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Sample records for spectroscopic thermodynamic microscopic

  1. On thermodynamic and microscopic reversibility

    SciTech Connect

    Crooks, Gavin E.

    2011-07-12

    The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa.

  2. Single nanoparticle tracking spectroscopic microscope

    DOEpatents

    Yang, Haw; Cang, Hu; Xu, Cangshan; Wong, Chung M.

    2011-07-19

    A system that can maintain and track the position of a single nanoparticle in three dimensions for a prolonged period has been disclosed. The system allows for continuously imaging the particle to observe any interactions it may have. The system also enables the acquisition of real-time sequential spectroscopic information from the particle. The apparatus holds great promise in performing single molecule spectroscopy and imaging on a non-stationary target.

  3. Microscopically constrained mean-field models from chiral nuclear thermodynamics

    NASA Astrophysics Data System (ADS)

    Rrapaj, Ermal; Roggero, Alessandro; Holt, Jeremy W.

    2016-06-01

    We explore the use of mean-field models to approximate microscopic nuclear equations of state derived from chiral effective field theory across the densities and temperatures relevant for simulating astrophysical phenomena such as core-collapse supernovae and binary neutron star mergers. We consider both relativistic mean-field theory with scalar and vector meson exchange as well as energy density functionals based on Skyrme phenomenology and compare to thermodynamic equations of state derived from chiral two- and three-nucleon forces in many-body perturbation theory. Quantum Monte Carlo simulations of symmetric nuclear matter and pure neutron matter are used to determine the density regimes in which perturbation theory with chiral nuclear forces is valid. Within the theoretical uncertainties associated with the many-body methods, we find that select mean-field models describe well microscopic nuclear thermodynamics. As an additional consistency requirement, we study as well the single-particle properties of nucleons in a hot/dense environment, which affect e.g., charged-current weak reactions in neutron-rich matter. The identified mean-field models can be used across a larger range of densities and temperatures in astrophysical simulations than more computationally expensive microscopic models.

  4. Microscopic Foundations of the MEIßNER Effect: Thermodynamic Aspects

    NASA Astrophysics Data System (ADS)

    Bru, J.-B.; de Siqueira Pedra, W.

    2013-08-01

    We analyze the Meißner effect from first principles of quantum mechanics. We show in particular the existence of superconducting states minimizing the magnetic free-energy of BCS-like models and carrying surface currents which annihilate the total magnetic induction inside the bulk in the thermodynamic limit. This study is a step towards a complete explanation of the Meißner effect from microscopic models. It remains indeed to prove that those states are dynamically stable, i.e. quasi-stationary at low temperatures. Note that our analysis shows that the Meißner effect is not necessarily related to an effective magnetic susceptibility equal to -1.

  5. Fluorination of graphene: a spectroscopic and microscopic study.

    PubMed

    Wang, Bei; Wang, Junjie; Zhu, Jun

    2014-02-25

    Since the advent of graphene, there has been intense interest in exploring the possibility of incorporating fluorinated graphene (FG), an ultrathin insulator, into graphene electronics as barriers, gate dielectrics, and optoelectronic elements. Here we report on the synthesis of FG from single-layer graphene sheets grown by chemical vapor deposition (CVD) using CF4 plasma. We examine its properties systematically via microscopic and spectroscopic probes. Our studies show that, by controlling the conditions of the plasma, FG of varying fluorine coverage can be produced; however, the resulting material contains a mixture of CFx (x = 1-3) bonds. Existing grain boundaries and lattice defects of CVD graphene play an important role in controlling its rate of fluorination and the damage of the sheet. Combining topography and current mapping, we demonstrate that the spatial distribution of fluorine on CVD graphene is highly inhomogeneous, where multilayer islands and structural features such as folds, wrinkles, and ripples are less fluorinated and consequently form a conductive network through which charge transport occurs. It is the properties of this network that manifest in the electrical transport of FG sheets. Our experiments reveal the many challenges of deriving electronics-quality FG from current CVD graphene while at the same time point to the possible solutions and potential of FG in graphene electronics and optoelectronics. PMID:24471932

  6. Grasping the Second Law of Thermodynamics at University: The Consistency of Macroscopic and Microscopic Explanations

    ERIC Educational Resources Information Center

    Leinonen, Risto; Asikainen, Mervi A.; Hirvonen, Pekka E.

    2015-01-01

    This study concentrates on evaluating the consistency of upper-division students' use of the second law of thermodynamics at macroscopic and microscopic levels. Data were collected by means of a paper and pencil test (N = 48) focusing on the macroscopic and microscopic features of the second law concerned with heat transfer processes. The data…

  7. Uranyl sorption by smectites: spectroscopic assessment of thermodynamic modeling.

    PubMed

    Chisholm-Brause, C J; Berg, J M; Little, K M; Matzner, R A; Morris, D E

    2004-09-15

    Batch sorption experiments and thermodynamic modeling of the interaction of UO2(2+) and its hydrolysis products with two smectitic clay minerals, the reference material SWy-1 [McKinley et al., Clays Clay Miner. 43 (1995) 586] and the soil isolate LK-1 [Turner et al., Geochim. Cosmochim. Acta 30 (1996) 3399], have established a conceptual framework for uranyl/smectite surface complexation based on general reactions between aqueous uranyl species and the reactive sites on the mineral surfaces. In this report, we have formulated and spectroscopically tested a set of hypotheses based on this conceptual framework using samples prepared under similar or identical conditions to evaluate the agreement between surface complexation/speciation as enumerated by spectroscopic characterization and that elaborated by the surface complexation model. Both steady-state and time-resolved optical emission spectral data are presented for uranyl on both smectite minerals as well as on the analogue phases SiO2 and Al(OH)3 spanning the pH range from approximately 4 to 8 and the background electrolyte concentrations from approximately 0.001 to 0.1 M. The spectral data enable the explicit identification of an outer-sphere exchange-site population of the hydrated cation [UO2(OH2)5(2+) ] in SWy-1. Spectral data also clearly establish the existence of inner-sphere surface complexes on the analogue phases and on the amphoteric clay crystallite edge sites [aluminol (>Al-OH) and silanol (>Si-OH)]. Based on the spectral characteristics of these uranyl edge-site populations, it is possible to readily infer for the SiO2, Al(OH)3, and SWy-1 samples the evolution in surface speciation with increasing pH to more hydrolyzed uranyl-surface complexes consistent with the conceptual model. The spectral domain characteristics of the edge-site populations on LK-1 with increasing pH suggest that there is no change in the hydrolysis of the uranyl-surface species. However, emission lifetime data are interpreted

  8. Microscopic diagonal entropy and its connection to basic thermodynamic relations

    SciTech Connect

    Polkovnikov, Anatoli

    2011-02-15

    We define a diagonal entropy (d-entropy) for an arbitrary Hamiltonian system as S{sub d}=-{Sigma}{sub n{rho}nn}ln{rho}{sub nn} with the sum taken over the basis of instantaneous energy states. In equilibrium this entropy coincides with the conventional von Neumann entropy S{sub n} = -Tr{rho} ln {rho}. However, in contrast to S{sub n}, the d-entropy is not conserved in time in closed Hamiltonian systems. If the system is initially in stationary state then in accord with the second law of thermodynamics the d-entropy can only increase or stay the same. We also show that the d-entropy can be expressed through the energy distribution function and thus it is measurable, at least in principle. Under very generic assumptions of the locality of the Hamiltonian and non-integrability the d-entropy becomes a unique function of the average energy in large systems and automatically satisfies the fundamental thermodynamic relation. This relation reduces to the first law of thermodynamics for quasi-static processes. The d-entropy is also automatically conserved for adiabatic processes. We illustrate our results with explicit examples and show that S{sub d} behaves consistently with expectations from thermodynamics.

  9. Conformational Contribution to Thermodynamics of Binding in Protein-Peptide Complexes through Microscopic Simulation

    PubMed Central

    Das, Amit; Chakrabarti, J.; Ghosh, Mahua

    2013-01-01

    We extract the thermodynamics of conformational changes in biomacromolecular complexes from the distributions of the dihedral angles of the macromolecules. These distributions are obtained from the equilibrium configurations generated via all-atom molecular dynamics simulations. The conformational thermodynamics data we obtained for calmodulin-peptide complexes using our methodology corroborate well with the experimentally observed conformational and binding entropies. The conformational free-energy changes and their contributions for different peptide-binding regions of calmodulin are evaluated microscopically. PMID:23528087

  10. Spectroscopic and thermodynamic properties of L-ornithine monohydrochloride

    SciTech Connect

    Raja, M. Dinesh; Kumar, C. Maria Ashok; Arulmozhi, S.; Madhavan, J.

    2015-06-24

    L-Ornithine Monohydrochloride (LOMHCL) has been investigated with the help of B3LYP density functional theory with 6-31 G (d, p) basis set. Fourier transform infrared and Fourier transform Raman spectra is to identify the various functional groups. The theoretical frequencies showed very good agreement with experimental values. On the basis of the thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between standard heat capacities (C) standard entropies (S), and standard enthalpy changes (H) and temperatures. Second harmonic generation (SHG) efficiency of the grown crystal has been studied.

  11. Simultaneous microscopic measurements of thermal and spectroscopic fields of a phase change material

    NASA Astrophysics Data System (ADS)

    Romano, M.; Ryu, M.; Morikawa, J.; Batsale, J. C.; Pradere, C.

    2016-05-01

    In this paper, simultaneous microscopic measurements of thermal and spectroscopic fields of a paraffin wax n-alkane phase change material are reported. Measurements collected using an original set-up are presented and discussed with emphasis on the ability to perform simultaneous characterization of the system when the proposed imaging process is used. Finally, this work reveals that the infrared wavelength contains two sets of important information. Furthermore, this versatile and flexible technique is well adapted to characterize many systems in which the mass and heat transfers effects are coupled.

  12. Grasping the second law of thermodynamics at university: The consistency of macroscopic and microscopic explanations

    NASA Astrophysics Data System (ADS)

    Leinonen, Risto; Asikainen, Mervi A.; Hirvonen, Pekka E.

    2015-12-01

    [This paper is part of the Focused Collection on Upper Division Physics Courses.] This study concentrates on evaluating the consistency of upper-division students' use of the second law of thermodynamics at macroscopic and microscopic levels. Data were collected by means of a paper and pencil test (N =4 8 ) focusing on the macroscopic and microscopic features of the second law concerned with heat transfer processes. The data analysis was based on a qualitative content analysis where students' responses to the macroscopic- and microscopic-level items were categorized to provide insight into the consistency of the students' ideas; if students relied on the same idea at both levels, they ended up in the same category at both levels, and their use of the second law was consistent. The most essential finding is that a majority of students, 52%-69% depending on the physical system under evaluation, used the second law of thermodynamics consistently at macroscopic and microscopic levels; approximately 40% of the students used it correctly in terms of physics while others relied on erroneous ideas, such as the idea of conserving entropy. The most common inconsistency harbored by 10%-15% of the students (depending on the physical system under evaluation) was students' tendency to consider the number of accessible microstates to remain constant even if the entropy was stated to increase in a similar process; other inconsistencies were only seen in the answers of a few students. In order to address the observed inconsistencies, we would suggest that lecturers should utilize tasks that challenge students to evaluate phenomena at macroscopic and microscopic levels concurrently and tasks that would guide students in their search for contradictions in their thinking.

  13. Microscope and spectroscope results are not limited by Heisenberg's Uncertainty Principle!

    NASA Astrophysics Data System (ADS)

    Prasad, Narasimha S.; Roychoudhuri, Chandrasekhar

    2011-09-01

    A reviewing of many published experimental and theoretical papers demonstrate that the resolving powers of microscopes, spectroscopes and telescopes can be enhanced by orders of magnitude better than old classical limits by various advanced techniques including de-convolution of the CW-response function of these instruments. Heisenberg's original analogy of limited resolution of a microscope, to support his mathematical uncertainty relation, is no longer justifiable today. Modern techniques of detecting single isolated atoms through fluorescence also over-ride this generalized uncertainty principle. Various nano-technology techniques are also making atoms observable and location precisely measurable. Even the traditional time-frequency uncertainty relation or bandwidth limit δvδt >= 1 can be circumvented while doing spectrometry with short pulses by deriving and de-convolving the pulse-response function of the spectrometer just as we do for CW input.

  14. Thermodynamic and spectroscopic investigations of aluminas and thermodynamic studies of other solid systems

    SciTech Connect

    Healy, M.H.

    1987-01-01

    This dissertation describes thermodynamic studies of the adsorption of a variety of liquid and gaseous bases on to a variety of solid acids, such as transition aluminas, a sulfonic acid resin (Dowex), graphite and anthracite coal. Fourier transform infrared spectroscopy studies were also conducted to identify the type, strength, and quantity of acid sites present on two transition aluminas, delta-theta and kappa. Heats of immersion of delta-theta and kappa aluminas into a variety of adsorbates of differing base strengths and geometries were obtained to quantify heterogeneous Lewis acid-base behavior. An in situ infrared spectroscopy investigation was conducted using four basic adsorbates to identify the acidic sites present on delta-theta and kappa aluminas. For two adsorbates, pyridine and 2,6-lutidine, adsorption studies were conducted between 298 and 983 K and at adsorbate pressures spanning from 1.33 Pascal (Pa) to 1.33 kPa. The adsorption of acetonitrile and n-butylamine was conducted at 298K using adsorbate pressures ranging from 0.66 Pa to 8.65 kPa. With all of the adsorbates a Lewis acid coordination site, designated as an outer or weaker site, and hydrogen-bonded complexes are identified. Broensted acid coordination is detected only when a strongly basic adsorbate, n-butylamine, is employed as the probe molecule. The strength of the sites, as quantified with pyridine is similar on both aluminas; however, with acetonitrile, a stronger coordination complex is formed on kappa alumina than on delta-theta alumina. The environment surrounding the acid site affects the adsorption of 2,6-lutidine; although it is a stronger base towards protonic acids than pyridine and might be expected to interact more strongly with alumina, only a weakly bound species is formed.

  15. A comparison of microscopic and spectroscopic identification methods for analysis of microplastics in environmental samples.

    PubMed

    Song, Young Kyoung; Hong, Sang Hee; Jang, Mi; Han, Gi Myung; Rani, Manviri; Lee, Jongmyoung; Shim, Won Joon

    2015-04-15

    The analysis of microplastics in various environmental samples requires the identification of microplastics from natural materials. The identification technique lacks a standardized protocol. Herein, stereomicroscope and Fourier transform infrared spectroscope (FT-IR) identification methods for microplastics (<1mm) were compared using the same samples from the sea surface microlayer (SML) and beach sand. Fragmented microplastics were significantly (p<0.05) underestimated and fiber was significantly overestimated using the stereomicroscope both in the SML and beach samples. The total abundance by FT-IR was higher than by microscope both in the SML and beach samples, but they were not significantly (p>0.05) different. Depending on the number of samples and the microplastic size range of interest, the appropriate identification method should be determined; selecting a suitable identification method for microplastics is crucial for evaluating microplastic pollution. PMID:25682567

  16. Laser apparatus and method for microscopic and spectroscopic analysis and processing of biological cells

    DOEpatents

    Gourley, P.L.; Gourley, M.F.

    1997-03-04

    An apparatus and method are disclosed for microscopic and spectroscopic analysis and processing of biological cells. The apparatus comprises a laser having an analysis region within the laser cavity for containing one or more biological cells to be analyzed. The presence of a cell within the analysis region in superposition with an activated portion of a gain medium of the laser acts to encode information about the cell upon the laser beam, the cell information being recoverable by an analysis means that preferably includes an array photodetector such as a CCD camera and a spectrometer. The apparatus and method may be used to analyze biomedical cells including blood cells and the like, and may include processing means for manipulating, sorting, or eradicating cells after analysis. 20 figs.

  17. Laser apparatus and method for microscopic and spectroscopic analysis and processing of biological cells

    DOEpatents

    Gourley, Paul L.; Gourley, Mark F.

    1997-01-01

    An apparatus and method for microscopic and spectroscopic analysis and processing of biological cells. The apparatus comprises a laser having an analysis region within the laser cavity for containing one or more biological cells to be analyzed. The presence of a cell within the analysis region in superposition with an activated portion of a gain medium of the laser acts to encode information about the cell upon the laser beam, the cell information being recoverable by an analysis means that preferably includes an array photodetector such as a CCD camera and a spectrometer. The apparatus and method may be used to analyze biomedical cells including blood cells and the like, and may include processing means for manipulating, sorting, or eradicating cells after analysis thereof.

  18. Raman spectroscopic and scanning electron microscopic analysis of a novel biological colonisation of volcanic rocks

    NASA Astrophysics Data System (ADS)

    Jorge Villar, Susana E.; Edwards, Howell G. M.; Benning, Liane G.

    2006-09-01

    A novel type of colonisation of a basaltic rock, collected on the Arctic island of Svalbard, Norway, during the AMASE expedition in 2004, was characterised using Raman spectroscopy and Scanning Electron Microscopy (SEM). The sample contains two different types of extremophile communities, one occurring behind a radial white crystallisation and the other occurring inside a dark vacuole. Several types of minerals and microbial colonies have been identified by both Raman spectroscopy and SEM analyses. It is the first time that photosynthetic communities have been documented to colonise the inside of dark basaltic rocks. Our discovery has important implications for planetary exploration because it extends the analytical capability and our understanding of microbial rock colonisations to subaerial volcanic outcrops and has wide implications towards the search for life in extraterrestrial planets. In this work we also demonstrate that the use of different laser wavelengths for Raman spectroscopic studies and complementary microscopic analysis are critical for a comprehensive organic and inorganic compound identification.

  19. Insight into the microscopic structure of an AdS black hole from a thermodynamical phase transition.

    PubMed

    Wei, Shao-Wen; Liu, Yu-Xiao

    2015-09-11

    Comparing with an ordinary thermodynamic system, we investigate the possible microscopic structure of a charged anti-de Sitter black hole completely from the thermodynamic viewpoint. The number density of the black hole molecules is introduced to measure the microscopic degrees of freedom of the black hole. We found that the number density suffers a sudden change accompanied by a latent heat when the black hole system crosses the small-large black hole coexistence curve, while when the system passes the critical point, it encounters a second-order phase transition with a vanishing latent heat due to the continuous change of the number density. Moreover, the thermodynamic scalar curvature suggests that there is a weak attractive interaction between two black hole molecules. These phenomena might cast new insight into the underlying microscopic structure of a charged anti-de Sitter black hole. PMID:26406818

  20. Steepest-entropy-ascent quantum thermodynamic modeling of decoherence in two different microscopic composite systems

    NASA Astrophysics Data System (ADS)

    Cano-Andrade, Sergio; Beretta, Gian Paolo; von Spakovsky, Michael R.

    2015-01-01

    The steepest-entropy-ascent quantum thermodynamic (SEAQT) framework is used to model the decoherence that occurs during the state evolution of two different microscopic composite systems. The test cases are a two-spin-1/2-particle composite system and a particle-photon field composite system like that experimentally studied in cavity quantum electrodynamics. The first system is used to study the characteristics of the nonlinear equation of motion of the SEAQT framework when modeling the state evolution of a microscopic composite system with particular interest in the phenomenon of decoherence. The second system is used to compare the numerical predictions of the SEAQT framework with experimental cavity quantum electrodynamic data available in the literature. For the two different numerical cases presented, the time evolution of the density operator of the composite system as well as that of the reduced operators belonging to the two constituents is traced from an initial nonequilibrium state of the composite along its relaxation towards stable equilibrium. Results show for both cases how the initial entanglement and coherence is dissipated during the state relaxation towards a state of stable equilibrium.

  1. Thermodynamic and Spectroscopic Studies of Lanthanides(III) Complexation with Polyamines in Dimethyl Sulfoxide

    SciTech Connect

    Di Bernardo, Plinio; Zanonato, Pier Luigi; Melchior, Andrea; Portanova, Roberto; Tolazzi, Marilena; Choppin, Gregory R.; Wang, Zheming

    2008-01-01

    The thermodynamic parameters of complexation of Ln(III) cations with tris(2-aminoethyl)amine (tren) and tetraethylenepentamine (tetren) were determined in dimethyl sulfoxide (DMSO) by potentiometry and calorimetry. The excitation and emission spectra and luminescence decay constants of Eu3+ and Tb3+ complexed by tren and tetren, as well as those of the same lanthanides(III) complexed with diethylenetriamine (dien) and triethylenetetramine (trien), were also obtained in the same solvent. The combination of thermodynamic and spectroscopic data showed that, in the 1:1 complexes, all nitrogens of the ligands bound to the lanthanides except in the case of tren, in which only pendant N bound. For the larger ligands (trien, tren, tetren) in the higher complexes (ML2), there was less complete binding by available donors, presumably due to steric crowding. FT-IR studies were carried out in an acetonitrile/DMSO mixture, suitably chosen in order to follow the changes in the primary solvation sphere of lanthanide(III) due to complexation of amine ligands. Results show that the mean number of molecules of DMSO removed from the inner coordination sphere of lanthanides(III) is lower than ligand denticity and that the coordination number of the metal ions increases with amine complexation from ~8 to ~10. Independently of the number and structure of the amines, linear trends, similar for all lanthanides, were obtained by plotting the values of ΔGj°, ΔHj° and TΔSj° for the complexation of ethylenediamine (en), dien, trien, tren and tetren as a function of the number of amine metal-coordinated nitrogen atoms. The main factors on which the thermodynamic functions of lanthanide(III) complexation reactions in DMSO depend are discussed.

  2. Microcanonical thermostatistics as foundation of thermodynamics: The microscopic origin of condensation and phase separations

    NASA Astrophysics Data System (ADS)

    Gross, D. H. E.

    2005-10-01

    Conventional thermo-statistics address infinite homogeneous systems within the canonical ensemble. However, some 150 years ago the original motivation of thermodynamics was the description of steam engines, i.e., boiling water. Its essential physics is the separation of the gas phase from the liquid. Of course, boiling water is inhomogeneous and as such cannot be treated by canonical thermo-statistics. Then it is not astonishing that a phase transition of first order is signaled canonically by a Yang Lee singularity. Thus it is only treated correctly by microcanonical Boltzmann Planck statistics. This is elaborated in the present article. It turns out that the Boltzmann Planck statistics is much richer and gives fundamental insight into statistical mechanics and especially into entropy. This can even be done to some extend rigorously and analytically. The microcanonical entropy has a very simple physical meaning: It measures the microscopic uncertainty that we have about the system, i.e., the number of points in 6N-dim phase, which are consistent with our information about the system. It can rigorously be split into an ideal-gas part and a configuration part which contains all the physics and especially is responsible for all phase transitions. The deep and essential difference between “extensive” and “intensive” control parameters, i.e., microcanonical and canonical statistics, is exemplified by rotating, self-gravitating systems.

  3. From microscope to telescope: Using laboratory spectroscopic measurements to constrain the thermal evolution of silicate bodies in the solar system

    NASA Astrophysics Data System (ADS)

    Klima, Rachel L.; Young, Brianna C.; Rivkin, Andy S.

    2015-11-01

    Spectral measurements of planets and asteroids have long been used to inventory the composition of their surfaces. If laboratory techniques can be extrapolated to the larger spatial scales of remote observations, infrared spectroscopic measurements offer the potential to delve even deeper into the thermal evolution of these bodies. However, the scattering of light and mixing from the microscopic through macroscopic scales greatly complicates the analysis of components present even when surfaces are viewed at comparably high spatial resolution (<10-100 m/pixel). For this project, we have prepared and measured a set of meteorites and terrestrial analog rocks to perform coordinated spectroscopic studies, from microscopic spectral measurements across individual grains through measurement of bulk mineral and rock samples in ultra-high vacuum (UHV), to investigate two questions: (1) can microscopic mineral textures related to cation ordering and exsolution be reliably distinguished from physical mixtures as occur in regoliths and (2) can internally bound water in minerals be distinguished from water that has adsorbed from the environment. In each case, we explore how well the laboratory techniques address these questions and, through spectral modeling, what the limitations and challenges are for extrapolating these measurements to remote observations.

  4. Mechanism of Arsenic Adsorption on Magnetite Nanoparticles from Water: Thermodynamic and Spectroscopic Studies.

    PubMed

    Liu, Cheng-Hua; Chuang, Ya-Hui; Chen, Tsan-Yao; Tian, Yuan; Li, Hui; Wang, Ming-Kuang; Zhang, Wei

    2015-07-01

    Removal of arsenic (As) from water supplies is needed to reduce As exposure through drinking water and food consumption in many regions of the world. Magnetite nanoparticles (MNPs) are promising and novel adsorbents for As removal because of their great adsorption capacity for As and easy separation. This study aimed to investigate the adsorption mechanism of arsenate, As(V), and arsenite, As(III), on MNPs by macroscopic adsorption experiments in combination with thermodynamic calculation and microspectroscopic characterization using synchrotron-radiation-based X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS). Adsorption reactions are favorable endothermic processes as evidenced by increased adsorption with increasing temperatures, and high positive enthalpy change. EXAFS spectra suggested predominant formation of bidentate binuclear corner-sharing complexes ((2)C) for As(V), and tridentate hexanuclear corner-sharing ((3)C) complexes for As(III) on MNP surfaces. The macroscopic and microscopic data conclusively identified the formation of inner-sphere complexes between As and MNP surfaces. More intriguingly, XANES and XPS results revealed complex redox transformation of the adsorbed As on MNPs exposed to air: Concomitant with the oxidation of MNPs, the oxidation of As(III) and MNPs was expected, but the observed As(V) reduction was surprising because of the role played by the reactive Fe(II). PMID:26055623

  5. Understanding Thermodynamic and Spectroscopic Properties of Tetragonal Mn12 Single-Molecule Magnets from Combined Density Functional Theory/Spin-Hamiltonian Calculations.

    PubMed

    Ghassemi Tabrizi, Shadan; Arbuznikov, Alexei V; Kaupp, Martin

    2016-09-01

    We apply broken-symmetry density functional theory to determine isotropic exchange-coupling constants and local zero-field splitting (ZFS) tensors for the tetragonal Mn12(t)BuAc single-molecule magnet. The obtained parametrization of the many-spin Hamiltonian (MSH), taking into account all 12 spin centers, is assessed by comparing theoretical predictions for thermodynamic and spectroscopic properties with available experimental data. The magnetic susceptibility (calculated by the finite-temperature Lanczos method) is well approximated, and the intermultiplet excitation spectrum from inelastic neutron scattering (INS) experiments is correctly reproduced. In these respects, the present parametrization of the 12-spin model represents a significant improvement over previous theoretical estimates of exchange-coupling constants in Mn12, and additionally offers a refined interpretation of INS spectra. Treating anisotropic interactions at the third order of perturbation theory, the MSH is mapped onto the giant-spin Hamiltonian describing the S = 10 ground multiplet. Although the agreement with high-field EPR experiments is not perfect, the results clearly point in the right direction and for the first time rationalize the angular dependence of the transverse-field spectra from a fully microscopic viewpoint. Importantly, transverse anisotropy of the effective S = 10 manifold is explicitly shown to arise largely from the ZFS-induced mixing of exchange multiplets. This effect is given a thorough analysis in the approximate D2d spin-permutational symmetry group of the exchange Hamiltonian. PMID:27482933

  6. Microscopic theories of model macromolecular fluids and fullerenes: The role of thermodynamic consistency

    NASA Astrophysics Data System (ADS)

    Caccamo, Carlo; Pellicane, Giuseppe

    2002-09-01

    We investigate the accuracy of two well-known integral equation theories (IETs) of the fluid state, namely, the modified hypernetted chain (MHNC) approximation and the hybridized mean spherical approximation (HMSA), as applied to systems characterized by short-range interactions. The theoretical approaches are implemented by enforcing their thermodynamic consistency according to two different strategies: in one case the equality of the isothermal compressibility, as calculated via the virial and fluctuation routes from structure to thermodynamics, is imposed ["local" consistency (LC)] in the other case the equality of the pressure as calculated either via the two previous routes, or via the virial and the energy routes, is imposed ["global" consistency (GC)]. We show that for the class of potentials at issue the GC is in general considerably more accurate than the LC. We document this result by investigating the performances of the MHNC and the HMSA, as applied to the calculation of the thermodynamic and structural properties of the hard-core Yukawa (HCY) potential, the Derjaguin-Landau-Vervey-Overbeek (DLVO) potential and the Girifalco potential for fullerenes. The obtained results are then compared with Monte Carlo simulation data, that we also produce for the same model systems. As far as the HCY potential is concerned, the investigation covers a range of the Yukawa inverse decay length, z, spanning from z=1.8 when the interaction mimics the Lennard-Jones 12-6 potential, to z=7 when the potential mimics the "effective" short range interaction between globular proteins in a highly charge-screened aqueous solution. IETs are then applied to the DLVO potential with charge and Hamaker constant values which fit the dynamical interaction factor of lysozyme in a solution of high ionic strength, and to the Girifalco potential with parameters appropriate to model C60 and C70. It emerges from the present study that the GC is able to provide Helmholtz free energies and

  7. Feedback under the microscope - I. Thermodynamic structure and AGN-driven shocks in M87

    NASA Astrophysics Data System (ADS)

    Million, E. T.; Werner, N.; Simionescu, A.; Allen, S. W.; Nulsen, P. E. J.; Fabian, A. C.; Böhringer, H.; Sanders, J. S.

    2010-10-01

    We present the first in a series of papers discussing the thermodynamic properties of M87 and the central regions of the Virgo Cluster in unprecedented detail. Using a deep Chandra exposure (574 ks), we present high-resolution thermodynamic maps created from the spectra of ~16000 independent regions, each with ~1000 net counts. The excellent spatial resolution of the thermodynamic maps reveals the dramatic and complex temperature, pressure, entropy and metallicity structure of the system. The `X-ray arms', driven outwards from M87 by the central active galactic nuclei (AGN), are prominent in the brightness, temperature and entropy maps. Excluding the `X-ray arms', the diffuse cluster gas at a given radius is strikingly isothermal. This suggests either that the ambient cluster gas, beyond the arms, remains relatively undisturbed by AGN uplift or that conduction in the intracluster medium (ICM) is efficient along azimuthal directions, as expected under action of the heat-flux-driven buoyancy instability (HBI). We confirm the presence of a thick (~40 arcsec or ~3kpc) ring of high-pressure gas at a radius of ~180 arcsec (~14kpc) from the central AGN. We verify that this feature is associated with a classical shock front, with an average Mach number M = 1.25. Another, younger shock-like feature is observed at a radius of ~40 arcsec (~3kpc) surrounding the central AGN, with an estimated Mach number M >~ 1.2. As shown previously, if repeated shocks occur every ~10 Myr, as suggested by these observations, then AGN-driven weak shocks could produce enough energy to offset radiative cooling of the ICM. A high significance enhancement of Fe abundance is observed at radii 350-400 arcsec (27-31kpc). This ridge is likely formed in the wake of the rising bubbles filled with radio-emitting plasma that drag cool, metal-rich gas out of the central galaxy. We estimate that at least ~1.0 × 106 solar masses of Fe has been lifted and deposited at a radius of 350-400 arcsec

  8. Upconversion in Nd{sup 3+}-doped glasses: Microscopic theory and spectroscopic measurements

    SciTech Connect

    Oliveira, S. L.; Sousa, D. F. de; Andrade, A. A.; Nunes, L. A. O.; Catunda, T.

    2008-01-15

    In this work, we report a systematic investigation of upconversion losses and their effects on fluorescence quantum efficiency and fractional thermal loading in Nd{sup 3+}-doped fluoride glasses. The energy transfer upconversion ({gamma}{sub up}) parameter, which describes upconversion losses, was experimentally determined using different methods: thermal lens (TL) technique and steady state luminescence (SSL) measurements. Additionally, the upconversion parameter was also obtained from energy transfer models and excited state absorption measurements. The results reveal that the microscopic treatment provided by the energy transfer models is similar to the macroscopic ones achieved from the TL and SSL measurements because similar {gamma}{sub up} parameters were obtained. Besides, the achieved results also point out the migration-assisted energy transfer according to diffusion-limited regime rather than hopping regime as responsible for the upconversion losses in Nd-doped glasses.

  9. New fluorescence reactions in DNA cytochemistry. 2. Microscopic and spectroscopic studies on fluorescent aluminum complexes

    SciTech Connect

    Del Castillo, P.; Llorente, A.R.; Gomez, A.; Gosalvez, J.; Goyanes, V.J.; Stockert, J.C. )

    1990-02-01

    Metal-dye complexes are widely applied in light microscopic techniques for chromatin staining (e.g., hematoxylin and carmine), but fluorescent complexes between phosphate-binding cations and suitable ligands have been little used. Preformed and postformed Al complexes with different anionic dyes induced strong and selective fluorescence reactions in nuclei from chicken blood smears, frozen sections, paraffin-embedded sections and Epon-embedded sections of mouse and rat tissues, mitotic chromosomes, meiotic chromosomes and kinetoplasts of Trypanosoma cruzi epimastigotes. The DNA-dependent fluorescence of these structures showed a very low fading rate. The emission colors were related to the ligand. The most suitable compounds for forming fluorescent Al chelates were 8-hydroxyquinoline, morin, nuclear fast red and purpurin. Staining with diluted carmine solutions and InCl3 mordanting, followed by 8-hydroxyquinoline, also induced chromatin fluorescence. After treating isolated mouse chromosomes with the preformed complex Al-nuclear fast red, x-ray microanalysis indicated a P:Al:dye binding ratio of about 40:15:1. The selectivity, stability and easy formation of these fluorescent Al complexes are obvious advantages for their use as new cytochemical probes in cytologic studies.

  10. Ultra-High Resolution Spectroscopic Remote Sensing: A Microscope on Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Kostiuk, Theodor

    2010-01-01

    Remote sensing of planetary atmospheres is not complete without studies of all levels of the atmosphere, including the dense cloudy- and haze filled troposphere, relatively clear and important stratosphere and the upper atmosphere, which are the first levels to experience the effects of solar radiation. High-resolution spectroscopy can provide valuable information on these regions of the atmosphere. Ultra-high spectral resolution studies can directly measure atmospheric winds, composition, temperature and non-thermal phenomena, which describe the physics and chemistry of the atmosphere. Spectroscopy in the middle to long infrared wavelengths can also probe levels where dust of haze limit measurements at shorter wavelength or can provide ambiguous results on atmospheric species abundances or winds. A spectroscopic technique in the middle infrared wavelengths analogous to a radio receiver. infrared heterodyne spectroscopy [1], will be describe and used to illustrate the detailed study of atmospheric phenomena not readily possible with other methods. The heterodyne spectral resolution with resolving power greater than 1,000.000 measures the true line shapes of emission and absorption lines in planetary atmospheres. The information on the region of line formation is contained in the line shapes. The absolute frequency of the lines can be measured to I part in 100 ,000,000 and can be used to accurately measure the Doppler frequency shift of the lines, directly measuring the line-of-sight velocity of the gas to --Im/s precision (winds). The technical and analytical methods developed and used to measure and analyze infrared heterodyne measurements will be described. Examples of studies on Titan, Venus, Mars, Earth, and Jupiter will be presented. 'These include atmospheric dynamics on slowly rotating bodies (Titan [2] and Venus [3] and temperature, composition and chemistry on Mars 141, Venus and Earth. The discovery and studies of unique atmospheric phenomena will also be

  11. High vacuum tip-enhanced Raman spectroscope based on a scanning tunneling microscope.

    PubMed

    Fang, Yurui; Zhang, Zhenglong; Sun, Mengtao

    2016-03-01

    In this paper, we present the construction of a high-vacuum tip-enhanced Raman spectroscopy (HV-TERS) system that allows in situ sample preparation and measurement. A detailed description of the prototype instrument is presented with experimental validation of its use and novel ex situ experimental results using the HV-TERS system. The HV-TERS system includes three chambers held under a 10(-7) Pa vacuum. The three chambers are an analysis chamber, a sample preparation chamber, and a fast loading chamber. The analysis chamber is the core chamber and contains a scanning tunneling microscope (STM) and a Raman detector coupled with a 50 × 0.5 numerical aperture objective. The sample preparation chamber is used to produce single-crystalline metal and sub-monolayer molecular films by molecular beam epitaxy. The fast loading chamber allows ex situ preparation of samples for HV-TERS analysis. Atomic resolution can be achieved by the STM on highly ordered pyrolytic graphite. We demonstrate the measurement of localized temperature using the Stokes and anti-Stokes TERS signals from a monolayer of 1,2-benzenedithiol on a gold film using a gold tip. Additionally, plasmonic catalysis can be monitored label-free at the nanoscale using our device. Moreover, the HV-TERS experiments show simultaneously activated infrared and Raman vibrational modes, Fermi resonance, and some other non-linear effects that are not observed in atmospheric TERS experiments. The high spatial and spectral resolution and pure environment of high vacuum are beneficial for basic surface studies. PMID:27036755

  12. High vacuum tip-enhanced Raman spectroscope based on a scanning tunneling microscope

    NASA Astrophysics Data System (ADS)

    Fang, Yurui; Zhang, Zhenglong; Sun, Mengtao

    2016-03-01

    In this paper, we present the construction of a high-vacuum tip-enhanced Raman spectroscopy (HV-TERS) system that allows in situ sample preparation and measurement. A detailed description of the prototype instrument is presented with experimental validation of its use and novel ex situ experimental results using the HV-TERS system. The HV-TERS system includes three chambers held under a 10-7 Pa vacuum. The three chambers are an analysis chamber, a sample preparation chamber, and a fast loading chamber. The analysis chamber is the core chamber and contains a scanning tunneling microscope (STM) and a Raman detector coupled with a 50 × 0.5 numerical aperture objective. The sample preparation chamber is used to produce single-crystalline metal and sub-monolayer molecular films by molecular beam epitaxy. The fast loading chamber allows ex situ preparation of samples for HV-TERS analysis. Atomic resolution can be achieved by the STM on highly ordered pyrolytic graphite. We demonstrate the measurement of localized temperature using the Stokes and anti-Stokes TERS signals from a monolayer of 1,2-benzenedithiol on a gold film using a gold tip. Additionally, plasmonic catalysis can be monitored label-free at the nanoscale using our device. Moreover, the HV-TERS experiments show simultaneously activated infrared and Raman vibrational modes, Fermi resonance, and some other non-linear effects that are not observed in atmospheric TERS experiments. The high spatial and spectral resolution and pure environment of high vacuum are beneficial for basic surface studies.

  13. Thermodynamic Performance Characteristics of a Brownian Microscopic Heat Engine Driven by Discrete and Periodic Temperature Field

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-Ping; He, Ji-Zhou; He, Xian; Xiao, Yu-Ling

    2010-11-01

    A Brownian microscopic heat engine with a particle hopping on a one-dimensional lattice driven by a discrete and periodic temperature field in a periodic sawtooth potential is investigated. In order to clarify the underlying physical pictures of the heat engine, the heat flow via the potential energy and the kinetic energy of the particles are considered simultaneously. Based on describing the jumps among the three states, the expressions of the efficiency and power output of the heat engine are derived analytically. The general performance characteristic curves are plotted by numerical calculation. It is found that the power output-efficiency curve is a loop-shaped one, which is similar to one for a real irreversible heat engine. The influence of the ratio of the temperature of the hot and cold reservoirs and the sawtooth potential on the maximum efficiency and power output is analyzed for some given parameters. When the heat flows via the kinetic energy is neglected, the power output-efficiency curve is an open-shaped one, which is similar to one for an endroeversible heat engine.

  14. Binary iron-chromium oxide as negative electrode for lithium-ion micro-batteries - spectroscopic and microscopic characterization

    NASA Astrophysics Data System (ADS)

    Tian, Bingbing; Światowska, Jolanta; Maurice, Vincent; Zanna, Sandrine; Seyeux, Antoine; Marcus, Philippe

    2015-10-01

    (Fe,Cr)-binary oxide thin film electrodes were prepared as negative electrode material for lithium-ion micro-batteries by thermal growth on a stainless steel (AISI 410, FeCr12.5) current collector. The mechanisms of lithiation/delithiation were investigated by means of electrochemical (CV, galvanostatic cycling), spectroscopic (XPS, ToF-SIMS) and microscopic (SEM, AFM) analytical techniques. The as-prepared (Fe, Cr)-binary oxide electrodes exhibit a good cycling performance except the first discharge/charge cycle where a high irreversible capacity is observed due to formation of a solid electrolyte interphase (SEI) layer. The influence of substituting an oxidized iron by an oxidized chromium (CrxFe2-xO3 phase) was evaluated. The data show that the inferior electrochemical conversion activity of substituted oxidized chromium results in hindering lithium transport in the bulk thin film electrode. It was observed that the irreversible morphology modifications together with SEI evolution are critical to capacity degradation while retaining good coulombic efficiency.

  15. Interaction of Lipopolysaccharide and Phospholipid in Mixed Membranes: Solid-State 31P-NMR Spectroscopic and Microscopic Investigations

    PubMed Central

    Nomura, Kaoru; Inaba, Takehiko; Morigaki, Kenichi; Brandenburg, Klaus; Seydel, Ulrich; Kusumoto, Shoichi

    2008-01-01

    Lipopolysaccharide (LPS), which constitutes the outermost layer of Gram-negative bacterial cells as a typical component essential for their life, induces the first line defense system of innate immunity of higher animals. To understand the basic mode of interaction between bacterial LPS and phospholipid cell membranes, distribution patterns were studied by various physical methods of deep rough mutant LPS (ReLPS) of Escherichia coli incorporated in phospholipid bilayers as simple models of cell membranes. Solid-state 31P-NMR spectroscopic analysis suggested that a substantial part of ReLPS is incorporated into 1,2-dimyristoyl-sn-glycero-3-phosphocholine lipid bilayers when multilamellar vesicles were prepared from mixtures of these. In egg L-α-phosphatidylcholine (egg-PC)-rich membranes, ReLPS undergoes micellization. In phosphatidylethanolamine-rich membranes, however, micellization was not observed. We studied by microscopic techniques the location of ReLPS in membranes of ReLPS/egg-PC (1:10 M/M) and ReLPS/egg-PC/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) (1:9:1 M/M/M). The influence of ReLPS on the physicochemical properties of the membranes was studied as well. Microscopic images of both giant unilamellar vesicles and supported planar lipid bilayers showed that LPS was uniformly incorporated in the egg-PC lipid bilayers. In the egg-PC/POPG (9:1 M/M) lipid bilayers, however, ReLPS is only partially incorporated and becomes a part of the membrane in a form of aggregates (or as mixed aggregates with the lipids) on the bilayer surface. The lipid lateral diffusion coefficient measurements at various molar ratios of ReLPS/egg-PC/POPG indicated that the incorporated ReLPS reduces the diffusion coefficients of the phospholipids in the membrane. The retardation of diffusion became more significant with increasing POPG concentrations in the membrane at high ReLPS/phospholipid ratios. This work demonstrated that the phospholipid composition has critical

  16. Spectroscopic and thermodynamic properties of molecular hydrogen dissolved in water at pressures up to 200 MPa

    SciTech Connect

    Borysow, Jacek Rosso, Leonardo del; Celli, Milva; Ulivi, Lorenzo; Moraldi, Massimo

    2014-04-28

    We have measured the Raman Q-branch of hydrogen in a solution with water at a temperature of about 280 K and at pressures from 20 to 200 MPa. From a least-mean-square fitting analysis of the broad Raman Q-branch, we isolated the contributions from the four lowest individual roto-vibrational lines. The vibrational lines were narrower than the pure rotational Raman lines of hydrogen dissolved in water measured previously, but significantly larger than in the gas. The separations between these lines were found to be significantly smaller than in gaseous hydrogen and their widths were slightly increasing with pressure. The lines were narrowing with increasing rotational quantum number. The Raman frequencies of all roto-vibrational lines were approaching the values of gas phase hydrogen with increasing pressure. Additionally, from the comparison of the integrated intensity signal of Q-branch of hydrogen to the integrated Raman signal of the water bending mode, we have obtained the concentration of hydrogen in a solution with water along the 280 K isotherm. Hydrogen solubility increases slowly with pressure, and no deviation from a smooth behaviour was observed, even reaching thermodynamic conditions very close to the transition to the stable hydrogen hydrate. The analysis of the relative hydrogen concentration in solution on the basis of a simple thermodynamic model has allowed us to obtain the molar volume for the hydrogen gas/water solution. Interestingly, the volume relative to one hydrogen molecule in solution does not decrease with pressure and, at high pressure, is larger than the volume pertinent to one molecule of water. This is in favour of the theory of hydrophobic solvation, for which a larger and more stable structure of the water molecules is expected around a solute molecule.

  17. Spectroscopic and Microscopic Studies on the Mechanism of Mitochondrial Toxicity Induced by CdTe QDs Modified with Different Ligands.

    PubMed

    Lai, Lu; Jin, Jian-Cheng; Xu, Zi-Qiang; Ge, Yu-Shu; Jiang, Feng-Lei; Liu, Yi

    2015-08-01

    Quantum dots (QDs) are increasingly applied in sensing, drug delivery, biomedical imaging, electronics industries, etc. Consequently, it is urgently required to examine their potential threat to humans and the environment. In the present work, the toxicity of CdTe QDs with nearly identical maximum emission wavelength but modified with two different ligands (MPA and BSA) to mitochondria was investigated using flow cytometry, spectroscopic, and microscopic methods. The results showed that QDs induced mitochondrial permeability transition (MPT), which resulted in mitochondrial swelling, collapse of the membrane potential, inner membrane permeability to H(+) and K(+), the increase of membrane fluidity, depression of respiration, alterations of ultrastructure, and the release of cytochrome c. Furthermore, the protective effects of CsA and EDTA confirmed QDs might be able to induce MPT via a Ca(2+)-dependent domain. However, the difference between the influence of CdTe QDs and that of Cd(2+) on mitochondrial membrane fluidity indicated the release of Cd(2+) was not the sole reason that QDs induced mitochondrial dysfunction, which might be related to the nanoscale effect of QDs. Compared with MPA-CdTe QDs, BSA-CdTe QDs had a greater effect on the mitochondrial swelling, membrane fluidity, and permeabilization to H(+) and K(+) by mitochondrial inner membrane, which was caused the fact that BSA was more lipophilic than MPA. This study provides an important basis for understanding the mechanism of the toxicity of CdTe QDs to mitochondria, and valuable information for safe use of QDs in the future. PMID:25758230

  18. Synthesis, molecular structure, spectroscopic analysis, thermodynamic parameters and molecular modeling studies of (2-methoxyphenyl)oxalate

    NASA Astrophysics Data System (ADS)

    Şahin, Zarife Sibel; Kantar, Günay Kaya; Şaşmaz, Selami; Büyükgüngör, Orhan

    2015-05-01

    The aim of this study is to find out the molecular characteristic and structural parameters that govern the chemical behavior of a new (2-methoxyphenyl)oxalate compound and to compare predictions made from theory with experimental observations. The title compound, (2-methoxyphenyl)oxalate, (I), (C16H14O6), has been synthesized. The compound has been characterized by elemental analysis, IR, 1H NMR, 13C NMR spectroscopies and single crystal X-ray diffraction techniques. Optimized molecular structure, harmonic vibrational frequencies, 1H and 13C NMR chemical shifts have been investigated by B3LYP/6-31G(d,p) method using density functional theory (DFT). The calculated results show that the predicted geometry can well reproduce structural parameters. In addition, global chemical reactivity descriptors, molecular electrostatic potential map (MEP), frontier molecular orbitals (FMOs), Mulliken population method and natural population analysis (NPA) and thermodynamic properties have also been studied. The energetic behavior of title compound has been examined in solvent media using polarizable continuum model (PCM).

  19. Redox, thermodynamic and spectroscopic of some transition metal complexes containing heterocyclic Schiff base ligands

    NASA Astrophysics Data System (ADS)

    Abu-Hussen, Azza A. A.; Linert, Wolfgang

    2009-09-01

    Complexes of two series of Schiff base ligands, H 2L a and H 2L b derived from the reaction of 2,6-diacetyl pyridine with semicarbazide, H 2L a and thiosemicarbazide, H 2L b, with the metal ions, Co(II), Ni(II), Cu(II), VO(IV) and UO 2(VI) have been prepared. The ligands are characterized by elemental analysis, IR, UV-vis and 1H NMR. The structures of the complexes are investigated with the IR, UV-vis, X-band ESR spectra, 1H NMR and thermal gravimetric analysis as well as conductivity and magnetic moment measurements. The IR-spectra reveal the presence of variable modes of chelation for the investigated ligands. A variety of binuclear or mononuclear complexes were obtained with the two ligands in tri-, tetra or pentadentate forms. The bonding sites are the pyridine nitrogen, two azomethine nitrogen atoms and ketonic oxygen in case of H 2L a or sulphur atoms in case of H 2L b. The Coats-Redfern equation has been used to calculate the kinetic and thermodynamic parameters for the different thermal decomposition steps of some complexes. Cyclic voltammograms of Co(II) and Ni(II) show quasi-reversible peaks. The redox properties and the nature of the electro-active species of the complexes have been characterized.

  20. Growth and spectroscopic, thermodynamic and nonlinear optical studies of L-threonine phthalate crystal

    NASA Astrophysics Data System (ADS)

    Theras, J. Elberin Mary; Kalaivani, D.; Jayaraman, D.; Joseph, V.

    2015-10-01

    L-threonine phthalate (LTP) single crystal has been grown using a solution growth technique at room temperature. Single crystal X-ray diffraction analysis reveals that LTP crystallizes in monoclinic crystal system with space group C2/c. The optical absorption studies show that the crystal is transparent in the entire visible region with a cut-off wavelength 309 nm. The optical band gap is found to be 4.05 eV. The functional groups of the synthesized compound have been identified by FTIR spectral analysis. The functional groups present in the material were also confirmed by FT-RAMAN spectroscopy. Surface morphology and the presence of various elements were studied by SEM-EDAX analysis. The thermal stability of LTP single crystal has been analyzed by TGA/DTA studies. The thermodynamic parameters such as activation energy, entropy, enthalpy and Gibbs free energy were determined for the grown material using TG data and Coats-Redfern relation. Since the grown crystal is centrosymmetric, Z-Scan studies were carried out for analyzing the third order nonlinear optical property. The nonlinear absorption coefficient, nonlinear refractive index and susceptibility have been measured using Z-Scan technique.

  1. Microscopic and thermodynamic properties of the HFA134a-water interface: atomistic computer simulations and tensiometry under pressure.

    PubMed

    Peguin, Robson P S; Selvam, Parthiban; da Rocha, Sandro R P

    2006-10-10

    A combined computational and experimental approach is used to determine the interfacial thermodynamic and structural properties of the liquid 1,1,1,2-tetrafluoroethane (HFA134a)-vapor and liquid HFA134a-water (HFA134a|W) interfaces at 298 K and saturation pressure. Molecular dynamics (MD) computer simulations reveal a stable interface between HFA134a and water. The "10-90" interfacial thickness is comparable with those typically reported for organic-water systems. The interfacial tension of the HFA134a|W interface obtained from the pressure tensor analysis of the MD trajectory is in good agreement with the experimental value determined using in situ high-pressure tensiometry. These results indicate that the potential models utilized are capable of describing the intermolecular interactions between these two fluids. The tension of the HFA134a|W interface is significantly lower than those typically observed for conventional oil-water interfaces and similar to that of the compressed CO(2)-water interface, observed at moderate CO(2) pressures. The MD and tensiometric results are also compared and contrasted with the HFA134a|W and chlorofluorocarbon-water tension values estimated from a parametric relationship. This represents the first report of the interfacial and microscopic properties of the (propellant) hydrofluoroalkanes (HFA)|W interface. The results presented here are of relevance in the design of surfactants capable of forming and stabilizing water-in-HFA microemulsions. Reverse aqueous microemulsions in HFA-based pressurized metered-dose inhalers are candidate formulations for the systemic delivery of biomolecules to and through the lungs. PMID:17014124

  2. Spectroscopic determination of the thermodynamics of cobalt and zinc binding to GATA proteins.

    PubMed

    Ghering, Amy B; Shokes, Jacob E; Scott, Robert A; Omichinski, James G; Godwin, Hilary A

    2004-07-01

    Vertebrate GATA proteins regulate processes that are vital to development, and each possesses two tandem GATA finger domains: an N-terminal GATA finger and a C-terminal GATA finger. These GATA fingers require Zn(2+) to fold, to bind DNA recognition elements, and to regulate transcription. While the GATA-1 C-terminal finger is necessary and sufficient to bind to single GATA DNA sites, the N-terminal finger interacts with DNA such that the double finger unit (DF domain) has a binding and transactivation profile that is tuned by the DNA-binding site. Co(2+) was used as a spectroscopic probe in a series of competition titrations to determine the affinity of Co(2+) and Zn(2+) for the C-terminal finger from chicken GATA-1 and the double finger from human GATA-1 (referred to in this report as CF and DF). For CF, these experiments yielded K(b)(Co) = 1.0 (+/-1.3) x 10(7) M(-1) and K(b)(Zn) = 2.0 (+/-1.3) x 10(10) M(-1). For DF, these experiments yielded equilibrium constants for the process of two M(2+) binding to form M(2+)(2)-DF of beta(2)(Co) = 2.5 (+/-1.6) x 10(14) M(-2) and beta(2)(Zn) = 6.3 (+/-2.5) x 10(20) M(-2). The ZnS(4) coordination environment of Zn(2+)-bound CF was confirmed with X-ray absorption spectroscopy. A detailed analysis of these data suggests that the N-terminal and C-terminal fingers of DF act as independent and identical Zn(2+)-binding sites and each finger binds Zn(2+) with an affinity equivalent to that of CF. PMID:15222747

  3. Supramolecular interactions of nonsteroidal anti-inflammatory drug in nanochannels of molecular containers: a spectroscopic, thermogravimetric and microscopic investigation.

    PubMed

    Maity, Banibrata; Chatterjee, Aninda; Ahmed, Sayeed Ashique; Seth, Debabrata

    2014-11-10

    Supramolecular host-guest complexation between the nonsteroidal anti-inflammatory drug indomethacin (IMC) and molecular containers were investigated. The weakly fluorescent drug molecule becomes highly fluorescent on complexation with different molecular containers, and time-resolved fluorescence emission spectroscopy reveals that the lifetime components of IMC significantly increase in the presence of molecular containers, compared with the lifetimes in neat water. The respective solid host-guest complexes were synthesised and characterised by Fourier transform infrared and (1) H nuclear magnetic resonance spectroscopic analysis. Microscopy techniques were used to analyse modifications of the surface morphology, owing to the formation of supramolecular complexes. The effect of the molecular container on the optical properties of IMC has also been investigated to determine the effect of nanochannels of different size and structure. PMID:25146319

  4. The microcanonical thermodynamics of finite systems: the microscopic origin of condensation and phase separations, and the conditions for heat flow from lower to higher temperatures.

    PubMed

    Gross, D H E; Kenney, J F

    2005-06-01

    Microcanonical thermodynamics [D. H. E. Gross, Microcanonical Thermodynamics, Phase Transitions in "Small" Systems (World Scientific, Singapore, 2001)] allows the application of statistical mechanics both to finite and even small systems and also to the largest, self-gravitating ones. However, one must reconsider the fundamental principles of statistical mechanics especially its key quantity, entropy. Whereas in conventional thermostatistics, the homogeneity and extensivity of the system and the concavity of its entropy are central conditions, these fail for the systems considered here. For example, at phase separation, the entropy S(E) is necessarily convex to make e(S(E)-E/T) bimodal in E. Particularly, as inhomogeneities and surface effects cannot be scaled away, one must be careful with the standard arguments of splitting a system into two subsystems, or bringing two systems into thermal contact with energy or particle exchange. Not only the volume part of the entropy must be considered; the addition of any other external constraint [A. Wehrl, Rev. Mod. Phys. 50, 221 (1978)], such as a dividing surface, or the enforcement of gradients of the energy or particle profile, reduce the entropy. As will be shown here, when removing such constraints in regions of a negative heat capacity, the system may even relax under a flow of heat (energy) against a temperature slope. Thus the Clausius formulation of the second law: "Heat always flows from hot to cold," can be violated. Temperature is not a necessary or fundamental control parameter of thermostatistics. However, the second law is still satisfied and the total Boltzmann entropy increases. In the final sections of this paper, the general microscopic mechanism leading to condensation and to the convexity of the microcanonical entropy at phase separation is sketched. Also the microscopic conditions for the existence (or nonexistence) of a critical end point of the phase separation are discussed. This is explained for

  5. Colored grounds of gilt stucco surfaces as analyzed by a combined microscopic, spectroscopic and elemental analytical approach.

