This document summarizes research on the surface alignment and anchoring transitions of lyotropic chromonic liquid crystals (LCLCs). The key points are:
1) LCLCs can have homeotropic alignment, with molecular aggregates perpendicular to the substrate surface, as well as planar (tangential) alignment.
2) Homeotropic alignment undergoes a transition to planar alignment over time (10-20 hours). These anchoring transitions are discontinuous.
3) The anchoring transitions can be described by a double-well potential model with minima for tangential and homeotropic orientations. This suggests both entropy and enthalpy contribute to surface phenomena in LCLCs.
Observing small, long-range homonuclear coupling pathways in COSY or GCOSY spectra generally requires the time-consuming acquisition of spectra with large numbers of increments of the evolution period, t1. Covariance processing of spectra acquired with modest numbers of t1 increments, however, allows the observation of long-range coupling correlations with considerable instrument time savings. In this work results obtained from covariance processed GCOSY spectra are fully analyzed and compared to normally processed GCOSY and 80 ms zTOCSY spectra. RCOSY-type correlations are observed when remote protons both exhibit correlations to the same coupling partner. Artifact correlations are observed when protons couple to different protons that overlap or partially overlap.
Small, long-range homonuclear coupling pathways in COSY or GCOSY spectra by the acquisition of spectra with large numbers of increments of the evolution period, t1, than would normally be used. Alternatively, covariance processing of COSY-type spectra acquired with modest numbers of t1 increments, however, allows the observation of multi-stage correlations. In this work results obtained from covariance processed GCOSY spectra are fully analyzed and compared to normally processed COSY and 80 ms TOCSY spectra. Multi-stage or “RCOSY-type” correlations are observed when remote protons both exhibit correlations to the same coupling partner e.g. A→B and B→C gives rise to an A→C correlation. Artifact correlations are observed when protons couple to other protons that overlap or partially overlap.
This document describes a study using integral equation theory and Monte Carlo simulation to determine the structure and thermodynamics of a colloidal solution where particles interact via Yukawa or Sogami potentials. The authors use the hybridized mean spherical approximation within the integral equation theory to calculate properties like the pair correlation function, structure factor, internal energy and pressure. They find good quantitative agreement between results from integral equation theory using a Sogami potential and results from Monte Carlo simulation. The theoretical results are also compared to experimental data and show agreement when using a Sogami potential.
This document summarizes research on hydrographene, a material that is intermediate between graphene and graphane. Hydrographene is obtained by partially hydrogenating graphene. The document proposes modeling hydrographene using percolation theory, where hydrogenated carbon sites are removed from the honeycomb lattice. This predicts a phase transition from graphene to graphane at a critical hydrogenation density. It also predicts hydrographene will be ferromagnetic based on its carbon network structure. Two types of hydrogenation are considered: single-sided, where only one sublattice is hydrogenated, and double-sided, where both sublattices are hydrogenated. Single-sided hydrogenation is found to produce larger magnetic moments. The percolation model
This document summarizes research on the structure and phase behavior of Cu-Ni nanoalloys. It uses thermodynamic modeling to predict how the phase diagrams and mixing/demixing behavior depend on nanoparticle size, shape, and temperature. The modeling indicates Cu-Ni nanoalloys can form either mixed particles or Janus particles, depending on the synthesis temperature, with nickel preferentially segregating to surfaces. Phase maps are provided to guide experimentalists on controlling particle structure.
This document describes a proposed method to determine the unitarity triangle angle γ through an amplitude analysis of B± → (K+K−π+π−)DK± decays. A simulation study shows that with 1000 events and assuming rB = 0.10, a precision on γ of 15° is achievable. The analysis exploits interference between B− → D0K− and B− → Ḋ0K− decays, where the D0 and Ḋ0 decay to the four-body final state K+K−π+π−. A full decay model is formulated and the dominant D0 → K+K−π+π− amplitudes are based on a previous analysis.
This document discusses using spectroscopic ellipsometry to analyze molecular fractal surfaces through physical adsorption of water and other liquids. It provides background on existing surface adsorption theories and how they have been expanded to account for fractal surfaces. Experimental data is presented on water adsorption measured by ellipsometry on various surfaces like gold, silicon, and germanium. The data is analyzed using modified adsorption models that incorporate the fractal dimension of the surfaces to determine properties like monolayer coverage and surface dimensionality.
This document discusses spectrophotometry instruments and Beer's Law. It provides details on how Beer's Law states that the absorption of light by a solution is directly proportional to the concentration of the absorbing material in the solution. The document also discusses how spectrophotometers can be used to measure absorbance and determine the concentration of unknown solutions based on calibration curves. It provides an example using data from multiple solutions to determine the concentration of each in a mixture through simultaneous equations based on Beer's Law at different wavelengths.
Observing small, long-range homonuclear coupling pathways in COSY or GCOSY spectra generally requires the time-consuming acquisition of spectra with large numbers of increments of the evolution period, t1. Covariance processing of spectra acquired with modest numbers of t1 increments, however, allows the observation of long-range coupling correlations with considerable instrument time savings. In this work results obtained from covariance processed GCOSY spectra are fully analyzed and compared to normally processed GCOSY and 80 ms zTOCSY spectra. RCOSY-type correlations are observed when remote protons both exhibit correlations to the same coupling partner. Artifact correlations are observed when protons couple to different protons that overlap or partially overlap.
Small, long-range homonuclear coupling pathways in COSY or GCOSY spectra by the acquisition of spectra with large numbers of increments of the evolution period, t1, than would normally be used. Alternatively, covariance processing of COSY-type spectra acquired with modest numbers of t1 increments, however, allows the observation of multi-stage correlations. In this work results obtained from covariance processed GCOSY spectra are fully analyzed and compared to normally processed COSY and 80 ms TOCSY spectra. Multi-stage or “RCOSY-type” correlations are observed when remote protons both exhibit correlations to the same coupling partner e.g. A→B and B→C gives rise to an A→C correlation. Artifact correlations are observed when protons couple to other protons that overlap or partially overlap.
This document describes a study using integral equation theory and Monte Carlo simulation to determine the structure and thermodynamics of a colloidal solution where particles interact via Yukawa or Sogami potentials. The authors use the hybridized mean spherical approximation within the integral equation theory to calculate properties like the pair correlation function, structure factor, internal energy and pressure. They find good quantitative agreement between results from integral equation theory using a Sogami potential and results from Monte Carlo simulation. The theoretical results are also compared to experimental data and show agreement when using a Sogami potential.
