The University of Texas at Brownsville is an educational institution located in Brownsville, Texas. The university is on the land once occupied by Fort Brown. It is a member of the University of Texas System. The institution was formed from a partnership between Texas Southmost College and the University of Texas-Pan American at Brownsville. From 1991 to 2011, the University of Texas at Brownsville and Texas Southmost College became a substantial presence in South Texas education, providing unique opportunities for more than 17,000 students from Texas, as well as from Mexico and elsewhere. The partnership ended in 2011 as UTB became a standalone University of Texas institution, and Texas Southmost College returned to being an independent community college. UTB itself offers baccalaureate and an increasing number of graduate degrees in liberal arts, science, education, business, and professional programs designed to meet regional, national, and international needs.In 2015, the UT–Brownsville, originally an extension of then-Pan-American University at Texas Southmost College, will merge with the current UT–Pan American , a new medical school will be added, and the resulting institution will be named the University of Texas–Rio Grande Valley. Wikipedia.
Cordes J.M.,Cornell University |
Jenet F.A.,University of Texas at Brownsville
Astrophysical Journal | Year: 2012
We compare the detectability of gravitational bursts passing through the solar system with those passing near each millisecond pulsar in an N-pulsar timing array. The sensitivity to Earth-passing bursts can exploit the correlation expected in pulse arrival times while pulsar-passing bursts, though uncorrelated between objects, provide an N-fold increase in overall time baseline that can compensate for the lower sensitivity. Bursts with memory from mergers of supermassive black holes produce step functions in apparent spin frequency that are the easiest to detect in pulsar timing. We show that the burst rate and amplitude distribution, while strongly dependent on inadequately known cosmological evolution, may favor detection in the pulsar terms rather than the Earth timing perturbations. Any contamination of timing data by red spin noise makes burst detection more difficult because both signals grow with the length of the time data span T. Furthermore, the different bursts that could appear in one or more data sets of length T 10yr also affect the detectability of the gravitational wave stochastic background that, like spin noise, has a red power spectrum. A burst with memory is a worthwhile target in the timing of multiple pulsars in a globular cluster because it should produce a correlated signal with a time delay of less than about 10years in some cases. © 2012. The American Astronomical Society. All rights reserved..
Martirosyan K.S.,University of Texas at Brownsville
Journal of Materials Chemistry | Year: 2011
Metastable Intermolecular Composites or so-called Nanoenergetic Materials have been widely touted for their potential to fulfill dreams in high density energetic materials and nanotechnology. They are likely to become the next-generation explosives, propellants and primes as they enable flexibility in energy density and power release through control of particle size, tunable stoichiometry and choice of fuel and oxidizer. Despite intense examination by scientists and engineers worldwide the temperature progress and velocity of the thermal front propagation on the nanostructured formulations, however, gas pressure evolution and rate of gas release are not well investigated and understood. This issue has seriously impeded realization of various potential emerging applications envisioned in rocket solid fuels and explosives, which require a high pressure discharge in a short period of time as well as in bio-defeat systems. This highlight describes principles and development of Nanoenergetic Gas-Generators (NGG) systems comprising high PV (pressure × volume) values and energy densities (up to 25.7 kJ cm-3) that may have several potential civil and military applications. Our recent study revealed that Al/Bi2O3 and Al/I2O5 nanocomposites can generate a transient pressure pulse more than three times larger than that during the explosion of traditional thermite reactive mixtures. © 2011 The Royal Society of Chemistry.
Isokawa M.,University of Texas at Brownsville
Neural Plasticity | Year: 2012
The hippocampus has the extraordinary capacity to process and store information. Consequently, there is an intense interest in the mechanisms that underline learning and memory. Synaptic plasticity has been hypothesized to be the neuronal substrate for learning. Ca2+ and Ca2+- activated kinases control cellular processes of most forms of hippocampal synapse plasticity. In this paper, I aim to integrate our current understanding of Ca2+-mediated synaptic plasticity and metaplasticity in motivational and reward-related learning in the hippocampus. I will introduce two representative neuromodulators that are widely studied in reward-related learning (e.g., ghrelin and endocannabinoids) and show how they might contribute to hippocampal neuron activities and Ca2+-mediated signaling processes in synaptic plasticity. Additionally, I will discuss functional significance of these two systems and their signaling pathways for its relevance to maladaptive reward learning leading to addiction. © 2012 Masako Isokawa.
Ibragimov R.N.,University of Texas at Brownsville
Physics of Fluids | Year: 2011
We study the nonlinear incompressible fluid flows within a thin rotating spherical shell. The model uses the two-dimensional Navier-Stokes equations on a rotating three-dimensional spherical surface and serves as a simple mathematical descriptor of a general atmospheric circulation caused by the difference in temperature between the equator and the poles. Coriolis effects are generated by pseudoforces, which support the stable west-to-east flows providing the achievable meteorological flows rotating around the poles. This work addresses exact stationary and non-stationary solutions associated with the nonlinear Navier-Stokes. The exact solutions in terms of elementary functions for the associated Euler equations (zero viscosity) found in our earlier work are extended to the exact solutions of the Navier-Stokes equations (non-zero viscosity). The obtained solutions are expressed in terms of elementary functions, analyzed, and visualized. © 2011 American Institute of Physics.
