Hydrodynamic assessment of a semi-submersible aquaculture platform in uniform fluid environment

2021 ◽  
Vol 237 ◽  
pp. 109656
Author(s):  
Hang-Fei Liu ◽  
Chun-Wei Bi ◽  
Zhijing Xu ◽  
Yun-Peng Zhao
Keyword(s):  
Fluid Environment ◽  
Uniform Fluid

scholarly journals Dual Electrochemical Treatments to Improve Properties of Ti6Al4V Alloy

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2479
Author(s):  
Stefano Rossi ◽  
Luciana Volgare ◽  
Carine Perrin-Pellegrino ◽  
Carine Chassigneux ◽  
Erick Dousset ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Combined Treatment ◽  
Amorphous Film ◽  
Amorphous Layer ◽  
Good Alternative ◽  
Surface Treatments ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Fluid Environment

Surface treatments are considered as a good alternative to increase biocompatibility and the lifetime of Ti-based alloys used for implants in the human body. The present research reports the comparison of bare and modified Ti6Al4V substrates on hydrophilicity and corrosion resistance properties in body fluid environment at 37 °C. Several surface treatments were conducted separately to obtain either a porous oxide layer using nanostructuration (N) in ethylene glycol containing fluoride solution, or bulk oxide thin films through heat treatment at 450 °C for 3 h (HT), or electrochemical oxidation at 1 V for 3 h (EO), as well as combined treatments (N-HT and N-EO). In-situ X-ray diffraction and ex-situ transmission electron microscopy have shown that heat treatment gave first rise to the formation of a 30 nm thick amorphous layer which crystallized in rutile around 620 °C. Electrochemical oxidations gave rise to a 10 nm thick amorphous film on the top of the surface (EO) or below the amorphous nanotube layer (N-EO). Dual treated samples presented similar results with a more stable behavior for N-EO. Finally, for both corrosion and hydrophilicity points of view, the new combined treatment to get a total amorphous N-EO sample seems to be the best and even better than the partially crystallized N-HT sample.

scholarly journals Numerical Modeling of Sperm Swimming

Fluids ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 73
Author(s):  
Fang-Bao Tian ◽  
Li Wang
Keyword(s):  
Sperm Quality ◽  
Computational Studies ◽  
Theoretical Methods ◽  
Structure Interaction ◽  
Sperm Density ◽  
Fluid Environment ◽  
Complex Fluid ◽  
Fluid Rheology ◽  
Wall Interactions ◽  
Open Issues

Due to rising human infertility, sperm motility has been an important subject. Among the hundreds of millions of sperms on the journey up the oviducts, only a few excellent travelers will reach the eggs. This journey is affected by many factors, some of which include sperm quality, sperm density, fluid rheology and chemotaxis. In addition, the sperm swimming through different body tracks and fluids involves complex sperm flagellar, complex fluid environment, and multi-sperm and sperm-wall interactions. Therefore, this topic has generated substantial research interest. In this paper, we present a review of computational studies on sperm swimming from an engineering perspective with focus on both simplified theoretical methods and fluid–structure interaction methods. Several open issues in this field are highlighted.

The Use of the Chorioallantoic Membrane (CAM) of the Embryonic Chick for the Direct Assessment of Implant Toxicity

1985 ◽  
Vol 13 (4) ◽  
pp. 261-266
Author(s):  
P.P. Monro ◽  
D.P. Knight ◽  
W.S. Pringle ◽  
D.M. Fyfe ◽  
J.R. Shearer
Keyword(s):  
Chorioallantoic Membrane ◽  
In Vitro Techniques ◽  
Implant Materials ◽  
Metal Foils ◽  
Complex Interactions ◽  
Cobalt Nickel ◽  
Histological Criteria ◽  
Fluid Environment

The toxicity of implant materials requires investigation prior to clinical use. We have developed a method where materials are directly applied to the chorioallantoic membrane (CAM) of 9-day-old chick embryos and toxicity is assessed using histological criteria. We evaluated the method using metal foils. The number and organisation of fibroblasts seemed to be the most useful criteria for assessing metal toxicity. Differences were greatest after 10 days of culture on the CAM. The method is sensitive enough to enable us to discriminate between the less toxic aluminium and titanium and the highly toxic cobalt, nickel and tungsten. The proposed method has advantages over in vitro techniques which provide an abnormal fluid environment and in which the more complex interactions that are possible between implant materials and tissue in vivo cannot be modelled.

