Energetics of Ciliary Movement in Sabellaria and Mytilus

1969 ◽  
Vol 50 (3) ◽  
pp. 733-743
Author(s):  
M. A. SLEIGH ◽  
M. E. J. HOLWILL
Keyword(s):  
High Speed ◽  
Angular Frequency ◽  
Viscous Resistance ◽  
Ciliary Movement ◽  
Viscous Forces ◽  
Ciliary Motion ◽  
Elastic Forces ◽  
Gill Filaments ◽  
Recovery Stroke ◽  
Work Done

1. High-speed cinephotography has been used to study the movements performed by compound cilia from the segmental gills of Sabellaria and from the abfrontal face of the gill filaments of Mytilus. 2. The two types of cilium have distinctly different beat patterns. 3. Equations are derived which allow the calculation of the energy necessary to overcome viscous resistance during the effective and recovery strokes of a cilium in terms of its dimensions and angular frequency. 4. In Sabellaria cilia the energy needed to overcome viscous forces is greater for the effective stroke than for the recovery stroke, but the reverse is true for Mytilus abfrontal cilia. 5. Estimates of the work done to overcome elastic forces are probably too high, but it appears that the elastic work done in the recovery stroke is greater than that in the effective stroke for cilia of both types if the stiffness remains constant throughout the beat. 6. The energy released if each fibrillar arm causes the breakdown of one ATP molecule per beat cycle is greater than that required to overcome viscous resistance to ciliary motion.

A Quantitative Analysis of Ciliary Movement by Means of High-Speed Microcinematography

1970 ◽  
Vol 52 (3) ◽  
pp. 675-690 ◽  
Author(s):  
SHOJI A. BABA ◽  
YUKIO HIRAMOTO
Keyword(s):  
High Speed ◽  
Quantitative Description ◽  
Bending Moment ◽  
Viscous Resistance ◽  
Movement Duration ◽  
Ciliary Movement ◽  
Basal Angle ◽  
Active Processes ◽  
Bending Wave ◽  
Ciliary Shaft

1. An optical arrangement for high-speed microcinematography has been designed so as to record ciliary movement, and the movements of single large abfrontal cilia of Mytilus gill have been photographed at 400-500 frames/sec, with brief exposures of 1/20,000 sec. 2. A quantitative description of the movement of the cilium is presented in terms of the changes of the curvature at various regions of the ciliary shaft and of the change of the basal angle. 3. The principle of the description mentioned above is also applied to the movement of the cilium in media of high viscosities, and some parameters of the movement (duration, amplitude of the basal angle, maximum curvature and propagation velocity of the bending wave) are presented. 4. The resistance experienced by the cilium during its beating has been evaluated under some hydrodynamic assumptions, and the flow induced by the cilium and the bending moment of the ciliary shaft due to the viscous resistance have been calculated over a single beat. 5. The change of the degree of bending of the ciliary shaft (curvature) takes place in advance of the change of the bending moment at the same region in the distal as well as in the proximal regions of the ciliary shaft. This fact indicates that active processes are involved in bending and unbending of the ciliary shaft during its beat.

scholarly journals Contribution of Viscous Forces to Avalanche Dynamics

1989 ◽  
Vol 13 ◽  
pp. 202-206 ◽  
Author(s):  
K. Nishimura ◽  
N. Maeno
Keyword(s):  
Dry Friction ◽  
Kinematic Viscosity ◽  
Viscosity Coefficient ◽  
Viscous Force ◽  
Viscous Resistance ◽  
Resistance Factors ◽  
Viscous Forces ◽  
Viscosity Coefficients ◽  
Avalanche Dynamics ◽  
The Individual

Mini-avalanche systems were constructed both in a low-temperature laboratory and in a snowfield, and the behaviour of the flowing snow was observed in each case. Velocity profiles for the individual snow particles were determined and these implied that a viscous force, which has been neglected in most previous numerical simulations of snow-avalanche motion, needs to be taken into account for many avalanches. Kinematic viscosity coefficients for the fluidized snow were also measured using a modified Stormer-type viscometer. Substituting the dry-friction value and the kinematic viscosity coefficient for fluidized snow into the equation for avalanche motion, numerical simulation of natural events was achieved for the Shiai-dani region. Taking viscous resistance factors into account led to the conclusion that the magnitude of turbulent resistance of snow in avalanche systems is probably much smaller than that represented by the values previously in use.

