Manual of industrial diamonds plus dressing and grinding criteria for machining superalloys

Manual combines the important and controlling factors for the proper selection and use of diamond stones for cutting and dressing grinding wheels. This manual is a compilation of empirical data and incorporates an original companion treatise on the physical descriptions of the diamond stones, their grading, and their applications

Standardization of computational experiments in unsteady turbulent boundary-layer flow

Numerical experiments are proposed as standard cases to be computed by all who plan to analyze unsteady turbulent boundary layer behavior. In this way, differences between the results obtained by various methods can be compared in a completely defined environment. The test cases range in difficulty from time relaxation study of the steady flow on a flat plate to the analysis of unsteady reversed flow. Initial and boundary conditions are fully defined for each case and representative outputs are presented. It is recommended that tabulated samples of computations of these test cases be published in a compendium of results

A review of unsteady turbulent boundary-layer experiments

The essential results of a comprehensive review of existing unsteady turbulent boundary-layer experiments are presented. Different types of unsteady flow facilities are described, and the related unsteady turbulent boundary-layer experiments are cataloged and discussed. The measurements that were obtained in the various experiments are described, and a complete list of experimental results is presented. All the experiments that measured instantaneous values of velocity, turbulence intensity, or turbulent shear stress are identified, and the availability of digital data is indicated. The results of the experiments are analyzed, and several significant trends are identified. An assessment of the available data is presented, delineating gaps in the existing data, and indicating where new or extended information is needed. Guidelines for future experiments are included

Coxeter Complexes and Graph-Associahedra

Given a graph G, we construct a simple, convex polytope whose face poset is based on the connected subgraphs of G. This provides a natural generalization of the Stasheff associahedron and the Bott-Taubes cyclohedron. Moreover, we show that for any simplicial Coxeter system, the minimal blow-ups of its associated Coxeter complex has a tiling by graph-associahedra. The geometric and combinatorial properties of the complex as well as of the polyhedra are given. These spaces are natural generalizations of the Deligne-Knudsen-Mumford compactification of the real moduli space of curves.Comment: 18 pages, 9 figures; revised content and reference

Keep the Kids Inside? Juvenile Curfews and Urban Gun Violence

Gun violence is a chronic problem in the United States. Nationally in 2012, 11,622 people were killed by assault with a firearm. Many more people are injured by guns each year: in 2011, 693,000 individuals were treated in emergency rooms for injuries due to assaults by firearms and similar mechanisms. Gun violence takes a particularly large toll on young people: according to the Centers for Disease Control and Prevention (CDC), homicide accounted for 18 percent of deaths for males aged 15-19 and 20-24 — more than for any other age group. For black males, homicide is the leading cause of death for those age groups, explaining 48 percent and 50 percent of deaths, respectively. The vast majority of these are gun-related homicides