Double Potential Research Articles

Role of Adamantane Amide Based on L-Proline Double-H Potential Organocatalyst in Aldol Reaction with Product Separated via Host-guest Interaction

Chiral organocatalysts of 4-adamantane amide based on L-proline with double hydrogen potential were synthesized and used in asymmetric aldol reactions. The reactions were evaluated in toluene under‒20 °C. A series of aldol products was obtained from moderate to good yields(up to 98%) with excellent diastereoselectivities(up to >99:1) and enantioselectivities(up to >99%). The aldol products in the system were separated by α-cyclodextrin via host-guest interaction and determined by chiral HPLC. The catalyst could be reused up to five times. The 4-substitution position played an important role in diastereoselectivity and enantioselectivity.

Double Layer Potentials on Polygons and Pseudodifferential Operators on Lie Groupoids

We use an approach based on pseudodifferential operators on Lie groupoids to study the double layer potentials on plane polygons. Let $$\Omega $$ be a simply connected polygon in $$\mathbb {R}^2$$ . Denote by K the double layer potential operator on $$\Omega $$ associated with the Laplace operator $$\Delta $$ . We show that the operator K belongs to the groupoid $$C^*$$ -algebra that the first named author has constructed in an earlier paper (Carvalho and Qiao in Cent Eur J Math 11(1):27–54, 2013). By combining this result with general results in groupoid $$C^*$$ -algebras, we prove that the operators $$\pm I + K$$ are Fredholm between appropriate weighted Sobolev spaces, where I is the identity operator. Furthermore, we establish that the operators $$\pm I + K$$ are invertible between suitable weighted Sobolev spaces through techniques from Mellin transform. The invertibility of these operators implies a solvability result in weighted Sobolev spaces for the interior and exterior Dirichlet problems on $$\Omega $$ .

Reentrant atrial tachycardia originating from the sinus venosa region

A 78-year old woman with palpitation exhibited an atrial tachycardia (AT) of variable cycle lengths resembling atrial fibrillation (AF). Vague centrifugal activation was noted at the sinus venosa region where overdrive pacing demonstrated entrainment with concealed fusion and the stimulus to P wave approximated the electrogram to the P wave interval of 125ms. Application of radiofrequency energy to this site resulted in termination of the AT as well as formation of a fixed block line manifested by the presence of discrete double potentials. These observations indicated the reentrant mechanism of AT originating from the sinus venosa region.

Investigation of broadband attenuation with fractal diffusers as noise barrier top edge devices using indirect boundary element method

Computation of broadband noise barrier performance in three-dimension is computationally expensive. Indirect boundary element method with double layer potentials has been developed as a numerical tool in this acoustic study. It naturally permits noise barriers to be modelled as thin structures, thus reducing the computational cost when compared to the more abundant direct boundary element tools employed for noise barriers. The present numerical model has been validated with analytical solution. Its computational capabilities are compared with a direct boundary element tool, developed in-house. The applicability of this tool has been demonstrated with the study of fractal acoustic diffusers as noise barrier top-edge devices. Schroeder diffusers have been reported to provide good noise attenuation at their design frequency, when used as noise barrier top-edge devices. This study investigates the broadband performance of fractal diffusers as noise barrier top-edge devices.

Double layer potentials on three-dimensional wedges and pseudodifferential operators on Lie groupoids

Let W be a three-dimensional wedge, and K be the double layer potential operator associated to W and the Laplacian. We show that 12±K are isomorphisms between suitable weighted Sobolev spaces, which implies a solvability result in weighted Sobolev spaces for the Dirichlet problem on W. Furthermore, we show that the double layer potential operator K is an element in C⁎(G)⊗M2(C), where G is the action (transformation) groupoid M⋊G, with G={(10ab):a∈R,b∈R+}, which is a Lie group, and M is a kind of compactification of G. This result can be used to prove the Fredholmness of 12+KΩ, where Ω is “a domain with edge singularities” and KΩ the double layer potential operator associated to the Laplacian and Ω.

Polyacetylene: Myth and Reality.