Sexton K.,University of Texas at Brownsville
International Journal of Environmental Research and Public Health | Year: 2012
Systematic evaluation of cumulative health risks from the combined effects of multiple environmental stressors is becoming a vital component of risk-based decisions aimed at protecting human populations and communities. This article briefly examines the historical development of cumulative risk assessment as an analytical tool, and discusses current approaches for evaluating cumulative health effects from exposure to both chemical mixtures and combinations of chemical and nonchemical stressors. A comparison of stressor-based and effects-based assessment methods is presented, and the potential value of focusing on viable risk management options to limit the scope of cumulative evaluations is discussed. The ultimate goal of cumulative risk assessment is to provide answers to decision-relevant questions based on organized scientific analysis; even if the answers, at least for the time being, are inexact and uncertain. © 2012 by the authors; licensee MDPI, Basel, Switzerland.
Agency: NSF | Branch: Standard Grant | Program: | Phase: ARCTIC SYSTEM SCIENCE PROGRAM | Award Amount: 350.49K | Year: 2013
Boreal forests cover 40% of the vegetated land area above the Arctic Circle and are a critical component of arctic ecosystems. Global change models predict boreal forests will become increasingly susceptible to fire activity with climate warming. Because these forests contain a large proportion of global terrestrial carbon (C) stocks, changes in the fire regime are likely to alter global C cycling. Increased fire activity will increase C emissions to the atmosphere, with a potential positive feedback to climate warming. However, an altered fire regime may also initiate cascading effects on forest regrowth and permafrost degradation that could magnify or offset this feedback. Fire effects on these ecological mechanisms remain uncertain but will ultimately determine whether arctic ecosystems act as a C source or sink under future climate change scenarios. The primary objective of this research is to increase our understanding of post-fire C dynamics in boreal forests of the Siberian arctic by elucidating the ecological mechanisms by which increased fire severity could influence C accumulation and storage over the successional interval. The overarching hypothesis is that post-fire soil organic layer (SOL) depth regulates net ecosystem carbon balance (NECB) through indirect impacts on forest regrowth and permafrost stability because of its role as a barrier to seed germination and thermal regulator. The team will: 1) link near term fire effects on SOL depth to changes in larch recruitment and permafrost characteristics in experimental burn plots created in 2012, 2) determine the relationship between post-fire stand structure and above- and belowground C pools at the local and landscape level across stands of varying age and topographic positions, and 3) test via experimental manipulations and field observations the mechanisms by which fire-driven changes in stand density indirectly affect moss growth, SOL development, and susceptibility of deeper C pools to warming, decomposition, and release into the atmosphere. This research will offer novel insights into the importance of both vegetation and soil processes within arctic ecosystems in determining the net feedback of an intensified fire regime to the climate system.
Intellectual Merit: Larch forests of the Siberian arctic comprise 20% of all boreal forest ecosystems and are distinct from other boreal forests in that they consist of a single tree genus (Larix spp.) with a deciduous growth habit and often grow on continuous, C-rich ?yedoma? permafrost. Thus, their response to warming climate and an altered fire regime is likely to differ from boreal forests in other regions. Uncertainties regarding current C pools in Siberian boreal forests remain a significant factor affecting our ability to predict climate-induced changes to the global C cycle. The proposed study will contribute to our understanding of how arctic forest fires impact global C cycling and provide essential data necessary for scaling-up arctic C pools, estimating C emissions from arctic fires, and calibrating predictive models of future global C cycling.
Broader Impacts: This project will result in the training of undergraduate and graduate students from two predominantly undergraduate institutions and one Hispanic-Serving Institution. The PI and her students will develop outreach activities with local K-12 schools in south Texas to help teachers create lesson plans involving arctic science, boreal ecology, and climate change and involve researcher presentations to science classrooms to provide real-life examples of arctic research and expose K-12 students to different career and educational paths in the sciences.
Agency: NSF | Branch: Standard Grant | Program: | Phase: COMBUSTION, FIRE, & PLASMA SYS | Award Amount: 10.00K | Year: 2013
The XII International Symposium on Self-Propagating High Temperature Synthesis is hosted by University of Texas at Brownsville at South Padre Island, TX, October 21-24, 2013. Graduate students will have an opportunity to present their research results and to interact with experts from academia, government agencies, and industry across the United States and from abroad. The off-the-record format presentation and discussion led by the topic experts also offers the exchange of the emerging ideas of the field. The proposed funding is to provide support for registration for both GRS and GRC to student presenters.
