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Sample records for exhibiting monomer-dimer equilibrium

  1. SARS CoV Main Proteinase: The Monomer-Dimer Equilibrium Dissociation Constant

    SciTech Connect

    Graziano,V.; McGrath, W.; Yang, L.; Mangel, W.

    2006-01-01

    The SARS coronavirus main proteinase (SARS CoV main proteinase) is required for the replication of the severe acute respiratory syndrome coronavirus (SARS CoV), the virus that causes SARS. One function of the enzyme is to process viral polyproteins. The active form of the SARS CoV main proteinase is a homodimer. In the literature, estimates of the monomer-dimer equilibrium dissociation constant, K{sub D}, have varied more than 650000-fold, from <1 nM to more than 200 {mu}M. Because of these discrepancies and because compounds that interfere with activation of the enzyme by dimerization may be potential antiviral agents, we investigated the monomer-dimer equilibrium by three different techniques: small-angle X-ray scattering, chemical cross-linking, and enzyme kinetics. Analysis of small-angle X-ray scattering data from a series of measurements at different SARS CoV main proteinase concentrations yielded K{sub D} values of 5.8 {+-} 0.8 {mu}M (obtained from the entire scattering curve), 6.5 {+-} 2.2 {mu}M (obtained from the radii of gyration), and 6.8 {+-} 1.5 {mu}M (obtained from the forward scattering). The K{sub D} from chemical cross-linking was 12.7 {+-} 1.1 {mu}M, and from enzyme kinetics, it was 5.2 {+-} 0.4 {mu}M. While each of these three techniques can present different, potential limitations, they all yielded similar K{sub D} values.

  2. Adsorption equilibrium and kinetics of monomer-dimer monoclonal antibody mixtures on a cation exchange resin.

    PubMed

    Reck, Jason M; Pabst, Timothy M; Hunter, Alan K; Wang, Xiangyang; Carta, Giorgio

    2015-07-10

    Adsorption equilibrium and kinetics are determined for a monoclonal antibody (mAb) monomer and dimer species, individually and in mixtures, on a macroporous cation exchange resin both under the dilute limit of salt gradient elution chromatography and at high protein loads and low salt based on batch adsorption equilibrium and confocal laser scanning microscopy (CLSM) experiments. In the dilute limit and weak binding conditions, the dimer/monomer selectivity in 10mM phosphate at pH 7 varies between 8.7 and 2.3 decreasing with salt concentration in the range of 170-230mM NaCl. At high protein loads and strong binding conditions (0-60mM NaCl), the selectivity in the same buffer is near unity with no NaCl added, but increases gradually with salt concentration reaching high values between 2 and 15 with 60mM added NaCl. For these conditions, the two-component adsorption kinetics is controlled by pore diffusion and is predicted approximately by a dual shrinking core model using parameters based on single component equilibrium and kinetics measurements. PMID:26028510

  3. The Specific Monomer/Dimer Equilibrium of the Corticotropin-releasing Factor Receptor Type 1 Is Established in the Endoplasmic Reticulum

    PubMed Central

    Teichmann, Anke; Gibert, Arthur; Lampe, André; Grzesik, Paul; Rutz, Claudia; Furkert, Jens; Schmoranzer, Jan; Krause, Gerd; Wiesner, Burkhard; Schülein, Ralf

    2014-01-01

    G protein-coupled receptors (GPCRs) represent the most important drug targets. Although the smallest functional unit of a GPCR is a monomer, it became clear in the past decades that the vast majority of the receptors form dimers. Only very recently, however, data were presented that some receptors may in fact be expressed as a mixture of monomers and dimers and that the interaction of the receptor protomers is dynamic. To date, equilibrium measurements were restricted to the plasma membrane due to experimental limitations. We have addressed the question as to where this equilibrium is established for the corticotropin-releasing factor receptor type 1. By developing a novel approach to analyze single molecule fluorescence cross-correlation spectroscopy data for intracellular membrane compartments, we show that the corticotropin-releasing factor receptor type 1 has a specific monomer/dimer equilibrium that is already established in the endoplasmic reticulum (ER). It remains constant at the plasma membrane even following receptor activation. Moreover, we demonstrate for seven additional GPCRs that they are expressed in specific but substantially different monomer/dimer ratios. Although it is well known that proteins may dimerize in the ER in principle, our data show that the ER is also able to establish the specific monomer/dimer ratios of GPCRs, which sheds new light on the functions of this compartment. PMID:24966326

  4. Neutral zinc(II) O,O-di-alkyldithiopho- sphates-variable temperature 31P NMR and quantum chemical study of the ZDDP monomer-dimer equilibrium.

    PubMed

    Harrison, J J; Chan, C Y; Onopchenko, A; Pradhan, A R; Petersen, M

    2008-02-01

    A full line-shape analysis of the VT 31P NMR spectra was carried out for the monomer-dimer equilibrium of neutral ZDDP. The energy surface and the energetics of the monomer-dimer equilibrium (DeltaH degrees , DeltaG degrees , Ea, DeltaH(not equal), and DeltaG(not equal)) are reported for three variants wherein the alkyl groups in the ZDDP are 2-ethylhexyl, isopropyl, and isobutyl. We explored a reaction pathway between the monomer and dimer form by means of density functional theory (DFT). The linear combination of atomic orbitals (LCAO) code DMol3 was used together with a synchronous transient method to effectively locate transition states. Vibrational eigenmodes of all intermediates were computed to capture finite temperature effects. Methyl and ethyl were considered as alkyl groups. Two novel intermediates were located-a four-membered ring and a six-membered ring intermediate along the reaction coordinate. Comparison of the experimentally derived and computed energy surfaces was carried out. PMID:18098153

  5. A monomer-dimer equilibrium modulates the interaction of the sunflower homeodomain leucine-zipper protein Hahb-4 with DNA.

    PubMed Central

    Palena, C M; Gonzalez, D H; Chan, R L

    1999-01-01

    We have analysed the interaction of the sunflower homeodomain leucine-zipper (Hd-Zip) protein Hahb-4 with DNA. The complete Hd-Zip domain from Hahb-4 was able to select specific sequences from a random oligonucleotide mixture that contained a 9-bp core with four fixed and five degenerate positions. Analysis of the binding of some of the selected sequences suggests that Hahb-4 preferentially binds the dyad-symmetrical sequence CAAT(A/T)ATTG. Single-nucleotide replacements at positions 1, 5 or 9 of this sequence produced a decrease in binding of 2-4-fold. DNA binding as a function of protein concentration was non-hyperbolic. This behaviour could be explained by an equation in which dimer formation is a pre-requisite for DNA binding. A global dissociation constant (Kd) of 1.31x10(-14) M2 could be calculated. The removal of the leucine zipper promoted a change in specificity and a decrease in binding affinity (Kd=5. 03x10(-5) M). Mutation of Phe-20 of the homeodomain into Leu completely abolished DNA binding. The mutant protein, however, was able to inhibit DNA binding by the non-mutant form, presumably through the formation of heterodimers. The analysis of this inhibitory effect at different mutant concentrations allowed the estimation of the Kd for the dimer-monomer equilibrium [about (2-4)x10(-6) M]; from this, a Kd of 3-6x10(-9) M for the dimer-DNA complex could be estimated. The results obtained indicate that the formation of dimers is the main factor influencing the interaction of Hahb-4 with DNA. It is proposed that shifts in a dimer-monomer equilibrium could be used within the cell to modulate the interaction of this protein with target genes. PMID:10377247

  6. Monomer-dimer problem on some networks

    NASA Astrophysics Data System (ADS)

    Wu, Ruijuan; Yan, Weigen

    2016-09-01

    Zhang et al. (2012) obtained the exact formula for the number of all possible monomer-dimer arrangements and the asymptotic growth constant on a scale-free small-world network. In this note, we generalize this result and obtain the exact solution on the monomer-dimer model on many networks. Particularly, we prove that these networks have the same asymptotic growth constant of the number of monomer-dimer arrangements.

  7. Kinetics of the monomer-dimer reaction of yeast hexokinase PI.

    PubMed

    Hoggett, J G; Kellett, G L

    1992-10-15

    Kinetic studies of the glucose-dependent monomer-dimer reaction of yeast hexokinase PI at pH 8.0 in the presence of 0.1 M-KCl have been carried out using the fluorescence temperature-jump technique. A slow-relaxation effect was observed which was attributed from its dependence on enzyme concentration to the monomer-dimer reaction; the reciprocal relaxation times tau-1 varied from 3 s-1 at low concentrations of glucose to 42 s-1 at saturating concentrations. Rate constants for association (kass.) and dissociation (kdiss.) were determined as a function of glucose concentration using values of the equilibrium association constant of the monomer-dimer reaction derived from sedimentation ultracentrifugation studies under similar conditions, and also from the dependence of tau-2 on enzyme concentration. kass. was almost independent of glucose concentration and its value (2 x 10(5) M-1.s-1) was close to that expected for a diffusion-controlled process. The influence of glucose on the monomer-dimer reaction is entirely due to effects on kdiss., which increases from 0.21 s-1 in the absence of glucose to 25 s-1 at saturating concentrations. The monomer and dimer forms of hexokinase have different affinities and Km values for glucose, and the results reported here imply that there may be a significant lag in the response of the monomer-dimer reaction to changes in glucose concentrations in vivo with consequent hysteretic effects on the hexokinase activity. PMID:1445216

  8. Kinetics of the monomer-dimer reaction of yeast hexokinase PI.

    PubMed Central

    Hoggett, J G; Kellett, G L

    1992-01-01

    Kinetic studies of the glucose-dependent monomer-dimer reaction of yeast hexokinase PI at pH 8.0 in the presence of 0.1 M-KCl have been carried out using the fluorescence temperature-jump technique. A slow-relaxation effect was observed which was attributed from its dependence on enzyme concentration to the monomer-dimer reaction; the reciprocal relaxation times tau-1 varied from 3 s-1 at low concentrations of glucose to 42 s-1 at saturating concentrations. Rate constants for association (kass.) and dissociation (kdiss.) were determined as a function of glucose concentration using values of the equilibrium association constant of the monomer-dimer reaction derived from sedimentation ultracentrifugation studies under similar conditions, and also from the dependence of tau-2 on enzyme concentration. kass. was almost independent of glucose concentration and its value (2 x 10(5) M-1.s-1) was close to that expected for a diffusion-controlled process. The influence of glucose on the monomer-dimer reaction is entirely due to effects on kdiss., which increases from 0.21 s-1 in the absence of glucose to 25 s-1 at saturating concentrations. The monomer and dimer forms of hexokinase have different affinities and Km values for glucose, and the results reported here imply that there may be a significant lag in the response of the monomer-dimer reaction to changes in glucose concentrations in vivo with consequent hysteretic effects on the hexokinase activity. Images Fig. 1. PMID:1445216

  9. A Pfaffian Formula for Monomer-Dimer Partition Functions

    NASA Astrophysics Data System (ADS)

    Giuliani, Alessandro; Jauslin, Ian; Lieb, Elliott H.

    2016-04-01

    We consider the monomer-dimer partition function on arbitrary finite planar graphs and arbitrary monomer and dimer weights, with the restriction that the only non-zero monomer weights are those on the boundary. We prove a Pfaffian formula for the corresponding partition function. As a consequence of this result, multipoint boundary monomer correlation functions at close packing are shown to satisfy fermionic statistics. Our proof is based on the celebrated Kasteleyn theorem, combined with a theorem on Pfaffians proved by one of the authors, and a careful labeling and directing procedure of the vertices and edges of the graph.

  10. Monomer-dimer problem on random planar honeycomb lattice

    SciTech Connect

    Ren, Haizhen; Zhang, Fuji; Qian, Jianguo

    2014-02-15

    We consider the monomer-dimer (MD) problem on a random planar honeycomb lattice model, namely, the random multiple chain. This is a lattice system with non-periodic boundary condition, whose generating process is inspired by the growth of single walled zigzag carbon nanotubes. By applying algebraic and combinatorial techniques we establish a calculating expression of the MD partition function for bipartite graphs, which corresponds to the permanent of a matrix. Further, by using the transfer matrix argument we show that the computing problem of the permanent of high order matrix can be converted into some lower order matrices for this family of lattices, based on which we derive an explicit recurrence formula for evaluating the MD partition function of multiple chains and random multiple chains. Finally, we analyze the expectation of the number of monomer-dimer arrangements on a random multiple chain and the asymptotic behavior of the annealed MD entropy when the multiple chain becomes infinite in width and length, respectively.

  11. Monomer-dimer problem on random planar honeycomb lattice

    NASA Astrophysics Data System (ADS)

    Ren, Haizhen; Zhang, Fuji; Qian, Jianguo

    2014-02-01

    We consider the monomer-dimer (MD) problem on a random planar honeycomb lattice model, namely, the random multiple chain. This is a lattice system with non-periodic boundary condition, whose generating process is inspired by the growth of single walled zigzag carbon nanotubes. By applying algebraic and combinatorial techniques we establish a calculating expression of the MD partition function for bipartite graphs, which corresponds to the permanent of a matrix. Further, by using the transfer matrix argument we show that the computing problem of the permanent of high order matrix can be converted into some lower order matrices for this family of lattices, based on which we derive an explicit recurrence formula for evaluating the MD partition function of multiple chains and random multiple chains. Finally, we analyze the expectation of the number of monomer-dimer arrangements on a random multiple chain and the asymptotic behavior of the annealed MD entropy when the multiple chain becomes infinite in width and length, respectively.

  12. Das Lektin aus der Erbse Pisum sativum : Bindungsstudien, Monomer-Dimer-Gleichgewicht und Rückfaltung aus Fragmenten

    NASA Astrophysics Data System (ADS)

    Küster, Frank

    2002-11-01

    nicht-denaturierenden Bedingungen die Untereinheiten zwischen den Dimeren ausgetauscht werden. Die Renaturierung der unprozessierten Variante ist unter stark nativen Bedingungen zu 100 % möglich. Das prozessierte Protein dagegen renaturiert nur zu etwa 50 %, und durch die Prozessierung ist die Faltung stark verlangsamt, der Faltungsprozess ist erst nach mehreren Tagen abgeschlossen. Im Laufe der Renaturierung wird ein Intermediat populiert, in dem die längere der beiden Polypeptidketten ein Homodimer mit nativähnlicher Untereinheitenkontaktfläche bildet. Der geschwindigkeitsbestimmende Schritt der Renaturierung ist die Assoziation der entfalteten kürzeren Kette mit diesem Dimer. The lectin from Pisum sativum (garden pea) is a member of the family of legume lectins. These proteins share a high sequence homology, and the structure of their monomers, an all-ß-motif, is highly conserved. Their quaternary structures, however, show a great diversity which has been subject to cristallographic and theoretical studies. Pea lectin is a dimeric legume lectin with a special structural feature: After folding is completed in the cell, a short amino acid sequence is cut out of a loop, resulting in two independent polypeptide chains in each subunit. Both chains are closely intertwined and form one contiguous structural domain. Like all lectins, pea lectin binds to complex oligosaccharides, but its physiological role and its natural ligand are unknown. In this study, experiments to establish a functional assay for pea lectin have been conducted, and its folding, stability and monomer-dimer-equilibrium have been characterized. To investigate the specific role of the processing for stability and folding, an unprocessed construct was expressed in E. coli and compared to the processed form. Both proteins have the same kinetic stability against chemical denaturant. They denature extremely slowly, because only the isolated subunits can unfold, and the monomer-dimer-equilibrium favors

  13. Matching Measure, Benjamini-Schramm Convergence and the Monomer-Dimer Free Energy

    NASA Astrophysics Data System (ADS)

    Abért, Miklós; Csikvári, Péter; Hubai, Tamás

    2015-10-01

    We define the matching measure of a lattice L as the spectral measure of the tree of self-avoiding walks in L. We connect this invariant to the monomer-dimer partition function of a sequence of finite graphs converging to L. This allows us to express the monomer-dimer free energy of L in terms of the matching measure. Exploiting an analytic advantage of the matching measure over the Mayer series then leads to new, rigorous bounds on the monomer-dimer free energies of various Euclidean lattices. While our estimates use only the computational data given in previous papers, they improve the known bounds significantly.

  14. Limit theorems in the imitative monomer-dimer mean-field model via Stein's method

    NASA Astrophysics Data System (ADS)

    Chen, Wei-Kuo

    2016-08-01

    We consider the imitative monomer-dimer model on the complete graph introduced in the work of Alberici et al. [J. Math. Phys. 55, 063301-1-063301-27 (2014)]. It was shown that this model is described by the monomer density and has a phase transition along certain coexistence curve, where the monomer and dimer phases coexist. More recently, it was understood [D. Alberici et al., Commun. Math. Phys. (published online, 2016)] that the monomer density exhibits the central limit theorem away from the coexistence curve and enjoys a non-normal limit theorem at criticality with normalized exponent 3/4. By reverting the model to a weighted Curie-Weiss model with hard core interaction, we establish the complete description of the fluctuation properties of the monomer density on the full parameter space via Stein's method of exchangeable pairs. Our approach recovers what were established in the work of Alberici et al. [Commun. Math. Phys. (published online, 2016)] and furthermore allows to obtain the conditional central limit theorems along the coexistence curve. In all these results, the Berry-Esseen inequalities for the Kolmogorov-Smirnov distance are given.

  15. Exact solution of a monomer-dimer problem: A single boundary monomer on a nonbipartite lattice

    SciTech Connect

    Wu, F. Y.; Tzeng, Wen-Jer; Izmailian, N. Sh.

    2011-01-15

    We solve the monomer-dimer problem on a nonbipartite lattice, a simple quartic lattice with cylindrical boundary conditions, with a single monomer residing on the boundary. Due to the nonbipartite nature of the lattice, the well-known method of solving single-monomer problems with a Temperley bijection cannot be used. In this paper, we derive the solution by mapping the problem onto one of closed-packed dimers on a related lattice. Finite-size analysis of the solution is carried out. We find from asymptotic expansions of the free energy that the central charge in the logarithmic conformal field theory assumes the value c=-2.

  16. Monomer/Dimer Transition of the Caspase-Recruitment Domain of Human Nod1

    SciTech Connect

    Srimathi,T.; Robbins, S.; Dubas, R.; Hasegawa, M.; Inohara, N.; Park, Y.

    2008-01-01

    Nod1 is an essential cytoplasmic sensor for bacterial peptidoglycans in the innate immune system. The caspase-recruitment domain of Nod1 (Nod1{_}CARD) is indispensable for recruiting a downstream kinase, receptor-interacting protein 2 (RIP2), that activates nuclear factor-?B (NF-?B). The crystal structure of human Nod1{_}CARD at 1.9 Angstroms resolution reveals a novel homodimeric conformation. Our structural and biochemical analysis shows that the homodimerization of Nod1{_}CARD is achieved by swapping the H6 helices at the carboxy termini and stabilized by forming an interchain disulfide bond between the Cys39 residues of the two monomers in solution and in the crystal. In addition, we present experimental evidence for a pH-sensitive conformational change of Nod1{_}CARD. Our results suggest that the pH-sensitive monomer/dimer transition is a unique molecular property of Nod1{_}CARD.

  17. Evidences of monomer, dimer and trimer of recombinant human cyclophilin A.

    PubMed

    Zhang, Xin-Chao; Wang, Wei-Dong; Wang, Jin-Song; Pan, Ji-Cheng; Zou, Guo-Lin

    2011-12-01

    Cyclophilin A (CyPA) is a cytosolic receptor of immunosuppressive drug cyclosporin A (CsA) which possesses peptidyl-prodyl cis/trans isomerase (PPIase) activity. The recombinant human CyPA (rhCyPA) gene has been expressed in E. coli M15. Purification was performed using salting-out, as well as Sephacryl S-100 and DEAE-Sepharose CL-6B column chromatography. The molecular weight is about 18 kDa, confirmed by SDS-PAGE and mass spectrum. The results of Native-PAGE and immunoblotting showed the existence of three bands, which agreed well with the gel filtration results. The molecular mass of the three bands determined via CTAB gel electrophoresis and SDS-PAGE (rhCyPA cross-linked with glutaraldehyde) was 18 kDa, 36 kDa and 54 kDa respectively. Further more, the native rhCyPA and the cross-linked rhCyPA had the similar chromatographic behavior in gel filtration. All of the evidences above suggest that rhCyPA exists in forms of monomer, dimer and trimer. Moreover, we observed that even at low protein concentrations CyPA largely occurs as a dimer in solution, and enzyme kinetic parameters showed that activity of dimer was much higher than monomer or trimer, which probably have some biological significances. PMID:21728990

  18. The crystal structure of the global anaerobic transcriptional regulator FNR explains its extremely fine-tuned monomer-dimer equilibrium.

    PubMed

    Volbeda, Anne; Darnault, Claudine; Renoux, Oriane; Nicolet, Yvain; Fontecilla-Camps, Juan C

    2015-12-01

    The structure of the dimeric holo-fumarate and nitrate reduction regulator (FNR) from Aliivibrio fischeri has been solved at 2.65 Å resolution. FNR globally controls the transition between anaerobic and aerobic respiration in facultative anaerobes through the assembly/degradation of its oxygen-sensitive [4Fe-4S] cluster. In the absence of O2, FNR forms a dimer and specifically binds to DNA, whereas in its presence, the cluster is degraded causing FNR monomerization and DNA dissociation. We have used our crystal structure and the information previously gathered from numerous FNR variants to propose that this process is governed by extremely fine-tuned interactions, mediated by two salt bridges near the amino-terminal cluster-binding domain and an "imperfect" coiled-coil dimer interface. [4Fe-4S] to [2Fe-2S] cluster degradation propagates a conformational signal that indirectly causes monomerization by disrupting the first of these interactions and unleashing the "unzipping" of the FNR dimer in the direction of the carboxyl-terminal DNA binding domain. PMID:26665177

  19. The crystal structure of the global anaerobic transcriptional regulator FNR explains its extremely fine-tuned monomer-dimer equilibrium

    PubMed Central

    Volbeda, Anne; Darnault, Claudine; Renoux, Oriane; Nicolet, Yvain; Fontecilla-Camps, Juan C.

    2015-01-01

    The structure of the dimeric holo–fumarate and nitrate reduction regulator (FNR) from Aliivibrio fischeri has been solved at 2.65 Å resolution. FNR globally controls the transition between anaerobic and aerobic respiration in facultative anaerobes through the assembly/degradation of its oxygen-sensitive [4Fe-4S] cluster. In the absence of O2, FNR forms a dimer and specifically binds to DNA, whereas in its presence, the cluster is degraded causing FNR monomerization and DNA dissociation. We have used our crystal structure and the information previously gathered from numerous FNR variants to propose that this process is governed by extremely fine-tuned interactions, mediated by two salt bridges near the amino-terminal cluster-binding domain and an “imperfect” coiled-coil dimer interface. [4Fe-4S] to [2Fe-2S] cluster degradation propagates a conformational signal that indirectly causes monomerization by disrupting the first of these interactions and unleashing the “unzipping” of the FNR dimer in the direction of the carboxyl-terminal DNA binding domain. PMID:26665177

  20. Optical Fluoride Sensor Based on Monomer-Dimer Equilibrium of Scandium(III)-Octaethylporphyrin in a Plasticized Polymeric Film

    PubMed Central

    Kang, Youngjea; Kampf, Jeff W.; Meyerhoff, Mark E.

    2007-01-01

    A fluoride-selective optical sensor based on scandium(III) octaethylporphyrin (Sc(III)OEP) as an ionophore within a plasticized PVC film is described. The presence of fluoride ion in the aqueous sample phase increases the formation of a difluoro-bridged Sc(III)OEP dimer species in the polymer film. The ability of the Sc(III) porphyrin to form the dimeric structure in the presence of fluoride is confirmed by UV-Vis spectroscopy and X-ray crystallography. For more practical sensing applications, a pH chromoionophore (ETH 7075) is added to the plasticized PVC film along with Sc(III)OEP and the observed optical response is based on co-extraction of protons with sample phase fluoride to create the dimeric porphyrin and a protonated chromoionophore species. The selectivity pattern observed is F-≫ClO4-, SCN-, NO3->Br-, Cl-. Only organic salicylate is a significant interferent. Fast and reversible fluoride response is observed over the range of 10-4 ~10-2 M fluoride, allowing use of the sensing film in a waveguide configuration for flow-injection measurements. PMID:17719905

  1. Protonation effect on the electronic properties of 2-pyridone monomer, dimer and its water clusters: A theoretical study

    SciTech Connect

    Saed, Behnaz; Omidyan, Reza E-mail: reza.omidyan@u-psud.fr

    2014-01-14

    The CC2 (second order approximate coupled cluster method) has been applied to investigate protonation effect on electronic transition energies of 2-pyridone (2PY), 2-pyridone dimer, and micro-solvated 2-pyridone (0-2 water molecules). The PE profiles of protonated 2-pyridone (2PYH{sup +}) as well as monohydrated 2PYH{sup +} at the different electronic states have been investigated. The {sup 1}πσ* state in protonated species (2PYH{sup +}) is a barrier free and dissociative state along the O-H stretching coordinate. In this reaction coordinate, the lowest lying {sup 1}πσ* predissociates the bound S{sub 1}({sup 1}ππ*) state, connecting the latter to a conical intersection with the S{sub 0} state. These conical intersections lead the {sup 1}ππ* state to proceed as predissociative state and finally direct the excited system to the ground state. Furthermore, in presence of water molecule, the {sup 1}πσ* state still remains dissociative but the conical intersection between {sup 1}πσ* and ground state disappears. In addition, according to the CC2 calculation results, it has been predicted that protonation significantly blue shifts the S{sub 1}-S{sub 0} electronic transition of monomer, dimer, and microhydrated 2-pyridone.

  2. Immunoglobulin-free light chain monomer-dimer patterns help to distinguish malignant from premalignant monoclonal gammopathies: a pilot study.

    PubMed

    Kaplan, Batia; Golderman, Sizilia; Aizenbud, Boris; Esev, Konstantin; Kukuy, Olga; Leiba, Merav; Livneh, Avi; Ben-Zvi, Ilan

    2014-09-01

    Multiple myeloma (MM) and AL amyloidosis (AL) are two malignant forms of monoclonal gammopathies. For the purposes of prognosis and treatment, it is important to distinguish these diseases from the premalignant forms of monoclonal gammopathies, such as monoclonal gammopathy of unknown significance (MGUS) and smoldering myeloma (SMM). Routine serum/urine tests for monoclonal protein are insufficient for differential diagnosis. Thus, invasive procedures, such as tissue aspiration or biopsy, are applied. In this study, we aimed at characterization of serum-free light chain (FLC) monomer-dimer patterns to distinguish the malignant from the premalignant forms of monoclonal gammopathies. A quantitative Western blotting was applied to estimate the FLC monomer and dimer levels in AL, MM, MGUS, and SMM patients, and in control subjects (healthy individuals and patients with AA amyloidosis). AL and MM patients displayed an abnormally increased dimerization of monoclonal FLC, accompanied by higher clonality values of FLC dimers, as compared to that of monomers. These abnormalities of FLC patterns were not observed in patients with MGUS, SMM, AA amyloidosis, and healthy individuals. Analysis of FLC patterns helped to differentiate AL and MM from MGUS and SMM, a goal difficult to achieve using routine serum tests. Also, our technique might serve as a complimentary diagnostic tool in the cases with suspected AL amyloidosis, where the diagnosis of MM is excluded, while the results of amyloid typing by routine immunohistochemical techniques are inconclusive. PMID:24866208

  3. Monomer, dimer or cyclic helicate? Coordination diversity with hard-soft P,N-donor ligands.

    PubMed

    Constable, Edwin C; Hostettler, Nik; Housecroft, Catherine E; Murray, Niamh S; Schönle, Jonas; Soydaner, Umut; Walliser, Roché M; Zampese, Jennifer A

    2013-04-14

    We report the synthesis of copper(I) complexes of three ligands which contain a potential P,N,N,P-metal binding site. Elemental analysis confirms that the bulk products possess a composition of [CuL][PF6] where L = 1, 2 or 3. Electrospray mass spectrometry (ESI MS) provides evidence for speciation in MeCN or MeOH solutions and the formation of both [CuL]+ and [Cu2L2]2+; addition of NaCl to the ESI MS samples aids the observation of dinuclear species as [Cu2L2Cl]+ ions. NMR spectroscopic data for a CD3CN solution of [Cu(1)][PF6] were consistent with a mononuclear species, but more complex multinuclear spectra were observed for the same compound dissolved in CD2Cl2. In the solid state, dimeric species dominate. Crystals grown from CH2Cl2 solutions of [Cu(1)][PF6] are found to be [Cu2(1)2][PF6]2·6CH2Cl2; each Cu+ ion in the centrosymmetric cation is bound in an N,O,P,P-coordination sphere, the N-donor originating from the pyridine ring. In [Cu2(3)2][PF6]2, each bridging ligand in the centrosymmetric [Cu2(3)2]2+ ion acts as a P,N-chelate to each Cu+ ion. Competing with this dimeric assembly is that of a circular helicate in which each ligand 3 bridges adjacent pairs of copper(I) ions in a chiral, hexameric complex; both the Δ,Δ,Δ,Δ,Δ,Δ- and Λ,Λ,Λ,Λ,Λ,Λ-enantiomers are present in the crystal lattice; in [Cu6(3)6]6+, each ligand coordinates as a bis(P,N-chelate). The solution absorption spectra of [Cu(1)][PF6], [Cu(2)][PF6] and [Cu(3)][PF6] are dominated by ligand-based transitions and none of the copper(I) complexes exhibits emissive behaviour in solution. PMID:23389257

  4. Photoionization of cold gas phase coronene and its clusters: Autoionization resonances in monomer, dimer, and trimer and electronic structure of monomer cation

    NASA Astrophysics Data System (ADS)

    Bréchignac, Philippe; Garcia, Gustavo A.; Falvo, Cyril; Joblin, Christine; Kokkin, Damian; Bonnamy, Anthony; Parneix, Pascal; Pino, Thomas; Pirali, Olivier; Mulas, Giacomo; Nahon, Laurent

    2014-10-01

    Polycyclic aromatic hydrocarbons (PAHs) are key species encountered in a large variety of environments such as the Interstellar Medium (ISM) and in combustion media. Their UV spectroscopy and photodynamics in neutral and cationic forms are important to investigate in order to learn about their structure, formation mechanisms, and reactivity. Here, we report an experimental photoelectron-photoion coincidence study of a prototypical PAH molecule, coronene, and its small clusters, in a molecular beam using the vacuum ultraviolet (VUV) photons provided by the SOLEIL synchrotron facility. Mass-selected high resolution threshold photoelectron (TPES) and total ion yield spectra were obtained and analyzed in detail. Intense series of autoionizing resonances have been characterized as originating from the monomer, dimer, and trimer neutral species, which may be used as spectral fingerprints for their detection in the ISM by VUV absorption spectroscopy. Finally, a full description of the electronic structure of the monomer cation was made and discussed in detail in relation to previous spectroscopic optical absorption data. Tentative vibrational assignments in the near-threshold TPES spectrum of the monomer have been made with the support of a theoretical approach based on density functional theory.

  5. Photoionization of cold gas phase coronene and its clusters: Autoionization resonances in monomer, dimer, and trimer and electronic structure of monomer cation

    SciTech Connect

    Bréchignac, Philippe Falvo, Cyril; Parneix, Pascal; Pino, Thomas; Pirali, Olivier; Garcia, Gustavo A.; Nahon, Laurent; Joblin, Christine; Kokkin, Damian; Bonnamy, Anthony; Mulas, Giacomo

    2014-10-28

    Polycyclic aromatic hydrocarbons (PAHs) are key species encountered in a large variety of environments such as the Interstellar Medium (ISM) and in combustion media. Their UV spectroscopy and photodynamics in neutral and cationic forms are important to investigate in order to learn about their structure, formation mechanisms, and reactivity. Here, we report an experimental photoelectron-photoion coincidence study of a prototypical PAH molecule, coronene, and its small clusters, in a molecular beam using the vacuum ultraviolet (VUV) photons provided by the SOLEIL synchrotron facility. Mass-selected high resolution threshold photoelectron (TPES) and total ion yield spectra were obtained and analyzed in detail. Intense series of autoionizing resonances have been characterized as originating from the monomer, dimer, and trimer neutral species, which may be used as spectral fingerprints for their detection in the ISM by VUV absorption spectroscopy. Finally, a full description of the electronic structure of the monomer cation was made and discussed in detail in relation to previous spectroscopic optical absorption data. Tentative vibrational assignments in the near-threshold TPES spectrum of the monomer have been made with the support of a theoretical approach based on density functional theory.

  6. Photoionization of cold gas phase coronene and its clusters: autoionization resonances in monomer, dimer, and trimer and electronic structure of monomer cation.

    PubMed

    Bréchignac, Philippe; Garcia, Gustavo A; Falvo, Cyril; Joblin, Christine; Kokkin, Damian; Bonnamy, Anthony; Parneix, Pascal; Pino, Thomas; Pirali, Olivier; Mulas, Giacomo; Nahon, Laurent

    2014-10-28

    Polycyclic aromatic hydrocarbons (PAHs) are key species encountered in a large variety of environments such as the Interstellar Medium (ISM) and in combustion media. Their UV spectroscopy and photodynamics in neutral and cationic forms are important to investigate in order to learn about their structure, formation mechanisms, and reactivity. Here, we report an experimental photoelectron-photoion coincidence study of a prototypical PAH molecule, coronene, and its small clusters, in a molecular beam using the vacuum ultraviolet (VUV) photons provided by the SOLEIL synchrotron facility. Mass-selected high resolution threshold photoelectron (TPES) and total ion yield spectra were obtained and analyzed in detail. Intense series of autoionizing resonances have been characterized as originating from the monomer, dimer, and trimer neutral species, which may be used as spectral fingerprints for their detection in the ISM by VUV absorption spectroscopy. Finally, a full description of the electronic structure of the monomer cation was made and discussed in detail in relation to previous spectroscopic optical absorption data. Tentative vibrational assignments in the near-threshold TPES spectrum of the monomer have been made with the support of a theoretical approach based on density functional theory. PMID:25362317

  7. A Hydrodynamic Analysis of APOBEC3G Reveals a Monomer-Dimer-Tetramer Self-Association that has Implications for Anti-HIV Function†

    PubMed Central

    Salter, Jason D.; Krucinska, Jolanta; Raina, Jay; Smith, Harold C.; Wedekind, Joseph E.

    2009-01-01

    The innate antiviral factor APOBEC3G (A3G) possesses RNA binding activity and deaminates HIV-1 DNA. High-molecular-mass forms of A3G can be isolated from a variety of cell types, but exhibit limited deaminase activity relative to low-molecular-mass species prepared under RNA-depleted conditions. To investigate the fundamental oligomeric state and shape of A3G, we conducted sedimentation velocity analyses of the pure enzyme under RNA-deficient conditions. The results reveal a predominant dimer in equilibrium with minor monomeric and tetrameric species. Hydrodynamic modeling of the dimer supports an extended cylindrical shape that assembles into an elongated tetramer. Overall, the results provide physical restraints for the A3G quaternary structure that have implications for modulating antiviral function. PMID:19839647

  8. Small deviations from local equilibrium for a process which exhibits hydrodynamical behavior. I

    NASA Astrophysics Data System (ADS)

    de Masi, A.; Ianiro, N.; Presutti, E.

    1982-09-01

    The symmetric simple exclusion process where infinitely many particles move randomly on ℤ, jump with equal probability on nearest-neighbor sites, and interact by simple exclusion is considered. It is known that the only extremal invariant measures are Bernoulli, that each measure, in a suitable class, after a "macroscopic" time is locally described, at a zero-order approximation, by a Bernoulli measure with parameter depending on macroscopic space and time, and that the so-defined equilibrium profile satisfies the heat equation. Small deviations from local equilibrium in the hydrodynamical limit are investigated. It is proven, under suitable assumptions, that at first order the state is Gibbs with one- and two-body potentials whose strength depends only on macroscopic space and time and on the equilibrium profile. More precisely, the one-body potential is linear (on the microscopic positions of the particles) and proportional to the macroscopic space gradient of the equilibrium parameter at that time, so that Fourier law holds. The two-body potential varies on a macroscopic scale and does not depend on the microscopic positions of the particles; it is given by the value of the covariance of the Gaussian "macroscopic density fluctuation field."

  9. Small deviations from local equilibrium for a process which exhibits hydrodynamical behavior

    NASA Astrophysics Data System (ADS)

    Demasi, A.; Ianiro, N.; Presutti, E.

    1981-11-01

    Deviations from local equilibrium in a symmetric simple exclusion process are studied. Properties which mimic the hydrodynamical behavior of real physical systems are underlined. The only extremal invariant measures are the Bernoulli measures. Each measure in a suitable class, after a macroscopic time, at a zero order approximation, by a Bernoulli measure with parameter depending on macroscopic space and time. The so defined equilibrium profile satisfies the heat equation. It is proven that at first order, the state is the Gibbs phenomenon with one and two body potentials. Potential strength depends only on macroscopic space and time and on the equilibrium profile. The one body potential is linear (on the microscopic positions of the particles) and proportional to the macroscopic space gradient of the equilibrium parameter at that time, so that Fourier law holds. The two body potential varies on a macroscopic scale and is not dependent on the microscopic positions of the particles, which is given by the value of the covariance of the Gaussian macroscopic density fluctuation field.

  10. Monomers, Dimers, and Helices: Complexities of Cerium and Plutonium Phenanthrolinecarboxylates.

    PubMed

    Cary, Samantha K; Ferrier, Maryline G; Baumbach, Ryan E; Silver, Mark A; Lezama Pacheco, Juan; Kozimor, Stosh A; La Pierre, Henry S; Stein, Benjamin W; Arico, Alexandra A; Gray, Danielle L; Albrecht-Schmitt, Thomas E

    2016-05-01

    The reaction of Ce(III) or Pu(III) with 1,10-phenanthroline-2,9-dicarboxylic acid (PDAH2) results in the formation of new f-element coordination complexes. In the case of cerium, Ce(PDA)(H2O)2Cl·H2O (1) or [Ce(PDAH)(PDA)]2[Ce(PDAH)(PDA)] (2) was isolated depending on the Ce/ligand ratio in the reaction. The structure of 2 is composed of two distinct substructures that are constructed from the same monomer. This monomer is composed of a Ce(III) cation bound by one PDA(2-) dianionic ligand and one PDAH(-) monoanionic ligand, both of which are tetradentate. Bridging by the carboxylate moieties leads to either [Ce(PDAH)(PDA)]2 dimers or [Ce(PDAH)(PDA)]1∞ helical chains. For plutonium, Pu(PDA)2 (3) was the only product isolated regardless of the Pu/ligand ratio employed in the reaction. During the reaction of plutonium with PDAH2, Pu(III) is oxidized to Pu(IV), generating 3. This assignment is consistent with structural metrics and the optical absorption spectrum. Ambiguity in the assignment of the oxidation state of cerium in 1 and 2 from UV-vis-near-IR spectra invoked the use of Ce L3,2-edge X-ray absorption near-edge spectroscopy, magnetic susceptibility, and heat capacity measurements. These experiments support the assignment of Ce(III) in both compounds. The bond distances and coordination numbers are also consistent with these assignments. 3 contains 8-coordinate Pu(IV), whereas the cerium centers in 1 and 2 are 9- and/or 10-coordinate, which correlates with the increased size of Ce(III) versus Pu(IV). Taken together, these data provide an example of a system where the differences in the redox behavior between these f elements creates more complex chemistry with cerium than with plutonium. PMID:27070401

  11. The association-dissociation behavior of the ApoE proteins: kinetic and equilibrium studies

    PubMed Central

    Garai, Kanchan; Frieden, Carl

    2010-01-01

    The apolipoprotein E family consists of three major protein isoforms: apolipoprotein E4 (ApoE4), ApoE3 and ApoE2. The isoforms, which contain 299 residues, differ only by single amino acid changes but of the three only ApoE4 is a risk factor for Alzheimer’s Disease. At μM concentrations lipid-free ApoE exists predominantly as tetramers. In more dilute solutions, lower molecular weight species predominate. Using Fluorescence Correlation Spectroscopy (FCS), intermolecular Fluorescence Resonance Energy Transfer (FRET) and sedimentation methods we find that the association-dissociation reaction of ApoE can be modeled with a monomer-dimer-tetramer process. Equilibrium constants have been determined from the sedimentation data while the individual rate constants for association and dissociation are determined by measuring the kinetics of dissociation of ApoE and are in agreement with the equilibrium constants. Dissociation kinetics as measured by intermolecular FRET show two phases reflecting the dissociation of tetramer to dimer and of dimer to monomer with dissociation from tetramer to dimer being more rapid than the dimer to monomer dissociation. The rate constants differ for the different ApoE isoforms showing that the association-dissociation process is isoforms specific. Strikingly, the association rate constants are almost two orders of magnitude slower than expected for a diffusion controlled process. Dissociation kinetics were also monitored by tryptophan fluorescence in presence of acrylamide and the data found to be consistent with the monomer-dimer-tetramer model. The approach combining multiple methods establishes the reaction scheme of ApoE self-association. PMID:20923231

  12. Partition Equilibrium

    NASA Astrophysics Data System (ADS)

    Feldman, Michal; Tennenholtz, Moshe

    We introduce partition equilibrium and study its existence in resource selection games (RSG). In partition equilibrium the agents are partitioned into coalitions, and only deviations by the prescribed coalitions are considered. This is in difference to the classical concept of strong equilibrium according to which any subset of the agents may deviate. In resource selection games, each agent selects a resource from a set of resources, and its payoff is an increasing (or non-decreasing) function of the number of agents selecting its resource. While it has been shown that strong equilibrium exists in resource selection games, these games do not possess super-strong equilibrium, in which a fruitful deviation benefits at least one deviator without hurting any other deviator, even in the case of two identical resources with increasing cost functions. Similarly, strong equilibrium does not exist for that restricted two identical resources setting when the game is played repeatedly. We prove that for any given partition there exists a super-strong equilibrium for resource selection games of identical resources with increasing cost functions; we also show similar existence results for a variety of other classes of resource selection games. For the case of repeated games we identify partitions that guarantee the existence of strong equilibrium. Together, our work introduces a natural concept, which turns out to lead to positive and applicable results in one of the basic domains studied in the literature.

  13. Outdoor Exhibits

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The National Data Buoy Center (NDBC) at the John C. Stennis Space Center has exhibits located in front of the Visitors Center. These boat-shaped buoys are moored in areas of the ocean that experience hostile environmental conditions. The instruments installed gather information and relay it to the National Weather Service by satellite. Nomad buoys are 20 feet long and weigh 13,900 pounds. They provide information on wind speed and direction, humidity levels, air and sea surface temperature and air pressure. U.S. Coast Guard ships transport buoys to their mooring sites.

  14. Helical equilibrium

    SciTech Connect

    Yoshikawa, S.

    1981-08-01

    A straight, helical plasma equilibrium equation is solved numerically for a plasma with a helical magnetic axis. As is expected, by a suitable choice of the plasma boundary, the vacuum configuration is made line ..integral.. dl/B stable. As the plasma pressure increases, the line ..integral.. dl/B criterion will improve (again as expected). There is apparently no limit on the plasma ..beta.. from the equilibrium consideration. Thus helical-axis stellarator ..beta.. will presumably be limited by MHD stability ..beta.., and not by equilibrium ..beta...

  15. Temperature influences epimerization and composition of flavanol monomers, dimers and trimers during cocoa bean roasting.

    PubMed

    Kothe, Lisa; Zimmermann, Benno F; Galensa, Rudolf

    2013-12-15

    Cocoa consumption is suggested to promote many health benefits, since cocoa is a rich source of flavanols; but amounts and profiles of flavanols depend strongly on the bean type, origin and manufacturing process. Roasting is known as a crucial step in technical treatment of cocoa, which leads to flavanol losses and modifications, especially the epimerization of (-)-epicatechin to (-)-catechin. This study monitors the influence of cocoa bean roasting on the composition of flavanol monomers to trimers, with special focus on epimerization, which was quantified for procyanidin dimers, and also observed for trimers for the first time. Five dimeric and two trimeric potential epimerization products were detected and the extent of epimerization during cocoa roasting was shown to be a function of temperature. The data also showed remarkable variations in the change of flavanol content. The quantified flavanols decreased about 50% in Java beans and increased about 30% in Ivory Coast beans, despite being roasted under equal conditions. PMID:23993533

  16. Equilibrium Shaping

    NASA Astrophysics Data System (ADS)

    Izzo, Dario; Petazzi, Lorenzo

    2006-08-01

    We present a satellite path planning technique able to make identical spacecraft aquire a given configuration. The technique exploits a behaviour-based approach to achieve an autonomous and distributed control over the relative geometry making use of limited sensorial information. A desired velocity is defined for each satellite as a sum of different contributions coming from generic high level behaviours: forcing the final desired configuration the behaviours are further defined by an inverse dynamic calculation dubbed Equilibrium Shaping. We show how considering only three different kind of behaviours it is possible to acquire a number of interesting formations and we set down the theoretical framework to find the entire set. We find that allowing a limited amount of communication the technique may be used also to form complex lattice structures. Several control feedbacks able to track the desired velocities are introduced and discussed. Our results suggest that sliding mode control is particularly appropriate in connection with the developed technique.

  17. Tuning universality far from equilibrium

    PubMed Central

    Karl, Markus; Nowak, Boris; Gasenzer, Thomas

    2013-01-01

    Possible universal dynamics of a many-body system far from thermal equilibrium are explored. A focus is set on meta-stable non-thermal states exhibiting critical properties such as self-similarity and independence of the details of how the respective state has been reached. It is proposed that universal dynamics far from equilibrium can be tuned to exhibit a dynamical transition where these critical properties change qualitatively. This is demonstrated for the case of a superfluid two-component Bose gas exhibiting different types of long-lived but non-thermal critical order. Scaling exponents controlled by the ratio of experimentally tuneable coupling parameters offer themselves as natural smoking guns. The results shed light on the wealth of universal phenomena expected to exist in the far-from-equilibrium realm. PMID:23928853

  18. Universal Stress Protein Exhibits a Redox-Dependent Chaperone Function in Arabidopsis and Enhances Plant Tolerance to Heat Shock and Oxidative Stress

    PubMed Central

    Jung, Young Jun; Melencion, Sarah Mae Boyles; Lee, Eun Seon; Park, Joung Hun; Alinapon, Cresilda Vergara; Oh, Hun Taek; Yun, Dae-Jin; Chi, Yong Hun; Lee, Sang Yeol

    2015-01-01

    Although a wide range of physiological information on Universal Stress Proteins (USPs) is available from many organisms, their biochemical, and molecular functions remain unidentified. The biochemical function of AtUSP (At3g53990) from Arabidopsis thaliana was therefore investigated. Plants over-expressing AtUSP showed a strong resistance to heat shock and oxidative stress, compared with wild-type and Atusp knock-out plants, confirming the crucial role of AtUSP in stress tolerance. AtUSP was present in a variety of structures including monomers, dimers, trimers, and oligomeric complexes, and switched in response to external stresses from low molecular weight (LMW) species to high molecular weight (HMW) complexes. AtUSP exhibited a strong chaperone function under stress conditions in particular, and this activity was significantly increased by heat treatment. Chaperone activity of AtUSP was critically regulated by the redox status of cells and accompanied by structural changes to the protein. Over-expression of AtUSP conferred a strong tolerance to heat shock and oxidative stress upon Arabidopsis, primarily via its chaperone function. PMID:26734042

  19. Phase coexistence far from equilibrium

    NASA Astrophysics Data System (ADS)

    Dickman, Ronald

    2016-04-01

    Investigation of simple far-from-equilibrium systems exhibiting phase separation leads to the conclusion that phase coexistence is not well defined in this context. This is because the properties of the coexisting nonequilibrium systems depend on how they are placed in contact, as verified in the driven lattice gas with attractive interactions, and in the two-temperature lattice gas, under (a) weak global exchange between uniform systems, and (b) phase-separated (nonuniform) systems. Thus, far from equilibrium, the notions of universality of phase coexistence (i.e., independence of how systems exchange particles and/or energy), and of phases with intrinsic properties (independent of their environment) are lost.

  20. Ethics on Exhibit

    ERIC Educational Resources Information Center

    Vick, Randy M.

    2011-01-01

    This article discusses ethical questions raised by an exhibition of work by an artist with a history of mental illness and the exhibition's relevance to art therapy and “outsider art” discourse on the subject. Considerations for how such an exhibit could be handled had the circumstances included an art therapist and art therapy client are…

  1. General equilibrium of an ecosystem.

    PubMed

    Tschirhart, J

    2000-03-01

    Ecosystems and economies are inextricably linked: ecosystem models and economic models are not linked. Consequently, using either type of model to design policies for preserving ecosystems or improving economic performance omits important information. Improved policies would follow from a model that links the systems and accounts for the mutual feedbacks by recognizing how key ecosystem variables influence key economic variables, and vice versa. Because general equilibrium economic models already are widely used for policy making, the approach used here is to develop a general equilibrium ecosystem model which captures salient biological functions and which can be integrated with extant economic models. In the ecosystem model, each organism is assumed to be a net energy maximizer that must exert energy to capture biomass from other organisms. The exerted energies are the "prices" that are paid to biomass, and each organism takes the prices as signals over which it has no control. The maximization problem yields the organism's demand for and supply of biomass to other organisms as functions of the prices. The demands and supplies for each biomass are aggregated over all organisms in each species which establishes biomass markets wherein biomass prices are determined. A short-run equilibrium is established when all organisms are maximizing and demand equals supply in every biomass market. If a species exhibits positive (negative) net energy in equilibrium, its population increases (decreases) and a new equilibrium follows. The demand and supply forces in the biomass markets drive each species toward zero stored energy and a long-run equilibrium. Population adjustments are not based on typical Lotka-Volterra differential equations in which one entire population adjusts to another entire population thereby masking organism behavior; instead, individual organism behavior is central to population adjustments. Numerical simulations use a marine food web in Alaska to

  2. An Exhibit for Touching.

    ERIC Educational Resources Information Center

    Hunt, Susan

    1979-01-01

    An exhibit designed for visually handicapped persons presented by the Kalamazoo (Michigan) Institute of Art included bronze sculptures and oil paintings from the institute's permanent collection. (CL)

  3. San Rafael Schools Exhibit.

    ERIC Educational Resources Information Center

    San Rafael City Schools, CA.

