to review the chemical, mineralogical, and physical properties of the martian dust and soil.

  15. Characterisation of gaharu hydrosol: Physical, chemical and microbiological properties

    International Nuclear Information System (INIS)

    Nur Humaira Lau Abdullah; Salmah Moosa

    2010-01-01

    Gaharu hydrosol is produced during the hydro distillation of resinous wood part of Aquilaria sp. This aromatic water is being considered as a by-product in the industry. There is interest to turn this aromatic by-product into aroma therapy products. The present study is carried out in order to understand the properties of gaharu hydrosol, physically, chemically and microbiologically. Gaharu hydrosol from two different extraction facilities for example at Kedaik Agar wood Sdn. Bhd. and Malaysian Nuclear Agency were characterised in this study. All the gaharu hydrosol samples displayed acidic nature, with pH in the range of 3.62 - 4.53. Four antioxidant assays were carried out to ascertain the antioxidant capabilities of two gaharu hydrosol samples through the total phenolic content assay, ABTS + radical scavenging activity, DPPH· radical scavenging activity and ferric reducing activity (FRAP). The results revealed that the samples exhibited lower antioxidant capabilities as compared to the positive control. For microbial population study, fungi was not present in the samples as there was no growth observed on the Plate Sabouraud Dextrose Agar (SDA) using membrane filtration technique. The antibacterial activity of the gaharu hydrosol against Staphylococcus aureus and Pseudomonas aeruginosa was determined using agar dilution method and disk diffusion method. The results showed that the gaharu hydrosol did not inhibit the growth of both the bacteria. The results obtained from this study will be further evaluated for the development of new products using this aromatic gaharu by-product. (author)

  16. Physical Properties of Copper Based MMC Strengthened with Alumina

    Directory of Open Access Journals (Sweden)

    Kaczmar J. W.

    2014-06-01

    Full Text Available The aim of this work is the development of Cu-Al2O3 composites of copper Cu-ETP matrix composite materials reinforced by 20 and 30 vol.% Al2O3 particles and study of some chosen physical properties. Squeeze casting technique of porous compacts with liquid copper was applied at the pressure of 110 MPa. Introduction of alumina particles into copper matrix affected on the significant increase of hardness and in the case of Cu-30 vol. % of alumina particles to 128 HBW. Electrical resistivity was strongly affected by the ceramic alumina particles and addition of 20 vol. % of particles caused diminishing of electrical conductivity to 20 S/m (34.5% IACS. Thermal conductivity tests were performed applying two methods and it was ascertained that this parameter strongly depends on the ceramic particles content, diminishing it to 100 Wm-1K-1 for the composite material containing 30 vol.% of ceramic particles comparing to 400 Wm-1K-1 for the unreinforced copper. Microstructural analysis was carried out using SEM microscopy and indicates that Al2O3 particles are homogeneously distributed in the copper matrix. EDS analysis shows remains of silicon on the surface of ceramic particles after binding agent used during preparation of ceramic preforms.

  17. Thermo-physical properties of (Th,U)O2

    International Nuclear Information System (INIS)

    Yang, J. H.; Gang, K. W.; Lee, C. B.

    2003-01-01

    The temperature dependance of thermal expansion, thermal diffusivity and thermal conductivity in (Th 1-y U y )O 2 (y=0.0, 0.345, 0.645) system has been measured using dillatomeler and laser flash apparatus. The thermal expansion of (Th 1-y U y )0 2 linearly increases with U mole fraction y in the measured temperature range. The thermal conductivities of (Th 0.655 U 0. 3 45 )0 2 and (Th 0.. 3 55 U 0.645 )0 2 fuel were found to be lower than that of Th0 2 or U0 2 fuel The degradation of the thermal conductivity by the addition of U0 2 is large at low temperatures but becomes smaller as the temperature increases. The phonon -defect scattering might be associated with the degradation of the thermal conductivity. The measured thermo-physical properties of (Th,U)O 2 system can be well described in terms of the formation of a complete solid solution in the whole composibon range

  18. Theoretical investigation of chemical and physical properties of gaseous fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hermann, Fredrik

    1999-12-01

    This thesis is discussing the chemical and physical properties of different gaseous fuels. A mapping of about seventy gaseous fuels resulted in eleven type gases, these gases have mainly five components (inerts, H{sub 2}, CO, CH{sub 4} and higher order of hydrocarbons) of different quantities. Calculations of heating value and Wobbe number have been done. Dew point temperatures have been estimated by using three different programs. Flammability limits, laminar flame speed and auto ignition temperatures have been calculated by using a kinetic and chemical program developed by Mauss. Flammability limits have been compared with Le Chatelier's law and measurements. Problems related to combustion such as flash back, lift off and instability are closely connected with flame speed and flow patterns. These problems are discussed in terms of laminar flame speed and Reynolds' number. The main results of this study were: Auto ignition temperature for gas mixtures behavior is very complex and unpredictable. In general small quantities of hydrogen decrease the temperature of auto ignition. The calculations of flammability limits by the kinetic and chemical software showed good agreement to measurements. Low Btu gases requires large flow area in order to avoid large pressure drop.

  19. The Fundamental Physical Properties of Wolf-Rayet Stars

    Science.gov (United States)

    Massey, Philip

    Massive stars are the cosmic engines that power the far-infrared luminosities of distant galaxies, and dominate the ionization of nearby HII regions. They are the primary source of carbon and oxygen in the Universe, and their core collapses manufacture all of the elements heavier than Fe. The re-ionization of the early Universe was thanks to Population III massive stars, and the super-massive black holes we find in the cores of galaxies today were seeded as a result of the black holes that formed from the first generations of massive stars. Understanding massive star evolution is the key to unlocking many astrophysical problems. The largest uncertainty in massive star evolution is the question of how Wolf-Rayet (WR) stars form. Our proposal will determine the fundamental physical properties of WRs using four archival NASA data sets for a critical comparison with present day evolution models. It is generally assumed that massive stars spend most of their post-main-sequence lives WRs. For decades we have believed that WRs form as a result of stellar winds stripping off the H-rich outer layers of a star, leaving behind a bare stellar core. In this picture, WRs are a normal stage in the evolution of the most massive stars. Recently, this scenario has been called into question. Stellar wind mass- loss rates are now known to be significantly lower than previously thought, although whether this is a factor of 3 or 10 remains unclear. If the latter is correct, then this poses a serious problem for the formation of WRs. This has created a paradigm shift, with increased importance attached to the role of binary evolution, with Roche-lobe overflow performing the stripping. Attempts to distinguish which scenario is more prevalent is complicated by the possibility of past mergers; i.e., just because a WR is not a binary today does not prove it was not one in the past. We will tackle this question from a fresh perspective, determining reliable fundamental physical properties of

  20. Physical properties of chitosan dispersions in glycolic acid.

    Science.gov (United States)

    Anchisi, Carlo; Maccioni, Anna Maria; Cristina Meloni, Maria

    2004-07-01

    Evaporation-freezing and rheological behaviour of chitosan dispersions at different temperatures and with different molecular weights using glycolic acid as anionic systems were studied. Chitosans of high, 2,000,000, medium, 750,000, and low, 70,000 molecular weight (hC, mC, and lC, respectively) were employed alone or as mixtures (hC/mC, hC/lC, and mC/lC 1:1, w/w). Different concentrations of glycols were added to these base dispersions (propylene glycol and glycerine) to investigate how the above physical properties change. The different rheological and evaporation-freezing behaviours of chitosan dispersions were related both to the molecular weight of chitosan and the vehicle composition of the dispersions. Particularly, the rheological study showed a pseudoplastic and shear thinning behaviour for all chitosan dispersions with flow index values n, tending to <1 at increasing molecular weights. Chitosans dispersions containing glycols showed lower apparent viscosity values than the base dispersions of the corresponding chitosans, but the water loss and the freezing point were lower especially for chitosan dispersions containing glycerine. This work presents a wide range of dispersion series from which to choose the most suitable to formulate pharmaceutical and cosmetic products.

  1. Physical properties of orbital debris from spectroscopic observations

    Science.gov (United States)

    Jorgensen, K.; Africano, J.; Hamada, K.; Stansbery, E.; Sydney, P.; Kervin, P.

    2004-01-01

    Currently, certain physical properties, such as material type and albedo, of orbital debris are assumed when used to determine the size of the objects. A study to ascertain whether or not the assumed values are valid has begun using reflectance spectroscopy as a means of determining the material type of the object. What appears to some as a squiggly line is actually the reflectance of sunlight from the object. By comparing the location, depth, and width of the absorption features on the squiggly lines, the material type of the debris object is identified. Once the material type is known, the albedo of the object can be determined. This paper discusses the results from observations of large rocket bodies and satellites in both lower and geosynchronous Earth orbits (LEO and GEO, respectively) taken at the air force maui optical and supercomputing (AMOS) site located in Maui, Hawaii. Using the 1.6-m telescope and a spectral range of 0.3-0.9 μm, differences between rocket bodies of different types and launch dates, as well as satellites of different types and launch dates are determined. Variations seen in the squiggle lines are due to colors of paint, space weathering, and for the satellites, orientation and size of the solar panels. Future direction of the project will be discussed as well as plans for future observations.

  2. Soil physical properties affecting soil erosion in tropical soils

    International Nuclear Information System (INIS)

    Lobo Lujan, D.

    2004-01-01

    The total vegetated land area of the earth is about 11,500 hectare. Of this, about 12% is in South America. Of this, about 14% is degraded area. Water erosion, chemical degradation, wind erosion, and physical degradation have been reported as main types of degradation. In South America water erosion is a major process for soil degradation. Nevertheless, water erosion can be a consequence of degradation of the soil structure, especially the functional attributes of soil pores to transmit and retain water, and to facilitate root growth. Climate, soil and topographic characteristics determine runoff and erosion potential from agricultural lands. The main factors causing soil erosion can be divided into three groups: Energy factors: rainfall erosivity, runoff volume, wind strength, relief, slope angle, slope length; Protection factors: population density, plant cover, amenity value (pressure for use) and land management; and resistance factors: soil erodibility, infiltration capacity and soil management. The degree of soil erosion in a particular climatic zone, with particular soils, land use and socioeconomic conditions, will always result from a combination of the above mentioned factors. It is not easy to isolate a single factor. However, the soil physical properties that determine the soil erosion process, because the deterioration of soil physical properties is manifested through interrelated problems of surface sealing, crusting, soil compaction, poor drainage, impeded root growth, excessive runoff and accelerated erosion. When an unprotected soil surface is exposed to the direct impact of raindrops it can produce different responses: Production of smaller aggregates, dispersed particles, particles in suspension and translocation and deposition of particles. When this has occurred, the material is reorganized at the location into a surface seal. Aggregate breakdown under rainfall depends on soil strength and a certain threshold kinetic energy is needed to start

  3. Scanning nanoscale multiprobes for conductivity measurements

    DEFF Research Database (Denmark)

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

    2000-01-01

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

  4. Physical properties of emulsion systems with SiO2 nanoparticles

    Directory of Open Access Journals (Sweden)

    Sergeev Vitaly Vyacheslavovich

    2017-11-01

    Full Text Available One of the most relevant directions for research and development (R&D in the area of oil and gas fields development is to study physicochemical impact onto petroleum reservoir to enhance development rate and increase oil recovery factor. Wide range of fields where nanoscale particles can be applied within this direction shifted the level of physicochemical processes studies from microscale to nanoscale, that caused significant advancement of the oil and gas industry as a whole. As for physicochemical methods for petroleum reservoir stimulation, the rapid development of nanotechnologies considerably improves understanding of the processes that run at the boundaries of phases liquid-liquid, liquid-gas, liquid-rock phases, etc. The most studied processes are the processes of influence of nanoscale particles on the interface between liquid-gas and liquid-liquid phases [1–18]. At the moment it is known that nanoparticles of various minerals and metals can increase lifetime of gas bubbles in hydrocarbon media and the stability of globules in hydrocarbon or aqueous phase in various types of emulsions [1–7, 12]. But in the industry there is no single understanding and explanation of physicochemical processes occurring at the boundaries of phases in the presence of nanoparticles under reservoir conditions or even in bench tests on rock cores. In this connection, the direction of nanoscale particles application in the oil and gas fields development is promising for carrying out complex R&D in order to reveal new scientific information and introduce high-performance inventions into the industry. The article presents the results of the next stage in complex research of silicon dioxide nanoparticles (SiO2 impact onto rheological and stability properties of emulsion systems. The complex research is performed within the framework of international project «Development and implementation of water-blocking agents based on application of SiO2 nanoparticles

  5. Physical properties of magnesium affected soils in Colombia

    International Nuclear Information System (INIS)

    Garcia-Ocampo, A.

    2004-01-01

    Magnesium has some capacity to develop higher exchangeable sodium levels in clays and soil materials. The Mg +2 accumulation on the exchange complex of soils to a very high saturation levels affect their physical, chemical and biological properties. Colombia has a large area of these soils, located mainly in the main rivers valleys and in the Caribbean Region. In the Cauca River Valley there are about 117,000 hectares affected. There is a lack of information about the soil forming processes, the Mg +2 effects on soils, the type and source of compounds responsible for the magnesium enrichment, their relationship with the landscape and the way this accumulation occurs. To identify and quantify soil Mg +2 enriched areas over 2500 soil profiles from different landscape positions of the Cauca River Valley were studied. The information was processed to generate Mg-saturation maps, to identify the different soil profile types and to estimate the affected area. A topographic sequence from the alluvial inundation plain to the hills was used to explore the presence of diagnostic horizons and to determine the main soil characteristics and genetic, mineralogical or chemical evidences of soil forming processes. Two 180 kilometer transects parallel to the river were used to: a) study the type and source of Mg-compounds responsible for the Mg-enrichment and the way this accumulation occurs. b) the soil hydraulic properties like infiltration, saturated hydraulic conductivity and matrix potential at different depths were also measured. Samples of nine profiles were collected and the porosity and soil volume changes at different water content were examined. The program RETC was used for prediction of the hydraulic properties of non saturated soils. These properties involved the retention curve, the function of hydraulic conductivity and the diffusivity of the water in the soil. By grouping together the soil profiles, five main type of Mg-affected soils were identified as being

  6. Nanoscale relaxation oscillator

    Science.gov (United States)

    Zettl, Alexander K.; Regan, Brian C.; Aloni, Shaul

    2009-04-07

    A nanoscale oscillation device is disclosed, wherein two nanoscale droplets are altered in size by mass transport, then contact each other and merge through surface tension. The device may also comprise a channel having an actuator responsive to mechanical oscillation caused by expansion and contraction of the droplets. It further has a structure for delivering atoms between droplets, wherein the droplets are nanoparticles. Provided are a first particle and a second particle on the channel member, both being made of a chargeable material, the second particle contacting the actuator portion; and electrodes connected to the channel member for delivering a potential gradient across the channel and traversing the first and second particles. The particles are spaced apart a specified distance so that atoms from one particle are delivered to the other particle by mass transport in response to the potential (e.g. voltage potential) and the first and second particles are liquid and touch at a predetermined point of growth, thereby causing merging of the second particle into the first particle by surface tension forces and reverse movement of the actuator. In a preferred embodiment, the channel comprises a carbon nanotube and the droplets comprise metal nanoparticles, e.g. indium, which is readily made liquid.

