The use of off-shell potentials in Brueckner theory calculations of the nucleon optical potential
We calculate the nucleon optical-potential from the Hamada-Johnston potential using firstorder Brueckner theory. The new feature is that we use a fully complex off-shell potential in the energy denominator in the calculation of the t-matrix in place of the usually used real part of the on-shell potential. We find that for bombarding energies near 30 MeV the agreement with experimental data is satisfactory while at higher energies the general results from the on- and off-shell potentials are very similar. The reason for the better agreement at the lower energies using the off-shell potential in the energy denominator is that the calculated optical potential in this case has a much smaller imaginary part. (orig.)
Density dependence of microscopic nucleon optical potential in first order Brueckner theory
In the present work we apply the lowest order Brueckner theory of infinite nuclear matter to obtain nucleon-nucleus optical potential for p-40Ca elastic scattering at 200 MeV using Urbana V14 soft core internucleon potential. We have investigated the effect of target density on the calculated nucleon-nucleus optical potential. We find that the calculated optical potentials depend quite sensitively on the density distribution of the target nucleus. The important feature is that the real part of calculated central optical potential for all densities shows a wine-bottle-bottom type behaviour at this energy. We also discuss the effect of our new radial dependent effective mass correction. Finally, we compare the prediction of our calculated nucleon optical potential using V14 with the prediction using older hard core Hamada-Johnston internucleon potential for p-40Ca elastic scattering at 200 MeV. (author)
RONG Jian; MA Zhongyu
2004-01-01
The relativistic microscopic optical potential in the asymmetric nuclear matter is studied in the framework of the Dirac Brueckner-Hartree-Fock method. A new decomposition of the Dirac structure of the nuclear self-energy in nuclear matter is adopted. The self-energy of a nucleon with E＞ 0 in nuclear matter is calculated with the G matrix in the Hartree-Fock approach. The optical potential of a nucleon in the nuclear medium is identified with the nucleon self-energy. The energy and asymmetric parameter dependence of the relativistic optical potentials for proton and neutron are discussed. The resulting Schroedinger equivalent potentials have reasonable behaviors of the energy dependence. The asymmetric parameter dependence of relativistic optical potentials and Schroedinger potentials are emphasized.
Validity of Brueckner theory for the nucleon optical potential near 200 MeV
A comparison is made of the experimental cross sections for proton scattering from 12C, 40Ca and 208Pb near 200 MeV bombarding energy with the results obtained from optical potentials calculated from Brueckner theory. We confirm the results of earlier analyses that the calculated potentials cannot reproduce the experimental data. It is shown that the calculated imaginary part of the potentials is completely satisfactory and that it is the calculated real part which leads to the discrepancy between theory and experiment. The real part is found to have the wrong radial shape, it has too extreme a 'wine bottle' shape. We show that this is a consequence of the calculated dependence of the t-matrix on the internucleon separation, in particular on the very different ranges for the attractive and repulsive parts. This is a consequence of our use of a hard-core internucleon potential and we suggest that a soft-core or momentum-dependent potential might give a better account of the experimental data. (orig.)
The Bonn-potential and the relativistic Dirac-Brueckner approach to nuclear matter
A relativistic form of the Brueckner theory of nuclear matter is applied to an extended meson-exchange model for the NN-interaction containing explicit 2/sub π-/ and πrho-exchanges. It turns out that the relativistic saturation effects found earlier within the simplified one-boson-exchange (OBE) model maintain within this extended and more realistic model. In particular it is found that the relativistic effects caused by the explicit 2/sub π-/ and πrho-exchanges are well simulated by the fictitious σ-boson of the OBE model
Exact calculation of nucleon nucleus spin orbit potential in Brueckner theory
We have calculated the direct part of the spin orbit potential for the scattering of protons from 16O, 40Ca, 90Zr and 208Pb at 65 MeV to make a comparison of the spin orbit obtained by BR and our results obtained after removing the approximations which were assumed by BR. We have calculated the potential for different targets so as to study the mass number dependence of the calculated direct and imaginary parts of the spin orbit potential. We have employed Argonne v18 inter nucleon potential to solve Bethe-Goldstone integral equation to obtain t- matrices which were then folded numerically over the target densities. Effective mass correction has also been taken into account during the calculations. The nucleon densities used for the four targets were calculated using Relativistic mean field theory
Brockmann, R.; Machleidt, R.
1996-01-01
In this review, we give a thorough introduction into the Dirac-Brueckner approach including the mathematical details of the formalism involved. Furthermore, we present results for nuclear matter, NN scattering in the nuclear medium, and finite nuclei.
Nucleon self-energy in the relativistic Brueckner theory
Waindzoch, T.; Fuchs, C.; Faessler, A. [Inst. fuer Theoretische Physik, Univ. Tuebingen (Germany)
1998-06-01
The self-energy of the nucleon in nuclear matter is calculated in the relativistic Brueckner theory. We solve the Thompson equation for the two nucleon scattering in the medium using different Bonn potentials. The self-energy has a rather strong momentum dependence while the equation of state compares well with previous calculations. (orig.)
Brueckner-AMD Study of Light Nuclei
We applied the Brueckner theory to the Antisymmetrized Molecular Dynamics (AMD) and examined the reliability of the AMD calculations based on realistic nuclear interactions. In this method, the Bethe-Goldstone equation in the Brueckner theory is solved for every nucleon pair described by wave packets of AMD, and the G-matrix is calculated with single-particle orbits in AMD self-consistently. We apply this framework to not only α-nuclei but also N≠Z nuclei with A∼10. It is confirmed that these results present the description of reasonable cluster structures and energy-level schemes comparable with the experimental ones in light nuclei.
Brueckner-AMD study of light nuclei
We applied the Brueckner theory to the Antisymmetrized Molecular Dynamics (AMD), and show the reliability of the AMD calculations based on realistic nuclear interactions. Focusing our interest on a structure dependence of the tensor force, we investigate the α-α clusterization of 8Be. (author)
Brueckner-AMD study of light nuclei
In many states of light nuclei, the cluster structure is observed in addition to the shell structure. To understand the mechanism of clustering, we apply the Brueckner theory to the Antisymmetrized Molecular Dynamics (AMD) based on realistic nuclear interactions. The Bethe-Goldstone equation in the Brueckner theory is solved for every nucleon pair described by wave packets of AMD, and the G-matrix is calculated with single-particle orbits in AMD self-consistently. We show applicability of this method not only to self-conjugate nuclei but also to N ≠ Z nuclei with A ≤ 12. It is confirmed that these results present reasonable description of cluster structures and energy-level schemes in comparison with the experimental ones in light nuclei. For 8Be having a typical α + α cluster structure, the structure dependence of the G-matrix is investigated and the role of tensor force is shown to be important in understanding the clustering mechanism.
Relativistic meson-exchange NN-interaction and nuclear matter in the Dirac-Brueckner approach
Starting from the full Bonn meson-exchange model for the NN-interaction an OBEP is constructed in the framework of the Thompson version of the Blankenbecler-Sugar reduction of the Bethe-Salpeter equation. The pseudo-vector coupling of the pion to the nucleon is assumed. An excellent quantitative description of the deuteron and the latest phase-shift analyses of NN-scattering is achieved. This potential is applied to the system of infinite nuclear matter in the relativistic Dirac-Brueckner approach. Due to additional strongly density dependent relativistic saturation effects, which do not occur in conventional Brueckner theory, the empirical saturation energy and density of nuclear matter are reproduced. This potential may serve as a good starting point for the evaluation of the optical potential to be applied in nucleon-nucleus scattering
Momentum-dependent mean field based upon the Dirac-Brueckner approach for nuclear matter
A momentum-dependent mean field potential, suitable for application in the transport-model description of nucleus-nucleus collisions, is derived in a microscopic way. The derivation is based upon the Bonn meson-exchange model for the nucleon-nucleon interaction and the Dirac-Brueckner approach for nuclear matter. The properties of the microscopic mean field are examined and compared with phenomenological parametrizations which are commonly used in transport-model calculations
Relativistic Brueckner-Hartree-Fock theory for finite nuclei
Shen, Shihang; Liang, Haozhao; Meng, Jie; Ring, Peter; Zhang, Shuangquan
2016-01-01
Starting with a bare nucleon-nucleon interaction, for the first time the full relativistic Brueckner-Hartree-Fock equations are solved for finite nuclei in a Dirac-Woods-Saxon basis. No free parameters are introduced to calculate the ground-state properties of finite nuclei. The nucleus $^{16}$O is investigated as an example. The resulting ground-state properties, such as binding energy and charge radius, are considerably improved as compared with the non-relativistic Brueckner-Hartree-Fock results and much closer to the experimental data. This opens the door for \\emph{ab initio} covariant investigations of heavy nuclei.
The description of nuclear structures with the Brueckner-AMD
We propose a new approach of the Brueckner-AMD that makes the antisymmetrized molecular dynamics (AMD) calculations possible with realistic nuclear forces. In this method, we solve the Bethe-Goldstone equation and calculate the G-matrix for every nucleon pair described by wave packets of AMD. In addition, we calculate the G-matrix in the spin and parity projection correctly using the two-body correlation functions derived from the solutions of the Bethe-Goldstone equation. We report the results of applications to light nuclei with the Brueckner-AMD plus the spin and parity projection. (author)
The study of light nuclei with the Brueckner-AMD
We propose a new approach of the Brueckner-AMD that makes the antisymmetrized molecular dynamics (AMD) calculations possible with realistic nuclear forces. In this method, we solve the Bethe-Goldstone equation and calculate the G-matrix for every nucleon pair described by wave packets of AMD. In addition, we perform the spin and parity projection correctly using the two-body correlators derived from the solutions of the Bethe-Goldstone equation. We report the results of applications to light nuclei with the Brueckner-AMD plus the spin and parity projection
Brueckner-AMD method and its applications to light nuclei
We propose a new approach employing the Brueckner-AMD in which the G-matrix is calculated using the antisymmetrized molecular dynamics (AMD). Its applications to some light nuclei are demonstrated, and the high reliability of the description of the shell and cluster structures is discussed. (author)
From Brueckner approach to Skyrme-type energy density functional
A Skyrme-like effective interaction is built up from the equation of state of nuclear matter. The latter is calculated in the framework of the Brueckner-Hartree-Fock approximation with two- and three-body forces. A complete Skyrme parametrization requires a fit of the neutron and proton effective masses and the Landau parameters. The new parametrization is probed on the properties of a set of closed-shell and closed-subshell nuclei, including binding energies and charge radii
The Relativistic Dirac-Brueckner Approach to Nuclear Matter
Fuchs, Christian
2003-01-01
An overview on the relativistic Dirac-Brueckner approach to the nuclear many-body problem is given. Different approximation schemes are discussed, with particular emphasis on the nuclear self-energy and the saturation mechanism of nuclear matter. I will further discuss extensions of the standard approach, amongst other things the inclusion of non-nucleonic degrees of freedom, many-body forces and finally compare relativistic and non-relativistic approaches.
Brueckner rearrangement energies in s-shell hypernuclei
We consider rearrangement effects in light hypernuclei in the framework of the lowest order Brueckner theory. The energy change of the 4He core of Λ5He when the Λ hyperon is added to 4He is first estimated without much numerical computations. Next, rearrangement contributions in ΔΒΛΛ(ΛΛ6He) are estimated, which are important to deduce the strength of the ΛΛ interaction from the experimental ΔΒΛΛ(ΛΛ6He). (author)
A New Decomposition Approach of Dirac Brueckner Hartree-Fock G Matrix for Asymmetric Nuclear Matter
刘玲; 马中玉
2002-01-01
Asymmetric nuclear matter is investigated by the Dirac Brueckner Hartree-Fock (DBHF) approach with a new decomposition of the Dirac structure of nucleon self-energy from the G matrix. It is found that the isospin dependence of the scalar and vector potentials is relatively weak, although both potentials for neutron (proton)become deep (shallow) in the neutron-rich nuclear matter. The results in asymmetric nuclear matter are rather different from those obtained by a simple method, where the nucleon self-energy is deduced from the single-particle energy. The nuclear binding energy as a function of the asymmetry parameter fulfils the empirical parabolic law up to very extreme isospin asymmetric nuclear matter in the DBHF approach. The behaviour of the density dependence of the asymmetry energy is different from that obtained by non-relativistic approaches, although both give similar asymmetry energy at the nuclear saturation density.
Properties of dense, asymmetric nuclear matter in Dirac-Brueckner-Hartree-Fock approach
Katayama, Tetsuya
2013-01-01
Within the Dirac-Brueckner-Hartree-Fock approach, using the Bonn potentials, we investigate the properties of dense, asymmetric nuclear matter and apply it to neutron stars. In the actual calculations of the nucleon self-energies and the energy density of matter, we study in detail the validity of an angle-averaged approximation and an averaging of the total momentum squared of interacting two-nucleons in nuclear matter. For practical use, we provide convenient parametrizations for the equation of state for symmetric nuclear matter and pure neutron matter. We also parametrize the nucleon self-energies in terms of polynomials of nucleon momenta. Those parametrizations can accurately reproduce the numerical results up to high densities.
Description of nuclear structures in light nuclei with Brueckner-AMD
Katō K.; Yamamoto Y; Togashi T.
2010-01-01
We develop the new antisymmetrized molecular dynamics (AMD) method, Brueckner-AMD, which makes us perform the AMD calculations starting from the realistic nuclear force. In the Brueckner-AMD, the single-particle orbits of AMD can be applied straightforward to the Bethe-Goldstone equation in the Brueckner theory by using the AMD+Hartree-Fock method, and the G-matrices are determined with the single-particle energies of AMD self-consistently. In that sense, in this framework, the G-matrix...
Testing Dirac-Brueckner models in collective flow of heavy-ion collisions
We investigate differential in-plane and out-of-plane flow observables in heavy-ion reactions at intermediate energies from 0.2-2 AGeV within the framework of relativistic BUU transport calculations. The mean field is based on microscopic Dirac-Brueckner-Hartree-Fock (DB) calculations. We apply two different sets of DB predictions, those of ter Haar and Malfliet and more recent ones from the Tuebingen group, which are similar in general but differ in details. The latter DB calculations exclude spurious contributions from the negative-energy sector to the mean field which results in a slightly softer equation of state and a less repulsive momentum dependence of the nucleon-nucleus potential at high densities and high momenta. For the application to heavy-ion collisions in both cases non-equilibrium features of the phase space are taken into account on the level of the effective interaction. The systematic comparison to experimental data favours the less repulsive and softer model. Relative to non-relativistic approaches one obtains larger values of the effective nucleon mass. This produces a sufficient amount of repulsion to describe the differential flow data reasonably well. (orig.)
Neutron stars with Hyperons in Dirac-Brueckner-Hartree-Fock approach
Katayama, Tetsuya
2014-01-01
Using the Dirac-Brueckner-Hartree-Fock (DBHF) approach including the hyperon degrees of freedom, we investigate the properties of neutron-star matter. To handle the hyperons in matter, we first examine the importance of the space part of baryon self-energies at high densities, and secondly study the effect of negative-energy states of baryons, which can provide an unambiguous relationship between the in-medium reaction matrices for baryon-baryon scattering and the baryon self-energies. We solve the coupled, Bethe-Salpeter equations in the nuclear-matter rest frame by using the Bonn potentials. We assume that eight kinds of nonstrange and strange mesons ($\\sigma,\\,\\delta,\\,\\omega,\\,\\rho,\\,\\eta,\\,\\pi,\\,K,\\,K^{\\ast}$) take part in the interactions between two baryons. Then, we calculate the baryon self-energies, the energy density and pressure of matter. The present calculation provides a hard equation of state in neutron-star matter at high densities, which is generated by the effect of Pauli exclusion, the sho...
On the effective sigma-boson exchange in the relativistic Dirac-Brueckner approach to nuclear matter
A relativistic form of the Brueckner theory of nuclear matter is applied to an extended meson-exchange model for the NN-interaction which contains explicit 2π-and πrho-exchange. This model avoids the effective sigma-boson which is characteristic of the simplified meson exchange, as e.g. the one-boson-exchange (OBE) potential. It turns out that the relativistic saturation effects found earlier within the OBE model are confirmed by the extended and more realistic model. In particular it is found that the relativistic effects caused by the explicit 2π- and πrho-exchange are well simulated by the effective sigma-boson of the OBE model. (orig.)
Brueckner-Hartree-Fock and its renormalized calculations for finite nuclei
Hu, B S; Ma, Y Z; Wu, Q; Sun, Z H
2016-01-01
We have performed self-consistent Brueckner-Hartree-Fock (BHF) and its renormalized theory to the structure calculations of finite nuclei. The $G$-matrix is calculated within the BHF basis, and the exact Pauli exclusion operator is determined by the BHF spectrum. Self-consistent occupation probabilities are included in the renormalized Brueckner-Hartree-Fock (RBHF). Various systematics and convergences are studies. Good results are obtained for the ground-state energy and radius. RBHF can give a more reasonable single-particle spectrum and radius. We present a first benchmark calculation with other {\\it ab initio} methods using the same effective Hamiltonian. We find that the BHF and RBHF results are in good agreement with other $\\it{ab}$ $\\it{initio}$ methods.
The Bethe-Brueckner-Goldstone expansion in nuclear and neutron matter
The microscopic theory of nuclear matter is developed within the Bethe-Brueckner-Goldstone expansion. Starting from different realistic nucleon-nucleon interactions, the equation of state of symmetric nuclear matter and pure neutron matter is calculated up to three-hole level of approximation. The expansion shows to be convergent up to densities relevant for neutron stars studies. Within the same scheme, the nucleon strength function is calculated in the kinematical region pertinent to deep inelastic electron scattering. (author)
Nucleon effective mass in symmetric nuclear matter from the extended Brueckner-Hartree-Fock approach
GAN Sheng-Xin; ZUO Wei; U. Lombardo
2012-01-01
We have calculated the nucleon effective mass in symmetric nuclear matter within the framework of the Brueckner-Bethe-Goldstone (BBG) theory,which has been extended to include both the contributions from the ground-state correlation effect and the three-body force (TBF) rearrangement effect.The effective mass is predicted by including the ground-state correlation effect and the TBF rearrangement effect,and we discuss the momentum dependence and the density dependence of the effective mass.It is shown that the effect of ground state correlations plays an important role at low densities,while the TBF-induced rearrangement effect becomes predominant at high densities.
Neutron stars with Hyperons in Dirac-Brueckner-Hartree-Fock approach
Katayama, Tetsuya; Saito, Koichi
2014-01-01
Using the Dirac-Brueckner-Hartree-Fock (DBHF) approach including the hyperon degrees of freedom, we investigate the properties of neutron-star matter. To handle the hyperons in matter, we first examine the importance of the space part of baryon self-energies at high densities, and secondly study the effect of negative-energy states of baryons, which can provide an unambiguous relationship between the in-medium reaction matrices for baryon-baryon scattering and the baryon self-energies. We sol...
Kohno, M
2015-01-01
The nuclear saturation mechanism is discussed in terms of two-nucleon and three-nucleon interactions in chiral effective field theory (Ch-EFT), using the framework of lowest-order Brueckner theory. After the Coester band, which is observed in calculating saturation points with various nucleon-nucleon (NN) forces, is revisited using modern NN potentials and their low-momentum equivalent interactions, detailed account of the saturation curve of the Ch-EFT interaction is presented. The three-nucleon force (3NF) is treated by reducing it to an effective two-body interaction by folding the third nucleon degrees of freedom. Uncertainties due to the choice of the 3NF low-energy constants $c_D$ and $c_E$ are discussed. The reduction of the cutoff-energy dependence of the NN potential is explained by demonstrating the effect of the 3NF in the $^1$S$_0$ and $^3$S$_1$ states.
Kohno, M.
2015-12-01
The nuclear saturation mechanism is discussed in terms of two-nucleon and three-nucleon interactions in chiral effective field theory (Ch-EFT), using the framework of lowest-order Brueckner theory. After the Coester band, which is observed in calculating saturation points with various nucleon-nucleon (NN) forces, is revisited using modern NN potentials and their low-momentum equivalent interactions, a detailed account of the saturation curve of the Ch-EFT interaction is presented. The three-nucleon force (3NF) is treated by reducing it to an effective two-body interaction by folding the third nucleon degrees of freedom. Uncertainties due to the choice of the 3NF low-energy constants c_D and c_E are discussed. The reduction of the cutoff-energy dependence of the NN potential is explained by demonstrating the effect of the 3NF in the ^1S_0 and ^3S_1 states.
Microscopic Optical Potential of α-Nucleus Elastic Scattering
2008-01-01
<正>The nucleon microscopic optical model potentials (OMP) in the nuclear medium are studied in the framework of the Dirac-Brueckner-Hartree-Fock approach, which are of density- and energy-dependence.