    The San Rafael City Schools' exhibit which was displayed at the 1983 Marin County Fair (California) is described. The exhibit, entitled "Education - A Real Winner," consisted of 12 display panels illustrating the following aspects of the school system: (1) early history from 1861; (2) present board and administration; (3) present schools and…

  4. A Teaching Aids Exhibition.

    ERIC Educational Resources Information Center

    Mahanja, Salah

    1985-01-01

    Describes an exhibition for the benefit of teachers of English in Arab Primary Schools, which was prepared by third-year students at the Teachers College for Arab Teachers. The exhibition included games, songs, audiovisual aids, crossword puzzles, vocabulary, spelling booklets, preposition aids, and worksheet and lesson planning aids. (SED)

  5. Visitors Center Exhibits

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A child enjoys building his own LEGO model at a play table which was included in the exhibit 'Travel in Space' World Show. The exhibit consisted of 21 displays designed to teach children about flight and space travel from the Wright brothers to future generations of space vehicles.

  6. Communicating Science through Exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, P.; Harold, J.; Morrow, C.

    It is critically important for the public to better understand the scientific process. Museum exhibitions are an important part of informal science education that can effectively reach public audiences as well as school groups. They provide an important gateway for the public to learn about compelling scientific endeavors. There are many ways for scientists to help develop science exhibitions. The Space Science Institute (SSI) is a national leader in producing traveling science exhibitions and their associated educational programming (i.e. interactive websites, educator workshops, public talks, instructional materials). Two of its exhibitions, Space Weather Center and MarsQuest, are currently on tour. Another exhibition, Alien Earths, is in development. The Space Weather Center was developed in partnership with various research missions at NASA's Goddard Space Flight Center. MarsQuest is a 5000 square-foot traveling exhibition. The exhibit's second 3-year tour began this January at the Detroit Science Center. It is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and to learn more about their own planet in the process. The 3,000 square-foot traveling exhibition, called Alien Earths, will bring origins-related research and discoveries to students and the American public. Alien Earths has four interrelated exhibit areas: Our Place in Space, Star Birth, PlanetQuest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in ``habitable zones'' around other stars; and finally they will be able to learn about how scientists are looking for signs of life beyond Earth. Besides the exhibits, SSI is also developing interactive web sites based on exhibit themes. New technologies are transforming the Web from a static medium to an interactive environment with tremendous

  7. New Hurricane Exhibit

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A new exhibit in StenniSphere depicting NASA's role in hurricane prediction and research and SSC's role in helping the region recover from Hurricane Katrina. The cyclone-shaped exhibit focuses on the effects of the Aug. 29, 2005 storm and outlines how NASA is working to improve weather forecasting. Through photos, 3-D models and digital animations, the exhibit tells the story of what happened inside the storm and how NASA's scientific research can increase the accuracy of hurricane tracking and modeling.

  8. Communicating Science through Exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, Paul

    2005-04-01

    It is critically important for the public to better understand the scientific process. Museum exhibitions are an important part of informal science education that can effectively reach public audiences as well as school groups. They provide an important gateway for the public to learn about compelling scientific endeavors. Science exhibitions also provide a marvelous opportunity for scientists to become engaged in the exhibit development process. The Space Science Institute (SSI) is a national leader in producing traveling science exhibitions and their associated educational programming (i.e. interactive websites, educator workshops, public talks, instructional materials). The focus of this presentation will be on two of its exhibit projects: MarsQuest (on tour for four years) and Alien Earths (its tour began early in 2005). MarsQuest is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and to learn more about their own planet in the process. Alien Earths will bring origins-related research and discoveries to students and the American public. It has four interrelated exhibit areas: Our Place in Space, Star Birth, Planet Quest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in ``habitable zones'' around other stars; and finally they will be able to learn about how scientists are looking for signs of life beyond Earth. SSI is also developing interactive web sites based on exhibit themes. New technologies are transforming the Web from a static medium to an interactive environment with tremendous potential for informal education and inquiry-based investigations. This talk will focus on the role informal science projects play in effectively communicating science to a broad, public audience.

  9. Test Control Center exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Have you ever wondered how the engineers at John C. Stennis Space Center in Hancock County, Miss., test fire a Space Shuttle Main Engine? The Test Control Center exhibit at StenniSphere can answer your questions by simulating the test firing of a Space Shuttle Main Engine. A recreation of one of NASA's test control centers, the exhibit explains and portrays the 'shake, rattle and roar' that happens during a real test firing.

  10. Getting Freshman in Equilibrium.

    ERIC Educational Resources Information Center

    Journal of Chemical Education, 1983

    1983-01-01

    Various aspects of chemical equilibrium were discussed in six papers presented at the Seventh Biennial Conference on Chemical Education (Stillwater, Oklahoma 1982). These include student problems in understanding hydrolysis, helping students discover/uncover topics, equilibrium demonstrations, instructional strategies, and flaws to kinetic…

  11. Swamp to Space exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The menacing-looking alligator is really harmless. It is one of the realistic props to help convince visitors that the feel of the swamp is real in StenniSphere's Swamp to Space exhibit at John C. Stennis Space Center in Hancock County, Miss. The historical section of the Swamp to Space exhibit tells the story of why and how Stennis Space Center came to be. It also pays tribute to the families who moved their homes to make way for the space age in Mississippi.

  12. 1989 Architectural Exhibition Winners.

    ERIC Educational Resources Information Center

    School Business Affairs, 1990

    1990-01-01

    Winners of the 1989 Architectural Exhibition sponsored annually by the ASBO International's School Facilities Research Committee include the Brevard Performing Arts Center (Melbourne, Florida), the Capital High School (Santa Fe, New Mexico), Gage Elementary School (Rochester, Minnesota), the Lakewood (Ohio) High School Natatorium, and three other…

  13. Exhibitions in Sight

    ERIC Educational Resources Information Center

    Wasserman, Burton

    1978-01-01

    During this past year a vast number of art shows have been exhibited across the United States. Their most striking features were their range and diversity. Here are some comments on Ben Shahn's paintings and photography focusing on social realism, some works by the Polish Constructivists, interested in redefining form in relation to space, the…

  14. Chemical Principles Revisited: Chemical Equilibrium.

    ERIC Educational Resources Information Center

    Mickey, Charles D.

    1980-01-01

    Describes: (1) Law of Mass Action; (2) equilibrium constant and ideal behavior; (3) general form of the equilibrium constant; (4) forward and reverse reactions; (5) factors influencing equilibrium; (6) Le Chatelier's principle; (7) effects of temperature, changing concentration, and pressure on equilibrium; and (8) catalysts and equilibrium. (JN)

  15. Skylab Exhibit Ribbon Cutting

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A metal strap became tangled over one of the folded solar array panels when Skylab lost its micro meteoroid shield during its launch. Cutters like the ones used to free the solar array were used to cut the ribbon opening to the public a new full-scale Skylab cluster exhibit at the Alabama Space and Rocket Center in Huntsville, Alabama. Wielding the cutters are (left to right): Alabama Senator James B. Allen; Marshall Space Flight Center director, Dr. William R. Lucas, Huntsville Mayor, Joe Davis; Madison County Commission Chairman, James Record (standing behind Mayor Davis); and chairman of the Alabama Space Science Exhibit Commission, Jack Giles. Astronauts Conrad and Kerwin used the same type of tool in Earth orbit to cut the aluminum strap which jammed the Skylab solar array.

  16. Computing Equilibrium Chemical Compositions

    NASA Technical Reports Server (NTRS)

    Mcbride, Bonnie J.; Gordon, Sanford

    1995-01-01

    Chemical Equilibrium With Transport Properties, 1993 (CET93) computer program provides data on chemical-equilibrium compositions. Aids calculation of thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93/PC is version of CET93 specifically designed to run within 640K memory limit of MS-DOS operating system. CET93/PC written in FORTRAN.

  17. Starship 2040 Exhibit

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This photograph shows Justin Varnadore, son of a Marshall TV employee, at the controls of one of the many displays within the Starship 2040 exhibit on display at Joe Davis Stadium in Huntsville, Alabama. Developed by the Space Transportation Directorate at Marshall Space Flight Center (MSFC), the Starship 2040 exhibit is housed in a 48-ft (14.6-m) tractor and trailer rig, permitting it to travel around the Nation, demonstrating NASA's vision of what commercial spaceflight might be like 40 years from now. All the irnovations suggested aboard the exhibit (automated vehicle health monitoring systems, high-energy propulsion drive, navigational aids, and emergency and safety systems) are based on concepts and technologies now being studied at NASA Centers and partner institutions around the Nation. NASA is the Nation's premier agency for development of the space transportation system, including future-generation reusable launch vehicles. Such systems, the keys to a 'real' Starship 2040, require revolutionary advances in critical aerospace technologies, from thermal, magnetic, chemical, and propellantless propulsion systems to new energy sources such as space solar power or antimatter propulsion. These and other advances are now being studied, developed, and tested at NASA field centers and partner institutions all over the Nation.

  18. Online Exhibits & Concept Maps

    NASA Astrophysics Data System (ADS)

    Douma, M.

    2009-12-01

    Presenting the complexity of geosciences to the public via the Internet poses a number of challenges. For example, utilizing various - and sometimes redundant - Web 2.0 tools can quickly devour limited time. Do you tweet? Do you write press releases? Do you create an exhibit or concept map? The presentation will provide participants with a context for utilizing Web 2.0 tools by briefly highlighting methods of online scientific communication across several dimensions. It will address issues of: * breadth and depth (e.g. from narrow topics to well-rounded views), * presentation methods (e.g. from text to multimedia, from momentary to enduring), * sources and audiences (e.g. for experts or for the public, content developed by producers to that developed by users), * content display (e.g. from linear to non-linear, from instructive to entertaining), * barriers to entry (e.g. from an incumbent advantage to neophyte accessible, from amateur to professional), * cost and reach (e.g. from cheap to expensive), and * impact (e.g. the amount learned, from anonymity to brand awareness). Against this backdrop, the presentation will provide an overview of two methods of online information dissemination, exhibits and concept maps, using the WebExhibits online museum (www.webexhibits.org) and SpicyNodes information visualization tool (www.spicynodes.org) as examples, with tips on how geoscientists can use either to communicate their science. Richly interactive online exhibits can serve to engage a large audience, appeal to visitors with multiple learning styles, prompt exploration and discovery, and present a topic’s breadth and depth. WebExhibits, which was among the first online museums, delivers interactive information, virtual experiments, and hands-on activities to the public. While large, multidisciplinary exhibits on topics like “Color Vision and Art” or “Calendars Through the Ages” require teams of scholars, user interface experts, professional writers and editors

  19. Space Shuttle Cockpit exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Want to sit in the cockpit of the Space Shuttle and watch astronauts work in outer space? At StenniSphere, you can do that and much more. StenniSphere, the visitor center at John C. Stennis Space Center in Hancock County, Miss., presents 14,000-square-feet of interactive exhibits that depict America's race for space as well as a glimpse of the future. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

  20. Equilibrium games in networks

    NASA Astrophysics Data System (ADS)

    Li, Angsheng; Zhang, Xiaohui; Pan, Yicheng; Peng, Pan

    2014-12-01

    It seems a universal phenomenon of networks that the attacks on a small number of nodes by an adversary player Alice may generate a global cascading failure of the networks. It has been shown (Li et al., 2013) that classic scale-free networks (Barabási and Albert, 1999, Barabási, 2009) are insecure against attacks of as small as O(logn) many nodes. This poses a natural and fundamental question: Can we introduce a second player Bob to prevent Alice from global cascading failure of the networks? We proposed a game in networks. We say that a network has an equilibrium game if the second player Bob has a strategy to balance the cascading influence of attacks by the adversary player Alice. It was shown that networks of the preferential attachment model (Barabási and Albert, 1999) fail to have equilibrium games, that random graphs of the Erdös-Rényi model (Erdös and Rényi, 1959, Erdös and Rényi, 1960) have, for which randomness is the mechanism, and that homophyly networks (Li et al., 2013) have equilibrium games, for which homophyly and preferential attachment are the underlying mechanisms. We found that some real networks have equilibrium games, but most real networks fail to have. We anticipate that our results lead to an interesting new direction of network theory, that is, equilibrium games in networks.

  1. An Updated Equilibrium Machine

    ERIC Educational Resources Information Center

    Schultz, Emeric

    2008-01-01

    A device that can demonstrate equilibrium, kinetic, and thermodynamic concepts is described. The device consists of a leaf blower attached to a plastic container divided into two chambers by a barrier of variable size and form. Styrofoam balls can be exchanged across the barrier when the leaf blower is turned on and various air pressures are…

  2. Statistical physics of shear flow: a non-equilibrium problem

    NASA Astrophysics Data System (ADS)

    Evans, R. M. L.

    2010-09-01

    Complex fluids are easily and reproducibly driven into non-equilibrium steady states by the action of shear flow. The statistics of the microstructure of non-equilibrium fluids is important to the material properties of every complex fluid that flows, e.g. axle grease on a rotating bearing; blood circulating in capillaries; molten plastic flowing into a mould; the non-equilibrium onion phase of amphiphiles used for drug delivery; the list is endless. Such states are as diverse and interesting as equilibrium states, but are not governed by the same statistics as equilibrium materials. I review some recently discovered principles governing the probabilities of various types of molecular re-arrangements taking place within a sheared fluid. As well as providing new foundations for the study of non-equilibrium matter, the principles are applied to some simple models of particles interacting under flow, showing that the theory exhibits physically convincing behaviour.

  3. An Updated Equilibrium Machine

    NASA Astrophysics Data System (ADS)

    Schultz, Emeric

    2008-08-01

    A device that can demonstrate equilibrium, kinetic, and thermodynamic concepts is described. The device consists of a leaf blower attached to a plastic container divided into two chambers by a barrier of variable size and form. Styrofoam balls can be exchanged across the barrier when the leaf blower is turned on and various air pressures are applied. Equilibrium can be approached from different distributions of balls in the container under different conditions. The Le Châtelier principle can be demonstrated. Kinetic concepts can be demonstrated by changing the nature of the barrier, either changing the height or by having various sized holes in the barrier. Thermodynamic concepts can be demonstrated by taping over some or all of the openings and restricting air flow into container on either side of the barrier.

  4. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

    The entropy associated with absolute equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.

  5. The equilibrium dayside magnetosphere

    NASA Technical Reports Server (NTRS)

    Zavriyev, Anton; Hasegawa, Akira

    1989-01-01

    A method is presented of computing the dayside global earth magnetic field which is in equilibrium with the plasma pressure, based on satellite observations at a local region of the magnetosphere. The method, which utilizes a perturbation around a dipole magnetic field, involves computation of the global plasma pressure profile based on the equatorial (anisotropic) pressure data, derivation of the current profile which satisfies the equilibrium condition, and computation of the magnetic field using the current profile and the boundary current produced by the solar wind. The method is applied for the Active Magnetospheric Particle Tracer Explorers data, and the result of the computation is found to compare reasonably well with the observed magnetic field profile near the geomagnetic equator.

  6. Solids Far from Equilibrium

    NASA Astrophysics Data System (ADS)

    Godrèche, C.

    2011-03-01

    Preface; 1. Shape and growth of crystals P. Nozières; 2. Instabilities of planar solidification fronts B. Caroli, C. Caroli and B. Roulet; 3. An introduction to the kinetics of first-order phase transition J. S. Langer; 4. Dendritic growth and related topics Y. Pomeau and M. Ben Amar; 5. Growth and aggregation far from equilibrium L. M. Sander; 6. Kinetic roughening of growing surfaces J. Krug and H. Spohn; Acknowledgements; References; Index.

  7. Exoplanet Equilibrium Chemistry Calculations

    NASA Astrophysics Data System (ADS)

    Blumenthal, Sarah; Harrington, J.; Bowman, M.; Blecic, J.

    2013-10-01

    Recently, Agundez et al. (2012, A&A 548, A73) used a chemical kinetics code to study a model HD 209458b (equilibrium temperature of 1450 K, assuming full redistribution and 0 albedo). They found that thermochemistry dominates most of the dayside, but that significant compositional gradients may exist across the dayside. We calculate equilibrium-chemistry molecular abundances for several model exoplanets, using NASA's open-source Chemical Equilibrium Abundances code (McBride and Gordon 1996). We vary the degree of radiation redistribution to the dark side, ranging from total redistribution to instantaneous reradiation. Atomically, both the solar abundance multiple and the carbon fraction vary. Planet substellar temperatures range from just above 1200 K, where photochemistry should no longer be important, to those of hot planets (3000 K). We present synthetic abundance images for the key spectroscopic molecules CO, CH4, and H2O for several hot-Jupiter model planets. This work was supported by the NASA Planetary Atmospheres grant NNX12AI69G.

  8. Equilibrium Electroconvective Instability

    NASA Astrophysics Data System (ADS)

    Rubinstein, I.; Zaltzman, B.

    2015-03-01

    Since its prediction 15 years ago, hydrodynamic instability in concentration polarization at a charge-selective interface has been attributed to nonequilibrium electro-osmosis related to the extended space charge which develops at the limiting current. This attribution had a double basis. On the one hand, it has been recognized that neither equilibrium electro-osmosis nor bulk electroconvection can yield instability for a perfectly charge-selective solid. On the other hand, it has been shown that nonequilibrium electro-osmosis can. The first theoretical studies in which electro-osmotic instability was predicted and analyzed employed the assumption of perfect charge selectivity for the sake of simplicity and so did the subsequent studies of various time-dependent and nonlinear features of electro-osmotic instability. In this Letter, we show that relaxing the assumption of perfect charge selectivity (tantamount to fixing the electrochemical potential of counterions in the solid) allows for the equilibrium electroconvective instability. In addition, we suggest a simple experimental test for determining the true, either equilibrium or nonequilibrium, origin of instability in concentration polarization.

  9. Structural design using equilibrium programming

    NASA Technical Reports Server (NTRS)

    Scotti, Stephen J.

    1992-01-01

    Multiple nonlinear programming methods are combined in the method of equilibrium programming. Equilibrium programming theory has been appied to problems in operations research, and in the present study it is investigated as a framework to solve structural design problems. Several existing formal methods for structural optimization are shown to actually be equilibrium programming methods. Additionally, the equilibrium programming framework is utilized to develop a new structural design method. Selected computational results are presented to demonstrate the methods.

  10. Non-equilibrium DMFT - Polaritonics

    NASA Astrophysics Data System (ADS)

    Lubatsch, Andreas; Frank, Regine

    Non-equilibrium physics recently really becomes important with the progress of ultrafast laser sciences. However in our understanding there is still a gap between equilibrium physics and the non-equilibrium, even though numerical methods have been advanced in recent years. We compare in this talk novel results at hand with equilibrium physics. The comparison will show that especially theoretical efforts are needed to explain many - so far - unresolved problems and to predict novel research on the basis of ab initio computing. We specifically discuss several non-equilibrium extensions of DMFT, numerical methods as well as semi-analytical solvers.

  11. Thermal equilibrium of goats.

    PubMed

    Maia, Alex S C; Nascimento, Sheila T; Nascimento, Carolina C N; Gebremedhin, Kifle G

    2016-05-01

    The effects of air temperature and relative humidity on thermal equilibrium of goats in a tropical region was evaluated. Nine non-pregnant Anglo Nubian nanny goats were used in the study. An indirect calorimeter was designed and developed to measure oxygen consumption, carbon dioxide production, methane production and water vapour pressure of the air exhaled from goats. Physiological parameters: rectal temperature, skin temperature, hair-coat temperature, expired air temperature and respiratory rate and volume as well as environmental parameters: air temperature, relative humidity and mean radiant temperature were measured. The results show that respiratory and volume rates and latent heat loss did not change significantly for air temperature between 22 and 26°C. In this temperature range, metabolic heat was lost mainly by convection and long-wave radiation. For temperature greater than 30°C, the goats maintained thermal equilibrium mainly by evaporative heat loss. At the higher air temperature, the respiratory and ventilation rates as well as body temperatures were significantly elevated. It can be concluded that for Anglo Nubian goats, the upper limit of air temperature for comfort is around 26°C when the goats are protected from direct solar radiation. PMID:27157333

  12. Statistical physics ""Beyond equilibrium

    SciTech Connect

    Ecke, Robert E

    2009-01-01

    The scientific challenges of the 21st century will increasingly involve competing interactions, geometric frustration, spatial and temporal intrinsic inhomogeneity, nanoscale structures, and interactions spanning many scales. We will focus on a broad class of emerging problems that will require new tools in non-equilibrium statistical physics and that will find application in new material functionality, in predicting complex spatial dynamics, and in understanding novel states of matter. Our work will encompass materials under extreme conditions involving elastic/plastic deformation, competing interactions, intrinsic inhomogeneity, frustration in condensed matter systems, scaling phenomena in disordered materials from glasses to granular matter, quantum chemistry applied to nano-scale materials, soft-matter materials, and spatio-temporal properties of both ordinary and complex fluids.

  13. The Nash equilibrium: a perspective.

    PubMed

    Holt, Charles A; Roth, Alvin E

    2004-03-23

    In 1950, John Nash contributed a remarkable one-page PNAS article that defined and characterized a notion of equilibrium for n- person games. This notion, now called the "Nash equilibrium," has been widely applied and adapted in economics and other behavioral sciences. Indeed, game theory, with the Nash equilibrium as its centerpiece, is becoming the most prominent unifying theory of social science. In this perspective, we summarize the historical context and subsequent impact of Nash's contribution. PMID:15024100

  14. Grinding kinetics and equilibrium states

    NASA Technical Reports Server (NTRS)

    Opoczky, L.; Farnady, F.

    1984-01-01

    The temporary and permanent equilibrium occurring during the initial stage of cement grinding does not indicate the end of comminution, but rather an increased energy consumption during grinding. The constant dynamic equilibrium occurs after a long grinding period indicating the end of comminution for a given particle size. Grinding equilibrium curves can be constructed to show the stages of comminution and agglomeration for certain particle sizes.

  15. Traveling Exhibitions: translating current science into effective science exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, P.; Morrow, C.; Harold, J.

    The Space Science Institute (SSI) of Boulder, Colorado has recently developed two museum exhibits called the Space Weather Center and MarsQuest. It is currently planning to develop two other exhibitions called Cosmic Origins and InterActive Earth. Museum exhibitions provide research scientists the opportunity to engage in a number of activities that are vital to the success of earth and space outreach programs. The Space Weather Center was developed in partnership with various research missions at NASA's Goddard Space Flight Center. The focus of the presentation will be on the Institute's MarsQuest exhibition. This project is a 5000 square-foot, 2.5M, traveling exhibition that is now touring the country. The exhibit's 3-year tour is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and learn more about their own planet in the process. The associated planetarium show and education program will also be described, with particular emphasis on workshops to orient host museum staff (e.g. museum educators and docents). The workshops make innovative connections between the exhibitions interactive experiences and lesson plans aligned with the National Science Education Standards. SSI is also developing an interactive web site called MarsQuest On-line. The linkage between the web site, education program and exhibit will be discussed. MarsQuest and SSI's other exhibitions are good models for actively involving scientists and their discoveries to help improve informal science education in the museum community and for forging a stronger connection between formal and informal education.

  16. Exhibitions: Facing Outward, Pointing Inward

    ERIC Educational Resources Information Center

    McDonald, Joseph P.

    2007-01-01

    The Coalition of Essential Schools (CES) Exhibitions Project of the early 1990s produced a range of work that continues to inform the practice of using exhibitions as a "360 degree" method of transforming teaching and learning, community connections, school design, and assessment. Among that work was this paper coupling the origins of exhibitions…

  17. Napoleon Is in Equilibrium

    PubMed Central

    Phillips, Rob

    2016-01-01

    It has been said that the cell is the test tube of the twenty-first century. If so, the theoretical tools needed to quantitatively and predictively describe what goes on in such test tubes lag sorely behind the stunning experimental advances in biology seen in the decades since the molecular biology revolution began. Perhaps surprisingly, one of the theoretical tools that has been used with great success on problems ranging from how cells communicate with their environment and each other to the nature of the organization of proteins and lipids within the cell membrane is statistical mechanics. A knee-jerk reaction to the use of statistical mechanics in the description of cellular processes is that living organisms are so far from equilibrium that one has no business even thinking about it. But such reactions are probably too hasty given that there are many regimes in which, because of a separation of timescales, for example, such an approach can be a useful first step. In this article, we explore the power of statistical mechanical thinking in the biological setting, with special emphasis on cell signaling and regulation. We show how such models are used to make predictions and describe some recent experiments designed to test them. We also consider the limits of such models based on the relative timescales of the processes of interest. PMID:27429713

  18. Napoleon Is in Equilibrium

    NASA Astrophysics Data System (ADS)

    Phillips, Rob

    2015-03-01

    It has been said that the cell is the test tube of the twenty-first century. If so, the theoretical tools needed to quantitatively and predictively describe what goes on in such test tubes lag sorely behind the stunning experimental advances in biology seen in the decades since the molecular biology revolution began. Perhaps surprisingly, one of the theoretical tools that has been used with great success on problems ranging from how cells communicate with their environment and each other to the nature of the organization of proteins and lipids within the cell membrane is statistical mechanics. A knee-jerk reaction to the use of statistical mechanics in the description of cellular processes is that living organisms are so far from equilibrium that one has no business even thinking about it. But such reactions are probably too hasty given that there are many regimes in which, because of a separation of timescales, for example, such an approach can be a useful first step. In this article, we explore the power of statistical mechanical thinking in the biological setting, with special emphasis on cell signaling and regulation. We show how such models are used to make predictions and describe some recent experiments designed to test them. We also consider the limits of such models based on the relative timescales of the processes of interest.

  19. Rapid-Equilibrium Enzyme Kinetics

    ERIC Educational Resources Information Center

    Alberty, Robert A.

    2008-01-01

    Rapid-equilibrium rate equations for enzyme-catalyzed reactions are especially useful because if experimental data can be fit by these simpler rate equations, the Michaelis constants can be interpreted as equilibrium constants. However, for some reactions it is necessary to use the more complicated steady-state rate equations. Thermodynamics is…

  20. Against the Odds Exhibition Opens

    MedlinePlus

    ... the National Institutes of Health in Bethesda, Md. Photo courtesy of Bill Branson NIH Director Dr. Elias ... addresses visitors to the opening of the exhibition. Photo courtesy of Bill Branson Brothers Niko and Theo ...

  1. Against the Odds Exhibition Opens

    MedlinePlus

    ... Bar Home Current Issue Past Issues Special Section Against the Odds Exhibition Opens Past Issues / Spring 2008 ... Research in Bethesda. Photo courtesy of Bill Branson "Against the Odds" is a remarkable story of achievement ...

  2. Is Soret equilibrium a non-equilibrium effect?

    NASA Astrophysics Data System (ADS)

    Würger, Alois

    2013-04-01

    Recent thermophoretic experiments on colloidal suspensions revived an old debate, namely whether the Soret effect is properly described by thermostatics, or necessarily requires non-equilibrium thermodynamics. Based on colloidal transport theory and the entropy production of the related viscous flow, our analysis leads to the conclusion that the equilibrium approach may work for small ions, yet fails for colloidal particles and polymers. Regarding binary molecular mixtures, our results shed some doubt on the validity of thermostatic approaches that derive the Soret coefficient from equilibrium potentials.

  3. Greenhouse Earth: A Traveling Exhibition

    SciTech Connect

    Booth, W.H.; Caesar, S.

    1992-09-01

    The Franklin Institute Science Museum provided an exhibit entitled the Greenhouse Earth: A Traveling Exhibition. This 3500 square-foot exhibit on global climate change was developed in collaboration with the Association of Science-Technology Centers. The exhibit opened at The Franklin Institute on February 14, 1992, welcoming 291,000 visitors over its three-month stay. During its three-year tour, Greenhouse Earth will travel to ten US cities, reaching two million visitors. Greenhouse Earth aims to deepen public understanding of the scientific issues of global warming and the conservation measures that can be taken to slow its effects. The exhibit features hands-on exhibitry, interactive computer programs and videos, a theater production, a demonstration cart,'' guided tours, and lectures. supplemental educational programs at the Institute included a teachers preview, a symposium on climate change, and a satellite field trip.'' The development of Greenhouse Earth included front-end and formative evaluation procedures. Evaluation includes interviews with visitors, prototypes, and summative surveys for participating museums. During its stay in Philadelphia, Greenhouse Earth was covered by the local and national press, with reviews in print and broadcast media. Greenhouse Earth is the first large-scale museum exhibit to address global climate change.

  4. Small deviations from local equilibrium for a process which exhibits hydrodynamical behavior. II

    NASA Astrophysics Data System (ADS)

    de Masi, A.; Ferrari, P.; Ianiro, N.; Presutti, E.

    1982-09-01

    The symmetric simple exclusion process on ℤ with sources at ± L, L ɛ ℕ is considered. The stationary measure μL is studied in the limit as L diverges. The first order correction to its limit is proven to be of order 1 / L and it is explicitly computed. The result is in agreement with the analysis of the model from the hydrodynamical point of view initiated in Ref.1.

  5. The Nash Equilibrium Revisited: Chaos and Complexity Hidden in Simplicity

    NASA Astrophysics Data System (ADS)

    Fellman, Philip V.

    The Nash Equilibrium is a much discussed, deceptively complex, method for the analysis of non-cooperative games (McLennan and Berg, 2005). If one reads many of the commonly available definitions the description of the Nash Equilibrium is deceptively simple in appearance. Modern research has discovered a number of new and important complex properties of the Nash Equilibrium, some of which remain as contemporary conundrums of extraordinary difficulty and complexity (Quint and Shubik, 1997). Among the recently discovered features which the Nash Equilibrium exhibits under various conditions are heteroclinic Hamiltonian dynamics, a very complex asymptotic structure in the context of two-player bi-matrix games and a number of computationally complex or computationally intractable features in other settings (Sato, Akiyama and Farmer, 2002). This paper reviews those findings and then suggests how they may inform various market prediction strategies.

  6. Helical axis stellarator equilibrium model

    SciTech Connect

    Koniges, A.E.; Johnson, J.L.

    1985-02-01

    An asymptotic model is developed to study MHD equilibria in toroidal systems with a helical magnetic axis. Using a characteristic coordinate system based on the vacuum field lines, the equilibrium problem is reduced to a two-dimensional generalized partial differential equation of the Grad-Shafranov type. A stellarator-expansion free-boundary equilibrium code is modified to solve the helical-axis equations. The expansion model is used to predict the equilibrium properties of Asperators NP-3 and NP-4. Numerically determined flux surfaces, magnetic well, transform, and shear are presented. The equilibria show a toroidal Shafranov shift.

  7. Understanding thermal equilibrium through activities

    NASA Astrophysics Data System (ADS)

    Pathare, Shirish; Huli, Saurabhee; Nachane, Madhura; Ladage, Savita; Pradhan, Hemachandra

    2015-03-01

    Thermal equilibrium is a basic concept in thermodynamics. In India, this concept is generally introduced at the first year of undergraduate education in physics and chemistry. In our earlier studies (Pathare and Pradhan 2011 Proc. episteme-4 Int. Conf. to Review Research on Science Technology and Mathematics Education pp 169-72) we found that students in India have a rather unsatisfactory understanding of thermal equilibrium. We have designed and developed a module of five activities, which are presented in succession to the students. These activities address the students’ alternative conceptions that underlie their lack of understanding of thermal equilibrium and aim at enhancing their understanding of the concept.

  8. Equilibrium and Orientation in Cephalopods.

    ERIC Educational Resources Information Center

    Budelmann, Bernd-Ulrich

    1980-01-01

    Describes the structure of the equilibrium receptor system in cephalopods, comparing it to the vertebrate counterpart--the vestibular system. Relates the evolution of this complex system to the competition of cephalopods with fishes. (CS)

  9. Equilibrium Constants You Can Smell.

    ERIC Educational Resources Information Center

    Anderson, Michael; Buckley, Amy

    1996-01-01

    Presents a simple experiment involving the sense of smell that students can accomplish during a lecture. Illustrates the important concepts of equilibrium along with the acid/base properties of various ions. (JRH)

  10. Equilibrium ignition for ICF capsules

    SciTech Connect

    Lackner, K.S.; Colgate, S.A.; Johnson, N.L.; Kirkpatrick, R.C.; Menikoff, R.; Petschek, A.G.

    1993-12-31

    There are two fundamentally different approaches to igniting DT fuel in an ICF capsule which can be described as equilibrium and hot spot ignition. In both cases, a capsule which can be thought of as a pusher containing the DT fuel is imploded until the fuel reaches ignition conditions. In comparing high-gain ICF targets using cryogenic DT for a pusher with equilibrium ignition targets using high-Z pushers which contain the radiation. The authors point to the intrinsic advantages of the latter. Equilibrium or volume ignition sacrifices high gain for lower losses, lower ignition temperature, lower implosion velocity and lower sensitivity of the more robust capsule to small fluctuations and asymmetries in the drive system. The reduction in gain is about a factor of 2.5, which is small enough to make the more robust equilibrium ignition an attractive alternative.

  11. Edge equilibrium code for tokamaks

    SciTech Connect

    Li, Xujing; Drozdov, Vladimir V.

    2014-01-15

    The edge equilibrium code (EEC) described in this paper is developed for simulations of the near edge plasma using the finite element method. It solves the Grad-Shafranov equation in toroidal coordinate and uses adaptive grids aligned with magnetic field lines. Hermite finite elements are chosen for the numerical scheme. A fast Newton scheme which is the same as implemented in the equilibrium and stability code (ESC) is applied here to adjust the grids.

  12. A search for equilibrium states

    NASA Technical Reports Server (NTRS)

    Zeleznik, F. J.

    1982-01-01

    An efficient search algorithm is described for the location of equilibrium states in a search set of states which differ from one another only by the choice of pure phases. The algorithm has three important characteristics: (1) it ignores states which have little prospect for being an improved approximation to the true equilibrium state; (2) it avoids states which lead to singular iteration equations; (3) it furnishes a search history which can provide clues to alternative search paths.

  13. Considering High-Tech Exhibits?

    ERIC Educational Resources Information Center

    Routman, Emily

    1994-01-01

    Discusses a variety of high-tech exhibit media used in The Living World, an educational facility operated by The Saint Louis Zoo. Considers the strengths and weaknesses of holograms, video, animatronics, video-equipped microscopes, and computer interactives. Computer interactives are treated with special attention. (LZ)

  14. Shape characteristics of equilibrium and non-equilibrium fractal clusters

    NASA Astrophysics Data System (ADS)

    Mansfield, Marc L.; Douglas, Jack F.

    2013-07-01

    It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other

  15. Shape characteristics of equilibrium and non-equilibrium fractal clusters.

    PubMed

    Mansfield, Marc L; Douglas, Jack F

    2013-07-28

    It is often difficult in practice to discriminate between equilibrium and non-equilibrium nanoparticle or colloidal-particle clusters that form through aggregation in gas or solution phases. Scattering studies often permit the determination of an apparent fractal dimension, but both equilibrium and non-equilibrium clusters in three dimensions frequently have fractal dimensions near 2, so that it is often not possible to discriminate on the basis of this geometrical property. A survey of the anisotropy of a wide variety of polymeric structures (linear and ring random and self-avoiding random walks, percolation clusters, lattice animals, diffusion-limited aggregates, and Eden clusters) based on the principal components of both the radius of gyration and electric polarizability tensor indicates, perhaps counter-intuitively, that self-similar equilibrium clusters tend to be intrinsically anisotropic at all sizes, while non-equilibrium processes such as diffusion-limited aggregation or Eden growth tend to be isotropic in the large-mass limit, providing a potential means of discriminating these clusters experimentally if anisotropy could be determined along with the fractal dimension. Equilibrium polymer structures, such as flexible polymer chains, are normally self-similar due to the existence of only a single relevant length scale, and are thus anisotropic at all length scales, while non-equilibrium polymer structures that grow irreversibly in time eventually become isotropic if there is no difference in the average growth rates in different directions. There is apparently no proof of these general trends and little theoretical insight into what controls the universal anisotropy in equilibrium polymer structures of various kinds. This is an obvious topic of theoretical investigation, as well as a matter of practical interest. To address this general problem, we consider two experimentally accessible ratios, one between the hydrodynamic and gyration radii, the other

  16. Non-Equilibrium Volumetric Response of Shocked Polymers

    NASA Astrophysics Data System (ADS)

    Clements, Brad

    2009-06-01

    Polymers are well known for their non-equilibrium deviatoric behavior. However, recent investigations involving both high rate shock experiments and equilibrium measured thermodynamic quantities have reminded us that the volumetric behavior also exhibits a non-equilibrium response. An area where this work should be important is the impact of glassy polymers. At the time of impact and near the impact surface, the polymer's volumetric response will be described as being Hugoniot-like, i.e., standard shock Hugoniot jump conditions apply. However, at later times, release waves from neighboring free surfaces will cause the polymer's volumetric response to be far from Hugoniot. In this talk, experiments showing the non-equilibrium behavior will be described. Following that discussion, a continuum-level theory is proposed that will allow us to bridge the equilibrium and non-equilibrium behaviors with a single model that can go seamlessly from one regime to the other.[4pt] In collaboration with Philip Rae and Dana Dattelbaum, Los Alamos National Laboratory.

  17. Strongly Non-equilibrium Dynamics of Nanochannel Confined DNA

    NASA Astrophysics Data System (ADS)

    Reisner, Walter

    Nanoconfined DNA exhibits a wide-range of fascinating transient and steady-state non-equilibrium phenomena. Yet, while experiment, simulation and scaling analytics are converging on a comprehensive picture regarding the equilibrium behavior of nanochannel confined DNA, non-equilibrium behavior remains largely unexplored. In particular, while the DNA extension along the nanochannel is the key observable in equilibrium experiments, in the non-equilibrium case it is necessary to measure and model not just the extension but the molecule's full time-dependent one-dimensional concentration profile. Here, we apply controlled compressive forces to a nanochannel confined molecule via a nanodozer assay, whereby an optically trapped bead is slid down the channel at a constant speed. Upon contact with the molecule, a propagating concentration ``shockwave'' develops near the bead and the molecule is dynamically compressed. This experiment, a single-molecule implementation of a macroscopic cylinder-piston apparatus, can be used to observe the molecule response over a range of forcings and benchmark theoretical description of non-equilibrium behavior. We show that the dynamic concentration profiles, including both transient and steady-state response, can be modelled via a partial differential evolution equation combining nonlinear diffusion and convection. Lastly, we present preliminary results for dynamic compression of multiple confined molecules to explore regimes of segregation and mixing for multiple chains in confinement.

  18. Longwall - USA: International exhibition & conference

    SciTech Connect

    1996-12-31

    The Longwall-USA International Exhibition and Conference was held June 4-6, 1996 in Pittsburgh, PA. Seventeen papers are included in the proceedings that covered such topics as health and safety, development of gate roads, telemetry monitoring systems, fires, longwall miners, roof support technologies, dust control, moving car bunker systems, reducing longwall noise, vibration of longwall equipment, and the USBM`s strategic structures testing laboratory. A separate abstract with indexing was prepared for each paper for inclusion in the Energy Science and Technology Database.

  19. Adiabatic evolution of plasma equilibrium

    PubMed Central

    Grad, H.; Hu, P. N.; Stevens, D. C.

    1975-01-01

    A new theory of plasma equilibrium is introduced in which adiabatic constraints are specified. This leads to a mathematically nonstandard structure, as compared to the usual equilibrium theory, in which prescription of pressure and current profiles leads to an elliptic partial differential equation. Topologically complex configurations require further generalization of the concept of adiabaticity to allow irreversible mixing of plasma and magnetic flux among islands. Matching conditions across a boundary layer at the separatrix are obtained from appropriate conservation laws. Applications are made to configurations with planned islands (as in Doublet) and accidental islands (as in Tokamaks). Two-dimensional, axially symmetric, helically symmetric, and closed line equilibria are included. PMID:16578729

  20. Collaborative virtual environments art exhibition

    NASA Astrophysics Data System (ADS)

    Dolinsky, Margaret; Anstey, Josephine; Pape, Dave E.; Aguilera, Julieta C.; Kostis, Helen-Nicole; Tsoupikova, Daria

    2005-03-01

    This panel presentation will exhibit artwork developed in CAVEs and discuss how art methodologies enhance the science of VR through collaboration, interaction and aesthetics. Artists and scientists work alongside one another to expand scientific research and artistic expression and are motivated by exhibiting collaborative virtual environments. Looking towards the arts, such as painting and sculpture, computer graphics captures a visual tradition. Virtual reality expands this tradition to not only what we face, but to what surrounds us and even what responds to our body and its gestures. Art making that once was isolated to the static frame and an optimal point of view is now out and about, in fully immersive mode within CAVEs. Art knowledge is a guide to how the aesthetics of 2D and 3D worlds affect, transform, and influence the social, intellectual and physical condition of the human body through attention to psychology, spiritual thinking, education, and cognition. The psychological interacts with the physical in the virtual in such a way that each facilitates, enhances and extends the other, culminating in a "go together" world. Attention to sharing art experience across high-speed networks introduces a dimension of liveliness and aliveness when we "become virtual" in real time with others.

  1. Crows spontaneously exhibit analogical reasoning.

    PubMed

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. PMID:25532894

  2. Chemical Principles Revisited: Using the Equilibrium Concept.

    ERIC Educational Resources Information Center

    Mickey, Charles D., Ed.

    1981-01-01

    Discusses the concept of equilibrium in chemical systems, particularly in relation to predicting the position of equilibrium, predicting spontaneity of a reaction, quantitative applications of the equilibrium constant, heterogeneous equilibrium, determination of the solubility product constant, common-ion effect, and dissolution of precipitates.…

  3. DYNAMIC EQUILIBRIUM IN THERAPEUTIC SITUATIONS.

    ERIC Educational Resources Information Center

    CARROLL, EDWARD J.

    THE CONCEPT OF DYNAMIC EQUILIBRIUM IS USED TO EXAMINE THE OCCURRENCE OF CHANGE IN A THERAPEUTIC INTERVIEW AND TO PROPOSE A THEORY OF THERAPY. BY ANALYZING THE WORKINGS OF THE PSYCHOSOCIAL SYSTEM THROUGH THE GENERAL SYSTEMS THEORY, IT IS POSSIBLE TO SEE HOW CHANGE OCCURS IN AN INDIVIDUAL FAMILY OR COMMUNITY. APPLIED TO A FAMILY INTERVIEW, THE MODEL…

  4. Magnetospheric equilibrium with anisotropic pressure

    SciTech Connect

    Cheng, C.Z.

    1991-07-01

    Self-consistent magnetospheric equilibrium with anisotropic pressure is obtained by employing an iterative metric method for solving the inverse equilibrium equation in an optimal flux coordinate system. A method of determining plasma parallel and perpendicular pressures from either analytic particle distribution or particle distribution measured along the satellite's path is presented. The numerical results of axisymmetric magnetospheric equilibrium including the effects of finite beta, pressure anisotropy, and boundary conditions are presented for a bi-Maxwellian particle distribution. For the isotropic pressure cases, the finite beta effect produces an outward expansion of the constant magnetic flux surfaces in relation to the dipole field lines, and along the magnetic field the toroidal ring current is maximum at the magnetic equator. The effect of pressure anisotropy is found to further expand the flux surfaces outward. Along the magnetic field lines the westward ring current can be peak away from the equator due to an eastward current contribution resulting from pressure anisotropy. As pressure anisotropy increases, the peak westward current can become more singular. The outer boundary flux surface has significant effect on the magnetospheric equilibrium. For the outer flux boundary resembling dayside compressed flux surface due to solar wind pressure, the deformation of the magnetic field can be quite different from that for the outer flux boundary resembling the tail-like surface. 23 refs., 17 figs.

  5. Understanding Thermal Equilibrium through Activities

    ERIC Educational Resources Information Center

    Pathare, Shirish; Huli, Saurabhee; Nachane, Madhura; Ladage, Savita; Pradhan, Hemachandra

    2015-01-01

    Thermal equilibrium is a basic concept in thermodynamics. In India, this concept is generally introduced at the first year of undergraduate education in physics and chemistry. In our earlier studies (Pathare and Pradhan 2011 "Proc. episteme-4 Int. Conf. to Review Research on Science Technology and Mathematics Education" pp 169-72) we…

  6. An investigation of equilibrium concepts

    NASA Technical Reports Server (NTRS)

    Prozan, R. J.

    1982-01-01

    A different approach to modeling of the thermochemistry of rocket engine combustion phenomena is presented. The methodology described is based on the hypothesis of a new variational principle applicable to compressible fluid mechanics. This hypothesis is extended to treat the thermochemical behavior of a reacting (equilibrium) gas in an open system.

  7. Detection of Non-Equilibrium Fluctuations in Active Gels

    NASA Astrophysics Data System (ADS)

    Bacanu, Alexandru; Broedersz, Chase; Gladrow, Jannes; Mackintosh, Fred; Schmidt, Christoph; Fakhri, Nikta

    Active force generation at the molecular scale in cells can result in stochastic non-equilibrium dynamics on mesoscpopic scales. Molecular motors such as myosin can drive steady-state stress fluctuations in cytoskeletal networks. Here, we present a non-invasive technique to probe non-equilibrium fluctuations in an active gel using single-walled carbon nanotubes (SWNTs). SWNTs are semiflexible polymers with intrinsic fluorescence in the near infrared. Both thermal and active motor-induced forces in the network induce transverse fluctuations of SWNTs. We demonstrate that active driven shape fluctuations of the SWNTs exhibit dynamics that reflect the non-equilibrium activity, in particular the emergence of correlations between the bending modes. We discuss the observation of breaking of detailed balance in this configurational space of the SWNT probes. Supported by National Defense Science and Engineering Graduate Student Fellowship (NDSEG).

  8. Non-Equilibrium Properties from Equilibrium Free Energy Calculations

    NASA Technical Reports Server (NTRS)

    Pohorille, Andrew; Wilson, Michael A.

    2012-01-01

    Calculating free energy in computer simulations is of central importance in statistical mechanics of condensed media and its applications to chemistry and biology not only because it is the most comprehensive and informative quantity that characterizes the eqUilibrium state, but also because it often provides an efficient route to access dynamic and kinetic properties of a system. Most of applications of equilibrium free energy calculations to non-equilibrium processes rely on a description in which a molecule or an ion diffuses in the potential of mean force. In general case this description is a simplification, but it might be satisfactorily accurate in many instances of practical interest. This hypothesis has been tested in the example of the electrodiffusion equation . Conductance of model ion channels has been calculated directly through counting the number of ion crossing events observed during long molecular dynamics simulations and has been compared with the conductance obtained from solving the generalized Nernst-Plank equation. It has been shown that under relatively modest conditions the agreement between these two approaches is excellent, thus demonstrating the assumptions underlying the diffusion equation are fulfilled. Under these conditions the electrodiffusion equation provides an efficient approach to calculating the full voltage-current dependence routinely measured in electrophysiological experiments.

  9. Cystamine preparations exhibit anticoagulant activity.

    PubMed

    Aleman, Maria M; Holle, Lori A; Stember, Katherine G; Devette, Christa I; Monroe, Dougald M; Wolberg, Alisa S

    2015-01-01

    Transglutaminases are a superfamily of isoenzymes found in cells and plasma. These enzymes catalyze the formation of ε-N-(γ-glutamyl)-lysyl crosslinks between proteins. Cystamine blocks transglutaminase activity and is used in vitro in human samples and in vivo in mice and rats in studies of coagulation, immune dysfunction, and inflammatory disease. These studies have suggested cystamine blocks fibrin crosslinking and has anti-inflammatory effects, implicating transglutaminase activity in the pathogenesis of several diseases. We measured the effects of cystamine on fibrin crosslinking, tissue factor-triggered plasma clot formation and thrombin generation, and coagulation factor enzymatic activity. At concentrations that blocked fibrin crosslinking, cystamine also inhibited plasma clot formation and reduced thrombin generation. Cystamine inhibited the amidolytic activity of coagulation factor XI and thrombin towards chromogenic substrates. These findings demonstrate that cystamine exhibits anticoagulant activity during coagulation. Given the close relationship between coagulation and inflammation, these findings suggest prior studies that used cystamine to implicate transglutaminase activity in disease pathogenesis warrant re-examination. PMID:25915545

  10. Cystamine Preparations Exhibit Anticoagulant Activity

    PubMed Central

    Aleman, Maria M.; Holle, Lori A.; Stember, Katherine G.; Devette, Christa I.; Monroe, Dougald M.; Wolberg, Alisa S.

    2015-01-01

    Transglutaminases are a superfamily of isoenzymes found in cells and plasma. These enzymes catalyze the formation of ε-N-(γ-glutamyl)-lysyl crosslinks between proteins. Cystamine blocks transglutaminase activity and is used in vitro in human samples and in vivo in mice and rats in studies of coagulation, immune dysfunction, and inflammatory disease. These studies have suggested cystamine blocks fibrin crosslinking and has anti-inflammatory effects, implicating transglutaminase activity in the pathogenesis of several diseases. We measured the effects of cystamine on fibrin crosslinking, tissue factor-triggered plasma clot formation and thrombin generation, and coagulation factor enzymatic activity. At concentrations that blocked fibrin crosslinking, cystamine also inhibited plasma clot formation and reduced thrombin generation. Cystamine inhibited the amidolytic activity of coagulation factor XI and thrombin towards chromogenic substrates. These findings demonstrate that cystamine exhibits anticoagulant activity during coagulation. Given the close relationship between coagulation and inflammation, these findings suggest prior studies that used cystamine to implicate transglutaminase activity in disease pathogenesis warrant re-examination. PMID:25915545

  11. Mixed quantum-classical equilibrium in global flux surface hopping

    SciTech Connect

    Sifain, Andrew E.; Wang, Linjun; Prezhdo, Oleg V.

