E11 must be a symmetry of strings and branes

We construct the non-linear realisation of the semi-direct product of E11 and its vector representation in five and eleven dimensions and find the dynamical equations it predicts at low levels. Restricting these results to contain only the usual fields of supergravity and the generalised space-time to be the usual space-time we find the equations of motion of the five and eleven dimensional maximal supergravity theories. Since this non-linear realisation contains effects that are beyond the supergravity approximation and are thought to be present in an underlying theory we conclude that the low energy effective action of string and branes must possess an E11 symmetry.Comment: 17 pages, The eleven dimensional results are given in more detail and are shown to be uniquely determined. Typographical and transcription errors are also correcte

Generalised vielbeins and non-linear realisations

We briefly review why the non-linear realisation of the semi-direct product of a group with one of its representations leads to a field theory defined on a generalised space-time equipped with a generalised vielbein. We give formulae, which only involve matrix multiplication, for the generalised vielbein, the Cartan forms and their transformations. We consider the generalised space-time introduced in 2003 in the context of the non-linear realisation of the semi-direct product of E(11) and its first fundamental representation. For this latter theory we give explicit expressions for the generalised vielbein up to and including the levels associated with the dual graviton in four, five and eleven dimensions and for the IIB theory in ten dimensions. We also compute the generalised vielbein, up to the analogous level, for the non-linear realisation of the semi-direct product of very extended SL(2) with its first fundamental representation, which is a theory associated with gravity in four dimensions.Comment: 42 page

Reducing Uncertainties in the Production of the Gamma Emitting Nuclei 26Al, 44Ti, and 60Fe in Core Collapse Supernovae by Using Effective Helium Burning Rates

We have used effective reaction rates (ERR) for the helium burning reactions to predict the yield of the gamma-emitting nuclei 26Al, 44Ti, and 60Fe in core col- lapse supernovae. The variations in the predicted yields for values of the reaction rates allowed by the ERR are much smaller than obtained previously, and smaller than other uncertainties. A "filter" for supernova nucleosynthesis yields based on pre-supernova structure was used to estimate the effect of failed supernovae on the initial mass function-averaged yields; this substantially reduced the yields of all these isotopes, but the predicted yield ratio 60Fe/26Al was little affected. The robustness of this ratio is promising for comparison with data, but it is larger than observed in nature; possible causes for this discrepancy are discussed.Comment: 16 pages, 3 figure

Observation of Mammalian Similarity Through Allometric Scaling Laws

We discuss the problem of observation of natural similarity in skeletal evolution of terrestrial mammals. Analysis is given by means of testing of the power scaling laws established in long bone allometry, which describe development of bones (of length $L$ and diameter $D$) with body mass in terms of the growth exponents, \QTR{it}{e.g.} $\lambda =d\log L/d\log D$. The bone-size evolution scenario given three decades ago by McMahon was quiet explicit on the geometrical-shape and mechanical-force constraints that predicted $\lambda =2/3$. This remains too far from the mammalian allometric exponent $\lambda ^{(\exp)}=0.80\pm 0.2$, recently revised by Christiansen, that is a chief puzzle in long bone allometry. We give therefore new insights into McMahon's constraints and report on the first observation of the critical-elastic-force, bending-deformation, muscle-induced mechanism that underlies the allometric law with estimated $\lambda =0.80\pm 0.3$. This mechanism governs the bone-size evolution with avoiding skeletal fracture caused by muscle-induced peak stresses and is expected to be unique for small and large mammals.Comment: Keywords: allometric scaling, long bones, muscles, mammals 21 pages, 1 Table, 2 Figure

Pennsylvanian Subsurface Sequence Stratigraphy Based on 3D Seismic and Wireline Data in Western Osage County, Oklahoma

The Pennsylvanian System in the Mid-Continent United States has been studied for nearly a century. In north central Oklahoma, the Pennsylvanian is primarily composed of cyclothems. These cyclothems are sequences of alternating carbonate, clastic, and shale members. Because of this, these zones can be difficult to differentiate. This project provides valuable insight into better understanding the Pennsylvanian System in western Osage County, Oklahoma. The scope of this project is to perform a subsurface study to produce a detailed interpretation of the depositional history and stratigraphy of Pennsylvanian sequences in western Osage County. This study features 3D seismic and well log investigations that will be used together for local and regional subsurface interpretations. The seismic surveys used in the project are the Wild Creek and Gray Horse 3D surveys in western Osage County. The well logs, digital and raster, provide respectable well control for western Osage County. Together, interpretations from the seismic data and well logs will be used to provide a better understanding of the subsurface stratigraphy and depositional history of Pennsylvanian sequences in western Osage County, Oklahoma

Energy absorption and bending stiffness in CFRP laminates : the effect of 45º plies

The impact characteristics of cross-ply and angle-ply composite laminates were investigated, with an instrumented impact drop tester by performing gravity assisted drop tests on [0/90]6s and [0/45/90]4s laminates. The impact energy was kept constant at 12 J for all the tests. From the dynamic responses presented here as force history, energy history and force-displacement plots, relevant characteristics such as contact time, delamination load, absorbed energy, bending stiffness, after impact deflection etc were obtained. The plots were non-smooth, disclosing the salient features of the composites. It was important to note that the [0/45/90]4s was more resistant to impact bending, but incurred more damage as exhibited by its higher contact time and absorbed energy. The laminates were sectioned through the impact point and magnified macro and micro photographs were taken to show the failure modes, which include delamination, matrix cracking etc