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.

Toward complete statistics of massive binary stars: penultimate results from the cygnus ob2 radial velocity survey

Abstract: We analyze orbital solutions for 48 massive multiple-star systems in the Cygnus OB2 association, 23 of which are newly presented here, to find that the observed distribution of orbital periods is approximately uniform in log P for P 45 days, even after correction for completeness, indicating either a lower binary fraction or a shift toward low-mass companions. A high degree of similarity (91% likelihood) between the Cyg OB2 period distribution and that of other surveys suggests that the binary properties at P ≲ 25 days are determined by local physics of disk/clump fragmentation and are relatively insensitive to environmental and evolutionary factors. Fully 30% of the unbiased parent sample is a binary more » with period P < 45 days. Completeness corrections imply a binary fraction near 55% for P < 5000 days. The observed distribution of mass ratios 0.2 < q < 1 is consistent with uniform, while the observed distribution of eccentricities 0.1 < e < 0.6 is consistent with uniform plus an excess of e ≅ 0 systems. We identify six stars, all supergiants, that exhibit aperiodic velocity variations of ∼30 km s{sup –1} attributed to atmospheric fluctuations. « less

Instituting the marketing concept in a multinational setting: The role of national culture

Abstract: A growing concern among international marketing managers is how to increase the market orientation and thereby performance of their transnational organizations. This study broaches this issue by investigating how the marketing concept, the heart of the market orientation, may be established in a multinational setting and the effects of national culture on that process. From a wide array of literature, the authors construct a theoretical framework and propositions on how global organizations may transform this philosophy from an abstract platitude to an operational reality. Their findings suggest that the process consists of complex, interdependent steps—interpretation, adoption, and implementation of the marketing concept. Cultural values shape interpretation and facilitate or impede adoption and implementation. The overall framework and findings can be used to guide institutionalization of the marketing concept across the organizational span, in particular by anticipating culture-based reactions from international subsidiaries.

Supply chain management coordination mechanisms

Abstract: There is growing interest from industry and academic disciplines regarding coordination in supply chains, particularly addressing coordination mechanisms available to eliminate sub-optimization within supply chains. However, there is a disconnect between what is known in academic research about coordination mechanisms and what mechanisms practitioners apply and consider useful. This research fills a gap in the literature by conducting an in-depth qualitative study of supply chain coordination mechanisms, primarily price, non-price, and flow coordination mechanisms. Results suggest that: (1) managers prefer flow coordination mechanisms over price and non-price coordination mechanisms; (2) supply chain orientation and learning orientation are important for the implementation of flow coordination mechanisms; and (3) technology, capital, and volume are not pre-requisites for flow coordination mechanisms.

A combined direct numerical simulation-particle image velocimetry study of the turbulent near wake

Abstract: We investigate the near wake of a cylinder at values of Reynolds number corresponding to the onset and development of shear-layer instabilities. By combining quantitative experimental imaging (particle image velocimetry, PIV) and direct numerical simulations at Re = 3900/4000 and 10000, we show that the flow structure is notably altered. At higher Reynolds number, the lengths of both the wake bubble and the separating shear layer decrease substantially. Corresponding patterns of velocity fluctuations and Reynolds stress contract towards the base of the cylinder. The elevated values of Reynolds stress at upstream locations in the separated layer indicate earlier onset of shear-layer transition. These features are intimately associated with the details of the shear-layer instability, which leads to small-scale vortices. The simulated signatures of the shear-layer vortices are characterized by a broadband peak at Re = 3900 and a broadband high spectral-density 'plateau' at Re=10000 in the power spectra. The shear-layer frequencies from the present direct numerical simulations study agree well with previous experimentally measured values, and follow the power law suggested by other workers.