Three-body analytical potential for interacting helium atoms

Large basis set ab initio calculations have been carried out for a dense grid of points on the He, potential energy surface. Three-body contributions were extracted at every point, and a number of concise functional representations for the three-body potential surface were then examined. Three-body multipolar dispersion terms and other radial and angular terms were used in the representations, and an assessment of relative importance of the different terms is presented. Combined with a two-body He-He potential, the results of this work should offer a high quality interaction potential for simulations of aggregated helium

Too Little Or Too Much Competition? Integrating Legal And Relationship Marketing Strategies To Manage Market Entry Adversity

In the deregulated, yet highly regulated environment of the telecommunications industry, a rural telephone cooperative transformed itself into a successful integrated telecommunications company. Managing local political and legal environments along with using relationship marketing tactics implemented cross-functionally, this Midwestern company challenged incumbent monopolies for market share. While the company spent more than one year acquiring legal permission to access the market and another year building its fiber optic telecommunications network, it also constructed relationships with community leaders, politicians, media outlets, and thousands of residents. Its monopoly competitors utilized state laws and the legal process in an attempt to prevent the Midwestern companys entry into the market. Interestingly, the competitors ignored the necessity of relationship marketing and by the time the Midwestern companys first client was connected, it had a waiting list of eager new consumers. This case chronicles the actions taken to achieve the Midwestern companys major accomplishments and expansion and is appropriate for use in a graduate Business and Society, or Business, Government and Society course

Pairwise and many-body contributions to interaction potentials in He(n) clusters

High level ab initio calculations have been carried out to assess the pairwise additivity of potentials in the attractive or well regions of the potential surfaces of clusters of helium atoms. A large basis set was employed and calculations were done at the Brueckner orbital coupled cluster level. Differences between calculated potentials for several interacting atoms and the corresponding summed pair potentials reveal the three‐body and certain higher order contributions to the interaction strengths. Attraction between rare gas atoms develops from dispersion, and so helium clusters provide the most workable systems for analyzing nonadditivity of dispersion. The results indicate that the many‐body or nonpairwise contributions tend to be less than a few percent of the attractive interaction across regions around the minima of the potential energy surfaces of small clusters. Dipole–dipole–dipole dispersion and dipole–dipole–quadrupole dispersion are noticeable parts of the small three‐body terms

Student Perceptions Of Appropriate Classroom Policies Of College Professors

Student perceptions of classroom management practices and policies employed by college educators have not been widely studied.  Faculty have broad discretion to determine classroom management practices and policies, and faculty are generally evaluated at least annually with student evaluations of teaching as a significant component of  the evaluative process.  The focus of this paper is whether students perceive faculty as having the freedom or discretion to adopt specified behaviors or policies unrelated to course content decisions.&nbsp

Desalination with porous electrodes : Mechanisms of ion transport and adsorption

Capacitive deionization (CDI) is an electrochemical technology to adsorb ions from solution by alternately charging and discharging two porous electrodes. During charging, a voltage is applied between the electrodes, and ions are adsorbed into electrical double layers (EDLs) formed in the micropores of the electrode. As a result, feed water is desalinated. After the electrodes are saturated with salt, they are discharged and ions are released, resulting in a concentrated effluent stream. Recently there has been an growing scientific and commercial interest in CDI technology, and various applications are considered, such as wastewater remediation for cooling towers, water softening, and desalination of brackish water. In this Thesis we study mechanisms of ion transport and adsorption in CDI technology, and we address three topics: I) energy consumption and resistance identification, II) ion-selective adsorption, and III) long-term operation and pH changes.</p

Water content of ion-exchange membranes: Measurement technique and influence on the ion mobility

Ion-exchange membranes (IEMs) are essential components of several electrochemical water technologies where they promote the transport of certain ionic species over others. A characteristic property of IEMs concerns their ionic charge density (ICD) which is a key parameter for modeling ion transport. In literature, significant variations in ICD for similar membranes are reported. We analyzed the sources of variations of this property and traced those back to the water content measurement. In this manuscript, we developed a new technique for measuring the water content, i.e., via stacking layers of membranes. This technique reduces the impact of the surface water film on the water content measurement. Using this technique, we measured the water content of CEMs at different counter-ion forms and analyzed the contribution of the ionic hydration shells inside the membrane. The relative change in the measured water content for the studied membranes at different counter-ions (K+, Mg2+, or Ca2+) was below 23 % of the Na+ value. Furthermore, we examined the relation between the water volume fraction and the membrane tortuosity, where we compared the theoretical predictions of ion mobility based on the Mackie and Meares theory to the values calculated based on the membrane resistance measurements

Inverted and Programmable Poynting Effects in Metamaterials

The Poynting effect generically manifests itself as the extension of the material in the direction perpendicular to an applied shear deformation (torsion) and is a material parameter hard to design. Unlike isotropic solids, in designed structures, peculiar couplings between shear and normal deformations can be achieved and exploited for practical applications. Here, we engineer a metamaterial that can be programmed to contract or extend under torsion and undergo nonlinear twist under compression. First, we show that our system exhibits a novel type of inverted Poynting effect, where axial compression induces a nonlinear torsion. Then the Poynting modulus of the structure is programmed from initial negative values to zero and positive values via a pre-compression applied prior to torsion. Our work opens avenues for programming nonlinear elastic moduli of materials and tuning the couplings between shear and normal responses by rational design. Obtaining inverted and programmable Poynting effects in metamaterials inspires diverse applications from designing machine materials, soft robots and actuators to engineering biological tissues, implants and prosthetic devices functioning under compression and torsion.Comment: 9 pages, 6 figure

Thermal sensitivity as a measure of spontaneous morphine withdrawal in mice

Opioid withdrawal syndrome is a critical component of opioid abuse and consists of a wide array of symptoms including increases in pain sensitivity (hyperalgesia). A reliable preclinical model of hyperalgesia during opioid withdrawal is needed to evaluate possible interventions to alleviate withdrawal. The following study describes a method for assessing increases in thermal sensitivity on the hotplate in a mouse model of spontaneous morphine withdrawal

Simulation of truncated normal variables

We provide in this paper simulation algorithms for one-sided and two-sided truncated normal distributions. These algorithms are then used to simulate multivariate normal variables with restricted parameter space for any covariance structure.Comment: This 1992 paper appeared in 1995 in Statistics and Computing and the gist of it is contained in Monte Carlo Statistical Methods (2004), but I receive weekly requests for reprints so here it is