This document summarizes research on hydrographene, a material that is intermediate between graphene and graphane. Hydrographene is obtained by partially hydrogenating graphene. The document proposes modeling hydrographene using percolation theory, where hydrogenated carbon sites are removed from the honeycomb lattice. This predicts a phase transition from graphene to graphane at a critical hydrogenation density. It also predicts hydrographene will be ferromagnetic based on its carbon network structure. Two types of hydrogenation are considered: single-sided, where only one sublattice is hydrogenated, and double-sided, where both sublattices are hydrogenated. Single-sided hydrogenation is found to produce larger magnetic moments. The percolation model
This document summarizes research on the structure and phase behavior of Cu-Ni nanoalloys. It uses thermodynamic modeling to predict how the phase diagrams and mixing/demixing behavior depend on nanoparticle size, shape, and temperature. The modeling indicates Cu-Ni nanoalloys can form either mixed particles or Janus particles, depending on the synthesis temperature, with nickel preferentially segregating to surfaces. Phase maps are provided to guide experimentalists on controlling particle structure.
This document describes a proposed method to determine the unitarity triangle angle γ through an amplitude analysis of B± → (K+K−π+π−)DK± decays. A simulation study shows that with 1000 events and assuming rB = 0.10, a precision on γ of 15° is achievable. The analysis exploits interference between B− → D0K− and B− → Ḋ0K− decays, where the D0 and Ḋ0 decay to the four-body final state K+K−π+π−. A full decay model is formulated and the dominant D0 → K+K−π+π− amplitudes are based on a previous analysis.
This document discusses using spectroscopic ellipsometry to analyze molecular fractal surfaces through physical adsorption of water and other liquids. It provides background on existing surface adsorption theories and how they have been expanded to account for fractal surfaces. Experimental data is presented on water adsorption measured by ellipsometry on various surfaces like gold, silicon, and germanium. The data is analyzed using modified adsorption models that incorporate the fractal dimension of the surfaces to determine properties like monolayer coverage and surface dimensionality.
This document discusses spectrophotometry instruments and Beer's Law. It provides details on how Beer's Law states that the absorption of light by a solution is directly proportional to the concentration of the absorbing material in the solution. The document also discusses how spectrophotometers can be used to measure absorbance and determine the concentration of unknown solutions based on calibration curves. It provides an example using data from multiple solutions to determine the concentration of each in a mixture through simultaneous equations based on Beer's Law at different wavelengths.
1) A numerical model is developed to simulate the drainage of liquid through a vertical column of foam using the foam drainage equation.
2) Simulations of free drainage, forced drainage, coalescing waves, and pulse wetting are presented. The simulations show good agreement with theoretical predictions and experimental data.
3) Forced drainage produces a solitary wave front that moves through the foam at a constant velocity, while pulse wetting produces a diffusing wave front due to the non-constant liquid input.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals
Dynamical symmetry breaking in vibration-assisted transport through nanostruc...Vorname Nachname
This document summarizes a theoretical model of electron transport through a nanostructure with strong electron-vibron coupling. A single molecule is coupled to many vibronic modes, and at low energies transport is dominated by electron-vibron processes where an electron transfers through the molecule accompanied by the excitation or emission of vibrons. When the vibron frequencies form a harmonic series, energetically degenerate vibronic configurations can contribute to transport. Both negative differential conductance features and gate asymmetry are predicted due to interplay between Franck-Condon suppression and spin/orbital degeneracies, which give rise to slow transport channels.
Residence time distribution studies in flow through tubular electrochemical r...IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
This document discusses computer simulations of the structure and thermodynamics of colloidal solutions interacting through Yukawa or Lu-Marlow potentials. It presents:
1) A new attractive potential proposed by Lu and Marlow that takes into account particle size and is proportional to the inverse sixth power of distance for large separations.
2) Use of this potential and a repulsive electrostatic potential in a variational method to calculate theoretical structure factors, finding good agreement with experimental data.
3) Choice of hard spheres as a reference system and use of the Gibbs-Bogoliubov inequality to obtain an upper bound for the free energy of the colloidal system.
This document presents a study analyzing the absorption spectra of praseodymium(III) complexes with β-diketone ligands and nitrogen donor ligands. Praseodymium complexes were synthesized and characterized. Absorption spectra were recorded for the complexes in various solvents. Spectral energy parameters like the Slater-Condon parameter (FK), Lande spin orbit coupling (ξ4f), nephelauxetic ratio (β), and bonding parameter (b1/2) were calculated from the spectra. Marginal decreases in FK and ξ4f were observed and correlated with small increases in β. Pseudohypersensitive transitions showed wide variation in oscillator strength with minor changes in coordination, indicating sensitivity to
This document discusses gas absorption accompanied by a fast pseudo-first order photochemical reaction. It presents two cases - where the liquid reactant or the dissolved gas is activated by photons. In both cases, the specific absorption rate of the gas can be enhanced compared to no activation. Equations are derived to describe the concentration profiles and absorption rates for each case. Additional experimental data is needed to quantify the actual enhancement possible from photochemical activation in these situations.
M A S S T R A N S F E R O P E R A T I O N S I J N T U M O D E L P A P E...guest3f9c6b
This document contains questions from a Mass Transfer Operations exam. It includes 8 questions related to various mass transfer topics like classification of mass transfer operations, diffusion, distillation design, and mass transfer correlations. The questions involve calculations related to diffusion rates, mass transfer coefficients, distillation column design parameters, and phase equilibrium data.
This paper presents a rock physics model to calculate synthetic porosity logs as functions of pressure and gas saturation. The model uses the Krief and Gassmann equations to calculate compressional and shear velocities from which density and neutron responses are derived. Pseudo logs are generated for varying gas/water saturations and pressures. The model incorporates matrix, shale, and fluid properties. Changes in synthetic seismic data with depleting reservoir pressure are also estimated using changes in velocity and density with pressure. The modeling has applications for reservoir characterization, stimulation design, and sand control.