Iso-spin Dependent Microscopic Optical Model Potential Based on Dirac Bruckner Haretree Fock Method
无
2011-01-01
The microscopic optical model is investigated in the Dirac-Brueckner-Hartree-Fock (DBHF) framework with Bonn B meson exchange potential. Both real and imaginary parts of isospin-dependent self-energies are derived from a strict projection
Brueckner correlations following a boson mapping of the two-color delta model
We study the application of boson mapping methods to a two-color delta model of interacting quarks, with the purpose of extracting information of relevance to quark-model descriptions of nuclei. In an earlier treatment, the boson Hamiltonian resulting from the mapping was approximately diagonalized at the level of Hartree-Bose approximation. The results differed from those of an exact solution of the model at first order in the density. Furthermore, the results were worse than those arising from a BCS treatment of pair correlations at the quark level. Here we extend the analysis to a Brueckner treatment, so as to properly take into account the short-range repulsion between bosons originating from the quark Pauli principle. The resulting energy per quark reproduces the exact results through first order in the density and is significantly better than the BCS results. At higher densities, deviations appear, reflecting the need for a full cluster expansion in the treatment of short-range correlation effects. The relevance of these results to more realistic three-color quark models of nuclei is discussed. copyright 1996 The American Physical Society
Structures of the Vela pulsar and the glitch crisis from the Brueckner theory
Li, A; Wang, J B; Xu, R X
2015-01-01
Detailed structures of the Vela pulsar (PSR B0833-45, with a period of $89.33$ milliseconds) are predicted by adopting a recently-constructed unified treatment of all parts of neutron stars: the outer crust, the inner crust and the core based on modern microscopic Brueckner-Hartree-Fock calculations. To take the pulsar mass ranging from $1.0M_{\\odot}$ to $2.0M_{\\odot}$, we calculate the central density, the core/crust radii, the core/crust mass, the core/crustal thickness, the moment of inertia, and the crustal moment of inertia. Among them, the crustal moment of inertia could be effectively constrained from the accumulated glitch observations, which has been a great debate recently, known as "glitch crisis". Namely, superfluid neutrons contained in the inner crust, which are regarded as the origin of the glitch in the standard two-component model, could be largely entrained in the nuclei lattices, then there may not be enough superfluid neutrons ($\\sim 4/5$ less than the previous value) to trigger the large ...
Kambe, Takahide; Saito, Koichi
2016-01-01
As the interior density of a neutron star can become very high, it has been expected and discussed that quark matter may exist inside it. To describe the transition from hadron to quark phases (and vice versa), there are mainly two methods; one is the first-order phase transition, and the other is the crossover phenomenon. In the present study, using the flavor-SU (3) NJL model with the vector coupling interaction, we have calculated the equation of state for the quark phase at high density. Furthermore, for the hadron phase at low density, we have used two kinds of the equations of state; one is a relatively soft one by the QHD model, and the other is a stiff one calculated with relativistic Brueckner-Hartree-Fock approximation. Using those equations of state for the two phases, we have investigated the influence of various choices of parameters concerning the crossover region on the mass and radius of a neutron star.
Flavor Nuclei and One-Boson-Exchange Potentials
Bando, H.; Nagata, S.
1983-02-01
Binding energies of a flavour baryon, Λ(strange), Λc(charmed) and Λb(beauty), in nuclear matter and in the α-particle are investigated within the framework of the lowest-order Brueckner theory by employing the OBE potentials derived on the basis of the Nijmegen model D interaction.
On the Momentum Dependence of the Nucleon - Nucleus Optical Potential
Kleinmann, M.; Fritz, R.; Müther, H.; Ramos, A.
1994-01-01
The momentum dependence of the mean-field contribution to the real part of the optical model potential is investigated employing realistic nucleon-nucleon interactions. Within a non-relativistic approach a momentum dependence originates from the non-locality of the Fock exchange term. Deducing the real part of the optical model from a relativistic Dirac Brueckner Hartree Fock approximation for the self-energy of the nucleons yields an additional momentum dependence originating from the non-re...
Revisting the boiling of quark nuggets at nonzero chemical potential
Li, Ang; Liu, Tong; Gubler, Philipp; Xu, Ren-Xin
2013-01-01
The boiling of possible quark nuggets during the quark-hadron phase transition of the Universe at nonzero chemical potential is revisited within the microscopic Brueckner-Hartree-Fock approach employed for the hadron phase, using two kinds of baryon interactions as fundamental inputs. To describe the deconfined phase of quark matter, we use a recently developed quark mass density-dependent model with a fully self-consistent thermodynamic treatment of confinement. We study the baryon number li...
Choice of single-particle potential and the convergence of the effective interaction
The convergence of the expansion for the effective interaction is studied considering as example the shell model for the nuclei 18O and 18F. In this work the effective interaction is computed through third order in the Brueckner G matrix, using both a harmonic-oscillator (HO) basis and a Brueckner-Hartree-Fock (BHF) basis. The significant differences in the convergence behavior of the effective interaction in these two cases are reported. The results indicate that the choice of the BHF single-particle potential facilitates the convergence of the effective interaction in low-orders of the expansion, whereas the HO results exhibit a non-convergent behavior. The implications for the HO approach are discussed. All calculations have been performed considering a modern version of the Bonn one-boson-exchange potential for the nucleon-nucleon interaction. 23 refs., 4 figs., 2 tabs
Self consistent single particle potential and nuclear matter binding energy
We have obtained a self-consistent single-particle potential as a function of momentum for Fermi momenta kF= 1.4 fm. Self-consistent single particle potential is calculated from Brueckner g-matrix using Urbana v-14 interaction. Sixth order polynomial approximation is used as an input for the calculation of g-matrix. After achieving the self-consistent single particle potential we calculate the binding energy of infinite symmetric nuclear matter at different Fermi momenta, using soft-core Urbana v-14 interaction and hard-core Hamada Johnston interaction. Urbana v-14 interaction predicts overbinding of infinite nuclear matter, while HJ interaction predicts an underbound nuclear matter underbound. (author)
Microscopic optical model potentials for p-nucleus scattering at intermediate energies
A comparative study of the microscopic optical potentials viz., semimicroscopic with extended Jeukenne-Lejeune-Mahaux interaction and microscopic Brueckner theory using Hamada-Johnston as well as Urbana V14 soft-core internucleon interactions, has been carried out. These microscopic optical potentials are compared with that of Dirac phenomenology (DP) for the polarized proton-40Ca elastic scattering at 35 MeV and 200 MeV. These potentials have different shapes for 200 MeV below 4 fm. In particular, for the real part of the central potential, only the Dirac phenomenology and the microscopic optical potential calculated with the Hamada-Johnston interaction exhibit the well known wine-bottle-bottom shape. It is found that the calculated observables (cross section, analyzing power and spin rotation function) using these potentials having different shapes, compare well with the experiment
Single particle potentials of asymmetric nuclear matter in different spin-isospin channels
ZUO Wei; GAN Sheng-Xin; U.Lombardo
2012-01-01
We investigate the neutron and proton single particle (s.p.) potentials of asymmetric nuclear matter and their isospin dependence in various spin-isospin ST channels within the framework of the BruecknerHartree-Fock approach.It is shown that in symmetric nuclear matter,the s.p.potentials in both the isospinsinglet T =0 channel and isospin-triplet T =1 channel are essentially attractive,and the magnitudes in the two different channels are roughly the same.In neutron-rich nuclear matter,the isospin-splitting of the proton and neutron s.p.potentials turns out to be mainly determined by the isospin-singlet T =0 channel contribution which becomes more attractive for the proton and more repulsive for the neutron at higher asymmetries.
Optical-model potential in a relativistic quantum field model
Jaminon, M.; Mahaux, C.; Rochus, P.
1980-11-01
The average nucleon-nucleus potential at low and medium energy is investigated in the framework of a relativistic quantum field model. Using the same input parameters as Brockmann in his recent study of nuclear ground states, we calculate the self-consistent relativistic Hartree potential at positive energy in the case of infinite nuclear matter and of /sup 16/O and /sup 40/Ca. This potential is the sum of a scalar operator and of the fourth component of a vector operator. We construct its Schroedinger-equivalent potential by eliminating the small component of the Dirac spinor. The central part of this Schroedinger-equivalent potential is in fair agreement with empirical values at low and intermediate energy. Particular attention is paid to the intermediate energy domain, in which the calculated potential is repulsive in the nuclear interior and attractive at the nuclear surface. This is in keeping with some empirical evidence and is similar to results found in the framework of the nonrelativistic Brueckner-Hartree-Fock approximation. The spin-orbit potential of the relativistic Hartree model is also in good agreement with empirical values.
Separable NN potentials from inverse scattering for nuclear matter studies
Low-rank separable potentials greatly simplify perturbation-theory based many-body computations and are especially useful in finite temperature and nonequilibrium nuclear matter studies. With local potentials such calculations become very lengthy. In this paper, we present a first version of a separable potential constructed directly from available empirical nucleon-nucleon phase shifts (Elab3S1-3D1 channel, where the deuteron wave function serves as off-shell input at the binding energy. The simplest potential thus constructed in this channel has rank 4. The deuteron wave function is nevertheless empirically undetermined at high momenta, prompting us to adopt as well as construct several model wave functions that all fit the low momentum deuteron data while allowing variations at high momenta. The effects of these off-shell variations on predicted nuclear matter properties are discussed. No off-shell information is included in the other channels, leading to potentials of rank either 1 or 2. With this simple model potential we perform standard Brueckner nuclear matter ground state calculations and compare the results with Machleidt's using Bonn OBEP. The agreement is good in the S channels and in the singlet D2 channel. Other channels show larger discrepancies, the most significant of which coming from the 3P1 and 3D1 channels. These results are explained by the off-shell behavior of our model potential as compared to the Bonn OBEP. (Abstract Truncated)
Xu, Ruirui; Zhang, Yue; Tian, Yuan; van Dalen, E N E; Müther, H
2016-01-01
The Microscopic Otical Model Potential is evaluated within a relativistic scheme which provides a natural and consistent relation between the spin-orbit part and the central part of the potential. The Dirac-Brueckner-Hartree-Fock (DBHF) approach provides such a microscopic relativistic scheme, which is based on a realistic nucleon-nucleon interaction and reproduce the saturation properties of symmetric nuclear matter without any adjustable parameter. Its solution using the projection technique within the subtracted T-matrix (STM) representation provides a reliable extension to asymmetric nuclear matter, which is important to describe the features of the isospin asymmetric nuclei. Therefore, the present work aims to perform a global analysis of the isospin-dependent nucleon-nucleus MOP based on the DBHF calculation in symmetric and asymmetric nuclear matter. The DBHF is used to evaluate the relativistic structure of the nucleon self-energies in nuclear matter at various densities and asymmetries. The Schr\\"odi...
Realistic Low-Momentum Nucleon-Nucleon Potential
Kuo, T. T. S.; Bogner, S. K.; Coraggio, L.; Covello, A.; Itaco, N.
2002-04-01
A low-momentum nucleon-nucleon (NN) potential Vlow-k is derived from modern realistic NN potentials VNN by integrating out their high momentum modes. The Kuo-Lee-Ratcliff folded diagram method together with the Andreozzi-Lee-Suzuki iteration method is employed to carry out the integration. Our Vlow-k is confined within a cut-off momentum Λ, and it preserves the deuteron binding energy, low-energy phase shifts and low-momentum half-on-shell T-matrix of VNN. For Λ within ~ 2fm-1, the Vlow-k derived from various NN potential models are very close to each other, although these models themselves are very different. Vlow-k is a smooth potential for Λ in the vicinity 2fm-1, and appears to be suitable for being used directly as shell model effective interaction without first calculating the Brueckner G matrix. Preliminary shell-model calculations using Vlow-k have led to encouraging results.
Isobar contributions to the imaginary part of the optical-model potential for finite nuclei
A recently developed non-relativistic method for calculating the nucleon optical-model potential has been employed to evaluate the contributions from isobaric degrees of freedom to the imaginary part of the nucleon optical-model potential. To evaluate the imaginary part of the optical-model potential, the authors include the contributions from terms to second order in the Brueckner G-matrix with and without the inclusion of isobars Δ. Results for 16O are presented in this work. The contributions to the imaginary part are given by the two-particle-one-hole (2p1h) and three-particle-two-hole (3p2h) diagrams. The latter contributes at negative energies only and the contribution from isobar intermediate states is rather small. The 2p1h receives significant contributions from isobars at energies near the resonance and above the threshold for the excitation of ΔΔ states. In particular, the importance of ΔΔ configurations is rather sensitive to the treatment of short-range correlations. The parameterization of the self-energy in terms of local potentials is discussed. The depletion of the occupation of the single-particle orbits due to nucleon-nucleon correlations and Δ excitations is evaluated. 49 refs., 14 figs., 3 tabs
The single-particle potential of nuclear matter in the LOCV framework
Modarres, M., E-mail: mmodares@ut.ac.ir [Physics Department, University of Tehran, North-Kargar Ave., 1439955961 Tehran (Iran, Islamic Republic of); Rajabi, A. [Physics Department, Shahid Rajaei Teacher Training University, Lavizan, 16788 Tehran (Iran, Islamic Republic of)
2011-10-01
The density and momentum dependence of single-particle potential (SPP) and effective mass of symmetric nuclear matter are studied in the framework of lowest order constrained variational (LOCV) method. The Reid68, the Reid68-{Delta} and the Av{sub 18} interactions are considered as the input nucleon-nucleon potentials. It is shown that the SPP of nuclear matter, at fixed density, is an increasing function of nucleon momentum, and it has different behavior for the Reid type potentials with respect to Av{sub 18} interaction. We find good agreements between our LOCV SPP and those coming from others many-body techniques such as the (Dirac-)Brueckner-Hartree-Foch ((D)BHF), the fermion hypernetted chain (FHNC), mean field (MF), etc. On the other hand SPP dramatically depends on the density at low and high nucleon momentums. While the effective mass of nuclear matter increases as we increase the nucleon momentum, it decreases at the Fermi surface. Again, good agreements are observed between our calculated effective mass and those coming from the methods mentioned above.
Revisiting the boiling of primordial quark nuggets at nonzero chemical potential
Li, Ang; Liu, Tong; Gubler, Philipp; Xu, Ren-Xin
2015-03-01
The boiling of possible quark nuggets during the quark-hadron phase transition of the Universe at nonzero chemical potential is revisited within the microscopic Brueckner-Hartree-Fock approach employed for the hadron phase, using two kinds of baryon interactions as fundamental inputs. To describe the deconfined phase of quark matter, we use a recently developed quark mass density-dependent model with a fully self-consistent thermodynamic treatment of confinement. We study the baryon number limit Aboil (above which boiling may be important) with three typical values for the confinement parameter D. It is firstly found that the baryon interaction with a softer equation of state for the hadron phase would only lead to a small increase of Aboil . However, results depend sensitively on the confinement parameter in the quark model. Specifically, boiling might be important during the Universe cooling for a limited parameter range around D 1 / 2 = 170 MeV, a value satisfying recent lattice QCD calculations of the vacuum chiral condensate, while for other choices of this parameter, boiling might not happen and cosmological quark nuggets of 102 < A <1050 could survive.
Khoa, Dao T; Cuong, Do Cong
2007-01-01
A consistent folding model analysis of the ($\\Delta S=0, \\Delta T=1$) charge exchange \\pn reaction measured with $^{48}$Ca, $^{90}$Zr, $^{120}$Sn and $^{208}$Pb targets at the proton energies of 35 and 45 MeV is done within a two-channel coupling formalism. The nuclear ground state densities given by the Hartree-Fock-Bogoljubov formalism and the density dependent CDM3Y6 interaction were used as inputs for the folding calculation of the nucleon optical potential and \\pn form factor. To have an accurate isospin dependence of the interaction, a complex isovector density dependence of the CDM3Y6 interaction has been carefully calibrated against the microscopic Brueckner-Hatree-Fock calculation by Jeukenne, Lejeune and Mahaux before being used as folding input. Since the isovector coupling was used to explicitly link the isovector part of the nucleon optical potential to the cross section of \\pn reaction exciting the 0$^+$ isobaric analog states in $^{48}$Sc, $^{90}$Nb, $^{120}$Sb and $^{208}$Bi, the newly paramet...
Chakrabarti, Subhadip; Gilles, Robert Paul
2005-01-01
A network payoff function assigns a utility to all participants in a (social) network. In this paper we discuss properties of such network payoff functions that guarantee the existence of certain types of pairwise stable networks and the convergence of certain network formation processes. In particular we investigate network payoff functions that admit an exact network potential or an ordinal network potential. We relate these network potentials to exact and ordinal potentials of a non-cooper...
Mikkelsen, Henrik Hvenegaard; Søgaard, Thomas Friis
This article explores the social significance of violence as potentiality and performance among former headhunters. Taking its outset in an ethnographic study of violence and masculinity among the Philippine people known as the Bugkalot, we explore how violence as “performed violent potentiality...... today abandoned headhunting, the potentials for violence and dominance, which the act of headhunting sought to elicit, remains a critical aspect of masculinity. We propose that a focus on the social significance of performative violent potentiality among Bugkalot men can provide general insights that...... can also be used in other contexts to understand how men construct hegemonic masculinity by strategically adopting the interspace of civility and violence....
Durnev, M. A.
2008-01-01
Using the quark-antiquark interactions obtained in the framework of the bootstrap method we construct a potential model, investigate the possibility of describing of heavy quarkonia and calculate the bottomonium spectrum. The potential of the interaction was obtained as a nonrelativistic limit of the relativistic quark-antiquark amplitudes Q{\\bar Q} -> Q\\bar Q.
Lukeš, Jaroslav; Netuka, Ivan; Veselý, Jiří
1988-01-01
Within the tradition of meetings devoted to potential theory, a conference on potential theory took place in Prague on 19-24, July 1987. The Conference was organized by the Faculty of Mathematics and Physics, Charles University, with the collaboration of the Institute of Mathematics, Czechoslovak Academy of Sciences, the Department of Mathematics, Czech University of Technology, the Union of Czechoslovak Mathematicians and Physicists, the Czechoslovak Scientific and Technical Society, and supported by IMU. During the Conference, 69 scientific communications from different branches of potential theory were presented; the majority of them are in cluded in the present volume. (Papers based on survey lectures delivered at the Conference, its program as well as a collection of problems from potential theory will appear in a special volume of the Lecture Notes Series published by Springer-Verlag). Topics of these communications truly reflect the vast scope of contemporary potential theory. Some contributions deal...
The Brueckner-Hartree-Fock Equation of State for Nuclear Matter and Neutron Skin
Qing-Yang, Bu; Zeng-Hua, Li; Hans-Josef, Schulze
2016-03-01
Not Available Supported by the National Natural Science Foundation of China under Grant Nos 11075037 and 11475045, the Scientific Research Foundation for the Returned Overseas Chinese Scholars of the Ministry of Education of China, the Fundamental Research Funds for the Central Universities of China, the Shanghai Leading Academic Discipline Project under Grant No B107, and the ‘NewCompStar’, COST Action MP1304.
Helms, Lester L
2014-01-01
Potential Theory presents a clear path from calculus to classical potential theory and beyond, with the aim of moving the reader into the area of mathematical research as quickly as possible. The subject matter is developed from first principles using only calculus. Commencing with the inverse square law for gravitational and electromagnetic forces and the divergence theorem, the author develops methods for constructing solutions of Laplace's equation on a region with prescribed values on the boundary of the region. The latter half of the book addresses more advanced material aimed at those with the background of a senior undergraduate or beginning graduate course in real analysis. Starting with solutions of the Dirichlet problem subject to mixed boundary conditions on the simplest of regions, methods of morphing such solutions onto solutions of Poisson's equation on more general regions are developed using diffeomorphisms and the Perron-Wiener-Brelot method, culminating in application to Brownian motion. In ...
Budzynski, Scott
2015-01-01
Buildings and urban construction are understood in this paper as representations of the city. Their meanings, however, are often invisible, positing unrealized urban visions, which are both imbedded in and which call up chains of associations expressing desires and fears. Narratives of what the city should be often contain the rejection of the existing urban situation. Understanding architectural objects as potential underscores their imaginary nature. Freud, for example, uses the Roman ruins...
Generalized Morse Potential Symmetry and Satellite Potentials
Del Sol-Mesa, A; Smirnov, Yu F; Smirnov, Yu. F.
1998-01-01
We study in detail the bound state spectrum of the generalized Morse potential~(GMP), which was proposed by Deng and Fan as a potential function for diatomic molecules. By connecting the corresponding Schrödinger equation with the Laplace equation on the hyperboloid and the Schrödinger equation for the an $so(2,2)$ symmetry algebra, and obtain an explicit realization of the latter as $su(1,1) \\oplus su(1,1)$. We prove that some of the $so(2,2)$ generators connect among themselves wave functions belonging to different GMP's (called satellite potentials). The conserved quantity is some combination of the potential parameters instead of the level energy, as for potential algebras. Hence, $so(2,2)$ belongs to a new class of symmetry algebras. We also stress the usefulness of our algebraic results for simplifying the calculation of Frank-Condon factors for electromagnetic transitions between rovibrational levels based on different electronic states.
Earth Data Analysis Center, University of New Mexico — Crown fire potential was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The...
Kansas Data Access and Support Center — This digital spatial data set provides information on the spatial distribution of potential runoff-contributing areas in Kansas. Potential runoff-contributing areas...
Schuch, M.
For the first time, QUINCKE found in 1859 the phenomenon of electric streaming potential. Twenty years later HELMHOLTZ published a mathematical expression for the streaming potential. In the following years a number of scientists studied the phenomenon. BIKERMAN (1932) showed that each electric streaming potential causes an electric current in the contrary direction. SWARTZENDRUBER postulated in 1967 that this electric field tries to stop the streaming potential as a result of the energy balance.
Variational approaches to the nuclear-matter problem: A progress report
The elements of state-independent Jastrow Fermi-hypermetted chain theory, of state-dependent variational theory, and of the method of correlated basis functions are surveyed. Results from application of these 'variational' approaches to popular homework potentials and to semi-realistic models of the nucleon-nucleon interaction are collected, and compared with recent results from Brueckner-Bethe theory. The crisis in nuclear-matter theory, brought on by gross discrepancies between earlier Brueckner-Bethe and variational calculations, has abated. (orig.)