  7. Hybrid, Nanoscale Phospholipid/Block Copolymer Vesicles

    Directory of Open Access Journals (Sweden)

    Bo Liedberg

    2013-09-01

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

  8. Material physical properties of 12 chromium ferritic steel

    International Nuclear Information System (INIS)

    Ando, Masanori; Wakai, Takashi; Aoto, Kazumi

    2003-09-01

    High chromium ferritic steel is an attractive candidate for structural material of the next Fast Breeder Reactor, since both of thermal properties and high temperature strength of the steel are superior to those of conventional austenitic stainless steels. In this study, physical properties of 12Cr steels are measured and compared to those obtained in the previous studies to discuss about stochastic dispersions. The effect of measurement technique on Young's modulus and the influence of the specimen size on coefficient of thermal expansion are also investigated. The following conclusions are obtained. (1) Young's modulus of 12Cr steels obtained in this study tends to larger than those obtained in the previous studies especially in high temperature. Such a discrepancy is resulted from the difference in measurement technique. It was clarified that Young's modulus obtained by free vibration method is more adequate those obtained by the cantilever characteristic vibration method. Therefore, the authors recommend using the values obtained by free vibration method as Young's modulus of 12Cr steels. (2) Both instant and mean coefficient of thermal expansion of 12Cr steels obtained in this study is in a good agreement with those obtained in the previous studies. However, the obviously different values are obtained from the measurement by large size specimens. Such a discrepancy is resulted from heterogeneous during heating process of the specimens. Therefore, the authors recommend using the values obtained by φ4 x 20 mm specimens as instant and mean coefficient of thermal expansion of 12Cr steels. (3) Specific heat of 12Cr steels obtained in this study agree with those obtained in the previous studies with a few exceptions. (4)Thermal conductivity of 12Cr steels obtained in this study agree with those obtained in the previous studies. (5) It was confirmed that instant and mean coefficient of thermal expansion, density, specific heat and thermal conductivity of 12Cr steels

  9. Rocket Science at the Nanoscale.

    Science.gov (United States)

    Li, Jinxing; Rozen, Isaac; Wang, Joseph

    2016-06-28

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

  10. Crystal growth and physical properties of Ferro-pnictides

    Energy Technology Data Exchange (ETDEWEB)

    Aswartham, Saicharan

    2012-11-08

    . Single crystals of KFe{sub 2}As{sub 2} were grown with two different fluxes, namely, FeAs-flux and KAs-flux. The superconducting transition is found to be at 3.8 K in both the crystals. The influence of doping with selected elements like Na, Rh, Co and Cr has been investigated systematically in KFe{sub 2}As{sub 2} single crystals. With Na-doping at the K-site, yield (K{sub 1-x}Na{sub x})Fe{sub 2}As{sub 2}; superconductivity is suppressed to lower temperatures. Substitution of Co and Cr at Fe site, yield K(Fe{sub 0.95}Co{sub 0.05}){sub 2}As{sub 2}, K(Fe{sub 0.95}Cr{sub 0.05}){sub 2}As{sub 2} superconductivity is rapidly killed. Single crystals of (Ba{sub 0.6}Eu{sub 0.4})(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} with x = 0, 0.05, 0.1, 0.15 and 0.2 were grown with solution growth technique using Fe-As flux and investigated with several physical measurements. The growth conditions are highly optimized to grow flux free large single crystals especially in case of BaFe{sub 2}As{sub 2} family. The high quality of the crystals were revealed by several physical properties, for e.g. single crystals of Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} are of the highest quality which was confirmed by the magnetic ac susceptibility which showed a very sharp superconducting transition.

  11. ION SERIES AND THE PHYSICAL PROPERTIES OF PROTEINS. II.

    Science.gov (United States)

    Loeb, J

    1920-11-20

    1. Our results show clearly that the Hofmeister series is not the correct expression of the relative effect of ions on the swelling of gelatin, and that it is not true that chlorides, bromides, and nitrates have "hydrating," and acetates, tartrates, citrates, and phosphates "dehydrating," effects. If the pH of the gelatin is taken into considertion, it is found that for the same pH the effect on swelling is the same for gelatin chloride, nitrate, trichloracetate, tartrate, succinate, oxalate, citrate, and phosphate, while the swelling is considerably less for gelatin sulfate. This is exactly what we should expect on the basis of the combining ratios of the corresponding acids with gelatin since the weak dibasic and tribasic acids combine with gelatin in molecular proportions while the strong dibasic acid H(2)SO(4) combines with gelatin in equivalent proportions. In the case of the weak dibasic acids he anion in combination with gelatin is therefore monovalent and in the case of the strong H(2)SO(4) it is bivalent. Hence it is only the valency and not the nature of the ion in combination with gelatin which affects the degree of swelling. 2. This is corroborated in the experiments with alkalies which show that LiOH, NaOH, KOH, and NH(4)OH cause the same degree of swelling at the same pH of the gelatin solution and that this swelling is considerably higher than that caused by Ca(OH)(2) and Ba(OH)(2) for the same pH. This agrees with the results of the titration experiments which prove that Ca(OH)(2) and Ba(OH)(2) combine with gelatin in equivalent proportions and that hence the cation in combination with the gelatin salt with these two latter bases is bivalent. 3. The fact that proteins combine with acids and alkalies on the basis of the forces of primary valency is therefore not only in full agreement with the influence of ions on the physical properties of proteins but allows us to predict this influence qualitatively and quantitatively. 4. What has been stated in

  12. Analysis of Sigmoid Functionally Graded Material (S-FGM) Nanoscale Plates Using the Nonlocal Elasticity Theory

    OpenAIRE

    Jung, Woo-Young; Han, Sung-Cheon

    2013-01-01

    Based on a nonlocal elasticity theory, a model for sigmoid functionally graded material (S-FGM) nanoscale plate with first-order shear deformation is studied. The material properties of S-FGM nanoscale plate are assumed to vary according to sigmoid function (two power law distribution) of the volume fraction of the constituents. Elastic theory of the sigmoid FGM (S-FGM) nanoscale plate is reformulated using the nonlocal differential constitutive relations of Eringen and first-order shear defo...

  13. General Physical Properties of CGRaBS Blazars

    Science.gov (United States)

    Paliya, Vaidehi S.; Marcotulli, L.; Ajello, M.; Joshi, M.; Sahayanathan, S.; Rao, A. R.; Hartmann, D.

    2017-12-01

    We present the results of a multi-frequency, time-averaged analysis of blazars included in the Candidate Gamma-ray Blazar Survey catalog. Our sample consists of 324 γ-ray detected (γ-ray loud) and 191 γ-ray undetected (γ-ray quiet) blazars; we consider all the data up to 2016 April 1. We find that both the γ-ray loud and γ-ray quiet blazar populations occupy similar regions in the WISE color-color diagram, and γ-ray loud sources are brighter in the radio and X-ray bands. A simple one-zone synchrotron inverse-Compton emission model is applied to derive the physical properties of both populations. We find that the central black hole mass and accretion disk luminosity ({L}{disk}) computed from the modeling of the optical-UV emission with a Shakura-Sunyaev disk reasonably matches that estimated from the optical spectroscopic emission-line information. A significantly larger Doppler boosting in the γ-ray loud blazars is noted, and their jets are more radiatively efficient. On the other hand, the γ-ray quiet objects are more MeV-peaked and thus could be potential targets for next-generation MeV missions. Our results confirm earlier findings about the accretion-jet connection in blazars; however, many of the γ-ray quiet blazars tend to deviate from the recent claim that the jet power exceeds {L}{disk} in blazars. A broadband study, considering a larger set of γ-ray quiet objects and also including BL Lacs, will be needed to confirm/reject this hypothesis as well as to verify the evolution of the powerful high-redshift blazars into their low-power nearby counterparts.

  14. Waste Feed Evaporation: Physical Properties and Solubility Determination

    International Nuclear Information System (INIS)

    Calloway, T.B.

    2003-01-01

    Caustic adjustment of the UF recycle stream was required to prevent gel formation for the solutions tested. Actual amounts of caustic adjustment required will vary depending on the composition and volume ratios of the UF recycle. The concentration of recycles in the waste feed evaporator as required to blend with waste feed streams to provide a feed to the ultrafiltration process with a supernate specific gravity of 1.22 is feasible. No problems (such as severe foaming) were noted during the lab-scale testing that would preclude operation of the evaporator. The physical properties of the recycles and waste feed blends fit well to correlations based on sodium concentration and temperature. Evaporation of streams containing high levels of insoluble solids may lead to ''bumping'' or other undesirable behavior in the evaporator at insoluble solids. Sodium alumino-silicate solids were not noted in the evaporator feed or concentrate, but NAS did form in the blends of concentrated recycle and waste feeds. Strontium was found to precipitate during neutralization of the acid cleaning solution and remain precipitated during evaporation. Mercury was found to be significantly soluble in Envelope A simulants and the solubility of mercury increased during evaporation. No mercury was detected in the offgas system after evaporation using Envelope A simulants. Mercury was significantly less soluble in a simulant of AZ-102. Filtration of the Envelope A waste simulants was affected by the addition of recycle to the process, but the impact was primarily due to an increase in the amount of insoluble solids in the blended stream compared to the waste feed

  15. HETDEX: The Physical Properties of Lyman-alpha Emitters

    Science.gov (United States)

    Gronwall, Caryl; Blanc, G.; Ciardullo, R.; Finkelstein, S.; Gawiser, E.; Gebhardt, K.; HETDEX Collaboration

    2012-01-01

    Beginning in Fall 2012, the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) will map out 300 square degrees via a blind integral-field spectroscopic survey which will detect 800,000 Lyman-alpha emitters (LAEs) at 1.9 LAE power spectrum, but these emission-line sources are also important probes of galaxy evolution. LAEs are observed "in the act" of formation with low mass, little dust, very young ages, and a two-dimensional clustering scale-length that implies that they are the progenitors of today's Milky Way type galaxies. The unprecedented size of the HETDEX survey will allow us to explore the 3-D clustering of these objects and to measure their halo masses as a function of redshift. We will also be able to explore the physical properties of LAEs over a wide range of environments, and study how their luminosity functions, equivalent width distributions, and star formation rates change with galaxy density and redshift. In preparation for HETDEX, we undertook a 3 year pilot survey to test the feasibility of the experiment and design an optimal observing strategy. These observations were performed with a proto-type HETDEX spectrograph (VIRUS-P) on the McDonald 2.7-m telescope, and covered Ly-alpha in the redshift range 1.9 < z < 3.8. This survey discovered 104 Ly-alpha emitting galaxies in 169 sq. arcmin of sky, and reached objects with Ly-alpha line luminosities as faint as 3 x 1042 ergs/s. We will present the Ly-alpha luminosity function, equivalent width distributions, and star formation rates measured for this sample and discuss the implications of the pilot survey results for HETDEX.

  16. Aqueous aerosol SOA formation: impact on aerosol physical properties.

    Science.gov (United States)

    Woo, Joseph L; Kim, Derek D; Schwier, Allison N; Li, Ruizhi; McNeill, V Faye

    2013-01-01

    Organic chemistry in aerosol water has recently been recognized as a potentially important source of secondary organic aerosol (SOA) material. This SOA material may be surface-active, therefore potentially affecting aerosol heterogeneous activity, ice nucleation, and CCN activity. Aqueous aerosol chemistry has also been shown to be a potential source of light-absorbing products ("brown carbon"). We present results on the formation of secondary organic aerosol material in aerosol water and the associated changes in aerosol physical properties from GAMMA (Gas-Aerosol Model for Mechanism Analysis), a photochemical box model with coupled gas and detailed aqueous aerosol chemistry. The detailed aerosol composition output from GAMMA was coupled with two recently developed modules for predicting a) aerosol surface tension and b) the UV-Vis absorption spectrum of the aerosol, based on our previous laboratory observations. The simulation results suggest that the formation of oligomers and organic acids in bulk aerosol water is unlikely to perturb aerosol surface tension significantly. Isoprene-derived organosulfates are formed in high concentrations in acidic aerosols under low-NO(x) conditions, but more experimental data are needed before the potential impact of these species on aerosol surface tension may be evaluated. Adsorption of surfactants from the gas phase may further suppress aerosol surface tension. Light absorption by aqueous aerosol SOA material is driven by dark glyoxal chemistry and is highest under high-NO(x) conditions, at high relative humidity, in the early morning hours. The wavelength dependence of the predicted absorption spectra is comparable to field observations and the predicted mass absorption efficiencies suggest that aqueous aerosol chemistry can be a significant source of aerosol brown carbon under urban conditions.

  17. Physical properties of orbital debris from squiggly lines

    Science.gov (United States)

    Jorgensen, K.; Africano, J.; Hamada, K.; Stansbery, E.; Sydney, P.; Kervin, P.

    Currently, certain physical properties, such as material type and albedo, of orbital debris are assumed when used to determine the size of the objects. A study to ascertain whether or not the assumed values are valid has begun using reflectance spectroscopy as a means of determining the material type of the object. What appears to some as a squiggly line is actually the reflectance of sunlight from the object. By comparing the location, depth, and width of the absorption features on the squiggly lines, the material type of the debris object is identified. Once the material type is known, the albedo of the object can be determined. This paper discusses the results from observations of large rocket bodies and satellites in both lower and geosynchronous Earth orbits (LEO and GEO, respectively) taken at the Air Force Maui Optical Supercomputing (AMOS) site located in Maui, Hawaii. Using the 1.6- meter telescope and a spectral range of 0.3 to 0.9 microns, differences between rocket bodies of different types and launch dates, as well as satellites of different types and launch dates are determined. Variations seen in the squiggle lines are due to colors of paint, space weathering, and for the satellites, orientation and size of the solar panels. Initial findings from an additional observation run using the 3.67-meter telescope equipped with both a visible and near-infrared spectrometer (out to 2 microns) are also described. Future direction of the project will be discussed as well as plans for future observations.

