Lehigh University

About: Lehigh University is a education organization based out in Bethlehem, Pennsylvania, United States. It is known for research contribution in the topics: Catalysis & Fracture mechanics. The organization has 12684 authors who have published 26550 publications receiving 770061 citations.

Corporate Divestiture Intensity in Restructuring Firms: Effects of Governance, Strategy, and Performance

Abstract: Both inadequate governance and inappropriate strategy have been proposed as antecedents of the divestment activity of restructuring firms in the 1980s. We combined both views in a structural equati...

Branching and bounds tighteningtechniques for non-convex MINLP

Abstract: Many industrial problems can be naturally formulated using mixed integer non-linear programming (MINLP) models and can be solved by spatial Branch&Bound (sBB) techniques. We study the impact of two important parts of sBB methods: bounds tightening (BT) and branching strategies. We extend a branching technique originally developed for MILP, reliability branching, to the MINLP case. Motivated by the demand for open-source solvers for real-world MINLP problems, we have developed an sBB software package named couenne (Convex Over-and Under-ENvelopes for Non-linear Estimation) and used it for extensive tests on several combinations of BT and branching techniques on a set of publicly available and real-world MINLP instances. We also compare the performance of couenne with a state-of-the-art MINLP solver.

ADHD in the Schools: Assessment and Intervention Strategies

Abstract: Overview of ADHD. Assessment of ADHD in School Settings. ADHD and Learning Difficulties: What Is the Connection? Early Screening, Identification, and Intervention. School-Based Intervention Strategies. Medication Therapy. Adjunctive Interventions for ADHD. Communication with Parents, Professionals, and Students. Conclusions and Future Directions.

The characteristics of low-speed streaks in the near-wall region of a turbulent boundary layer

Abstract: Employing a high-speed video system and hydrogen bubble-wire flow visualization, the characteristics of the low-speed streaks which occur in the near-wall region of turbulent boundary layers have been examined for a Reynolds-number range of 740 [les ] Reθ < 5830. The results indicate that the statistics of non-dimensional spanwise streak spacing are essentially invariant with Reynolds number, exhibiting consistent values of and remarkably similar probability distributions conforming to lognormal behaviour. Further studies show that streak spacing increases with distance from the wall owing to a merging and intermittency process which occurs for y+ [simg ] 5. An additional observation is that, although low-speed streaks are not fixed in time and space, they demonstrate a tremendous persistence, often maintaining their integrity and reinforcing themselves for time periods up to an order of magnitude longer than the observed bursting times associated with wall region turbulence production. A mechanism for the formation of low-speed streaks is suggested which may explain both the observed merging behaviour and the streak persistence.