66 research outputs found
Tradeoffs in Brush Management for Water Yield and Habitat Management in Texas: Twin Buttes Drainage Area and Edwards Aquifer Recharge Zone
With the current population boom, the number of Texas residents will almost double by 2030. With the expected increase in demand for water, the scarcity of water is an urgent issue and research is being conducted to find ways to improve water yield. Rangelands provide the major catchments for both surface reservoirs and aquifers. Brush control as a means of increasing water yields was first studied in the 1970s (Bach and Conner 2000) and a number of studies have reviewed the feasibility of removing brush as a means to increase water yields (Wilcox 2002). For example, a study on the North Concho River watershed (Upper Colorado River Authority, 1998) indicated that removing brush could result in a significant increase in water yield and, in response to this report, the Legislature for the State of Texas appropriated funds to study the feasibility of this practice on eight additional watersheds (Bednarz et al., 2000). The Texas Agricultural Experiment Station sponsored additional studies for two of these eight watersheds (Twin Buttes and Edwards Aquifer) to determine the tradeoff between brush management for increased water yield and wildlife habitat improvement. These two watershed areas are the subjects of this report.
Since a significant portion of Texas lands are privately owned, it is important to account for landowners’ willingness to participate in any brush management program, especially when such programs are intended to produce off-site benefits. Landowner participation is generally dependent upon expected economic benefits received (Bach and Conner 2000).
In our study, 300 questionnaires were each sent to randomly selected landowners from both the Edwards Aquifer Recharge Zone and the Twin Buttes (Middle and South Concho River) Drainage Area. Names and addresses of rural landowners with tracts of 50 or more acres were compiled with the help of local county appraisal districts. In the questionnaire, survey participants were asked several questions to measure their willingness to participate in different scenarios, as well as the amount of compensation required. This report examines the results of the survey.
Of the 300 questionnaires sent to the Edwards Aquifer area, 131 were returned and usable, 50 were returned but unusable, and 119 were never returned. In the Twin Buttes area, 141 questionnaires were returned and usable, 38 were returned but were unusable, and 121 were not returned.
This report examines each watershed separately. All survey questions are considered. Results include mean, median, and quartile data, and frequency distributions
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Preprocessing Moist Lignocellulosic Biomass for Biorefinery Feedstocks
Biomass preprocessing is one of the primary operations in the feedstock assembly system of a lignocellulosic biorefinery. Preprocessing is generally accomplished using industrial grinders to format biomass materials into a suitable biorefinery feedstock for conversion to ethanol and other bioproducts. Many factors affect machine efficiency and the physical characteristics of preprocessed biomass. For example, moisture content of the biomass as received from the point of production has a significant impact on overall system efficiency and can significantly affect the characteristics (particle size distribution, flowability, storability, etc.) of the size-reduced biomass. Many different grinder configurations are available on the market, each with advantages under specific conditions. Ultimately, the capacity and/or efficiency of the grinding process can be enhanced by selecting the grinder configuration that optimizes grinder performance based on moisture content and screen size. This paper discusses the relationships of biomass moisture with respect to preprocessing system performance and product physical characteristics and compares data obtained on corn stover, switchgrass, and wheat straw as model feedstocks during Vermeer HG 200 grinder testing. During the tests, grinder screen configuration and biomass moisture content were varied and tested to provide a better understanding of their relative impact on machine performance and the resulting feedstock physical characteristics and uniformity relative to each crop tested
Water Level Observations in Mangrove Swamps During Two Hurricanes in Florida
Little is known about the effectiveness of mangroves in suppressing water level heights during landfall of tropical storms and hurricanes. Recent hurricane strikes along the Gulf Coast of the United States have impacted wetland integrity in some areas and hastened the need to understand how and to what degree coastal forested wetlands confer protection by reducing the height of peak water level. In recent years, U.S. Geological Survey Gulf Coast research projects in Florida have instrumented mangrove sites with continuous water level recorders. Our ad hoc network of water level recorders documented the rise, peak, and fall of water levels (6 0.5 hr) from two hurricane events in 2004 and 2005. Reduction of peak water level heights from relatively in-line gages associated with one storm surge event indicated that mangrove wetlands can reduce water level height by as much as 9.4 cm/km inland over intact, relatively unchannelized expanses. During the other event, reductions were slightly less for mangroves along a river corridor. Estimates of water level attenuation were within the range reported in the literature but erred on the conservative side. These synoptic data from single storm events indicate that intact mangroves may support a protective role in reducing maximum water level height associated with surge
