Whitney umbrella and slow-motion bifurcations of relaxation-type equations

2005 ◽  
Vol 126 (4) ◽  
pp. 1251-1258 ◽  
Author(s):  
A. A. Davydov
Keyword(s):  
Slow Motion ◽  
Whitney Umbrella

Current Issues: Advanced Digital Technology for Supervising Graduate Clinicians

2010 ◽  
Vol 20 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Glenn Tellis ◽  
Lori Cimino ◽  
Jennifer Alberti
Keyword(s):  
Real Time ◽  
Digital Technology ◽  
Clinical Training ◽  
State Of The Art ◽  
Clinical Skills ◽  
Slow Motion ◽  
Video Capture ◽  
Microsoft Excel ◽  
Clinical Supervisors ◽  
Training And Supervision

Abstract The purpose of this article is to provide clinical supervisors with information pertaining to state-of-the-art clinic observation technology. We use a novel video-capture technology, the Landro Play Analyzer, to supervise clinical sessions as well as to train students to improve their clinical skills. We can observe four clinical sessions simultaneously from a central observation center. In addition, speech samples can be analyzed in real-time; saved on a CD, DVD, or flash/jump drive; viewed in slow motion; paused; and analyzed with Microsoft Excel. Procedures for applying the technology for clinical training and supervision will be discussed.

Spin-Echo Experiment with NMR Spectra only Partially Narrowed by an Insufficiently Fast Motion

2003 ◽  
Vol 68 (7) ◽  
pp. 1193-1205
Author(s):  
Jaromír Jakeš
Keyword(s):  
Time Delay ◽  
Autocorrelation Function ◽  
Nmr Spectra ◽  
Spin Echo ◽  
Slow Motion ◽  
Linear Least Squares ◽  
Least Squares Adjustment ◽  
Fast Motion ◽  
Motional Narrowing ◽  
Gaussian Line

The spin-echo experiment on a spin system with only partial motional narrowing and an exponential field autocorrelation function is considered. The pattern of the intensity decrease in the echo spectra depends on the ratio τ/τc of the time delay τ in the echo experiment to the correlation time τc of the narrowing motion. With the large ratios (fast motion), the decrease is the same as in the case of extreme narrowing; to obtain undistorted T2 values, the ratio should be at least several units in the single-echo experiment and at least few decades in the multiple-echo experiment. With the small ratios (slow motion), the logarithmic decrease depends non-linearly on τ, and the T2 value found by the linear least-squares adjustment is much longer than that obtained from the extreme narrowing approximation. At very small ratios, the multiple echo yields about 3τc/(ωpτ)2 for T2 as compared with 1/(ωp2rc) obtained from the extreme narrowing approximation; ωp2 is the second moment of the Gaussian line being narrowed. The expression for T2 in the multiple spin echo is similar to that previously found for T2e in the solid multiple spin echo. The echo experiment changes the line shape, which at large τ/τc approaches the Lorentzian one. The case of a multiexponential field autocorrelation function is also briefly considered.

A Rheo-optical Investigation into the Viscoelastic Moduli of Acidified Milk Gel

1999 ◽  
Vol 9 (6) ◽  
pp. 246-253 ◽  
Author(s):  
E. O. Arikainen ◽  
J. C. Earnshaw ◽  
A. Wehling ◽  
E. Waghorne
Keyword(s):  
Correlation Function ◽  
Mean Square Displacement ◽  
Slow Motion ◽  
Casein Micelle ◽  
Optical Investigation ◽  
Viscoelastic Moduli ◽  
Decay Times ◽  
Delay Times ◽  
Intensity Correlation Function ◽  
Viscoelastic Modulus

Abstract Diffusing wave spectroscopy (DWS) in the backscattering geometry was employed to observe the evolution of the intensity correlation function during the acidification of skimmed milk by gluconic-δ-lactone (GDL). At the stage when the formation of casein particle gel is largely complete the correlation function at shorter decay times reveals the local structural arrest of the casein micelles, whereas at longer delay times it illustrates the hindered slow motion of casein micelle aggregates. We use the principles of the approach suggested by Mason, Gang and Weitz, linking the optically measured mean square displacement, <Δr2(t)>, of the microscopic particles in a dense colloid to its viscoelastic properties, to provide an estimate of the frequency dependent viscoelastic modulus of the acidified milk gel (AMG). We compare the viscoelastic moduli measured by the conventional mechanical rheometry with the optically measured ones. The results of the two different experimental methods are found to be in reasonable agreement.

scholarly journals The Fennoscandian Shield deep terrestrial virosphere suggests slow motion ‘boom and burst’ cycles