    PubMed

    Sansonetti, A; Striova, J; Biondelli, D; Castellucci, E M

    2010-08-01

    A survey of gilts applied to stucco surfaces that specifically focuses on the compositions of their colored grounds is reported. Gilt samples of a common geographical (Lombardy in Italy) and temporal provenance (17th-18th century) were studied in the form of polished cross-sections by optical and electron microscopy (SEM-EDS), micro-Raman (microRaman) spectroscopy and Fourier-transform infrared microspectroscopy (microFTIR). Comparing samples with superimposed grounds and gilts enabled light to be shed on the choice of specific materials, their stratigraphic functions, decorative effects, and technological performances. Iron oxide pigments were found in the older grounds, sometimes in the presence of lead white (2PbCO(3).Pb(OH)(2)) or minium (Pb(3)O(4)). In more recent grounds, chrome yellow (PbCrO(4)), chrome orange (PbCrO(4).PbO), cinnabar (alpha-HgS) and barium white (BaSO(4)), invariably mixed with lead white, were encountered. Evidence for the use of organic mordants (colophony and wax, or siccative oil) was obtained by microFTIR. This combined microFTIR and microRaman spectroscopic and elemental (SEM-EDS) analytical approach enhances knowledge of the composition of gold grounds, their variability and their chronological evolution. PMID:20174784

  6. Structural Analysis of Crystalline R(+)-α-Lipoic Acid-α-cyclodextrin Complex Based on Microscopic and Spectroscopic Studies

    PubMed Central

    Ikuta, Naoko; Endo, Takatsugu; Hosomi, Shota; Setou, Keita; Tanaka, Shiori; Ogawa, Noriko; Yamamoto, Hiromitsu; Mizukami, Tomoyuki; Arai, Shoji; Okuno, Masayuki; Takahashi, Kenji; Terao, Keiji; Matsugo, Seiichi

    2015-01-01

    R(+)-α-lipoic acid (RALA) is a naturally-occurring substance, and its protein-bound form plays significant role in the energy metabolism in the mitochondria. RALA is vulnerable to a variety of physical stimuli, including heat and UV light, which prompted us to study the stability of its complexes with cyclodextrins (CDs). In this study, we have prepared and purified a crystalline RALA-αCD complex and evaluated its properties in the solid state. The results of 1H NMR and PXRD analyses indicated that the crystalline RALA-αCD complex is a channel type complex with a molar ratio of 2:3 (RALA:α-CD). Attenuated total reflection/Fourier transform infrared analysis of the complex showed the shift of the C=O stretching vibration of RALA due to the formation of the RALA-αCD complex. Raman spectroscopic analysis revealed the significant weakness of the S–S and C–S stretching vibrations of RALA in the RALA-αCD complex implying that the dithiolane ring of RALA is almost enclosed in glucose ring of α-CD. Extent of this effect was dependent on the direction of the excitation laser to the hexagonal morphology of the crystal. Solid-state NMR analysis allowed for the chemical shift of the C=O peak to be precisely determined. These results suggested that RALA was positioned in the α-CD cavity with its 1,2-dithiolane ring orientated perpendicular to the plane of the α-CD ring. PMID:26501268

  7. Probing the microscopic hydrophobicity of smectite surfaces. A vibrational spectroscopic study of dibenzo-p-dioxin sorption to smectite.

    PubMed

    Rana, Kiran; Boyd, Stephen A; Teppen, Brian J; Li, Hui; Liu, Cun; Johnston, Cliff T

    2009-04-28

    The interaction of dibenzo-p-dioxin (DD), from aqueous suspension, with smectite was investigated using in situ vibrational spectroscopy (FTIR and Raman), structural and batch sorption techniques. Batch sorption isotherms were integrated with in situ attenuated total reflectance (ATR)-FTIR and Raman spectroscopy and X-ray diffraction. Sorption isotherms revealed that the affinity of DD for smectite in aqueous suspension was strongly influenced both by the type of smectite and by the nature of the exchangeable cation. Cs-saponite showed a much higher affinity over Rb-, K- and Na-exchange saponites. In addition, DD sorption was found to depend on clay type with DD showing a high affinity for the tetrahedrally substituted trioctahedral saponite over SWy-2 and Upton montmorillonites. A structural model is introduced to account for the influence of clay type. Raman and FTIR data provided complementary molecular-level insight into the sorption mechanisms. In the case of Cs-saponite, the selection rules of DD based on D(2h) symmetry were broken indicating a site-specific interaction between DD and intercalated Cs(+) ions in the interlayer of the clay. Polarized in situ ATR-FTIR spectra revealed that the molecular plane of sorbed DD was tilted with respect to the clay surface which was consistent with a d-spacing of 1.49 nm. Finally, cation-induced changes in both the skeletal ring vibrations and the asymmetric C-O-C stretching vibrations provided evidence for site specific interactions between the DD and exchangeable cations in the clay interlayer. Together, the combined macroscopic and spectroscopic data show a surprising link between a hydrophilic material and a planar hydrophobic aromatic hydrocarbon. PMID:19421512

  8. The effects of organic solvents on the folding pathway and associated thermodynamics of proteins: a microscopic view.

    PubMed

    Yu, Yuqi; Wang, Jinan; Shao, Qiang; Shi, Jiye; Zhu, Weiliang

    2016-01-01

    Protein folding is subject to the effects of solvation environment. A variety of organic solvents are used as additives for in vitro refolding of denatured proteins. Examination of the solvent effects on protein folding could be of fundamental importance to understand the molecular interactions in determining protein structure. This article investigated the folding of α-helix and β-hairpin structures in water and the solutions of two representative refolding additives (methanol (MeOH) and 1-Ethyl-3-methylimidazolium chloride (EMIM-Cl) ionic liquid) using REMD simulations. For both α-helix and β-hairpin in MeOH/water solution or α-helix in EMIM-Cl/water solution, the transient structures along the folding pathway are consistent with the counterparts in water but the relative statistical weights are changed, leading to the decrease in the overall folding free energy barrier. Accordingly, MeOH promotes the folding of both α-helix and β-hairpin but EMIM-Cl ionic liquid only promotes the folding of α-helix, consistent with experimental observations. The present study reveals for the first time the trivial effects on folding route but significant effects on folding thermodynamics from MeOH and EMIM-Cl, explaining the function of protein refolding additives and testifying the validity of the folding mechanism revealed by in vitro protein folding study using refolding additives. PMID:26775871

  9. The effects of organic solvents on the folding pathway and associated thermodynamics of proteins: a microscopic view

    PubMed Central

    Yu, Yuqi; Wang, Jinan; Shao, Qiang; Shi, Jiye; Zhu, Weiliang

    2016-01-01

    Protein folding is subject to the effects of solvation environment. A variety of organic solvents are used as additives for in vitro refolding of denatured proteins. Examination of the solvent effects on protein folding could be of fundamental importance to understand the molecular interactions in determining protein structure. This article investigated the folding of α-helix and β-hairpin structures in water and the solutions of two representative refolding additives (methanol (MeOH) and 1-Ethyl-3-methylimidazolium chloride (EMIM-Cl) ionic liquid) using REMD simulations. For both α-helix and β-hairpin in MeOH/water solution or α-helix in EMIM-Cl/water solution, the transient structures along the folding pathway are consistent with the counterparts in water but the relative statistical weights are changed, leading to the decrease in the overall folding free energy barrier. Accordingly, MeOH promotes the folding of both α-helix and β-hairpin but EMIM-Cl ionic liquid only promotes the folding of α-helix, consistent with experimental observations. The present study reveals for the first time the trivial effects on folding route but significant effects on folding thermodynamics from MeOH and EMIM-Cl, explaining the function of protein refolding additives and testifying the validity of the folding mechanism revealed by in vitro protein folding study using refolding additives. PMID:26775871

  10. Thermodynamic and Spectroscopic Studies of Trivalent f -element Complexation with Ethylenediamine- N,N '-di(acetylglycine)- N,N '-diacetic Acid

    DOE PAGESBeta

    Heathman, Colt R.; Grimes, Travis S.; Zalupski, Peter R.

    2016-03-21

    In this study, the coordination behavior and thermodynamic features of complexation of trivalent lanthanides and americium by ethylenediamine-N,N'-di(acetylglycine)-N,N'-diacetic acid (EDDAG-DA) (bisamide-substituted-EDTA) were investigated by potentiometric and spectroscopic techniques. Acid dissociation constants (Ka) and complexation constants (β) of lanthanides (except Pm) were determined by potentiometric analysis. Absorption spectroscopy was used to determine stability constants for the binding of trivalent americium and neodymium by EDDAG-DA under similar conditions. The potentiometry revealed 5 discernible protonation constants and 3 distinct metal–ligand complexes (identified as ML–, MHL, and MH2L+). Time-resolved fluorescence studies of Eu-(EDDAG-DA) solutions (at varying pH) identified a constant inner-sphere hydration number ofmore » 3, suggesting that glycine functionalities contained in the amide pendant arms are not involved in metal complexation and are protonated under more acidic conditions. The thermodynamic studies identified that f-element coordination by EDDAG-DA is similar to that observed for ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA). However, coordination via two amidic oxygens of EDDAG-DA lowers its trivalent f-element complex stability by roughly 3 orders of magnitude relative to EDTA.« less

  11. Thermodynamic and Spectroscopic Studies of Trivalent f-element Complexation with Ethylenediamine-N,N'-di(acetylglycine)-N,N'-diacetic Acid.

    PubMed

    Heathman, Colt R; Grimes, Travis S; Zalupski, Peter R

    2016-03-21

    The coordination behavior and thermodynamic features of complexation of trivalent lanthanides and americium by ethylenediamine-N,N'-di(acetylglycine)-N,N'-diacetic acid (EDDAG-DA) (bisamide-substituted-EDTA) were investigated by potentiometric and spectroscopic techniques. Acid dissociation constants (K(a)) and complexation constants (β) of lanthanides (except Pm) were determined by potentiometric analysis. Absorption spectroscopy was used to determine stability constants for the binding of trivalent americium and neodymium by EDDAG-DA under similar conditions. The potentiometry revealed 5 discernible protonation constants and 3 distinct metal-ligand complexes (identified as ML(-), MHL, and MH2L(+)). Time-resolved fluorescence studies of Eu-(EDDAG-DA) solutions (at varying pH) identified a constant inner-sphere hydration number of 3, suggesting that glycine functionalities contained in the amide pendant arms are not involved in metal complexation and are protonated under more acidic conditions. The thermodynamic studies identified that f-element coordination by EDDAG-DA is similar to that observed for ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA). However, coordination via two amidic oxygens of EDDAG-DA lowers its trivalent f-element complex stability by roughly 3 orders of magnitude relative to EDTA. PMID:26930023

  12. Quest for Environmentally-Benign Ligands for Actinide Separations: Thermodynamic, Spectroscopic, and Structural Characterization of U(VI) Complexes with Oxa-Diamide and Related Ligands

    SciTech Connect

    Advanced Light Source; Tian, Guoxin; Rao, Linfeng; Teat, Simon J.; Liu, Guokui

    2009-01-05

    Complexation of U(VI) with N,N,N{prime},N{prime}-tetramethyl-3-oxa-glutaramide (TMOGA) and N,N-dimethyl-3-oxa-glutaramic acid (DMOGA) was studied in comparison with their dicarboxylate analog, oxydiacetic acid (ODA). Thermodynamic parameters, including stability constants, enthalpy and entropy of complexation, were determined by spectrophotometry, potentiometry and calorimetry. Single-crystal X-ray diffractometry, EXAFS spectroscopy, FT-IR absorption and laser-induced luminescence spectroscopy were used to obtain structural information on the U(VI) complexes. Like ODA, TMOGA and DMOGA form tridentate U(VI) complexes, with three oxygen atoms (the amide, ether and/or carboxylate oxygen) coordinating to the linear UO{sub 2}{sup 2+} cation via the equatorial plane. The stability constants, enthalpy and entropy of complexation all decrease in the order ODA > DMOGA > TMOGA, showing that the complexation is entropy driven and the substitution of a carboxylate group with an amide group reduces the strength of complexation with U(VI) due to the decrease in the entropy of complexation. The trend in the thermodynamic stability of the complexes correlates very well with the structural and spectroscopic data obtained by single crystal XRD, FT-IR and laser-induced luminescence spectroscopy.

  13. Interactions fulvate-metal (Zn(2+), Cu(2+) and Fe(2+)): theoretical investigation of thermodynamic, structural and spectroscopic properties.

    PubMed

    Bertoli, Alexandre C; Garcia, Jerusa S; Trevisan, Marcello G; Ramalho, Teodorico C; Freitas, Matheus P

    2016-04-01

    The use of theoretical calculation to determine structural properties of fulvate-metal complex (zinc, copper and iron) is here related. The species were proposed in the ratio 1:1 and 2:1 for which the molecular structure was obtained through the semi-empirical method PM6. The calculation of thermodynamic stability ([Formula: see text]) predicted that the iron complex were more exo-energetic. Metallic ions were coordinated to the phtalate groups of the model-structure of fulvic acid Suwannee River and the calculations of vibrational frequencies suggested that hydrogen bonds may help on the stability of the complex formation. PMID:26857737

  14. Kinetics and thermodynamics of glycans and glycoproteins binding to Holothuria scabra lectin: a fluorescence and surface plasmon resonance spectroscopic study.

    PubMed

    Gowda, Nagaraj M; Gaikwad, Sushama M; Khan, M Islam

    2013-11-01

    Holothuria scabra produces a monomeric lectin (HSL) of 182 kDa. HSL showed strong antibacterial activity and induced bacterial agglutination under in vitro conditions, indicating its role in animals' innate immune responses. Very few lectins have been reported from echinoderms and none of these lectins have been explored in detail for their sugar-binding kinetics. Affinity, kinetics and thermodynamic analysis of glycans and glycoproteins binding to HSL were studied by fluorescence and surface plasmon resonance spectroscopy. Lectin binds with higher affinity to O-linked than N-linked asialo glycans, and the affinities were relatively higher than that for sialated glycans and glycoproteins. T-antigen α-methyl glycoside was the most potent ligand having the highest affinity (Ka 8.32 ×10(7) M(-1)). Thermodynamic and kinetic analysis indicated that the binding of galactosyl Tn-antigen and asialo glycans is accompanied by an enthalpic contribution in addition to higher association rate coupled by low activation energy for the association process. Presence of sialic acid or protein matrix inhibits binding. Higher affinity of HSL for O-glycans than N-glycans had biological implications; since HSL specifically recognizes bacteria, which have mucin or O-glycan cognate on their cell surfaces and play a major role in animal innate immunity. Since, HSL had higher affinity to T-antigen, makes it a useful tool for cancer diagnostic purpose. PMID:23736907

  15. Spectroscopic and thermodynamic studies on the binding of sanguinarine and berberine to triple and double helical DNA and RNA structures.

    PubMed

    Das, Suman; Kumar, Gopinatha Suresh; Ray, Arghya; Maiti, Motilal

    2003-04-01

    A comparative study on the interaction of sanguinarine and berberine with DNA and RNA triplexes and their parent duplexes was performed, by using a combination of spectrophotometric, UV thermal melting, circular dichroic and thermodynamic techniques. Formation of the DNA and RNA triplexes was confirmed from UV-melting and circular dichroic measurements. The interaction process was characterized by increase of thermal melting temperature, perturbation in circular dichroic spectrum and the typical hypochromic and bathochromic effects in the absorption spectrum. Scatchard analysis indicated that both the alkaloids bound to the triplex and duplex structures in a non-cooperative manner and the binding was stronger to triplexes than to parent duplexes. Thermal melting studies further indicated that sanguinarine stabilized the Hoogsteen base paired third strand of both DNA and RNA triplexes more tightly compared to their Watson-Crick strands, while berberine stabilized the third strand only without affecting the Watson-Crick strand. However, sanguinarine stabilized the parent duplexes while no stabilization was observed with berberine under identical conditions. Circular dichroic studies were also consistent with the observation that perturbations of DNA and RNA triplexes were more compared to their parent duplexes in presence of the alkaloids. Thermodynamic data revealed that binding of sanguinarine and berberine to triplexes (T.AxT and U.AxU) and duplexes (A.T and A.U) showed negative enthalpy changes and positive entropy changes but that of sanguinarine to C.GxC(+) triplex and G.C duplex exhibited negative enthalpy and negative entropy changes. Taken together, these results suggest that both sanguinarine and berberine can bind and stabilize the DNA and RNA triplexes more strongly than their respective parent duplexes. PMID:12643773

  16. Integrated approaches of x-ray absorption spectroscopic and electron microscopic techniques on zinc speciation and characterization in a final sewage sludge product.

    PubMed

    Kim, Bojeong; Levard, Clément; Murayama, Mitsuhiro; Brown, Gordon E; Hochella, Michael F

    2014-05-01

    Integration of complementary techniques can be powerful for the investigation of metal speciation and characterization in complex and heterogeneous environmental samples, such as sewage sludge products. In the present study, we combined analytical transmission electron microscopy (TEM)-based techniques with X-ray absorption spectroscopy (XAS) to identify and characterize nanocrystalline zinc sulfide (ZnS), considered to be the dominant Zn-containing phase in the final stage of sewage sludge material of a full-scale municipal wastewater treatment plant. We also developed sample preparation procedures to preserve the organic and sulfur-rich nature of sewage sludge matrices for microscopic and spectroscopic analyses. Analytical TEM results indicate individual ZnS nanocrystals to be in the size range of 2.5 to 7.5 nm in diameter, forming aggregates of a few hundred nanometers. Observed lattice spacings match sphalerite. The ratio of S to Zn for the ZnS nanocrystals is estimated to be 1.4, suggesting that S is present in excess. The XAS results on the Zn speciation in the bulk sludge material also support the TEM observation that approximately 80% of the total Zn has the local structure of a 3-nm ZnS nanoparticle reference material. Because sewage sludge is frequently used as a soil amendment on agricultural lands, future studies that investigate the oxidative dissolution rate of ZnS nanoparticles as a function of size and aggregation state and the change of Zn speciation during post sludge-processing and soil residency are warranted to help determine the bioavailability of sludge-born Zn in the soil environment. PMID:25602819

  17. Dimerization of the octaethylporphyrin {pi} cation radical complex of cobalt(II): Thermodynamic, kinetic, and spectroscopic studies

    SciTech Connect

    Ni, Y.; Lee, S.; Wayland, B.B.

    1999-08-23

    One electron oxidation of cobalt(II) can occur from either the cobalt d or porphyrin {pi} orbitals depending on the choice of porphyrin and reaction media. Oxidation of (octaethylporphyrinato)cobalt(II), (OEP)Co{sup II} (1), in the presence of ligands such as H{sub 2}O and CO produces diamagnetic five and six coordinate complexes of cobalt(III). In the absence of additional ligands to coordinate with Co(III) the first oxidation of [(OEP)Co{sup II}]{sup +} (2). Metalloporphyrin {pi} cation radical complexes and dimers of the OEP derivatives have been extensively investigated. This article reports on the interconversion of the paramagnetic (S = 1) monomer, [(OEP)Co{sup II}]{sup +} (2), with a diamagnetic dimer, [(OEP)-Co{sup II}]{sub 2}{sup 2+} (3), in dichloromethane solvant. {sup 1}H NMR shift and line width studies in CD{sub 2}Cl{sub 2} are applied in evaluating the thermodynamic and activation parameters for homolytic dissociation of the diamagnetic dimer (3).

  18. The adsorption of C4 unsaturated hydrocarbons on highly dehydrated silica. An IR-spectroscopic and thermodynamic study.

    PubMed

    Magnacca, Giuliana; Morterra, Claudio

    2005-04-26

    The adsorptive interaction of 1-butyne and 1-butene with a highly dehydrated pyrogenic silica system has been studied to understand the thermodynamic behavior of the adsorption process by the application of the Langmuir model and of the Van't Hoff equation. In situ FTIR spectroscopy allowed the characterization of the adsorption phenomenon in terms of involved surface sites, gas-volumetric determinations yielded quantitative information relative to the adsorption process, and microcalorimetric results allowed the comparison between calculated and experimental data. K(eq) and Delta(ads)G degrees were obtained from Langmuir's model application; Delta(ads)H data were obtained from the Van't Hoff equation and by the isosteric heats method and were compared with experimental values. The virtual constancy of Delta(ads)H with equilibrium pressure and surface coverage (Langmuir model) allowed us to obtain the Delta(ads)H degrees values and, consequently, the Delta(ads)S degrees values for the systems of interest. PMID:15835958

  19. Spectroscopic (FT-IR and FT-Raman) studies, NBO, HOMO-LUMO, NMR analyses and thermodynamics functions of 5-bromo-2-methoxybenzaldehyde

    NASA Astrophysics Data System (ADS)

    Balachandran, V.; Santhi, G.; Karpagam, V.

    2013-04-01

    The (FT-IR and FT-Raman) spectral properties of 5-bromo-2-methoxybenzaldehyde (BMB) are studied using density functional theory (DFT) employing B3LYP/6-311++G (d) and B3LYP/6-311++G (d, p) levels of theory. There are four conformers, C1, C2, C3, and C4 for this molecule. The computational results diagnose the most stable conformer of BMB as the C1 form. The optimized geometrical parameters obtained by B3LYP/6-311++G (d, p) method show good agreement with experimental X-ray data. A study on the electronic properties, such as HOMO and LUMO energies, is performed. The isotropic chemical shift computed by 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the BMB calculated using the gauge invariant atomic orbital (GIAO) method also shows good agreement with experimental observations. The MEP surface reflects the chemical reactivity of a molecule. The thermodynamic functions (heat capacity, internal heat energy, Gibbs energy and entropy) from spectroscopic data by statistical methods were obtained for the range of temperature 100-1000 K. The energetic behavior of the compound in different solvent medium (water, ethanol, and methanol) was examined by applying polarizable continuum model (PCM). The complete molecular orbital simulations and theoretical UV-visible spectra carried out in this study yield better understanding of charge delocalization pattern and stability of the title molecules to a greater extent.

  20. Effect of steric hindrance on carbon dioxide absorption into new amine solutions: thermodynamic and spectroscopic verification through solubility and NMR analysis.

    PubMed

    Park, Jung-Yeon; Yoon, Sang Jun; Lee, Huen

    2003-04-15

    Acid gas absorption technology is of great importance in these days for the prevention of global warming and the resulting worldwide climate change. More efficient process design and development for the removal of acid gases has become important, together with the development of new absorbents as one of urgent areas of research in addressing global-warming problems. In the present work, aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD), a sterically hindered amine, has been examined as a potential CO2 absorbent and compared with the most commonly used absorbent, monoethanolamine (MEA) solution, through equilibrium solubility measurements and 13C NMR spectroscopic analyses. The solubilities of CO2 in aqueous 10 mass % AHPD solutions were higher than those in aqueous 10 mass % MEA solutions above 4 kPa at 298.15 K, but below 4 kPa, the solubility behavior appeared to be the opposite. The solubility difference between these two solutions increased with the CO2 partial pressures above the crossover pressure. Equilibrated CO2-MEA-H2O and CO2-AHPD-H2O solutions at various CO2 partal pressures ranging from 0.01 to 3000 kPa were analyzed by 13C NMR spectroscopy to provide a more microscopic understanding of the reaction mechanisms in the two solutions. In the CO2-amine-H2O solutions, amine reacted with CO2 to form mainly the protonated amine (AMH+), bicarbonate ion (HCO3-), and carbamate anion (AMCO2-), where the quantitative ratio of bicarbonate ion to carbamate anion strongly influenced the CO2 loading in the amine solutions. A profusion of bicarbonate ions, but a very small amount of carbamate anions, was identified in the CO2-AHPD-H2O solution, whereas a considerable amount of carbamate anions was formed in the CO2-MEA-H2O solution. AHPD contains more hydroxyl groups than nonhindered MEA, and hence, the chemical shifts in its 13C NMR spectra were strongly influenced by the solution pH values. In contrast, MEA appeared to be insensitive to pH. The

  1. Stochastic thermodynamics

    NASA Astrophysics Data System (ADS)

    Eichhorn, Ralf; Aurell, Erik

    2014-04-01

    theory for small deviations from equilibrium, in which a general framework is constructed from the analysis of non-equilibrium states close to equilibrium. In a next step, Prigogine and others developed linear irreversible thermodynamics, which establishes relations between transport coefficients and entropy production on a phenomenological level in terms of thermodynamic forces and fluxes. However, beyond the realm of linear response no general theoretical results were available for quite a long time. This situation has changed drastically over the last 20 years with the development of stochastic thermodynamics, revealing that the range of validity of thermodynamic statements can indeed be extended deep into the non-equilibrium regime. Early developments in that direction trace back to the observations of symmetry relations between the probabilities for entropy production and entropy annihilation in non-equilibrium steady states [5-8] (nowadays categorized in the class of so-called detailed fluctuation theorems), and the derivations of the Bochkov-Kuzovlev [9, 10] and Jarzynski relations [11] (which are now classified as so-called integral fluctuation theorems). Apart from its fundamental theoretical interest, the developments in stochastic thermodynamics have experienced an additional boost from the recent experimental progress in fabricating, manipulating, controlling and observing systems on the micro- and nano-scale. These advances are not only of formidable use for probing and monitoring biological processes on the cellular, sub-cellular and molecular level, but even include the realization of a microscopic thermodynamic heat engine [12] or the experimental verification of Landauer's principle in a colloidal system [13]. The scientific program Stochastic Thermodynamics held between 4 and 15 March 2013, and hosted by The Nordic Institute for Theoretical Physics (Nordita), was attended by more than 50 scientists from the Nordic countries and elsewhere, amongst them

  2. First-principles calculation of thermodynamic stability of acids and bases under pH environment: A microscopic pH theory

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Hyun; Kim, Kwiseon; Zhang, S. B.

    2012-04-01

    Despite being one of the most important thermodynamic variables, pH has yet to be incorporated into first-principles thermodynamics to calculate stability of acidic and basic solutes in aqueous solutions. By treating the solutes as defects in homogeneous liquids, we formulate a first-principles approach to calculate their formation energies under proton chemical potential, or pH, based on explicit molecular dynamics. The method draws analogy to first-principle calculations of defect formation energies under electron chemical potential, or Fermi energy, in semiconductors. From this, we propose a simple pictorial representation of the general theory of acid-base chemistry. By performing first-principles molecular dynamics of liquid water models with solutes, we apply the formulation to calculate formation energies of various neutral and charged solutes such as H+, OH-, NH3, NH4+, HCOOH, and HCOO- in water. The deduced auto-dissociation constant of water and the difference in the pKa values of NH3 and HCOOH show good agreement with known experimental values. Our first-principles approach can be further extended and applied to other bio- and electro-chemical molecules such as amino acids and redox reaction couples that could exist in aqueous environments to understand their thermodynamic stability.

  3. First-Principles Calculation of Thermodynamic Stability of Acids and Bases under pH Environment: A Microscopic pH Theory

    SciTech Connect

    Kim, Y. H.; Kim, K.; Zhang, S. B.

    2012-04-07

    Despite being one of the most important thermodynamic variables, pH has yet to be incorporated into first-principles thermodynamics to calculate stability of acidic and basic solutes in aqueous solutions. By treating the solutes as defects in homogeneous liquids, we formulate a first-principles approach to calculate their formation energies under proton chemical potential, or pH, based on explicit molecular dynamics. The method draws analogy to first-principle calculations of defect formation energies under electron chemical potential, or Fermi energy, in semiconductors. From this, we propose a simple pictorial representation of the general theory of acid-base chemistry. By performing first-principles molecular dynamics of liquid water models with solutes, we apply the formulation to calculate formation energies of various neutral and charged solutes such as H{sup +}, OH{sup -}, NH{sub 3}, NH{sub 4}{sup +}, HCOOH, and HCOO{sup -} in water. The deduced auto-dissociation constant of water and the difference in the pKa values of NH{sub 3} and HCOOH show good agreement with known experimental values. Our first-principles approach can be further extended and applied to other bio- and electro-chemical molecules such as amino acids and redox reaction couples that could exist in aqueous environments to understand their thermodynamic stability.

  4. Spectroscopic and microscopic studies of self-assembled nc-Si/a-SiC thin films grown by low pressure high density spontaneous plasma processing.

    PubMed

    Das, Debajyoti; Kar, Debjit

    2014-12-14

    In view of suitable applications in the window layer of nc-Si p-i-n solar cells in superstrate configuration, the growth of nc-Si/a-SiC composite films was studied, considering the trade-off relation between individual characteristics of its a-SiC component to provide a wide optical-gap and electrically conducting nc-Si component to simultaneously retain enough crystalline linkages to facilitate proper crystallization to the i-nc-Si absorber-layer during its subsequent growth. Self-assembled nc-Si/a-SiC thin films were spontaneously grown by low-pressure planar inductively coupled plasma CVD, operating in electromagnetic mode, providing high atomic-H density. Spectroscopic simulations of ellipsometry and Raman data, and systematic chemical and structural analysis by XPS, TEM, SEM and AFM were performed. Corresponding to optimized inclusion of C essentially incorporated as Si-C bonds in the network, the optical-gap of the a-SiC component widened, void fraction including the incubation layer thickness reduced. While the bulk crystallinity decreased only marginally, Si-ncs diminished in size with narrower distribution and increased number density. With enhanced C-incorporation, formation of C-C bonds in abundance deteriorates the Si continuous bonding network and persuades growth of an amorphous dominated silicon-carbon heterostructure containing high-density tiny Si-ncs. Stimulated nanocrystallization identified in the Si-network, induced by a limited amount of carbon incorporation, makes the material most suitable for applications in nc-Si solar cells. The novelty of the present work is to enable spontaneous growth of self-assembled superior quality nc-Si/a-SiC thin films and simultaneous spectroscopic simulation-based optimization of properties for utilization in devices. PMID:25342429

  5. The application of thermodynamic and spectroscopic techniques to adhesion in the polyimide/Ti 6-4 and polyphenylquinoxaline/Ti 6-4 systems

    NASA Technical Reports Server (NTRS)

    Dias, S.; Wightman, J. P.

    1984-01-01

    The results of calorimetric measurements of Ti adherend surfaces are presented. The measurements were carried out after several chemical pretreatments and after fracture of several lap shear samples aged at high temperature. The exact composition of the Ti samples was Ti(6 percent Al-4 percent V). The adhesives used were polyimides and polyphenylquinoxalines (PPQ). Each chemical pretreatment was accompanied by a unique spectroscopic feature which was characterized by XPS, SEM, and specular reflectance infrared spectroscopy. The energetics of the interaction between primer solutions and the Ti adherend were evaluated by microcalorimetry. Changes in the structure of the surface oxide layer upon heating of the adherend were deduced from immersion temperatures of the PI and PPQ solutions. The XPS and SEM data are given is a table.

  6. Comments to Irreversibility in Thermodynamics

    NASA Technical Reports Server (NTRS)

    Zak, M.

    1995-01-01

    The problem of irreversibility in thermodynamics was revisited and analyzed on the microscopic, stochastic, and macroscopic levels of description. It was demonstrated that Newtonian dynamics can be represented in the Reynolds form, a new phenomenological force with non-Lipschitz properties was introduced, and additional non- Lipschitz thermodynamical forces were incorporated into macroscopic models of transport phenomena.

  7. Femtosecond photoelectron point projection microscope

    SciTech Connect

    Quinonez, Erik; Handali, Jonathan; Barwick, Brett

    2013-10-15

    By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect.

  8. Amorphous SiO2 surface models: energetics of the dehydroxylation process, strain, ab initio atomistic thermodynamics and IR spectroscopic signatures.

    PubMed

    Comas-Vives, Aleix

    2016-03-14

    In this contribution, realistic amorphous SiO2 models of 2.1 × 2.1 nm with silanol densities ranging 1.1-7.2 OH per nm(2) are obtained by means of ab initio calculations via the dehydroxylation of a fully hydroxylated silica surface. The dehydroxyation process is considered to take place via direct condensation of adjacent silanol groups and silica migration steps. The latter reconstructions are needed in order to obtain highly dehydroxylated silica surfaces with favorable energetics and without the formation of defects. The obtained surface phase diagram of different silica models as a function of temperature and PH2O is able to correctly describe the silanol density under different conditions, and the IR spectroscopic signatures of the silanols are in qualitative agreement with the experiment. The amorphous silica models presented here have a high degree of heterogeneity as found from the big variability obtained in the energetics of the dehydroxylation steps. It was also found that the resulting average Si-O distance of the newly formed siloxane bridges serves as a descriptor of the strain introduced in the silica surface. All these factors can be crucial in order to simulate the activity of catalysts grafted onto silica with different silanol densities, especially the one containing ca. 1 OH per nm(2), which can serve as a model for the SiO2 surface pretreated under high vacuum and at 700 °C. PMID:26898649

  9. Spectroscopic and thermodynamic study of charge transfer interaction between vitamin B 6 and p-chloranil in aqueous ethanol mixtures of varying composition

    NASA Astrophysics Data System (ADS)

    Datta, Kakali; Roy, Dalim Kumar; Mukherjee, Asok K.

    2008-07-01

    Charge transfer complexes of 1:1 stoichiometry have been found to form between vitamin B 6 (pyridoxine hydrochloride) and a series of electron acceptors including p-chloranil. Since vitamin B 6 is soluble in water while the electron acceptors are insoluble in water but soluble in ethanol, the medium chosen for study is water-ethanol mixture. From the trends in the CT absorption bands the vertical ionization potential of vitamin B 6 has been determined to be 8.12 eV. The enthalpy and entropy of formation of the complex between p-chloranil and vitamin B 6 have been determined by estimating the formation constant ( K) spectroscopically at four different temperatures in 75% ethanol-water mixture. Again, the magnitude of K has been found to decrease noticeably with decrease in dielectric constant of the medium (as the percentage of ethanol in the aqueous-ethanol mixture is increased). A plausible explanation for this has been given in terms of hydrolysis of pyridoxine hydrochloride.

  10. Spectroscopic investigation (FTIR spectrum), NBO, HOMO-LUMO energies, NLO and thermodynamic properties of 8-Methyl-N-vanillyl-6-nonenamideby DFT methods

    NASA Astrophysics Data System (ADS)

    Sherin Percy Prema Leela, J.; Hemamalini, R.; Muthu, S.; Al-Saadi, Abdulaziz A.

    2015-07-01

    Capsicum a hill grown vegetable is also known as red pepper or chili pepper. Capsaicin(8-Methyl-N-vanillyl-6-nonenamide) is the active component in chili peppers, which is currently used in the treatment of osteoarthritis, psoriasis and cancer. Fourier transform infrared (FT-IR) spectrum of Capsaicin in the solid phase were recorded in the region 4000-400 cm-1 and analyzed. The vibrational frequencies of the title compound were obtained theoretically by DFT/B3LYP calculations employing the standard 6-311++G(d,p) basis set and were compared with Fourier transform infrared spectrum. Complete vibrational assignment analysis and correlation of the fundamental modes for the title compound were carried out. The vibrational harmonic frequencies were scaled using scale factor, yielding a good agreement between the experimentally recorded and the theoretically calculated values. Stability of the molecule arising from hyper conjugative interactions, charge delocalization and intra molecular hydrogen bond-like weak interaction has been analyzed using Natural bond orbital (NBO) analysis by using B3LYP/6-311++G(d,p) method. The results show that electron density (ED) in the σ∗ and π∗ antibonding orbitals and second-order delocalization energies E (2) confirm the occurrence of intra molecular charge transfer (ICT) within the molecule. The dipole moment (μ), polarizability (α) and the hyperpolarizability (β) values of the molecule has been computed. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures were calculated.

  11. Molecular structure, vibrational spectroscopic, hyperpolarizability, natural bond orbital analysis, frontier molecular orbital analysis and thermodynamic properties of 2,3,4,5,6-pentafluorophenylacetic acid.

    PubMed

    Balachandran, V; Karunakaran, V

    2014-06-01

    The FT-IR (4000-400cm(-)(1)) and FT-Raman spectra (3500-100cm(-)(1)) of 2,3,4,5,6-pentafluorophenylacetic acid (PAA) have been recorded. Density functional theory calculation with LSDA/6-31+G(d,p) and B3LYP/6-31+G(d,p) basis sets have been used to determine ground state molecular geometries (bond lengths and bond angles), harmonic vibrational frequencies, infrared intensities, Raman intensities and bonding features of the title compound. The assignments of the vibrational spectra have been carried out with the help of normal coordinate analysis (NCA) following the scaled quantum mechanical force field (SQMFF) methodology. The first order hyperpolarizability (β0) and related properties (β, α0 and Δα) of PAA are calculated using B3LYP/6-31+G(d,p) method on the finite-field approach. The calculated first hyperpolarizability shows that the molecule is an attractive molecule for future applications in non-linear optics. The stability of molecule has been analyzed by using NBO analysis. The calculated HOMO and LUMO energies show that charge transfer occurs within this molecule. Mulliken population analysis on atomic charges is also calculated. Thermodynamic properties (heat capacity, enthalpy, Gibb's free energy and entropy) of the title compound at different temperatures were calculated. PMID:24662720

  12. Comparative vibrational spectroscopic studies, HOMO-LUMO, NBO analyses and thermodynamic functions of p-cresol and 2-methyl-p-cresol based on DFT calculations

    NASA Astrophysics Data System (ADS)

    Balachandran, V.; Murugan, M.; Nataraj, A.; Karnan, M.; Ilango, G.

    2014-11-01

    In the present study structural properties of p-cresol, and 2-methoxy-p-cresol have been studied by using B3LYP/cc-pvdz and B3PW91/cc-pvdz of Density Functional Theory (DFT) utilizing Becke three exchange functional and Lee Yang Paar correlation functional. The Fourier transform infrared and Fourier transform Raman spectra of title molecules were recorded (solid phase). Optimized geometry, harmonic vibrational frequencies and various thermodynamic parameters of the title compounds were calculated with B3LYP/cc-pvdz, and B3PW91/cc-pvdz basis sets. Non-linear optical (NLO) behavior of the p-cresol and 2-methoxy-p-cresol were investigated by determining of electric dipole moment, polarizability α, and hyperpolarizability β using the above mentioned basis sets. The molecular properties such as ionization potential, electronegativity, chemical potential, electrophilicity have been deduced from HOMO-LUMO analysis employing the same basis sets. A detailed interpretation of the infrared and Raman spectra of title molecules were reported. UV spectrum was measured in different solvent. The energy and oscillator strength are calculated by Time Dependant Density Functional Theory (TD-DFT) results. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. The complete assignments were performed on the basis of the potential energy distribution (PED) of vibrational modes, calculated with scaled quantum mechanics (SQM) method. Finally the theoretical FT-IR, FT-Raman, and UV spectra of the title molecules have also been constructed.

  13. Thermodynamic stability, spectroscopic identification, and gas storage capacity of CO2-CH4-N2 mixture gas hydrates: implications for landfill gas hydrates.

    PubMed

    Lee, Hyeong-Hoon; Ahn, Sook-Hyun; Nam, Byong-Uk; Kim, Byeong-Soo; Lee, Gang-Woo; Moon, Donghyun; Shin, Hyung Joon; Han, Kyu Won; Yoon, Ji-Ho

    2012-04-01

    Landfill gas (LFG), which is primarily composed of CH(4), CO(2), and N(2), is produced from the anaerobic digestion of organic materials. To investigate the feasibility of the storage and transportation of LFG via the formation of hydrate, we observed the phase equilibrium behavior of CO(2)-CH(4)-N(2) mixture hydrates. When the specific molar ratio of CO(2)/CH(4) was 40/55, the equilibrium dissociation pressures were gradually shifted to higher pressures and lower temperatures as the mole fraction of N(2) increased. X-ray diffraction revealed that the CO(2)-CH(4)-N(2) mixture hydrate prepared from the CO(2)/CH(4)/N(2) (40/55/5) gas mixture formed a structure I clathrate hydrate. A combination of Raman and solid-state (13)C NMR measurements provided detailed information regarding the cage occupancy of gas molecules trapped in the hydrate frameworks. The gas storage capacity of LFG hydrates was estimated from the experimental results for the hydrate formations under two-phase equilibrium conditions. We also confirmed that trace amounts of nonmethane organic compounds do not affect the cage occupancy of gas molecules or the thermodynamic stability of LFG hydrates. PMID:22380606

  14. Spectroscopic investigation (FTIR spectrum), NBO, HOMO-LUMO energies, NLO and thermodynamic properties of 8-Methyl-N-vanillyl-6-nonenamideby DFT methods.

    PubMed

    Leela, J Sherin Percy Prema; Hemamalini, R; Muthu, S; Al-Saadi, Abdulaziz A

    2015-07-01

    Capsicum a hill grown vegetable is also known as red pepper or chili pepper. Capsaicin(8-Methyl-N-vanillyl-6-nonenamide) is the active component in chili peppers, which is currently used in the treatment of osteoarthritis, psoriasis and cancer. Fourier transform infrared (FT-IR) spectrum of Capsaicin in the solid phase were recorded in the region 4000-400 cm(-1) and analyzed. The vibrational frequencies of the title compound were obtained theoretically by DFT/B3LYP calculations employing the standard 6-311++G(d,p) basis set and were compared with Fourier transform infrared spectrum. Complete vibrational assignment analysis and correlation of the fundamental modes for the title compound were carried out. The vibrational harmonic frequencies were scaled using scale factor, yielding a good agreement between the experimentally recorded and the theoretically calculated values. Stability of the molecule arising from hyper conjugative interactions, charge delocalization and intra molecular hydrogen bond-like weak interaction has been analyzed using Natural bond orbital (NBO) analysis by using B3LYP/6-311++G(d,p) method. The results show that electron density (ED) in the σ∗ and π∗ antibonding orbitals and second-order delocalization energies E (2) confirm the occurrence of intra molecular charge transfer (ICT) within the molecule. The dipole moment (μ), polarizability (α) and the hyperpolarizability (β) values of the molecule has been computed. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures were calculated. PMID:25813174

  15. Microscopic colitis.

    PubMed

    Pardi, Darrell S

    2014-02-01

    Microscopic colitis is a frequent cause of chronic watery diarrhea, especially in older persons. Common associated symptoms include abdominal pain, arthralgias, and weight loss. The incidence of microscopic colitis had been increasing, although more recent studies have shown a stabilization of incidence rates. The diagnosis is based on characteristic histologic findings in a patient with diarrhea. Microscopic colitis can occur at any age, including in children, but it is primarily seen in the elderly. Several treatment options exist to treat the symptoms of microscopic colitis, although only budesonide has been well studied in randomized clinical trials. PMID:24267602

  16. (1)H NMR spectroscopic elucidation in solution of the kinetics and thermodynamics of spin crossover for an exceptionally robust Fe(2+) complex.

    PubMed

    Petzold, Holm; Djomgoue, Paul; Hörner, Gerald; Speck, J Matthäus; Rüffer, Tobias; Schaarschmidt, Dieter

    2016-09-21

    A series of Fe(2+) spin crossover (SCO) complexes [Fe(5/6)](2+) employing hexadentate ligands (5/6) with cis/trans-1,2-diamino cyclohexanes (4) as central building blocks were synthesised. The ligands were obtained by reductive amination of 4 with 2,2'-bipyridyl-6-carbaldehyde or 1,10-phenanthroline-2-carbaldehyde 3. The chelating effect and the rigid structure of the ligands 5/6 lead to exceptionally robust Fe(2+) and Zn(2+) complexes conserving their structure even in coordinating solvents like dmso at high temperatures. Their solution behavior was investigated using variable temperature (VT) (1)H NMR spectroscopy and VT Vis spectroscopy. SCO behavior was found for all Fe(2+) complexes in this series centred around and far above room temperature. For the first time we have demonstrated that the thermodynamics as well as kinetics for SCO can be deduced by using VT (1)H NMR spectroscopy. An alternative scheme using a linear correction term C(1) to model chemical shifts for Fe(2+) SCO complexes is presented. The rate constant for the SCO of [Fe(rac-trans-5)](2+) obtained by VT (1)H NMR was validated by Laser Flash Photolysis (LFP), with excellent agreement (1/(kHL + kLH) = 33.7/35.8 ns for NMR/LFP). The solvent dependence of the transition temperature T1/2 and the solvatochromism of complex [Fe(rac-trans-5)](2+) were ascribed to hydrogen bond formation of the secondary amine to the solvent. Enantiomerically pure complexes can be prepared starting with R,R- or S,S-1,2-diaminocyclohexane (R,R-trans-4 or S,S-trans-4). The high robustness of the complexes reduces a possible ligand scrambling and allows preparation of quasiracemic crystals of [Zn(R,R-5)][Fe(S,S-5)](ClO4)4·(CH3CN) composed of a 1 : 1 mixture of the Zn and Fe complexes with inverse chirality. PMID:27506162

  17. Microscopic Polyangiitis

    MedlinePlus

    ... include purplish bumps and spots pictured below (palpable purpura). These areas range in size from several millimeters ... Syndrome (EGPA) Cryoglobulinemia Giant Cell Arteritis Henoch-Schönlein Purpura Microscopic Polyangiitis Polyarteritis Nodosa Rheumatoid Vasculitis Takayasu’s Arteritis ...

  18. Thermodynamics of Biological Processes

    PubMed Central

    Garcia, Hernan G.; Kondev, Jane; Orme, Nigel; Theriot, Julie A.; Phillips, Rob

    2012-01-01

    There is a long and rich tradition of using ideas from both equilibrium thermodynamics and its microscopic partner theory of equilibrium statistical mechanics. In this chapter, we provide some background on the origins of the seemingly unreasonable effectiveness of ideas from both thermodynamics and statistical mechanics in biology. After making a description of these foundational issues, we turn to a series of case studies primarily focused on binding that are intended to illustrate the broad biological reach of equilibrium thinking in biology. These case studies include ligand-gated ion channels, thermodynamic models of transcription, and recent applications to the problem of bacterial chemotaxis. As part of the description of these case studies, we explore a number of different uses of the famed Monod–Wyman–Changeux (MWC) model as a generic tool for providing a mathematical characterization of two-state systems. These case studies should provide a template for tailoring equilibrium ideas to other problems of biological interest. PMID:21333788

  19. Microscopic Polyangiitis

    PubMed Central

    Chung, Sharon A.; Seo, Philip

    2010-01-01

    Synopsis In 1923, Friedrich Wohlwill described two patients with a “microscopic form of periarteritis nodosa”, which was distinct from classical polyarteritis nodosa. This disease, now known as microscopic polyangiitis (MPA), is a primary systemic vasculitis characterized by inflammation of the small-caliber blood vessels and the presence of circulating antineutrophil cytoplasmic antibodies (ANCA). Typically, microscopic polyangiitis presents with glomerulonephritis and pulmonary capillaritis, although involvement of the skin, nerves, and gastrointestinal tract is not uncommon. Treatment of MPA generally requires use of a cytotoxic agent (such as cyclophosphamide) in addition to high-dose glucocorticoids. Recent research has focused on identifying alternate treatment strategies that minimize or eliminate exposure to cytotoxic agents. This article will review the history, pathogenesis, clinical manifestations, and treatment of MPA. PMID:20688249

  20. Martian Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The microscopic imager (circular device in center) is in clear view above the surface at Meridiani Planum, Mars, in this approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity. The image was taken on the 9th sol of the rover's journey. The microscopic imager is located on the rover's instrument deployment device, or arm. The arrow is pointing to the lens of the instrument. Note the dust cover, which flips out to the left of the lens, is open. This approximated color image was created using the camera's violet and infrared filters as blue and red.

  1. Thermodynamic Diagrams

    NASA Astrophysics Data System (ADS)

    Chaston, Scot

    1999-02-01

    Thermodynamic data such as equilibrium constants, standard cell potentials, molar enthalpies of formation, and standard entropies of substances can be a very useful basis for an organized presentation of knowledge in diverse areas of applied chemistry. Thermodynamic data can become particularly useful when incorporated into thermodynamic diagrams that are designed to be easy to recall, to serve as a basis for reconstructing previous knowledge, and to determine whether reactions can occur exergonically or only with the help of an external energy source. Few students in our chemistry-based courses would want to acquire the depth of knowledge or rigor of professional thermodynamicists. But they should nevertheless learn how to make good use of thermodynamic data in their professional occupations that span the chemical, biological, environmental, and medical laboratory fields. This article discusses examples of three thermodynamic diagrams that have been developed for this purpose. They are the thermodynamic energy account (TEA), the total entropy scale, and the thermodynamic scale diagrams. These diagrams help in the teaching and learning of thermodynamics by bringing the imagination into the process of developing a better understanding of abstract thermodynamic functions, and by allowing the reader to keep track of specialist thermodynamic discourses in the literature.

  2. Melt Structure and Properties: a Spectroscopic Perspective

    NASA Astrophysics Data System (ADS)

    Stebbins, J.

    2006-12-01

    Entropy, volume, and their P/T derivatives are at the heart of models of the thermodynamics of silicate melts and magmas. Quantitative characterization of glass structure is leading to important new insights into the links from "Microscopic to Macroscopic" that can at least guide interpretations of data and in some cases even have predictive power. A few recent examples will be discussed here. The often-large configurational components to heat capacities, thermal expansivities, and compressibilities of melts strongly indicate that structural changes with temperature and pressure are of key importance. At least some aspects of thermal increases in configurational (as opposed to vibrational) disorder are amenable to spectroscopic detection, either with in situ methods or on glasses with varying quench rates and thus varying fictive temperatures. In some systems, such changes are now clear, and can be shown to make significant contributions to properties. These include network cation coordination in systems such as borate liquids (BO4 to BO3 at higher T), and Al-Si disordering in aluminosilicates. In general, however, progress in this rich problem has only begun. It has long been suspected from thermodynamic analyses (and theoretical simulations) that configurational changes in melts play a key role in volume compression at high pressure, over and above that which can be expressed in "normal" equations of state or from those expected from bond compression and bending. Scattering and spectroscopic studies have revealed some of the important aspects of pressure-induced structural changes, but again we are just at the beginning of full understanding. For example, binary silicate glasses quenched from high-P melts clearly record some systematic increases in Si coordination, while aluminosilicates record systematic pressure and compositional (modifier cation field strength) effects on Al coordination in recovered samples with large, quenched-in density increases

  3. Perspective on quantum thermodynamics

    NASA Astrophysics Data System (ADS)

    Millen, James; Xuereb, André

    2016-01-01

    Classical thermodynamics is unrivalled in its range of applications and relevance to everyday life. It enables a description of complex systems, made up of microscopic particles, in terms of a small number of macroscopic quantities, such as work and entropy. As systems get ever smaller, fluctuations of these quantities become increasingly relevant, prompting the development of stochastic thermodynamics. Recently we have seen a surge of interest in exploring the quantum regime, where the origin of fluctuations is quantum rather than thermal. Many questions, such as the role of entanglement and the emergence of thermalisation, lie wide open. Answering these questions may lead to the development of quantum heat engines and refrigerators, as well as to vitally needed simple descriptions of quantum many-body systems.

  4. Thermodynamic holography

    PubMed Central

    Wei, Bo-Bo; Jiang, Zhan-Feng; Liu, Ren-Bao

    2015-01-01

    The holographic principle states that the information about a volume of a system is encoded on the boundary surface of the volume. Holography appears in many branches of physics, such as optics, electromagnetism, many-body physics, quantum gravity, and string theory. Here we show that holography is also an underlying principle in thermodynamics, a most important foundation of physics. The thermodynamics of a system is fully determined by its partition function. We prove that the partition function of a finite but arbitrarily large system is an analytic function on the complex plane of physical parameters, and therefore the partition function in a region on the complex plane is uniquely determined by its values along the boundary. The thermodynamic holography has applications in studying thermodynamics of nano-scale systems (such as molecule engines, nano-generators and macromolecules) and provides a new approach to many-body physics. PMID:26478214

  5. Thermodynamic holography.

    PubMed

    Wei, Bo-Bo; Jiang, Zhan-Feng; Liu, Ren-Bao

    2015-01-01

    The holographic principle states that the information about a volume of a system is encoded on the boundary surface of the volume. Holography appears in many branches of physics, such as optics, electromagnetism, many-body physics, quantum gravity, and string theory. Here we show that holography is also an underlying principle in thermodynamics, a most important foundation of physics. The thermodynamics of a system is fully determined by its partition function. We prove that the partition function of a finite but arbitrarily large system is an analytic function on the complex plane of physical parameters, and therefore the partition function in a region on the complex plane is uniquely determined by its values along the boundary. The thermodynamic holography has applications in studying thermodynamics of nano-scale systems (such as molecule engines, nano-generators and macromolecules) and provides a new approach to many-body physics. PMID:26478214

  6. Nonequilibrium thermodynamics of nucleation.

    PubMed

    Schweizer, M; Sagis, L M C

    2014-12-14

    We present a novel approach to nucleation processes based on the GENERIC framework (general equation for the nonequilibrium reversible-irreversible coupling). Solely based on the GENERIC structure of time-evolution equations and thermodynamic consistency arguments of exchange processes between a metastable phase and a nucleating phase, we derive the fundamental dynamics for this phenomenon, based on continuous Fokker-Planck equations. We are readily able to treat non-isothermal nucleation even when the nucleating cores cannot be attributed intensive thermodynamic properties. In addition, we capture the dynamics of the time-dependent metastable phase being continuously expelled from the nucleating phase, and keep rigorous track of the volume corrections to the dynamics. Within our framework the definition of a thermodynamic nuclei temperature is manifest. For the special case of nucleation of a gas phase towards its vapor-liquid coexistence, we illustrate that our approach is capable of reproducing recent literature results obtained by more microscopic considerations for the suppression of the nucleation rate due to nonisothermal effects. PMID:25494727

  7. Nonequilibrium thermodynamics of nucleation

    SciTech Connect

    Schweizer, M.; Sagis, L. M. C.

    2014-12-14

    We present a novel approach to nucleation processes based on the GENERIC framework (general equation for the nonequilibrium reversible-irreversible coupling). Solely based on the GENERIC structure of time-evolution equations and thermodynamic consistency arguments of exchange processes between a metastable phase and a nucleating phase, we derive the fundamental dynamics for this phenomenon, based on continuous Fokker-Planck equations. We are readily able to treat non-isothermal nucleation even when the nucleating cores cannot be attributed intensive thermodynamic properties. In addition, we capture the dynamics of the time-dependent metastable phase being continuously expelled from the nucleating phase, and keep rigorous track of the volume corrections to the dynamics. Within our framework the definition of a thermodynamic nuclei temperature is manifest. For the special case of nucleation of a gas phase towards its vapor-liquid coexistence, we illustrate that our approach is capable of reproducing recent literature results obtained by more microscopic considerations for the suppression of the nucleation rate due to nonisothermal effects.

  8. Ballistic-Electron-Emission Microscope

    NASA Technical Reports Server (NTRS)

    Kaiser, William J.; Bell, L. Douglas

    1990-01-01

    Ballistic-electron-emission microscope (BEEM) employs scanning tunneling-microscopy (STM) methods for nondestructive, direct electrical investigation of buried interfaces, such as interface between semiconductor and thin metal film. In BEEM, there are at least three electrodes: emitting tip, biasing electrode, and collecting electrode, receiving current crossing interface under investigation. Signal-processing device amplifies electrode signals and converts them into form usable by computer. Produces spatial images of surface by scanning tip; in addition, provides high-resolution images of buried interface under investigation. Spectroscopic information extracted by measuring collecting-electrode current as function of one of interelectrode voltages.

  9. Using the Antenna Effect as a Spectroscopic Tool; Photophysics and Solution Thermodynamics of the Model Luminescent Hydroxypyridonate Complex [EuIII(3,4,3-LI(1,2-HOPO))]-

    SciTech Connect

    Abergel, Rebecca J.; D'Aleo, Anthony; Ng Pak Leung, Clara; Shuh, David; Raymond, Kenneth

    2009-11-20

    While widely used in bioassays, the spectrofluorimetric method described here uses the antenna effect as a tool to probe the thermodynamic parameters of ligands that sensitize lanthanide luminescence. The Eu3+ coordination chemistry, solution thermodynamic stability and photophysical properties of the spermine-based hydroxypyridonate octadentate chelator 3,4,3-LI(1,2-HOPO) are reported. The complex [EuIII(3,4,3-LI(1,2-HOPO))]- luminesces with a long lifetime (805 mu s) and a quantum yield of 7.0percent in aqueous solution, at pH 7.4. These remarkable optical properties were exploited to determine the high (and proton-independent) stability of the complex (log beta 110 = 20.2(2)) and to define the influence of the ligand scaffold on the stability and photophysical properties.

  10. Using the Antenna Effect as a Spectroscopic Tool; Photophysics and Solution Thermodynamics of the Model Luminescent Hydroxypyridonate Complex [EuIII(3,4,3-LI(1,2-HOPO))]-

    PubMed Central

    Abergel, Rebecca J.; D'Aléo, Anthony; Leung, Clara Ng Pak; Shuh, David K.; Raymond, Kenneth N.

    2009-01-01

    While widely used in bioassays, the spectrofluorimetric method described here uses the antenna effect as a tool to probe the thermodynamic parameters of ligands that sensitize lanthanide luminescence. The Eu3+ coordination chemistry, solution thermodynamic stability and photophysical properties of the spermine-based hydroxypyridonate octadentate chelator 3,4,3-LI(1,2-HOPO) are reported. The complex [EuIII(3,4,3-LI(1,2-HOPO))]- luminesces with a long lifetime (805 μs) and a quantum yield of 7.0% in aqueous solution, at pH 7.4. These remarkable optical properties were exploited to determine the high (and proton-independent) stability of the complex (log β110 = 20.2(2)) and to define the influence of the ligand scaffold on the stability and photophysical properties. PMID:19902920

  11. Entanglement thermodynamics

    NASA Astrophysics Data System (ADS)

    Schliemann, John

    2014-09-01

    We investigate further the relationship between the entanglement spectrum of a composite many-body system and the energy spectrum of a subsystem making use of concepts of canonical thermodynamics. In many important cases the entanglement Hamiltonian is, in the limit of strong coupling between subsystems, proportional to the energy Hamiltonian of the subsystem. The proportionality factor is an appropriately defined coupling parameter, suggesting to interpret the latter as a inverse temperature. We identify a condition on the entanglement Hamiltonian which rigorously guarantees this interpretation to hold and removes any ambiguity in the definition of the entanglement Hamiltonian regarding contributions proportional to the unit operator. Illustrations of our findings are provided by spin ladders of arbitrary spin length, and by bilayer quantum Hall systems at total filling factor ν = 2. Within mean-field description, the latter system realizes an entanglement spectrum of free fermions with just two levels of equal modulus where the analogies to canonical thermodynamics are particularly close.