Polyacetylene, the simplest and oldest of potentially conducting polymers, has never been made in a form that permits rigorous determination of its structure. Trans polyacetylene in its fully extended form will have a potential energy surface with two equivalent minima. It has been assumed that this results in bond length alternation. It is, rather, very likely that the zero-point energy is above the Peierls barrier. The experimental studies that purport to show bond alternation are reviewed and shown to be compromised by serious experimental inconsistencies or by the presence, for which there is considerable evidence, of finite chain polyenes. In this view, addition of dopants results in conductivity by facilitation of charge transport between finite polyenes. The double minimum potential that necessarily occurs for polyacetylene, if viewed as the result of elongation of finite chains, originates from admixture of the 11Ag ground electronic state with the 21Ag excited electronic singlet state. This excitation is diradical (two electron) in character. The polyacetylene limit is an equal admixture of these two 1Ag states making theory intractable for long chains. A method is outlined for preparation of high molecular weight polyacetylene with fully extended chains that are prevented from reacting with neighboring chains.

The doubling potential of T lymphocytes allows clinical-grade production of a bank of genetically modified monoclonal T-cell populations

Background aimsTo produce an anti-leukemic effect after hematopoietic stem cell transplantation we have long considered the theoretical possibility of using banks of HLA-DP specific T-cell clones transduced with a suicide gene. For that application as for any others, a clonal strategy is constrained by the population doubling (PD) potential of T cells, which has been rarely explored or exploited. MethodsWe used clinical-grade conditions and two donors who were homozygous and identical for all HLA-alleles except HLA-DP. After mixed lymphocyte culture and transduction, we obtained 14 HLA-DP–specific T-cell clones transduced with the HSV-TK suicide gene. Clones were then selected on the basis of their specificity and functional characteristics and evaluated for their doubling potential. ResultsAfter these steps of selection the clone NAT-DP4(TK), specific for HLA-DPB1*04:01/04:02, which produced high levels of interferon-γ (IFNγ), tumor necrosis factor (TNF), interleukin-2 (IL-2) and granulocyte-macrophage colony-stimulating factor (GM-CSF), was fully sequenced. It has two copies of the HSV-TK suicide transgene whose localizations were determined. Four billion NAT-DP4(TK) cells were frozen after 50 PDs. Thawed NAT-DP4(TK) cells retain the potential to undergo 50 additional PDs, a potential very far beyond that required to produce a biological effect. This PD potential was confirmed on 6/16 additional different T-cell clones. This type of well-defined clone can also support a second genetic modification with CAR constructs. ConclusionThe possibility of choosing rare donors and exploiting the natural proliferative potential of T lymphocytes may dramatically reduce the clinical and immunologic complexity of adoptive transfer protocols that rely on the use of third-party T-cell populations.

Propagator for symmetric double delta potential using path decomposition method

Using the method of path decomposition, the space-time propagator for the one-dimensional symmetric double delta potential is determined and tested on the limiting cases a → 0 (single delta) and β → ∞ (infinite square well), which are exactly obtained.

Communication: Electronic flux induced by crossing the transition state.

We present a new effect of chemical reactions, e.g., isomerizations, that occurs when the reactants pass along the transition state, on the way to products. It is based on the well-known fact that at the transition state, the electronic structure of one isomer changes to the other. We discover that this switch of electronic structure causes a strong electronic flux that is well distinguishable from the usual flux of electrons that travel with the nuclei. As a simple but clear example, the effect is demonstrated here for bond length isomerization of Na2 (21Σu+), with adiabatic crossing the barrier between the inner and outer wells of the double minimum potential that support different "Rydberg" and "ionic" type electronic structures, respectively.

The role of water in the anomalies of pyro- and thermodepolarization properties of pyroactive polymer films at stepwise heating

The paper presents the results of investigations of the temperature dependencies of pyroelectric coefficient and thermodepolarization currents of pyroelectric polymer films (hydrophobic VDF/TrFE copolymer and hydrophilic Langmuir films of azo compounds), which were prepared using water. The anomalies of these properties were observed at 4, 28, 35, 45°C for films of azo compounds and 20, 35, 49, 72 and 100°C for VDF/TrFE. These temperature points are close to temperatures of anomalies of physical properties of water. At the listed temperature points, water clusters and the molecule itself are destroyed. Similar anomalies have been previously observed in crystallohydrates, “polymer-water” systems and ferroelectrics of Triglycine Sulphate family, in the structure of which there is a network of OH…O hydrogen bonds of the same length as in water. The key property of the hydrogen bond is the presence of discrete protons energy levels, which at stepwise heating (slow kinetics) leads to the transformation or destruction of the hydrogen-bonding network, as well as to the refilling of proton energy levels in the double minimum potential, the release of deep traps, and to the change of charge carrier types, their mobility and conducting paths.