    2015-06-14

    Global flux surface hopping (GFSH) generalizes fewest switches surface hopping (FSSH)—one of the most popular approaches to nonadiabatic molecular dynamics—for processes exhibiting superexchange. We show that GFSH satisfies detailed balance and leads to thermodynamic equilibrium with accuracy similar to FSSH. This feature is particularly important when studying electron-vibrational relaxation and phonon-assisted transport. By studying the dynamics in a three-level quantum system coupled to a classical atom in contact with a classical bath, we demonstrate that both FSSH and GFSH achieve the Boltzmann state populations. Thermal equilibrium is attained significantly faster with GFSH, since it accurately represents the superexchange process. GFSH converges closer to the Boltzmann averages than FSSH and exhibits significantly smaller statistical errors.

  12. Phonon Mapping in Flowing Equilibrium

    NASA Astrophysics Data System (ADS)

    Ruff, J. P. C.

    2015-03-01

    When a material conducts heat, a modification of the phonon population occurs. The equilibrium Bose-Einstein distribution is perturbed towards flowing-equilibrium, for which the distribution function is not analytically known. Here I argue that the altered phonon population can be efficiently mapped over broad regions of reciprocal space, via diffuse x-ray scattering or time-of-flight neutron scattering, while a thermal gradient is applied across a single crystal sample. When compared to traditional transport measurements, this technique offers a superior, information-rich new perspective on lattice thermal conductivity, wherein the band and momentum dependences of the phonon thermal current are directly resolved. The proposed method is benchmarked using x-ray thermal diffuse scattering measurements of single crystal diamond under transport conditions. CHESS is supported by the NSF & NIH/NIGMS via NSF Award DMR-1332208.

  13. Connective stability of competitive equilibrium

    NASA Technical Reports Server (NTRS)

    Siljak, D. D.

    1975-01-01

    The purpose of this paper is to derive necessary and sufficient conditions for the connective stability of nonlinear matrix systems described by the equation x-dot = A(t, x) x, where the matrix A(t, x) has time-varying nonlinear elements. The results obtained can be used to study the stability of competitive equilibrium in fields as diverse as economics and engineering, model ecosystems, and the arms race.-

  14. Punctuated equilibrium comes of age

    NASA Astrophysics Data System (ADS)

    Gould, Stephan Jay; Eldredge, Niles

    1993-11-01

    The intense controversies that surrounded the youth of punctuated equilibrium have helped it mature to a useful extension of evolutionary theory. As a complement to phyletic gradualism, its most important implications remain the recognition of stasis as a meaningful and predominant pattern within the history of species, and in the recasting of macroevolution as the differential success of certain species (and their descendants) within clades.

  15. Components of fitness become effectively neutral in equilibrium populations.

    PubMed Central

    Reeve, R; Smith, E; Wallace, B

    1990-01-01

    If, because of trade-offs or similar considerations, components of fitness are negatively correlated in equilibrium populations, they may then exhibit no correlation with total fitness. Lack of correlation with fitness is a fundamental characteristic of selective neutrality. Hence, selectively important traits become subsumed under neutral traits when the definition of neutrality is extended to include factors (genetic or phenotypic) that "behave as if they are neutral." PMID:2308960

  16. Dimerization of the type IV pilin from Pseudomonas aeruginosa strain K122-4 results in increased helix stability as measured by time-resolved hydrogen-deuterium exchange

    PubMed Central

    Lento, Cristina; Wilson, Derek J.; Audette, Gerald F.

    2015-01-01

    Truncated pilin monomers from Pseudomonas aeruginosa strain K122-4 (ΔK122) have been shown to enter a monomer-dimer equilibrium in solution prior to oligomerization into protein nanotubes. Here, we examine the structural changes occurring between the monomeric and dimeric states of ΔK122 using time-resolved hydrogen-deuterium exchange mass spectrometry. Based on levels of deuterium uptake, the N-terminal α-helix and the loop connecting the second and third strands of the anti-parallel β-sheet contribute significantly to pilin dimerization. Conversely, the antiparallel β-sheet and αβ loop region exhibit increased flexibility, while the receptor binding domain retains a rigid conformation in the equilibrium state. PMID:26798830

  17. Dimerization of the type IV pilin from Pseudomonas aeruginosa strain K122-4 results in increased helix stability as measured by time-resolved hydrogen-deuterium exchange.

    PubMed

    Lento, Cristina; Wilson, Derek J; Audette, Gerald F

    2016-01-01

    Truncated pilin monomers from Pseudomonas aeruginosa strain K122-4 (ΔK122) have been shown to enter a monomer-dimer equilibrium in solution prior to oligomerization into protein nanotubes. Here, we examine the structural changes occurring between the monomeric and dimeric states of ΔK122 using time-resolved hydrogen-deuterium exchange mass spectrometry. Based on levels of deuterium uptake, the N-terminal α-helix and the loop connecting the second and third strands of the anti-parallel β-sheet contribute significantly to pilin dimerization. Conversely, the antiparallel β-sheet and αβ loop region exhibit increased flexibility, while the receptor binding domain retains a rigid conformation in the equilibrium state. PMID:26798830

  18. Morphodynamic equilibrium of alluvial estuaries

    NASA Astrophysics Data System (ADS)

    Tambroni, Nicoletta; Bolla Pittaluga, Michele; Canestrelli, Alberto; Lanzoni, Stefano; Seminara, Giovanni

    2014-05-01

    The evolution of the longitudinal bed profile of an estuary, with given plan-form configuration, subject to given tidal forcing at the mouth and prescribed values of water and sediment supply from the river is investigated numerically. Our main goal is to ascertain whether, starting from some initial condition, the bed evolution tends to reach a unique equilibrium configuration asymptotically in time. Also, we investigate the morphological response of an alluvial estuary to changes in the tidal range and hydrologic forcing (flow and sediment supply). Finally, the solution helps characterizing the transition between the fluvially dominated region and the tidally dominated region of the estuary. All these issues play an important role also in interpreting how the facies changes along the estuary, thus helping to make correct paleo-environmental and sequence-stratigraphic interpretations of sedimentary successions (Dalrymple and Choi, 2007). Results show that the model is able to describe a wide class of settings ranging from tidally dominated estuaries to fluvially dominated estuaries. In the latter case, the solution is found to compare satisfactory with the analytical asymptotic solution recently derived by Seminara et al. (2012), under the hypothesis of fairly 'small' tidal oscillations. Simulations indicate that the system always moves toward an equilibrium configuration in which the net sediment flux in a tidal cycle is constant throughout the estuary and equal to the constant sediment flux discharged from the river. For constant width, the bed equilibrium profile of the estuarine channel is characterized by two distinct regions: a steeper reach seaward, dominated by the tide, and a less steep upstream reach, dominated by the river and characterized by the undisturbed bed slope. Although the latter reach, at equilibrium, is not directly affected by the tidal wave, however starting from an initial uniform stream with the constant 'fluvial' slope, the final

  19. Torque equilibrium attitude control for Skylab reentry

    NASA Technical Reports Server (NTRS)

    Glaese, J. R.; Kennel, H. F.

    1979-01-01

    All the available torque equilibrium attitudes (most were useless from the standpoint of lack of electrical power) and the equilibrium seeking method are presented, as well as the actual successful application during the 3 weeks prior to Skylab reentry.

  20. 29 CFR 2200.70 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... separate file designated for rejected exhibits. (e) Return of physical exhibits. A party may on motion request the return of a physical exhibit within 30 days after expiration of the time for filing a petition... proceeding. (f) Request for custody of physical exhibit. Any person may on motion to the Executive...

  1. 29 CFR 2200.70 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... separate file designated for rejected exhibits. (e) Return of physical exhibits. A party may on motion request the return of a physical exhibit within 30 days after expiration of the time for filing a petition... proceeding. (f) Request for custody of physical exhibit. Any person may on motion to the Executive...

  2. 29 CFR 2200.70 - Exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... separate file designated for rejected exhibits. (e) Return of physical exhibits. A party may on motion request the return of a physical exhibit within 30 days after expiration of the time for filing a petition... proceeding. (f) Request for custody of physical exhibit. Any person may on motion to the Executive...

  3. Exhibits Enhanced by Stand-Alone Computers.

    ERIC Educational Resources Information Center

    Van Rennes, Eve C.

    Both the development and evaluation of one of a set of computer programs designed for use by visitors as adjuncts to museum exhibits are described. Museum displays used were (1) a static, behind-glass exhibit on evolution; (2) a hands-on primitive stone age tools exhibit; and (3) a Foucault pendulum. A computer placed next to each exhibit served…

  4. Open problems in non-equilibrium physics

    SciTech Connect

    Kusnezov, D.

    1997-09-22

    The report contains viewgraphs on the following: approaches to non-equilibrium statistical mechanics; classical and quantum processes in chaotic environments; classical fields in non-equilibrium situations: real time dynamics at finite temperature; and phase transitions in non-equilibrium conditions.

  5. Thermal equilibrium in Einstein's elevator.

    PubMed

    Sánchez-Rey, Bernardo; Chacón-Acosta, Guillermo; Dagdug, Leonardo; Cubero, David

    2013-05-01

    We report fully relativistic molecular-dynamics simulations that verify the appearance of thermal equilibrium of a classical gas inside a uniformly accelerated container. The numerical experiments confirm that the local momentum distribution in this system is very well approximated by the Jüttner function-originally derived for a flat spacetime-via the Tolman-Ehrenfest effect. Moreover, it is shown that when the acceleration or the container size is large enough, the global momentum distribution can be described by the so-called modified Jüttner function, which was initially proposed as an alternative to the Jüttner function. PMID:23767501

  6. Princeton spectral equilibrium code: PSEC

    SciTech Connect

    Ling, K.M.; Jardin, S.C.

    1984-03-01

    A fast computer code has been developed to calculate free-boundary solutions to the plasma equilibrium equation that are consistent with the currents in external coils and conductors. The free-boundary formulation is based on the minimization of a mean-square error epsilon while the fixed-boundary solution is based on a variational principle and spectral representation of the coordinates x(psi,theta) and z(psi,theta). Specific calculations using the Columbia University Torus II, the Poloidal Divertor Experiment (PDX), and the Tokamak Fusion Test Reactor (TFTR) geometries are performed.

  7. Conformations of Proteins in Equilibrium

    NASA Astrophysics Data System (ADS)

    Micheletti, Cristian; Banavar, Jayanth R.; Maritan, Amos

    2001-08-01

    We introduce a simple theoretical approach for an equilibrium study of proteins with known native-state structures. We test our approach with results on well-studied globular proteins, chymotrypsin inhibitor (2ci2), barnase, and the alpha spectrin SH3 domain, and present evidence for a hierarchical onset of order on lowering the temperature with significant organization at the local level even at high temperatures. A further application to the folding process of HIV-1 protease shows that the model can be reliably used to identify key folding sites that are responsible for the development of drug resistance.

  8. Non-equilibrium phase transitions

    SciTech Connect

    Mottola, E.; Cooper, F.M.; Bishop, A.R.; Habib, S.; Kluger, Y.; Jensen, N.G.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Non-equilibrium phase transitions play a central role in a very broad range of scientific areas, ranging from nuclear, particle, and astrophysics to condensed matter physics and the material and biological sciences. The aim of this project was to explore the path to a deeper and more fundamental understanding of the common physical principles underlying the complex real time dynamics of phase transitions. The main emphasis was on the development of general theoretical tools to deal with non-equilibrium processes, and of numerical methods robust enough to capture the time-evolving structures that occur in actual experimental situations. Specific applications to Laboratory multidivisional efforts in relativistic heavy-ion physics (transition to a new phase of nuclear matter consisting of a quark-gluon plasma) and layered high-temperature superconductors (critical currents and flux flow at the National High Magnetic Field Laboratory) were undertaken.

  9. Magnetospheric equilibrium with anisotropic pressure

    SciTech Connect

    Cheng, C.Z. )

    1992-02-01

    Self-consistent magnetospheric equilibria with anisotropic pressure are obtained by employing an iterative metric method for solving the inverse equilibrium equation in an optimal flux coordinate system. A method of determining plasma parallel and perpendicular pressures from either analytic particle distributions or particle distributions measured along a satellite's path is presented. The numerical results of axisymmetric magnetospheric equilibria including the effects of finite beta, pressure anisotropy, and boundary conditions are presented for a bi-Maxwellian particle distribution. For the isotropic pressure cases the finite beta effect produces an outward expansion of the constant magnetic flux surfaces in relation to the dipole field lines, and along the magnetic field the toroidal ring current is maximum at the magnetic equator. The effect of pressure anisotropy is found to further expand the flux surfaces outward. Along the magnetic field lines the westward ring current can be peak away from the equator owing to an eastward current contribution resulting from pressure anisotropy. As pressure anisotropy increases, the peak westward current can become more singular. The outer boundary flux surface has a significant effect on the magnetospheric equilibrium. For the outer flux boundary resembling the dayside compressed flux surface due to solar wind pressure, the deformation of the magnetic field can be quite different from that for the outer flux boundary resembling the taillike flux surface.

  10. Equilibrium Studies of Designed Metalloproteins.

    PubMed

    Gibney, B R

    2016-01-01

    Complete thermodynamic descriptions of the interactions of cofactors with proteins via equilibrium studies are challenging, but are essential to the evaluation of designed metalloproteins. While decades of studies on protein-protein interaction thermodynamics provide a strong underpinning to the successful computational design of novel protein folds and de novo proteins with enzymatic activity, the corresponding paucity of data on metal-protein interaction thermodynamics limits the success of computational metalloprotein design efforts. By evaluating the thermodynamics of metal-protein interactions via equilibrium binding studies, protein unfolding free energy determinations, proton competition equilibria, and electrochemistry, a more robust basis for the computational design of metalloproteins may be provided. Our laboratory has shown that such studies provide detailed insight into the assembly and stability of designed metalloproteins, allow for parsing apart the free energy contributions of metal-ligand interactions from those of porphyrin-protein interactions in hemeproteins, and even reveal their mechanisms of proton-coupled electron transfer. Here, we highlight studies that reveal the complex interplay between the various equilibria that underlie metalloprotein assembly and stability and the utility of making these detailed measurements. PMID:27586343

  11. Are the Concepts of Dynamic Equilibrium and the Thermodynamic Criteria for Spontaneity, Nonspontaneity, and Equilibrium Compatible?

    ERIC Educational Resources Information Center

    Silverberg, Lee J.; Raff, Lionel M.

    2015-01-01

    Thermodynamic spontaneity-equilibrium criteria require that in a single-reaction system, reactions in either the forward or reverse direction at equilibrium be nonspontaneous. Conversely, the concept of dynamic equilibrium holds that forward and reverse reactions both occur at equal rates at equilibrium to the extent allowed by kinetic…

  12. Thermodynamic equilibrium at heterogeneous pressure

    NASA Astrophysics Data System (ADS)

    Vrijmoed, Johannes C.; Podladchikov, Yuri Y.

    2014-05-01

    Recent advances in metamorphic petrology point out the importance of grain-scale pressure variations in high-temperature metamorphic rocks. Pressures derived from chemical zonation using unconventional geobarometry based on equal chemical potentials fit mechanically feasible pressure variations. Here a thermodynamic equilibrium method is presented that predicts chemical zoning as a result of pressure variations by Gibbs energy minimization. Equilibrium thermodynamic prediction of the chemical zoning in the case of pressure heterogeneity is done by constraint Gibbs minimization using linear programming techniques. Compositions of phases considered in the calculation are discretized into 'pseudo-compounds' spanning the entire compositional space. Gibbs energies of these discrete compounds are generated for a given range and resolution of pressures for example derived by barometry or from mechanical model predictions. Gibbs energy minimization is subsequently performed considering all compounds of different composition and pressure. In addition to constraining the system composition a certain proportion of the system is constraint at a specified pressure. Input pressure variations need to be discretized and each discrete pressure defines an additional constraint for the minimization. The proportion of the system at each different pressure is equally distributed over the number of input pressures. For example if two input pressures P1 and P2 are specified, two constraints are added: 50 percent of the system is constraint at P1 while the remaining 50 percent is constraint at P2. The method has been tested for a set of 10 input pressures obtained by Tajčmanová et al. (2014) using their unconventional geobarometry method in a plagioclase rim around kyanite. Each input pressure is added as constraint to the minimization (1/10 percent of the system for each discrete pressure). Constraining the system composition to the average composition of the plagioclase rim

  13. Modeling equilibrium Fe isotope fractionation

    NASA Astrophysics Data System (ADS)

    Anbar, A.; Jarzecki, A.; Spiro, T.

    2003-04-01

    Research into the stable isotope biogeochemistry of Fe and other transition metals has been driven primarily by analytical innovations which have revealed significant isotope effects in nature and the laboratory. Further development of these new isotope systems requires complementary theoretical research to guide analytical efforts. The results of the first such studies show some discrepancies with experiments. For example, Johnson et al. (2002) report an experimentally-determined 56Fe/54Fe equilibrium fractionation factor between Fe(II) and Fe(III) aquo complexes of ˜1.0025. This effect is ˜50% smaller than predicted theoretically by Schauble et al. (2001). It is important to resolve such discrepancies. Equilibrium isotope fractionation factors can be predicted from vibrational spectroscopic data of isotopically-substituted complexes, or from theoretical predictions of some or all of these frequencies obtained using force field models. The pioneering work of Schauble et al. (2001) utilized a modified Urey-Bradley force field (MUBFF) model. This approach is limiting in at least three ways: First, it is not ab initio, requiring as input some measured vibrational frequencies. Such data are not always available, or may have significant uncertainties. Second, the MUBFF does not include potentially important effects of solvent interaction. Third, because it makes certain assumptions about molecular symmetry, the MUBFF-based approach is not able to model the spectra of mixed-ligand complexes. To address these limitations, we are evaluating the use of density functional theory (DFT) as an ab initio method to predict vibrational frequencies of isotopically-substituted complexes and, hence, equilibrium fractionation factors. In a preliminary examination of the frequency shift upon isotope substitution of the bending and asymmetric stretching modes of the tetrahedral FeCl_42- complex, we find substantial differences between MUBFF and DFT predictions. Results for other Fe

  14. Modeling rocky coastline evolution and equilibrium

    NASA Astrophysics Data System (ADS)

    Limber, P. W.; Murray, A. B.

    2010-12-01

    Many of the world’s rocky coastlines exhibit planform roughness in the form of alternating headlands and embayments. Along cliffed coasts, it is often assumed that headlands consist of rock that is more resistant to wave attack than in neighboring bays, because of either structural or lithologic variations. Bays would then retreat landward faster than headlands, creating the undulating planform profiles characteristic of a rocky coastal landscape. While the interplay between alongshore rock strength and nearshore wave energy is, in some circumstances, a fundamental control on coastline shape, beach sediment is also important. Laboratory experiments and field observations have shown that beach sediment, in small volumes, can act as an abrasive tool to encourage sea cliff retreat. In large volumes, though, sediment discourages wave attack on the cliff face, acting as a protective barrier. This nonlinearity suggests a means for headland persistence, even without alongshore variations in rock strength: bare-rock headlands could retreat more slowly than, or at the same rate as, neighboring sediment-filled embayments because of alongshore variations in the availability of beach sediment. Accordingly, nearshore sediment dynamics (i.e. sediment production from sea cliff retreat and alongshore sediment transport) could promote the development of autogenic planform geometry. To explore these ideas, we present numerical and analytical modeling of large-scale (> one kilometer) and long-term (millennial-scale) planform rocky coastline evolution, in which sediment is supplied by both sea cliff erosion and coastal rivers and is distributed by alongshore sediment transport. We also compare model predictions with real landscapes. Previously, our modeling exercises focused on a basic rocky coastline configuration where lithologically-homogeneous sea cliffs supplied all beach sediment and maintained a constant alongshore height. Results showed that 1) an equilibrium alongshore

  15. An Astrobiology Microbes Exhibit and Education Module

    NASA Astrophysics Data System (ADS)

    Lindstrom, M. M.; Allen, J. S.; Mortillaro, C.; Ducceschi, C.; Rawlings, P.; Stocco, K.; Tobola, K.; Olendzenski, L.; Angermiller, L.

    2001-03-01

    A JSC-SCH team has produced an astrobiology exhibit and education module to augment the 'Microbes!' traveling exhibit. The astrobiology section focuses on life in extreme environments and considers the possibility of extraterrestrrial life.

  16. Learning by Doing, Creating a Museum Exhibit.

    ERIC Educational Resources Information Center

    Main, Sarah; Kallquist, Dierdre

    2000-01-01

    Describes an exhibit called Kid's Kitchen, built within a major exhibit called Biodiversity: Life Supporting Life, in order to discuss environmental prompts hidden within the kitchen designed to surprise students and get them thinking. (ASK)

  17. Equilibrium Potentials of Membrane Electrodes

    PubMed Central

    Wang, Jui H.; Copeland, Eva

    1973-01-01

    A simple thermodynamic theory of the equilibrium potentials of membrane electrodes is formulated and applied to the glass electrode for measurement of pH. The new formulation assumes the selective adsorption or binding of specific ions on the surface of the membrane which may or may not be permeable to the ion, and includes the conventional derivation based on reversible ion transport across membranes as a special case. To test the theory, a platinum wire was coated with a mixture of stearic acid and methyl-tri-n-octyl-ammonium stearate. When this coated electrode was immersed in aqueous phosphate solution, its potential was found to be a linear function of pH from pH 2 to 12 with a slope equal to the theoretical value of 59.0 mV per pH unit at 24°. PMID:4516194

  18. Neoclassical equilibrium in gyrokinetic simulations

    SciTech Connect

    Garbet, X.; Dif-Pradalier, G.; Nguyen, C.; Sarazin, Y.; Grandgirard, V.; Ghendrih, Ph.

    2009-06-15

    This paper presents a set of model collision operators, which reproduce the neoclassical equilibrium and comply with the constraints of a full-f global gyrokinetic code. The assessment of these operators is based on an entropy variational principle, which allows one to perform a fast calculation of the neoclassical diffusivity and poloidal velocity. It is shown that the force balance equation is recovered at lowest order in the expansion parameter, the normalized gyroradius, hence allowing one to calculate correctly the radial electric field. Also, the conventional neoclassical transport and the poloidal velocity are reproduced in the plateau and banana regimes. The advantages and drawbacks of the various model operators are discussed in view of the requirements for neoclassical and turbulent transport.

  19. String fluid in local equilibrium

    NASA Astrophysics Data System (ADS)

    Schubring, Daniel; Vanchurin, Vitaly

    2014-10-01

    We study the solutions of string fluid equations under the assumption of a local equilibrium which was previously obtained in the context of the kinetic theory. We show that the fluid can be foliated into noninteracting submanifolds whose equations of motion are exactly that of the wiggly strings considered previously by Vilenkin and Carter. In a special case of negligible statistical variance in either the left- or the right-moving directions of microscopic strings, the submanifolds are described by the action of a null-current-carrying chiral string. When both variances vanish the submanifolds are described by the Nambu-Goto action and the string fluid reduces to the string dust introduced by Stachel.

  20. 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

  1. Equilibrium calculations of firework mixtures

    SciTech Connect

    Hobbs, M.L.; Tanaka, Katsumi; Iida, Mitsuaki; Matsunaga, Takehiro

    1994-12-31

    Thermochemical equilibrium calculations have been used to calculate detonation conditions for typical firework components including three report charges, two display charges, and black powder which is used as a fuse or launch charge. Calculations were performed with a modified version of the TIGER code which allows calculations with 900 gaseous and 600 condensed product species at high pressure. The detonation calculations presented in this paper are thought to be the first report on the theoretical study of firework detonation. Measured velocities for two report charges are available and compare favorably to predicted detonation velocities. However, the measured velocities may not be true detonation velocities. Fast deflagration rather than an ideal detonation occurs when reactants contain significant amounts of slow reacting constituents such as aluminum or titanium. Despite such uncertainties in reacting pyrotechnics, the detonation calculations do show the complex nature of condensed phase formation at elevated pressures and give an upper bound for measured velocities.

  2. 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

  3. Hierarchical condensation near phase equilibrium

    NASA Astrophysics Data System (ADS)

    Olemskoi, A. I.; Yushchenko, O. V.; Borisyuk, V. N.; Zhilenko, T. I.; Kosminska, Yu. O.; Perekrestov, V. I.

    2012-06-01

    A novel mechanism of new phase formation is studied both experimentally and theoretically in the example of quasi-equilibrium stationary condensation in an ion-plasma sputterer. Copper condensates are obtained to demonstrate that a specific network structure is formed as a result of self-assembly in the course of deposition. The fractal pattern related is inherent in the phenomena of diffusion limited aggregation. Condensate nuclei are shown to form statistical ensemble of hierarchically subordinated objects distributed in ultrametric space. The Langevin equation and the Fokker-Planck equation related are found to describe stationary distribution of thermodynamic potential variations at condensation. Time dependence of the formation probability of branching structures is found to clarify the experimental situation.

  4. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  5. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  6. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  7. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  8. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  9. Radiative-convective equilibrium models of Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Appleby, J. F.; Hogan, J. S.

    1984-09-01

    Radiative-convective equilibrium models for Jupiter and Saturn have been produced in a study concentrating on the stratospheric energy balance and the possible role of aerosol heating. These models are compared directly with the thermal structure profiles obtained from Voyager radio occultation measurements. The method is based on a straightforward flux divergence formulation derived from earlier work. The balance between absorbed and emitted energies is computed iteratively at each level in the atmosphere, assuming local thermodynamic equilibrium and employing a standard treatment of opacities. Results for Jupiter indicate that a dust-free model furnishes a good mean thermal profile for the stratosphere when compared with the Voyager 1 radio occultation measurements. Observations of the equatorial region exhibit periodic vertical structure. The Saturn models are relatively simple and in good agreement with the Voyager 2 radio occultation temperature profiles at all levels. Aerosol heating played a minor role in Saturn's midlatitude stratospheric energy balance at the time of the Voyager 2 encounter.

  10. Testing Punctuated Equilibrium Theory Using Evolutionary Activity Statistics

    NASA Astrophysics Data System (ADS)

    Woodberry, O. G.; Korb, K. B.; Nicholson, A. E.

    The Punctuated Equilibrium hypothesis (Eldredge and Gould,1972) asserts that most evolutionary change occurs during geologically rapid speciation events, with species exhibiting stasis most of the time. Punctuated Equilibrium is a natural extension of Mayr's theories on peripatric speciation via the founder effect, (Mayr, 1963; Eldredge and Gould, 1972) which associates changes in diversity to a population bottleneck. That is, while the formation of a foundation bottleneck brings an initial loss of genetic variation, it may subsequently result in the emergence of a child species distinctly different from its parent species. In this paper we adapt Bedau's evolutionary activity statistics (Bedau and Packard, 1991) to test these effects in an ALife simulation of speciation. We find a relative increase in evolutionary activity during speciations events, indicating that punctuation is occurring.

  11. Graphical representation for thermal equilibrium when transition temperatures are present

    NASA Astrophysics Data System (ADS)

    Rojas, Roberto

    2016-01-01

    We propose the use of graphics in order to get a quick insight of the thermal equilibrium of two bodies, when a transition temperature is present in the interval between both initial temperatures. We have found two convenient variables in order to represent the mathematical condition for the partial or complete transition of each component. In mixing hot water and cold ice, the proposed graphical representation exhibits straight lines separating four regions corresponding to different equilibrium states, going from one containing just ice up to the other containing just water, and two states in between with increased ice or increased water. This graphical representation helps to avoid typical student errors in learning elementary physics.

  12. Mathematical modeling of non-equilibrium sorption

    NASA Astrophysics Data System (ADS)

    Kaliev, Ibragim A.; Mukhambetzhanov, Saltanbek T.; Sabitova, Gulnara S.; Sakhit, Anghyz E.

    2016-08-01

    We consider the system of equations modeling the process of non-equilibrium sorption. Difference approximation of differential problem by the implicit scheme is formulated. The solution of the difference problem is constructed using the sweep method. Based on the numerical results we can conclude the following: when the relaxation time decreases to 0, then the solution of non-equilibrium problem tends with increasing time to solution of the equilibrium problem.

  13. Philicities, Fugalities, and Equilibrium Constants.

    PubMed

    Mayr, Herbert; Ofial, Armin R

    2016-05-17

    The mechanistic model of Organic Chemistry is based on relationships between rate and equilibrium constants. Thus, strong bases are generally considered to be good nucleophiles and poor nucleofuges. Exceptions to this rule have long been known, and the ability of iodide ions to catalyze nucleophilic substitutions, because they are good nucleophiles as well as good nucleofuges, is just a prominent example for exceptions from the general rule. In a reaction series, the Leffler-Hammond parameter α = δΔG(⧧)/δΔG° describes the fraction of the change in the Gibbs energy of reaction, which is reflected in the change of the Gibbs energy of activation. It has long been considered as a measure for the position of the transition state; thus, an α value close to 0 was associated with an early transition state, while an α value close to 1 was considered to be indicative of a late transition state. Bordwell's observation in 1969 that substituent variation in phenylnitromethanes has a larger effect on the rates of deprotonation than on the corresponding equilibrium constants (nitroalkane anomaly) triggered the breakdown of this interpretation. In the past, most systematic investigations of the relationships between rates and equilibria of organic reactions have dealt with proton transfer reactions, because only for few other reaction series complementary kinetic and thermodynamic data have been available. In this Account we report on a more general investigation of the relationships between Lewis basicities, nucleophilicities, and nucleofugalities as well as between Lewis acidities, electrophilicities, and electrofugalities. Definitions of these terms are summarized, and it is suggested to replace the hybrid terms "kinetic basicity" and "kinetic acidity" by "protophilicity" and "protofugality", respectively; in this way, the terms "acidity" and "basicity" are exclusively assigned to thermodynamic properties, while "philicity" and "fugality" refer to kinetics

  14. Equilibrium sampling by reweighting nonequilibrium simulation trajectories

    NASA Astrophysics Data System (ADS)

    Yang, Cheng; Wan, Biao; Xu, Shun; Wang, Yanting; Zhou, Xin

    2016-03-01

    Based on equilibrium molecular simulations, it is usually difficult to efficiently visit the whole conformational space of complex systems, which are separated into some metastable regions by high free energy barriers. Nonequilibrium simulations could enhance transitions among these metastable regions and then be applied to sample equilibrium distributions in complex systems, since the associated nonequilibrium effects can be removed by employing the Jarzynski equality (JE). Here we present such a systematical method, named reweighted nonequilibrium ensemble dynamics (RNED), to efficiently sample equilibrium conformations. The RNED is a combination of the JE and our previous reweighted ensemble dynamics (RED) method. The original JE reproduces equilibrium from lots of nonequilibrium trajectories but requires that the initial distribution of these trajectories is equilibrium. The RED reweights many equilibrium trajectories from an arbitrary initial distribution to get the equilibrium distribution, whereas the RNED has both advantages of the two methods, reproducing equilibrium from lots of nonequilibrium simulation trajectories with an arbitrary initial conformational distribution. We illustrated the application of the RNED in a toy model and in a Lennard-Jones fluid to detect its liquid-solid phase coexistence. The results indicate that the RNED sufficiently extends the application of both the original JE and the RED in equilibrium sampling of complex systems.

  15. Equilibrium sampling by reweighting nonequilibrium simulation trajectories.

    PubMed

    Yang, Cheng; Wan, Biao; Xu, Shun; Wang, Yanting; Zhou, Xin

    2016-03-01

    Based on equilibrium molecular simulations, it is usually difficult to efficiently visit the whole conformational space of complex systems, which are separated into some metastable regions by high free energy barriers. Nonequilibrium simulations could enhance transitions among these metastable regions and then be applied to sample equilibrium distributions in complex systems, since the associated nonequilibrium effects can be removed by employing the Jarzynski equality (JE). Here we present such a systematical method, named reweighted nonequilibrium ensemble dynamics (RNED), to efficiently sample equilibrium conformations. The RNED is a combination of the JE and our previous reweighted ensemble dynamics (RED) method. The original JE reproduces equilibrium from lots of nonequilibrium trajectories but requires that the initial distribution of these trajectories is equilibrium. The RED reweights many equilibrium trajectories from an arbitrary initial distribution to get the equilibrium distribution, whereas the RNED has both advantages of the two methods, reproducing equilibrium from lots of nonequilibrium simulation trajectories with an arbitrary initial conformational distribution. We illustrated the application of the RNED in a toy model and in a Lennard-Jones fluid to detect its liquid-solid phase coexistence. The results indicate that the RNED sufficiently extends the application of both the original JE and the RED in equilibrium sampling of complex systems. PMID:27078486

  16. Determining Equilibrium Position For Acoustical Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Aveni, G.; Putterman, S.; Rudnick, J.

    1989-01-01

    Equilibrium position and orientation of acoustically-levitated weightless object determined by calibration technique on Earth. From calibration data, possible to calculate equilibrium position and orientation in presence of Earth gravitation. Sample not levitated acoustically during calibration. Technique relies on Boltzmann-Ehrenfest adiabatic-invariance principle. One converts resonant-frequency-shift data into data on normalized acoustical potential energy. Minimum of energy occurs at equilibrium point. From gradients of acoustical potential energy, one calculates acoustical restoring force or torque on objects as function of deviation from equilibrium position or orientation.

  17. 1-D EQUILIBRIUM DISCRETE DIFFUSION MONTE CARLO

    SciTech Connect

    T. EVANS; ET AL

    2000-08-01

    We present a new hybrid Monte Carlo method for 1-D equilibrium diffusion problems in which the radiation field coexists with matter in local thermodynamic equilibrium. This method, the Equilibrium Discrete Diffusion Monte Carlo (EqDDMC) method, combines Monte Carlo particles with spatially discrete diffusion solutions. We verify the EqDDMC method with computational results from three slab problems. The EqDDMC method represents an incremental step toward applying this hybrid methodology to non-equilibrium diffusion, where it could be simultaneously coupled to Monte Carlo transport.

  18. Passive equilibrium studies on ZT-P

    SciTech Connect

    Pickrell, M.M.; Reass, W.A.

    1987-12-01

    The poloidal field system of ZT-P was modified by the addition of a transformer, which coupled the magnetizing and equilibrium circuits. ZT-P is a small, air core, Reversed Field Pinch, operated at the Los Alamos National Laboratory. It is used as test bed for the much larger ZT-H, RFP experiment, now under construction at LANL. Planned experiments include size scaling measurements and determining the effect of low time constant measurements and determining the effect of low time constant shell operation. ZT-P has had an entirely passive equilibrium system, which did not provide a well centered equilibrium, although a tolerable equilibrium was realized by removing half of the equilibrium coil set. The transformer was added to the poloidal field system to adjust the equilibrium current for a centered plasma, while using the entire coil set. It also had the effect of reducing the dependence of the equilibrium on the plasma resistance. Stable, well centered discharges were achieved over a broad range of plasma currents. The improved equilibrium also lowered the loop voltage and extended the discharge lifetime. These experiments also investigated the unique problems of equilibrium systems on air core RFP devices. 26 refs., 6 figs.

  19. EASI - EQUILIBRIUM AIR SHOCK INTERFERENCE

    NASA Technical Reports Server (NTRS)

    Glass, C. E.

    1994-01-01

    New research on hypersonic vehicles, such as the National Aero-Space Plane (NASP), has raised concerns about the effects of shock-wave interference on various structural components of the craft. State-of-the-art aerothermal analysis software is inadequate to predict local flow and heat flux in areas of extremely high heat transfer, such as the surface impingement of an Edney-type supersonic jet. EASI revives and updates older computational methods for calculating inviscid flow field and maximum heating from shock wave interference. The program expands these methods to solve problems involving the six shock-wave interference patterns on a two-dimensional cylindrical leading edge with an equilibrium chemically reacting gas mixture (representing, for example, the scramjet cowl of the NASP). The inclusion of gas chemistry allows for a more accurate prediction of the maximum pressure and heating loads by accounting for the effects of high temperature on the air mixture. Caloric imperfections and specie dissociation of high-temperature air cause shock-wave angles, flow deflection angles, and thermodynamic properties to differ from those calculated by a calorically perfect gas model. EASI contains pressure- and temperature-dependent thermodynamic and transport properties to determine heating rates, and uses either a calorically perfect air model or an 11-specie, 7-reaction reacting air model at equilibrium with temperatures up to 15,000 K for the inviscid flowfield calculations. EASI solves the flow field and the associated maximum surface pressure and heat flux for the six common types of shock wave interference. Depending on the type of interference, the program solves for shock-wave/boundary-layer interaction, expansion-fan/boundary-layer interaction, attaching shear layer or supersonic jet impingement. Heat flux predictions require a knowledge (from experimental data or relevant calculations) of a pertinent length scale of the interaction. Output files contain flow

  20. Equilibrium coexistence of three amphiboles

    USGS Publications Warehouse

    Robinson, P.; Jaffe, H.W.; Klein, C., Jr.; Ross, M.

    1969-01-01

    Electron probe and wet chemical analyses of amphibole pairs from the sillimanite zone of central Massachusetts and adjacent New Hampshire indicated that for a particular metamorphic grade there should be a restricted composition range in which three amphiboles can coexist stably. An unequivocal example of such an equilibrium three amphibole rock has been found in the sillimanite-orthoclase zone. It contains a colorless primitive clinoamphibole, space group P21/m, optically and chemically like cummingtonite with blue-green hornblende exsolution lamellae on (100) and (-101) of the host; blue-green hornblende, space group C2/m, with primitive cummingtonite exsolution lamellae on (100) and (-101) of the host; and pale pinkish tan anthophyllite, space group Pnma, that is free of visible exsolution lamellae but is a submicroscopic intergrowth of two orthorhombic amphiboles. Mutual contacts and coarse, oriented intergrowths of two and three host amphiboles indicate the three grew as an equilibrium assemblage prior to exsolution. Electron probe analyses at mutual three-amphibole contacts showed little variation in the composition of each amphibole. Analyses believed to represent most closely the primary amphibole compositions gave atomic proportions on the basis of 23 oxygens per formula unit as follows: for primitive cummingtonite (Na0.02Ca0.21- Mn0.06Fe2+2.28Mg4.12Al0.28) (Al0.17Si7.83), for hornblende (Na0.35Ca1.56Mn0.02Fe1.71Mg2.85Al0.92) (Al1.37Si6.63), and for anthophyllite (Na0.10Ca0.06Mn0.06Fe2.25Mg4.11Al0.47) (Al0.47Si7.53). The reflections violating C-symmetry, on X-ray single crystal photographs of the primitive cummingtonite, are weak and diffuse, and suggest a partial inversion from a C-centered to a primitive clinoamphibole. Single crystal photographs of the anthophyllite show split reflections indicating it is an intergrowth of about 80% anthophyllite and about 20% gedrite which differ in their b crystallographic dimensions. Split reflections are

  1. Ringed Accretion Disks: Equilibrium Configurations

    NASA Astrophysics Data System (ADS)

    Pugliese, D.; Stuchlík, Z.

    2015-12-01

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  2. Superconductive microstrip exhibiting negative differential resistivity

    DOEpatents

    Huebener, R.P.; Gallus, D.E.

    1975-10-28

    A device capable of exhibiting negative differential electrical resistivity over a range of values of current and voltage is formed by vapor- depositing a thin layer of a material capable of exhibiting superconductivity on an insulating substrate, establishing electrical connections at opposite ends of the deposited strip, and cooling the alloy into its superconducting range. The device will exhibit negative differential resistivity when biased in the current- induced resistive state.

  3. Equilibrium polymerization on the equivalent-neighbor lattice

    NASA Technical Reports Server (NTRS)

    Kaufman, Miron

    1989-01-01

    The equilibrium polymerization problem is solved exactly on the equivalent-neighbor lattice. The Flory-Huggins (Flory, 1986) entropy of mixing is exact for this lattice. The discrete version of the n-vector model is verified when n approaches 0 is equivalent to the equal reactivity polymerization process in the whole parameter space, including the polymerized phase. The polymerization processes for polymers satisfying the Schulz (1939) distribution exhibit nonuniversal critical behavior. A close analogy is found between the polymerization problem of index the Schulz r and the Bose-Einstein ideal gas in d = -2r dimensions, with the critical polymerization corresponding to the Bose-Einstein condensation.

  4. Equilibrium Tail Distribution Due to Touschek Scattering

    SciTech Connect

    Nash,B.; Krinsky, S.

    2009-05-04

    Single large angle Coulomb scattering is referred to as Touschek scattering. In addition to causing particle loss when the scattered particles are outside the momentum aperture, the process also results in a non-Gaussian tail, which is an equilibrium between the Touschek scattering and radiation damping. Here we present an analytical calculation for this equilibrium distribution.

  5. A Holistic Equilibrium Theory of Organization Development

    ERIC Educational Resources Information Center

    Yang, Baiyin; Zheng, Wei

    2005-01-01

    This paper proposes a holistic equilibrium theory of organizational development (OD). The theory states that there are three driving forces in organizational change and development--rationality, reality, and liberty. OD can be viewed as a planned process of change in an organization so as to establish equilibrium among these three interacting…

  6. Zeroth Law, Entropy, Equilibrium, and All That

    ERIC Educational Resources Information Center

    Canagaratna, Sebastian G.

    2008-01-01

    The place of the zeroth law in the teaching of thermodynamics is examined in the context of the recent discussion by Gislason and Craig of some problems involving the establishment of thermal equilibrium. The concept of thermal equilibrium is introduced through the zeroth law. The relation between the zeroth law and the second law in the…

  7. Equilibrium figures in geodesy and geophysics.

    NASA Astrophysics Data System (ADS)

    Moritz, H.

    There is an enormous literature on geodetic equilibrium figures, but the various works have not always been interrelated, also for linguistic reasons (English, French, German, Italian, Russian). The author attempts to systematize the various approaches and to use the standard second-order theory for a study of the deviation of the actual earth and of the equipotential reference ellipsoid from an equilibrium figure.

  8. Implementing an Equilibrium Law Teaching Sequence for Secondary School Students to Learn Chemical Equilibrium

    ERIC Educational Resources Information Center

    Ghirardi, Marco; Marchetti, Fabio; Pettinari, Claudio; Regis, Alberto; Roletto, Ezio

    2015-01-01

    A didactic sequence is proposed for the teaching of chemical equilibrium law. In this approach, we have avoided the kinetic derivation and the thermodynamic justification of the equilibrium constant. The equilibrium constant expression is established empirically by a trial-and-error approach. Additionally, students learn to use the criterion of…

  9. Disturbances in equilibrium function after major earthquake

    NASA Astrophysics Data System (ADS)

    Honma, Motoyasu; Endo, Nobutaka; Osada, Yoshihisa; Kim, Yoshiharu; Kuriyama, Kenichi

    2012-10-01

    Major earthquakes were followed by a large number of aftershocks and significant outbreaks of dizziness occurred over a large area. However it is unclear why major earthquake causes dizziness. We conducted an intergroup trial on equilibrium dysfunction and psychological states associated with equilibrium dysfunction in individuals exposed to repetitive aftershocks versus those who were rarely exposed. Greater equilibrium dysfunction was observed in the aftershock-exposed group under conditions without visual compensation. Equilibrium dysfunction in the aftershock-exposed group appears to have arisen from disturbance of the inner ear, as well as individual vulnerability to state anxiety enhanced by repetitive exposure to aftershocks. We indicate potential effects of autonomic stress on equilibrium function after major earthquake. Our findings may contribute to risk management of psychological and physical health after major earthquakes with aftershocks, and allow development of a new empirical approach to disaster care after such events.

  10. Probing local equilibrium in nonequilibrium fluids.

    PubMed

    del Pozo, J J; Garrido, P L; Hurtado, P I

    2015-08-01

    We use extensive computer simulations to probe local thermodynamic equilibrium (LTE) in a quintessential model fluid, the two-dimensional hard-disks system. We show that macroscopic LTE is a property much stronger than previously anticipated, even in the presence of important finite-size effects, revealing a remarkable bulk-boundary decoupling phenomenon in fluids out of equilibrium. This allows us to measure the fluid's equation of state in simulations far from equilibrium, with an excellent accuracy comparable to the best equilibrium simulations. Subtle corrections to LTE are found in the fluctuations of the total energy which strongly point to the nonlocality of the nonequilibrium potential governing the fluid's macroscopic behavior out of equilibrium. PMID:26382354

  11. How Far from Equilibrium Is Active Matter?

    NASA Astrophysics Data System (ADS)

    Fodor, Étienne; Nardini, Cesare; Cates, Michael E.; Tailleur, Julien; Visco, Paolo; van Wijland, Frédéric

    2016-07-01

    Active matter systems are driven out of thermal equilibrium by a lack of generalized Stokes-Einstein relation between injection and dissipation of energy at the microscopic scale. We consider such a system of interacting particles, propelled by persistent noises, and show that, at small but finite persistence time, their dynamics still satisfy a time-reversal symmetry. To do so, we compute perturbatively their steady-state measure and show that, for short persistent times, the entropy production rate vanishes. This endows such systems with an effective fluctuation-dissipation theorem akin to that of thermal equilibrium systems. Last, we show how interacting particle systems with viscous drags and correlated noises can be seen as in equilibrium with a viscoelastic bath but driven out of equilibrium by nonconservative forces, hence providing energetic insight into the departure of active systems from equilibrium.

  12. Encountering Nanotechnology in an Interactive Exhibition

    ERIC Educational Resources Information Center

    Murriello, Sandra E.; Knobel, Marcelo

    2008-01-01

    This article offers findings from a learning sciences-informed evaluation of a nanoscience and nanotechnology exhibition called Nano-Aventura (NanoAdventure), based on four interactive-collaborative games and two narrated videos. This traveling exhibition was developed in Brazil by the Museu Exploratorio de Ciencias for children and teenagers…

  13. Science Fiction Exhibits as STEM Gateways

    NASA Astrophysics Data System (ADS)

    Robie, Samantha

    Women continue to hold less than a quarter of all STEM jobs in the United States, prompting many museums to develop programs and exhibits with the express goal of interesting young girls in scientific fields. At the same time, a number of recent museum exhibits have harnessed the popularity of pop culture and science fiction in order to interest general audiences in STEM subject matter, as well as using the exhibits as springboards to expand or shift mission goals and focus. Because science fiction appears to be successful at raising interest in STEM fields, it may be an effective way to garner the interest of young girls in STEM in particular. This research seeks to describe the ways in which museums are currently using science fiction exhibits to interest young girls in STEM fields and careers. Research focused on four institutions across the country hosting three separate exhibits, and included staff interviews and content analysis of exhibit descriptions, promotional materials, a summative evaluation and supplementary exhibit productions. In some ways, science fiction exhibits do serve young girls, primarily through the inclusion of female role models, staff awareness, and prototype testing to ensure interactives are attractive to girls as well as to boys. However, STEM appears to be underutilized, which may be partly due to a concern within the field that the outcome of targeting a specific gender could be construed as "stereotyping".

  14. Strategies for Determining Exhibit Effectiveness. Final Report.

    ERIC Educational Resources Information Center

    Shettel, Harris H.; And Others

    This project was designed to develop research strategies and hypotheses for evaluating the effectiveness of exhibits. An exhibit on the role of the Federal Government in science and technology was used as the subject matter. Two basic groups of viewers were used, casual viewers and paid experimental viewers. Both were tested on knowledge gained…

  15. An Attention Model for Museum Exhibits.

    ERIC Educational Resources Information Center

    Lightner, John W.

    A qualitative study determined which factors in the museum exhibit environment or within the museum visitor may influence the visitor to attend an exhibit. Observations and interviews were conducted of 14 groups that visited a Chesapeake & Ohio steam locomotive at the Henry Ford Museum in Dearborn, Michigan. An inductive or grounded theory…

  16. Learning4Life on the Exhibit Floor

    ERIC Educational Resources Information Center

    Sullivan, Margaret

    2009-01-01

    The exhibit floor is a wealth of knowledge. One can read, view, and listen to information presented in many formats. Somewhere on the exhibit floor there are experts on every topic, ready and waiting for one's questions. But like any research topic, frequently a structured search is required to find the best answers. This article discusses how to…

  17. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (respondent) necessary for the rendition of service requested by the applicant. (6) Exhibit G—Flow diagram showing daily design capacity and reflecting operation with proposed transmission facilities. A flow...—Flow diagram reflecting maximum capabilities. If Exhibit G does not reflect the maximum deliveries...

  18. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (respondent) necessary for the rendition of service requested by the applicant. (6) Exhibit G—Flow diagram showing daily design capacity and reflecting operation with proposed transmission facilities. A flow...—Flow diagram reflecting maximum capabilities. If Exhibit G does not reflect the maximum deliveries...

  19. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  20. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 14 2013-01-01 2013-01-01 false Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  1. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 14 2011-01-01 2011-01-01 false Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  2. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 14 2014-01-01 2014-01-01 false Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  3. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 14 2012-01-01 2012-01-01 false Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  4. Spatial distributions at equilibrium under heterogeneous transient subdiffusion

    PubMed Central

    Berry, Hugues; Soula, Hédi A.

    2014-01-01

    Experimental measurements of the mobility of macromolecules, especially proteins, in cells and their membranes consistently report transient subdiffusion with possibly position-dependent—non-homogeneous—properties. However, the spatiotemporal dynamics of protein mobility when transient subdiffusion is restricted to a subregion of space is still unclear. Here, we investigated the spatial distribution at equilibrium of proteins undergoing transient subdiffusion due to continuous-time random walks (CTRW) in a restricted subregion of a two-dimensional space. Our Monte-Carlo simulations suggest that this process leads to a non-homogeneous spatial distribution of the proteins at equilibrium, where proteins increasingly accumulate in the CTRW subregion as its anomalous properties are increasingly marked. In the case of transient CTRW, we show that this accumulation is dictated by the asymptotic Brownian regime and not by the initial anomalous transient dynamics. Moreover, our results also show that this dominance of the asymptotic Brownian regime cannot be simply generalized to other scenarios of transient subdiffusion. In particular, non-homogeneous transient subdiffusion due to hindrance by randomly-located immobile obstacles does not lead to such a strong local accumulation. These results suggest that, even though they exhibit the same time-dependence of the mean-squared displacement, the different scenarios proposed to account for subdiffusion in the cell lead to different protein distribution in space, even at equilibrium and without coupling with reaction. PMID:25429273

  5. Formation of large micellar aggregates before equilibrium in diluted solutions

    NASA Astrophysics Data System (ADS)

    de Moraes, J. N. B.; Figueiredo, W.