  12. Microscopic Chondritic Chemical Reactors

    NASA Astrophysics Data System (ADS)

    Maurette, Michel

    Maurette (1998a and 1998b) gives a more detailed discussion of previous works supporting the role of unmelted micrometeorites in prebiotic chemistry. Krueger and Kissel (1987) quoted thermodynamic computations suggesting that the μm-size C-rich grains that they discovered in the tail of Halley’s comet with their time-of-flight mass spectrometer on board the Vega spacecraft, when added to a prebiotic soup of organics, could trigger the formation of nucleic acids. Anders (1989) relied on the characteristics of the tiny stratospheric micrometeorites with sizes of about 5 15 μm, which amount to less than about 1% of the micrometeorite mass flux, to argue that micrometeorites played a major role in the delivery of organics to the Earth. As first quoted by Ponchelet (1989), we proposed in 1989 that much larger micrometeorites, similar to Antarctic micrometeorites, might have been functioning as individual microscopic chemical reactors on the early Earth during their interactions with gases and waters (Maurette et al., 1990, 1991b, 1998a, 1998b). Subsequently, Chyba and Sagan (1992) ceased fully supporting the role of the direct impact of comets in the delivery of such organics, and started to refer that of micrometeorites.

  13. Descriptive thermodynamics

    NASA Astrophysics Data System (ADS)

    Ford, David; Huntsman, Steven

    2006-06-01

    Thermodynamics (in concert with its sister discipline, statistical physics) can be regarded as a data reduction scheme based on partitioning a total system into a subsystem and a bath that weakly interact with each other. Whereas conventionally, the systems investigated require this form of data reduction in order to facilitate prediction, a different problem also occurs, in the context of communication networks, markets, etc. Such “empirically accessible” systems typically overwhelm observers with the sort of information that in the case of (say) a gas is effectively unobtainable. What is required for such complex interacting systems is not prediction (this may be impossible when humans besides the observer are responsible for the interactions) but rather, description as a route to understanding. Still, the need for a thermodynamical data reduction scheme remains. In this paper, we show how an empirical temperature can be computed for finite, empirically accessible systems, and further outline how this construction allows the age-old science of thermodynamics to be fruitfully applied to them.

  14. Spectroscopic imaging in electron microscopy

    SciTech Connect

    Pennycook, Stephen J; Colliex, C.

    2012-01-01

    In the scanning transmission electron microscope, multiple signals can be simultaneously collected, including the transmitted and scattered electron signals (bright field and annular dark field or Z-contrast images), along with spectroscopic signals such as inelastically scattered electrons and emitted photons. In the last few years, the successful development of aberration correctors for the electron microscope has transformed the field of electron microscopy, opening up new possibilities for correlating structure to functionality. Aberration correction not only allows for enhanced structural resolution with incident probes into the sub-angstrom range, but can also provide greater probe currents to facilitate mapping of intrinsically weak spectroscopic signals at the nanoscale or even the atomic level. In this issue of MRS Bulletin, we illustrate the power of the new generation of electron microscopes with a combination of imaging and spectroscopy. We show the mapping of elemental distributions at atomic resolution and also the mapping of electronic and optical properties at unprecedented spatial resolution, with applications ranging from graphene to plasmonic nanostructures, and oxide interfaces to biology.

  15. Influence of Microscopic Diffusive Process on Uranyl Precipitation and Dissolution in Subsurface Sediments at Hanford Site, USA

    SciTech Connect

    Liu, Chongxuan; Zachara, John M.; McKinley, James P.; Wang, Zheming; Majors, Paul D.

    2004-03-29

    Uranium in DOE Hanford sediments was found to be distributed as uranyl silicate precipitates almost exclusively within interiors of sediment grains. The precipitates were minute, generally 1-3 {micro}m across in either radiating or parallel arrays in intraparticle microfractures of a few microns width and variable connectivity to particle surfaces. Grain-scale porosity, tortuosity and diffusivity of tracer (H2O) and U(VI) were measured and imaged using various spectroscopic techniques. Simulations using a microscopic reactive diffusion model suggested that diffusion-limited mass transport generated a favorable thermodynamic condition within the grain microfractures for precipitation and concentration of uranium from waste plumes. The rate and extent of uranyl precipitate dissolution were studied in various electrolytes with variable pH under ambient CO2 pressure. Uranium speciation and distribution before and after dissolution were monitored by spectroscopic and imaging techniques . Experimental, spectroscopic and modeling results collectively indicated that dissolution of uranyl precipitates was controlled by diffusion-limited dissolution kinetics.

  16. Microscopic treatment of solute trapping and drag

    NASA Astrophysics Data System (ADS)

    Humadi, Harith; Hoyt, J. J.; Provatas, Nikolas

    2016-01-01

    The long wavelength limit of a recent microscopic phase-field crystal (PFC) theory of a binary alloy mixture is used to derive an analytical approximation for the segregation coefficient as a function of the interface velocity, and relate it to the two-point correlation function of the liquid and the thermodynamic properties of solid and liquid phases. Our results offer the first analytical derivation of solute segregation from a microscopic model, and support recent molecular dynamics and numerical PFC simulations. Our results also provide an independent framework, motivated from classical density functional theory, from which to elucidate the fundamental nature of solute drag, which is still highly contested in the literature.

  17. Natural thermodynamics

    NASA Astrophysics Data System (ADS)

    Annila, Arto

    2016-02-01

    The principle of increasing entropy is derived from statistical physics of open systems assuming that quanta of actions, as undividable basic build blocks, embody everything. According to this tenet, all systems evolve from one state to another either by acquiring quanta from their surroundings or by discarding quanta to the surroundings in order to attain energetic balance in least time. These natural processes result in ubiquitous scale-free patterns: skewed distributions that accumulate in a sigmoid manner and hence span log-log scales mostly as straight lines. Moreover, the equation for least-time motions reveals that evolution is by nature a non-deterministic process. Although the obtained insight in thermodynamics from the notion of quanta in motion yields nothing new, it accentuates that contemporary comprehension is impaired when modeling evolution as a computable process by imposing conservation of energy and thereby ignoring that quantum of actions are the carriers of energy from the system to its surroundings.

  18. Advances in thermodynamics

    SciTech Connect

    Sieniutycz, S. ); Salamon, P. )

    1990-01-01

    This book covers: nonequilibrium thermodynamics for solar energy applications; finite-time thermodynamics as applied to solar power conversion; thermodynamics and economics; exergy analysis; and an analysis of cumulative exergy consumption and exergy losses.

  19. Molecular structure, vibrational spectroscopic (FT-IR, FT-Raman), UV-vis spectra, first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis, thermodynamic properties of benzophenone 2,4-dicarboxylic acid by ab initio HF and density functional method.

    PubMed

    Chaitanya, K

    2012-02-01

    The FT-IR (4000-450 cm(-1)) and FT-Raman spectra (3500-100 cm(-1)) of benzophenone 2,4-dicarboxylic acid (2,4-BDA) have been recorded in the condensed state. Density functional theory calculation with B3LYP/6-31G(d,p) basis set have been used to determine ground state molecular geometries (bond lengths and bond angles), harmonic vibrational frequencies, infrared intensities, Raman activities and bonding features of the title compounds. The assignments of the vibrational spectra have been carried out with the help of normal co-ordinate analysis (NCA) following the scaled quantum mechanical force field (SQMFF) methodology. The first order hyperpolarizability (β0) and related properties (β, α0 and Δα) of 2,4-BDA is calculated using HF/6-31G(d,p) method on the finite-field approach. The stability of molecule has been analyzed by using NBO analysis. The calculated first hyperpolarizability shows that the molecule is an attractive molecule for future applications in non-linear optics. The calculated HOMO and LUMO energies show that charge transfer occurs within these molecules. Mulliken population analysis on atomic charges is also calculated. Because of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated. Finally, the UV-vis spectra and electronic absorption properties were explained and illustrated from the frontier molecular orbitals. PMID:22137747

  20. Molecular structure, vibrational spectroscopic (FT-IR, FT-Raman), UV-vis spectra, first order hyperpolarizability, NBO analysis, HOMO and LUMO analysis, thermodynamic properties of benzophenone 2,4-dicarboxylic acid by ab initio HF and density functional method

    NASA Astrophysics Data System (ADS)

    Chaitanya, K.

    2012-02-01

    The FT-IR (4000-450 cm -1) and FT-Raman spectra (3500-100 cm -1) of benzophenone 2,4-dicarboxylic acid (2,4-BDA) have been recorded in the condensed state. Density functional theory calculation with B3LYP/6-31G(d,p) basis set have been used to determine ground state molecular geometries (bond lengths and bond angles), harmonic vibrational frequencies, infrared intensities, Raman activities and bonding features of the title compounds. The assignments of the vibrational spectra have been carried out with the help of normal co-ordinate analysis (NCA) following the scaled quantum mechanical force field (SQMFF) methodology. The first order hyperpolarizability ( β0) and related properties ( β, α0 and Δ α) of 2,4-BDA is calculated using HF/6-31G(d,p) method on the finite-field approach. The stability of molecule has been analyzed by using NBO analysis. The calculated first hyperpolarizability shows that the molecule is an attractive molecule for future applications in non-linear optics. The calculated HOMO and LUMO energies show that charge transfer occurs within these molecules. Mulliken population analysis on atomic charges is also calculated. Because of vibrational analyses, the thermodynamic properties of the title compound at different temperatures have been calculated. Finally, the UV-vis spectra and electronic absorption properties were explained and illustrated from the frontier molecular orbitals.

  1. The Scanning Optical Microscope.

    ERIC Educational Resources Information Center

    Sheppard, C. J. R.

    1978-01-01

    Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

  2. TEAM Electron Microscope Animation

    SciTech Connect

    2012-01-01

    The TEAM Electron Microscope, a device that enables atomic-scale imaging in 3-D, has a rotating stage that can hold and position samples inside electron microscopes with unprecedented stability, position-control accuracy, and range of motion.The TEAM Stage makes one of the world's most powerful electron microscopes even better, and enables previously impossible experiments.

  3. Global ab initio potential energy surface for the O2((3)Σ(g)(-)) + N2((1)Σ(g)(-)) interaction. Applications to the collisional, spectroscopic, and thermodynamic properties of the complex.

    PubMed

    Bartolomei, Massimiliano; Carmona-Novillo, Estela; Hernández, Marta I; Campos-Martínez, José; Moszyński, Robert

    2014-08-21

    A detailed characterization of the interaction between the most abundant molecules in air is important for the understanding of a variety of phenomena in atmospherical science. A completely ab initio global potential energy surface (PES) for the O2((3)Σg(–)) + N2((1)Σg(+)) interaction is reported for the first time. It has been obtained with the symmetry-adapted perturbation theory utilizing a density functional description of monomers [SAPT(DFT)] extended to treat the interaction involving high-spin open-shell complexes. The computed interaction energies of the complex are in a good agreement with those obtained by using the spin-restricted coupled cluster methodology with singles, doubles, and noniterative triple excitations [RCCSD(T)]. A spherical harmonics expansion of the interaction potential containing a large number of terms due to the anisotropy of the interaction has been built from the ab initio data. The expansion coefficients, which are functions of the intermolecular distance, are matched in the long-range with the analytical functions based on the recent ab initio calculations of the electric properties of the monomers [M. Bartolomei et al. J. Comput. Chem. 2011, 32, 279]. The PES is tested against the second virial coefficient B(T) data and the integral cross sections measured with rotationally hot effusive beams, leading in both cases to a very good agreement. The lowest lying states of the complex have been computed and relevant spectroscopic features of the interacting complex are reported. A comparison with a previous experimentally derived PES is also provided. PMID:24824559

  4. Thermodynamic interpolation

    SciTech Connect

    Maiden, D E

    1998-10-01

    A method for constructing bicubic interpolation polynomials for the pressure P and internal energy E that are thermodynamically consistent at the mesh ponts and continuous across mesh boundaries is presented. The slope boundary conditions for the pressure and energy are derived from finite differences of the data and from Maxwell's consistency relation. Monotonicity of the sound speed and the specific heat is obtained by a bilinear interpolation of the slopes of the tabulated data. Monotonicity of the functions near steep gradients may be achieved by mesh refinement or by using a non-consistent bilinear to the data. Mesh refinement is very efficient for uniform-linear or uniform-logarithmic spaced data because a direct table lookup can be used. The direct method was compared to binary search and was 37 percent faster for logarithmic-spaced data and 106 percent faster for linear-spaced data. This improvement in speed is very important in the radiation-transport opacity-lookup part of the calculation. Interpolation in P-E space, with mesh refinement, can be made simple, robust, and conserve energy. In the final analysis the interpolation of the free energy and entropy (Maiden and Cook) remains a competitor.

  5. Thermodynamics of Radiation Modes

    ERIC Educational Resources Information Center

    Pina, Eduardo; de la Selva, Sara Maria Teresa

    2010-01-01

    We study the equilibrium thermodynamics of the electromagnetic radiation in a cavity of a given volume and temperature. We found three levels of description, the thermodynamics of one mode, the thermodynamics of the distribution of frequencies in a band by summing over the frequencies in it and the global thermodynamics by summing over all the…

  6. Thermodynamics. II - The extended thermodynamic system

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.

    1981-01-01

    The algebraic theory of thermodynamics developed in a previous paper is extended to include the algebraic structure that arises from the introduction of a physical body into the theory. The extension is based on very general definitions of both the thermodynamic states of a body and subsystems of that body. The algebraic analysis, which includes bodies in nonuniform states, shows that the set of all thermodynamic states of a body has the same algebraic structure as the set of thermodynamic states and that composite systems are induced by the algebraic structure of thermodynamic states. The analysis also justifies a variational treatment of thermodynamic bodies in uniform as well as nonuniform states. The variational calculation includes all conventional methods of calculation as special cases and helps to illuminate the origin and interpretation of the electrochemical potential.

  7. Duality relation between radiation thermodynamics and cosmic string loop thermodynamics

    SciTech Connect

    Jou, D.; Mongiovi, M. S.; Sciacca, M.

    2011-05-15

    We discuss thermodynamics of electromagnetic radiation, with p=(1/3){rho} and S{proportional_to}T{sup 3}V, and of cosmic string loops, with p=-(1/3){rho} and S{proportional_to}T{sup -3}V, where p stands for pressure, T temperature, {rho} energy density, S entropy, and V volume. We write the thermodynamic formalisms under a common framework that illustrates their formal relationship and allows us to go from one to the other through a smooth transformation. From a microscopic perspective, these relations arise from the energy relations u({lambda})=hc/{lambda} for the photons of electromagnetic radiation, and u(l)=(c{sup 4}/a{sup 2}G)l for cosmic string loops, a being a numerical (dimensionless) constant and {lambda} and l the radiation wavelength and the length of a loop; G, c, and h are the gravitational constant, the speed of light in vacuo, and the Planck constant, respectively. The corresponding thermodynamic behaviors are seen to be connected through a related thermal duality corresponding to the change of T by T*=T{sub c}{sup 2}/T, with T{sub c} a reference temperature related to h, c, and G.

  8. Cryogenic immersion microscope

    DOEpatents

    Le Gros, Mark; Larabell, Carolyn A.

    2010-12-14

    A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

  9. Thermal-Wave Microscope

    NASA Technical Reports Server (NTRS)

    Jones, Robert E.; Kramarchuk, Ihor; Williams, Wallace D.; Pouch, John J.; Gilbert, Percy

    1989-01-01

    Computer-controlled thermal-wave microscope developed to investigate III-V compound semiconductor devices and materials. Is nondestructive technique providing information on subsurface thermal features of solid samples. Furthermore, because this is subsurface technique, three-dimensional imaging also possible. Microscope uses intensity-modulated electron beam of modified scanning electron microscope to generate thermal waves in sample. Acoustic waves generated by thermal waves received by transducer and processed in computer to form images displayed on video display of microscope or recorded on magnetic disk.

  10. Recurrence tracking microscope

    SciTech Connect

    Saif, Farhan

    2006-03-15

    In order to probe nanostructures on a surface we present a microscope based on the quantum recurrence phenomena. A cloud of atoms bounces off an atomic mirror connected to a cantilever and exhibits quantum recurrences. The times at which the recurrences occur depend on the initial height of the bouncing atoms above the atomic mirror, and vary following the structures on the surface under investigation. The microscope has inherent advantages over existing techniques of scanning tunneling microscope and atomic force microscope. Presently available experimental technology makes it possible to develop the device in the laboratory.

  11. Measuring Thermodynamic Length

    SciTech Connect

    Crooks, Gavin E

    2007-09-07

    Thermodynamic length is a metric distance between equilibrium thermodynamic states. Among other interesting properties, this metric asymptotically bounds the dissipation induced by a finite time transformation of a thermodynamic system. It is also connected to the Jensen-Shannon divergence, Fisher information, and Rao's entropy differential metric. Therefore, thermodynamic length is of central interestin understanding matter out of equilibrium. In this Letter, we will consider how to denethermodynamic length for a small system described by equilibrium statistical mechanics and how to measure thermodynamic length within a computer simulation. Surprisingly, Bennett's classic acceptance ratio method for measuring free energy differences also measures thermodynamic length.

  12. Far-from-equilibrium measurements of thermodynamic length

    SciTech Connect

    Feng, Edward H.; Crooks, Gavin E.

    2008-11-05

    Thermodynamic length is a path function that generalizes the notion of length to the surface of thermodynamic states. Here, we show how to measure thermodynamic length in far-from-equilibrium experiments using the work fluctuation relations. For these microscopic systems, it proves necessary to define the thermodynamic length in terms of the Fisher information. Consequently, the thermodynamic length can be directly related to the magnitude of fluctuations about equilibrium. The work fluctuation relations link the work and the free energy change during an external perturbation on a system. We use this result to determine equilibrium averages at intermediate points of the protocol in which the system is out-of-equilibrium. This allows us to extend Bennett's method to determine the potential of mean force, as well as the thermodynamic length, in single molecule experiments.

  13. LEAD SORPTION ON RUTHENIUM OXIDE: A MACROSCOPIC AND SPECTROSCOPIC STUDY

    EPA Science Inventory

    The sorption and desorption of Pb on RuO2 xH2O were examined kinetically and thermodynamically via spectroscopic and macroscopic investigations. X-ray absorption spectroscopy (XAS) was employed to determine the sorption mechanism with regard to identity of nearest atomic neighbo...

  14. Mailing microscope slides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  15. The Light Microscope.

    ERIC Educational Resources Information Center

    Baker, W. L.

    1995-01-01

    Describes the function of the various parts of the microscope and their integration in the formation of an optical image. Presents a procedure for setting up a microscope to obtain maximum resolution and contrast for each objective lens at all magnifications. (JRH)

  16. Photography through the Microscope.

    ERIC Educational Resources Information Center

    McNeil, D. W.

    1992-01-01

    Describes how to illuminate and optically stain slides for microscope use and how to interface a 35mm camera with a microscope using an adaptor. Provides equipment descriptions and sources, details about illumination, image formation, darkfield adaptors, centerable filter adaptors, darkfield stops, rheinburg filters, and choosing specimens to…

  17. The Homemade Microscope.

    ERIC Educational Resources Information Center

    Baker, Roger C., Jr.

    1991-01-01

    Directions for the building of a pocket microscope that will make visible the details of insect structure and living bacteria are described. Background information on the history of microscopes and lenses is provided. The procedures for producing various types of lenses are included. (KR)

  18. Surface imaging microscope

    NASA Astrophysics Data System (ADS)

    Rogala, Eric W.; Bankman, Isaac N.

    2008-04-01

    The three-dimensional shapes of microscopic objects are becoming increasingly important for battlespace CBRNE sensing. Potential applications of microscopic 3D shape observations include characterization of biological weapon particles and manufacturing of micromechanical components. Aerosol signatures of stand-off lidar systems, using elastic backscatter or polarization, are dictated by the aerosol particle shapes and sizes that must be well characterized in the lab. A low-cost, fast instrument for 3D surface shape microscopy will be a valuable point sensor for biological particle sensing applications. Both the cost and imaging durations of traditional techniques such as confocal microscopes, atomic force microscopes, and electron scanning microscopes are too high. We investigated the feasibility of a low-cost, fast interferometric technique for imaging the 3D surface shape of microscopic objects at frame rates limited only by the camera in the system. The system operates at two laser wavelengths producing two fringe images collected simultaneously by a digital camera, and a specialized algorithm we developed reconstructs the surface map of the microscopic object. The current implementation assembled to test the concept and develop the new 3D reconstruction algorithm has 0.25 micron resolution in the x and y directions, and about 0.1 micron accuracy in the z direction, as tested on a microscopic glass test object manufactured with etching techniques. We describe the interferometric instrument, present the reconstruction algorithm, and discuss further development.

  19. Microcomputer Calculation of Thermodynamic Properties from Molecular Parameters of Gases.

    ERIC Educational Resources Information Center

    Venugopalan, Mundiyath

    1990-01-01

    Described in this article is a problem-solving activity which integrates the application of microcomputers with the learning of physical chemistry. Students use the program with spectroscopic data to calculate the thermodynamic properties and compare them with the values from the thermochemical tables. (Author/KR)

  20. Thermodynamic aspects of nonequilibrium current fluctuations

    NASA Astrophysics Data System (ADS)

    Jou, D.; Llebot, J. E.; Casas-Vázquez, J.

    1982-06-01

    Starting from a macroscopic nonequilibrium entropy, we obtain an expression for the nonequilibrium fluctuations of the electric current in a metallic resistor. Our method goes further than previous theories of irreversible thermodynamics and, as well as microscopic entropies, it leads to results of the same order of magnitude but not completely coincident with the full nonequilibrium corrections obtained from kinetic methods by Tremblay et al.

  1. Stereoscopic Video Microscope

    NASA Astrophysics Data System (ADS)

    Butterfield, James F.

    1980-11-01

    The new electronic technology of three-dimensional video combined with the established. science of microscopy has created. a new instrument. the Stereoscopic Video Microscope. The specimen is illuminated so the stereoscopic objective lens focuses the stereo-pair of images side-by-side on the video camera's pick-up, tube. The resulting electronic signal can be enhanced, digitized, colorized, quantified, its polarity reverse., and its gray scale expanJed non-linearally. The signal can be transmitted over distances and can be stored on video. tape for later playback. The electronic signal is converted to a stereo-pair of visual images on the video monitor's cathode-ray-tube. A stereo-hood is used to fuse the two images for three-dimensional viewing. The conventional optical microscope has definite limitations, many of which can be eliminated by converting the optical image to an electronic signal in the video microscope. The principal aHvantages of the Stereoscopic Video Microscope compared to the conventional optical microscope are: great ease of viewing; group viewing; ability to easily recohd; and, the capability of processing the electronic signal for video. enhancement. The applications cover nearly all fields of microscopy. These include: microelectronics assembly, inspection, and research; biological, metallurgical, and che.illical research; and other industrial and medical uses. The Stereo-scopic Video Microscope is particularly useful for instructional and recordkeeping purposes. The video microscope can be monoscopic or three dimensional.

  2. Introducing thermodynamics through energy and entropy

    NASA Astrophysics Data System (ADS)

    de Abreu, Rodrigo; Guerra, Vasco

    2012-07-01

    We suggest a simple approach to introducing thermodynamics, beginning with the concept of internal energy of deformable bodies. From a series of thought experiments involving ideal gases, we show that the internal energy depends on the volume and on a second parameter, leading to the development of the concept of entropy. By introducing entropy before the notions of temperature and heat, the proposed approach avoids some of the major conceptual difficulties with the traditional presentation. The relationship between mechanics and thermodynamics naturally emerges, mechanics corresponding to isentropic thermodynamics. The questions of evolution to equilibrium and irreversibility are studied under the light of the action of the "dynamic force" and its dissipative character, evincing the benefits of keeping in mind the microscopic picture.

  3. [Microscopic colitis: update 2014].

    PubMed

    Burgmann, Konstantin; Fraga, Montserrat; Schoepfer, Alain M; Yun, Pu

    2014-09-01

    Microscopic colitis, which includes lymphocytic colitis and collagenous colitis, represents a frequent cause of chronic watery diarrhea especially in the elderly population. Several medications, such as nonsteroidal antiinflammatory drugs, proton pump inhibitors or antidepressants, as well as cigarette smoking have been recognized as risk factors for microscopic colitis. The diagnosis of microscopic colitis is based on a macroscopically normal ileo-colonoscopy and several biopsies from the entire colon, which demonstrate the pathognomonic histopathologic findings. Therapy is mainly based on the use of budesonide. Other medications, such as mesalazine, cholestyramine and bismuth, have been evaluated as well but the evidence is less solid. PMID:25276996

  4. Mars Life? - Microscopic Structures

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the center of this electron microscope image of a small chip from a meteorite are several tiny structures that are possible microscopic fossils of primitive, bacteria-like organisms that may have lived on Mars more than 3.6 billion years ago. A two-year investigation by a NASA research team found organic molecules, mineral features characteristic of biological activity and possible microscopic fossils such as these inside of an ancient Martian rock that fell to Earth as a meteorite. The largest possible fossils are less than 1/100th the diameter of a human hair in size while most are ten times smaller.

  5. Thermodynamics: Frontiers and Foundations.

    Energy Science and Technology Software Center (ESTSC)

    2009-07-27

    Version 00 Dr. J.D. Lewins has now released the following new book for free distribution: Thermodynamics: Frontiers and Foundations, Preface by Sir Alan Cottrell Introduction 1. Four-Square Foundations: The Laws of Thermodynamics 2. Maximum Entropy and Minimum Energy: The Master Functions and Equations 3. Ideal Gases and their Applications 4. Real Fluids and Some Applications 5. Van der Waals: A Model for Real Fluids 6. Surface Tension: Bubbles and Drops 7. Inert and Reactive Mixtures;more » An introduction to Chemical Thermodynamics 8. Radiation Thermodynamics: Solar Power Potential 9. Outposts of the Empire 10. A Glimpse into Statistical Thermodynamics Envoi« less

  6. Thermodynamics: Frontiers and Foundations.

    SciTech Connect

    JEFFERY,; LEWINS, D.

    2009-07-27

    Version 00 Dr. J.D. Lewins has now released the following new book for free distribution: Thermodynamics: Frontiers and Foundations, Preface by Sir Alan Cottrell Introduction 1. Four-Square Foundations: The Laws of Thermodynamics 2. Maximum Entropy and Minimum Energy: The Master Functions and Equations 3. Ideal Gases and their Applications 4. Real Fluids and Some Applications 5. Van der Waals: A Model for Real Fluids 6. Surface Tension: Bubbles and Drops 7. Inert and Reactive Mixtures; An introduction to Chemical Thermodynamics 8. Radiation Thermodynamics: Solar Power Potential 9. Outposts of the Empire 10. A Glimpse into Statistical Thermodynamics Envoi

  7. Large area fabrication of plasmonic nanoparticle grating structure by conventional scanning electron microscope

    SciTech Connect

    Sudheer, Tiwari, P.; Rai, V. N.; Srivastava, A. K.; Mukharjee, C.

    2015-06-24

    Plasmonic nanoparticle grating (PNG) structure of different periods has been fabricated by electron beam lithography using silver halide based transmission electron microscope film as a substrate. Conventional scanning electron microscope is used as a fabrication tool for electron beam lithography. Optical microscope and energy dispersive spectroscopy (EDS) have been used for its morphological and elemental characterization. Optical characterization is performed by UV-Vis absorption spectroscopic technique.

  8. Energy functions for rubber from microscopic potentials

    NASA Astrophysics Data System (ADS)

    Johal, A. S.; Dunstan, D. J.

    2007-04-01

    The finite deformation theory of rubber and related materials is based on energy functions that describe the macroscopic response of these materials under deformation. Energy functions and elastic constants are here derived from a simple microscopic (ball-and-spring) model. Exact uniaxial force-extension relationships are given for Hooke's Law and for the thermodynamic entropy-based microscopic model using the Gaussian and the inverse Langevin statistical approximations. Methods are given for finding the energy functions as expansions of tensor invariants of deformation, with exact solutions for functions that can be expressed as expansions in even powers of the extension. Comparison with experiment shows good agreement with the neo-Hookean energy function and we show how this derives directly from the simple Gaussian statistical model with a small modification.

  9. Microscopic treatment of solute trapping and drag.

    PubMed

    Humadi, Harith; Hoyt, J J; Provatas, Nikolas

    2016-01-01

    The long wavelength limit of a recent microscopic phase-field crystal (PFC) theory of a binary alloy mixture is used to derive an analytical approximation for the segregation coefficient as a function of the interface velocity, and relate it to the two-point correlation function of the liquid and the thermodynamic properties of solid and liquid phases. Our results offer the first analytical derivation of solute segregation from a microscopic model, and support recent molecular dynamics and numerical PFC simulations. Our results also provide an independent framework, motivated from classical density functional theory, from which to elucidate the fundamental nature of solute drag, which is still highly contested in the literature. PMID:26871012

  10. Hyperspectral confocal microscope

    NASA Astrophysics Data System (ADS)

    Sinclair, Michael B.; Haaland, David M.; Timlin, Jerilyn A.; Jones, Howland D. T.

    2006-08-01

    We have developed a new, high performance, hyperspectral microscope for biological and other applications. For each voxel within a three-dimensional specimen, the microscope simultaneously records the emission spectrum from 500 nm to 800 nm, with better than 3 nm spectral resolution. The microscope features a fully confocal design to ensure high spatial resolution and high quality optical sectioning. Optical throughput and detection efficiency are maximized through the use of a custom prism spectrometer and a backside thinned electron multiplying charge coupled device (EMCCD) array. A custom readout mode and synchronization scheme enable 512-point spectra to be recorded at a rate of 8300 spectra per second. In addition, the EMCCD readout mode eliminates curvature and keystone artifacts that often plague spectral imaging systems. The architecture of the new microscope is described in detail, and hyperspectral images from several specimens are presented.

  11. Hyperspectral confocal microscope.

    PubMed

    Sinclair, Michael B; Haaland, David M; Timlin, Jerilyn A; Jones, Howland D T

    2006-08-20

    We have developed a new, high performance, hyperspectral microscope for biological and other applications. For each voxel within a three-dimensional specimen, the microscope simultaneously records the emission spectrum from 500 nm to 800 nm, with better than 3 nm spectral resolution. The microscope features a fully confocal design to ensure high spatial resolution and high quality optical sectioning. Optical throughput and detection efficiency are maximized through the use of a custom prism spectrometer and a backside thinned electron multiplying charge coupled device (EMCCD) array. A custom readout mode and synchronization scheme enable 512-point spectra to be recorded at a rate of 8300 spectra per second. In addition, the EMCCD readout mode eliminates curvature and keystone artifacts that often plague spectral imaging systems. The architecture of the new microscope is described in detail, and hyperspectral images from several specimens are presented. PMID:16892134

  12. Assessment of Petrological Microscopes.

    ERIC Educational Resources Information Center

    Mathison, Charter Innes

    1990-01-01

    Presented is a set of procedures designed to check the design, ergonomics, illumination, function, optics, accessory equipment, and image quality of a microscope being considered for purchase. Functions for use in a petrology or mineralogy laboratory are stressed. (CW)

  13. Computerized Measuring Microscope

    NASA Astrophysics Data System (ADS)

    Schoonmaker, Thomas D.

    1980-05-01

    In the manufacturing of printed circuit boards, microscopic analysis is an essential process control activity. An inspector microscopically analyzes board samples to deter-mine board lot quality and process conditions. Prior to computerizing, this sustained measurement-taking involved the tedious process of recording raw data, converting microscope filar readings, calculating averages, logging information in a job notebook, and completing detailed final lab reports. It is evident from this brief task description that this time-consuming repetitious data recording routine was an added burden to the already fatiguing visual inspection method and therefore was a prime candidate for automatic data capture and printout. Secondly, the creation of a permanent and easily accessible data base would improve process feedback and provide for a system with quick identification of any suspect boards if further assembly/testing exhibited board-related failures. This paper describes the evolution and implementation of a computer-aided microscopic inspection operation.

  14. Microscope collision protection apparatus

    DOEpatents

    DeNure, Charles R.

    2001-10-23

    A microscope collision protection apparatus for a remote control microscope which protects the optical and associated components from damage in the event of an uncontrolled collision with a specimen, regardless of the specimen size or shape. In a preferred embodiment, the apparatus includes a counterbalanced slide for mounting the microscope's optical components. This slide replaces the rigid mounts on conventional upright microscopes with a precision ball bearing slide. As the specimen contacts an optical component, the contacting force will move the slide and the optical components mounted thereon. This movement will protect the optical and associated components from damage as the movement causes a limit switch to be actuated, thereby stopping all motors responsible for the collision.

  15. Infrared microscope inspection apparatus

    DOEpatents

    Forman, Steven E.; Caunt, James W.

    1985-02-26

    Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.

  16. Infrared microscope inspection apparatus

    DOEpatents

    Forman, S.E.; Caunt, J.W.

    1985-02-26

    Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface. 4 figs.

  17. 3D microscope

    NASA Astrophysics Data System (ADS)

    Iizuka, Keigo

    2008-02-01

    In order to circumvent the fact that only one observer can view the image from a stereoscopic microscope, an attachment was devised for displaying the 3D microscopic image on a large LCD monitor for viewing by multiple observers in real time. The principle of operation, design, fabrication, and performance are presented, along with tolerance measurements relating to the properties of the cellophane half-wave plate used in the design.

  18. Hypoxia in Microscopic Tumors

    PubMed Central

    Li, Xiao-Feng; O’Donoghue, Joseph A

    2008-01-01

    Tumor hypoxia has been commonly observed in a broad spectrum of primary solid malignancies. Hypoxia is associated with tumor progression, increased aggressiveness, enhanced metastatic potential and poor prognosis. Hypoxic tumor cells are resistant to radiotherapy and some forms of chemotherapy. Using an animal model, we recently showed that microscopic tumors less than 1 mm diameter were severely hypoxic. In this review, models and techniques for the study of hypoxia in microscopic tumors are discussed. PMID:18384940

  19. The second laws of quantum thermodynamics

    PubMed Central

    Brandão, Fernando; Horodecki, Michał; Ng, Nelly; Oppenheim, Jonathan; Wehner, Stephanie

    2015-01-01

    The second law of thermodynamics places constraints on state transformations. It applies to systems composed of many particles, however, we are seeing that one can formulate laws of thermodynamics when only a small number of particles are interacting with a heat bath. Is there a second law of thermodynamics in this regime? Here, we find that for processes which are approximately cyclic, the second law for microscopic systems takes on a different form compared to the macroscopic scale, imposing not just one constraint on state transformations, but an entire family of constraints. We find a family of free energies which generalize the traditional one, and show that they can never increase. The ordinary second law relates to one of these, with the remainder imposing additional constraints on thermodynamic transitions. We find three regimes which determine which family of second laws govern state transitions, depending on how cyclic the process is. In one regime one can cause an apparent violation of the usual second law, through a process of embezzling work from a large system which remains arbitrarily close to its original state. These second laws are relevant for small systems, and also apply to individual macroscopic systems interacting via long-range interactions. By making precise the definition of thermal operations, the laws of thermodynamics are unified in this framework, with the first law defining the class of operations, the zeroth law emerging as an equivalence relation between thermal states, and the remaining laws being monotonicity of our generalized free energies. PMID:25675476

  20. The second laws of quantum thermodynamics.

    PubMed

    Brandão, Fernando; Horodecki, Michał; Ng, Nelly; Oppenheim, Jonathan; Wehner, Stephanie

    2015-03-17

    The second law of thermodynamics places constraints on state transformations. It applies to systems composed of many particles, however, we are seeing that one can formulate laws of thermodynamics when only a small number of particles are interacting with a heat bath. Is there a second law of thermodynamics in this regime? Here, we find that for processes which are approximately cyclic, the second law for microscopic systems takes on a different form compared to the macroscopic scale, imposing not just one constraint on state transformations, but an entire family of constraints. We find a family of free energies which generalize the traditional one, and show that they can never increase. The ordinary second law relates to one of these, with the remainder imposing additional constraints on thermodynamic transitions. We find three regimes which determine which family of second laws govern state transitions, depending on how cyclic the process is. In one regime one can cause an apparent violation of the usual second law, through a process of embezzling work from a large system which remains arbitrarily close to its original state. These second laws are relevant for small systems, and also apply to individual macroscopic systems interacting via long-range interactions. By making precise the definition of thermal operations, the laws of thermodynamics are unified in this framework, with the first law defining the class of operations, the zeroth law emerging as an equivalence relation between thermal states, and the remaining laws being monotonicity of our generalized free energies. PMID:25675476

  1. Integrated elastic microscope device

    NASA Astrophysics Data System (ADS)

    Lee, W. M.; Wright, D.; Watkins, R.; Cen, Zi

    2015-03-01

    The growing power of imaging and computing power of smartphones is creating the possibility of converting your smartphone into a high power pocket microscopy system. High quality miniature microscopy lenses attached to smartphone are typically made with glass or plastics that can only be produce at low cost with high volume. To revise the paradigm of microscope lenses, we devised a simple droplet lens fabrication technique that which produces low cost and high performance lens. Each lens is integrated into thin 3-D printed holder with complimentary light emitted diode (LEDs) that clips onto majority of smartphones. The integrated device converts a smartphone into a high power optical microscope/dermatoscope at around $2. This low cost device has wide application in a multitude of practical uses such as material inspection, dermascope and educational microscope.

  2. Electron microscope studies

    SciTech Connect

    Crewe, A.V.; Kapp, O.H.

    1992-07-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

  3. Making Art with Microscopes

    ERIC Educational Resources Information Center

    Benedis-Grab, Gregory

    2011-01-01

    Interdisciplinary teaching is a great way to focus on overarching concepts and help students make connections across disciplines. Historically, art and science have been connected disciplines. The botanical prints of the 18th and 19th centuries and early work with microscopes are two examples of a need for strong artistic skills in the science…

  4. Microscopic plasma Hamiltonian

    NASA Technical Reports Server (NTRS)

    Peng, Y.-K. M.

    1974-01-01

    A Hamiltonian for the microscopic plasma model is derived from the Low Lagrangian after the dual roles of the generalized variables are taken into account. The resulting Hamilton equations are shown to agree with the Euler-Lagrange equations of the Low Lagrangian.

  5. Microscope on Mars

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image taken at Meridiani Planum, Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's microscopic imager (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  6. Molecular Thermodynamics for Cell Biology as Taught with Boxes

    ERIC Educational Resources Information Center

    Mayorga, Luis S.; Lopez, Maria Jose; Becker, Wayne M.

    2012-01-01

    Thermodynamic principles are basic to an understanding of the complex fluxes of energy and information required to keep cells alive. These microscopic machines are nonequilibrium systems at the micron scale that are maintained in pseudo-steady-state conditions by very sophisticated processes. Therefore, several nonstandard concepts need to be…

  7. Thermodynamics and combustion modeling

    NASA Technical Reports Server (NTRS)

    Zeleznik, Frank J.

    1986-01-01

    Modeling fluid phase phenomena blends the conservation equations of continuum mechanics with the property equations of thermodynamics. The thermodynamic contribution becomes especially important when the phenomena involve chemical reactions as they do in combustion systems. The successful study of combustion processes requires (1) the availability of accurate thermodynamic properties for both the reactants and the products of reaction and (2) the computational capabilities to use the properties. A discussion is given of some aspects of the problem of estimating accurate thermodynamic properties both for reactants and products of reaction. Also, some examples of the use of thermodynamic properties for modeling chemically reacting systems are presented. These examples include one-dimensional flow systems and the internal combustion engine.

  8. Calibration method for spectroscopic systems

    DOEpatents

    Sandison, David R.

    1998-01-01

    Calibration spots of optically-characterized material placed in the field of view of a spectroscopic system allow calibration of the spectroscopic system. Response from the calibration spots is measured and used to calibrate for varying spectroscopic system operating parameters. The accurate calibration achieved allows quantitative spectroscopic analysis of responses taken at different times, different excitation conditions, and of different targets.

  9. Calibration method for spectroscopic systems

    DOEpatents

    Sandison, D.R.

    1998-11-17

    Calibration spots of optically-characterized material placed in the field of view of a spectroscopic system allow calibration of the spectroscopic system. Response from the calibration spots is measured and used to calibrate for varying spectroscopic system operating parameters. The accurate calibration achieved allows quantitative spectroscopic analysis of responses taken at different times, different excitation conditions, and of different targets. 3 figs.

  10. Microscopic Theory of α-Particle Resonance Spectra

    NASA Astrophysics Data System (ADS)

    Tchuvil'sky, Yury M.; Volya, Alexander

    The nuclear clustering problem is treated microscopically using the shell model configuration interaction approach. The approach, referred to as Cluster-Nucleon Configuration Interaction Model, is facilitated by the SU(3) symmetry of the cluster channels and by Orthogonality Condition Model. The spectroscopic factors for the 6He+α channel for states of the radioactive nucleus 10Be are computed. A number of states with pronounced α-clustering properties is predicted. The results are compared to the experimental data.

  11. Thermodynamic estimation: Ionic materials

    SciTech Connect

    Glasser, Leslie

    2013-10-15

    Thermodynamics establishes equilibrium relations among thermodynamic parameters (“properties”) and delineates the effects of variation of the thermodynamic functions (typically temperature and pressure) on those parameters. However, classical thermodynamics does not provide values for the necessary thermodynamic properties, which must be established by extra-thermodynamic means such as experiment, theoretical calculation, or empirical estimation. While many values may be found in the numerous collected tables in the literature, these are necessarily incomplete because either the experimental measurements have not been made or the materials may be hypothetical. The current paper presents a number of simple and relible estimation methods for thermodynamic properties, principally for ionic materials. The results may also be used as a check for obvious errors in published values. The estimation methods described are typically based on addition of properties of individual ions, or sums of properties of neutral ion groups (such as “double” salts, in the Simple Salt Approximation), or based upon correlations such as with formula unit volumes (Volume-Based Thermodynamics). - Graphical abstract: Thermodynamic properties of ionic materials may be readily estimated by summation of the properties of individual ions, by summation of the properties of ‘double salts’, and by correlation with formula volume. Such estimates may fill gaps in the literature, and may also be used as checks of published values. This simplicity arises from exploitation of the fact that repulsive energy terms are of short range and very similar across materials, while coulombic interactions provide a very large component of the attractive energy in ionic systems. Display Omitted - Highlights: • Estimation methods for thermodynamic properties of ionic materials are introduced. • Methods are based on summation of single ions, multiple salts, and correlations. • Heat capacity, entropy

  12. Femtosecond scanning tunneling microscope

    SciTech Connect

    Taylor, A.J.; Donati, G.P.; Rodriguez, G.; Gosnell, T.R.; Trugman, S.A.; Some, D.I.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). By combining scanning tunneling microscopy with ultrafast optical techniques we have developed a novel tool to probe phenomena on atomic time and length scales. We have built and characterized an ultrafast scanning tunneling microscope in terms of temporal resolution, sensitivity and dynamic range. Using a novel photoconductive low-temperature-grown GaAs tip, we have achieved a temporal resolution of 1.5 picoseconds and a spatial resolution of 10 nanometers. This scanning tunneling microscope has both cryogenic and ultra-high vacuum capabilities, enabling the study of a wide range of important scientific problems.

  13. Ion photon emission microscope

    DOEpatents

    Doyle, Barney L.

    2003-04-22

    An ion beam analysis system that creates microscopic multidimensional image maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the ion-induced photons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted photons are collected in the lens system of a conventional optical microscope, and projected on the image plane of a high resolution single photon position sensitive detector. Position signals from this photon detector are then correlated in time with electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these photons initially.

  14. Acoustic imaging microscope

    DOEpatents

    Deason, Vance A.; Telschow, Kenneth L.

    2006-10-17

    An imaging system includes: an object wavefront source and an optical microscope objective all positioned to direct an object wavefront onto an area of a vibrating subject surface encompassed by a field of view of the microscope objective, and to direct a modulated object wavefront reflected from the encompassed surface area through a photorefractive material; and a reference wavefront source and at least one phase modulator all positioned to direct a reference wavefront through the phase modulator and to direct a modulated reference wavefront from the phase modulator through the photorefractive material to interfere with the modulated object wavefront. The photorefractive material has a composition and a position such that interference of the modulated object wavefront and modulated reference wavefront occurs within the photorefractive material, providing a full-field, real-time image signal of the encompassed surface area.

  15. Thermodynamic products for Sen black hole

    NASA Astrophysics Data System (ADS)

    Pradhan, Parthapratim

    2016-03-01

    We investigate the properties of inner and outer horizon thermodynamics of Sen black hole (BH) both in Einstein frame (EF) and string frame (SF). We also compute area (or entropy) product, area (or entropy) sum of the said BH in EF as well as SF. In the EF, we observe that the area (or entropy) product is universal, whereas area (or entropy) sum is not universal. On the other hand, in the SF, area (or entropy) product and area (or entropy) sum don't have any universal behaviour because they all are depends on Arnowitt-Deser-Misner (ADM) mass parameter. We also verify that the first law is satisfied at the Cauchy horizon as well as event horizon (EH). In addition, we also compute other thermodynamic products and sums in the EF as well as in the SF. We further compute the Smarr mass formula and Christodoulou's irreducible mass formula for Sen BH. Moreover, we compute the area bound and entropy bound for both the horizons. The upper area bound for EH is actually the Penrose like inequality, which is the first geometric inequality in BHs. Furthermore, we compute the central charges of the left and right moving sectors of the dual CFT in Sen/CFT correspondence using thermodynamic relations. These thermodynamic relations on the multi-horizons give us further understanding the microscopic nature of BH entropy (both interior and exterior).

  16. Microscopic enteritis: Bucharest consensus.

    PubMed

    Rostami, Kamran; Aldulaimi, David; Holmes, Geoffrey; Johnson, Matt W; Robert, Marie; Srivastava, Amitabh; Fléjou, Jean-François; Sanders, David S; Volta, Umberto; Derakhshan, Mohammad H; Going, James J; Becheanu, Gabriel; Catassi, Carlo; Danciu, Mihai; Materacki, Luke; Ghafarzadegan, Kamran; Ishaq, Sauid; Rostami-Nejad, Mohammad; Peña, A Salvador; Bassotti, Gabrio; Marsh, Michael N; Villanacci, Vincenzo

    2015-03-01

    Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5(th) International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy. PMID:25759526

  17. Focusing the surgical microscope.

    PubMed

    Socea, Sergiu D; Barak, Yoreh; Blumenthal, Eytan Z

    2015-01-01

    A well-focused operating microscope addresses several needs that are all secondary to the surgeon's need to see clearly at all times. These needs include: the assistant; the sharpness of the video and monitor; as well as field of view, asthenopia, and focusing issues related to zoom, accommodation, and presbyopia. We provide a practical approach to achieve optimal focus that we call the sloping paper calibration method. PMID:25891029

  18. Microscopic and macroscopic dynamics

    SciTech Connect

    Hoover, W.G.; Hoover, C.G.; De Groot, A.J.; Pierce, T.G. |

    1993-06-01

    Atomistic Molecular Dynamics and Lagrangian Continuum Mechanics can be very similarly adapted to massively-parallel computers. Millions of degrees of freedom can be treated. The two complementary approaches, microscopic and macroscopic, are being applied to increasingly realistic flows of fluids and solids. The two approaches can also be combined in a hybrid simulation scheme. Hybrids combine the fundamental constitutive advantage of atoms with the size advantage of the continuum picture.

  19. Microscopic enteritis: Bucharest consensus

    PubMed Central

    Rostami, Kamran; Aldulaimi, David; Holmes, Geoffrey; Johnson, Matt W; Robert, Marie; Srivastava, Amitabh; Fléjou, Jean-François; Sanders, David S; Volta, Umberto; Derakhshan, Mohammad H; Going, James J; Becheanu, Gabriel; Catassi, Carlo; Danciu, Mihai; Materacki, Luke; Ghafarzadegan, Kamran; Ishaq, Sauid; Rostami-Nejad, Mohammad; Peña, A Salvador; Bassotti, Gabrio; Marsh, Michael N; Villanacci, Vincenzo

    2015-01-01

    Microscopic enteritis (ME) is an inflammatory condition of the small bowel that leads to gastrointestinal symptoms, nutrient and micronutrient deficiency. It is characterised by microscopic or sub-microscopic abnormalities such as microvillus changes and enterocytic alterations in the absence of definite macroscopic changes using standard modern endoscopy. This work recognises a need to characterize disorders with microscopic and submicroscopic features, currently regarded as functional or non-specific entities, to obtain further understanding of their clinical relevance. The consensus working party reviewed statements about the aetiology, diagnosis and symptoms associated with ME and proposes an algorithm for its investigation and treatment. Following the 5th International Course in Digestive Pathology in Bucharest in November 2012, an international group of 21 interested pathologists and gastroenterologists formed a working party with a view to formulating a consensus statement on ME. A five-step agreement scale (from strong agreement to strong disagreement) was used to score 21 statements, independently. There was strong agreement on all statements about ME histology (95%-100%). Statements concerning diagnosis achieved 85% to 100% agreement. A statement on the management of ME elicited agreement from the lowest rate (60%) up to 100%. The remaining two categories showed general agreement between experts on clinical presentation (75%-95%) and pathogenesis (80%-90%) of ME. There was strong agreement on the histological definition of ME. Weaker agreement on management indicates a need for further investigations, better definitions and clinical trials to produce quality guidelines for management. This ME consensus is a step toward greater recognition of a significant entity affecting symptomatic patients previously labelled as non-specific or functional enteropathy. PMID:25759526

  20. Thermal Lens Microscope

    NASA Astrophysics Data System (ADS)

    Uchiyama, Kenji; Hibara, Akihide; Kimura, Hiroko; Sawada, Tsuguo; Kitamori, Takehiko

    2000-09-01

    We developed a novel laser microscope based on the thermal lens effect induced by a coaxial beam comprised of excitation and probe beams. The signal generation mechanism was confirmed to be an authentic thermal lens effect from the measurement of signal and phase dependences on optical configurations between the sample and the probe beam focus, and therefore, the thermal lens effect theory could be applied. Two-point spatial resolution was determined by the spot size of the excitation beam, not by the thermal diffusion length. Sensitivity was quite high, and the detection ability, evaluated using a submicron microparticle containing dye molecules, was 0.8 zmol/μm2, hence a distribution image of trace chemical species could be obtained quantitatively. In addition, analytes are not restricted to fluorescent species, therefore, the thermal lens microscope is a promising analytical microscope. A two-dimensional image of a histamine molecule distribution, which was produced in mast cells at the femtomole level in a human nasal mucous polyp, was obtained.

  1. Virtual pinhole confocal microscope

    SciTech Connect

    George, J.S.; Rector, D.M.; Ranken, D.M.; Peterson, B.; Kesteron, J.

    1999-06-01

    Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

  2. Thermodynamic interpretation of time for rolling tachyons

    SciTech Connect

    Balasubramanian, Vijay; Jokela, Niko; Majumder, Jaydeep; Keski-Vakkuri, Esko

    2007-03-15

    We show that the open string worldsheet description of brane decay (discussing a specific example of a rolling tachyon background) can be related to a sequence of points of thermodynamic equilibrium of a grand canonical ensemble of point charges on a circle, the Dyson gas. Subsequent instants of time are related to neighboring values of the chemical potential or the average particle number N. The free energy of the system decreases in the direction of larger N or later times, thus defining a thermodynamic arrow of time. Time evolution equations are mapped to differential equations relating thermal expectation values of certain observables at different points of thermal equilibrium. This suggests some lessons concerning emergence of time from an underlying microscopic structure in which the concept of time is absent.

  3. [Authentication of Trace Material Evidence in Forensic Science Field with Infrared Microscopic Technique].

    PubMed

    Jiang, Zhi-quan; Hu, Ke-liang

    2016-03-01

    In the field of forensic science, conventional infrared spectral analysis technique is usually unable to meet the detection requirements, because only very a few trace material evidence with diverse shapes and complex compositions, can be extracted from the crime scene. Infrared microscopic technique is developed based on a combination of Fourier-transform infrared spectroscopic technique and microscopic technique. Infrared microscopic technique has a lot of advantages over conventional infrared spectroscopic technique, such as high detection sensitivity, micro-area analysisand nondestructive examination. It has effectively solved the problem of authentication of trace material evidence in the field of forensic science. Additionally, almost no external interference is introduced during measurements by infrared microscopic technique. It can satisfy the special need that the trace material evidence must be reserved for witness in court. It is illustrated in detail through real case analysis in this experimental center that, infrared microscopic technique has advantages in authentication of trace material evidence in forensic science field. In this paper, the vibration features in infrared spectra of material evidences, including paints, plastics, rubbers, fibers, drugs and toxicants, can be comparatively analyzed by means of infrared microscopic technique, in an attempt to provide powerful spectroscopic evidence for qualitative diagnosis of various criminal and traffic accident cases. The experimental results clearly suggest that infrared microscopic technique has an incomparable advantage and it has become an effective method for authentication of trace material evidence in the field of forensic science. PMID:27400510

  4. Molecular structural investigation of adenosine using spectroscopic and quantum computational calculations

    NASA Astrophysics Data System (ADS)

    Bakkiyaraj, D.; Periandy, S.; Xavier, S.

    2016-09-01

    In this study; spectroscopic investigation of adenosine having clinical importance was studied computationally and obtained results were compared with experimental ones. In this scope, geometric optimization and conformational analysis were studied and vibrational spectroscopic properties were studied on the most stable form. NMR and TD-DFT studies on the title compound were conducted with its experimental data. In addition atomic charge distribution, NBO, frontier molecular analysis, thermodynamic analysis and hyperpolarization features were studied.

  5. Q: How do Microscopes Work?

    ERIC Educational Resources Information Center

    Zimov, Sarah

    2004-01-01

    Microscopes allow scientists to examine everyday objects in extraordinary ways. They provide high-resolution images that show objects in fine detail. This brief article describes the many types of microscopes and how they are used in different scientific venues.

  6. Thermodynamics: A Stirling effort

    NASA Astrophysics Data System (ADS)

    Horowitz, Jordan M.; Parrondo, Juan M. R.

    2012-02-01

    The realization of a single-particle Stirling engine pushes thermodynamics into stochastic territory where fluctuations dominate, and points towards a better understanding of energy transduction at the microscale.

  7. Electrochemical thermodynamic measurement system

    DOEpatents

    Reynier, Yvan; Yazami, Rachid; Fultz, Brent T.

    2009-09-29

    The present invention provides systems and methods for accurately characterizing thermodynamic and materials properties of electrodes and electrochemical energy storage and conversion systems. Systems and methods of the present invention are configured for simultaneously collecting a suite of measurements characterizing a plurality of interconnected electrochemical and thermodynamic parameters relating to the electrode reaction state of advancement, voltage and temperature. Enhanced sensitivity provided by the present methods and systems combined with measurement conditions that reflect thermodynamically stabilized electrode conditions allow very accurate measurement of thermodynamic parameters, including state functions such as the Gibbs free energy, enthalpy and entropy of electrode/electrochemical cell reactions, that enable prediction of important performance attributes of electrode materials and electrochemical systems, such as the energy, power density, current rate and the cycle life of an electrochemical cell.

  8. The Thermodynamics of Portfolios

    NASA Astrophysics Data System (ADS)

    Piotrowski, E. W.; Sladkowski, J.

    2001-02-01

    We propose a new method of valuation of portfolios and their respective investing strategies. To this end we define a canonical ensemble of portfolios that allows to use the formalism of thermodynamics.

  9. Thermodynamics and Frozen Foods.

    ERIC Educational Resources Information Center

    Kerr, William L.; Reid, David S.