This document summarizes a simulation of a steam coal gasifier using computational fluid dynamics (CFD) and plug flow modeling approaches. The CFD model tracks the fluid and particle phases using mass and momentum equations, while the plug flow model uses a material balance. Results show reasonable agreement between the models in predicting effluent concentrations. The plug flow model allows for faster investigation of a wider range of conditions, while CFD provides more detailed hydrodynamic insights but requires more time to set up and run. Both methods provide complementary understanding of gasifier performance.
DFT vibrationally averaged isotopic dipole moments of propane, propyne and wa...Antônio Arapiraca
Post Born–Oppenheimer isotopic effects and zero-point vibrational averages were previously inbodied in calculations of the dipole moments of isotopic species of some apolar molecules within the HF-SCF approximation (Arapiraca, 2011) [27]. Many other molecules, however, demand the inclusion of electronic correlation for this goal. Here, DFT calculations are reported for the isotopic effects on dipole moments of molecules with increasing permanent dipole moments, namely propane ( 0.1 debye), propyne (0.7 debye) and water (1.9 debye). The results account well for the experimental values and isotopic trends of the dipole moments of these molecules. 2014 Elsevier
This document discusses zero-bias conductance (ZBC) spectra of a normal-metal/insulator/ferromagnetic superconductor junction as a function of the potential strength of the interface. It finds that the ZBC versus potential strength shows a clear difference for spin singlet s-wave pairing, spin triplet opposite spin pairing, and spin triplet equal spin pairing. For s-wave pairing, the ZBC is smaller than 2 and decreases with potential strength. For opposite and equal spin pairing, the ZBC reaches a minimum value at a certain potential strength. The minimum value for opposite spin pairing depends on the exchange field of the ferromagnetic superconductor, while for equal spin pairing the ZBC is not sensitive to the exchange field.
Surface plasmon resonance (SPR) is a phenomenon that occurs when light strikes a metal surface such as gold or silver under specific conditions. This causes surface plasmons to be generated at the metal-dielectric interface, which reduces the intensity of reflected light. SPR is highly sensitive to changes in the refractive index near the metal surface. This property allows SPR to detect the binding of molecules to the metal surface in real-time. Traditionally, SPR is used in biosensor instruments to study biomolecular interactions like protein-ligand binding. However, these instruments have limitations such as high cost and low throughput. The document discusses using SPR with colloidal gold particles as an alternative approach.
The BET method makes three main assumptions about gas adsorption: 1) it occurs on a flat, uniform surface; 2) there is no interaction between adsorbed gas molecules; and 3) multi-layer adsorption is possible. The BET equation relates the volume of gas adsorbed at a given pressure to the volume required for monolayer coverage and the saturation pressure of the gas. BET analysis uses an adsorption isotherm from multiple pressure points to calculate the specific surface area of a material. It is most accurate for surfaces that are flat and uniform with a consistent heat of adsorption for each layer.
This document describes computer simulations of freezing and sublimation processes under various boundary conditions for cylinders and spheres. The simulations solve the moving boundary problem using exact solutions derived for the phase front velocity. Results are presented for cylinders and spheres solidifying or sublimating with and without external heat sources or sinks. Specific solutions are verified for cases such as a sublimating cylinder with a heat sink, a self-freezing cylinder without a heat source, and a self-sublimating sphere. Tables summarizing the results are also presented.
The electronic band parameters calculated by the Triangular potential model f...IOSR Journals
This work reports on theoretical investigation of superlattices based on Cd1-xZnxS quantum dots
embedded in an insulating material. This system, assumed to a series of flattened cylindrical quantum dots with
a finite barrier at the boundary, is studied using the triangular potential. The electronic states and the effective
mass of 1 Γ miniband have been computed as a function of inter-quantum dot separation for different zinc
compositions. Calculations have been made for electrons, heavy holes and light holes. Results are discussed and
compared with those of the Kronig-Penney and sinusoidal potentials
Mobility Measurements Probe Conformational Changes in Membrane-embedded prote...richardgmorris
The function of membrane-embedded proteins such as ion channels depends crucially on their conformation. We demonstrate how conformational changes in asymmetric membrane proteins may be inferred from measurements of their diffusion. Such proteins cause local deformations in the membrane, which induce an extra hydrodynamic drag on the protein. Using membrane tension to control the magnitude of the deformations and hence the drag, measurements of diffusivity can be used to infer--- via an elastic model of the protein--- how conformation is changed by tension. Motivated by recent experimental results [Quemeneur et al., Proc. Natl. Acad. Sci. USA, 111 5083 (2014)] we focus on KvAP, a voltage-gated potassium channel. The conformation of KvAP is found to change considerably due to tension, with its `walls', where the protein meets the membrane, undergoing significant angular strains. The torsional stiffness is determined to be 26.8 kT at room temperature. This has implications for both the structure and function of such proteins in the environment of a tension-bearing membrane.
Quantum Theory of Spin and Anomalous Hall effects in Graphene Mirco Milletari'
1) The document discusses quantum theories of spin and anomalous Hall effects in graphene, focusing on developing a full quantum mechanical approach rather than semiclassical approximations.
2) It presents a model of adatom-decorated graphene to induce intrinsic spin-orbit coupling and explores resonant skew scattering and the crossover between quantum side-jump and skew scattering dominated regimes.
3) The document develops a diagrammatic approach to calculate the spin Hall conductivity beyond the Gaussian approximation, taking into account correlated disorder effects, and finds that coherent processes may dominate the anomalous contribution.
Flow Control of Elastic Plates in Triangular Arrangementijceronline
Three flexible plates arranged in a triangular configuration are numerically simulated to study their hydrodynamic interactions. The plates can flap passively in stable patterns. Four typical flapping patterns are identified by varying the interval distance and expansion angle between the plates. At small distances, the upstream plate experiences drag reduction while the downstream plates have increased drag due to interactions. The plates always flap at the same frequency. When distances are large, the plates behave independently like single plates. The study provides insights into fish schooling hydrodynamics and underwater robot design.
The document discusses the determination of dipole moments of polar molecules in non-polar solvents. It defines the dipole moment as the separation of positive and negative charges in a molecule. The dipole moment is determined by measuring the relative permittivity and refractive index of solutions, which relate to molecular polarization from an applied electric field. The Debye equation describes this relationship and can be used to calculate dipole moments from experimental data.