    2013-06-01

    We study the formation of premicelles for different values of the concentration of amphiphile molecules in water. Our model consists of a square lattice with water molecules occupying one cell of the lattice while the amphiphilic molecules, represented by chains of five interconnected sites, occupy five cells of the lattice. We perform Monte Carlo simulations in the NVT ensemble, for a fixed temperature and different concentration of amphiphiles, ranging from below to above the critical micelle concentration. We start our simulations from a monomeric state and follow in time all the aggregates sizes until the equilibrium state is reached. We pay particular attention to two aggregate sizes, one related to the minimum and the other to the maximum of the aggregate-size distribution curve obtained at equilibrium. We show that these aggregates evolve in time exhibiting a maximum concentration well before the equilibrium state, revealing the formation of premicelles. The times to reach these maximum concentrations decrease exponentially with the total concentration of the system.

  6. Museum Exhibitions: Optimizing Development Using Evaluation

    NASA Astrophysics Data System (ADS)

    Dusenbery, P. B.

    2002-12-01

    The Space Science Institute (SSI) of Boulder, Colorado, has recently developed two museum exhibits called the Space Weather Center and MarsQuest. It is currently planning to develop a third exhibit called InterActive Earth. The Space Weather Center was developed in partnership with various research missions at NASA's Goddard Space Flight Center. The development of these exhibitions included a comprehensive evaluation plan. I will report on the important role evaluation plays in exhibit design and development using MarsQuest and InterActive Earth as models. The centerpiece of SSI's Mars Education Program is the 5,000-square-foot traveling exhibition, MarsQuest: Exploring the Red Planet, which was developed with support from the National Science Foundation (NSF), NASA, and several corporate donors. The MarsQuest exhibit is nearing the end of a highly successful, fully-booked three-year tour. The Institute plans to send an enhanced and updated MarsQuest on a second three-year tour and is also developing Destination: Mars, a mini-version of MarsQuest designed for smaller venues. They are designed to inspire and empower participants to extend the excitement and science content of the exhibitions into classrooms and museum-based education programs in an ongoing fashion. The centerpiece of the InterActive Earth project is a traveling exhibit that will cover about 4,000 square feet. The major goal of the proposed exhibit is to introduce students and the public to the complexity of the interconnections in the Earth system, and thereby, to inspire them to better understand planet Earth. Evaluation must be an integral part of the exhibition development process. For MarsQuest, a 3-phase evaluation (front end, formative and summative) was conducted by Randi Korn and Associates in close association with the development team. Sampling procedures for all three evaluation phases ensured the participation of all audiences, including family groups, students, and adults. Each phase of

  7. Local Nash Equilibrium in Social Networks

    PubMed Central

    Zhang, Yichao; Aziz-Alaoui, M. A.; Bertelle, Cyrille; Guan, Jihong

    2014-01-01

    Nash equilibrium is widely present in various social disputes. As of now, in structured static populations, such as social networks, regular, and random graphs, the discussions on Nash equilibrium are quite limited. In a relatively stable static gaming network, a rational individual has to comprehensively consider all his/her opponents' strategies before they adopt a unified strategy. In this scenario, a new strategy equilibrium emerges in the system. We define this equilibrium as a local Nash equilibrium. In this paper, we present an explicit definition of the local Nash equilibrium for the two-strategy games in structured populations. Based on the definition, we investigate the condition that a system reaches the evolutionary stable state when the individuals play the Prisoner's dilemma and snow-drift game. The local Nash equilibrium provides a way to judge whether a gaming structured population reaches the evolutionary stable state on one hand. On the other hand, it can be used to predict whether cooperators can survive in a system long before the system reaches its evolutionary stable state for the Prisoner's dilemma game. Our work therefore provides a theoretical framework for understanding the evolutionary stable state in the gaming populations with static structures. PMID:25169150

  8. Equilibrium and pre-equilibrium processes in the Mn55(Li6,xp) and Fe57(α,xp) reactions

    NASA Astrophysics Data System (ADS)

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Bürger, A.; Görgen, A.; Guttormsen, M.; Larsen, A. C.; Massey, T. N.; Siem, S.; Kalbach, C.

    2011-05-01

    Spectra of outgoing neutrons and protons from the Li6 + Mn55 reaction and protons from the α + Fe57 reaction have been measured with beams of 15-MeV Li6 ions and 30-MeV α particles. These reactions proceed through the same Ni61 nucleus at the same excitation energy, thus allowing the difference in reaction mechanisms to be studied. It is shown that spectra from the first reaction measured at backward angles are due to emission from a traditional compound nucleus reaction, in which the intermediate nucleus has reached statistical equilibrium; the spectra from the second reaction contain a significant fraction of pre-equilibrium emission at all angles. Level density parameters of the residual nucleus Co60 have been obtained from the first reaction. Both emission spectra and angular distributions have been measured for the second reaction. It was found that the pre-equilibrium component exhibits a forward-peaked angular distribution, as expected, but with a steeper slope than predicted and with an unusual slight rise at angles above 120°. The backward-angle rise is explained qualitatively by the dominance of the multistep compound mechanism at backward angles.

  9. Critical top tension for static equilibrium configuration of a steel catenary riser

    NASA Astrophysics Data System (ADS)

    Athisakul, Chainarong; Klaycham, Karun; Chucheepsakul, Somchai

    2014-12-01

    This paper aims to present the critical top tension for static equilibrium configurations of a steel catenary riser (SCR) by using the finite element method. The critical top tension is the minimum top tension that can maintain the equilibrium of the SCR. If the top tension is smaller than the critical value, the equilibrium of the SCR does not exist. If the top tension is larger than the critical value, there are two possible equilibrium configurations. These two configurations exhibit the nonlinear large displacement. The configuration with the smaller displacement is stable, while the one with larger displacement is unstable. The numerical results show that the increases in the riser's vertical distances, horizontal offsets, riser's weights, internal flow velocities, and current velocities increase the critical top tensions of the SCR. In addition, the parametric studies are also performed in order to investigate the limit states for the analysis and design of the SCR.

  10. Imaging the equilibrium state and magnetization dynamics of partially built hard disk write heads

    SciTech Connect

    Valkass, R. A. J. Yu, W.; Shelford, L. R.; Keatley, P. S.; Loughran, T. H. J.; Hicken, R. J.; Cavill, S. A.; Laan, G. van der; Dhesi, S. S.; Bashir, M. A.; Gubbins, M. A.; Czoschke, P. J.; Lopusnik, R.

    2015-06-08

    Four different designs of partially built hard disk write heads with a yoke comprising four repeats of NiFe (1 nm)/CoFe (50 nm) were studied by both x-ray photoemission electron microscopy (XPEEM) and time-resolved scanning Kerr microscopy (TRSKM). These techniques were used to investigate the static equilibrium domain configuration and the magnetodynamic response across the entire structure, respectively. Simulations and previous TRSKM studies have made proposals for the equilibrium domain configuration of similar structures, but no direct observation of the equilibrium state of the writers has yet been made. In this study, static XPEEM images of the equilibrium state of writer structures were acquired using x-ray magnetic circular dichroism as the contrast mechanism. These images suggest that the crystalline anisotropy dominates the equilibrium state domain configuration, but competition with shape anisotropy ultimately determines the stability of the equilibrium state. Dynamic TRSKM images were acquired from nominally identical devices. These images suggest that a longer confluence region may hinder flux conduction from the yoke into the pole tip: the shorter confluence region exhibits clear flux beaming along the symmetry axis, whereas the longer confluence region causes flux to conduct along one edge of the writer. The observed variations in dynamic response agree well with the differences in the equilibrium magnetization configuration visible in the XPEEM images, confirming that minor variations in the geometric design of the writer structure can have significant effects on the process of flux beaming.

  11. Natural gas at thermodynamic equilibrium Implications for the origin of natural gas

    PubMed Central

    2009-01-01

    It is broadly accepted that so-called 'thermal' gas is the product of thermal cracking, 'primary' thermal gas from kerogen cracking, and 'secondary' thermal gas from oil cracking. Since thermal cracking of hydrocarbons does not generate products at equilibrium and thermal stress should not bring them to equilibrium over geologic time, we would not expect methane, ethane, and propane to be at equilibrium in subsurface deposits. Here we report compelling evidence of natural gas at thermodynamic equilibrium. Molecular compositions are constrained to equilibrium, and isotopic compositions are also under equilibrium constraints: The functions [(CH4)*(C3H8)] and [(C2H6)2] exhibit a strong nonlinear correlation (R2 = 0.84) in which the quotient Q progresses to K as wet gas progresses to dry gas. There are striking similarities between natural gas and catalytic gas generated from marine shales. A Devonian/Mississippian New Albany shale generates gas with Q converging on K over time as wet gas progresses to dry gas at 200°C. The position that thermal cracking is the primary source of natural gas is no longer tenable. It is challenged by its inability to explain the composition of natural gas, natural gases at thermodynamic equilibrium, and by the existence of a catalytic path to gas that better explains gas compositions. PMID:19531233

  12. Equilibrium and kinetic selectivity profiling on the human adenosine receptors.

    PubMed

    Guo, Dong; Dijksteel, Gabrielle S; van Duijl, Tirsa; Heezen, Maxime; Heitman, Laura H; IJzerman, Adriaan P

    2016-04-01

    Classical evaluation of target selectivity is usually undertaken by measuring the binding affinity of lead compounds against a number of potential targets under equilibrium conditions, without considering the kinetics of the ligand-receptor interaction. In the present study we propose a combined strategy including both equilibrium- and kinetics-based selectivity profiling. The adenosine receptor (AR) was chosen as a prototypical drug target. Six in-house AR antagonists were evaluated in a radioligand displacement assay for their affinity and in a competition association assay for their binding kinetics on three AR subtypes. One of the compounds with a promising kinetic selectivity profile was also examined in a [(35)S]-GTPγS binding assay for functional activity. We found that XAC and LUF5964 were kinetically more selective for the A1R and A3R, respectively, although they are non-selective in terms of their affinity. In comparison, LUF5967 displayed a strong equilibrium-based selectivity for the A1R over the A2AR, yet its kinetic selectivity thereon was less pronounced. In a GTPγS assay, LUF5964 exhibited insurmountable antagonism on the A3R while having a surmountable effect on the A1R, consistent with its kinetic selectivity profile. This study provides evidence that equilibrium and kinetic selectivity profiling can both be important in the early phases of the drug discovery process. Our proposed combinational strategy could be considered for future medicinal chemistry efforts and aid the design and discovery of different or even better leads for clinical applications. PMID:26930564

  13. Equilibrium and non-equilibrium emission of complex fragments

    SciTech Connect

    Bowman, D.R.

    1989-08-01

    Complex fragment emission (Z{gt}2) has been studied in the reactions of 50, 80, and 100 MeV/u {sup 139}La + {sup 12}C, and 80 MeV/u {sup 139}La + {sup 27}Al, {sup nat}Cu, and {sup 197}Au. Charge, angle, and energy distributions were measured inclusively and in coincidence with other complex fragments, and were used to extract the source rapidities, velocity distributions, and cross sections. The experimental emission velocity distributions, charge loss distributions, and cross sections have been compared with calculations based on statistical compound nucleus decay. The binary signature of the coincidence events and the sharpness of the velocity distributions illustrate the primarily 2-body nature of the {sup 139}La + {sup 12}C reaction mechanism between 50 and 100 MeV/u. The emission velocities, angular distributions, and absolute cross sections of fragments of 20{le}Z{le}35 at 50 MeV/u, 19{le}Z{le}28 at 80 MeV/u, and 17{le}Z{le}21 at 100 MeV/u indicate that these fragments arise solely from the binary decay of compound nuclei formed in incomplete fusion reactions in which the {sup 139}La projectile picks up about one-half of the {sup 12}C target. In the 80 MeV/u {sup 139}La + {sup 27}Al, {sup nat}Cu, and {sup 197}Au reactions, the disappearance of the binary signature in the total charge and velocity distributions suggests and increase in the complex fragment and light charged particle multiplicity with increasing target mass. As in the 80 and 100 MeV/u {sup 139}La + {sup 12}C reactions, the lighter complex fragments exhibit anisotropic angular distributions and cross sections that are too large to be explained exclusively by statistical emission. 143 refs., 67 figs.

  14. Non-equilibrium Transport of Light

    NASA Astrophysics Data System (ADS)

    Wang, Chiao-Hsuan; Taylor, Jacob

    Non-equilibrium Transport of Light The thermalization of light under conditions of parametric coupling to a bath provides a robust chemical potential for light. We study non-equilibrium transport of light using non-equilibrium Green's function approach under the parametric coupling scheme, and explore a potential photonic analogue to the Landauer transport equation. Our results provide understandings of many-body states of photonic matter with chemical potential imbalances. The transport theory of light paves the way for quantum simulation and even practical applications of diode-like circuits using quantum photonic sources in the microwave and optical domain.

  15. The Making of a Museum Exhibition.

    ERIC Educational Resources Information Center

    Bleecker, Samuel E.

    1979-01-01

    Discusses the preparation of the Reptile and Amphibian exhibition at the American Museum of Natural History. Various steps involved in developing the ten showcases in a six-year period are presented. (SA)

  16. 18 CFR 32.2 - Required exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... of operating such facilities. Exhibit B. A general or key map on a scale not greater than 20 miles to... facilities used for the generation and transmission of electric energy, indicating on said map the...

  17. 32 CFR 705.24 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... tractor-trailer transportation should be forwarded prior to November 15th previous to the year desired. A... time for which an exhibit is authorized will be determined by the nature of the event and the type...

  18. 32 CFR 705.24 - Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... tractor-trailer transportation should be forwarded prior to November 15th previous to the year desired. A... time for which an exhibit is authorized will be determined by the nature of the event and the type...

  19. Exhibit of School Architecture, 1996. Special Section.

    ERIC Educational Resources Information Center

    Texas Architect, 1997

    1997-01-01

    Presents selected winners of the Texas 1996 Exhibit of School Architecture Design Competition. The Caudill and honor award-winning projects are listed along with facility photos, brief descriptions, project credits, and the names of the construction companies used. (GR)

  20. Exhibit of School Architecture, 1997. Special Section.

    ERIC Educational Resources Information Center

    Texas Architect, 1998

    1998-01-01

    Presents selected winners of the Texas 1997 Exhibit of School Architecture Design Competition. The Caudill and honor award winning projects are listed along with facility photos, brief descriptions, project credits, and the names of the construction companies used. (GR)

  1. When Do Children Exhibit a "Yes" Bias?

    ERIC Educational Resources Information Center

    Okanda, Mako; Itakura, Shoji

    2010-01-01

    This study investigated whether one hundred and thirty-five 3- to 6-year-old children exhibit a yes bias to various yes-no questions and whether their knowledge status affects the production of a yes bias. Three-year-olds exhibited a yes bias to all yes-no questions such as "preference-object" and "knowledge-object" questions pertaining to…

  2. Reaching the Public through Traveling Exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, P. B.; Harold, J. B.; Morrow, C. A.

    2004-11-01

    The Space Science Institute (SSI) of Boulder, Colorado has recently developed two museum exhibits called Alien Earths and MarsQuest. It has just started to develop another exhibit called Giant Planets. These exhibitions provide research scientists the opportunity to engage in a number of activities that are vital to the success of these major outreach programs. Alien Earths was developed in partnership with various research missions. The focus of the presentation will be on MarsQuest and Giant Planets. MarsQuest is a 5000 square-foot, \\$3M, traveling exhibition that is now touring the country. The exhibit's second 3-year tour will enable millions of Americans to share in the excitement of the scientific exploration of Mars and learn more about their own planet in the process. The associated planetarium show and education program will also be described, with particular emphasis on workshops to orient museum staff (e.g. museum educators and docents) and workshops for master educators near host museums and science centers. The workshops make innovative connections between the exhibition's interactive experiences and lesson plans aligned with the National Science Education Standards. These exhibit programs are good models for actively involving scientists and their discoveries to help improve informal science education in the museum community and for forging a stronger connection between formal and informal education. The presentation will also discuss how Giant Planets, a proposed 3500 square-foot traveling exhibition on the mysteries and discoveries of the outer planets, will be able to take advantage of the connections and resources that have been developed by the MarsQuest project.

  3. An Astrobiology Microbes Exhibit and Education Module

    NASA Technical Reports Server (NTRS)

    Lindstrom, Marilyn M.; Allen, Jaclyn S.; Stocco, Karen; Tobola, Kay; Olendzenski, Lorraine

    2001-01-01

    Telling the story of NASA-sponsored scientific research to the public in exhibits is best done by partnerships of scientists and museum professionals. Likewise, preparing classroom activities and training teachers to use them should be done by teams of teachers and scientists. Here we describe how we used such partnerships to develop a new astrobiology augmentation to the Microbes! traveling exhibit and a companion education module. "Additional information is contained in the original extended abstract."

  4. The Conceptual Change Approach to Teaching Chemical Equilibrium

    ERIC Educational Resources Information Center

    Canpolat, Nurtac; Pinarbasi, Tacettin; Bayrakceken, Samih; Geban, Omer

    2006-01-01

    This study investigates the effect of a conceptual change approach over traditional instruction on students' understanding of chemical equilibrium concepts (e.g. dynamic nature of equilibrium, definition of equilibrium constant, heterogeneous equilibrium, qualitative interpreting of equilibrium constant, changing the reaction conditions). This…

  5. Universality far from equilibrium: from superfluid Bose gases to heavy-ion collisions.

    PubMed

    Berges, J; Boguslavski, K; Schlichting, S; Venugopalan, R

    2015-02-13

    Isolated quantum systems in extreme conditions can exhibit unusually large occupancies per mode. This overpopulation gives rise to new universality classes of many-body systems far from equilibrium. We present theoretical evidence that important aspects of non-Abelian plasmas in the ultrarelativistic limit admit a dual description in terms of a Bose condensed scalar field theory. PMID:25723203

  6. Universality far from equilibrium: From superfluid Bose gases to heavy-ion collisions

    DOE PAGESBeta

    Schlichting, S.; Venugopalan, R.; Berges, J.; Boguslavski, K.

    2015-02-10

    Isolated quantum systems in extreme conditions can exhibit unusually large occupancies per mode. In addition, this over-population gives rise to new universality classes of many-body systems far from equilibrium. We present theoretical evidence that important aspects of non-Abelian plasmas in the ultra-relativistic limit admit a dual description in terms of a Bose condensed scalar field theory.

  7. Sex differences in science museum exhibit attraction

    NASA Astrophysics Data System (ADS)

    Arámbula Greenfield, Teresa

    This study examines the relative attraction of hands-on, interactive science museum exhibits for females and males. Studies have demonstrated that such exhibits can be effective learning experiences for children, with both academic and affective benefits. Other studies have shown that girls and boys do not always experience the same science-related educational opportunities and that, even when they do, they do not necessarily receive the same benefits from them. These early differences can lead to more serious educational and professional disparities later in life. As interactive museum exhibits represent a science experience that is-readily available to both girls and boys, the question arose as to whether they were being used similarly by the two groups as well as by adult women and men. It was found that both girls and boys used all types of exhibits, but that girls were more likely than boys to use puzzles and exhibits focusing on the human body; boys were more likely than girls to use computers and exhibits illustrating physical science principles. However, this was less true of children accompanied by adults (parents) than it was of unaccompanied children on school field trips who roamed the museum more freely.Received: 16 February 1994; Revised: 3 February 1995;

  8. An Elementary Discussion of Chemical Equilibrium.

    ERIC Educational Resources Information Center

    David, Carl W.

    1988-01-01

    This discussion uses a more difficult reaction as the prototype to derive the standard equation for chemical equilibrium. It can be used by students who can understand and use partial derivatives. (CW)

  9. Spreadsheet Templates for Chemical Equilibrium Calculations.

    ERIC Educational Resources Information Center

    Joshi, Bhairav D.

    1993-01-01

    Describes two general spreadsheet templates to carry out all types of one-equation chemical equilibrium calculations encountered by students in undergraduate chemistry courses. Algorithms, templates, macros, and representative examples are presented to illustrate the approach. (PR)

  10. Stochastic approach to equilibrium and nonequilibrium thermodynamics

    NASA Astrophysics Data System (ADS)

    Tomé, Tânia; de Oliveira, Mário J.

    2015-04-01

    We develop the stochastic approach to thermodynamics based on stochastic dynamics, which can be discrete (master equation) and continuous (Fokker-Planck equation), and on two assumptions concerning entropy. The first is the definition of entropy itself and the second the definition of entropy production rate, which is non-negative and vanishes in thermodynamic equilibrium. Based on these assumptions, we study interacting systems with many degrees of freedom in equilibrium or out of thermodynamic equilibrium and how the macroscopic laws are derived from the stochastic dynamics. These studies include the quasiequilibrium processes; the convexity of the equilibrium surface; the monotonic time behavior of thermodynamic potentials, including entropy; the bilinear form of the entropy production rate; the Onsager coefficients and reciprocal relations; and the nonequilibrium steady states of chemical reactions.

  11. Equilibrium Reconstruction on the Large Helical Device

    SciTech Connect

    Samuel A. Lazerson, D. Gates, D. Monticello, H. Neilson, N. Pomphrey, A. Reiman S. Sakakibara, and Y. Suzuki

    2012-07-27

    Equilibrium reconstruction is commonly applied to axisymmetric toroidal devices. Recent advances in computational power and equilibrium codes have allowed for reconstructions of three-dimensional fields in stellarators and heliotrons. We present the first reconstructions of finite beta discharges in the Large Helical Device (LHD). The plasma boundary and magnetic axis are constrained by the pressure profile from Thomson scattering. This results in a calculation of plasma beta without a-priori assumptions of the equipartition of energy between species. Saddle loop arrays place additional constraints on the equilibrium. These reconstruction utilize STELLOPT, which calls VMEC. The VMEC equilibrium code assumes good nested flux surfaces. Reconstructed magnetic fields are fed into the PIES code which relaxes this constraint allowing for the examination of the effect of islands and stochastic regions on the magnetic measurements.

  12. Points of Equilibrium in Electrostatic Fields.

    ERIC Educational Resources Information Center

    Rogers, Peter J.

    1979-01-01

    Discusses the electric field line pattern for four equal charges of the same sign placed at the corners of a square. The electric field intensity and the point of equilibrium are interpreted, taking into account three dimensions. (HM)

  13. IEHI: Ionization Equilibrium for Heavy Ions

    NASA Astrophysics Data System (ADS)

    Cranmer, Steven R.

    2015-07-01

    IEHI, written in Fortran, outputs a simple "coronal" ionization equilibrium (i.e., collisional ionization and auto-ionization balanced by radiative and dielectronic recombination) for a plasma at a given electron temperature.

  14. Surface roughness effects on equilibrium temperature.

    NASA Technical Reports Server (NTRS)

    Houchens, A. F.; Hering, R. G.

    1972-01-01

    An analysis is presented for evaluation of equilibrium temperature distribution on radiatively adiabatic, adjoint planes which are uniformly irradiated by a collimated solar flux. The analysis employs a semigrey spectral model. Radiation properties for surface emitted radiation are obtained from the expressions of electromagnetic theory for smooth surfaces. Rough surface properties for solar radiation are given by the Beckmann bidirectional reflectance model. Numerical solutions to the governing equations yield equilibrium temperature distributions for a range of the influencing parameters. Surface roughness has little influence on equilibrium temperature for materials with high values for solar absorptance. However, for low or intermediate values of solar absorptance, roughness effects on the spatial distribution of reflected solar radiation can significantly alter equilibrium temperature particularly at surface elements where radiant interaction is small.

  15. Stochastic approach to equilibrium and nonequilibrium thermodynamics.

    PubMed

    Tomé, Tânia; de Oliveira, Mário J

    2015-04-01

    We develop the stochastic approach to thermodynamics based on stochastic dynamics, which can be discrete (master equation) and continuous (Fokker-Planck equation), and on two assumptions concerning entropy. The first is the definition of entropy itself and the second the definition of entropy production rate, which is non-negative and vanishes in thermodynamic equilibrium. Based on these assumptions, we study interacting systems with many degrees of freedom in equilibrium or out of thermodynamic equilibrium and how the macroscopic laws are derived from the stochastic dynamics. These studies include the quasiequilibrium processes; the convexity of the equilibrium surface; the monotonic time behavior of thermodynamic potentials, including entropy; the bilinear form of the entropy production rate; the Onsager coefficients and reciprocal relations; and the nonequilibrium steady states of chemical reactions. PMID:25974471

  16. Equilibrium fluctuation energy of gyrokinetic plasma

    SciTech Connect

    Krommes, J.A.; Lee, W.W.; Oberman, C.

    1985-11-01

    The thermal equilibrium electric field fluctuation energy of the gyrokinetic model of magnetized plasma is computed, and found to be smaller than the well-known result (k)/8..pi.. = 1/2T/(1 + (klambda/sub D/)/sup 2/) valid for arbitrarily magnetized plasmas. It is shown that, in a certain sense, the equilibrium electric field energy is minimum in the gyrokinetic regime. 13 refs., 2 figs.

  17. The Theory of Variances in Equilibrium Reconstruction

    SciTech Connect

    Zakharov, Leonid E.; Lewandowski, Jerome; Foley, Elizabeth L.; Levinton, Fred M.; Yuh, Howard Y.; Drozdov, Vladimir; McDonald, Darren

    2008-01-14

    The theory of variances of equilibrium reconstruction is presented. It complements existing practices with information regarding what kind of plasma profiles can be reconstructed, how accurately, and what remains beyond the abilities of diagnostic systems. The σ-curves, introduced by the present theory, give a quantitative assessment of quality of effectiveness of diagnostic systems in constraining equilibrium reconstructions. The theory also suggests a method for aligning the accuracy of measurements of different physical nature.

  18. Edge Equilibrium Code (EEC) For Tokamaks

    SciTech Connect

    Li, Xujling

    2014-02-24

    The edge equilibrium code (EEC) described in this paper is developed for simulations of the near edge plasma using the finite element method. It solves the Grad-Shafranov equation in toroidal coordinate and uses adaptive grids aligned with magnetic field lines. Hermite finite elements are chosen for the numerical scheme. A fast Newton scheme which is the same as implemented in the equilibrium and stability code (ESC) is applied here to adjust the grids

  19. Using Comparative Planetology in Exhibit Development

    NASA Astrophysics Data System (ADS)

    Dusenbery, P. B.; Harold, J. B.; Morrow, C. A.

    2004-12-01

    It is critically important for the public to better understand the scientific process. Museum exhibitions are an important part of informal science education that can effectively reach public audiences as well as school groups. They provide an important gateway for the public to learn about compelling scientific endeavors. The Space Science Institute (SSI) is a national leader in producing traveling science exhibitions and their associated educational programming (i.e. interactive websites, educator workshops, public talks, instructional materials). The focus of this presentation will be on three of its exhibit projects: MarsQuest (currently on tour), Alien Earths (in fabrication), and Giant Planets (in development). MarsQuest is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and to learn more about their own planet in the process. Alien Earths will bring origins-related research and discoveries to students and the American public. It has four interrelated exhibit areas: Our Place in Space, Star Birth, PlanetQuest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in "habitable zones" around other stars; and finally they will be able to learn about how scientists are looking for signs of life beyond Earth. Giant Planets: Exploring the Outer Solar System will take advantage of the excitement generated by the Cassini mission and bring planetary and origins research and discoveries to students and the public. It will be organized around four thematic areas: Our Solar System; Colossal Worlds; Moons, Rings, and Fields; and Make Space for Kids. Giant Planets will open in 2007. This talk will focus on the importance of making Earth comparisons in the conceptual design of each exhibit and will show several examples of how these comparisons were manifested in

  20. Theory for non-equilibrium statistical mechanics.

    PubMed

    Attard, Phil

    2006-08-21

    This paper reviews a new theory for non-equilibrium statistical mechanics. This gives the non-equilibrium analogue of the Boltzmann probability distribution, and the generalization of entropy to dynamic states. It is shown that this so-called second entropy is maximized in the steady state, in contrast to the rate of production of the conventional entropy, which is not an extremum. The relationships of the new theory to Onsager's regression hypothesis, Prigogine's minimal entropy production theorem, the Langevin equation, the formula of Green and Kubo, the Kawasaki distribution, and the non-equilibrium fluctuation and work theorems, are discussed. The theory is worked through in full detail for the case of steady heat flow down an imposed temperature gradient. A Monte Carlo algorithm based upon the steady state probability density is summarized, and results for the thermal conductivity of a Lennard-Jones fluid are shown to be in agreement with known values. Also discussed is the generalization to non-equilibrium mechanical work, and to non-equilibrium quantum statistical mechanics. As examples of the new theory two general applications are briefly explored: a non-equilibrium version of the second law of thermodynamics, and the origin and evolution of life. PMID:16883388

  1. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... engineering design data in explanation and support of the diagrams and the proposed project, setting forth: (i... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Exhibits. 156.5 Section 156.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT...

  2. 10 CFR 205.303 - Required exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... pertinent Federal and State laws. (c) Exhibit C. A general map showing the applicant's overall electric system and a detailed map highlighting the location of the facilities or the proposed facilities to be used for the generation and transmission of the electric energy to be exported. The detailed map...

  3. 10 CFR 205.303 - Required exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... pertinent Federal and State laws. (c) Exhibit C. A general map showing the applicant's overall electric system and a detailed map highlighting the location of the facilities or the proposed facilities to be used for the generation and transmission of the electric energy to be exported. The detailed map...

  4. 18 CFR 34.4 - Required exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... stockholders has been obtained. (c) Exhibit C. The Balance Sheet and attached notes for the most recent 12... computation of interest coverage Actual for the year ended mm-dd-yy OMB control No. 1902-0043, pro forma for the year ended mm-dd-yy Net income Add: Interest on Long-Term Debt, Interest on Short-Term Debt,...

  5. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Exhibits. 156.5 Section 156.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF... outlet connections at each compressor station. (iv) Pressures and volumes of gas at each intake...

  6. After Terror Charges, Artist Exhibits Academic Freedom

    ERIC Educational Resources Information Center

    Wilson, Robin

    2008-01-01

    Steven Kurtz, a professor of visual studies at the State University of New York, has been working with various bacteria as part of his counterculture exhibit artworks for nearly 20 years. Four years ago, federal agents raided his home in a bioterrorism investigation. The federal agents had been called to the house by local police officers…

  7. Do Online Students Exhibit Different Learning Styles

    ERIC Educational Resources Information Center

    Hausler, Joel; Sanders, John W.; Young, Barbara

    2007-01-01

    We examined the relationship between learning styles and student type. This research seeks to examine if online students exhibit different learning styles from onsite students; and, if so, what accommodations relating to learning style differences may be made for online students? Students (N = 80) were asked to complete an online survey in order…

  8. The medial prefrontal cortex exhibits money illusion

    PubMed Central

    Weber, Bernd; Rangel, Antonio; Wibral, Matthias; Falk, Armin

    2009-01-01

    Behavioral economists have proposed that money illusion, which is a deviation from rationality in which individuals engage in nominal evaluation, can explain a wide range of important economic and social phenomena. This proposition stands in sharp contrast to the standard economic assumption of rationality that requires individuals to judge the value of money only on the basis of the bundle of goods that it can buy—its real value—and not on the basis of the actual amount of currency—its nominal value. We used fMRI to investigate whether the brain's reward circuitry exhibits money illusion. Subjects received prizes in 2 different experimental conditions that were identical in real economic terms, but differed in nominal terms. Thus, in the absence of money illusion there should be no differences in activation in reward-related brain areas. In contrast, we found that areas of the ventromedial prefrontal cortex (vmPFC), which have been previously associated with the processing of anticipatory and experienced rewards, and the valuation of goods, exhibited money illusion. We also found that the amount of money illusion exhibited by the vmPFC was correlated with the amount of money illusion exhibited in the evaluation of economic transactions. PMID:19307555

  9. 49 CFR 250.2 - Required exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... (8) As Exhibit 8, a copy of applicant's most recent year-end general balance sheet certified by... general balance sheet as of a date no less recent than the end of the third month preceding the date of the filing of the application. The unaudited balance sheet shall be presented in account form...

  10. 49 CFR 250.2 - Required exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... (8) As Exhibit 8, a copy of applicant's most recent year-end general balance sheet certified by... general balance sheet as of a date no less recent than the end of the third month preceding the date of the filing of the application. The unaudited balance sheet shall be presented in account form...

  11. 18 CFR 50.7 - Applications: exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Applications: exhibits. 50.7 Section 50.7 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT APPLICATIONS FOR PERMITS TO SITE INTERSTATE ELECTRIC TRANSMISSION FACILITIES §...

  12. 32 CFR 705.24 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... favorably only when not in conflict with recruiting requirements. (i) Requests for exhibits must be... among the Armed Forces, or with other agencies of the Federal Government. (i) All Navy activities will... concerned, via the chain of command. (3) The official OASD(PA) Request Form for Armed Forces...

  13. 18 CFR 50.7 - Applications: exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Applications: exhibits. 50.7 Section 50.7 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT APPLICATIONS FOR PERMITS TO SITE...

  14. 18 CFR 50.7 - Applications: exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Applications: exhibits. 50.7 Section 50.7 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT APPLICATIONS FOR PERMITS TO SITE...

  15. 18 CFR 50.7 - Applications: exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Applications: exhibits. 50.7 Section 50.7 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT APPLICATIONS FOR PERMITS TO SITE...

  16. 18 CFR 153.8 - Required exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... facilities in the United States and Canada or Mexico; (5) Exhibit E. If the proposal is to import or export... Seismic Risk Map of the United States, or where there is a risk of surface faulting or ground liquefaction... the Seismic Review of LNG Facilities,” NBSIR 84-2833. This document may be obtained from the...

  17. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... such enterprises or operations, a detailed explanation of each such relationship, including the... relationship. (5) Exhibit F—Location of facilities. A geographical map of suitable scale and detail showing all...—Construction, operation, and management. A concise statement setting forth arrangements for...

  18. 18 CFR 157.14 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... explanation of each such relationship, including the percentage of voting strength represented by such... detailed explanation of each such relationship. (5) Exhibit E—Other pending applications and filings. A... abandoned. This map, or an additional map, shall clearly show the relationship of the new facilities to...

  19. 10 CFR 205.303 - Required exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...; Applications; Administrative Procedures and Sanctions Application for Authorization to Transmit Electric Energy... used for the generation and transmission of the electric energy to be exported. The detailed map shall... or fixing of rates for the purchase, sale or transmission of electric energy. (f) Exhibit F....

  20. 24 CFR 180.645 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Exhibits. 180.645 Section 180.645... OPPORTUNITY CONSOLIDATED HUD HEARING PROCEDURES FOR CIVIL RIGHTS MATTERS Procedures at Hearing § 180.645... evidence could not reasonably be anticipated at that time. (c) Authenticity. The authenticity of...

  1. 18 CFR 157.14 - Exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Act (42 U.S.C. 7101-7352); E.O. 12009, 3 CFR 142) Editorial Note: For Federal Register citations affecting § 157.14, see the List of CFR Sections Affected, which appears in the Finding Aids section of the...) Exhibit G—Flow diagrams showing daily design capacity and reflecting operation with and without...

  2. 18 CFR 157.14 - Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Act (42 U.S.C. 7101-7352); E.O. 12009, 3 CFR 142) Editorial Note: For Federal Register citations affecting § 157.14, see the List of CFR Sections Affected, which appears in the Finding Aids section of the...) Exhibit G—Flow diagrams showing daily design capacity and reflecting operation with and without...

  3. 18 CFR 157.14 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Act (42 U.S.C. 7101-7352); E.O. 12009, 3 CFR 142) Editorial Note: For Federal Register citations affecting § 157.14, see the List of CFR Sections Affected, which appears in the Finding Aids section of the...) Exhibit G—Flow diagrams showing daily design capacity and reflecting operation with and without...

  4. Non-Equilibrium Transitions of Heliospheric plasma

    NASA Astrophysics Data System (ADS)

    Livadiotis, G.; McComas, D. J.

    2011-12-01

    Recent advances in Space Physics theory have established the connection between non-extensive Statistical Mechanics and space plasmas by providing a theoretical basis for the empirically derived kappa distributions commonly used to describe the phase space distribution functions of these systems [1]. The non-equilibrium temperature and the kappa index that govern these distributions are the two independent controlling parameters of non-equilibrium systems [1-3]. The significance of the kappa index is primarily given by its role in identifying the non-equilibrium stationary states, and measuring their "thermodynamic distance" from thermal equilibrium [4], while its physical meaning is connected to the correlation between the system's particles [5]. For example, analysis of the IBEX high Energetic Neutral Atom spectra [6] showed that the vast majority of measured kappa indices are between ~1.5 and ~2.5, consistent with the far-equilibrium "cavity" of minimum entropy discovered by Livadiotis & McComas [2]. Spontaneous procedures that can increase the entropy, move the system gradually toward equilibrium, that is the state with the maximum (infinite) kappa index. Other external factors that may decrease the entropy, move the system back to states further from equilibrium where the kappa indices are smaller. Newly formed pick-up ions can play this critical role in the solar wind and other space plasmas. We have analytically shown that their highly ordered motion can reduce the average entropy in the plasma beyond the termination shock, inside the inner heliosheath [7]. Non-equilibrium transitions have a key role in understanding the governing thermodynamical processes of space plasmas. References 1. Livadiotis, G., & McComas, D. J. 2009, JGR, 114, 11105. 2. Livadiotis, G., & McComas, D. J. 2010a, ApJ, 714, 971. 3. Livadiotis, G., & McComas, D. J. 2010c, in AIP Conf. Proc. 9, Pickup Ions Throughout the Heliosphere and Beyond, ed. J. LeRoux, V. Florinski, G. P. Zank, & A

  5. MarsQuest: A National Traveling Exhibition

    NASA Astrophysics Data System (ADS)

    Lee, S. W.; Dusenbery, P. B.

    1998-09-01

    With the successful landing of Mars Pathfinder and the arrival of Mars Global Surveyor, a new decade of Mars exploration has commenced. MarsQuest, a 5000 square foot traveling exhibition, is being developed to further bring the excitement and discoveries of this "Decade of Mars Exploration" to the public. MarsQuest is partially funded by the Informal Science Education Program of the National Science Foundation and NASA's Office of Space Science. The Space Science Institute (SSI) in Boulder, CO, is leading the project. Scientific and educational advisors from many different universities and government laboratories, most of whom are directly involved in the active and planned Mars missions, will ensure the scientific accuracy, timeliness, and relevance of the key concepts presented in the exhibition and accompanying programs. The traveling exhibit is the primary element of the MarsQuest project. The exhibition experience, carefully keyed to current events in Mars exploration, will transport visitors to the surface of the Red Planet via large murals, dioramas, and numerous interactive displays. There they will have the opportunity to share in the spirit and thrill of exploration, and come to appreciate the similarities and differences between Earth and Mars. A planetarium show, geared to the goals of the MarsQuest project, will be an important sensory addition to the traveling exhibit. The planetarium/star-theater venue presents a unique environment where audience members can literally be surrounded by Mars images. Education and outreach programs comprise the remainder of the MarsQuest project. The goal of these is to make scientific concepts and scientific and engineering processes understandable to students via Mars-inspired curricula. MarsQuest will open in late-1999, traveling to about nine sites throughout the United States and reaching an estimated two to three million children and adults during its planned three-year tour. Mars - coming soon to a museum near

  6. Planetary cratering 2: Studies of saturation equilibrium

    NASA Astrophysics Data System (ADS)

    Hartmann, William K.; Gaskell, Robert W.

    1997-01-01

    A realistic computer model has been developed to display images of imaginary cratered surfaces, taking into account empirically measured input size distributions of primary and secondary craters, ejecta blanket morphology including feathering with distance, obliteration due to ejecta from outside the imaged area, lighting effects, etc. The model allows us to track surface evolution of morphology as new craters are added. Using the model as well as lunar photos, we have studied the approach to saturation equilibrium (defined as a condition when no further proportionate increase in crater density occurs as input cratering increases). We find that an identifiable saturation equilibrium occurs close to a level previously identified for this state (Hartmann 1984), typically fluctuating around a crater density from about 0.4 to 2 times that level. This result is fairly robust vis-a-vis the range of model parameters we have chosen. Flooding, basin ejecta blankets, and other obliterative effects can introduce structure and oscillations within this range, even after saturation equilibrium is achieved. These findings may constrain or revise certain earlier interpretations of satellite and planet surface evolution and impactor populations which were predicated on the assumed absence of saturation equilibrium. In our fourth experimental run, we found that suppression of "sandblasting" by sub-resolution impacts allows the smallest secondaries to rise above the saturation equilibrium line, a result that might be relevant to a similar situation on Gaspra and perhaps some other asteroids.

  7. IONIZATION EQUILIBRIUM TIMESCALES IN COLLISIONAL PLASMAS

    SciTech Connect

    Smith, Randall K.; Hughes, John P. E-mail: jph@physics.rutgers.ed

    2010-07-20

    Astrophysical shocks or bursts from a photoionizing source can disturb the typical collisional plasma found in galactic interstellar media or the intergalactic medium. The spectrum emitted by this plasma contains diagnostics that have been used to determine the time since the disturbing event, although this determination becomes uncertain as the elements in the plasma return to ionization equilibrium. A general solution for the equilibrium timescale for each element arises from the elegant eigenvector method of solution to the problem of a non-equilibrium plasma described by Masai and Hughes and Helfand. In general, the ionization evolution of an element Z in a constant electron temperature plasma is given by a coupled set of Z + 1 first-order differential equations. However, they can be recast as Z uncoupled first-order differential equations using an eigenvector basis for the system. The solution is then Z separate exponential functions, with the time constants given by the eigenvalues of the rate matrix. The smallest of these eigenvalues gives the scale of the slowest return to equilibrium independent of the initial conditions, while conversely the largest eigenvalue is the scale of the fastest change in the ion population. These results hold for an ionizing plasma, a recombining plasma, or even a plasma with random initial conditions, and will allow users of these diagnostics to determine directly if their best-fit result significantly limits the timescale since a disturbance or is so close to equilibrium as to include an arbitrarily long time.

  8. Torque equilibrium attitude control for Skylab reentry

    NASA Technical Reports Server (NTRS)

    Glaese, J. R.; Kennel, H. F.

    1980-01-01

    The method of torque equilibrium attitude control used to control the reentry of Skylab to an altitude below 150 km without the use of thruster fuel once the attitude was established is discussed. The Skylab attitude and pointing control system, which included rate gyros, sun sensors, star tracker, the Apollo telescope mount digital computer, control moment gyros and cold-gas attitude thrusters, is presented. The 12 torque equilibrium attitudes found at which aerodynamic, gravity gradient and gyroscopic torques would balance are indicated, and the three of those at which the solar power supply would be adequate for attitude control are illustrated. The equilibrium seeking method employed is then examined, and the operation and performance of the torque equilibrium attitude control system during the three weeks prior to Skylab reentry are discussed. It is concluded that the torque equilibrium attitude control method developed for Skylab was successful in performing its assigned mission, and will be valuable for the design of future, low-altitude spacecraft or tethered vehicles.

  9. New Asymptotic Behavior of the Surface-Atom Force out of Thermal Equilibrium

    SciTech Connect

    Antezza, Mauro; Pitaevskii, Lev P.; Stringari, Sandro

    2005-09-09

    The Casimir-Polder-Lifshitz force felt by an atom near the surface of a substrate is calculated out of thermal equilibrium in terms of the dielectric function of the material and of the atomic polarizability. The new force decays like 1/z{sup 3} at large distances (i.e., slower than at equilibrium), exhibits a sizable temperature dependence, and is attractive or repulsive depending on whether the temperature of the substrate is higher or smaller than the one of the environment. Our predictions can be relevant for experiments with ultracold atomic gases. Both dielectric and metal substrates are considered.

  10. Magnetospheric equilibrium configurations and slow adiabatic convection

    NASA Technical Reports Server (NTRS)

    Voigt, Gerd-Hannes

    1986-01-01

    This review paper demonstrates how the magnetohydrostatic equilibrium (MHE) theory can be used to describe the large-scale magnetic field configuration of the magnetosphere and its time evolution under the influence of magnetospheric convection. The equilibrium problem is reviewed, and levels of B-field modelling are examined for vacuum models, quasi-static equilibrium models, and MHD models. Results from two-dimensional MHE theory as they apply to the Grad-Shafranov equation, linear equilibria, the asymptotic theory, magnetospheric convection and the substorm mechanism, and plasma anisotropies are addressed. Results from three-dimensional MHE theory are considered as they apply to an intermediate analytical magnetospheric model, magnetotail configurations, and magnetopause boundary conditions and the influence of the IMF.

  11. Equilibrium versus disequilibrium of barchan dunes

    NASA Astrophysics Data System (ADS)

    El belrhiti, Hicham; Douady, Stéphane

    2011-02-01

    Barchans are crescentic dunes which occur in mainly mono-directional winds. Shape, aspect ratios and velocities of these dunes have been studied as if they were in equilibrium. However, following a study of the shape and migration of 11 barchans of different sizes for 18 months in the field on Moroccan Atlantic Sahara, we show that they only appear to be in a stationary state if studied over a long timeframe (at the scale of the year or several years), but are never in equilibrium at the scale of weeks or months. Rather, they are always 'trying' to reach a possible equilibrium state but never have enough time to accomplish this. This may be the main reason for the large variation observed in previous measurements, and justifies some caution in what can be deduced from them.

  12. Non-equilibrium quantum heat machines

    NASA Astrophysics Data System (ADS)

    Alicki, Robert; Gelbwaser-Klimovsky, David

    2015-11-01

    Standard heat machines (engine, heat pump, refrigerator) are composed of a system (working fluid) coupled to at least two equilibrium baths at different temperatures and periodically driven by an external device (piston or rotor) sometimes called the work reservoir. The aim of this paper is to go beyond this scheme by considering environments which are stationary but cannot be decomposed into a few baths at thermal equilibrium. Such situations are important, for example in solar cells, chemical machines in biology, various realizations of laser cooling or nanoscopic machines driven by laser radiation. We classify non-equilibrium baths depending on their thermodynamic behavior and show that the efficiency of heat machines powered by them is limited by the generalized Carnot bound.

  13. MCNP modelling of the PBMR equilibrium core

    SciTech Connect

    Albornoz, F.; Korochinsky, S.

    2006-07-01

    A complete MCNP model of the PBMR equilibrium core is presented, which accounts for the same fuel regions defined in the PBMR core management code, as well as for complete fuel and reflector temperature distributions. This comprehensive 3D model is the means to calculate and characterize the neutron and photon boundary sources of the equilibrium core, and is also used to support some specific core neutronic studies needing detailed geometry modelling. Due to the geometrical modelling approach followed, an unrealistic partial cutting of fuel kernels and pebbles is introduced in the model. The variations introduced by this partial cutting both on the packing fraction and on the uranium load of the modelled core and its corresponding effect on core reactivity and flux levels, have been investigated and quantified. A complete set of high-temperature cross-section data was applied to the calculation of the PBMR equilibrium core, and its effect on the calculated core reactivity is also reported. (authors)

  14. Analytic prediction of airplane equilibrium spin characteristics

    NASA Technical Reports Server (NTRS)

    Adams, W. M., Jr.

    1972-01-01

    The nonlinear equations of motion are solved algebraically for conditions for which an airplane is in an equilibrium spin. Constrained minimization techniques are employed in obtaining the solution. Linear characteristics of the airplane about the equilibrium points are also presented and their significance in identifying the stability characteristics of the equilibrium points is discussed. Computer time requirements are small making the method appear potentially applicable in airplane design. Results are obtained for several configurations and are compared with other analytic-numerical methods employed in spin prediction. Correlation with experimental results is discussed for one configuration for which a rather extensive data base was available. A need is indicated for higher Reynolds number data taken under conditions which more accurately simulate a spin.

  15. Extragradient methods for searching for equilibrium points in the parametric problem of equilibrium programming

    NASA Astrophysics Data System (ADS)

    Artem'eva, L. A.

    2014-12-01

    The parametric problem of equilibrium programming is examined. The mathematical programming problem, the search for a saddle-point, the multicriteria search for a Pareto point, etc. are particular cases of this parametric problem. The primal and dual variants of the extragradient method are proposed as a tool for searching for equilibrium points. The convergence of both variants is analyzed.

  16. Semiparametric energy-based models of systems exhibiting criticality

    NASA Astrophysics Data System (ADS)

    Humplik, Jan; Tkacik, Gasper

    Over the last decade, several empirical studies have found evidence that many biological and natural systems exhibit critical fluctuations analogous to those observed during second-order phase transitions in equilibrium systems. In many cases, these fluctuations were shown to be equivalent to a thermodynamic version of Zipf's law-if the system is sufficiently large, then a log-log plot of the probability of a state vs. its rank yields a straight line with slope - 1 . Because the origin of critical fluctuations cannot be traced to a unique mechanism, it is important that data-driven phenomenological models of natural systems are flexible enough so as to easily capture any kind of criticality. Here we study a class of models with exactly this property. This class consists of energy-based models in which the exponential Boltzmann factor is replaced by an arbitrary nonlinear function. We demonstrate the usefulness of our method by modeling the spiking activity of a population of retinal neurons, and the distribution of light intensities in small patches of natural images. In light of recent work on models with hidden variables, the proposed method can separate interactions induced by an unknown fluctuating environment from interactions intrinsic to the system.

  17. Growth states of catalytic reaction networks exhibiting energy metabolism

    NASA Astrophysics Data System (ADS)

    Kondo, Yohei; Kaneko, Kunihiko

    2011-07-01

    All cells derive nutrition by absorbing some chemical and energy resources from the environment; these resources are used by the cells to reproduce the chemicals within them, which in turn leads to an increase in their volume. In this study we introduce a protocell model exhibiting catalytic reaction dynamics, energy metabolism, and cell growth. Results of extensive simulations of this model show the existence of four phases with regard to the rates of both the influx of resources and cell growth. These phases include an active phase with high influx and high growth rates, an inefficient phase with high influx but low growth rates, a quasistatic phase with low influx and low growth rates, and a death phase with negative growth rate. A mean field model well explains the transition among these phases as bifurcations. The statistical distribution of the active phase is characterized by a power law, and that of the inefficient phase is characterized by a nearly equilibrium distribution. We also discuss the relevance of the results of this study to distinct states in the existing cells.

