Snakes, the evolution of mystery in nature

Fundamentals of Vibrations

Hydrodynamics and surface properties influence biofilm proliferation.

Over the past decades, several materials utilized as biocarriers for immobilization of microorganisms have been gaining popularity showing different degrees of effectiveness. However, information concerning their effects on sequencing batch biofilm reactors (SBBR) performance is still lacking. There is currently no single widely acceptable material documented for proper biofilm formation, as most materials cannot achieve satisfactory level. Problems of biocarrier also exists due to the emergence of newer and more complex pollutants. Therefore, resource-efficient and environmentally friendly biocarriers are a call of the hour. This article thus, presents a systematic literature review of existing research articles on the various advances made between 2005 and 2021 about biocarrier physical properties, and performances with specific focus on their contributions in biofilm formation, nutrients and organic matter removal. This is to establish their role as central elements in biofilm formation. The review further described the operational challenges, mass transfer considerations, and recommendations made during successful utilization of the biocarriers in SBBR systems. Future research areas that may ultimately lead to large-scale commercial application of this biocarriers and will result in sustainable and environmentally friendly solution to the problems created during wastewater treatment have also been identified. This paper suggests that future researchers investigate the efficiency of composite biocarriers. It is believed that information contained in this review will increase readers fundamental knowledge, guide future researchers and be incorporated into future works on experimentally-based studies on biocarriers in SBBR systems.

A systematic literature review of biocarriers : central elements for biofilm formation, organic and nutrients removal in sequencing batch biofilm reactor

日本ロボット学会誌 = Journal of the Robotics Society of Japan

Stiff scales adorn the exterior surfaces of fishes, snakes, and many reptiles. They provide protection from external piercing attacks and control over global deformation behavior to aid locomotion, slithering, and swimming across a wide range of environmental condition. In this report, we investigate the dynamic behavior of biomimetic scale substrates for further understanding the origins of the nonlinearity that involve various aspect of scales interaction, sliding kinematics, interfacial friction, and their combination. Particularly, we study the vibrational characteristics through an analytical model and numerical investigations for the case of a simply supported scale covered beam. Our results reveal for the first time that biomimetic scale beams exhibit viscous damping behavior even when only Coulomb friction is postulated for free vibrations. We anticipate and quantify the anisotropy in the damping behavior with respect to curvature. We also find that unlike static pure bending where friction increases bending stiffness, a corresponding increase in natural frequency for the dynamic case does not arise for simply supported beam. Since both scale geometry, distribution and interfacial properties can be easily tailored, our study indicates a biomimetic strategy to design exceptional synthetic materials with tailorable damping behavior.

Frictional Damping from Biomimetic Scales.

In this letter, we investigate the geometrically tailorable elasticity in the twisting behavior of biomimetic scale-covered slender soft substrate. Motivated by our qualitative experiments showing a significant torsional rigidity increase, we develop an analytical model and carry out extensive finite element (FE) simulations to validate our model. We discover a regime differentiated and reversible mechanical response straddling linear, nonlinear, and rigid behavior. The response is highly tailorable through the geometric arrangement and orientation of the scales. The work outlines analytical relationships between geometry, deformation modes and kinematics, which can be used for designing biomimetic scale-covered metamaterials.

https://iopscience.iop.org/article/10.1209/0295-5075/127/24002/pdf

Tailorable twisting of biomimetic scale-covered substrate

Bending of biomimetic scale covered beams under discrete non-periodic engagement

In this letter, we investigate the geometrically tailorable elasticity in the twisting behavior of biomimetic scale-covered slender soft substrate Motivated by our qualitative experiments showing a significant torsional rigidity increase, we develop an analytical model and carry out extensive finite element (FE) simulations to validate our model We discover a regime differentiated and reversible mechanical response straddling linear, nonlinear, and rigid behavior The response is highly tailorable through the geometric arrangement and orientation of the scales The work outlines analytical relationships between geometry, deformation modes and kinematics, which can be used for designing biomimetic scale-covered metamaterials

Hessein Ali

Papers

Hydrodynamics and surface properties influence biofilm proliferation.

Frictional Damping from Biomimetic Scales.

Tailorable twisting of biomimetic scale-covered substrate

Bending of biomimetic scale covered beams under discrete non-periodic engagement

Tailorable Twisting of Biomimetic Scale-Covered Substrate