My_papers_Nastishin_PRL_2012_Elasticity of Lyotropic Chromonic Liquid Crystal...Myroslava Omelchenko
This document reports on a study that uses a magnetic Frederiks transition technique to measure the elastic constants (splay K1, twist K2, bend K3) of the lyotropic chromonic liquid crystal sunset yellow formed through reversible aggregation of organic molecules in water. The key findings are:
1) K1 and K3 are comparable in magnitude and about an order of magnitude higher than K2.
2) At higher concentrations and lower temperatures, K1 and the ratios K1/K3 and K1/K2 increase, which is attributed to elongation of the self-assembled lyotropic chromonic liquid crystal aggregates.
3) This concentration and temperature dependence of the elastic constants
1) The document discusses modeling of various material parameters such as dielectric constant, bandgap, electron affinity, effective masses, and mobility as functions of composition in semiconductor alloys. It also discusses modeling of fields, recombination, carrier transport, and excess carriers in semiconductor heterojunctions.
2) Equations are provided for modeling parameters like cutoff frequency and capacitance-voltage characteristics of semiconductor diodes and transistors.
3) The relationships between material grading and device characteristics such as current-voltage behavior in diodes are examined.
1) A numerical model is developed to simulate the drainage of liquid through a vertical column of foam using the foam drainage equation.
2) Simulations of free drainage, forced drainage, coalescing waves, and pulse wetting are presented. The simulations show good agreement with theoretical predictions and experimental data.
3) Forced drainage produces a solitary wave front that moves through the foam at a constant velocity, while pulse wetting produces a diffusing wave front due to the non-constant liquid input.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals
Dynamical symmetry breaking in vibration-assisted transport through nanostruc...Vorname Nachname
This document summarizes a theoretical model of electron transport through a nanostructure with strong electron-vibron coupling. A single molecule is coupled to many vibronic modes, and at low energies transport is dominated by electron-vibron processes where an electron transfers through the molecule accompanied by the excitation or emission of vibrons. When the vibron frequencies form a harmonic series, energetically degenerate vibronic configurations can contribute to transport. Both negative differential conductance features and gate asymmetry are predicted due to interplay between Franck-Condon suppression and spin/orbital degeneracies, which give rise to slow transport channels.
Residence time distribution studies in flow through tubular electrochemical r...IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
This document discusses computer simulations of the structure and thermodynamics of colloidal solutions interacting through Yukawa or Lu-Marlow potentials. It presents:
1) A new attractive potential proposed by Lu and Marlow that takes into account particle size and is proportional to the inverse sixth power of distance for large separations.
2) Use of this potential and a repulsive electrostatic potential in a variational method to calculate theoretical structure factors, finding good agreement with experimental data.
3) Choice of hard spheres as a reference system and use of the Gibbs-Bogoliubov inequality to obtain an upper bound for the free energy of the colloidal system.
This document presents a study analyzing the absorption spectra of praseodymium(III) complexes with β-diketone ligands and nitrogen donor ligands. Praseodymium complexes were synthesized and characterized. Absorption spectra were recorded for the complexes in various solvents. Spectral energy parameters like the Slater-Condon parameter (FK), Lande spin orbit coupling (ξ4f), nephelauxetic ratio (β), and bonding parameter (b1/2) were calculated from the spectra. Marginal decreases in FK and ξ4f were observed and correlated with small increases in β. Pseudohypersensitive transitions showed wide variation in oscillator strength with minor changes in coordination, indicating sensitivity to
This document discusses gas absorption accompanied by a fast pseudo-first order photochemical reaction. It presents two cases - where the liquid reactant or the dissolved gas is activated by photons. In both cases, the specific absorption rate of the gas can be enhanced compared to no activation. Equations are derived to describe the concentration profiles and absorption rates for each case. Additional experimental data is needed to quantify the actual enhancement possible from photochemical activation in these situations.
M A S S T R A N S F E R O P E R A T I O N S I J N T U M O D E L P A P E...guest3f9c6b
This document contains questions from a Mass Transfer Operations exam. It includes 8 questions related to various mass transfer topics like classification of mass transfer operations, diffusion, distillation design, and mass transfer correlations. The questions involve calculations related to diffusion rates, mass transfer coefficients, distillation column design parameters, and phase equilibrium data.
This paper presents a rock physics model to calculate synthetic porosity logs as functions of pressure and gas saturation. The model uses the Krief and Gassmann equations to calculate compressional and shear velocities from which density and neutron responses are derived. Pseudo logs are generated for varying gas/water saturations and pressures. The model incorporates matrix, shale, and fluid properties. Changes in synthetic seismic data with depleting reservoir pressure are also estimated using changes in velocity and density with pressure. The modeling has applications for reservoir characterization, stimulation design, and sand control.
This document summarizes a simulation of a steam coal gasifier using computational fluid dynamics (CFD) and plug flow modeling approaches. The CFD model tracks the fluid and particle phases using mass and momentum equations, while the plug flow model uses a material balance. Results show reasonable agreement between the models in predicting effluent concentrations. The plug flow model allows for faster investigation of a wider range of conditions, while CFD provides more detailed hydrodynamic insights but requires more time to set up and run. Both methods provide complementary understanding of gasifier performance.
DFT vibrationally averaged isotopic dipole moments of propane, propyne and wa...Antônio Arapiraca
Post Born–Oppenheimer isotopic effects and zero-point vibrational averages were previously inbodied in calculations of the dipole moments of isotopic species of some apolar molecules within the HF-SCF approximation (Arapiraca, 2011) [27]. Many other molecules, however, demand the inclusion of electronic correlation for this goal. Here, DFT calculations are reported for the isotopic effects on dipole moments of molecules with increasing permanent dipole moments, namely propane ( 0.1 debye), propyne (0.7 debye) and water (1.9 debye). The results account well for the experimental values and isotopic trends of the dipole moments of these molecules. 2014 Elsevier
This document discusses zero-bias conductance (ZBC) spectra of a normal-metal/insulator/ferromagnetic superconductor junction as a function of the potential strength of the interface. It finds that the ZBC versus potential strength shows a clear difference for spin singlet s-wave pairing, spin triplet opposite spin pairing, and spin triplet equal spin pairing. For s-wave pairing, the ZBC is smaller than 2 and decreases with potential strength. For opposite and equal spin pairing, the ZBC reaches a minimum value at a certain potential strength. The minimum value for opposite spin pairing depends on the exchange field of the ferromagnetic superconductor, while for equal spin pairing the ZBC is not sensitive to the exchange field.
