University of North Carolina at Charlotte

About: University of North Carolina at Charlotte is a education organization based out in Charlotte, North Carolina, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 8772 authors who have published 22239 publications receiving 562529 citations. The organization is also known as: UNC Charlotte & UNCC.

Effect of low-temperature rolling on the tensile behavior of commercially pure tungsten

Abstract: We have evaluated the tensile behavior of commercially pure tungsten (W) as a function of low-temperature rolling. It is observed that rolling below the nominal recrystallization temperature 1523 K (1250 °C) concomitantly enhances the ductility and strength of W. Strain-rate jump tests and stress-relaxation experiments show that low-temperature rolling also renders reduced strain-rate sensitivity and activation volumes associated with the plastic deformation of W. For W samples rolled at 873 K (600 °C), with a total equivalent strain of ∼2.5 (including a previous rolling strain of 1.7 introduced at 1073 K [800 °C]), the activation volume for plastic deformation is around 10b3 (b is the magnitude of the Burgers vector of W). This is in agreement with a double-kink mechanism with the spreading between the kinks controlled by the forest dislocation density. Fractographic observations indicate that the rolled W exhibits a laminar structure. The layer thickness is a function of rolling temperature, rather than a function of rolling strain introduced.

A Survey of Stackelberg Differential Game Models in Supply and Marketing Channels

Abstract: Stackelberg differential game models have been used to study sequential decision making in non-cooperative games in diverse fields. In this paper, we survey recent applications of Stackelberg differential game models to the supply chain management and marketing channels literatures. A common feature of these applications is the specification of the game structure: a decentralized channel composed of a manufacturer and independent retailers, and a sequential decision procedure with demand and supply dynamics and coordination issues. In supply chain management, Stackelberg differential games have been used to investigate inventory issues, wholesale and retail pricing strategies, and outsourcing in dynamic environments. The underlying demand typically has growth dynamics or seasonal variation. In marketing, Stackelberg differential games have been used to model cooperative advertising programs, store brand and national brand advertising strategies, shelf space allocation, and pricing and advertising decisions. The demand dynamics are usually extensions of the classical advertising capital models or sales-advertising response models. We begin by explaining the Stackelberg differential game solution methodology and then provide a description of the models and results reported in the literature.

Astrojumper: Motivating exercise with an immersive virtual reality exergame

Abstract: We present the design and evaluation of Astrojumper, an immersive virtual reality exergame developed to motivate players to engage in rigorous, full-body exercise. We performed a user study with 30 people between the ages of 6 and 50 who played the game for 15 min. Regardless of differences in age, gender, activity level, and video game experience, participants rated Astrojumper extremely positively and experienced a significant increase in heart rate after gameplay. Additionally, we found that participants' ratings of perceived workout intensity positively correlated with their level of motivation. Overall, our results demonstrate that Astrojumper effectively motivates both children and adults to exercise through immersive virtual reality technology and a simple, yet engaging, game design.

Small and Medium-Sized Bridgehead Bicyclic Lactams: A Systematic ab Initio Molecular Orbital Study

Abstract: Optimized ab initio molecular orbital calculations on nine bridgehead bicyclic lactams ranging from the 2.2.2 to the 4.3.3 series indicate variations in structural properties, resonance energies, proton affinities, and core orbital ionization energies that reflect the trans-cycloalkene analogy. The smaller lactams are calculated to be N-protonated, the larger O-protonated, and the “crossover” is predicted to occur around the 3.3.1 system. On the basis of resonance energies, larger bridgehead bicyclic lactams could be considered to be hyperstable as Schleyer and co-workers define the concept for larger bridgehead alkenes. This, hyperstability should be apparent in the kinetics of the nucleophilic substitution reactions of the lactams, such as hydrolysis, but not in the thermochemistry of these reactions.