  18. Soil physical properties of high mountain fields under bauxite mining

    Directory of Open Access Journals (Sweden)

    Dalmo Arantes de Barros

    2013-10-01

    Full Text Available Mining contributes to the life quality of contemporary society, but can generate significant impacts, these being mitigated due to environmental controls adopted. This study aimed to characterize soil physical properties in high-altitude areas affected by bauxite mining, and to edaphic factors responses to restoration techniques used to recover mined areas in Poços de Caldas plateau, MG, Brazil. The experiment used 3 randomized block design involving within 2 treatments (before mining intervention and after environmental recovery, and 4 replicates (N=24. In each treatment, soil samples with deformed structures were determined: granulometry, water-dispersible clay content, flocculation index, particle density, stoniness level, water aggregate stability, and organic matter contend. Soil samples with preserved structures were used to determine soil density and the total volume of pores, macropores, and micropores. Homogenization of stoniness between soil layers as a result of soil mobilization was observed after the mined area recovery. Stoniness decreased in 0.10-0.20 m layer after recovery, but was similar in the 0-0.10 m layer in before and after samples. The recovery techniques restored organic matter levels to pre-mining levels. However, changes in soil, including an increase in soil flocculation degree and a decrease in water-dispersible clays, were still apparent post-recovery. Furthermore, mining operations caused structural changes to the superficial layer of soil, as demonstrated by an increase in soil density and a decrease in total porosity and macroporosity. Decreases in the water stability of aggregates were observed after mining operations.

  19. Physical and chemical properties for sandstone and bentonites

    International Nuclear Information System (INIS)

    Sato, Haruo

    2004-01-01

    Physical and chemical properties such as porosity, pore-size distribution, dry density, solid density, mineralogy and chemical composition, which are important parameters for the understanding and analysis of the diffusion phenomena of radionuclides and ions in bentonite and in the geosphere, were measured. The measurements were performed for sandstone, of which fundamental data and information are limited. For bentonite, 3 kinds of bentonites with different smectite contents (Kunigel-V1, Kunipia-F, MX80) were used. In the measurements of the physical and chemical properties of rock, the measurements of solid density by pychnometer, the measurements of porosity, dry density and solid density by water saturation method, the measurements of porosity, dry density, solid density, pore-size distribution and specific surface area of pores by Hg porosimetry, the identifications of constituent minerals by X-ray Diffractometry (XRD), the measurement of chemical composition by whole rock analysis, the observations of micropore structure by Laser Confocal Microscope (LCM), the measurements of water vaporization curves and the measurements of the homogeneity of the rock by penetration of KMnO 4 were performed. While, in the measurements of the physical and chemical properties for bentonite, water basis water content, water content, porosity, dry density, solid density and their distributions in samples were measured, and the degree of inhomogeneity was quantitatively evaluated by comparing with data and information reported up to date. The porosities of sandstone are 15.6±0.21% for water saturation method and 15.5±0.2% for Hg porosimetry, and similar values were obtained in both methods. The solid densities ranged 2.65-2.69 Mg/m 3 for 3 methods, and the average value was 2.668±0.012 Mg/m 3 . The average pore size was 88.8±0.5nm, and pore sizes ≤10μm shared 80% of total pore volume and pore sizes ≤1μm shared 40%. The specific surface area of the pores is 4.09±0.017 m

  20. Summary of tank waste physical properties at the Hanford Site

    International Nuclear Information System (INIS)

    Nguyen, Q.H.

    1994-04-01

    This report summarizes the physical parameters measured from Hanford Site tank wastes. Physical parameters were measured to determine the physical nature of the tank wastes to develop simulants and design in-tank equipment. The physical parameters were measured mostly from core samples obtained directly below tank risers. Tank waste physical parameters were collected through a database search, interviewing and selecting references from documents. This report shows the data measured from tank waste but does not describe how the analyses wee done. This report will be updated as additional data are measured or more documents are reviewed

  1. Curing characteristics tensile and physical properties of rice straw filled standard Malaysian rubber

    Science.gov (United States)

    Alnaid, A.; Noriman, N. Z.; Dahham, O. S.; Hamzah, R.; Adam, T.; Al-Samarrai, M. N.; Mohammed, M.; Azlan, U. A. A.

    2017-10-01

    In this research, the effects of Rice Straw (RS) reinforced Standard Malaysian Rubber (SMRL) on curing characteristics, tensile properties and physical properties were investigated. All compounds were prepared using two roll mill at five different RS loading (10, 20, 30, 40, 50 phr). In addition, two different size of RS, fine size (FS) at 300 μm and coarse size (CS) at 10 mm were used. The properties such as cure characteristics, tensile properties and physical properties were determined. Results indicated that the fine size of RS filled SMRL contributed to the better properties such as tensile, hardness and crosslink density compare to coarser size of RS filled SMRL at same loading.

  2. Nanoscale thermoelectric materials

    International Nuclear Information System (INIS)

    Failamani, F.

    2015-01-01

    the binary Zr-B system. Interestingly, the FeB phases are formed only by addition of small amounts of group IV metals to TaB. These high temperature phases may serve as nano particles to decrease the thermal conductivity of the composite by reducing the phonon mean free path on the grain boundaries, thus improving ZT. In order to define an electrode material suitable for long-term operation in contact with Sb-based skutterudite thermoelectrics at the hot end of the TE-device, the detailed knowledge of the binary metal - antimony phase diagrams and properties of phases formed in the diffusion zone are required. Hitherto, only the Nb-Sb phase diagram has been reported with some controversial results, whilst the {V,Ta}-Sb phase diagrams have not been constructed yet. Chapter 3 summarizes the investigation on the {V,Nb,Ta}-Sb systems to close this gap and to remove ambiguities from the Nb-Sb diagram. Moreover physical properties of {V,Nb,Ta}Sb2 that are formed in the diffusion zones have been studied in the temperature region relevant for automotive application of skutterudite thermoelectrics (up to 600°C). A novel ternary compound with composition close to “Ba2V5Sb9” was observed in the diffusion zones between V and n-type Ba0.3Co4Sb12 at 600°C. Structural investigation revealed the correct formula as Ba5V12Sb19+x, isotypic with Ba5Ti12Sb19+x, however, with some additional site occupation and disorder. Search for isotypic compounds among the rest of early transition metals revealed that Nb and Ta form the corresponding phases at 700°C. However, only the formation of Ba5Nb12Sb19+x was confirmed by both XRPD and XRSC data, while neither the bulk nor the single crystal of Ba5Ta12Sb19+x could be obtained to confirm its formation. A detailed study on the crystal structure and its impact on the physical (transport and thermal) properties of these compounds are presented in chapter 4. In our search for new TE materials we studied the {La,Ce}-(Ni,Zn)-Si systems. The

  3. Physical properties of inland valley soils of central Cross River State ...

    African Journals Online (AJOL)

    Physical properties of inland valley soils of central Cross River State, Nigeria. ... The physical properties of six Inland valley pedons in central Cross River State, Nigeria were investigated. The percent total sand ... The surface layers were generally loamy in texture while the subsoil layers were clayey. The mean bulk density ...

  4. Study on Physical Properties and Chemical Composition of Some Myanmar Gems

    International Nuclear Information System (INIS)

    Kyaw Myint Htoo; Tun Khin; Sein Htoon

    2004-05-01

    Physical properties of some Myanmar gems were studied by using refractometer, dichroscope, polariscope, SG test, UV test and microscope. Then, chemical composition were investigated by XRF-technique. After that, gem identification, evaluation, colour improvement were studied according to these physical properties and chemical composition

  5. Physical and Digital Security Mechanisms: Properties, Combinations and Trade-offs

    NARCIS (Netherlands)

    van Cleeff, A.

    2015-01-01

    The usage of information technology implies the replacement of physical systems with digital systems: we use information technology because some properties of software, such as high speed, low cost and high accuracy, are more desirable than the corresponding properties of physical systems.

  6. Static electric field enhancement in nanoscale structures

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-28

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

  7. Quantitative temperature-depending mapping of mechanical properties of bitumen at the nanoscale using the AFM operated with PeakForce TappingTM mode

    NARCIS (Netherlands)

    Fischer, H.R.; Stadler, H.; Erina, N.

    2013-01-01

    The mechanical properties of bitumen, such as elasticity/Young's modulus, stickiness/adhesion, hardness and energy loss, and sample deformation were acquired quantitatively and simultaneously with the topology at the microscale, discriminating clearly two separate phases within the bitumen.

  8. Physical properties optimization of polycrystalline LiFeAs

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Shiv J., E-mail: s.j.singh@ifw-dresden.de [Leibniz-Institute for Solid State and Material Research, IFW-Dresden, 01171 Dresden Germany (Germany); Research Center for Environmentally Friendly Materials Engineering, Muroran Institute of Technology, 27-1 Mizumoto-cho, Muroran, Hokkaido, 050-8585 (Japan); Gräfe, Uwe; Beck, Robert; Wolter, Anja U.B.; Grafe, Hans-Joachim [Leibniz-Institute for Solid State and Material Research, IFW-Dresden, 01171 Dresden Germany (Germany); Hess, Christian [Leibniz-Institute for Solid State and Material Research, IFW-Dresden, 01171 Dresden Germany (Germany); Center for Transport and Devices of Emergent Materials, Technische Universität Dresden, 01069 Dresden (Germany); Wurmehl, Sabine [Leibniz-Institute for Solid State and Material Research, IFW-Dresden, 01171 Dresden Germany (Germany); Institut für Festkörperphysik, Technische Universität Dresden, 01069 Dresden (Germany); Büchner, Bernd [Leibniz-Institute for Solid State and Material Research, IFW-Dresden, 01171 Dresden Germany (Germany); Center for Transport and Devices of Emergent Materials, Technische Universität Dresden, 01069 Dresden (Germany); Institut für Festkörperphysik, Technische Universität Dresden, 01069 Dresden (Germany)

    2016-10-15

    Highlights: • Synthesis of polycrystalline LiFeAs in a very broad heating temp. range (200–900 °C). • These samples are characterized by various physical and magnetic measurements. • Interestingly, the LiFeAs phase starts to form at 200 °C with T{sub c} of 19.2 K. • 600 °C synthesis temperature yields optimal high quality polycrystalline LiFeAs. • The properties of the best sample are consistent with that of LiFeAs single crystal. - Abstract: We present a study of parameter optimization for synthesizing truly stoichiometric polycrystalline LiFeAs. Stoichiometric LiFeAs has been prepared in a very broad range of synthesis temperature (200–900 °C) under otherwise exactly the same conditions, and has been characterized by structural, magnetic, transport, nuclear quadrupole resonance (NQR), and specific heat measurements. Our study showed that the LiFeAs phase is formed at 200 °C with a large amount of impurity phases. The amount of these impurity phases reduces with increasing synthesis temperature and the clean LiFeAs phase is obtained at a synthesis temperature of 600 °C. Magnetic susceptibility and resistivity measurements confirmed that the superconducting properties such as the critical temperature T{sub c}, and the upper critical field H{sub c2} do not depend on the synthesis temperature (≤ 700 °C), remaining at almost the same value of ∼19 K and ∼40 T, respectively. However, the width ΔT{sub c} of the transition and the NQR line width decrease with increasing the synthesis temperature and reached to minimum value for the synthesis temperature of 600 °C. Our careful analysis suggests that the best sample obtained at 600 °C is optimal concerning the low resistivity, high residual resistivity ratio (RRR), low ΔT{sub c}, high T{sub c} and H{sub c2}, and a small NQR line width with values which are comparable to that reported for LiFeAs single crystals. Specific heat measurements confirmed the bulk superconducting nature of the samples

  9. Study of chemical and physical properties of irradiated Guar Gum

    International Nuclear Information System (INIS)

    Hussein, H. A. S.

    2012-07-01

    This study was carried out to evaluate the effect of different gamma radiation doses to decontamination of micro-organisms present in Guar Gum powder. As well as to study the effect of radiation on the chemical and physical properties of the carbohydrate components of the Gum's material. Two types of samples were used in this study (powder and liquid). All samples were collected from commercially available Guar Gum (G G), which were obtained from the company (Sudanese Guar Gum ltd). Samples putted in polyethylene tightly closed container, then irradiated by applying different doses (2.5, 5, 7.5, 10, 20,30,40,and 50 kGy) from Co-60 source at room temperature in air. And take zero kGy as control. Irradiated powder samples of (2.5, 5, 7.5, 10 kGy) were investigated for contamination by using growth media agar and the result showed that 2.5 kGy is appropriate dose to remove the contamination of the samples. And then analyzed using fourier transform infrared (FTTR) x-ray fluorescence (X RF) and spectroscopy. The FTIR spectroscopy results suggested that there were no major chemical functional group transformation during irradiation. No change occurs by using low dose as 2.5 kGy. Also evaluation impact of radiation on liquid Samples (Aqueous solutions prepared in tow concentration of 1% and 5% wv that is by exposing the samples to the same dose of gamma rays) the effect of irradiation on it were investigated by using ultra violet spectroscopy ( UV.Vis), results showed that low dose has steeply effect in solutions specially in low concentration, it was more pronoun than that in high concentration, high dose has made change similar to that it made in powder. Also for both concentrations of liquid samples and for solutions made of irradiated powder pH measured and viscosity which used in investigations of molecular weight of liquid and powder, comparing the results of impact in the form of powder with the results of effects in the solutions found that the effects of

  10. Optical and physical properties of ceramic crystal laser materials

    Science.gov (United States)

    Simmons, Jed A.

