Potential In Conjunction Research Articles

Pine Tip Moth (Lepidoptera: Tortricidae) Infestation Rates as Influenced by Site and Stand Characteristics in Loblolly Pine Plantations in East Texas

Three young loblolly pine plantations grown on contrasting soil types produced quantitatively and qualitatively different host material for pine tip moths during 1985 and 1986. Amounts, periodicity, and availability of soil moisture regulated internal moisture conditions within host trees. Host xylem moisture potential in conjunction with soil nutrient status governed tree growth and influenced pine tip moth infestation rates. Pines on a sandy site exhibited the poorest growth with lowest infestation rates, indicative of low-quality hosts with little if any tolerance to damage. A clayey site produced vigorous plant growth with moderate infestation rates. The less apparent hosts appeared capable of withstanding pine tip moth attack and overcoming damage. Pines on a loamy site grew at moderate rates and received the highest infestation rates. This moderate growth indicated susceptible stand conditions.

REVERSIBLE EXTRACTION OF IONIC SPECIES USING ELECTROCHEMICALLY ASSISTED ION EXCHANGE Part 1: Cobalt(II) using alpha-Zirconium Hydrogen Phosphate.

Abstract In electrochemically assisted ion exchange (EIX), a water splitting reaction is used to promote the ion-exchange properties of materials which are incorporated into electrodes. Thus cobalt(II) may be extracted using alpha-zirconium hydrogen phosphate (ZrP) in a matrix of an unreactive polymer in which a platinised titanium electrode is embedded. Although ZrP is an inefficient ion-exchanger under normal (non-assisted ) conditions, EIX promotes the cation exchange behaviour by generation of hydroxyl ions (0H-) at the cathode. There was no observable precipitation of cobalt(II) hydroxide and no plating-out of the cobalt. The process of exchange proceeds entirely by an ion exchange mechanism. There is some base hydrolysis of the ZrP in the vicinity of the cathode, particularly in the first few cycles. Elution may be achieved by reversal of the applied electrical potential in conjunction with a solution pH of less than 2.3. For comparable electrodes, the rate of exchange, using EIX, is significantly g...

Finite element solution of the transonic full-potential equation for the flow past axisymmetric configurations

AbstractA finite element method is used for the solution of the full-potential equation in conservation of mass form. The finite element analysis allows the boundary conditions to be treated in simple and exact manner, without the use of a mapping scheme. An efficient finite element computational grid is employed in order to obtain an accurate converged solution. An iterative method is used to solve the full-potential equation. The iteration is in two parts, new values for the velocity potential are found by matrix inversion while the density is not updated, then new values of the density are found from the isentropic relation. The density field is then relaxed using new values for the potential in conjunction with an artificial viscosity. Results are obtained for different types of axisymmetric configurations. Comparison is made with available experimental data and good agreement is found for the pressure coefficient distribution over a suitable blunted cone-cylinder axisymmetric body. Further comparisons with experimental data are required in order to assess the method.

Amorphization induced by chemical disorder in crystalline NiZr2: A molecular-dynamics study based on an n-body potential.

We present the first molecular-dynamics study of the amorphization of a crystalline alloy (${\mathrm{NiZr}}_{2}$) induced by chemical disorder. We used a n-body potential in conjunction with isobaric-isothermal molecular dynamics. The behavior of the pair distribution function suggests that the instability leading to the amorphous state is a first-order phase transformation.

Relationship between culture redox potential and culture fluorescence inCorynebacterium glutamicum

Transient experiments were performed during a batch fermentation ofCorynebacterium glutamicum ATCC 14296 in which the flow of air to the reactor was cut off. The fluorescence of the culture was observed to vary linearly with the culture redox potential during the transient. This observation was made below the sensitivity limit of a dissolved oxygen probe. It appears that redox potential in conjunction with fluorescence measurements are of utility in studying extra- and intracellular reduction states, particularly in the microaerobic regime.

Spectroscopic-factor discrepancies in ( 9Be, 10B) for different ejectile excitations

Angular distributions have been measured for the ( 9Be, 10B[3 +, 0.0]) and ( 9Be, 10B[1 +, 0.72]) reactions on 63Cu, 54Fe, 26, 24Mg and 16O at 43 MeV and on 40Ca at 45 and 30 MeV. EFR-DWBA calculations which used optical potentials obtained from the measured elastic scattering of 9Be from 26Mg, 16O and 40Ca and 10B from 25Mg and 39K have generally reproduced well the shape of the cross sections. Initially, a standard prescription was used in the form-factor calculation and Cohen and Kurath spectroscopic factors were assumed for 9Be- 10B. Inconsistencies, concerning whether 10B was left in its ground or first excited state, of up to 60% were found between the extracted target spectroscopic factors. This anomaly was insensitive to changes in either optical-potential or bound-state parameters. A simple calculation of a two-step process could not account for the anomaly. Use of modified spectroscopic factors for the 9Be- 10B system essentially removed the discrepancies except for the magnesium targets, and an improved form-factor description further alleviated the anomaly. This form-factor method uses a shell-model potential in conjunction with a surface-peaked potential, the depth of which is adjusted to give the correct asymptotic form to the wave function.

Vibrational properties of pure and hydrogenated amorphous silicon

The vibrational densities of states of pure and hydrogenated amorphous silicon have been calculated from several computer models. First, the standard phonon method is applied to a supercell using the Keating potential in conjunction with a short range repulsive potential between the hydrogen atoms and their neighboring silicon atoms. The results are compared to experimental and the effect of the repulsive potential is also discussed. Second, the cluster-Bethe-lattice method is used with the Born potential. The results from both approaches are compared to each other.

