Browsing by Subject "control"

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An Evaluation of the Use and Effectiveness of Temporary Sediment Controls
(University of Texas at Austin, 1995-08) Barrett, M.E.; Kearney, J.E.; McCoy, T.G.; Malina, J.F. Jr.; Charbeneau, R.J.; Ward, G.H.
Cold Atom Ballistics By Coherent Control
(2008-04) Reichl, L. E.; Holder, B. P.; Reichl, Linda E.; Holder, Benjamin P.
We use the technique of Stimulated Raman adiabatic passage (STIRAP) to affect transport of ultracold atoms between two optical lattices in relative motion. We show, using Floquet analysis and degenerate perturbation theory, that the dynamics of atoms in a particular time-dependent optical lattice system can be reduced to the 3-level STIRAP model, allowing for a simple description of their coherent acceleration.
Drought-Influenced Mortality of Tree Species with Different Predawn Leaf Water Dynamics in a Decade-Long Study of a Central US forest
(2015) Gu, L.; Pallardy, S. G.; Hosman, K. P.; Sun, Y.; Sun, Y.
Using decade-long continuous observations of tree mortality and predawn leaf water potential (psi(pd)) at the Missouri Ozark AmeriFlux (MOFLUX) site, we studied how the mortality of important tree species varied and how such variations may be predicted. Water stress determined inter-annual variations in tree mortality with a time delay of 1 year or more, which was correlated fairly tightly with a number of quantitative predictors formulated based on psi(pd) and precipitation regimes. Predictors based on temperature and vapor pressure deficit anomalies worked reasonably well, particularly for moderate droughts. The exceptional drought of the year 2012 drastically increased the mortality of all species, including drought-tolerant oaks, in the subsequent year. The drought-influenced tree mortality was related to the species position along the spectrum of psi(pd) regulation capacity with those in either ends of the spectrum being associated with elevated risk of death. Regardless of species and drought intensity, the psi(pd) of all species recovered rapidly after sufficiently intense rain events in all droughts. This result, together with a lack of immediate leaf and branch desiccation, suggests an absence of catastrophic hydraulic disconnection in the xylem and that tree death was caused by significant but indirect effects. Species differences in the capacity of regulating psi(pd) and its temporal integral were magnified under moderate drought intensities but diminished towards wet and dry extremes. Severe droughts may overwhelm the capacity of even drought-tolerant species to maintain differential levels of water potential as the soil becomes exhausted of available water in the rooting zone, thus rendering them more susceptible to death if predisposed by other factors such as age.
Electric ship power system - research at The University of Texas at Austin
(IEEE, 2005-07) Hebner, R.E.
Recognizing the importance of electric ships and the myriad of technical challenges they present, the University of Texas at Austin, with seed funding from the Office of Naval Research, established a virtual electrical ship research and development center. The reason for the virtual center is that the complex challenges of the future require multidisciplinary solutions. The virtual center contains staff members from Electrical Engineering, Mechanical Engineering and two research centers who work collaboratively with a number of other universities and with industry. This program has two anticipated significant outcomes. At the system level, the first anticipated outcome is to develop a comprehensive set of modeling approaches that guide the evolution of electric ship power systems. The second outcome is an approach to the replacement of the hydraulic system on current ships with electrical actuators on future ships.
Evaluation of the Benefits of Flood-Control Storage at Multipurpose Reservoirs
(University of Texas at Austin, 1975-04) Ford, D.T.
Health4Kids: Participant Certificate of Completion
(2022) Latino Research Institute
The certificate of completion templates awarded to all Health4Kids participants that completed 12 months of the study.
Health4Kids: Take Home Materials
(2022) Latino Research Institute
Materials (in English and Spanish) included in the take home folder provided to Health4Kids study participants.
Health4Kids: Text Messages
(2022) Latino Research Institute
Communication plan and documentation of the text messages sent to Health4Kids study participants. For more information about text messaging procedures, reference the Health4Kids manual of procedures.
Intelligent Microgrids
(0000-00-00) Uriarte, F.; Hebner, R.
On the Influence of Thermal Lensing During Selective Laser Melting
(University of Texas at Austin, 2018) Goossens, Louca R.; Kinds, Yannis; Kruth, Jean-Pierre; Van Hooreweder, Brecht
Multi kilowatt single mode lasers are increasingly being used in Selective Laser Melting (SLM), typically with the aim of improving productivity. However, the high power densities present in the optical path lead to a thermally induced focal shift i.e. thermal lensing. Whilst thermal lensing has been studied for many processes, its impact on parts produced by SLM is currently unknown. Therefore this work discusses the characteristics of a thermally induced focal shift supplemented by a method for the compensation of this effect. In addition, SLM parts with and without thermal lensing compensation are compared in order to show the effect on final part quality.