Cahn--Hilliard Inpainting with the Double Obstacle Potential

The inpainting of damaged images has a wide range of applications, and many different mathematical methods have been proposed to solve this problem. Inpainting with the help of Cahn--Hilliard models has been particularly successful, and it turns out that Cahn--Hilliard inpainting with the double obstacle potential can lead to better results compared to inpainting with a smooth double well potential. However, a mathematical analysis of this approach is missing so far. In this paper we give first analytical results for a Cahn--Hilliard double obstacle inpainting model regarding existence of global solutions to the time-dependent problem and stationary solutions to the time-independent problem without constraints on the parameters involved. With the help of numerical results we show the effectiveness of the approach for binary and grayscale images.

Scattering Study of Fermions due to Double Dirac Delta Potential in Quaternionic Relativistic Quantum Mechanics

We have studied the scattering problem of relativistic fermions from a quaternionic double Dirac delta potential. We have used Dirac equation in the presence of the scalar and vector potentials in the quaternionic formalism of relativistic quantum mechanics to study the problem. The wave functions of different regions have been derived. Then, using the reflection coefficient, transmission coefficient, and the continuity equation, the scattering problem has been investigated in detail. It has been shown that we have faced some fluctuations in the reflection and transmission coefficients.

Investigation of the elastic and inelastic scattering of 4He from 11B in the energy range 29-50.5 MeV

We have measured the angular distributions for the elastic and inelastic scattering of 4He from 11B in the isochronous cyclotron U-150 M INP RK. The extracted α-particles beam has been accelerated to energy 29 MeV and then directed to 11B target. The experimental results were analyzed within the framework of both the optical model using different complex potential and the double folding potential obtained with different density-dependent NN interactions which give the corresponding values of the nuclear incompressibility K in the Hartree-Fock calculation of nuclear matter.

Investigation of α-particle scattering from 13C at 29 MeV

We have measured the angular distributions for the elastic and inelastic scattering of α-particles from 13C in the isochronous cyclotron U-150M INP (Almaty, Kazakhstan). The experimental results were analyzed within the framework of both the optical model using different complex potentials and the double folding potential obtained with different density-dependent nucleon-nucleon interactions.

The Visualization of the Space Probability Distribution for a Particle Moving in a Double Ring-Shaped Coulomb Potential

The analytical solutions to a double ring-shaped Coulomb potential (RSCP) are presented. The visualizations of the space probability distribution (SPD) are illustrated for the two- (contour) and three-dimensional (isosurface) cases. The quantum numbers (n,l,m) are mainly relevant for those quasi-quantum numbers (n′,l′,m′) via the double RSCP parameter c. The SPDs are of circular ring shape in spherical coordinates. The properties for the relative probability values (RPVs) P are also discussed. For example, when we consider the special case (n,l,m)=(6,5,0), the SPD moves towards two poles of z-axis when P increases. Finally, we discuss the different cases for the potential parameter b, which is taken as negative and positive values for c>0. Compared with the particular case b=0, the SPDs are shrunk for b=-0.5, while they are spread out for b=0.5.

Singular Integral Operators and Elliptic Boundary-Value Problems. I

The book consists of three Parts I-III and Part I is presented here. In this book, we develop a new approach mainly based on the author’s papers. Many results are published here for the first time. Chapter 1 is introductory. The necessary background from functional analysis is given there for completeness. In this book, we mostly use weighted Ho¨lder spaces, and they are considered in Ch. 2. Chapter 3 plays the main role: in weighted Ho¨lder spaces we consider there estimates of integral operators with homogeneous difference kernels, which cover potential-type integrals and singular integrals as well as Cauchy-type integrals and double layer potentials. In Ch. 4, analogous estimates are established in weighted Lebesgue spaces. Integrals with homogeneous difference kernels will play an important role in Part III of the monograph, which will be devoted to elliptic boundary-value problems. They naturally arise in integral representations of solutions of first-order elliptic systems in terms of fundamental matrices or their parametrixes. Investigation of boundary-value problems for second-order and higher-order elliptic equations or systems is reduced to first-order elliptic systems.

