The Effects of Cracks and Fluids on Post-Seismic Healing

2020 ◽  
Author(s):  
Alison Malcolm ◽  
Somayeh Khajehpour Tadavani ◽  
Kristin Poduska
Keyword(s):  
Nonlinear Response ◽  
Laboratory Experiments ◽  
Recovery Process ◽  
Seismic Events ◽  
Wave Interactions ◽  
Material Control ◽  
Turn On ◽  
Nonlinear Mechanism ◽  
Underlying Mechanisms ◽  
Changing Noise

<p>It is now well established that large seismic events change the surrounding velocities, and that these velocities slowly recover over time.  Precisely which mechanisms control the recovery process are less well understood.  We present the results of laboratory experiments to better characterise what properties of the underlying material control the recovery process.  We do this by mixing two waves, one which perturbs the velocity of the sample (as an earthquake does in field data) and one which senses the change in velocity (as in changing noise correlations).  This is an inherently nonlinear experiment as we mix two waves and measure the effects of this wave mixing.  Within our experiments, we vary the properties of the samples to understand which are most important in controlling the nonlinear response.  We focus on two mechanisms.  The first is fractures and how changes in fracture properties change the nonlinear response.  The second is fluids, in particular the effect of low saturations on the nonlinear response.  By changing the fluids and fractures we can turn on and off the nonlinear mechanism, helping us to move toward a better understanding of the underlying mechanisms of these wave-wave interactions.</p>

Optimization of phosphorus precipitation from swine manure slurries to enhance recovery

2003 ◽  
Vol 48 (1) ◽  
pp. 139-146 ◽  
Author(s):  
R.T. Burns ◽  
L.B. Moody ◽  
I. Celen ◽  
J.R. Buchanan
Keyword(s):  
Reaction Time ◽  
Laboratory Experiments ◽  
Swine Manure ◽  
High Strength ◽  
Recovery Process ◽  
Molar Ratio ◽  
Swine Waste ◽  
High Concentration ◽  
Low Concentration ◽  
Addition Rate

Laboratory experiments were conducted using magnesium chloride (MgCl2·6H2O, 64% solution) to force the precipitation of phosphorus and reduce the concentration of soluble phosphorus (PO43-) in two swine wastes. One of the swine wastes tested contained a high concentration of PO43- (initially ≈1,000 mg/L), and the other swine waste tested contained a low concentration of PO43- (initially ≈230 mg/L). The precipitation reactions were performed to determine the required reaction time, pH, magnesium addition rate and seed material for future precipitate recovery work. For the high and low concentration waste, a 10-minute reaction time at a pH of 8.6 was sufficient to remove 98 and 96% of the PO43- from solution. A molar ratio of Mg2+:PO43- of 1.6:1 was determined to be effective for PO43- removal from both the low and high strength wastes. At a molar ratio of 1.6:1, the PO3- in the high concentration waste was reduced from 590 to 12 mg/L. In the low concentration waste, the PO43- concentration was reduced from 157 to 15 mg/L. Seeding the reaction did not significantly enhance the recovery process.

scholarly journals Episodic Bouts of Activity Accompany Recovery of Rhythmic Output By a Neuromodulator- and Activity-Deprived Adult Neural Network

2003 ◽  
Vol 90 (4) ◽  
pp. 2720-2730 ◽  
Author(s):  
Jason A. Luther ◽  
Alice A. Robie ◽  
John Yarotsky ◽  
Christopher Reina ◽  
Eve Marder ◽  
...  
Keyword(s):  
Neural Network ◽  
Neuronal Network ◽  
Recovery Process ◽  
Stomatogastric Ganglion ◽  
Cancer Borealis ◽  
Pyloric Network ◽  
Underlying Mechanisms ◽  
Over Time ◽  
Phase Relationships ◽  
Pyloric Rhythm

The pyloric rhythm of the stomatogastric ganglion of the crab, Cancer borealis, slows or stops when descending modulatory inputs are acutely removed. However, the rhythm spontaneously resumes after one or more days in the absence of neuromodulatory input. We recorded continuously for days to characterize quantitatively this recovery process. Activity bouts lasting 40–900 s began several hours after removal of neuromodulatory input and were followed by stable rhythm recovery after 1–4 days. Bout duration was not related to the intervals (0.3–800 min) between bouts. During an individual bout, the frequency rapidly increased and then decreased more slowly. Photoablation of back-filled neuromodulatory terminals in the stomatogastric ganglion (STG) neuropil had no effect on activity bouts or recovery, suggesting that these processes are intrinsic to the STG neuronal network. After removal of neuromodulatory input, the phase relationships of the components of the triphasic pyloric rhythm were altered, and then over time the phase relationships moved toward their control values. Although at low pyloric rhythm frequency the phase relationships among pyloric network neurons depended on frequency, the changes in frequency during recovery did not completely account for the change in phase seen after rhythm recovery. We suggest that activity bouts represent underlying mechanisms controlling the restructuring of the pyloric network to allow resumption of an appropriate output after removal of neuromodulatory input.

