743 research outputs found

    Modeling the Effect of Out-of-Plane Fiber Orientation in Lumber Specimens

    Get PDF
    A method is presented to account for the effect of three-dimensional fiber orientations near knots in a two-dimensional lumber tensile strength prediction model. Data we have collected show that grain angles dive from 15 to 90 degrees out of the wide face plane of flat-grained lumber within a region of about one knot radius from the visual edge of a knot. The diving nature of the grain angles is accounted for in a two-dimensional model, called GASPP+, by transforming a three-dimensional material compliance matrix, and extracting the appropriate coefficients for use in a two-dimensional compliance matrix. Failure criteria are modified to reflect the decreased strength associated with nonzero dive angles. These modifications led to accurate tensile behavior predictions, as evidenced by load-displacement plots and ultimate load measurements of lumber specimens. It is shown that consideration of dive angles is important in predicting the tensile strength and failure mode of thin lumber specimens. Lumber specimen thickness and the manner of loading influence the magnitude of the dive effect on strength

    The Importance of Family to Youth Living in Violent Communities

    Get PDF
    The purpose of this study was to investigate family functioning in the relationship between community violence exposure and 1) self-esteem and 2) confrontational coping in a sample of urban youth. Adhering to the tenets of community based participatory research, academic and community partners collaborated on a cross-sectional study with 110 community dwelling urban youth, ages 10–16 living in a city located in the Northeastern United States. As part of a larger survey, this analysis included selected items on lifetime community violence exposure, family functioning, self-esteem and use of confrontational coping strategies in response to community violence. Over 90% of the youth reported some type of lifetime community violence exposure. Controlling for age and gender, older youth and those with healthier family functioning had higher self-esteem; community violence exposure was not associated with self-esteem. Healthier family functioning was associated with decreased use of confrontational coping, though increasing amounts of community violence exposure was still associated with increased confrontational coping. Family can be protective in violent environments. Results from this study directly informed an intervention aimed at youth violence prevention. This study highlights how psychiatric and mental health nurses may be able to address the complex interplay of factors for youth living in violent environments

    Youth\u27s Strategies for Staying Safe and Coping With the Stress of Living in Violent Communities.

    Get PDF
    Youth living in urban environments of pervasive violence are exposed to a variety of violence-related stressors. This qualitative descriptive study sought to ascertain how community-dwelling youth perceived exposure to violence and how these youth identified and used available resources. The intent of this community-based participatory research study was to help inform the design of a youth violence prevention center intervention. Semi-structured interviews were conducted with a purposive sample of 18 youth ages 10-16. Youth reported high levels of exposure to neighborhood violence. A theme of identifying and navigating safe and unsafe places emerged. Other stressors were more proximal and included interpersonal issues and conflicts. Youth used neighborhood and individual resources to cope with stressors. Youth maintained a high level of vigilance and developed clear strategies to safely navigate violent neighborhoods. Implications for youth due to the constant vigilance and exquisite sensitivity to stressors of chronic neighborhood violence are discussed

    A new tyrannosaurid (Dinosauria: Theropoda) from the Upper Cretaceous Menefee Formation of New Mexico

    Get PDF
    The giant tyrannosaurids were the apex predators of western North America and Asia during the close of the Cretaceous Period. Although many tyrannosaurid species are known from numerous skeletons representing multiple growth stages, the early evolution of Tyrannosauridae remains poorly known, with the well-known species temporally restricted to the middle Campanian-latest Maastrichtian (∼77–66 Ma). The recent discovery of a new tyrannosaurid, Lythronax argestes, from the Wahweap Formation of Utah provided new data on early Campanian (∼80 Ma) tyrannosaurids. Nevertheless, the early evolution of Tyrannosauridae is still largely unsampled. We report a new tyrannosaurid represented by an associated skeleton from the lower Campanian Allison Member of the Menefee Formation of New Mexico. Despite fragmentation of much of the axial and appendicular skeleton prior to discovery, the frontals, a metacarpal, and two pedal phalanges are well-preserved. The frontals exhibit an unambiguous autapomorphy and a second potential autapomorphy that distinguish this specimen from all other tyrannosaurids. Therefore, the specimen is made the holotype of the new genus and species Dynamoterror dynastes. A phylogenetic analysis places Dynamoterror dynastes in the tyrannosaurid subclade Tyrannosaurinae. Laser-scanning the frontals and creation of a composite 3-D digital model allows the frontal region of the skull roof of Dynamoterror to be reconstructed