Ortiz, Luis E.
2015-01-01
Potential games, originally introduced in the early 1990's by Lloyd Shapley, the 2012 Nobel Laureate in Economics, and his colleague Dov Monderer, are a very important class of models in game theory. They have special properties such as the existence of Nash equilibria in pure strategies. This note introduces graphical versions of potential games. Special cases of graphical potential games have already found applicability in many areas of science and engineering beyond economics, including ar...
Handbook of interatomic potentials
This Handbook collects together interatomic potentials for a large number of metals. Most of the potentials describe the interactions of host metal atoms with each other, and these, in some cases, may be applied to solid and liquid metals. In addition, there are potentials (a) for a metallic impurity alloyed with the host, (b) for a small number of chemical impurities in the metal (eg H, O), and (c) for rare-gas impurities, notably He. The Handbook is intended to be a convenient source of potentials for bulk, surface and defect calculations, both static and dynamic. (author)
On Relations between Bessel Potential Spaces and Riesz Potential Spaces
Kurokawa, Takahide
2000-01-01
We present a relation between the Bessel potential spaces and the Riesz potential spaces. The ideas of the proof are to characterize each potential spaces and to give a correspondence between individual Bessel potentials and Riesz potentials.
Hershkowitz, N.; Forest, C.; Wang, E. Y.; Intrator, T.
1987-01-01
Nonmonotonic plasma potential structures are a common feature of many double layers and sheaths. Steady state plasma potential wells separating regions having different plasma potentials are often found in laboratory experiments. In order to exist, such structures all must find a solution to a common problem. Ions created by charge exchange or ionization in the region of the potential well are electrostatically confined and tend to accumulate and fill up the potential well. The increase in positive charge should eliminate the well. Nevertheless, steady state structures are found in which the wells do not fill up. This means that it is important to take into account processes which 'pump' ions from the well. As examples of ion pumping of plasma wells, potential dips in front of a positively biased electro collecting anode in a relatively cold, low density multidipole plasma is considered. Pumping is provided by ion leaks from the edges of the potential dip or by oscillating the applied potential. In the former case the two dimensional character of the problem is shown to be important.
The general properties of the nucleon-nucleon potentials are reviewed. The comparison between experimental nucleon-nucleon phase shifts and deuteron properties and the theoretical ones derived with Hamada-Johnston, Reid, Paris and Bonn potentials is discussed. Also, Hartree-Fock calculations for several spherical nuclei using Skyrme's density-dependent effective nucleon-nucleon interaction are presented systematically.(author)
Schultz, Jørgen Munthe
1996-01-01
This chapter describes the chosen methods for estimating the potential energy savings if ordinary window glazing is exchanged with aerogel glazing as well as commercial low-energy glazings.......This chapter describes the chosen methods for estimating the potential energy savings if ordinary window glazing is exchanged with aerogel glazing as well as commercial low-energy glazings....
Schjerning, Ole; Rosenzweig, Mary; Pottegård, Anton;
2016-01-01
BACKGROUND: Several case reports and epidemiological studies have raised concern about the abuse potential of pregabalin, the use of which has increased substantially over the last decade. Pregabalin is, in some cases, used for recreational purposes and it has incurred attention among drug abusers...... for causing euphoric and dissociative effects when taken in doses exceeding normal therapeutic dosages or used by alternative routes of administration, such as nasal insufflation or venous injection. The magnitude of the abuse potential and the mechanism behind it are not fully known. OBJECTIVE: The...... aim of this study was to present a systematic review of the data concerning the abuse potential of pregabalin. METHODS: We performed a systematic literature search and reviewed the preclinical, clinical and epidemiological data on the abuse potential of pregabalin. RESULTS: We included preclinical (n...
Elderberry: Botany, Horticulture, Potential
Horticultural Review allows extensive reviews of the state of the knowledge on certain topics or crops. Elderberry: Botany, Horticulture, Potential, is outlined with an Introduction, Botany, Horticulture, Propagation, Uses and Conclusion sections. This review compiles literature from around the w...
Relativistic gauge invariant potentials
A global method characterizing the invariant connections on an abelian principal bundle under a group of transformations is applied in order to get gauge invariant electromagnetic (elm.) potentials in a systematic way. So, we have classified all the elm. gauge invariant potentials under the Poincare subgroups of dimensions 4, 5, and 6, up to conjugation. It is paid attention in particular to the situation where these subgroups do not act transitively on the space-time manifold. We have used the same procedure for some galilean subgroups to get nonrelativistic potentials and study the way they are related to their relativistic partners by means of contractions. Some conformal gauge invariant potentials have also been derived and considered when they are seen as consequence of an enlargement of the Poincare symmetries. (orig.)
LIU BO
2006-01-01
@@ With commerce and entertainment increasingly intertwined and the Chinese economy becoming more internationally integrated, Meetings,Incentives, Conference and Exhibitions (MICE) travel, is regarded by many travel agencies as one of the most potentially profitable tourism trends of the future.
The Hubble Effective Potential
Janssen, T. M.; Miao, S. P.; Prokopec, T.; Woodard, R. P.
2009-01-01
We generalize the effective potential to scalar field configurations which are proportional to the Hubble parameter of a homogeneous and isotropic background geometry. This may be useful in situations for which curvature effects are significant. We evaluate the one loop contribution to the Hubble Effective Potential for a massless scalar with arbitrary conformal and quartic couplings, on a background for which the deceleration parameter is constant. Among other things, we find that inflationa...
The Hubble effective potential
We generalize the effective potential to scalar field configurations which are proportional to the Hubble parameter of a homogeneous and isotropic background geometry. This may be useful in situations for which curvature effects are significant. We evaluate the one loop contribution to the Hubble Effective Potential for a massless scalar with arbitrary conformal and quartic couplings, on a background for which the deceleration parameter is constant. Among other things, we find that inflationary particle production leads to symmetry restoration at late times
Exploiting the plasma potential
The concept of plasma potential arises from the interaction of a plasma with a boundary. Due to the high mobility of electrons, a potential difference develops between the two so that a positive space-charge region, the 'sheath', shields the plasma from the boundary. Losses of ions at the boundary, however, means that shielding is ineffective unless ions enter the sheath region with a sufficiently high velocity (the 'Bohm criterion'). Since this ion flux cannot be generated by thermal motion, there is a potential variation within the plasma itself (the 'presheath'), which accelerates the ions towards the plasma edge. The potential difference between a plasma and a boundary has been exploited in a wide variety of plasma surface engineering applications. The surface of a substrate immersed in a plasma will be subject to bombardment by ions accelerated across the sheath which will not only heat the substrate but can also sputter atoms out of the surface, modify the properties of films deposited onto the surface or result in bombarding species being incorporated into the surface. While energetic ion bombardment can be supplied by directed ion beams, it is more easily applied uniformly over complex surfaces by biasing a substrate immersed in a plasma with an appropriate negative potential, either DC or rectified rf. This is a feature of ion assisted deposition processes, both PVD and CVD, ion assisted thermochemical diffusion processes, such as plasma nitriding, and, in the limit of high bias potentials (10-100 kV), Plasma Immersion Ion Implantation (PIII or PI3 - Trade Mark). This paper reviews some of the interesting and intriguing aspects of the behaviour of low pressure rf plasmas when large perturbations occur to the potential distribution described above. These observations have been made as part of our work over the last ten years on the use of low pressure plasmas and high energy ion bombardment to extend the range of applicability of plasma nitriding, in
Assessing offshore wind potential
Quantifying wind potential is a pivotal initial step in developing and articulating a state’s policies and strategies for offshore wind industry development. This is particularly important in the Great Lakes States where lessons from other offshore environments are not directly applicable. This paper presents the framework developed for conducting a preliminary assessment of offshore wind potential. Information on lake bathymetry and wind resources were combined in simulating alternative scenarios of technically feasible turbine construction depths and distance concerns by stakeholders. These yielded estimates of developable offshore wind areas and potential power generation. While concerns about the visibility of turbines from shore reduce the power that can be generated, engineering solutions that increase the depths at which turbines can be sited increase such potential power output. This paper discusses the costs associated with technical limitations on depth and the social costs related to public sentiments about distance from the shoreline, as well as the possible tradeoffs. The results point to a very large untapped energy resource in the Michigan’s Great Lakes, large enough to prompt policy action from the state government. - Highlights: ▶ We build a theoretical framework for modeling offshore wind power production. ▶ Illustration of the impact of technology and social limitations on offshore wind energy development. ▶ Geospatial modeling of the offshore wind potential of the Great Lakes.
Recently, the Trend Analysis Program (TAP) of the American Council of Life Insurance commissioned the Futures Group of Glastonbury, Connecticut, to examine the potential for large-scale catastrophic events in the near future. TAP was specifically concerned with five potential crises: the warming of the earth's atmosphere, the water shortage, the collapse of the physical infrastructure, the global financial crisis, and the threat of nuclear war. We are often unprepared to take action; in these cases, we lose an advantage we might have otherwise had. This is the whole idea behind forecasting: to foresee possibilities and to project how we can respond. If we are able to create forecasts against which we can test policy options and choices, we may have the luxury of adopting policies ahead of events. Rather than simply fighting fires, we have the option of creating a future more to our choosing. Short descriptions of these five potential crises and, in some cases, possible solutions are presented
Duguleana C.
2014-12-01
Full Text Available Economic and financial crisis has hit Romania since the second half of 2008, causing a significant drop in production and household income. The consequences of this crisis include rising unemployment and falling household consumption expenditure. Thus, in June 2008, the unemployment rate was 3.7% and in March 2010 it reached 8.4% level. Final consumption expenditure of households fell by 9.2% in 2009 and by 3.3% in 2010. The slowly begun recovery in 2011 revealed that unemployment in the Romanian economy has a significant structural component. As a result, the potential GDP remains low. The paper presents a method for estimating the potential GDP to determine the gap between real GDP affected by cyclical factors and the productive potential of the economy, used in any circumstances.
Hyperon-hyperon interactions with the Nijmegen ESC08 model
Rijken, T.A. [Radboud University, IMAPP, AJ Nijmegen (Netherlands); Schulze, H.J. [Universita di Catania, Dipartimento di Fisica, Catania (Italy); INFN, Catania (Italy)
2016-02-15
We discuss the properties of the hyperon-hyperon interactions in the recent Nijmegen ESC08 potential, in particular the importance of the coupled-channel structure and related existence of bound states. Brueckner-Hartree-Fock calculations of hypernuclear matter employing these interactions are presented and the structure of hyperon (neutron) stars within this approach is computed. Low maximum masses are found. (orig.)
Calculation of effective forces in nuclei from the Hamada- Johnston potential is described. This work begins from the theories of Brueckner and Bethe and applies them to finite systems. Various renormalizations of the force are discussed. The density dependence of the effective forces is considered in detail. Arguments for the partial breakdown of the shell model in heavy nuclei are given. (author)
It is argued on theoretical and phenomenological grounds that confinement of quarks is intrinsically a many-body interaction. The Born-Oppenheimer approximation to the bag model is shown to give rise to a static potential energy that consists of a sum of two-body Coulomb terms and a many-body confining term. Following the success of this potential in heavy Q anti Q systems it is being applied to Q2 anti Q2. Preliminary calculations suggest that dimeson bound states with exotic flavor, such as bb anti s anti s, exist. 13 refs., 5 figs
Biomethanation and Its Potential
Angelidaki, Irini; Karakashev, Dimitar Borisov; Batstone, Damien J.;
2011-01-01
potential is very important for design for optimal process design, configuration, and effective evaluation of economic feasibility. A wide variety of process applications for biomethanation of wastewaters, slurries, and solid waste have been developed. They utilize different reactor types (fully mixed......, plugflow, biofilm, UASB, etc.) and process conditions (retention times, loading rates, temperatures, etc.) in order to maximize the energy output from the waste and also to decrease retention time and enhance process stability. Biomethanation has strong potential for the production of energy from organic...... residues and wastes. It will help to reduce the use of fossil fuels and thus reduce CO2 emission....
Jordi Lucero
2009-01-01
Full Text Available This problem was to calculate the path a robot would take to navigate an obstacle field and get to its goal. Three obstacles were given as negative potential fields which the robot avoided, and a goal was given a positive potential field that attracted the robot. The robot decided each step based on its distance, angle, and influence from every object. After each step, the robot recalculated and determined its next step until it reached its goal. The robot's calculations and steps were simulated with Microsoft Excel.
The author focuses on wastes considered hazardous under the Resource Conservation and Recovery Act. This chapter discusses wastes that are of interest as well as the factors affecting the quantity of waste considered available for waste reduction. Estimates are provided of the quantities of wastes generated. Estimates of the potential for waste reduction are meaningful only to the extent that one can understand the amount of waste actually being generated. Estimates of waste reduction potential are summarized from a variety of government and nongovernment sources
Gorni, Gianluca; Zampieri, Gaetano
2012-01-01
We present a geometric characterization of the nonlinear smooth functions $V: R\\to R$ for which the origin is a global isochronous center for the scalar equation $\\ddot x=-V'(x)$. We revisit Stillinger and Dorignac isochronous potentials $V$ and show a new simple explicit family. Implicit examples are easily produced.
Dabidian, Hooman; Al-Ani, Mohammed Wafaa; Francke, Christopher Hassaan; Redwan, Ahmed
2013-01-01
While it will require further political stability and security, tourism in Iraq stands to be a major growth sector. The Iraqi tourism sector is currently underdeveloped and in a state of neglect, due to decades of war, closed regimes and recurrent instability and insecurity. However, as Iraq continues to develop and stabilizes, it can begin to meet its tremendous potential as a global tour...
ICT Enhanced Buildings Potentials
Christiansson, Per
2007-01-01
with focus on virtual building models support, new services and user environment definitions and development, virtual spaces and augmented reality, intelligent building components, application ontologies, and ICT systems integration to illustrate ICT enhanced buildings potentials and R&D needs. ...
Munack, A.; Schroder, O. [Johann Heinrich von Thunen Inst., Braunschweig (Germany); Krahl, J. [Coburg Univ. of Applied Sciences, Coburg (Germany); Bunger, J. [Inst. for Prevention and Occupational Medicine of the German Social Accident Insurance, Ruhr-Univ. Inst., Bochum (Germany)
2010-07-01
This paper discussed the potential of biofuels with particular reference to the situation in Germany and Europe. Emphasis was on technical potential, such as biofuel production, utilization and environmental aspects. The Institute of Agricultural Technology and Biosystems Engineering ran vTI emission tests on diesel engines to evaluate the environmental impacts of biofuels. This testing facility is able to drive heavy-duty diesel engines in both stationary and dynamic test cycles, such as the European ESC and ETC. Additional analyses were conducted to determine the fine and ultra-fine particles, polycyclic aromatic hydrocarbons (PAH), aldehydes, ketones, and the usual regulated exhaust gas compounds. Ames tests were conducted to assess the mutagenic potential of tailpipe emissions. Previous study results showed that neat vegetable oils can render the exhaust high in mutagenic potency. Some of the non-regulated exhaust gas compounds were found to vary nonlinearly with the blend composition. B20 was found to have high mutagenic potential and was subject to sedimentation.
Electrostatic potential molecular surfaces.
Weiner, P K; R. Langridge; Blaney, J M; Schaefer, R; Kollman, P A
1982-01-01
Color-coded computer graphics representations of the electrostatic potentials of trypsin, trypsin-inhibitor, prealbumin and its thyroxine complex, fragments of double-helical DNA, and a netropsin--DNA complex illustrate the electrostatic and topographic complementarity in macromolecule-ligand interactions. This approach is powerful in revealing intermolecular specificity and shows promise of having predictive value in drug design.
The most important floods in the rivers of Albania are caused mainly from the intensive rainfall during the period December-March. Occasionally snow melts have some contribution on flood magnitude. Based on the observed data in 54 hydrologic stations, the parameters of floods are calculated, using Gumbel and Pearson III distribution. Using these parameters and the floods factors, a multiple regional correlation between them is estimated. The specific discharge (module) of the peak, corresponding to a return period of 100 years and a surface of the catchment area of 100 km2 , was computed for other 50 small basins by means of the multiple regression aquation. This module was chosen as an indicator of the flood potential. A map of this indicator was established for the Albanian territory, serving as a flood potential indicator but also as a certain risk of inundation. (Author)
Integrable Cosmological Potentials
Sokolov, V V
2016-01-01
The problem of classification of the Einstein--Friedman cosmological Hamiltonians $H$ with a single scalar inflaton field $\\varphi$ that possess an additional integral of motion polynomial in momenta on the shell of the Friedman constraint $H=0$ is considered. Necessary and sufficient conditions for the existence of first, second, and third degree integrals are derived. These conditions have the form of ODEs for the cosmological potential $V(\\varphi)$. In the case of linear and quadratic integrals we find general solutions of the ODEs and construct the corresponding integrals explicitly. A new wide class of Hamiltonians that possess a cubic integral is derived. The corresponding potentials are represented in a parametric form in terms of the associated Legendre functions. Six families of special elementary solutions are described and sporadic superintegrable cases are discussed.
Nonadiabatic Ponderomotive Potentials
Dodin IY, Fisch NJ
2005-10-03
An approximate integral of the Manley-Rowe type is found for a particle moving in a high-frequency field, which may interact resonantly with natural particle oscillations. An effective ponderomotive potential is introduced accordingly and can capture nonadiabatic particle dynamics. We show that nonadiabatic ponderomotive barriers can trap classical particles, produce cooling effect, and generate one-way walls for resonant species. Possible atomic applications are also envisioned.
Nonadiabatic Ponderomotive Potentials
An approximate integral of the Manley-Rowe type is found for a particle moving in a high-frequency field, which may interact resonantly with natural particle oscillations. An effective ponderomotive potential is introduced accordingly and can capture nonadiabatic particle dynamics. We show that nonadiabatic ponderomotive barriers can trap classical particles, produce cooling effect, and generate one-way walls for resonant species. Possible atomic applications are also envisioned
Biodiesel potential in Iceland
Borkowska, Swietlana, 1980-
2009-01-01
The importance of increasing the global share of biofuels in transportation goes without saying. Iceland, where the consumption of fossil fuels is considerable, has a viable potential for introducing biodiesel in its otherwise exceptional renewable overall energy portfolio. In this study, a full picture of the possibilities of biodiesel production in Iceland was provided. After the theoretical introduction of allmajor aspects of a biodiesel economy, an assessment of i...
Microfluidics realizes potential
Paula Gould
2004-01-01
Advanced fabrication technologies are being used to make microscale tools for fluid manipulation. Interest in the development of microfluidic devices has been encouraged by the number of fluid-based processes that could benefit from miniaturization. A number of companies are now marketing fluidic ‘lab-on-a-chip’ systems for applications in biomedical research, environmental testing, and medical diagnostics. However, the full commercial potential of this technology has yet to be realized.
Motor evoked potential polyphasia
Chowdhury, Fahmida A.; Pawley, Adam D.; Ceronie, Bryan; Nashef, Lina; Robert D C Elwes; Richardson, Mark P
2015-01-01
Objective: We compared the motor evoked potential (MEP) phases using transcranial magnetic stimulation in patients with idiopathic generalized epilepsy (IGE), their relatives, and healthy controls, hypothesizing that patients and their unaffected relatives may share a subtle pathophysiologic abnormality. Methods: In a cross-sectional study, we investigated 23 patients with IGE, 34 first-degree relatives, and 30 matched healthy controls. Transcranial magnetic stimulation was performed to produ...
Exploring Vietnam's oil potential
A brief review is given of the oil production potential in Vietnam. Since Since 1987, the country has been open to foreign investment in offshore exploration but has suffered from a US embargo on trade and economic ties. Nevertheless some exploration has occurred and twenty production sharing contracts with international oil companies has been signed. To date most of the finds have been non-commercial but optimism remains high. (U.K.)
Unlocking Indonesia's Geothermal Potential
Asian Development Bank (ADB)
2015-01-01
This report was produced jointly by the Asian Development Bank and the World Bank and is based on a series of technical assistance activities conducted during 2013-2014. The study documents key issues that have constrained the development of Indonesia's geothermal power development sector, including tari?s, tendering processes, financial considerations, permitting, and inter-agency coordination. The report then makes a set of comprehensive recommendations to unlock the potential of the sector...
PSYCHOLOGICAL PERSONALITY POTENTIAL
Aleksey, Al
2014-01-01
The publication presents the analysis of the theoretical aspects of the model of socio-psychological personality in the context of the determinants of innovation. On the basis of provisions on socio-axiological characteristics of the person that has the potential-vector nature, the constructed formal scheme psychological «charge-discharge» in the chain of life manifestations of personality. In the framework of the psychological theories of personality, consciousness, activity developed the id...
Curtright, Thomas
2011-01-01
Continuous interpolates are described for classical dynamical systems defined by discrete time-steps. Functional conjugation methods play a central role in obtaining the interpolations. The interpolates corrrespond to particle motion in an underlying potential, V. Typically, V has no lower bound and can exhibit switchbacks wherein V changes form when turning points are encountered by the particle. The logistic map is used to illustrate these features.
Bullying - transformative potentiality?
Charlotte Mathiassen
2013-01-01
In this article, I argue that a person’s experience of having been bullied as a child can holdtransformative potentiality. This means that childhood exposure to bullying can both producenegative effects and provide fuel for transformative intention and actions. By exploring twoseparate narratives, I demonstrate how these individuals’ different ways of handling past incidentsare entangled with both present and future, as well as how they are closely connected to both thespecific situations and...