The Smartphone as a Pacifying Technology

2020 ◽  
Vol 47 (2) ◽  
pp. 237-255 ◽  
Author(s):  
Shiri Melumad ◽  
Michel Tuan Pham
Keyword(s):  
Large Scale ◽  
Laboratory Experiments ◽  
Stress Relief ◽  
Unique Combination ◽  
Personal Nature ◽  
Scale Field ◽  
Large Scale Field ◽  
Underlying Mechanisms ◽  
The Relationship ◽  
Actual Stress

Abstract In light of consumers’ growing dependence on their smartphones, this article investigates the nature of the relationship that consumers form with their smartphone and its underlying mechanisms. We propose that in addition to obvious functional benefits, consumers in fact derive emotional benefits from their smartphone—in particular, feelings of psychological comfort and, if needed, actual stress relief. In other words, in a sense, smartphones are not unlike adult pacifiers. This psychological comfort arises from a unique combination of properties that turn smartphones into a reassuring presence for their owners: the portability of the device, its personal nature, the subjective sense of privacy experienced while on the device, and the haptic gratification it affords. Results from one large-scale field study and three laboratory experiments support the proposed underlying mechanisms and document downstream consequences of the psychological comfort that smartphones provide. The findings show, for example, that (a) in moments of stress, consumers exhibit a greater tendency to seek out their smartphone (study 2); and (b) engaging with one’s smartphone provides greater stress relief than engaging in the same activity with a comparable device such as one’s laptop (study 3) or a similar smartphone belonging to someone else (study 4).

scholarly journals S36. TREATING NEGATIVE SYMPTOMS OF SCHIZOPHRENIA WITH A MOTIVE-SPECIFIC INTERVENTION: A RANDOMIZED BRIEF INTERVENTION TRIAL

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S45-S46
Author(s):  
Rahel Horisberger ◽  
Stefan Kaiser ◽  
Matthias Hartmann
Keyword(s):  
Negative Symptoms ◽  
Influencing Factor ◽  
Recovery Process ◽  
First Episode ◽  
Future Research ◽  
Symptom Scale ◽  
Social Motives ◽  
Group Relationships ◽  
Underlying Mechanisms ◽  
The Individual

Abstract Background Motivational deficits seem to be one of the main barriers in the recovery process among psychosis patients and have been shown to be very treatment resistant. Motives are conscious and unconscious affect-based needs that influence behavior toward specific incentives. Thus, they constitute the basis of motivated behavior or the lack thereof. In this study, we investigated how individual differences in social motives relate to the phenomenology of motivational negative symptoms in patients with schizophrenia. Methods Fifty-nine patients with a diagnosis of schizophrenia were included into the sample. Negative symptoms were measured with the Brief Negative Symptom Scale and social motives with the Questionnaire for the Zurich Model of Social Motivation. Between-group differences, Pearson correlations and regression analysis were calculated. We replicated and extended the results in a second sample of forty-five psychosis patients, using the same methods. Results A comparison of healthy controls and schizophrenia patients revealed significant differences in social motives. Within the patient group, relationships between the characteristics of the individual motives, in particular the achievement motive, and the severity of the motivational negative symptoms, i.e. of asociality, avolition and anhedonia, could be described. In contrast, social motives cannot be associated with diminished expression, the non-motivational dimension of negative symptoms. The duration of the disease seems to be an additional influencing factor: When comparing the motivational dispositions of first episode patients with those of healthy people, no differences were found. However, a relationship between the duration of the disease and the characteristics of social motives can be described. Discussion Explicit social motives stand in a relationship with motivational negative symptoms. Since implicit and explicit motives may diverge, the aim of our future research is to additionally investigate the association with implicit motives. The inclusion of psychological factors helps to extend and improve psychotherapeutic interventions for psychosis patients. Since negative symptoms do not respond well to pharmacotherapy, further efforts in this direction are needed to understand the underlying mechanisms of this disease and to develop effective psychotherapy tools in the future.

Laboratory experiments on counter-propagating collisions of solitary waves. Part 1. Wave interactions

2014 ◽  
Vol 749 ◽  
pp. 577-596 ◽  
Author(s):  
Yongshuai Chen ◽  
Harry Yeh
Keyword(s):  
Solitary Waves ◽  
Water Surface ◽  
Laboratory Experiments ◽  
Wave Amplitude ◽  
Relative Reduction ◽  
Wave Interactions ◽  
Oblique Collision ◽  
Laboratory Results ◽  
Surface Profiles ◽  
Good Agreement

