scholarly journals From Blowing Wind to Running Water: Unifying Sediment Transport

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Thomas P�htz ◽  
Abram Clark ◽  
Manousos Valyrakis ◽  
Orencio Dur�n
Keyword(s):  
Sediment Transport ◽  
Computer Simulations ◽  
Laboratory Experiments ◽  
Running Water ◽  
The Past ◽  
Oil Water

Laboratory experiments and grain-scale computer simulations during the past decade have led to a more universal understanding of flow-driven sediment transport across flows in oil, water, and air.

A Scientific Search for Altruism

2018 ◽  
Author(s):  
C. Daniel Batson
Keyword(s):  
Human Nature ◽  
Scientific Method ◽  
Laboratory Experiments ◽  
Fundamental Question ◽  
Empathic Concern ◽  
Altruistic Motivation ◽  
The Past ◽  
Past Half Century ◽  
Series Of Experiments ◽  
Past Half

This book provides an example of how the scientific method can be used to address a fundamental question about human nature. For centuries—indeed for millennia—the egoism–altruism debate has echoed through Western thought. Egoism says that the motivation for everything we do, including all of our seemingly selfless acts of care for others, is to gain one or another self-benefit. Altruism, while not denying the force of self-benefit, says that under certain circumstances we can care for others for their sakes, not our own. Over the past half-century, social psychologists have turned to laboratory experiments to provide a scientific resolution of this human nature debate. The experiments focused on the possibility that empathic concern—other-oriented emotion elicited by and congruent with the perceived welfare of someone in need—produces altruistic motivation to remove that need. With carefully constructed experimental designs, these psychologists have tested the nature of the motivation produced by empathic concern, determining whether it is egoistic or altruistic. This series of experiments has provided an answer to a fundamental question about what makes us tick. Framed as a detective story, the book traces this scientific search for altruism through the numerous twists and turns that led to the conclusion that empathy-induced altruism is indeed part of our nature. It then examines the implications of this conclusion—negative implications as well as positive—both for our understanding of who we are as humans and for how we might create a more humane society.

Acaricide resistance in the red tick, Rhipicephalus evertsi Neumann.

1961 ◽  
Vol 51 (4) ◽  
pp. 755-764 ◽  
Author(s):  
G. B. Whitehead ◽  
J. A. F. Baker
Keyword(s):  
South Africa ◽  
Laboratory Experiments ◽  
Sodium Arsenite ◽  
Field Trials ◽  
Cross Resistance ◽  
Acaricide Resistance ◽  
The Past ◽  
High Degree

Early in 1959, observations on the farm Tayside, in the East London district of South Africa, suggested that populations of the ‘two-host’ red tick, Rhipicephalns evertsi Neum., were more difficult to control with toxaphene preparations than they had been in the past. Resistance to toxaphene was suspected, and both field and laboratory experiments were carried out to investigate this possibility. Field trials indicated an increase in tolerance by Tayside populations of the tick to toxaphene, γ BHC and dieldrin, but showed no increased tolerance to sodium arsenite or DDT. Similar results were obtained in laboratory experiments where Tayside adults were compared with those of other populations of the tick known to be sensitive to insecticides. Laboratory experiments with larvae indicated a high degree of resistance to toxaphene and γ BHC in the Tayside population, but no increased tolerance to sodium arsenite, Delnav, Sevin or DDT could be detected. This pattern of cross-resistance is similar to that occurring in resistant populations of Boophilus dccoloratus(Koch).

Do we Worry about the Past and Grieve for the Future? Situated Anxiety or Depression, Mood Valence and Affective Time Travel, Separated by Experiment in a Questionnaire

2021 ◽  
Author(s):  
David A. Booth
Keyword(s):  
Negative Affect ◽  
Laboratory Experiments ◽  
Affective Response ◽  
Anxiety And Depression ◽  
Convenience Sample ◽  
Verbal Stimuli ◽  
Psychometric Scales ◽  
The Past ◽  
The Future ◽  
Fear And Anxiety

Some psychologists have viewed sadness and depression as reactions to past loss, while regarding fear and anxiety as responses to future threat. Such assumptions conflict with common experience of gloom about the future and worry about the past. Recent research on these issues by experiment and/or by questionnaire remains inconclusive. The psychometric questionnaires purport to be situation-free and the laboratory experiments use artificial tasks; hence, neither approach addresses realities in the present, past or future. In recent psychometrics, the distinction between anxiety and depression has been dissolved into one category of negative affect. One widely used inventory for separating the two emotions conflates depression with the absence of a good mood. These deficiencies were addressed in a diverse convenience sample (N = 379) by running an experiment entirely within a questionnaire. Each of the 40 question items was a miniature vignette, describing a past or future emotive situation while in bad or good mood. Five categories of situation varied in proportion of threat to loss. Strength and valence of affective response were measured by degree of autobiographical assent to or dissent from an item. This inventory provides fully affect-balanced situation-oriented depression / anxiety scaling.Effect sizes from analysis of variance showed that anxiety arises from past as well as future threats, while depression is at least as strongly oriented to losses in the future as in the past. Variation in category of situation or in valence of mood also had substantial effects. It is concluded that worry and gloom travel freely across time and situations, whether present mood is bad or good. Both laboratory experiments and psychometric scales come closer to actual processes of emotion and motivation when they revivify familiar situations using valence-balanced verbal stimuli.

