An experimental investigation was performed of the acoustic effects of jet-pylon interaction for separate flow and chevron nozzles of both bypass ratio five and eight. The models corresponded to an approximate scale factor of nine. Cycle conditions from approach to takeoff were tested at wind tunnel free jet Mach numbers of 0.1, 0.2 and 0.28. An eight-chevron core nozzle, a sixteen chevron fan ...

In this paper, the authors summarize the results of a parametric study devoted to evaluate the seismic behavior of low to medium rise regular special moment-resisting steel frames with hysteretic energy dissipation devices mounted on chevron steel bracing. For that purpose, 270 different building models were designed considering typical story heights and bay widths used in Mexican practice. The...

The muscle segments of fish have a folded shape, termed a chevron, which is thought to be optimal for the undulating body movements of swimming. However, the mechanism shaping the chevron during embryogenesis is not understood. Here, we used time-lapse microscopy of developing zebrafish embryos spanning the entire somitogenesis period to quantify the dynamics of chevron shape development. By co...

The bacterial colicin-immunity proteins Im7 and Im9 fold by different mechanisms. Experimentally, at pH 7.0 and 10°C, Im7 folds in a three-state manner via an intermediate but Im9 folding is two-state-like. Accordingly, Im7 exhibits a chevron rollover, whereas the chevron arm for Im9 folding is linear. Here we address the biophysical basis of their different behaviors by using native-centric mo...

Building structures are subject to displacement under the influence of forces resulting from earthquake. The most common method of controlling such displacements in steel structures, which are usually of lateral type, is the use of braces. Depending on designing requirements and feasibility, braces are available in various forms. Configuration of bracing systems is generally of concentric or ec...

In 1901 the Gulf Refining Company was chartered to provide refining and sales support to the Spindletop oil field in southeast Texas (Gulf Oil History, 2003). A refinery was built immediately after on a 4,000 acre site. The facility was acquired in 1985 by Chevron as a part of a merger with Gulf (‘Congratulations Premcor 100 Years,’ 2001). In February 1995, Chevron sold the Port Arthur plant wi...

The Chevron doctrine’s apparent simplicity has long captivated judges, lawyers, and scholars. According to the standard formulation, Chevron involves just two straightforward steps: (1) Is a statute clear? (2) If not, is the agency’s interpretation of the statute reasonable? Despite the influence of this two-step framework, Chevron has come under fire in recent years. Some critics bemoan what t...