    1993-01-01

    The heat content of a food at a given temperature can be described by the thermodynamic property of enthalpy. Presents a method to construct a simple calorimeter for measuring the enthalpy changes of different foods during freezing. (MDH)

  10. Thermodynamics of Bioreactions.

    PubMed

    Held, Christoph; Sadowski, Gabriele

    2016-06-01

    Thermodynamic principles have been applied to enzyme-catalyzed reactions since the beginning of the 1930s in an attempt to understand metabolic pathways. Currently, thermodynamics is also applied to the design and analysis of biotechnological processes. The key thermodynamic quantity is the Gibbs energy of reaction, which must be negative for a reaction to occur spontaneously. However, the application of thermodynamic feasibility studies sometimes yields positive Gibbs energies of reaction even for reactions that are known to occur spontaneously, such as glycolysis. This article reviews the application of thermodynamics in enzyme-catalyzed reactions. It summarizes the basic thermodynamic relationships used for describing the Gibbs energy of reaction and also refers to the nonuniform application of these relationships in the literature. The review summarizes state-of-the-art approaches that describe the influence of temperature, pH, electrolytes, solvents, and concentrations of reacting agents on the Gibbs energy of reaction and, therefore, on the feasibility and yield of biological reactions. PMID:27276551

  11. High-Definition Infrared Spectroscopic Imaging

    PubMed Central

    Reddy, Rohith K.; Walsh, Michael J.; Schulmerich, Matthew V.; Carney, P. Scott; Bhargava, Rohit

    2013-01-01

    The quality of images from an infrared (IR) microscope has traditionally been limited by considerations of throughput and signal-to-noise ratio (SNR). An understanding of the achievable quality as a function of instrument parameters, from first principals is needed for improved instrument design. Here, we first present a model for light propagation through an IR spectroscopic imaging system based on scalar wave theory. The model analytically describes the propagation of light along the entire beam path from the source to the detector. The effect of various optical elements and the sample in the microscope is understood in terms of the accessible spatial frequencies by using a Fourier optics approach and simulations are conducted to gain insights into spectroscopic image formation. The optimal pixel size at the sample plane is calculated and shown much smaller than that in current mid-IR microscopy systems. A commercial imaging system is modified, and experimental data are presented to demonstrate the validity of the developed model. Building on this validated theoretical foundation, an optimal sampling configuration is set up. Acquired data were of high spatial quality but, as expected, of poorer SNR. Signal processing approaches were implemented to improve the spectral SNR. The resulting data demonstrated the ability to perform high-definition IR imaging in the laboratory by using minimally-modified commercial instruments. PMID:23317676

  12. Microscopic molecular superfluid response: theory and simulations.

    PubMed

    Zeng, Tao; Roy, Pierre-Nicholas

    2014-04-01

    Since its discovery in 1938, superfluidity has been the subject of much investigation because it provides a unique example of a macroscopic manifestation of quantum mechanics. About 60 years later, scientists successfully observed this phenomenon in the microscopic world though the spectroscopic Andronikashvili experiment in helium nano-droplets. This reduction of scale suggests that not only helium but also para-H2 (pH2) can be a candidate for superfluidity. This expectation is based on the fact that the smaller number of neighbours and surface effects of a finite-size cluster may hinder solidification and promote a liquid-like phase. The first prediction of superfluidity in pH2 clusters was reported in 1991 based on quantum Monte Carlo simulations. The possible superfluidity of pH2 was later indirectly observed in a spectroscopic Andronikashvili experiment in 2000. Since then, a growing number of studies have appeared, and theoretical simulations have been playing a special role because they help guide and interpret experiments. In this review, we go over the theoretical studies of pH2 superfluid clusters since the experiment of 2000. We provide a historical perspective and introduce the basic theoretical formalism along with key experimental advances. We then present illustrative results of the theoretical studies and comment on the possible future developments in the field. We include sufficient theoretical details such that the review can serve as a guide for newcomers to the field. PMID:24647079

  13. Microscopic molecular superfluid response: theory and simulations

    NASA Astrophysics Data System (ADS)

    Zeng, Tao; Roy, Pierre-Nicholas

    2014-04-01

    Since its discovery in 1938, superfluidity has been the subject of much investigation because it provides a unique example of a macroscopic manifestation of quantum mechanics. About 60 years later, scientists successfully observed this phenomenon in the microscopic world though the spectroscopic Andronikashvili experiment in helium nano-droplets. This reduction of scale suggests that not only helium but also para-H2 (pH2) can be a candidate for superfluidity. This expectation is based on the fact that the smaller number of neighbours and surface effects of a finite-size cluster may hinder solidification and promote a liquid-like phase. The first prediction of superfluidity in pH2 clusters was reported in 1991 based on quantum Monte Carlo simulations. The possible superfluidity of pH2 was later indirectly observed in a spectroscopic Andronikashvili experiment in 2000. Since then, a growing number of studies have appeared, and theoretical simulations have been playing a special role because they help guide and interpret experiments. In this review, we go over the theoretical studies of pH2 superfluid clusters since the experiment of 2000. We provide a historical perspective and introduce the basic theoretical formalism along with key experimental advances. We then present illustrative results of the theoretical studies and comment on the possible future developments in the field. We include sufficient theoretical details such that the review can serve as a guide for newcomers to the field.

  14. Adirondack Under the Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image was taken by the Mars Exploration Rover Spirit front hazard-identification camera after the rover's first post-egress drive on Mars Sunday, Jan. 15, 2004. Engineers drove the rover approximately 3 meters (10 feet) from the Columbia Memorial Station toward the first rock target, seen in the foreground. The football-sized rock was dubbed Adirondack because of its mountain-shaped appearance. Scientists have begun using the microscopic imager instrument at the end of the rover's robotic arm to examine the rock and understand how it formed.

  15. Low frequency acoustic microscope

    DOEpatents

    Khuri-Yakub, Butrus T.

    1986-11-04

    A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.

  16. Atomic Force Microscope

    SciTech Connect

    Day, R.D.; Russell, P.E.

    1988-12-01

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  17. Photography with a Microscope

    NASA Astrophysics Data System (ADS)

    Rost, Fred; Oldfield, Ron

    2000-03-01

    This beautifully illustrated book describes the methods used to record images viewed through a microscope. The text describes the principles and practices of photomicrography, and is written for all who take photomicrographs, beginners and/or experienced practitioners. The authors describe techniques that may be applied to many disciplines for teaching, research, archives, or pleasure. The book includes chapters on standard photography, modern digital techniques, methods for improving contrast, and a short chapter on drawing. In addition to its value as a work of reference, the authors' clear, didactic style makes this book suitable as a textbook for courses in photomicrography and/or elementary light microscopy.

  18. Solid state optical microscope

    DOEpatents

    Young, Ian T.

    1983-01-01

    A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

  19. Solid state optical microscope

    DOEpatents

    Young, I.T.

    1983-08-09

    A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal. 2 figs.

  20. Stochastic Independence as a Resource for Small-Scale Thermodynamics

    NASA Astrophysics Data System (ADS)

    Lostaglio, Matteo; Mueller, Markus P.; Pastena, Michele

    It is well-known in thermodynamics that the creation of correlations costs work. It seems then a truism that if a thermodynamic transformation A --> B is impossible, so will be any transformation that in sending A to B also correlates among them some auxiliary systems C. Surprisingly, we show that this is not the case for non-equilibrium thermodynamics of microscopic systems. On the contrary, the creation of correlations greatly extends the set of accessible states, to the point that we can perform on individual systems and in a single shot any transformation that would otherwise be possible only if the number of systems involved was very large. We also show that one only ever needs to create a vanishingly small amount of correlations (as measured by mutual information) among a small number of auxiliary systems (never more than three). The many, severe constraints of microscopic thermodynamics are reduced to the sole requirement that the non-equilibrium free energy decreases in the transformation. This shows that, in principle, reliable extraction of work equal to the free energy of a system can be performed by microscopic engines.

  1. Electron microscope phase enhancement

    DOEpatents

    Jin, Jian; Glaeser, Robert M.

    2010-06-15

    A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.

  2. Microscopic Rayleigh Droplet Beams

    NASA Astrophysics Data System (ADS)

    Doak, R. B.

    2005-11-01

    A periodically triggered Rayleigh Droplet Beam (RDB) delivers a perfectly linear and periodic stream of identical, monoenergetic droplets that are phase-locked to the trigger signal. The droplet diameter and spacing are easily adjusted of choice of nozzle diameter and trigger frequency. Any liquid of low viscosity may be emloyed as the beam fluid. Although the field of nanofluidics is expanding rapidly, little effort has yet been devoted to ``external flows'' such as RDB's. At ASU we have generated RDB's of water and methanol down to 2 microns in droplet diameter. Nozzle clogging is the sole impediment to smaller droplets. Microscopic Rayleigh droplet beams offer tremendous potential for fundamental physical measurements, fluid dynamics research, and nanofabrication. This talk will describe the apparatus and techniques used at ASU to generate RDB's (surprisingly simple and inexpensive), discuss the triboelectric phenomena that play a role (surprisingly significant), present some initial experimental fluid dynamics measurements, and briefly survey RDB applications. Our particular interest in RDB's is as microscopic transport systems to deliver hydrated, undenatured proteins into vacuum for structure determination via serial diffraction of x-rays or electrons. This may offer the first general method for structure determination of non-crystallizable proteins.

  3. Microscopic Tribotactic Walkers

    NASA Astrophysics Data System (ADS)

    Steimel, Joshua; Aragones, Juan; Alexander-Katz, Alfredo

    2014-03-01

    The translational motion of a rotating object near a surface is strongly dependent on the friction between the object and the surface. The process of friction is inherently directional and the friction coefficient can be anisotropic even in the absence of a net friction coefficient gradient. This is macroscopically observed in the ordering motif of some animal hair or scales and a microscopic analog can be imagined where the friction coefficient is determined by the strength and density of reversible bonds between a rotating object and the substrate. For high friction coefficients most of the rotational motion is converted into translational motion; conversely for low friction coefficients the object primarily rotates in place. We exploited this property to design and test a new class of motile system that displays tribotaxis, which is the process by which an object detects differences in the local friction coefficient and moves accordingly either to regions of higher or lower friction. These synthetic tribotactic microscopic walkers, composed of a pair of functionalized superparamagnetic beads, detect gradients in the spatial friction coefficient and migrate towards high friction areas when actuated in a random fashion. The effective friction between the walkers and the substrate is controlled by the local density of active receptors in the substrate. The tribotactic walkers also displayed trapping in high friction areas where the density of free receptors is higher.

  4. Forensic Scanning Electron Microscope

    NASA Astrophysics Data System (ADS)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  5. Spectroscopic infrared ellipsometry

    NASA Astrophysics Data System (ADS)

    Roseler, A.

    1992-03-01

    The spectroscopic infrared ellipsometry (SIRE) by means of the combination of a photometric ellipsometer with a Fourier transform spectrometer is used to measure optical properties in the infrared. From the observed four Stokes parameters, the spectrum of the degree of polarization after the reflection at the sample is calculated and discussed.

  6. Spectroscopic wear detector

    NASA Technical Reports Server (NTRS)

    Madzsar, George C. (Inventor)

    1993-01-01

    The elemental composition of a material exposed to hot gases and subjected to wear is determined. Atoms of an elemental species not appearing in this material are implanted in a surface at a depth based on the maximum allowable wear. The exhaust gases are spectroscopically monitored to determine the exposure of these atoms when the maximum allowable wear is reached.

  7. THz wave emission microscope

    NASA Astrophysics Data System (ADS)

    Yuan, Tao

    Sensing and imaging using Terahertz (THz) radiation has attracted more and more interest in the last two decades thanks to the abundant material 'finger prints' in the THz frequency range. The low photon energy also makes THz radiation an attractive tool for nondestructive evaluation of materials and devices, biomedical applications, security checks and explosive screening. Due to the long wavelength, the far-field THz wave optical systems have relatively low spatial resolution. This physical limitation confines THz wave sensing and imaging to mostly macro-size samples. To investigate local material properties or micro-size structures and devices, near-field technology has to be employed. In this dissertation, the Electro-Optical THz wave emission microscope is investigated. The basic principle is to focus the femtosecond laser to a tight spot on a thin THz emitter layer to produce a THz wave source with a similar size as the focus spot. The apparatus provides a method for placing a THz source with sub-wavelength dimension in the near-field range of the investigated sample. Spatial resolution to the order of one tenth of the THz wavelength is demonstrated by this method. The properties of some widely used THz wave emission materials under tight focused pump light are studied. As an important branch of THz time domain spectroscopy (THz-TDS), THz wave emission spectroscopy has been widely used as a tool to investigate the material physics, such as energy band structure, carrier dynamics, material nonlinear properties and dynamics. As the main work of this dissertation, we propose to combine the THz wave emission spectroscopy with scanning probe microscopy (SPM) to build a tip-assisted THz wave emission microscope (TATEM), which is a valuable extension to current SPM science and technology. Illuminated by a femtosecond laser, the biased SPM tip forms a THz wave source inside the sample beneath the tip. The source size is proportional to the apex size of the tip so

  8. Thermodynamics of catalytic nanoparticle morphology

    NASA Astrophysics Data System (ADS)

    Zwolak, Michael; Sharma, Renu; Lin, Pin Ann

    Metallic nanoparticles are an important class of industrial catalysts. The variability of their properties and the environment in which they act, from their chemical nature & surface modification to their dispersion and support, allows their performance to be optimized for many chemical processes useful in, e.g., energy applications and other areas. Their large surface area to volume ratio, as well as varying sizes and faceting, in particular, makes them an efficient source for catalytically active sites. These characteristics of nanoparticles - i.e., their morphology - can often display intriguing behavior as a catalytic process progresses. We develop a thermodynamic model of nanoparticle morphology, one that captures the competition of surface energy with other interactions, to predict structural changes during catalytic processes. Comparing the model to environmental transmission electron microscope images of nickel nanoparticles during carbon nanotube (and other product) growth demonstrates that nickel deformation in response to the nanotube growth is due to a favorable interaction with carbon. Moreover, this deformation is halted due to insufficient volume of the particles. We will discuss the factors that influence morphology and also how the model can be used to extract interaction strengths from experimental observations.

  9. Imaging arrangement and microscope

    DOEpatents

    Pertsinidis, Alexandros; Chu, Steven

    2015-12-15

    An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.

  10. Embryos, microscopes, and society.

    PubMed

    Maienschein, Jane

    2016-06-01

    Embryos have different meanings for different people and in different contexts. Seen under the microscope, the biological embryo starts out as one cell and then becomes a bunch of cells. Gradually these divide and differentiate to make up the embryo, which in humans becomes a fetus at eight weeks, and then eventually a baby. At least, that happens in those cases that carry through normally and successfully. Yet a popular public perception imagines the embryo as already a little person in the very earliest stages of development, as if it were predictably to become an adult. In actuality, cells can combine, pull apart, and recombine in a variety of ways and still produce embryos, whereas most embryos never develop into adults at all. Biological embryos and popular imaginations of embryos diverge. This paper looks at some of the historical reasons for and social implications of that divergence. PMID:26996410

  11. Mars Under the Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This magnified look at the martian soil near the Mars Exploration Rover Opportunity's landing site, Meridiani Planum, shows coarse grains sprinkled over a fine layer of sand. The image was captured by the rover's microscopic imager on the 10th day, or sol, of its mission. Scientists are intrigued by the spherical rocks, which can be formed by a variety of geologic processes, including cooling of molten lava droplets and accretion of concentric layers of material around a particle or 'seed.'

    The examined patch of soil is 3 centimeters (1.2 inches) across. The circular grain in the lower left corner is approximately 3 millimeters (.12 inches) across, or about the size of a sunflower seed.

  12. Atomic Force Microscope Operation

    NASA Technical Reports Server (NTRS)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for animation (large file)

    This animation is a scientific illustration of the operation of NASA's Phoenix Mars Lander's Atomic Force Microscope, or AFM. The AFM is part of Phoenix's Microscopy, Electrochemistry, and Conductivity Analyzer, or MECA.

    The AFM is used to image the smallest Martian particles using a very sharp tip at the end of one of eight beams.

    The beam of the AFM is set into vibration and brought up to the surface of a micromachined silicon substrate. The substrate has etched in it a series of pits, 5 micrometers deep, designed to hold the Martian dust particles.

    The microscope then maps the shape of particles in three dimensions by scanning them with the tip.

    At the end of the animation is a 3D representation of the AFM image of a particle that was part of a sample informally called 'Sorceress.' The sample was delivered to the AFM on the 38th Martian day, or sol, of the mission (July 2, 2008).

    The image shows four round pits, only 5 microns in depth, that were micromachined into the silicon substrate.

    A Martian particle only one micrometer, or one millionth of a meter, across is held in the upper left pit.

    The rounded particle shown at the highest magnification ever seen from another world is a particle of the dust that cloaks Mars. Such dust particles color the Martian sky pink, feed storms that regularly envelop the planet and produce Mars' distinctive red soil.

    The AFM was developed by a Swiss-led consortium, with Imperial College London producing the silicon substrate that holds sampled particles.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  13. Thermodynamics of Nonadditive Systems

    NASA Astrophysics Data System (ADS)

    Latella, Ivan; Pérez-Madrid, Agustín; Campa, Alessandro; Casetti, Lapo; Ruffo, Stefano

    2015-06-01

    The usual formulation of thermodynamics is based on the additivity of macroscopic systems. However, there are numerous examples of macroscopic systems that are not additive, due to the long-range character of the interaction among the constituents. We present here an approach in which nonadditive systems can be described within a purely thermodynamics formalism. The basic concept is to consider a large ensemble of replicas of the system where the standard formulation of thermodynamics can be naturally applied and the properties of a single system can be consequently inferred. After presenting the approach, we show its implementation in systems where the interaction decays as 1 /rα in the interparticle distance r , with α smaller than the embedding dimension d , and in the Thirring model for gravitational systems.

  14. Thermodynamics of Nitinol

    NASA Astrophysics Data System (ADS)

    McNichols, J. L., Jr.; Cory, J. S.

    1987-02-01

    A self-consistent macroscopic thermodynamics is developed for the calculation of work, heat, and dissipation for thermodynamic paths of the shape memory alloy, Nitinol. The thermodynamic system analyzed is a Nitinol helix for which extensive force-length-temperature (FLT) equation of state measurements have been made. The Nitinol system exhibits significant hysteresis and is determined to be a nonequilibrium thermostatic system. A set of equations of state are provided which correlate all reversible and irreversible Nitinol thermodynamic paths to both the set of helix (FLT) thermodynamic state variables and to new ``history'' state variables. It is shown that these equations predict observed cyclic behaviors not previously interpreted. In the absence of calorimetric measurements for the Nitinol helix system, a physical assumption is made that reversible paths are of constant phase. This assumption is used to estimate the reversible path thermal and mechanical heat capacities for the Nitinol system. With the state equations and the estimated reversible path heat capacities, the nonequilibrium thermostatic formalism is employed to derive expressions for the heat flow for any Nitinol thermodynamic path. It is shown that predicted calorimetric quantities are in good qualitative agreement with measurements. It is also shown that the calorimetric quantities are sensitive to state equation coefficients, which in turn are sensitive to cold-working or ``conditioning'' of the material. The large heat of transformation, ˜2.4 cal/g, an estimated isentropic temperature change of 22 °C and the large dimensional changes associated with the shape memory effect, imply that Nitinol may be useful for many applications, including use as a working medium for low-grade thermal-energy conversion (i.e., heat engines).

  15. Thermodynamics of graphene

    NASA Astrophysics Data System (ADS)

    Rusanov, A. I.

    2014-12-01

    The 21st century has brought a lot of new results related to graphene. Apparently, graphene has been characterized from all points of view except surface science and, especially, surface thermodynamics. This report aims to close this gap. Since graphene is the first real two-dimensional solid, a general formulation of the thermodynamics of two-dimensional solid bodies is given. The two-dimensional chemical potential tensor coupled with stress tensor is introduced, and fundamental equations are derived for energy, free energy, grand thermodynamic potential (in the classical and hybrid forms), enthalpy, and Gibbs energy. The fundamentals of linear boundary phenomena are formulated with explaining the concept of a dividing line, the mechanical and thermodynamic line tensions, line energy and other linear properties with necessary thermodynamic equations. The one-dimensional analogs of the Gibbs adsorption equation and Shuttleworth-Herring relation are presented. The general thermodynamic relationships are illustrated with calculations based on molecular theory. To make the reader sensible of the harmony of chemical and van der Waals forces in graphene, the remake of the classical graphite theory is presented with additional variable combinations of graphene sheets. The calculation of the line energy of graphene is exhibited including contributions both from chemical bonds and van der Waals forces (expectedly, the latter are considerably smaller than the former). The problem of graphene holes originating from migrating vacancies is discussed on the basis of the Gibbs-Curie principle. An important aspect of line tension is the planar sheet/nanotube transition where line tension acts as a driving force. Using the bending stiffness of graphene, the possible radius range is estimated for achiral (zigzag and armchair) nanotubes.

  16. Viscoplasticity: A thermodynamic formulation

    NASA Technical Reports Server (NTRS)

    Freed, A. D.; Chaboche, J. L.

    1989-01-01

    A thermodynamic foundation using the concept of internal state variables is given for a general theory of viscoplasticity, as it applies to initially isotropic materials. Three fundamental internal state variables are admitted. They are: a tensor valued back stress for kinematic effects, and the scalar valued drag and yield strengths for isotropic effects. All three are considered to phenomenologically evolve according to competitive processes between strain hardening, strain induced dynamic recovery, and time induced static recovery. Within this phenomenological framework, a thermodynamically admissible set of evolution equations is put forth. This theory allows each of the three fundamental internal variables to be composed as a sum of independently evolving constituents.

  17. Thermodynamics of lattice OCD

    SciTech Connect

    Matsuoka, H.

    1985-01-01

    The thermodynamic consequences of QCD are explored in the framework of lattice gauge theory. Attention is focused upon the nature of the chiral symmetry restoration transition at finite temperature and at finite baryon density, and possible strategies for identifying relevant thermodynamic phases are discussed. Some numerical results are presented on the chiral symmetry restoration in the SU(2) gauge theory at high baryon density. The results suggest that with T approx. = 110 MeV there is a second order restoration transition at the critical baryon density n/sub B//sup c/ approx. = 0.62 fm/sup -3/.

  18. Lagrangian formulation of irreversible thermodynamics and the second law of thermodynamics

    SciTech Connect

    Glavatskiy, K. S.

    2015-05-28

    We show that the equations which describe irreversible evolution of a system can be derived from a variational principle. We suggest a Lagrangian, which depends on the properties of the normal and the so-called “mirror-image” system. The Lagrangian is symmetric in time and therefore compatible with microscopic reversibility. The evolution equations in the normal and mirror-imaged systems are decoupled and describe therefore independent irreversible evolution of each of the systems. The second law of thermodynamics follows from a symmetry of the Lagrangian. Entropy increase in the normal system is balanced by the entropy decrease in the mirror-image system, such that there exists an “integral of evolution” which is a constant. The derivation relies on the property of local equilibrium, which states that the local relations between the thermodynamic quantities in non-equilibrium are the same as in equilibrium.

  19. Lagrangian formulation of irreversible thermodynamics and the second law of thermodynamics.

    PubMed

    Glavatskiy, K S

    2015-05-28

    We show that the equations which describe irreversible evolution of a system can be derived from a variational principle. We suggest a Lagrangian, which depends on the properties of the normal and the so-called "mirror-image" system. The Lagrangian is symmetric in time and therefore compatible with microscopic reversibility. The evolution equations in the normal and mirror-imaged systems are decoupled and describe therefore independent irreversible evolution of each of the systems. The second law of thermodynamics follows from a symmetry of the Lagrangian. Entropy increase in the normal system is balanced by the entropy decrease in the mirror-image system, such that there exists an "integral of evolution" which is a constant. The derivation relies on the property of local equilibrium, which states that the local relations between the thermodynamic quantities in non-equilibrium are the same as in equilibrium. PMID:26026433

  20. Proper alignment of the microscope.

    PubMed

    Rottenfusser, Rudi

    2013-01-01

    The light microscope is merely the first element of an imaging system in a research facility. Such a system may include high-speed and/or high-resolution image acquisition capabilities, confocal technologies, and super-resolution methods of various types. Yet more than ever, the proverb "garbage in-garbage out" remains a fact. Image manipulations may be used to conceal a suboptimal microscope setup, but an artifact-free image can only be obtained when the microscope is optimally aligned, both mechanically and optically. Something else is often overlooked in the quest to get the best image out of the microscope: Proper sample preparation! The microscope optics can only do its job when its design criteria are matched to the specimen or vice versa. The specimen itself, the mounting medium, the cover slip, and the type of immersion medium (if applicable) are all part of the total optical makeup. To get the best results out of a microscope, understanding the functions of all of its variable components is important. Only then one knows how to optimize these components for the intended application. Different approaches might be chosen to discuss all of the microscope's components. We decided to follow the light path which starts with the light source and ends at the camera or the eyepieces. To add more transparency to this sequence, the section up to the microscope stage was called the "Illuminating Section", to be followed by the "Imaging Section" which starts with the microscope objective. After understanding the various components, we can start "working with the microscope." To get the best resolution and contrast from the microscope, the practice of "Koehler Illumination" should be understood and followed by every serious microscopist. Step-by-step instructions as well as illustrations of the beam path in an upright and inverted microscope are included in this chapter. A few practical considerations are listed in Section 3. PMID:23931502

  1. Transmission electron microscope CCD camera

    DOEpatents

    Downing, Kenneth H.

    1999-01-01

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  2. Black Hole Thermodynamics in an Undergraduate Thermodynamics Course.

    ERIC Educational Resources Information Center

    Parker, Barry R.; McLeod, Robert J.

    1980-01-01

    An analogy, which has been drawn between black hole physics and thermodynamics, is mathematically broadened in this article. Equations similar to the standard partial differential relations of thermodynamics are found for black holes. The results can be used to supplement an undergraduate thermodynamics course. (Author/SK)

  3. Spectroscopic Low Coherence Interferometry

    NASA Astrophysics Data System (ADS)

    Bosschaart, Nienke; van Leeuwen, T. G.; Aalders, Maurice C.; Hermann, Boris; Drexler, Wolfgang; Faber, Dirk J.

    Low-coherence interferometry (LCI) allows high-resolution volumetric imaging of tissue morphology and provides localized optical properties that can be related to the physiological status of tissue. This chapter discusses the combination of spatial and spectroscopic information by means of spectroscopic OCT (sOCT) and low-coherence spectroscopy (LCS). We describe the theory behind these modalities for the assessment of spatially resolved optical absorption and (back)scattering coefficient spectra. These spectra can be used for the highly localized quantification of chromophore concentrations and assessment of tissue organization on (sub)cellular scales. This leads to a wealth of potential clinical applications, ranging from neonatology for the determination of billibrubin concentrations, to oncology for the optical assessment of the aggressiveness of a cancerous lesion.

  4. Thermodynamics of convective circulations

    NASA Astrophysics Data System (ADS)

    Adams, D. K.; Renno, N. O.

    2003-04-01

    The heat engine framework has proven successful for studies of atmospheric phenomena ranging from small to large scales. At large scales, the heat engine framework provides estimates of convective available potential energy, convective velocities, and fractional area covered by convection. At the smaller end of the spectrum, the framework provides estimates of the intensity of convective vortices such as dust devils and waterspouts. The heat engine framework sheds light on the basic physics of planetary atmospheres. In particular, it allows the calculation of their thermodynamic efficiency. Indeed, this is a fundamental number for atmospheric circulations because it quantifies the amount of heat that is converted into kinetic energy. As such, it is a valuable number not only for comparison of models with nature, but also for the intercomparison of models. In the present study, we generalize the heat engine framework to large-scale circulations, both open (e.g., the Hadley circulation) and closed (e.g., the general circulation) and apply it to an idealized global climate model to ascertain the thermodynamic efficiency of model circulations, both global and regional. Our results show that the thermodynamic efficiency is sensitive to model resolution and provides a baseline for minimum model resolution in climate studies. The value of the thermodynamic efficiency of convective circulations in nature is controversial. It has been suggested that both nature and numerical models are extremely irreversible. We show that both the global and the Hadley circulation of the idealized model are, to a first approximation, reversible.

  5. Program Computes Thermodynamic Functions

    NASA Technical Reports Server (NTRS)

    Mcbride, Bonnie J.; Gordon, Sanford

    1994-01-01

    PAC91 is latest in PAC (Properties and Coefficients) series. Two principal features are to provide means of (1) generating theoretical thermodynamic functions from molecular constants and (2) least-squares fitting of these functions to empirical equations. PAC91 written in FORTRAN 77 to be machine-independent.

  6. Thermodynamics of Resource Recycling.

    ERIC Educational Resources Information Center

    Hauserman, W. B.

    1988-01-01

    Evaluates the overall economic efficiency of a closed resource cycle. Uses elementary thermodynamic definitions of overall thermal efficiency for determining an economically quantifiable basis. Selects aluminum for investigation and includes a value-entropy diagram for a closed aluminum cycle. (MVL)

  7. Thermodynamics of Dilute Solutions.

    ERIC Educational Resources Information Center

    Jancso, Gabor; Fenby, David V.

    1983-01-01

    Discusses principles and definitions related to the thermodynamics of dilute solutions. Topics considered include dilute solution, Gibbs-Duhem equation, reference systems (pure gases and gaseous mixtures, liquid mixtures, dilute solutions), real dilute solutions (focusing on solute and solvent), terminology, standard states, and reference systems.…

  8. Thermodynamics with Design Problems.

    ERIC Educational Resources Information Center

    Cilento, E. V.; Sears, J. T.

    1983-01-01

    Discusses how basic thermodynamics concepts are integrated with design problems. Includes course goals, instructional strategies, and major advantages/disadvantages of the integrated design approach. Advantages include making subject more concrete, emphasizing interrelation of variables, and reinforcing concepts by use in design analysis; whereas…

  9. Focus on stochastic thermodynamics

    NASA Astrophysics Data System (ADS)

    Van den Broeck, Christian; Sasa, Shin-ichi; Seifert, Udo

    2016-02-01

    We introduce the thirty papers collected in this ‘focus on’ issue. The contributions explore conceptual issues within and around stochastic thermodynamics, use this framework for the theoretical modeling and experimental investigation of specific systems, and provide further perspectives on and for this active field.

  10. On Teaching Thermodynamics

    ERIC Educational Resources Information Center

    Debbasch, F.

    2011-01-01

    The logical structure of classical thermodynamics is presented in a modern, geometrical manner. The first and second law receive clear, operatively oriented statements and the Gibbs free energy extremum principle is fully discussed. Applications relevant to chemistry, such as phase transitions, dilute solutions theory and, in particular, the law…

  11. Spectroscopic Binary Stars

    NASA Astrophysics Data System (ADS)

    Batten, A.; Murdin, P.

    2000-11-01

    Historically, spectroscopic binary stars were binary systems whose nature was discovered by the changing DOPPLER EFFECT or shift of the spectral lines of one or both of the component stars. The observed Doppler shift is a combination of that produced by the constant RADIAL VELOCITY (i.e. line-of-sight velocity) of the center of mass of the whole system, and the variable shift resulting from the o...

  12. Fluctuating Thermodynamics for Biological Processes

    NASA Astrophysics Data System (ADS)

    Ham, Sihyun

    Because biomolecular processes are largely under thermodynamic control, dynamic extension of thermodynamics is necessary to uncover the mechanisms and driving factors of fluctuating processes. The fluctuating thermodynamics technology presented in this talk offers a practical means for the thermodynamic characterization of conformational dynamics in biomolecules. The use of fluctuating thermodynamics has the potential to provide a comprehensive picture of fluctuating phenomena in diverse biological processes. Through the application of fluctuating thermodynamics, we provide a thermodynamic perspective on the misfolding and aggregation of the various proteins associated with human diseases. In this talk, I will present the detailed concepts and applications of the fluctuating thermodynamics technology for elucidating biological processes. This work was supported by Samsung Science and Technology Foundation under Project Number SSTF-BA1401-13.

  13. Athena microscopic Imager investigation

    USGS Publications Warehouse

    Herkenhoff, K. E.; Squyres, S. W.; Bell, J.F., III; Maki, J.N.; Arneson, H.M.; Bertelsen, P.; Brown, D.I.; Collins, S.A.; Dingizian, A.; Elliott, S.T.; Goetz, W.; Hagerott, E.C.; Hayes, A.G.; Johnson, M.J.; Kirk, R.L.; McLennan, S.; Morris, R.V.; Scherr, L.M.; Schwochert, M.A.; Shiraishi, L.R.; Smith, G.H.; Soderblom, L.A.; Sohl-Dickstein, J. N.; Wadsworth, M.V.

    2003-01-01

    The Athena science payload on the Mars Exploration Rovers (MER) includes the Microscopic Imager (MI). The MI is a fixed-focus camera mounted on the end of an extendable instrument arm, the Instrument Deployment Device (IDD). The MI was designed to acquire images at a spatial resolution of 30 microns/pixel over a broad spectral range (400-700 nm). The MI uses the same electronics design as the other MER cameras but has optics that yield a field of view of 31 ?? 31 mm across a 1024 ?? 1024 pixel CCD image. The MI acquires images using only solar or skylight illumination of the target surface. A contact sensor is used to place the MI slightly closer to the target surface than its best focus distance (about 66 mm), allowing concave surfaces to be imaged in good focus. Coarse focusing (???2 mm precision) is achieved by moving the IDD away from a rock target after the contact sensor has been activated. The MI optics are protected from the Martian environment by a retractable dust cover. The dust cover includes a Kapton window that is tinted orange to restrict the spectral bandpass to 500-700 nm, allowing color information to be obtained by taking images with the dust cover open and closed. MI data will be used to place other MER instrument data in context and to aid in petrologic and geologic interpretations of rocks and soils on Mars. Copyright 2003 by the American Geophysical Union.

  14. The microscope mission

    NASA Astrophysics Data System (ADS)

    Touboul, Pierre; Foulon, Bernard; Lafargue, Laurent; Metris, Gilles

    2002-04-01

    The MICROSCOPE mission had been selected at the end of 1999 by the French space agency Cnes for a launch scheduled in 2004. The scientific objective of the mission is the test of the Equivalence Principle (EP) up to an accuracy of 10 -15 with its well-known manifestation, the universality of free fall. This principle, at the origin of general relativity, is only consolidated by experimental results and presently with an accuracy of several 10 -13. The micro-satellite developed by Cnes weighs less than 120 kg and is compatible with a low-cost launch like ASAP ARIANE V. The instrument is composed of two differential electrostatic accelerometers operating at finely stabilised room temperature. Each accelerometer includes two cylindrical and concentric test masses, made of platinum or titanium alloys. The experiment consists in controlling the two masses in the same orbital motion. Because of the drag compensation system of the satellite including field effect electrical thrusters, this motion is quite purely gravitational. The electrostatic control forces used in the differential accelerometers are finely measured. The principle of the experiment is presented, the configuration of the instrument and of the satellite is detailed with regard to the present development status. The specifications for the major parameters of the experiment are detailed.

  15. Spectroscopic Modeling of Single Element Plasma

    SciTech Connect

    Ghomeishi, Mostafa; Yap, S. L.; Wong, C. S.; Saboohi, S.; Chan, L. S.

    2011-03-30

    A strategy for spectroscopic analysis of single element plasmas is through modeling. An experimental investigation or generation of a specified emission spectrum can be attempted based on the modeling results which are currently under investigating by many researchers in the world. In the emission spectroscopy, the K-shell emission is more interesting than emissions from other shells due to their unique EUV and SXR frequencies that can be applied in various scientific and industrial applications. Population information of our model is based on a steady state kinetic code which is calculated for a given electron temperature and an estimated electron density. Thus for each single element plasma it needs large amounts of experimental or theoretical database. Depending on the parameter of the plasma, theories based on local thermodynamic equilibrium (LTE) and non-LTE are considered. In the non-LTE case, the Corona model is used and the total absolute number densities are calculated based on the ion densities that are related to the electron density corresponds to the mean charge of the ions. The spectra generated by the model can then be compared with spectroscopic data obtained experimentally.

  16. Spectroscopically Unlocking Exoplanet Characteristics

    NASA Astrophysics Data System (ADS)

    Lewis, Nikole

    2016-05-01

    Spectroscopy plays a critical role in a number of areas of exoplanet research. The first exoplanets were detected by precisely measuring Doppler shifts in high resolution (R ~ 100,000) stellar spectra, a technique that has become known as the Radial Velocity (RV) method. The RV method provides critical constraints on exoplanet masses, but is currently limited to some degree by robust line shape predictions. Beyond the RV method, spectroscopy plays a critical role in the characterization of exoplanets beyond their mass and radius. The Hubble Space Telescope has spectroscopically observed the atmospheres of exoplanets that transit their host stars as seen from Earth giving us key insights into atmospheric abundances of key atomic and molecular species as well as cloud optical properties. Similar spectroscopic characterization of exoplanet atmospheres will be carried out at higher resolution (R ~ 100-3000) and with broader wavelength coverage with the James Webb Space Telescope. Future missions such as WFIRST that seek to the pave the way toward the detection and characterization of potentially habitable planets will have the capability of directly measuring the spectra of exoplanet atmospheres and potentially surfaces. Our ability to plan for and interpret spectra from exoplanets relies heavily on the fidelity of the spectroscopic databases available and would greatly benefit from further laboratory and theoretical work aimed at optical properties of atomic, molecular, and cloud/haze species in the pressure and temperature regimes relevant to exoplanet atmospheres.

  17. Thermodynamic signatures of edge states in Topological Insulators

    NASA Astrophysics Data System (ADS)

    Quelle, Anton; Cobanera, Emilio; Morais Smith, Cristinae

    Topological insulators are states of matter distinguished by the presence of symmetry protected metallic boundary modes. These edge modes have been characterised in terms of transport and spectroscopic measurements, but a thermodynamic description has been lacking. The challenge arises because in conventional thermodynamics the potentials are required to scale linearly with extensive variables like volume, which does not allow for a general treatment of boundary effects. In this paper, we overcome this challenge with Hill thermodynamics. In this extension of the thermodynamic formalism, the grand potential is split into an extensive, conventional contribution, and the subdivision potential, which is the central construct of Hill's theory. For topologically non-trivial electronic matter, the subdivision potential captures measurable contributions to the density of states and the heat capacity: it is the thermodynamic manifestation of the topological edge structure. Furthermore, the subdivision potential reveals phase transitions of the edge even when they are not manifested in the bulk, thus opening a variety of new possibilities for investigating, manipulating, and characterizing topological quantum matter solely in terms of equilibrium boundary physics.

  18. The Latest in Handheld Microscopes

    ERIC Educational Resources Information Center

    Wighting, Mervyn J.; Lucking, Robert A.; Christmann, Edwin P.

    2004-01-01

    Around 1590, Zacharias Jansenn of Holland invented the microscope. Jansenn, an eyeglass maker by trade, experimented with lenses and discovered that things appeared closer with combinations of lenses. Over the past 400 years, several refinements to microscopes have occurred, making it possible to magnify objects between 200 and 1,500 times their…

  19. Scientists View Battery Under Microscope

    SciTech Connect

    2015-04-10

    PNNL researchers use a special microscope setup that shows the inside of a battery as it charges and discharges. This battery-watching microscope is located at EMSL, DOE's Environmental Molecular Sciences Laboratory that resides at PNNL. Researchers the world over can visit EMSL and use special instruments like this, many of which are the only one of their kind available to scientists.

  20. Microbial surface thermodynamics and applications.

    PubMed

    Strevett, Keith A; Chen, Gang

    2003-06-01

    Microbial surface thermodynamics is the reflection of microbial physicochemical and biological characteristics and it bridges micro-scale structures with macro-scale biological functions. Microbial surface thermodynamics is theoretically based on colloid surface thermodynamics using the classical theory of colloidal stability, Derjauin-Landau-Verwey-Overbeek (DLVO) theory. An extended DLVO theory is applied to for the hydration forces not considered in the classical DLVO theory. Herein, a review of current application of microbial surface thermodynamic theory is presented. Microbial surface thermodynamic theory is the fundamental theory in interpreting microbial hydrophilicity or hydrophobicity, microbial attachment, and microbial biofilm development. PMID:12837508

  1. Thermodynamic analysis of spectra

    SciTech Connect

    Mitchell, G. E.; Shriner, J. F. Jr.

    2008-04-04

    Although random matrix theory had its initial application to neutron resonances, there is a relative scarcity of suitable nuclear data. The primary reason for this is the sensitivity of the standard measures used to evaluate spectra--the spectra must be essential pure (no state with a different symmetry) and complete (no states missing). Additional measures that are less sensitive to these experimental limitations are of significant value. The standard measure for long range order is the {delta}{sub 3} statistic. In the original paper that introduced this statistic, Dyson and Mehta also attempted to evaluate spectra with thermodynamic variables obtained from the circular orthogonal ensemble. We consider the thermodynamic 'internal energy' and evaluate its sensitivity to experimental limitations such as missing and spurious levels. Monte Carlo simulations suggest that the internal energy is less sensitive to mistakes than is {delta}{sub 3}, and thus the internal energy can serve as a addition to the tool kit for evaluating experimental spectra.

  2. Dynamically tunable transformation thermodynamics

    NASA Astrophysics Data System (ADS)

    García-Meca, Carlos; Barceló, Carlos

    2016-04-01

    Recently, the introduction of transformation thermodynamics has provided a way to design thermal media that alter the flow of heat according to any spatial deformation, enabling the construction of novel devices such as thermal cloaks or concentrators. However, in its current version, this technique only allows static deformations of space. Here, we develop a space–time theory of transformation thermodynamics that incorporates the possibility of performing time-varying deformations. This extra freedom greatly widens the range of achievable effects, providing an additional degree of control for heat management applications. As an example, we design a reconfigurable thermal cloak that can be opened and closed dynamically, therefore being able to gradually adjust the temperature distribution of a given region.

  3. Thermodynamics of nuclear transport

    NASA Astrophysics Data System (ADS)

    Wang, Ching-Hao; Mehta, Pankaj; Elbaum, Michael

    Molecular transport across the nuclear envelope is important for eukaryotes for gene expression and signaling. Experimental studies have revealed that nuclear transport is inherently a nonequilibrium process and actively consumes energy. In this work we present a thermodynamics theory of nuclear transport for a major class of nuclear transporters that are mediated by the small GTPase Ran. We identify the molecular elements responsible for powering nuclear transport, which we term the ``Ran battery'' and find that the efficiency of transport, measured by the cargo nuclear localization ratio, is limited by competition between cargo molecules and RanGTP to bind transport receptors, as well as the amount of NTF2 (i.e. RanGDP carrier) available to circulate the energy flow. This picture complements our current understanding of nuclear transport by providing a comprehensive thermodynamics framework to decipher the underlying biochemical machinery. Pm and CHW were supported by a Simons Investigator in the Mathematical Modeling in Living Systems grant (to PM).

  4. Statistical Thermodynamics of Biomembranes

    PubMed Central

    Devireddy, Ram V.

    2010-01-01

    An overview of the major issues involved in the statistical thermodynamic treatment of phospholipid membranes at the atomistic level is summarized: thermodynamic ensembles, initial configuration (or the physical system being modeled), force field representation as well as the representation of long-range interactions. This is followed by a description of the various ways that the simulated ensembles can be analyzed: area of the lipid, mass density profiles, radial distribution functions (RDFs), water orientation profile, Deuteurium order parameter, free energy profiles and void (pore) formation; with particular focus on the results obtained from our recent molecular dynamic (MD) simulations of phospholipids interacting with dimethylsulfoxide (Me2SO), a commonly used cryoprotective agent (CPA). PMID:19460363

  5. Canonical fluid thermodynamics

    NASA Technical Reports Server (NTRS)

    Schmid, L. A.

    1972-01-01

    The space-time integral of the thermodynamic pressure plays the role of the thermodynamic potential for compressible, adiabatic flow in the sense that the pressure integral for stable flow is less than for all slightly different flows. This stability criterion can be converted into a variational minimum principle by requiring the molar free-enthalpy and the temperature, which are the arguments of the pressure function, to be generalized velocities, that is, the proper-time derivatives of scalar spare-time functions which are generalized coordinates in the canonical formalism. In a fluid context, proper-time differentiation must be expressed in terms of three independent quantities that specify the fluid velocity. This can be done in several ways, all of which lead to different variants (canonical transformations) of the same constraint-free action integral whose Euler-Lagrange equations are just the well-known equations of motion for adiabatic compressible flow.

  6. THERMODYNAMICS AND SOLUBILITY OF (UxNp1-x)O2(am) SOLID SOLUTION IN THE CARBONATE SYSTEM

    SciTech Connect

    Rai, Dhanpat; Hess, Nancy J.; Yui, Mikazu; Felmy, Andrew R.; Moore, Dean A.

    2004-03-15

    ABSTRACT -The formation of a solid solution can significantly affect the solubility of a minor component. The objectives of this study were to determine the nature of U(IV) and Np(IV) solid solutions and their thermodynamic properties. For this purpose, co-precipitates of U(IV) and Np(IV) [(UxNp1-x )O2(am), with values for x of 0.95, 0.85, 0.50, 0.15, and 0.05] were prepared, characterized, and used to determine their solubility as a function of K2CO3 concentrations ranging from 1.0 m to 5.0 m in the presence of 0.01 m Na2S2O4 and 0.01 m KOH, and as a function of KHCO3 concentrations ranging from 0.1 m to 0.8 m in the presence of 0.01 m Na2S2O4. The solubility data show that the equilibrium in these systems is reached in <7 days, the solubility-controlling solids are amorphous, and that we were successful in maintaining U and Np in the tetravalent state. A scanning electron microscope equipped with energy dispersive spectrometry and x-ray absorption spectroscopic analyses of the solids indicated the equilibrated co-precipitates to be solid solutions. A close agreement between the thermodynamic predictions, assuming an ideal solid solution, and the experimental solubilities shows that U(IV) and Np(IV) form an ideal solid solution and that non-ideal solid solution behavior for this system can be ruled out.

  7. Contact symmetries and Hamiltonian thermodynamics

    SciTech Connect

    Bravetti, A.; Lopez-Monsalvo, C.S.; Nettel, F.

    2015-10-15

    It has been shown that contact geometry is the proper framework underlying classical thermodynamics and that thermodynamic fluctuations are captured by an additional metric structure related to Fisher’s Information Matrix. In this work we analyse several unaddressed aspects about the application of contact and metric geometry to thermodynamics. We consider here the Thermodynamic Phase Space and start by investigating the role of gauge transformations and Legendre symmetries for metric contact manifolds and their significance in thermodynamics. Then we present a novel mathematical characterization of first order phase transitions as equilibrium processes on the Thermodynamic Phase Space for which the Legendre symmetry is broken. Moreover, we use contact Hamiltonian dynamics to represent thermodynamic processes in a way that resembles the classical Hamiltonian formulation of conservative mechanics and we show that the relevant Hamiltonian coincides with the irreversible entropy production along thermodynamic processes. Therefore, we use such property to give a geometric definition of thermodynamically admissible fluctuations according to the Second Law of thermodynamics. Finally, we show that the length of a curve describing a thermodynamic process measures its entropy production.

  8. Spectroscopic survey of LAMOST

    NASA Astrophysics Data System (ADS)

    Zhao, Yongheng

    2014-07-01

    LAMOST is a special reflecting Schmidt telescope. LAMOST breaks through the bottleneck of the large scale spectroscopic survey observation with both large aperture (effective aperture of 3.6 - 4.9m) and wide field of view (5 degrees). It is an innovative active reflecting Schmidt configuration achieved by changing mirror surface continuously to achieve a series different reflecting Schmidt system in different moments. By using the parallel controllable fiber positioning technique, the focal surface of 1.75 meters in diameter accommodates 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST is the telescope of the highest spectrum acquiring rate. As a national large scientific project, LAMOST project was proposed formally in 1996. The construction was started in 2001 and completed in 2008. After commission period, LAMOST pilot survey was started in October 2011 and spectroscopic survey began in September 2012. From October 2011 to June 2013, LAMOST has obtained more than 2 million spectra of celestial objects. There are 1.7 million spectra of stars, in which the stellar parameters (effective temperature, surface gravity, metalicitiy and radial velocity) of more than 1 million stars was obtained. In the first period of spectroscopic survey of LAMOST, 5 million of stellar spectra will be obtained and will make substantial contribution to the study of the stellar astrophysics and the structure of the Galaxy, such as the spheroid substructure of the Galaxy, the galactic gravitational potential and the distribution of the dark matter in the Galaxy, the extremely metal poor stars and hypervelocity stars, the 3D extinction in the Galaxy, the structure of thin and thick disks of the Galaxy, and so on.

  9. The discovery of thermodynamics

    NASA Astrophysics Data System (ADS)

    Weinberger, Peter

    2013-07-01

    Based on the idea that a scientific journal is also an "agora" (Greek: market place) for the exchange of ideas and scientific concepts, the history of thermodynamics between 1800 and 1910 as documented in the Philosophical Magazine Archives is uncovered. Famous scientists such as Joule, Thomson (Lord Kelvin), Clausius, Maxwell or Boltzmann shared this forum. Not always in the most friendly manner. It is interesting to find out, how difficult it was to describe in a scientific (mathematical) language a phenomenon like "heat", to see, how long it took to arrive at one of the fundamental principles in physics: entropy. Scientific progress started from the simple rule of Boyle and Mariotte dating from the late eighteenth century and arrived in the twentieth century with the concept of probabilities. Thermodynamics was the driving intellectual force behind the industrial revolution, behind the enormous social changes caused by this revolution. The history of thermodynamics is a fascinating story, which also gives insights into the mechanism that seem to govern science.

  10. Enzyme-Inhibitor Association Thermodynamics

    PubMed Central

    Resat, Haluk; Marrone, Tami J.; McCammon, J. Andrew

    1997-01-01

    Studying the thermodynamics of biochemical association reactions at the microscopic level requires efficient sampling of the configurations of the reactants and solvent as a function of the reaction pathways. In most cases, the associating ligand and receptor have complementary interlocking shapes. Upon association, loosely connected or disconnected solvent cavities at and around the binding site are formed. Disconnected solvent regions lead to severe statistical sampling problems when simulations are performed with explicit solvent. It was recently proposed that, when such limitations are encountered, they might be overcome by the use of the grand canonical ensemble. Here we investigate one such case and report the association free energy profile (potential of mean force) between trypsin and benzamidine along a chosen reaction coordinate as calculated using the grand canonical Monte Carlo method. The free energy profile is also calculated for a continuum solvent model using the Poisson equation, and the results are compared to the explicit water simulations. The comparison shows that the continuum solvent approach is surprisingly successful in reproducing the explicit solvent simulation results. The Monte Carlo results are analyzed in detail with respect to solvation structure. In the binding site channel there are waters bridging the carbonyl oxygen groups of Asp189 with the NH2 groups of benzamidine, which are displaced upon inhibitor binding. A similar solvent-bridging configuration has been seen in the crystal structure of trypsin complexed with bovine pancreatic trypsin inhibitor. The predicted locations of other internal waters are in very good agreement with the positions found in the crystal structures, which supports the accuracy of the simulations. ImagesFIGURE 5 PMID:9017183

  11. Evaporation and instabilities of microscopic capillary bridges

    PubMed Central

    Maeda, Nobuo; Israelachvili, Jacob N.; Kohonen, Mika M.

    2003-01-01

    The formation and disappearance of liquid bridges between two surfaces can occur either through equilibrium or nonequilibrium processes. In the first instance, the bridge molecules are in thermodynamic equilibrium with the surrounding vapor medium. In the second, chemical potential gradients result in material transfer; mechanical instabilities, because of van der Waals force jumps on approach or a Rayleigh instability on rapid separation, may trigger irreversible film coalescence or bridge snapping. We have studied the growth and disappearance mechanisms of laterally microscopic liquid bridges of three hydrocarbon liquids in slit-like pores. At rapid slit-opening rates, the bridges rupture by means of a mechanical instability described by the Young–Laplace equation. Noncontinuum but apparently reversible behavior is observed when a bridge is held at nanoscopic surface separations H close to the thermodynamic equilibrium Kelvin length, 2rKcosθ, where rK is the Kelvin radius and θ is the contact angle. During the course of slow evaporation (at H > 2rKcosθ) and subsequent regrowth by capillary condensation (at H < 2rKcosθ), the refractive index of the bridge may vary continuously and reversibly between that of the bulk liquid and vapor. The evaporation process becomes irreversible only at the very final stage of evaporation, when the refractive index of the fluid attains virtually that of the vapor. Measured refractive index profiles and the time-dependence of evaporating neck diameters also seem to differ from predictions based on a continuum picture of bridge evaporation far from the critical point. We discuss these findings in terms of the probable density profiles in evolving liquid bridges. PMID:12538868

  12. Spectroscopic studies of protein folding: Linear and nonlinear methods

    PubMed Central

    Serrano, Arnaldo L; Waegele, Matthias M; Gai, Feng

    2012-01-01

    Although protein folding is a simple outcome of the underlying thermodynamics, arriving at a quantitative and predictive understanding of how proteins fold nevertheless poses huge challenges. Therefore, both advanced experimental and computational methods are continuously being developed and refined to probe and reveal the atomistic details of protein folding dynamics and mechanisms. Herein, we provide a concise review of recent developments in spectroscopic studies of protein folding, with a focus on new triggering and probing methods. In particular, we describe several laser-based techniques for triggering protein folding/unfolding on the picosecond and/or nanosecond timescales and various linear and nonlinear spectroscopic techniques for interrogating protein conformations, conformational transitions, and dynamics. PMID:22109973

  13. Spectroscopic Studies of the Several Isomers of UO3

    SciTech Connect

    Sweet, Lucas E.; Reilly, Dallas D.; Abrecht, David G.; Buck, Edgar C.; Meier, David E.; Su, Yin-Fong; Brauer, Carolyn S.; Schwantes, Jon M.; Tonkyn, Russell G.; Szecsody, James E.; Blake, Thomas A.; Johnson, Timothy J.

    2013-09-26

    Uranium trioxide is known to adopt seven different structural forms. While these structural forms have been well characterized using x-ray or neutron diffraction techniques, little work has been done to characterize their spectroscopic properties, particularly of the pure phases. Since the structural isomers of UO3 all have similar thermodynamic stabilities and most tend to hydrolyze under open atmospheric conditions, mixtures of UO3 phases and the hydrolysis products are common. Much effort went into isolating pure phases of UO3. Utilizing x-ray diffraction as a sample identification check, UV/Vis/NIR spectroscopic signatures of α-UO3, β-UO3, γ-UO3 and UO2(OH)2 products were obtained. The spectra of the pure phases can now be used to characterize typical samples of UO3, which are often mixtures of isomers.

  14. Spectroscopic survey of LAMOST

    NASA Astrophysics Data System (ADS)

    Zhao, Yongheng

    2015-08-01

    LAMOST is a special reflecting Schmidt telescope. LAMOST breaks through the bottleneck of the large scale spectroscopic survey observation with both large aperture (effective aperture of 3.6 - 4.9m) and wide field of view (5 degrees). It is an innovative active reflecting Schmidt configuration achieved by changing mirror surface continuously to achieve a series different reflecting Schmidt system in different moments. By using the parallel controllable fiber positioning technique, the focal surface of 1.75 meters in diameter accommodates 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST is the telescope of the highest spectrum acquiring rate.In the spectroscopic survey of LAMOST from October 2011 to June 2014, LAMOST has obtained more than 4.13 million spectra of celestial objects. There are 3.27 million spectra of stars, in which the stellar parameters of 2.16 million stars were obtained.In the five-year regular survey upto 2017, LAMOST will obtaine 5 million stellar spectra, which would make substantial contribution to the study of the stellar astrophysics and the structure of the Galaxy, such as the spheroid substructure of the Galaxy, the galactic gravitational potential and the distribution of the dark matter in the Galaxy, the extremely metal poor stars and hypervelocity stars, the 3D extinction in the Galaxy, the structure of thin and thick disks of the Galaxy, and so on.

  15. Low-energy nuclear spectroscopy in a microscopic multiphonon approach

    NASA Astrophysics Data System (ADS)

    Lo Iudice, N.; Ponomarev, V. Yu; Stoyanov, Ch; Sushkov, A. V.; Voronov, V. V.

    2012-04-01

    The low-lying spectra of heavy nuclei are investigated within the quasiparticle-phonon model. This microscopic approach goes beyond the quasiparticle random-phase approximation by treating a Hamiltonian of separable form in a microscopic multiphonon basis. It is therefore able to describe the anharmonic features of collective modes as well as the multiphonon states, whose experimental evidence is continuously growing. The method can be put in close correspondence with the proton-neutron interacting boson model. By associating the microscopic isoscalar and isovector quadrupole phonons with proton-neutron symmetric and mixed-symmetry quadrupole bosons, respectively, the microscopic states can be classified, just as in the algebraic model, according to their phonon content and their symmetry. In addition, these states disclose the nuclear properties which are to be ascribed to genuine shell effects, not included in the algebraic approach. Due to its flexibility, the method can be implemented numerically for systematic studies of spectroscopic properties throughout entire regions of vibrational nuclei. The spectra and multipole transition strengths so computed are in overall good agreement with the experimental data. By exploiting the correspondence of the method with the interacting boson model, it is possible to embed the microscopic states into this algebraic frame and, therefore, face the study of nuclei far from shell closures, not directly accessible to merely microscopic approaches. Here, it is shown how this task is accomplished through systematic investigations of magnetic dipole and, especially, electric dipole modes along paths moving from the vibrational to the transitional regions. The method is very well suited to the study of well-deformed nuclei. It provides reliable descriptions of low-lying magnetic as well as electric multipole modes of nuclei throughout the rare-earth and actinide regions. Attention is focused here on the low-lying 0+ states

  16. Microscopic expression for heat in the adiabatic basis.

    PubMed

    Polkovnikov, Anatoli

    2008-11-28

    We derive a microscopic expression for the instantaneous diagonal elements of the density matrix rho(nn)(t) in the adiabatic basis for an arbitrary time-dependent process in a closed Hamiltonian system. If the initial density matrix is stationary (diagonal) then this expression contains only squares of absolute values of matrix elements of the evolution operator, which can be interpreted as transition probabilities. We then derive the microscopic expression for the heat defined as the energy generated due to transitions between instantaneous energy levels. If the initial density matrix is passive [diagonal with rho(nn)(0) monotonically decreasing with energy] then the heat is non-negative in agreement with basic expectations of thermodynamics. Our findings also can be used for systematic expansion of various observables around the adiabatic limit. PMID:19113464

  17. (Center of excellence: Microlaser microscope)

    SciTech Connect

    Webb, R.H.