  18. Growth states of catalytic reaction networks exhibiting energy metabolism.

    PubMed

    Kondo, Yohei; Kaneko, Kunihiko

    2011-07-01

    All cells derive nutrition by absorbing some chemical and energy resources from the environment; these resources are used by the cells to reproduce the chemicals within them, which in turn leads to an increase in their volume. In this study we introduce a protocell model exhibiting catalytic reaction dynamics, energy metabolism, and cell growth. Results of extensive simulations of this model show the existence of four phases with regard to the rates of both the influx of resources and cell growth. These phases include an active phase with high influx and high growth rates, an inefficient phase with high influx but low growth rates, a quasistatic phase with low influx and low growth rates, and a death phase with negative growth rate. A mean field model well explains the transition among these phases as bifurcations. The statistical distribution of the active phase is characterized by a power law, and that of the inefficient phase is characterized by a nearly equilibrium distribution. We also discuss the relevance of the results of this study to distinct states in the existing cells. PMID:21867233

  19. Evidence for equilibrium gels of valence-limited particles.

    PubMed

    Dudukovic, Nikola A; Zukoski, Charles F

    2014-10-21

    We explore the formation and structure of gels produced from solutions of the aromatic dipeptide derivative molecule fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) in dimethyl sulfoxide (DMSO). Mixing these solutions with water results in the self-assembly of Fmoc-FF molecules into space-filling fibrous networks, exhibiting mechanical properties characteristic of gels. Using confocal fluorescence microscopy, we observe the gel transition in situ and find that, upon the addition of water, the solution undergoes a rapid transition to a non-equilibrium state forming ∼ 2 μm spheres, followed by the formation of fibers 5-10 nm in diameter, nucleating at a sphere surface and expanding into the solution as the remaining spheres dissolve, extending the network. The gel aging process is associated with the network becoming increasingly uniform through apparent redissolution/reaggregation of the Fmoc-FF molecules, corresponding to the observed increase in the elastic modulus to a plateau value. We demonstrate that this increase in uniformity and elastic modulus can be expedited by controlling the temperature of the system, as well as that these gels are thermally reversible, further indicating that the system is in equilibrium in its fibrous network state. X-ray scattering information suggests that the packing of the molecules within a fiber is based on π-π stacking of β-sheets, consistent with models proposed in the literature for similar systems, implying that each particle (molecule) possesses a limited number of interaction sites. These observations provide experimental evidence that these low molecular weight gelator molecules can be considered valence-limited "patchy" particles, which associate at low enough temperature to form equilibrium gels. PMID:25155031

  20. Putting A Human Face on Equilibrium

    NASA Astrophysics Data System (ADS)

    Glickstein, Neil

    2005-03-01

    A short biography of chemist Fritz Haber is used to personalize the abstract concepts of equilibrium chemistry for high school students in an introductory course. In addition to giving the Haber Bosch process an historic, an economic, and a scientific background the reading and subsequent discussion allows students for whom the human perspective is of paramount importance a chance to investigate the irony of balance or equilibrium in Haber's life story. Since the inclusion of the Haber biography, performance in the laboratory and on examinations for those students who are usually only partially engaged has dramatically improved.

  1. Isodynamic axisymmetric equilibrium near the magnetic axis

    SciTech Connect

    Arsenin, V. V.

    2013-08-15

    Plasma equilibrium near the magnetic axis of an axisymmetric toroidal magnetic confinement system is described in orthogonal flux coordinates. For the case of a constant current density in the vicinity of the axis and magnetic surfaces with nearly circular cross sections, expressions for the poloidal and toroidal magnetic field components are obtained in these coordinates by using expansion in the reciprocal of the aspect ratio. These expressions allow one to easily derive relationships between quantities in an isodynamic equilibrium, in which the absolute value of the magnetic field is constant along the magnetic surface (Palumbo’s configuration)

  2. Equilibrium stellar systems with genetic algorithms

    NASA Astrophysics Data System (ADS)

    Gularte, E.; Carpintero, D. D.

    In 1979, M Schwarzschild showed that it is possible to build an equilibrium triaxial stellar system. However, the linear programmation used to that goal was not able to determine the uniqueness of the solution, nor even if that solution was the optimum one. Genetic algorithms are ideal tools to find a solution to this problem. In this work, we use a genetic algorithm to reproduce an equilibrium spherical stellar system from a suitable set of predefined orbits, obtaining the best solution attainable with the provided set. FULL TEXT IN SPANISH

  3. Algorithm For Hypersonic Flow In Chemical Equilibrium

    NASA Technical Reports Server (NTRS)

    Palmer, Grant

    1989-01-01

    Implicit, finite-difference, shock-capturing algorithm calculates inviscid, hypersonic flows in chemical equilibrium. Implicit formulation chosen because overcomes limitation on mathematical stability encountered in explicit formulations. For dynamical portion of problem, Euler equations written in conservation-law form in Cartesian coordinate system for two-dimensional or axisymmetric flow. For chemical portion of problem, equilibrium state of gas at each point in computational grid determined by minimizing local Gibbs free energy, subject to local conservation of molecules, atoms, ions, and total enthalpy. Major advantage: resulting algorithm naturally stable and captures strong shocks without help of artificial-dissipation terms to damp out spurious numerical oscillations.

  4. Computing Properties Of Chemical Mixtures At Equilibrium

    NASA Technical Reports Server (NTRS)

    Mcbride, B. J.; Gordon, S.

    1995-01-01

    Scientists and engineers need data on chemical equilibrium compositions to calculate theoretical thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93 is general program that calculates chemical equilibrium compositions and properties of mixtures for any chemical system for which thermodynamic data are available. Includes thermodynamic data for more than 1,300 gaseous and condensed species and thermal-transport data for 151 gases. Written in FORTRAN 77.

  5. Far-from-equilibrium kinetic processes

    NASA Astrophysics Data System (ADS)

    Rubí, J. Miguel; Pérez-Madrid, Agustin

    2015-12-01

    We analyze the kinetics of activated processes that take place under far-from-equilibrium conditions, when the system is subjected to external driving forces or gradients or at high values of affinities. We use mesoscopic non-equilibrium thermodynamics to show that when a force is applied, the reaction rate depends on the force. In the case of a chemical reaction at high affinity values, the reaction rate is no longer constant but depends on affinity, which implies that the law of mass action is no longer valid. This result is in good agreement with the kinetic theory of reacting gases, which uses a Chapman-Enskog expansion of the probability distribution.

  6. Dynamically defined measures and equilibrium states

    NASA Astrophysics Data System (ADS)

    Werner, Ivan

    2011-12-01

    A technique of dynamically defined measures is developed and its relation to the theory of equilibrium states is shown. The technique uses Carathéodory's method and the outer measure introduced in a previous work by I. Werner [Math. Proc. Camb. Phil. Soc. 140(2), 333-347 (2006), 10.1017/S0305004105009072]. As an application, equilibrium states for contractive Markov systems [I. Werner, J. London Math. Soc. 71(1), 236-258 (2005), 10.1112/S0024610704006088] are obtained.

  7. Isodynamic axisymmetric equilibrium near the magnetic axis

    NASA Astrophysics Data System (ADS)

    Arsenin, V. V.

    2013-08-01

    Plasma equilibrium near the magnetic axis of an axisymmetric toroidal magnetic confinement system is described in orthogonal flux coordinates. For the case of a constant current density in the vicinity of the axis and magnetic surfaces with nearly circular cross sections, expressions for the poloidal and toroidal magnetic field components are obtained in these coordinates by using expansion in the reciprocal of the aspect ratio. These expressions allow one to easily derive relationships between quantities in an isodynamic equilibrium, in which the absolute value of the magnetic field is constant along the magnetic surface (Palumbo's configuration).

  8. Pions in and out of equilibrium

    SciTech Connect

    Gavin, S.

    1991-12-01

    Can final state scattering wrestle the secondaries in nucleus-nucleus collisions into a fluid state near local thermal equilibrium What do the pion p{sub T} spectra measured in pp, pA and SPS light ion experiments already tell us about the approach to equilibrium To begin to address these questions, we must face the nonequilibrium nature of hadronic evolution in the late stages of these collisions. I will outline efforts to apply transport theory to the nonequilibrium pion fluid at midrapidity focusing on two phenomena: partial thermalization and pion conservation.

  9. Pions in and out of equilibrium

    SciTech Connect

    Gavin, S.

    1991-12-01

    Can final state scattering wrestle the secondaries in nucleus-nucleus collisions into a fluid state near local thermal equilibrium? What do the pion p{sub T} spectra measured in pp, pA and SPS light ion experiments already tell us about the approach to equilibrium? To begin to address these questions, we must face the nonequilibrium nature of hadronic evolution in the late stages of these collisions. I will outline efforts to apply transport theory to the nonequilibrium pion fluid at midrapidity focusing on two phenomena: partial thermalization and pion conservation.

  10. Multimodal audio guide for museums and exhibitions

    NASA Astrophysics Data System (ADS)

    Gebbensleben, Sandra; Dittmann, Jana; Vielhauer, Claus

    2006-02-01

    In our paper we introduce a new Audio Guide concept for exploring buildings, realms and exhibitions. Actual proposed solutions work in most cases with pre-defined devices, which users have to buy or borrow. These systems often go along with complex technical installations and require a great degree of user training for device handling. Furthermore, the activation of audio commentary related to the exhibition objects is typically based on additional components like infrared, radio frequency or GPS technology. Beside the necessity of installation of specific devices for user location, these approaches often only support automatic activation with no or limited user interaction. Therefore, elaboration of alternative concepts appears worthwhile. Motivated by these aspects, we introduce a new concept based on usage of the visitor's own mobile smart phone. The advantages in our approach are twofold: firstly the Audio Guide can be used in various places without any purchase and extensive installation of additional components in or around the exhibition object. Secondly, the visitors can experience the exhibition on individual tours only by uploading the Audio Guide at a single point of entry, the Audio Guide Service Counter, and keeping it on her or his personal device. Furthermore, since the user usually is quite familiar with the interface of her or his phone and can thus interact with the application device easily. Our technical concept makes use of two general ideas for location detection and activation. Firstly, we suggest an enhanced interactive number based activation by exploiting the visual capabilities of modern smart phones and secondly we outline an active digital audio watermarking approach, where information about objects are transmitted via an analog audio channel.

  11. Naval Meteorology and Oceanography Command exhibit entrance

    NASA Technical Reports Server (NTRS)

    2000-01-01

    StenniSphere at NASA's John C. Stennis Space Center in Hancock County, Miss., invites visitors to discover why America comes to Stennis Space Center before going into space. Designed to entertain while educating, StenniSphere includes informative displays and exhibits from NASA and other agencies located at Stennis, such as this one from the Naval Meteorology and Oceanography Command. Visitors can 'travel' three-dimensionally under the sea and check on the weather back home in the Weather Center.

  12. Naval Meteorology and Oceanography Command exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Designed to entertain while educating, StenniSphere at the John C. Stennis Space Center in Hancock County, Miss., includes informative displays and exhibits from NASA and other agencies located at Stennis, such as this one from the Naval Meteorology and Oceanography Command. Visitors can 'travel' three-dimensionally under the sea and check on the weather back home in the Weather Center. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

  13. The E = mc{sup 2} exhibition

    SciTech Connect

    Henderson, D.; Peshkin, M.

    1995-08-01

    The goal of this DOE-supported exhibition is to demystify Einstein`s formula E = mc{sup 2} by illustrating the interchangeability of matter (m) and energy (E), c{sup 2} being the exchange rate. The exhibition has two major parts, {open_quotes}matter into energy{close_quotes} and {open_quotes}energy into matter{close_quotes}, plus a video to connect them. {open_quotes}Matter into energy{close_quotes} has now been completed and has been placed on the museum floor. Positrons from a {sup 22}Na source are annihilated to produce gamma rays that are caught in NaI detectors. The viewer can alter the alignment of the detectors and observe the consequences for the rates of single and coincident counts. The viewer can also observe the effects of placing absorbers in front of the counters. Prototype explanatory graphics were placed around the exhibit and those will probably be changed after we have some experience with their effectiveness. The connecting video is in the process of being produced in collaboration with Fermilab. A cloud chamber for {open_quotes}energy into matter{close_quotes}, where gamma rays from a small Th source will produce observable pairs, was purchased and work to make the pairs visible has commenced.

  14. Art exhibit focuses on African astronomy

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-07-01

    Connections between Africans and astronomy are the focus of a new exhibition in the National Museum of African Art in Washington, D. C. "African Cosmos: Stellar Arts," which includes artwork, cultural items, and scientific displays from ancient to contemporary times, is the first major exhibit "that brings together arts and science focused on Africa's contribution to keen observations of the heavens over time," curator Christine Mullen Kreamer said at a 20 June news briefing. Among the exhibit's nearly 100 objects are an ancient Egyptian mummy board that includes a representation of the sky goddess Nut, sculptures by the Dogon people of Mali depicting figures in relation to the cosmos, a video that uses data from two square degrees of the Hubble Space Telescope Cosmic Evolution Survey, and a nearly floor-to-ceiling "Rainbow Serpent" constructed of plastic containers by Benin artist Hazoume. An untitled acrylic painting (Figure 1) by South African Gavin Jantjes evokes a myth of the Khoi San people of southern Africa, as it portrays a girl throwing evening fire embers into the night sky, where they remained as the Milky Way.

  15. Bumblebees exhibit the memory spacing effect

    NASA Astrophysics Data System (ADS)

    Toda, Nicholas R. T.; Song, Jeremy; Nieh, James C.

    2009-10-01

    Associative learning is key to how bees recognize and return to rewarding floral resources. It thus plays a major role in pollinator floral constancy and plant gene flow. Honeybees are the primary model for pollinator associative learning, but bumblebees play an important ecological role in a wider range of habitats, and their associative learning abilities are less well understood. We assayed learning with the proboscis extension reflex (PER), using a novel method for restraining bees (capsules) designed to improve bumblebee learning. We present the first results demonstrating that bumblebees exhibit the memory spacing effect. They improve their associative learning of odor and nectar reward by exhibiting increased memory acquisition, a component of long-term memory formation, when the time interval between rewarding trials is increased. Bombus impatiens forager memory acquisition (average discrimination index values) improved by 129% and 65% at inter-trial intervals (ITI) of 5 and 3 min, respectively, as compared to an ITI of 1 min. Memory acquisition rate also increased with increasing ITI. Encapsulation significantly increases olfactory memory acquisition. Ten times more foragers exhibited at least one PER response during training in capsules as compared to traditional PER harnesses. Thus, a novel conditioning assay, encapsulation, enabled us to improve bumblebee-learning acquisition and demonstrate that spaced learning results in better memory consolidation. Such spaced learning likely plays a role in forming long-term memories of rewarding floral resources.

  16. Phase diagram of KHF2 and non-equilibrium effects

    NASA Technical Reports Server (NTRS)

    Hobson, M. C.; Kellner, J. D.

    1978-01-01

    The equilibrium diagram for the KHF2-H2O system was constructed from cooling and heating curves for the compositions between 5 wt% and 40 wt% KHF2 and the results are shown. The phase diagrams shown is typical of that of a two component system with miscible liquid phases and whole solid phases consist of pure components. A eutectic point was found at approximately 15% KHF2 which remains completely liquid down to a temperature of -9.0 C. No hydrate formation was observed and no anomalous behavior such as the occurrence of solid transitions or metastable states was observed. The effect of rapid freezing on the equilibrium diagram did not appear, and cooling curves exhibited only one halt. Also, at rapid freezing rates, the supercooling of the solutions was smaller than those observed at the slow cooling rates. The existence of a eutectic composition and the slow rate of dissolution of the salt are used to interpret heat absorption behavior in practical applications of the KHF2-H2O system.

  17. The interplay of nonlinearity and architecture in equilibrium cytoskeletal mechanics.

    PubMed

    Wang, Shenshen; Shen, Tongye; Wolynes, Peter G

    2011-01-01

    The interplay between cytoskeletal architecture and the nonlinearity of the interactions due to bucklable filaments plays a key role in modulating the cell's mechanical stability and affecting its structural rearrangements. We study a model of cytoskeletal structure treating it as an amorphous network of hard centers rigidly cross-linked by nonlinear elastic strings, neglecting the effects of motorization. Using simulations along with a self-consistent phonon method, we show that this minimal model exhibits diverse thermodynamically stable mechanical phases that depend on excluded volume, cross-link concentration, filament length, and stiffness. Within the framework set by the free energy functional formulation and making use of the random first order transition theory of structural glasses, we further estimate the characteristic densities for a kinetic glass transition to occur in this model system. Network connectivity strongly modulates the transition boundaries between various equilibrium phases, as well as the kinetic glass transition density. PMID:21219010

  18. Dynamic equilibrium explanation for nanobubbles unusual temperature and saturation dependence

    NASA Astrophysics Data System (ADS)

    Leal, L. Gary

    2013-11-01

    Recent experimental evidence demonstrates that nanobubbles exhibit unusual behavior in response to changes in temperature and gas saturation in the liquid, an observation that may shed light on the mysterious origin of their stability. In this talk, we discuss an alternate formulation of the dynamic equilibrium mechanism for nanobubbles that predicts rich behavior in agreement with these measurements. Namely, we show that stable nanobubbles exist in narrow temperature and dissolved gas concentration ranges, that there is a maximum and minimum possible bubble size, and that nanobubble radii decrease with temperature. We also discuss these predictions in the context of other current hypotheses for nanobubble stability such as the recently-proposed diffusive ``traffic jam'' model.

  19. Local Quasi-equilibrium Description of Multiscale Systems

    NASA Astrophysics Data System (ADS)

    Santamaría-Holek, Iván; Pérez-Madrid, Augustin; Miguel Rubí, J.

    2016-04-01

    Systems whose dynamics result from the existence of a wide variety of time and length scales frequently exhibit slow relaxation behavior, manifested through the aging compartment of the correlations and the nonexponential decay of the response function. Experiments performed in systems such as amorphous polymers and supercooled liquids and glasses seem to indicate that these systems undergo, in general, non-Markovian and nonstationary dynamics. Hence, in this contribution, we present a dynamical description of slow relaxation systems based on a generalization of Onsager's theory to nonequilibrium aging states. By assuming the existence of a local quasi-equilibrium state characterized by a nonstationary probability distribution the entropy of the system is expressed in terms of the conditional probability density by means of the Gibbs entropy postulate. Thus, by taking into account probability conservation and the rules of nonequilibrium thermodynamics, the generalized Fokker-Planck equation is derived.

  20. Tactic, reactive, and functional droplets outside of equilibrium.

    PubMed

    Lach, Sławomir; Yoon, Seok Min; Grzybowski, Bartosz A

    2016-08-22

    Under non-equilibrium conditions, liquid droplets coupled to their environment by sustained flows of matter and/or energy can become "active" systems capable of various life-like functions. When "fueled" by even simple chemical reactions, such droplets can become tactic and can perform "intelligent" tasks such as maze solving. With more complex chemistries, droplets can support basic forms of metabolism, grow, self-replicate, and exhibit evolutionary changes akin to biological cells. There are also first exciting examples of active droplets connected into larger, tissue-like systems supporting droplet-to-droplet communication, and giving rise to collective material properties. As practical applications of droplets also begin to appear (e.g., in single-cell diagnostics, new methods of electricity generation, optofluidics, or sensors), it appears timely to review and systematize progress in this highly interdisciplinary area of chemical research, and also think about the avenues (and the roadblocks) for future work. PMID:27293207

  1. Non-equilibrium diffusion combustion of a fuel droplet

    NASA Astrophysics Data System (ADS)

    Tyurenkova, Veronika V.

    2012-06-01

    A mathematical model for the non-equilibrium combustion of droplets in rocket engines is developed. This model allows to determine the divergence of combustion rate for the equilibrium and non-equilibrium model. Criterion for droplet combustion deviation from equilibrium is introduced. It grows decreasing droplet radius, accommodation coefficient, temperature and decreases on decreasing diffusion coefficient. Also divergence from equilibrium increases on reduction of droplet radius. Droplet burning time essentially increases under non-equilibrium conditions. Comparison of theoretical and experimental data shows that to have adequate solution for small droplets it is necessary to use the non-equilibrium model.

  2. Punctuated equilibrium in an evolving bacterial population

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Indranath; Bose, Indrani

    1999-08-01

    Recently, Lenski et al. have carried out an experiment on bacterial evolution. Their findings support the theory of punctuated equilibrium in biological evolution. We show that the M=2 Bak-Sneppen model can explain some of the experimental results in a qualitative manner.

  3. Payload specialists Patrick Baudry conducts equilibrium experiments

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Payload specialists Patrick Baudry participates in an experiment involving equilibrium and vertigo. He is anchored to the orbiter floor by foot restraints and is wearing a device over his eyes to measure angular head movement and up and down eye movement.

  4. Equilibrium thermodynamics in modified gravitational theories

    NASA Astrophysics Data System (ADS)

    Bamba, Kazuharu; Geng, Chao-Qiang; Tsujikawa, Shinji

    2010-04-01

    We show that it is possible to obtain a picture of equilibrium thermodynamics on the apparent horizon in the expanding cosmological background for a wide class of modified gravity theories with the Lagrangian density f(R,ϕ,X), where R is the Ricci scalar and X is the kinetic energy of a scalar field ϕ. This comes from a suitable definition of an energy-momentum tensor of the “dark” component that respects to a local energy conservation in the Jordan frame. In this framework the horizon entropy S corresponding to equilibrium thermodynamics is equal to a quarter of the horizon area A in units of gravitational constant G, as in Einstein gravity. For a flat cosmological background with a decreasing Hubble parameter, S globally increases with time, as it happens for viable f(R) inflation and dark energy models. We also show that the equilibrium description in terms of the horizon entropy S is convenient because it takes into account the contribution of both the horizon entropy S' in non-equilibrium thermodynamics and an entropy production term.

  5. Calculating Shocks In Flows At Chemical Equilibrium

    NASA Technical Reports Server (NTRS)

    Eberhardt, Scott; Palmer, Grant

    1988-01-01

    Boundary conditions prove critical. Conference paper describes algorithm for calculation of shocks in hypersonic flows of gases at chemical equilibrium. Although algorithm represents intermediate stage in development of reliable, accurate computer code for two-dimensional flow, research leading up to it contributes to understanding of what is needed to complete task.

  6. Teaching Chemical Equilibrium with the Jigsaw Technique

    ERIC Educational Resources Information Center

    Doymus, Kemal

    2008-01-01

    This study investigates the effect of cooperative learning (jigsaw) versus individual learning methods on students' understanding of chemical equilibrium in a first-year general chemistry course. This study was carried out in two different classes in the department of primary science education during the 2005-2006 academic year. One of the classes…

  7. A Progression of Static Equilibrium Laboratory Exercises

    ERIC Educational Resources Information Center

    Kutzner, Mickey; Kutzner, Andrew

    2013-01-01

    Although simple architectural structures like bridges, catwalks, cantilevers, and Stonehenge have been integral in human societies for millennia, as have levers and other simple tools, modern students of introductory physics continue to grapple with Newton's conditions for static equilibrium. As formulated in typical introductory physics…

  8. Equilibrium rotation in field-reversed configurations

    SciTech Connect

    Steinhauer, Loren

    2008-01-15

    The turbulence that drives anomalous transport in field-reversed configurations (FRCs) is believed to break the otherwise closed magnetic surfaces inside the separatrix. This places electrons in the core of the plasma in electrical contact with those in the periphery. This effect was proposed and investigated in the context of spheromaks [D. D. Ryutov, Phys. Plasmas 14, 022506 (2007)]. The opening up of internal magnetic field lines serves to regulate the electrostatic potential in the interior of the plasma, and in turn drives ion rotation. In effect, 'end-shorting', a well-known phenomenon in the FRC scrape-off layer, also extends into the plasma interior. For conditions relevant to experiments, the ion rotation can be expressed in terms of equilibrium properties (density and temperature gradients) and as such is the 'equilibrium' rotation. This theory is incomplete in that it neglects evolving, transport-related effects that modify the equilibrium and, indirectly, the rotation rate. Consequently, the equilibrium rotation theory is only partially successful in predicting experimental results: although it predicts the average rotation well, the estimated degree of rotational shear seems unlikely, especially at late times in the plasma lifetime.

  9. Equilibrium free energies from nonequilibrium processes

    SciTech Connect

    Jarzynski, C.

    1997-10-29

    A recent result, relating the (irreversible) work performed on a system during a non quasistatic process, to the Helmholtz free energy difference between two equilibrium states of the system, is discussed. A proof of this result is given for the special case when the evolution of the system in question is modeled by a Langevin equation in configuration space.

  10. Conditions for the Existence of Market Equilibrium.

    ERIC Educational Resources Information Center

    Bryant, William D. A.

    1997-01-01

    Maintains that most graduate-level economics textbooks rarely mention the need for consumers to be above their minimum wealth position as a condition for market equilibrium. Argues that this omission leaves students with a mistaken sense about the range of circumstances under which market equilibria can exist. (MJP)

  11. General Equilibrium Models: Improving the Microeconomics Classroom

    ERIC Educational Resources Information Center

    Nicholson, Walter; Westhoff, Frank

    2009-01-01

    General equilibrium models now play important roles in many fields of economics including tax policy, environmental regulation, international trade, and economic development. The intermediate microeconomics classroom has not kept pace with these trends, however. Microeconomics textbooks primarily focus on the insights that can be drawn from the…

  12. The 'Schwarzschild-Kerr' Equilibrium Configurations

    SciTech Connect

    Manko, V. S.; Ruiz, E.

    2010-12-07

    We discuss the possibility of equilibrium between a Schwarzschild black hole possessing zero intrinsic angular momentum and a hyperextreme Kerr source. The balance occurs due to frame-dragging exerted by the latter source on the black-hole constituent, thus giving rise to a non-zero horizon's angular velocity parallel to the angular momentum of the Kerr object.

  13. Generalized convective quasi-equilibrium principle

    NASA Astrophysics Data System (ADS)

    Yano, Jun-Ichi; Plant, Robert S.

    2016-03-01

    A generalization of Arakawa and Schubert's convective quasi-equilibrium principle is presented for a closure formulation of mass-flux convection parameterization. The original principle is based on the budget of the cloud work function. This principle is generalized by considering the budget for a vertical integral of an arbitrary convection-related quantity. The closure formulation includes Arakawa and Schubert's quasi-equilibrium, as well as both CAPE and moisture closures as special cases. The formulation also includes new possibilities for considering vertical integrals that are dependent on convective-scale variables, such as the moisture within convection. The generalized convective quasi-equilibrium is defined by a balance between large-scale forcing and convective response for a given vertically-integrated quantity. The latter takes the form of a convolution of a kernel matrix and a mass-flux spectrum, as in the original convective quasi-equilibrium. The kernel reduces to a scalar when either a bulk formulation is adopted, or only large-scale variables are considered within the vertical integral. Various physical implications of the generalized closure are discussed. These include the possibility that precipitation might be considered as a potentially-significant contribution to the large-scale forcing. Two dicta are proposed as guiding physical principles for the specifying a suitable vertically-integrated quantity.

  14. Spontaneity and Equilibrium II: Multireaction Systems

    ERIC Educational Resources Information Center

    Raff, Lionel M.

    2014-01-01

    The thermodynamic criteria for spontaneity and equilibrium in multireaction systems are developed and discussed. When N reactions are occurring simultaneously, it is shown that G and A will depend upon N independent reaction coordinates, ?a (a = 1,2, ..., N), in addition to T and p for G or T and V for A. The general criteria for spontaneity and…

  15. Assessing Students' Conceptual Understanding of Solubility Equilibrium.

    ERIC Educational Resources Information Center

    Raviolo, Andres

    2001-01-01

    Presents a problem on solubility equilibrium which involves macroscopic, microscopic, and symbolic levels of representation as a resource for the evaluation of students, and allows for assessment as to whether students have acquired an adequate conceptual understanding of the phenomenon. Also diagnoses difficulties with regard to previous…

  16. Competitive Equilibrium and Classroom Pit Markets.

    ERIC Educational Resources Information Center

    Ruffle, Bradley J.

    2003-01-01

    Describes a pit-market experiment using the work of Charles A. Holt to illustrate to students the real world relevance of the competitive equilibrium concept. Explains how to set up and conduct a pit-market experiment, discusses features of the data, and provides accompanying materials. (JEH)

  17. Chemical Equilibrium Composition of Aqueous Systems

    Energy Science and Technology Software Center (ESTSC)

    1996-12-30

    MINEQL is a subroutine package to calculate equilibrium composition of an aqueous system, accounting for mass transfer. MINEQL-EIR contains an additional base on enthalpy and heat capacity data and has the option to do calculations at temperatures different from 25 degrees C.

  18. Effective equilibrium theory of nonequilibrium quantum transport

    NASA Astrophysics Data System (ADS)

    Dutt, Prasenjit; Koch, Jens; Han, Jong; Le Hur, Karyn

    2011-12-01

    The theoretical description of strongly correlated quantum systems out of equilibrium presents several challenges and a number of open questions persist. Here, we focus on nonlinear electronic transport through an interacting quantum dot maintained at finite bias using a concept introduced by Hershfield [S. Hershfield, Phys. Rev. Lett. 70 2134 (1993)] whereby one can express such nonequilibrium quantum impurity models in terms of the system's Lippmann-Schwinger operators. These scattering operators allow one to reformulate the nonequilibrium problem as an effective equilibrium problem associated with a modified Hamiltonian. In this paper, we provide a pedagogical analysis of the core concepts of the effective equilibrium theory. First, we demonstrate the equivalence between observables computed using the Schwinger-Keldysh framework and the effective equilibrium approach, and relate Green's functions in the two theoretical frameworks. Second, we expound some applications of this method in the context of interacting quantum impurity models. We introduce a novel framework to treat effects of interactions perturbatively while capturing the entire dependence on the bias voltage. For the sake of concreteness, we employ the Anderson model as a prototype for this scheme. Working at the particle-hole symmetric point, we investigate the fate of the Abrikosov-Suhl resonance as a function of bias voltage and magnetic field.

  19. Equilibrium Molecular Thermodynamics from Kirkwood Sampling

    PubMed Central

    2015-01-01

    We present two methods for barrierless equilibrium sampling of molecular systems based on the recently proposed Kirkwood method (J. Chem. Phys.2009, 130, 134102). Kirkwood sampling employs low-order correlations among internal coordinates of a molecule for random (or non-Markovian) sampling of the high dimensional conformational space. This is a geometrical sampling method independent of the potential energy surface. The first method is a variant of biased Monte Carlo, where Kirkwood sampling is used for generating trial Monte Carlo moves. Using this method, equilibrium distributions corresponding to different temperatures and potential energy functions can be generated from a given set of low-order correlations. Since Kirkwood samples are generated independently, this method is ideally suited for massively parallel distributed computing. The second approach is a variant of reservoir replica exchange, where Kirkwood sampling is used to construct a reservoir of conformations, which exchanges conformations with the replicas performing equilibrium sampling corresponding to different thermodynamic states. Coupling with the Kirkwood reservoir enhances sampling by facilitating global jumps in the conformational space. The efficiency of both methods depends on the overlap of the Kirkwood distribution with the target equilibrium distribution. We present proof-of-concept results for a model nine-atom linear molecule and alanine dipeptide. PMID:25915525

  20. Exploring Chemical Equilibrium in Hot Jovians

    NASA Astrophysics Data System (ADS)

    Blumenthal, Sarah; Harrington, Joseph; Mandell, Avi; Hébrard, Eric; Venot, Olivia; Cubillos, Patricio; Blecic, Jasmina; Challener, Ryan

    2016-01-01

    It has been established that equilibrium chemistry is usually achieved deep in the atmosphere of hot Jovians where timescales are short (Line and Yung 2013). Thus, equilibrium chemistry has been used as a starting point (setting initial conditions) for evaluating disequilibrium processes. We explore parameters of setting these initial conditions including departures from solar metallicity, the number of species allowed in a system, the types of species allowed in a system, and different thermodynamic libraries in an attempt to create a standard for evaluating equilibrium chemistry. NASA's open source code Chemical Equilibrium and Applications (CEA) is used to calculate model planet abundances by varying the metallicity, in the pressure regime 0.1 to 1 bar. These results are compared to a variety of exoplanets(Teq between 600 and 2100K) qualitatively by color maps of the dayside with different temperature redistributions. Additionally, CEA (with an up-dated thermodynamic library) is compared with the thermochemical model presented in Venotet al. (2012) for HD 209458b and HD 189733b. This same analysis is then applied to the cooler planet HD 97658b. Spectra are generated and we compare both models' outputs using the open source codetransit (https://github.com/exosports/transit) using the opacities of 15 molecules. We make the updated CEA thermodyanamic library and supporting Python scripts to do the CEA analyses available open source. Thiswork was supported by NASA Planetary Atmospheres grant NNX12AI69G.

  1. Exploring Equilibrium Chemistry for Hot Exoplanets

    NASA Astrophysics Data System (ADS)

    Blumenthal, Sarah; Harrington, Joseph; Mandell, Avi; Hébrard, Eric; Venot, Olivia; Cubillos, Patricio; Challener, Ryan

    2015-11-01

    It has been established that equilibrium chemistry is usually achieved deep in the atmosphere of hot Jovians where timescales are short (Line and Young 2013). Thus, equilibrium chemistry has been used as a starting point (setting initial conditions) for evaluating disequilibrium processes. We explore parameters of setting these initial conditions including departures from solar metallicity, the number of species allowed in a system, the types of species allowed in a system, and different thermodynamic libraries in an attempt to create a standard for evaluating equilibrium chemistry. NASA's open source code Chemical Equilibrium and Applications (CEA) is used to calculate model planet abundances by varying the metallicity, in the pressure regime of 0.1 to 1 bar. These results are compared to a variety of exoplanets (Teq between 600 and 2100K) qualitatively by color maps of the dayside with different temperature redistributions. Additionally, CEA (with an updated thermodynamic library) is validated with the thermochemical model presented in Venot et al. (2012) for HD 209458b and HD 189733b. This same analysis has then been extended to the cooler planet HD 97658b. Spectra are generated from both models’ abundances using the open source code transit (https://github.com/exosports/transit) using the opacities of 15 molecules. We make the updated CEA thermodyanamic library and supporting Python scripts to do the CEA analyses available open source. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G.

  2. Equilibrium and off-equilibrium trap-size scaling in one-dimensional ultracold bosonic gases

    SciTech Connect

    Campostrini, Massimo; Vicari, Ettore

    2010-12-15

    We study some aspects of equilibrium and off-equilibrium quantum dynamics of dilute bosonic gases in the presence of a trapping potential. We consider systems with a fixed number of particles and study their scaling behavior with increasing the trap size. We focus on one-dimensional bosonic systems, such as gases described by the Lieb-Liniger model and its Tonks-Girardeau limit of impenetrable bosons, and gases constrained in optical lattices as described by the Bose-Hubbard model. We study their quantum (zero-temperature) behavior at equilibrium and off equilibrium during the unitary time evolution arising from changes of the trapping potential, which may be instantaneous or described by a power-law time dependence, starting from the equilibrium ground state for an initial trap size. Renormalization-group scaling arguments and analytical and numerical calculations show that the trap-size dependence of the equilibrium and off-equilibrium dynamics can be cast in the form of a trap-size scaling in the low-density regime, characterized by universal power laws of the trap size, in dilute gases with repulsive contact interactions and lattice systems described by the Bose-Hubbard model. The scaling functions corresponding to several physically interesting observables are computed. Our results are of experimental relevance for systems of cold atomic gases trapped by tunable confining potentials.

  3. Non-equilibrium statistical mechanics of geophysical flows

    NASA Astrophysics Data System (ADS)

    Bouchet, F.; Simonnet, E.

    2010-12-01

    We describe the dynamics of two-dimensional and quasi-geostrophic flows with stochastic forces. It exhibits extremely long correlations times, related to multi-scale dynamics, and collective behaviors such as bistability and multistability. We show that in regimes of weak forces and dissipation, dominated by the large scales inertial dynamics, equilibrium statistical mechanics provides extremely precise predictions for the self-organized large scale flows. This is true for amuch larger range of parameters than would have been expected, explaining a renewed interest for statistical mechanics approaches. Non-equilibrium theory, based on kinetic theories (or equivalently Mori-Zwanzig projections) gives explicit predictions for algebraic correlations of the velocity field, and for the large scale mean flow. We also describe briefly recent applications to ocean jets and vortices, explaining the detailed structure of inertial mid-basin jets and both the structure, and westward and poleward drifts of oceans rings and eddies. References: F. BOUCHET and E. SIMONNET, Random Changes of Flow Topology in Two-Dimensional and Geophysical Turbulence, Physical Review Letters 102 (2009), no. 9, 094504-+. F. BOUCHET and J. SOMMERIA, Emergence of intense jets and Jupiter's Great Red Spot as maximum-entropy structures, Journal of Fluid Mechanics 464 (2002), 165-207. A. VENAILLE and F. BOUCHET, Ocean rings and jets as statistical equilibrium states, submitted to JPO F. BOUCHET and A. VENAILLE, Statistical mechanics of two-dimensional and geophysical flows, submitted to Physics Reports Non-equilibrium phase transitions in the dynamics of the 2D Navier-Stokes equations with stochastic forces in a doubly periodic domain of aspect ratio d. The two main plots are the time series and probability density functions (PDFs) of the modulus of the largest scale Fourrier component, illustrating random changes between dipoles (|z1| close to 0.55) and unidirectional flows (|z1| close to 0.). The small

  4. Collective Flocking Dynamics: Long Rang Order in a Non-Equilibrium 2D XY Model

    NASA Astrophysics Data System (ADS)

    Tu, Yuhai

    1996-03-01

    We propose and study a non-equilibrium continuum dynamical model for the collective motion of large groups of biological organisms (e.g., flocks of birds, slime molds, schools of fishs, etc.) (J. Toner and Y. Tu, Phys. Rev. Lett.), 75(23), 4326(1995) Our model becomes highly non-trivial, and different from the equilibrium model, for dequilibrium systems, our model exhibits a broken continuous symmetry even in d=2. Our model describes a large universality class of microscopic rules, including those recently simulated by Vicsek et. al.( T. Vicsek et. al. , Phys. Rev. Lett.) 75, 1226(95).

  5. Equilibrium gas flow computations. I - Accurate and efficient calculation of equilibrium gas properties

    NASA Technical Reports Server (NTRS)

    Liu, Yen; Vinokur, Marcel

    1989-01-01

    This paper treats the accurate and efficient calculation of thermodynamic properties of arbitrary gas mixtures for equilibrium flow computations. New improvements in the Stupochenko-Jaffe model for the calculation of thermodynamic properties of diatomic molecules are presented. A unified formulation of equilibrium calculations for gas mixtures in terms of irreversible entropy is given. Using a highly accurate thermo-chemical data base, a new, efficient and vectorizable search algorithm is used to construct piecewise interpolation procedures with generate accurate thermodynamic variable and their derivatives required by modern computational algorithms. Results are presented for equilibrium air, and compared with those given by the Srinivasan program.

  6. A metafluid exhibiting strong optical magnetism.

    PubMed

    Sheikholeslami, Sassan N; Alaeian, Hadiseh; Koh, Ai Leen; Dionne, Jennifer A

    2013-09-11

    Advances in the field of metamaterials have enabled unprecedented control of light-matter interactions. Metamaterial constituents support high-frequency electric and magnetic dipoles, which can be used as building blocks for new materials capable of negative refraction, electromagnetic cloaking, strong visible-frequency circular dichroism, and enhancing magnetic or chiral transitions in ions and molecules. While all metamaterials to date have existed in the solid-state, considerable interest has emerged in designing a colloidal metamaterial or "metafluid". Such metafluids would combine the advantages of solution-based processing with facile integration into conventional optical components. Here we demonstrate the colloidal synthesis of an isotropic metafluid that exhibits a strong magnetic response at visible frequencies. Protein-antibody interactions are used to direct the solution-phase self-assembly of discrete metamolecules comprised of silver nanoparticles tightly packed around a single dielectric core. The electric and magnetic response of individual metamolecules and the bulk metamaterial solution are directly probed with optical scattering and spectroscopy. Effective medium calculations indicate that the bulk metamaterial exhibits a negative effective permeability and a negative refractive index at modest fill factors. This metafluid can be synthesized in large-quantity and high-quality and may accelerate development of advanced nanophotonic and metamaterial devices. PMID:23919764

  7. Nematic liquid crystals exhibiting high birefringence

    NASA Astrophysics Data System (ADS)

    Thingujam, Kiranmala; Bhattacharjee, Ayon; Choudhury, Basana; Dabrowski, Roman

    2016-06-01

    Two fluorinated isothiocyanato nematic liquid crystalline compounds, 4'-butylcyclohexyl-3, 5-difluoro-4-isothiocyanatobiphenyl and 4'-pentylcyclohexyl-3, 5-difluoro-4-isothiocynatobiphenyl are studied in detail to obtain their different physical parameters. Optical polarizing microscopy, differential scanning calorimetry, density and dielectric studies have been carried out for the two samples. Both the samples were found to have high clearing temperature (>100 °C) and exhibit small enthalpy of transition. The two samples exhibit high optical birefringence (Δ n > 0.2). The values of order parameters for the two samples were obtained using different approaches, namely, Vuks', Neugebauer's, modified Vuks' and direct extrapolation method from birefringence data. Experimentally obtained values of order parameters have also been compared with theoretical Maier-Saupe values. The parallel and perpendicular components of dielectric permittivity values of the two compounds were also calculated and their anisotropy values were found to be small. The effect of temperature on the molecular dipole moment μ and the angle of inclination β of the dipole axis with the director have also been investigated in this work.

  8. Figures of Equilibrium among Binary Asteroids

    NASA Astrophysics Data System (ADS)

    Hestroffer, D.; Tanga, P.

    2005-12-01

    The original idea of Farinella et al. [1] that rubble pile asteroids can have figures of equilibrium, is rehabilitated. Albeit asteroids generally have a broad distribution of shapes and do not follow sequences of (hydrostatic) equilibrium, we show that some asteroids are indeed Jacobi or Darwin ellipsoids. Such statement is obtained from an analysis of their ellipsoidal shape (a:b:c) together with recent measures of their mass and bulk density [2,3]. This means that both their shape and adimensional rotation frequency sbond Ω =Ω /(π ρ G) follow sequences of equilibrium [4,5]. Jacobi and Darwin figures are obtained for uniformly rotating mass of (inviscid as well as compressible) fluids and relatively large angular momentum. Interestingly these objects appear to preferably be binaries. We moreover show that the porosity of such objects is relatively large (approx. 40%) indicating that they are loose rubble piles, yet with dense packing. Last we show that, given the observed bulk-densities, these bodies must be homogeneous bodies of uniform density distribution. Thus, though solid-solid friction must occur in such aggregates, the surface of these bodies is a surface of level similar to that of inviscid fluids. Comparison to other asteroids of similar mass either possessing a moonlet or with no known satellites should shed light on their formation history and/or constrains on collisional evolution. Binaries with low eccentricities and inclination (hence prograde orbit) should preferably be the outcome of catastrophic disruption as is supposed for members of dynamical family [6,7]. Future work and analysis of the typical reaccumulation time scales, typical angular momentum, possible post-reaccumulation cosmic shaking, etc. shall help to know how the fate of collisions or catastrophic breakup of a parent body can differ yielding to binaries with equilibrium figures. In any case the existence of a figure of equilibrium appears to be highly correlated to the presence

  9. Equilibrium and non-equilibrium dynamics simultaneously operate in the Galápagos islands.

    PubMed

    Valente, Luis M; Phillimore, Albert B; Etienne, Rampal S

    2015-08-01

    Island biotas emerge from the interplay between colonisation, speciation and extinction and are often the scene of spectacular adaptive radiations. A common assumption is that insular diversity is at a dynamic equilibrium, but for remote islands, such as Hawaii or Galápagos, this idea remains untested. Here, we reconstruct the temporal accumulation of terrestrial bird species of the Galápagos using a novel phylogenetic method that estimates rates of biota assembly for an entire community. We show that species richness on the archipelago is in an ascending phase and does not tend towards equilibrium. The majority of the avifauna diversifies at a slow rate, without detectable ecological limits. However, Darwin's finches form an exception: they rapidly reach a carrying capacity and subsequently follow a coalescent-like diversification process. Together, these results suggest that avian diversity of remote islands is rising, and challenge the mutual exclusivity of the non-equilibrium and equilibrium ecological paradigms. PMID:26105791

  10. Shape-Memory PVDF Exhibiting Switchable Piezoelectricity.

    PubMed

    Hoeher, Robin; Raidt, Thomas; Novak, Nikola; Katzenberg, Frank; Tiller, Joerg C

    2015-12-01

    In this study, a material is designed which combines the properties of shape-memory and electroactive polymers. This is achieved by covalent cross-linking of polyvinylidene fluoride. The resulting polymer network exhibits excellent shape-memory properties with a storable strain of 200%, and fixity as well as recovery values of 100%. Programming upon rolling induces the transformation from the nonelectroactive α-phase to the piezoelectric β-phase. The highest β-phase content is found to be 83% for a programming strain of 200% affording a d33 value of -30 pm V(-1). This is in good accordance with literature known values for piezoelectric properties. Thermal triggering this material does not only result in a shape change but also renders the material nonelectroactive. PMID:26332996

  11. Supercomputing meets seismology in earthquake exhibit

    ScienceCinema

    Blackwell, Matt; Rodger, Arthur; Kennedy, Tom

    2014-07-22

    When the California Academy of Sciences created the "Earthquake: Evidence of a Restless Planet" exhibit, they called on Lawrence Livermore to help combine seismic research with the latest data-driven visualization techniques. The outcome is a series of striking visualizations of earthquakes, tsunamis and tectonic plate evolution. Seismic-wave research is a core competency at Livermore. While most often associated with earthquakes, the research has many other applications of national interest, such as nuclear explosion monitoring, explosion forensics, energy exploration, and seismic acoustics. For the Academy effort, Livermore researchers simulated the San Andreas and Hayward fault events at high resolutions. Such calculations require significant computational resources. To simulate the 1906 earthquake, for instance, visualizing 125 seconds of ground motion required over 1 billion grid points, 10,000 time steps, and 7.5 hours of processor time on 2,048 cores of Livermore's Sierra machine.

  12. Nanoporous frameworks exhibiting multiple stimuli responsiveness

    NASA Astrophysics Data System (ADS)

    Kundu, Pintu K.; Olsen, Gregory L.; Kiss, Vladimir; Klajn, Rafal

    2014-04-01

    Nanoporous frameworks are polymeric materials built from rigid molecules, which give rise to their nanoporous structures with applications in gas sorption and storage, catalysis and others. Conceptually new applications could emerge, should these beneficial properties be manipulated by external stimuli in a reversible manner. One approach to render nanoporous frameworks responsive to external signals would be to immobilize molecular switches within their nanopores. Although the majority of molecular switches require conformational freedom to isomerize, and switching in the solid state is prohibited, the nanopores may provide enough room for the switches to efficiently isomerize. Here we describe two families of nanoporous materials incorporating the spiropyran molecular switch. These materials exhibit a variety of interesting properties, including reversible photochromism and acidochromism under solvent-free conditions, light-controlled capture and release of metal ions, as well reversible chromism induced by solvation/desolvation.

  13. New Monolayered Materials Exhibiting Unusual Electronic Properties

    NASA Astrophysics Data System (ADS)

    Lopez-Bezanilla, Alejandro; Martin, Ivar; Littlewood, Peter B.

    Computationally based approaches are allowing to progress in the discovery and design of nano-scaled materials. Here we propose a series of new mono-layered compounds with exotic properties. By means of density functional theory calculations we demonstrate that the pentagonal arrangement of SiC2 yields an inverted distribution of the p-bands which leads to an unusual electronic behaviour of the material under strain [J. Phys. Chem. C, 2015, 119 (33), pp 19469]. A different pentagonal arrangement of C atoms enables the formation of Dirac cones which, unlike graphene, exhibit a strain-mediated tunable band gap. This work is supported by DOE-BES under Contract No. DE-AC02-06CH11357.

  14. Supercomputing meets seismology in earthquake exhibit

    SciTech Connect

    Blackwell, Matt; Rodger, Arthur; Kennedy, Tom

    2013-10-03

    When the California Academy of Sciences created the "Earthquake: Evidence of a Restless Planet" exhibit, they called on Lawrence Livermore to help combine seismic research with the latest data-driven visualization techniques. The outcome is a series of striking visualizations of earthquakes, tsunamis and tectonic plate evolution. Seismic-wave research is a core competency at Livermore. While most often associated with earthquakes, the research has many other applications of national interest, such as nuclear explosion monitoring, explosion forensics, energy exploration, and seismic acoustics. For the Academy effort, Livermore researchers simulated the San Andreas and Hayward fault events at high resolutions. Such calculations require significant computational resources. To simulate the 1906 earthquake, for instance, visualizing 125 seconds of ground motion required over 1 billion grid points, 10,000 time steps, and 7.5 hours of processor time on 2,048 cores of Livermore's Sierra machine.

  15. Application of an imaging system to a museum exhibition for developing interactive exhibitions

    NASA Astrophysics Data System (ADS)

    Miyata, Kimiyoshi; Inoue, Yuka; Takiguchi, Takahiro; Tsumura, Norimichi; Nakaguchi, Toshiya; Miyake, Yoichi

    2009-10-01

    In the National Museum of Japanese History, 215,759 artifacts are stored and used for research and exhibitions. In museums, due to the limitation of space in the galleries, a guidance system is required to satisfy visitors' needs and to enhance their understanding of the artifacts. We introduce one exhibition using imaging technology to improve visitors' understanding of a kimono (traditional Japanese clothing) exhibition. In the imaging technology introduced, one data projector, one display with touch panel interface, and magnifiers were used as exhibition tools together with a real kimono. The validity of this exhibition method was confirmed by results from a visitors' interview survey. Second, to further develop the interactive guidance system, an augmented reality system that consisted of cooperation between the projector and a digital video camera was also examined. A white paper board in the observer's hand was used as a projection screen and also as an interface to control the images projected on the board. The basic performance of the proposed system was confirmed; however continuous development was necessary for applying the system to actual exhibitions.

  16. A Traveling Exhibit of Cassini Image Science

    NASA Astrophysics Data System (ADS)

    Burns, Joseph A.; Hedman, M. M.; Tiscareno, M. S.; Ebel, D.; Mac Low, M.; Lovett, L. E.; Burns, J. K.; Schaff, N.; Bilson, E. M.