Kilbourn, Kyle
In the movement from understanding the past towards creating the future design anthropology, as a discipline, will turn from one with archival qualities to one endowed with potentials for change. One challenge facing design anthropology is how to show relevance for theory generation while also...... incorporating critique as a way to open up the design space in meaningful ways. To consider theory as a form of practice is to explore how one practices theory. Instead of a textual form that reframes our perceptions, theory becomes experiential and in this way changes our actions. The Schönian notion of seeing...
Using state of the art lattice techniques we investigate the static baryon potential. We employ the multi-hit procedure for the time links and a variational approach to determine the ground state with sufficient accuracy that, for distances up to ∼ 1.2 fm, we can distinguish the Y- and Δ- Ansaetze for the baryonic Wilson area law. Our analysis shows that the Δ-Ansatz is favoured. This result is also supported by the gauge-invariant nucleon wave function which we measure for the first time
International Evoked Potentials Symposium
1980-01-01
The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting m...
Non-relativistic de Broglie–Bohm theory describes particles moving under the guidance of the wave function. In de Broglie's original formulation, the particle dynamics is given by a first-order differential equation. In Bohm's reformulation, it is given by Newton's law of motion with an extra potential that depends on the wave function—the quantum potential—together with a constraint on the possible velocities. It was recently argued, mainly by numerical simulations, that relaxing this velocity constraint leads to a physically untenable theory. We provide further evidence for this by showing that for various wave functions the particles tend to escape the wave packet. In particular, we show that for a central classical potential and bound energy eigenstates the particle motion is often unbounded. This work seems particularly relevant for ways of simulating wave function evolution based on Bohm's formulation of the de Broglie–Bohm theory. Namely, the simulations may become unstable due to deviations from the velocity constraint. (paper)
The potentialities of terrorism
The potential hazard of terrorists obtaining plutonium and building a nuclear device is examined within the perspective of other terrorist activities. Various sources are quoted on the possibility of a terrorist group having the resources, including skilled personnel, to build a bomb. The potential damage engendered by such a device is hypothesized to be less than that of many other terrorist actions which could be easily accomplished. Other activities, poison or nerve gas, gasoline dropped on a football stadium, destruction of a large dam, poisoning food or water supply and armed action against a tanker carrying liquefied natural gas, are cited as examples of terrorist incidents more devastating than building a crude plutonium bomb. Resistance to blackmail strategies is seen as the only reliable way to thwart their activities in the long run. Although plutonium must be guarded carefully, it is demonstrated as being far from the only or most devastating means of blackmail. It is concluded that the threat of terrorist activities is being used by anti-nuclear groups to support emotionally based dislike of nuclear power. (J.T.A.)
Industrial potential of lipoxygenases.
Heshof, Ruud; de Graaff, Leo H; Villaverde, Juan J; Silvestre, Armando J D; Haarmann, Thomas; Dalsgaard, Trine K; Buchert, Johanna
2016-08-01
Lipoxygenases (LOXs) are iron- or manganese-containing oxidative enzymes found in plants, animals, bacteria and fungi. LOXs catalyze the oxidation of polyunsaturated fatty acids to the corresponding highly reactive hydroperoxides. Production of hydroperoxides by LOX can be exploited in different applications such as in bleaching of colored components, modification of lipids originating from different raw materials, production of lipid derived chemicals and production of aroma compounds. Most application research has been carried out using soybean LOX, but currently the use of microbial LOXs has also been reported. Development of LOX composition with high activity by heterologous expression in suitable production hosts would enable full exploitation of the potential of LOX derived reactions in different applications. Here, we review the biological role of LOXs, their heterologous production, as well as potential use in different applications. LOXs may fulfill an important role in the design of processes that are far more environmental friendly than currently used chemical reactions. Difficulties in screening for the optimal enzymes and producing LOX enzymes in sufficient amounts prevent large-scale application so far. With this review, we summarize current knowledge of LOX enzymes and the way in which they can be produced and applied. PMID:25641326
Koustubh Ajit Kabe
2012-09-01
In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynamics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of thermodynamics. Nine fundamental black hole dynamical relations have been developed akin to the four fundamental thermodynamic relations of Maxwell. The specific heats , and , have been defined. For a black hole, these quantities are negative. The d equation has been obtained as an application of these fundamental relations. Time reversible processes observing constancy of surface gravity are considered and an equation connecting the internal energy of the black hole , the additional available energy defined as the first free energy function , and the surface gravity , has been obtained. Finally as a further application of the fundamental relations, it has been proved for a homogeneous gravitational field in black hole space times or a de Sitter black hole that $C_{\\Omega,\\Phi}-C_{J,Q}=\\kappa \\left[\\left(\\dfrac{\\partial J}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial \\Omega}{\\partial \\kappa}\\right)_{J,Q}+\\left(\\dfrac{\\partial Q}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial\\Phi}{\\partial \\kappa}\\right)_{J,Q}\\right]$. This is dubbed as the homogeneous fluid approximation in context of the black holes.
Evaluation of hydrocarbon potential
Cashman, P.H.; Trexler, J.H. Jr. [Univ. of Nevada, Reno, NV (United States)
1992-09-30
Task 8 is responsible for assessing the hydrocarbon potential of the Yucca Mountain vincinity. Our main focus is source rock stratigraphy in the NTS area in southern Nevada. (In addition, Trexler continues to work on a parallel study of source rock stratigraphy in the oil-producing region of east central Nevada, but this work is not funded by Task 8.) As a supplement to the stratigraphic studies, we are studying the geometry and kinematics of deformation at NTS, particularly as these pertain to reconstructing Paleozoic stratigraphy and to predicting the nature of the Late Paleozoic rocks under Yucca Mountain. Our stratigraphic studies continue to support the interpretation that rocks mapped as the {open_quotes}Eleana Formation{close_quotes} are in fact parts of two different Mississippian units. We have made significant progress in determining the basin histories of both units. These place important constraints on regional paleogeographic and tectonic reconstructions. In addition to continued work on the Eleana, we plan to look at the overlying Tippipah Limestone. Preliminary TOC and maturation data indicate that this may be another potential source rock.
Schwanniomyces: a potential superyeast
Ingledew, W.M.
1987-01-01
In 1977, when our quest to determine the industrial potential of the genus Schwanniomyces began, little was known about this microbe. The genus was first described by Kloecker in 1909, after the isolation in the Antilles of Schwanniomyces occidentalis. A number of biological descriptions (see Ferreira and Phaff) and other species were also described. In addition, it was known that close to 100 yeasts were able to assimilate at least part of the starch molecule. Then, Augustin et al. and Costamagna et al. reported the ability of Schwanniomyces spp. to produce extracellular alpha-amylase and utilize starch. Later discoveries would indicate that both alpha-amylase and glucoamylase were present, and from then on, research with the yeast Schwanniomyces would become very competitive - especially in Canada and Europe. (Refs. 53).
Bullying - transformative potentiality?
Charlotte Mathiassen
2013-10-01
Full Text Available In this article, I argue that a person’s experience of having been bullied as a child can holdtransformative potentiality. This means that childhood exposure to bullying can both producenegative effects and provide fuel for transformative intention and actions. By exploring twoseparate narratives, I demonstrate how these individuals’ different ways of handling past incidentsare entangled with both present and future, as well as how they are closely connected to both thespecific situations and contexts in which the person lives and his/her movements across suchsituations and contexts. The concept of dynamic effectuality is introduced to describe thisphenomenon. Furthermore, I claim that, by analysing the dynamic effectuality of individuals’ pastexperiences with bullying and their present adult lives, certain processes can be found – includingrevenge, transformative intention and collective transformative actions.
Astrocytes Potentiate Synaptic Transmission
Nadkarni, Suhita
2005-03-01
A recent experimental study shows that astrocytes, a subtype of glia, are able to influence the spontaneous activity in the brain via calcium dependent glutamate release. We model the coupling mechanism between an astrocyte and a neuron based on experimental data. This coupling is dynamic and bi-directional, such that the modulations in intracellular calcium concentrations in astrocytes affect neuronal excitability and vice versa via a glutamatergic pathway. We demonstrate through simple neural-glial circuits that increases in the intracellular calcium concentration in astrocytes nearby can enhance spontaneous activity in a neuron, a significant mechanism said to be involved in plasticity and learning. The pattern of this marked increase in spontaneous firing rate in our model quantitatively follows that observed in the experiment. Further, depending on the type of synaptic connections diverging from the neuron, it can either inhibit or excite the ensuing dynamics and potentiate synaptic transmission, thus reinstating the integral role played by astrocytes in normal neuronal dynamics.
Not utilized learning potentials
Kragelund, Linda
not-conscious disjuncture, in development of the concept pseudo-everyday life activities and in a categorizing model for and a theory about student nurses' learning processes. The theory includes relations between 4 types of disjuncture, 3 types of content in the learning processes, and factors that...... provoke transformation from one type of disjuncture to another. Students and mentors are not aware that students are in potential learning situations when they interact on their own with patients, and that it is non-routine for students to act with patients in pseudo-everyday life activities. It may...... When the Danish Nursing Education in 2002 became a Bachelor Degree the clinical part of the education was reduced. Therefore, it was necessary to optimize learning in practice. I made a qualitative investigation to describe student nurses' learning processes in non-routine situations where...
Potential for nuclear terrorism
The question of whether or not terrorists will ''go nuclear'' is discussed. It is possible, although there is no historical evidence that any criminal or terrorist group ever made any attempt to acquire nuclear material for use in an explosive or dispersal device. In terms of intentions, psychotics are potential nuclear terrorists, but in terms of capabilities, they are the farthest away from being able to acquire a nuclear weapon. The history of nuclear incidents in the U.S. and abroad is reviewed. As the nuclear industry expands, the number of low-level incidents (bomb threats, pilferage, etc.) will increase also, but not necessarily escalate to more serious incidents. Terrorists may ''go nuclear'' solely for the publicity value; nuclear hoaxes may be attenpted. Nuclear terrorism seems more attractive as a threat than as an action. But the nature of the threat may change in the future, and the danger of imitation of a successful nuclear terrorist act is pointed out
Power and Biological Potential
Hoehler, T. M.; Som, S. M.; Kempes, C.; Jørgensen, B. B.
2014-12-01
Habitability, biomass abundance, growth rates, and rates of evolution are constrained by the availability of biologically accessible energy through time -- power. It is well understood that life requires energy not only to grow, but also to support standing biomass without new growth. Quantifying this "maintenance energy" requirement is critical for understanding the biological potential of low energy systems, including many systems of astrobiological interest, but field- and culture-based estimates differ by as much as three orders of magnitude. Here, we evaluate and compare these estimates to environmental energy supply in two examples: methanogenic metabolism in serpentinizing systems and a hypothetical "thermotrophic" metabolism. In both cases, evaluation of the power budget introduces constraint and resolution beyond that provided by evaluation of Gibbs energy change for metabolic reactions.
Intrinsic anion oxidation potentials.
Johansson, Patrik
2006-11-01
Anions of lithium battery salts have been investigated by electronic structure calculations with the objective to find a computational measure to correlate with the observed (in)stability of nonaqueous lithium battery electrolytes vs oxidation often encountered in practice. Accurate prediction of intrinsic anion oxidation potentials is here made possible by computing the vertical free energy difference between anion and neutral radical (Delta Gv) and further strengthened by an empirical correction using only the anion volume as a parameter. The 6-311+G(2df,p) basis set, the VSXC functional, and the C-PCM SCRF algorithm were used. The Delta Gv calculations can be performed using any standard computational chemistry software. PMID:17078600
Potential vorticity in magnetohydrodynamics
Webb, G. M.; Mace, R. L.
2015-01-01
A version of Noether's second theorem using Lagrange multipliers is used to investigate fluid relabelling symmetries conservation laws in magnetohydrodynamics (MHD). We obtain a new generalized potential vorticity type conservation equation for MHD which takes into account entropy gradients and the J × B force on the plasma due to the current J and magnetic induction B. This new conservation law for MHD is derived by using Noether's second theorem in conjunction with a class of fluid relabelling symmetries in which the symmetry generator for the Lagrange label transformations is non-parallel to the magnetic field induction in Lagrange label space. This is associated with an Abelian Lie pseudo algebra and a foliated phase space in Lagrange label space. It contains as a special case Ertel's theorem in ideal fluid mechanics. An independent derivation shows that the new conservation law is also valid for more general physical situations.
Corrosion potential analysis system
Kiefer, Karl F.
1998-03-01
Many cities in the northeastern U.S. transport electrical power from place to place via underground cables, which utilize voltages from 68 kv to 348 kv. These cables are placed in seamless steel pipe to protect the conductors. These buried pipe-type-cables (PTCs) are carefully designed and constantly pressurized with transformer oil to prevent any possible contamination. A protective coating placed on the outside diameter of the pipe during manufacture protects the steel pipe from the soil environment. Notwithstanding the protection mechanisms available, the pipes remain vulnerable to electrochemical corrosion processes. If undetected, corrosion can cause the pipes to leak transformer oil into the environment. These leaks can assume serious proportions due to the constant pressure on the inside of the pipe. A need exists for a detection system that can dynamically monitor the corrosive potential on the length of the pipe and dynamically adjust cathodic protection to counter local and global changes in the cathodic environment surrounding the pipes. The northeastern United States contains approximately 1000 miles of this pipe. This milage is critical to the transportation and distribution of power. So critical, that each of the pipe runs has a redundant double running parallel to it. Invocon, Inc. proposed and tested a technically unique and cost effective solution to detect critical corrosion potential and to communicate that information to a central data collection and analysis location. Invocon's solution utilizes the steel of the casing pipe as a communication medium. Each data gathering station on the pipe can act as a relay for information gathered elsewhere on the pipe. These stations must have 'smart' network configuration algorithms that constantly test various communication paths and determine the best and most power efficient route through which information should flow. Each network station also performs data acquisition and analysis tasks that ultimately
Swanberg, Chandler A.; Morgan, Paul; Boulos, F. K.
1983-04-01
One hundred and sixty samples of groundwater from nearly all parts of Egypt have been collected and chemically analyzed in order to assess the country's geothermal potential. The samples considered to be thermal include 20 wells ( T > 35° C), 4 springs ( T > 30° C) and 1 spring not included in the present inventory. The remaining samples, together with data from the literature, establish background chemistry. The hottest springs are located along the east shore of the Gulf of Suez: Uyun Musa (48°C) and 'Ain Hammam Faraoun (70°C). Additional warm springs are located along both shores of the Gulf of Suez and this region is the most promising for geothermal development. The Eastern Desert of Egypt, particularly the coastal area adjacent to the Red Sea has above normal heat flow ( ~ 72.0 Egypt can be considered thermal including several reported "hot springs." Application of the silica, NaKCa. and NaKCaMg geothermometers does not indicate the presence of a high temperature geothermal resource at any area we visited.
ASTAXANTHIN: A POTENTIAL CAROTENOID
Jyotika Dhankhar et al.
2012-05-01
Full Text Available Astaxanthin, a member of the carotenoid family, is a dark-red pigment which is the main carotenoid found in the marine world of algae and aquatic animals. Astaxanthin, is present in many types of seafood, including salmon, trout, red sea bream, shrimp and lobster, as well as in birds such as flamingo and quail. Synthetic Astaxanthin dominates the world market but recent interest in natural sources of the pigment has increased substantially. Common sources of natural Astaxanthin, are the green algae haematococcus pluvialis, the red yeast, Phaffia rhodozyma, as well as crustacean byproducts. Astaxanthin possesses unusual antioxidant property which has caused a surge in the nutraceutical market of the encapsulated products. Numerous studies have shown that astaxanthin has potential health-promoting effects in the prevention and treatment of various diseases, such as cancers, chronic inflammatory diseases, metabolic syndrome, diabetes, diabetic nephropathy, cardiovascular diseases, gastrointestinal diseases, liver diseases, neurodegenerative diseases, eye diseases, skin diseases, exercise-induced fatigue, male infertility, and renal failure. In this article, the currently available scientific literature regarding the most significant activities of astaxanthin is reviewed.
Bioremedication: Potentials and pitfalls
The three main types of marine oil spill bioremediation involve fertilizers, seeding, and open-water applications. Fertilizers contain nutrients that trigger the growth of indigenous oil-degrading microorganisms. Seeding involves adding exogenous microbes to an oiled environment to promote increased biodegradation rates. The effectiveness of using either seeding or fertilizers in the open ocean has not been well established and most of the scientific community and many oil professionals remain skeptical about the utility of bioremediation at sea because rigorously controlled and documented experiments have not yet been done. Several companies have advocated using bioremediation for open ocean oil spills, but they have not yet produced convincing evidence that their products work as claimed. A potentially significant problem at sea is keeping the microorganisms in contact with the oil long enough for degradation to occur. The jury is still out regarding regulatory and public acceptance of bioremediation as a technique to clean up oil spills in general. Commercialization of bioremediation products is hindered by lack of protocols for testing and approval, although efforts are underway to devise such mechanisms
Neuroprotective potential of phytochemicals
G Phani Kumar
2012-01-01
Full Text Available Cognitive dysfunction is a major health problem in the 21st century, and many neuropsychiatric disorders and neurodegenerative disorders, such as schizophrenia, depression, Alzheimer′s Disease dementia, cerebrovascular impairment, seizure disorders, head injury and Parkinsonism, can be severly functionally debilitating in nature. In course of time, a number of neurotransmitters and signaling molecules have been identified which have been considered as therapeutic targets. Conventional as well newer molecules have been tried against these targets. Phytochemicals from medicinal plants play a vital role in maintaining the brain′s chemical balance by influencing the function of receptors for the major inhibitory neurotransmitters. In traditional practice of medicine, several plants have been reported to treat cognitive disorders. In this review paper, we attempt to throw some light on the use of medicinal herbs to treat cognitive disorders. In this review, we briefly deal with some medicinal herbs focusing on their neuroprotective active phytochemical substances like fatty acids, phenols, alkaloids, flavonoids, saponins, terpenes etc. The resistance of neurons to various stressors by activating specific signal transduction pathways and transcription factors are also discussed. It was observed in the review that a number of herbal medicines used in Ayurvedic practices as well Chinese medicines contain multiple compounds and phytochemicals that may have a neuroprotective effect which may prove beneficial in different neuropsychiatric and neurodegenerative disorders. Though the presence of receptors or transporters for polyphenols or other phytochemicals of the herbal preparations, in brain tissues remains to be ascertained, compounds with multiple targets appear as a potential and promising class of therapeutics for the treatment of diseases with a multifactorial etiology.
Most of the locations in Turkey receive abundant solar-energy, because Turkey lies in a sunny belt between 36 deg. and 42 deg. N latitudes. Average annual temperature is 18 to 20 deg. C on the south coast, falls to 14-16 deg. C on the west coat, and fluctuates between 4 and 18 deg. C in the central parts. The yearly average solar-radiation is 3.6 kW h/m2 day, and the total yearly radiation period is ∼2610 h. In this study, a new formulation based on meteorological and geographical data was developed to determine the solar-energy potential in Turkey using artificial neural-networks (ANNs). Scaled conjugate gradient (SCG), Pola-Ribiere conjugate gradient (CGP), and Levenberg-Marquardt (LM) learning algorithms and logistic sigmoid (logsig) transfer function were used in the networks. Meteorological data for last four years (2000-2003) from 12 cities (Canakkale, Kars, Hakkari, Sakarya, Erzurum, Zonguldak, Balikesir, Artvin, Corum, Konya, Siirt, and Tekirdag) spread over Turkey were used in order to train the neural-network. Meteorological and geographical data (latitude, longitude, altitude, month, mean sunshine-duration, and mean temperature) are used in the input layer of the network. Solar-radiation is in the output layer. The maximum mean absolute percentage error was found to be less than 3.832% and R2 values to be about 99.9738% for the selected stations. The ANN models show greater accuracy for evaluating solar-resource possibilities in regions where a network of monitoring stations has not been established in Turkey. This study confirms the ability of the ANN to predict solar-radiation values accurately
RANGELAND SEQUESTRATION POTENTIAL ASSESSMENT
Lee Spangler; George F. Vance; Gerald E. Schuman; Justin D. Derner
2012-03-31
Rangelands occupy approximately half of the world's land area and store greater than 10% of the terrestrial biomass carbon and up to 30% of the global soil organic carbon. Although soil carbon sequestration rates are generally low on rangelands in comparison to croplands, increases in terrestrial carbon in rangelands resulting from management can account for significant carbon sequestration given the magnitude of this land resource. Despite the significance rangelands can play in carbon sequestration, our understanding remains limited. Researchers conducted a literature review to identify sustainably management practices that conserve existing rangeland carbon pools, as well as increase or restore carbon sequestration potentials for this type of ecosystem. The research team also reviewed the impact of grazing management on rangeland carbon dynamics, which are not well understood due to heterogeneity in grassland types. The literature review on the impact of grazing showed a wide variation of results, ranging from positive to negative to no response. On further review, the intensity of grazing appears to be a major factor in controlling rangeland soil organic carbon dynamics. In 2003, researchers conducted field sampling to assess the effect of several drought years during the period 1993-2002. Results suggested that drought can significantly impact rangeland soil organic carbon (SOC) levels, and therefore, carbon sequestration. Resampling was conducted in 2006; results again suggested that climatic conditions may have overridden management effects on SOC due to the ecological lag of the severe drought of 2002. Analysis of grazing practices during this research effort suggested that there are beneficial effects of light grazing compared to heavy grazing and non-grazing with respect to increased SOC and nitrogen contents. In general, carbon storage in rangelands also increases with increased precipitation, although researchers identified threshold levels of
PV potential and potential PV rent in European regions
Hansen, Anders Chr.; Thorn, Paul
2013-01-01
The paper provides a GIS based model for assessing the potentials of photovoltaic electricity in Europe by NUTS 2 regions. The location specific energy potential per PV-‐panel area is estimated based on observations of solar irradiation, conversion efficiency, levelised costs and the social value...... of PV-‐electricity. Combined with the potential density of PV-‐panel area based on land cover and environental restrictions, the PV energy potential and the potential PV ressource rent is calculated. These calculations enbable the model to estimate the regional patterns at NUTS 2 level of the...