Summary—Fluid Environment of the Teeth

1966 ◽  
Vol 45 (3) ◽  
pp. 670-671
Author(s):  
Gordon H. Rovelstad
Keyword(s):  
Fluid Environment

A New Technology for Three-Dimensional Cell Culture: The Hydrodynamic Focusing Bioreactor

1999 ◽  
Author(s):  
Yow-Min D. Tsao ◽  
Steve R. Gonda
Keyword(s):  
Cell Culture ◽  
New Technology ◽  
Three Dimensional ◽  
Culture Vessel ◽  
Air Bubbles ◽  
Hydrodynamic Focusing ◽  
Shaped Cell ◽  
Fluid Environment ◽  
Dimensional Cell ◽  
Low Shear

Abstract The Hydrodynamic Focusing Bioreactor (HDFB) developed by NASA at the Johnson Space Center provides a unique hydrofocusing capability that simultaneously enables a low-shear culture environment and a unique hydrofocusing-based “herding” of suspended cells, cell aggregates, and air bubbles. The HDFB is a rotating dome-shaped cell culture vessel with a centrally located sampling port and an internal rotating viscous spinner attached to a rotating base. The vessel and viscous spinner can rotate at different speeds and in either the same or different directions. Adjusting the differential rotation rate between the vessel and spinner results in a controllable hydrodynamic focusing force. The resultant hydrodynamic force suspends the cells in a low-shear fluid environment that supports the formation of delicate three-dimensional tissue assemblies. Both suspension and anchorage-dependent cells have been successfully cultured.

Microfluidic device for generating regionalized concentration gradients under a stable and uniform fluid microenvironment

2018 ◽  
Vol 29 (1) ◽  
pp. 015008 ◽  
Author(s):  
Juan Wei ◽  
Chong Liu ◽  
Yang Jiang ◽  
Chunzheng Duan ◽  
Li Chen ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Concentration Gradients ◽  
Uniform Fluid

scholarly journals Wear and Corrosion of Wrought A6061 Aluminium Alloy in DOT3 Brake Fluid

2018 ◽  
Vol 7 (2.14) ◽  
pp. 512 ◽  
Author(s):  
Olawale Ajibola ◽  
Oladeji Ige ◽  
Peter Olubambi
Keyword(s):  
Corrosion Rate ◽  
Test Method ◽  
Alloy Sample ◽  
Corrosive Media ◽  
Chemical Corrosion ◽  
Brake Fluid ◽  
Wear And Corrosion ◽  
Cast Specimen ◽  
Fluid Environment ◽  
A6061 Alloy

The twofold impact of wear and corrosion on wrought A6061 alloy in hydraulic DOT3 brake fluid environment was studied. The wear studies were performed on the samples using a developed wear-jig. Weight loss corrosion test method was used to determine the corrosion rate of the wrought A6061 alloy samples immersed in the brake fluid for a total of 1680 hours. From the results of wear tests carried out on the A6061 alloy sample with brake oil, the highest wear value of 5.24x10-7 mg/mm2/cycle (approx.) was obtained from 6 N (approx) force after 130 minutes. The wrought A6061 alloy material demonstrated the highest corrosion rates nearly 3.0 x10-2 mg/mm2/yr within the early 168 hours of immersion in brake fluid. The result is practically lower than the corrosion rate of cast specimen in DOT3 brake oil or some other alloys immersed in other corrosive media that were previously reported in the literature. The results show that small amount of chemical corrosion is sufficient to cause and accelerate mechanical wear of the material in usage.

scholarly journals Elastic Response of Acoustic Coating on Fluid-Loaded Rib-Stiffened Cylindrical Shells

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Christopher Gilles Doherty ◽  
Steve C. Southward ◽  
Andrew J. Hull
Keyword(s):  
Cylindrical Shell ◽  
Cylindrical Shells ◽  
Coupled System ◽  
Elastic Response ◽  
System Response ◽  
Elastic Cylindrical Shell ◽  
Fluid Environment ◽  
Reinforcing Ribs ◽  
Double Index ◽  
Stress Boundary Conditions

Reinforced cylindrical shells are used in numerous industries; common examples include undersea vehicles, aircraft, and industrial piping. Current models typically incorporate approximation theories to determine shell behavior, which are limited by both thickness and frequency. In addition, many applications feature coatings on the shell interior or exterior that normally have thicknesses which must also be considered. To increase the fidelity of such systems, this work develops an analytic model of an elastic cylindrical shell featuring periodically spaced ring stiffeners with a coating applied to the outer surface. There is an external fluid environment. Beginning with the equations of elasticity for a solid, spatial-domain displacement field solutions are developed incorporating unknown wave propagation coefficients. These fields are used to determine stresses at the boundaries of the shell and coating, which are then coupled with stresses from the stiffeners and fluid. The stress boundary conditions contain double-index infinite summations, which are decoupled, truncated, and recombined into a global matrix equation. The solution to this global equation results in the displacement responses of the system as well as the exterior scattered pressure field. An incident acoustic wave excitation is considered. Thin-shell reference models are used for validation, and the predicted system response to an example simulation is examined. It is shown that the reinforcing ribs and coating add significant complexity to the overall cylindrical shell model; however, the proposed approach enables the study of structural and acoustic responses of the coupled system.

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