Explicitly-correlated double ionization potentials and double electron attachment equation-of-motion coupled cluster methods

Double ionization and double electron attachment equation-of-motion methods, based on linearly approximated explicitly correlated coupled-cluster singles and doubles [CCSD(F12)] are formulated and implemented. An extension of double electron attachment operator is introduced for proper account of short-range correlation effects in states with two additional electrons. Numerical tests for set of doubly ionized and doubly electron attached states of several molecules have shown a good agreement between obtained explicitly-correlated results and the corresponding complete basis set limit values already at double-ζ level.

Influence of designed electrode surfaces on double layer capacitance in aqueous electrolyte: Insights from standard models

Standard models, Helmholtz, Gouy-Chapman, Stern and Grahame models have been validated on the electrical double layers (EDLs) formed from three different electrode surfaces, i.e., plain, semi-sphere and cylindrical pore in aqueous electrolyte. The double layer potential (ϕ) and areal capacitance (Cdl) were estimated in the three models using MATLAB Simulink. It was found that the areal capacitance of the double layer strongly influenced by the nature/ type of the electrode surface in contact with the electrolyte. The cylindrical-type pore surface exhibited the large areal capacitance. The charge-discharge and impedance characteristics of the EDLs were also analyzed.

The spectra of harmonic layer potential operators on domains with rotationally symmetric conical points

We study the adjoint of the double layer potential associated with the Laplacian (the adjoint of the Neumann–Poincaré operator), as a map on the boundary surface Γ of a domain in R3 with conical points. The spectrum of this operator directly reflects the well-posedness of related transmission problems across Γ. In particular, if the domain is understood as an inclusion with complex permittivity ϵ, embedded in a background medium with unit permittivity, then the polarizability tensor of the domain is well-defined when (ϵ+1)/(ϵ−1) belongs to the resolvent set in energy norm. We study surfaces Γ that have a finite number of conical points featuring rotational symmetry. On the energy space, we show that the essential spectrum consists of an interval. On L2(Γ), i.e. for square-integrable boundary data, we show that the essential spectrum consists of a countable union of curves, outside of which the Fredholm index can be computed as a winding number with respect to the essential spectrum. We provide explicit formulas, depending on the opening angles of the conical points. We reinforce our study with very precise numerical experiments, computing the energy space spectrum and the spectral measures of the polarizability tensor in two different examples. Our results indicate that the densities of the spectral measures may approach zero extremely rapidly in the continuous part of the energy space spectrum.

Selection of electrogenic bacteria for microbial fuel cell in removing Victoria blue R from wastewater

ABSTRACTThis study was conducted to select electrogenic bacteria from wastewater sludge. Phylogenetic analysis revealed that Proteobacteria was the dominant phylum in the microbial fuel cell (MFC) during the decomposition process of organic pollutants. Five culturable bacteria strains – namely, Bacillus subtilis, Flavobacterium sp., Aeromonas hydrophila, Citrobacter freundii, and Stenotrophomonas sp. – have a double potential in dye removal and electricity generation. We inoculated the mixed electrogenic bacteria at a specific ratio and treated them with a triphenylmethane dye, Victoria blue R (VBR), to evaluate their electricity generation ability for the artificial and real wastewater. The results of the VBR shock-loading experiment indicated that the inoculated MFC could adapt to shock loading in 1–2 days and exhibited high removal efficiency (95–100%) for 100–800 mg L−1 VBR with a power density of 8.62 ± 0.10 to 34.81 ± 0.25 mW m−2. The selected electrogenic bacteria in the MFC could use VBR as only electron donor for power generation. The matrix effects of the real wastewater on VBR removal and electricity generation of MFC were insignificant. VBR degradation by the electrogenic bacteria involves a stepwise demethylation process to yield partially dealkylated VBR species. In addition, these results demonstrate the feasibility of inoculating culturable bacteria strains to develop an efficient MFC for purifying wastewater.