Agency: NSF | Branch: Standard Grant | Program: | Phase: MAJOR RESEARCH INSTRUMENTATION | Award Amount: 437.97K | Year: 2011
The objective of this grant application is to acquire a cutting-edge commercial multi-functional instrument Cryogen-free Cryocooler-based Physical Property Measurement System (PPMS EverCool-II, Quantum Design, USA) to support fundamental and interdisciplinary research projects and the applied physics education program in the Rio Grande Valley, South Texas region. The equipment will be installed at the University of Texas at Brownsville and will be used as a shared characterization facility. This instrument is designed to measure a variety of materials properties including magnetic, transport, and thermal under different temperatures (1.9 - 1000 K), magnetic fields (up to 9 T) and environments (from atmospheric pressure to high vacuum). The system is cryogen-free and no costly liquid cryogens are required. The attractive feature of the PPMS is a cryocooler to achieve cryogenic temperatures. The PPMS EverCool-II is a highly automated instrument. It can perform unattended measurements after the user has installed a sample and configured the measurement. This acquisition will enhance the existing research and educational infrastructure and will provide the state-of-the-art measurement system to a broad range of users in State of Texas, thereby elevating advanced materials research and educational programs in the Rio Grande Valley to a globally competitive level.
Agency: NSF | Branch: Continuing grant | Program: | Phase: LIGO RESEARCH SUPPORT | Award Amount: 450.00K | Year: 2012
Gravitational-wave (GW) searches using LIGOs landmark fifth and sixth science runs have led to major observational results, including astrophysical constraints that have begun to surpass those from electromagnetic or particle observations. Preparations for the start of the advanced detector era are now eagerly underway, with LIGO, Virgo and GEO600 in a transition period and new interferometers under construction. These advanced detectors, expected to come on-line starting around 2015, will be ~10 times more sensitive, searching a volume of the Universe ~1000 times larger than at present, virtually guaranteeing the first detection of GWs. This award supports research in areas that are relevant to LIGO data analysis during this transition period, and that will build the foundation for techniques required in the advanced detector era: (i) searches for a cosmological or astrophysical GW background, (ii) statistical searches for GWs from gamma-ray bursts, (iii) developing new methods to search for GWs from supernovae, and (iv) detector characterization.
The first project will improve our sensitivity to GW backgrounds using the most recent data from both the LIGO and Virgo detectors. The second will develop methods to optimally use the information contained in the electromagnetic or particle signature of an astrophysical event (such as gamma-ray data from NASA missions like Swift and Fermi) in GW searches. The third will explore methods to enhance the sensitivity of searches involving GWs from weak sources like supernovae, and the fourth will look into the detector data to characterize low-frequency non-stationary noise and track possible instrumental artefacts as well. The graduate students supported by this grant will receive direct training in GW data analysis, thus adding to the growing community of researchers in this field. Since the University of Texas at Brownsville (UTB) is an Hispanic serving institution, the research activities will expose students who are traditionally under-represented in the areas of science and technology to forefront scientific research. On-going major outreach programs at UTB will be able to leverage this research, creating awareness among high-school students about exciting scientific projects such as LIGO.
Agency: NSF | Branch: Standard Grant | Program: | Phase: COMPUTATIONAL MATHEMATICS | Award Amount: 78.93K | Year: 2012
Binary neutron star inspiral is the most certain source of gravitational waves detectable by Earth-based observatories like the US LIGO project, and simulations of such binaries should facilitate eventual detections. These simulations require initial conditions: solutions to the initial value problem of general relativity for the coupled gravity-matter system. The conformal thin sandwich method is an excellent approach for solving the initial value problem; however, although not an intrinsic assumption of the method, in practice the approach has assumed conformal flatness (as have other valuable approaches). Conformal flatness yields unphysical junk radiation. By numerically constructing helically symmetric solutions to the Einstein equations, the PI will extract initial data (or conformal thin sandwich trial data) which does not rely on conformal flatness, and therefore contains the correct initial gravitational wave content. The mixed PDEs arising from the helical reduction of the Einstein equations (or their approximation in the post-Minkowski formalism) will be solved with innovative techniques: sparse modal spectral-tau methods with new preconditioning strategies. In part, these strategies may rely on randomized algorithms for the interpolative decomposition. Spectral methods deliver superb accuracy for smooth problems(neutron star spacetimes are smooth almost everywhere), and sparsity affords a fast matrix-vector multiply when using a Krylov-subspace method to iteratively solve a linear system. Whereas the preconditioning of nodal (collocation) spectral methods is well studied, less is known about modal preconditioning. Our techniques have been successfully applied to models of the binary neutron star problem. Moreover, the problems physical structure has already been explored with different, but limited, techniques.
This project is to combine two sets of techniques (each already developed) and further develop the first set (spectral-tau methods), in order to obtain new results for a leading problem in gravitational wave physics. The PI will develop these mathematical methods by applying them to the specific neutron star problem described above. This strategy of specificity is often used in the development of techniques, which then prove to be more general. Because the scientific problem is of great interest, much is known about it, and results therefore exist withwhich comparisons can be made. These comparisons facilitate the development of mathematical algorithms. Conversely, new mathematical methods deliver more and/or better solutions which enhances scientific understanding.