FastFloor Residential Testing Report

The goal of the FastFloor Residential project is to create a new floor system that is lightweight, fast to construct and nonproprietary. FastFloor Residential strives to achieve this by using 3 in. deep steel deck of 18 gauge that is fastened back-to-back to create a cellular deck. The cellular deck is then topped with a cementitious panel that is screwed to the steel deck. A series of physical four-point bending tests on this unique cellular steel deck composite with cementitious panels floor system were conducted in the Thin-Walled Structures Lab at Johns Hopkins University. The goal of the testing is to understand the behavior of the composite action between the steel deck and cementitious panel, identify the failure modes, and evaluate the strength and stiffness of the composite floor system.American Institute of Steel Construction (AISC), Steel Deck Institute (SDI

Shear Response of Fastened Assemblies of Cementitious Panel to Steel Deck for FastFloor Residential Project

Technical report on small-scale push-out testingThe goal of the FastFloor Residential project is to create a new steel floor system that is lightweight, fast to construct, and nonproprietary. FastFloor Residential strives to achieve this by exploring prototypes such as the one shown in Figure 1, employing 18 gauge 3 in. deep steel deck fastened back-to-back to create a cellular deck, then topped with ¾ in thick cementitious (structural) panel screwed to the steel deck. This report summarizes a series of push-out tests that were conducted in the Thin-Walled Structures Lab at Johns Hopkins University. The push-out tests provide the shear response of the fasteners used to attach the cementitious panel to the steel deck. Repeatability of response, fastener spacing, and installation conditions (overdriven screws) are all explored in the testing.American Institute of Steel Construction (AISC), Steel Deck Institute (SDI

Persistence for stochastic difference equations: A mini-review

Understanding under what conditions populations, whether they be plants, animals, or viral particles, persist is an issue of theoretical and practical importance in population biology. Both biotic interactions and environmental fluctuations are key factors that can facilitate or disrupt persistence. One approach to examining the interplay between these deterministic and stochastic forces is the construction and analysis of stochastic difference equations $X_{t+1}=F(X_t,\xi_{t+1})$ where $X_t \in \R^k$ represents the state of the populations and $\xi_1,\xi_2,...$ is a sequence of random variables representing environmental stochasticity. In the analysis of these stochastic models, many theoretical population biologists are interested in whether the models are bounded and persistent. Here, boundedness asserts that asymptotically $X_t$ tends to remain in compact sets. In contrast, persistence requires that $X_t$ tends to be "repelled" by some "extinction set" $S_0\subset \R^k$. Here, results on both of these proprieties are reviewed for single species, multiple species, and structured population models. The results are illustrated with applications to stochastic versions of the Hassell and Ricker single species models, Ricker, Beverton-Holt, lottery models of competition, and lottery models of rock-paper-scissor games. A variety of conjectures and suggestions for future research are presented.Comment: Accepted for publication in the Journal of Difference Equations and Application

Associated Production of Bottomonia and Higgs Bosons at Hadron Colliders

We study the associated production of bottomonia and Higgs bosons at hadron colliders within the factorization formalism of nonrelativistic quantum chromodynamics providing all contributing partonic cross sections in analytic form. While such processes tend to be suppressed in the standard model, they may have interesting cross sections in its minimal supersymmetric extension, especially at large values of tan(beta), where the bottom Yukawa couplings are enhanced. We present numerical results for the processes involving the lighter CP-even h^0 boson and the CP-odd A^0 boson appropriate for the Fermilab Tevatron and the CERN LHC.Comment: 33 pages, 7 figures, Latex, to appear in Phys. Rev.

Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

Lung adenocarcinoma promotion by air pollutants

A complete understanding of how exposure to environmental substances promotes cancer formation is lacking. More than 70 years ago, tumorigenesis was proposed to occur in a two-step process: an initiating step that induces mutations in healthy cells, followed by a promoter step that triggers cancer development1. Here we propose that environmental particulate matter measuring ≤2.5 μm (PM2.5), known to be associated with lung cancer risk, promotes lung cancer by acting on cells that harbour pre-existing oncogenic mutations in healthy lung tissue. Focusing on EGFR-driven lung cancer, which is more common in never-smokers or light smokers, we found a significant association between PM2.5 levels and the incidence of lung cancer for 32,957 EGFR-driven lung cancer cases in four within-country cohorts. Functional mouse models revealed that air pollutants cause an influx of macrophages into the lung and release of interleukin-1β. This process results in a progenitor-like cell state within EGFR mutant lung alveolar type II epithelial cells that fuels tumorigenesis. Ultradeep mutational profiling of histologically normal lung tissue from 295 individuals across 3 clinical cohorts revealed oncogenic EGFR and KRAS driver mutations in 18% and 53% of healthy tissue samples, respectively. These findings collectively support a tumour-promoting role for PM2.5 air pollutants and provide impetus for public health policy initiatives to address air pollution to reduce disease burden

FastFloor Residential Testing Report

The goal of the FastFloor Residential project is to create a new floor system that is lightweight, fast to construct and nonproprietary. FastFloor Residential strives to achieve this by using 3 in. deep steel deck of 18 gauge that is fastened back-to-back to create a cellular deck. The cellular deck is then topped with a cementitious panel that is screwed to the steel deck. A series of physical four-point bending tests on this unique cellular steel deck composite with cementitious panels floor system were conducted in the Thin-Walled Structures Lab at Johns Hopkins University. The goal of the testing is to understand the behavior of the composite action between the steel deck and cementitious panel, identify the failure modes, and evaluate the strength and stiffness of the composite floor system.American Institute of Steel Construction (AISC), Steel Deck Institute (SDI