Surface plasmon resonance (SPR) is a phenomenon that occurs when light strikes a metal surface such as gold or silver under specific conditions. This causes surface plasmons to be generated at the metal-dielectric interface, which reduces the intensity of reflected light. SPR is highly sensitive to changes in the refractive index near the metal surface. This property allows SPR to detect the binding of molecules to the metal surface in real-time. Traditionally, SPR is used in biosensor instruments to study biomolecular interactions like protein-ligand binding. However, these instruments have limitations such as high cost and low throughput. The document discusses using SPR with colloidal gold particles as an alternative approach.
The BET method makes three main assumptions about gas adsorption: 1) it occurs on a flat, uniform surface; 2) there is no interaction between adsorbed gas molecules; and 3) multi-layer adsorption is possible. The BET equation relates the volume of gas adsorbed at a given pressure to the volume required for monolayer coverage and the saturation pressure of the gas. BET analysis uses an adsorption isotherm from multiple pressure points to calculate the specific surface area of a material. It is most accurate for surfaces that are flat and uniform with a consistent heat of adsorption for each layer.
This document describes computer simulations of freezing and sublimation processes under various boundary conditions for cylinders and spheres. The simulations solve the moving boundary problem using exact solutions derived for the phase front velocity. Results are presented for cylinders and spheres solidifying or sublimating with and without external heat sources or sinks. Specific solutions are verified for cases such as a sublimating cylinder with a heat sink, a self-freezing cylinder without a heat source, and a self-sublimating sphere. Tables summarizing the results are also presented.
The electronic band parameters calculated by the Triangular potential model f...IOSR Journals
This work reports on theoretical investigation of superlattices based on Cd1-xZnxS quantum dots
embedded in an insulating material. This system, assumed to a series of flattened cylindrical quantum dots with
a finite barrier at the boundary, is studied using the triangular potential. The electronic states and the effective
mass of 1 Γ miniband have been computed as a function of inter-quantum dot separation for different zinc
compositions. Calculations have been made for electrons, heavy holes and light holes. Results are discussed and
compared with those of the Kronig-Penney and sinusoidal potentials
Mobility Measurements Probe Conformational Changes in Membrane-embedded prote...richardgmorris
The function of membrane-embedded proteins such as ion channels depends crucially on their conformation. We demonstrate how conformational changes in asymmetric membrane proteins may be inferred from measurements of their diffusion. Such proteins cause local deformations in the membrane, which induce an extra hydrodynamic drag on the protein. Using membrane tension to control the magnitude of the deformations and hence the drag, measurements of diffusivity can be used to infer--- via an elastic model of the protein--- how conformation is changed by tension. Motivated by recent experimental results [Quemeneur et al., Proc. Natl. Acad. Sci. USA, 111 5083 (2014)] we focus on KvAP, a voltage-gated potassium channel. The conformation of KvAP is found to change considerably due to tension, with its `walls', where the protein meets the membrane, undergoing significant angular strains. The torsional stiffness is determined to be 26.8 kT at room temperature. This has implications for both the structure and function of such proteins in the environment of a tension-bearing membrane.
Quantum Theory of Spin and Anomalous Hall effects in Graphene Mirco Milletari'
1) The document discusses quantum theories of spin and anomalous Hall effects in graphene, focusing on developing a full quantum mechanical approach rather than semiclassical approximations.
2) It presents a model of adatom-decorated graphene to induce intrinsic spin-orbit coupling and explores resonant skew scattering and the crossover between quantum side-jump and skew scattering dominated regimes.
3) The document develops a diagrammatic approach to calculate the spin Hall conductivity beyond the Gaussian approximation, taking into account correlated disorder effects, and finds that coherent processes may dominate the anomalous contribution.
Flow Control of Elastic Plates in Triangular Arrangementijceronline
Three flexible plates arranged in a triangular configuration are numerically simulated to study their hydrodynamic interactions. The plates can flap passively in stable patterns. Four typical flapping patterns are identified by varying the interval distance and expansion angle between the plates. At small distances, the upstream plate experiences drag reduction while the downstream plates have increased drag due to interactions. The plates always flap at the same frequency. When distances are large, the plates behave independently like single plates. The study provides insights into fish schooling hydrodynamics and underwater robot design.
The document discusses the determination of dipole moments of polar molecules in non-polar solvents. It defines the dipole moment as the separation of positive and negative charges in a molecule. The dipole moment is determined by measuring the relative permittivity and refractive index of solutions, which relate to molecular polarization from an applied electric field. The Debye equation describes this relationship and can be used to calculate dipole moments from experimental data.
My_papers_Nastishin_PRL_2012_Elasticity of Lyotropic Chromonic Liquid Crystal...Myroslava Omelchenko
This document reports on a study that uses a magnetic Frederiks transition technique to measure the elastic constants (splay K1, twist K2, bend K3) of the lyotropic chromonic liquid crystal sunset yellow formed through reversible aggregation of organic molecules in water. The key findings are:
1) K1 and K3 are comparable in magnitude and about an order of magnitude higher than K2.
2) At higher concentrations and lower temperatures, K1 and the ratios K1/K3 and K1/K2 increase, which is attributed to elongation of the self-assembled lyotropic chromonic liquid crystal aggregates.
3) This concentration and temperature dependence of the elastic constants
1) The document discusses modeling of various material parameters such as dielectric constant, bandgap, electron affinity, effective masses, and mobility as functions of composition in semiconductor alloys. It also discusses modeling of fields, recombination, carrier transport, and excess carriers in semiconductor heterojunctions.
2) Equations are provided for modeling parameters like cutoff frequency and capacitance-voltage characteristics of semiconductor diodes and transistors.
3) The relationships between material grading and device characteristics such as current-voltage behavior in diodes are examined.
This document summarizes research on Casimir torque in the weak coupling approximation. It examines manifestations of Casimir torque between planar objects characterized by delta function potentials. The key findings are:
1) An exact calculation of the Casimir torque between a finite rectangular plate above a semi-infinite plate is presented and agrees well with the proximity force approximation when the plate separation is small compared to their sizes.