    Historically ceramic crystal laser material has had disadvantages compared to single crystal laser material. However, progress has been made in the last decade and a half to overcome the disadvantages associated with ceramic crystal. Today, because of the promise of ceramic crystal as a high power laser material, investigation into its properties, both physical and optical, is warranted and important. Thermal expansion was measured in this thesis for Nd:YAG (yttrium aluminum garnet) ceramic crystal using an interferometric method. The interferometer employed a spatially filtered HeNe at 633 nm wavelength. Thermal expansion coefficients measured for the ceramic crystal samples were near the reported values for single crystal Nd:YAG. With a similar experimental setup as that for the thermal expansion measurements, dn/dT for ceramic crystal Nd:YAG was measured and found to be slightly higher than the reported value for single crystal. Depolarization loss due to thermal gradient induced stresses can limit laser performance. As a result this phenomenon was modeled for ceramic crystal materials and compared to single crystals for slab and rod shaped gain media. This was accomplished using COMSOL Multiphysics, and MATLAB. Results indicate a dependence of the depolarization loss on the grain size where the loss decreases with decreased grain size even to the point where lower loss may be expected in ceramic crystals than in single crystal samples when the grain sizes in the ceramic crystal are sufficiently small. Deformation-induced thermal lensing was modeled for a single crystal slab and its relevance to ceramic crystal is discussed. Data indicates the most notable cause of deformation-induced thermal lensing is a consequence of the deformation of the top and bottom surfaces. Also, the strength of the lensing along the thickness is greater than the width and greater than that due to other causes of lensing along the thickness of the slab. Emission spectra, absorption

  11. Physical and chemical properties of long-term salinized soils

    Directory of Open Access Journals (Sweden)

    Celestino Ruggiero

    2011-02-01

    Full Text Available In some areas, particularly in the Mediterranean regions, saline water is a source of water for crop irrigation. Consequently during the time, the use of this water may cause significant modifications of the soil physic-chemical properties and plant toxicity. The purpose of this investigation was to assess the variation of soil stability index and of ECe, ESP, pH, exchangeable potassium, bulk density, soil hydraulic conductivity and water retention curve (h(θ, for a clay sandy soil, which was irrigated over 12 years with saline water. The soil stability index was evaluated by 2 methods: after wetting the sample (Water Stability Index = WSI and without the pre-wetting step (Water Stability Dry Index = WSDI. The measures have been taken at three depths along the soil profile: 0-0.30, 0.30-0.60 and 0.60-0.90 m. The saline water was obtained by adding commercial sea salt to the irrigation water with the result of a final concentrations of 0.25 (2.5 g l-1, 0.5 (5 g l-1 and 1% (10 g l-1. A non-salinized control was also included. The increasing salinity of the irrigation water increased at all the depths ECe, ESP and pH, while exchangeable potassium decreased. Assessment of soil aggregates stability without samples pre-wetting (WSDI allowed us to better discriminate among the different samples examined. Aggregate stability for each of the soil layers decreased at increasing salinity of the irrigation water. Long term salinization affected the aggregate stability of the deepest layers. The soil hydraulic conductivity decreased also, while bulk density increased. The shape of the soil water retention curve was also affected by salinity. In the salinized plots less water is relaxed within -150 ÷ -12 cm ψ range. The available water was reduced at increasing salinity. Irrigation with saline water on clay-sandy soils increases ECe, pH and ESP, all of which negatively affect the soil aggregate stability. Damage to the soil structure remarkably reduces the

  12. Physical and chemical properties of long-term salinized soils

    Directory of Open Access Journals (Sweden)

    Celestino Ruggiero

    2006-06-01

    Full Text Available In some areas, particularly in the Mediterranean regions, saline water is a source of water for crop irrigation. Consequently during the time, the use of this water may cause significant modifications of the soil physic-chemical properties and plant toxicity. The purpose of this investigation was to assess the variation of soil stability index and of ECe, ESP, pH, exchangeable potassium, bulk density, soil hydraulic conductivity and water retention curve (h(θ, for a clay sandy soil, which was irrigated over 12 years with saline water. The soil stability index was evaluated by 2 methods: after wetting the sample (Water Stability Index = WSI and without the pre-wetting step (Water Stability Dry Index = WSDI. The measures have been taken at three depths along the soil profile: 0-0.30, 0.30-0.60 and 0.60-0.90 m. The saline water was obtained by adding commercial sea salt to the irrigation water with the result of a final concentrations of 0.25 (2.5 g l-1, 0.5 (5 g l-1 and 1% (10 g l-1. A non-salinized control was also included. The increasing salinity of the irrigation water increased at all the depths ECe, ESP and pH, while exchangeable potassium decreased. Assessment of soil aggregates stability without samples pre-wetting (WSDI allowed us to better discriminate among the different samples examined. Aggregate stability for each of the soil layers decreased at increasing salinity of the irrigation water. Long term salinization affected the aggregate stability of the deepest layers. The soil hydraulic conductivity decreased also, while bulk density increased. The shape of the soil water retention curve was also affected by salinity. In the salinized plots less water is relaxed within -150 ÷ -12 cm ψ range. The available water was reduced at increasing salinity. Irrigation with saline water on clay-sandy soils increases ECe, pH and ESP, all of which negatively affect the soil aggregate stability. Damage to the soil structure remarkably reduces the

  13. Physical Properties and Crop Management for Corn in an Albaqualf

    Directory of Open Access Journals (Sweden)

    Robson Giacomeli

    Full Text Available ABSTRACT Rice monoculture in lowlands can cause problems for management practices in crop fields, for example, in weed control. For this reason, corn in rotation with irrigated rice in lowlands may be advantageous, despite problems with soil compaction and water excess. The objective of this study was to evaluate soil physical properties and corn performance in soil management systems in an Albaqualf soil (lowlands. Two experiments were conducted in the field, in the 2013/14 and 2014/15 crop seasons. The experimental design was randomized blocks with two factors. There were three levels for the first factor, consisting of soil management practices: soil chiseling 45 days before sowing to a depth of 0.3 m; conventional tillage with two diskings to a depth of 0.1 m and subsequent leveling of the soil; and no-till. The second factor was composed of two levels: sowing on raised seedbeds, and without raised seedbeds. The soil parameters of bulk density, total porosity, macroporosity, microporosity, volumetric moisture, and soil resistance to mechanical penetration (RP were evaluated. The corn parameters were plant height, shoot dry matter, leaf area, height of the first ear of corn, grains per ear, and grain yield. Soil chiseling resulted in lower RP and higher macroporosity in the 0.1-0.2 and 0.2-0.3 m layers. In raised seedbeds, the 0.00-0.05, 0.05-0.10, and 0.10-0.20 m layers were lower in RP and bulk density. Moreover, higher soil macroporosity was observed in relation to the treatment without raised seedbeds. In general, the highest grain yields were found in the treatments with lower RP and higher macroporosity in the root system region. Increased porosity accelerated water drainage in the soil, reducing the time that soil airspace was filled with water, which is a limiting factor for root development. In Albaqualf soils, planting corn in chiseled soil provides higher corn yields compared to conventional tillage, and planting corn on raised

  14. Physical and Mechanical Properties of Pasir-pasir Wood (Xanthophyllum SP) From North Sumatera

    OpenAIRE

    Sunandar, Ahmad Dany

    2007-01-01

    As a lasser know species, it is important to explore physical and mechanical properties of pasi-pasir (Xanthophyllum sp) wood. This research was conducted to observe physical and mechanical properties of pasir-pasir (Xanthophyllum sp) originated from North Sumatera. Sample were collected from North Tapanuli District, North Sumatera. Tree samples were divided into three sections and sampled for physical and mechanical test were collected from every section. The results revealed that this wood ...

  15. Effect of barium doping on the physical properties of zinc oxide ...

    Indian Academy of Sciences (India)

    2015-11-27

    Home; Journals; Pramana – Journal of Physics; Volume 87; Issue 1. Effect of barium doping on the physical properties of zinc oxide ... Proceedings of the International Workshop/Conference on Computational Condensed Matter Physics and Materials Science (IWCCMP-2015). Posted on November 27, 2015. Guest Editors: ...

  16. High-pressure physical properties of magnesium silicate post ...

    Indian Academy of Sciences (India)

    Department of Physics, Lanzhou City University, Lanzhou 730070, China; School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070, China; State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050, China; Laboratory for Shock ...

  17. PREFACE: Nanoscale science and technology

    Science.gov (United States)

    Bellucci, Stefano

    2008-11-01

    modulated by tuning the strength of the spin-orbit interaction as well as by changing a constructive parameter of the junctions. Nanomechanical properties of conch shell by M Petraroli, showed how to use nanoindentation methods to explore, at the nanoscale, the mechanical properties of the Conus Mediterraneus conch, in order to compare nanohardness and elastic modulus with respect to the microstructural architecture and sample orientation. For the experimental tests a Nano Indenter XP (MTS Nano Instruments, Oak Ridge TN) has been used. The mechanical tests have been carried out on the inner surface of the shell and on three layers of its cross section (inner, middle and outer). On each of these surfaces the indentation has been performed at different maximum depth: from 250 nm to 4 μm, with a step of 250 nm. Data obtained suggest the following considerations: the inner surface of the conch shell, from the mechanical point of view, results homogeneous, while the shell structure is not homogeneous along its cross section; nanohardness and elastic modulus grow from the inner side to the outer side. No sensible difference has been observed with regards to the nanoindentation depth. The analysis supports the idea that artificial bio-inspired super-composites could be realized in the near future. CsPbCl3 nanocrystals dispersed in the Rb0,8Cs0,2Cl matrix: vibrational studies by P Savchyn reported the results of the infrared spectroscopy measurements and analysis intended to clarify the influence of CsPbCl3 nano-complexes, dispersed in the Rb0,8Cs0,2Cl matrix on the vibrational spectra of the host. Selected papers, based on conference original presentations and follow-up discussions, appear in the present dedicated issue of Journal of Physics: Condensed Matter. Tutorial lectures delivered at the school will be published by Springer Verlag Heidelberg, Germany, in their Lecture Notes in Nanoscale Science and Technology Series. The next edition of the meeting, n&n2008, planned in 20

  18. Patterns and determinants of wood physical and mechanical properties across major tree species in China.

    Science.gov (United States)

    Zhu, JiangLing; Shi, Yue; Fang, LeQi; Liu, XingE; Ji, ChengJun

    2015-06-01

    The physical and mechanical properties of wood affect the growth and development of trees, and also act as the main criteria when determining wood usage. Our understanding on patterns and controls of wood physical and mechanical properties could provide benefits for forestry management and bases for wood application and forest tree breeding. However, current studies on wood properties mainly focus on wood density and ignore other wood physical properties. In this study, we established a comprehensive database of wood physical properties across major tree species in China. Based on this database, we explored spatial patterns and driving factors of wood properties across major tree species in China. Our results showed that (i) compared with wood density, air-dried density, tangential shrinkage coefficient and resilience provide more accuracy and higher explanation power when used as the evaluation index of wood physical properties. (ii) Among life form, climatic and edaphic variables, life form is the dominant factor shaping spatial patterns of wood physical properties, climatic factors the next, and edaphic factors have the least effects, suggesting that the effects of climatic factors on spatial variations of wood properties are indirectly induced by their effects on species distribution.

  19. Soil chemical and physical properties that differentiate urban land-use and cover types

    Science.gov (United States)

    R.V. Pouyat; I.D. Yesilonis; J. Russell-Anelli; N.K. Neerchal

    2007-01-01

    We investigated the effects of land use and cover and surface geology on soil properties in Baltimore, MD, with the objectives to: (i) measure the physical and chemical properties of surface soils (0?10 cm) by land use and cover; and (ii) ascertain whether land use and cover explain differences in these properties relative to surface geology. Mean and median values of...

  20. Molecular Photovoltaics in Nanoscale Dimension

    Directory of Open Access Journals (Sweden)

    Andrei V. Pakoulev

    2011-01-01

    Full Text Available This review focuses on the intrinsic charge transport in organic photovoltaic (PVC devices and field-effect transistors (SAM-OFETs fabricated by vapor phase molecular self-assembly (VP-SAM method. The dynamics of charge transport are determined and used to clarify a transport mechanism. The 1,4,5,8-naphthalene-tetracarboxylic diphenylimide (NTCDI SAM devices provide a useful tool to study the fundamentals of polaronic transport at organic surfaces and to discuss the performance of organic photovoltaic devices in nanoscale. Time-resolved photovoltaic studies allow us to separate the charge annihilation kinetics in the conductive NTCDI channel from the overall charge kinetic in a SAM-OFET device. It has been demonstrated that tuning of the type of conductivity in NTCDI SAM-OFET devices is possible by changing Si substrate doping. Our study of the polaron charge transfer in organic materials proposes that a cation-radical exchange (redox mechanism is the major transport mechanism in the studied SAM-PVC devices. The role and contribution of the transport through delocalized states of redox active surface molecular aggregates of NTCDI are exposed and investigated. This example of technological development is used to highlight the significance of future technological development of nanotechnologies and to appreciate a structure-property paradigm in organic nanostructures.

  1. Molecular photovoltaics in nanoscale dimension.

    Science.gov (United States)

    Burtman, Vladimir; Zelichonok, Alexander; Pakoulev, Andrei V

    2011-01-05

    This review focuses on the intrinsic charge transport in organic photovoltaic (PVC) devices and field-effect transistors (SAM-OFETs) fabricated by vapor phase molecular self-assembly (VP-SAM) method. The dynamics of charge transport are determined and used to clarify a transport mechanism. The 1,4,5,8-naphthalene-tetracarboxylic diphenylimide (NTCDI) SAM devices provide a useful tool to study the fundamentals of polaronic transport at organic surfaces and to discuss the performance of organic photovoltaic devices in nanoscale. Time-resolved photovoltaic studies allow us to separate the charge annihilation kinetics in the conductive NTCDI channel from the overall charge kinetic in a SAM-OFET device. It has been demonstrated that tuning of the type of conductivity in NTCDI SAM-OFET devices is possible by changing Si substrate doping. Our study of the polaron charge transfer in organic materials proposes that a cation-radical exchange (redox) mechanism is the major transport mechanism in the studied SAM-PVC devices. The role and contribution of the transport through delocalized states of redox active surface molecular aggregates of NTCDI are exposed and investigated. This example of technological development is used to highlight the significance of future technological development of nanotechnologies and to appreciate a structure-property paradigm in organic nanostructures.

  2. Physical and strength properties of Azadirachta indica , (a. Juss ...

    African Journals Online (AJOL)

    A total of 160 test samples were used from three trees randomly selected from the study area. Preparations of test samples, actual testing and determination of different properties were carried out following standard methods. All strength property values were adjusted to 12% moisture content. Results showed A. indica to ...

  3. Influence of Different Waxes on the Physical Properties of Linear ...

    African Journals Online (AJOL)

    The influence of three different waxes on the thermal and mechanical properties of linear low-density polyethylene (LLDPE) was investigated. The samples were prepared through melt blending in a Brabender mixer. The thermal properties of the samples were determined using differential scanning calorimetry (DSC) and ...

  4. High-pressure physical properties of magnesium silicate post ...

    Indian Academy of Sciences (India)

    lable experimental results and the recent theoretical results. The Debye temperature, heat capacity and thermal ... experimental determination of elastic properties at extreme conditions is, however, not an easy task. ... Determination of thermal properties of MgSiO3 post- perovskite is of particular geophysical interest ...

