FRIDAY MORNING, 11 MAY 2018 GREENWAY J, 8:00 A.M. TO 10:30 A.M. Session 5aPA Physical Acoustics: General Topics in Physical Acoustics II Sam Wallen, Chair The University of Texas at Austin Contributed Papers 8:00 that Berea Sandstone has significant hysteretic behavior under temperature cycling. It was also revealed that the qualitative elastic behavior of Berea 5aPA1. Generation of ultrasonic waves in vegetable tissue via non- Sandstone is unchanged with increasing relaxation time from the thermal David A. Collazos-Burbano (Ctr. for Bioinformatics ablative laser pulses. shock induced by rapid cooling of the sample. and Photonics (CIBioFi), Universidad del Valle, calle 13 No. 100-00, Univalle, 351, of 2009, Cali, Valle del Cauca 760032, Colombia, david. 8:30 [email protected]), Carlos A. Melo-Luna (Quantum Technol- ogies, Information and Complexity Group (QuanTIC), Universidad del 5aPA3. Elastic constants of self-healing polyethylene co-methacrylic Valle, Cali, Valle del cauca, Colombia), Joao L. Ealo (Vibrations and acid determined via resonant ultrasound spectroscopy. Kenneth A. Acoust. Lab. (LaVA), Mech. Eng. School, Universidad del Valle, Cali, Pestka II, Jacob W. Hull, Jonathan D. Buckley (Chemistry and Phys., Long- Colombia), and John H. Reina (Quantum Technologies, Information and wood Univ., 201 High St., Farmville, VA 23909, [email protected]), Complexity Group (QuanTIC), Universidad del Valle, Cali, Valle del and Stephen J. Kalista (The Dept. of Biomedical Eng., Rensselaer Polytech- Cauca, Colombia) nic Inst., Troy, NY) The study of vegetable tissue is essential in plant growth analysis. The Self-healing polyethylene co-methacrylic acid (EMAA) is a thermoplas- elasticity is an important characteristic when firmness is studied in fruits or tic material that can be shaped into structures that are capable of autono- when turgidity is tested in plant leaves. This property gives information mously healing after being cut, punctured, or shot. In this work, we present about the ripeness of fruits, the water content in leaves, and, in general, the results from several samples of self-healing EMAA-0.6 Na, with 60% of the morphological and physiological state of plants. Hence, the propagation of methacrylic acid groups neutralized by sodium, known as DuPont Surlyn elastic waves in these media is a useful tool that gives information about the 8920. This ionomer, unlike typical crystals with extremely high quality fac- developmental stage of the plant. In this sense, laser ultrasonics is a promis- tors and easily identifiable ultrasonic resonances, is a relatively soft poly- ing method in the characterization of composite materials. In a certain way, meric material with significant damping, resulting in sample resonances that vegetable tissues can be thought of as a kind of biological composite can overlap and are often difficult to identify and isolate. In this work, we abstracted as a stratified plate of several layers. In this work, as a first show the resonant spectrum of several different EMAA-0.6 Na samples as approximation, we propose a methodology to generate guided waves in veg- well as the methods used to isolate individual resonances and determine the etable tissues by using laser ultrasonics techniques. We implement a pulsed elastic constants. laser system to induce ultrasonic waves without damage on the samples. Besides, we develop a methodology for processing the propagated acoustic 8:45 waves. This analysis allows us the assessment of dispersive properties, a 5aPA4. An ultrafast broadband digital signal processing approach to useful tool when determining important descriptors such as firmness index, pulse echo measurements. Blake Sturtevant, Dipen N. Sinha, and Cristian water content, and provide useful information to feed biophysical models, Pantea (Mater. Phys. and Applications, Los Alamos National Lab., MPA- among others. 11, MS D429, Los Alamos, NM 87545, [email protected]) 8:15 Pulse-Echo (PE) measurements are commonly used to determine the sound velocity in a sample of known length. In PE measurements, the inter- 5aPA2. Probing dynamic response to temperature changes in Berea face between the transducer and buffer rod, and that between the buffer rod Sandstone using acoustic time-of-flight and resonant ultrasound spec- and sample, introduces a total phase shift, U, to the acoustic wave that must troscopy. Eric S. Davis, Cristian Pantea, Blake Sturtevant, and Dipen N. Sinha (Los Alamos National Lab., P.O. Box 1663, Los Alamos, NM 87545, be accounted for if high accuracy in the velocity is desired. The appropriate time correction, s=U/x, is traditionally determined by measuring the time- [email protected]) of-flight of multiple acoustic waves with different angular frequencies, x.A In this