AbstractCollisions of counter-propagating solitary waves are investigated experimentally. Precision measurements of water-surface profiles are made with the use of the laser induced fluorescence (LIF) technique. During the collision, the maximum wave amplitude exceeds that calculated by the superposition of the incident solitary waves, and agrees well with both the asymptotic prediction of Su & Mirie (J. Fluid Mech., vol. 98, 1980, pp. 509–525) and the numerical simulation of Craig et al. (Phys. Fluids, vol. 18, 2006, 057106). The collision causes attenuation in wave amplitude: the larger the wave, the greater the relative reduction in amplitude. The collision also leaves imprints on the interacting waves with phase shifts and small dispersive trailing waves. Maxworthy’s (J. Fluid Mech., vol. 76, 1976, pp. 177–185) experimental results show that the phase shift is independent of incident wave amplitude. On the contrary, our laboratory results exhibit the dependence of wave amplitude that is in support of Su & Mirie’s theory. Though the dispersive trailing waves are very small and transient, the measured amplitude and wavelength are in good agreement with Su & Mirie’s theory. Furthermore, we investigate the symmetric head-on collision of the highest waves possible in our laboratory. Our laboratory results show that the runup and rundown of the collision are not simple reversible processes. The rundown motion causes penetration of the water surface below the still-water level. This penetration causes the post-collision waveform to be asymmetric, with each departing wave tilting slightly backward with respect to the direction of its propagation; the penetration is also the origin of the secondary dispersive trailing wavetrain. The present work extends the studies of head-on collisions to oblique collisions. The theory of Su & Mirie, which was developed only for head-on collisions, predicts well in oblique collision cases, which suggests that the obliqueness of the collision may not be important for this ‘weak’ interaction process.

scholarly journals  Brine-Dependent Recovery Processes (Smart-Water/Low-Salinity-Water) in Carbonate and Sandstone Petroleum Reservoirs: Review of Laboratory-Field Studies, Interfacial Mechanisms and Modeling Attempts

2018 ◽  
Author(s):  
Adedapo N. Awolayo ◽  
Hemanta K. Sarma ◽  
Long X. Nghiem
Keyword(s):  
Oil Recovery ◽  
Carbonate Rocks ◽  
Ionic Composition ◽  
Recovery Process ◽  
Field Studies ◽  
Field Trials ◽  
Research Area ◽  
Wettability Alteration ◽  
Smart Water ◽  
Underlying Mechanisms

Brine-dependent recovery process has seen much global research efforts in the past two decades because of their benefits over other oil recovery methods. The process involves the tweaking of the ionic composition and strength of the injected water to improve oil production. In recent years, several studies ranging from laboratory coreflood experiments by many researchers to field trials by several companies admit to the potential of recovering additional oil in sandstone and carbonate reservoirs. Sandstone and carbonate rocks are composed of completely different minerals, with varying degree of complexity and heterogeneity, but wettability alteration has been widely considered as the consequence rather than the cause of brine-dependent recovery. However, there is no consensus on the cause as several mechanisms have been proposed to relate the wettability changes to the improved recovery. This review paper aims to provide a state-of-the-art development in published research and various efforts of the industry. This review outlines an overview of laboratory and field observations, descriptions of underlying mechanisms and their validity, the complexity of the oil-brine-rock interactions, modelling works, and comparison between sandstone and carbonate rocks. The provided information is intended to provide the reader with up-to-date information, point to relevant studies for those who are new and those implementing either laboratory- or field-scale projects to speed up the process of further investigations in this research area. Overall, the outcome of this review would potentially be of immense benefit to the oil industry.

Injured Distance Runners: A Case of Identity Work as Self-Help

2005 ◽  
Vol 22 (1) ◽  
pp. 38-58 ◽  
Author(s):  
John Hockey
Keyword(s):  
Athletic Identity ◽  
Recovery Process ◽  
Identity Work ◽  
Differential Association ◽  
Distance Runners ◽  
Long Distance ◽  
Vital Part ◽  
Turn On ◽  
Self Help ◽  
The Face

This article examines the importance of “identity work” for the maintenance of athletic identity in the face of prolonged injury, and the part that type of work played in successful athletic rehabilitation. It is based on collaborative autoethnographic research undertaken by two middle/long distance runners during a 2-year period of injury and rehabilitation. The narrative delineates the various kinds of identity work that were crucial to the process of rehabilitation, focusing in turn on routines and settings, appearance and embodiment, identity talk, and differential association. The article concludes by conceptualizing identity work as a strategy that can play a vital part in the recovery process of injured athletes.

scholarly journals Low-order models of wave interactions in the transition to baroclinic chaos

1996 ◽  
Vol 3 (3) ◽  
pp. 150-165 ◽  
Author(s):  
W.-G. Früh
Keyword(s):  
Laboratory Experiments ◽  
Phase Locking ◽  
Zonal Flow ◽  
Wave Interactions ◽  
Discontinuous Bifurcation ◽  
Two Layer Model ◽  
Resonant Triads ◽  
Multi Mode ◽  
Recent Laboratory ◽  
Low Order

Abstract. A hierarchy of low-order models, based on the quasi-geostrophic two-layer model, is used to investigate complex multi-mode flows. The different models were used to study distinct types of nonlinear interactions, namely wave- wave interactions through resonant triads, and zonal flow-wave interactions. The coupling strength of individual triads is estimated using a phase locking probability density function. The flow of primary interest is a strongly modulated amplitude vacillation, whose modulation is coupled to intermittent bursts of weaker wave modes. This flow was found to emerge in a discontinuous bifurcation directly from a steady wave solution. Two mechanism were found to result in this flow, one involving resonant triads, and the other involving zonal flow-wave interactions together with a strong β-effect. The results will be compared with recent laboratory experiments of multi-mode baroclinic waves in a rotating annulus of fluid subjected to a horizontal temperature gradient.

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