  5. Nanoscale Architectures for Energy Applications

    Science.gov (United States)

    Wong, Stanislaus

    2009-03-01

    In my group, we have developed a number of different potential architecture systems for gaining insights into energy storage and photovoltaics. In one manifestation of our efforts, generating a heterojunction comprising nanotubes and nanocrystals, externally bound and connected, has been significant. The unique, innovative, and important aspect of this particular nanoscale architecture is that it takes advantage of the tunability, in terms of size, shape, and chemistry, of nanotubes and nanocrystals, to create a sharp junction interface, whose properties are inherently manipulable, tailorable, and hence, predictable. For example, the electrical resistance of nanotube-nanoparticle networks is dependent on the nanoscale junctions that exist between these constituent nanomaterials as well as on microscale and macroscale connectivity. Thus, rational design of these nanomaterials is critical to a fundamental understanding of charge transport in single molecules and the determination of their conductance. Results on these systems can therefore be used to increase understanding of intrinsic factors affecting carrier mobility, such as electronic structure, carrier trapping, and delocalization. In a second manifestation, three-dimensional, dendritic micron- scale spheres of alkali metal hydrogen titanate 1D nanostructures (i.e.: nanowires and nanotubes) have been generated using a modified hydrothermal technique in the presence of hydrogen peroxide and an alkali metal hydroxide solution. Sea-urchin-like assemblies of these 1D nanostructures have been transformed into their hydrogen titanate analogues by neutralization as well as into their corresponding semiconducting, anatase titania nanostructured counterparts through a moderate high-temperature annealing dehydration process without destroying the 3D hierarchical structural motif. The as-prepared hollow spheres of titanate and titania 1D nanostructures have overall diameters, ranging from 0.8 μm to 1.2 μm, while the

  6. Physics understanding the properties of matter and energy

    CERN Document Server

    2015-01-01

    Without physics, modern life would not exist. Instead of electric light, we would read by the light of candles. We couldn''t build skyscrapers. We could not possibly bridge rivers, much less build a jet or interplanetary craft. Computers and smartphones would be unimaginable. Physics is concerned with the most fundamental aspects of matter and energy and how they interact to make the physical universe work. In accessible language and with explanatory graphics and visual aids, this book introduces readers to the science that is at the very center of all other sciences and essential to our very

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

    Science.gov (United States)

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

  8. Effects of welding and post-weld heat treatments on nanoscale precipitation and mechanical properties of an ultra-high strength steel hardened by NiAl and Cu nanoparticles

    International Nuclear Information System (INIS)

    Jiao, Z.B.; Luan, J.H.; Guo, W.; Poplawsky, J.D.; Liu, C.T.

    2016-01-01

    The effects of welding and post-weld heat treatment (PWHT) on nanoscale co-precipitation, grain structure, and mechanical properties of an ultra-high strength steel were studied through a combination of atom probe tomography (APT) and mechanical tests. Our results indicate that the welding process dissolves all pre-existing nanoparticles and causes grain coarsening in the fusion zone, resulting in a soft and ductile weld without any cracks in the as-welded condition. A 550 °C PWHT induces fine-scale re-precipitation of NiAl and Cu co-precipitates with high number densities and ultra-fine sizes, leading to a large recovery of strength but a loss of ductility with intergranular failure, whereas a 600 °C PWHT gives rise to coarse-scale re-precipitation of nanoparticles together with the formation of a small amount of reverted austenite, resulting in a great recovery in both strength and ductility. Our analysis indicates that the degree of strength recovery is dependent mainly upon the re-precipitation microstructure of nanoparticles, together with grain size and reversion of austenite, while the ductility recovery is sensitive to the grain-boundary structure. APT reveals that the grain-boundary segregation of Mn and P may be the main reason for the 550 °C embrittlement, and the enhanced ductility at 600 °C is ascribed to a possible reduction of the segregation and reversion of austenite.

  9. An ontology on property for physical, chemical, and biological systems.

    Science.gov (United States)

    Dybkaer, René

    2004-01-01

    Current metrological literature, including the International vocabulary of basic and general terms in metrology (VIM 1993), presents a special language slowly evolved without consistent use of the procedures of terminological work; furthermore, nominal properties are excluded by definition. Both deficiencies create problems in fields, such as laboratory medicine, which have to report results of all types of property, preferably in a unified systematic format. The present text aims at forming a domain ontology around "property", with intensional definitions and systematic terms, mainly using the terminological tools--with some additions--provided by the International Standards ISO 704, 1087-1, and 10241. "System" and "component" are defined, "quantity" is discussed, and the generic concept "property" is given as 'inherent state- or process-descriptive feature of a system including any pertinent components'. Previously, the term 'kind-of-quantity' and quasi-synonyms have been used as primitives; the proposed definition of "kind-of-property" is 'common defining aspect of mutually comparable properties'. "Examination procedure", "examination method", "examination principle", and "examination" are defined, avoiding the term 'test'. The need to distinguish between instances of "characteristic", "property", "type of characteristic", "kind-of-property", and "property value" is emphasized; the latter is defined together with "property value scale". These fundamental concepts are presented in a diagram, and the effect of adding essential characteristics to give expanded definitions is exemplified. Substitution usually leads to unwieldy definitions, but reveals circularity as does exhaustive consecutive listing of defining concepts. The top concept may be generically divided according to many terminological dimensions, especially regarding which operators are allowed among the four sets =, not equal to; ; +, -; and x, :. The coordinate concepts defined are termed by the

  10. Geophysical testing of rock and its relationships to physical properties

    Science.gov (United States)

    2011-02-01

    Testing techniques were designed to characterize spatial variability in geotechnical engineering physical parameters of : rock formations. Standard methods using seismic waves, which are routinely used for shallow subsurface : investigation, have lim...

  11. Structural Dependence of Physical Properties in Sodium Boroaluminosilicate Glasses

    DEFF Research Database (Denmark)

    Zheng, Qiuju; Potuzak, Marcel; Mauro, John C.

    Boroaluminosilicate glasses have found applications in many fields. The extent and nature of the mixing of network formers like SiO2, B2O3, and Al2O3 play an important role in controlling the macroscopic properties. To understand the structure-property correlations in these glasses, we study...... a series of sodium boroaluminosilicate glasses with various [Al2O3]/[SiO2] ratios to access different regimes of sodium behavior. We determine dynamic properties, elastic moduli, and hardness of these glasses. The results reveal an existence of local minimum for density, fragility index, Young’s and shear...

  12. Lunar physical properties from analysis of magnetometer data

    Science.gov (United States)

    Daily, W. D.

    1979-01-01

    The electromagnetic properties of the lunar interior are discussed with emphasis on (1) bulk, crustal, and local anomalous conductivity; (2) bulk magnetic permeability measurements, iron abundance estimates, and core size limits; (3) lunar ionosphere and atmosphere; and (4) crustal magnetic remanence: scale size measurements and constraints on remanence origin. Appendices treat the phase relationship between the energetic particle flux modulation and current disc penetrations in the Jovian magnetosphere (Pioneer 10 inbound) theories for the origin of lunar magnetism; electrical conductivity anomalies associated with circular lunar maria; electromagnetic properties of the Moon; Mare Serenitatis conductivity anomaly detected by Apollo 16 and Lunokhod 2 magnetometers; and lunar properties from magnetometer data: effects of data errors.

  13. Micro- and nanoscale phenomena in tribology

    CERN Document Server

    Chung, Yip-Wah

    2011-01-01

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

  14. Nanoscale microwave microscopy using shielded cantilever probes

    KAUST Repository

    Lai, Keji

    2011-04-21

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

  15. Physical, sensory and chemical properties of bread prepared from ...

    African Journals Online (AJOL)

    , sensory and chemical properties of bread prepared from wheat and vitamin A enriched cassava flour blends. Materials and Methods: Cissus gum was extracted from cissus stem and prepared into powder while vitamin A enriched cassava ...

  16. Permeation Behavior and Physical Properties of Natural Rubber Nanocomposites

    National Research Council Canada - National Science Library

    Zukas, Walter; Sennett, Michael; Welsh, Elizabeth; Rodriguez, Axel; Ziegler, David; Touchet, Paul

    2004-01-01

    .... A study was carried out to examine the effects of varying nanoparticle morphology and composition on the mechanical and barrier properties of polymer nanocomposites made with natural rubber (NR...

  17. SYNTHSIS AND PHYSICAL PROPERTIES OF SILVER NANOCOMPOSITES POLYMER ELECTROLYTE

    OpenAIRE

    加藤, 仁和

    2016-01-01

    The silver nano composite polymer electrolytes are prepared by the method of two kinds of the ultrafine particle direct dispersion method and in situ synthesis. The structure of the silver nano composite polymer electrolyte is characterized by Fourier transform infrared spectrometer spectrophotometer (FT-IR), Raman spectroscopy (Raman), and Thermally Stimulated Current (TSC) .The optical property is evaluated by the optical absorption. The electrical property is also evaluated by the ac i...

  18. SIFAT FISIK, KIMIA, DAN FUNGSIONAL DAMAR [Brief Review on: Physical, Chemical and Functional Properties of Dammar

    Directory of Open Access Journals (Sweden)

    Noryawati Mulyono1

    2004-12-01

    Full Text Available Dammar is one of Indonesian forestry products which is abundant. It has unique physical, chemical and functional properties. The important physical properties of dammar include its solubility in some organic solvents, softening temperature, viscosity and its absorbance. The important chemical properties reviewed here include its properties as resin, composition of terpenoid compounds present in dammar, and essential oil yielded from distillation of fresh dammar. Physical and chemical properties of dammar need to be studied further in order to optimize its functional properties. So far, dammar is widely used as weighting agent and source of essential oil. However, now, some species of dammar are being explored and developed for sal flour, fat source, triacylglycerol substituent for cocoa butter and wood preservatives.

  19. Integrating Condensed Matter Physics into a Liberal Arts Physics Curriculum

    Science.gov (United States)

    Collett, Jeffrey

    2008-03-01

    The emergence of nanoscale science into the popular consciousness presents an opportunity to attract and retain future condensed matter scientists. We inject nanoscale physics into recruiting activities and into the introductory and the core portions of the curriculum. Laboratory involvement and research opportunity play important roles in maintaining student engagement. We use inexpensive scanning tunneling (STM) and atomic force (AFM) microscopes to introduce students to nanoscale structure early in their college careers. Although the physics of tip-surface interactions is sophisticated, the resulting images can be interpreted intuitively. We use the STM in introductory modern physics to explore quantum tunneling and the properties of electrons at surfaces. An interdisciplinary course in nanoscience and nanotechnology course team-taught with chemists looks at nanoscale phenomena in physics, chemistry, and biology. Core quantum and statistical physics courses look at effects of quantum mechanics and quantum statistics in degenerate systems. An upper level solid-state physics course takes up traditional condensed matter topics from a structural perspective by beginning with a study of both elastic and inelastic scattering of x-rays from crystalline solids and liquid crystals. Students encounter reciprocal space concepts through the analysis of laboratory scattering data and by the development of the scattering theory. The course then examines the importance of scattering processes in band structure and in electrical and thermal conduction. A segment of the course is devoted to surface physics and nanostructures where we explore the effects of restricting particles to two-dimensional surfaces, one-dimensional wires, and zero-dimensional quantum dots.

  20. Statistical physics ""Beyond equilibrium

    Energy Technology Data Exchange (ETDEWEB)

    Ecke, Robert E [Los Alamos National Laboratory

    2009-01-01

    The scientific challenges of the 21st century will increasingly involve competing interactions, geometric frustration, spatial and temporal intrinsic inhomogeneity, nanoscale structures, and interactions spanning many scales. We will focus on a broad class of emerging problems that will require new tools in non-equilibrium statistical physics and that will find application in new material functionality, in predicting complex spatial dynamics, and in understanding novel states of matter. Our work will encompass materials under extreme conditions involving elastic/plastic deformation, competing interactions, intrinsic inhomogeneity, frustration in condensed matter systems, scaling phenomena in disordered materials from glasses to granular matter, quantum chemistry applied to nano-scale materials, soft-matter materials, and spatio-temporal properties of both ordinary and complex fluids.

  1. Magnetism, chemical bonding and hyperfine properties in the nanoscale antiferromagnet [Fe(O Me)2(O2 C C H2 Cl)]10

    International Nuclear Information System (INIS)

    Zeng, Z.; Duan, Y.; Guenzburger, Diana

    1996-09-01

    The electronic and magnetic properties of the nanometer-size antiferromagnet (the ferric wheel molecule) are investigated with the first-principles spin-polarized Discrete Variational Method, in the framework of Density Functional theory. Magnetic moments, densities of the states and charge and spin-density maps are obtained. The Moessbauer hyperfine parameters Isomer shift, Quadrupole Splitting and Hyperfine Field are obtained from the calculations and compared to reported experimental values when available. (author). 33 refs., 8 figs., 4 tabs

  2. Nanoscale waveguiding methods

    Directory of Open Access Journals (Sweden)

    Wang Chia-Jean

    2007-01-01

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

  3. Ultrasound-assisted synthesis of poly(MMA-co-BA)/ZnO nanocomposites with enhanced physical properties.

    Science.gov (United States)

    Poddar, Maneesh Kumar; Sharma, Sachin; Pattipaka, Srinivas; Pamu, D; Moholkar, Vijayanand S

    2017-11-01

    The present study reports synthesis and characterization of poly(MMA-co-BA)/ZnO nanocomposites using ultrasound-assisted in-situ emulsion polymerization. Methyl methacrylate (MMA) was copolymerized with butyl acrylate (BA), for enhanced ductility of copolymer matrix, in presence of nanoscale ZnO particles. Ultrasound generated strong micro-turbulence in reaction mixture, which resulted in higher encapsulation and uniform dispersion of ZnO (in native form - without surface modification) in polymer matrix, as compared to mechanical stirring. The nanocomposites were characterized for physical properties and structural morphology using standard techniques such as XRD, FTIR, particle size analysis, UV-Visible spectroscopy, electrical conductivity, TGA, DSC, FE-SEM and TEM. Copolymerization of MMA and BA (in presence of ZnO) followed second order kinetics. Thermal stability (T 10% =324.9°C) and glass transition temperature (T g =67.8°C) of poly(MMA-co-BA)/ZnO nanocomposites showed significant enhancement (35.1°C for 1wt% ZnO and 15.7°C for 4wt% ZnO, respectively), as compared to pristine poly(MMA-co-BA). poly(MMA-co-BA)/ZnO (5wt%) nanocomposites possessed the highest electrical conductivity of 0.192μS/cm and peak UV absorptivity of 0.55 at 372nm. Solution rheological study of nanocomposites revealed enhancement in viscosity with increasing ZnO loading. Maximum viscosity of 0.01Pa-s was obtained for 5wt% ZnO loading. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. PHYSICS

    CERN Multimedia

    D. Acosta

    2010-01-01

    A remarkable amount of progress has been made in Physics since the last CMS Week in June given the exponential growth in the delivered LHC luminosity. The first major milestone was the delivery of a variety of results to the ICHEP international conference held in Paris this July. For this conference, CMS prepared 15 Physics Analysis Summaries on physics objects and 22 Summaries on new and interesting physics measurements that exploited the luminosity recorded by the CMS detector. The challenge was incorporating the largest batch of luminosity that was delivered only days before the conference (300 nb-1 total). The physics covered from this initial running period spanned hadron production measurements, jet production and properties, electroweak vector boson production, and even glimpses of the top quark. Since then, the accumulated integrated luminosity has increased by a factor of more than 100, and all groups have been working tremendously hard on analysing this dataset. The September Physics Week was held ...