scholarly journals SHEETFLOW SEDIMENT TRANSPORT UNDER SKEWED - ASYMMETRIC WAVES AND CURRENTS

2012 ◽  
Vol 1 (33) ◽  
pp. 50 ◽  
Author(s):  
Le Phuong Dong ◽  
Shinji Sato
Keyword(s):  
Sediment Transport ◽  
Laboratory Experiments ◽  
Fine Sand ◽  
Sand Transport ◽  
Phase Lag ◽  
Half Cycle ◽  
Experimental Conditions ◽  
Wide Range ◽  
Waves And Currents ◽  
Asymmetric Flows

Prototype scale laboratory experiments have been conducted to investigate the sheetflow sediment transport of uniform sands under different skewed-asymmetric oscillatory flows. Experimental results reveal that in most of the case with fine sand, the “cancelling effect”, which balances the on-/off-shore net transport under pure asymmetric/skewed flows and results a moderate net transport, was developed for combined skewed-asymmetric flow. However, under some certain conditions (T > 5s) with coarse sands, the onshore sediment transport was enhanced by 50% under combined skewed-asymmetric flows. Sand transport mechanism under oscillatory sheetflow conditions is also studied by comparing the maximum bed shear stress and the phase lag parameter at each half cycle. A comparison of measurements including the new experimental data with a number of practical sand transport formulations shows that the Dong et al. (2013) formulation performs the best in predicting the measured net transport rates over a wide range of experimental conditions

scholarly journals SURVEY TECHNIQUES/PROCEDURES AND DATA PROCESSING FOR MONITORING NEARSHORE SEDIMENT TRANSPORT

1982 ◽  
Vol 1 (18) ◽  
pp. 97
Author(s):  
J. Zacks
Keyword(s):  
Sediment Transport ◽  
Surf Zone ◽  
Survey Techniques ◽  
The Past ◽  
Bed Elevation ◽  
Innovative Methods ◽  
Survey Error ◽  
Nearshore Sediment Transport ◽  
The Many ◽  
The Cost

The cost of many coastal projects is often increased by the expensive beach repair and maintenance required to remedy the destabilising effects of structures on the adjoining coastline. Physical and/or mathematical models have been developed for use in planning these projects in order to predict and quantify the effects of marine sediment transport on the coastal topography. Such models need to be calibrated against prototype data and one method of gauging volumetric sediment movement is by successive bathymetric/ topographic profiting surveys which are performed seasonally and annually. Since large quantities of sediment are related to small changes in bed elevation it is clear that this profiling needs to be done with the utmost precision* The areas most affected extend from the beach through the surf zone to water depths of about 25 metres. The surf zone in particular is a dynamic and hostile area which falls outside the traditional activities of both the hydrographic and land surveyors. Consequently innovative methods, deficient in sound survey principle and practice, have often been pursued in this area without any attempt being made to assess the tolerance on the data. This paper attempts to show that it is possible to produce reliable and verifiable results to the required accuracy by using conventional survey equipment and techniques, also by taking the necessary precautions against the many possible sources of survey error. The procedures and techniques described have evolved from NRIO's involvement over the past decade in major projects at Richards Bay, Durban, Koeberg and in False Bay. The results of a recent verification investigation are fully reported in this paper.

Design and Analysis of Computer Experiments

2017 ◽  
pp. 264-279
Author(s):  
Xinwei Deng ◽  
Ying Hung ◽  
C. Devon Lin
Keyword(s):  
Complex Systems ◽  
Mathematical Models ◽  
Gaussian Process ◽  
Computer Simulations ◽  
Process Modeling ◽  
Computer Experiments ◽  
Space Filling ◽  
Science And Engineering ◽  
The Past ◽  
Statistical Approaches

Computer experiments refer to the study of complex systems using mathematical models and computer simulations. The use of computer experiments becomes popular for studying complex systems in science and engineering. The design and analysis of computer experiments have received broad attention in the past decades. In this chapter, we present several widely used statistical approaches for design and analysis of computer experiments, including space-filling designs and Gaussian process modeling. A special emphasis is given to recently developed design and modeling techniques for computer experiments with quantitative and qualitative factors.

THE APPLICATION OF MICROBIOLOGICALLY ENHANCED OIL RECOVERY TO THE ALTON FIELD, QUEENSLAND, AUSTRALIA

1987 ◽  
Vol 27 (1) ◽  
pp. 378
Author(s):  
B.F. Towler ◽  
B. Bubela
Keyword(s):  
Interfacial Tension ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Laboratory Experiments ◽  
Stock Tank ◽  
Remaining Oil ◽  
Oil Water

The Alton Field has produced 1.875 million stock tank barrels of oil and is nearing the end of its primary life. It is proposed to enhance the recovery from the field microbiologically. Surfactant producing bacteria will be injected into the reservoir in order to lower the oil/water interfacial tension and mobilise the remaining oil. Laboratory experiments on artifical cores have demonstrated the viability of this process. This MEOR project will initially be done in a one-well cyclic Huff and Puff program.

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