Prey handling and diet of Louisiana pine snakes (Pituophis ruthveni) and black pine snakes (P. melanoleucus lodingi), with comparisons to other selected colubrid snakes
Diet and prey handling behavior were determined for Louisiana pine snakes (Pituophis ruthveni) and black pine snakes (P. melanoleucus lodingi). Louisiana pine snakes prey heavily on Baird\u27s pocket gophers (Geomys breviceps), with which they are sympatric, and exhibit specialized behaviors that facilitate handling this prey species within the confines of burrow systems. Black pine snakes, which are not sympatric with pocket gophers, did not exhibit these specialized behaviors. For comparative purposes, prey handling of P. sayi sayi and Elaphe obsoleta lindheimeri was also examined
The AEPEX CubeSat Mission: Quantifying Energetic Particle Precipitation through Bremsstrahlung X-Ray Imaging
Fundamental gaps exist in the understanding and observation of energetic particle precipitation (EPP),a solar-terrestrial coupling mechanism that is vital for climatelogical modeling of the atmosphere and magnetosphere. The Atmospheric Effects of Precipitation through Energetic X-rays (AEPEX) mission is a 6U CubeSat that will measure energetic electron spectra and X-ray images in order to quantify the spatial scales and amount of energy input into the atmosphere, and therefore lost from the magnetosphere, via EPP. AEPEX includes two instruments; AEPEX’s FIRE (Focused Investigations of Relativistic Electron) instrument (AFIRE), a TRL 9 electron detector previously flown on the FIREBIRD mission; and the Atmospheric X-ray Imaging Spectrometer (AXIS), an instrument being developed at CU Boulder that will take novel images and spectra of 50–300 keV X-ray photons. This work describes the AEPEX mission overview, the detailed design and operation of AXIS, and initial test and calibration results
Identifying beliefs underlying pre-drivers’ intentions to take risks: an application of the theory of planned behaviour
Novice motorists are at high crash risk during the first few months of driving. Risky behaviours such as speeding and driving while distracted are well-documented contributors to crash risk during this period. To reduce this public health burden, effective road safety interventions need to target the pre-driving period. We use the Theory of Planned Behaviour (TPB) to identify the pre-driver beliefs underlying intentions to drive over the speed limit (N = 77), and while over the legal alcohol limit (N = 72), talking on a hand-held mobile phone (N = 77) and feeling very tired (N = 68). The TPB explained between 41% and 69% of the variance in intentions to perform these behaviours. Attitudes were strong predictors of intentions for all behaviours. Subjective norms and perceived behavioural control were significant, though weaker, independent predictors of speeding and mobile phone use. Behavioural beliefs underlying these attitudes could be separated into those reflecting perceived disadvantages (e.g., speeding increases my risk of crash) and advantages (e.g., speeding gives me a thrill). Interventions that can make these beliefs safer in pre-drivers may reduce crash risk once independent driving has begun
Theory of Planned Behaviour and Parasuicide: An Exploratory Study
Recent evidence suggests that parasuicide (deliberate self-harm) should be considered in terms of ‘normal’ rather than ‘abnormal’ behaviour. This study aimed to address this assertion by applying a social cognition model, for the first time, to parasuicidal behaviour. An extended theory of planned behaviour (TPB) model was tested on 55 individuals drawn from hospital and non-hospital populations. Thirty-eight percent of the sample (n=21) reported a history of deliberate self-harm. Findings supported the utility of the TPB: attitudes, subjective norm, self-efficacy, moral norm and anticipated affect discriminated significantly between those with and without a history of parasuicide. The extended TPB explained more than 50% of the variance associated with intentions to deliberately self-harm. These findings have considerable theoretical and practical implications for intervention. Future research should investigate the utility of the TPB employed within a prospective framework
La Grange Comprehensive Plan 2018 - 2038
In the Fall of 2017, the City of La Grange and Texas Target Communities partnered to create
a task force to represent the community. The task force was integral to the planning process,
contributing the thoughts, desires, and opinions of community members—as well as their
enthusiasm about La Grange’s future. This fifteen-month planning process ended in August
2018. The result of this collaboration is the La Grange Comprehensive Plan, which is the
official policy guide for the community’s growth over the next twenty years.La Grange Comprehensive Plan 2018 - 2038 provides a guide for the future growth of the City.
