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 ...

A proper composition of stiffness and ductility parameters is required to obtain a resistant and economic structure. Accordingly, Chevron Knee Braced Frame (CKBF) seems appropriate due to its proper seismic performance. The advantage of this system comes to having the capability of rapid and cheap replacement of chevron knee elements after an earthquake occurs. In this research, response modifi...

Braces were introduced by Rump to study non-degenerate involutive set-theoretic solutions of the Yang–Baxter equation. To study non-involutive solutions one needs skew braces, a non-commutative analog of braces. In this talk we discuss basic properties of skew braces and how these structures are related to the Yang-Baxter equation. We also discuss interesting connections between skew braces and...

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...

This study is devoted to seismic collapse safety analysis of performance based optimally seismic designed steel chevron braced frame structures. An efficient meta-heuristic algorithm namely, center of mass optimization is utilized to achieve the seismic optimization process. The seismic collapse performance of the optimally designed steel chevron braced frames is assessed by performing incremen...

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...

This paper examines the extremely low cycle fatigue (ELCF) fracture of concentrically loaded square hollow section (SHS) braces subjected to cyclic loading. Numerical analyses are presented for both individual bracing members and integrated into braced frames (CBFs). The behaviour was predicted using solid finite element (FE) simulations that employed a ductile model nonlinear damage evolution ...

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...

Controversy exists with regard to the effects of chevron osteotomy on blood supply and subsequent development of avascular necrosis (AVN) of the first metatarsal head. The aim of this study was to assess the incidence of avascular necrosis in our centre following chevron osteotomy for hallux valgus, using bone scintigraphy. Thirty nine patients who had a chevron osteotomy for treatment of hallu...