COMPETITIVENESS OF POTENTIAL INDUSTRIAL PRODUCTION
САБАДИРЬОВА, А.Л.; Одеський державний економічний університет; САЛАВЕЛІС, Д.Є.; Одеський державний економічний університет
2011-01-01
In the article the considered tendencies of forming of competitiveness of potential of enterprises industrial, factors of competitiveness of potential of enterprises at processing industry on the terms of modern market environment.
Nonlinear potentials in function spaces
Rao, Murali; Vondraček, Zoran
2002-01-01
We introduce a framework for a nonlinear potential theory without a kernel on a reflexive, strictly convex and smooth Banach space of functions. Nonlinear potentials are defined as images of nonnegative continuous linear functionals on that space under the duality mapping. We study potentials and reduced functions by using a variant of the Gauss-Frostman quadratic functional. The framework allows a development of other main concepts of nonlinear potential theory such as capa...
Instantons and the interquark potential
It is argued that the contributions to the interquark potential from instantons of all scale sizes may be calculated in a consistent, cut-off-independent manner using the dilute-gas approximation; and that an interquark potential dominated at intermediate distances by these contributions is similar to already successful phenomenological potentials. (orig.)
Measurement of proton autoneutralization potential
A proton space charge having multi-MeV kinetic energy was injected through a thin ground plane to extract electrons and produce a time-dependent autoneutralization space potential. An electon-emitting floating-potential resistive divider was used to measure the space potential during 20 ns of the proton current pulse. During this time, proton kinetic energy fell from 10.6 MeV to 8.5 MeV and thus the space potential (taken as 1.09 x the floating potential) fell from 5.8 kV to 4.6 kV
Potential energy of dinuclear system
The effective calculation method of the dinuclear system potential energy is proposed. The analytical expressions are obtained to calculate the nuclear part of the nucleus-nucleus potential in the double folding form. The relationship of this potential with proximity potential is found. The influence of deformation and orientation of the nuclei on the interaction potential is investigated. Due to the balance in binding energies the excited states of some nuclei can be imagined as dinuclear or trinuclear systems. (author). 27 refs.; 8 figs
Isospectral Potentials from Modified Factorization
Berger, Micheal S
2010-01-01
Factorization of quantum mechanical potentials has a long history extending back to the earliest days of the subject. In the present paper, the non-uniqueness of the factorization is exploited to derive new isospectral non-singular potentials. Many one-parameter families of potentials can be generated from known potentials using a factorization that involves superpotentials defined in terms of excited states of a potential. For these cases an operator representation is available. If ladder operators are known for the original potential, then a straightforward procedure exists for defining such operators for its isospectral partners. The generality of the method is illustrated with a number of examples which may have many possible applications in atomic and molecular physics.
Isospectral potentials from modified factorization
Berger, Micheal S.; Ussembayev, Nail S.
2010-08-01
Factorization of quantum-mechanical potentials has a long history extending back to the earliest days of the subject. In the present article, the nonuniqueness of the factorization is exploited to derive new isospectral nonsingular potentials. Many one-parameter families of potentials can be generated from known potentials using a factorization that involves superpotentials defined in terms of excited states of a potential. For these cases an operator representation is available. If ladder operators are known for the original potential, then a straightforward procedure exists for defining such operators for its isospectral partners. The generality of the method is illustrated with a number of examples which may have many possible applications in atomic and molecular physics.
Perfect Actions with Chemical Potential
Bietenholz, W
1998-01-01
We show how to include a chemical potential \\mu in perfect lattice actions. It turns out that the standard procedure of multiplying the quark fields \\Psi, an example, the case of free fermions with chemical potential is worked out explicitly. Even after truncation, cut-off effects in the pressure and the baryon density are small. Using a (quasi-)perfect action, numerical QCD simulations for non-zero chemical potential become more powerful, because coarse lattices are sufficient for extracting continuum physics.
Career Potential of Future Expert
Oksana Petrovna Tsaritsentseva
2015-01-01
This article is devoted to description and analysis of individual career potential. Topicality of the problem andthe degree of its readiness in the modern science are stated at the beginning of the article.Notions of “career”, career factors, career potential and inner resources of personality being a part of careerpotential structure due to their essence and structure are exposed and analyzed in represented work. Diagnosticprogram which gives an opportunity to study individual career potenti...
Orbits in a logarithmic potential
Hooverman, R. H.
2014-04-15
The characteristics of charged particle orbits in the logarithmic electrostatic potential field surrounding a straight conducting wire at a fixed potential are investigated. The equations of motion of an electron in a logarithmic potential are derived, the limiting cases are considered, and the results of numerical integration of the equations of motion are presented along with sketches of a few representative orbits. (C.E.S.)
Potential turbulence in tokamak plasmas
Microscopic potential turbulence in tokamak plasmas are investigated by a multi-sample-volume heavy ion beam probe. The wavenumber/frequency spectra S(k,ω) of the plasmas potential fluctuation as well as density fluctuation are obtained for the first time. The instantaneous turbulence-driven particle flux, calculated from potential and density turbulence has oscillations of which amplitude is about 100 times larger than the steady-state outwards flux, showing sporadic behaviours. We also observed large-scale coherent potential oscillations with the frequency around 10-40 kHz. (author)
Hydel power: potential and problems
On paper the potential India has for generating hydroelectricity is immense - estimated at 84,044 MW (at 60% plant load factor). This too is based on actual assessed exploitable hydro electric potential and it translates into annual energy generation of 600 billion kWh. However, only 12,436 MW or 14.8% of the total assessed potential was developed at the end of March 1995. Add to this another 5,917 MW of hydel capacity which is under development. This leaves almost 65,691 MW or 78% of unexploited potential
Theoretical Optical Potential Derived From Nucleon-Nucleon Chiral Potentials
Vorabbi, M; Giusti, C
2015-01-01
Background: Elastic scattering is probably the main event in the interactions of nucleons with nuclei. Even if this process has been extensively studied in the last years, a consistent description starting from microscopic two- and many-body forces is still missing. Purpose: In this work we study the domain of applicability of microscopic chiral potentials in the construction of an optical potential. Methods: We basically followed the KMT approach to build a microscopic complex optical potential and then we performed some test calculations on $^{16}$O at different energies. Results: Our conclusion is that a particular set of potentials (with spectral function regularization and a cut-off for the Lippmann-Schwinger equation at relatively high energies $\\sim 600$ MeV) has the best performances reproducing the scattering observables. Conclusions: Our work shows that building an optical potential within Chiral Perturbation Theory is a promising approach to the description of elastic proton scattering, in particul...
Two loop effective Kaehler potential
In this talk we study the renormalization of the effective Kaehler potential at one and two loops for general four dimensional (non-renormalizable) N = 1 supersymmetric theories described by arbitrary Kaehler potential, superpotential and gauge kinetic function. We consider the Wess-Zumino model as an example. (author)
Nested potentials and robust equilibria
UNO, Hiroshi
2011-01-01
This paper introduces the notion of nested best-response potentials for complete in- formation games. It is shown that a unique maximizer of such a potential is a Nash equilibrium that is robust to incomplete information in the sense of Kajii and Morris (1997, mimeo).
Supermodular Games and Potential Games
Brânzei, R.; Mallozzi, L.; Tijs, S.H.
2001-01-01
Potential games and supermodular games are attractive games, especially because under certain conditions they possess pure Nash equilibria. Subclasses of games with a potential are considered which are also strategically equivalent to supermodular games. The focus is on two-person zero-sum games and
Supermodular games and potential games
Brânzei, R.; Mallozzi, L.; Tijs, S.H.
2003-01-01
Potential games and supermodular games are attractive games, especially because under certain conditions they possess pure Nash equilibria. Subclasses of games with a potential are considered which are also strategically equivalent to supermodular games. The focus is on two-person zero-sum games and two-person Cournot games.
Ambipolar potential formation in TMX
TMX experimental data on ambipolar potential control and on the accompanying electrostatic confinement are reported. New results on the radial dependence of the central-cell confining potential are given. Radial and axial particle losses as well as scaling of the central-cell axial confinement are discussed
Fertility potential after unilateral orchiopexy
Cortes, D; Thorup, J M; Lindenberg, S
1996-01-01
. CONCLUSIONS: The age matched number of spermatogonia per tubular cross section is significant in regard to fertility potential, and a value of 1% or less (approximately Sertoli cells only) may predict low fertility potential. To our knowledge Sertoli cells only have not been observed before 15 months of life...
Potential flow through channel constriction.
Lee, J.K.
1984-01-01
Potential flow through an eccentric, normal constriction of zero thickness in an infinitely long, straight channel of constant width and unit depth is studied by use of a Schwarz-Christoffel transformation. The transformation is integrated by a direct approach. Parametric equations for streamlines are obtained and used to compute an average streamline length for a potential-flow field. -from ASCE Publications Information
Kornhuber, Hans H; Deecke, Lüder
2016-07-01
A method of chronological data storage and reverse computation is described by which bio-electrical phenomena preceding 'spontaneous' events within the nervous system can be analysed if these events appear repeatedly and are capable of triggering a computer.Slow brain potentials accompanying voluntary and passive movements of the limbs were analysed by this method. These potentials were recorded from different points of the scalp from 12 healthy subjects in 94 experiments with more than 100 movements in each record. At times artifacts were superimposed upon cerebral potentials. The former were identified, and, as far as possible, eliminated.Voluntary hand or foot movements are preceded by a slowly increasing surface-negative cortical potential of 10-15 μV, called readiness potential. This potential is maximal over the contralateral precentral region, but shows bilateral spread and is larger over the frontal than over the occipital areas. The readiness potential increases with intentional engagement and is reduced by mental indifference of the subject.Voluntary movements are followed by a complex potential with an early positive phase that begins 30-90 msec after the onset of movement. The late potentials following voluntary movements are similar to those after passive movements. Both resemble the late bilateral components of the evoked potentials after electrical stimulation of peripheral nerves. Some variable differences between the early components of the potentials after the onset of active and passive movements require further investigation.No relation between the onset of voluntary movements and the phase of the alpha rhythm could be detected.Further applications of reverse computation are addressed. Similarities between the readiness potential and G. WALTER'S expectancy wave in conditioned reflexes, and the sources of artifacts through eye movements etc. are discussed. PMID:27392465
Imagined Potentialities of Healthcare Technologies
Boulus, Nina
2011-01-01
This paper will focus on health care technologies and initiatives, particularly, Electronic Health Records (EHRs). These technologies are ascribed various potentialities, attributing them the capacity to do a wide range of things, from improving efficiency to saving medical costs and even saving...... actions taken toward, these technologies. To better understand the material and discursive processes that are at play in shaping our present and future understanding of EHR technologies, the paper offers the analytical notion of imagined potentialities, whereby a technology is imagined to possess an...... inherent capacity to produce a change. The term potentiality has a long history in Western philosophy, in particularly in Aristotle’s metaphysics where he distinguishes between potentiality and actuality. Potentiality refers to the capacity that a thing can be said to have; the capacity to come into...
Potential Theory of Multicomponent Adsorption
Shapiro, Alexander; Stenby, Erling Halfdan
1998-01-01
We developed a theory of multicomponent adsorption on the basis of the potential concept originally suggested by Polanyi. The mixture is considered as a heterogeneous substance segregated in the external field emitted by the adsorbent. The same standard equation of state, with no additional fitting...... potential theory and the spreading pressure concept is established, and problems of the theory consistency are studied. Numerical algorithms are suggested for evaluation of the segregated state of the mixture in the potential field of adsorption forces. Comparison with experimental data shows good agreement...... and high degree of predictability of the theory developed....
Potential theory on infinite networks
Soardi, Paolo M
1994-01-01
The aim of the book is to give a unified approach to new developments in discrete potential theory and infinite network theory. The author confines himself to the finite energy case, but this does not result in loss of complexity. On the contrary, the functional analytic machinery may be used in analogy with potential theory on Riemann manifolds. The book is intended for researchers with interdisciplinary interests in one of the following fields: Markov chains, combinatorial graph theory, network theory, Dirichlet spaces, potential theory, abstract harmonic analysis, theory of boundaries.
The reconstruction of inflationary potentials
Lin, Jianmang; Gao, Qing; Gong, Yungui
2016-07-01
The observational data on the anisotropy of the cosmic microwave background constraints the scalar spectral tilt ns and the tensor to scalar ratio r which depend on the first and second derivatives of the inflaton potential. The information can be used to reconstruct the inflaton potential in the polynomial form up to some orders. However, for some classes of potentials, ns and r behave as ns(N) and r(N) universally in terms of the number of e-folds N. The universal behaviour of ns(N) can be used to reconstruct a class of inflaton potentials. By parametrizing one of the parameters ns(N), ɛ(N) and φ(N), and fitting the parameters in the models to the observational data, we obtain the constraints on the parameters and reconstruct the classes of the inflationary models which include the chaotic inflation, T-model, hilltop inflation, s-dual inflation, natural inflation and R2 inflation.
Soliton dynamics in complex potentials
Soliton propagation dynamics under the presence of a complex potential are investigated. Cases of both symmetric and non-symmetric potentials are studied in terms of their effect on soliton dynamics. The existence of an invariant of soliton propagation under specific symmetry conditions for the real and the imaginary part of the potential is shown. The rich set of dynamical features of soliton propagation include dynamical trapping, periodic and nonperiodic soliton mass variation and non-reciprocal dynamics. These features are systematically investigated with the utilization of an effective particle phase space approach which is shown in remarkable agreement with direct numerical simulations. The generality of the results enables the consideration of potential applications where the inhomogeneity of the gain and loss is appropriately engineered in order to provide desirable soliton dynamics
Potential Theory for Directed Networks
Zhang, Qian-Ming; Wang, Wen-Qiang; Zhu, Yu-Xiao; Zhou, Tao
2012-01-01
Uncovering mechanisms underlying the network formation is a long-standing challenge for data mining and network analysis. In particular, the microscopic organizing principles of directed networks are less understood than those of undirected networks. This article proposes a hypothesis named potential theory, which assumes that every directed link corresponds to a decrease of a unit potential and subgraphs with definable potential values on all nodes are preferred. Combining the potential theory with the clustering and homophily mechanisms, we deduce that the Bi-fan consisting of 4 nodes and 4 directed links is the most favoured local structure in directed networks. Our hypothesis get positive supports from extensive experiments on 15 directed networks drawn from disparate fields, as indicated by the most accurate and robust performance of Bi-fan predictor within the link prediction framework. In summary, our main contributions are twofold: (i) We propose a new mechanism for the organization of directed networ...
Quantum chaos in multiwell potentials
Till the present time signatures of quantum chaos were studied mostly for the billiard-type systems, for dumped one-dimensional systems or for two-dimensional systems with potential energy surface of simple geometry. Almost nothing is known about the quantum chaos for generic Hamiltonian systems, including multiwell potentials, though those are the models describing the dynamics of transition between different states, for example, nuclear isomeric transitions and decay of superdeformed states of nuclei. An important feature of classical dynamics in generic multiwell potentials is the so-called mixed state, namely: regular and chaotic regimes coexist at the same energy, being localized in different local minima of the potential. The aim of our work is to show that studies of quantum chaos in the mixed state are promising and in many cases optimal. (author)
Operational schedule 2011 & potential performance
Meddahi, M
2011-01-01
The assumed LHC beam parameters for 2011 are summarised. The overview of the 2011 schedule is presented and including hardware commissioning, beams re-commissioning, re-validation, scrubbing, technical stops, MD, ions and special physics run requests. A strategy for stepping up in intensity is proposed and potential issues are described together with possible actions. Finally, the potential peak and integrated luminosity are given.
Triton photodisintegration with realistic potentials
Schadow, W.; Sandhas, W.
1997-01-01
The photodisintegration of $^{3}$H is treated by means of coupled integral equations using separable versions of the Paris and the Bonn potentials in their kernel. The differential cross section for the inverse reaction is obtained via detailed balance. For the latter process good agreement with the data is found when including final-state interaction, meson exchange currents, higher partial waves in the potential, and electric quadrupole contributions in the electromagnetic interaction.
CENTRAL ASIA: ECONOMIC COOPERATION POTENTIAL
Rakhmatullina, Gulnur
2007-01-01
The Central Asian republics are rich in energy resources: three of them (Kazakhstan, Uzbekistan, and Turkmenistan) can boast of oil and gas deposits, while the other two (Kyrgyzstan and Tajikistan) have vast hydropower potential. This means that harmonized energy policy designed to meet their demands in energy, energy exports, and stronger positions in ensuring international energy security makes sense. By the same token, these countries can, potentially, develop metallurgy, machine building,...
ANALYSIS OF ENTERPRISE MARKETING POTENTIAL
Krіvoruchko, О.; Pіpenko, I.
2010-01-01
Methodological fundamentals of enterprise marketing potential analysis have been devised on the basis of substantiation of the main activities, content, sequence and direction, means and methods of their implementation. The introduced fundamentals stipulate determining the changing level of marketing potential with time, ascertaining the influence of the structure of factors, which form them correspondence between an enterprise supply and demand of market entities considering the importance o...
Propagator for finite range potentials
The Schroedinger equation in integral form is applied to the one-dimensional scattering problem in the case of a general finite range, nonsingular potential. A simple expression for the Laplace transform of the transmission propagator is obtained in terms of the associated Fredholm determinant, by means of matrix methods; the particular form of the kernel and the peculiar aspects of the transmission problem play an important role. The application to an array of delta potentials is shown
Potential of Ecotourism in Finland
Pöyhönen, Annukka
2015-01-01
The objective of this thesis was to examine the potential and the potential of ecotourism in Finland. The research focuses on different dimensions of ecotourism business as well as the stage we are at in Finland when it comes to ecotourism business. One of the main points was also to clarify the meanings of and the differences between ecotourism, nature-based tourism and sustainable tourism. Desktop research was chosen as the main research method. The intention was use it to survey existi...
STUDENTS’ POTENTIAL FOR AUTHENTIC LEADERSHIP
Djurdja Solesa-Grijak; Dragan Solesa; Nedjo Kojic
2015-01-01
To know yourself and to act accordingly has been seen as a moral imperative throughout history. The aim of this research was to determine potential of students for authentic leadership and relation between their authentic personality and potential for authentic leadership. The sample consisted of students (N=133) from Serbia (male – 59% and female – 41%). The average age of students was M=21.9. Instruments used were Authenticity Scale (Wood et al., 2008) and Authentic Leadership Self-Assessme...
Scalar potentials in extended supergravities
The paper on scalar potentials in extended supergravities is a contribution to the book commemorating the sixtieth birthday of E.S. Fradkin. It is shown that in extended supergravities the overall scalar potentials can be written as a sum of squares of boosted structure constants of the gauge group K, which is a subgroup of the isometry group G of the corresponding σ-model over G/H (H is a subgroup of G). (U.K.)
Molecular potentials and relaxation dynamics
The use of empirical pseudopotentials, in evaluating interatomic potentials, provides an inexpensive and convenient method for obtaining highly accurate potential curves and permits the modeling of core-valence correlation, and the inclusion of relativistic effects when these are significant. Recent calculations of the X1Σ+ and a3Σ+ states of LiH, NaH, KH, RbH, and CsH and the X2Σ+ states of their anions are discussed. Pseudopotentials, including core polarization terms, have been used to replace the core electrons, and this has been coupled with the development of compact, higly-optimized basis sets for the corresponding one- and two-electron atoms. Comparisons of the neutral potential curves with experiment and other ab initio calculations show good agreement (within 1000 cm-1 over most of the potential curves) with the difference curves being considerably more accurate. In the method of computer molecular dynamics, the force acting on each particle is the resultant of all interactions with other atoms in the neighborhood and is obtained as the derivative of an effective many-body potential. Exploiting the pseudopotential approach, in obtaining the appropriate potentials may be very fruitful in the future. In the molecular dynamics example considered here, the conventional sum-of-pairwise-interatomic-potentials (SPP) approximation is used with the potentials derived either from experimental spectroscopic data or from Hartree-Fock calculations. The problem is the collisional de-excitation of vibrationally excited molecular hydrogen at an Fe surface. The calculations have been carried out for an initial vibrotational state v = 8, J = 1 and a translational temperature corresponding to a gas temperature of 5000K. Different angles of approach and different initial random impact points on the surface have been selected. For any given collision with the wall, the molecule may pick up or lose vibrotatonal and translational energy
Estimation of potential uranium resources
Potential estimates, like reserves, are limited by the information on hand at the time and are not intended to indicate the ultimate resources. Potential estimates are based on geologic judgement, so their reliability is dependent on the quality and extent of geologic knowledge. Reliability differs for each of the three potential resource classes. It is greatest for probable potential resources because of the greater knowledge base resulting from the advanced stage of exploration and development in established producing districts where most of the resources in this class are located. Reliability is least for speculative potential resources because no significant deposits are known, and favorability is inferred from limited geologic data. Estimates of potential resources are revised as new geologic concepts are postulated, as new types of uranium ore bodies are discovered, and as improved geophysical and geochemical techniques are developed and applied. Advances in technology that permit the exploitation of deep or low-grade deposits, or the processing of ores of previously uneconomic metallurgical types, also will affect the estimates
MODELING WORLD BIOENERGY CROP POTENTIAL
Hagiwara, Kensuke; Hanasaki, Naota; Kanae, Shinjiro
Bioenergy is regarded as clean energy due to its characteristics and expected to be a new support of world energy de¬mand, but there are few integrated assessments of the potential of bioenergy considering sustainable land use. We esti¬mated the global bioenergy potential with an integrated global water resources model, the H08. It can simulate the crop yields on global-scale at a spatial resolution of 0.50.5. Seven major crops in the world were considered; namely, maize, sugar beet, sugar cane, soybean, rapeseed, rice, and wheat, of which the first 5 are commonly used to produce biofuel now. Three different land-cover types were chosen as potential area for cultivation of biofuel-producing crop: fallow land, grassland, and portion of forests (excluding areas sensitive for biodiversity such as frontier forest). We attempted to estimate the maximum global bioenergy potential and it was estimated to be 1120EJ. Bioenergy potential depends on land-use limitations for the protection of bio-diversity and security of food. In another condition which assumed more land-use limitations, bioenergy potential was estimated to be 70-233EJ.