2) Cusps in the torque arise when the corners of the finite plate pass over the edge of the semi-infinite plate.
3) A similar calculation is done for a disk above a semi-infinite plate, again finding good agreement with the proximity force approximation.
We apply the recently derived constraintless Clairaut-type formalism (by S. Duplij) to the Cho-Duan-Ge decom- position in SU(2) QCD. We find nontrivial corrections to the physical equations of motion and that the contribution of the topological degrees of freedom is qualitatively different from that found by treating the monopole potential as though it were dynamic. We also find alterations to the field commutation relations that undermine the particle interpretation in the presence of the chromomonopole condensate.
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1. Surface alignment and anchoring transitions in nematic lyotropic chromonic liquid
crystal.
V. G. Nazarenko1
, O. P. Boiko1,2
, H.-S. Park2
, O. M. Brodyn1
, M. M.
Omelchenko2
, L. Tortora2
, Yu. A. Nastishin2,3
, and O. D. Lavrentovich2∗
1
Institute of Physics, prospect Nauky 46, Kiev-39, 03039, Ukraine
2
Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH 44242
3
Institute of Physical Optics, 23 Dragomanov str., Lviv, 79005, Ukraine
(Dated: April 30, 2010)
The surface alignment of lyotropic chromonic liquid crystals (LCLCs) can be not only planar
(tangential) but also homeotropic, with the self-assembled aggregates perpendicular to the substrate,
as demonstrated by mapping optical retardation and by three-dimensional imaging of the director
field. With time, the homeotropic nematic undergoes a transition into a tangential state. The
anchoring transitions are discontinuous and can be described by a double-well anchoring potential
with two minima corresponding to tangential and homeotropic orientation.
PACS numbers: 61.30.-v ; 42.65.-k ; 42.70.Df
Spatial bounding of a liquid crystal (LC) lifts the de-
generacy of the molecular orientation specified by the
director n and sets an ”easy axis” n0 at the surface.
Deviation of n from n0 requires some work thus estab-
lishing the phenomenon of ”surface anchoring” that has
been explored extensively for the thermotropic LCs [1–
11]. For lyotropic LCs, such as water solutions of poly-
electrolytes, surfactants, dyes, etc., the studies of anchor-
ing are scarce. The view is that the anchoring of lyotropic
LCs is determined by the excluded volume effect, which
favors the longest dimension of building units to be par-
allel to a substrate [12–15]. We demonstrate that for the
nematic lyotropic chromonic LC (LCLC) [16], n0 can be
both parallel to a substrate (planar or tangential align-
ment, denoted ”P”) and perpendicular (homeotropic, or
H alignment), with discontinuos transitions between the
two, thus suggesting that both entropy and enthalpy con-
trol the surface phenomena.
Reversible chromonic assembly and mesomorphism are
displayed broadly by dyes, drugs and nucleotides [16].
In water, LCLC molecules stack face-to-face, forming
elongated aggregates. The aggregates are not fixed
by covalent bonds, being polidisperse with the aver-
age length l ∝
√
φ ln (E/kBT) that depends on tem-
perature T, volume fraction φ, and the stacking energy
E ∼ (4 − 10) kBT [17]. We study disodium cromogly-
cate (DSCG) [16], C23H14O11Na2 (Spectrum Inc, pu-
rity 98%), dissolved in water at 15 wt % (mixture A)
and 12.5wt% doped with 1.5wt% of Na2SO4 (mixture
B). H alignment was achieved by treating glass plates
with 1% water solution of N,N-dimethyl-N-octadecyl-3-
aminopropyl trimethoxysilyl chloride (DMOAP) [2]. The
two plates are separated by Mylar strips; the cell thick-
ness d was measured by light interference technique. The
cells were filled at TNI + 10 K, sealed with UV-cured
Norland epoxy glue, and cooled down to T = 298 K
with a rate 5 K/ min in the thermal stage HS-1 (In-
stec, Inc.). We used LC PolScope for in-plane mapping
of optical retardation R (x, y) =
d
0
|no − neff | dz, where
neff = n−2
o cos2
θ + n−2
e sin2
θ
−1/2
, θ is the angle be-
tween n and the normal z to the cell, no and ne are the
ordinary and extraordinary refractive indices. At 546
nm and T = 298 K, we determined no = 1.37 ± 0.01
and ∆nA = no − ne = 0.020 ± 0.002 for A and ∆nB =
0.015 ± 0.002 for B [18]. To image n (x, y, z), we used
flurescence confocal polarizing microscopy (FCPM), by
doping the sample with 0.003 wt.% of fluorescent acri-
dine orange (AO, Sigma-Aldrich) and probing it with a
focused laser beam [19]. The fluorescence depends on the
angle between n and polarization P of light, being maxi-
mum for P ⊥ n and minimum for P n, suggesting that
AO intercalates between the DSCG molecules.
The initial unaligned texture coarsens and then shows
dark expanding nuclei of the H state that fill the entire
cell, Fig.1. The H alignment is stable as verified by ap-
plying a strong magnetic field, up to 7 kG, to tilt n. Once
the field is switched off, the H orientation is restored. Af-
ter a certain time τH ≈10-20 hours, the LCLC undergoes
an H-P transition through nucleation and expansion of
birefringent domains, Fig.1c,d. These appear not only at
the periphery but also in the middle of samples, Fig.1c.
Two similar cells, one left under normal conditions and
another one immersed in a mineral oil, demonstrated sim-
FIG. 1: Textural evolution of mixture A in the cell with d =50
µm at T = 298 K, between crossed polarizers. Dark nuclei of
the H state appear at τ ≈10 min after the isotropic-nematic
transition (a), H orientation at τ=25 min (b); appearance,
τ=670 min (c) and expansion, τ=810 min (d) of bright P
regions.
