Not Just Going with the Flow: The Effects of Fluid Flow on Bacteria and Plankton

2019 ◽  
Vol 35 (1) ◽  
pp. 213-237 ◽  
Author(s):  
Jeanette D. Wheeler ◽  
Eleonora Secchi ◽  
Roberto Rusconi ◽  
Roman Stocker
Keyword(s):  
Spatial Distribution ◽  
Fluid Flow ◽  
Human Body ◽  
Chaotic Motion ◽  
Nutrient Acquisition ◽  
Movement Behavior ◽  
Motion Characteristic

Microorganisms often live in habitats characterized by fluid flow, from lakes and oceans to soil and the human body. Bacteria and plankton experience a broad range of flows, from the chaotic motion characteristic of turbulence to smooth flows at boundaries and in confined environments. Flow creates forces and torques that affect the movement, behavior, and spatial distribution of microorganisms and shapes the chemical landscape on which they rely for nutrient acquisition and communication. Methodological advances and closer interactions between physicists and biologists have begun to reveal the importance of flow–microorganism interactions and the adaptations of microorganisms to flow. Here we review selected examples of such interactions from bacteria, phytoplankton, larvae, and zooplankton. We hope that this article will serve as a blueprint for a more in-depth consideration of the effects of flow in the biology of microorganisms and that this discussion will stimulate further multidisciplinary effort in understanding this important component of microorganism habitats.

Heat transfer modeling within the microclimate between 3D human body and clothing: effects of ventilation openings and fire intensity

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Miao Tian ◽  
Jun Li
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Temperature Distribution ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Human Body ◽  
Thermal Environment ◽  
Heat Transfer Process ◽  
Fire Intensity ◽  
Content Type

PurposeThe purpose of this study is to determine the effect of ventilation openings and fire intensity on heat transfer and fluid flow within the microclimate between 3D human body and clothing.Design/methodology/approachOn account of interaction effects of fire and ventilation openings on heat transfer process, a 3D transient computational fluid dynamics model considering the real shape of human body and clothing was developed. The model was validated by comparing heat flux history and distribution with experimental results. Heat transfer modes and fluid flow were investigated under three levels of fire intensity for the microclimate with ventilation openings and closures.FindingsTemperature distribution on skin surface with open microclimate was heavily depended on the heat transfer through ventilation openings. Higher temperature for the clothing with confined microclimate was affected by the position and direction of flames injection. The presence of openings contributed to the greater velocity at forearms, shanks and around neck, which enhanced the convective heat transfer within microclimate. Thermal radiation was the dominant heat transfer mode within the microclimate for garment with closures. On the contrary, convective heat transfer within microclimate for clothing with openings cannot be neglected.Practical implicationsThe findings provided fundamental supports for the ease and pattern design of the improved thermal protective systems, so as to realize the optimal thermal insulation of the microclimate on the garment level in the future.Originality/valueThe outcomes broaden the insights of results obtained from the mesoscale models. Different high skin temperature distribution and heat transfer modes caused by thermal environment and clothing structure provide basis for advanced thermal protective clothing design.

scholarly journals Laminar flow past the bottom with obstacles – a suspension approximation

2015 ◽  
Vol 63 (3) ◽  
pp. 685-695
Author(s):  
R. Wojnar ◽  
W. Bielski
Keyword(s):  
Experimental Data ◽  
Spatial Distribution ◽  
Fluid Flow ◽  
Laminar Flow ◽  
Gravity Force ◽  
Fluid Viscosity ◽  
Suspension Concentration ◽  
Flow Past ◽  
Flow Through

Abstract From Albert Einstein’s study (1905) it is known that suspension introduced to a fluid modifies its viscosity. We propose to describe the influence of obstacles on the Stokesian flow as a such modification. Hence, we treat the fluid flow through small obstacles as a flow with suspension. The flow is developing past the plane bottom under the gravity force. The spatial distribution of suspension concentration is treated as given, and is regarded as an approximation of different obstacles which modify the fluid flow and change its viscosity. The different densities of suspension are considered, beginning of small suspension concentration until 40%. The influence of suspension concentration on fluid viscosity is analyzed, and Brinkman’s formula as fitting best to experimental data is applied.

scholarly journals CHARACTERIZATION OF HETEROGENEITIES AT THE RESERVOIR SCALE: SPATIAL DISTRIBUTION AND INFLUENCE ON FLUID FLOW

2006 ◽  
Author(s):  
Michael R. Gross ◽  
Kajari Ghosh ◽  
Alex K. Manda ◽  
Sumanjit Aich
Keyword(s):  
Spatial Distribution ◽  
Fluid Flow

Dilatancy and spatial distribution of aftershocks

1974 ◽  
Vol 64 (6) ◽  
pp. 1707-1713
Author(s):  
Indra N. Gupta
Keyword(s):  
Spatial Distribution ◽  
Fluid Flow ◽  
Groundwater Flow ◽  
Compressive Stress ◽  
Seismic Velocity ◽  
Stress Axis ◽  
Shallow Earthquake ◽  
Preferred Direction ◽  
Seismic Velocity Changes ◽  
Velocity Changes

abstract The pre-earthquake dilatancy, postulated to explain certain premonitory seismic velocity changes, may provide a preferred direction of groundwater flow persisting after the occurrence of a shallow earthquake. This direction is parallel to and nearly coincident with the compressive stress axis associated with the focal mechanism of the principal shock. Aftershocks may result from a redistribution of pore pressure and fluid flow not only along faults but also along this direction of relatively large permeability. This suggestion provides a possible explanation for certain observations of aftershocks aligned along the compressive stress direction.

scholarly journals Cell adhesion and fluid flow jointly initiate genotype spatial distribution in biofilms

2018 ◽  
Vol 14 (4) ◽  
pp. e1006094 ◽  
Author(s):  
Ricardo Martínez-García ◽  
Carey D. Nadell ◽  
Raimo Hartmann ◽  
Knut Drescher ◽  
Juan A. Bonachela
Keyword(s):  
Spatial Distribution ◽  
Fluid Flow ◽  
Cell Adhesion

A New Model and its Implications for the Origin of Writing: The La Marche Antler Revisited

1995 ◽  
Vol 5 (2) ◽  
pp. 163-206 ◽  
Author(s):  
Francesco d'Errico
Keyword(s):  
Spatial Distribution ◽  
Theoretical Model ◽  
Present Article ◽  
Early Development ◽  
Human Body ◽  
Technical Analysis ◽  
Memory System ◽  
Modern Humans ◽  
New Model ◽  
Artificial Memory

Current models for the origin of writing do not pay sufficient attention to the origin and early development of means adopted by modern humans to record, transmit and process information outside the human body. The present article attempts to fill this gap by elaborating a theoretical model able to classify and describe the variability of these systems. The model is applied to the study of the engraved antler from La Marche, one of the better-known Palaeolithic objects to have been interpreted as an early system of notation. Technical analysis of the marks, through application of a range of experimental criteria, suggests that the sets of marks carved on this object should be interpreted as an artificial memory system with a complex code based on the morphology and the spatial distribution of the engraved marks. These results have important implications for current theories on the origin of writing.

Sign in / Sign up

Export Citation Format

Share Document