    1992-01-01

    This Center-of-Excellence grant has two components: development of an imaging system based on microlaser arrays forms a central project among a group of laser diagnostic and therapeutic efforts primarily funded outside the grant. In these first 8 months we have set up the Microlaser Microscope using small microlaser arrays. We have emphasized the basics of microlaser handling and electronic addressing and the optics of the microscope. Details of electronics and optics given here will be used in the larger arrays which should be available soon. After a description of the central Microlaser Microscope project, we touch briefly on the other projects of the Center, which have been outstandingly fruitful this year. Publications are necessarily concerned with the smaller projects, since the Microlaser Microscope is in its early stages.

  18. Center of excellence: Microlaser microscope

    NASA Astrophysics Data System (ADS)

    Webb, R. H.

    This Center-of-Excellence grant has two components: development of an imaging system based on microlaser arrays forms a central project among a group of laser diagnostic and therapeutic efforts primarily funded outside the grant. In these first 8 months we have set up the Microlaser Microscope using small microlaser arrays. We have emphasized the basics of microlaser handling and electronic addressing and the optics of the microscope. Details of electronics and optics given here will be used in the larger arrays which should be available soon. After a description of the central Microlaser Microscope project, we touch briefly on the other projects of the Center, which have been outstandingly fruitful this year. Publications are necessarily concerned with the smaller projects, since the Microlaser Microscope is in its early stages.

  19. Mars Life? - Microscopic Tubular Structures

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This electron microscope image shows extremely tiny tubular structures that are possible microscopic fossils of bacteria-like organisms that may have lived on Mars more than 3.6 billion years ago. A two-year investigation by a NASA research team found organic molecules, mineral features characteristic of biological activity and possible microscopic fossils such as these inside of an ancient Martian rock that fell to Earth as a meteorite. The largest possible fossils are less than 1/100th the diameter of a human hair in size while most are ten times smaller. The fossil-like structures were found in carbonate minerals formed along pre-existing fractures in the meteorite in a fashion similar to the way fossils occur in limestone on Earth, although on a microscopic scale.

  20. Microscopic Procedures for Plant Meiosis.

    ERIC Educational Resources Information Center

    Braselton, James P.

    1997-01-01

    Describes laboratory techniques designed to familiarize students with meiosis and how microscopic preparations of meiosis are made. These techniques require the use of fresh or fixed flowers. Contains 18 references. (DDR)

  1. Adirondack Under the Microscope-2

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This overhead look at the martian rock dubbed Adirondack was captured by the Mars Exploration Rover Spirit's panoramic camera. It shows the approximate region where the rover's microscopic imager began its first close-up inspection.

  2. Microscopic derivation of discrete hydrodynamics.

    PubMed

    Español, Pep; Anero, Jesús G; Zúñiga, Ignacio

    2009-12-28

    By using the standard theory of coarse graining based on Zwanzig's projection operator, we derive the dynamic equations for discrete hydrodynamic variables. These hydrodynamic variables are defined in terms of the Delaunay triangulation. The resulting microscopically derived equations can be understood, a posteriori, as a discretization on an arbitrary irregular grid of the Navier-Stokes equations. The microscopic derivation provides a set of discrete equations that exactly conserves mass, momentum, and energy and the dissipative part of the dynamics produces strict entropy increase. In addition, the microscopic derivation provides a practical implementation of thermal fluctuations in a way that the fluctuation-dissipation theorem is satisfied exactly. This paper points toward a close connection between coarse-graining procedures from microscopic dynamics and discretization schemes for partial differential equations. PMID:20059064

  3. The second law of thermodynamics under unitary evolution and external operations

    SciTech Connect

    Ikeda, Tatsuhiko N.; Sakumichi, Naoyuki; Polkovnikov, Anatoli; Ueda, Masahito

    2015-03-15

    The von Neumann entropy cannot represent the thermodynamic entropy of equilibrium pure states in isolated quantum systems. The diagonal entropy, which is the Shannon entropy in the energy eigenbasis at each instant of time, is a natural generalization of the von Neumann entropy and applicable to equilibrium pure states. We show that the diagonal entropy is consistent with the second law of thermodynamics upon arbitrary external unitary operations. In terms of the diagonal entropy, thermodynamic irreversibility follows from the facts that quantum trajectories under unitary evolution are restricted by the Hamiltonian dynamics and that the external operation is performed without reference to the microscopic state of the system.

  4. Spectroscopic and quantum chemical studies on 4-acryloyl morpholine

    NASA Astrophysics Data System (ADS)

    Arjunan, V.; Rani, T.; Santhanalakshmi, K.; Mohan, S.

    2011-09-01

    Fourier transform infrared (FTIR) and FT-Raman spectra have been recorded and an extensive spectroscopic investigations have been carried out on 4-acryloyl morpholine (4AM). Theoretical quantum chemical studies have also been performed. From the ab initio and DFT analysis using HF, B3LYP and B3PW91 methods with 6-31G(d,p) and 6-311G++(d,p) basis sets the energies, structural, thermodynamical and vibrational characteristics of the compound were determined. The energy difference between the chair equatorial and chair axial conformers of 4AM have been calculated by density functional theory (DFT) method. The optimized geometrical parameters, theoretical wavenumbers and thermodynamic properties of the molecule are compared with the experimental values. The effect of acryloyl group on the characteristic frequencies of the morpholine ring has been analysed. The mixing of the fundamental modes with the help of potential energy distribution (PED) through normal co-ordinate analysis has been discussed.

  5. HIGH TEMPERATURE MICROSCOPE AND FURNACE

    DOEpatents

    Olson, D.M.

    1961-01-31

    A high-temperature microscope is offered. It has a reflecting optic situated above a molten specimen in a furnace and reflecting the image of the same downward through an inert optic member in the floor of the furnace, a plurality of spaced reflecting plane mirrors defining a reflecting path around the furnace, a standard microscope supported in the path of and forming the end terminus of the light path.

  6. Shock compression dynamics under a microscope.

    NASA Astrophysics Data System (ADS)

    Dlott, Dana

    2015-06-01

    We have developed a tabletop laser flyer launch system1 that solves many of the problems that plagued previous efforts. Using a novel mechanism where a spatially-uniform laser pulse creates a shock in a glass substrate just underneath a metal foil, we can launch tiny (0.7 mm diameter x 100 μm thick) flyers at speeds ranging from 0-5 km/s and the foils are flat, cold and intact. This tabletop launch system, where we often launch 100 flyers per day, provides a platform for a wide variety of time-resolved spectroscopies. The shocked material is viewed by a microscope objective that transmits near-infrared light from a photon Doppler velocimeter to monitor the flyer, and collects the light for spectroscopic and video images. Fluorescent probes, which have been highly developed for the biomedical sciences, have proven especially useful for these experiments. Using emission measurements, we have investigated the fundamental mechanisms of many shock wave effects including: viscoelastic compression of high molecular weight polymers, visualization of shocks in porous media such as sand, where we can observe the behavior of individual grains of sand, shock attenuation by passing the shock through reactive materials that undergo endothermic chemical reactions, and shock initiation of nanoenergetic materials.

  7. Thermodynamics of Thermoelectric Materials

    NASA Astrophysics Data System (ADS)

    Doak, Jeff W.

    One challenge facing society is the responsible use of our energy resources. Increasing the efficiency of energy generation provides one path to solving this challenge. One commonality among most current energy generation methods is that waste heat is generated during the generation process. Thermoelectrics can provide a solution to increasing the efficiency of power generation and automotive systems by converting waste heat directly to electricity. The current barrier to implementation of thermoelectric systems is the low efficiencies of underlying thermoelectric materials. The efficiency of a thermoelectric material depends on the electronic and thermal transport properties of the material; a good thermoelectric material should be an electronic conductor and a thermal insulator, traits which generally oppose one another. The thermal properties of a thermoelectric material can be improved by forming nanoscale precipitates with the material which scatter phonons, reducing the thermal conductivity. The electronic properties of a thermoelectric material can be improved by doping the material to increase the electronic conductivity or by alloying the material to favorably alter its band structure. The ability of these chemical modifications to affect the thermoelectric efficiency of material are ultimately governed by the chemical thermodynamics of the system. PbTe is a prototypical thermoelectric material: Alloying PbTe with PbS (or other materials) creates nanostructures which scatter phonons and reduce the lattice thermal conductivity. Doping PbTe with Na increases the hole concentration, increasing the electronic conductivity. In this work, we investigate the thermodynamics of PbTe and similar systems using first principles to understand the underlying mechanisms controlling the formation of nanostructures and the amount of doping allowed in these systems. In this work we: 1) investigate the thermodynamics of pseudo-binary alloys of IV--VI systems to identify the

  8. RNA Thermodynamic Structural Entropy

    PubMed Central

    Garcia-Martin, Juan Antonio; Clote, Peter

    2015-01-01

    Conformational entropy for atomic-level, three dimensional biomolecules is known experimentally to play an important role in protein-ligand discrimination, yet reliable computation of entropy remains a difficult problem. Here we describe the first two accurate and efficient algorithms to compute the conformational entropy for RNA secondary structures, with respect to the Turner energy model, where free energy parameters are determined from UV absorption experiments. An algorithm to compute the derivational entropy for RNA secondary structures had previously been introduced, using stochastic context free grammars (SCFGs). However, the numerical value of derivational entropy depends heavily on the chosen context free grammar and on the training set used to estimate rule probabilities. Using data from the Rfam database, we determine that both of our thermodynamic methods, which agree in numerical value, are substantially faster than the SCFG method. Thermodynamic structural entropy is much smaller than derivational entropy, and the correlation between length-normalized thermodynamic entropy and derivational entropy is moderately weak to poor. In applications, we plot the structural entropy as a function of temperature for known thermoswitches, such as the repression of heat shock gene expression (ROSE) element, we determine that the correlation between hammerhead ribozyme cleavage activity and total free energy is improved by including an additional free energy term arising from conformational entropy, and we plot the structural entropy of windows of the HIV-1 genome. Our software RNAentropy can compute structural entropy for any user-specified temperature, and supports both the Turner’99 and Turner’04 energy parameters. It follows that RNAentropy is state-of-the-art software to compute RNA secondary structure conformational entropy. Source code is available at https://github.com/clotelab/RNAentropy/; a full web server is available at http

  9. Dynamics versus thermodynamics

    NASA Astrophysics Data System (ADS)

    Berdichevsky, V. L.

    1991-05-01

    An effort is made to characterize the ways in which the approaches of statistical mechanics and thermodynamics can be useful in the study of the dynamic behavior of structures. This meditation proceeds through consideration of such wide-ranging and deliberately provocative questions as: 'What are to be considered values in a stress-distribution function?' and 'How many degrees-of-freedom has a beam?'; it then gives attention to the hierarchy of vibrations, the interaction of the mechanism of dissipation with invisible degrees of freedom, and a plausible view of vibrations for the case of small dissipation.

  10. Stochastic thermodynamics of resetting

    NASA Astrophysics Data System (ADS)

    Fuchs, Jaco; Goldt, Sebastian; Seifert, Udo

    2016-03-01

    Stochastic dynamics with random resetting leads to a non-equilibrium steady state. Here, we consider the thermodynamics of resetting by deriving the first and second law for resetting processes far from equilibrium. We identify the contributions to the entropy production of the system which arise due to resetting and show that they correspond to the rate with which information is either erased or created. Using Landauer's principle, we derive a bound on the amount of work that is required to maintain a resetting process. We discuss different regimes of resetting, including a Maxwell demon scenario where heat is extracted from a bath at constant temperature.

  11. Interfacial solvation thermodynamics.

    PubMed

    Ben-Amotz, Dor

    2016-10-19

    Previous studies have reached conflicting conclusions regarding the interplay of cavity formation, polarizability, desolvation, and surface capillary waves in driving the interfacial adsorptions of ions and molecules at air-water interfaces. Here we revisit these questions by combining exact potential distribution results with linear response theory and other physically motivated approximations. The results highlight both exact and approximate compensation relations pertaining to direct (solute-solvent) and indirect (solvent-solvent) contributions to adsorption thermodynamics, of relevance to solvation at air-water interfaces, as well as a broader class of processes linked to the mean force potential between ions, molecules, nanoparticles, proteins, and biological assemblies. PMID:27545849

  12. Automated markerless full field hard x-ray microscopic tomography at sub-50 nm 3-dimension spatial resolution

    SciTech Connect

    Wang Jun; Karen Chen Yuchen; Yuan Qingxi; Tkachuk, Andrei; Hornberger, Benjamin; Feser, Michael; Erdonmez, Can

    2012-04-02

    A full field transmission x-ray microscope (TXM) has been developed and commissioned at the National Synchrotron Light Source at Brookhaven National Laboratory. The capabilities we developed in auto-tomography, local tomography, and spectroscopic imaging that overcome many of the limitations and difficulties in existing transmission x-ray microscopes are described and experimentally demonstrated. Sub-50 nm resolution in 3-dimension (3D) with markerless automated tomography has been achieved. These capabilities open up scientific opportunities in many research fields.

  13. Automated markerless full field hard x-ray microscopic tomography at sub-50nm 3-dimension spatial resolution

    SciTech Connect

    Wang J.; Yu-chen Chen, K.; Yuan, W.; Tkachuk, A.; Erdonmez, C.

    2012-04-04

    A full field transmission x-ray microscope (TXM) has been developed and commissioned at the National Synchrotron Light Source at Brookhaven National Laboratory. The capabilities we developed in auto-tomography, local tomography, and spectroscopic imaging that overcome many of the limitations and difficulties in existing transmission x-ray microscopes are described and experimentally demonstrated. Sub-50 nm resolution in 3-dimension (3D) with markerless automated tomography has been achieved. These capabilities open up scientific opportunities in many research fields.

  14. Automated markerless full field hard x-ray microscopic tomography at sub-50 nm 3-dimension spatial resolution

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Karen Chen, Yu-chen; Yuan, Qingxi; Tkachuk, Andrei; Erdonmez, Can; Hornberger, Benjamin; Feser, Michael

    2012-04-01

    A full field transmission x-ray microscope (TXM) has been developed and commissioned at the National Synchrotron Light Source at Brookhaven National Laboratory. The capabilities we developed in auto-tomography, local tomography, and spectroscopic imaging that overcome many of the limitations and difficulties in existing transmission x-ray microscopes are described and experimentally demonstrated. Sub-50 nm resolution in 3-dimension (3D) with markerless automated tomography has been achieved. These capabilities open up scientific opportunities in many research fields.

  15. Thermodynamics and Kinetics of RNA Unfolding and Refolding

    NASA Astrophysics Data System (ADS)

    Li, Pan T. X.; Tinoco, Ignacio

    Emergence of novel functions of non-coding RNAs imposes a new challenge for thermodynamics-based structural prediction of RNA. Here we review bulk and single-molecule techniques to measure the thermodynamics and kinetics of RNA folding and unfolding. RNA can be denatured by heat, chemicals, force, and by depletion of divalent cations. Various spectroscopic, calorimetric, chemical and biochemical methods have been used to study RNA structures. We emphasize single-molecule force unfolding as a new and powerful technique to study RNA structure and folding. Using optical tweezers, single RNA molecules can be stretched and relaxed; their changes in extension reflect structural rearrangements. We discuss determination of Gibb free energy of folding from mechanical work under both equilibrium and non-equilibrium conditions. Force can be applied to affect reaction rates as well as to manipulate molecular structure. Folding and unfolding kinetics can be monitored in real time.

  16. Thermodynamical interpretation of the geometrical variables associated with null surfaces

    NASA Astrophysics Data System (ADS)

    Chakraborty, Sumanta; Padmanabhan, T.

    2015-11-01

    The emergent gravity paradigm interprets gravitational field equations as describing the thermodynamic limit of the underlying statistical mechanics of microscopic degrees of freedom of the spacetime. The connection is established by attributing a heat density T s to the null surfaces where T is the appropriate Davies-Unruh temperature and s is the entropy density. The field equations can be obtained from a thermodynamic variational principle which extremizes the total heat density of all null surfaces. The explicit form of s determines the nature of the theory. We explore the consequences of this paradigm for an arbitrary null surface and highlight the thermodynamic significance of various geometrical quantities. In particular, we show that (a) a conserved current, associated with the time development vector in a natural fashion, has direct thermodynamic interpretation in all Lanczos-Lovelock models of gravity; (b) one can generalize the notion of gravitational momentum, introduced in T. Padmanabhan, [arXiv:1506.03814] to all Lanczos-Lovelock models of gravity such that the conservation of the total momentum leads to the relevant field equations; (c) the thermodynamic variational principle which leads to the field equations of gravity can also be expressed in terms of the gravitational momentum in all Lanczos-Lovelock models; and (d) three different projections of gravitational momentum related to an arbitrary null surface in the spacetime lead to three different equations, all of which have thermodynamic interpretation. The first one reduces to a Navier-Stokes equation for the transverse drift velocity. The second can be written as a thermodynamic identity T d S =d E +P d V . The third describes the time evolution of the null surface in terms of suitably defined surface and bulk degrees of freedom. The implications are discussed.

  17. Spectrophotometric, Fourier transform infrared spectroscopic and theoretical studies of the charge-transfer complexes between methyldopa [(S)-2 amino-3-(3,4-dihydroxyphenyl)-2-methyl propanoic acid] and the acceptors (chloranilic acid, o-chloranil and dichlorodicyanobenzoquinone) in acetonitrile and their thermodynamic properties

    NASA Astrophysics Data System (ADS)

    Sharma, K.; Sharma, S. P.; Lahiri, S. C.

    Methyldopa is a much used antihypertensive drug. It is the subject matter of study mostly for the determination and estimation of methyldopa in pharmaceutical properties. These considerations led us to study the charge-transfer interactions between methyldopa, a centrally acting antihypertensive agent of limited use with the known acceptors like o-chloranil (o-ClN), chloranilic acid (ClA) and dichlorodicyanobenzoquinone (DDQ). Methyldopa (MDP) formed beautifully colored complexes (having absorption maxima at 581 nm and 368 nm; 519 nm; 583.5 nm, 547 nm and 346 nm, respectively) with the acceptors mentioned before. The physico-chemical properties of the complexes were studied using UV-visible spectrophotometry and FTIR measurements. The composition, the accurate association constants and thermodynamics of the complexes were determined spectrophotometrically. Attempts were made to interpret the thermodynamics of complexes in terms of IDV, EAV and hνCT. Solid CT complexes between MDP + o-ClN, MDP + ClA and MDP + DDQ were prepared and FTIR spectra of the complexes were studied. The energies hνCT of the charge-transfer complexes and vertical ionization potential IDV of methyldopa were compared with the theoretical values of hνCT obtained from HOMO and LUMO of the donors and acceptors calculated using Density Function Theory utilizing different basis sets. The agreement between the results can be regarded to be reasonable. Oscillator strengths and dipole strengths of the complexes were determined theoretically and experimentally and the limitations of the calculations were outlined.

  18. Scanning Miniature Microscopes without Lenses

    NASA Technical Reports Server (NTRS)

    Wang, Yu

    2009-01-01

    The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the

  19. The α decay spectroscopic factor of heavy and superheavy nuclei

    NASA Astrophysics Data System (ADS)

    Seif, W. M.

    2013-10-01

    The spectroscopic factor which refers to the preformation probability of an α cluster inside parent radioactive nuclei is investigated. The study is based on the cluster model of α decay that is extended to account for the deformation degrees of freedom. The calculations are carried out for 179 even(Z)-even(N) parent nuclei in the mass region of A = 144-294. Taking into account the deformations of daughter nuclei, the semi-microscopic calculations of the α-daughter interaction potential are performed using the Hamiltonian energy density approach in terms of the SLy4 Skyrme-like effective interaction. The calculated potential is then implemented to find both the assault frequency and the penetration probability of the α particle by means of the Wentzel-Kramers-Brillouin approximation at different orientations of the deformed daughter. By averaging the obtained decay widths over different orientations, the half-lives of the mentioned α decays are then estimated. Taking into account the errors on both the released energy and the experimental half-life times, the extracted half-lives are employed in turn to deduce the α spectroscopic factor. The results show a periodic behaviour of the spectroscopic factor as a function of the charge and neutron numbers characterized by several local maxima and minima. The predicted minima are mainly related to the proton and neutron shell and subshell closures. In addition to the well-known closed shells of the nucleonic numbers 50, 82, and 126, the obtained values of the spectroscopic factor give some evidence for the presence of closed subshells of nucleonic numbers 70, 102 (104) and 152 (150). A simple formula is suggested to roughly estimate the spectroscopic factor in terms of the numbers of protons and neutrons of the parent nucleus outside its closed shells. The parameters of this formula are fitted to the deduced values of the spectroscopic factor.

  20. Useful microscopic concepts for high pressure phenomena

    NASA Astrophysics Data System (ADS)

    Recio, J.; Menéndez, J.; Álvarez-Uría, Ruth; Marqués, Miriam; Ouahrani, Tarik; Baonza, Valentín

    2013-06-01

    A better understanding of the macroscopic behavior of crystalline solids under pressure can be achieved introducing microscopic concepts as the local compressibility (κi = -1/V∂V/∂p ) and the local pressure (pi = -∂E/∂Vi ). Both are derived from topological analysis of crystalline electron densities. This formalism allows for a partition of the unit cell volume (V) into disjoint atomic-like regions such that V = ∑iVi , i runs over all different atomic constituents. Using this topological partition, the compressibility of the crystal is recovered: κ = ∑iVi/Vκi . Although local pressures are not additive, their reciprocals are: 1/p = ∑i1/pi , where p is the thermodynamic pressure. This fact leads to the interpretation of the atomic constituents of crystals as parallel mechanical resistors when pressure is applied. Consequently, atomic-like mechanical resistances and mechanical conductances can be defined. After extensive first principles calculations, computed results of these local properties reveal systematic trends for crystal families under pressure, as we illustrate for II-VI binary semiconductors and oxide spinels. Funded by Spanish MINECO and MICINN through CSD2007-00045 and CTQ2012-38599 projects.

  1. Thermodynamic properties of cerium mononitride

    NASA Astrophysics Data System (ADS)

    Aristova, N. M.; Belov, G. V.

    2014-09-01

    Data on the thermodynamic properties of cerium mononitride CeN in the solid state are analyzed. Relations approximating the temperature dependence of the thermodynamic functions of CeN(cr.) in the temperature range of 298.15-2900 K are obtained. Using the relations of thermodynamics known for this temperature range, the thermodynamic functions of cerium mononitride (entropy, Gibbs energy, and enthalpy variation) are calculated. The resulting data is entered into the database of the IVTANTHERMO software package and is used to analyze the thermal stability of CeN(cr.), and to estimate its boiling point at atmospheric pressure.

  2. Predictive thermodynamics for condensed phases.

    PubMed

    Glasser, Leslie; Jenkins, H Donald Brooke

    2005-10-01

    Thermodynamic information is central to assessment of the stability and reactivity of materials. However, because of both the demanding nature of experimental thermodynamics and the virtually unlimited number of conceivable compounds, experimental data is often unavailable or, for hypothetical materials, necessarily impossible to obtain. We describe simple procedures for thermodynamic prediction for condensed phases, both ionic and organic covalent, principally via formula unit volumes (or density); our volume-based approach (VBT) provides a new thermodynamic tool for such assessment. These methods, being independent of detailed knowledge of crystal structures, are applicable to liquids and amorphous materials as well as to crystalline solids. Examples of their use are provided. PMID:16172676

  3. Thermodynamics of geothermal fluids

    SciTech Connect

    Rogers, P.S.Z.

    1981-03-01

    A model to predict the thermodynamic properties of geothermal brines, based on a minimum amount of experimental data on a few key systems, is tested. Volumetric properties of aqueous sodium chloride, taken from the literature, are represented by a parametric equation over the range 0 to 300{sup 0}C and 1 bar to 1 kbar. Density measurements at 20 bar needed to complete the volumetric description also are presented. The pressure dependence of activity and thermal properties, derived from the volumetric equation, can be used to complete an equation of state for sodium chloride solutions. A flow calorimeter, used to obtain heat capacity data at high temperatures and pressures, is described. Heat capacity measurements, from 30 to 200{sup 0}C and 1 bar to 200 bar, are used to derive values for the activity coefficient and other thermodynamic properties of sodium sulfate solutions as a function of temperature. Literature data on the solubility of gypsum in mixed electrolyte solutions have been used to evaluate model parameters for calculating gypsum solubility in seawater and natural brines. Predictions of strontium and barium sulfate solubility in seawater also are given.

  4. Dissipative work in thermodynamics

    NASA Astrophysics Data System (ADS)

    Anacleto, Joaquim; Pereira, Mário G.; Ferreira, J. M.

    2011-01-01

    This work explores the concept of dissipative work and shows that such a kind of work is an invariant non-negative quantity. This feature is then used to get a new insight into adiabatic irreversible processes; for instance, why the final temperature in any adiabatic irreversible process is always higher than that attained in a reversible process having the same initial state and equal final pressure or volume. Based on the concept of identical processes, numerical simulations of adiabatic irreversible compression and expansion were performed, enabling a better understanding of differences between configuration and dissipative work. The positive nature of the dissipative work was used to discuss the case where the dissipated energy ends up in the surroundings, while the invariance of such work under a system-surroundings interchange enabled the resulting modification in thermodynamical quantities to be determined. The ideas presented in this study are primarily intended for undergraduate students with a background in thermodynamics, but they may also be of interest to graduate students and teachers.

  5. Thermodynamics of Error Correction

    NASA Astrophysics Data System (ADS)

    Sartori, Pablo; Pigolotti, Simone

    2015-10-01

    Information processing at the molecular scale is limited by thermal fluctuations. This can cause undesired consequences in copying information since thermal noise can lead to errors that can compromise the functionality of the copy. For example, a high error rate during DNA duplication can lead to cell death. Given the importance of accurate copying at the molecular scale, it is fundamental to understand its thermodynamic features. In this paper, we derive a universal expression for the copy error as a function of entropy production and work dissipated by the system during wrong incorporations. Its derivation is based on the second law of thermodynamics; hence, its validity is independent of the details of the molecular machinery, be it any polymerase or artificial copying device. Using this expression, we find that information can be copied in three different regimes. In two of them, work is dissipated to either increase or decrease the error. In the third regime, the protocol extracts work while correcting errors, reminiscent of a Maxwell demon. As a case study, we apply our framework to study a copy protocol assisted by kinetic proofreading, and show that it can operate in any of these three regimes. We finally show that, for any effective proofreading scheme, error reduction is limited by the chemical driving of the proofreading reaction.

  6. Thermodynamics of diffusion

    NASA Astrophysics Data System (ADS)

    Matuszak, Daniel

    Diffusion is the migration of molecules in the reference frame of a system's center of mass and it is a physical process that occurs in all chemical and biological systems. Diffusion generally involves intermolecular interactions that lead to clustering, adsorption, and phase transitions; as such, it is difficult to describe theoretically on a molecular level in systems containing both intermolecular repulsions and attractions. This work describes a simple thermodynamic approach that accounts for intermolecular attractions and repulsions (much like how the van der Waals equation does) to model and help provide an understanding of diffusion. The approach is an extension of the equilibrium Lattice Density Functional Theory of Aranovich and Donohue; it was developed with Mason and Lonsdale's guidelines on how to construct and test a transport theory. In the framework of lattice fluids, this new approach gives (a) correct equilibrium limits, (b) Fickian behavior for non-interacting systems, (c) correct departures from Fickian behavior in non-ideal systems, (d) the correct Maxwell-Stefan formulation, (e) symmetry behavior upon re-labeling species, (f) reasonable non-equilibrium phase behavior, (g) agreement with Molecular Dynamics simulations, (h) agreement with the theory of non-equilibrium thermodynamics, (i) a vanishing diffusive flux at the critical point, and (j) other qualitatively-correct behaviors when applied to problems in porous membranes and in packed beds.

  7. Thermodynamics. [algebraic structure

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.

    1976-01-01

    The fundamental structure of thermodynamics is purely algebraic, in the sense of atopological, and it is also independent of partitions, composite systems, the zeroth law, and entropy. The algebraic structure requires the notion of heat, but not the first law. It contains a precise definition of entropy and identifies it as a purely mathematical concept. It also permits the construction of an entropy function from heat measurements alone when appropriate conditions are satisfied. Topology is required only for a discussion of the continuity of thermodynamic properties, and then the weak topology is the relevant topology. The integrability of the differential form of the first law can be examined independently of Caratheodory's theorem and his inaccessibility axiom. Criteria are established by which one can determine when an integrating factor can be made intensive and the pseudopotential extensive and also an entropy. Finally, a realization of the first law is constructed which is suitable for all systems whether they are solids or fluids, whether they do or do not exhibit chemical reactions, and whether electromagnetic fields are or are not present.

  8. Approximating the detection limit of an infrared spectroscopic imaging microscope operating in an attenuated total reflection (ATR) modality: theoretical and empirical results for an instrument using a linear array detector and a 1.5 millimeter germanium hemisphere internal reflection element.

    PubMed

    Lanzarotta, Adam

    2015-01-01

    Theoretical and empirical detection limits have been estimated for aripiprazole (analyte) in alpha lactose monohydrate (matrix model pharmaceutical formulation) using a micro-attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopic imaging instrument equipped with a linear array detector and a 1.5 mm germanium hemisphere internal reflection element (IRE). The instrument yielded a theoretical detection limit of 0.0035% (35 parts per million (ppm)) when operating under diffraction-limited conditions, which was 49 times lower than what was achieved with a traditional macro-ATR instrument operating under practical conditions (0.17%, 1700 ppm). However, these results may not be achievable for most analyses because the detection limits will be particle size limited, rather than diffraction limited, for mixtures with average particle diameters greater than 8.3 μm (most pharmaceutical samples). For example, a theoretical detection limit of 0.028% (280 ppm) was calculated for an experiment operating under particle size-limited conditions where the average particle size was 23.4 μm. These conditions yielded a detection limit of 0.022% (220 ppm) when measured empirically, which was close to the theoretical value and only eight times lower than that of a faster, more simplistic macro-ATR instrument. Considering the longer data acquisition and processing times characteristic of the micro-ATR imaging approach (minutes or even hours versus seconds), the cost-benefit ratio may not often be favorable for the analysis of analytes in matrices that exhibit only a few overlapping absorptions (low-interfering matrices such as alpha lactose monohydrate) using this technique compared to what can be achieved using macro-ATR. However, the advantage was significant for detecting analytes in more complex matrices (those that exhibited several overlapping absorptions with the analyte) because the detection limit of the macro-ATR approach was highly formulation

  9. Biochemical Thermodynamics under near Physiological Conditions

    ERIC Educational Resources Information Center

    Mendez, Eduardo

    2008-01-01

    The recommendations for nomenclature and tables in Biochemical Thermodynamics approved by IUBMB and IUPAC in 1994 can be easily introduced after the chemical thermodynamic formalism. Substitution of the usual standard thermodynamic properties by the transformed ones in the thermodynamic equations, and the use of appropriate thermodynamic tables…

  10. Raman spectroscopic investigations of hydrothermal solutions

    SciTech Connect

    Yang, M.M.

    1988-01-01

    There is still very little information about the stoichiometries, structures and stabilities of metal complexes at high temperatures and pressures. Raman spectroscopy is ideally suited to probe and study concentrated electrolyte solutions at the molecular level. This thesis includes the design and construction of a Raman cell operable up to 300C and 15MPa. In order to obtain quantitative thermodynamic information from Raman spectroscopic measurements, a chemically inert internal standard must be used. Perchlorate is commonly used for this purpose at low temperatures, but it may be unstable at high temperatures and its explosive properties make it undesirable. A new preferred internal standard; trifluoromethanesulfonic acid is introduced and its spectra p to 300C discussed. The use of this compound as a high temperature internal standard enabled stepwise stability constants of zinc-bromo complexes to be determined. Although bromide is not an important ligand in geologic systems, its chemical similarity to chloride can provide insights into the study of zinc-chloro species which do not have very informative Raman spectra. The importance of organic ligands in geologic settings such as the Mississippi-Valley Type Pb-Zn sulfide deposits is now being realized. Chapter four presents the first high temperature spectroscopic measurements of lead and zinc acetate aqueous solutions. Not only do these studies verify the stability of lead and zinc acetate complexes up to 250 C but they also show that the type of complex formed is a function of pH, metal-ligand ratio and temperature, thus having important implications for zoning of Pb-Zn sulfide deposits.

  11. Spectrophotometric, Fourier transform infrared spectroscopic and theoretical studies of the charge-transfer complexes between methyldopa [(S)-2 amino-3-(3,4-dihydroxyphenyl)-2-methyl propanoic acid] and the acceptors (chloranilic acid, o-chloranil and dichlorodicyanobenzoquinone) in acetonitrile and their thermodynamic properties.

    PubMed

    Sharma, K; Sharma, S P; Lahiri, S C

    2012-06-15

    Methyldopa is a much used antihypertensive drug. It is the subject matter of study mostly for the determination and estimation of methyldopa in pharmaceutical properties. These considerations led us to study the charge-transfer interactions between methyldopa, a centrally acting antihypertensive agent of limited use with the known acceptors like o-chloranil (o-ClN), chloranilic acid (ClA) and dichlorodicyanobenzoquinone (DDQ). Methyldopa (MDP) formed beautifully colored complexes (having absorption maxima at 581 nm and 368 nm; 519 nm; 583.5 nm, 547 nm and 346 nm, respectively) with the acceptors mentioned before. The physico-chemical properties of the complexes were studied using UV-visible spectrophotometry and FTIR measurements. The composition, the accurate association constants and thermodynamics of the complexes were determined spectrophotometrically. Attempts were made to interpret the thermodynamics of complexes in terms of I(D)(V), E(A)(V) and hν(CT). Solid CT complexes between MDP+o-ClN, MDP+ClA and MDP+DDQ were prepared and FTIR spectra of the complexes were studied. The energies hν(CT) of the charge-transfer complexes and vertical ionization potential I(D)(V) of methyldopa were compared with the theoretical values of hν(CT) obtained from HOMO and LUMO of the donors and acceptors calculated using Density Function Theory utilizing different basis sets. The agreement between the results can be regarded to be reasonable. Oscillator strengths and dipole strengths of the complexes were determined theoretically and experimentally and the limitations of the calculations were outlined. PMID:22446770

  12. Macroscopic-microscopic mass models

    SciTech Connect

    Nix, J.R.; Moller, P.

    1995-07-01

    We discuss recent developments in macroscopic-microscopic mass models, including the 1992 finite-range droplet model, the 1992 extended- Thomas-Fermi Strutinsky-integral model, and the 1994 Thomas-Fermi model, with particular emphasis on how well they extrapolate to new regions of nuclei. We also address what recent developments in macroscopic-microscopic mass models are teaching us about such physically relevant issues as the nuclear curvature energy, a new congruence energy arising from a greater-than-average overlap of neutron and proton wave functions, the nuclear incompressibility coefficient, and the coulomb redistribution energy arising from a central density depression. We conclude with a brief discussion of the recently discovered rock of metastable superheavy nuclei near {sup 272}110 that had been correctly predicted by macroscopic-microscopic models, along with a possible new tack for reaching an island near {sup 290}110 beyond our present horizon.

  13. Microscope and method of use

    DOEpatents

    Bongianni, Wayne L.

    1984-01-01

    A method and apparatus for electronically focusing and electronically scanning microscopic specimens are given. In the invention, visual images of even moving, living, opaque specimens can be acoustically obtained and viewed with virtually no time needed for processing (i.e., real time processing is used). And planar samples are not required. The specimens (if planar) need not be moved during scanning, although it will be desirable and possible to move or rotate nonplanar specimens (e.g., laser fusion targets) against the lens of the apparatus. No coupling fluid is needed, so specimens need not be wetted. A phase acoustic microscope is also made from the basic microscope components together with electronic mixers.

  14. High Resolution Neutral Atom Microscope

    NASA Astrophysics Data System (ADS)

    Bucay, Igal; Castillo-Garza, Rodrigo; Stratis, Georgios; Raizen, Mark

    2015-03-01

    We are developing a high resolution neutral atom microscope based on metastable atom electron spectroscopy (MAES). When a metastable atom of a noble gas is near a solid, a surface electron will tunnel to an empty energy level of the metastable atom, thereby ejecting the excited electron from the atom. The emitted electrons carry information regarding the local topography and electronic, magnetic, and chemical structures of most hard materials. Furthermore, using a chromatic aberration corrected magnetic hexapole lens we expect to attain a spatial resolution below 10 nm. We will use this microscope to investigate how local phenomena can give rise to macroscopic effects in materials that cannot be probed using a scanning tunneling microscope, namely insulating transition metal oxides.

  15. Mosaic of Commemorative Microscope Substrate

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Written by electron beam lithography in the Microdevices Laboratory of NASA's Jet Propulsion Laboratory, this Optical Microscope substrate helps the Phoenix Mars Mission science team learn how to assemble individual microscope images into a mosaic by aligning rows of text.

    Each line is about 0.1 millimeter tall, the average thickness of a human hair. Except for the Mogensen twins, the names are of babies born and team members lost during the original development of MECA (the Microscopy, Electrochemistry and Conductivity Analyzer) for the canceled 2001 Mars lander mission. The plaque also acknowledges the MECA 2001 principal investigator, now retired.

    This image was taken by the MECA Optical Microscope on Sol 111, or the 111th day of the Phoenix mission (Sept. 16, 2008).

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by JPL, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  16. Microscope and method of use

    DOEpatents

    Bongianni, W.L.

    1984-04-17

    A method and apparatus for electronically focusing and electronically scanning microscopic specimens are given. In the invention, visual images of even moving, living, opaque specimens can be acoustically obtained and viewed with virtually no time needed for processing (i.e., real time processing is used). And planar samples are not required. The specimens (if planar) need not be moved during scanning, although it will be desirable and possible to move or rotate nonplanar specimens (e.g., laser fusion targets) against the lens of the apparatus. No coupling fluid is needed, so specimens need not be wetted. A phase acoustic microscope is also made from the basic microscope components together with electronic mixers. 7 figs.

  17. Thermodynamics of the Earth

    NASA Astrophysics Data System (ADS)

    Stacey, Frank D.

    2010-04-01

    Applications of elementary thermodynamic principles to the dynamics of the Earth lead to robust, quantitative conclusions about the tectonic effects that arise from convection. The grand pattern of motion conveys deep heat to the surface, generating mechanical energy with a thermodynamic efficiency corresponding to that of a Carnot engine operating over the adiabatic temperature gradient between the heat source and sink. Referred to the total heat flux derived from the Earth's silicate mantle, the efficiency is 24% and the power generated, 7.7 × 1012 W, causes all the material deformation apparent as plate tectonics and the consequent geological processes. About 3.5% of this is released in seismic zones but little more than 0.2% as seismic waves. Even major earthquakes are only localized hiccups in this motion. Complications that arise from mineral phase transitions can be used to illuminate details of the motion. There are two superimposed patterns of convection, plate subduction and deep mantle plumes, driven by sources of buoyancy, negative and positive respectively, at the top and bottom of the mantle. The patterns of motion are controlled by the viscosity contrasts (>104 : 1) at these boundaries and are self-selected as the least dissipative mechanisms of heat transfer for convection in a body with very strong viscosity variation. Both are subjects of the thermodynamic efficiency argument. Convection also drives the motion in the fluid outer core that generates the geomagnetic field, although in that case there is an important energy contribution by compositional separation, as light solute is rejected by the solidifying inner core and mixed into the outer core, a process referred to as compositional convection. Uncertainty persists over the core energy balance because thermal conduction is a drain on core energy that has been a subject of diverse estimates, with attendant debate over the need for radiogenic heat in the core. The geophysical approach to

  18. Thermodynamic curvature and phase transitions in Kerr-Newman black holes

    SciTech Connect

    Ruppeiner, George

    2008-07-15

    Singularities in the thermodynamics of Kerr-Newman black holes are commonly associated with phase transitions. However, such interpretations are complicated by a lack of stability and, more significantly, by a lack of conclusive insight from microscopic models. Here, I focus on the later problem. I use the thermodynamic Riemannian curvature scalar R as a try to get microscopic information from the known thermodynamics. The hope is that this could facilitate matching black hole thermodynamics to known models of statistical mechanics. For the Kerr-Newman black hole, the sign of R is mostly positive, in contrast to that for ordinary thermodynamic models, where R is mostly negative. Cases with negative R include most of the simple critical point models. An exception is the Fermi gas, which has positive R. I demonstrate several exact correspondences between the two-dimensional Fermi gas and the extremal Kerr-Newman black hole. Away from the extremal case, R diverges to +{infinity} along curves of diverging heat capacities C{sub J,{phi}} and C{sub {omega}}{sub ,Q}, but not along the Davies curve of diverging C{sub J,Q}. Finding statistical mechanical models with like behavior might yield additional insight into the microscopic properties of black holes. I also discuss a possible physical interpretation of |R|.

  19. Layer-by-layer and intrinsic analysis of molecular and thermodynamic properties across soft interfaces

    SciTech Connect

    Sega, Marcello; Jedlovszky, Pál

    2015-09-21

    Interfaces are ubiquitous objects, whose thermodynamic behavior we only recently started to understand at the microscopic detail. Here, we borrow concepts from the techniques of surface identification and intrinsic analysis, to provide a complementary point of view on the density, stress, energy, and free energy distribution across liquid (“soft”) interfaces by analyzing the respective contributions coming from successive layers.

  20. Thermodynamics from Car to Kitchen

    ERIC Educational Resources Information Center

    Auty, Geoff

    2014-01-01

    The historical background to the laws of thermodynamics is explained using examples we can all observe in the world around us, focusing on motorised transport, refrigeration and solar heating. This is not to be considered as an academic article. The purpose is to improve understanding of thermodynamics rather than impart new knowledge, and for…

  1. Thermodynamics--A Practical Subject.

    ERIC Educational Resources Information Center

    Jones, Hugh G.

    1984-01-01

    Provides a simplified, synoptic overview of the area of thermodynamics, enumerating and explaining the four basic laws, and introducing the mathematics involved in a stepwise fashion. Discusses such basic tools of thermodynamics as enthalpy, entropy, Helmholtz free energy, and Gibbs free energy, and their uses in problem solving. (JM)

  2. Ch. 33 Modeling: Computational Thermodynamics

    SciTech Connect

    Besmann, Theodore M

    2012-01-01

    This chapter considers methods and techniques for computational modeling for nuclear materials with a focus on fuels. The basic concepts for chemical thermodynamics are described and various current models for complex crystalline and liquid phases are illustrated. Also included are descriptions of available databases for use in chemical thermodynamic studies and commercial codes for performing complex equilibrium calculations.

  3. Developing a Quantum Electron Microscope

    NASA Astrophysics Data System (ADS)

    Kohstall, Christoph; Klopfer, Brannon; Francis, Josh; Skulason, Gunnar; Juffmann, Thomas; Kasevich, Mark; QEM Team

    2014-03-01

    We develop a new electron microscope based on the interaction-free measurement principle. Such a Quantum Electron Microscope (QEM) may enable imaging of biological samples with radiation doses so small that they are non-lethal. The realization of the QEM will require precise control over the quantum motion of free electrons. On this poster, we discuss our approach to build a QEM including the realization of an electron resonator and an electron amplitude beam-splitter. On top of the QEM application, these developments will advance the electron analogue to photon quantum optics. Funded by the Gordon and Betty Moore Foundation.

  4. Advanced Microscopic Integrated Thermocouple Arrays

    NASA Technical Reports Server (NTRS)

    Pettigrew, Penny J.

    1999-01-01

    The purpose of this research is to develop and refine a technique for making microscopic thermocouple arrays for use in measuring the temperature gradient across a solid-liquid interface during the solidification process. Current thermocouple technology does not allow for real-time measurements across the interface due to the prohibitive size of available thermocouples. Microscopic thermocouple arrays will offer a much greater accuracy and resolution of temperature measurements across the solid-liquid interface which will lead to a better characterization of the solidification process and interface reaction which affect the properties of the resulting material.

  5. Long working distance interference microscope

    DOEpatents

    Sinclair, Michael B.; DeBoer, Maarten P.; Smith, Norman F.

    2004-04-13

    Disclosed is a long working distance interference microscope suitable for three-dimensional imaging and metrology of MEMS devices and test structures on a standard microelectronics probe station. The long working distance of 10-30 mm allows standard probes or probe cards to be used. This enables nanometer-scale 3-D height profiles of MEMS test structures to be acquired across an entire wafer. A well-matched pair of reference/sample objectives is not required, significantly reducing the cost of this microscope, as compared to a Linnik microinterferometer.

  6. Microscopic Materials on a Magnet

    NASA Technical Reports Server (NTRS)

    2008-01-01

    These images show a comparison of the weak magnet OM7 from the Optical Microscope on NASA's Phoenix Mars Lander before (left) and after (right) soil deposition.

    The microscope took the left image during Phoenix's Sol 15 (June 10, 2008) and the right image during Sol 21 (Jun 16, 2008).

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  7. Thermodynamics of Protein Aggregation

    NASA Astrophysics Data System (ADS)

    Osborne, Kenneth L.; Barz, Bogdan; Bachmann, Michael; Strodel, Birgit

    Amyloid protein aggregation characterizes many neurodegenerative disorders, including Alzheimer's, Parkinson's, and Creutz- feldt-Jakob disease. Evidence suggests that amyloid aggregates may share similar aggregation pathways, implying simulation of full-length amyloid proteins is not necessary for understanding amyloid formation. In this study we simulate GNNQQNY, the N-terminal prion-determining domain of the yeast protein Sup35 to investigate the thermodynamics of structural transitions during aggregation. We use a coarse-grained model with replica-exchange molecular dynamics to investigate the association of 3-, 6-, and 12-chain GNNQQNY systems and we determine the aggregation pathway by studying aggregation states of GN- NQQNY. We find that the aggregation of the hydrophilic GNNQQNY sequence is mainly driven by H-bond formation, leading to the formation of /3-sheets from the very beginning of the assembly process. Condensation (aggregation) and ordering take place simultaneously, which is underpinned by the occurrence of a single heat capacity peak only.

  8. Thermodynamics and cement science

    SciTech Connect

    Damidot, D.; Lothenbach, B.; Herfort, D.; Glasser, F.P.

    2011-07-15

    Thermodynamics applied to cement science has proved to be very valuable. One of the most striking findings has been the extent to which the hydrate phases, with one conspicuous exception, achieve equilibrium. The important exception is the persistence of amorphous C-S-H which is metastable with respect to crystalline calcium silicate hydrates. Nevertheless C-S-H can be included in the scope of calculations. As a consequence, from comparison of calculation and experiment, it appears that kinetics is not necessarily an insuperable barrier to engineering the phase composition of a hydrated Portland cement. Also the sensitivity of the mineralogy of the AFm and AFt phase compositions to the presence of calcite and to temperature has been reported. This knowledge gives a powerful incentive to develop links between the mineralogy and engineering properties of hydrated cement paste and, of course, anticipates improvements in its performance leading to decreasing the environmental impacts of cement production.

  9. Modern problems of thermodynamics

    NASA Astrophysics Data System (ADS)

    Novikov, I. I.

    2012-12-01

    The role of energy and methods of its saving for the development of human society and life are analyzed. The importance of future use of space energy flows and energy of water and air oceans is emphasized. The authors consider the idea of the unit for production of electric energy and pure substances using sodium chloride which reserves are limitless on the planet. Looking retrospectively at the development of power engineering from the elementary fire to modern electric power station, we see that the used method of heat production, namely by direct interaction of fuel and oxidizer, is the simplest. However, it may be possible to combust coal, i.e., carbon in salt melt, for instance, sodium chloride that would be more rational and efficient. If the stated problems are solved positively, we would master all energy properties of the substance; and this is the main problem of thermodynamics being one of the sciences on energy.

  10. Extensive quantities in thermodynamics

    NASA Astrophysics Data System (ADS)

    Mannaerts, Sebastiaan H.

    2014-05-01

    A literature survey shows little consistency in the definitions of the term ‘extensive quantity’ (a.k.a. extensive property) as used in thermodynamics. A majority assumes that extensive quantities are those that are proportional to mass. Taking the mathematical meaning of proportional and taking the ‘mass’ to be that of the system or subsystem, it is shown that the proportionality assumption is only correct for a few extensive quantities under condition of constant composition. A large subset of extensive quantities are completely independent of mass; for most systems extensive quantities are not proportional to mass, but mass is the (extensive) constant of proportionality. The definition by IUPAC, based on the additivity of extensive quantities, is the preferred baseline for discussing this subject. It is noted however, that two types of additivity need to be distinguished and that a few intensive quantities are also additive. This paper leaves several interesting questions open to further scrutiny.

  11. Thermodynamics of Glass Melting

    NASA Astrophysics Data System (ADS)

    Conradt, Reinhard

    First, a model based on linear algebra is described by which the thermodynamic properties of industrial multi-component glasses and glass melts can be accurately predicted from their chemical composition. The model is applied to calculate the heat content of glass melts at high temperatures, the standard heat of formation of glasses from the elements, and the vapor pressures of individual oxides above the melt. An E-fiber glass composition is depicted as an example. Second, the role of individual raw materials in the melting process of E-glass is addressed, with a special focus on the decomposition kinetics and energetic situation of alkaline earth carriers. Finally, the heat of the batch-to-melt conversion is calculated. A simplified reaction path model comprising heat turnover, content of residual solid matter, and an approach to batch viscosity is outlined.

  12. Chemical and process thermodynamics

    SciTech Connect

    Kyle, B.G.

    1984-01-01

    The book is intended mainly to be used as a text for undergraduate chemical engineering studies. Presented is a unified and up-to-date treatment of the major chemical and engineering applications of thermodynamics. Special features include a four chapter sequence on phase equilibrium which begins with simple concepts discussions. More difficult concepts are introduced gradually. Partial molar properties and infinite dilution activity coefficients appear toward the end of the sequence. Solution behavior, including activity coefficients via UNIVAC, is covered. Chapter 14 discusses heat exchange, separation processes, and second law analysis of chemical processes. Chapter 12 provides a firm foundation for chemical equilibrium, and Chapter 13 includes complex chemical equilibrium and free energy minimization. A selection of end-of-chapter problems is included to help the student apply principles and concepts in practical situations.

  13. Thermodynamics of feldspathoid solutions

    NASA Astrophysics Data System (ADS)

    Sack, Richard O.; Ghiorso, Mark S.

    We have developed models for the thermody-namic properties of nephelines, kalsilites, and leucites in the simple system NaAlSiO4-KAlSiO4-Ca0.5AlSiO4-SiO2-H2O that are consistent with all known constraints on subsolidus equilibria and thermodynamic properties, and have integrated them into the existing MELTS software package. The model for nepheline is formulated for the simplifying assumptions that (1) a molecular mixing-type approximation describes changes in the configurational entropy associated with the coupled exchange substitutions □Si?NaAl and □Ca? Na2 and that (2) Na+ and K+ display long-range non-convergent ordering between a large cation and the three small cation sites in the Na4Al4Si4O16 formula unit. Notable features of the model include the prediction that the mineral tetrakalsilite (``panunzite'', sensu stricto) results from anti-ordering of Na and K between the large cation and the three small cation sites in the nepheline structure at high temperatures, an average dT/dP slope of about 55°/kbar for the reaction over the temperature and pressure ranges 800-1050 °C and 500-5000 bars, roughly symmetric (i.e. quadratic) solution behavior of the K-Na substitution along joins between fully ordered components in nepheline, and large positive Gibbs energies for the nepheline reciprocal reactions and and for the leucite reciprocal reaction

  14. Thermodynamic similarity of physical systems

    NASA Astrophysics Data System (ADS)

    Ciccariello, Salvino

    2016-02-01

    Two different physical systems A and B are said to be thermodynamically similar if one of the thermodynamic potentials of system A is proportional to the corresponding potential of B after expressing the state variables of system A in terms of those of B by a transformation reversible throughout the state variables' domain. The thermodynamic similarity has a transitive nature so that physical systems divide into classes of thermodynamically similar systems that have similar phase diagrams. Considering the simplest physical systems, one finds that a class of thermodynamically similar systems is formed by the ideal classical gas, the Fermi and the Bose ideal quantum gases, whatever the dimensions of the confining spaces, and the one dimensional hard rod gas. Another class is formed by the physical systems characterized by interactions that coincide by a scaling of the distance and the coupling constant.

  15. Multivariate Chemical Image Fusion of Vibrational Spectroscopic Imaging Modalities.

    PubMed

    Gowen, Aoife A; Dorrepaal, Ronan M

    2016-01-01

    Chemical image fusion refers to the combination of chemical images from different modalities for improved characterisation of a sample. Challenges associated with existing approaches include: difficulties with imaging the same sample area or having identical pixels across microscopic modalities, lack of prior knowledge of sample composition and lack of knowledge regarding correlation between modalities for a given sample. In addition, the multivariate structure of chemical images is often overlooked when fusion is carried out. We address these challenges by proposing a framework for multivariate chemical image fusion of vibrational spectroscopic imaging modalities, demonstrating the approach for image registration, fusion and resolution enhancement of chemical images obtained with IR and Raman microscopy. PMID:27384549

  16. Spectroscopic classification of supernova candidates

    NASA Astrophysics Data System (ADS)

    Hodgkin, S. T.; Hall, A.; Fraser, M.; Campbell, H.; Wyrzykowski, L.; Kostrzewa-Rutkowska, Z.; Pietro, N.

    2014-09-01

    We report the spectroscopic classification of four supernovae at the 2.5m Isaac Newton Telescope on La Palma, using the Intermediate Dispersion Spectrograph and the R300V grating (3500-8000 Ang; ~6 Ang resolution).

  17. Dynamical and thermodynamical control of open quantum Brownian motion

    NASA Astrophysics Data System (ADS)

    Petruccione, Francesco; Sinayskiy, Ilya

    Open quantum Brownian motion was introduced as a new type of quantum Brownian motion for Brownian particles with internal quantum degrees of freedom. Recently, an example of the microscopic derivation of open quantum Brownian motion has been presented [I. Sinayskiy and F. Petruccione, Phys. Scr. T165, 014017 (2015)]. The microscopic derivation allows to relate the dynamical properties of open Quantum Brownian motion and the thermodynamical properties of the environment. In the present work, we study the possibility of control of the external degrees of freedom of the ''walker'' (position) by manipulating the internal one, e.g. spin, polarization, occupation numbers. In the particular example of the known microscopic derivation the connection between dynamics of the ''walker'' and thermodynamical parameters of the system is established. For the system of open Brownian walkers coupled to the same environment controllable creation of quantum correlations is investigated. This work is based upon research supported by the South African Research Chair Initiative of the Department of Science and Technology and National Research Foundation.

  18. Spectroscopic optical coherence elastography

    PubMed Central

    Adie, Steven G.; Liang, Xing; Kennedy, Brendan F.; John, Renu; Sampson, David D.; Boppart, Stephen A.

    2010-01-01

    We present an optical technique to image the frequency-dependent complex mechanical response of a viscoelastic sample. Three-dimensional hyperspectral data, comprising two-dimensional B-mode images and a third dimension corresponding to vibration frequency, were acquired from samples undergoing external mechanical excitation in the audio-frequency range. We describe the optical coherence tomography (OCT) signal when vibration is applied to a sample and detail the processing and acquisition techniques used to extract the local complex mechanical response from three-dimensional data that, due to a wide range of vibration frequencies, possess a wide range of sample velocities. We demonstrate frequency-dependent contrast of the displacement amplitude and phase of a silicone phantom containing inclusions of higher stiffness. Measurements of an ex vivo tumor margin demonstrate distinct spectra between adipose and tumor regions, and images of displacement amplitude and phase demonstrated spatially-resolved contrast. Contrast was also observed in displacement amplitude and phase images of a rat muscle sample. These results represent the first demonstration of mechanical spectroscopy based on B-mode OCT imaging. Spectroscopic optical coherence elastography (S-OCE) provides a high-resolution imaging capability for the detection of tissue pathologies that are characterized by a frequency-dependent viscoelastic response. PMID:21164898

  19. Spectroscopic optical coherence elastography.

    PubMed

    Adie, Steven G; Liang, Xing; Kennedy, Brendan F; John, Renu; Sampson, David D; Boppart, Stephen A

    2010-12-01

    We present an optical technique to image the frequency-dependent complex mechanical response of a viscoelastic sample. Three-dimensional hyperspectral data, comprising two-dimensional B-mode images and a third dimension corresponding to vibration frequency, were acquired from samples undergoing external mechanical excitation in the audio-frequency range. We describe the optical coherence tomography (OCT) signal when vibration is applied to a sample and detail the processing and acquisition techniques used to extract the local complex mechanical response from three-dimensional data that, due to a wide range of vibration frequencies, possess a wide range of sample velocities. We demonstrate frequency-dependent contrast of the displacement amplitude and phase of a silicone phantom containing inclusions of higher stiffness. Measurements of an ex vivo tumor margin demonstrate distinct spectra between adipose and tumor regions, and images of displacement amplitude and phase demonstrated spatially-resolved contrast. Contrast was also observed in displacement amplitude and phase images of a rat muscle sample. These results represent the first demonstration of mechanical spectroscopy based on B-mode OCT imaging. Spectroscopic optical coherence elastography (S-OCE) provides a high-resolution imaging capability for the detection of tissue pathologies that are characterized by a frequency-dependent viscoelastic response. PMID:21164898

  20. Light-Fueled Microscopic Walkers.

    PubMed

    Zeng, Hao; Wasylczyk, Piotr; Parmeggiani, Camilla; Martella, Daniele; Burresi, Matteo; Wiersma, Diederik Sybolt

    2015-07-01

    The first microscopic artificial walker equipped with liquid-crystalline elastomer muscle is reported. The walker is fabricated by direct laser writing, is smaller than any known living terrestrial creatures, and is capable of several autonomous locomotions on different surfaces. PMID:26033690

  1. Switch on Micro*scope!

    ERIC Educational Resources Information Center

    Roland, Sarah; Bahr, Michele; Olendzenski, Lorraine; Patterson, David J.