  5. Correlations between physical properties of jawbone and dental implant initial stability.

    Science.gov (United States)

    Seong, Wook-Jin; Kim, Uk-Kyu; Swift, James Q; Hodges, James S; Ko, Ching-Chang

    2009-05-01

    There is confusion in the literature about how physical properties of bone vary between maxillary and mandibular regions and which physical properties affect initial implant stability. The purpose of this study was to determine correlations between physical properties of bone and initial implant stability, and to determine how physical properties and initial stability vary among regions of jawbone. Four pairs of edentulous maxillae and mandibles were retrieved from fresh human cadavers. Six implants per pair were placed in different anatomical regions (maxillary anterior, right and left maxillary posterior, mandibular anterior, right and left mandibular posterior). Immediately after surgery, initial implant stability was measured with a resonance frequency device and a tapping device. Implant surgeries and initial stability measurements were performed within 72 hours of death. Elastic modulus (EM) and hardness were measured using nano-indentation. Composite apparent density (cAD) was measured using Archimedes' principle. Bone-implant contact percentage and cortical bone thickness were recorded histomorphometrically. Mixed linear models and univariate-correlation analyses were used (alpha=.05). Generally, mandibular bone had higher initial implant stability and physical properties than maxillary bone. Initial implant stability was higher in the anterior region than in the posterior. EM was higher in the posterior region than in the anterior; the reverse was true for cAD. Of the properties evaluated, cAD had the highest correlation with initial implant stability (r=0.82). Both physical properties of bone and initial implant stability differed between regions of jawbone.

  6. STP: A mathematically and physically consistent library of steam properties

    International Nuclear Information System (INIS)

    Aguilar, F.; Hutter, A.C.; Tuttle, P.G.

    1982-01-01

    A new FORTRAN library of subroutines has been developed from the fundamental equation of Keenan et al. to evaluate a large set of water properties including derivatives such as sound speed and isothermal compressibility. The STP library uses the true saturation envelope of the Keenan et al. fundamental equation. The evaluation of the true envelope by a continuation method is explained. This envelope, along with other design features, imparts an exceptionally high degree of thermodynamic and mathematical consistency to the STP library, even at the critical point. Accuracy and smoothness, library self-consistency, and designed user convenience make the STP library a reliable and versatile water property package

  7. Nanoscale phase boundaries: a new twist to novel functionalities

    Science.gov (United States)

    Zhang, J. X.; Zeches, R. J.; He, Q.; Chu, Y.-H.; Ramesh, R.

    2012-09-01

    In functional materials, nanoscale phase boundaries exhibit exotic phenomena that are notably absent in their parent phases. Over the past two decades, much of the research into complex oxides (such as cuprate superconductors, CMR manganites and relaxor ferroelectrics) has demonstrated the key role that nanoscale inhomogeneities play in controlling the electronic and/or ionic structure of these materials. One of the key characteristics in such systems is the strong susceptibility to external perturbations, such as magnetic, electric and mechanical fields. A direct consequence of the accommodation of a large number of cationic substitutions in complex oxides is the emergence of a number of physical phenomena from essentially the same crystal framework. Recently, multiferroic behavior, which is characterized by the co-existence and potential coupling of multiple ferroic order parameters, has captured considerable worldwide research interest. The perovskite, BiFeO3, exhibits robust ferroelectricity coupled with antiferromagnetism at room temperature. A rather unique feature of this material system is its ability to ``morph'' its ground state when an external mechanical constraint is imposed on it. A particularly striking example is observed when a large (~4 to 5%) compressive strain is imposed on a thin film through the epitaxial constraint from the underlying substrate. Under these conditions, the ground state rhombohedral phase transforms into a tetragonal-like (or a derivative thereof) phase with a rather large unit cell (c/a ratio of ~1.26). When the epitaxial constraint is partially relaxed by increasing the film thickness, this tetragonal-like phase evolves into a ``mixed-phase'' state, consisting of a nanoscale admixture of the rhombohedral-like phase embedded in the tetragonal-like phase. Such a system gives us a new pathway to explore a variety of mechanical, magnetic and transport phenomena in constrained dimensions. This article reviews our progress to date

  8. Proximate, Physical And Sensory Properties Of Soy-Sweet Potato ...

    African Journals Online (AJOL)

    ... with those of cookies made from whole wheat. Results showed that there was no significant (p>0.05) difference in cookie physical characteristics, as compared with the control sample, except in spread factor and fragility. Cookie spread was found to be influenced by the presence of sugar, oil and water absorption of flour.

  9. Physical properties of seeds of African walnut ( Plukenetia ...

    African Journals Online (AJOL)

    A study of the physical and proximate traits of seeds of African walnut (Plukenetia conophorum) from four locations (states) in south-eastern Nigeria was carried out in 2011. The locations considered were Enugu, Anambra, Abia and Rivers. Results of statistical analysis showed remarkable variation (p < 0.05) in all the seed ...

  10. Evaluation of physical properties of different digital intraoral sensors.

    Science.gov (United States)

    Al-Rawi, Wisam; Teich, Sorin

    2013-09-01

    Digital technologies provide clinically acceptable results comparable to traditional films while having other advantages such as the ability to store and manipulate images, immediate evaluation of the image diagnostic quality, possible reduction in patient radiation exposure, and so on. The purpose of this paper is to present the results of the evaluation of the physical design of eight CMOS digital intraoral sensors. Sensors tested included: XDR (Cyber Medical Imaging, Los Angeles, CA, USA), RVG 6100 (Carestream Dental LLC, Atlanta, GA, USA), Platinum (DEXIS LLC., Hatfield, PA, USA), CDR Elite (Schick Technologies, Long Island City, NY, USA), ProSensor (Planmeca, Helsinki, Finland), EVA (ImageWorks, Elmsford, NY, USA), XIOS Plus (Sirona, Bensheim, Germany), and GXS-700 (Gendex Dental Systems, Hatfield, PA, USA). The sensors were evaluated for cable configuration, connectivity interface, presence of back-scattering radiation shield, plate thickness, active sensor area, and comparing the active imaging area to the outside casing and to conventional radiographic films. There were variations among the physical design of different sensors. For most parameters tested, a lack of standardization exists in the industry. The results of this study revealed that these details are not always available through the material provided by the manufacturers and are often not advertised. For all sensor sizes, active imaging area was smaller compared with conventional films. There was no sensor in the group that had the best physical design. Data presented in this paper establishes a benchmark for comparing the physical design of digital intraoral sensors.

  11. Probing the nanoscale phase separation and photophysics properties of low-bandgap polymer:fullerene blend film by near-field spectroscopic mapping.

    Science.gov (United States)

    Wang, Xiao; Azimi, Hamed; Mack, Hans-Georg; Morana, Mauro; Egelhaaf, Hans-Joachim; Meixner, Alfred J; Zhang, Dai

    2011-10-04

    The effect of the additive 1,8-octanedithiol (ODT) on the nanometer-scale morphology and local photophysical properties of low-bandgap polymer blends of poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b'] dithiophene)- alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) and [6,6]-phenyl C(61) -butyric acid methyl ester (PCBM) is investigated. Phase separations of the PCPDTBT:PCBM blend film induced by ODT are visualized by the morphological changes from fibril-shaped features to spherical bumps, by the dramatically increased photoluminescence emission from PCPDTBT that was originally largely quenched, and by the fluctuations of spectral features at different locations of the sample surface. The correlations between the morphology and the local photophysical properties of the blend film with/without ODT at both the micrometer and nanometer scales are revealed by confocal and high-resolution near-field spectroscopic mapping techniques. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Profile distribution of some physical and chemical properties of ...

    African Journals Online (AJOL)

    Silt showed high variability at all topographic positions while clay content was low at the crest and high at the middle and lower slopes. Lateral variability of the soil properties indicated high variability in clay fraction along the toposequence. Silt fraction, organic carbon and organic matter showed medium variability whereas ...

  13. Effect of ozone gas processing on physical and chemical properties ...

    African Journals Online (AJOL)

    In this study, the physiochemical properties of proteins. (i.e., gluten, glutenin, and gliadin) isolated from non-ozone-treated flour were examined by studying chemical characteristics using SDS-. PAGE, free SH groups, differential scanning calorimetry (DSC) parameters, secondary structure, and rheological measurements.

  14. Physical-Chemical Properties, Storage Stability and Sensory ...

    African Journals Online (AJOL)

    Physico-chemical properties, storage stability and sensory evaluation of pumpkin seed oil was carried out and compared with other vegetable oils commonly used in Tanzania in order to evaluate its potential as an edible oil with the aim of promoting its utilization in rural areas. Pumpkin seeds were collected from different ...

  15. Effect of solution physical chemistry on the rheological properties of ...

    African Journals Online (AJOL)

    Knowledge on rheological properties of sludge is important for the design of pumping and transport facilities and as a tool in process control during treatment. Concentrated activated sludge is known to behave as a non-Newtonian material. The contribution to non- Newtonian behaviour is believed to originate from the ...

  16. Influence of substrate temperature on certain physical properties ...

    Indian Academy of Sciences (India)

    MS received 16 July 2015; revised 19 November 2015; accepted 18 April 2016; published online 12 November 2016. Abstract. Nanocrystalline Ag-doped ... adhesive property. Moreover, silver-doped materials are chemically durable and release silver ions for a long period of time [11]. Silver-doped indium and ceram-.

  17. Evaluation of physical properties of locally produced Gonometa ...

    African Journals Online (AJOL)

    Silk is a luxurious fibre with a unique combination of properties. However, this and other factors such as the costly production process make silk a very expensive fabric and therefore unaffordable for many consumers. Mixed fabrics might provide a solution to this problem of relative cost if the Gonometa postica silk could be ...

  18. Some Physical Properties of Vernonia amygdalina and Garcinia ...

    African Journals Online (AJOL)

    The effect of polymer concentrations on some of the physicochemical properties of Vernonia amygdalina (Linn) and Garcinia kola (Heckel) extracts loaded microspheres was evaluated. Microspheres of the aqueous extracts was prepared by emulsion solvent evaporation using polyethylene glycol (PEG) mixtures of ...

  19. Antibacterial effects and physical properties of glass-ionomer cements containing chlorhexidine for the ART approach.

    NARCIS (Netherlands)

    Takahashi, Y.; Imazato, S.; Kaneshiro, A.V.; Ebisu, S.; Frencken, J.E.F.M.; Tay, F.R.

    2006-01-01

    OBJECTIVES: Since atraumatic restorative treatment (ART) involves removal of carious lesions with manual instruments, improvement of filling materials to guarantee greater success should be considered. This study aimed to evaluate antibacterial, physical, and bonding properties of glass-ionomer

  20. Material designs and new physical properties in MX- and MMX-chain compounds

    CERN Document Server

    Yamashita, Masahiro

    2014-01-01

    This book details the structures, physical properties, theoretical treatments, applications, and perspectives of MX and MMX chain compounds for chemists and physicists. It also examines various photoinduced phase transitions and their dynamics.

  1. Evaluation of correlation between physical properties and ultrasonic pulse velocity of fired clay samples.

    Science.gov (United States)

    Özkan, İlker; Yayla, Zeliha

    2016-03-01

    The aim of this study is to establish a correlation between physical properties and ultrasonic pulse velocity of clay samples fired at elevated temperatures. Brick-making clay and pottery clay were studied for this purpose. The physical properties of clay samples were assessed after firing pressed clay samples separately at temperatures of 850, 900, 950, 1000, 1050 and 1100 °C. A commercial ultrasonic testing instrument (Proceq Pundit Lab) was used to evaluate the ultrasonic pulse velocity measurements for each fired clay sample as a function of temperature. It was observed that there became a relationship between physical properties and ultrasonic pulse velocities of the samples. The results showed that in consequence of increasing densification of the samples, the differences between the ultrasonic pulse velocities were higher with increasing temperature. These findings may facilitate the use of ultrasonic pulse velocity for the estimation of physical properties of fired clay samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Physical properties of a sediment core from the Central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Khadge, N.H.

    A box core of 7.5 m was collected from the Central Indian Basin for the purpose of geotechnical studies and depthwise variation of physical properties and clay mineralogy. Water content, Atterberg limits, specific gravity are measured at regular...

  3. Physical and chemical properties of San Francisco Bay waters, 1969-1976 (NODC Accession 8400194)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — One magnetic tape containing the physical and chemical properties of San Francisco Bay waters was forwarded to NODC by Mr. Richard Smith of the U.S Geological Survey...

  4. some tensile properties of unsaturated polyester resin reinforced wi

    African Journals Online (AJOL)

    Dr Obe

    large improvement in physical and mechanical properties. Literature survey shows that these improvements are achieved with less than 10% volume additions of nanoscale particles (typically on the order of. 1% to 5% for layered silicates and carbon nanotubes), which is in sharp contrast to conventional polymer fillers [2].

  5. Nanoscale Electronic Devices

    Science.gov (United States)

    Jing, Xiaoye

    Continuous downscaling in microelectronics has pushed conventional CMOS technology to its physical limits, while Moore's Law has correctly predicted the trend for decades, each step forward is accompanied with unprecedented technological difficulties and near-exponential increase in cost. At the same time, however, demands for low-power, low-cost and high-speed devices have never diminished, instead, even more stringent requirements have been imposed on device performances. It is therefore crucial to explore alternative materials and device architectures in order to alleviate the pressure caused by downscaling. To this end, we investigated two different approaches: (1) InSb nanowire based field effect transistors (NWFETs) and (2) single walled carbon nanotube (SWCNT) -- peptide nucleic acid (PNA) --SWCNT conjugate. Two types of InSb nanowires were synthesized by template-assisted electrochemistry and chemical vapor deposition (CVD) respectively. In both cases, NWFETs were fabricated by electron beam lithography (EBL) and crystallinity was confirmed by transmission electron microscopy (TEM) and selected area diffraction (SAD) patterns. For electrochemistry nanowire, ambipolar conduction was observed with strong p-type conduction, the effect of thermal annealing on the conductivity was analyzed, a NWFET model that took into consideration the underlapped region in top-gated NWFET was proposed. Hole mobility in the channel was calculated to be 292.84 cm2V-1s -1 with a density of 1.5x1017/cm3. For CVD nanowire, the diameter was below 40nm with an average of 20nm. Vapor-liquid-solid (VLS) process was speculated to be the mechanism responsible for nanowire growth. The efficient gate control was manifested by high ION/I OFF ratio which was on the order of 106 and a small inverse subthreshold slope (functionalized single walled carbon nanotubes to synthesize the conjugate and characterized its electrical properties. Negative differential resistance (NDR) was observed

  6. Toxicity and physical properties of atrazine and its degradation products: A literature survey

    Energy Technology Data Exchange (ETDEWEB)

    Pugh, K.C.

    1994-10-01

    The Tennessee Valley Authority`s Environmental Research Center has been developing a means of detoxifying atrazine waste waters using TiO{sub 2} photocatalysis. The toxicity and physical properties of atrazine and its degradation products will probably be required information in obtaining permits from the United States Environmental Protection Agency for the demonstration of any photocatalytic treatment of atrazine waste waters. The following report is a literature survey of the toxicological and physical properties of atrazine and its degradation products.