    2007-10-01

    An exhibit of Cassini's images will open at NYC's American Museum of Natural History in March 2008 and then visit the Johnson Art Museum (Cornell) throughout fall 2008, including during next year's DPS. It is under consideration by several other venues in the States and overseas. The exhibit will feature 40-50 images, ranging from letter size to large posters, taken by remote-sensing instruments aboard Cassini and Huygens. Photos will be organized into a half-dozen thematic clusters (e.g., organized by celestial target or by physical process); a panel will introduce each grouping with individual images identified briefly. The Saturn system is a perfect vehicle to educate citizens about planetary science and origins. The images’ beauty should capture the public's attention, allowing us to then engage their curiosity about the relevant science. Among the Saturn system's broad suite of objects are Enceladus and Titan, two satellites of astrobiological interest; moreover, the rings display many processes active in other astrophysical disks. Several auxiliary ideas will be implemented. In Ithaca, we will project images at night against the museum's sand-colored exterior walls. A 10-12 minute musical composition has been commissioned from Roberto Sierra to open the show. We will encourage school children to participate in a human orrery circling the museum and will seek volunteers to participate in several Saturnalia. At Cornell we will involve the university and local communities, by taping their reactions to the images’ exquisite beauty as well as to their scientific content. Cassini will be the E/PO focus of next year's DPS meeting; those materials will be employed throughout the fall at New York schools and be available to travel with the show. We intend to work with NYC partners to offer teacher credits for associated weekend courses. We will produce classroom materials, including a DVD, for teacher use.

  17. Extract from Ceratonia siliqua Exhibits Depigmentation Properties.

    PubMed

    Lall, Namrita; Kishore, Navneet; Momtaz, Saeideh; Hussein, Ahmed; Naidoo, Sanushka; Nqephe, Mabatho; Crampton, Bridget

    2015-11-01

    Skin hyper-pigmentation is a condition initiated by the overproduction of melanin existing in the melanocytes. Melanin pigment is responsible for the colour of skin in humans. It is formed through a series of oxidative reactions involving the amino acid tyrosine in the presence of the key enzyme tyrosinase. In continuation with our efforts to identify tyrosinase inhibitors from plants sources, the methanol extract from leaf, bark and fruit of Ceratonia siliqua were screened for tyrosinase inhibition and diphenolase activity. The bark extract exhibited significant inhibition on mushroom tyrosinase using L-tyrosine as a substrate and showed diphenolase activity. The extract further significantly lowered tyrosinase mRNA levels in B16-F10 mouse melanocytes. Bioassay-guided fractionation led to the isolation of six compounds. Compounds (-)-epicatechin-3-O-gallate, 1,2,3,6-tetra-O-galloyl-ß-D-glucose and gallocatechin-3-O-gallate showed tyrosinase inhibitions with the IC50 values of 27.52, 83.30 and 28.30 µg/mL, respectively. These compounds also exhibited L-DOPA activities with IC50 values of >200, 150 and 200 µg/mL, respectively. A clinical study was conducted using 20 volunteers in a patch testing trial for irritancy potential and skin depigmentation. The clinical results showed the sample to be non-irritant with irritancy potential of -34.21 and depigmentation trial showed an improvement in the even skin tone of UV induced pigmentation at 3% after 28 days of application. PMID:26201055

  18. Quiescent Fibroblasts Exhibit High Metabolic Activity

    PubMed Central

    Lemons, Johanna M. S.; Feng, Xiao-Jiang; Bennett, Bryson D.; Legesse-Miller, Aster; Johnson, Elizabeth L.; Raitman, Irene; Pollina, Elizabeth A.; Rabitz, Herschel A.; Rabinowitz, Joshua D.; Coller, Hilary A.

    2010-01-01

    Many cells in mammals exist in the state of quiescence, which is characterized by reversible exit from the cell cycle. Quiescent cells are widely reported to exhibit reduced size, nucleotide synthesis, and metabolic activity. Much lower glycolytic rates have been reported in quiescent compared with proliferating lymphocytes. In contrast, we show here that primary human fibroblasts continue to exhibit high metabolic rates when induced into quiescence via contact inhibition. By monitoring isotope labeling through metabolic pathways and quantitatively identifying fluxes from the data, we show that contact-inhibited fibroblasts utilize glucose in all branches of central carbon metabolism at rates similar to those of proliferating cells, with greater overflow flux from the pentose phosphate pathway back to glycolysis. Inhibition of the pentose phosphate pathway resulted in apoptosis preferentially in quiescent fibroblasts. By feeding the cells labeled glutamine, we also detected a “backwards” flux in the tricarboxylic acid cycle from α-ketoglutarate to citrate that was enhanced in contact-inhibited fibroblasts; this flux likely contributes to shuttling of NADPH from the mitochondrion to cytosol for redox defense or fatty acid synthesis. The high metabolic activity of the fibroblasts was directed in part toward breakdown and resynthesis of protein and lipid, and in part toward excretion of extracellular matrix proteins. Thus, reduced metabolic activity is not a hallmark of the quiescent state. Quiescent fibroblasts, relieved of the biosynthetic requirements associated with generating progeny, direct their metabolic activity to preservation of self integrity and alternative functions beneficial to the organism as a whole. PMID:21049082

  19. Out-of-equilibrium fluctuations in stochastic long-range interacting systems

    NASA Astrophysics Data System (ADS)

    Gupta, Shamik; Dauxois, Thierry; Ruffo, Stefano

    2016-03-01

    For a many-particle system with long-range interactions and evolving under stochastic dynamics, we study for the first time the out-of-equilibrium fluctuations of the work done on the system by a time-dependent external force. For equilibrium initial conditions, the work distributions for a given protocol of variation of the force in time and the corresponding time-reversed protocol exhibit a remarkable scaling and a symmetry when expressed in terms of the average and the standard deviation of the work. The distributions of the work per particle predict, by virtue of the Crooks fluctuation theorem, the equilibrium free-energy density of the system. For a large number N of particles, the latter is in excellent agreement with the value computed by considering the Langevin dynamics of a single particle in a self-consistent mean field generated by its interaction with other particles. The agreement highlights the effective mean-field nature of the original many-particle dynamics for large N. For initial conditions in non-equilibrium stationary states (NESSs), we study the distribution of a quantity similar to dissipated work that satisfies the non-equilibrium generalization of the Clausius inequality, namely, the Hatano-Sasa equality, for transitions between NESSs. Besides illustrating the validity of the equality, we show that the distribution has exponential tails that decay differently on the left and on the right.

  20. Non-equilibrium steady states in two-temperature Ising models with Kawasaki dynamics

    NASA Astrophysics Data System (ADS)

    Borchers, Nick; Pleimling, Michel; Zia, R. K. P.

    2013-03-01

    From complex biological systems to a simple simmering pot, thermodynamic systems held out of equilibrium are exceedingly common in nature. Despite this, a general theory to describe these types of phenomena remains elusive. In this talk, we explore a simple modification of the venerable Ising model in hopes of shedding some light on these issues. In both one and two dimensions, systems attached to two distinct heat reservoirs exhibit many of the hallmarks of phase transition. When such systems settle into a non-equilibrium steady-state they exhibit numerous interesting phenomena, including an unexpected ``freezing by heating.'' There are striking and surprising similarities between the behavior of these systems in one and two dimensions, but also intriguing differences. These phenomena will be explored and possible approaches to understanding the behavior will be suggested. Supported by the US National Science Foundation through Grants DMR-0904999, DMR-1205309, and DMR-1244666

  1. Uniqueness of Nash equilibrium in vaccination games.

    PubMed

    Bai, Fan

    2016-12-01

    One crucial condition for the uniqueness of Nash equilibrium set in vaccination games is that the attack ratio monotonically decreases as the vaccine coverage level increasing. We consider several deterministic vaccination models in homogeneous mixing population and in heterogeneous mixing population. Based on the final size relations obtained from the deterministic epidemic models, we prove that the attack ratios can be expressed in terms of the vaccine coverage levels, and also prove that the attack ratios are decreasing functions of vaccine coverage levels. Some thresholds are presented, which depend on the vaccine efficacy. It is proved that for vaccination games in homogeneous mixing population, there is a unique Nash equilibrium for each game. PMID:27465224

  2. Equilibrium Macroscopic Structure Revisited from Spatial Constraint

    NASA Astrophysics Data System (ADS)

    Yuge, Koretaka

    2016-02-01

    In classical systems, we reexamine how macroscopic structures in equilibrium state connect with spatial constraint on the systems. For example, volume and density as the constraint for liquids in rigid box, and crystal lattice as the constraint for crystalline solids. We find that in disordered states, equilibrium macroscopic structure, depending on temperature and on multibody interactions in the system, can be well characterized by a single special microscopic structure independent of temperature and of interactions. The special microscopic structure depends only on the spatial constraint. We demonstrate the present findings providing (i) significantly efficient and systematic prediction of macroscopic structures for possible combination of constituents in multicomponent systems using first-principles calculations, and (ii) unique and accurate prediction of multibody interactions in given system from measured macroscopic structure, without performing trial-and-error simulation.

  3. Absence of equilibrium chiral magnetic effect

    NASA Astrophysics Data System (ADS)

    Zubkov, M. A.

    2016-05-01

    We analyze the (3 +1 )D equilibrium chiral magnetic effect (CME). We apply derivative expansion to the Wigner transform of the two-point Green function. This technique allows us to express the response of electric current to the external electromagnetic field strength through the momentum space topological invariant. We consider the wide class of the lattice regularizations of quantum field theory (that includes, in particular, the regularization with Wilson fermions) and also certain lattice models of solid state physics (including those of Dirac semimetals). It appears that in these models the mentioned topological invariant vanishes identically at nonzero chiral chemical potential. That means that the bulk equilibrium CME is absent in those systems.

  4. Instability of quantum equilibrium in Bohm's dynamics

    PubMed Central

    Colin, Samuel; Valentini, Antony

    2014-01-01

    We consider Bohm's second-order dynamics for arbitrary initial conditions in phase space. In principle, Bohm's dynamics allows for ‘extended’ non-equilibrium, with initial momenta not equal to the gradient of phase of the wave function (as well as initial positions whose distribution departs from the Born rule). We show that extended non-equilibrium does not relax in general and is in fact unstable. This is in sharp contrast with de Broglie's first-order dynamics, for which non-standard momenta are not allowed and which shows an efficient relaxation to the Born rule for positions. On this basis, we argue that, while de Broglie's dynamics is a tenable physical theory, Bohm's dynamics is not. In a world governed by Bohm's dynamics, there would be no reason to expect to see an effective quantum theory today (even approximately), in contradiction with observation. PMID:25383020

  5. Punctuated equilibrium in a neontological context.

    PubMed

    Monroe, Melanie J; Bokma, Folmer

    2010-09-01

    The theory of punctuated equilibrium, which proposes that biological species evolve rapidly when they originate rather than gradually over time, has sparked intense debate between palaeontologists and evolutionary biologists about the mode of character evolution and the importance of natural selection. Difficulty in interpreting the fossil record prevented consensus, and it remains disputed as to what extent gradual change in established species is responsible for phenotypic differences between species. Against the historical background of the concept of evolution concentrated in speciation events, we review attempts to investigate tempo and mode of evolution using present-day species since the introduction of the theory of punctuated equilibrium in 1972. We discuss advantages, disadvantages, and prospects of using neontological data, methodological advances, and the findings of some recent studies. PMID:20514523

  6. Spectra from pair-equilibrium plasmas

    NASA Technical Reports Server (NTRS)

    Zdziarski, A. A.

    1984-01-01

    A numerical model of relativistic nonmagnetized plasma with uniform temperature and electron density distributions is considered, and spectra from plasma in pair equilibrium are studied. A range of dimensionless temperature (T) greater than about 0.2 is considered. The spectra from low pair density plasmas in pair equilibrium vary from un-Comptonized bremsstrahlung spectra at Thomson cross section tau(N) much less than one to Comptonized bremsstrahlung spectra with tau(N) over one. For high pair density plasmas the spectra are flat for T greater than about one, and have broad intensity peaks at energy roughly equal to 3T for T less than one. In the latter region the total luminosity is approximately twice the annihilation luminosity. All spectra are flat in the X-ray region, in contradiction to observed AGN spectra. For dimensionless luminosity greater than about 100, the cooling time becomes shorter than the Thomson time.

  7. Adaptive resolution simulation in equilibrium and beyond

    NASA Astrophysics Data System (ADS)

    Wang, H.; Agarwal, A.

    2015-09-01

    In this paper, we investigate the equilibrium statistical properties of both the force and potential interpolations of adaptive resolution simulation (AdResS) under the theoretical framework of grand-canonical like AdResS (GC-AdResS). The thermodynamic relations between the higher and lower resolutions are derived by considering the absence of fundamental conservation laws in mechanics for both branches of AdResS. In order to investigate the applicability of AdResS method in studying the properties beyond the equilibrium, we demonstrate the accuracy of AdResS in computing the dynamical properties in two numerical examples: The velocity auto-correlation of pure water and the conformational relaxation of alanine dipeptide dissolved in water. Theoretical and technical open questions of the AdResS method are discussed in the end of the paper.

  8. Equilibrium fluctuation theorems compatible with anomalous response

    NASA Astrophysics Data System (ADS)

    Velazquez, L.; Curilef, S.

    2010-12-01

    Previously, we have derived a generalization of the canonical fluctuation relation between heat capacity and energy fluctuations C = β2langδU2rang, which is able to describe the existence of macrostates with negative heat capacities C < 0. In this work, we extend our previous results for an equilibrium situation with several control parameters to account for the existence of states with anomalous values in other response functions. Our analysis leads to the derivation of three different equilibrium fluctuation theorems: the fundamental and the complementary fluctuation theorems, which represent the generalization of two fluctuation identities already obtained in previous works, and the associated fluctuation theorem, a result that has no counterpart in the framework of Boltzmann-Gibbs distributions. These results are applied to study the anomalous susceptibility of a ferromagnetic system, in particular, the case of the 2D Ising model.

  9. Phase Equilibrium Investigations of Planetary Materials

    NASA Technical Reports Server (NTRS)

    Grove, T. L.

    2005-01-01

    This grant provided funds to carry out phase equilibrium studies on the processes of chemical differentiation of the moon and the meteorite parent bodies, during their early evolutionary history. Several experimental studies examined processes that led to the formation of lunar ultramafic glasses. Phase equilibrium studies were carried out on selected low-Ti and high-Ti lunar ultramafic glass compositions to provide constraints on the depth range, temperature and processes of melt generation and/or assimilation. A second set of experiments examined the role of sulfide melts in core formation processes in the earth and terrestrial planets. The major results of each paper are discussed, and copies of the papers are attached as Appendix I.

  10. Equilibrium configurations of degenerate fluid spheres

    SciTech Connect

    Whitman, P.G.

    1985-04-01

    Equilibrium configurations of degenerate fluid spheres which assume a polytropic form in the ultrahigh-density regime are considered. We show that analytic solutions more general than those of Misner and Zapolsky exist which possess the asymptotic equation of state. Simple expressions are derived which indicate this nature of the fluids in the extreme relativistic limit, and the stability of these interiors is considered in the asymptotic region.

  11. Entropy production in non-equilibrium systems described by the generalized Langevin equation

    NASA Astrophysics Data System (ADS)

    Sevilla, Francisco J.; Piña-Perez, Omar

    2014-03-01

    The generalized Langevin equation for a charged particle under the influence of time-dependent external fields, is employed to study the effects of non-Markovian dissipative terms in the entropy production of non-equilibrium states exhibiting non-zero mass flux. We present results for the case in which the fluctuation-dissipation relation holds. FJS and OPP acknowledge financial support from PAPIIT-IN113114 and PAEP-UNAM respectively.

  12. Equilibrium Gold Nanoclusters Quenched with Biodegradable Polymers

    PubMed Central

    Murthy, Avinash K.; Stover, Robert J.; Borwankar, Ameya U.; Nie, Golay D.; Gourisankar, Sai; Truskett, Thomas M.; Sokolov, Konstantin V.; Johnston, Keith P.

    2013-01-01

    Although sub-100 nm nanoclusters of metal nanoparticles are of interest in many fields including biomedical imaging, sensors and catalysis, it has been challenging to control their morphologies and chemical properties. Herein, a new concept is presented to assemble equilibrium Au nanoclusters of controlled size by tuning the colloidal interactions with a polymeric stabilizer, PLA(1k)-b-PEG(10k)-b-PLA(1k). The nanoclusters form upon mixing a dispersion of ~5 nm Au nanospheres with a polymer solution followed by partial solvent evaporation. A weakly adsorbed polymer quenches the equilibrium nanocluster size and provides steric stabilization. Nanocluster size is tuned from ~20 nm to ~40 nm by experimentally varying the final Au nanoparticle concentration and the polymer/Au ratio, along with the charge on the initial Au nanoparticle surface. Upon biodegradation of the quencher, the nanoclusters reversibly and fully dissociate to individual ~5 nm primary particles. Equilibrium cluster size is predicted semi-quantitatively with a free energy model that balances short-ranged depletion and van der Waals attractions with longer-ranged electrostatic repulsion, as a function of the Au and polymer concentrations. The close spacings of the Au nanoparticles in the clusters produce strong NIR extinction over a broad range of wavelengths from 650 to 900 nm, which is of practical interest in biomedical imaging. PMID:23230905

  13. BINARY NEUTRON STARS IN QUASI-EQUILIBRIUM

    SciTech Connect

    Taniguchi, Keisuke; Shibata, Masaru

    2010-05-15

    Quasi-equilibrium sequences of binary neutron stars are constructed for a variety of equations of state in general relativity. Einstein's constraint equations in the Isenberg-Wilson-Mathews approximation are solved together with the relativistic equations of hydrostationary equilibrium under the assumption of irrotational flow. We focus on unequal-mass sequences as well as equal-mass sequences, and compare those results. We investigate the behavior of the binding energy and total angular momentum along a quasi-equilibrium sequence, the endpoint of sequences, and the orbital angular velocity as a function of time, changing the mass ratio, the total mass of the binary system, and the equation of state of a neutron star. It is found that the orbital angular velocity at the mass-shedding limit can be determined by an empirical formula derived from an analytic estimation. We also provide tables for 160 sequences, which will be useful as a guideline of numerical simulations for the inspiral and merger performed in the near future.

  14. Equilibrium gold nanoclusters quenched with biodegradable polymers.

    PubMed

    Murthy, Avinash K; Stover, Robert J; Borwankar, Ameya U; Nie, Golay D; Gourisankar, Sai; Truskett, Thomas M; Sokolov, Konstantin V; Johnston, Keith P

    2013-01-22

    Although sub-100 nm nanoclusters of metal nanoparticles are of interest in many fields including biomedical imaging, sensors, and catalysis, it has been challenging to control their morphologies and chemical properties. Herein, a new concept is presented to assemble equilibrium Au nanoclusters of controlled size by tuning the colloidal interactions with a polymeric stabilizer, PLA(1k)-b-PEG(10k)-b-PLA(1k). The nanoclusters form upon mixing a dispersion of ~5 nm Au nanospheres with a polymer solution followed by partial solvent evaporation. A weakly adsorbed polymer quenches the equilibrium nanocluster size and provides steric stabilization. Nanocluster size is tuned from ~20 to ~40 nm by experimentally varying the final Au nanoparticle concentration and the polymer/Au ratio, along with the charge on the initial Au nanoparticle surface. Upon biodegradation of the quencher, the nanoclusters reversibly and fully dissociate to individual ~5 nm primary particles. Equilibrium cluster size is predicted semiquantitatively with a free energy model that balances short-ranged depletion and van der Waals attractions with longer-ranged electrostatic repulsion, as a function of the Au and polymer concentrations. The close spacings of the Au nanoparticles in the clusters produce strong NIR extinction over a broad range of wavelengths from 650 to 900 nm, which is of practical interest in biomedical imaging. PMID:23230905

  15. Hamiltonian approach to the magnetostatic equilibrium problem

    SciTech Connect

    Tessarotto, M.; Zheng, Lin Jin; Johnson, J.L.

    1995-02-01

    The purpose of this paper is to investigate the classical scalar-pressure magnetostatic equilibrium problem for non-symmetric configurations in the framework of a Hamiltonian approach. Requiring that the equilibrium admits locally, in a suitable subdomain, a family of nested toroidal magnetic surfaces, the Hamiltonian equations describing the magnetic flux lines in such a subdomain are obtained for general curvilinear coordinate systems. The properties of such Hamiltonian system are investigated. A representation of the magnetic field in terms of arbitrary general curvilinear coordinates is thus obtained. Its basic feature is that the magnetic field must fulfill suitable periodicity constraints to be imposed on arbitrary rational magnetic surfaces for general non-symmetric toroidal equilibria, i.e., it is quasi-symmetric. Implications for the existence of magnetostatic equilibria are pointed out. In particular, it is proven that a generalized equilibrium equation exists for such quasi-symmetric equilibria, which extends the Grad-Shafranov equation to fully three-dimensional configurations. As an application, the case is considered of quasi-helical equilibria, i.e., displaying a magnetic field magnitude depending on the poloidal ({chi}) and toroidal ({var_theta}) angles only in terms of {alpha}={chi}-N{theta} with N an arbitrary integer.

  16. Analytical Ultracentrifugation: Sedimentation Velocity and Sedimentation Equilibrium

    PubMed Central

    Cole, James L.; Lary, Jeffrey W.; Moody, Thomas; Laue, Thomas M.

    2009-01-01

    Analytical ultracentrifugation (AUC) is a versatile and powerful method for the quantitative analysis of macromolecules in solution. AUC has broad applications for the study of biomacromolecules in a wide range of solvents and over a wide range of solute concentrations. Three optical systems are available for the analytical ultracentrifuge (absorbance, interference and fluorescence) that permit precise and selective observation of sedimentation in real time. In particular, the fluorescence system provides a new way to extend the scope of AUC to probe the behavior of biological molecules in complex mixtures and at high solute concentrations. In sedimentation velocity, the movement of solutes in high centrifugal fields is interpreted using hydrodynamic theory to define the size, shape and interactions of macromolecules. Sedimentation equilibrium is a thermodynamic method where equilibrium concentration gradients at lower centrifugal fields are analyzed to define molecule mass, assembly stoichiometry, association constants and solution nonideality. Using specialized sample cells and modern analysis software, researchers can use sedimentation velocity to determine the homogeneity of a sample and define whether it undergoes concentration-dependent association reactions. Subsequently, more thorough model-dependent analysis of velocity and equilibrium experiments can provide a detailed picture of the nature of the species present in solution and their interactions. PMID:17964931

  17. Bifurcated helical core equilibrium states in tokamaks

    NASA Astrophysics Data System (ADS)

    Cooper, W. A.; Chapman, I. T.; Schmitz, O.; Turnbull, A. D.; Tobias, B. J.; Lazarus, E. A.; Turco, F.; Lanctot, M. J.; Evans, T. E.; Graves, J. P.; Brunetti, D.; Pfefferlé, D.; Reimerdes, H.; Sauter, O.; Halpern, F. D.; Tran, T. M.; Coda, S.; Duval, B. P.; Labit, B.; Pochelon, A.; Turnyanskiy, M. R.; Lao, L.; Luce, T. C.; Buttery, R.; Ferron, J. R.; Hollmann, E. M.; Petty, C. C.; van Zeeland, M.; Fenstermacher, M. E.; Hanson, J. M.; Lütjens, H.

    2013-07-01

    Tokamaks with weak to moderate reversed central shear in which the minimum inverse rotational transform (safety factor) qmin is in the neighbourhood of unity can trigger bifurcated magnetohydrodynamic equilibrium states, one of which is similar to a saturated ideal internal kink mode. Peaked prescribed pressure profiles reproduce the ‘snake’ structures observed in many tokamaks which has led to a novel explanation of the snake as a bifurcated equilibrium state. Snake equilibrium structures are computed in simulations of the tokamak à configuration variable (TCV), DIII-D and mega amp spherical torus (MAST) tokamaks. The internal helical deformations only weakly modulate the plasma-vacuum interface which is more sensitive to ripple and resonant magnetic perturbations. On the other hand, the external perturbations do not alter the helical core deformation in a significant manner. The confinement of fast particles in MAST simulations deteriorate with the amplitude of the helical core distortion. These three-dimensional bifurcated solutions constitute a paradigm shift that motivates the applications of tools developed for stellarator research in tokamak physics investigations.

  18. Recovery of postural equilibrium control following spaceflight

    NASA Technical Reports Server (NTRS)

    Paloski, W. H.; Reschke, M. F.; Black, F. O.; Doxey, D. D.; Harm, D. L.

    1992-01-01

    Decreased postural stability is observed in most astronauts immediately following spaceflight. Because ataxia may present postflight operational hazards, it is important to determine the incidence of postural instability immediately following landing and the dynamics of recovery of normal postural equilibrium control. It is postulated that postflight postural instability results from in-flight adaptive changes in central nervous system (CNS) processing of sensory information from the visual, vestibular, and proprioceptive systems. The purpose of the present investigation was to determine the magnitude and time course of postflight recovery of postural equilibrium control and, hence, readaptation of CNS processing of sensory information. Thirteen crew members from six spaceflight missions were studied pre- and postflight using a modified commercial posturography system. Postural equilibrium control was found to be seriously disrupted immediately following spaceflight in all subjects. Readaptation to the terrestrial environment began immediately upon landing, proceeded rapidly for the first 10-12 hours, and then proceeded much more slowly for the subsequent 2-4 days until preflight stability levels were reachieved. It is concluded that the overall postflight recovery of postural stability follows a predictable time course.

  19. Statistical approach to partial equilibrium analysis

    NASA Astrophysics Data System (ADS)

    Wang, Yougui; Stanley, H. E.

    2009-04-01

    A statistical approach to market equilibrium and efficiency analysis is proposed in this paper. One factor that governs the exchange decisions of traders in a market, named willingness price, is highlighted and constitutes the whole theory. The supply and demand functions are formulated as the distributions of corresponding willing exchange over the willingness price. The laws of supply and demand can be derived directly from these distributions. The characteristics of excess demand function are analyzed and the necessary conditions for the existence and uniqueness of equilibrium point of the market are specified. The rationing rates of buyers and sellers are introduced to describe the ratio of realized exchange to willing exchange, and their dependence on the market price is studied in the cases of shortage and surplus. The realized market surplus, which is the criterion of market efficiency, can be written as a function of the distributions of willing exchange and the rationing rates. With this approach we can strictly prove that a market is efficient in the state of equilibrium.

  20. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    NASA Astrophysics Data System (ADS)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  1. Radioactive equilibrium in ancient marine sediments

    USGS Publications Warehouse

    Breger, I.A.

    1955-01-01

    Radioactive equilibrium in eight marine sedimentary formations has been studied by means of direct determinations of uranium, radium and thorium. Alpha-particle counting has also been carried out in order to cross-calibrate thick-source counting techniques. The maximum deviation from radioactive equilibrium that has been noted is 11 per cent-indicating that there is probably equilibrium in all the formations analyzed. Thick-source alpha-particle counting by means of a proportional counter or an ionization chamber leads to high results when the samples contain less than about 10 p.p.m. of uranium. For samples having a higher content of uranium the results are in excellent agreement with each other and with those obtained by direct analytical techniques. The thorium contents that have been obtained correspond well to the average values reported in the literature. The uranium content of marine sediments may be appreciably higher than the average values that have been reported for sedimentary rocks. Data show that there is up to fourteen times the percentage of uranium as of thorium in the formations studied and that the percentage of thorium never exceeds that of uranium. While the proximity of a depositional environment to a land mass may influence the concentration of uranium in a marine sediment, this is not true with thorium. ?? 1955.

  2. Exhibition of Stochastic Resonance in Vestibular Perception

    NASA Technical Reports Server (NTRS)

    Galvan-Garza, R. C.; Clark, T. K.; Merfeld, D. M.; Bloomberg, J. J.; Oman, C. M.; Mulavara, A. P.

    2016-01-01

    Astronauts experience sensorimotor changes during spaceflight, particularly during G-transitions. Post flight sensorimotor changes include spatial disorientation, along with postural and gait instability that may degrade operational capabilities of the astronauts and endanger the crew. A sensorimotor countermeasure that mitigates these effects would improve crewmember safety and decrease risk. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor perception through the phenomenon of stochastic resonance (SR), when the response of a nonlinear system to a weak input signal is enhanced by the application of a particular nonzero level of noise. This study aims to advance the development of SVS as a potential countermeasure by 1) demonstrating the exhibition of stochastic resonance in vestibular perception, a vital component of sensorimotor function, 2) investigating the repeatability of SR exhibition, and 3) determining the relative contribution of the semicircular canals (SCC) and otolith (OTO) organs to vestibular perceptual SR. A constant current stimulator was used to deliver bilateral bipolar SVS via electrodes placed on each of the mastoid processes, as previously done. Vestibular perceptual motion recognition thresholds were measured using a 6-degree of freedom MOOG platform and a 150 trial 3-down/1-up staircase procedure. In the first test session, we measured vestibular perceptual thresholds in upright roll-tilt at 0.2 Hz (SCC+OTO) with SVS ranging from 0-700 µA. In a second test session a week later, we re-measured roll-tilt thresholds with 0, optimal (from test session 1), and 1500 µA SVS levels. A subset of these subjects, plus naive subjects, participated in two additional test sessions in which we measured thresholds in supine roll-rotation at 0.2 Hz (SCC) and upright y-translation at 1 Hz

  3. Multi-period equilibrium/near-equilibrium in electricity markets based on locational marginal prices

    NASA Astrophysics Data System (ADS)

    Garcia Bertrand, Raquel

    In this dissertation we propose an equilibrium procedure that coordinates the point of view of every market agent resulting in an equilibrium that simultaneously maximizes the independent objective of every market agent and satisfies network constraints. Therefore, the activities of the generating companies, consumers and an independent system operator are modeled: (1) The generating companies seek to maximize profits by specifying hourly step functions of productions and minimum selling prices, and bounds on productions. (2) The goals of the consumers are to maximize their economic utilities by specifying hourly step functions of demands and maximum buying prices, and bounds on demands. (3) The independent system operator then clears the market taking into account consistency conditions as well as capacity and line losses so as to achieve maximum social welfare. Then, we approach this equilibrium problem using complementarity theory in order to have the capability of imposing constraints on dual variables, i.e., on prices, such as minimum profit conditions for the generating units or maximum cost conditions for the consumers. In this way, given the form of the individual optimization problems, the Karush-Kuhn-Tucker conditions for the generating companies, the consumers and the independent system operator are both necessary and sufficient. The simultaneous solution to all these conditions constitutes a mixed linear complementarity problem. We include minimum profit constraints imposed by the units in the market equilibrium model. These constraints are added as additional constraints to the equivalent quadratic programming problem of the mixed linear complementarity problem previously described. For the sake of clarity, the proposed equilibrium or near-equilibrium is first developed for the particular case considering only one time period. Afterwards, we consider an equilibrium or near-equilibrium applied to a multi-period framework. This model embodies binary

  4. Virtual Exhibition and Fruition of Archaeological Finds

    NASA Astrophysics Data System (ADS)

    Manferdini, A. M.; Garagnani, S.

    2011-09-01

    During the last two decades, since digital technologies have become more sophisticated in acquiring real data and building faithful copies of them, their improvements have suggested interesting applications in the field of valorisation of Historical, Cultural and Artistic Heritage, with significant consequences in the share and widespread of knowledge. But although several technologies and methodologies for 3d digitization have recently been developed and improved, the lack of a standard procedure and the costs connected to their use still doesn't encourage the systematic digital acquisition of wide collections and heritage. The aim of this paper is to show the state of the art of a project whose aim is to provide a methodology and a procedure to create digital reproductions of artefacts for Institutions called to preserve, manage and enhance the fruition of archaeological finds inside museums or through digital exhibitions. Our project's aim is to find the most suitable procedure to digitally acquire archaeo logical artefacts that usually have small dimensions and have very complex and detailed surfaces. Within our methodology, particular attention has been paid to the use of widely shared and open-source visualization systems that enhance the involvement of the user by emphasizing three-dimensional characteristics of artefacts through virtual reality.

  5. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Exhibit A—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  6. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C—Provisions Exhibit... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  7. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Exhibit A—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  8. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Exhibit A—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  9. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Exhibit A—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  10. On the Concept "Chemical Equilibrium": The Associative Framework.

    ERIC Educational Resources Information Center

    Gussarsky, Esther; Gorodetsky, Malka

    1990-01-01

    Word associations were used to map high school students' concepts of "chemical equilibrium" and "equilibrium." It was found that the preconception of the two concepts was differentiated on noncritical dimensions. (Author/CW)

  11. Existence of best proximity pairs and equilibrium pairs

    NASA Astrophysics Data System (ADS)

    Kim, Won Kyu; Lee, Kyoung Hee

    2006-04-01

    In this paper, using the fixed point theorem for Kakutani factorizable multifunctions, we shall prove new existence theorems of best proximity pairs and equilibrium pairs for free abstract economies, which include the previous fixed point theorems and equilibrium existence theorems.

  12. Thermodynamics and Kinetics of Chemical Equilibrium in Solution.

    ERIC Educational Resources Information Center

    Leenson, I. A.

    1986-01-01

    Discusses theory of thermodynamics of the equilibrium in solution and dissociation-dimerization kinetics. Describes experimental procedure including determination of molar absorptivity and equilibrium constant, reaction enthalpy, and kinetics of the dissociation-dimerization reaction. (JM)

  13. Marine bacteria exhibit a bipolar distribution.

    PubMed

    Sul, Woo Jun; Oliver, Thomas A; Ducklow, Hugh W; Amaral-Zettler, Linda A; Sogin, Mitchell L

    2013-02-01

    The microbial cosmopolitan dispersion hypothesis often invoked to explain distribution patterns driven by high connectivity of oceanographic water masses and widespread dispersal ability has never been rigorously tested. By using a global marine bacterial dataset and iterative matrix randomization simulation, we show that marine bacteria exhibit a significantly greater dispersal limitation than predicted by our null model using the "everything is everywhere" tenet with no dispersal limitation scenario. Specifically, marine bacteria displayed bipolar distributions (i.e., species occurring exclusively at both poles and nowhere else) significantly less often than in the null model. Furthermore, we observed fewer taxa present in both hemispheres but more taxa present only in a single hemisphere than expected under the null model. Each of these trends diverged further from the null expectation as the compared habitats became more geographically distant but more environmentally similar. Our meta-analysis supported a latitudinal gradient in bacterial diversity with higher richness at lower latitudes, but decreased richness toward the poles. Bacteria in the tropics also demonstrated narrower latitudinal ranges at lower latitudes and relatively larger ranges in higher latitudes, conforming to the controversial macroecological pattern of the "Rapoport rule." Collectively, our findings suggest that bacteria follow biogeographic patterns more typical of macroscopic organisms, and that dispersal limitation, not just environmental selection, likely plays an important role. Distributions of microbes that deliver critical ecosystem services, particularly those in polar regions, may be vulnerable to the same impacts that environmental stressors, climate warming, and degradation in habitat quality are having on biodiversity in animal and plant species. PMID:23324742

  14. Waves in geomaterials exhibiting negative stiffness behaviour

    NASA Astrophysics Data System (ADS)

    Esin, Maxim; Dyskin, Arcady; Pasternak, Elena

    2016-04-01

    Negative stiffness denotes the type of material behaviour when the force applied to the body decreases the body's deformation increases. Some geomaterials, for instance, rocks, demonstrate behaviour of this type at certain loads: during the compression tests the loading curves exhibit descending branch (post-peak softening). One of the possible mechanisms of the negative stiffness appearance in geomaterials is rotation of non-spherical grains. It is important to emphasize that in this case the descending branch may be reversible given that the testing machine is stiff enough (in general case it means an importance of boundary conditions). Existence of geomaterials with a negative modulus associated with rotations may have significant importance. In particular, important is understanding of the wave propagation in such materials. We study the stability of geomaterials with negative stiffness inclusions and wave propagation in it using two approaches: Cosserat continuum and discrete mass-spring models. In both cases we consider the rotational degrees of freedom in addition to the conventional translational ones. We show that despite non positiveness of the energy the materials with negative stiffness elements can be stable if certain conditions are met. In the case of Cosserat continuum the Cosserat shear modulus (the modulus relating the non-symmetrical part of shear stress and internal rotations) is allowed to assume negative values as long as its value does not exceed the value of the standard (positive) shear modulus. In the case of discrete mass-spring systems (with translational and rotational springs) the concentration of negative stiffness springs and the absolute values of negative spring stiffness are limited. The critical concentration when the system loses stability and the amplitude of the oscillations tends to infinity is equal to 1/2 and 3/5 for two- and three-dimensional cases respectively.

  15. Rats exhibit reference-dependent choice behavior.

    PubMed

    Bhatti, Mehwish; Jang, Hyeran; Kralik, Jerald D; Jeong, Jaeseung

    2014-07-01

    Human preferences depend on whether a chosen outcome appears to be a loss or a gain compared with what had been expected, i.e., in comparison to a reference point. Because reference dependence has such a strong influence on human decision-making, it is important to uncover its origins, which will in turn help delineate the underlying mechanisms. It remains unknown whether rats use reference points in decision-making, and yet, the study of rats could help address the question of whether reference dependence is evolutionarily conserved among mammals and could provide a nonhuman animal model to investigate the neural mechanisms underlying this important cognitive process. The aim of the current study was to determine whether rats show reference-dependent choice behavior. We developed a novel paradigm by modifying the "T" maze by installing "pockets" to the left and right of the "T" stem that held reward pellets so rats would potentially develop reference values for each option prior to choice. We found that the rats were indeed sensitive to the way alternatives were presented. That is, they exhibited reference-dependent choice behavior by avoiding the choice option framed as a loss (e.g., having four reward pellets in the pocket, but receiving only one), at least under conditions with certain outcomes and clear differences between the reference and outcome quantities. Despite the small number of rats in this study, this species-level capacity suggests that reference dependence in general and loss aversion in particular may be conserved traits that evolved at or before the emergence of mammals. PMID:24657593

  16. Coupled discretization of multicomponent diffusion problems in equilibrium and non-equilibrium plasmas

    NASA Astrophysics Data System (ADS)

    Peerenboom, Kim; Ten Thije Boonkkamp, Jan; van Dijk, Jan; Kroesen, Gerrit

    2013-09-01

    Solving balance equations is the essence of any fluid simulation of reactive, multicomponent plasmas. For plasmas in chemical non-equilibrium, balance equations are solved for all species of interest. When reactions are very fast with respect to transport time scales - and the plasma approaches chemical equilibrium - species abundances can be obtained from equilibrium relations. However, in many cases, balance equations still need to be solved for the elements, since the elemental composition can vary significantly in reactive multicomponent plasmas. Both in equilibrium and in non-equilibrium the species diffusive fluxes in these balance equations are governed by the Stefan-Maxwell equations. The use of Stefan-Maxwell diffusion leads to a coupled set of balance equations. Furthermore, this coupled set of equations is subject to charge and mass conservation constraints. Due to these complications the set of balance equations is often artificially decoupled to fit in the traditional finite volume discretization schemes and the constraints are explicitly applied. This approach can lead to very poor convergence behavior. We will present a new approach using a finite volume discretization scheme that takes into account the coupling and treats the constraints implicitly.

  17. Fractal Geometry of Equilibrium Payoffs in Discounted Supergames

    NASA Astrophysics Data System (ADS)

    Berg, Kimmo; Kitti, Mitri

    2014-08-01

    This paper examines the pure-strategy subgame-perfect equilibrium payoffs in discounted supergames with perfect monitoring. It is shown that the equilibrium payoffs can be identified as sub-self-affine sets or graph-directed iterated function systems. We propose a method to estimate the Hausdorff dimension of the equilibrium payoffs and relate it to the equilibrium paths and their graph presentation.

  18. [Principle of genetic equilibrium for two gene loci].

    PubMed

    Pan, Shen-Yuan; Qu, Ai; Hui, Peng; Li, Ai-Ling

    2004-03-01

    Because linkage equilibrium is introduced by directly quoting the conclusions or imprecise mathematical reasoning in most of textbooks, many students are puzzled with the problem of linkage equilibrium when they learn population genetics. Based on the radical conditions of genetic equilibrium, the principle of linkage equilibrium condition and process, for two gene loci is introduced by precise mathematical reasoning. The article may provide reference to teachers and students in the teaching and learning of population genetics. PMID:15639991

  19. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  20. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  1. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  2. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  3. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  4. 14 CFR 67.205 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Ear, nose, throat, and equilibrium. 67.205... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a second-class...

  5. 14 CFR 67.305 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Ear, nose, throat, and equilibrium. 67.305... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Third-Class Airman Medical Certificate § 67.305 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a third-class...

  6. 14 CFR 67.305 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Ear, nose, throat, and equilibrium. 67.305... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Third-Class Airman Medical Certificate § 67.305 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a third-class...

  7. 14 CFR 67.105 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Ear, nose, throat, and equilibrium. 67.105... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a first-class...

  8. 14 CFR 67.105 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Ear, nose, throat, and equilibrium. 67.105... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a first-class...

  9. 14 CFR 67.305 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Ear, nose, throat, and equilibrium. 67.305... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Third-Class Airman Medical Certificate § 67.305 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a third-class...

  10. 14 CFR 67.105 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Ear, nose, throat, and equilibrium. 67.105... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a first-class...

  11. 14 CFR 67.205 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Ear, nose, throat, and equilibrium. 67.205... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a second-class...

  12. 14 CFR 67.305 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Ear, nose, throat, and equilibrium. 67.305... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Third-Class Airman Medical Certificate § 67.305 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a third-class...

  13. 14 CFR 67.205 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Ear, nose, throat, and equilibrium. 67.205... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a second-class...

  14. 14 CFR 67.305 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Ear, nose, throat, and equilibrium. 67.305... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Third-Class Airman Medical Certificate § 67.305 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a third-class...

  15. 14 CFR 67.205 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Ear, nose, throat, and equilibrium. 67.205... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a second-class...

  16. 14 CFR 67.205 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Ear, nose, throat, and equilibrium. 67.205... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a second-class...

  17. 14 CFR 67.105 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Ear, nose, throat, and equilibrium. 67.105... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a first-class...

  18. 14 CFR 67.105 - Ear, nose, throat, and equilibrium.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Ear, nose, throat, and equilibrium. 67.105... (CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105 Ear, nose, throat, and equilibrium. Ear, nose, throat, and equilibrium standards for a first-class...

  19. Investigating High School Students' Understanding of Chemical Equilibrium Concepts

    ERIC Educational Resources Information Center

    Karpudewan, Mageswary; Treagust, David F.; Mocerino, Mauro; Won, Mihye; Chandrasegaran, A. L.

    2015-01-01

    This study investigated the year 12 students' (N = 56) understanding of chemical equilibrium concepts after instruction using two conceptual tests, the "Chemical Equilibrium Conceptual Test 1" ("CECT-1") consisting of nine two-tier multiple-choice items and the "Chemical Equilibrium Conceptual Test 2"…

  20. Towards breaking temperature equilibrium in multi-component Eulerian schemes

    SciTech Connect

    Grove, John W; Masser, Thomas

    2009-01-01

    We investigate the effects ofthermal equilibrium on hydrodynamic flows and describe models for breaking the assumption ofa single temperature for a mixture of components in a cell. A computational study comparing pressure-temperature equilibrium simulations of two dimensional implosions with explicit front tracking is described as well as implementation and J-D calculations for non-equilibrium temperature methods.

  1. Hanging an Airplane: A Case Study in Static Equilibrium

    ERIC Educational Resources Information Center

    Katz, Debora M.

    2009-01-01

    Our classrooms are filled with engineering majors who take a semester-long course in static equilibrium. Many students find this class too challenging and drop their engineering major. In our introductory physics class, we often breeze through static equilibrium; to physicists equilibrium is just a special case of Newton's second law. While it is…

  2. Equilibrium and shot noise in mesoscopic systems

    SciTech Connect

    Martin, T.

    1994-10-01

    Within the last decade, there has been a resurgence of interest in the study of noise in Mesoscopic devices, both experimentally and theoretically. Noise in solid state devices can have different origins: there is 1/f noise, which is believed to arise from fluctuations in the resistance of the sample due to the motion of impurities. On top of this contribution is a frequency independent component associated with the stochastic nature of electron transport, which will be the focus of this paper. If the sample considered is small enough that dephasing and inelastic effects can be neglected, equilibrium (thermal) and excess noise can be completely described in terms of the elastic scattering properties of the sample. As mentioned above, noise arises as a consequence of random processes governing the transport of electrons. Here, there are two sources of randomness: first, electrons incident on the sample occupy a given energy state with a probability given by the Fermi-Dirac distribution function. Secondly, electrons can be transmitted across the sample or reflected in the same reservoir where they came from with a probability given by the quantum mechanical transmission/reflection coefficients. Equilibrium noise refers to the case where no bias voltage is applied between the leads connected to the sample, where thermal agitation alone allows the electrons close to the Fermi level to tunnel through the sample. In general, equilibrium noise is related to the conductance of the sample via the Johnson-Nyquist formula. In the presence of a bias, in the classical regime, one expects to recover the full shot noise < {Delta}{sup 2}I >= 2I{Delta}{mu} as was observed a long time ago in vacuum diodes. In the Mesoscopic regime, however, excess noise is reduced below the shot noise level. The author introduces a more intuitive picture, where the current passing through the device is a superposition of pulses, or electron wave packets, which can be transmitted or reflected.

  3. Equilibrium defects and concentrations in nickel aluminide

    SciTech Connect

    Bai, B.; Collins, G.S.

    1999-07-01

    Perturbed angular correlation of gamma rays was applied to determine properties of equilibrium defects in B2 NiAl near the stoichiometric composition. Point defects were detected through quadrupole interactions they induce at In probe atoms on the Al sublattice. Well-resolved signals were observed for probe atoms having zero, one or two Ni-vacancies (V{sub Ni}) in the first neighbor shell. The fractions of probes in different sites are analyzed using a thermodynamic model to determine defect properties as follows. The equilibrium high-temperature defect is determined to be the triple defect combination (two V{sub Ni} and one Ni-antisite atom) through the variation of the vacancy concentration with composition and not, for example, the Schottky vacancy pair. The binding enthalpy of V{sub Ni} with a probe atom was determined to be in the range 0.18--0.24 eV. Site fractions were measured for three samples having 50.03, 50.14 and 50.91 at.% Ni at temperatures up to 1300 C. Vacancy concentrations were deduced from the site fractions and binding enthalpy. The equilibrium constant for formation of the triple defect was determined as a function of temperature from the vacancy concentrations and sample compositions. The formation enthalpy was found to be in the range 1.65--1.83 eV, depending on the binding enthalpy. The formation entropy was found to be {minus}3.2(4)k{sub B}. The large, negative value of the formation entropy probably cannot be explained in terms of a binding entropy, and the authors speculate that triple defects harden the B2 lattice, perhaps by disrupting the well-known 1/3 {l{underscore}angle}111{r{underscore}angle} soft mode lattice instability in B2 and bcc materials.

  4. Multicomponent Equilibrium Models for Testing Geothermometry Approaches

    SciTech Connect

    Cooper, D. Craig; Palmer, Carl D.; Smith, Robert W.; McLing, Travis L.

    2013-02-01

    Geothermometry is an important tool for estimating deep reservoir temperature from the geochemical composition of shallower and cooler waters. The underlying assumption of geothermometry is that the waters collected from shallow wells and seeps maintain a chemical signature that reflects equilibrium in the deeper reservoir. Many of the geothermometers used in practice are based on correlation between water temperatures and composition or using thermodynamic calculations based a subset (typically silica, cations or cation ratios) of the dissolved constituents. An alternative approach is to use complete water compositions and equilibrium geochemical modeling to calculate the degree of disequilibrium (saturation index) for large number of potential reservoir minerals as a function of temperature. We have constructed several “forward” geochemical models using The Geochemist’s Workbench to simulate the change in chemical composition of reservoir fluids as they migrate toward the surface. These models explicitly account for the formation (mass and composition) of a steam phase and equilibrium partitioning of volatile components (e.g., CO2, H2S, and H2) into the steam as a result of pressure decreases associated with upward fluid migration from depth. We use the synthetic data generated from these simulations to determine the advantages and limitations of various geothermometry and optimization approaches for estimating the likely conditions (e.g., temperature, pCO2) to which the water was exposed in the deep subsurface. We demonstrate the magnitude of errors that can result from boiling, loss of volatiles, and analytical error from sampling and instrumental analysis. The estimated reservoir temperatures for these scenarios are also compared to conventional geothermometers. These results can help improve estimation of geothermal resource temperature during exploration and early development.

  5. Thermo-chemical dynamics and chemical quasi-equilibrium of plasmas in thermal non-equilibrium

    SciTech Connect

    Massot, Marc; Graille, Benjamin; Magin, Thierry E.

    2011-05-20

    We examine both processes of ionization by electron and heavy-particle impact in spatially uniform plasmas at rest in the absence of external forces. A singular perturbation analysis is used to study the following physical scenario, in which thermal relaxation becomes much slower than chemical reactions. First, electron-impact ionization is investigated. The dynamics of the system rapidly becomes close to a slow dynamics manifold that allows for defining a unique chemical quasi-equilibrium for two-temperature plasmas and proving that the second law of thermodynamics is satisfied. Then, all ionization reactions are taken into account simultaneously, leading to a surprising conclusion: the inner layer for short time scale (or time boundary layer) directly leads to thermal equilibrium. Global thermo-chemical equilibrium is reached within a short time scale, involving only chemical reactions, even if thermal relaxation through elastic collisions is assumed to be slow.

  6. Stochastic linearization of turbulent dynamics of dispersive waves in equilibrium and non-equilibrium state

    NASA Astrophysics Data System (ADS)

    Jiang, Shixiao W.; Lu, Haihao; Zhou, Douglas; Cai, David

    2016-08-01

    Characterizing dispersive wave turbulence in the long time dynamics is central to understanding of many natural phenomena, e.g., in atmosphere ocean dynamics, nonlinear optics, and plasma physics. Using the β-Fermi–Pasta–Ulam nonlinear system as a prototypical example, we show that in thermal equilibrium and non-equilibrium steady state the turbulent state even in the strongly nonlinear regime possesses an effective linear stochastic structure in renormalized normal variables. In this framework, we can well characterize the spatiotemporal dynamics, which are dominated by long-wavelength renormalized waves. We further demonstrate that the energy flux is nearly saturated by the long-wavelength renormalized waves in non-equilibrium steady state. The scenario of such effective linear stochastic dynamics can be extended to study turbulent states in other nonlinear wave systems.