2. 2
FIG. 2: H-P transition viewed as (a) grey scale map of R in
the plane of cell (d =12 µm) and as variation of R along the
lines 1,2, and 3 (inset); b) FCPM vertial cross section of a cell
with tilted boundary.
ilar evolution. Therefore, a possible slow drying is not a
major contributor to the effect, although the dynamics
of aggregate assembly most certainly is. The H-P tran-
sition might be direct, with R abruptly changing from
0 to Rmax = ∆nAd, line 1, or through an intermediate
state with R ≈ ∆nAd/2, lines 2, 3 in Fig.2a. The tilt
βx = ∂R/∂x at the states boundaries vary broadly, from
∼100 nm/µm, to ∼1 nm/µm. FCPM of the vertical
cross sections shows that the boundaries represent sharp
walls that are either vertical (larger βx) or tilted (smaller
βx). For example, Fig.2b shows a tilted (∼ 30o
) bound-
ary separating an H sublayer with n||z and P sublayer
with n⊥z; at either of the two H plates, the transition
from n||z to n⊥z is abrupt.
In thermotropic LCs, H-P transitions are continuous
[4, 10]. Discontinuous transitions were reported for in-
plane realignment at anisotropic crystalline substrates
[1, 8] and for patterned plates with spatially varying easy
axis [11]. To quantify the surface effects further, we use
hybrid aligned wedge cells [5], assembled from two dif-
ferent plates, an H plate with DMOAP and an P plate
with buffed polyimide SE-7511 (Nissan). The dihedral
angle is small, < 0.1o
. The cells show a critical thickness
dc at which R (d) changes abruptly, Fig.3, 4. At d < dc,
if the experiment is performed at the beginning of τH for
mixture A, the stable state is the H state; for the case
B, the stable is the P state. At d > dc, R increases with
with d, featuring a slope α = ∂R/∂d; αA = 0.017±0.002
in A and αB = 0.0067 ± 0.002 in B cells, Fig. 3. The
values of dc vary in the range 5-10 µm from sample to
sample, and within the sample, as does α above dc.
FCPM shows that the transitions in the hybrid wedges
feature boundaries that are either vertical, Fig. 4a, tilted
FIG. 3: R(d) for mixtures A and B in the hybrid aligned
wedges
(similar to the one in Fig.2b), or practically horizontal,
Fig.4c. We compare the cross sections of the thin and
thick parts of the same wedge, Fig.4b,c,d. The thin part
is a uniform H state, with fluorescence equally strong
for any in-plane orientation of P, Fig.4b. In the thick
part, Fig.4c, the top 1/3 is occupied with an H layer,
as evidenced in Fig.4d by an overlap of the fluorescence
profiles. In the bottom 2/3, n is close to planar, as the
fluorescence is weak, Fig.4c,d.
The director in a hybrid cell is determined by the bal-
ance of elastic and anchoring forces. At d → ∞, the
conflicting boundary conditions are satisfied by reorient-
ing n from n0⊥z at the P plate, to n0||z at the H plate.
As d decreases, the elastic torque ∝ (θP − θH) /d, de-
termined by the actual polar angles θP and θH at the
plates, becomes stronger, forcing θP and θH to deviate
from their ”easy” values π/2 and 0. At some thick-
ness, the plate with weaker anchoring might give up,
FIG. 4: Vertical FCPM views of the hybrid aligned wedges
with mixture A; (a) vertical boundary between different di-
rector configurations; (b) homeotropic thin, d = 7 µm and
(c) hybrid thick, d = 16 µm, parts of the same wedge and
comparison of their fluorescent profiles (d).
3. 3
allowing n to be uniform. The details depend on the
anchoring potential fs [5]. As shown by Sluckin and
Poniewierski [7], the simplest potential capable to pre-
dict the first-order transitions in semiinfinite samples is
fs = W2(n · z)2
+ W4(n · z)4
. This form also describes
well reorientation of thermotropic LCs by external fields
[3, 6]. For a hybrid cell, the free energy per unit area
should include both anchoring and elastic terms:
f =
1
2
d
0
K(θ)
dθ
dz
2
dz + W2H sin2
θH + W4H sin4
θH + W2P cos2
θP + W4P cos4
θP , (1)
where K (θ) = K1 sin2
θ + K3 cos2
θ, K1 and K3 are the
splay and bend elastic constants, respectively; the an-
choring coefficients satisfy the inequalities W2H > 0,
W2P > 0, W4H > −W2H and W4P > − W2P , to
guarantee the easy axes n0⊥z at the P plate and n0||z
at the H plate. For analytical treatment, we assume
K1 = K3 = K and keep θ fixed at the plate with a
stronger anchoring, as supported by FCPM, Fig.2b, 4.
For the case A, θH = 0, thus f = fP (θP ) =
Kθ2
P /(2d) + W2P cos2
θP + W4P cos4
θP . The values of
θP that minimize fP are found from the conditions
∂fP /∂θP = 0 and ∂2
fP /∂θ2
P > 0. When d → ∞
and W4P < −W2P /2, fP has an absolute minimum at
θP = π/2 and a local one at θP = 0. The two are sep-
arated by a barrier at θP b = arccos − W2P
2W4P
. For finite
d >> K/W2P , fP with −W2P < W4P < −W2P /2 pre-
serves its double-well features. In particular, θP = 0
is still a local minimum. The coordinate θP,min of the
absolute minimum, however, becomes smaller than π/2,
because of the elastic torque ∝ θP /d. We evaluate
fP near θP ≈ π/2 to find θP,min ≈ π
2 1 − K
2dW2P +K .
The difference ∆fP = fP (θP min) − fP (0) vanishes at
d0P ≈ π2
K
8(W2P +W4P ) . For d < d0P , the uniform H state
θ (z) = 0 is stable, while for d > d0P , the hybrid state
has the lowest energy. The transition is discontinu-
ous, with a big jump ∆θP ≈ π3
8(1+W4P /W2P )+2π2 in the
range 1.31 ≤ ∆θP ≤ 1.57 that corresponds to the lim-
its −W2P < W4P < −W2P /2. Similarly for the case B,
θP = π/2 and f = fH (θH) = K (π/2 − θH)
2
/(2d) +
W2H sin2
θH + W4H sin4
θH. There is a critical thick-
ness d0H ≈ π2
K
8(W2H +W4H ) below which the uniform P state
θ (z) = π/2 is stable and above which the hybrid state
with θH min = π
2
K
2dW2H +K << 1 is stable. The transition
is discontinuous in θH. The qualitative features of this
analytical description remain intact when the full form
of f in Eq.(1) is analyzed numerically.