This document was developed by Texas Target Communities in partnership with the City of
La Grange.Texas Target Communitie
Suppressing quantum errors by scaling a surface code logical qubit
Practical quantum computing will require error rates that are well below what
is achievable with physical qubits. Quantum error correction offers a path to
algorithmically-relevant error rates by encoding logical qubits within many
physical qubits, where increasing the number of physical qubits enhances
protection against physical errors. However, introducing more qubits also
increases the number of error sources, so the density of errors must be
sufficiently low in order for logical performance to improve with increasing
code size. Here, we report the measurement of logical qubit performance scaling
across multiple code sizes, and demonstrate that our system of superconducting
qubits has sufficient performance to overcome the additional errors from
increasing qubit number. We find our distance-5 surface code logical qubit
modestly outperforms an ensemble of distance-3 logical qubits on average, both
in terms of logical error probability over 25 cycles and logical error per
cycle ( compared to ). To investigate
damaging, low-probability error sources, we run a distance-25 repetition code
and observe a logical error per round floor set by a single
high-energy event ( when excluding this event). We are able
to accurately model our experiment, and from this model we can extract error
budgets that highlight the biggest challenges for future systems. These results
mark the first experimental demonstration where quantum error correction begins
to improve performance with increasing qubit number, illuminating the path to
reaching the logical error rates required for computation.Comment: Main text: 6 pages, 4 figures. v2: Update author list, references,
Fig. S12, Table I
Non-Abelian braiding of graph vertices in a superconducting processor
Indistinguishability of particles is a fundamental principle of quantum
mechanics. For all elementary and quasiparticles observed to date - including
fermions, bosons, and Abelian anyons - this principle guarantees that the
braiding of identical particles leaves the system unchanged. However, in two
spatial dimensions, an intriguing possibility exists: braiding of non-Abelian
anyons causes rotations in a space of topologically degenerate wavefunctions.
Hence, it can change the observables of the system without violating the
principle of indistinguishability. Despite the well developed mathematical
description of non-Abelian anyons and numerous theoretical proposals, the
experimental observation of their exchange statistics has remained elusive for
decades. Controllable many-body quantum states generated on quantum processors
offer another path for exploring these fundamental phenomena. While efforts on
conventional solid-state platforms typically involve Hamiltonian dynamics of
quasi-particles, superconducting quantum processors allow for directly
manipulating the many-body wavefunction via unitary gates. Building on
predictions that stabilizer codes can host projective non-Abelian Ising anyons,
we implement a generalized stabilizer code and unitary protocol to create and
braid them. This allows us to experimentally verify the fusion rules of the
anyons and braid them to realize their statistics. We then study the prospect
of employing the anyons for quantum computation and utilize braiding to create
an entangled state of anyons encoding three logical qubits. Our work provides
new insights about non-Abelian braiding and - through the future inclusion of
error correction to achieve topological protection - could open a path toward
fault-tolerant quantum computing
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