Three-body potential among alpha particles

We propose a three-body potential among alpha particles based on a single ${\ensuremath{\alpha}}^{*}$ excitation and adjust its parameters so that the experimental binding energy and charge radius of $^{12}\mathrm{C}$ in the $3\ensuremath{-}\ensuremath{\alpha}$ model is obtained. With this potential we calculate the elastic and the ${0}_{1}^{+}$\ensuremath{\rightarrow}${0}_{2}^{+}$ inelastic form factor and reduced transition probabilities. The three-body potential in conjunction with an Ali-Bodmer two-body potential yields a satisfactory fit to the ${0}_{1}^{+}$\ensuremath{\rightarrow}${0}_{2}^{+}$ inelastic form factor and a very good agreement with the measured reduced transition probability.NUCLEAR STRUCTURE $3\ensuremath{-}\ensuremath{\alpha}$ model of $^{12}\mathrm{C}$, three-body potential among alpha particles, elastic and inelastic form factors of electron scattering, reduced transition probabilities.

Constitutive Equations for Damaging Materials

The paper focuses on the derivation of the constitutive law for a material containing flat, planar microcracks. The damage law is derived from the dissipation potential in conjunction with the orthogonality principle. The dissipation potential is shown to exist in the space of conjugate thermodynamic forces related to the stress intensity factors. Both brittle and ductile materials are considered within the framework of the small deformation theory and the time-independent processes.

Theory of quantum-mechanical effects on the thermodynamic properties of Lennard-Jones fluids

In this paper we consider the problem of computing the quantum-mechanical corrections to the thermodynamic properties of systems whose two-particle interaction may be described by a Lennard-Jones 6-12 potential. Using a procedure first developed by Feynman, together with physical arguments, we develop an effective two-particle 6-12 potential which includes quantum-mechanical corrections. Using this potential in conjunction with the theory of corresponding states we compute the quantum effects on: (i) the second virial coefficient, (ii) the critical-point location, (iii) the surface tension, (iv) the critical-point amplitudes and exponents, (v) the correction to scaling amplitudes and exponents, (vi) the liquid-gas and solid-liquid phase boundaries, and (vii) the Debye temperature at the melting point. In all cases there is good qualitative and frequently quantitative agreement with experimental results. The theory is limited to "high temperatures" since exchange effects are not included.

Pseudopotential study of alkali metals: Unified approach

A comprehensive unified calculation of both the lattice static and dynamical properties for the whole alkali-metal group (except Cs) in the pseudopotential framework is presented. Both Ashcroft and Heine-Abarenkov pseudopotentials combined with different forms of static dielectric functions have been used to calculate cohesive energy, equilibrium lattice parameters, second-order elastic constants, pressure derivatives of second-order elastic constants, and phonon dispersion in the symmetry directions for the four alkali metals Li, Na, K, and Rb. The mode Gr\uneisen parameters have been calculated for Na and K, for which experimental data are available. It is found that the two-parameter Heine-Abarenkov potential in conjunction with a dielectric function of a very simple form proposed recently by Taylor yields satisfactory results. The Heine-Abarenkov potential, coupled with the self-consistent dielectric function of Vashishta and Singwi, gives similar results. This agreement is justified from a comparison of the correction factor introduced by the two dielectric functions, over the screening function of Lindhard.

Dielectric screening and phonon frequencies of palladium, platinum, and vanadium

In this addendum the dielectric screening and the phonon frequencies are calculated using the isotropic noninteracting $s\ensuremath{-}d$-band model for fcc and bcc metals. The isotropic noninteracting band models for nonrelativistic Pd and Pt are constructed considering three principal symmetry directions [100], [110], and [111], while for vanadium we construct the isotropic noninteracting band model considering three principal symmetry directions [100], [110], and [111], and three off-symmetry directions [310], [311], and [221]. The contributions to the dielectric matrix $\ensuremath{\epsilon}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}+\stackrel{\ensuremath{\rightarrow}}{\mathrm{G}}, \stackrel{\ensuremath{\rightarrow}}{\mathrm{q}}+\stackrel{\ensuremath{\rightarrow}}{\mathrm{G}})$, which arise due to intraband and interband transitions are calculated using the formalism of the previous papers. The Animalu transition-metal-model potential is used for the bare-ion potential in conjunction with the dielectric matrix which takes into account the local-field corrections. The results for all the three metals are found to be in reasonably good agreement with the experimental values.

Properties of high-gradient magnetogravimetric systems--I. Single rods and gratings with oval and circular cross sections

The properties of two-dimensional rod systems are examined, use being made of the complex potential in conjunction with the conformal-transformation technique. The concept of prescribed trajectories whereby stronger, effective, levitational forces can be obtained is introduced. It is shown that the high-gradient magnetogravimetric-separation system is amenable to scale-up since sufficient levitational force, in terms of the equivalent specific gravity, is generated. Examples of gratings with circular and different oval cross sections, which are subject to the magnetizing field in two alternative directions, are discussed.

Properties of Gases and Gaseous Mixtures with a Morse Potential

Second virial coefficients, viscosity, thermal conductivity and diffusion coefficients of binary gas mixtures have been computed for the MORSE potential in conjunction with a set of combination rules for the unlike interactions. These calculated values are compared with the experimenta l values with a view to derive inferences regarding the adequacy of the recently proposed MORSE potential. On the basis of this detailed comparison of theory and experiment some specific and useful conclusions have been drawn which enable one to understand the relative footing of this potential in reference to the other two realistic potentials, viz. L-J (12-6) and exp-six.