Evaluation of a vertical-scale, fixed-index instrument display panel for the X-15 airplane

Analog simulation to compare pilot performance in using operational X-15 instrument panel, and vertical scale, fixed index instrument display pane

Fast Determination of Soil Behavior in the Capillary Zone Using Simple Laboratory Tests

INE/AUTC 13.1

Correlation of creep rate with microstructural changes during high temperature creep

Creep tests were conducted on Haynes 188 cobalt-base alloy and alpha titanium. The tests on Haynes 188 were conducted at 1600 F and 1800 F for stresses from 3 to 20 ksi, and the as-received, mill-annealed results were compared to specimens given 5%, 10%, and 15% room temperature prestrains and then annealed one hour at 1800 F. The tests on alpha titanium were performed at 7,250 and 10,000 psi at 500 C. One creep test was done at 527 C and 10,000 psi to provide information on kinetics. Results for annealed titanium were compared to specimens given 10% and 20% room temperature prestrains followed by 100 hours recovery at 550 C. Electron microscopy was used to relate dislocation and precipitate structure to the creep behavior of the two materials. The results on Haynes 188 alloy reveal that the time to reach 0.5% creep strain at 1600 F increases with increasing prestrain for exposure times less than 1,000 hours, the increase at 15% prestrain being more than a factor of ten

Writing in Translation: Robert Sullivan’s 'Star Waka' and Craig Santos Perez’s 'from unincorporated territory'

This article reads the multilingual poetics of Robert Sullivan's 'Star Waka' and Craig Santos Perez’s 'from unincorporated territory', showing how each poet deploys a range of formal, thematic, and imagistic strategies for expressing a contemporary transnationalism. Rather than identify a language of the metropole resisted by a threatened yet contestatory ‘local’ language, Sullivan and Perez cast apparently regional languages as equally traveled as the colonial languages that threaten to mask or silence them. In so doing, these poets argue not just for the vitality and resurgence of Maori and Chamorro respectively; they ultimately privilege neither ‘first’ nor ‘second’ language, neither ‘source’ nor ‘target,’ metropole nor colony, locating their argument for sovereignty in a kinetic space of translation, identifying the process of moving between heterogeneous languages which are irreducible to national literatures — even though they have been co-opted into nationalist discourses both oppressive and resistant — as equally valuable as the recourse to self-expression in an oppressed or minority language. This practice, which we term ‘writing in translation,’ offers evidence for a wider postcolonial turn, identified by critics such as Subramanian Shankar, Jacob Edmonds, and Gaytri Spivak, from seeing translation principally as evidence of colonial/imperial rupture and instead identifying within it a poetics of emergent discourse in which translation allows the multiple idioms and registers to co-exist, displaying a range of power structures and social hierarchies simultaneously

"Save the Land from Uncle Sam": Using Life Insurance Premium Financing in Estate Planning

Perpetuating the legacy of landownership requires careful estate planning by today’s farmers and ranchers.2 Unfortunately, the federal estate tax can be particularly destructive to these estates where there is a desire to pass on legacy holdings to succeeding generations, but the estate lacks adequate cash for the family to pay the resulting taxes

A generalized Drucker–Prager viscoplastic yield surface model for asphalt concrete

A Generalized Drucker-Prager (GD-P) viscoplastic yield surface model was developed and validated for asphalt concrete. The GD-P model was formulated based on fabric tensor modified stresses to consider the material inherent anisotropy. A smooth and convex octahedral yield surface function was developed in the GD-P model to characterize the full range of the internal friction angles from 0 to 90 degrees. In contrast, the existing Extended Drucker-Prager (ED-P) was demonstrated to be applicable only for a material that has an internal friction angle less than 22 degrees. Laboratory tests were performed to evaluate the anisotropic effect and to validate the GD-P model. Results indicated that 1) the yield stresses of an isotropic yield surface model are greater in compression and less in extension than that of an anisotropic model, which can result in an under-prediction of the viscoplastic deformation; and 2) the yield stresses predicted by the GD-P model matched well with the experimental results of the octahedral shear strength tests at different normal and confining stresses. By contrast, the ED-P model over-predicted the octahedral yield stresses, which can lead to an under-prediction of the permanent deformation. In summary, the rutting depth of an asphalt pavement would be underestimated without considering anisotropy and convexity of the yield surface for asphalt concrete. The proposed GD-P model was demonstrated to be capable of overcoming these limitations of the existing yield surface models for the asphalt concrete.Financial support was provided by the U.S. Department of Transportation (USDOT) and the Texas state general revenue funds through Southwest Region University Transportation Center (SWUTC No. 600451-00006). The validation shear tests of this study are based upon the work supported by the National Science Foundation under Grant No. 0943140.This is the accepted manuscript version. The final version is available from Springer at http://dx.doi.org/10.1617/s11527-014-0425-1

Neural Networks Modeling of Stress Growth in Asphalt Overlays due to Load and Thermal Effects during Reflection Cracking

Although several techniques have been introduced to reduce reflective cracking, one of the primary forms of distress in hot-mix asphalt (HMA) overlays of flexible and rigid pavements, the underlying mechanism and causes of reflective cracking are not yet well understood. Fracture mechanics is used to understand the stable and progressive crack growth that often occurs in engineering components under varying applied stress. The stress intensity factor (SIF) is its basis and describes the stress state at the crack tip. This can be used with the appropriate material properties to calculate the rate at which the crack will propagate in a linear elastic manner. Unfortunately, the SIF is difficult to compute or measure, particularly if the crack is situated in a complex three-dimensional (3D) geometry or subjected to a non-simple stress state. In this study, the neural networks (NN) methodology is successfully used to model the SIF as cracks grow upward through a HMA overlay as a result of both load and thermal effects with and without reinforcing interlayers. Nearly 100,000 runs of a finite-element program were conducted to calculate the SIFs at the tip of the reflection crack for a wide variety of crack lengths and pavement structures. The coefficient of determination (R2) of all the developed NN models except one was above 0.99. Owing to the rapid prediction of SIFs using developed NN models, the overall computer run time for a 20-year reflection cracking prediction of a typical overlay was significantly reduced