On the propagation and reflection of curved shock waves

Curved shock waves, particularly converging shock waves, have applications in a wide variety of elds, yet they are severely under-represented in the literature. Shock re ection is typically categorised in terms of the shock Mach number and incident angle, but these parameters both vary with time for a curved shock wave. A facility capable of producing shock waves with an arbitrary two-dimensional pro le was designed and manufactured. A planar shock from the end of a conventional shock tube is passed through a narrow slit and turned through a 90 bend, generating a shock with an initial shape matching the pro le of the slit. The facility was rst used to study the propagation of shock waves of arbitrary shape. This included a brief computational uid dynamics (CFD) study of the interaction between straight and concave segments on a shock front, followed by CFD and experimental studies into the propagation of shock waves consisting of both concave and convex segments, with initially sharp and rounded pro les. Shocks with Mach numbers between 1.2 and 1.45 were generated, and the behaviour of the shock waves produced by the experimental facility agreed favourably with the CFD simulations, particularly for the higher Mach numbers. A detailed study into the re ection of converging cylindrical shock wave segments was then carried out. CFD simulations for Mach numbers at the apex of the wedge varying from 1.2 to 2.1, for wedge angles between 15 and 60 , and experiments with apex Mach numbers between 1.5 and 2.1 and wedge angles between 15 and 50 were carried out. The sonic condition usually used for predicting the planar shock re ection con guration was successful at predicting the initial re ection con guration. If the initial re ection was regular, then the shock was cleanly re ected o the surface, with no discontinuities in the re ected shock front. However, if the initial re ection was a Mach re ection, this would inevitably transition into a transitioned regular re ection, with the residual Mach stem and shear layer still present behind the re ection point. Collision of the Mach stem with the corner at the end of the wedge generated a small region of very high pressure, which lasted for several microseconds. A simple theoretical model was developed for estimating the Mach stem height and transition point for a converging cylindrical shock segment encountering a straight wedge. The model gives reasonable predictions for shocks of moderate strength and wedge angles below 40 , but deviates from experimental results for wedges at 40 and above

On the propagation and reflection of curved shock waves

Curved shock waves, particularly converging shock waves, have applications in a wide variety of elds, yet they are severely under-represented in the literature. Shock re ection is typically categorised in terms of the shock Mach number and incident angle, but these parameters both vary with time for a curved shock wave. A facility capable of producing shock waves with an arbitrary two-dimensional pro le was designed and manufactured. A planar shock from the end of a conventional shock tube is passed through a narrow slit and turned through a 90 bend, generating a shock with an initial shape matching the pro le of the slit. The facility was rst used to study the propagation of shock waves of arbitrary shape. This included a brief computational uid dynamics (CFD) study of the interaction between straight and concave segments on a shock front, followed by CFD and experimental studies into the propagation of shock waves consisting of both concave and convex segments, with initially sharp and rounded pro les. Shocks with Mach numbers between 1.2 and 1.45 were generated, and the behaviour of the shock waves produced by the experimental facility agreed favourably with the CFD simulations, particularly for the higher Mach numbers. A detailed study into the re ection of converging cylindrical shock wave segments was then carried out. CFD simulations for Mach numbers at the apex of the wedge varying from 1.2 to 2.1, for wedge angles between 15 and 60 , and experiments with apex Mach numbers between 1.5 and 2.1 and wedge angles between 15 and 50 were carried out. The sonic condition usually used for predicting the planar shock re ection con guration was successful at predicting the initial re ection con guration. If the initial re ection was regular, then the shock was cleanly re ected o the surface, with no discontinuities in the re ected shock front. However, if the initial re ection was a Mach re ection, this would inevitably transition into a transitioned regular re ection, with the residual Mach stem and shear layer still present behind the re ection point. Collision of the Mach stem with the corner at the end of the wedge generated a small region of very high pressure, which lasted for several microseconds. A simple theoretical model was developed for estimating the Mach stem height and transition point for a converging cylindrical shock segment encountering a straight wedge. The model gives reasonable predictions for shocks of moderate strength and wedge angles below 40 , but deviates from experimental results for wedges at 40 and above

Electric dipole moments and the search for new physics

Static electric dipole moments of nondegenerate systems probe mass scales for physics beyond the Standard Model well beyond those reached directly at high energy colliders. Discrimination between different physics models, however, requires complementary searches in atomic-molecular-and-optical, nuclear and particle physics. In this report, we discuss the current status and prospects in the near future for a compelling suite of such experiments, along with developments needed in the encompassing theoretical framework.Comment: Contribution to Snowmass 2021; updated with community edits and endorsement

Return of Genomic Results to Research Participants: The Floor, the Ceiling, and the Choices In Between

As more research studies incorporate next-generation sequencing (including whole-genome or whole-exome sequencing), investigators and institutional review boards face difficult questions regarding which genomic results to return to research participants and how. An American College of Medical Genetics and Genomics 2013 policy paper suggesting that pathogenic mutations in 56 specified genes should be returned in the clinical setting has raised the question of whether comparable recommendations should be considered in research settings. The Clinical Sequencing Exploratory Research (CSER) Consortium and the Electronic Medical Records and Genomics (eMERGE) Network are multisite research programs that aim to develop practical strategies for addressing questions concerning the return of results in genomic research. CSER and eMERGE committees have identified areas of consensus regarding the return of genomic results to research participants. In most circumstances, if results meet an actionability threshold for return and the research participant has consented to return, genomic results, along with referral for appropriate clinical follow-up, should be offered to participants. However, participants have a right to decline the receipt of genomic results, even when doing so might be viewed as a threat to the participants’ health. Research investigators should be prepared to return research results and incidental findings discovered in the course of their research and meeting an actionability threshold, but they have no ethical obligation to actively search for such results. These positions are consistent with the recognition that clinical research is distinct from medical care in both its aims and its guiding moral principles

Proceedings of Patient Reported Outcome Measure’s (PROMs) Conference Oxford 2017: Advances in Patient Reported Outcomes Research

A33-Effects of Out-of-Pocket (OOP) Payments and Financial Distress on Quality of Life (QoL) of People with Parkinson’s (PwP) and their Carer

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good