Study of aircraft in intraurban transportation systems, volume 1

An analysis of an effective short range, high density computer transportation system for intraurban systems is presented. The seven county Detroit, Michigan, metropolitan area, was chosen as the scenario for the analysis. The study consisted of an analysis and forecast of the Detroit market through 1985, a parametric analysis of appropriate short haul aircraft concepts and associated ground systems, and a preliminary overall economic analysis of a simplified total system designed to evaluate the candidate vehicles and select the most promising VTOL and STOL aircraft. Data are also included on the impact of advanced technology on the system, the sensitivity of mission performance to changes in aircraft characteristics and system operations, and identification of key problem areas that may be improved by additional research. The approach, logic, and computer models used are adaptable to other intraurban or interurban areas

Femoral Neck Shaft Angle in Men with Fragility Fractures

Introduction. Femoral neck shaft angle (NSA) has been reported to be an independent predictor of hip fracture risk in men. We aimed to assess the role of NSA in UK men. Methods. The NSA was measured manually from the DXA scan printout in men with hip (62, 31 femoral neck and 31 trochanteric), symptomatic vertebral (91), and distal forearm (67) fractures and 389 age-matched control subjects. Age, height, weight, and BMD (g/cm2: lumbar spine, femoral neck, and total femur) measurements were performed. Results. There was no significant difference in mean NSA between men with femoral neck and trochanteric hip fractures, so all further analyses of hip fractures utilised the combined data. There was no difference in NSA between those with hip fractures and those without (either using the combined data or analysing trochanteric and femoral neck shaft fractures separately), nor between fracture subjects as a whole and controls. Mean NSA was smaller in those with vertebral fractures (129.2° versus 131°: P = 0.001), but larger in those with distal forearm fractures (129.8° versus 128.5°: P = 0.01). Conclusions. The conflicting results suggest that femoral NSA is not an important determinant of hip fracture risk in UK men

The Capaciousness of No: Affective Refusals as Literacy Practices

© 2020 The Authors. Reading Research Quarterly published by Wiley Periodicals, Inc. on behalf of International Literacy Association The authors considered the capacious feeling that emerges from saying no to literacy practices, and the affective potential of saying no as a literacy practice. The authors highlight the affective possibilities of saying no to normative understandings of literacy, thinking with a series of vignettes in which children, young people, and teachers refused literacy practices in different ways. The authors use the term capacious to signal possibilities that are as yet unthought: a sense of broadening and opening out through enacting no. The authors examined how attention to affect ruptures humanist logics that inform normative approaches to literacy. Through attention to nonconscious, noncognitive, and transindividual bodily forces and capacities, affect deprivileges the human as the sole agent in an interaction, thus disrupting measurements of who counts as a literate subject and what counts as a literacy event. No is an affective moment. It can signal a pushback, an absence, or a silence. As a theoretical and methodological way of thinking/feeling with literacy, affect proposes problems rather than solutions, countering solution-focused research in which the resistance is to be overcome, co-opted, or solved. Affect operates as a crack or a chink, a tiny ripple, a barely perceivable gesture, that can persist and, in doing so, hold open the possibility for alternative futures

Nuclear Reaction Network for Primordial Nucleosynthesis: a detailed analysis of rates, uncertainties and light nuclei yields

We analyze in details the standard Primordial Nucleosynthesis scenario. In particular we discuss the key theoretical issues which are involved in a detailed prediction of light nuclide abundances, as the weak reaction rates, neutrino decoupling and nuclear rate modeling. We also perform a new analysis of available data on the main nuclear processes entering the nucleosynthesis reaction network, with particular stress on their uncertainties as well as on their role in determining the corresponding uncertainties on light nuclide theoretical estimates. The current status of theoretical versus experimental results for 2H, 3He, 4He and 7Li is then discussed using the determination of the baryon density as obtained from Cosmic Microwave Background anisotropies.Comment: LaTeX, 83 pages, 30 .pdf figures. Some typos in the units of R-functions in appendix D and relative plots fixe

Cracking behaviour of high-strength AA2024 aluminium alloy produced by Laser Powder Bed Fusion