    2005-01-01

    Scientists at the Marine Biological Laboratory in Woods Hole, Massachusetts, have created micro*scope, a free, searchable knowledge environment for exploring the microbial world. Microbiology can easily be incorporated into the curriculum, because microbial communities are easy to access. Organisms grow quickly, making certain arrays of…

  2. Toolmaker's Microscope With Video Monitor

    NASA Technical Reports Server (NTRS)

    Ahmed, Arif S.

    1988-01-01

    Display accessories increase resolution and flexibility of use. Toolmaker's microscope equipped with video monitor, auxiliary lighting, and high-resolution readout devices enables noncontacting measurements of tiny slots, indentations, and similar features on parts. Measures places difficult or impossible to reach by mechanical means.

  3. Scanning tunneling microscope nanoetching method

    DOEpatents

    Li, Yun-Zhong; Reifenberger, Ronald G.; Andres, Ronald P.

    1990-01-01

    A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

  4. Chasing Meteors With a Microscope.

    ERIC Educational Resources Information Center

    Jones, Richard C.

    1993-01-01

    Describes types of meteors and micrometeorites that enter the Earth's atmosphere. Presents an activity where students collect micrometeorites with a strip of tape in an undisturbed outdoor area. After 24 hours, they examine the tape by sandwiching it between 2 glass slides and view through a microscope at 100X. (PR)

  5. Nature Study with the Microscope.

    ERIC Educational Resources Information Center

    Sollberger, Dwight E.

    1991-01-01

    Identifies specific instruction difficulties, potential problems, solutions, and activities for successful use of microscopes in the classroom. Procedures are outlined for guiding students in creating their own slides with monocotyledon and dicotyledon stems, fern spores, stomata, lichens, and red onions. (MCO)

  6. The microscope in the hatchery

    USGS Publications Warehouse

    Fish, F.F.

    1935-01-01

    Without the aid of the microscope, it is safe to assume that fish Culture would now stand exactly where it did seventy-five years ago when methods of artificial fertilization were first applied. It is also safe to assume that the results from fish culture would be as unsatisfactory as they were at that time when the fishery resources were steadily declining in spite of the increased liberation of advanced fry from the hatcheries. During the past few years the microscope has saved millions of fish in our hatcheries which otherwise would have been sacrificed to disease. Moreover, the microscope has permitted all of the recent work in selective breeding, nutritional requirements, and disease control. This work marks most of the progress fish culture has made during the past twenty-five years. This progress forms the first definite step away from the old system of hatching and distributing fish, a system which was founded by the ancient Chinese. The microscope has been the key which enabled the fish culturist to solve the riddle of success which has stood, unanswered, for 2,500 years.

  7. Curriculum Guidelines for Microscopic Anatomy.

    ERIC Educational Resources Information Center

    Journal of Dental Education, 1993

    1993-01-01

    The American Association of Dental Schools' guidelines for curricula in microscopic anatomy offer an overview of the histology curriculum, note primary educational goals, outline specific content for general and oral histology, suggest prerequisites, and make recommendations for sequencing. Appropriate faculty and facilities are also suggested.…

  8. The Biggest Microscopic Image Ever

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This is a mosaic of four individual frames taken by the microscopic imager that have been very carefully stitched together to reveal the entire 5-centimeter-diameter (almost 2-inch) hole left on the rock dubbed 'Humphrey.' The holes were created by the Mars Exploration Rover Spirit's rock abrasion tool. The mosaic, created on March 7, 2004, is the first of its kind of an abraded surface on Mars, and gave scientists their first ever microscopic imager view of the entire drilled area. While it is easy for the panoramic camera and the navigation cameras to fit an area this size into their field of view, the microscopic imager can only capture a portion of the ground area with each image.

    Scientists are interested in many of the small features on 'Humphrey' uncovered by the rock abrasion tool and made visible by the microscopic imager. The sinuous veins within the rock could be evidence that water was trickling through the material while it was deep underground, whereas the dark 'age spots' in the center of the hole may be crystals of the mineral olivine.

  9. Imaging spectroscopic analysis at the Advanced Light Source

    SciTech Connect

    MacDowell, A. A.; Warwick, T.; Anders, S.; Lamble, G.M.; Martin, M.C.; McKinney, W.R.; Padmore, H.A.

    1999-05-12

    One of the major advances at the high brightness third generation synchrotrons is the dramatic improvement of imaging capability. There is a large multi-disciplinary effort underway at the ALS to develop imaging X-ray, UV and Infra-red spectroscopic analysis on a spatial scale from. a few microns to 10nm. These developments make use of light that varies in energy from 6meV to 15KeV. Imaging and spectroscopy are finding applications in surface science, bulk materials analysis, semiconductor structures, particulate contaminants, magnetic thin films, biology and environmental science. This article is an overview and status report from the developers of some of these techniques at the ALS. The following table lists all the currently available microscopes at the. ALS. This article will describe some of the microscopes and some of the early applications.

  10. Spectroscopic Chemical Analysis Methods and Apparatus

    NASA Technical Reports Server (NTRS)

    Hug, William F.; Reid, Ray D.

    2012-01-01

    This invention relates to non-contact spectroscopic methods and apparatus for performing chemical analysis and the ideal wavelengths and sources needed for this analysis. It employs deep ultraviolet (200- to 300-nm spectral range) electron-beam-pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor lightemitting devices, and hollow cathode metal ion lasers. Three achieved goals for this innovation are to reduce the size (under 20 L), reduce the weight [under 100 lb (.45 kg)], and reduce the power consumption (under 100 W). This method can be used in microscope or macroscope to provide measurement of Raman and/or native fluorescence emission spectra either by point-by-point measurement, or by global imaging of emissions within specific ultraviolet spectral bands. In other embodiments, the method can be used in analytical instruments such as capillary electrophoresis, capillary electro-chromatography, high-performance liquid chromatography, flow cytometry, and related instruments for detection and identification of unknown analytes using a combination of native fluorescence and/or Raman spectroscopic methods. This design provides an electron-beampumped semiconductor radiation-producing method, or source, that can emit at a wavelength (or wavelengths) below 300 nm, e.g. in the deep ultraviolet between about 200 and 300 nm, and more preferably less than 260 nm. In some variations, the method is to produce incoherent radiation, while in other implementations it produces laser radiation. In some variations, this object is achieved by using an AlGaN emission medium, while in other implementations a diamond emission medium may be used. This instrument irradiates a sample with deep UV radiation, and then uses an improved filter for separating wavelengths to be detected. This provides a multi-stage analysis of the sample. To avoid the difficulties related to producing deep UV semiconductor sources, a pumping approach has been developed that uses

  11. Routes towards an abstract thermodynamics in the late nineteenth century

    NASA Astrophysics Data System (ADS)

    Bordoni, Stefano

    2013-12-01

    Two different traditions of research emerged from Rudolf Clausius's version of thermodynamics. While James Clerk Maxwell and Ludwig Boltzmann pursued the integration of thermodynamics with the kinetic theory of gases, others relied on a macroscopic and more abstract approach that set aside specific mechanical models. This second approach blossomed in about two decades in different countries of Europe and in the United States. François Massieu, Josiah Willard Gibbs, Hermann Helmholtz, and then Pierre Duhem explored the connections between the contents of thermodynamics and the formal structures of analytical mechanics. Others like the young Max Planck and Arthur von Oettingen pursued a sort of formal symmetry between thermal and mechanical variables. In the British Isles, Joseph John Thomson developed a dynamical approach to physics and chemistry, making use of the tools of abstract mechanics without excluding microscopic motions. Some developments were logically interconnected, as it was for Massieu's, Gibbs's, Helmholtz's, and Duhem's, even though they occurred in a largely independent manner. Duhem put forward the most original and most systematic reinterpretation of thermodynamics, which involved a bold upgrading of analytical mechanics and a bold mathematical unification of physics and chemistry. A strong commitment to unification was one of the hallmarks of all these theoretical researches.

  12. Light microscopic and electron microscopic histopathology of an iris microhaemangioma.

    PubMed Central

    Meades, K V; Francis, I C; Kappagoda, M B; Filipic, M

    1986-01-01

    A patient who had been observed to have an iris microhaemangioma (capillary haemangioma), confirmed on fluorescein iris angiography, came to cataract surgery. The lesion was excised at the time of surgery and submitted to light and electron microscopic study. It had the features of a hamartoma of the capillary haemangioma type, with its characteristics being specific for vessels seen in iris tissue. Images PMID:3964627

  13. Thermodynamic phase transitions in a frustrated magnetic metamaterial

    PubMed Central

    Anghinolfi, L.; Luetkens, H.; Perron, J.; Flokstra, M. G.; Sendetskyi, O.; Suter, A.; Prokscha, T.; Derlet, P. M.; Lee, S. L.; Heyderman, L. J.

    2015-01-01

    Materials with interacting magnetic degrees of freedom display a rich variety of magnetic behaviour that can lead to novel collective equilibrium and out-of-equilibrium phenomena. In equilibrium, thermodynamic phases appear with the associated phase transitions providing a characteristic signature of the underlying collective behaviour. Here we create a thermally active artificial kagome spin ice that is made up of a large array of dipolar interacting nanomagnets and undergoes phase transitions predicted by microscopic theory. We use low energy muon spectroscopy to probe the dynamic behaviour of the interacting nanomagnets and observe peaks in the muon relaxation rate that can be identified with the critical temperatures of the predicted phase transitions. This provides experimental evidence that a frustrated magnetic metamaterial can be engineered to admit thermodynamic phases. PMID:26387444

  14. Thermodynamic phase transitions in a frustrated magnetic metamaterial.

    PubMed

    Anghinolfi, L; Luetkens, H; Perron, J; Flokstra, M G; Sendetskyi, O; Suter, A; Prokscha, T; Derlet, P M; Lee, S L; Heyderman, L J

    2015-01-01

    Materials with interacting magnetic degrees of freedom display a rich variety of magnetic behaviour that can lead to novel collective equilibrium and out-of-equilibrium phenomena. In equilibrium, thermodynamic phases appear with the associated phase transitions providing a characteristic signature of the underlying collective behaviour. Here we create a thermally active artificial kagome spin ice that is made up of a large array of dipolar interacting nanomagnets and undergoes phase transitions predicted by microscopic theory. We use low energy muon spectroscopy to probe the dynamic behaviour of the interacting nanomagnets and observe peaks in the muon relaxation rate that can be identified with the critical temperatures of the predicted phase transitions. This provides experimental evidence that a frustrated magnetic metamaterial can be engineered to admit thermodynamic phases. PMID:26387444

  15. Rotating black hole thermodynamics with a particle probe

    SciTech Connect

    Gwak, Bogeun; Lee, Bum-Hoon

    2011-10-15

    The thermodynamics of Myers-Perry black holes in general dimensions are studied using a particle probe. When undergoing particle absorption, the changes of the entropy and irreducible mass are shown to be dependent on the particle radial momentum. The black hole thermodynamic behaviors are dependent on dimensionality for specific rotations. For a 4-dimensional Kerr black hole, its black hole properties are maintained for any particle absorption. 5-dimensional black holes can avoid a naked ring singularity by absorbing a particle in specific momenta ranges. Black holes over 6 dimensions become ultraspinning black holes through a specific form of particle absorption. The microscopical changes are interpreted in limited cases of Myers-Perry black holes using Kerr/CFT correspondence. We systematically describe the black hole properties changed by particle absorption in all dimensions.

  16. Thermodynamic product formula for a Taub-NUT black hole

    NASA Astrophysics Data System (ADS)

    Pradhan, P.

    2016-01-01

    We derive various important thermodynamic relations of the inner and outer horizons in the background of the Taub-NUT (Newman-Unti-Tamburino) black hole in four-dimensional Lorentzian geometry. We compare these properties with the properties of the Reissner-Nordström black hole. We compute the area product, area sum, area subtraction, and area division of black hole horizons. We show that they all are not universal quantities. Based on these relations, we compute the area bound of all horizons. From the area bound, we derive an entropy bound and an irreducible mass bound for both horizons. We further study the stability of such black holes by computing the specific heat for both horizons. It is shown that due to the negative specific heat, the black hole is thermodynamically unstable. All these calculations might be helpful in understanding the nature of the black hole entropy (both interior and exterior) at the microscopic level.

  17. Structural fluctuation of proteins induced by thermodynamic perturbation

    SciTech Connect

    Hirata, Fumio; Akasaka, Kazuyuki

    2015-01-28

    A theory to describe structural fluctuations of protein induced by thermodynamic perturbations, pressure, temperature, and denaturant, is proposed. The theory is formulated based on the three methods in the statistical mechanics: the generalized Langevin theory, the linear response theory, and the three dimensional interaction site model (3D-RISM) theory. The theory clarifies how the change in thermodynamic conditions, or a macroscopic perturbation, induces the conformational fluctuation, which is a microscopic property. The theoretical results are applied, on the conceptual basis, to explain the experimental finding by Akasaka et al., concerning the NMR experiment which states that the conformational change induced by pressure corresponds to structural fluctuations occurring in the ambient condition. A method to evaluate the structural fluctuation induced by pressure is also suggested by means of the 3D-RISM and the site-site Kirkwood-Buff theories.

  18. Geometric microcanonical thermodynamics for systems with first integrals.

    PubMed

    Franzosi, Roberto

    2012-05-01

    In the general case of a many-body Hamiltonian system described by an autonomous Hamiltonian H and with K ≥ 0 independent conserved quantities, we derive the microcanonical thermodynamics. Using simple approach, based on differential geometry, we derive the microcanonical entropy and the derivatives of the entropy with respect to the conserved quantities. In such a way, we show that all the thermodynamical quantities, such as the temperature, the chemical potential, and the specific heat, are measured as a microcanonical average of the appropriate microscopic dynamical functions that we have explicitly derived. Our method applies also in the case of nonseparable Hamiltonians, where the usual definition of kinetic temperature, derived by the virial theorem, does not apply. PMID:23004688

  19. Third law of thermodynamics for the dissipative cyclotron motion

    SciTech Connect

    Kumar, Jishad

    2013-11-15

    We derive the heat capacity and the entropy of an exactly solvable model of a charged particle in the combined presence of a uniform homogeneous magnetic field and a finite dissipative quantum heat bath consisting of non interacting harmonic oscillators. The quantities are calculated from the reduced partition function of the damped system which is calculated using the imaginary time functional integral method within the framework of the well known microscopic system-plus-bath model. Unlike the typical choice of an ohmic spectral density of the bath oscillators, we consider the quantum heat bath is having a spectral density corresponding to a thermal harmonic noise. Subsequently we analyse the specific heat and entropy at low and high temperatures. The specific heat and the entropy obtained satisfy the third law of thermodynamics. The heat capacity vanishes as the temperature approaches its absolute zero value, as predicted by the third law of thermodynamics, and satisfies the classical equipartition theorem at high temperatures.

  20. Fisher information and the thermodynamics of scale-invariant systems

    NASA Astrophysics Data System (ADS)

    Hernando, A.; Vesperinas, C.; Plastino, A.

    2010-02-01

    We present a thermodynamic formulation for scale-invariant systems based on the minimization with constraints of the Fisher information measure. In such a way a clear analogy between these systems’ thermal properties and those of gases and fluids is seen to emerge in a natural fashion. We focus our attention on the non-interacting scenario, speaking thus of scale-free ideal gases (SFIGs) and present some empirical evidences regarding such disparate systems as electoral results, city populations and total citations in Physics journals, that seem to indicate that SFIGs do exist. We also illustrate the way in which Zipf’s law can be understood in a thermodynamical context as the surface of a finite system. Finally, we derive an equivalent microscopic description of our systems which totally agrees with previous numerical simulations found in the literature.

  1. Thermodynamics of information exchange between two coupled quantum dots

    NASA Astrophysics Data System (ADS)

    Kutvonen, Aki; Sagawa, Takahiro; Ala-Nissila, Tapio

    2016-03-01

    We propose a setup based on two coupled quantum dots where thermodynamics of a measurement can be quantitatively characterized. The information obtained in the measurement can be utilized by performing feedback in a manner apparently breaking the second law of thermodynamics. In this way the setup can be operated as a Maxwell's demon, where both the measurement and feedback are performed separately by controlling an external parameter. This is analogous to the case of the original Szilard engine. Since the setup contains both the microscopic demon and the engine itself, the operation of the whole measurement-feedback cycle can be explained in detail at the level of single realizations. In addition, we derive integral fluctuation relations for both the bare and coarse-grained entropy productions in the setup.

  2. Computing Thermodynamic And Transport Properties

    NASA Technical Reports Server (NTRS)

    Mcbride, B.; Gordon, Sanford

    1993-01-01

    CET89 calculates compositions in chemical equilibrium and properties of mixtures of any chemical system for which thermodynamic data available. Provides following options: obtains chemical-equilibrium compositions and corresponding thermodynamic mixture properties for assigned thermodynamic states; calculates dilute-gas transport properties of complex chemical mixtures; obtains Chapman-Jouguet detonation properties for gaseous mixtures; calculates properties of incident and reflected shocks in terms of assigned velocities; and calculates theoretical performance of rocket for both equilibrium and frozen compositions during expansion. Rocket performance based on optional models of finite or infinite area combustor.

  3. Actinide Thermodynamics at Elevated Temperatures

    SciTech Connect

    Friese, Judah I.; Rao, Linfeng; Xia, Yuanxian; Bachelor, Paula P.; Tian, Guoxin

    2007-11-16

    The postclosure chemical environment in the proposed Yucca Mountain repository is expected to experience elevated temperatures. Predicting migration of actinides is possible if sufficient, reliable thermodynamic data on hydrolysis and complexation are available for these temperatures. Data are scarce and scattered for 25 degrees C, and nonexistent for elevated temperatures. This collaborative project between LBNL and PNNL collects thermodynamic data at elevated temperatures on actinide complexes with inorganic ligands that may be present in Yucca Mountain. The ligands include hydroxide, fluoride, sulfate, phosphate and carbonate. Thermodynamic parameters of complexation, including stability constants, enthalpy, entropy and heat capacity of complexation, are measured with a variety of techniques including solvent extraction, potentiometry, spectrophotometry and calorimetry

  4. The Thermodynamic Properties of Cubanite

    NASA Technical Reports Server (NTRS)

    Berger, E. L.; Lauretta, D. S.; Keller, L. P.

    2012-01-01

    CuFe2S3 exists in two polymorphs, a low-temperature orthorhombic form (cubanite) and a high-temperature cubic form (isocubanite). Cubanite has been identified in the CI-chondrite and Stardust collections. However, the thermodynamic properties of cubanite have neither been measured nor estimated. Our derivation of a thermodynamic model for cubanite allows constraints to be placed on the formation conditions. This data, along with the temperature constraint afforded by the crystal structure, can be used to assess the environments in which cubanite formation is (or is not) thermodynamically favored.

  5. Stochastic thermodynamics of information processing

    NASA Astrophysics Data System (ADS)

    Cardoso Barato, Andre

    2015-03-01

    We consider two recent advancements on theoretical aspects of thermodynamics of information processing. First we show that the theory of stochastic thermodynamics can be generalized to include information reservoirs. These reservoirs can be seen as a sequence of bits which has its Shannon entropy changed due to the interaction with the system. Second we discuss bipartite systems, which provide a convenient description of Maxwell's demon. Analyzing a special class of bipartite systems we show that they can be used to study cellular information processing, allowing for the definition of an entropic rate that quantifies how much a cell learns about a fluctuating external environment and that is bounded by the thermodynamic entropy production.

  6. Thermodynamic Metrics and Optimal Paths

    SciTech Connect

    Sivak, David; Crooks, Gavin

    2012-05-08

    A fundamental problem in modern thermodynamics is how a molecular-scale machine performs useful work, while operating away from thermal equilibrium without excessive dissipation. To this end, we derive a friction tensor that induces a Riemannian manifold on the space of thermodynamic states. Within the linear-response regime, this metric structure controls the dissipation of finite-time transformations, and bestows optimal protocols with many useful properties. We discuss the connection to the existing thermodynamic length formalism, and demonstrate the utility of this metric by solving for optimal control parameter protocols in a simple nonequilibrium model.

  7. The Equilibrium Thermodynamics of Various Peptide Sequences

    NASA Astrophysics Data System (ADS)

    Yaşar, Fatih

    The equilibrium thermodynamic properties of two peptide sequences of β-casein in the α-helix regions were studied by three-dimensional molecular modeling in vacuum. All the three-dimensional conformations of each peptide sequences were obtained by multicanonical simulations using ECEPP/2 force field and each simulation was started from completely random initial conformation. No a-priori information about ground-state is used in the simulations. In the present study, we calculated the average values of total energy, specific heat, fourth-order cumulant for two peptide sequences of β-casein as a function of temperature. We observed that the specific heat shows two peaks as a function of temperature for both peptides. Because our sequences have highly helical structure and two peaks in the specific heat, we have also studied the helix-coil transitions to determine these peaks. Our data indeed show these peptides have highly helical structure and better agreement with the results of spectroscopic techniques and other prediction methods.

  8. A thermodynamic self-consistent theory of asymmetric hard-core Yukawa mixtures.

    PubMed

    Pellicane, Giuseppe; Caccamo, Carlo

    2016-10-19

    We perform structural and thermodynamic calculations in the framework of the modified hypernetted chain (MHNC) integral equation closure to the Ornstein-Zernike equation for binary mixtures of size-different particles interacting with hard-core Yukawa pair potentials. We use the Percus-Yevick (PY) bridge functions of a binary mixture of hard-sphere (HSM) particles. The hard-sphere diameters of the PY bridge functions of the HSM system are adjusted so to achieve thermodynamic consistency between the virial and compressibility equations of state. We show the benefit of thermodynamic consistency by comparing the MHNC results with the available computer simulation data reported in the literature, and we demonstrate that the self-consistent thermodynamic theory provides a better reproduction of the simulation data over other microscopic theories. PMID:27545096

  9. Nanocarpets for Trapping Microscopic Particles

    NASA Technical Reports Server (NTRS)

    Noca, Flavio; Chen, Fei; Hunt, Brian; Bronikowski, Michael; Hoenk, Michael; Kowalczyk, Robert; Choi, Daniel

    2004-01-01

    Nanocarpets that is, carpets of carbon nanotubes are undergoing development as means of trapping microscopic particles for scientific analysis. Examples of such particles include inorganic particles, pollen, bacteria, and spores. Nanocarpets can be characterized as scaled-down versions of ordinary macroscopic floor carpets, which trap dust and other particulate matter, albeit not purposefully. Nanocarpets can also be characterized as mimicking both the structure and the particle-trapping behavior of ciliated lung epithelia, the carbon nanotubes being analogous to cilia. Carbon nanotubes can easily be chemically functionalized for selective trapping of specific particles of interest. One could, alternatively, use such other three-dimensionally-structured materials as aerogels and activated carbon for the purposeful trapping of microscopic particles. However, nanocarpets offer important advantages over these alternative materials: (1) Nanocarpets are amenable to nonintrusive probing by optical means; and (2) Nanocarpets offer greater surface-to-volume ratios.

  10. Shear Brillouin light scattering microscope.

    PubMed

    Kim, Moonseok; Besner, Sebastien; Ramier, Antoine; Kwok, Sheldon J J; An, Jeesoo; Scarcelli, Giuliano; Yun, Seok Hyun

    2016-01-11

    Brillouin spectroscopy has been used to characterize shear acoustic phonons in materials. However, conventional instruments had slow acquisition times over 10 min per 1 mW of input optical power, and they required two objective lenses to form a 90° scattering geometry necessary for polarization coupling by shear phonons. Here, we demonstrate a confocal Brillouin microscope capable of detecting both shear and longitudinal phonons with improved speeds and with a single objective lens. Brillouin scattering spectra were measured from polycarbonate, fused quartz, and borosilicate in 1-10 s at an optical power level of 10 mW. The elastic constants, phonon mean free path and the ratio of the Pockels coefficients were determined at microscopic resolution. PMID:26832263

  11. Hyperbaric Hydrothermal Atomic Force Microscope

    DOEpatents

    Knauss, Kevin G.; Boro, Carl O.; Higgins, Steven R.; Eggleston, Carrick M.

    2003-07-01

    A hyperbaric hydrothermal atomic force microscope (AFM) is provided to image solid surfaces in fluids, either liquid or gas, at pressures greater than normal atmospheric pressure. The sample can be heated and its surface imaged in aqueous solution at temperatures greater than 100.degree. C. with less than 1 nm vertical resolution. A gas pressurized microscope base chamber houses the stepper motor and piezoelectric scanner. A chemically inert, flexible membrane separates this base chamber from the sample cell environment and constrains a high temperature, pressurized liquid or gas in the sample cell while allowing movement of the scanner. The sample cell is designed for continuous flow of liquid or gas through the sample environment.

  12. Hyperbaric hydrothermal atomic force microscope

    DOEpatents

    Knauss, Kevin G.; Boro, Carl O.; Higgins, Steven R.; Eggleston, Carrick M.

    2002-01-01

    A hyperbaric hydrothermal atomic force microscope (AFM) is provided to image solid surfaces in fluids, either liquid or gas, at pressures greater than normal atmospheric pressure. The sample can be heated and its surface imaged in aqueous solution at temperatures greater than 100.degree. C. with less than 1 nm vertical resolution. A gas pressurized microscope base chamber houses the stepper motor and piezoelectric scanner. A chemically inert, flexible membrane separates this base chamber from the sample cell environment and constrains a high temperature, pressurized liquid or gas in the sample cell while allowing movement of the scanner. The sample cell is designed for continuous flow of liquid or gas through the sample environment.

  13. Mars Life? - Microscopic Tubular Structures

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This electron microscope image shows tubular structures of likely Martian origin. These structures are very similar in size and shape to extremely tiny microfossils found in some Earth rocks. This photograph is part of a report by a NASA research team published in the Aug. 16, 1996, issue of the journal Science. A two-year investigation by the team found organic molecules, mineral features characteristic of biological activity and possible microscopic fossils such as these inside of an ancient Martian rock that fell to Earth as a meteorite. The largest possible fossils are less than 1/100th the diameter of a human hair in size while most are ten times smaller.

  14. Thermodynamics of the hot BIon

    NASA Astrophysics Data System (ADS)

    Grignani, Gianluca; Harmark, Troels; Marini, Andrea; Obers, Niels A.; Orselli, Marta

    2011-10-01

    We investigate the thermodynamics of the recently obtained finite temperature BIon solution of [G. Grignani, T. Harmark, A. Marini, N.A. Obers, M. Orselli, Heating up the BIon, arXiv:1012.1494 [hep-th

  15. Thermodynamic efficiency of solar concentrators.

    PubMed

    Shatz, Narkis; Bortz, John; Winston, Roland

    2010-04-26

    The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. We discuss consequences of Fermat's principle of geometrical optics and review étendue dilution and optical loss mechanisms associated with nonimaging concentrators. We develop an expression for the optical thermodynamic efficiency which combines the first and second laws of thermodynamics. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. We provide examples illustrating the use of this new metric for concentrating photovoltaic systems for solar power applications, and in particular show how skewness mismatch limits the attainable optical thermodynamic efficiency. PMID:20607882

  16. Thermodynamic efficiency of solar concentrators.

    PubMed

    Shatz, Narkis; Bortz, John; Winston, Roland

    2010-04-26

    The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. We discuss consequences of Fermat's principle of geometrical optics and review étendue dilution and optical loss mechanisms associated with nonimaging concentrators. We develop an expression for the optical thermodynamic efficiency which combines the first and second laws of thermodynamics. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. We provide examples illustrating the use of this new metric for concentrating photovoltaic systems for solar power applications, and in particular show how skewness mismatch limits the attainable optical thermodynamic efficiency. PMID:20588573

  17. Apparatus Would Stain Microscope Slides

    NASA Technical Reports Server (NTRS)

    Breeding, James D.

    1993-01-01

    Proposed apparatus meters specific amounts of fluid out of containers at specific times to stain microscope slides. Intended specifically for semiautomated staining of microbiological and hematological samples in microgravity, leakproof apparatus used in other environments in which technicians have little time to allocate to staining procedures and/or exposure to toxic staining agents or to micro-organisms to be stained hazardous. Apparatus adapted to perform almost any staining procedure and accommodates multiple staining reagents, useful for small or remote clinical laboratories.

  18. Optical Analysis of Microscope Images

    NASA Astrophysics Data System (ADS)

    Biles, Jonathan R.

    Microscope images were analyzed with coherent and incoherent light using analog optical techniques. These techniques were found to be useful for analyzing large numbers of nonsymbolic, statistical microscope images. In the first part phase coherent transparencies having 20-100 human multiple myeloma nuclei were simultaneously photographed at 100 power magnification using high resolution holographic film developed to high contrast. An optical transform was obtained by focussing the laser onto each nuclear image and allowing the diffracted light to propagate onto a one dimensional photosensor array. This method reduced the data to the position of the first two intensity minima and the intensity of successive maxima. These values were utilized to estimate the four most important cancer detection clues of nuclear size, shape, darkness, and chromatin texture. In the second part, the geometric and holographic methods of phase incoherent optical processing were investigated for pattern recognition of real-time, diffuse microscope images. The theory and implementation of these processors was discussed in view of their mutual problems of dimness, image bias, and detector resolution. The dimness problem was solved by either using a holographic correlator or a speckle free laser microscope. The latter was built using a spinning tilted mirror which caused the speckle to change so quickly that it averaged out during the exposure. To solve the bias problem low image bias templates were generated by four techniques: microphotography of samples, creation of typical shapes by computer graphics editor, transmission holography of photoplates of samples, and by spatially coherent color image bias removal. The first of these templates was used to perform correlations with bacteria images. The aperture bias was successfully removed from the correlation with a video frame subtractor. To overcome the limited detector resolution it is necessary to discover some analog nonlinear intensity

  19. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction.... Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of...

  20. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction.... Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of...

  1. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction.... Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of...

  2. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction.... Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of...

  3. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction.... Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of...

  4. Super-parallel MR microscope.

    PubMed

    Matsuda, Yoshimasa; Utsuzawa, Shin; Kurimoto, Takeaki; Haishi, Tomoyuki; Yamazaki, Yukako; Kose, Katsumi; Anno, Izumi; Marutani, Mitsuhiro

    2003-07-01

    A super-parallel MR microscope in which multiple (up to 100) samples can be imaged simultaneously at high spatial resolution is described. The system consists of a multichannel transmitter-receiver system and a gradient probe array housed in a large-bore magnet. An eight-channel MR microscope was constructed for verification of the system concept, and a four-channel MR microscope was constructed for a practical application. Eight chemically fixed mouse fetuses were simultaneously imaged at the 200 micro m(3) voxel resolution in a 1.5 T superconducting magnet of a whole-body MRI, and four chemically fixed human embryos were simultaneously imaged at 120 micro m(3) voxel resolution in a 2.35 T superconducting magnet. Although the spatial resolutions achieved were not strictly those of MR microscopy, the system design proposed here can be used to attain a much higher spatial resolution imaging of multiple samples, because higher magnetic field gradients can be generated at multiple positions in a homogeneous magnetic field. PMID:12815693

  5. Duties to Extraterrestrial Microscopic Organisms

    NASA Astrophysics Data System (ADS)

    Cockell, C. S.

    Formulating a normative axiology for the treatment of extraterrestrial microscopic organisms, should they ever be found, requires an extension of environmental ethics to beyond the Earth. Using an ethical framework for the treatment of terrestrial micro-organisms, this paper elaborates a similar ethic for the treatment of extraterrestrial microscopic organisms. An ethic of `teloempathy' allows for the moral considerability of any organism that has `interests', based on rudimentary qualities of conativism, and therefore allows for an identical treatment of all life, related or not related to life on Earth. Although, according to this ethic, individual extraterrestrial microscopic organisms have a good of their own and even `rights', at this level the ethic can only be theoretical, allowing for the inevitable destruction of many individual organisms during the course of human exploratory missions, similarly to the daily destruction of microbes by humans on Earth. A holistic teloempathy, an operative ethic, not only provides a framework for human exploration, but it also has important implications for planetary protection and proposals to implement planetary-scale atmospheric alterations on other bodies. Even prior to the discovery of extraterrestrial life, or the discovery of a complete absence of such life, this exercise yields important insights into the moral philosophy that guides our treatment of terrestrial micro-organisms.

  6. [Wegener's granulomatosis and microscopic polyangiitis].

    PubMed

    Pagnoux, Christian

    2008-03-15

    Wegener's granulomatosis and microscopic polyangiitis are among the main systemic necrotizing vasculitides predominantly affecting small vessels. Their prevalences range from 24 to 157 cases per million inhabitants. Mean age at onset is usually 40 to 60 years old. Most common and suggestive features of Wegener's granulomatosis are upper (sinusitis, crusting rhinitis, saddle nose deformity, otitis media) and lower (excavated lung nodules, alveolar hemorrhage) respiratory tract, and kidney involvements. Alveolar hemorrhage and crescentic necrotizing glomerulonephritis are also characteristic manifestations of microscopic polyangiitis. Mononeuritis multiplex and necrotic purpura are frequent symptoms in both diseases. Antineutrophil cytoplasm autoantibodies (ANCA) directed against proteinase 3 can be found in the serum of 90% of the patients with diffuse forms of Wegener's granulomatosis, whereas ANCA with anti-myeloperoxidase specificity, whose pathogenic role is now well documented, can be detected in more than 60% of those with microscopic polyangiitis. Histologically, Wegener's granulomatosis can be differentiated from its counterpart when the inflammatory infiltrates have a granulomatous pattern. Therapy relies on the combination of corticosteroids and pulse intravenous cyclophosphamide, which can be switched, as soon as remission is achieved, to azathioprine or methotrexate, for a total duration of treatment of at least 18 months. Ten-year survival rate now exceeds 80%, but relapses are frequent. The precise place of new biologics, such as rituximab, needs to be further defined. PMID:18524109

  7. Compact Microscope Imaging System Developed

    NASA Technical Reports Server (NTRS)

    McDowell, Mark

    2001-01-01

    The Compact Microscope Imaging System (CMIS) is a diagnostic tool with intelligent controls for use in space, industrial, medical, and security applications. The CMIS can be used in situ with a minimum amount of user intervention. This system, which was developed at the NASA Glenn Research Center, can scan, find areas of interest, focus, and acquire images automatically. Large numbers of multiple cell experiments require microscopy for in situ observations; this is only feasible with compact microscope systems. CMIS is a miniature machine vision system that combines intelligent image processing with remote control capabilities. The software also has a user-friendly interface that can be used independently of the hardware for post-experiment analysis. CMIS has potential commercial uses in the automated online inspection of precision parts, medical imaging, security industry (examination of currency in automated teller machines and fingerprint identification in secure entry locks), environmental industry (automated examination of soil/water samples), biomedical field (automated blood/cell analysis), and microscopy community. CMIS will improve research in several ways: It will expand the capabilities of MSD experiments utilizing microscope technology. It may be used in lunar and Martian experiments (Rover Robot). Because of its reduced size, it will enable experiments that were not feasible previously. It may be incorporated into existing shuttle orbiter and space station experiments, including glove-box-sized experiments as well as ground-based experiments.

  8. Microscope Image of Scavenged Particles

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image from NASA's Phoenix Mars Lander's Optical Microscope shows a strongly magnetic surface which has scavenged particles from within the microscope enclosure before a sample delivery from the lander's Robotic Arm. The particles correspond to the larger grains seen in fine orange material that makes up most of the soil at the Phoenix site. They vary in color, but are of similar size, about one-tenth of a millimeter.

    As the microscope's sample wheel moved during operation, these particles also shifted, clearing a thin layer of the finer orange particles that have also been collected. Together with the previous image, this shows that the larger grains are much more magnetic than the fine orange particles with a much larger volume of the grains being collected by the magnet. The image is 2 milimeters across.

    It is speculated that the orange material particles are a weathering product from the larger grains, with the weathering process both causing a color change and a loss of magnetism.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by JPL, Pasadena, Calif. Spacecraft development was by Lockheed Martin Space Systems, Denver.

  9. Thermodynamic Properties of HCFC-124

    NASA Astrophysics Data System (ADS)

    Fukushima, Masato; Watanabe, Naohiro

    Thermodynamic properties of HCFC-124, such as saturated densities, vapor pressures and PVT properties, were measured and the critical parameters were determined through those experimental results. The correlations for vapor pressure, saturated liquid density and PVT properties deduced from those experimental results were compared with the measured data and also with the estimates of the other correlations published in literatures. The thermodynamic functions, such as enthalpy, entropy, heat capacity, etc., can reasonably be calculated from the correlation equations in this paper.

  10. Thermodynamics of nonsingular bouncing universes

    NASA Astrophysics Data System (ADS)

    Ferreira, Pedro C.; Pavón, Diego

    2016-01-01

    Homogeneous and isotropic, nonsingular, bouncing world models are designed to evade the initial singularity at the beginning of the cosmic expansion. Here, we study the thermodynamics of the subset of these models governed by general relativity. Considering the entropy of matter and radiation and considering the entropy of the apparent horizon to be proportional to its area, we argue that these models do not respect the generalized second law of thermodynamics, also away from the bounce.

  11. Simulating Metabolism with Statistical Thermodynamics

    SciTech Connect

    Cannon, William R.

    2014-08-04

    Kinetic probabilities of state are usually based on empirical measurements, while thermodynamic state probabilities are based on the assumption that chemical species are distributed to according to a multinomial Boltzmann distribution. While the use of kinetic simulations is desirable, obtaining all the mass action rate constants necessary to carry out kinetic simulations is an overwhelming challenge. Here, the kinetic probability of a state is compared in depth to the thermodynamic probability of a state for sets of coupled reactions. The entropic and energetic contributions to thermodynamic stable states are described and compared to entropic and energetic contributions of kinetic steady states. It is shown that many kinetic steady states are possible for a system of coupled reactions depending on the relative values of the mass action rate constants, but only one of these corresponds to a thermodynamically stable state. Furthermore, the thermodynamic stable state corresponds to a minimum free energy state. The use of thermodynamic simulations of state to model metabolic processes is attractive, since metabolite levels and energy requirements of pathways can be evaluated using only standard free energies of formation as parameters in the probability distribution. In chemical physics, the assumption of a Boltzmann distribution is the basis of transition state theory for modeling transitory species. Application to stable species, such as those found in metabolic processes, is a less severe assumption that would enable the use of simulations of state.

  12. Thermodynamics of firms' growth

    PubMed Central

    Zambrano, Eduardo; Hernando, Alberto; Hernando, Ricardo; Plastino, Angelo

    2015-01-01

    The distribution of firms' growth and firms' sizes is a topic under intense scrutiny. In this paper, we show that a thermodynamic model based on the maximum entropy principle, with dynamical prior information, can be constructed that adequately describes the dynamics and distribution of firms' growth. Our theoretical framework is tested against a comprehensive database of Spanish firms, which covers, to a very large extent, Spain's economic activity, with a total of 1 155 142 firms evolving along a full decade. We show that the empirical exponent of Pareto's law, a rule often observed in the rank distribution of large-size firms, is explained by the capacity of economic system for creating/destroying firms, and that can be used to measure the health of a capitalist-based economy. Indeed, our model predicts that when the exponent is larger than 1, creation of firms is favoured; when it is smaller than 1, destruction of firms is favoured instead; and when it equals 1 (matching Zipf's law), the system is in a full macroeconomic equilibrium, entailing ‘free’ creation and/or destruction of firms. For medium and smaller firm sizes, the dynamical regime changes, the whole distribution can no longer be fitted to a single simple analytical form and numerical prediction is required. Our model constitutes the basis for a full predictive framework regarding the economic evolution of an ensemble of firms. Such a structure can be potentially used to develop simulations and test hypothetical scenarios, such as economic crisis or the response to specific policy measures. PMID:26510828

  13. Thermodynamics of firms' growth.

    PubMed

    Zambrano, Eduardo; Hernando, Alberto; Fernández Bariviera, Aurelio; Hernando, Ricardo; Plastino, Angelo

    2015-11-01

    The distribution of firms' growth and firms' sizes is a topic under intense scrutiny. In this paper, we show that a thermodynamic model based on the maximum entropy principle, with dynamical prior information, can be constructed that adequately describes the dynamics and distribution of firms' growth. Our theoretical framework is tested against a comprehensive database of Spanish firms, which covers, to a very large extent, Spain's economic activity, with a total of 1,155,142 firms evolving along a full decade. We show that the empirical exponent of Pareto's law, a rule often observed in the rank distribution of large-size firms, is explained by the capacity of economic system for creating/destroying firms, and that can be used to measure the health of a capitalist-based economy. Indeed, our model predicts that when the exponent is larger than 1, creation of firms is favoured; when it is smaller than 1, destruction of firms is favoured instead; and when it equals 1 (matching Zipf's law), the system is in a full macroeconomic equilibrium, entailing 'free' creation and/or destruction of firms. For medium and smaller firm sizes, the dynamical regime changes, the whole distribution can no longer be fitted to a single simple analytical form and numerical prediction is required. Our model constitutes the basis for a full predictive framework regarding the economic evolution of an ensemble of firms. Such a structure can be potentially used to develop simulations and test hypothetical scenarios, such as economic crisis or the response to specific policy measures. PMID:26510828

  14. Indentation device for in situ Raman spectroscopic and optical studies

    NASA Astrophysics Data System (ADS)

    Gerbig, Y. B.; Michaels, C. A.; Forster, A. M.; Hettenhouser, J. W.; Byrd, W. E.; Morris, D. J.; Cook, R. F.

    2012-12-01

    Instrumented indentation is a widely used technique to study the mechanical behavior of materials at small length scales. Mechanical tests of bulk materials, microscopic, and spectroscopic studies may be conducted to complement indentation and enable the determination of the kinetics and physics involved in the mechanical deformation of materials at the crystallographic and molecular level, e.g., strain build-up in crystal lattices, phase transformations, and changes in crystallinity or orientation. However, many of these phenomena occurring during indentation can only be observed in their entirety and analyzed in depth under in situ conditions. This paper describes the design, calibration, and operation of an indentation device that is coupled with a Raman microscope to conduct in situ spectroscopic and optical analysis of mechanically deformed regions of Raman-active, transparent bulk material, thin films or fibers under contact loading. The capabilities of the presented device are demonstrated by in situ studies of the indentation-induced phase transformations of Si thin films and modifications of molecular conformations in high density polyethylene films.

  15. Statistical thermodynamics of charge-stabilized colloids

    NASA Astrophysics Data System (ADS)

    Torres Valderrama, A.

    2008-06-01

    This thesis is a theoretical study of equilibrium statistical thermodynamic properties of colloidal systems in which electrostatic interactions play a dominant role, namely, charge-stabilized colloidal suspensions. Such systems are fluids consisting of a mixture of a large number of mesoscopic particles and microscopic ions which interact via the Coulomb force, suspended in a molecular fluid. Quantum statistical mechanics is essential to fully understand the properties and stability of such systems. A less fundamental but for many purposes, sufficient description, is provided by classical statistical mechanics. In such approximation the system is considered as composed of a great number of charged classical particles with additional hard-core repulsions. The kinetic energy or momentum integrals become independent Gaussians, and hence their contribution to the free energy can be trivially evaluated. The contribution of the potential energy to the free energy on the other hand, depends upon the configuration of all the particles and becomes highly non-trivial due to the long-range character of the Coulomb force and the extremely different length scales involved in the problem. Using the microscopic model described above, we focus on the calculation of equilibrium thermodynamic properties (response functions), correlations (structure factors), and mechanical properties (forces and stresses), which can be measured in experiments and computed by Monte Carlo simulations. This thesis is divided into three parts. In part I, comprising chapters 2 and 3, we focus on finite-thickness effects in colloidal platelets and rigid planar membranes. In chapter 2 we study electrolyte-mediated interactions between two of such colloidal objects. Several aspects of these interactions are considered including the nature (attractive or repulsive) of the force between the objects, the osmotic properties for different types of surfaces and image charge effects. In part II, which includes

  16. Determination of Fe(II) by Optimized Thermal Lens Microscope

    NASA Astrophysics Data System (ADS)

    Cabrera, Humberto; Korte, Dorota; Franko, Mladen

    2015-09-01

    A simple and accurate method for the determination of Fe(II) species in liquid solutions was developed. The measurement principle was realized by the photothermal effect and performed by the use of a thermal lens microscope (TLM) in its optimized, mode-mismatched configuration with a counter-propagating probe beam (PB) and an excitation beam (EB). Additionally, due to the combination of the collimated PB and tightly focused EB measurement, the detection limit was significantly decreased. Our preliminary results demonstrated that a TLM enables the detection of iron ions at the levels of \\upmu g{\\cdot }{L}^{-1}, which makes this technique an alternative to traditional spectroscopic methods as a promising detector for the ultrasensitive determination of different compounds in liquid solutions.

  17. Microscopic analysis of currency and stock exchange markets

    NASA Astrophysics Data System (ADS)

    Kador, L.

    1999-08-01

    Recently it was shown that distributions of short-term price fluctuations in foreign-currency exchange exhibit striking similarities to those of velocity differences in turbulent flows. Similar profiles represent the spectral-diffusion behavior of impurity molecules in disordered solids at low temperatures. It is demonstrated that a microscopic statistical theory of the spectroscopic line shapes can be applied to the other two phenomena. The theory interprets the financial data in terms of information which becomes available to the traders and their reactions as a function of time. The analysis shows that there is no characteristic time scale in financial markets, but that instead stretched-exponential or algebraic memory functions yield good agreement with the price data. For an algebraic function, the theory yields truncated Lévy distributions which are often observed in stock exchange markets.

  18. Ab initio atomistic thermodynamics study on the oxidation mechanism of binary and ternary alloy surfaces

    NASA Astrophysics Data System (ADS)

    Liu, Shi-Yu; Liu, Shiyang; Li, De-Jun; Wang, Sanwu; Guo, Jing; Shen, Yaogen

    2015-02-01

    Utilizing a combination of ab initio density-functional theory and thermodynamics formalism, we have established the microscopic mechanisms for oxidation of the binary and ternary alloy surfaces and provided a clear explanation for the experimental results of the oxidation. We construct three-dimensional surface phase diagrams (SPDs) for oxygen adsorption on three different Nb-X(110) (X = Ti, Al or Si) binary alloy surfaces. On the basis of the obtained SPDs, we conclude a general microscopic mechanism for the thermodynamic oxidation, that is, under O-rich conditions, a uniform single-phase SPD (type I) and a nonuniform double-phase SPD (type II) correspond to the sustained complete selective oxidation and the non-sustained partial selective oxidation by adding the X element, respectively. Furthermore, by revealing the framework of thermodynamics for the oxidation mechanism of ternary alloys through the comparison of the surface energies of two separated binary alloys, we provide an understanding for the selective oxidation behavior of the Nb ternary alloy surfaces. Using these general microscopic mechanisms, one could predict the oxidation behavior of any binary and multi-component alloy surfaces based on thermodynamics considerations.

  19. Ab initio atomistic thermodynamics study on the oxidation mechanism of binary and ternary alloy surfaces

    SciTech Connect

    Liu, Shi-Yu; Liu, Shiyang; Li, De-Jun; Wang, Sanwu; Guo, Jing; Shen, Yaogen

    2015-02-14

    Utilizing a combination of ab initio density-functional theory and thermodynamics formalism, we have established the microscopic mechanisms for oxidation of the binary and ternary alloy surfaces and provided a clear explanation for the experimental results of the oxidation. We construct three-dimensional surface phase diagrams (SPDs) for oxygen adsorption on three different Nb-X(110) (X = Ti, Al or Si) binary alloy surfaces. On the basis of the obtained SPDs, we conclude a general microscopic mechanism for the thermodynamic oxidation, that is, under O-rich conditions, a uniform single-phase SPD (type I) and a nonuniform double-phase SPD (type II) correspond to the sustained complete selective oxidation and the non-sustained partial selective oxidation by adding the X element, respectively. Furthermore, by revealing the framework of thermodynamics for the oxidation mechanism of ternary alloys through the comparison of the surface energies of two separated binary alloys, we provide an understanding for the selective oxidation behavior of the Nb ternary alloy surfaces. Using these general microscopic mechanisms, one could predict the oxidation behavior of any binary and multi-component alloy surfaces based on thermodynamics considerations.

  20. Thermodynamic anomaly in magnesium hydroxide decomposition

    SciTech Connect

    Reis, T.A.

    1983-08-01

    The Origin of the discrepancy in the equilibrium water vapor pressure measurements for the reaction Mg(OH)/sub 2/(s) = MgO(s) + H/sub 2/O(g) when determined by Knudsen effusion and static manometry at the same temperature was investigated. For this reaction undergoing continuous thermal decomposition in Knudsen cells, Kay and Gregory observed that by extrapolating the steady-state apparent equilibrium vapor pressure measurements to zero-orifice, the vapor pressure was approx. 10/sup -4/ of that previously established by Giauque and Archibald as the true thermodynamic equilibrium vapor pressure using statistical mechanical entropy calculations for the entropy of water vapor. This large difference in vapor pressures suggests the possibility of the formation in a Knudsen cell of a higher energy MgO that is thermodynamically metastable by about 48 kJ / mole. It has been shown here that experimental results are qualitatively independent of the type of Mg(OH)/sub 2/ used as a starting material, which confirms the inferences of Kay and Gregory. Thus, most forms of Mg(OH)/sub 2/ are considered to be the stable thermodynamic equilibrium form. X-ray diffraction results show that during the course of the reaction only the equilibrium NaCl-type MgO is formed, and no different phases result from samples prepared in Knudsen cells. Surface area data indicate that the MgO molar surface area remains constant throughout the course of the reaction at low decomposition temperatures, and no significant annealing occurs at less than 400/sup 0/C. Scanning electron microscope photographs show no change in particle size or particle surface morphology. Solution calorimetric measurements indicate no inherent hgher energy content in the MgO from the solid produced in Knudsen cells. The Knudsen cell vapor pressure discrepancy may reflect the formation of a transient metastable MgO or Mg(OH)/sub 2/-MgO solid solution during continuous thermal decomposition in Knudsen cells.

  1. A DVD Spectroscope: A Simple, High-Resolution Classroom Spectroscope

    ERIC Educational Resources Information Center

    Wakabayashi, Fumitaka; Hamada, Kiyohito

    2006-01-01

    Digital versatile disks (DVDs) have successfully made up an inexpensive but high-resolution spectroscope suitable for classroom experiments that can easily be made with common material and gives clear and fine spectra of various light sources and colored material. The observed spectra can be photographed with a digital camera, and such images can…

  2. A Student-Built Scanning Tunneling Microscope

    ERIC Educational Resources Information Center

    Ekkens, Tom

    2015-01-01

    Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself.…

  3. Microscopic Analysis of Activated Sludge. Training Manual.

    ERIC Educational Resources Information Center

    Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

    This training manual presents material on the use of a compound microscope to analyze microscope communities, present in wastewater treatment processes, for operational control. Course topics include: sampling techniques, sample handling, laboratory analysis, identification of organisms, data interpretation, and use of the compound microscope.…

  4. Molecular cage occupancy of clathrate hydrates at infinite dilution: experimental determination and thermodynamic significance.

    PubMed

    Seol, Jiwoong; Lee, Jong-Won; Kim, Do-Youn; Takeya, Satoshi; Ripmeester, John A; Lee, Huen

    2010-01-21

    This study focuses on the cage occupancy of guest molecules in the infinitely dilute state. At the extreme conditions of highly diluted guest concentrations the direct measurements of the cage occupancy ratio representing the competitive inclusion of multiguest species appear to be so difficult because of spectroscopic intensity limitation, but its thermodynamic significance might be considerable due to the fact that the infinite-dilution value of the cage occupancy ratio can provide the valuable thermodynamic information as a very unique and guest-specific parameter. To experimentally identify gaseous guest populations in structure I (sI) and structure II (sII) cages, we used the solid-state nuclear magnetic resonance (NMR), gas chromatography, and direct gas measurements. Furthermore, we derived the simple and generalized thermodynamic equation related to cage occupancies at infinite dilution from the van der Waals-Platteeuw model. Both experimental and predicted values agree well within the experimental error range. PMID:20000371

  5. Coaxial atomic force microscope tweezers

    NASA Astrophysics Data System (ADS)

    Brown, K. A.; Aguilar, J. A.; Westervelt, R. M.

    2010-03-01

    We demonstrate coaxial atomic force microscope (AFM) tweezers that can trap and place small objects using dielectrophoresis (DEP). An attractive force is generated at the tip of a coaxial AFM probe by applying a radio frequency voltage between the center conductor and a grounded shield; the origin of the force is found to be DEP by measuring the pull-off force versus applied voltage. We show that the coaxial AFM tweezers can perform three-dimensional assembly by picking up a specified silica microsphere, imaging with the microsphere at the end of the tip, and placing it at a target destination.

  6. Stimulated Brillouin Scattering Microscopic Imaging

    NASA Astrophysics Data System (ADS)

    Ballmann, Charles W.; Thompson, Jonathan V.; Traverso, Andrew J.; Meng, Zhaokai; Scully, Marlan O.; Yakovlev, Vladislav V.

    2015-12-01

    Two-dimensional stimulated Brillouin scattering microscopy is demonstrated for the first time using low power continuous-wave lasers tunable around 780 nm. Spontaneous Brillouin spectroscopy has much potential for probing viscoelastic properties remotely and non-invasively on a microscopic scale. Nonlinear Brillouin scattering spectroscopy and microscopy may provide a way to tremendously accelerate the data aquisition and improve spatial resolution. This general imaging setup can be easily adapted for specific applications in biology and material science. The low power and optical wavelengths in the water transparency window used in this setup provide a powerful bioimaging technique for probing the mechanical properties of hard and soft tissue.

  7. Stimulated Brillouin Scattering Microscopic Imaging.

    PubMed

    Ballmann, Charles W; Thompson, Jonathan V; Traverso, Andrew J; Meng, Zhaokai; Scully, Marlan O; Yakovlev, Vladislav V

    2015-01-01

    Two-dimensional stimulated Brillouin scattering microscopy is demonstrated for the first time using low power continuous-wave lasers tunable around 780 nm. Spontaneous Brillouin spectroscopy has much potential for probing viscoelastic properties remotely and non-invasively on a microscopic scale. Nonlinear Brillouin scattering spectroscopy and microscopy may provide a way to tremendously accelerate the data aquisition and improve spatial resolution. This general imaging setup can be easily adapted for specific applications in biology and material science. The low power and optical wavelengths in the water transparency window used in this setup provide a powerful bioimaging technique for probing the mechanical properties of hard and soft tissue. PMID:26691398

  8. Microscopic tubes in igneous rocks

    NASA Technical Reports Server (NTRS)

    Richter, D.; Simmons, G.

    1977-01-01

    Microscopic tubes have been observed in several igneous rocks and may be quite common. They occur in single crystals and have either elliptical or circular cross-sections 1 to 5 microns in diameter and are ten to hundreds of microns long. Microtubes may be hollow or partially or completely filled with another phase, but are distinct from acicular crystals of accessory minerals such as rutile. Microtubes can form by at least three processes: (1) the partial annealing of microcracks, (2) the natural etching of dislocations, or (3) the primary inclusion of fluid material during crystal growth.

  9. Stimulated Brillouin Scattering Microscopic Imaging

    PubMed Central

    Ballmann, Charles W.; Thompson, Jonathan V.; Traverso, Andrew J.; Meng, Zhaokai; Scully, Marlan O.; Yakovlev, Vladislav V.

    2015-01-01

    Two-dimensional stimulated Brillouin scattering microscopy is demonstrated for the first time using low power continuous-wave lasers tunable around 780 nm. Spontaneous Brillouin spectroscopy has much potential for probing viscoelastic properties remotely and non-invasively on a microscopic scale. Nonlinear Brillouin scattering spectroscopy and microscopy may provide a way to tremendously accelerate the data aquisition and improve spatial resolution. This general imaging setup can be easily adapted for specific applications in biology and material science. The low power and optical wavelengths in the water transparency window used in this setup provide a powerful bioimaging technique for probing the mechanical properties of hard and soft tissue. PMID:26691398

  10. Solid-state optical microscope

    DOEpatents

    Young, I.T.

