Rearward-facing steps in laminar supersonic flows with and without suction

An experimental investigation of heat-transfer and pressure distributions within regions of laminar separated flows produced by two-dimensional rearward-facing steps has been carried out at freestream Mach numbers of around 4 in the range of step height-to-boundary layer thickness varying from 0.1 to 2.4. With no suction from the separated area, the ratio of the maximum post-step heat transfer to the attached-flow values was less than unity. The maximum heating-rate region was located far downstream of the reattachment plate stagnation point. Mass suction from the separated area increased the local heating rates, this effect was however relatively weak for purely laminar flow conditions and the competing effect of the step height clearly predominated. At step heights comparable with boundary-layer thickness, even removing the entire approaching boundary layer was not sufficient to raise the post-step heating rates above the flat-plate values

Effects of velocity profile and inclination on dual-jet-induced pressures on a flat plate in a crosswind

An experimental study was conducted to determine surface pressure distributions on a flat plate with dual subsonic, circular jets exhausting from the surface into a crossflow. The jets were arranged in both side-by-side and tandem configurations and were injected at 90 deg and 60 deg angles to the plate, with jet-to-crossflow velocity ratio of 2.2 and 4. The major objective of the study was to determine the effect of a nonuniform (vs uniform) jet velocity profile, simulating the exhaust of a turbo-fan engine. Nonuniform jets with a high-velocity outer annulus and a low-velocity core induced stronger negative pressure fields than uniform jets with the same mass flow rate. However, nondimensional lift losses (lift loss/jet thrust lift) due to such nonuniform jets were lower than lift losses due to uniform jets. Changing the injection angle from 90 deg to 60 deg resulted in moderate (for tandem jets) to significant (for side-by-side jets) increases in the induced negative pressures, even though the surface area influenced by the jets tended to reduce as the angle decreased. Jets arranged in the side-by-side configuration led to significant jet-induced lift losses exceeding, in some cases, lift losses reported for single jets

Inviscid Large deviation principle and the 2D Navier Stokes equations with a free boundary condition

Using a weak convergence approach, we prove a LPD for the solution of 2D stochastic Navier Stokes equations when the viscosity converges to 0 and the noise intensity is multiplied by the square root of the viscosity. Unlike previous results on LDP for hydrodynamical models, the weak convergence is proven by tightness properties of the distribution of the solution in appropriate functional spaces

Design definition study of a NASA/Navy lift/cruise fan technology V/STOL airplane: Risk assessment addendum to the final report

An assessment of risk, in terms of delivery delays, cost overrun, and performance achievement, associated with the V/STOL technology airplane is presented. The risk is discussed in terms of weight, structure, aerodynamics, propulsion, mechanical drive, and flight controls. The analysis ensures that risks associated with the design and development of the airplane will be eliminated in the course of the program and a useful technology airplane that meets the predicted cost, schedule, and performance can be produced

Asymptotics of the solutions of the stochastic lattice wave equation

We consider the long time limit theorems for the solutions of a discrete wave equation with a weak stochastic forcing. The multiplicative noise conserves the energy and the momentum. We obtain a time-inhomogeneous Ornstein-Uhlenbeck equation for the limit wave function that holds both for square integrable and statistically homogeneous initial data. The limit is understood in the point-wise sense in the former case, and in the weak sense in the latter. On the other hand, the weak limit for square integrable initial data is deterministic

Effect of resonant magnetic perturbations on low collisionality discharges in MAST and a comparison with ASDEX Upgrade

Sustained ELM mitigation has been achieved on MAST and AUG using RMPs with a range of toroidal mode numbers over a wide region of low to medium collisionality discharges. The ELM energy loss and peak heat loads at the divertor targets have been reduced. The ELM mitigation phase is typically associated with a drop in plasma density and overall stored energy. In one particular scenario on MAST, by carefully adjusting the fuelling it has been possible to counteract the drop in density and to produce plasmas with mitigated ELMs, reduced peak divertor heat flux and with minimal degradation in pedestal height and confined energy. While the applied resonant magnetic perturbation field can be a good indicator for the onset of ELM mitigation on MAST and AUG there are some cases where this is not the case and which clearly emphasise the need to take into account the plasma response to the applied perturbations. The plasma response calculations show that the increase in ELM frequency is correlated with the size of the edge peeling-tearing like response of the plasma and the distortions of the plasma boundary in the X-point region.Comment: 31 pages, 28 figures. This is an author-created, un-copyedited version of an article submitted for publication in Nuclear Fusion. IoP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i

TNF-Like Weak Inducer of Apoptosis (TWEAK) Promotes Beta Cell Neogenesis from Pancreatic Ductal Epithelium in Adult Mice