  7. Equilibrium of an elastically confined liquid drop

    NASA Astrophysics Data System (ADS)

    Kwon, Hyuk-Min; Kim, Ho-Young; Puëll, Jérôme; Mahadevan, L.

    2008-05-01

    When a liquid drop is confined between an elastic plate and a rigid substrate, it spreads spontaneously due to the effects of interfacial forces, eventually reaching an equilibrium shape determined by the balance between elastic and capillary effects. We provide an analytical theory for the static shape of the sheet and the extent of liquid spreading and show that our experiments are quantitatively consistent with the theory. The theory is relevant for the first step of painting when a brush is brought down on to canvas. More mundanely, it allows us to understand the stiction of microcantilevers to wafer substrates occurring in microelectromechanical fabrication processes.

  8. Secular equilibrium of radium in Western coal

    SciTech Connect

    Casella, V.R.; Fleissner, J.G.; Styron, C.E.

    1980-01-01

    Concentrations of radium-226, radium-228, and thorium-228 in coal from six Western states have been measured by gamma spectroscopy. The existence of secular equilibrium was verified for radium-226 and previously measured uranium-238 and also for radium-228 and thorium-228. The measured radionuclide concentrations for Western coal averaged about 0.3 pCi/g for radium-226 and 0.2 pCi/g for radium-228 and thorium-228. These average values are not greatly different from those in coal from other provinces of the United States.

  9. Adaptive Implicit Non-Equilibrium Radiation Diffusion

    SciTech Connect

    Philip, Bobby; Wang, Zhen; Berrill, Mark A; Rodriguez Rodriguez, Manuel; Pernice, Michael

    2013-01-01

    We describe methods for accurate and efficient long term time integra- tion of non-equilibrium radiation diffusion systems: implicit time integration for effi- cient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while control- ling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton-Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

  10. Process for operating equilibrium controlled reactions

    DOEpatents

    Nataraj, Shankar; Carvill, Brian Thomas; Hufton, Jeffrey Raymond; Mayorga, Steven Gerard; Gaffney, Thomas Richard; Brzozowski, Jeffrey Richard

    2001-01-01

    A cyclic process for operating an equilibrium controlled reaction in a plurality of reactors containing an admixture of an adsorbent and a reaction catalyst suitable for performing the desired reaction which is operated in a predetermined timed sequence wherein the heating and cooling requirements in a moving reaction mass transfer zone within each reactor are provided by indirect heat exchange with a fluid capable of phase change at temperatures maintained in each reactor during sorpreaction, depressurization, purging and pressurization steps during each process cycle.

  11. Non-equilibrium Dynamics of DNA Nanotubes

    NASA Astrophysics Data System (ADS)

    Hariadi, Rizal Fajar

    Can the fundamental processes that underlie molecular biology be understood and simulated by DNA nanotechnology? The early development of DNA nanotechnology by Ned Seeman was driven by the desire to find a solution to the protein crystallization problem. Much of the later development of the field was also driven by envisioned applications in computing and nanofabrication. While the DNA nanotechnology community has assembled a versatile tool kit with which DNA nanostructures of considerable complexity can be assembled, the application of this tool kit to other areas of science and technology is still in its infancy. This dissertation reports on the construction of non-equilibrium DNA nanotube dynamic to probe molecular processes in the areas of hydrodynamics and cytoskeletal behavior. As the first example, we used DNA nanotubes as a molecular probe for elongational flow measurement in different micro-scale flow settings. The hydrodynamic flow in the vicinity of simple geometrical objects, such as a rigid DNA nanotube, is amenable to rigorous theoretical investigation. We measured the distribution of elongational flows produced in progressively more complex settings, ranging from the vicinity of an orifice in a microfluidic chamber to within a bursting bubble of Pacific ocean water. This information can be used to constrain theories on the origin of life in which replication involves a hydrodynamically driven fission process, such as the coacervate fission proposed by Oparin. A second theme of this dissertation is the bottom-up construction of a de novo artificial cytoskeleton with DNA nanotubes. The work reported here encompasses structural, locomotion, and control aspects of non-equilibrium cytoskeletal behavior. We first measured the kinetic parameters of DNA nanotube assembly and tested the accuracy of the existing polymerization models in the literature. Toward recapitulation of non-equilibrium cytoskeletal dynamics, we coupled the polymerization of DNA

  12. Dynamics of Charged Particles in an Adiabatic Thermal Beam Equilibrium

    NASA Astrophysics Data System (ADS)

    Chen, Chiping; Wei, Haofei

    2010-11-01

    Charged-particle motion is studied in the self-electric and self-magnetic fields of a well-matched, intense charged-particle beam and an applied periodic solenoidal magnetic focusing field. The beam is assumed to be in a state of adiabatic thermal equilibrium. The phase space is analyzed and compared with that of the well-known Kapchinskij-Vladimirskij (KV)-type beam equilibrium. It is found that the widths of nonlinear resonances in the adiabatic thermal beam equilibrium are narrower than those in the KV-type beam equilibrium. Numerical evidence is presented, indicating almost complete elimination of chaotic particle motion in the adiabatic thermal beam equilibrium.

  13. Equilibrium and Stability Analysis of PEGASUS Plasmas

    NASA Astrophysics Data System (ADS)

    Sontag, Aaron

    2001-10-01

    Magnetic equilibrium analyses of low-A discharges in the PEGASUS Toroidal Experiment have been performed using EFIT and a locally developed code which incorporates a nonlinear least-squares fitting routine coupled to a Grad-Shafranov solver. Induced currents in the continuous, resistive vessel wall are estimated using a time-evolving current filament model and are constrained during the reconstruction by wall-mounted flux loops and B-dot coils. With I_wall/Ip up to 2, the poloidal field due to the walls often dominates early in the discharge. A recent upgrade of the internal magnetics set to include 20 poloidal flux loops, a poloidal array of 20 B-dot coils, and a diamagnetic loop has increased the accuracy of equilibrium reconstructions. Plasmas with A < 1.3, Ip on the order of 0.15 MA, 0.2 < li < 0.8, and betat < 25% have been analyzed. The presence of a broad q ~ 2 region inside the plasma corresponds to the growth of a large 2/1 internal mode. Ideal stability analyses have been performed using DCON.

  14. Temperature of systems out of thermodynamic equilibrium

    NASA Astrophysics Data System (ADS)

    Garden, J.-L.; Richard, J.; Guillou, H.

    2008-07-01

    Two phenomenological approaches are currently used in the study of the vitreous state. One is based on the concept of fictive temperature introduced by Tool [J. Res. Natl. Bur. Stand. 34, 199 (1945)] and recently revisited by Nieuwenhuizen [Phys. Rev. Lett. 80, 5580 (1998)]. The other is based on the thermodynamics of irreversible processes initiated by De Donder at the beginning of the last century [L'Affinité (Gauthier-Villars, Paris, 1927)] and recently used by Möller et al. for a thorough study of the glass transition [J. Chem. Phys. 125, 094505 (2006)]. This latter approach leads to the possibility of describing the glass transition by means of the freezing-in of one or more order parameters connected to the internal structural degrees of freedom involved in the vitrification process. In this paper, the equivalence of the two preceding approaches is demonstrated, not only for glasses but in a very general way for any system undergoing an irreversible transformation. This equivalence allows the definition of an effective temperature for all systems departed from equilibrium generating a positive amount of entropy. In fact, the initial fictive temperature concept of Tool leads to the generalization of the notion of temperature for systems out of thermodynamic equilibrium, for which glasses are just particular cases.

  15. Emergence and pseudo-equilibrium in geomorphology

    NASA Astrophysics Data System (ADS)

    Phillips, Jonathan D.

    2011-09-01

    Many geomorphic system states and behaviors often interpreted as tendencies toward establishment and maintenance of steady-state equilibrium are actually emergent outcomes of two simple principles: gradient selection and threshold-mediated modulation. The principle of gradient selection is simply that geomorphic features associated with gradient-driven flows persist and grow relative to other features and pathways. The principle of threshold-mediated modulation reflects the inherent limits on system development along any particular pathway. Thresholds not only define a restricted state space for any given geomorphic system, but may also result in oscillatory behavior around an intermediate condition that resembles fluctuations around a steady-state equilibrium. Together, these principles often produce outcomes that mimic steady-state equilibria. Examples are given involving several aspects of fluvial systems (channel profiles, alluvial channel changes, and drainage density), hillslope gradients, and barchan dunes. Steady-states indeed occur in Earth surface systems, and are a useful simplification in some models. However, the assumption that such states are somehow normative, or the only natural condition, is incorrect, and can lead to problems in geomorphic interpretations, environmental restoration and management, and conceptions of how Earth systems work.

  16. Mineral equilibrium in fractionated nebular systems

    NASA Technical Reports Server (NTRS)

    Wood, John A.; Hashimoto, Akihiko

    1993-01-01

    We investigated the equilibrium mineral assemblages in chemically fractionated nebular systems, using a computer routine that finds the set of minerals and gases which minimizes the Gibbs free energy of a system with stipulated elemental abundances. Diagrams are presented showing the equilibrium mineralogy, as a function of temperature (400-2300 K), for unfractionated solar material and five fractionated systems. The fractionated systems were defined by mixing, in various proportions, the following four volatility components that solar material can be divided into: refractory dust, carbonaceous matter, ices, and H2 gas. Dust enrichment is seen to increase temperatures of condensation/evaporation and the Fe(2+) content of mafic minerals and to permit existence of stable melt phases. Enrichment of dust and organic matter produces mineral assemblages that are similar in many ways to those of enstatite chondrites, but with mafic minerals that are far more reduced than those in primitive enstatite chondrites. Enrichment of dust, organics, and ices leads to highly ferrous mineralogies even at the highest temperatures but does not predict the stability of hydrous phases above about 450 K.

  17. Non-equilibrium many body dynamics

    SciTech Connect

    Creutz, M.; Gyulassy, M.

    1997-09-22

    This Riken BNL Research Center Symposium on Non-Equilibrium Many Body Physics was held on September 23-25, 1997 as part of the official opening ceremony of the Center at Brookhaven National Lab. A major objective of theoretical work at the center is to elaborate on the full spectrum of strong interaction physics based on QCD, including the physics of confinement and chiral symmetry breaking, the parton structure of hadrons and nuclei, and the phenomenology of ultra-relativistic nuclear collisions related to the up-coming experiments at RHIC. The opportunities and challenges of nuclear and particle physics in this area naturally involve aspects of the many body problem common to many other fields. The aim of this symposium was to find common theoretical threads in the area of non-equilibrium physics and modern transport theories. The program consisted of invited talks on a variety topics from the fields of atomic, condensed matter, plasma, astrophysics, cosmology, and chemistry, in addition to nuclear and particle physics. Separate abstracts have been indexed into the database for contributions to this workshop.

  18. Gyrokinetic Statistical Absolute Equilibrium and Turbulence

    SciTech Connect

    Jian-Zhou Zhu and Gregory W. Hammett

    2011-01-10

    A paradigm based on the absolute equilibrium of Galerkin-truncated inviscid systems to aid in understanding turbulence [T.-D. Lee, "On some statistical properties of hydrodynamical and magnetohydrodynamical fields," Q. Appl. Math. 10, 69 (1952)] is taken to study gyrokinetic plasma turbulence: A finite set of Fourier modes of the collisionless gyrokinetic equations are kept and the statistical equilibria are calculated; possible implications for plasma turbulence in various situations are discussed. For the case of two spatial and one velocity dimension, in the calculation with discretization also of velocity v with N grid points (where N + 1 quantities are conserved, corresponding to an energy invariant and N entropy-related invariants), the negative temperature states, corresponding to the condensation of the generalized energy into the lowest modes, are found. This indicates a generic feature of inverse energy cascade. Comparisons are made with some classical results, such as those of Charney-Hasegawa-Mima in the cold-ion limit. There is a universal shape for statistical equilibrium of gyrokinetics in three spatial and two velocity dimensions with just one conserved quantity. Possible physical relevance to turbulence, such as ITG zonal flows, and to a critical balance hypothesis are also discussed.

  19. Mineral equilibrium in fractionated nebular systems

    NASA Astrophysics Data System (ADS)

    Wood, J. A.; Hashimoto, A.

    1993-05-01

    We investigated the equilibrium mineral assemblages in chemically fractionated nebular systems, using a computer routine that finds the set of minerals and gases which minimizes the Gibbs free energy of a system with stipulated elemental abundances. Diagrams are presented showing the equilibrium mineralogy, as a function of temperature (400-2300 K), for unfractionated solar material and five fractionated systems. The fractionated systems were defined by mixing, in various proportions, the following four volatility components that solar material can be divided into: refractory dust, carbonaceous matter, ices, and H2 gas. Dust enrichment is seen to increase temperatures of condensation/evaporation and the Fe(2+) content of mafic minerals and to permit existence of stable melt phases. Enrichment of dust and organic matter produces mineral assemblages that are similar in many ways to those of enstatite chondrites, but with mafic minerals that are far more reduced than those in primitive enstatite chondrites. Enrichment of dust, organics, and ices leads to highly ferrous mineralogies even at the highest temperatures but does not predict the stability of hydrous phases above about 450 K.

  20. Equilibrium Model of Precipitation in Microalloyed Steels

    NASA Astrophysics Data System (ADS)

    Xu, Kun; Thomas, Brian G.; O'Malley, Ron

    2011-02-01

    The formation of precipitates during thermal processing of microalloyed steels greatly influences their mechanical properties. Precipitation behavior varies with steel composition and temperature history and can lead to beneficial grain refinement or detrimental transverse surface cracks. This work presents an efficient computational model of equilibrium precipitation of oxides, sulfides, nitrides, and carbides in steels, based on satisfying solubility limits including Wagner interaction between elements, mutual solubility between precipitates, and mass conservation of alloying elements. The model predicts the compositions and amounts of stable precipitates for multicomponent microalloyed steels in liquid, ferrite, and austenite phases at any temperature. The model is first validated by comparing with analytical solutions of simple cases, predictions using the commercial package JMat-PRO, and previous experimental observations. Then it is applied to track the evolution of precipitate amounts during continuous casting of two commercial steels (1004 LCAK and 1006Nb HSLA) at two different casting speeds. This model is easy to modify to incorporate other precipitates, or new thermodynamic data, and is a useful tool for equilibrium precipitation analysis.

  1. Structural design using equilibrium programming formulations

    NASA Astrophysics Data System (ADS)

    Scotti, Stephen J.

    1995-06-01

    Solutions to increasingly larger structural optimization problems are desired. However, computational resources are strained to meet this need. New methods will be required to solve increasingly larger problems. The present approaches to solving large-scale problems involve approximations for the constraints of structural optimization problems and/or decomposition of the problem into multiple subproblems that can be solved in parallel. An area of game theory, equilibrium programming (also known as noncooperative game theory), can be used to unify these existing approaches from a theoretical point of view (considering the existence and optimality of solutions), and be used as a framework for the development of new methods for solving large-scale optimization problems. Equilibrium programming theory is described, and existing design techniques such as fully stressed design and constraint approximations are shown to fit within its framework. Two new structural design formulations are also derived. The first new formulation is another approximation technique which is a general updating scheme for the sensitivity derivatives of design constraints. The second new formulation uses a substructure-based decomposition of the structure for analysis and sensitivity calculations. Significant computational benefits of the new formulations compared with a conventional method are demonstrated.

  2. Symmetries in fluctuations far from equilibrium.

    PubMed

    Hurtado, Pablo I; Pérez-Espigares, Carlos; del Pozo, Jesús J; Garrido, Pedro L

    2011-05-10

    Fluctuations arise universally in nature as a reflection of the discrete microscopic world at the macroscopic level. Despite their apparent noisy origin, fluctuations encode fundamental aspects of the physics of the system at hand, crucial to understand irreversibility and nonequilibrium behavior. To sustain a given fluctuation, a system traverses a precise optimal path in phase space. Here we show that by demanding invariance of optimal paths under symmetry transformations, new and general fluctuation relations valid arbitrarily far from equilibrium are unveiled. This opens an unexplored route toward a deeper understanding of nonequilibrium physics by bringing symmetry principles to the realm of fluctuations. We illustrate this concept studying symmetries of the current distribution out of equilibrium. In particular we derive an isometric fluctuation relation that links in a strikingly simple manner the probabilities of any pair of isometric current fluctuations. This relation, which results from the time-reversibility of the dynamics, includes as a particular instance the Gallavotti-Cohen fluctuation theorem in this context but adds a completely new perspective on the high level of symmetry imposed by time-reversibility on the statistics of nonequilibrium fluctuations. The new symmetry implies remarkable hierarchies of equations for the current cumulants and the nonlinear response coefficients, going far beyond Onsager's reciprocity relations and Green-Kubo formulas. We confirm the validity of the new symmetry relation in extensive numerical simulations, and suggest that the idea of symmetry in fluctuations as invariance of optimal paths has far-reaching consequences in diverse fields. PMID:21493865

  3. Symmetries in fluctuations far from equilibrium

    PubMed Central

    Hurtado, Pablo I.; Pérez-Espigares, Carlos; del Pozo, Jesús J.; Garrido, Pedro L.

    2011-01-01

    Fluctuations arise universally in nature as a reflection of the discrete microscopic world at the macroscopic level. Despite their apparent noisy origin, fluctuations encode fundamental aspects of the physics of the system at hand, crucial to understand irreversibility and nonequilibrium behavior. To sustain a given fluctuation, a system traverses a precise optimal path in phase space. Here we show that by demanding invariance of optimal paths under symmetry transformations, new and general fluctuation relations valid arbitrarily far from equilibrium are unveiled. This opens an unexplored route toward a deeper understanding of nonequilibrium physics by bringing symmetry principles to the realm of fluctuations. We illustrate this concept studying symmetries of the current distribution out of equilibrium. In particular we derive an isometric fluctuation relation that links in a strikingly simple manner the probabilities of any pair of isometric current fluctuations. This relation, which results from the time-reversibility of the dynamics, includes as a particular instance the Gallavotti–Cohen fluctuation theorem in this context but adds a completely new perspective on the high level of symmetry imposed by time-reversibility on the statistics of nonequilibrium fluctuations. The new symmetry implies remarkable hierarchies of equations for the current cumulants and the nonlinear response coefficients, going far beyond Onsager’s reciprocity relations and Green–Kubo formulas. We confirm the validity of the new symmetry relation in extensive numerical simulations, and suggest that the idea of symmetry in fluctuations as invariance of optimal paths has far-reaching consequences in diverse fields. PMID:21493865

  4. The empirical equilibrium structure of diacetylene

    NASA Astrophysics Data System (ADS)

    Thorwirth, Sven; Harding, Michael E.; Muders, Dirk; Gauss, Jürgen

    2008-09-01

    High-level quantum-chemical calculations are reported at the MP2 and CCSD(T) levels of theory for the equilibrium structure and the harmonic and anharmonic force fields of diacetylene, H sbnd C tbnd C sbnd C tbnd C sbnd H. The calculations were performed employing Dunning's hierarchy of correlation-consistent basis sets cc-pV XZ, cc-pCV XZ, and cc-pwCV XZ, as well as the ANO2 basis set of Almlöf and Taylor. An empirical equilibrium structure based on experimental rotational constants for 13 isotopic species of diacetylene and computed zero-point vibrational corrections is determined (reemp:r=1.0615 Å,r=1.2085 Å,r=1.3727 Å) and in good agreement with the best theoretical structure (CCSD(T)/cc-pCV5Z: r=1.0617 Å, r=1.2083 Å, r=1.3737 Å). In addition, the computed fundamental vibrational frequencies are compared with the available experimental data and found in satisfactory agreement.

  5. Equilibrium Reconstructions and Eddy Currents in LTX

    NASA Astrophysics Data System (ADS)

    Schmitt, J. C.; Bialek, J.; Hansen, C. H.; Majeski, R.; Menard, J. E.

    2015-11-01

    The Lithium Tokamak eXperiment (LTX) is a spherical tokamak with a close-fitting low-recycling wall of lithium deposited on a stainless steel-lined copper shell. The combination of low resistivity of the copper shell, toroidal and poloidal breaks in the shell and transient coil and plasma currents results in long-lived non-axisymmetric eddy currents in the shell which produce a non-axisymmetric magnetic field. Magnetic sensors measure a ``local'' magnetic field in the toroidal break region that differs from the toroidally-averaged field. To use these signals as constraints in 2-D axisymmetric equilibrium reconstructions requires compensation of the 3-D components present in the signals. The work will will discuss the results of the 3-D modeling of the eddy currents and magnetic fields with the VALEN code, along with the progress made with equilibrium reconstructions with PSI-TRI and LRDfit. Work supported by US DOE contract DE-AC02-09CH11466.

  6. In command of non-equilibrium.

    PubMed

    Roduner, Emil; Radhakrishnan, Shankara Gayathri

    2016-05-21

    The second law of thermodynamics is well known for determining the direction of spontaneous processes in the laboratory, life and the universe. It is therefore often called the arrow of time. Less often discussed but just as important is the effect of kinetic barriers which intercept equilibration and preserve highly ordered, high energy non-equilibrium states. Examples of such states are many modern materials produced intentionally for technological applications. Furthermore, all living organisms fuelled directly by photosynthesis and those fuelled indirectly by living on high energy nutrition represent preserved non-equilibrium states. The formation of these states represents the local reversal of the arrow of time which only seemingly violates the second law. It has been known since the seminal work of Prigogine that the stabilisation of these states inevitably requires the dissipation of energy in the form of waste heat. It is this feature of waste heat dissipation following the input of energy that drives all processes occurring at a non-zero rate. Photosynthesis, replication of living organisms, self-assembly, crystal shape engineering and distillation have this principle in common with the well-known Carnot cycle in the heat engine. Drawing on this analogy, we subsume these essential and often sophisticated driven processes under the term machinery of life. PMID:27146424

  7. Equilibrium stellar systems with spindle singularities

    NASA Technical Reports Server (NTRS)

    Shapiro, Stuart L.; Teukolsky, Saul A.

    1992-01-01

    Equilibrium sequences of axisymmetric Newtonian clusters that tend toward singular states are constructed. The distribution functions are chosen to be of the form f = f(E, Jz). The numerical method then determines the density and gravitational potential self-consistently to satisfy Poisson's equation. For the prolate models, spindle singularities arise from the depletion of angular momentum near the symmetry axis. While the resulting density enhancement is confined to the region near the axis, the influence of the spindle extends much further out through its tidal gravitational field. Centrally condensed prolate clusters may contain strong-field regions even though the spindle mass is small and the mean cluster eccentricity is not extreme. While the calculations performed here are entirely Newtonian, the issue of singularities is an important topic in general relativity. Equilibrium solutions for relativistic star clusters can provide a testing ground for exploring this issue. The methods used in this paper for building nonspherical clusters can be extended to relativistic systems.

  8. Equilibrium properties of hcp titanium and zirconium

    SciTech Connect

    Lu, Z.; Singh, D.; Krakauer, H.

    1987-11-15

    The electronic and structural properties of hexagonal-close-packed titanium and zirconium are determined from self-consistent linearized augmented-plane-wave (LAPW) calculations within the framework of the local-density-functional approximation (LDA). The equilibrium lattice parameters, bulk moduli, Poisson's ratios, and cohesive energies are obtained from the total energies calculated as functions of the a and c lattice parameters. As found in other LDA calculations, the cohesive energies are overestimated compared to experiment, but otherwise generally good agreement with experiment is obtained. The uncertainty in the results due to the particular choice of the LDA exchange-correlation potential is also examined by performing parallel calculations using the Kohn-Sham-Gaspar X..cap alpha.. (..cap alpha.. = (2/3) exchange-only potential. We find that these calculations yield equilibrium volumes which differ by 6--8 % (with the X..cap alpha.. results in better agreement with experiment) with proportional differences in other structural properties, which we take to be an indication of the intrinsic reliability of the LDA.

  9. Equilibrium properties of hcp titanium and zirconium

    NASA Astrophysics Data System (ADS)

    Lu, Zhi-Wei; Singh, David; Krakauer, Henry

    1987-11-01

    The electronic and structural properties of hexagonal-close-packed titanium and zirconium are determined from self-consistent linearized augmented-plane-wave (LAPW) calculations within the framework of the local-density-functional approximation (LDA). The equilibrium lattice parameters, bulk moduli, Poisson's ratios, and cohesive energies are obtained from the total energies calculated as functions of the a and c lattice parameters. As found in other LDA calculations, the cohesive energies are overestimated compared to experiment, but otherwise generally good agreement with experiment is obtained. The uncertainty in the results due to the particular choice of the LDA exchange-correlation potential is also examined by performing parallel calculations using the Kohn-Sham-Gaspar Xα (α=(2/3) exchange-only potential. We find that these calculations yield equilibrium volumes which differ by 6-8 % (with the Xα results in better agreement with experiment) with proportional differences in other structural properties, which we take to be an indication of the intrinsic reliability of the LDA.

  10. Equilibrium crystal phases of triblock Janus colloids.

    PubMed

    Reinhart, Wesley F; Panagiotopoulos, Athanassios Z

    2016-09-01

    Triblock Janus colloids, which are colloidal spheres decorated with attractive patches at each pole, have recently generated significant interest as potential building blocks for functional materials. Their inherent anisotropy is known to induce self-assembly into open structures at moderate temperatures and pressures, where they are stabilized over close-packed crystals by entropic effects. We present a numerical investigation of the equilibrium phases of triblock Janus particles with many different patch geometries in three dimensions, using Monte Carlo simulations combined with free energy calculations. In all cases, we find that the free energy difference between crystal polymorphs is less than 0.2 kBT per particle. By varying the patch fraction and interaction range, we show that large patches stabilize the formation of structures with four bonds per patch over those with three. This transition occurs abruptly above a patch fraction of 0.30 and has a strong dependence on the interaction range. Furthermore, we find that a short interaction range favors four bonds per patch, with longer range increasingly stabilizing structures with only three bonds per patch. By quantifying the effect of patch geometry on the stability of the equilibrium crystal structures, we provide insights into the fundamental design rules for constructing complex colloidal crystals. PMID:27609002

  11. Diluted equilibrium sterile neutrino dark matter

    NASA Astrophysics Data System (ADS)

    Patwardhan, Amol V.; Fuller, George M.; Kishimoto, Chad T.; Kusenko, Alexander

    2015-11-01

    We present a model where sterile neutrinos with rest masses in the range ˜keV to ˜MeV can be the dark matter and be consistent with all laboratory, cosmological, and large-scale structure, as well as x-ray constraints. These sterile neutrinos are assumed to freeze out of thermal and chemical equilibrium with matter and radiation in the very early Universe, prior to an epoch of prodigious entropy generation ("dilution") from out-of-equilibrium decay of heavy particles. In this work, we consider heavy, entropy-producing particles in the ˜TeV to ˜EeV rest-mass range, possibly associated with new physics at high-energy scales. The process of dilution can give the sterile neutrinos the appropriate relic densities, but it also alters their energy spectra so that they could act like cold dark matter, despite relatively low rest masses as compared to conventional dark matter candidates. Moreover, since the model does not rely on active-sterile mixing for producing the relic density, the mixing angles can be small enough to evade current x-ray or lifetime constraints. Nevertheless, we discuss how future x-ray observations, future lepton number constraints, and future observations and sophisticated simulations of large-scale structure could, in conjunction, provide evidence for this model and/or constrain and probe its parameters.

  12. Structural design using equilibrium programming formulations

    NASA Technical Reports Server (NTRS)

    Scotti, Stephen J.

    1995-01-01

    Solutions to increasingly larger structural optimization problems are desired. However, computational resources are strained to meet this need. New methods will be required to solve increasingly larger problems. The present approaches to solving large-scale problems involve approximations for the constraints of structural optimization problems and/or decomposition of the problem into multiple subproblems that can be solved in parallel. An area of game theory, equilibrium programming (also known as noncooperative game theory), can be used to unify these existing approaches from a theoretical point of view (considering the existence and optimality of solutions), and be used as a framework for the development of new methods for solving large-scale optimization problems. Equilibrium programming theory is described, and existing design techniques such as fully stressed design and constraint approximations are shown to fit within its framework. Two new structural design formulations are also derived. The first new formulation is another approximation technique which is a general updating scheme for the sensitivity derivatives of design constraints. The second new formulation uses a substructure-based decomposition of the structure for analysis and sensitivity calculations. Significant computational benefits of the new formulations compared with a conventional method are demonstrated.

  13. Equilibrium spin pulsars unite neutron star populations

    NASA Astrophysics Data System (ADS)

    Ho, Wynn C. G.; Klus, H.; Coe, M. J.; Andersson, Nils

    2014-02-01

    Many pulsars are formed with a binary companion from which they can accrete matter. Torque exerted by accreting matter can cause the pulsar spin to increase or decrease, and over long times, an equilibrium spin rate is achieved. Application of accretion theory to these systems provides a probe of the pulsar magnetic field. We compare the large number of recent torque measurements of accreting pulsars with a high-mass companion to the standard model for how accretion affects the pulsar spin period. We find that many long spin period (P ≳ 100 s) pulsars must possess either extremely weak (B < 1010 G) or extremely strong (B > 1014 G) magnetic fields. We argue that the strong-field solution is more compelling, in which case these pulsars are near spin equilibrium. Our results provide evidence for a fundamental link between pulsars with the slowest spin periods and strong magnetic fields around high-mass companions and pulsars with the fastest spin periods and weak fields around low-mass companions. The strong magnetic fields also connect our pulsars to magnetars and strong-field isolated radio/X-ray pulsars. The strong field and old age of our sources suggest their magnetic field penetrates into the superconducting core of the neutron star.

  14. Turbulence modeling for non-equilibrium flow

    NASA Technical Reports Server (NTRS)

    Durbin, P. A.

    1995-01-01

    The work performed during this year has involved further assessment and extension of the k-epsilon-v(exp 2) model, and initiation of work on scalar transport. The latter is introduced by the contribution of Y. Shabany to this volume. Flexible, computationally tractable models are needed for engineering CFD. As computational technology has progressed, the ability and need to use elaborate turbulence closure models has increased. The objective of our work is to explore and develop new analytical frameworks that might extend the applicability of the modeling techniques. In past years the development of a method for near-wall modeling was described. The method has been implemented into a CFD code and its viability has been demonstrated by various test cases. Further tests are reported herein. Non-equilibrium near-wall models are needed for some heat transfer applications. Scalar transport seems generally to be more sensitive to non-equilibrium effects than is momentum transport. For some applications turbulence anisotropy plays a role and an estimate of the full Reynolds stress tensor is needed. We have begun work on scalar transport per se, but in this brief I will only report on an extension of the k-epsilon-v(exp 2) model to predict the Reynolds stress tensor.

  15. Equilibrium & Nonequilibrium Fluctuation Effects in Biopolymer Networks

    NASA Astrophysics Data System (ADS)

    Kachan, Devin Michael

    Fluctuation-induced interactions are an important organizing principle in a variety of soft matter systems. In this dissertation, I explore the role of both thermal and active fluctuations within cross-linked polymer networks. The systems I study are in large part inspired by the amazing physics found within the cytoskeleton of eukaryotic cells. I first predict and verify the existence of a thermal Casimir force between cross-linkers bound to a semi-flexible polymer. The calculation is complicated by the appearance of second order derivatives in the bending Hamiltonian for such polymers, which requires a careful evaluation of the the path integral formulation of the partition function in order to arrive at the physically correct continuum limit and properly address ultraviolet divergences. I find that cross linkers interact along a filament with an attractive logarithmic potential proportional to thermal energy. The proportionality constant depends on whether and how the cross linkers constrain the relative angle between the two filaments to which they are bound. The interaction has important implications for the synthesis of biopolymer bundles within cells. I model the cross-linkers as existing in two phases: bound to the bundle and free in solution. When the cross-linkers are bound, they behave as a one-dimensional gas of particles interacting with the Casimir force, while the free phase is a simple ideal gas. Demanding equilibrium between the two phases, I find a discontinuous transition between a sparsely and a densely bound bundle. This discontinuous condensation transition induced by the long-ranged nature of the Casimir interaction allows for a similarly abrupt structural transition in semiflexible filament networks between a low cross linker density isotropic phase and a higher cross link density bundle network. This work is supported by the results of finite element Brownian dynamics simulations of semiflexible filaments and transient cross-linkers. I

  16. 29 CFR 2204.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false Net worth exhibit. 2204.202 Section 2204.202 Labor... COMMISSION Information Required From Applicants § 2204.202 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant as of the date specified by § 2204.105(c). The exhibit...

  17. 29 CFR 2204.202 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Net worth exhibit. 2204.202 Section 2204.202 Labor... COMMISSION Information Required From Applicants § 2204.202 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant as of the date specified by § 2204.105(c). The exhibit...

  18. Temporary and Travelling Exhibitions. Museums and Monuments, X.

    ERIC Educational Resources Information Center

    Daifuku, Hiroshi; And Others

    The permanent exhibition, the most typical form of museum exhibition, has failed to attract repeated visitation, since visitors quickly become familiar with the objects shown. The temporary exhibition evolved as a result for the need of repeated visitation. The temporary exhibition, set up for a period of one to six months, introduces fresh…

  19. Development of Exhibit on Arctic Climate Change Called The Arctic: A Friend Acting Strangely Exhibition

    SciTech Connect

    Stauffer, Barbara W.

    2006-04-01

    The exhibition, The Arctic: A Friend Acting Strangely, was developed at the Smithsonian Institution’s National Museum of Natural History (NMNH) as a part of the museum’s Forces of Change exhibit series on global change. It opened to the public in Spring 2006, in conjunction with another Forces of Change exhibit on the Earth’s atmosphere called Change Is in the Air. The exhibit was a 2000 square-foot presentation that explored the forces and consequences of the changing Arctic as documented by scientists and native residents alike. Native peoples of the Arctic have always lived with year-to-year fluctuations in weather and ice conditions. In recent decades, they have witnessed that the climate has become unpredictable, the land and sea unfamiliar. An elder in Arctic Canada recently described the weather as uggianaqtuq —an Inuit word that can suggest strange, unexpected behavior, sometimes described as that of “a friend acting strangely.” Scientists too have been documenting dramatic changes in the Arctic. Air temperatures have warmed over most—though not all—of the Arctic since the 1950s; Arctic precipitation may have increased by as much as 8%; seasonal melting of the Greenland Ice Sheet has increased on average by 16% since 1979; polar-orbiting satellites have measured a 15¬–20% decline in sea ice extent since the 1970s; aircraft reconnaissance and ship observations show a steady decrease in sea ice since the 1950s. In response to this warming, plant distributions have begun to shift and animals are changing their migration routes. Some of these changes may have beneficial effects while others may bring hardship or have costly implications. And, many scientists consider arctic change to be a ‘bell-weather’ for large-scale changes in other regions of the world. The exhibition included text, photos artifacts, hands-on interactives and other exhibitry that illustrated the changes being documented by indigenous people and scientists alike.

  20. Universality in equilibrium and away from it: A personal perspective

    SciTech Connect

    Munoz, Miguel A.

    2011-03-24

    In this talk/paper I discuss the concept of universality in phase transitions and the question of whether universality classes are more robust in equilibrium than away from it. In both of these situations, the main ingredients determining universality are symmetries, conservation laws, the dimension of the space and of the order-parameter and the presence of long-range interactions or quenched disorder. The existence of detailed-balance and fluctuation-dissipation theorems imposes severe constraints on equilibrium systems, allowing to define universality classes in a very robust way; instead, non-equilibrium allows for more variability. Still, quite robust non-equilibrium universality classes have been identified in the last decades. Here, I discuss some examples in which (i) non-equilibrium phase transitions are simply controlled by equilibrium critical points, i.e. non-equilibrium ingredients turn out to be irrelevant in the renormalization group sense and (ii) non-equilibrium situations in which equilibrium seems to come out of the blue, generating an adequate effective description of intrinsically non-equilibrium problems. Afterwards, I shall describe different genuinely non-equilibrium phase transitions in which introducing small, apparently innocuous changes (namely: presence or absence of an underlying lattice, parity conservation in the overall number of particles, existence of an un-accessible vacuum state, deterministic versus stochastic microscopic rules, presence or absence of a Fermionic constraint), the critical behavior is altered, making the case for lack of robustness. However, it will be argued that in all these examples, there is an underlying good reason (in terms of general principles) for universality to be altered. The final conclusions are that: (i) robust universality classes exist both in equilibrium and non-equilibrium; (ii) symmetry and conservation principles are crucial in both, (iii) non-equilibrium allows for more variability (i

  1. Comparison of equilibrium and non-equilibrium distribution coefficients for the human drug carbamazepine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The distribution coefficient (KD) for the human drug carbamazepine was measured using a non-equilibrium technique. Repacked soil columns were prepared using an Airport silt loam (Typic Natrustalf) with an average organic matter content of 2.45%. Carbamazepine solutions were then leached through th...

  2. Trunk biomechanical models based on equilibrium at a single-level violate equilibrium at other levels.

    PubMed

    Arjmand, N; Shirazi-Adl, A; Parnianpour, M

    2007-05-01

    Accurate estimation of muscle forces in various occupational tasks is critical for a reliable evaluation of spinal loads and subsequent assessment of risk of injury and management of back disorders. The majority of biomechanical models of multi-segmental spine estimate muscle forces and spinal loads based on the balance of net moments at a single level with no consideration for the equilibrium at remaining levels. This work aimed to quantify the extent of equilibrium violation and alterations in estimations when such models are performed at different levels. Results are compared with those of kinematics-driven model that satisfies equilibrium at all levels and EMG data. Regardless of the method used (optimization or EMG-assisted), single-level free body diagram models yielded estimations that substantially altered depending on the level considered (i.e., level dependency). Equilibrium of net moment was also grossly violated at remaining levels with the error increasing in more demanding tasks. These models may, however, be used to estimate spinal compression forces. PMID:17136359

  3. Reconstructing equilibrium entropy and enthalpy profiles from non-equilibrium pulling.

    PubMed

    Jeong, Daun; Andricioaei, Ioan

    2013-03-21

    The Jarzynski identity can be applied to instances when a microscopic system is pulled repeatedly but quickly along some coordinate, allowing the calculation of an equilibrium free energy profile along the pulling coordinate from a set of independent non-equilibrium trajectories. Using the formalism of Wiener stochastic path integrals in which we assign temperature-dependent weights to Langevin trajectories, we derive exact formulae for the temperature derivatives of the free energy profile. This leads naturally to analytical expressions for decomposing a free energy profile into equilibrium entropy and internal energy profiles from non-equilibrium pulling. This decomposition can be done from trajectories evolved at a unique temperature without repeating the measurement as done in finite-difference decompositions. Three distinct analytical expressions for the entropy-energy decomposition are derived: using a time-dependent generalization of the weighted histogram analysis method, a quasi-harmonic spring limit, and a Feynman-Kac formula. The three novel formulae of reconstructing the pair of entropy-energy profiles are exemplified by Langevin simulations of a two-dimensional model system prototypical for force-induced biomolecular conformational changes. Connections to single-molecule experimental means to probe the functionals needed in the decomposition are suggested. PMID:23534630

  4. Equilibrium and non-equilibrium cluster phases in colloids with competing interactions.

    PubMed

    Mani, Ethayaraja; Lechner, Wolfgang; Kegel, Willem K; Bolhuis, Peter G

    2014-07-01

    The phase behavior of colloids that interact via competing interactions - short-range attraction and long-range repulsion - is studied by computer simulation. In particular, for a fixed strength and range of repulsion, the effect of the strength of an attractive interaction (ε) on the phase behavior is investigated at various colloid densities (ρ). A thermodynamically stable equilibrium colloidal cluster phase, consisting of compact crystalline clusters, is found below the fluid-solid coexistence line in the ε-ρ parameter space. The mean cluster size is found to linearly increase with the colloid density. At large ε and low densities, and at small ε and high densities, a non-equilibrium cluster phase, consisting of elongated Bernal spiral-like clusters, is observed. Although gelation can be induced either by increasing ε at constant density or vice versa, the gelation mechanism is different in either route. While in the ρ route gelation occurs via a glass transition of compact clusters, gelation in the ε route is characterized by percolation of elongated clusters. This study both provides the location of equilibrium and non-equilibrium cluster phases with respect to the fluid-solid coexistence, and reveals the dependencies of the gelation mechanism on the preparation route. PMID:24824226

  5. The Feeling of "Face" in Confucian Society: From a Perspective of Psychosocial Equilibrium.

    PubMed

    Han, Kuei-Hsiang

    2016-01-01

    Previous research on the feeling of "face" has long described "face" as a complicated phenomenon in Confucian societies. Indeed, the feeling of face is highly context dependent. One may have very different (having or losing) face perception if the same face event occurs in a different context. To better capture the features of how face is felt, effects on possible responses need to be considered. Therefore, this article adopts a perspective of psychosocial equilibrium to elaborate people's feeling of face in Taiwan, a Confucian society. The first section illustrates the concept of psychosocial equilibrium and its psychodynamic effects on people's feeling of face. Then, the second section of this article takes positive social situations (having face events) as backdrop to exhibit how people balance their psychosocial equilibrium with different relationships. Following the positive social situations, the third section of this article then focuses on the negative situations (losing face events) to explain how losing face is felt due to unbalance of psychosocial equilibrium with one's relation in that specific context. PMID:27486411

  6. The Feeling of “Face” in Confucian Society: From a Perspective of Psychosocial Equilibrium

    PubMed Central

    Han, Kuei-Hsiang

    2016-01-01

    Previous research on the feeling of “face” has long described “face” as a complicated phenomenon in Confucian societies. Indeed, the feeling of face is highly context dependent. One may have very different (having or losing) face perception if the same face event occurs in a different context. To better capture the features of how face is felt, effects on possible responses need to be considered. Therefore, this article adopts a perspective of psychosocial equilibrium to elaborate people’s feeling of face in Taiwan, a Confucian society. The first section illustrates the concept of psychosocial equilibrium and its psychodynamic effects on people’s feeling of face. Then, the second section of this article takes positive social situations (having face events) as backdrop to exhibit how people balance their psychosocial equilibrium with different relationships. Following the positive social situations, the third section of this article then focuses on the negative situations (losing face events) to explain how losing face is felt due to unbalance of psychosocial equilibrium with one’s relation in that specific context. PMID:27486411

  7. Rarefied hypersonic flow simulations using the Navier-Stokes equations with non-equilibrium boundary conditions

    NASA Astrophysics Data System (ADS)

    Greenshields, Christopher J.; Reese, Jason M.

    2012-07-01

    This paper investigates the use of Navier-Stokes-Fourier equations with non-equilibrium boundary conditions (BCs) for simulation of rarefied hypersonic flows. It revisits a largely forgotten derivation of velocity slip and temperature jump by Patterson, based on Grad's moment method. Mach 10 flow around a cylinder and Mach 12.7 flow over a flat plate are simulated using both computational fluid dynamics using the temperature jump BCs of Patterson and Smoluchowski and the direct simulation Monte-Carlo (DSMC) method. These flows exhibit such strongly non-equilibrium behaviour that, following Patterson's analysis, they are strictly beyond the range of applicability of the BCs. Nevertheless, the results using Patterson's temperature jump BC compare quite well with the DSMC and are consistently better than those using the standard Smoluchowski temperature jump BC. One explanation for this better performance is that an assumption made by Patterson, based on the flow being only slightly non-equilibrium, introduces an additional constraint to the resulting BC model in the case of highly non-equilibrium flows.

  8. Equilibrium and non-equilibrium properties of finite-volume crystallites

    NASA Astrophysics Data System (ADS)

    Degawa, Masashi

    Finite volume effects on equilibrium and non-equilibrium properties of nano-crystallites are studied theoretically and compared to both experiment and simulation. When a system is isolated or its size is small compared to the correlation length, all equilibrium and close-to-equilibrium properties will depend on the system boundary condition. Specifically for solid nano-crystallites, their finite size introduces global curvature to the system, which alters its equilibrium properties compared to the thermodynamic limit. Also such global curvature leads to capillary-induced morphology changes of the surface. Interesting dynamics can arise when the crystallite is supported on a substrate, with crossovers of the dominant driving force from the capillary force and crystallite-substrate interactions. To address these questions, we introduce thermodynamic functions for the boundary conditions, which can be derived from microscopic models. For nano-crystallites, the boundary is the surface (including interfaces), the thermodynamic description is based on the steps that define the shape of the surface, and the underlying microscopic model includes kinks. The global curvature of the surface introduces metastable states with different shapes governed by a constant of integration of the extra boundary condition, which we call the shape parameter c. The discrete height of the steps introduces transition states in between the metastable states, and the lowest energy accessible structure (energy barrier less 10k BT) as a function of the volume has been determined. The dynamics of nano-crystallites as they relax from a non-equilibrium structure is described quantitatively in terms of the motion of steps in both capillary-induced and interface-boundary-induced regimes. The step-edge fluctuations of the top facet are also influenced by global curvature and volume conservation and the effect yields different dynamic scaling exponents from a pure 1D system. Theoretical results are

  9. Non equilibrium statistical mechanics of geophysical flows

    NASA Astrophysics Data System (ADS)

    Bouchet, F.

    2012-04-01

    Onsager first proposed to explain the self organization of turbulent flows using the statistical mechanics framework. Generalization of those ideas to the class of 2D-Euler and Quasi-Gestrophic models led to the Robert-Sommeria-Miller theory. This approach was successful in modeling many geophysical phenomena: the Great Red Spot of Jupiter [2, 1], drift of mesoscale ocean vortices [3, 1], self-organization of Quasi-Geostrophic dynamics in mid-basin jets similar to the Gulf-Stream and the Kuroshio [3, 1], and so on. However, this type of equilibrium theories fail to take into account forces and dissipation. This is a strong limitation for many geophysical phenomena. Interestingly, it is possible to circumvent these difficulties using the most modern theoretical development of non-equilibrium statistical mechanics: large deviation [4] and instanton theories. As an example, we will discuss geophysical turbulent flows which have more than one attractor (bistability or mutistability). For instance, paths of the Kuroshio [5], the Earth's magnetic field reversal, atmospheric flows [6], MHD experiments [7], 2D turbulence experiments [8, 9], 3D flows [10] show this kind of behavior. On Navier-Stokes and Quasi-Geostrophic turbulent flows, we predict the conditions for existence of rare transitions between attractors, and the dynamics of those transitions. We discuss how these results are probably connected to the long debated existence of multi-stability in the atmosphere and oceans, and how non-equilibrium statistical mechanics can allow to settle this issue. Generalization of statistical mechanics to more comprehensive hydrodynamical models, which include gravity wave dynamics and allow for the possibility of energy transfer through wave motion, would be extremely interesting. Namely, both are essential in understanding energy balance of geophysical flows. However, due to difficulties in essential theoretical parts of the statistical mechanics approach, previous methods

  10. Bose-Einstein Condensation and Condensation of q-Particles in Equilibrium and Nonequilibrium Thermodynamics

    NASA Astrophysics Data System (ADS)

    Accardi, Luigi; Fidaleo, Francesco

    2016-04-01

    In the setting of the principle of local equilibrium which asserts that the temperature is a function of energy levels of the system, we exhibit plenty of steady states describing condensation of free bosons which are not in thermal equilibrium. The surprising facts are that the condensation can occur both in dimension less than 3 in configuration space, and even in excited energy levels. The investigation relative to nonequilibrium suggests a new approach to the condensation which allows a unified analysis involving also condensation of q-particles, -1 ≤ q ≤ 1, where q = ±1 corresponds to the Bose/Fermi alternative. For such q-particles, it is shown that condensation can occur only if 0 exhibiting condensation phenomena naturally occur even in the usual situation of equilibrium thermodynamics involving bosons. The new approach proposed in the present paper for the situation of second quantisation of free particles, is based on the theory of distributions, which might hopefully be extended to more general cases.