    1981-01-07

    A solid state optical microscope is described wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. Means for scanning in one of two orthogonal directions are provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

  11. Discovery Through the Computational Microscope

    PubMed Central

    Lee, Eric H.; Hsin, Jen; Sotomayor, Marcos; Comellas, Gemma; Schulten, Klaus

    2010-01-01

    Summary All-atom molecular dynamics simulations have become increasingly popular as a tool to investigate protein function and dynamics. However, researchers are concerned about the short time scales covered by simulations, the apparent impossibility to model large and integral biomolecular systems, and the actual predictive power of the molecular dynamics methodology. Here we review simulations that were in the past both hotly disputed and considered key successes, namely of proteins with mainly mechanical functions (titin, fibrinogen, ankyrin, and cadherin). The simulation work covered shows how state-of-the-art modeling alleviates some of the prior concerns, and how unrefuted discoveries are made through the “computational microscope". PMID:19836330

  12. Endoscopic and Microscopic Microvascular Decompression.

    PubMed

    Piazza, Matthew; Lee, John Y K

    2016-07-01

    The introduction of the endoscope into the neurosurgeon's armamentarium has revolutionized ventral and anterior skull-base surgery and, more recently, has been used in the surgical treatment of cerebellopontine angle (CPA) pathology. The utilization of the endoscope in microvascular decompression (MVD) for trigeminal neuralgia and other associated cranial nerve hyperactivity syndromes allows for unparalleled panoramic views and illumination of the neurovascular structures within the CPA and identification of vessel-nerve contact traditionally unseen using the microscope. In this article, the technical advantages and challenges of using the endoscope for MVD, operative technique, and patient outcomes of endoscopic MVD are discussed. PMID:27324997

  13. Thermodynamic aspects of materials science

    NASA Astrophysics Data System (ADS)

    Rusanov, A. I.

    2016-01-01

    As materials science studies physicochemical properties of materials, it needs a support of thermodynamics, which predicts general regularities for physicochemical properties of matter. This survey deals with solid materials the thermodynamic description of which is especially complicated. The achievements of last years provide better insight in the chemical potential anisotropy and, on this grounding, in the anisotropy of chemical affinity governing all processes in solid materials. The survey summarizes novel approaches and thermodynamic equations and then exhibits their use in materials science. As examples, the solubility, creep and corrosion of materials are analyzed. A newly discovered phenomenon, the strain sign effect in corrosion under stress (e.g., a difference in the corrosion rate on the opposite sides of a bent metallic plate), is described and explained thermodynamically. A modern theory of the strength of materials developed during last years is also presented with the characterization of crack properties, the mechanisms of crack propagation and estimation of the ultimate stress. The development of this area required the introduction of a novel thermodynamic potential that formed the basis for the theory of strength. The bibliography includes 47 references.

  14. Thermodynamic Limit in Statistical Physics

    NASA Astrophysics Data System (ADS)

    Kuzemsky, A. L.

    2014-03-01

    The thermodynamic limit in statistical thermodynamics of many-particle systems is an important but often overlooked issue in the various applied studies of condensed matter physics. To settle this issue, we review tersely the past and present disposition of thermodynamic limiting procedure in the structure of the contemporary statistical mechanics and our current understanding of this problem. We pick out the ingenious approach by Bogoliubov, who developed a general formalism for establishing the limiting distribution functions in the form of formal series in powers of the density. In that study, he outlined the method of justification of the thermodynamic limit when he derived the generalized Boltzmann equations. To enrich and to weave our discussion, we take this opportunity to give a brief survey of the closely related problems, such as the equipartition of energy and the equivalence and nonequivalence of statistical ensembles. The validity of the equipartition of energy permits one to decide what are the boundaries of applicability of statistical mechanics. The major aim of this work is to provide a better qualitative understanding of the physical significance of the thermodynamic limit in modern statistical physics of the infinite and "small" many-particle systems.

  15. Swimming bacteria power microscopic gears

    PubMed Central

    Sokolov, Andrey; Apodaca, Mario M.; Grzybowski, Bartosz A.; Aranson, Igor S.

    2010-01-01

    Whereas the laws of thermodynamics prohibit extraction of useful work from the Brownian motion of particles in equilibrium, these motions can be “rectified” under nonequilibrium conditions, for example, in the presence of asymmetric geometrical obstacles. Here, we describe a class of systems in which aerobic bacteria Bacillus subtilis moving randomly in a fluid film power submillimeter gears and primitive systems of gears decorated with asymmetric teeth. The directional rotation is observed only in the regime of collective bacterial swimming and the gears’ angular velocities depend on and can be controlled by the amount of oxygen available to the bacteria. The ability to harness and control the power of collective motions appears an important requirement for further development of mechanical systems driven by microorganisms. PMID:20080560

  16. Swimming bacteria power microscopic gears

    SciTech Connect

    Sokolov, Andrey; Apodaca, Mario M.; Grzybowski, Bartosz A.; Aranson, Igor S.

    2010-01-19

    Whereas the laws of thermodynamics prohibit extraction of useful work from the Brownian motion of particles in equilibrium, these motions can be “rectified” under nonequilibrium conditions, for example, in the presence of asymmetric geometrical obstacles. Here, we describe a class of systems in which aerobic bacteria Bacillus subtilis moving randomly in a fluid film power submillimeter gears and primitive systems of gears decorated with asymmetric teeth. The directional rotation is observed only in the regime of collective bacterial swimming and the gears’ angular velocities depend on and can be controlled by the amount of oxygen available to the bacteria. The ability to harness and control the power of collective motions appears an important requirement for further development of mechanical systems driven by microorganisms.

  17. Swimming bacteria power microscopic gears.

    SciTech Connect

    Sokolov, A.; Apodaca, M. M.; Grzybowski, B. A.; Aranson, I. S.; Materials Science Division; Princeton Univ.; Northwestern Univ.

    2010-01-19

    Whereas the laws of thermodynamics prohibit extraction of useful work from the Brownian motion of particles in equilibrium, these motions can be 'rectified' under nonequilibrium conditions, for example, in the presence of asymmetric geometrical obstacles. Here, we describe a class of systems in which aerobic bacteria Bacillus subtilis moving randomly in a fluid film power submillimeter gears and primitive systems of gears decorated with asymmetric teeth. The directional rotation is observed only in the regime of collective bacterial swimming and the gears angular velocities depend on and can be controlled by the amount of oxygen available to the bacteria. The ability to harness and control the power of collective motions appears an important requirement for further development of mechanical systems driven by microorganisms.

  18. Scanned optical fiber confocal microscope

    NASA Astrophysics Data System (ADS)

    Dickensheets, David L.; Kino, Gordon S.

    1994-04-01

    The size and weight of conventional optical microscopes often makes them inconvenient for use on the human body or for in-situ examination during materials processing. We describe a new fiber-optic scanning confocal optical microscope which could have a total outside diameter as small as 1 mm, and should lend itself to applications in endoscopy or to optical in vivo histology. The first experimental device utilizes a single-mode optical fiber for illumination and detection. The scanning element is a mechanically resonant fused silica cantilever 1.5 cm long and 0.8 mm across, with a micromachined two-phase zone plate objective mounted at one end. The cantilever is electrostatically scanned near resonance in two dimensions, generating a Lissajous pattern which is scan converted to conventional video for real time display or digitization. The objective lens has N.A. equals 0.25 at (lambda) equals 0.6328 micrometers , with a measured spot size of 1.8 micrometers FWHM.

  19. Sensing mode atomic force microscope

    DOEpatents

    Hough, Paul V.; Wang, Chengpu

    2004-11-16

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  20. Sensing mode atomic force microscope

    DOEpatents

    Hough, Paul V. C.; Wang, Chengpu

    2006-08-22

    An atomic force microscope is described having a cantilever comprising a base and a probe tip on an end opposite the base; a cantilever drive device connected to the base; a magnetic material coupled to the probe tip, such that when an incrementally increasing magnetic field is applied to the magnetic material an incrementally increasing force will be applied to the probe tip; a moveable specimen base; and a controller constructed to obtain a profile height of a specimen at a point based upon a contact between the probe tip and a specimen, and measure an adhesion force between the probe tip and the specimen by, under control of a program, incrementally increasing an amount of a magnetic field until a release force, sufficient to break the contact, is applied. An imaging method for atomic force microscopy involving measuring a specimen profile height and adhesion force at multiple points within an area and concurrently displaying the profile and adhesion force for each of the points is also described. A microscope controller is also described and is constructed to, for a group of points, calculate a specimen height at a point based upon a cantilever deflection, a cantilever base position and a specimen piezo position; calculate an adhesion force between a probe tip and a specimen at the point by causing an incrementally increasing force to be applied to the probe tip until the probe tip separates from a specimen; and move the probe tip to a new point in the group.

  1. Sensing mode atomic force microscope

    DOEpatents

    Hough, Paul V. C.; Wang, Chengpu

    2003-01-01

    An atomic force microscope utilizes a pulse release system and improved method of operation to minimize contact forces between a probe tip affixed to a flexible cantilever and a specimen being measured. The pulse release system includes a magnetic particle affixed proximate the probe tip and an electromagnetic coil. When energized, the electromagnetic coil generates a magnetic field which applies a driving force on the magnetic particle sufficient to overcome adhesive forces exhibited between the probe tip and specimen. The atomic force microscope includes two independently displaceable piezo elements operable along a Z-axis. A controller drives the first Z-axis piezo element to provide a controlled approach between the probe tip and specimen up to a point of contact between the probe tip and specimen. The controller then drives the first Z-axis piezo element to withdraw the cantilever from the specimen. The controller also activates the pulse release system which drives the probe tip away from the specimen during withdrawal. Following withdrawal, the controller adjusts the height of the second Z-axis piezo element to maintain a substantially constant approach distance between successive samples.

  2. Inspection with Robotic Microscopic Imaging

    NASA Technical Reports Server (NTRS)

    Pedersen, Liam; Deans, Matthew; Kunz, Clay; Sargent, Randy; Chen, Alan; Mungas, Greg

    2005-01-01

    Future Mars rover missions will require more advanced onboard autonomy for increased scientific productivity and reduced mission operations cost. One such form of autonomy can be achieved by targeting precise science measurements to be made in a single command uplink cycle. In this paper we present an overview of our solution to the subproblems of navigating a rover into place for microscopic imaging, mapping an instrument target point selected by an operator using far away science camera images to close up hazard camera images, verifying the safety of placing a contact instrument on a sample or finding nearby safe points, and analyzing the data that comes back from the rover. The system developed includes portions used in the Multiple Target Single Cycle Instrument Placement demonstration at NASA Ames in October 2004, and portions of the MI Toolkit delivered to the Athena Microscopic Imager Instrument Team for the MER mission still operating on Mars today. Some of the component technologies are also under consideration for MSL mission infusion.

  3. Martian Magnets Under the Microscope

    NASA Technical Reports Server (NTRS)

    2004-01-01

    NASA's Mars Exploration Rover Spirit acquired this microscopic imager view of its capture magnet on sol 92 (April 6, 2004). Both Spirit and the Mars Exploration Rover Opportunity are equipped with a number of magnets. The capture magnet, as seen here, has a stronger charge than its sidekick, the filter magnet. The lower-powered filter magnet captures only the most magnetic airborne dust with the strongest charges, while the capture magnet picks up all magnetic airborne dust.

    The magnets' primary purpose is to collect the martian magnetic dust so that scientists can analyze it with the rovers' Moessbauer spectrometers. While there is plenty of dust on the surface of Mars, it is difficult to confirm where it came from, and when it was last airborne. Because scientists are interested in learning about the properties of the dust in the atmosphere, they devised this dust-collection experiment.

    The capture magnet is about 4.5 centimeters (1.8 inches) in diameter and is constructed with a central cylinder and three rings, each with alternating orientations of magnetization. Scientists have been monitoring the continual accumulation of dust since the beginning of the mission with panoramic camera and microscopic imager images. They had to wait until enough dust accumulated before they could get a Moessbauer spectrometer analysis. The results of that analysis, performed on sol 92, have not been sent back to Earth yet.

  4. Black Hole Thermodynamic Products in Einstein Gauss Bonnet Gravity

    NASA Astrophysics Data System (ADS)

    Biswas, Ritabrata

    2016-07-01

    By now, there are many hints from string theory that collective excitations of solitonic objects can be described by effective low energy theories. The entropy of general rotating black holes in five dimensions may be interpreted as an indication that, it derives from two independent microscopic contributions and each of these may be attributed to a gas of strings. In the present work, we consider a charged black hole in five dimensional Einstein Gauss Bonnet gravity. In spite of presenting the thermodynamic quantities' product as summation/ subtraction of two independent integers, our motive is to check whether the product of the same quantity for event horizon and Cauchy horizon is free of mass, i.e., global, or not. We derive the thermodynamic products of characteristic parameters to mark which are global. We further interpret the stability of the black holes by computing the specific heat for both horizons. Stable and unstable phases of horizons are pointed out. The phase transitions with respect to the charge in nature of specific heat are also observed. All these calculation might be helpful to understand the microscopic nature of such black holes.

  5. Thermodynamic and Structural Investigation of Synthetic Actinide-Peptide Scaffolds.

    PubMed

    Safi, Samir; Jeanson, Aurélie; Roques, Jérome; Solari, Pier Lorenzo; Charnay-Pouget, Florence; Den Auwer, Christophe; Creff, Gaëlle; Aitken, David J; Simoni, Eric

    2016-01-19

    The complexation of uranium and europium, in oxidation states +VI and +III, respectively, was investigated with pertinent bio-inorganic systems. Three aspartate-rich pentapeptides with different structural properties were selected for study to rationalize the structure-affinity relationships. Thermodynamic results, crosschecked by both isothermal titration calorimetry and time-resolved laser fluorescence spectroscopy, showed different affinity depending on the peptide for both Eu(III) and U(VI). The thermodynamic aspects were correlated to structural predictions, which were acquired by density functional theory quantum chemical calculations and from IR and extended X-ray absorption fine structure experiments. The combination of these microscopic properties revealed that carbonyl-metal interactions affected the entropy in the case of europium, while the larger uranyl cation was mostly affected by preorganization and steric effects, so that the affinity was enhanced through enthalpy. The approach described here revealed various microscopic aspects governing peptide actinide affinity. Highlighting these mechanisms should certainly contribute to the rational synthesis of higher affinity biomimetic aspartic ligands. PMID:26727631

  6. Living Matter Observations with a Novel Hyperspectral Supercontinuum Confocal Microscope for VIS to Near-IR Reflectance Spectroscopy

    PubMed Central

    Bertani, Francesca R.; Ferrari, Luisa; Mussi, Valentina; Botti, Elisabetta; Costanzo, Antonio; Selci, Stefano

    2013-01-01

    A broad range hyper-spectroscopic microscope fed by a supercontinuum laser source and equipped with an almost achromatic optical layout is illustrated with detailed explanations of the design, implementation and data. The real novelty of this instrument, a confocal spectroscopic microscope capable of recording high resolution reflectance data in the VIS-IR spectral range from about 500 nm to 2.5 μm wavelengths, is the possibility of acquiring spectral data at every physical point as defined by lateral coordinates, X and Y, as well as at a depth coordinate, Z, as obtained by the confocal optical sectioning advantage. With this apparatus we collect each single scanning point as a whole spectrum by combining two linear spectral detector arrays, one CCD for the visible range, and one InGaAs infrared array, simultaneously available at the sensor output channel of the home made instrument. This microscope has been developed for biomedical analysis of human skin and other similar applications. Results are shown illustrating the technical performances of the instrument and the capability in extracting information about the composition and the structure of different parts or compartments in biological samples as well as in solid statematter. A complete spectroscopic fingerprinting of samples at microscopic level is shown possible by using statistical analysis on raw data or analytical reflectance models based on Abelés matrix transfer methods. PMID:24233077

  7. Microscopic and spectroscopic analysis of tungsten trioxide and titanium-doped tungsten trioxide thin films

    NASA Astrophysics Data System (ADS)

    Yun, Young Taek

    Tungsten oxide (WO3) has been a subject of high interest for its unique properties, and recently for its importance in different types of industrial applications which ranges from non-emissive displays, optical, microelectronic, catalytic/photocatalytic, humidity, temperature, gas, and biosensor devices. In this study, WO3 and Ti doped thin films were prepared using radio frequency magnetron reactive sputtering at different substrate temperatures ranging from room temperature to 500 °C in increments of 100 °C. After forming a hypothesis based on knowledge of established WO3 properties, we attempt in this work to investigate how the doping influences the roughness and the mean grain size of the nanoparticles on the surface layer of the thin films, its structure, and crystallinity. Therefore we pursued analysis by Atomic Force Microscopy (AFM), X-ray diffraction (XRD), and Raman spectroscopy, using a comparative approach. The outcomes of these analyses demonstrate that higher temperatures are necessary for growing crystalline material if doping is used. Also, smaller nanoparticles are obtained when a small amount of dopant, e.g. 5% Ti, is incorporated. Both XRD and Raman measurement indicate morphological changes of the doped material. Finally, annealing of the amorphous doped samples at temperatures of 600 °C and 900 °C did not contribute significantly to material properties improvement.

  8. Microscopic and spectroscopic investigation of bioactive glasses for antibiotic controlled release

    NASA Astrophysics Data System (ADS)

    Cavalu, S.; Banica, F.; Gruian, C.; Vanea, E.; Goller, G.; Simon, V.

    2013-05-01

    Bioactive glass with the composition 0.55SiO2·0.41CaO·0.04P2O5 was prepared following the sol-gel route as controlled delivery systems for tetracycline (TC). The maturation and drying of the gel under different conditions led to different behavior regarding the loading and release of TC from these matrices. The pore size modifications upon TC loading evidenced by BET method show different ability of the glass matrices with respect to TC incorporation, also supported by experimental EPR and fluorescence spectroscopy. EPR spectra of both TC solution and immobilized TC on the porous structure of glass specimens demonstrated changes in tetracycline structure during loading and upon adsorption. The TC release profile monitored by differential pulse voltammetry shows a maximum concentration after 2 h and a continuously slow release during the next 24 h. The obtained results demonstrate that the pores size modification related to different maturation and drying procedures seems to be a determinative factor in tetracycline release process.

  9. Nd(III)-induced rice mitochondrial dysfunction investigated by spectroscopic and microscopic methods.

    PubMed

    Xia, Cai-Fen; Lv, Long; Chen, Xin-You; Fu, Bo-Qiao; Lei, Ke-Lin; Qin, Cai-Qin; Liu, Yi

    2015-04-01

    The production capacity and yield of neodymium (Nd) in China have ranked the first in the world. Because of its unique biophysical and biochemical properties, Nd compounds have entered into the agricultural environment greatly to promote plant growth. Mitochondria play a crucial role in respiration and metabolism during the growth of plants. However, little is known about the mechanism by which Nd act at the mitochondrial level in plant cells. In this study, rice mitochondrial swelling, collapsed transmembrane potential and decreased membrane fluidity were examined to be important factors for mitochondria permeability transition pore (mPTP) opening induced by Nd(III). The protection of cyclosporin A (CsA) and dithiothreitol (DTT) could confirm that Nd(III) could trigger mPTP opening. Additionally, mitochondrial membrane breakdown observed by TEM and the release of cytochrome c (Cyt c) could also elucidate the mPTP opening from another point of view. At last, the study showed that Nd(III) could restrain the mitochondrial membrane lipid peroxide, so it might interact with anionic lipid too. This detection will be conductive to the safe application of Nd compounds in agriculture and food industry. PMID:25650179

  10. Microscopic and spectroscopic features of gunpowder and its documentation in gunshot wounds in charred bodies.

    PubMed

    Dolinak, David; Wise, Steven H; Jones, Curtiss

    2008-12-01

    Determining the direction and range of fire of gunshot wounds in charred bodies can be difficult because soot resulting from thermal injury can grossly be identical to soot arising from a contact or close-range firearm discharge. Two charred bodies had gunshot wounds of the head and neck region that were distorted by thermal effect, precluding determination of the direction and range of fire by gross findings alone. By microscopy, deep wound tissue from each charred body had foreign material suggestive of gunpowder. Samples of the foreign material were examined by Fourier transform infrared (FT-IR) microscopy and determined to be cellulose nitrate (nitrocellulose), a main component of gunpowder. In addition, 12 cases of suicide in well-preserved bodies with contact gunshot wounds were examined with FT-IR microscopy, confirming the presence of cellulose nitrate in 6 (50%) of the cases. Identification of cellulose nitrate in the tracks of gunshot wounds can assist in the determination of direction and range of fire when the surface features are charred. PMID:19259016

  11. Microscopic and Spectroscopic Analyses of Chlorhexidine Tolerance in Delftia acidovorans Biofilms

    PubMed Central

    Rema, Tara; Lawrence, John R.; Dynes, James J.; Hitchcock, Adam P.

    2014-01-01

    The physicochemical responses of Delftia acidovorans biofilms exposed to the commonly used antimicrobial chlorhexidine (CHX) were examined in this study. A CHX-sensitive mutant (MIC, 1.0 μg ml−1) was derived from a CHX-tolerant (MIC, 15.0 μg ml−1) D. acidovorans parent strain using transposon mutagenesis. D. acidovorans mutant (MT51) and wild-type (WT15) strain biofilms were cultivated in flow cells and then treated with CHX at sub-MIC and inhibitory concentrations and examined by confocal laser scanning microscopy (CLSM), scanning transmission X-ray microscopy (STXM), and infrared (IR) spectroscopy. Specific morphological, structural, and chemical compositional differences between the CHX-treated and -untreated biofilms of both strains were observed. Apart from architectural differences, CLSM revealed a negative effect of CHX on biofilm thickness in the CHX-sensitive MT51 biofilms relative to those of the WT15 strain. STXM analyses showed that the WT15 biofilms contained two morphochemical cell variants, whereas only one type was detected in the MT51 biofilms. The cells in the MT51 biofilms bioaccumulated CHX to a similar extent as one of the cell types found in the WT15 biofilms, whereas the other cell type in the WT15 biofilms did not bioaccumulate CHX. STXM and IR spectral analyses revealed that CHX-sensitive MT51 cells accumulated the highest levels of CHX. Pretreating biofilms with EDTA promoted the accumulation of CHX in all cells. Thus, it is suggested that a subpopulation of cells that do not accumulate CHX appear to be responsible for greater CHX resistance in D. acidovorans WT15 biofilm in conjunction with the possible involvement of bacterial membrane stability. PMID:25022584

  12. Spectroscopic, microscopic and catalytic properties of silver nanoparticles synthesized using Saraca indica flower

    NASA Astrophysics Data System (ADS)

    Vidhu, V. K.; Philip, Daizy

    2014-01-01

    The bioprospective field is dynamic area of research in the recent years. The present article reports a green synthetic route for the production of highly stable, bio-inspired silver nanoparticles using dried Saraca indica flower. The method is facile, cost effective, simple and reproducible. The reduction of silver ions and the formation of silver nanoparticles has been monitored using UV-visible spectroscopy. The TEM, SAED and XRD result reveal that the silver nanoparticles are crystalline in nature. FTIR spectra are used to identify the biomolecules that bind on the surface of silver nanoparticles, which increased the stability of the particles. S. indica flower extract plays its role as an excellent reducing agent of silver ions and the biosynthesized silver nanoparticles are safer to environment. Also the size dependent catalytic activity of silver nanoparticles in the reduction of cationic dye, Methylene blue by NaBH4 is studied by UV-visible spectroscopy. The efficiency of synthesized nanoparticles as an excellent catalyst is proved by the reduction of Methylene blue which is confirmed by the decrease in the absorbance with time and is attributed to electron relay effect.

  13. Precise autofocusing microscope with rapid response

    NASA Astrophysics Data System (ADS)

    Liu, Chien-Sheng; Jiang, Sheng-Hong

    2015-03-01

    The rapid on-line or off-line automated vision inspection is a critical operation in the manufacturing fields. Accordingly, this present study designs and characterizes a novel precise optics-based autofocusing microscope with a rapid response and no reduction in the focusing accuracy. In contrast to conventional optics-based autofocusing microscopes with centroid method, the proposed microscope comprises a high-speed rotating optical diffuser in which the variation of the image centroid position is reduced and consequently the focusing response is improved. The proposed microscope is characterized and verified experimentally using a laboratory-built prototype. The experimental results show that compared to conventional optics-based autofocusing microscopes, the proposed microscope achieves a more rapid response with no reduction in the focusing accuracy. Consequently, the proposed microscope represents another solution for both existing and emerging industrial applications of automated vision inspection.

  14. Non-hermitian quantum thermodynamics

    DOE PAGESBeta

    Gardas, Bartłomiej; Deffner, Sebastian; Saxena, Avadh

    2016-03-22

    Thermodynamics is the phenomenological theory of heat and work. Here we analyze to what extent quantum thermodynamic relations are immune to the underlying mathematical formulation of quantum mechanics. As a main result, we show that the Jarzynski equality holds true for all non-hermitian quantum systems with real spectrum. This equality expresses the second law of thermodynamics for isothermal processes arbitrarily far from equilibrium. In the quasistatic limit however, the second law leads to the Carnot bound which is fulfilled even if some eigenenergies are complex provided they appear in conjugate pairs. Lastly, we propose two setups to test our predictions,more » namely with strongly interacting excitons and photons in a semiconductor microcavity and in the non-hermitian tight-binding model.« less

  15. Non-hermitian quantum thermodynamics

    NASA Astrophysics Data System (ADS)

    Gardas, Bartłomiej; Deffner, Sebastian; Saxena, Avadh

    2016-03-01

    Thermodynamics is the phenomenological theory of heat and work. Here we analyze to what extent quantum thermodynamic relations are immune to the underlying mathematical formulation of quantum mechanics. As a main result, we show that the Jarzynski equality holds true for all non-hermitian quantum systems with real spectrum. This equality expresses the second law of thermodynamics for isothermal processes arbitrarily far from equilibrium. In the quasistatic limit however, the second law leads to the Carnot bound which is fulfilled even if some eigenenergies are complex provided they appear in conjugate pairs. Furthermore, we propose two setups to test our predictions, namely with strongly interacting excitons and photons in a semiconductor microcavity and in the non-hermitian tight-binding model.

  16. Local non-equilibrium thermodynamics

    PubMed Central

    Jinwoo, Lee; Tanaka, Hajime

    2015-01-01

    Local Shannon entropy lies at the heart of modern thermodynamics, with much discussion of trajectory-dependent entropy production. When taken at both boundaries of a process in phase space, it reproduces the second law of thermodynamics over a finite time interval for small scale systems. However, given that entropy is an ensemble property, it has never been clear how one can assign such a quantity locally. Given such a fundamental omission in our knowledge, we construct a new ensemble composed of trajectories reaching an individual microstate, and show that locally defined entropy, information, and free energy are properties of the ensemble, or trajectory-independent true thermodynamic potentials. We find that the Boltzmann-Gibbs distribution and Landauer's principle can be generalized naturally as properties of the ensemble, and that trajectory-free state functions of the ensemble govern the exact mechanism of non-equilibrium relaxation. PMID:25592077

  17. Non-hermitian quantum thermodynamics

    PubMed Central

    Gardas, Bartłomiej; Deffner, Sebastian; Saxena, Avadh

    2016-01-01

    Thermodynamics is the phenomenological theory of heat and work. Here we analyze to what extent quantum thermodynamic relations are immune to the underlying mathematical formulation of quantum mechanics. As a main result, we show that the Jarzynski equality holds true for all non-hermitian quantum systems with real spectrum. This equality expresses the second law of thermodynamics for isothermal processes arbitrarily far from equilibrium. In the quasistatic limit however, the second law leads to the Carnot bound which is fulfilled even if some eigenenergies are complex provided they appear in conjugate pairs. Furthermore, we propose two setups to test our predictions, namely with strongly interacting excitons and photons in a semiconductor microcavity and in the non-hermitian tight-binding model. PMID:27003686

  18. Local non-equilibrium thermodynamics.

    PubMed

    Jinwoo, Lee; Tanaka, Hajime

    2015-01-01

    Local Shannon entropy lies at the heart of modern thermodynamics, with much discussion of trajectory-dependent entropy production. When taken at both boundaries of a process in phase space, it reproduces the second law of thermodynamics over a finite time interval for small scale systems. However, given that entropy is an ensemble property, it has never been clear how one can assign such a quantity locally. Given such a fundamental omission in our knowledge, we construct a new ensemble composed of trajectories reaching an individual microstate, and show that locally defined entropy, information, and free energy are properties of the ensemble, or trajectory-independent true thermodynamic potentials. We find that the Boltzmann-Gibbs distribution and Landauer's principle can be generalized naturally as properties of the ensemble, and that trajectory-free state functions of the ensemble govern the exact mechanism of non-equilibrium relaxation. PMID:25592077

  19. A Simple Statistical Thermodynamics Experiment

    NASA Astrophysics Data System (ADS)

    LoPresto, Michael C.

    2010-03-01

    Comparing the predicted and actual rolls of combinations of both two and three dice can help to introduce many of the basic concepts of statistical thermodynamics, including multiplicity, probability, microstates, and macrostates, and demonstrate that entropy is indeed a measure of randomness, that disordered states (those of higher entropy) are more likely than more ordered ones. It can also show that predictions based on statistics are more accurate with larger samples of data. What follows is a simple experiment introducing some of the basic elements of statistical thermodynamics that can be a light and even fun way to end a unit on thermodynamics, often the end of a challenging first semester of introductory physics.

  20. Nonequilibrium thermodynamics of an interface

    NASA Astrophysics Data System (ADS)

    Schweizer, Marco; Öttinger, Hans Christian; Savin, Thierry

    2016-05-01

    Interfacial thermodynamics has deep ramifications in understanding the boundary conditions of transport theories. We present a formulation of local equilibrium for interfaces that extends the thermodynamics of the "dividing surface," as introduced by Gibbs, to nonequilibrium settings such as evaporation or condensation. By identifying the precise position of the dividing surface in the interfacial region with a gauge degree of freedom, we exploit gauge-invariance requirements to consistently define the intensive variables for the interface. The model is verified under stringent conditions by employing high-precision nonequilibrium molecular-dynamics simulations of a coexisting vapor-liquid Lennard-Jones fluid. We conclude that the interfacial temperature is determined using the surface tension as a "thermometer," and it can be significantly different from the temperatures of the adjacent phases. Our findings lay foundations for nonequilibrium interfacial thermodynamics.

  1. Nonequilibrium thermodynamics of an interface.

    PubMed

    Schweizer, Marco; Öttinger, Hans Christian; Savin, Thierry

    2016-05-01

    Interfacial thermodynamics has deep ramifications in understanding the boundary conditions of transport theories. We present a formulation of local equilibrium for interfaces that extends the thermodynamics of the "dividing surface," as introduced by Gibbs, to nonequilibrium settings such as evaporation or condensation. By identifying the precise position of the dividing surface in the interfacial region with a gauge degree of freedom, we exploit gauge-invariance requirements to consistently define the intensive variables for the interface. The model is verified under stringent conditions by employing high-precision nonequilibrium molecular-dynamics simulations of a coexisting vapor-liquid Lennard-Jones fluid. We conclude that the interfacial temperature is determined using the surface tension as a "thermometer," and it can be significantly different from the temperatures of the adjacent phases. Our findings lay foundations for nonequilibrium interfacial thermodynamics. PMID:27300960

  2. Non-hermitian quantum thermodynamics.

    PubMed

    Gardas, Bartłomiej; Deffner, Sebastian; Saxena, Avadh

    2016-01-01

    Thermodynamics is the phenomenological theory of heat and work. Here we analyze to what extent quantum thermodynamic relations are immune to the underlying mathematical formulation of quantum mechanics. As a main result, we show that the Jarzynski equality holds true for all non-hermitian quantum systems with real spectrum. This equality expresses the second law of thermodynamics for isothermal processes arbitrarily far from equilibrium. In the quasistatic limit however, the second law leads to the Carnot bound which is fulfilled even if some eigenenergies are complex provided they appear in conjugate pairs. Furthermore, we propose two setups to test our predictions, namely with strongly interacting excitons and photons in a semiconductor microcavity and in the non-hermitian tight-binding model. PMID:27003686

  3. Thermodynamics of Quasi-One Oxides

    NASA Astrophysics Data System (ADS)

    Kuo, Yung-Kang

    1995-11-01

    creation of solitons up to 7 Tesla. In addition, the variation of c_{P} vs. magnetic field is approximately consistent with excitation of (triplet) magnons. Most interestingly, scaling of the Arrhenius plot of c_{P} - beta T^3 in various fields is observed. We present the measurements of the specific heat (by ac calorimetry), Young's modulus (by a vibrating reed technique), and susceptibility (with a Faraday balance) on the same crystal of blue bronze rm K_ {0.3}MoO_3 for which the thermal expansion had previously been measured. All these measured thermodynamic response functions were fitted by using the free energy expression developed by Chen, Albright, and Sengers (CAS) in the 3D XY (d = 3, n = 2) model. The small variation of critical fitting parameters obtained for the five CAS fits indicates that the same function fits all quantities well, which allows the prefactors in the Testardi and Ehrenfest relations to be unambiguously determined, which had not previously been possible for a phase transition in a quasi-one-dimensional material. While the large value of one fitting parameter (u), raises a yet unresolved question about the microscopic meaningfulness of the CAS approach for CDW's, the model provides a useful fitting function from which thermodynamic properties can be unambiguously extracted for comparison with microscopic models.

  4. Atomic Spectroscopic Databases at NIST

    NASA Technical Reports Server (NTRS)

    Reader, J.; Kramida, A. E.; Ralchenko, Yu.

    2006-01-01

    We describe recent work at NIST to develop and maintain databases for spectra, transition probabilities, and energy levels of atoms that are astrophysically important. Our programs to critically compile these data as well as to develop a new database to compare plasma calculations for atoms that are not in local thermodynamic equilibrium are also summarized.

  5. Microscopic Theory of the Thermodynamic Properties of Sr3Ru2O7

    NASA Astrophysics Data System (ADS)

    Wei-Cheng, Lee; Congjun, Wu

    2016-03-01

    Not Available Supported by the NSF DMR-1410375 and AFOSR FA9550-14-1-0168, the President's Research Catalyst Award (No CA-15-327861) from the University of California Office of the President, and the CAS/SAFEA International Partnership Program for Creative Research Teams.

  6. Black hole thermodynamics as seen through a microscopic model of a relativistic Bose gas

    NASA Astrophysics Data System (ADS)

    Skákala, Jozef; Shankaranarayanan, S.

    2016-02-01

    Equations of gravity when projected on spacetime horizons resemble Navier-Stokes equation of a fluid with a specific equation of state [T. Damour, Surface effects of black hole physics, in Proc. M. Grossman Meeting (North Holland, 1982), p. 587, T. Padmanabhan, Phys. Rev. D 83 (2011) 044048, arXiv:gr-qc/1012.0119, S. Kolekar and T. Padmanabhan, Phys. Rev. D 85 (2011) 024004, arXiv:gr-qc/1012.5421]. We show that this equation of state describes massless ideal relativistic gas. We use these results, and build an explicit and simple molecular model of the fluid living on the Schwarzschild and Reissner-Nordström black hole horizons. For the spin zero Bose gas, our model makes two predictions: (i) The horizon area/entropy is quantized as given by Bekenstein’s quantization rule, (ii) The model explains the correct type of proportionality between horizon area and entropy. However, for the physically relevant range of parameters, the proportionality constant is never equal to 1/4.

  7. Employing Multiple Spectroscopic Techniques Simultaneously to Observe Protein Unfolding

    NASA Astrophysics Data System (ADS)

    Crowe, Michael; Kelty, Ben; Link, Justin

    2015-03-01

    A protein's function is directly related to its native, folded structure. In order to study the structure of proteins, the unfolding process may be characterized. In our study, by using the spectroscopic techniques of circular dichroism (CD), absorption, and fluorescence simultaneously, we examined the unfolding of horse heart cytochrome c, a well-studied, model protein by gradually increasing the concentration of the chemical denaturant, guanidine hydrochloride. The signal changes from these modalities over the course of the unfolding reaction provides some of the thermodynamic properties like Gibbs free energy for insight into the stability of the protein. This allows us to compare the three techniques under the exact same conditions. The objective of this session is to present recent work in developing a protocol to observe the unfolding of cytochrome c using fluorescence, absorbance, and CD simultaneously.

  8. Actinide solubility and spectroscopic speciation in alkaline Hanford waste solutions

    SciTech Connect

    Rao, L.; Felmy, A.R.; Rai, D.

    1996-10-01

    Information on the solubility and the speciation of actinide elements, especially plutonium and neptunium, in alkaline solutions is of importance in the development of separation techniques for the Hanford tank HLW supernatant. In the present study, experimental data on the solubilities of plutonium in simulated Hanford tank solutions were analyzed with Pitzer`s specific ion-interaction approach, which is applicable in dilute to highly concentrated electrolyte solutions. In order to investigate the formation of actinide species in alkaline solutions with ligands (e.g., hydroxide, aluminate and carbonate), spectroscopic measurements of neptunium (V), as a chemical analog of plutonium (V), were conducted. Based on the solubility data and available information on both solid and aqueous species, a thermodynamic model was proposed. The applicability and limitations of this model are discussed.

  9. Microscopic overdiagnosis of intestinal amoebiasis.

    PubMed

    Rayan, Hanan Z E

    2005-12-01

    To determine the misdiagnosis of intestinal amoebiasis associated to microscopic examination of faeces, 50 stool samples of patients infected with Entamoeba histolytica were collected from different Primary Health Care Centers, hospitals and private laboratories in Ismailia G. The samples were examined using Wheatley's trichrome staining technique to differrentiate E. histolytica E. dispar complex from other non-pathogenic intestinal amoebae and multiplex polymerase chain reaction (PCR). PCR differentiated between the two morphologic identical species (E. histolytica and E. dispar) and had the advantage to save time and resources. E. histolytica was detected in only 5 (10%) samples and in association with E. dispar in 8 (16%) samples. On the other hand, 20 samples (40%) were E. dispar. The other 17 samples were negative. E. coli, E. hartmanni and polymorphs were commonly misdiagnosed as E. histolytica. PMID:16333901

  10. Role of Microscopic Flexibility in Tightly Curved DNA

    PubMed Central

    2015-01-01

    The genetic material in living cells is organized into complex structures in which DNA is subjected to substantial contortions. Here we investigate the difference in structure, dynamics, and flexibility between two topological states of a short (107 base pair) DNA sequence in a linear form and a covalently closed, tightly curved circular DNA form. By employing a combination of all-atom molecular dynamics (MD) simulations and elastic rod modeling of DNA, which allows capturing microscopic details while monitoring the global dynamics, we demonstrate that in the highly curved regime the microscopic flexibility of the DNA drastically increases due to the local mobility of the duplex. By analyzing vibrational entropy and Lipari–Szabo NMR order parameters from the simulation data, we propose a novel model for the thermodynamic stability of high-curvature DNA states based on vibrational untightening of the duplex. This novel view of DNA bending provides a fundamental explanation that bridges the gap between classical models of DNA and experimental studies on DNA cyclization, which so far have been in substantial disagreement. PMID:25155114

  11. Thermodynamics of Oligonucleotide Duplex Melting

    ERIC Educational Resources Information Center

    Schreiber-Gosche, Sherrie; Edwards, Robert A.

    2009-01-01

    Melting temperatures of oligonucleotides are useful for a number of molecular biology applications, such as the polymerase chain reaction (PCR). Although melting temperatures are often calculated with simplistic empirical equations, application of thermodynamics provides more accurate melting temperatures and an opportunity for students to apply…

  12. A Simple Statistical Thermodynamics Experiment

    ERIC Educational Resources Information Center

    LoPresto, Michael C.

    2010-01-01

    Comparing the predicted and actual rolls of combinations of both two and three dice can help to introduce many of the basic concepts of statistical thermodynamics, including multiplicity, probability, microstates, and macrostates, and demonstrate that entropy is indeed a measure of randomness, that disordered states (those of higher entropy) are…

  13. Recycling, Thermodynamics and Environmental Thrift

    ERIC Educational Resources Information Center

    Berry, R. Stephen

    1972-01-01

    Compares the cost, in terms of thermodynamic potential, of manufacturing automobiles from raw mineral resources or from recycled vehicles, and of the production of extended-life products. Uses this as an example for arguing that new technologies, with efficiencies closer to the theoretical themodynamic minima, are needed if a society is to…

  14. THERMODYNAMICS USED IN ENVIRONMENTAL ENGINEERING

    EPA Science Inventory

    Thermodynamics is a science in which energy transformations are studied as well as their relationships to the changes in the chemical properties of a system. It is the fundamental basis of many engineering fields. The profession of environmental engineering is no exception. In pa...

  15. Thermodynamic properties of gadolinium disilicide

    SciTech Connect

    Lukashenko, G.M.; Polotskaya, R.I.

    1986-11-01

    The authors determine the Gibbs energy, enthalpy, formation heat, and other thermodynamic properties of gadolinium disilicide by measuring the electromotive force in the 830-960 K temperature range in electrolytes consisting of molten tin and various chlorides. The relationship of these properties to crystal structure is briefly discussed.

  16. Some Considerations about Thermodynamic Cycles

    ERIC Educational Resources Information Center

    da Silva, M. F. Ferreira

    2012-01-01

    After completing their introductory studies on thermodynamics at the university level, typically in a second-year university course, most students show a number of misconceptions. In this work, we identify some of those erroneous ideas and try to explain their origins. We also give a suggestion to attack the problem through a systematic and…

  17. Thermodynamics on the Molality Scale

    ERIC Educational Resources Information Center

    Canagaratna, Sebastian G.; Maheswaran, M.

    2013-01-01

    For physical measurements, the compositions of solutions, especially electrolyte solutions, are expressed in terms of molality rather than mole fractions. The development of the necessary thermodynamic equations directly in terms of molality is not common in textbooks, and the treatment in the literature is not very systematic. We develop a…

  18. Spectroscopic characterization of polymers: report

    SciTech Connect

    Koenig, J.L.

    1987-10-01

    Polymer characterization has presented major difficulties to the analytical chemist, who has had to develop techniques to cope with the challenge. Even the elementary problem of measuring molecular weight is not easy. Yet such measurements are essential, because the physical, mechanical, and flow properties depend on the length of the polymer chain. Because of the limited solubility and high viscosity of polymers, many classical techniques have been of little use or have had to be extensively modified to measure the molecular weight of polymers. Size-exclusion chromatographic techniques such as gel permeation have been developed to measure these molecular weight distributions. Special chromatographic instruments with a range of spectroscopic detectors (including infrared and laser-light scattering) have emerged commercially to aid the analytical chemist in the fundamental endeavor to measure the length of the polymer chain and its distribution. The author describes the advantages and disadvantages and disadvantages of various spectroscopic techniques.

  19. Robot-assisted microscope for neurosurgery.

    PubMed

    Giorgi, C; Eisenberg, H; Costi, G; Gallo, E; Garibotto, G; Casolino, D S

    1995-01-01

    We describe the implementation of a robotic arm connected to a neurosurgical operative microscope. A force feedback sensor drives the motors of the arm in response to the positioning of the microscope by the surgeon. Computer graphic techniques allow tracking of the current position of the microscope within the volumetric reconstruction of the brain. The integration of the prototype into the neurosurgical operating room is currently being evaluated. Preliminary comments on this experimental phase are offered. PMID:9079441

  20. The Athena Microscopic Imager Investigation

    NASA Technical Reports Server (NTRS)

    Herkenhoff, K. E.; Aquyres, S. W.; Bell, J. F., III; Maki, J. N.; Arneson, H. M.; Brown, D. I.; Collins, S. A.; Dingizian, A.; Elliot, S. T.; Geotz, W.

    2003-01-01

    The Athena science payload on the Mars Exploration Rovers (MER) includes the Microscopic Imager (MI) [1]. The MI is a fixed-focus camera mounted on the end of an extendable instrument arm, the Instrument Deployment Device (IDD; see Figure 1).The MI was designed to acquire images at a spatial resolution of 30 microns/pixel over a broad spectral range (400 - 700 nm; see Table 1). Technically, the microscopic imager is not a microscope: it has a fixed magnification of 0.4 and is intended to produce images that simulate a geologist s view through a common hand lens. In photographers parlance, the system makes use of a macro lens. The MI uses the same electronics design as the other MER cameras [2, 3] but has optics that yield a field of view of 31 31 mm across a 1024 1024 pixel CCD image (Figure 2). The MI acquires images using only solar or skylightillumination of the target surface. A contact sensor is used to place the MI slightly closer to the target surface than its best focus distance (about 66 mm), allowing concave surfaces to be imaged in good focus. Because the MI has a relatively small depth of field (3 mm), a single MI image of a rough surface will contain both focused and unfocused areas. Coarse focusing will be achieved by moving the IDD away from a rock target after the contact sensor is activated. Multiple images taken at various distances will be acquired to ensure good focus on all parts of rough surfaces. By combining a set of images acquired in this way, a completely focused image can be assembled. Stereoscopic observations can be obtained by moving the MI laterally relative to its boresight. Estimates of the position and orientation of the MI for each acquired image will be stored in the rover computer and returned to Earth with the image data. The MI optics will be protected from the Martian environment by a retractable dust cover. The dust cover includes a Kapton window that is tinted orange to restrict the spectral bandpass to 500-700 nm

  1. Scanning evanescent electro-magnetic microscope

    DOEpatents

    Xiang, Xiao-Dong; Gao, Chen

    2001-01-01

    A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

  2. Scanning evanescent electro-magnetic microscope

    DOEpatents

    Xiang, Xiao-Dong; Gao, Chen; Schultz, Peter G.; Wei, Tao

    2003-01-01

    A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

  3. Foldscope: Origami-Based Paper Microscope

    PubMed Central

    Cybulski, James S.; Clements, James; Prakash, Manu

    2014-01-01

    Here we describe an ultra-low-cost origami-based approach for large-scale manufacturing of microscopes, specifically demonstrating brightfield, darkfield, and fluorescence microscopes. Merging principles of optical design with origami enables high-volume fabrication of microscopes from 2D media. Flexure mechanisms created via folding enable a flat compact design. Structural loops in folded paper provide kinematic constraints as a means for passive self-alignment. This light, rugged instrument can survive harsh field conditions while providing a diversity of imaging capabilities, thus serving wide-ranging applications for cost-effective, portable microscopes in science and education. PMID:24940755

  4. Quantum Statistical Mechanical Derivation of the Second Law of Thermodynamics: A Hybrid Setting Approach

    NASA Astrophysics Data System (ADS)

    Tasaki, Hal

    2016-04-01

    Based on quantum statistical mechanics and microscopic quantum dynamics, we prove Planck's and Kelvin's principles for macroscopic systems in a general and realistic setting. We consider a hybrid quantum system that consists of the thermodynamic system, which is initially in thermal equilibrium, and the "apparatus" which operates on the former, and assume that the whole system evolves autonomously. This provides a satisfactory derivation of the second law for macroscopic systems.

  5. Quantum Statistical Mechanical Derivation of the Second Law of Thermodynamics: A Hybrid Setting Approach.

    PubMed

    Tasaki, Hal

    2016-04-29

    Based on quantum statistical mechanics and microscopic quantum dynamics, we prove Planck's and Kelvin's principles for macroscopic systems in a general and realistic setting. We consider a hybrid quantum system that consists of the thermodynamic system, which is initially in thermal equilibrium, and the "apparatus" which operates on the former, and assume that the whole system evolves autonomously. This provides a satisfactory derivation of the second law for macroscopic systems. PMID:27176507

  6. Thermodynamics and statistical mechanics. [thermodynamic properties of gases

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The basic thermodynamic properties of gases are reviewed and the relations between them are derived from the first and second laws. The elements of statistical mechanics are then formulated and the partition function is derived. The classical form of the partition function is used to obtain the Maxwell-Boltzmann distribution of kinetic energies in the gas phase and the equipartition of energy theorem is given in its most general form. The thermodynamic properties are all derived as functions of the partition function. Quantum statistics are reviewed briefly and the differences between the Boltzmann distribution function for classical particles and the Fermi-Dirac and Bose-Einstein distributions for quantum particles are discussed.

  7. Systematic coarse graining flowing polymer melts: thermodynamically guided simulations and resulting constitutive model.

    PubMed

    Iig, Patrick

    2011-01-01

    Complex fluids, such as polymers, colloids, liquid-crystals etc., show intriguing viscoelastic properties, due to the complicated interplay between flow-induced structure formation and dynamical behavior. Starting from microscopic models of complex fluids, a systematic coarse-graining method is presented that allows us to derive closed-form and thermodynamically consistent constitutive equations for such fluids. Essential ingredients of the proposed approach are thermodynamically guided simulations within a consistent coarse-graining scheme. In addition to this new type of multiscale simulations, we reconstruct the building blocks that constitute the thermodynamically consistent coarse-grained model. We illustrate the method for low-molecular polymer melts, which are subject to different imposed flow fields like planar shear and different elongational flows. The constitutive equation for general flow conditions we obtain shows rheological behavior including shear thinning, normal stress differences, and elongational viscosities in good agreement with reference results. PMID:21678766

  8. Mars Under the Microscope (color)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This magnified look at the martian soil near the Mars Exploration Rover Opportunity's landing site, Meridiani Planum, shows coarse grains sprinkled over a fine layer of sand. The image was captured by the rover's microscopic imager on the 10th day, or sol, of its mission and roughly approximates the color a human eye would see. Scientists are intrigued by the spherical rocks, which can be formed by a variety of geologic processes, including cooling of molten lava droplets and accretion of concentric layers of material around a particle or 'seed.'

    The examined patch of soil is 3 centimeters (1.2 inches) across. The circular grain in the lower left corner is approximately 3 millimeters (.12 inches) across, or about the size of a sunflower seed.

    This color composite was obtained by merging images acquired with the orange-tinted dust cover in both its open and closed positions. The blue tint at the lower right corner is a tag used by scientists to indicate that the dust cover is closed.

  9. Mars Under the Microscope (stretched)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This magnified look at the martian soil near the Mars Exploration Rover Opportunity's landing site, Meridiani Planum, shows coarse grains sprinkled over a fine layer of sand. The image was captured on the 10th day, or sol, of the rover's mission by its microscopic imager, located on the instrument deployment device, or 'arm.' Scientists are intrigued by the spherical rocks, which can be formed by a variety of geologic processes, including cooling of molten lava droplets and accretion of concentric layers of material around a particle or 'seed.'

    The examined patch of soil is 3 centimeters (1.2 inches) across. The circular grain in the lower left corner is approximately 3 millimeters (.12 inches) across, or about the size of a sunflower seed.

    This stretched color composite was obtained by merging images acquired with the orange-tinted dust cover open and closed. The varying hints of orange suggest differences in mineral composition. The blue tint at the lower right corner is a tag used by scientists to indicate that the dust cover is closed.

  10. Scanning Microscopes Using X Rays and Microchannels

    NASA Technical Reports Server (NTRS)

    Wang, Yu

    2003-01-01

    Scanning microscopes that would be based on microchannel filters and advanced electronic image sensors and that utilize x-ray illumination have been proposed. Because the finest resolution attainable in a microscope is determined by the wavelength of the illumination, the xray illumination in the proposed microscopes would make it possible, in principle, to achieve resolutions of the order of nanometers about a thousand times as fine as the resolution of a visible-light microscope. Heretofore, it has been necessary to use scanning electron microscopes to obtain such fine resolution. In comparison with scanning electron microscopes, the proposed microscopes would likely be smaller, less massive, and less expensive. Moreover, unlike in scanning electron microscopes, it would not be necessary to place specimens under vacuum. The proposed microscopes are closely related to the ones described in several prior NASA Tech Briefs articles; namely, Miniature Microscope Without Lenses (NPO-20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43; and Reflective Variants of Miniature Microscope Without Lenses (NPO-20610), NASA Tech Briefs, Vol. 26, No. 9 (September 2002) page 6a. In all of these microscopes, the basic principle of design and operation is the same: The focusing optics of a conventional visible-light microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. A microchannel plate containing parallel, microscopic-cross-section holes much longer than they are wide is placed between a specimen and an image sensor, which is typically the CCD. The microchannel plate must be made of a material that absorbs the illuminating radiation reflected or scattered from the specimen. The microchannels must be positioned and dimensioned so that each one is registered with a pixel on the image sensor. Because most of the radiation incident on the microchannel walls becomes absorbed, the radiation that reaches the

  11. Thermodynamic Modeling and Experimental Study of the Fe-Cr-Zr System

    SciTech Connect

    Yang, Ying; Tan, Lizhen; Bei, Hongbin; Busby, Jeremy T

    2013-01-01

    Wide applications of zircaloys, stainless steels and their interactions in nuclear reactors require the knowledge on phase stability and thermodynamic property of the Fe-Cr-Zr system. This knowledge is also important to develop new Zr-contained Fe-Cr ferritic steels. This work aims at developing thermodynamic models for describing phase stability and thermodynamic property of the Fe-Cr-Zr system using the Calphad approach coupled with experimental study. Thermodynamic descriptions of the Fe-Cr and Cr-Zr systems were either directly adopted or slightly modified from literature. The Fe-Zr system has been remodeled to accommodate recent ab-initio calculation of formation enthalpies of various Fe-Zr compounds. Reliable ternary experimental data and thermodynamic models were mainly available in the Zr-rich region. Therefore, selected ternary alloys located in the vicinity of the eutectic valley of (Fe,Cr,Zr) and (Fe,Cr)2Zr laves phase in the Fe-rich region have been experimentally investigated in this study. Microstructure has been examined by using scanning electron microscope, energy-dispersive Xray spectroscopy and X-ray diffraction. These experimental results, along with the literature data were then used to develop thermodynamic models for phases in the Fe-Cr-Zr system. Calculated phase equilibria and thermodynamic properties of the ternary system yield satisfactory agreements with available experimental data, which gives the confidence to use these models as building blocks for developing a Zr, Fe and Cr contained multicomponent thermodynamic database for broader applications in nuclear reactors.

  12. Redefinition of the mode Grüneisen parameter for polyatomic substances and thermodynamic implications

    PubMed Central

    Hofmeister, Anne M.; Mao, Ho-kwang

    2002-01-01

    Although the value of the thermal Grüneisen parameter (γth) should be obtained by averaging spectroscopic measurements of mode Grüneisen parameters [γi ≡ (KT/νi)∂νi/∂P, where KT is isothermal bulk modulus, ν is frequency, and P is pressure], in practice, the average 〈γi〉 is up to 25% lower than γth. This discrepancy limits the accuracy of inferring physical properties from spectroscopic data and their application to geophysics. The problem arises because the above formula is physically meaningful only for monatomic or diatomic solids. We redefine γi to allow for the presence of functional groups in polyatomic crystal structures, and test the formula against spinel- and olivine-group minerals that have well-constrained spectra at pressure, band assignments, thermodynamic properties, and elastic moduli, and represent two types of functional groups. Our revised formula [γi ≡ (KX/νi)∂νi/∂P] uses polyhedral bulk moduli (KX) appropriate to the particular atomic motion associated with each vibrational mode, which results in equal values for 〈γi〉, γth, and γLA (the Grüneisen parameter of the longitudinal acoustic mode). Similar revisions lead to the pressure derivatives of these parameters being equal. Accounting for differential compression intrinsic to structures with functional groups improves the accuracy with which spectroscopic models predict thermodynamic properties and link to elastic properties. PMID:11805314

  13. Spectroscopic study of carbonaceous dust particles grown in benzene plasma

    SciTech Connect

    Lee, Szetsen; Chen, H.-F.; Chin, C.-J.

    2007-06-01

    Carbonaceous dust particles have been synthesized from benzene using an rf glow discharge. Scanning electron microscope inspection revealed that the plasma-synthesized dust particles can be classified into two types. Shell-structured dust particles showed a wide size distribution from 3 to40 {mu}m. The other type, with different degrees of aggregation, appeared to be dense and spherical with a very distinctive yellow color and size distribution from 100 nm to 2 {mu}m. Analyses using micro-Raman and Fourier transform infrared microscopy indicated that the main components of the dust particles are polyphenyls and hydrogenated amorphous carbon (HAC). The luminescence background in Raman spectra and the infrared C-H stretching vibrational features observed around 3.4 {mu}m for the dust particles are attributed to HAC. The formation mechanisms and spectroscopic characterization of carbonaceous dust particles are discussed.

  14. Spectroscopic studies of superconductors. Part A: Infrared and Raman spectra

    SciTech Connect

    Bozovic, I.; Marel, D. van der

    1996-12-31

    During the ten years that followed the discovery of superconductivity above 30 K in lanthanum barium cuprate by Bednorz and Mueller, the condensed matter physics community has been engaged in an unprecedented worldwide effort in materials processing, characterization of physical properties, and theoretical modeling of superconductors. The present conference has brought together a group of researchers who are actively involved in the experimental determination of the physical properties of high-{Tc} superconductors, the quest for the microscopic mechanism (or mechanisms) of superconductivity, the search for new physical phenomena in these materials, or the search for new classes of superconducting materials. The distinguishing feature and the unifying theme of this conference was the use of spectroscopic techniques as the primary tools in pursuing these goals. Separate abstracts were prepared for 32 papers in this conference.