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Karin Holmfeldt ◽  
Emelie Nilsson ◽  
Domenico Simone ◽  
Margarita Lopez-Fernandez ◽  
Xiaofen Wu ◽  
...  
Keyword(s):  
Antibiotic Production ◽  
Nutrient Recycling ◽  
Slow Motion ◽  
Deep Biosphere ◽  
Wide Range ◽  
Domains Of Life ◽  
Microbial Turnover ◽  
Rna Transcript ◽  
Viral Isolates ◽  
Antagonistic Interactions

AbstractThe deep biosphere contains members from all three domains of life along with viruses. Here we investigate the deep terrestrial virosphere by sequencing community nucleic acids from three groundwaters of contrasting chemistries, origins, and ages. These viromes constitute a highly unique community compared to other environmental viromes and sequenced viral isolates. Viral host prediction suggests that many of the viruses are associated with Firmicutes and Patescibacteria, a superphylum lacking previously described active viruses. RNA transcript-based activity implies viral predation in the shallower marine water-fed groundwater, while the deeper and more oligotrophic waters appear to be in ‘metabolic standby’. Viral encoded antibiotic production and resistance systems suggest competition and antagonistic interactions. The data demonstrate a viral community with a wide range of predicted hosts that mediates nutrient recycling to support a higher microbial turnover than previously anticipated. This suggests the presence of ‘kill-the-winner’ oscillations creating slow motion ‘boom and burst’ cycles.

scholarly journals Southeast Asian clearwing moths buzz like their model bees

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Marta Skowron Volponi ◽  
Luca Pietro Casacci ◽  
Paolo Volponi ◽  
Francesca Barbero
Keyword(s):  
Slow Motion ◽  
Southeast Asian ◽  
Batesian Mimicry ◽  
Evolutionary Models ◽  
Acoustic Parameters ◽  
Warning Signals ◽  
Visual Model ◽  
Flying Insects

Abstract Background The endless struggle to survive has driven harmless species to evolve elaborate strategies of deceiving predators. Batesian mimicry involves imitations of noxious species’ warning signals by palatable mimics. Clearwing moths (Lepidoptera: Sesiidae), incapable of inflicting painful bites or stings, resemble bees or wasps in their morphology and sometimes imitate their behaviours. An entirely unexplored type of deception in sesiids is acoustic mimicry. We recorded the buzzing sounds of two species of Southeast Asian clearwing moths, Heterosphecia pahangensis and H. hyaloptera and compared them to their visual model bee, Tetragonilla collina, and two control species of bees occurring in the same habitat. Recordings were performed on untethered, flying insects in nature. Results Based on eight acoustic parameters and wingbeat frequencies calculated from slow-motion videos, we found that the buzzes produced by both clearwing moths highly resemble those of T. collina but differ from the two control species of bees. Conclusions Acoustic similarities to bees, alongside morphological and behavioural imitations, indicate that clearwing moths display multimodal mimicry of their evolutionary models.

scholarly journals A New Method to Verify the Measurement Speed and Accuracy of Frequency Modulated Interferometers

2021 ◽  
Vol 11 (13) ◽  
pp. 5787
Author(s):  
Toan-Thang Vu ◽  
Thanh-Tung Vu ◽  
Van-Doanh Tran ◽  
Thanh-Dong Nguyen ◽  
Ngoc-Tam Bui
Keyword(s):  
Phase Change ◽  
High Speed ◽  
Measurement Accuracy ◽  
Slow Motion ◽  
New Method ◽  
Virtual Displacement ◽  
Electro Optic ◽  
Lock In ◽  
Speed And Accuracy ◽  
Electro Optic Modulator

The measurement speed and measurement accuracy of a displacement measuring interferometer are key parameters. To verify these parameters, a fast and high-accuracy motion is required. However, the displacement induced by a mechanical actuator generates disadvantageous features, such as slow motion, hysteresis, distortion, and vibration. This paper proposes a new method for a nonmechanical high-speed motion using an electro-optic modulator (EOM). The method is based on the principle that all displacement measuring interferometers measure the phase change to calculate the displacement. This means that the EOM can be used to accurately generate phase change rather than a mechanical actuator. The proposed method is then validated by placing the EOM into an arm of a frequency modulation interferometer. By using two lock-in amplifiers, the phase change in an EOM and, hence, the corresponding virtual displacement could be measured by the interferometer. The measurement showed that the system could achieve a displacement at 20 kHz, a speed of 6.08 mm/s, and a displacement noise level < 100 pm//√Hz above 2 kHz. The proposed virtual displacement can be applied to determine both the measurement speed and accuracy of displacement measuring interferometers, such as homodyne interferometers, heterodyne interferometers, and frequency modulated interferometers.

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