Aim/Hypothesis The adult mammalian pancreas has limited ability to regenerate in order to restore adequate insulin production from multipotent progenitors, the identity and function of which remain poorly understood. Here we test whether the TNF family member TWEAK (TNF-like weak inducer of apoptosis) promotes β-cell neogenesis from proliferating pancreatic ductal epithelium in adult mice. Methods: C57Bl/6J mice were treated with Fc-TWEAK and pancreas harvested at different time points for analysis by histology and immunohistochemistry. For lineage tracing, 4 week old double transgenic mice CAII-CreERTM: R26R-eYFP were implanted with tamoxifen pellet, injected with Fc-TWEAK or control Ig twice weekly and analyzed at day 18 for TWEAK-induced duct cell progeny by costaining for insulin and YFP. The effect of TWEAK on pancreatic regeneration was determined by pancytokeratin immunostaining of paraffin embedded sections from wildtype and TWEAK receptor (Fn14) deficient mice after Px. Results: TWEAK stimulates proliferation of ductal epithelial cells through its receptor Fn14, while it has no mitogenic effect on pancreatic α- or β-cells or acinar cells. Importantly, TWEAK induces transient expression of endogenous Ngn3, a master regulator of endocrine cell development, and induces focal ductal structures with characteristics of regeneration foci. In addition, we identify by lineage tracing TWEAK-induced pancreatic β-cells derived from pancreatic duct epithelial cells. Conversely, we show that Fn14 deficiency delays formation of regenerating foci after Px and limits their expansion. Conclusions/Interpretation We conclude that TWEAK is a novel factor mediating pancreatic β-cell neogenesis from ductal epithelium in normal adult mice

PERANAN SISTEM FULL DAY SCHOOL DALAM MENUMBUHKAN SEMANGAT BELAJAR PESERTA DIDIK PADA PEMBELAJARAN PPKn (Studi Deskriptif di SMA Negeri 1 Gantar Kec. Gantar Kab. Indramayu)

Sebelum diterapkannya sistem full day school di dunia pendidikan yang peserta didiknya diharuskan untuk berada di sekolah selama 9 jam masih banyak siswa yang mengeluh atau malas untuk belajar, apalagi dengan diterapkannya sistem full day school yang siswanya diharuskan belajar di sekolah selama 11 jam dengan rentang waktu dari pukul 07.00-16.00 WIB. Untuk mengatasi adanya gesekan yang mungkin akan menimbulkan perpecahan, maka setiap sekolah menerapkan beberapa sanksi untuk memperbaiki sikap dan moral para peserta didikya, salah satu cara yang dilakukan adalah dengan adanya penerapan sanksi-sanksi bagi siapapun yang melanggar peraturan sekolah. Adapun tujuan dalam penelitian ini yaitu: 1) Mengetahui keadaan di sekolah dalam menumbuhkan semangat belajar peserta didik pada pembelajaran PPKn di SMA Negeri 1 Gantar. 2) Mengetahui pelaksanaan sistem full day school dalam menumbuhkan semangat belajar peserta didik pada pembelajaran PPKn di SMA Negeri 1 Gantar. 3) Mengetahui peranan sistem full day school dalam menumbuhkan semangat belajar peserta didik pada pembelajaran PPKn di SMA Negeri 1 Gantar. 4) Mengetahui hambatan yang muncul dan upaya yang dilakukan dalam menumbuhkan semangat belajar peserta didik pada pembelajaran PPKn di SMA Negeri 1 Gantar. Penelitian ini menggunakan studi deskriptif dengan pendakatan kualitatif, dalam penelitian ini yang menjadi subjek adalah Guru mata pelajaran PPKn dan peserta didik kelas XI MIPA 1 dan XII IPS SMA Negeri 1 Gantar. Pengumpulan data dan Instrumen penelitian dalam metode kualitatif yaitu observasi, wawancara, angket, studi dokumentasi. Hasil dari penelitian ini sebagai berikut: Melalui wawancara, peranan sistem full day school dalam menumbuhkan semangat belajar peserta sangat berperan dan membantu peserta didik dalam belajar. Dan untuk meningkatkan prestasi peserta didik dengan cara model pembelajaran yang menarik serta sarana dan prasarana yang memadai. Hasil angket yang penulis deskripsikan, keadaan di sekolah dalam menumbuhkan semangat belajar peserta didik di SMA Negeri 1 Gantar dapat di lihat di atas dalam diagram 4.2 menyatakan 56,60% peserta didik menyetujui bahwa peserta didik menyukai suasana belajar yang menyenangkan, adapun 44% lainnya menjawab setuju. Dan untuk meningkatkan semangat belajar peserta didik dapat meningkatkan prestasi belajar dapat di lihat di dalam diagram 4.5 menyatakan 0% ragu bahwa prestasi belajar tidak di pengaruhi oleh semangat belajar peserta didik adapun 20,75% sangat setuju, 24,53% setuju, dan 37,74% tidak setuju. Kata Kunci: Sistem Full Day School, Semangat Belajar Peserta Didi

Exact soliton solutions, shape changing collisions and partially coherent solitons in coupled nonlinear Schroedinger equations

We present the exact bright one-soliton and two-soliton solutions of the integrable three coupled nonlinear Schroedinger equations (3-CNLS) by using the Hirota method, and then obtain them for the general $N$-coupled nonlinear Schroedinger equations (N-CNLS). It is pointed out that the underlying solitons undergo inelastic (shape changing) collisions due to intensity redistribution among the modes. We also analyse the various possibilities and conditions for such collisions to occur. Further, we report the significant fact that the various partial coherent solitons (PCS) discussed in the literature are special cases of the higher order bright soliton solutions of the N-CNLS equations.Comment: 4 pages, RevTex, 1 EPS figure To appear in Physical Review Letter