study, through-transmission acoustic time-of-flight experiments single PE measurement can take several minutes, depending on experimen- and bulk resonance tracking were used to study the anomalous elastic tal details such as the number of frequencies measured and the amount of behavior in Berea Sandstone with temperature cycling. Previously published signal averaging performed. Several minutes of data acquisition is tolerable results (Davis et al., 2016) using Resonant Ultrasound Spectroscopy (RUS) for static experiments, but it is too long for many dynamic processes of in- indicated that Berea Sandstone softens by as much as 10% when cooled terest in biology, pulsed magnetic fields, or any other rapidly changing sys- from 205C to 110C. This result is in contrast to the behavior of most tem. This work describes an approach to PE in which a single broadband materials, which stiffen when cooled. The time-of-flight experiments con- signal is collected and later processed offline using standard digital signal firmed the RUS results and revealed the need for additional analysis of this processing techniques. We demonstrate that a single captured waveform can phenomenon. By tracking the location of resonant frequencies at each tem- be processed to yield the same information as 80 separate waveforms col- perature step, the qualitative behavior of the sample was obtained without lected over an 80 MHz span, enabling accurate PE measurements on sub- the need for a rigorous RUS analysis. The results from this analysis showed second time scales. 1960 J. Acoust. Soc. Am., Vol. 143, No. 3, Pt. 2, March 2018 175th Meeting: Acoustical Society of America 1960 9:00 9:45 5aPA5. Two-point statistics of synthetic three-dimensional polycrystal- 5aPA7. A study on warning sound for drowsiness driving prevention line microstructures. Musa Norouzian and Joseph A. Turner (Dept. of system. Ik-Soo Ann (Cultural Contents, Soongsil Univ., 369 Sangdo-ro. Mech. and Mater. Eng., Univ. of Nebraska-Lincoln, W342 Nebraska Hall, Dongjak-gu, Seoul 156-743, South Korea, [email protected]) Lincoln, NE 68588-0526, [email protected]) The Korea Expressway Corporation has studied various preventive The two-point spatial statistics of a heterogeneous material are crucial in measures to prevent drowsiness driving accidents, such as providing various ultrasonic attenuation and backscatter calculations. In this presentation, sev- drowsiness driven prevention measures, establishing drowsiness rest areas, eral common assumptions used for modeling polycrystals are examined. In and operating alarms on drowsiness driving in highway tunnel have been most studies, the spatial and tensorial elements of the covariance function implemented. Recently, the Korea Transportation Safety has also used the are assumed to be decoupled. Also, two-point correlation models often monitoring of the driven state (DSM—Driven State Monitoring) and the assume a single effective grain size for polycrystalline materials and a spa- driving information of the vehicle (VDI—Vehicle Driving Information) to tial correlation function that has an exponential decay at a rate directly pro- confirm the state of the driver in the running car and perform a drowsiness portional to the average grain diameter. This investigation uses the driving and we are showing a good reaction by introducing a drowsiness Dream.3D software platform to generate three-dimensional (3D) realiza- driven prevention system which sounds vibration and warning sound. As tions of polycrystalline materials in order to study their two-point statistics. described earlier, when a driver wakes up during a drowsiness operation, a Using lognormal distributions with fixed means but different widths, a vari- warning sound plays an important role by installing it in a tunnel or in a car. ety of different polycrystalline microstructures are simulated. The results In this paper, we further developed the warning sound for battle against show that the spatial correlation function is directly influenced by the grain drowsiness used in the tunnel of the existing highway and studied focusing size distribution. For a fixed mean grain size, wider distributions exhibit lon- on using inside the vehicle. This research aims to verify and further improve ger range correlations than narrower ones. The results also show that decou- the warning sound part of the in-vehicle drowsiness driven prevention sys- pling of the tensorial and spatial elements of the covariance function may tem which is just introduced and enforced, effectively and contribute effec- not be valid for all lognormal grain size distributions. These results are tively to prevent drowsiness driven accidents. anticipated to have an important impact on ultrasonic attenuation and back- scatter models.