Alpha Ni optical model potentials
Billah, M. M.; Abdullah, M. N. A.; Das, S. K.; Uddin, M. A.; Basak, A. K.; Reichstein, I.; Sen Gupta, H. M.; Malik, F. B.
2005-11-01
The present work reports the analyses of the experimental differential cross-sections of α elastic scattering on 58,60,62,64Ni, over a wide range of incident energies, in terms of four types of optical potentials, namely shallow (molecular), deep non-monotonic, squared Woods-Saxon and semi-microscopic folding. All the four potentials produce a reasonable description of the experimental data. The potential parameters, calculated from the energy density functional theory using a realistic two-nucleon interaction, resemble closely the molecular potential parameters, which produce the best description of the experimental data for the four isotopes. The volume integrals and the energy variation of the parameters indicate the effect of the shell-model structure on the potentials. The folding potentials, without any need for renormalization, are found to describe reasonably well the elastic scattering cross-section data for the four isotopes within the energy range considered. In conformity with the previous observation on Ca isotopes, the number of nucleons, 4A=49, existing in α-like clusters in the target nucleus, is the same for the four isotopes, considered herein.
Active Spacecraft Potential Control Investigation
Torkar, K.; Nakamura, R.; Tajmar, M.; Scharlemann, C.; Jeszenszky, H.; Laky, G.; Fremuth, G.; Escoubet, C. P.; Svenes, K.
2016-03-01
In tenuous plasma the floating potential of sunlit spacecraft reaches tens of volts, positive. The corresponding field disturbs measurements of the ambient plasma by electron and ion sensors and can reduce micro-channel plate lifetime in electron detectors owing to large fluxes of attracted photoelectrons. Also the accuracy of electric field measurements may suffer from a high spacecraft potential. The Active Spacecraft Potential Control (ASPOC) neutralizes the spacecraft potential by releasing positive charge produced by indium ion emitters. The method has been successfully applied on other spacecraft such as Cluster and Double Star. Two ASPOC units are present on each spacecraft. Each unit contains four ion emitters, whereby one emitter per instrument is operated at a time. ASPOC for the Magnetospheric Multiscale (MMS) mission includes new developments in the design of the emitters and the electronics. New features include the use of capillaries instead of needles, new materials for the emitters and their internal thermal insulators, an extended voltage and current range of the electronics, both for ion emission and heating purposes, and a more capable control software. This enables lower spacecraft potentials, higher reliability, and a more uniform potential structure in the spacecraft's sheath compared to previous missions. Results from on-ground testing demonstrate compliance with requirements. Model calculations confirm the findings from previous applications that the plasma measurements will not be affected by the beam's space charge. Finally, the various operating modes to adapt to changing boundary conditions are described along with the main data products.
Economic potential of inertial fusion
Beyond the achievement of scientific feasibility, the key question for fusion energy is: does it have the economic potential to be significantly cheaper than fission and coal energy. If fusion has this high economic potential then there are compelling commercial and geopolitical incentives to accelerate the pace of the fusion program in the near term, and to install a global fusion energy system in the long term. Without this high economic potential, fusion's success depends on the failure of all alternatives, and there is no real incentive to accelerate the program. If my conjectures on the economic potential of inertial fusion are approximately correct, then inertial fusion energy's ultimate costs may be only half to two-thirds those of advanced fission and coal energy systems. Relative cost escalation is not assumed and could increase this advantage. Both magnetic and inertial approaches to fusion potentially have a two-fold economic advantage which derives from two fundamental properties: negligible fuel costs and high quality energy which makes possible more efficient generation of electricity. The wining approach to fusion may excel in three areas: electrical generating efficiency, minimum material costs, and adaptability to manufacture in automated factories. The winning approach must also rate highly in environmental potential, safety, availability factor, lifetime, small 0 and M costs, and no possibility of utility-disabling accidents
Microscopic optical potential from Argonne inter-nucleon potentials
In the present work we describe our results concerning the calculation of equation of state of symmetric zero temperature nuclear matter and the microscopic optical potential using the soft-core Argonne inter-nucleon potentials in first order Brueckner–Hartree–Fock (BHF) theory. The nuclear matter saturates at a density 0.228 nucleon/fm3 with 17.52 MeV binding energy per nucleon for Argonne av-14 and at 0.228 nucleon/fm3 with 17.01 MeV binding energy per nucleon for Argonne av-18. As a test case we present an analysis of 65 and 200 MeV protons scattering from 208Pb. The Argonne av-14 has been used for the first time to calculate nucleon optical potential in BHF and analyze the nucleon scattering data. We also compare our reaction matrix results with those using the old hard-core Hamada–Johnston and the soft-core Urbana uv-14 and Argonne av-18 inter-nucleon potentials. Our results indicate that the microscopic potential obtained using av-14 gives marginally better agreement with the experimental data than the other three Hamiltonians used in the present work. (author)
Streaming potential measurements of biosurfaces
Van Wagenen, R. A.; Andrade, J. D.; Hibbs, J. B., Jr.
1976-01-01
A technique based on the measurement of streaming potentials has been developed to evaluate the electrokinetic region of the cell periphery. This approach is feasible for cell lines propagated in in-vitro cell cultures in monolayer form. The advantage of this system is that cells may be evaluated in the living state atttached to a substrate; it is not necessary to subject the cells to enzymatic, chemical, or mechanical trauma required to obtain monodisperse suspensions which are then normally evaluated by microelectrophoresis. In this manner, it should be possible to study the influence of substrate and environmental factors on the charge density and potential at the cell periphery. The apparatus and procedure are described as well as some results concerning the electrokinetic potential of borosilicate capillaries as a function of ionic strength, pH, and temperature. The effect that turbulence and entrance flow conditions have on accurate streaming-potential measurements is discussed. The electrokinetic potential of BALB/c 3T12 fibroblasts has been quantified as a function of pH, ionic strength, glutaraldehyde fixation, and Giemsa staining.
Visualizing motion in potential wells
Jolly, Pratibha; Zollman, Dean; Rebello, N. Sanjay; Dimitrova, Albena
1998-01-01
The concept of potential-energy diagrams is of fundamental importance in the study of quantum physics. Yet, students are rarely exposed to this powerful alternative description in introductory classes and thus have difficulty comprehending its significance when they encounter it in beginning-level quantum courses. We describe a learning unit that incorporates a sequence of computer-interfaced experiments using dynamics or air-track systems. This unit is designed to make the learning of potential-energy diagrams less abstract. Students begin by constructing the harmonic or square-well potential diagrams using either the velocity data and assuming conservation of energy or the force-displacement graph for the elastic interaction of an object constrained by springs or bouncing off springy blocks. Then, they investigate the motion of a rider magnet interacting with a configuration of field magnets and plot directly the potential-energy diagrams using a magnetic field sensor. The ease of measurement allows exploring the motion in a large variety of potential shapes in a short duration class.
Lethal, potentially lethal lesion model
Curtis, S.B.
1983-07-01
A theoretical framework to describe the formation of lethal mutations by radiation is presented. Lesions that are repaired (and misrepaired) in each type of experiment described (delayed plating and split dose) are assumed to be the same. In this model the same (potentially lethal) lesions cause both sublethal and potentially lethal damage. Potentially lethal damage is defined as damage which may be modified by alterations in postirradiation conditions. Sublethal damage is cellular damage whose accumulation may lead to lethality. A crucial consideration in the expression of the damage is the kind of medium in which the cells are placed during the repair period. Fresh or growth medium (F-medium) is assumed to cause fixation of damage after about 3 hours, while no fixation (only misrepair) occurs in conditioned medium (C-medium).
Accelerating cosmologies from exponential potentials
It is learnt that exponential potentials of the form V ∼ exp(-2cφ/Mp) arising from the hyperbolic or flux compactification of higher-dimensional theories are of interest for getting short periods of accelerated cosmological expansions. Using a similar potential but derived for the combined case of hyperbolic-flux compactification, we study a four-dimensional flat (or open) FRW cosmologies and give analytic (and numerical) solutions with exponential behavior of scale factors. We show that, for the M-theory motivated potentials, the cosmic acceleration of the universe can be eternal if the spatial curvature of the 4d spacetime is negative, while the acceleration is only transient for a spatially flat universe. We also briefly discuss about the mass of massive Kaluza-Klein modes and the dynamical stabilization of the compact hyperbolic extra dimensions. (author)
Entrepreneurial Attitudes among Potential Entrepreneurs
Akhtar Ali (Corresponding author
2011-09-01
Full Text Available This article explores entrepreneurial attitudes among potential entrepreneurs in Pakistan. Multi-stage sampling maximized representation. Four hundred and eighty masters of business administration (MBA students (potential entrepreneurs from six public sector Pakistani universities returned completed questionnaires. Three factors emerged: entrepreneurial acceptability, entrepreneurial intentions and personal factors. Moreover, the perceptions of the potential entrepreneurs on locus of control, self efficacy, subjective norms and instrumental readiness were also analyzed. The majority of students showed generally positive attitudes towards entrepreneurship at all six universities. Overall there was a significant difference between negative and positive attitudes (negative mean 184, positive mean 284. There was also some impact of demographic variables, such as university, parental income and profession. Both genders exhibited similar attitudes at most of the sample institutions. The implications for practice and policy are discussed.
Imagined Potentialities of Healthcare Technologies
Boulus-Rødje, Nina
This paper will focus on health care technologies and initiatives, particularly, Electronic Health Records (EHRs). These technologies are ascribed various potentialities, attributing them the capacity to do a wide range of things, from improving efficiency to saving medical costs and even saving...... lives. These complex and often conflicting imagined potentialities lead to inflicted burden on designers, policy makers and healthcare practitioners who are faced with different realities on the ground. The conflicting notions have real life effects as these impact our present understanding of, and...... actions taken toward, these technologies. To better understand the material and discursive processes that are at play in shaping our present and future understanding of EHR technologies, the paper offers the analytical notion of imagined potentialities, whereby a technology is imagined to possess an...
Neutron and proton optical potentials
The neutron and proton optical model potentials (OMP) are discussed in terms of microscopic (MOMP) and phenomenological (POMP) models. For the MOMP, two approaches are discussed, the nucleus matter approach [Jeukenne-Lejeune-Mahaux (JLM) and Brieva-Rook-von Geramb (BRVG), potentials] and the finite nuclei approach (Osterfeld and Madsen). For the POMP, the Lane charge-exchange potential and its validity over a wide mass range is reviewed. In addition to the Lane symmetry term, the Coulomb correction to both the real and imaginary parts of the OMP is discussed for the above models. The use of the OMP to calculate collective inelastic scattering and observed differences between the neutron- and proton-deformation parameters is also illustrated. 25 refs., 3 figs
The potential of biogas energy
Biogas technology has been known about for a long time, but in recent years the interest in it has significantly increased, especially due to the higher costs and the rapid depletion of fossil fuels as well as their environmental considerations. The main objective of the present study is to investigate the potential of biogas energy in the 15 European Union (EU) countries and in Turkey, which is seeking admission to the EU and is trying to meet EU environmental standards. Biogas energy potential of the 15 EU countries is estimated to be about 800 PJ. Besides this, Turkey's annual animal waste potential is obtained to be about 11.81 million tons with a biogas energy equivalent of 53.6 PJ. It is expected that this study will be helpful in developing highly applicable and productive planning for energy policies towards the optimum utilization of biogas energy. (author)
Fertility potential after unilateral orchiopexy
Cortes, D; Thorup, J M; Lindenberg, S
1996-01-01
PURPOSE: We evaluated whether adult fertility potential was better when unilateral orchiopexy was done at ages 2 to 6 years or later, and we identified those at risk for infertility. MATERIALS AND METHODS: Unilateral orchiopexy was performed simultaneously with testicular biopsy in 11 patients 2...... statistically similar fertility potentials were found in adulthood. Five of the 65 patients (7.7%, 95% confidence limits 2.5 to 17%) may experience infertility, representing 33% of both groups with less than 1% of the age matched number of spermatogonia per tubular transverse section (approximately no germ...... cells) in the biopsy specimen at orchiopexy. CONCLUSIONS: Between ages 2 and 12 years the timing of unilateral orchiopexy may vary without an effect on subsequent fertility potential. When biopsy at surgery lacks germ cells, there is an approximately 33% age independent risk of subsequent infertility...
Wind energy potential in Bulgaria
In this study, wind characteristic and wind energy potential in Bulgaria were analyzed using the wind speed data. The wind energy potential at different sites in Bulgaria has been investigated by compiling data from different sources and analyzing it using a software tool. The wind speed distribution curves were obtained by using the Weibull and Rayleigh probability density functions. The results relating to wind energy potential are given in terms of the monthly average wind speed, wind speed probability density function (PDF), wind speed cumulative density function (CDF), and wind speed duration curve. A technical and economic assessment has been made of electricity generation from three wind turbines having capacity of (60, 200, and 500 kW). The yearly energy output capacity factor and the electrical energy cost of kWh produced by the three different turbines were calculated
Handbook methane potential; Handbok metanpotential
Carlsson, My (AnoxKaldnes AB (Sweden)); Schnurer, Anna (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden))
2011-07-15
Before using a organic material for biogas production it is essential to evaluate the methane production potential. The methane potential is one important tool possible to use during planning of new plants but also when new materials are considered for already running biogas plants. The chemical composition of different organic material varies extensively and this will have an impact on both the degradability and the methane potential. Information about the methane potential of a specific material can sometimes be found in the literature or can be calculated after a chemical/ physical or biological characterization. Here, the BMP test (Biochemical Methane Potential) is a commonly used method. Today the BMP test is a commonly used method to determine the methane potential. Many national and international research groups, consultants as well as personal at biogas plants are using this method and there is a lot of data available in the literature from such tests. In addition there are several protocols giving guidelines on how to execute a BMP-test. The BMP-test is performed in many different ways, not always under optimized conditions, and there is a lack of information on how to interpret the obtained data. This report summarizes knowledge from the literature and the experience from a Swedish referee group, consisting of persons being active performers of BMP-tests. The report does not include a standardized protocol as the procedure can be performed in different ways depending on available equipment and on the type of material to be tested. Instead the report discusses different factors of great importance for a successful test giving reliable results. The report also summarizes important information concerning the interpretation and how to present results in order to allow comparison of data from different test.
Biowaste energy potential in Kenya
Energy affects all aspects of national development. Hence the current global energy crisis demands greater attention to new initiatives on alternative energy sources that are renewable, economically feasible and sustainable. The agriculture-dependent developing countries in Africa can mitigate the energy crisis through innovative use of the available but underutilised biowaste such as organic residues from maize, barley, cotton, tea and sugarcane. Biogas technology is assumed to have the capacity to economically and sustainably convert these vast amounts of biowaste into renewable energy, thereby replacing the unsustainable fossil energy sources, and reducing dependency on fossil fuels. However, the total energy potential of biogas production from crop residues available in Kenya has never been evaluated and quantified. To this end, we selected five different types of residues (maize, barley, cotton, tea and sugarcane) from Kenya and evaluated their energy potential through biomethane potential analysis at 30 C and a test time of 30 days. The specific methane yields for maize, barley, cotton, tea and sugarcane residues obtained under batch conditions were respectively 363, 271, 365, 67 and 177 m3 per tonne volatile solids. In terms of energy potential, maize, cotton and barley residues were found to be better substrates for methane production than tea and sugarcane residues and could be considered as potential substrates or supplements for methane production without compromising food security in the country. The evaluated residues have a combined national annual maximum potential of about 1313 million cubic meters of methane which represent about 3916 Gigawatt hour (GWh) of electricity and 5887 GWh of thermal energy. The combined electrical potential is equivalent to 73% of the country's annual power production of 5307 GWh. Utilization of the residues that are readily available on a 'free on site' basis for energy production could substitute the fossil fuels that
Neurotechnology premises, potential, and problems
Giordano, James
2012-01-01
New technologies that allow us to investigate mechanisms and functions of the brain have shown considerable promise in treating brain disease and injury. These emerging technologies also provide a means to assess and manipulate human consciousness, cognitions, emotions, and behaviors, bringing with them the potential to transform society. Neurotechnology: Premises, Potential, and Problems explores the technical, moral, legal, and sociopolitical issues that arise in and from today,s applications of neuroscience and technology and discusses their implications for the future. Some of the issues r
Hertz potentials in higher dimensions
We generalise the Hertz potentials to all spacetime dimensions D ≥4 and to all antisymmetric tensor fields. We show that the Whittaker-Debye-Bromwich reduction of the Hertz potential can be successfully exploited in all dimensions and for all antisymmetric tensor fields if the underlying spacetime is a warped product manifold. We illustrate the Hertzian approach by constructing the multipole expansions of all antisymmetric tensor fields on a D-dimensional Schwarzschild solution. A no-hair theorem for the D-dimensional black holes follows from these multipole expansions. (author)
Brane Potentials and Moduli Spaces
It is shown that the supergravity moduli spaces of D1-D5 and D2-D6 brane systems coincide with those of the Coulomb branches of the associated non-abelian gauge theories. We further discuss situations in which worldvolume brane actions include a potential term generated by probing certain supergravity backgrounds. We find that in many cases, the appearance of the potential is due to the application of the Scherk-Schwarz mechanism. We give some examples and discuss the existence of novel supersymmetric brane configurations. (author)
Biowaste energy potential in Kenya
Nzila, Charles; Dewulf, Jo; van Langenhove, Herman [Laboratory for Environmental and Organic Chemistry, Gent University, Copure Links 653 - B9000 Gent (Belgium); Spanjers, Henri [Lettinga Associates Foundation, Wageningen, P.O Box 500 - 6700 AM Wageningen (Netherlands); Kiriamiti, Henry [Department of Chemical and Process Engineering, Moi university, P.O. Box 3900, 30100 Eldoret (Kenya)
2010-12-15
Energy affects all aspects of national development. Hence the current global energy crisis demands greater attention to new initiatives on alternative energy sources that are renewable, economically feasible and sustainable. The agriculture-dependent developing countries in Africa can mitigate the energy crisis through innovative use of the available but underutilised biowaste such as organic residues from maize, barley, cotton, tea and sugarcane. Biogas technology is assumed to have the capacity to economically and sustainably convert these vast amounts of biowaste into renewable energy, thereby replacing the unsustainable fossil energy sources, and reducing dependency on fossil fuels. However, the total energy potential of biogas production from crop residues available in Kenya has never been evaluated and quantified. To this end, we selected five different types of residues (maize, barley, cotton, tea and sugarcane) from Kenya and evaluated their energy potential through biomethane potential analysis at 30 C and a test time of 30 days. The specific methane yields for maize, barley, cotton, tea and sugarcane residues obtained under batch conditions were respectively 363, 271, 365, 67 and 177 m{sup 3} per tonne volatile solids. In terms of energy potential, maize, cotton and barley residues were found to be better substrates for methane production than tea and sugarcane residues and could be considered as potential substrates or supplements for methane production without compromising food security in the country. The evaluated residues have a combined national annual maximum potential of about 1313 million cubic meters of methane which represent about 3916 Gigawatt hour (GWh) of electricity and 5887 GWh of thermal energy. The combined electrical potential is equivalent to 73% of the country's annual power production of 5307 GWh. Utilization of the residues that are readily available on a 'free on site' basis for energy production could substitute
Effective potential models for hadrons
Lucha, Wolfgang; Lucha, Wolfgang; Schoberl, Franz F
1996-01-01
The aim of these lectures is to give a self-contained introduction to nonrelativistic potential models, to their formulation as well as to their possible applications. At the price of some lack of (in a mathematical sense) rigorous derivations, we try to give a feeling and understanding for the simplest conceivable method to extract the explicit form of the forces acting between quarks from the interplay between experimental observations and theoretical considerations. According to this spirit, we demonstrate, in detail, how to obtain the underlying Hamiltonian and how to determine the Lorentz structure of the quark--(anti-)quark interaction potential from well-established experimental facts.