  11. Uranium removal from aqueous solution by coir pith: equilibrium and kinetic studies.

    PubMed

    Parab, Harshala; Joshi, Shreeram; Shenoy, Niyoti; Verma, Rakesh; Lali, Arvind; Sudersanan, M

    2005-07-01

    Basic aspects of uranium adsorption by coir pith have been investigated by batch equilibration. The influence of different experimental parameters such as final solution pH, adsorbent dosage, sorption time, temperature and various concentrations of uranium on uptake were evaluated. Maximum uranium adsorption was observed in the pH range 4.0-6.0. The Freundlich and Langmuir adsorption models were used for the mathematical description of the adsorption equilibrium. The equilibrium data fitted well to both the equilibrium models in the studied concentration range of uranium (200-800 mg/l) and temperatures (305-336 K). The coir pith exhibited the highest uptake capacity for uranium at 317 K, at the final solution pH value of 4.3 and at the initial uranium concentration of 800 mg/l. The kinetics of the adsorption process followed a second-order adsorption. The adsorbent used proved to be suitable for removal of uranium from aqueous solutions. 0.2 N HCl was effective in uranium desorption. The results indicated that the naturally abundant coir pith of otherwise nuisance value exhibited considerable potential for application in removal of uranium from aqueous solution. PMID:15734311

  12. Dynamic scaling for the growth of non-equilibrium fluctuations during thermophoretic diffusion in microgravity.

    PubMed

    Cerbino, Roberto; Sun, Yifei; Donev, Aleksandar; Vailati, Alberto

    2015-01-01

    Diffusion processes are widespread in biological and chemical systems, where they play a fundamental role in the exchange of substances at the cellular level and in determining the rate of chemical reactions. Recently, the classical picture that portrays diffusion as random uncorrelated motion of molecules has been revised, when it was shown that giant non-equilibrium fluctuations develop during diffusion processes. Under microgravity conditions and at steady-state, non-equilibrium fluctuations exhibit scale invariance and their size is only limited by the boundaries of the system. In this work, we investigate the onset of non-equilibrium concentration fluctuations induced by thermophoretic diffusion in microgravity, a regime not accessible to analytical calculations but of great relevance for the understanding of several natural and technological processes. A combination of state of the art simulations and experiments allows us to attain a fully quantitative description of the development of fluctuations during transient diffusion in microgravity. Both experiments and simulations show that during the onset the fluctuations exhibit scale invariance at large wave vectors. In a broader range of wave vectors simulations predict a spinodal-like growth of fluctuations, where the amplitude and length-scale of the dominant mode are determined by the thickness of the diffuse layer. PMID:26419420

  13. Adaptive behaviour and multiple equilibrium states in a predator-prey model.

    PubMed

    Pimenov, Alexander; Kelly, Thomas C; Korobeinikov, Andrei; O'Callaghan, Michael J A; Rachinskii, Dmitrii

    2015-05-01

    There is evidence that multiple stable equilibrium states are possible in real-life ecological systems. Phenomenological mathematical models which exhibit such properties can be constructed rather straightforwardly. For instance, for a predator-prey system this result can be achieved through the use of non-monotonic functional response for the predator. However, while formal formulation of such a model is not a problem, the biological justification for such functional responses and models is usually inconclusive. In this note, we explore a conjecture that a multitude of equilibrium states can be caused by an adaptation of animal behaviour to changes of environmental conditions. In order to verify this hypothesis, we consider a simple predator-prey model, which is a straightforward extension of the classic Lotka-Volterra predator-prey model. In this model, we made an intuitively transparent assumption that the prey can change a mode of behaviour in response to the pressure of predation, choosing either "safe" of "risky" (or "business as usual") behaviour. In order to avoid a situation where one of the modes gives an absolute advantage, we introduce the concept of the "cost of a policy" into the model. A simple conceptual two-dimensional predator-prey model, which is minimal with this property, and is not relying on odd functional responses, higher dimensionality or behaviour change for the predator, exhibits two stable co-existing equilibrium states with basins of attraction separated by a separatrix of a saddle point. PMID:25732186

  14. Dynamic scaling for the growth of non-equilibrium fluctuations during thermophoretic diffusion in microgravity

    PubMed Central

    Cerbino, Roberto; Sun, Yifei; Donev, Aleksandar; Vailati, Alberto

    2015-01-01

    Diffusion processes are widespread in biological and chemical systems, where they play a fundamental role in the exchange of substances at the cellular level and in determining the rate of chemical reactions. Recently, the classical picture that portrays diffusion as random uncorrelated motion of molecules has been revised, when it was shown that giant non-equilibrium fluctuations develop during diffusion processes. Under microgravity conditions and at steady-state, non-equilibrium fluctuations exhibit scale invariance and their size is only limited by the boundaries of the system. In this work, we investigate the onset of non-equilibrium concentration fluctuations induced by thermophoretic diffusion in microgravity, a regime not accessible to analytical calculations but of great relevance for the understanding of several natural and technological processes. A combination of state of the art simulations and experiments allows us to attain a fully quantitative description of the development of fluctuations during transient diffusion in microgravity. Both experiments and simulations show that during the onset the fluctuations exhibit scale invariance at large wave vectors. In a broader range of wave vectors simulations predict a spinodal-like growth of fluctuations, where the amplitude and length-scale of the dominant mode are determined by the thickness of the diffuse layer. PMID:26419420

  15. Universal far-from-equilibrium dynamics of a holographic superconductor.

    PubMed

    Sonner, Julian; Del Campo, Adolfo; Zurek, Wojciech H

    2015-01-01

    Symmetry-breaking phase transitions are an example of non-equilibrium processes that require real-time treatment, a major challenge in strongly coupled systems without long-lived quasiparticles. Holographic duality provides such an approach by mapping strongly coupled field theories in D dimensions into weakly coupled quantum gravity in D+1 anti-de Sitter spacetime. Here we use holographic duality to study the formation of topological defects-winding numbers-in the course of a superconducting transition in a strongly coupled theory in a 1D ring. When the system undergoes the transition on a given quench time, the condensate builds up with a delay that can be deduced using the Kibble-Zurek mechanism from the quench time and the universality class of the theory, as determined from the quasinormal mode spectrum of the dual model. Typical winding numbers deposited in the ring exhibit a universal fractional power law dependence on the quench time, also predicted by the Kibble-Zurek Mechanism. PMID:26100330

  16. Equilibrium and pre-equilibrium processes in the {sup 55}Mn({sup 6}Li,xp) and {sup 57}Fe({alpha},xp) reactions

    SciTech Connect

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Massey, T. N.; Buerger, A.; Goergen, A.; Guttormsen, M.; Larsen, A. C.; Siem, S.; Kalbach, C.

    2011-05-15

    Spectra of outgoing neutrons and protons from the {sup 6}Li + {sup 55}Mn reaction and protons from the {alpha} + {sup 57}Fe reaction have been measured with beams of 15-MeV {sup 6}Li ions and 30-MeV {alpha} particles. These reactions proceed through the same {sup 61}Ni nucleus at the same excitation energy, thus allowing the difference in reaction mechanisms to be studied. It is shown that spectra from the first reaction measured at backward angles are due to emission from a traditional compound nucleus reaction, in which the intermediate nucleus has reached statistical equilibrium; the spectra from the second reaction contain a significant fraction of pre-equilibrium emission at all angles. Level density parameters of the residual nucleus {sup 60}Co have been obtained from the first reaction. Both emission spectra and angular distributions have been measured for the second reaction. It was found that the pre-equilibrium component exhibits a forward-peaked angular distribution, as expected, but with a steeper slope than predicted and with an unusual slight rise at angles above 120 deg. The backward-angle rise is explained qualitatively by the dominance of the multistep compound mechanism at backward angles.

  17. Punctuated equilibrium dynamics in human communications

    NASA Astrophysics Data System (ADS)

    Peng, Dan; Han, Xiao-Pu; Wei, Zong-Wen; Wang, Bing-Hong

    2015-10-01

    A minimal model based on network incorporating individual interactions is proposed to study the non-Poisson statistical properties of human behavior: individuals in system interact with their neighbors, the probability of an individual acting correlates to its activity, and all the individuals involved in action will change their activities randomly. The model reproduces varieties of spatial-temporal patterns observed in empirical studies of human daily communications, providing insight into various human activities and embracing a range of realistic social interacting systems, particularly, intriguing bimodal phenomenon. This model bridges priority queueing theory and punctuated equilibrium dynamics, and our modeling and analysis is likely to shed light on non-Poisson phenomena in many complex systems.

  18. Equilibrium and Kinetics of Block Copolymers Micelles

    NASA Astrophysics Data System (ADS)

    Mysona, Joshua; Morse, David

    Both equilibrium properties of micelles, such as the critical micelle concentration (CMC), and dynamical properties such as the micelle lifetime are difficult to study in simulations because of the slow dynamics of the processes by which micelles are created and destroyed. We first discuss a method of precisely identifying the CMC in a simple model of block copolymer micelles in a homopolymer matrix, which makes use of thermodynamic integration to compute the free energy of formation. We then examine the free energy barriers to competing mechanisms for creating and destroying micelles, which could occur predominantly either by a step-wise process involving insertion and extraction of single molecules or by fission and fusion of entire micelles.

  19. Radiative equilibrium and escape of Pluto's atmosphere

    NASA Astrophysics Data System (ADS)

    Erwin, Justin; Koskinen, Tommi T.; Yelle, Roger V.

    2015-11-01

    Observations of Pluto’s extend atmosphere by the New Horizons spacecraft motivate an update to our modeling effort on Pluto’s atmosphere. New Horizons observations have already improved our constraints on planet radius and surface pressure, which are key to modeling the atmospheric structure. We model the radiative conductive equilibrium in the lower atmosphere combined with the UV driven escape model of the upper atmosphere. The non-LTE radiative transfer model in the lower atmosphere include heating and cooling by CH4, CO, and HCN. The escape model of the upper atmosphere is updated to include diffusion and escape of each molecular component. These results will be used to aid in the analysis and better understanding of the full atmospheric structure.

  20. Thermal equilibrium of two quantum Brownian particles

    SciTech Connect

    Valente, D. M.; Caldeira, A. O.

    2010-01-15

    The influence of the environment in the thermal equilibrium properties of a bipartite continuous variable quantum system is studied. The problem is treated within a system-plus-reservoir approach. The considered model reproduces the Brownian motion when the two particles are isolated and induces an effective interaction between them, depending on the choice of the spectral function of the bath. The coupling between the system and the environment guarantees the translational invariance of the system in the absence of an external potential. The entanglement between the particles is measured by the logarithmic negativity, which is shown to monotonically decrease with the increase of the temperature. A range of finite temperatures is found in which entanglement is still induced by the reservoir.

  1. Conformational equilibrium in supramolecular chemistry: Dibutyltriuret case

    PubMed Central

    Mroczyńska, Karina; Kaczorowska, Małgorzata; Kolehmainen, Erkki; Grubecki, Ireneusz; Pietrzak, Marek

    2015-01-01

    Summary The association of substituted benzoates and naphthyridine dianions was used to study the complexation of dibutyltriuret. The title molecule is the simplest molecule able to form two intramolecular hydrogen bonds. The naphthyridine salt was used to break two intramolecular hydrogen bonds at a time while with the use of substituted benzoates the systematic approach to study association was achieved. Both, titrations and variable temperature measurements shed the light on the importance of conformational equilibrium and its influence on association in solution. Moreover, the associates were observed by mass spectrometry. The DFT-based computations for complexes and single bond rotational barriers supports experimental data and helps understanding the properties of multiply hydrogen bonded complexes. PMID:26664631

  2. Information thermodynamics of near-equilibrium computation.

    PubMed

    Prokopenko, Mikhail; Einav, Itai

    2015-06-01

    In studying fundamental physical limits and properties of computational processes, one is faced with the challenges of interpreting primitive information-processing functions through well-defined information-theoretic as well as thermodynamic quantities. In particular, transfer entropy, characterizing the function of computational transmission and its predictability, is known to peak near critical regimes. We focus on a thermodynamic interpretation of transfer entropy aiming to explain the underlying critical behavior by associating information flows intrinsic to computational transmission with particular physical fluxes. Specifically, in isothermal systems near thermodynamic equilibrium, the gradient of the average transfer entropy is shown to be dynamically related to Fisher information and the curvature of system's entropy. This relationship explicitly connects the predictability, sensitivity, and uncertainty of computational processes intrinsic to complex systems and allows us to consider thermodynamic interpretations of several important extreme cases and trade-offs. PMID:26172697

  3. Equilibrium properties of chemically reacting gases

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The equilibrium energy, enthalpy, entropy, specific heat at constant volume and constant pressure, and the equation of state of the gas are all derived for chemically reacting gas mixtures in terms of the compressibility, the mol fractions, the thermodynamic properties of the pure gas components, and the change in zero point energy due to reaction. Results are illustrated for a simple diatomic dissociation reaction and nitrogen is used as an example. Next, a gas mixture resulting from combined diatomic dissociation and atomic ionization reactions is treated and, again, nitrogen is used as an example. A short discussion is given of the additional complexities involved when precise solutions for high-temperature air are desired, including effects caused by NO produced in shuffle reactions and by other trace species formed from CO2, H2O and Ar found in normal air.

  4. Anisotropic pressure tokamak equilibrium and stability considerations

    SciTech Connect

    Salberta, E.R.; Grimm, R.C.; Johnson, J.L.; Manickam, J.; Tang, W.M.

    1987-02-01

    Investigation of the effect of pressure anisotropy on tokamak equilibrium and stability is made with an MHD model. Realistic perpendicular and parallel pressure distributions, P/sub perpendicular/(psi,B) and P/sub parallel/(psi,B), are obtained by solving a one-dimensional Fokker-Planck equation for neutral beam injection to find a distribution function f(E, v/sub parallel//v) at the position of minimum field on each magnetic surface and then using invariance of the magnetic moment to determine its value at each point on the surface. The shift of the surfaces of constant perpendicular and parallel pressure from the flux surfaces depends strongly on the angle of injection. This shift explains the observed increase or decrease in the stability conditions. Estimates of the stabilizing effect of hot trapped ions indicates that a large fraction must be nonresonant and thus decoupled from the bad curvature before it becomes important.

  5. Extant mammal body masses suggest punctuated equilibrium.

    PubMed

    Mattila, Tiina M; Bokma, Folmer

    2008-10-01

    Is gradual microevolutionary change within species simultaneously the source of macroevolutionary differentiation between species? Since its first publication, Darwin's original idea that phenotypic differences between species develop gradually over time, as the accumulation of small selection-induced changes in successive generations has been challenged by palaeontologists claiming that, instead, new species quickly acquire their phenotypes to remain virtually unchanged until going extinct again. This controversy, widely known as the 'punctuated equilibrium' debate, remained unresolved, largely owing to the difficulty of distinguishing biological species from fossil remains. We analysed body masses of 2143 existing mammal species on a phylogeny comprising 4510 (i.e. nearly all) extant species to estimate rates of gradual (anagenetic) and speciational (cladogenetic) evolution. Our Bayesian estimates from mammals as well as separate sub-clades such as primates and carnivores suggest that gradual evolution is responsible for only a small part of body size variation between mammal species. PMID:18595835

  6. The Equilibrium Spreading Tension of Pulmonary Surfactant.

    PubMed

    Dagan, Maayan P; Hall, Stephen B

    2015-12-01

    Monomolecular films at an air/water interface coexist at the equilibrium spreading tension (γ(e)) with the bulk phase from which they form. For individual phospholipids, γ(e) is single-valued, and separates conditions at which hydrated vesicles adsorb from tensions at which overcompressed monolayers collapse. With pulmonary surfactant, isotherms show that monolayers compressed on the surface of bubbles coexist with the three-dimensional collapsed phase over a range of surface tensions. γ(e) therefore represents a range rather than a single value of surface tension. Between the upper and lower ends of this range, rates of collapse for spread and adsorbed films decrease substantially. Changes during adsorption across this narrow region of coexistence between the two- and three-dimensional structures at least partially explain how alveolar films of pulmonary surfactant become resistant to collapse. PMID:26583569

  7. Oppositely charged colloids out of equilibrium

    NASA Astrophysics Data System (ADS)

    Vissers, T.

    2010-11-01

    Colloids are particles with a size in the range of a few nanometers up to several micrometers. Similar to atomic and molecular systems, they can form gases, liquids, solids, gels and glasses. Colloids can be used as model systems because, unlike molecules, they are sufficiently large to be studied directly with light microscopy and move sufficiently slow to study their dynamics. In this thesis, we study binary systems of polymethylmethacrylate (PMMA) colloidal particles suspended in low-polar solvent mixtures. Since the ions can still partially dissociate, a surface charge builds up which causes electrostatic interactions between the colloids. By carefully tuning the conditions inside the suspension, we make two kinds of particles oppositely charged. To study our samples, we use Confocal Laser Scanning Microscopy (CLSM). The positively and negatively charged particles can be distinguished by a different fluorescent dye. Colloids constantly experience a random motion resulting from random kicks of surrounding solvent molecules. When the attractions between the oppositely charged particles are weak, the particles can attach and detach many times and explore a lot of possible configurations and the system can reach thermodynamic equilibrium. For example, colloidal ‘ionic’ crystals consisting of thousands to millions of particles can form under the right conditions. When the attractions are strong, the system can become kinetically trapped inside a gel-like state. We observe that when the interactions change again, crystals can even emerge again from this gel-like phase. By using local order parameters, we quantitatively study the crystallization of colloidal particles and identify growth defects inside the crystals. We also study the effect of gravity on the growth of ionic crystals by using a rotating stage. We find that sedimentation can completely inhibit crystal growth and plays an important role in crystallization from the gel-like state. The surface

  8. Nash equilibrium and multi criterion aerodynamic optimization

    NASA Astrophysics Data System (ADS)

    Tang, Zhili; Zhang, Lianhe

    2016-06-01

    Game theory and its particular Nash Equilibrium (NE) are gaining importance in solving Multi Criterion Optimization (MCO) in engineering problems over the past decade. The solution of a MCO problem can be viewed as a NE under the concept of competitive games. This paper surveyed/proposed four efficient algorithms for calculating a NE of a MCO problem. Existence and equivalence of the solution are analyzed and proved in the paper based on fixed point theorem. Specific virtual symmetric Nash game is also presented to set up an optimization strategy for single objective optimization problems. Two numerical examples are presented to verify proposed algorithms. One is mathematical functions' optimization to illustrate detailed numerical procedures of algorithms, the other is aerodynamic drag reduction of civil transport wing fuselage configuration by using virtual game. The successful application validates efficiency of algorithms in solving complex aerodynamic optimization problem.

  9. Plasmon damping in graphene out of equilibrium

    NASA Astrophysics Data System (ADS)

    Sun, Zhiyuan; Basov, Dimitri; Fogler, Michael

    Motivated by recent experiments with graphene under high photoexcitation, we study theoretically plasmons of graphene in the two-temperature regime, i.e., the regime where electrons are much hotter than the lattice. We calculate the plasmon damping due to scattering of electrons by acoustic phonons, which is the dominant intrinsic contribution in clean graphene. As the system relaxes to equilibrium, the plasmon frequency adiabatically changes with time. We show that this causes a partial compensation of the plasmon damping. A similar mechanism may apply to another collective mode (the energy wave) predicted to exist in graphene in the low-frequency hydrodynamic regime. Implications for infrared and THz pump-probe experiments are discussed.

  10. Equilibrium spin pulsars unite neutron star populations

    NASA Astrophysics Data System (ADS)

    Ho, Wynn; Klus, Helen; Coe, Malcolm; Andersson, Nils

    2015-08-01

    We compare the large number of recent torque measurements of accreting pulsars with a high-mass companion to the standard model for how accretion affects the pulsar spin period. We find that many long spin period (P > 100 s) pulsars must possess either extremely weak (B < 10^10 G) or extremely strong (B > 10^14 G) magnetic fields. We argue that the strong-field solution is more compelling, in which case these pulsars are near spin equilibrium. Our results provide evidence for a fundamental link between pulsars with the slowest spin periods and strong magnetic fields around high-mass companions and pulsars with the fastest spin periods and weak fields around low-mass companions. The strong magnetic fields also connect our pulsars to magnetars and strong-field isolated radio/X-ray pulsars. The strong field and old age of our sources suggests their magnetic field penetrates into the superconducting core of the neutron star.

  11. Equilibrium and Stability of Coronal Helmet Streamers

    NASA Astrophysics Data System (ADS)

    Glukhov, Vyacheslav Sergeevich

    1997-05-01

    Equilibrium states and stability of partially open magentic field structures in the solar corona are studied. Soft X-ray observations of the birth and evolution of a giant coronal helmet streamer suggest that the energy source responsible for the X-ray manifestation of the structure is most probably located in the lower corona. The downward heat flux is the indication that a significant part of the source's energy is transported to the top of the structure and converted there to a disposable form. It is shown that by applying the thermodynamic equilibrium model of the corona to the two-dimensional X-ray data it is possible to reconstruct the three-dimensional form of the coronal helmet. The general significance of the projective geometry effects for the observation of the solar corona is discussed. The hypothesis of thermal pressure increase as the cause of the observed helmet expansion is verified numerically. It is shown that in the solar corona a relatively small variations of the pressure distribution in the closed field region can cause huge variations in the geometry of a coronal helmet streamer. Numerical simulations of the morphology and energy accumulation in helmet-like structures subject to photospheric shear motion show that the magnetic field surrounding a partially open structure can inhibit catastrophic expansion of the structure as its energy grows. Stability of a coronal streamer in the framework of the neutral current sheet model is studied theoretically. It is shown that effects of viscosity and the finite Larmor radius dominate effects of inertial fluid motion in the tearing mode instability of a neutral current sheet. Two new regimes of the instability are discovered. It is proven that in the solar corona the rates of growth of the neutral current sheet instability are much smaller than previously believed. Implications of the obtained results are discussed.

  12. Experimental studies in non-equilibrium physics

    NASA Astrophysics Data System (ADS)

    Cressman, John Robert, Jr.

    This work is a collection of three experiments aimed at studying different facets of non-equilibrium dynamics. Chapter I concerns strongly compressible turbulence, which turns out to be very different from incompressible turbulence. The focus is on the dispersion of contaminants in such a flow. This type of turbulence can be studied, at very low mach number, by measuring the velocity fields of particles that float on a turbulently stirred body of water. It turns out that in the absence of incompressibility, the turbulence causes particles to cluster rather than to disperse. The implications of the observations are far reaching and include the transport of pollutants on the oceans surface, phytoplankton growth, as well as industrial applications. Chapter II deals with the effects of polymer additives on drag reduction and turbulent suppression, a well-known phenomenon that is not yet understood. In an attempt to simplify the problem, the effects of a polymer additive were investigated in a vortex street formed in a flowing soap film. Measurements suggest that an increase in elongational viscosity is responsible for a substantial reduction in periodic velocity fluctuations. This study also helps to illuminate the mechanism responsible for vortex separation in the wake of a bluff body. Chapter III describes an experiment designed to test a theoretical approach aimed at generalizing the classical fluctuation dissipation theorem (FDT). This theorem applies to systems driven only slightly away from thermal equilibrium, whereas ours, a liquid crystal under-going electroconvection, is so strongly driven, that the FDT does not apply. Both theory and experiment focus on the flux in global power fluctuations. Physical limitations did not permit a direct test of the theory, however it was possible to establish several interesting characteristics of the system: the source of the fluctuations is the transient defect structures that are generated when the system is driven hard

  13. Radiation temperature of non-equilibrium plasmas

    SciTech Connect

    Arunasalam, V.

    1991-07-01

    In fusion devices measurements of the radiation temperature T{sub r} ({omega}, k) near the electron cyclotron frequency {omega}{sub C} and the second harmonic 2{omega}{sub C} in directions nearly perpendicular to the confining magnetic field B (i.e., k {approx} k {perpendicular}) serve to map out the electron temperature profiles T{sub e}(r,t). For optically thick plasma at thermodynamic equilibrium T{sub r} = T{sub e}. However, there is increasing experimental evidence for the presence of non-equilibrium electron distributions (such as a drifting Maxwellian with appreciable values of the streaming parameter {omicron} = v{sub d}/v{sub t}, a bi- Maxwellian, and anisotropic Maxwellian with T {perpendicular} {ne} T {parallel}, etc.,) in tokamak plasmas, especially in the presence of radio-frequency heating. Here, we examine (both non-relativistically and relativistically) the dependence of T{sub r} on {omicron}, T{perpendicular}/T{parallel}, T{sub h}/T{sub b}, n{sub h}/n{sub b}etc., where n{sub b}, n{sub h}, T{sub b}, T{sub h} are the densities and temperatures, respectively, of the bulk and the hot components of the bi-Maxwellian plasma. Our bi-Maxwellian results predict that the ratio T{sub r}/T{sub e} is a very sensitive function of the ratios n{sub h}/n{sub b} and T{sub h}/T{sub b}. Further, these relativistic and non-relativistic results satisfy the well-known limit c {yields} {infinity} correspondence principle'', showing that the intensity of the emission and absorption line is independent of the line broadening mechanism. 44 refs., 2 figs.

  14. Marsh Equilibrium Theory: A Paleo Perspective

    NASA Astrophysics Data System (ADS)

    Morris, J. T.; Kemp, A.; Barber, D. C.; Culver, S. J.; Kegel, J.; Horton, B.

    2014-12-01

    Salt marshes adapt to changes in sea level by means of biogeomorphological feedback. These feedbacks maintain a dynamic equilibrium with sea level, within limits. Reconstructions of sea-level changes derived from salt-marsh sediment provide a paleo perspective for evaluating these feedbacks and for predicting the ecological effects of future sea-level rise. The Marsh Equilibrium Model (MEM) was modified to accommodate long records of sea level and sediment physical and chemical variables derived from high resolution (decadal and decimeter) reconstruction of sea level spanning the late Holocene using foraminifera preserved in North Carolina salt-marsh sediments. Model outputs from a run of nearly 1100-yr show periods of time when the marsh was predicted to be positioned near the top of the tidal frame (inundation time near zero) and times when the marsh was much deeper in the intertidal zone (inundation time of ca. 0.4). An elevation at mean sea level would correspond to an inundation time of 0.5, which is close to the lower limit of the vegetation and is indicative of a marsh that is just forming or, alternatively, a marsh that is on the verge of collapse. The model also indicates that the standing biomass on the marsh surface and sediment organic matter (SOM) content would have varied in harmony with the inundation time. In times past when the inundation time and the opportunity for mineral sedimentation decreased, the sediment organic matter (SOM) content increased. The low SOM concentration near the marsh surface today is consistent with a marsh that is low in the tidal frame. The SOM depth profile is a function of the relative elevation of the marsh, as well as changes in the input of inorganic sediment to the estuary. To effectively manage and preserve valuable salt-marsh ecosystems it is critical to accurately predict their response to projected sea-level changes.

  15. A Progression of Static Equilibrium Laboratory Exercises

    NASA Astrophysics Data System (ADS)

    Kutzner, Mickey; Kutzner, Andrew

    2013-10-01

    Although simple architectural structures like bridges, catwalks, cantilevers, and Stonehenge have been integral in human societies for millennia, as have levers and other simple tools, modern students of introductory physics continue to grapple with Newton's conditions for static equilibrium. As formulated in typical introductory physics textbooks, these two conditions appear as ΣF=0(1) and Στ=0,(2) where each torque τ is defined as the cross product between the lever arm vector r and the corresponding applied force F, τ =r×F,(3) having magnitude, τ =Frsinθ.(4) The angle θ here is between the two vectors F and r. In Eq. (1), upward (downward) forces are considered positive (negative). In Eq. (2), counterclockwise (clockwise) torques are considered positive (negative). Equation (1) holds that the vector sum of the external forces acting on an object must be zero to prevent linear accelerations; Eq. (2) states that the vector sum of torques due to external forces about any axis must be zero to prevent angular accelerations. In our view these conditions can be problematic for students because a) the equations contain the unfamiliar summation notation Σ, b) students are uncertain of the role of torques in causing rotations, and c) it is not clear why the sum of torques is zero regardless of the choice of axis. Gianino5 describes an experiment using MBL and a force sensor to convey the meaning of torque as applied to a rigid-body lever system without exploring quantitative aspects of the conditions for static equilibrium.

  16. Uncertainty Quantification of Equilibrium Climate Sensitivity

    NASA Astrophysics Data System (ADS)

    Lucas, D. D.; Brandon, S. T.; Covey, C. C.; Domyancic, D. M.; Johannesson, G.; Klein, R.; Tannahill, J.; Zhang, Y.

    2011-12-01

    Significant uncertainties exist in the temperature response of the climate system to changes in the levels of atmospheric carbon dioxide. We report progress to quantify the uncertainties of equilibrium climate sensitivity using perturbed parameter ensembles of the Community Earth System Model (CESM). Through a strategic initiative at the Lawrence Livermore National Laboratory, we have been developing uncertainty quantification (UQ) methods and incorporating them into a software framework called the UQ Pipeline. We have applied this framework to generate a large number of ensemble simulations using Latin Hypercube and other schemes to sample up to three dozen uncertain parameters in the atmospheric (CAM) and sea ice (CICE) model components of CESM. The parameters sampled are related to many highly uncertain processes, including deep and shallow convection, boundary layer turbulence, cloud optical and microphysical properties, and sea ice albedo. An extensive ensemble database comprised of more than 46,000 simulated climate-model-years of recent climate conditions has been assembled. This database is being used to train surrogate models of CESM responses and to perform statistical calibrations of the CAM and CICE models given observational data constraints. The calibrated models serve as a basis for propagating uncertainties forward through climate change simulations using a slab ocean model configuration of CESM. This procedure is being used to quantify the probability density function of equilibrium climate sensitivity accounting for uncertainties in climate model processes. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was funded by the Uncertainty Quantification Strategic Initiative Laboratory Directed Research and Development Project at LLNL under project tracking code 10-SI-013. (LLNL-ABS-491765)

  17. Strange scaling and relaxation of finite-size fluctuation in thermal equilibrium

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Yoshiyuki Y.

    2016-07-01

    We numerically exhibit two strange phenomena of finite-size fluctuation in thermal equilibrium of a paradigmatic long-range interacting system having a second-order phase transition. One is a nonclassical finite-size scaling at the critical point, which differs from the prediction by statistical mechanics. With the aid of this strange scaling, the scaling theory for infinite-range models conjectures the nonclassical values of critical exponents for the correlation length. The other is relaxation of the fluctuation strength from one level to another in spite of being in thermal equilibrium. A scenario is proposed to explain these phenomena from the viewpoint of the Casimir invariants and their nonexactness in finite-size systems, where the Casimir invariants are conserved in the Vlasov dynamics describing the long-range interacting systems in the limit of large population. This scenario suggests appearance of the reported phenomena in a wide class of isolated long-range interacting systems.

  18. Non-equilibrium behaviour in coacervate-based protocells under electric-field-induced excitation.

    PubMed

    Yin, Yudan; Niu, Lin; Zhu, Xiaocui; Zhao, Meiping; Zhang, Zexin; Mann, Stephen; Liang, Dehai

    2016-01-01

    Although numerous strategies are now available to generate rudimentary forms of synthetic cell-like entities, minimal progress has been made in the sustained excitation of artificial protocells under non-equilibrium conditions. Here we demonstrate that the electric field energization of coacervate microdroplets comprising polylysine and short single strands of DNA generates membrane-free protocells with complex, dynamical behaviours. By confining the droplets within a microfluidic channel and applying a range of electric field strengths, we produce protocells that exhibit repetitive cycles of vacuolarization, dynamical fluctuations in size and shape, chaotic growth and fusion, spontaneous ejection and sequestration of matter, directional capture of solute molecules, and pulsed enhancement of enzyme cascade reactions. Our results highlight new opportunities for the study of non-equilibrium phenomena in synthetic protocells, provide a strategy for inducing complex behaviour in electrostatically assembled soft matter microsystems and illustrate how dynamical properties can be activated and sustained in microcompartmentalized media. PMID:26876162

  19. Non-equilibrium behaviour in coacervate-based protocells under electric-field-induced excitation

    PubMed Central

    Yin, Yudan; Niu, Lin; Zhu, Xiaocui; Zhao, Meiping; Zhang, Zexin; Mann, Stephen; Liang, Dehai

    2016-01-01

    Although numerous strategies are now available to generate rudimentary forms of synthetic cell-like entities, minimal progress has been made in the sustained excitation of artificial protocells under non-equilibrium conditions. Here we demonstrate that the electric field energization of coacervate microdroplets comprising polylysine and short single strands of DNA generates membrane-free protocells with complex, dynamical behaviours. By confining the droplets within a microfluidic channel and applying a range of electric field strengths, we produce protocells that exhibit repetitive cycles of vacuolarization, dynamical fluctuations in size and shape, chaotic growth and fusion, spontaneous ejection and sequestration of matter, directional capture of solute molecules, and pulsed enhancement of enzyme cascade reactions. Our results highlight new opportunities for the study of non-equilibrium phenomena in synthetic protocells, provide a strategy for inducing complex behaviour in electrostatically assembled soft matter microsystems and illustrate how dynamical properties can be activated and sustained in microcompartmentalized media. PMID:26876162

  20. Strange scaling and relaxation of finite-size fluctuation in thermal equilibrium.

    PubMed

    Yamaguchi, Yoshiyuki Y

    2016-07-01

    We numerically exhibit two strange phenomena of finite-size fluctuation in thermal equilibrium of a paradigmatic long-range interacting system having a second-order phase transition. One is a nonclassical finite-size scaling at the critical point, which differs from the prediction by statistical mechanics. With the aid of this strange scaling, the scaling theory for infinite-range models conjectures the nonclassical values of critical exponents for the correlation length. The other is relaxation of the fluctuation strength from one level to another in spite of being in thermal equilibrium. A scenario is proposed to explain these phenomena from the viewpoint of the Casimir invariants and their nonexactness in finite-size systems, where the Casimir invariants are conserved in the Vlasov dynamics describing the long-range interacting systems in the limit of large population. This scenario suggests appearance of the reported phenomena in a wide class of isolated long-range interacting systems. PMID:27575102

  1. Non-equilibrium behaviour in coacervate-based protocells under electric-field-induced excitation

    NASA Astrophysics Data System (ADS)

    Yin, Yudan; Niu, Lin; Zhu, Xiaocui; Zhao, Meiping; Zhang, Zexin; Mann, Stephen; Liang, Dehai

    2016-02-01

    Although numerous strategies are now available to generate rudimentary forms of synthetic cell-like entities, minimal progress has been made in the sustained excitation of artificial protocells under non-equilibrium conditions. Here we demonstrate that the electric field energization of coacervate microdroplets comprising polylysine and short single strands of DNA generates membrane-free protocells with complex, dynamical behaviours. By confining the droplets within a microfluidic channel and applying a range of electric field strengths, we produce protocells that exhibit repetitive cycles of vacuolarization, dynamical fluctuations in size and shape, chaotic growth and fusion, spontaneous ejection and sequestration of matter, directional capture of solute molecules, and pulsed enhancement of enzyme cascade reactions. Our results highlight new opportunities for the study of non-equilibrium phenomena in synthetic protocells, provide a strategy for inducing complex behaviour in electrostatically assembled soft matter microsystems and illustrate how dynamical properties can be activated and sustained in microcompartmentalized media.

  2. ATP in equilibrium with 32Pi exchange catalyzed by plasma membrane Ca(2+)-ATPase from kidney proximal tubules

    SciTech Connect

    Vieyra, A.; Caruso-Neves, C.; Meyer-Fernandes, J.R. )

    1991-06-05

    The Ca(2+)-stimulated adenosine 5{prime}-triphosphate-orthophosphate (ATP in equilibrium with 32Pi) exchange reaction was studied using a vesicular preparation derived from plasma membrane of kidney proximal tubules. With native inside-out vesicles, ATP in equilibrium with 32Pi was stimulated by micromolar Ca2+ concentrations. Treatment of the vesicles with the Ca2+ ionophore A23187 that abolished Ca2+ accumulation, strongly inhibited ATP in equilibrium with 32Pi. When Ca(2+)-ATPase was solubilized with the nonionic detergent octaethylene glycol mono n-dodecyl ether, maximal activation of ATP in equilibrium with 32Pi required millimolar Ca2+ concentrations. These Ca2+ concentrations inhibited ATP hydrolysis. ATP in equilibrium with 32Pi exhibited a Michaelian dependence on Pi and Mg2+, was stimulated by ATP, and depended on the ATP/ADP ratio. ATP in equilibrium with 32Pi was modified by the osmolytes urea, trimethylamine-N-oxide, and sucrose, which are representative of the methylamines and polyols that normally accumulate in renal tissue. These compounds did not modify the apparent affinity for Pi; they affected the response to ADP in the same fashion as the overall rate of ATP in equilibrium 32Pi, and their effects depended on medium pH. These data show that the Ca(2+)-ATPase from plasma membrane kidney proximal tubules can operate simultaneously in forward and backward directions. They also show that ATP in equilibrium with 32Pi is modulated by the ligands Ca2+, ATP, ADP, Pi, Mg2+, and H+, and by organic solutes found in renal tissue.

  3. A survey of upwind methods for flows with equilibrium and non-equilibrium chemistry and thermodynamics

    NASA Technical Reports Server (NTRS)

    Grossman, B.; Garrett, J.; Cinnella, P.

    1989-01-01

    Several versions of flux-vector split and flux-difference split algorithms were compared with regard to general applicability and complexity. Test computations were performed using curve-fit equilibrium air chemistry for an M = 5 high-temperature inviscid flow over a wedge, and an M = 24.5 inviscid flow over a blunt cylinder for test computations; for these cases, little difference in accuracy was found among the versions of the same flux-split algorithm. For flows with nonequilibrium chemistry, the effects of the thermodynamic model on the development of flux-vector split and flux-difference split algorithms were investigated using an equilibrium model, a general nonequilibrium model, and a simplified model based on vibrational relaxation. Several numerical examples are presented, including nonequilibrium air chemistry in a high-temperature shock tube and nonequilibrium hydrogen-air chemistry in a supersonic diffuser.

  4. The Lewis Chemical Equilibrium Program with parametric study capability

    NASA Technical Reports Server (NTRS)

    Sevigny, R.

    1981-01-01

    The program was developed to determine chemical equilibrium in complex systems. Using a free energy minimization technique, the program permits calculations such as: chemical equilibrium for assigned thermodynamic states; theoretical rocket performance for both equilibrium and frozen compositions during expansion; incident and reflected shock properties; and Chapman-Jouget detonation properties. It is shown that the same program can handle solid coal in an entrained flow coal gasification problem.

  5. Equilibrium time correlation functions and the dynamics of fluctuations

    SciTech Connect

    Luban, Marshall; Luscombe, James H.

    1999-12-01

    Equilibrium time correlation functions are of great importance because they probe the equilibrium dynamical response to external perturbations. We discuss the properties of time correlation functions for several systems that are simple enough to illustrate the calculational steps involved. The discussion underscores the need for avoiding language which misleadingly suggests that thermal equilibrium is associated with a quiescent or moribund state of the system. (c) 1999 American Association of Physics Teachers.

  6. Abrupt PN junctions: Analytical solutions under equilibrium and non-equilibrium

    NASA Astrophysics Data System (ADS)

    Khorasani, Sina

    2016-08-01

    We present an explicit solution of carrier and field distributions in abrupt PN junctions under equilibrium. An accurate logarithmic numerical method is implemented and results are compared to the analytical solutions. Analysis of results shows reasonable agreement with numerical solution as well as the depletion layer approximation. We discuss extensions to the asymmetric junctions. Approximate relations for differential capacitance C-V and current-voltage I-V characteristics are also found under non-zero external bias.

  7. BOOK REVIEW: Relativistic Figures of Equilibrium

    NASA Astrophysics Data System (ADS)

    Mars, M.

    2009-08-01

    Compact fluid bodies in equilibrium under its own gravitational field are abundant in the Universe and a proper treatment of them can only be carried out using the full theory of General Relativity. The problem is of enormous complexity as it involves two very different regimes, namely the interior and the exterior of the fluid, coupled through the surface of the body. This problem is very challenging both from a purely theoretical point of view, as well as regarding the obtaining of realistic models and the description of their physical properties. It is therefore an excellent piece of news that the book 'Relativistic Figures of Equilibrium' by R Meinel, M Ansorg, A Kleinwächter, G Neugebauer and D Petroff has been recently published. This book approaches the topic in depth and its contents will be of interest to a wide range of scientists working on gravitation, including theoreticians in general relativity, mathematical physicists, astrophysicists and numerical relativists. This is an advanced book that intends to present some of the present-day results on this topic. The most basic results are presented rather succinctly, and without going into the details, of their derivations. Although primarily not intended to serve as a textbook, the presentation is nevertheless self-contained and can therefore be of interest both for experts on the field as well as for anybody wishing to learn more about rotating self-gravitating compact bodies in equilibrium. It should be remarked, however, that this book makes a rather strong selection of topics and concentrates fundamentally on presenting the main results obtained by the authors during their research in this field. The book starts with a chapter where the fundamental aspects of rotating fluids in equilibrium, including its thermodynamic properties, are summarized. Of particular interest are the so-called mass-shedding limit, which is the limit where the body is rotating so fast that it is on the verge of starting

  8. Equilibrium econophysics: A unified formalism for neoclassical economics and equilibrium thermodynamics

    NASA Astrophysics Data System (ADS)

    Sousa, Tânia; Domingos, Tiago

    2006-11-01

    We develop a unified conceptual and mathematical structure for equilibrium econophysics, i.e., the use of concepts and tools of equilibrium thermodynamics in neoclassical microeconomics and vice versa. Within this conceptual structure the results obtained in microeconomic theory are: (1) the definition of irreversibility in economic behavior; (2) the clarification that the Engel curve and the offer curve are not descriptions of real processes dictated by the maximization of utility at constant endowment; (3) the derivation of a relation between elasticities proving that economic elasticities are not all independent; (4) the proof that Giffen goods do not exist in a stable equilibrium; (5) the derivation that ‘economic integrability’ is equivalent to the generalized Le Chatelier principle and (6) the definition of a first order phase transition, i.e., a transition between separate points in the utility function. In thermodynamics the results obtained are: (1) a relation between the non-dimensional isothermal and adiabatic compressibilities and the increase or decrease in the thermodynamic potentials; (2) the distinction between mathematical integrability and optimization behavior and (3) the generalization of the Clapeyron equation.

  9. Carbon nanotubes as mechanical probes of equilibrium and non-equilibrium cytoskeletal networks

    NASA Astrophysics Data System (ADS)

    Fakhri, Nikta; Pasquali, Matteo; Mackintosh, Frederick C.; Schmidt, Christoph F.

    2012-02-01

    Networks of filamentous proteins underlie the mechanics of cells. The activity of motor proteins typically creates strong fluctuations that drive the system out of equilibrium. Understanding the behavior of such networks requires probes that ideally span the characteristic length-scales, from nanometers to micrometers. Single-walled carbon nanotubes (SWNTs) are nanometer-diameter filaments with micrometer length and tunable bending stiffness. On a Brownian energy scale they have persistence lengths of about 20-100 micrometers and show significant thermal fluctuations on the cellular scale of a few microns. Diffusive motion and local bending dynamics of SWNTs embedded in an active polymeric network reflect forces and fluctuations of the embedding medium. We study the motion of individual SWNTs in equilibrium and non-equilibrium networks by near infrared fluorescence microscopy. We show that SWNTs reptate in the network. We will discuss the possibility of using SWNTs as multi-scale probes relating their local dynamic behavior to the viscoelastic properties of the surrounding network.

  10. Teaching Chemical Equilibrium and Thermodynamics in Undergraduate General Chemistry Classes.

    ERIC Educational Resources Information Center

    Banerjee, Anil C.

    1995-01-01

    Discusses some of the conceptual difficulties encountered by undergraduate students in learning certain aspects of chemical equilibrium and thermodynamics. Discusses teaching strategies for dealing with these difficulties. (JRH)

  11. Mirabilite solubility in equilibrium sea ice brines

    NASA Astrophysics Data System (ADS)

    Butler, Benjamin Miles; Papadimitriou, Stathys; Santoro, Anna; Kennedy, Hilary

    2016-06-01

    The sea ice microstructure is permeated by brine channels and pockets that contain concentrated seawater-derived brine. Cooling the sea ice results in further formation of pure ice within these pockets as thermal equilibrium is attained, resulting in a smaller volume of increasingly concentrated residual brine. The coupled changes in temperature and ionic composition result in supersaturation of the brine with respect to mirabilite (Na2SO4·10H2O) at temperatures below -6.38 °C, which consequently precipitates within the sea ice microstructure. Here, mirabilite solubility in natural and synthetic seawater derived brines, representative of sea ice at thermal equilibrium, has been measured in laboratory experiments between 0.2 and -20.6 °C, and hence we present a detailed examination of mirabilite dynamics within the sea ice system. Below -6.38 °C mirabilite displays particularly large changes in solubility as the temperature decreases, and by -20.6 °C its precipitation results in 12.90% and 91.97% reductions in the total dissolved Na+ and SO42- concentrations respectively, compared to that of conservative seawater concentration. Such large non-conservative changes in brine composition could potentially impact upon the measurement of sea ice brine salinity and pH, whilst the altered osmotic conditions may create additional challenges for the sympagic organisms that inhabit the sea ice system. At temperatures above -6.38 °C, mirabilite again displays large changes in solubility that likely aid in impeding its identification in field samples of sea ice. Our solubility measurements display excellent agreement with that of the FREZCHEM model, which was therefore used to supplement our measurements to colder temperatures. Measured and modelled solubility data were incorporated into a 1D model for the growth of first-year Arctic sea ice. Model results ultimately suggest that mirabilite has a near ubiquitous presence in much of the sea ice on Earth, and illustrate the

  12. A Memristive Hyperchaotic System without Equilibrium

    PubMed Central

    Gambuzza, Lucia Valentina

    2014-01-01

    A new memristive system is presented in this paper. The peculiarity of the model is that it does not display any equilibria and exhibits periodic, chaotic, and also hyperchaotic dynamics in a particular range of the parameters space. The behavior of the proposed system is investigated through numerical simulations, such as phase portraits, Lyapunov exponents, and Poincaré sections, and circuital implementation confirmed the hyperchaotic dynamic. PMID:25133225

  13. African Past: Migrant Present. A Guide to the Exhibition.

    ERIC Educational Resources Information Center

    Twining, Mary Arnold; Roark-Calnek, Sue

    This exhibit guide describes an exhibition of African folk arts produced by seasonal migrant farmworkers in western New York State. Workers come from the American South, Haiti, Puerto Rico, and Jamaica. The exhibition pieces were collected through the BOCES Geneseo Migrant Center's Folk Arts Program and Creative Artists Migrant Program Services…

  14. Online Cultural Heritage Exhibitions: A Survey of Strategic Issues

    ERIC Educational Resources Information Center

    Liew, Chern Li

    2006-01-01

    Purpose: This paper seeks to report findings from a study that looked at a range of strategic issues faced in the development, management and maintenance of online cultural heritage exhibitions. The study examined exhibitions from different types of cultural agencies and asked questions about whether, for instance, the exhibitions are part of the…

  15. 49 CFR 826.22 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Net worth exhibit. 826.22 Section 826.22... Net worth exhibit. (a) Each applicant except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the net worth of the applicant...

  16. 14 CFR 1262.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Net worth exhibit. 1262.202 Section 1262.202... PROCEEDINGS Information Required From Applicants § 1262.202 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant and any affiliates (as defiined in § 1262.104(f) when...

  17. 10 CFR 12.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Net worth exhibit. 12.202 Section 12.202 Energy NUCLEAR... Required From Applicants § 12.202 Net worth exhibit. (a) Each applicant, except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the...

  18. 19 CFR 212.11 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Net worth exhibit. 212.11 Section 212.11 Customs... IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 212.11 Net worth exhibit... with its application a detailed exhibit showing the net worth of the applicant and any affiliates...

  19. 17 CFR 201.42 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Net worth exhibit. 201.42... Regulations Pertaining to the Equal Access to Justice Act § 201.42 Net worth exhibit. (a) Each applicant... a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  20. 49 CFR 6.19 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Net worth exhibit. 6.19 Section 6.19... PROCEEDINGS Information Required from Applicants § 6.19 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant and any affiliates (as defined in this part) when...

  1. 39 CFR 960.10 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Net worth exhibit. 960.10 Section 960.10 Postal... JUSTICE ACT IN POSTAL SERVICE PROCEEDINGS Information Required From Applicants § 960.10 Net worth exhibit... with its application a detailed exhibit showing the net worth of the applicant and any affiliates...

  2. 31 CFR 6.9 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Net worth exhibit. 6.9 Section 6.9... EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 6.9 Net worth exhibit. (a) Each... application a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  3. 7 CFR 1.191 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Net worth exhibit. 1.191 Section 1.191 Agriculture... § 1.191 Net worth exhibit. (a) An applicant, except a qualified tax-exempt organization or cooperative association, must provide with its application a detailed exhibit showing the net worth of the applicant...

  4. 10 CFR 12.202 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Net worth exhibit. 12.202 Section 12.202 Energy NUCLEAR... Required From Applicants § 12.202 Net worth exhibit. (a) Each applicant, except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the...

  5. 49 CFR 826.22 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Net worth exhibit. 826.22 Section 826.22... Net worth exhibit. (a) Each applicant except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the net worth of the applicant...

  6. 7 CFR 1.191 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Net worth exhibit. 1.191 Section 1.191 Agriculture... § 1.191 Net worth exhibit. (a) An applicant, except a qualified tax-exempt organization or cooperative association, must provide with its application a detailed exhibit showing the net worth of the applicant...

  7. 17 CFR 148.12 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Net worth exhibit. 148.12... Required from Applicants § 148.12 Net worth exhibit. (a) Each applicant except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the...

  8. 17 CFR 148.12 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false Net worth exhibit. 148.12... Required from Applicants § 148.12 Net worth exhibit. (a) Each applicant except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the...

  9. 14 CFR 1262.202 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Net worth exhibit. 1262.202 Section 1262... AGENCY PROCEEDINGS Information Required From Applicants § 1262.202 Net worth exhibit. (a) Each applicant... detailed exhibit showing the net worth of the applicant and any affiliates (as defiined in §...

  10. 10 CFR 1023.311 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Net worth exhibit. 1023.311 Section 1023.311 Energy... Access to Justice Act Information Required from Applicants § 1023.311 Net worth exhibit. (a) Each... application a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  11. 17 CFR 201.42 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Net worth exhibit. 201.42... Regulations Pertaining to the Equal Access to Justice Act § 201.42 Net worth exhibit. (a) Each applicant... a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  12. 49 CFR 1016.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 false Net worth exhibit. 1016.202 Section 1016.202... BY PARTIES TO BOARD ADJUDICATORY PROCEEDINGS Information Required From Applicants § 1016.202 Net worth exhibit. (a) Each applicant must provide with its application a detailed exhibit showing the...

  13. 5 CFR 2610.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Net worth exhibit. 2610.202 Section 2610... THE EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 2610.202 Net worth exhibit. (a... with its application a detailed exhibit showing the net worth of the applicant and any affiliates...

  14. 31 CFR 6.9 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Net worth exhibit. 6.9 Section 6.9... EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 6.9 Net worth exhibit. (a) Each... application a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  15. 49 CFR 6.19 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Net worth exhibit. 6.19 Section 6.19... PROCEEDINGS Information Required from Applicants § 6.19 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant and any affiliates (as defined in this part) when...

  16. 10 CFR 1023.311 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Net worth exhibit. 1023.311 Section 1023.311 Energy... Access to Justice Act Information Required from Applicants § 1023.311 Net worth exhibit. (a) Each... application a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  17. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 3 2014-10-01 2014-10-01 false Eligibility for international exhibitions. 1160.4... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement for an international exhibition made under these regulations shall cover: (a) Eligible items...

  18. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 3 2011-10-01 2011-10-01 false Eligibility for international exhibitions. 1160.4... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement for an international exhibition made under these regulations shall cover: (a) Eligible items...

  19. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 3 2012-10-01 2012-10-01 false Eligibility for international exhibitions. 1160.4... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement for an international exhibition made under these regulations shall cover: (a) Eligible items...

  20. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Eligibility for international exhibitions. 1160.4... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement for an international exhibition made under these regulations shall cover: (a) Eligible items...