  7. Comments on Thermal Physical Properties Testing Methods of Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Jingchao Xie

    2013-01-01

    Full Text Available There is no standard testing method of the thermal physical properties of phase change materials (PCM. This paper has shown advancements in this field. Developments and achievements in thermal physical properties testing methods of PCM were commented, including differential scanning calorimetry, T-history measurement, the water bath method, and differential thermal analysis. Testing principles, advantages and disadvantages, and important points for attention of each method were discussed. A foundation for standardized testing methods for PCM was made.

  8. PHYSICAL PROPERTIES OF CHESTNUT (Castanea sativa Mill. WOOD OBTAINED FROM MAÇKA-ÇATAK REGION

    Directory of Open Access Journals (Sweden)

    Nurgül Ay

    2002-04-01

    Full Text Available In this study, physical properties of chestnut were investigated. 8 trees used for experiments were obtained fromTrabzon-Maçka- Çatak region. Samples were prepared according to the related standarts. Oven-dried and air-dried density, volume weight, the amount of shrinkage, the ratio of cell walls, air cavities, the moisture content of wood at green condition, and the fiber saturation point as physical properties were determined.

  9. Optical generation of intense ultrashort magnetic pulses at the nanoscale

    Science.gov (United States)

    Tsiatmas, Anagnostis; Atmatzakis, Evangelos; Papasimakis, Nikitas; Fedotov, Vassili; Luk'yanchuk, Boris; Zheludev, Nikolay I.; García de Abajo, F. Javier

    2013-11-01

    Generating, controlling and sensing strong magnetic fields at ever shorter time and length scales is important for both fundamental solid-state physics and technological applications such as magnetic data recording. Here, we propose a scheme for producing strong ultrashort magnetic pulses localized at the nanoscale. We show that a bimetallic nanoring illuminated by femtosecond laser pulses responds with transient thermoelectric currents of picosecond duration, which in turn induce Tesla-scale magnetic fields in the ring cavity. Our method provides a practical way of generating intense nanoscale magnetic fields with great potential for materials characterization, terahertz radiation generation and data storage applications.

  10. Topology optimization for nano-scale heat transfer

    DEFF Research Database (Denmark)

    Evgrafov, Anton; Maute, Kurt; Yang, Ronggui

    2009-01-01

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

  11. Bacterial promoter prediction: Selection of dynamic and static physical properties of DNA for reliable sequence classification.

    Science.gov (United States)

    Ryasik, Artem; Orlov, Mikhail; Zykova, Evgenia; Ermak, Timofei; Sorokin, Anatoly

    2018-01-30

    Predicting promoter activity of DNA fragment is an important task for computational biology. Approaches using physical properties of DNA to predict bacterial promoters have recently gained a lot of attention. To select an adequate set of physical properties for training a classifier, various characteristics of DNA molecule should be taken into consideration. Here, we present a systematic approach that allows us to select less correlated properties for classification by means of both correlation and cophenetic coefficients as well as concordance matrices. To prove this concept, we have developed the first classifier that uses not only sequence and static physical properties of DNA fragment, but also dynamic properties of DNA open states. Therefore, the best performing models with accuracy values up to 90% for all types of sequences were obtained. Furthermore, we have demonstrated that the classifier can serve as a reliable tool enabling promoter DNA fragments to be distinguished from promoter islands despite the similarity of their nucleotide sequences.

  12. Gold processing residue from Jacobina Basin: chemical and physical properties

    OpenAIRE

    Lima, Luiz Rogério Pinho de Andrade; Bernardez, Letícia Alonso; Barbosa, Luís Alberto Dantas

    2007-01-01

    p. 848-852 Gold processing residues or tailings are found in several areas in the Itapicuru River region (Bahia, Brazil), and previous studies indicated significant heavy metals content in the river sediments. The present work focused on an artisanal gold processing residue found in a site from this region. Samples were taken from the processing residue heaps and used to perform a physical and chemical characterization study using X-ray diffraction, scanning electron microscopy, neutron...

  13. Physical properties of Kentucky's AML landslides: Case studies analyzed

    International Nuclear Information System (INIS)

    Iannacchione, A.T.; Vallejo, L.E.

    1994-01-01

    Once an abandoned mined land (AML) landslide occurs and is identified as an emergency, engineers must rapidly implement a slope stabilization design. Correct slope remediation solutions are generally derived from well-executed geotechnical examinations. This paper summarizes a large body of geotechnical data compiled by the US office of Surface Mining Reclamation and Enforcement (OSM) from AML landslides in eastern Kentucky. Special attention is placed on the examination of subsurface failures, phreatic water levels, soil profiles, and soil composition information from numerous borehole exploration programs. Strength properties calculated from laboratory procedures and stability analysis techniques were also reviewed. Laboratory-determined soil shear strength values were found to be higher than those inferred from stability analysis. This suggests that postfailure determinations of the phreatic surface may be largely inappropriate when used in stability analysis or that laboratory-measured shear strengths are ineffective in replicating in situ colluvium/spoil slope properties

  14. Physical properties of kraft black liquor. Final report. Phase I

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, A.L.

    1983-12-01

    Methods were selected, equipment installed, and procedures developed for determining rheological properties; for determining thermal properties (stability, density, thermal expansion, and heat capacity); for purification and characterization of lignin (glass transition, stability, weight average molecular weight, and number average molecular weight); and for performing chemical analyses (negative inorganic ions, positive inorganic ions, acid organic salts, lignin, and total solids). A strategy for pulping to supply test liquors was developed, and a statistically designed pulping experiment was specified for a Southern softwood species. Arrangements were made for performing initial pulping work in an industrial pilot plant, and a preliminary set of pulping experiments were conducted. Liquors from the preliminary pulping experiments were used to test procedures and to determine reproducibility of the experiment. Literature was also surveyed and preliminary selection of designs for a pilot digester, and for equipment to determine surface tension were made.

  15. Determination of physical properties of fibrous thermal insulation

    Directory of Open Access Journals (Sweden)

    Jeandel G.

    2012-10-01

    Full Text Available The objective of this study is to characterize both experimentally and theoretically, conductive and radiative heat transfer within polyester batting. This material is derived from recycled bottles (PET with fibres of constant diameters. Two other mineral and plant fibrous insulation materials, (glass wool and hemp wool are also characterized for comparative purposes. To determine the overall thermophysical properties of the tested materials, heat flux measurement are carried out using a device developed in house. The radiative properties of the material are determined by an inverse method based on measurements of transmittance and reflectance using a FTIR spectrometer and by solving the equation of radiative heat transfer. These measures are compared to results of numerical simulations.

  16. Physical properties of Cu nanoparticles: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Kart, H.H., E-mail: hkart@pau.edu.tr [Department of Physics, Pamukkale University, Kınıklı Campus, 20017 Denizli (Turkey); Yildirim, H.; Ozdemir Kart, S. [Department of Physics, Pamukkale University, Kınıklı Campus, 20017 Denizli (Turkey); Çağin, T. [Department of Materials Science and Engineering, Texas A and M University, College Station, TX 77845-3003 (United States); Department of Chemical Engineering, Texas A and M University, College Station, TX 77845-3122 (United States)

    2014-09-15

    Thermodynamical, structural and dynamical properties of Cu nanoparticles are investigated by using Molecular Dynamics (MD) simulations at various temperatures. In this work, MD simulations of the Cu-nanoparticles are performed by means of the MPiSiM codes by utilizing from Quantum Sutton-Chen (Q-SC) many-body force potential to define the interactions between the Cu atoms. The diameters of the copper nanoparticles are varied from 2 nm to 10 nm. MD simulations of Cu nanoparticles are carried out at low and high temperatures to study solid and liquid properties of Cu nanoparticles. Simulation results such as melting point, radial distribution function are compared with the available experimental bulk results. Radial distribution function, mean square displacement, diffusion coefficient, Lindemann index and Honeycutt–Andersen index are also calculated for estimating the melting point of the Copper nanoparticles. - Highlights: • Solid and liquid properties of Cu nanoparticles are studied. • Molecular dynamics utilizing the Quantum Sutton Chen potential is used in this work. • Melting temperatures of nanoparticles are strongly depended on nanoparticle sizes. • Heat capacity, radial distribution function and diffusion coefficients are studied. • Structures of nanoparticles are analyzed by Lindemann and Honeycutt–Andersen index.

  17. Physical properties of Cu nanoparticles: A molecular dynamics study

    International Nuclear Information System (INIS)

    Kart, H.H.; Yildirim, H.; Ozdemir Kart, S.; Çağin, T.

    2014-01-01

    Thermodynamical, structural and dynamical properties of Cu nanoparticles are investigated by using Molecular Dynamics (MD) simulations at various temperatures. In this work, MD simulations of the Cu-nanoparticles are performed by means of the MPiSiM codes by utilizing from Quantum Sutton-Chen (Q-SC) many-body force potential to define the interactions between the Cu atoms. The diameters of the copper nanoparticles are varied from 2 nm to 10 nm. MD simulations of Cu nanoparticles are carried out at low and high temperatures to study solid and liquid properties of Cu nanoparticles. Simulation results such as melting point, radial distribution function are compared with the available experimental bulk results. Radial distribution function, mean square displacement, diffusion coefficient, Lindemann index and Honeycutt–Andersen index are also calculated for estimating the melting point of the Copper nanoparticles. - Highlights: • Solid and liquid properties of Cu nanoparticles are studied. • Molecular dynamics utilizing the Quantum Sutton Chen potential is used in this work. • Melting temperatures of nanoparticles are strongly depended on nanoparticle sizes. • Heat capacity, radial distribution function and diffusion coefficients are studied. • Structures of nanoparticles are analyzed by Lindemann and Honeycutt–Andersen index

  18. Local Lithiation via Nanobattery Probes: Battery Interfaces at the Nanoscale

    Science.gov (United States)

    Larson, Jonathan; Talin, Alec; Pearse, Alexander; Reutt-Robey, Janice

    Greater knowledge of interfacial charge/mass transport processes in battery materials - especially as a function of lithiation - is essential to understand and overcome materials limitations in performance. Increased use of nanostructured and/or nanoscale electrodes in energy storage systems, calls for research tools that allow for direct, local probes of materials interfaces and inhomogeneity. Here we present a new approach to measure local interfacial structure, electronics, and electrochemical properties as a function of local chemical changes, like lithiation. Building upon our laboratory's recent success in developing scanning probe techniques for energy storage science, we introduce novel probes layered with nanothin, functional energy-storage materials. We perform in situ measurements of the electronic properties of oxide-clad probes, via electron tunneling spectroscopy, determining effective electron transport gaps. We then utilize these probes as fine Li sources and as nanobattery probes for local cycling against a silicon anode substrate. Post lithiation, conventional in-situ STM and SEM reveal local physical changes in the cycled Si(111) anode surface. U.S. DOE, Energy Frontier Research Center; DESC0001160.

  19. Development of an ASPEN PLUS physical property database for biofuels components

    Energy Technology Data Exchange (ETDEWEB)

    Wooley, R.J.; Putsche, V.

    1996-04-01

    Physical property data for many of the key components used in the simulation for the ethanol from lignocellulose process are not available in the standard ASPEN PLUS property databases. Indeed, many of the properties necessary to successfully simulate this process are not available anywhere. In addition, inputting the available properties into each simulation is awkward and tedious, and mistakes can be easily introduced when a long list of physical property equation parameters is entered. Therefore, one must evaluate the literature, estimate properties where necessary, and determine a set of consistent physical properties for all components of interest. The components must then be entered into an in-house NREL ASPEN PLUS database so they can be called on without being retyped into each specific simulation. The first phase of this work is complete. A complete set of properties for the currently identifiable important compounds in the ethanol process is attached. With this as the starting base the authors can continue to search for and evaluate new properties or have properties measured in the laboratory and update the central database.

  20. Integrating soil physical and biological properties in contrasting tillage systems in organic and conventional farming

    NARCIS (Netherlands)

    Crittenden, S.J.; Goede, de R.G.M.

    2016-01-01

    Though soil physical and soil biological properties are intrinsically linked in the soil environment they are often studied separately. This work adds value to analyses of soil biophysical quality of tillage systems under organic and conventional farming systems by correlating physical and

  1. influence of tillage practices on physical properties of a sandy loam

    African Journals Online (AJOL)

    DR. AMINU

    investigated after 9-15 years of management. During the growing ... Key words: Tillage, Tillage systems, Soil Physical properties, Moisture storage, Physical quality ... channel. GPS etrex, courtesy GARMIN Corporation 1999-. 2002) was used in determining coordinates of the sites. Treatments and Experimental Design.

  2. Probing the structure and nano-scale mechanical properties of polymer surfaces with scanning force microscopy and sum frequency vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gracias, David Hugo [Univ. of California, Berkeley, CA (United States)

    1999-05-01

    Scanning Force Microscopy (SFM) has been used to quantitatively measure the elastic modulus, friction and hardness of polymer surfaces with special emphasis on polyethylene and polypropylene. In the experiments, tips of different radii of curvature ranging from 20 nm to 1000 nm have been used and the high pressure applied by the SFM have been observed to affect the values obtained in the measurements. The contact of the SFM tip with the polymer surface is explained by fitting the experimental curves to theoretical predictions of contact mechanics. Sum Frequency Generation (SFG) Vibrational Spectroscopy has been used to measure vibrational spectra of polymer surfaces in the vibrational range of 2700 to 3100 cm-1. Strong correlations are established between surface chemistry and surface structure as probed by SFG and mechanical properties measured by SFM on the surfaces. In these studies segregation of low surface energy moieties, from the bulk of the polymer to the surface have been studied. It was found that surface segregation occurs in miscible polymer blends and a small concentration of surface active polymer can be used to totally modify the surface properties of the blend. A novel high vacuum SFM was built to do temperature dependent measurements of mechanical changes occurring at the surface of polypropylene during the glass transition of the polymer. Using this instrument the modulus and friction of polypropylene was measured in the range of room temperature to ˜-60°C. An increase in the ordering of the backbone of the polymer chains below the glass transition measured by SFG correlates well with the increase in modulus measured on the same surface with SFM. Friction measurements have been done on polyethylene with three different instruments by applying loads ranging from nN to sub newton i.e. over eight orders of magnitude. Pressure and contact area effects were observed to play a significant role in determining the frictional response of the polymer

  3. Design of Surface Modifications for Nanoscale Sensor Applications

    Directory of Open Access Journals (Sweden)

    Erik Reimhult

    2015-01-01

    Full Text Available Nanoscale biosensors provide the possibility to miniaturize optic, acoustic and electric sensors to the dimensions of biomolecules. This enables approaching single-molecule detection and new sensing modalities that probe molecular conformation. Nanoscale sensors are predominantly surface-based and label-free to exploit inherent advantages of physical phenomena allowing high sensitivity without distortive labeling. There are three main criteria to be optimized in the design of surface-based and label-free biosensors: (i the biomolecules of interest must bind with high affinity and selectively to the sensitive area; (ii the biomolecules must be efficiently transported from the bulk solution to the sensor; and (iii the transducer concept must be sufficiently sensitive to detect low coverage of captured biomolecules within reasonable time scales. The majority of literature on nanoscale biosensors deals with the third criterion while implicitly assuming that solutions developed for macroscale biosensors to the first two, equally important, criteria are applicable also to nanoscale sensors. We focus on providing an introduction to and perspectives on the advanced concepts for surface functionalization of biosensors with nanosized sensor elements that have been developed over the past decades (criterion (iii. We review in detail how patterning of molecular films designed to control interactions of biomolecules with nanoscale biosensor surfaces creates new possibilities as well as new challenges.