Effective potential models for hadrons
The aim of these lectures is to give a self-contained introduction to nonrelativistic potential models, to their formulation as well as to their possible applications. At the price of some lack of (in a mathematical sense) rigorous derivations, we try to give a feeling and understanding for the simplest conceivable method to extract the explicit form of the forces acting between quarks from the interplay between experimental observations and theoretical considerations. According to this spirit, we demonstrate, in detail, how to obtain the underlying Hamiltonian and how to determine the Lorentz structure of the quark-(anti-)quark interaction potential from well-established experimental facts. (author)
Diatomic interaction potential theory applications
Goodisman, Jerry
2013-01-01
Diatomic Interaction Potential Theory, Volume 2: Applications discusses the variety of applicable theoretical material and approaches in the calculations for diatomic systems in their ground states. The volume covers the descriptions and illustrations of modern calculations. Chapter I discusses the calculation of the interaction potential for large and small values of the internuclear distance R (separated and united atom limits). Chapter II covers the methods used for intermediate values of R, which in principle means any values of R. The Hartree-Fock and configuration interaction schemes des
Anisotropic Inflation with General Potentials
Shi, Jiaming; Qiu, Taotao
2015-01-01
Anomalies in recent observational data indicate that there might be some "anisotropic hair" generated in an inflation period. To obtain general information about the effects of this anisotropic hair to inflation models, we studied anisotropic inflation models that involve one vector and one scalar using several types of potentials. We determined the general relationship between the degree of anisotropy and the fraction of the vector and scalar fields, and concluded that the anisotropies behave independently of the potentials. We also generalized our study to the case of multi-directional anisotropies.
Bitcoin's Potential for Going Mainstream
Kasiyanto, Safari
2016-01-01
This paper reviews the possibility of bringing Bitcoin into the mainstream. In so doing, it elaborates the potential and obstacles of the Bitcoin system and what it would take for it to go mainstream. A cross-cutting discussion provides a helicopter view and encompasses the technical, economic, soci
High Potentials: A CEO Perspective
Hermans, Jeanine
2007-01-01
Finding high potentials has been identified as one of the major challenges for society and for higher education. But how does one find the talented individuals who will design the future of society? Can and should universities cooperate or compete with business and industry for these talents? Three CEOs reflect on this worldwide competition for…
Ionization Potentials for Isoelectronic Series.
Agmon, Noam
1988-01-01
Presents a quantitative treatment of ionization potentials of isoelectronic atoms. By looking at the single-electron view of calculating the total energy of an atom, trends in the screening and effective quantum number parameters are examined. Approaches the question of determining electron affinities. (CW)
EMPLOYMENT POTENTIAL AND ITS USE
Л.І. ВОРОТІНА
2011-12-01
Full Text Available In the article the basic problems of the use of labor potential and certain directions are considered in relation to development of strategic plans of defense of social interests of workers in the conditions of passing of Ukraine to the market relations. This article, summarizing the row of researches of author, is devoted the question of the use most mass from «on-the-road» resources – labor potential. In it the terms of injury of conformities to law are analyzed recreations of this potential, which, providing the current survival of economy, create limitation its stable development. This process is considered similarly as disparity of market transformations to social interests of most workers, as they unlike the financial factors of production are his conscious and active element. This foreshortening of recreation of labor potential within the framework of paradigm of reforms is still ignored, although neglect of nature of man and taking of it to the «aggregate which reflektiruet» can have investigation disintegration of his creative energy and by its transformation in social rejections.
LHC Physics Potential versus Energy
Quigg, Chris; /Fermilab
2009-08-01
Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for gg, u{bar d}, and qq interactions over the energy range relevant to the Large Hadron Collider, along with example analyses for specific processes.
Smartphones: A Potential Discovery Tool
Starkweather, Wendy; Stowers, Eva
2009-01-01
The anticipated wide adoption of smartphones by researchers is viewed by the authors as a basis for developing mobile-based services. In response to the UNLV Libraries’ strategic plan’s focus on experimentation and outreach, the authors investigate the current and potential role of smartphones as a valuable discovery tool for library users.
Evolutionary potential games on lattices
Szabó, György; Borsos, István
2016-04-01
Game theory provides a general mathematical background to study the effect of pair interactions and evolutionary rules on the macroscopic behavior of multi-player games where players with a finite number of strategies may represent a wide scale of biological objects, human individuals, or even their associations. In these systems the interactions are characterized by matrices that can be decomposed into elementary matrices (games) and classified into four types. The concept of decomposition helps the identification of potential games and also the evaluation of the potential that plays a crucial role in the determination of the preferred Nash equilibrium, and defines the Boltzmann distribution towards which these systems evolve for suitable types of dynamical rules. This survey draws parallel between the potential games and the kinetic Ising type models which are investigated for a wide scale of connectivity structures. We discuss briefly the applicability of the tools and concepts of statistical physics and thermodynamics. Additionally the general features of ordering phenomena, phase transitions and slow relaxations are outlined and applied to evolutionary games. The discussion extends to games with three or more strategies. Finally we discuss what happens when the system is weakly driven out of the "equilibrium state" by adding non-potential components representing games of cyclic dominance.
Variational approach for quarkonium potentials
A variational method based on Coulomb and harmonic oscillator trial functions has been investigated in the context of single and superposition of power potentials which are commonly used for quarkonium systems. Ground state energies being upper bounds are calculated and emerge surprisingly close to their exact values considering the simplicity of the method
Local optical potentials for mesons
Full text: Local optical models are very useful to describe many nuclear reactions, with the parameters often determined from fits to data. Elastic meson-nucleus scattering can be described by such potentials, but there is a strong ambiguity in the parameters [1], making the model hard to apply. Consideration of meson-nucleus inelastic scattering to collective states can be described in the local DWBA, built on local optical models. If the parameters of the optical potential are varied so as to find simultaneous agreement with both elastic and inelastic scattering, the ambiguity is removed, and a unique local optical potential can be defined for mesons [2,3]. The methods used to determine these parameters, examples of the fits and the meaning of the results will be explained. The result is a widely usable set of parameters in a simple local optical potential for pion and kaon interactions with nuclei, found to describe these reactions over a wide range of beam energies and nuclear masses. This accomplishment should allow a wider range of nuclear reaction models to include mesons in a simple way
New potentials for conformal mechanics
We find under some mild assumptions that the most general potential of one-dimensional conformal systems with time-independent couplings is expressed as V = V0 + V1, where V0 is a homogeneous function with respect to a homothetic motion in configuration space and V1 is determined from an equation with source a homothetic potential. Such systems admit at most an SL(2,R) conformal symmetry which, depending on the couplings, is embedded in Diff(R) in three different ways. In one case, SL(2,R) is also embedded in Diff(S1). Examples of such models include those with potential V = αx2 + βx−2 for arbitrary couplings α and β, the Calogero models with harmonic oscillator couplings and nonlinear models with suitable metrics and potentials. In addition, we give the conditions on the couplings for a class of gauge theories to admit a SL(2,R) conformal symmetry. We present examples of such systems with general gauge groups and global symmetries that include the isometries of AdS2 × S3 and AdS2 × S3 × S3 which arise as backgrounds in AdS2/CFT1. (paper)
Revisiting double Dirac delta potential
Ahmed, Zafar; Kumar, Sachin; Sharma, Mayank; Sharma, Vibhu
2016-07-01
We study a general double Dirac delta potential to show that this is the simplest yet still versatile solvable potential to introduce double wells, avoided crossings, resonances and perfect transmission (T = 1). Perfect transmission energies turn out to be the critical property of symmetric and anti-symmetric cases wherein these discrete energies are found to correspond to the eigenvalues of a Dirac delta potential placed symmetrically between two rigid walls. For well(s) or barrier(s), perfect transmission (or zero reflectivity, R(E)) at energy E=0 is non-intuitive. However, this has been found earlier and called the ‘threshold anomaly’. Here we show that it is a critical phenomenon and we can have 0≤slant R(0)\\lt 1 when the parameters of the double delta potential satisfy an interesting condition. We also invoke a zero-energy and zero curvature eigenstate (\\psi (x)={Ax}+B) of the delta well between two symmetric rigid walls for R(0)=0. We resolve that the resonant energies and the perfect transmission energies are different and they arise differently.
Health Educational Potentials of Technologies
Magnussen, Rikke; Aagaard-Hansen, Jens
2012-01-01
The field of health promotion technology has been in an exponential growth in recent years and smart phone applications, exer-games and self-monitoring devices has become part of fitness activities and health education. In this work-in-progress-paper theoretical perspectives for categorising and...... analysing health educational potentials of technologies are presented....
Electromagnetic potentials without gauge transformations
In this paper, we show that the use of the Helmholtz theorem enables the derivation of uniquely determined electromagnetic potentials without the necessity of using gauge transformation. We show that the electromagnetic field comprises two components, one of which is characterized by instantaneous action at a distance, whereas the other propagates in retarded form with the velocity of light. In our attempt to show the superiority of the new proposed method to the standard one, we argue that the action-at-a-distance components cannot be considered as a drawback of our method, because the recommended procedure for eliminating the action at a distance in the Coulomb gauge leads to theoretical subtleties that allow us to say that the needed gauge transformation is not guaranteed. One of the theoretical consequences of this new definition is that, in addition to the electric E and magnetic B fields, the electromagnetic potentials are real physical quantities. We show that this property of the electromagnetic potentials in quantum mechanics is also a property of the electromagnetic potentials in classical electrodynamics.
Health Educational Potentials of Technologies.
Magnussen, Rikke; Aagaard-Hansen, Jens
2012-01-01
The field of health promotion technology has been in an exponential growth in recent years and smart phone applications, exer-games and self-monitoring devices has become part of fitness activities and health education. In this work-in-progress-paper theoretical perspectives for categorising and analysing health educational potentials of technologies are presented.
Riesz potential versus fractional Laplacian
Ortigueira, Manuel Duarte
2014-09-01
This paper starts by introducing the Grünwald-Letnikov derivative, the Riesz potential and the problem of generalizing the Laplacian. Based on these ideas, the generalizations of the Laplacian for 1D and 2D cases are studied. It is presented as a fractional version of the Cauchy-Riemann conditions and, finally, it is discussed with the n-dimensional Laplacian.
Zika: Fighting a Potential Epidemic.
Berlin, Joey
2016-01-01
As Zika became an emerging threat, Texas scrambled to coordinate a prevention-and-response strategy against potential local transmission. TMA urged lawmakers in Washington, D.C., to agree on a funding package to combat the spread of Zika. PMID:27532808
Geothermal heat. Potential, danger, efficiency; Erdwaerme. Potential, Gefahr, Nutzen
Reichel, Wolfgang [Ingenieurbuero Timmer Reichel GmbH, Haan (Germany)
2010-07-01
The author of the contribution under consideration reports on the potential, danger and utilization of geothermal heat. Geothermal heat promises the solution of numerous energy problems. From the use of near-surface layers which substantially are affected by enviromental impacts such as solar radiation up to the depth use of the heat flow from the interior of the earth, there exist very different energy sources which are to be considered separately for each application.
The hydrogeothermal potential of Southern Hesse; Das hydrogeothermische Potential Suedhessens
Fitzer, C.; Fluhrer, S.; Sanner, B.; Knoblich, K. [Giessen Univ. (Germany). Inst. fuer Angewandte Geowissenschaften
1997-12-01
The paper investigates rock series suited as storage media and the temperature distribution in the subsurface of Southern Hesse. It gives an idea of the possibilities for hydrogeothermal energy use in the area. The densily populated Rhein-Main-region provides a good demand potential for geothermal heat. A substantially elevated geothermal gradient of about 60 K/km as compared to the continental average of 30 K/km could be demonstrated in the northern part of the Upper Rhine Graben. Thermal anomalies could be localised. The Rotliegend-layers (Perm) provide the highest geothermal ressources in the region. In more shallow depth, the Hydrobia layers (Teritary) show reasonable values. To the north, the potential of these series decreases. Hence hydrogeothermal energy use should not be considered in the northern part of Southern Hesse. The highest potential can be expected from the Rotliegend layers in the area of Stockstadt and Biebesheim. (orig.) [Deutsch] Die Untersuchung geht auf die moeglichen Speichergesteine und die Temperaturverteilung im Untergrund Suedhessens ein und gibt einen ersten Eindruck von den Moeglichkeiten zur Nutzung der Hydrogeothermie in der Region. Fuer geothermische Waerme besteht im dicht besiedelten Rhein-Main-Gebiet eine gute Abnehmerstruktur. Im noerdlichen Oberrheingraben konnte im Mittel ein deutlich erhoehter Temperaturgradient von etwa 60 K/km gegenueber dem kontinentalen Krustendurchschnittswert von 30 K/km nachgewiesen werden. Waemeanomalien wurden lokalisiert. Die Rotliegendschichten weisen im untersuchten Gebiet eindeutig die hoechsten Ressourcen auf. In geringerer Tiefenlage erzielen die Hydrobienschichten noch beachtliche Werte. Nach Norden nimmt das Potential der Schichten ab. Daher ist von einer Nutzung der Hydrogeothermie im noerdlichen Bereich Suedhessens eher abzuraten. Die hoechsten Ressourcen in Suedhessen sind im Bereich von Stockstadt und Biebesheim in den Rotliegenschichten zu erwarten. (orig.)
Hot neutron matter from a Self-Consistent Green's Functions approach
Rios, A; Vidaña, I
2008-01-01
A systematic study of the microscopic and thermodynamical properties of pure neutron matter at finite temperature within the Self-Consistent Green's Function approach is performed. The model dependence of these results is analyzed by both comparing the results obtained with two different microscopic interactions, the CD-BONN and the Argonne V18 potentials, and by analyzing the results obtained with other approaches, such as the Brueckner--Hartree--Fock approximation, the variational approach and the virial expansion.
Theory of Heavy Flavor in the Quark-Gluon Plasma
Rapp, Ralf
2011-01-01
Heavy-quark interactions in the Quark-Gluon Plasma are analyzed in terms of a selfconsistent Brueckner scheme using a thermodynamic $T$-matrix based on a potential model. The interrelations between quarkonium correlators, spectral functions and zero-modes, and open heavy-flavor transport and susceptibilities are elaborated. Independent constraints from thermal lattice QCD can be used to improve predictions for heavy-quark phenomenology in heavy-ion collisions.
Theory of Heavy Flavor in the Quark-Gluon Plasma
Rapp, Ralf [Cyclotron Institute and Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843-3366 (United States)
2011-07-15
Heavy-quark interactions in the Quark-Gluon Plasma are analyzed in terms of a selfconsistent Brueckner scheme using a thermodynamic T-matrix based on a potential model. The interrelations between quarkonium correlators, spectral functions and zero-modes, and open heavy-flavor transport and susceptibilities are elaborated. Independent constraints from thermal lattice QCD can be used to improve predictions for heavy-quark phenomenology in heavy-ion collisions.
Theory of Heavy Flavor in the Quark-Gluon Plasma
Heavy-quark interactions in the Quark-Gluon Plasma are analyzed in terms of a selfconsistent Brueckner scheme using a thermodynamic T-matrix based on a potential model. The interrelations between quarkonium correlators, spectral functions and zero-modes, and open heavy-flavor transport and susceptibilities are elaborated. Independent constraints from thermal lattice QCD can be used to improve predictions for heavy-quark phenomenology in heavy-ion collisions.
Single particle spectrum and binding energy of nuclear matter
Baldo, M; Fiasconaro, A.
2000-01-01
In non-relativistic Brueckner calculations of nuclear matter, the self-consistent single particle potential is strongly momentum dependent. To simplify the calculations, a parabolic approximation is often used in the literature. The variation in the binding energy value introduced by the parabolic approximation is quantitatively analyzed in detail. It is found that the approximation can introduce an uncertainty of 1-2 MeV near the saturation density.
The Landau parameters of nuclear matter in relativistic Hartree approximation
The Landau parameters of nuclear matter have been calculated in relativistic Hartree approximation as a function of a renormalization scale. The results have then been compared to the empirical values deduced from constraints on isoscalar compression modes, spin-orbit splitting in nuclei and energy dependence of the nucleon-nucleus optical potential. For comparison, the results obtained for relativistic non-linear models and Dirac-Brueckner-Hartree-Fock calculations are also shown. (author)
Dirac Hartree-Fock for Finite Nuclei Employing realistic Forces
Müther, R. Fritz H.; Machleidt, R.
1993-01-01
We discuss two different approximation schemes for the self-consistent solution of the {\\it relativistic} Brueckner-Hartree-Fock equation for finite nuclei. In the first scheme, the Dirac effects are deduced from corresponding nuclear matter calculations, whereas in the second approach the local-density approximation is used to account for the effects of correlations. The results obtained by the two methods are very similar. Employing a realistic one-boson-exchange potential (Bonn~A), the pre...
The Biodiversity Informatics Potential Index
Ariño Arturo H
2011-12-01
Full Text Available Abstract Background Biodiversity informatics is a relatively new discipline extending computer science in the context of biodiversity data, and its development to date has not been uniform throughout the world. Digitizing effort and capacity building are costly, and ways should be found to prioritize them rationally. The proposed 'Biodiversity Informatics Potential (BIP Index' seeks to fulfill such a prioritization role. We propose that the potential for biodiversity informatics be assessed through three concepts: (a the intrinsic biodiversity potential (the biological richness or ecological diversity of a country; (b the capacity of the country to generate biodiversity data records; and (c the availability of technical infrastructure in a country for managing and publishing such records. Methods Broadly, the techniques used to construct the BIP Index were rank correlation, multiple regression analysis, principal components analysis and optimization by linear programming. We built the BIP Index by finding a parsimonious set of country-level human, economic and environmental variables that best predicted the availability of primary biodiversity data accessible through the Global Biodiversity Information Facility (GBIF network, and constructing an optimized model with these variables. The model was then applied to all countries for which sufficient data existed, to obtain a score for each country. Countries were ranked according to that score. Results Many of the current GBIF participants ranked highly in the BIP Index, although some of them seemed not to have realized their biodiversity informatics potential. The BIP Index attributed low ranking to most non-participant countries; however, a few of them scored highly, suggesting that these would be high-return new participants if encouraged to contribute towards the GBIF mission of free and open access to biodiversity data. Conclusions The BIP Index could potentially help in (a identifying
The Tectonic Potentials of Concrete
Egholm Pedersen, Ole
2013-01-01
industrial paradigm of standardization, have been put forward. This development is carried forward by computers and digital fabrication, but has yet to find its way into the production of building components. With regards to concrete casting, however, existing research do offer advancement towards an...... increased customisation of casting moulds. The hypothesis of this research is that the techniques used in this research do not fully address the tectonic potentials of concrete which gives rise to the primary research question: Is it possible to enhance existing or develop new concrete casting techniques...... which allows for individualisation and resource optimisation, while matching or enhancing the tectonic potentials found in existing, repetitive concrete casting techniques? The research is comprised of two modes of inquiry: an empirical study of contemporary casting methods and subsequently six case...
Linear inflation from quartic potential
Kannike, Kristjan; Raidal, Martti
2016-01-01
We show that linear inflation appears as an attractor solution in the Coleman-Weinberg inflation provided the inflaton has a non-minimal coupling to gravity and the Planck scale is dynamically generated. Thus linear inflation appears in the context of a well-defined quantum field theory framework from quartic potentials without introducing any {\\it ad hoc} interaction or unbounded scalar potential by hand. The minimal scenario has only one free parameter -- the inflaton's non-minimal coupling to gravity -- that determines all physical parameters such as the tensor-to-scalar ratio and the reheating temperature of the Universe. Should the more precise future measurements of inflationary parameters point towards linear inflation, the dynamical origin of inflation would be strongly supported.
Papers presented at the European wind energy conference on the potential of wind farms are presented. The aim of the conference was to bring into focus the problems, experiences and potential of the application of wind power in wind power farms as a contribution to the European and global energy supply. It was considered that the interchange of experience among representatives of science, utilities, industry, environment and energy planning, together with those who represent financial and insurance interests, would create a better understanding of all aspects of wind power for its future successful development. The subjects covered concern surveys of national planning and policies regarding wind energy utilization and national and global development of wind turbine arrays. The performance of some individual wind farms is described. Papers also deal with utility and project planning, wind prediction and certification, wind loads and fatigus, wakes, noise and control. (AB)
Pharmacological potential of cerium oxidenanoparticles
Celardo, Ivana; Pedersen, Jens Z.; Traversa, Enrico; Ghibelli, Lina
2011-04-01
Nanotechnology promises a revolution in pharmacology to improve or create ex novo therapies. Cerium oxidenanoparticles (nanoceria), well-known as catalysts, possess an astonishing pharmacological potential due to their antioxidant properties, deriving from a fraction of Ce3+ ions present in CeO2. These defects, compensated by oxygen vacancies, are enriched at the surface and therefore in nanosized particles. Reactions involving redox cycles between the Ce3+ and Ce4+oxidation states allow nanoceria to react catalytically with superoxide and hydrogen peroxide, mimicking the behavior of two key antioxidant enzymes, superoxide dismutase and catalase, potentially abating all noxious intracellularreactive oxygen species (ROS) via a self-regenerating mechanism. Hence nanoceria, apparently well tolerated by the organism, might fight chronic inflammation and the pathologies associated with oxidative stress, which include cancer and neurodegeneration. Here we review the biological effects of nanoceria as they emerge from in vitro and in vivo studies, considering biocompatibility and the peculiar antioxidant mechanisms.
Translating barriers into potential improvements
Altintzoglou, Themistoklis; Hansen, Karina Birch; Valsdottir, Thora;
2010-01-01
Purpose: The aim of this study is to explore potential barriers to seafood consumption by The aim of this study is to explore potential barriers to seafood consumption by young adults and the parents of young children. Knowledge of these barriers will be used to assist the development of new....... Practical implications: Inputs for NPD related to convenience, attractiveness, quality, Inputs for NPD related to convenience, attractiveness, quality, trustworthiness, knowledge and requirements about seafood preparation are discussed. Originality/value: The present study combines qualitative methods to...... lead to practical input The present study combines qualitative methods to lead to practical input for NPD focusing on overcoming the barriers that keep consumers from choosing existing healthy seafood products. The importance of the consumers' confidence in their ability to successfully prepare a...
