Daniel Huff | Northwestern University (original) (raw)
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The University of Texas Health Science Center at Houston
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Papers by Daniel Huff
Journal of Neurochemistry, 1984
Transport of seven different amino acids into brain slices increased as donor rats aged from 1 to... more Transport of seven different amino acids into brain slices increased as donor rats aged from 1 to 6 days. Uptakes of 2-aminoisobutyric acid, 2-(methylamino)isobutyric acid, and L-alanine then decreased by day 14, while uptakes of other amino acids continued to increase or remained fairly constant. Neutral a-amino acid transport systems were characterized by measuring inhibition of uptakes and kinetics for representative amino acids at different ages. Results indicate that 2-aminoisobutyrate and 2-(methy1amino)isobutyrate used only one (and the same) system in brain slices from 6-day-old rats, with characteristics of system A (the major sodiumdependent system in most mammalian cells). They used at least two systems at ages 1 , 14, and 23 days, but, of these, only at 1 day did they use the same systems in the
Structural Health Monitoring 2017
The detection and localization of in situ damage in complex sandwich material such as X-COR sandw... more The detection and localization of in situ damage in complex sandwich material such as X-COR sandwich composites using guided wave based structural health monitoring techniques is difficult due to the highly dispersive media and complex geometry, which complicates the interpretation of the reflected wave modes induced by damage. In this paper, a novel reference-free damage localization framework is developed, whereby converted wave modes are studied using their time-space representations constructed from sensor arrays signals. The source of each wave mode is subsequently localized using linear regression techniques. The X-COR sandwich structure utilized in this research was manufactured to include seeded facesheet delaminations. Macro-fiber composite sensors were bonded to the panel surface and used to validate the developed framework. Excellent agreement is shown between the predicted and actual locations of delamination and actuator. The results indicate that mode conversion is an effective damage indicator, and the proposed time-space based damage localization framework is a promising structural health monitoring tool for highly dispersive media.
SPIE Proceedings, 2013
ABSTRACT We describe a stochastic ltering approach for tracking progressive fatigue damage in str... more ABSTRACT We describe a stochastic ltering approach for tracking progressive fatigue damage in structures, wherein physically based damage evolution information is combined with active sensing guided wave measurements. The input waveform used to excite dispersive modes within the structure is adaptively con gured at each time step in order to maximize the damage estimation performance. The damage evolution model is based on Paris Law, and hidden Markov modeling of time-frequency features obtained from received signals is used to de ne the measurement model. Damage state estimation is performed using a particle lter. Results are presented for fatigue crack estimation in an aluminum specimen.
Journal of Neurochemistry - J NEUROCHEM, 1984
Transport of representative neutral a-amino acids was measured in brain slices after injecting th... more Transport of representative neutral a-amino acids was measured in brain slices after injecting thyroxine into donor rats of various ages from 1 to 23 days old. The hormone did not alter uptake in slices from 1day-old rats even when treatment was begun on pregnant rats as much as 10 days before delivery. Injecting thyroxine until age 6 days, however, decreased the activity of transport system A (the major sodium-dependent system in most mammalian cells) and caused appearance of a new transport system used by the model amino acids, 2-aminoisobutyric acid and 2-(methy1amino)isobutyric acid. Uptake at 6 days was similar to that found in slices from older, untreated rats (e.g., those 14 days old). These
Journal of Neurochemistry, 1984
Transport of seven different amino acids into brain slices increased as donor rats aged from 1 to... more Transport of seven different amino acids into brain slices increased as donor rats aged from 1 to 6 days. Uptakes of 2-aminoisobutyric acid, 2-(methylamino)isobutyric acid, and L-alanine then decreased by day 14, while uptakes of other amino acids continued to increase or remained fairly constant. Neutral a-amino acid transport systems were characterized by measuring inhibition of uptakes and kinetics for representative amino acids at different ages. Results indicate that 2-aminoisobutyrate and 2-(methy1amino)isobutyrate used only one (and the same) system in brain slices from 6-day-old rats, with characteristics of system A (the major sodiumdependent system in most mammalian cells). They used at least two systems at ages 1 , 14, and 23 days, but, of these, only at 1 day did they use the same systems in the
Structural Health Monitoring 2017
The detection and localization of in situ damage in complex sandwich material such as X-COR sandw... more The detection and localization of in situ damage in complex sandwich material such as X-COR sandwich composites using guided wave based structural health monitoring techniques is difficult due to the highly dispersive media and complex geometry, which complicates the interpretation of the reflected wave modes induced by damage. In this paper, a novel reference-free damage localization framework is developed, whereby converted wave modes are studied using their time-space representations constructed from sensor arrays signals. The source of each wave mode is subsequently localized using linear regression techniques. The X-COR sandwich structure utilized in this research was manufactured to include seeded facesheet delaminations. Macro-fiber composite sensors were bonded to the panel surface and used to validate the developed framework. Excellent agreement is shown between the predicted and actual locations of delamination and actuator. The results indicate that mode conversion is an effective damage indicator, and the proposed time-space based damage localization framework is a promising structural health monitoring tool for highly dispersive media.
SPIE Proceedings, 2013
ABSTRACT We describe a stochastic ltering approach for tracking progressive fatigue damage in str... more ABSTRACT We describe a stochastic ltering approach for tracking progressive fatigue damage in structures, wherein physically based damage evolution information is combined with active sensing guided wave measurements. The input waveform used to excite dispersive modes within the structure is adaptively con gured at each time step in order to maximize the damage estimation performance. The damage evolution model is based on Paris Law, and hidden Markov modeling of time-frequency features obtained from received signals is used to de ne the measurement model. Damage state estimation is performed using a particle lter. Results are presented for fatigue crack estimation in an aluminum specimen.
Journal of Neurochemistry - J NEUROCHEM, 1984
Transport of representative neutral a-amino acids was measured in brain slices after injecting th... more Transport of representative neutral a-amino acids was measured in brain slices after injecting thyroxine into donor rats of various ages from 1 to 23 days old. The hormone did not alter uptake in slices from 1day-old rats even when treatment was begun on pregnant rats as much as 10 days before delivery. Injecting thyroxine until age 6 days, however, decreased the activity of transport system A (the major sodium-dependent system in most mammalian cells) and caused appearance of a new transport system used by the model amino acids, 2-aminoisobutyric acid and 2-(methy1amino)isobutyric acid. Uptake at 6 days was similar to that found in slices from older, untreated rats (e.g., those 14 days old). These