Adjudication and the Adaptive Capacity of Pecan Farmers in the Lower Rio Grande

Despite growing uncertainty of water availability in the future and popular understandings of water conservation in agriculture, a growing number of farmers in the Lower Rio Grande Basin are rapidly transitioning to pecan orchards, a long-term and highly water-dependent crop. Drivers of landscape change can be environmental, historic, socioeconomic, or institutional. Adaptation to change is understood as responses to external stimuli and is limited to a threshold by which an actor can meet their goals. Much of the current scholarship focuses on a given population’s adaptive capacity toward global climate change, however, most water policy in the western United States is part and parcel a response to burgeoning climate crises. By framing agrarian change in terms of the capacity to adapt to water policy, adjudication, and litigation, I explore what externalities and mechanisms of uncertainty influence agricultural management decisions. I use multiple regression models to unpack some of the interplay between physical and institutional factors, spatial relationships, and cropping patterns. The analysis is evaluated based on qualitative surveys of farmers’ perceptions of the drivers of change. I argue that the ability to acquire water rights to meet or exceed adjudicated irrigation amounts has disproportionately ensured the livelihood and environmental resilience of farmers with higher property value and larger farms in less rural areas. Current markets and ongoing adjudication has given advantage to pecan orchards over other crops

Clay Shale Foundation Slide at Waco Dam, Texas

A major slide occurred during construction of the dam in 1961. It was caused by a combination of unusually high pore pressures in the clay shale foundation and a low residual shear strength. The dam was completed with wide berms to provide stability. Since completion there has been a very slow decrease in foundation pore pressure

Kerrville Ponding Dam, Guadalupe River, Texas

Kerrville Ponding Dam is a relatively small channel dam in the Guadalupe River in Kerrville, Texas. The dam is 22 feet (6.7M) high and 600 feet (183M) long and provides a water supply for the City of Kerrville. The dam was constructed during 1979-1980. Seepage problems in the abutments were observed during the initial filling of the reservoir. Some minor corrections to the problems were made at that time. In June 1981, after a moderate flood flow passed over the dam, additional seepage problems occurred. The downstream slope protection was displaced to the extent that cracks appeared in the concrete. This damage lead to a more significant amount of repair. On December 31, 1984 the dam was overtopped by a flood to a depth of 10.5 feet (3.2M) above the spillway elevation. The dam suffered severe damage including loss of a portion of the concrete cap and significant erosion of the clay core over approximately one-third of the length of the dam, and seepage related damage at both the abutment areas. Figure 1 shows the conditions of the structure in January 1985. The dam suffered a “Type 1 Accident” as defined according to International Commission on Large Dams (ICOLD)

All Coronal Loops are the Same: Evidence to the Contrary

The 1998 April 20 spectral line data from the Coronal Diagnostics Spectrometer (CDS) on the {\it Solar and Heliospheric Observatory} (\SOHO) shows a coronal loop on the solar limb. Our original analysis of these data showed that the plasma was multi-thermal, both along the length of the loop and along the line of sight. However, more recent results by other authors indicate that background subtraction might change these conclusions, so we consider the effect of background subtraction on our analysis. We show Emission Measure (EM) Loci plots of three representative pixels: loop apex, upper leg, and lower leg. Comparisons of the original and background-subtracted intensities show that the EM Loci are more tightly clustered after background subtraction, but that the plasma is still not well represented by an isothermal model. Our results taken together with those of other authors indicate that a variety of temperature structures may be present within loops.Comment: Accepted for publication in ApJ Letter

Suppressing delaminations in composites across a range of loading modes

This study presents two means of achieving high fracture toughness throughout the entire mixed Mode I/II test range, using customised placement of composite and metal Z-pins in hybrid arrays, and novel hybrid metal/composite Z-pins. The study shows that hybrid arrays that contain an equal number of composite and metal Z-pins exhibit a notable increase in the apparent fracture toughness in Mode II compared to 100% composite pins, while maintaining adequate Mode I performance. Hybrid metal/composite Z-pins, which consist of a composite exterior and a metal core have been shown to offer a single Z-pin solution for high fracture toughness under mixed Mode I/II loads without compromising either Mode I or Mode II performance of individual composite or metal Z-pins respectively. The composite exterior of the hybrid Z-pin ensures high resistance to pull-out failure, whilst the metal core guarantees high energy absorption at high mixed mode load angles via plastic deformation

Simulation of a scintillator-based Compton telescope with micropattern readout

Abstract—We describe simulations of a Compton telescope gamma-ray detector. The model is based on scintillation detectors and low-mass, photosensitive micro-pattern detectors, particu-larly the plasma panel sensor. The detector model has ten to twenty layers, to maximize the probability of Compton scattering while minimizing multiple scattering in a single layer. The simulations explore optimizing the micro-pattern detector pixel geometry, the scintillator material, the total detector thickness, and the number of layers. In addition, we explored algorithms for determining the interaction position, total energy and dis-criminating Compton scattering from other processes. Our initial results indicate that this kind of Compton telescope can be much more efficient that silicon or germanium-based telescopes while providing very good position resolution. I