  4. Preparation, Characterization, and Ionic Transport Properties of Nanoscale Ln2Zr2O7 (Ln = Ce, Pr, Nd, Sm, Gd, Dy, Er, and Yb) Energy Materials

    Science.gov (United States)

    Solomon, Sam; George, Aneesh; Thomas, Jijimon Kumpakkattu; John, Annamma

    2015-01-01

    Nanoparticles of lanthanide (Ln)-based zirconates have been prepared through the autoignited combustion technique. The structure of the system was analyzed by powder x-ray diffraction and vibrational spectroscopic tools. The compounds with Ln = Ce, Pr, Nd, Sm, and Gd have pyrochlore cubic structure, whereas those with Ln = Dy, Er, and Yb possess anion-deficient disordered cubic fluorite structure. The optical properties of the powder were analyzed using ultraviolet-visible spectroscopy. Pellets of the compounds were sintered in the range from 1325°C to 1530°C for 2 h. The surface morphology of sintered Nd2Zr2O7 was analyzed by scanning electron microscopy. Impedance spectroscopic studies of the samples were carried out at different temperatures. The conductivity increased to the order of 10-2 S/m at 750°C, and the highest conductivity of 13.21 × 10-2 S/m was obtained for Er2Zr2O7. All samples of this system are suitable candidates for fabrication of electrolytes for use in solid oxide fuel cells, particularly at moderate temperatures.

  5. Effect of hydrogen on Fe and Pd alloying and physical properties

    Czech Academy of Sciences Publication Activity Database

    Jirásková, Yvonna; Buršík, Jiří; Zemanová, Adéla; Čízek, J.; Hruška, P.; Životský, O.

    2017-01-01

    Roč. 42, č. 10 (2017), s. 6885-6901 ISSN 0360-3199 R&D Projects: GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : positron-lifetime spectroscopy * neutron-diffraction * magnetic-properties * palladium-hydrogen * induced defects * iron Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.582, year: 2016

  6. PREFACE: International Conference on Dynamics of Systems on the Nanoscale (DySoN 2012)

    Science.gov (United States)

    Solov'yov, Andrey V.

    2013-06-01

    Conference logo The Second International Conference 'Dynamics of Systems on the Nanoscale' (DySoN 2012) took place in Saint Petersburg, Russia between 30 September and 4 October 2012. The venue was the Courtyard by Marriott St Petersburg Vasilievsky Hotel, 2nd line of Vasilievsky Island 61/30A, 199178. The conference was organized by the Frankfurt Institute for Advanced Studies - Goethe University, A F Ioffe Physical-Technical Institute and Saint Petersburg State Polytechnic University. This DySoN conference has been built upon a series of International Symposia 'Atomic Cluster Collisions: structure and dynamics from the nuclear to the biological scale' (ISACC 2003, ISACC 2007, ISACC 2008, ISACC 2009 and ISACC 2011). During these meetings it has become clear that there is a need for an interdisciplinary conference covering a broader range of topics than just atomic cluster collisions, related to the Dynamics of Systems on a Nanoscale. Therefore, in 2010 it was decided to launch a new conference series under the title 'Dynamics of Systems on the Nanoscale'. The first DySoN conference took place at the National Research Council, Rome, Italy in 2010. The DySoN 2012 is the second conference in this series. The DySoN 2012 Conference promoted the growth and exchange of interdisciplinary scientific information on the structure, formation and dynamics of animate and inanimate matter on the nanometer scale. There are many examples of complex many-body systems of micro- and nanometer scale size exhibiting unique features, properties and functions. These systems may have very different nature and origin, e.g. atomic and molecular clusters, nanoobjects, ensembles of nanoparticles, nanostructures, biomolecules, biomolecular and mesoscopic systems. A detailed understanding of the structure and dynamics of these systems on the nanometer scale is an important fundamental task, the solution of which is necessary in numerous applications of nano- and biotechnology, material science

  7. Impact of petroleum products on soil composition and physical-chemical properties

    Science.gov (United States)

    Brakorenko, N. N.; Korotchenko, T. V.

    2016-03-01

    The article describes the grain-size distribution, physical and mechanical properties, swelling and specific electrical resistivity of soils before and after the contact with petroleum products. The changes in mechanical properties of soils contaminated with petroleum products have been stated. It leads to the increase in compressibility values, decline in internal friction angle and cohesion.

  8. Physical properties, structure and fracturing of the Chelyabinsk LL5 meteorite body

    Czech Academy of Sciences Publication Activity Database

    Grokhovsky, V. I.; Kohout, Tomáš; Gritsevich, M.; Koneva, E. V.

    2014-01-01

    Roč. 49, Special issue 1 (2014), pdf 5364-pdf 5364 ISSN 1086-9379. [Annual Meeting of the Meteoritical Society /77./. 08.09.2014-13.09.2014, Casablanca] Institutional support: RVO:67985831 Keywords : Chelyabinsk * LL chondrite * physical properties * structure * mechanical properties * stress Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics http://www.hou.usra.edu/meetings/metsoc2014/pdf/5364.pdf

  9. Bibliography of physical and chemical properties of plutonium and of some of its compounds

    International Nuclear Information System (INIS)

    Lefevre, J.

    1957-02-01

    This document proposes two lists of bibliographical references which respectively concern the physical properties of metallic plutonium and intermetallic plutonium compounds (addressed topics in these documents are state diagrams, crystal structure, and so on), and the chemical properties of plutonium and of some of its compounds (addressed topics are heavy elements, transuranium elements, and so on)

  10. Mutual associations among microstructural, physical and mechanical properties of human cancellous bone

    DEFF Research Database (Denmark)

    Ding, Ming; Odgaard, A; Danielsen, CC

    2002-01-01

    were tested to determine the mechanical properties and the physical/compositional properties were evaluated. The type of structure together with anisotropy correlated well with Young's modulus of human tibial cancellous bone. The plate-like structure reflected high mechanical stress and the rod...

  11. The Spectrophotometer II: A Module on the Spectral Properties of Light. Tech Physics Series.

    Science.gov (United States)

    Frank, Nathaniel; And Others

    This module is designed to give the learner an understanding of the nature of light and how its properties are used in the design of spectrophotometers. Problems promote the use of spectrophotometers in qualitative analysis, the optical elements used in a monochromator, and the physical properties of the prism and the diffraction grating. Other…

  12. Physical properties of the Creutzfeldt-Jakob disease agent

    Energy Technology Data Exchange (ETDEWEB)

    Sklaviadis, T.K.; Manuelidis, L.; Manuelidis, E.E.

    1989-03-01

    In this report, the authors present the first physical characterization of the Creutzfeld-Jakob disease agent. Preparations with high yields of infectivity (assayed infectious units) were obtained by a novel, gentle procedure in which initially sedimenting Gp34 (prion protein) was disaggregated by a variety of criteria with no subsequent loss of infectivity. Studies with this preparation indicate that most of the Creutzfeldt-Jakob disease agent has both a viruslike size and density. In velocity sedimentation and isopycnic sucrose gradients, infectivity comigrated with nucleic acid-protein complexes of appreciable size.

  13. Physical properties of the Creutzfeldt-Jakob disease agent

    International Nuclear Information System (INIS)

    Sklaviadis, T.K.; Manuelidis, L.; Manuelidis, E.E.

    1989-01-01

    In this report, the authors present the first physical characterization of the Creutzfeld-Jakob disease agent. Preparations with high yields of infectivity (assayed infectious units) were obtained by a novel, gentle procedure in which initially sedimenting Gp34 (prion protein) was disaggregated by a variety of criteria with no subsequent loss of infectivity. Studies with this preparation indicate that most of the Creutzfeldt-Jakob disease agent has both a viruslike size and density. In velocity sedimentation and isopycnic sucrose gradients, infectivity comigrated with nucleic acid-protein complexes of appreciable size

  14. NATO Advanced Research Workshop on Physical Properties of Nano systems

    CERN Document Server

    Bonca, Janez

    2011-01-01

    Recent advances in nanoscience have demonstrated that fundamentally new physical phenomena are found when systems are reduced to sizes comparable to the fundamental microscopic length scales of the material investigated. There has been great interest in this research due, in particular, to its role in the development of spintronics, molecular electronics and quantum information processing. The contributions to this volume describe new advances in many of these fundamental and fascinating areas of nanophysics, including carbon nanotubes, graphene, magnetic nanostructures, transport through coupled quantum dots, spintronics, molecular electronics, and quantum information processing.

  15. Physical properties of salt, anhydrite and gypsum : preliminary report

    Science.gov (United States)

    Robertson, Eugene C.; Robie, Richard A.; Books, Kenneth G.

    1958-01-01

    This summary is the result of a search of the available literature. Emphasis is placed on the mechanical and calorimetric properties of salt; the measurements of elastic, thermal, magnetic, and mass properties of salt are merely tabulated. Under hydrostatic pressure 100 percent at a nearly constant stress difference of about 300 kg/cm2. Similarily, under temperatures > 400?C at one atmosphere, salt deforms plastically to strains > 100 percent under stress differences of about 100 kg/cm2. Entha1pies were calculated for various temperatures to 2,000? C from the low temperature and high temperature heat capacities and the heats of solution of the following minerals: salt (or halite), NaCl; anhydrite, CaS04; quartz, Si02; and calcite, CaC03. Three combinations of these minerals were assumed to represent three possible natural salt beds, and the heats required to raise the temperature of each to 1,500?C and to 2,000?C were calculated. For a half and half mixture of salt and anhydrite, 1,300 cal/gm were required to raise the temperature to 2,000?C. For an evaporite containing 60 percent salt and about equal amounts of anhydrite, calcite, and quartz, 1,100 cal/gm are required to raise the temperature to 2,OOO?C. Most of the measurements of the elastic moduli were made on single crystals of salt, anhydrite, and gypsum. For the most part, the measurements of density, magnetic susceptibility, and other properties were made on natural salt samples.

  16. Influence of vermicompost on soil chemical and physical properties ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-18

    Jul 18, 2008 ... 3.8400 a. 1.9833 a. 4.9367 ab. 1.6133 b. 38.66 b. 15. 4.2533 a. 1.1400 a. 5.7067 a. 1.5633 c. 40.33 a. In each column means with similar letters do not significantly differ (P ≥ 0.05). Table 4. Effect of vermicompost on soil chemical properties. Treatment with vermicompost (t ha-1). pH. EC (mScm-1). Organic.

  17. Complex Study of the Physical Properties of Reticulated Vitreous Carbon

    Science.gov (United States)

    Alifanov, O. M.; Cherepanov, V. V.; Morzhukhina, A. V.

    2015-01-01

    We give an example of using a two-level identifi cation system incorporating an augmented mathematical model covering the structure, the thermal, electrophysical, and optical properties of nonmetallic ultraporous reticulated materials. The model, when combined with a nonstationary thermal experiment and methods of the theory of inverse heat transfer problems, permits determining the little studied characteristics of the above materials. We present some of the results of investigations of reticulated vitreous carbon confirming the possibility of using it in a number of engineering applications.

  18. Influence of texture on the physical properties of materials

    International Nuclear Information System (INIS)

    Penelle, R.; Baudin, T.

    1996-01-01

    The principles of crystallographic texture characterization by the means of X-ray or neutron diffraction statistical techniques are reviewed, and examples of their application to the study of the effects of texture on the properties of materials are presented: texture of magnetic steels, magneto-crystalline anisotropy, elasticity anisotropy and Young's modulus, plastic anisotropy (textural hardening), residual stresses. Neutron diffraction allows for the continuous monitoring of the recrystallization texture generation kinetics during in-situ annealing or for the follow-up of phase transformations. Backscattered electron diffraction allows for the quantification of the spatial distribution of grain and grain joint orientations and thus microstructure reconstruction

  19. Physical properties of encapsulate spent fuel in canisters

    International Nuclear Information System (INIS)

    1999-01-01

    Spent fuel and high-level wastes will be permanently stored in a deep geological repository (AGP). Prior to this, they will be encapsulated in canisters. The present report is dedicated to the study of such canisters under the different physical demands that they may undergo, be those in operating or accident conditions. The physical demands of interest include mechanical demands, both static and dynamic, and thermal demands. Consideration is given to the complete file of the canister, from the time when it is empty and without lid to the final conditions expected in the repository. Thermal analyses of canisters containing spent fuel are often carried out in two dimensions, some times with hypotheses of axial symmetry and some times using a plane transverse section through the centre of the canister. The results obtained in both types of analyses are compared here to those of complete three-dimensional analyses. The latter generate more reliable information about the temperatures that may be experienced by the canister and its contents; they also allow calibrating the errors embodied in the two-dimensional calculations. (Author)

  20. The interaction of physical properties of seawater via statistical approach

    Science.gov (United States)

    Hamzah, Firdaus Mohamad; Jaafar, Othman; Sabri, Samsul Rijal Mohd; Ismail, Mohd Tahir; Jaafar, Khamisah; Arbin, Norazman

    2015-09-01

    It is of importance to determine the relationships between physical parameters in marine ecology. Model and expert opinion are needed for exploration of the form of relationship between two parameters due to the complexity of the ecosystems. These need justification with observed data over a particular periods. Novel statistical techniques such as nonparametric regression is presented to investigate the ecological relationships. These are achieved by demonstrating the features of pH, salinity and conductivity at in Straits of Johor. The monthly data measurements from 2004 until 2013 at a chosen sampling location are examined. Testing for no-effect followed by linearity testing for the relationships between salinity and pH; conductivity and pH, and conductivity and salinity are carried out, with the ecological objectives of investigating the evidence of changes in each of the above physical parameters. The findings reveal the appropriateness of smooth function to explain the variation of pH in response to the changes in salinity whilst the changes in conductivity with regards to different concentrations of salinity could be modelled parametrically. The analysis highlights the importance of both parametric and nonparametric models for assessing ecological response to environmental change in seawater.