    A "superstorm": When moral panic and new risk discourses converge in the media

    Get PDF
    This is an Author's Accepted Manuscript of an article published in Health, Risk and Society, 15(6), 681-698, 2013, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/13698575.2013.851180.There has been a proliferation of risk discourses in recent decades but studies of these have been polarised, drawing either on moral panic or new risk frameworks to analyse journalistic discourses. This article opens the theoretical possibility that the two may co-exist and converge in the same scare. I do this by bringing together more recent developments in moral panic thesis, with new risk theory and the concept of media logic. I then apply this theoretical approach to an empirical analysis of how and with what consequences moral panic and new risk type discourses converged in the editorials of four newspaper campaigns against GM food policy in Britain in the late 1990s. The article analyses 112 editorials published between January 1998 and December 2000, supplemented with news stories where these were needed for contextual clarity. This analysis shows that not only did this novel food generate intense media and public reactions; these developed in the absence of the type of concrete details journalists usually look for in risk stories. Media logic is important in understanding how journalists were able to engage and hence how a major scare could be constructed around convergent moral panic and new risk type discourses. The result was a media ‘superstorm’ of sustained coverage in which both types of discourse converged in highly emotive mutually reinforcing ways that resonated in a highly sensitised context. The consequence was acute anxiety, social volatility and the potential for the disruption of policy and social change

    Low-Energy Probes of a Warped Extra Dimension

    Full text link
    We investigate a natural realization of a light Abelian hidden sector in an extended Randall-Sundrum (RS) model. In addition to the usual RS bulk we consider a second warped space containing a bulk U(1)_x gauge theory with a characteristic IR scale of order a GeV. This Abelian hidden sector can couple to the standard model via gauge kinetic mixing on a common UV brane. We show that if such a coupling induces significant mixing between the lightest U(1)_x gauge mode and the standard model photon and Z, it can also induce significant mixing with the heavier U(1)_x Kaluza-Klein (KK) modes. As a result it might be possible to probe several KK modes in upcoming fixed-target experiments and meson factories, thereby offering a new way to investigate the structure of an extra spacetime dimension.Comment: 26 pages, 1 figure, added references, corrected minor typos, same as journal versio

    Deep \u3cem\u3eChandra\u3c/em\u3e, \u3cem\u3eHST\u3c/em\u3e-Cos, and MegaCam Observations of the Phoenix Cluster: Extreme Star Formation and AGN Feedback on Hundred Kiloparsec Scales

    Get PDF
    We present new ultraviolet, optical, and X-ray data on the Phoenix galaxy cluster (SPT-CLJ2344-4243). Deep optical imaging reveals previously undetected filaments of star formation, extending to radii of ~50–100 kpc in multiple directions. Combined UV-optical spectroscopy of the central galaxy reveals a massive (2 x 109 M⊙), young (~4.5 Myr) population of stars, consistent with a time-averaged star formation rate of 610 ± 50 M⊙ yr−1. We report a strong detection of O ᴠɪ λλ1032,1038, which appears to originate primarily in shock-heated gas, but may contain a substantial contribution (\u3e1000 M⊙ yr−1) from the cooling intracluster medium (ICM). We confirm the presence of deep X-ray cavities in the inner ~10 kpc, which are among the most extreme examples of radio-mode feedback detected to date, implying jet powers of 2–7 x 1045 erg s−1. We provide evidence that the active galactic nucleus inflating these cavities may have only recently transitioned from quasar-mode to radio-mode, and may currently be insufficient to completely offset cooling. A model-subtracted residual X-ray image reveals evidence for prior episodes of strong radio-mode feedback at radii of ~100 kpc, with extended ghost cavities indicating a prior epoch of feedback roughly 100 Myr ago. This residual image also exhibits significant asymmetry in the inner ~200 kpc (0.15R500), reminiscent of infalling cool clouds, either due to minor mergers or fragmentation of the cooling ICM. Taken together, these data reveal a rapidly evolving cool core which is rich with structure (both spatially and in temperature), is subject to a variety of highly energetic processes, and yet is cooling rapidly and forming stars along thin, narrow filaments
    corecore