Most wrought aluminium alloys of the 2000 series are difficult to manufacture by laser powder bed fusion (L-PBF) due to the formation of cracks during building. To date, the effects of processing regimes on crack formation are still not well understood. In this study we performed a detailed microstructural characterisation of crack development in the AlCuMg alloy AA2024 to quantify the extent of cracking and porosity arising from a range of different process parameters. Two samples, produced with different build parameters, were selected for in-depth study by scanning and transmission electron microscopy; these had similar low levels of porosity but high (H - 2.6 ± 0.4 mm/mm2) and low (L - 1.5 ± 0.3 mm/mm2) crack densities respectively. Based on distinct morphological features and characteristic length, we differentiate hot cracks from solid state cracks. Hot tears form at high angle grain boundaries and are associated with micron-sized gas pores as well as intermetallic phases in both samples. The solidification and cracking behaviour are modelled with the aid of a Scheil-Gulliver model that includes solute trapping. This approach predicts differences in hot-crack-susceptibilities, due to different solidification velocities, in line with experimental observations. The sample H, of high crack density, also experiences the higher cooling rate, and hence strain rate, which contributes to the greater propagation of cold cracks in the low fracture toughness AA2024. The observation of cracking associated with microporosity and the use of a Scheil-based solidification model, including solute trapping, provide new insights into the complex problem of hot tearing during L-PBF

Comparison between three-dimensional linear and nonlinear tsunami generation models

The modeling of tsunami generation is an essential phase in understanding tsunamis. For tsunamis generated by underwater earthquakes, it involves the modeling of the sea bottom motion as well as the resulting motion of the water above it. A comparison between various models for three-dimensional water motion, ranging from linear theory to fully nonlinear theory, is performed. It is found that for most events the linear theory is sufficient. However, in some cases, more sophisticated theories are needed. Moreover, it is shown that the passive approach in which the seafloor deformation is simply translated to the ocean surface is not always equivalent to the active approach in which the bottom motion is taken into account, even if the deformation is supposed to be instantaneous.Comment: 39 pages, 16 figures; Accepted to Theoretical and Computational Fluid Dynamics. Several references have been adde

Nonlinear Lattice Waves in Random Potentials

Localization of waves by disorder is a fundamental physical problem encompassing a diverse spectrum of theoretical, experimental and numerical studies in the context of metal-insulator transition, quantum Hall effect, light propagation in photonic crystals, and dynamics of ultra-cold atoms in optical arrays. Large intensity light can induce nonlinear response, ultracold atomic gases can be tuned into an interacting regime, which leads again to nonlinear wave equations on a mean field level. The interplay between disorder and nonlinearity, their localizing and delocalizing effects is currently an intriguing and challenging issue in the field. We will discuss recent advances in the dynamics of nonlinear lattice waves in random potentials. In the absence of nonlinear terms in the wave equations, Anderson localization is leading to a halt of wave packet spreading. Nonlinearity couples localized eigenstates and, potentially, enables spreading and destruction of Anderson localization due to nonintegrability, chaos and decoherence. The spreading process is characterized by universal subdiffusive laws due to nonlinear diffusion. We review extensive computational studies for one- and two-dimensional systems with tunable nonlinearity power. We also briefly discuss extensions to other cases where the linear wave equation features localization: Aubry-Andre localization with quasiperiodic potentials, Wannier-Stark localization with dc fields, and dynamical localization in momentum space with kicked rotors.Comment: 45 pages, 19 figure

Myospora metanephrops (n. g., n. sp.) from marine lobsters and a proposal for erection of a new order and family (Crustaceacida; Myosporidae) in the Class Marinosporidia (Phylum Microsporidia) q

a b s t r a c t In this study we describe, the first microsporidian parasite from nephropid lobsters. Metanephrops challengeri were captured from an important marine fishery situated off the south coast of New Zealand. Infected lobsters displayed an unusual external appearance and were lethargic. Histology was used to demonstrate replacement of skeletal and other muscles by merogonic and sporogonic stages of the parasite, while transmission electron microscopy revealed the presence of diplokaryotic meronts, sporonts, sporoblasts and spore stages, all in direct contact with the host sarcoplasm. Analysis of the ssrDNA gene sequence from the lobster microsporidian suggested a close affinity with Thelohania butleri, a morphologically dissimilar microsporidian from marine shrimps. Whilst morphological features of the lobster parasite are consistent with members of the family Nosematidae, molecular data place the parasite closer to members of the family Thelohanidae. Due to the contradiction between morphological and molecular taxonomic data, we propose the erection of a new genus in which the lobster parasite is the type species (Myospora metanephrops). Furthermore, we recommend the erection of a new family (Myosporidae) and a new order (Crustaceacida) to contain this genus. The taxonomic framework presented could be further applied to the re-classification of existing members of the Phylum Microsporidia. Crow