  15. Thermodynamic model of nonequilibrium phase transitions.

    PubMed

    Martyushev, L M; Konovalov, M S

    2011-07-01

    Within the scope of a thermodynamic description using the maximum entropy production principle, transitions from one nonequilibrium (kinetic) regime to another are considered. It is shown that in the case when power-law dependencies of thermodynamic flux on force are similar for two regimes, only a transition accompanied by a positive jump of thermodynamic flux is possible between them. It is found that the difference in powers of the dependencies of thermodynamic fluxes on forces results in a number of interesting nonequilibrium transitions between kinetic regimes, including the reentrant one with a negative jump of thermodynamic flux. PMID:21867119

  16. Thermodynamic properties of modified gravity theories

    NASA Astrophysics Data System (ADS)

    Bamba, Kazuharu

    2016-06-01

    We review thermodynamic properties of modified gravity theories, such as F(R) gravity and f(T) gravity, where R is the scalar curvature and T is the torsion scalar in teleparallelism. In particular, we explore the equivalence between the equations of motion for modified gravity theories and the Clausius relation in thermodynamics. In addition, thermodynamics of the cosmological apparent horizon is investigated in f(T) gravity. We show both equilibrium and nonequilibrium descriptions of thermodynamics. It is demonstrated that the second law of thermodynamics in the universe can be met, when the temperature of the outside of the apparent horizon is equivalent to that of the inside of it.

  17. Nonequilibrium thermodynamics of an interface

    NASA Astrophysics Data System (ADS)

    Savin, Thierry; Schweizer, Marco; Öttinger, Hans Christian

    Interfacial thermodynamics has deep ramifications in understanding the boundary conditions of transport theories. We present a formulation of local equilibrium for interfaces that extends the thermodynamics of the ``dividing surface,'' as introduced by Gibbs, to nonequilibrium settings such as evaporation or condensation. By identifying the precise position of the dividing surface in the interfacial region with a gauge degree of freedom, we exploit gauge-invariance requirements to consistently define the intensive variables for the interface. The model is verified under stringent conditions by employing high-precision nonequilibrium molecular dynamics simulations of a coexisting vapor-liquid Lennard-Jones fluid. We conclude that the interfacial temperature is determined using the surface tension as a ``thermometer,'' and can be significantly different from the temperatures of the adjacent phases.

  18. Thermodynamic effects on developed cavitation

    NASA Technical Reports Server (NTRS)

    Holl, J. W.; Billet, M. L.; Weir, D. S.

    1975-01-01

    The results of an investigation of thermodynamic effects are presented. Distributions of temperature and pressure in a developed cavity were measured for zero- and quarter-caliber ogives. A semiempirical entrainment theory was developed to correlate the measured temperature depression in the cavity. This theory correlates the maximum temperature depression expressed in dimensionless form as the Jakob number in terms of the dimensionless numbers of Nusselt, Reynolds, Froude, and Peclet, and dimensionless cavity length, L/D. The results show that in general, the temperature depression increases with L/D and temperature and the cavitation number based on measured cavity pressure is a function of L/D for a given model contour, independent of the thermodynamic effect.

  19. The Thermodynamics of Soil Solutions

    NASA Astrophysics Data System (ADS)

    Bohn, Hinrich

    Soil chemistry has spawned a number of textbooks in the last 5 years, and this is one of the best. The mathematical treatment makes the reading heavy going, but it will provide many rewards. The book's scope is too narrow and the treatment too detailed for beginning soil chemistry courses, but it is excellent for advanced soil chemistry courses. It is also an excellent book for those wishing an introduction to the thermodynamics of terrestrial waters contacting sediments. Some people object to the use of equilibrium in natural open systems because, in the strict sense, they never reach equilibrium. Soils seem to be close enough, and their rate of change slow enough, that equilibrium thermodynamics often apply. Brought into the laboratory and made a closed system, soils can attain at least a partial equilibrium.

  20. Thermodynamics of stochastic Turing machines

    NASA Astrophysics Data System (ADS)

    Strasberg, Philipp; Cerrillo, Javier; Schaller, Gernot; Brandes, Tobias

    2015-10-01

    In analogy to Brownian computers we explicitly show how to construct stochastic models which mimic the behavior of a general-purpose computer (a Turing machine). Our models are discrete state systems obeying a Markovian master equation, which are logically reversible and have a well-defined and consistent thermodynamic interpretation. The resulting master equation, which describes a simple one-step process on an enormously large state space, allows us to thoroughly investigate the thermodynamics of computation for this situation. Especially in the stationary regime we can well approximate the master equation by a simple Fokker-Planck equation in one dimension. We then show that the entropy production rate at steady state can be made arbitrarily small, but the total (integrated) entropy production is finite and grows logarithmically with the number of computational steps.

  1. Dissipation Bound for Thermodynamic Control

    NASA Astrophysics Data System (ADS)

    Machta, Benjamin B.

    2015-12-01

    Biological and engineered systems operate by coupling function to the transfer of heat and/or particles down a thermal or chemical gradient. In idealized deterministically driven systems, thermodynamic control can be exerted reversibly, with no entropy production, as long as the rate of the protocol is made slow compared to the equilibration time of the system. Here we consider fully realizable, entropically driven systems where the control parameters themselves obey rules that are reversible and that acquire directionality in time solely through dissipation. We show that when such a system moves in a directed way through thermodynamic space, it must produce entropy that is on average larger than its generalized displacement as measured by the Fisher information metric. This distance measure is subextensive but cannot be made small by slowing the rate of the protocol.

  2. Thermodynamic geometry of supercooled water.

    PubMed

    May, Helge-Otmar; Mausbach, Peter; Ruppeiner, George

    2015-03-01

    The thermodynamic curvature scalar R is evaluated for supercooled water with a two-state equation of state correlated with the most recent available experimental data. This model assumes a liquid-liquid critical point. Our investigation extends the understanding of the thermodynamic behavior of R considerably. We show that R diverges to -∞ when approaching the assumed liquid-liquid critical point. This limit is consistent with all of the fluid critical point models known so far. In addition, we demonstrate a sign change of R along the liquid-liquid line from negative near the critical point to positive on moving away from the critical point in the low density "ice-like" liquid phase. We also trace out the Widom line in phase space. In addition, we investigate increasing correlation length in supercooled water and compare our results with recent published small angle x-ray scattering measurements. PMID:25871088

  3. Dissipation Bound for Thermodynamic Control.

    PubMed

    Machta, Benjamin B

    2015-12-31

    Biological and engineered systems operate by coupling function to the transfer of heat and/or particles down a thermal or chemical gradient. In idealized deterministically driven systems, thermodynamic control can be exerted reversibly, with no entropy production, as long as the rate of the protocol is made slow compared to the equilibration time of the system. Here we consider fully realizable, entropically driven systems where the control parameters themselves obey rules that are reversible and that acquire directionality in time solely through dissipation. We show that when such a system moves in a directed way through thermodynamic space, it must produce entropy that is on average larger than its generalized displacement as measured by the Fisher information metric. This distance measure is subextensive but cannot be made small by slowing the rate of the protocol. PMID:26764981

  4. Thermodynamics of stochastic Turing machines.

    PubMed

    Strasberg, Philipp; Cerrillo, Javier; Schaller, Gernot; Brandes, Tobias

    2015-10-01

    In analogy to Brownian computers we explicitly show how to construct stochastic models which mimic the behavior of a general-purpose computer (a Turing machine). Our models are discrete state systems obeying a Markovian master equation, which are logically reversible and have a well-defined and consistent thermodynamic interpretation. The resulting master equation, which describes a simple one-step process on an enormously large state space, allows us to thoroughly investigate the thermodynamics of computation for this situation. Especially in the stationary regime we can well approximate the master equation by a simple Fokker-Planck equation in one dimension. We then show that the entropy production rate at steady state can be made arbitrarily small, but the total (integrated) entropy production is finite and grows logarithmically with the number of computational steps. PMID:26565165

  5. Chemical reactions in endoreversible thermodynamics

    NASA Astrophysics Data System (ADS)

    Wagner, Katharina; Hoffmann, Karl Heinz

    2016-01-01

    Endoreversible thermodynamics is a theory for the (approximate) description of thermodynamic non-equilibrium systems, which allows us to capture the ever present irreversibilities of real processes. For instance in heat engines the dissipation due to finite heat transport capabilities, as well as the resulting limitations in the energy fluxes, can be incorporated into the theory. It has thus been very successful in closing the gap between observed and theoretically predicted efficiencies. Here an extension of the theory is provided, with which chemical reactions can be included in the formalism. This opens up a wide field of applications for endoreversible modeling and the investigation of dissipative processes, for instance in fuel cells or batteries.

  6. Stochastic thermodynamics with information reservoirs.

    PubMed

    Barato, Andre C; Seifert, Udo

    2014-10-01

    We generalize stochastic thermodynamics to include information reservoirs. Such information reservoirs, which can be modeled as a sequence of bits, modify the second law. For example, work extraction from a system in contact with a single heat bath becomes possible if the system also interacts with an information reservoir. We obtain an inequality, and the corresponding fluctuation theorem, generalizing the standard entropy production of stochastic thermodynamics. From this inequality we can derive an information processing entropy production, which gives the second law in the presence of information reservoirs. We also develop a systematic linear response theory for information processing machines. For a unicyclic machine powered by an information reservoir, the efficiency at maximum power can deviate from the standard value of 1/2. For the case where energy is consumed to erase the tape, the efficiency at maximum erasure rate is found to be 1/2. PMID:25375481

  7. Thermodynamic Model of Spatial Memory

    NASA Astrophysics Data System (ADS)

    Kaufman, Miron; Allen, P.

    1998-03-01

    We develop and test a thermodynamic model of spatial memory. Our model is an application of statistical thermodynamics to cognitive science. It is related to applications of the statistical mechanics framework in parallel distributed processes research. Our macroscopic model allows us to evaluate an entropy associated with spatial memory tasks. We find that older adults exhibit higher levels of entropy than younger adults. Thurstone's Law of Categorical Judgment, according to which the discriminal processes along the psychological continuum produced by presentations of a single stimulus are normally distributed, is explained by using a Hooke spring model of spatial memory. We have also analyzed a nonlinear modification of the ideal spring model of spatial memory. This work is supported by NIH/NIA grant AG09282-06.

  8. The 4th Thermodynamic Principle?

    SciTech Connect

    Montero Garcia, Jose de la Luz; Novoa Blanco, Jesus Francisco

    2007-04-28

    It should be emphasized that the 4th Principle above formulated is a thermodynamic principle and, at the same time, is mechanical-quantum and relativist, as it should inevitably be and its absence has been one of main the theoretical limitations of the physical theory until today.We show that the theoretical discovery of Dimensional Primitive Octet of Matter, the 4th Thermodynamic Principle, the Quantum Hexet of Matter, the Global Hexagonal Subsystem of Fundamental Constants of Energy and the Measurement or Connected Global Scale or Universal Existential Interval of the Matter is that it is possible to be arrived at a global formulation of the four 'forces' or fundamental interactions of nature. The Einstein's golden dream is possible.

  9. Nonequilibrium thermodynamics of pressure solution

    NASA Astrophysics Data System (ADS)

    Lehner, F. K.; Bataille, J.

    1984-01-01

    This paper is concerned with the thermodynamic theory of solution and precipitation processes in wet crustal rocks and with the mechanism of steady pressure-solution slip in ‘contact zones,’ such as grain-to-grain contacts, fracture surfaces, and permeable gouge layers, that are infiltrated by a mobile aqueous solution phase. A local dissipation jump condition at the phase boundary is fundamental to identifying the thermodynamic force driving the solution and precipitation process and is used here in setting up linear phenomenological relations to model near-equilibrium phase transformation kinetics. The local thermodynamic equilibrium of a stressed pure solid in contact with its melt or solution phase is governed by Gibbs's relation, which is rederived here, in a manner emphasizing its independence of constitutive assumptions for the solid while neglecting surface tension and diffusion in the solid. Fluid-infiltrated contact zones, such as those formed by rough surfaces, cannot generally be in thermodynamic equilibrium, especially during an ongoing process of pressure-solution slip, and the existing equilibrium formulations are incorrect in overlooking dissipative processes tending to eliminate fluctuations in superficial free energies due to stress concentrations near asperities, defects, or impurities. Steady pressure-solution slip is likely to exhibit a nonlinear dependence of slip rate on shear stress and effective normal stress, due to a dependence of the contact-zone state on the latter. Given that this dependence is negligible within some range, linear relations for pressure-solution slip can be derived for the limiting cases of diffusion-controlled and interface-reaction-controlled rates. A criterion for rate control by one of these mechanisms is set by the magnitude of the dimensionless quantity kδ/2C pD, where k is the interfacial transfer coefficient, δ is the mean diffusion path length, C p is the solubility at pressure p, and D is the mass

  10. Horizon thermodynamics and spacetime mappings

    NASA Astrophysics Data System (ADS)

    Faraoni, Valerio; Vitagliano, Vincenzo

    2014-03-01

    When black holes are dynamical, event horizons are replaced by apparent and trapping horizons. Conformal and Kerr-Schild transformations are widely used in relation to dynamical black holes, and we study the behavior under such transformations of quantities related to the thermodynamics of these horizons, such as the Misner-Sharp-Hernandez mass (internal energy), the Kodama vector, surface gravity, and temperature. The transformation properties are not those expected on the basis of naive arguments.

  11. General Thermodynamic Heat Engine Models

    NASA Astrophysics Data System (ADS)

    Nuwayhid, R. Y.; Moukalled, F.; Denton, J. C.

    2002-11-01

    Heat engine models, starting from the most fundamental Carnot case, are analyzed. Two major methods of viewing the power plant as a thermodynamic heat engine are presented and studied. Realistic models are sought by introducing internal heat transport or bypass heat leak treatments. Simple treatments are presented to convey the general modeling ideas without unnecessary complications. Some new results are obtained and certain old results are commented on.

  12. Gluon Thermodynamics at Intermediate Coupling

    SciTech Connect

    Andersen, Jens O.; Strickland, Michael; Su Nan

    2010-03-26

    We calculate the thermodynamic functions of Yang-Mills theory to three-loop order using the hard-thermal-loop perturbation theory reorganization of finite temperature quantum field theory. We show that at three-loop order hard-thermal-loop perturbation theory is compatible with lattice results for the pressure, energy density, and entropy down to temperatures T{approx}2-3T{sub c}.

  13. Robotic CCD microscope for enhanced crystal recognition

    DOEpatents

    Segelke, Brent W.; Toppani, Dominique

    2007-11-06

    A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.

  14. Getting the Most out of the Microscope

    ERIC Educational Resources Information Center

    Price, Fred W.

    1973-01-01

    Discusses some of the misconceptions that students and instructors have regarding the microscope and provides stepwise instructions to enable the biology student to acquire a sound scientific technique for setting up and using the light microscope with minimal expenditure of time and effort. (JR)

  15. Thermodynamic States in Explosion Fields

    SciTech Connect

    Kuhl, A L

    2010-03-12

    We investigate the thermodynamic states occurring in explosion fields from condensed explosive charges. These states are often modeled with a Jones-Wilkins-Lee (JWL) function. However, the JWL function is not a Fundamental Equation of Thermodynamics, and therefore cannot give a complete specification of such states. We use the Cheetah code of Fried to study the loci of states of the expanded detonation products gases from C-4 charges, and their combustion products air. In the Le Chatelier Plane of specific-internal-energy versus temperature, these loci are fit with a Quadratic Model function u(T), which has been shown to be valid for T < 3,000 K and p < 1k-bar. This model is used to derive a Fundamental Equation u(v,s) for C-4. Given u(v,s), one can use Maxwell's Relations to derive all other thermodynamic functions, such as temperature: T(v,s), pressure: p(v,s), enthalpy: h(v,s), Gibbs free energy: g(v,s) and Helmholz free energy: f(v,s); these loci are displayed in figures for C-4. Such complete equations of state are needed for numerical simulations of blast waves from explosive charges, and their reflections from surfaces.

  16. Thermodynamical journey in plant biology

    PubMed Central

    Barbacci, Adelin; Magnenet, Vincent; Lahaye, Marc

    2015-01-01

    Nonequilibrium irreversible thermodynamics constitute a meaningful point of view suitable to explore life with a rich paradigm. This analytical framework can be used to span the gap from molecular processes to plant function and shows great promise to create a holistic description of life. Since living organisms dissipate energy, exchange entropy and matter with their environment, they can be assimilated to dissipative structures. This concept inherited from nonequilibrium thermodynamics has four properties which defines a scale independent framework suitable to provide a simpler and more comprehensive view of the highly complex plant biology. According to this approach, a biological function is modeled as a cascade of dissipative structures. Each dissipative structure, corresponds to a biological process, which is initiated by the amplification of a fluctuation. Evolution of the process leads to the breakage of the system symmetry and to the export of entropy. Exporting entropy to the surrounding environment corresponds to collecting information about it. Biological actors which break the symmetry of the system and which store information are by consequence, key actors on which experiments and data analysis focus most. This paper aims at illustrating properties of dissipative structure through familiar examples and thus initiating the dialogue between nonequilibrium thermodynamics and plant biology. PMID:26175747

  17. Predicting RNA pseudoknot folding thermodynamics.

    PubMed

    Cao, Song; Chen, Shi-Jie

    2006-01-01

    Based on the experimentally determined atomic coordinates for RNA helices and the self-avoiding walks of the P (phosphate) and C4 (carbon) atoms in the diamond lattice for the polynucleotide loop conformations, we derive a set of conformational entropy parameters for RNA pseudoknots. Based on the entropy parameters, we develop a folding thermodynamics model that enables us to compute the sequence-specific RNA pseudoknot folding free energy landscape and thermodynamics. The model is validated through extensive experimental tests both for the native structures and for the folding thermodynamics. The model predicts strong sequence-dependent helix-loop competitions in the pseudoknot stability and the resultant conformational switches between different hairpin and pseudoknot structures. For instance, for the pseudoknot domain of human telomerase RNA, a native-like and a misfolded hairpin intermediates are found to coexist on the (equilibrium) folding pathways, and the interplay between the stabilities of these intermediates causes the conformational switch that may underlie a human telomerase disease. PMID:16709732

  18. Imaging Schwarzschild multilayer X-ray microscope

    NASA Astrophysics Data System (ADS)

    Hoover, Richard B.; Baker, Phillip C.; Shealy, David L.; Core, David B.; Walker, Arthur B. C., Jr.; Barbee, Troy W., Jr.; Kerstetter, Ted

    1993-01-01

    We have designed, analyzed, fabricated, and tested Schwarzschild multilayer X-ray microscopes. These instruments use flow-polished Zerodur mirror substrates which have been coated with multilayers optimized for maximum reflectivity at normal incidence at 135 A. They are being developed as prototypes for the Water Window Imaging X-Ray Microscope. Ultrasmooth mirror sets of hemlite grade sapphire have been fabricated and they are now being coated with multilayers to reflect soft X-rays at 38 A, within the biologically important 'water window'. In this paper, we discuss the fabrication of the microscope optics and structural components as well as the mounting of the optics and assembly of the microscopes. We also describe the optical alignment, interferometric and visible light testing of the microscopes, present interferometrically measured performance data, and provide the first results of optical imaging tests.

  19. Spectroscopic signature for ferroelectric ice

    NASA Astrophysics Data System (ADS)

    Wójcik, Marek J.; Gług, Maciej; Boczar, Marek; Boda, Łukasz

    2014-09-01

    Various forms of ice exist within our galaxy. Particularly intriguing type of ice - ‘ferroelectric ice' was discovered experimentally and is stable in temperatures below 72 K. This form of ice can generate enormous electric fields and can play an important role in planetary formation. In this letter we present Car-Parrinello simulation of infrared spectra of ferroelectric ice and compare them with spectra of hexagonal ice. Librational region of the spectra can be treated as spectroscopic signature of ice XI and can be of help to identify ferroelectric ice in the Universe.

  20. The far ultraviolet spectroscopic explorer

    NASA Technical Reports Server (NTRS)

    Boggess, A.

    1982-01-01

    The scientific objectives and performance characteristics of a new astronomy mission referred to as the far ultraviolet spectroscopic explorer, or FUSE are being defined by a team involving people experienced instrumental requirements that best meet the scientific needs. The team is intended to have a lifetime of about one year, ending with the submission of a report to NASA which could be used as the basis for an engineering design study. The principal objective of FUSE is to obtain astronomical spectra at wavelengths shorter than is possible with the Space Telescope.

  1. High-energy spectroscopic astrophysics

    NASA Astrophysics Data System (ADS)

    Güdel, Manuel; Walter, Roland

    After three decades of intense research in X-ray and gamma-ray astronomy, the time was ripe to summarize basic knowledge on X-ray and gamma-ray spectroscopy for interested students and researchers ready to become involved in new high-energy missions. This volume exposes both the scientific basics and modern methods of high-energy spectroscopic astrophysics. The emphasis is on physical principles and observing methods rather than a discussion of particular classes of high-energy objects, but many examples and new results are included in the three chapters as well.

  2. The transmission X-ray microscope end-station at the ESRF

    NASA Astrophysics Data System (ADS)

    Kaulich, B.; Niemann, B.; Rostaing, G.; Oestreich, S.; Salomé, M.; Barrett, R.; Susini, J.

    2000-05-01

    A full-field imaging or transmission X-ray microscope (TXM) working in the photon energy of 3-7 keV was built at the ID21 beamline of the ESRF and is operational since the beginning of this year. The TXM is designed to work in absorption as well as in Zernike phase contrast modes and also offers the possibility for micro-spectroscopic investigations (XAS, element mapping). In this contribution, we give a technical description and characterization of the TXM end-station and discuss its imaging performance.

  3. Development and Trial Measurements of Hard X-ray Photoelectron Emission Microscope

    SciTech Connect

    Taniuchi, T.; Oshima, M.; Wakita, T.; Takagaki, M.; Kawamura, N.; Suzuki, M.; Nakamura, T.; Kobayashi, K.; Akinaga, H.; Muraoka, H.; Ono, K.

    2007-01-19

    Photoelectron emission microscope (PEEM) study is performed using hard x-ray illumination. We have successfully obtained images with high spatial resolution of 40 nm with hard x-rays. Spectro-microscopy of Co micro-patterns on Si substrates, which can be applied to XAFS measurements on a minute scale by PEEM. Magnetic imaging has been demonstrated at the Pt L-edges on perpendicular magnetic recording pattern of CoCrPt alloy. These results are the first step toward a new spectroscopic microscopy and magnetic imaging in a hard x-ray region.

  4. Scanning Capacitace Microscope/Atomic Force Microscope/Scanning Tunneling Microscope Study of Ion-Implanted Silicon Surfaces

    NASA Astrophysics Data System (ADS)

    Tomiye, Hideto; Kawami, Hiroshi; Izawa, Michiyoshi; Yoshimura, Masamichi; Yao, Takafumi

    1995-06-01

    We have investigated the local electrical properties of ion-implanted Si using a combined scanning capacitance microscope (SCaM)/atomic force microscope (AFM)/scanning tunneling microscope (STM) with special attention paid to the effect of annealing. The STM image shows that the as-implanted area is insulating, while the unimplanted area is conductive, in an unannealed sample. Both STM and SCaM images clearly indicate that the implanted area is conductive with n-type behavior after annealing. However, the unimplanted area did not show p-type behavior but slightly n-type behavior due to the diffusion of P impurities during annealing.

  5. Polymorphic phase behavior of lysophosphatidylethanolamine dispersions. A thermodynamic and spectroscopic characterization.

    PubMed Central

    Slater, J L; Huang, C H; Adams, R G; Levin, I W

    1989-01-01

    We have investigated the phase behavior of aqueous dispersions of a series of synthetic lysophosphatidylethanolamines as a function of the acyl chain length. Lysophosphatidylethanolamines exhibit phase polymorphism encompassing a well-ordered crystalline phase which may arise either from a metastable interdigitated lamellar gel phase or a metastable micellar phase. The time course of interconversion between these various phases have been outlined by observing the low temperature incubation time dependence of the calorimetric thermograms. We have determined differences in structure of these phases by Raman spectroscopy and 31P nuclear magnetic resonance spectroscopy. It appears that a principal contribution to this polymorphic phase behavior lies in the nature of headgroup hydration and headgroup-headgroup interactions. PMID:2775827

  6. Atomic Force Microscope Mediated Chromatography

    NASA Technical Reports Server (NTRS)

    Anderson, Mark S.

    2013-01-01

    The atomic force microscope (AFM) is used to inject a sample, provide shear-driven liquid flow over a functionalized substrate, and detect separated components. This is demonstrated using lipophilic dyes and normal phase chromatography. A significant reduction in both size and separation time scales is achieved with a 25-micron-length column scale, and one-second separation times. The approach has general applications to trace chemical and microfluidic analysis. The AFM is now a common tool for ultra-microscopy and nanotechnology. It has also been demonstrated to provide a number of microfluidic functions necessary for miniaturized chromatography. These include injection of sub-femtoliter samples, fluidic switching, and sheardriven pumping. The AFM probe tip can be used to selectively remove surface layers for subsequent microchemical analysis using infrared and tip-enhanced Raman spectroscopy. With its ability to image individual atoms, the AFM is a remarkably sensitive detector that can be used to detect separated components. These diverse functional components of microfluidic manipulation have been combined in this work to demonstrate AFM mediated chromatography. AFM mediated chromatography uses channel-less, shear-driven pumping. This is demonstrated with a thin, aluminum oxide substrate and a non-polar solvent system to separate a mixture of lipophilic dyes. In conventional chromatographic terms, this is analogous to thin-layer chromatography using normal phase alumina substrate with sheardriven pumping provided by the AFM tip-cantilever mechanism. The AFM detection of separated components is accomplished by exploiting the variation in the localized friction of the separated components. The AFM tip-cantilever provides the mechanism for producing shear-induced flows and rapid pumping. Shear-driven chromatography (SDC) is a relatively new concept that overcomes the speed and miniaturization limitations of conventional liquid chromatography. SDC is based on a

  7. The spectroscopic search for the trace aerosols in the planetary atmospheres - the results of numerical simulations

    NASA Astrophysics Data System (ADS)

    Blecka, Maria I.

    2010-05-01

    The passive remote spectrometric methods are important in examinations the atmospheres of planets. The radiance spectra inform us about values of thermodynamical parameters and composition of the atmospheres and surfaces. The spectral technology can be useful in detection of the trace aerosols like biological substances (if present) in the environments of the planets. We discuss here some of the aspects related to the spectroscopic search for the aerosols and dust in planetary atmospheres. Possibility of detection and identifications of biological aerosols with a passive InfraRed spectrometer in an open-air environment is discussed. We present numerically simulated, based on radiative transfer theory, spectroscopic observations of the Earth atmosphere. Laboratory measurements of transmittance of various kinds of aerosols, pollens and bacterias were used in modeling.

  8. In situ microscopic studies on the structural and chemical behaviors of lithium-ion battery materials

    NASA Astrophysics Data System (ADS)

    Shao, Minhua

    2014-12-01

    The direct observation of the microstructural evolution and state-of-charge (SOC) distribution in active materials is crucial to understand the lithiation/delithiation mechanisms during electrochemical cycling of lithium-ion batteries (LIBs). Owing to their high spatial resolutions and capability to map chemical states by combining other spectroscopic techniques, microscopic techniques including X-ray fluorescence (XRF) microscopy, Raman microscopy, transmission X-ray microscopy (TXM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) play significant roles in real time monitoring the dynamic changes in the LIB electrodes and materials. This paper reviews the recent progress of using in situ microscopic techniques to study LIB materials, including Si-, Sn-, Ge-, C- and metal oxides-based anode materials, and layered oxysulfide, metal fluorides, LiCoO2, LiNi0.8Co0.15Al0.05O2, LiMn2O4, LiFePO4 cathode materials.

  9. Magnetic fingerprint of individual Fe4 molecular magnets under compression by a scanning tunnelling microscope.

    PubMed

    Burgess, Jacob A J; Malavolti, Luigi; Lanzilotto, Valeria; Mannini, Matteo; Yan, Shichao; Ninova, Silviya; Totti, Federico; Rolf-Pissarczyk, Steffen; Cornia, Andrea; Sessoli, Roberta; Loth, Sebastian

    2015-01-01

    Single-molecule magnets (SMMs) present a promising avenue to develop spintronic technologies. Addressing individual molecules with electrical leads in SMM-based spintronic devices remains a ubiquitous challenge: interactions with metallic electrodes can drastically modify the SMM's properties by charge transfer or through changes in the molecular structure. Here, we probe electrical transport through individual Fe4 SMMs using a scanning tunnelling microscope at 0.5 K. Correlation of topographic and spectroscopic information permits identification of the spin excitation fingerprint of intact Fe4 molecules. Building from this, we find that the exchange coupling strength within the molecule's magnetic core is significantly enhanced. First-principles calculations support the conclusion that this is the result of confinement of the molecule in the two-contact junction formed by the microscope tip and the sample surface. PMID:26359203

  10. Magnetic fingerprint of individual Fe4 molecular magnets under compression by a scanning tunnelling microscope

    NASA Astrophysics Data System (ADS)

    Burgess, Jacob A. J.; Malavolti, Luigi; Lanzilotto, Valeria; Mannini, Matteo; Yan, Shichao; Ninova, Silviya; Totti, Federico; Rolf-Pissarczyk, Steffen; Cornia, Andrea; Sessoli, Roberta; Loth, Sebastian

    2015-09-01

    Single-molecule magnets (SMMs) present a promising avenue to develop spintronic technologies. Addressing individual molecules with electrical leads in SMM-based spintronic devices remains a ubiquitous challenge: interactions with metallic electrodes can drastically modify the SMM's properties by charge transfer or through changes in the molecular structure. Here, we probe electrical transport through individual Fe4 SMMs using a scanning tunnelling microscope at 0.5 K. Correlation of topographic and spectroscopic information permits identification of the spin excitation fingerprint of intact Fe4 molecules. Building from this, we find that the exchange coupling strength within the molecule's magnetic core is significantly enhanced. First-principles calculations support the conclusion that this is the result of confinement of the molecule in the two-contact junction formed by the microscope tip and the sample surface.

  11. Magnetic fingerprint of individual Fe4 molecular magnets under compression by a scanning tunnelling microscope

    PubMed Central

    Burgess, Jacob A.J.; Malavolti, Luigi; Lanzilotto, Valeria; Mannini, Matteo; Yan, Shichao; Ninova, Silviya; Totti, Federico; Rolf-Pissarczyk, Steffen; Cornia, Andrea; Sessoli, Roberta; Loth, Sebastian

    2015-01-01

    Single-molecule magnets (SMMs) present a promising avenue to develop spintronic technologies. Addressing individual molecules with electrical leads in SMM-based spintronic devices remains a ubiquitous challenge: interactions with metallic electrodes can drastically modify the SMM's properties by charge transfer or through changes in the molecular structure. Here, we probe electrical transport through individual Fe4 SMMs using a scanning tunnelling microscope at 0.5 K. Correlation of topographic and spectroscopic information permits identification of the spin excitation fingerprint of intact Fe4 molecules. Building from this, we find that the exchange coupling strength within the molecule's magnetic core is significantly enhanced. First-principles calculations support the conclusion that this is the result of confinement of the molecule in the two-contact junction formed by the microscope tip and the sample surface. PMID:26359203

  12. Thermodynamic Studies for Drug Design and Screening

    PubMed Central

    Garbett, Nichola C.; Chaires, Jonathan B.

    2012-01-01

    Introduction A key part of drug design and development is the optimization of molecular interactions between an engineered drug candidate and its binding target. Thermodynamic characterization provides information about the balance of energetic forces driving binding interactions and is essential for understanding and optimizing molecular interactions. Areas covered This review discusses the information that can be obtained from thermodynamic measurements and how this can be applied to the drug development process. Current approaches for the measurement and optimization of thermodynamic parameters are presented, specifically higher throughput and calorimetric methods. Relevant literature for this review was identified in part by bibliographic searches for the period 2004 – 2011 using the Science Citation Index and PUBMED and the keywords listed below. Expert opinion The most effective drug design and development platform comes from an integrated process utilizing all available information from structural, thermodynamic and biological studies. Continuing evolution in our understanding of the energetic basis of molecular interactions and advances in thermodynamic methods for widespread application are essential to realize the goal of thermodynamically-driven drug design. Comprehensive thermodynamic evaluation is vital early in the drug development process to speed drug development towards an optimal energetic interaction profile while retaining good pharmacological properties. Practical thermodynamic approaches, such as enthalpic optimization, thermodynamic optimization plots and the enthalpic efficiency index, have now matured to provide proven utility in design process. Improved throughput in calorimetric methods remains essential for even greater integration of thermodynamics into drug design. PMID:22458502

  13. Early history of extended irreversible thermodynamics (1953-1983): An exploration beyond local equilibrium and classical transport theory

    NASA Astrophysics Data System (ADS)

    Lebon, G.; Jou, D.

    2015-03-01

    This paper gives a historical account of the early years (1953-1983) of extended irreversible thermodynamics (EIT). The salient features of this formalism are to upgrade the thermodynamic fluxes of mass, momentum, energy, and others, to the status of independent variables, and to explore the consistency between generalized transport equations and a generalized version of the second law of thermodynamics. This requires going beyond classical irreversible thermodynamics by redefining entropy and entropy flux. EIT provides deeper foundations, closer relations with microscopic formalisms, a wider spectrum of applications, and a more exciting conceptual appeal to non-equilibrium thermodynamics. We first recall the historical contributions by Maxwell, Cattaneo, and Grad on generalized transport equations. A thermodynamic theory wide enough to cope with such transport equations was independently proposed between 1953 and 1983 by several authors, each emphasizing different kinds of problems. In 1983, the first international meeting on this theory took place in Bellaterra (Barcelona). It provided the opportunity for the various authors to meet together for the first time and to discuss the common points and the specific differences of their previous formulations. From then on, a large amount of applications and theoretical confirmations have emerged. From the historical point of view, the emergence of EIT has been an opportunity to revisit the foundations and to open new avenues in thermodynamics, one of the most classical and well consolidated physical theories.

  14. Fast and Adaptive Auto-focusing Microscope

    NASA Astrophysics Data System (ADS)

    Obara, Takeshi; Igarashi, Yasunobu; Hashimoto, Koichi

    Optical microscopes are widely used in biological and medical researches. By using the microscope, we can observe cellular movements including intracellular ions and molecules tagged with fluorescent dyes at a high magnification. However, a freely motile cell easily escapes from a 3D field of view of the typical microscope. Therefore, we propose a novel auto-focusing algorithm and develop a auto-focusing and tracking microscope. XYZ positions of a microscopic stage are feedback controlled to focus and track the cell automatically. A bright-field image is used to estimate a cellular position. XY centroids are used to estimate XY positions of the tracked cell. To estimate Z position, we use a diffraction pattern around the cell membrane. This estimation method is so-called Depth from Diffraction (DFDi). However, this method is not robust for individual differences between cells because the diffraction pattern depends on each cellular shape. Therefore, in this study, we propose a real-time correction of DFDi by using 2D Laplacian of an intracellular area as a goodness of the focus. To evaluate the performance of our developed algorithm and microscope, we auto-focus and track a freely moving paramecium. In this experimental result, the paramecium is auto-focused and kept inside the scope of the microscope during 45s. The evaluated focal error is within 5µm, while a length and a thickness of the paramecium are about 200µm and 50µm, respectively.

  15. Automatic Focus Adjustment of a Microscope

    NASA Technical Reports Server (NTRS)

    Huntsberger, Terrance

    2005-01-01

    AUTOFOCUS is a computer program for use in a control system that automatically adjusts the position of an instrument arm that carries a microscope equipped with an electronic camera. In the original intended application of AUTOFOCUS, the imaging microscope would be carried by an exploratory robotic vehicle on a remote planet, but AUTOFOCUS could also be adapted to similar applications on Earth. Initially control software other than AUTOFOCUS brings the microscope to a position above a target to be imaged. Then the instrument arm is moved to lower the microscope toward the target: nominally, the target is approached from a starting distance of 3 cm in 10 steps of 3 mm each. After each step, the image in the camera is subjected to a wavelet transform, which is used to evaluate the texture in the image at multiple scales to determine whether and by how much the microscope is approaching focus. A focus measure is derived from the transform and used to guide the arm to bring the microscope to the focal height. When the analysis reveals that the microscope is in focus, image data are recorded and transmitted.

  16. Thermodynamics and Kinetics of Phase Transformations in Hydrogen Storage Materials

    SciTech Connect

    Ceder, Gerbrand; Marzari, Nicola

    2011-08-31

    The aim of this project is to develop and apply computational materials science tools to determine and predict critical properties of hydrogen storage materials. By better understanding the absorption/desorption mechanisms and characterizing their physical properties it is possible to explore and evaluate new directions for hydrogen storage materials. Particular emphasis is on the determination of the structure and thermodynamics of hydrogen storage materials, the investigation of microscopic mechanisms of hydrogen uptake and release in various materials and the role of catalysts in this process. As a team we have decided to focus on a single material, NaAlH{sub 4}, in order to fully be able to study the many aspects of hydrogen storage. We have focused on phase stability, mass transport and size-dependent reaction mechanisms in this material.

  17. Spectroscopic analysis of element concentrations in aluminum alloy using nanosecond laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Luo, Wenfeng; Tang, Jie; Gao, Cunxiao; Wang, Haojing; Zhao, Wei

    2010-06-01

    A plasma generated by 1064 nm Nd:YAG laser irradiation of aluminum alloy in air at atmospheric pressure was studied spectroscopically. The electron density was inferred by measuring the Stark broadened line profile of Cu(I) 324.75 nm, while the electron temperature was determined using the Boltzmann plot method with ten neutral iron lines. Based on the results, local thermodynamic equilibrium was studied. Moreover, calibration curves were presented for samples containing Si, Fe, Cu, Mn, Mg, Ni, Zn and Ti, and the limit of detection of trace elements was calculated based on experimental results.

  18. Interaction of methotrexate with trypsin analyzed by spectroscopic and molecular modeling methods

    NASA Astrophysics Data System (ADS)

    Wang, Yanqing; Zhang, Hongmei; Cao, Jian; Zhou, Qiuhua

    2013-11-01

    Trypsin is one of important digestive enzymes that have intimate correlation with human health and illness. In this work, the interaction of trypsin with methotrexate was investigated by spectroscopic and molecular modeling methods. The results revealed that methotrexate could interact with trypsin with about one binding site. Methotrexate molecule could enter into the primary substrate-binding pocket, resulting in inhibition of trypsin activity. Furthermore, the thermodynamic analysis implied that electrostatic force, hydrogen bonding, van der Waals and hydrophobic interactions were the main interactions for stabilizing the trypsin-methotrexate system, which agreed well with the results from the molecular modeling study.

  19. Seismic isolation of an electron microscope

    SciTech Connect

    Godden, W.G.; Aslam, M.; Scalise, D.T.

    1980-01-01

    A unique two-stage dynamic-isolation problem is presented by the conflicting design requirements for the foundations of an electron microscope in a seismic region. Under normal operational conditions the microscope must be isolated from ambient ground noise; this creates a system extremely vulnerable to seismic ground motions. Under earthquake loading the internal equipment forces must be limited to prevent damage or collapse. An analysis of the proposed design solution is presented. This study was motivated by the 1.5 MeV High Voltage Electron Microscope (HVEM) to be installed at the Lawrence Berkeley Laboratory (LBL) located near the Hayward Fault in California.

  20. The microscopes of Antoni van Leeuwenhoek.

    PubMed

    van Zuylen, J

    1981-03-01

    The seventeenth-century Dutch microscopist, Antoni van Leeuwenhoek, was the first man to make a protracted study of microscopical objects, and, unlike his contemporary Robert Hooke, he viewed by transmitted light. Leeuwenhoek made over 500 of his own, curious, simple microscopes, but now only nine are known to exist. The exact nature of the lenses Leeuwenhoek made, has for long been a puzzle. The existing microscopes have now been examined in detail, and their optical characteristics measured and tabulated. It is proposed that the lens of highest magnification, x 266, was made using a special blown bubble technique. PMID:7012367

  1. Mars Life? - Microscopic Egg-shaped Structures

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This electron microscope image shows egg-shaped structures, some of which may be possible microscopic fossils of Martian origin as discussed by NASA research published in the Aug. 16, 1996, issue of the journal Science. A two-year investigation found organic molecules, mineral features characteristic of biological activity and possible microscopic fossils such as these inside of an ancient Martian rock that fell to Earth as a meteorite. The largest possible fossils are less than 1/100th the diameter of a human hair in size while most are ten times smaller.

  2. Microscopes for NASA's Phoenix Mars Lander

    NASA Technical Reports Server (NTRS)

    2007-01-01

    One part of the Microscopy, Electrochemistry, and Conductivity Analyzer instrument for NASA's Phoenix Mars Lander is a pair of telescopes with a special wheel (on the right in this photograph) for presenting samples to be inspected with the microscopes. A horizontally mounted optical microscope (on the left in this photograph) and an atomic force microscope will examine soil particles and possibly ice particles.

    The shapes and the size distributions of soil particles may tell scientists about environmental conditions the material has experienced. Tumbling rounds the edges. Repeated wetting and freezing causes cracking. Clay minerals formed during long exposure to water have distinctive, platy particles shapes.

  3. A large granite stage and measuring microscope.

    NASA Technical Reports Server (NTRS)

    Alston-Garnjost, M.; Davis, J. W.; Dauber, P. M.; Smits, R. G.

    1971-01-01

    A stage and measuring microscope servocontrolled by a computer have been constructed. The travel of the stage is 0.5 x 0.5 m and the travel of the microscope objective is 7.5 cm. The measuring accuracy is 1 micron in the x-y plane and 5 microns along the z axis. The mechanical and optical construction of the stage and microscope, as well as the way in which the control electronics are organized, permit great flexibility of operation. Possible applications include the scanning and measuring of astronomical plates, the laying out of patterns of semiconductor devices of very large sizes, and the measurement of precision grids.

  4. Recent Opportunity Microscopic Imager Results

    NASA Astrophysics Data System (ADS)

    Herkenhoff, K. E.; Arvidson, R. E.; Jolliff, B. L.; Yingst, R.; Team, A.

    2013-12-01

    Opportunity arrived at exposures of Endeavour crater rim rocks in August 2011, on a hill dubbed 'Cape York.' These rocks have been the goal of exploration by Opportunity for the past few years because spectral evidence for phyllosilicates was observed at this location in orbital remote sensing data. As Opportunity circum¬navigated Cape York, the Microscopic Imager (MI) was used to examine the fine-scale textures of various soils and rocky outcrops. As reported previously, Opportunity discovered multiple bright linear features along the western periphery of Cape York that have been interpreted as veins of Ca sulfate deposited in fractures within the bedrock of Cape York. Opportunity then explored the northern and eastern sides of Cape York, including the area around 'Matijevic Hill' that shows evidence for phyllosilicates in CRISM data acquired from the Mars Reconnaissance Orbiter. One of the first outcrops examined near Matijevic Hill, dubbed 'Kirkwood,' is dominated by millimeter-size spherules. Unlike the hematite-rich concretions observed by Opportunity on Meridiani Planum, the aggregated 'newberries' in the Kirkwood exposure display internal structure and resistant rims. Compositionally, the spherule-rich rock is very similar to a nearby spherule-poor outcrop dubbed 'Whitewater Lake.' Thus these spherules have a more basalt-like composition compared to the hematite-rich concretions of the Burns Formation. The origin of the Kirkwood outcrop is uncertain, but the setting on the rim of the 22-km diameter Endeavour crater suggests that perhaps impact melting was involved in lapilli formation, possibly followed by mobilization and sorting in the ejecta blanket. Alternatively, the newberries may be diagenetic iron oxide concretions that are less well cemented than the 'blueberries' of the younger sulfate-rich Burns Formation. The Whitewater Lake outcrops contain the phyllosilicate phases observed from orbit, and are the oldest materials yet investigated by

  5. Fundamental limitations for quantum and nanoscale thermodynamics.

    PubMed

    Horodecki, Michał; Oppenheim, Jonathan

    2013-01-01

    The relationship between thermodynamics and statistical physics is valid in the thermodynamic limit-when the number of particles becomes very large. Here we study thermodynamics in the opposite regime-at both the nanoscale and when quantum effects become important. Applying results from quantum information theory, we construct a theory of thermodynamics in these limits. We derive general criteria for thermodynamical state transitions, and, as special cases, find two free energies: one that quantifies the deterministically extractable work from a small system in contact with a heat bath, and the other that quantifies the reverse process. We find that there are fundamental limitations on work extraction from non-equilibrium states, owing to finite size effects and quantum coherences. This implies that thermodynamical transitions are generically irreversible at this scale. As one application of these methods, we analyse the efficiency of small heat engines and find that they are irreversible during the adiabatic stages of the cycle. PMID:23800725

  6. Fundamental limitations for quantum and nanoscale thermodynamics

    NASA Astrophysics Data System (ADS)

    Horodecki, Michał; Oppenheim, Jonathan

    2013-06-01

    The relationship between thermodynamics and statistical physics is valid in the thermodynamic limit—when the number of particles becomes very large. Here we study thermodynamics in the opposite regime—at both the nanoscale and when quantum effects become important. Applying results from quantum information theory, we construct a theory of thermodynamics in these limits. We derive general criteria for thermodynamical state transitions, and, as special cases, find two free energies: one that quantifies the deterministically extractable work from a small system in contact with a heat bath, and the other that quantifies the reverse process. We find that there are fundamental limitations on work extraction from non-equilibrium states, owing to finite size effects and quantum coherences. This implies that thermodynamical transitions are generically irreversible at this scale. As one application of these methods, we analyse the efficiency of small heat engines and find that they are irreversible during the adiabatic stages of the cycle.

  7. Thermodynamic studies on lithium ferrites

    SciTech Connect

    Rakshit, S.K.; Parida, S.C.; Naik, Y.P.; Chaudhary, Ziley Singh; Venugopal, V.

    2011-05-15

    Thermodynamic studies on ternary oxides of Li-Fe-O systems were carried out using differential scanning calorimetry, Knudsen effusion mass spectrometry, and solid-state electrochemical technique based on fluoride electrolyte. Heat capacities of LiFe{sub 5}O{sub 8}(s) and LiFeO{sub 2}(s) were determined in the temperature range 127-861 K using differential scanning calorimetry. Gibbs energies of formation of LiFe{sub 5}O{sub 8}(s) and LiFeO{sub 2}(s) were determined using Knudsen effusion mass spectrometry and solid-state galvanic cell technique. The combined least squares fits can be represented as {Delta}{sub f}G{sub m}{sup o}(LiFe{sub 5}O{sub 8},s,T)/kJ mol{sup -1} ({+-}6)=-2341+0.6764(T/K) (588{<=}T/K{<=}971) {Delta}{sub f}G{sub m}{sup o}(LiFeO{sub 2},s,T)/kJ mol{sup -1} ({+-}3)=-708+0.1656(T/K) (569{<=}T/K{<=}1021) The temperature independent term of the above equations represents {Delta}{sub f}H{sup o}{sub m}(T{sub av}) and temperature dependent term represents negative change in entropy of the respective compounds. Thermodynamic analysis shows that LiFe{sub 5}O{sub 8}(s) is more stable compared to LiFeO{sub 2}(s). -- Graphical abstract: Comparison of {Delta}{sub f}G{sub m}{sup o}(T) of lithium ferrites determined using different techniques. Display Omitted Highlights: {yields} Thermodynamic studies on Li-Fe-O system using DSC, KEQMS and galvanic cell. {yields} Heat capacities of LiFe{sub 5}O{sub 8}(s) and LiFeO{sub 2}(s) were determined using DSC 127-861 K. {yields} {Delta}{sub f}G{sup o}{sub m} of these compounds were determined and compared. {yields} Thermodynamic tables for LiFe{sub 5}O{sub 8}(s) and LiFeO{sub 2}(s) were constructed.

  8. Thermodynamic laws in isolated systems

    NASA Astrophysics Data System (ADS)

    Hilbert, Stefan; Hänggi, Peter; Dunkel, Jörn

    2014-12-01

    The recent experimental realization of exotic matter states in isolated quantum systems and the ensuing controversy about the existence of negative absolute temperatures demand a careful analysis of the conceptual foundations underlying microcanonical thermostatistics. Here we provide a detailed comparison of the most commonly considered microcanonical entropy definitions, focusing specifically on whether they satisfy or violate the zeroth, first, and second laws of thermodynamics. Our analysis shows that, for a broad class of systems that includes all standard classical Hamiltonian systems, only the Gibbs volume entropy fulfills all three laws simultaneously. To avoid ambiguities, the discussion is restricted to exact results and analytically tractable examples.

  9. Thermodynamic Properties of Supported Catalysts

    SciTech Connect

    Gorte, Raymond J.

    2014-03-26

    The goals of this work were to develop Coulometric Titration as a method for characterizing the thermodynamic redox properties of oxides and to apply this technique to the characterization of ceria- and vanadia-based catalysts. The redox properties of ceria and vanadia are a major part of what makes these materials catalytically active but their properties are also dependent on their structure and the presence of other oxides. Quantifying these properties through the measurement of oxidation energetics was the goal of this work.

  10. Thermodynamics of Lifshitz black holes

    NASA Astrophysics Data System (ADS)

    Devecioǧlu, Deniz Olgu; Sarıoǧlu, Özgür

    2011-06-01

    We apply the recently extended conserved Killing charge definition of Abbott-Deser-Tekin formalism to compute, for the first time, the energies of analytic Lifshitz black holes in higher dimensions. We then calculate the temperature and the entropy of this large family of solutions, and study and discuss the first law of black hole thermodynamics. Along the way we also identify the possible critical points of the relevant quadratic curvature gravity theories. Separately, we also apply the generalized Killing charge definition to compute the energy and the angular momentum of the warped AdS3 black hole solution of the three-dimensional new massive gravity theory.

  11. Statistical thermodynamics of soft surfaces

    NASA Astrophysics Data System (ADS)

    Safran, S. A.

    2002-03-01

    We review the continuum, statistical thermodynamics of surfaces and interfaces in soft matter where both the energy and entropy of the surface are comparable. These systems include complex fluids that are dominated by either surface tension or the interfacial curvature, such as: fluid and solid interfaces, colloidal dispersions, macromolecular solutions, membranes, and other self-assembling aggregates such as micelles, vesicles, and microemulsions. The primary focus is on the theoretical concepts, their universality, and the role of fluctuations and inhomogeneities with connections to relevant experimental systems.

  12. Mechanics and thermodynamics in lubrication

    NASA Technical Reports Server (NTRS)

    Cameron, A.; Gentle, C. R.

    1973-01-01

    The causes for breakdown in the lubricant film of mineral oils are discussed. It is stated that the critical point is caused by desorption of the naturally occurring surface active agent and can be described by thermodynamic analysis. The effect of different metals in lubrication is surveyed. The problem of breakdown in elastohydrodynamic lubrication is treated phenomenologically by studying traction. The topics considered are classical and non-Newtonian explanations, anomalous film thickness and viscosity effects, surface roughness contributions, and solidification of the lubricant. Reasons for the apparent granular traction characteristics are examined.

  13. Thermodynamic data for uranium fluorides

    SciTech Connect

    Leitnaker, J.M.

    1983-03-01

    Self-consistent thermodynamic data have been tabulated for uranium fluorides between UF/sub 4/ and UF/sub 6/, including UF/sub 4/ (solid and gas), U/sub 4/F/sub 17/ (solid), U/sub 2/F/sub 9/ (solid), UF/sub 5/ (solid and gas), U/sub 2/F/sub 10/ (gas), and UF/sub 6/ (solid, liquid, and gas). Included are thermal function - the heat capacity, enthalpy, and free energy function, heats of formation, and vaporization behavior.

  14. Thermodynamic laws in isolated systems.

    PubMed

    Hilbert, Stefan; Hänggi, Peter; Dunkel, Jörn

    2014-12-01

    The recent experimental realization of exotic matter states in isolated quantum systems and the ensuing controversy about the existence of negative absolute temperatures demand a careful analysis of the conceptual foundations underlying microcanonical thermostatistics. Here we provide a detailed comparison of the most commonly considered microcanonical entropy definitions, focusing specifically on whether they satisfy or violate the zeroth, first, and second laws of thermodynamics. Our analysis shows that, for a broad class of systems that includes all standard classical Hamiltonian systems, only the Gibbs volume entropy fulfills all three laws simultaneously. To avoid ambiguities, the discussion is restricted to exact results and analytically tractable examples. PMID:25615053

  15. Some problems in relativistic thermodynamics

    SciTech Connect

    Veitsman, E. V.

    2007-11-15

    The relativistic equations of state for ideal and real gases, as well as for various interface regions, have been derived. These dependences help to eliminate some controversies in the relativistic thermodynamics based on the special theory of relativity. It is shown, in particular, that the temperature of system whose velocity tends to the velocity of light in vacuum varies in accordance with the Ott law T = T{sub 0}/{radical}1 - v{sup 2}/c{sup 2}. Relativistic dependences for heat and mass transfer, for Ohm's law, and for a viscous flow of a liquid have also been derived.

  16. Conceptual understanding of thermodynamics: A study of undergraduate and graduate students

    NASA Astrophysics Data System (ADS)

    Patron, Francis

    1997-11-01

    There is a perception among college students that physical chemistry is an impossibly difficult subject. The hypothesis guiding this study is that this perception is caused by the mismatch between the physical chemistry curriculum and the cognitive needs of students, whose learning styles, misconceptions, and difficulties are not explicitly addressed. A qualitative approach was used to examine students' conceptions of concepts such as internal energy, enthalpy, heat capacity, entropy, and Gibbs free energy. Students' views about science, physical chemistry, and thermodynamics were also examined. The subjects of the study were nine undergraduate and graduate students taking introductory or review courses in thermodynamics. Data were obtained from twenty-five individual interviews, thirteen of which took place while respondents were taking a course and twelve after they had completed it. The interviews were tape-recorded and transcribed and the transcripts were analyzed by a cross-case comparison method. The results show that graduate students had many of the same difficulties and misconceptions as undergraduate students. After a semester, students retained a minimal understanding of the main ideas of thermodynamics and the connections between them. They had a limited understanding of the relevance of thermodynamics to chemistry. Students regarded mathematical derivations as a fundamental component of thermodynamics and relied exclusively on mathematical equations to represent concepts such as enthalpy. Mathematical presentations were emphasized in lectures. The mathematical and pictorial symbols that students copied from the blackboard did not necessarily hold the same meaning for them as they did for professors. Many students had difficulty connecting mathematical symbols to physical concepts. They often confused the macroscopic and microscopic pictures and did not understand the concept of equilibrium. They never mentioned equilibrium in their descriptions of the

  17. Thermodynamics of Enzyme-Catalyzed Reactions Database

    National Institute of Standards and Technology Data Gateway

    SRD 74 Thermodynamics of Enzyme-Catalyzed Reactions Database (Web, free access)   The Thermodynamics of Enzyme-Catalyzed Reactions Database contains thermodynamic data on enzyme-catalyzed reactions that have been recently published in the Journal of Physical and Chemical Reference Data (JPCRD). For each reaction the following information is provided: the reference for the data, the reaction studied, the name of the enzyme used and its Enzyme Commission number, the method of measurement, the data and an evaluation thereof.

  18. Quantum thermodynamics: a nonequilibrium Green's function approach.

    PubMed

    Esposito, Massimiliano; Ochoa, Maicol A; Galperin, Michael

    2015-02-27

    We establish the foundations of a nonequilibrium theory of quantum thermodynamics for noninteracting open quantum systems strongly coupled to their reservoirs within the framework of the nonequilibrium Green's functions. The energy of the system and its coupling to the reservoirs are controlled by a slow external time-dependent force treated to first order beyond the quasistatic limit. We derive the four basic laws of thermodynamics and characterize reversible transformations. Stochastic thermodynamics is recovered in the weak coupling limit. PMID:25768745

  19. A pragmatic guide to multiphoton microscope design

    PubMed Central

    Young, Michael D.; Field, Jeffrey J.; Sheetz, Kraig E.; Bartels, Randy A.; Squier, Jeff

    2016-01-01

    Multiphoton microscopy has emerged as a ubiquitous tool for studying microscopic structure and function across a broad range of disciplines. As such, the intent of this paper is to present a comprehensive resource for the construction and performance evaluation of a multiphoton microscope that will be understandable to the broad range of scientific fields that presently exploit, or wish to begin exploiting, this powerful technology. With this in mind, we have developed a guide to aid in the design of a multiphoton microscope. We discuss source selection, optical management of dispersion, image-relay systems with scan optics, objective-lens selection, single-element light-collection theory, photon-counting detection, image rendering, and finally, an illustrated guide for building an example microscope. PMID:27182429

  20. X ray imaging microscope for cancer research

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Shealy, David L.; Brinkley, B. R.; Baker, Phillip C.; Barbee, Troy W., Jr.; Walker, Arthur B. C., Jr.

    1991-01-01

    The NASA technology employed during the Stanford MSFC LLNL Rocket X Ray Spectroheliograph flight established that doubly reflecting, normal incidence multilayer optics can be designed, fabricated, and used for high resolution x ray imaging of the Sun. Technology developed as part of the MSFC X Ray Microscope program, showed that high quality, high resolution multilayer x ray imaging microscopes are feasible. Using technology developed at Stanford University and at the DOE Lawrence Livermore National Laboratory (LLNL), Troy W. Barbee, Jr. has fabricated multilayer coatings with near theoretical reflectivities and perfect bandpass matching for a new rocket borne solar observatory, the Multi-Spectral Solar Telescope Array (MSSTA). Advanced Flow Polishing has provided multilayer mirror substrates with sub-angstrom (rms) smoothnesss for the astronomical x ray telescopes and x ray microscopes. The combination of these important technological advancements has paved the way for the development of a Water Window Imaging X Ray Microscope for cancer research.