The thickness d0 should not be confused with the ex-
perimental dc. These two in the first order transitions
are very different, because of the barriers featured by fP
and fH, and because of the surface defect of line ten-
sion ∼ K that separate areas with a different tilt. These
defects are seen as cusps in the R (x) dependencies in
Fig.2a. The nuclei of new alignment should be of a size
exceeding ∼ K/ |∆f| to overcome the nucleation barrier
∼ K2
/ |∆f| and expand. The maximum ∆f is W2 +W4.
To estimate W2 +W4, we first recall that the entropy con-
tribution to the surface energy of a LC formed by long
units is [12] σ ≈ kBT ln l
A , where A ≈5 nm is the distance
between the axes of aggregates [16]. For DSCG, l/A ∼ 10
[20], so that σ is a few units of kBT, the same order of
magnitude as the stacking energy E [17]. Thus W2 + W4
is expected to be on the order of ∼ kBT/A2
∼ 10−4
J/m2
.
This estimate, together with K ∼ 10 pN [21], leads to d0
∼ 0.1 µm, much smaller than dc ∼ 10 µm. The reason is
the large nucleation barrier ∼ K2
/ (W2 + W4) ∼ 10−18
J
>> kBT, which signals that nucleation is heterogeneous
(assisted by inhomogeneities). This feature leads to the
important conclusions that in our system, the metastable
states can be long-lived (an analog of a strongly ”super-
cooled” phase) and that the spurious R, α, and β are
related to factors such as surface roughness. The esti-
mates above are rough and might be altered by factors
such as electrostatic interactions, non-analytical form of
the anchoring potential, etc. However, the main feature,
a strongly discontinuous character of transformations, al-
lows to explain qualitatively the effects such as dc = d0.
The general expression R =
d
0
|no − neff | dz trivially
fits the data in Fig.3 at d < dc, with α=0 in the H
state and α ≈ ∆nB= 0.015 in the P case. For the
deformed states at d > dc, the classical approach is
that the dependencies R (d) are determined by smooth
variations of n with a constant scalar order parameter
S. For the A case, RA (θP ) = dJ(θP , 0)/I(θP , 0), while
for the B case, RB (θH) = dJ(π/2, θH)/I(π/2, θH),
where J (ζ, η) =
η
ζ
K (θ) (no − neff ) dθ,
I (ζ, η) =
η
ζ
K (θ)dθ [5]. For K1 = K3 = K,
RB (d) = d∆nB (π − 2θH + sin 2θH) / (2π − 4θH) and
αB = ∂RB/∂d = ∆nB
2 1 + π2
24
K3
W 3
2H d3 = 0.0075 or
larger at d > dc. The experimental αB = 0.0067 is
by 10% smaller. The difference can be accounted for
4. 4
by the fact that K1 < K3. Numerical evaluation of R
with K1 = K3 shows that αB = 0.0067 corresponds
to K1/K3 ≈ 0.4, a reasonable result [21]. For αA, a
reasonable explanation is much harder to arrive at. The-
oretically, in A case, RA = d∆nA (θP − sin 2θP ) /2θP ,
and αA ≈ ∆nA
2 1 − K2
2W 2
2P d2 0.01. The experimental
value αA ≈ 0.017 is 70% larger. The discrepancy
cannot be explained by K1/K3 = 1. To show this, we
assumed θP = π/2 (to maximize the theoretical αA)
and then evaluated R for K1/K3 = 1. By changing
the ratio K1/K3 in the range 10−5
to 105
, we find αA
changing from 0.0067 to 0.0133, still smaller than the
experimental value. In principle, αA ≈ 0.017 can be
obtained by allowing a nonzero θH ≈ 0.1. However,
with θH ≈ 0.1, one should measure, say R ≈148 nm at
d = 8.7 µm, and the actual result is much smaller, R
≈93 nm, Fig.3. We thus associate the spurious data on
α and R at d > dc with the tilted sharp boundaries such
as the ones shown in Fig.2b and 4c,d, with spatially
varying coordinate zb = zb (x, y). The boundaries
with sharply varying n imply a changing degree of
orientational order S. The latter is expected to happen
through the ”interchanging eigenvalues” of the tensor
order parameter in thin hybrid aligned cells [22] with
d ≈ ξbx, where ξbx is the biaxial correlation length. In
thermotropic nematics, ξbx = (10 − 100) nm, but in
LCLCs, we expect ξbx to be much larger, especially
when the structure reconstructs itself as a result of
anchoring transition and applied elastic or field torque.
In the transient regime, the gradients of the scalar
order parameter can be accommodated by redistribution
of the short and long aggregates in the intrinsically
polydisperse LCLC.
The experiments suggests the following basic features
of anchoring in LCLCs. (1) There are two possible easy
directions n0, a tangential (planar) and a homeotropic
one. In DSCG, the H alignment is stable only within a
finite period of time τH (hours and days). The anchoring
transitions are strongly discontinuous. These features are
described by double-well potentials with the local minima
at θ = 0 and π/2, separated by an energy barrier. (2)
The transient nature of H alignment and its spontaneous
transformation into the P state is the most intriguing
feature. In terms of the surface potential W2H sin2
θH +
W4H sin4
θH, this H-P transition at the DMOAP plate
corresponds to the change from W2H +W4H > 0 to W2H +
W4H < 0. Sluckin and Poniewierski [7] related W2H
and W4H to the temperature dependence S(T) so that
the transitions are temperature-driven. In our case, the
changes in W2H and W4H are of a kinetic nature. Since
the H state is observed after the samples are cooled down
from the isotropic phase, it should be accompanied by the
growth of aggregates, as l ∝
√
φ ln (E/kBT). Short and
long aggregates might align differently at the substrates,
say, normally and tangentially, entropy effect being one
of the reasons. With time, the aggregates grow further,
which might trigger an anchoring transition.
We are grateful to anonymous referee for useful sug-
gestions. The work was supported by NSF Materials
World Network on Lyotropic Chromonic Liquid Crystals
DMR076290, ARRA DMR 0906751, Ohio Research Clus-
ter on Surfaces in Advanced Materials, NAS of Ukraine
Grant #1.4.1B/109, Fundamental Research State Fund
Project UU24/018, and by the Ministry of Education and
Science of Ukraine, Project 0109U001062.
∗
Electronic address: olavrent@kent.edu
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