In plant corrosion potential monitoring
Examples of in plant redox and corrosion potential monitoring in light water reactors are given. All examples are from reactors in Sweden. The measurements have either been performed in side-stream autoclaves connected to the reactor systems by sampling lines, or in-situ in the system piping itself. Potential monitoring can give quite different results depending upon the experimental method. For environments with small concentrations of oxidants sampling lines can introduce large errors. During such circumstances in-situ measurements are necessary. Electrochemical monitoring is a valuable technique as a complement to conventional water chemistry follow-up in plants. It can be used for water chemistry surveillance and can reveal unintentional and harmful water chemistry transients. (author). 15 figs
Action Principle for Potential Flows
Frønsdal, Christian
2014-01-01
The restriction of hydrodynamics to non-viscous, potential (gradient, irrotational) flows is a theory both simple and elegant; a favorite topic of introductory textbooks. It is known that this theory (under the stated limitations) can be formulated as an action principle. It finds its principle application to adiabatic systems and cannot account for viscosity or dissipation. However, it can be generalized to include non-potential flows, as this paper shows. The new theory is a combination of Eulerian and Lagrangian hydrodynamics, with an extension to thermodynamics. It describes adiabatic phenomena but does not account for viscosity or dissipation. Nevertheless, it is an approach within which quasi-static processes can be described. In the adiabatic context it appears to be an improvement of the Navier-Stokes equation, the principal advantage being a natural concept of energy in the form of a first integral of the motion, conserved by virtue of the Euler-Lagrange equations.
Biomarkers of silicosis: Potential candidates
Tiwari R
2005-01-01
Full Text Available Silica dust is widely prevalent in the atmosphere and more common than the other types of dust, thus making silicosis the most frequently occurring pneumoconiosis. In India also, studies carried out by National Institute of Occupational Health have shown high prevalence of silicosis in small factories and even in nonoccupational exposed subjects. The postero-anterior chest radiographs remain the key tool in diagnosing and assessing the extent and severity of interstitial lung disease. Although Computed Tomography detects finer anatomical structure than radiography it could not get popularity because of its cost. On the basis of histological features of silicosis many potential biomarkers such as Cytokines, Tumor Necrosis Factor, Interleukin 1, Angiotensin Converting Enzyme, Serum Copper, Fas ligand (FasL, etc. have been tried. However, further studies are needed to establish these potential biomarkers as true biomarker of silicosis.
Introduction: Translating Potential into Profits
Lubinski, Christina; Kipping, Matthias
2015-01-01
Emerging markets trigger great expectations. Many foreign multinationals are eager to exploit the entrepreneurial opportunities potentially related to less developed but fast growing markets. This is not a new phenomenon. Multinationals from more developed countries have for long searched for...... opportunities in less developed markets and have dealt with the related challenges. Foreign environments with different needs and capabilities, unstable institutions and policies, stark fluctuations in the macroeconomic environment and unrealistic expectations are just some of the obstacles for ‘turning...... potential into profits.’ The history of multinational enterprises (MNEs) knows many examples of economies with these characteristics similar to modern understandings of ‘emerging markets.’ This special issue analyzes foreign multinationals in emerging markets from a historical perspective. It seeks to...
Lacasse with high redox potential
Maté, Diana M.; Valdivieso, Malena; Fernández, Layla; Alcalde Galeote, Miguel
2010-01-01
[EN] The invention relates to the directed evolution of a lacasse with high redox potential, functionally expressed in S. cerevisiae, which has a high production rate, high activity and high heat stability. The invention relates to the amino acid sequence of the lacas se and to the nucleotide sequence that codes for said lacas se. The lacasse of the invention is suitable for use in different sectors: nano-biotechnology, the paper industry, bioremediation, the textile industry, the fo...
Ethical potential in the enterprise
Vojtíšková, Tereza
2013-01-01
This bachelor thesis follows the importance of ethics in today's business environment. It examines what is the understanding of ethical principles and then their implementation in business. At the same time it critically assesses the impact of ethical perspectives on the example of a specific company. The aim of the study is to evaluate ethical potentials in the company from the perspective of the student's University of Economics. The bachelor thesis is divided into two main parts. The first...
SRS Controlled-Potential Coulometer
'The Savannah River Site has the analytical measurement capability to perform high-precision plutonium concentration measurements by controlled-potential coulometry. State-of-the-art controlled-potential coulometers were fabricated by the SRS Engineered Equipment and Systems Department and installed in the Analytical Laboratories'' process control laboratory. The Analytical Laboratories uses coulometry for routine accountability measurements of pure plutonium from the PUREX process and for verification of standard preparations used to calibrate other plutonium measurement systems routinely applied to process control, nuclear safety, and other accountability applications. The SRS Coulometer has a demonstrated measurement reliability of approximately 0.05 percent for 10 mg samples. The system has also been applied to the characterization of neptunium standard solutions with a comparable reliability. The SRS coulometer features: a patented current integration system; continuous electrical calibration versus Faraday''s Constants and Ohm''s Law; the control-potential adjustment technique for enhanced application of the Nernst Equation; a wide operating room temperature range; and a fully automated instrument control and data acquisition capability. The system has been operated for 10 years with minimal equipment failures and downtime. The coulometer and instrument controller have been periodically upgraded to remain current with available high-precision potential control and current integration components. A stability of 261 0.0015 percent RSD for the electronic calibration factor has been demonstrated. Most recently the system was converted from an Hewlett Packard computer platform to an IBM Computer Windows-based system. SRS Coulometers were installed at the Tokai-mura Reprocessing Facility in Japan in February 1999 and at the Mayak Production Association in Ozersk Russia in October 1998.'
Value distribution and potential theory
Eremenko, Alexandre
2003-01-01
We describe some results of value distribution theory of holomorphic curves and quasiregular maps, which are obtained using potential theory. Among the results discussed are: extensions of Picard's theorems to quasiregular maps between Riemannian manifolds, a version of the Second Main Theorem of Nevanlinna for curves in projective space and non-linear divisors, description of extremal functions in Nevanlinna theory and results related to Cartan's 1928 conjecture on holomorphic curves in the ...
Mismatch Negativity: Translating the Potential
JuanitaTodd
2013-01-01
The mismatch negativity (MMN) component of the auditory event-related potential has become a valuable tool in cognitive neuroscience. Its reduced size in persons with schizophrenia is of unknown origin but theories proposed include links to problems in experience-dependent plasticity reliant on N-methyl-d-aspartate glutamate receptors. In this review we address the utility of this tool in revealing the nature and time course of problems in perceptual inference in this illness together with it...
Potentialities of Revised Quantum Electrodynamics
Lehnert B.
2013-01-01
The potentialities of a revised quantum electrodynamic theory (RQED) earlier established by the author are reconsidered, also in respect to other fundamental theories such as those by Dirac and Higgs. The RQED theory is characterized by intrinsic linear symmetry breaking due to a nonzero divergence of the electric field strength in the vacuum state, as supported by the Zero Point Energy and the experimentally confirmed Casimir force. It includes the results of electron spin and antimatter by ...
Hydropower potential of the Vistula
Jędrzej Kosiński
2013-06-01
Full Text Available The present article discusses hydropower potential of the Vistula River in view of the formal conditions for power generation in Poland. Having compared different sources, it is shown that the Vistula hydropower infrastructure and the social/economic/environmental benefits thereof and public safety, ought to be given priority in government operations. Their neglect not only violates the Water Law provisions but also runs contrary to the national interest.
Hydropower potential of the Vistula
Jędrzej Kosiński; Wacław Zdulski
2013-01-01
The present article discusses hydropower potential of the Vistula River in view of the formal conditions for power generation in Poland. Having compared different sources, it is shown that the Vistula hydropower infrastructure and the social/economic/environmental benefits thereof and public safety, ought to be given priority in government operations. Their neglect not only violates the Water Law provisions but also runs contrary to the national interest.
Beautiful, but also potentially invasive
Lipták Boris; Vitázková Barbora
2015-01-01
Introduction of non-indigenous exotic species to new areas, where they may establish viable populations and become invasive, is a considerable problem in the protection of nature worldwide, as these species may alter the indigenous species population structure and potentially even decrease the biodiversity. The European fauna underwent through major negative changes on the continent and nowadays, it experiences another new treat, represented by the expanding aquarium pet trade, and with it, a...
Potential methane reservoirs beneath Antarctica.
Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H
2012-08-30
Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10(15) g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300 metres in West Antarctica and 700 metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage. PMID:22932387
Dirac solutions for quaternionic potentials
De Leo, Stefano
2014-01-01
In this paper, the quaternionic Dirac equation is solved for quaternionic potentials, iV0+jW0. The study shows two different solutions. The first solution contains particles and anti-particles and leads to the diffusion, tunneling and Klein energy zones. The complex limit is recovered from this solution. The second solution, which does not have a complex counterpart, can be seen as a V0-antiparticle or |W0|-particle.
ADVERGAMES: CHARACTERISTICS, LIMITATIONS AND POTENTIAL
Gurau Calin
2010-07-01
Full Text Available Advergames represent a new advertising concept that uses Internet technology to implement viral marketing campaigns. Despite the potential of this interactive advertising method, very few academic studies have been initiated to investigate the characteristics of advergames, and their influence on consumers’ perceptions and behaviour. Using secondary data, this paper attempts to evaluate the characteristics of effective advergames, and to analyse the effect of advergames on players’ perceptions and behaviour.
Study of Nonlocal Optical Potential
TIAN; Yuan
2013-01-01
It is generally known that nuclear optical potentials are theoretically expected to be non-local.The non-locality arises from the exchange of particles between the projectile and target and from coupling tonon-elastic channels.This non-locality was first introduced by Frahn and Lemmer,and developed further by Perey and Buck(PB).The kernel is of the form
Amplitude recruitment of cochlear potential
LI Xingqi; SUN Wei; SUN Jianhe; YU Ning; JIANG Sichang
2001-01-01
Intracellular recordings were made from outer hair cells (OHC) and the cochlear microphonics (CM) were recorded from scala media (SM) in three turn of guinea pig cochlea,the compound action potential (CAP) were recorded at the round window (RW) before and after the animal were exposed to white noise. The results suggest that the nonlinear properties with “saduration” of Input/output (I/O) function of OHC AC recepter potential and CM were founded; the nonlinear properties with “Low”, “Platean” and “high” of CAP also were investigated. After explosion, the threshold shift of CAP has about 10 dB. The I/O of OHC responses and CM were changed in a linearizing (i.e., nonlinearity loss), the “platean” of I/O CAP disappeared and the growth rate of CAP amplitude were larger than before explosion. The response amplitude recruitment of OHC appears to result from reduction in gain (i.e., hearing loss); It was due to the nonlinear growth function of OHC receptor potentials was changed in linearzing that the basilar membrance motion was changed in linearizing. Since intensity coding in the inner ear depends on an interactions of nonlinear basilar membrance and nerve fibers. So that it must lead to a linearizing of CAP as input responses.
Neuronal avalanches and coherence potentials
Plenz, D.
2012-05-01
The mammalian cortex consists of a vast network of weakly interacting excitable cells called neurons. Neurons must synchronize their activities in order to trigger activity in neighboring neurons. Moreover, interactions must be carefully regulated to remain weak (but not too weak) such that cascades of active neuronal groups avoid explosive growth yet allow for activity propagation over long-distances. Such a balance is robustly realized for neuronal avalanches, which are defined as cortical activity cascades that follow precise power laws. In experiments, scale-invariant neuronal avalanche dynamics have been observed during spontaneous cortical activity in isolated preparations in vitro as well as in the ongoing cortical activity of awake animals and in humans. Theory, models, and experiments suggest that neuronal avalanches are the signature of brain function near criticality at which the cortex optimally responds to inputs and maximizes its information capacity. Importantly, avalanche dynamics allow for the emergence of a subset of avalanches, the coherence potentials. They emerge when the synchronization of a local neuronal group exceeds a local threshold, at which the system spawns replicas of the local group activity at distant network sites. The functional importance of coherence potentials will be discussed in the context of propagating structures, such as gliders in balanced cellular automata. Gliders constitute local population dynamics that replicate in space after a finite number of generations and are thought to provide cellular automata with universal computation. Avalanches and coherence potentials are proposed to constitute a modern framework of cortical synchronization dynamics that underlies brain function.
Potentiality, Actuality, and Quantum Mechanics
Boris Koznjak
2007-12-01
Full Text Available In this paper a possible interpretative value of Aristotle’s fundamental ontological doctrine of potentiality (δύναµις and actuality (ἐνέργεια is considered in the context of operationally undoubtedly the most successful but interpretatively still controversial theory of modern physics – quantum mechanics – especially regarding understanding the nature of the world, the phenomena of which it describes and predicts so successfully. In particular, beings of the atomic world are interpreted as real potential beings (δυνάµει ὄντα actualized by the measurement process in appropriate experimental arrangement, and the problem of actual beings (ἐνεργείᾳ ὄντα of the atomic world (better known as the measurement problem in quantum mechanics is considered in the context of Aristotle’s threefold requirement for the priority of actuality over potentiality – in time (χρόνος, definition or knowledge (λόγος, and substantiality (οὐσία.
Prodigiosin and its potential applications.
Darshan, N; Manonmani, H K
2015-09-01
Since a decade, there has been a strong consumer demand for more natural products. This has augmented inclination towards substitution of synthetic colorants with natural pigments. Natural pigments not only have the capacity to increase the marketability of products, they also demonstrate valuable biological activities as antioxidants and anticancer agents. There is a long history of exploitation of natural products produced by bacteria as sources of pharmaceutically important, bioactive compounds. Among natural pigments, pigments from microbial sources are potentially suitable alternatives to synthetic pigments. The red pigment prodigiosin (PG) has unusual properties, which have long been documented. The red-pigmented prodiginines are bioactive secondary metabolites produced by both Gram-negative and Gram-positive bacteria. Prodigiosins are characterized by a common pyrrolyl pyrromethene skeleton, and the biological role of these pigments in the producer organisms remains unclear. Bacterial prodigiosins and their synthetic derivatives are effective proapoptotic agents against various cancer cell lines, with multiple cellular targets including multi-drug resistant cells with little or no toxicity towards normal cell lines. However, research into the biology of pigment production will stimulate interest in the bioengineering of strains to synthesize useful prodiginine derivatives. This review article highlights the characteristics and potential applications of prodigiosin pigment from Serratia as prodigiosins are real potential therapeutic drugs. PMID:26344956
Cannabinoids and their medicinal potential
Deepika Tikoo
2012-04-01
Full Text Available Cannabis sativa L preparations have been used therapeutically since many years. Inspite of their medicinal value, the danger of its abusive potential led to the ban on its use in clinical practice in many countries. The recent research and in depth knowledge about the cannabinoid system which throw a light on their disease management potential has paved way for the cannabinoids to become a new therapeutic focus of attention. Cannabinoids are a group of compounds that mediate their effects through cannabinoid receptors which include CB1, predominantly expressed in the brain and CB2 which is primarily found in the cells of the immune system. Despite the addictive properties of cannabis, the therapeutic value of cannabinoids is too high to be put aside. Numerous diseases such as anorexia, pain, inflammation, obesity, cardiovascular disorders, neurodegenerative diseases, cancer, gastrointestinal diseases, hepatic disorders, skin related diseases, respiratory disorders like asthma and eye diseases like glaucoma have suggested cannabinoid agonists/ antagonists/ cannabinoids related compounds as potential treatment options. Developments of new specific ligands for the cannabinoid receptors are now underway and it needs to be seen, if in future, they can prove to be a boon for the medical world. The paper reviews the current understanding of the cannabinoid receptors, their ligands and their possible role in various diseases supported by preclinical and clinical studies. [Int J Basic Clin Pharmacol 2012; 1(2.000: 48-59
Microscopic nuclear equation of state with three-body forces and neutron star structure
The equation of state (EOS) of nuclear matter is discussed within the Brueckner-Bethe-Goldstone approach. First the energy per particle E/A is calculated in the Brueckner-Hartree-Fock limit with the Argonne v18 potential, using the continuous choice as auxiliary potential. Then, the contribution of three-body clusters is determined by solving the Bethe-Faddeev equation, and the equivalence with the same calculations based on the standard choice as auxiliary potential, is demonstrated. In spite of reaching a quite good convergence of the hole-line expansion, the resulting EOS does not fit the empirical saturation density (ρ0 = 0.17 fm-3). To this end, three-body forces (TBF) are introduced. A first class of microscopic TBF comprises effects due to NN-bar virtual excitations via σ and ω-meson exchanges (the main relativistic correction to Brueckner theory), the 2π-exchange, and the virtual excitation of the lowest nucleonic resonance N*(1440). We compare with a phenomenological TBF, involving two parameters adjusted on the saturation density and energy. Next, using microscopic or phenomenological TBF, the symmetry energy of nuclear matter is computed, allowing to determine the EOS of beta-stable and charge neutral matter, and the properties of neutron stars, in particular the mass-radius curve
The electrostatic potential of a periodic lattice
Vaman, G.
2014-01-01
We calculate the electrostatic potential of a periodic lattice of arbitrary extended charges by using the Cartesian multipole formalism. This method allows the separation of the long-range potential from the contact potential (potential on the source). We write both the electrostatic potential and the interaction energy as convergent sums in the reciprocal space.
NN Correlations and Relativistic Hartree Fock in Finite Nuclei
Fritz, R
1993-01-01
Two different approximation schemes for the self-consistent solution of the relativistic Brueckner-Hartree-Fock equation for finite nuclei are discussed using realistic One-Boson-Exchange potentials. In a first scheme, the effects of correlations are deduced from a study of nuclear matter and parameterized in terms of an effective $\\sigma$, $\\omega$ and $\\pi$ exchange. Employing this effective interaction relativistic Hartree-Fock equations are solved for finite nuclei \\osi , \\caf\\ and \\cafe . In the second approach the effect of correlations are treated in the Brueckner-Hartree-Fock approximation directly for the finite nuclei, but the modifications of the Dirac spinors in the medium are derived from nuclear matter assuming a local-density approximation. Both approaches yield rather similar results for binding energies and radii in fair agreement with experimental data. The importance of the density dependent correlation effects is demonstrated and different ingredients to the spin-orbit splitting in the she...
Mean field and collisions in hot nuclei
Collisions between heavy nuclei produce nuclear matter of high density and excitation. Brueckner methods are used to calculate the momentum and temperature dependent mean field for nucleons propagating through nuclear matter during these collisions. The mean field is complex and the imaginary part is related to the ''two-body'' collision, while the real part relates to ''one-body'' collisions. A potential model for the N-N interactions is avoided by calculating the Reaction matrix directly from the T-matrix (i.e., N-N phase shifts) using a version of Brueckner theory previously published by the author. Results are presented for nuclear matter at normal and twice normal density and for temperatures up to 50 MeV. 23 refs., 7 figs
Hybrid star structure with the Field Correlator Method
Burgio, G. F.; Zappalà, D.
2016-03-01
We explore the relevance of the color-flavor locking phase in the equation of state (EoS) built with the Field Correlator Method (FCM) for the description of the quark matter core of hybrid stars. For the hadronic phase, we use the microscopic Brueckner-Hartree-Fock (BHF) many-body theory, and its relativistic counterpart, i.e. the Dirac-Brueckner (DBHF). We find that the main features of the phase transition are directly related to the values of the quark-antiquark potential V1, the gluon condensate G2 and the color-flavor superconducting gap Δ. We confirm that the mapping between the FCM and the CSS (constant speed of sound) parameterization holds true even in the case of paired quark matter. The inclusion of hyperons in the hadronic phase and its effect on the mass-radius relation of hybrid stars is also investigated.
Hybrid star structure with the Field Correlator Method
Burgio, G F
2015-01-01
We explore the relevance of the color-flavor locking phase in the equation of state (EoS) built with the Field Correlator Method (FCM) for the description of the quark matter core of hybrid stars. For the hadronic phase, we use the microscopic Brueckner-Hartree-Fock (BHF) many-body theory, and its relativistic counterpart, i.e. the Dirac-Brueckner (DBHF). We find that the main features of the phase transition are directly related to the values of the quark-antiquark potential $V_1$, the gluon condensate $G_2$ and the color-flavor superconducting gap $\\Delta$. We confirm that the mapping between the FCM and the CSS (constant speed of sound) parameterization holds true even in the case of paired quark matter. The inclusion of hyperons in the hadronic phase and its effect on the mass-radius relation of hybrid stars is also investigated.
Discrete Wave-Packet Representation in Nuclear Matter Calculations
Müther, H; Kukulin, V I; Pomerantsev, V N
2016-01-01
The Lippmann-Schwinger equation for the nucleon-nucleon $t$-matrix as well as the corresponding Bethe-Goldstone equation to determine the Brueckner reaction matrix in nuclear matter are reformulated in terms of the resolvents for the total two-nucleon Hamiltonians defined in free space and in medium correspondingly. This allows to find solutions at many energies simultaneously by using the respective Hamiltonian matrix diagonalization in the stationary wave packet basis. Among other important advantages, this approach simplifies greatly the whole computation procedures both for coupled-channel $t$-matrix and the Brueckner reaction matrix. Therefore this principally novel scheme is expected to be especially useful for self-consistent nuclear matter calculations because it allows to accelerate in a high degree single-particle potential iterations. Furthermore the method provides direct access to the properties of possible two-nucleon bound states in the nuclear medium. The comparison between reaction matrices f...