Design for Testability of High-Speed Advance Multipliers

2020 ◽  
pp. 175-190
Author(s):  
Suman Lata Tripathi
Keyword(s):  
High Speed ◽  
High Performance ◽  
Design For Testability ◽  
Online Testing ◽  
Efficient Design ◽  
Self Test ◽  
Built In Self Test ◽  
Work Done ◽  
Testing Work ◽  
Circuit Under Test

An efficient design for testability (DFT) has been a major thrust of area for today's VLSI engineers. A poorly designed DFT would result in losses for manufacturers with a considerable rework for the designers. BIST (built-in self-test), one of the promising DFT techniques, is rapidly modifying with the advances in technology as the device shrinks. The increasing complexities of the hardware have shifted the trend to include BISTs in high performance circuitry for offline as well as online testing. Work done here involves testing a circuit under test (CUT) with built in response analyser and vector generator with a monitor to control all the activities.

scholarly journals Deep phenotyping, including quantitative ciliary beating parameters, and extensive genotyping in primary ciliary dyskinesia

2019 ◽  
Vol 57 (4) ◽  
pp. 237-244 ◽  
Author(s):  
Sylvain Blanchon ◽  
Marie Legendre ◽  
Mathieu Bottier ◽  
Aline Tamalet ◽  
Guy Montantin ◽  
...  
Keyword(s):  
Primary Ciliary Dyskinesia ◽  
High Speed ◽  
Genetic Disorder ◽  
Beat Frequency ◽  
Ciliary Beat Frequency ◽  
Central Complex ◽  
Ciliary Beating ◽  
Recovery Stroke ◽  
Biallelic Mutations ◽  
Ciliary Dyskinesia

BackgroundPrimary ciliary dyskinesia (PCD) is a rare genetic disorder resulting in abnormal ciliary motility/structure, extremely heterogeneous at genetic and ultrastructural levels. We aimed, in light of extensive genotyping, to identify specific and quantitative ciliary beating anomalies, according to the ultrastructural phenotype.MethodsWe prospectively included 75 patients with PCD exhibiting the main five ultrastructural phenotypes (n=15/group), screened all corresponding PCD genes and measured quantitative beating parameters by high-speed video-microscopy (HSV).ResultsSixty-eight (91%) patients carried biallelic mutations. Combined outer/inner dynein arms (ODA/IDA) defect induces total ciliary immotility, regardless of the gene involved. ODA defect induces a residual beating with dramatically low ciliary beat frequency (CBF) related to increased recovery stroke and pause durations, especially in case of DNAI1 mutations. IDA defect with microtubular disorganisation induces a low percentage of beating cilia with decreased beating angle and, in case of CCDC39 mutations, a relatively conserved mean CBF with a high maximal CBF. Central complex defect induces nearly normal beating parameters, regardless of the gene involved, and a gyrating motion in a minority of ciliated edges, especially in case of RSPH1 mutations. PCD with normal ultrastructure exhibits heterogeneous HSV values, but mostly an increased CBF with an extremely high maximal CBF.ConclusionQuantitative HSV analysis in PCD objectives beating anomalies associated with specific ciliary ultrastructures and genotypes. It represents a promising approach to guide the molecular analyses towards the best candidate gene(s) to be analysed or to assess the pathogenicity of the numerous sequence variants identified by next-generation-sequencing.

Preparation of SiO2/PEG Shear Thickening System by Centrifugal Dispersion

2012 ◽  
Vol 560-561 ◽  
pp. 586-590 ◽  
Author(s):  
Biao Yang ◽  
Sheng Wang ◽  
Guo Zhi Xu ◽  
Fei Xin
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
High Speed ◽  
Rotation Speed ◽  
Loss Modulus ◽  
Shear Thickening ◽  
Angular Frequency ◽  
Revolution Speed ◽  
Centrifugal Dispersion ◽  
The Revolution

The nano-SiO2/polyethylene glycol (PEG) dispersion system was prepared by centrifugal mixing, and its rheological properties were investigated. The results showed the revolution and rotation speed during the centrifugal mixing have a significant effect on the rheological properties of SiO2/PEG system. When the revolution speed of the centrifugal mixer was fixed at a high speed of 1200rpm, the shear thickening effect of SiO2/PEG was gradually increased with the decrease of rotation speed, and the maximum viscosity (η) of 12340 mPa•s appeared at the rotation speed of 200 rpm. At the low revolution speed of 700 rpm, the increase of the rotation speed significantly enhanced the shear thickening effect. When the rotation speed was 700rpm, the maximum viscosity was up to 86130mPa s. In steady state experiments, the systems show a shear-thinning property under low shear rate. When the shear rate exceeded a critical value (γ= 24.92 s-1), the viscosity first increased, and then decreased sharply. In the dynamic experiments, with the increase of angular frequency (ω), the loss modulus (G″) also increased and the systems behaved as a shear-thickening fluid.

scholarly journals Seeing cilia: imaging modalities for ciliary motion and clinical connections

2018 ◽  
Vol 314 (6) ◽  
pp. L909-L921 ◽  
Author(s):  
Jacelyn E. Peabody ◽  
Ren-Jay Shei ◽  
Brent M. Bermingham ◽  
Scott E. Phillips ◽  
Brett Turner ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging Modalities ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Disease States ◽  
Transmission Electron ◽  
Ciliary Motion ◽  
Health And Disease ◽  
Motion Imaging ◽  
Ciliary Dyskinesia

The respiratory tract is lined with multiciliated epithelial cells that function to move mucus and trapped particles via the mucociliary transport apparatus. Genetic and acquired ciliopathies result in diminished mucociliary clearance, contributing to disease pathogenesis. Recent innovations in imaging technology have advanced our understanding of ciliary motion in health and disease states. Application of imaging modalities including transmission electron microscopy, high-speed video microscopy, and micron-optical coherence tomography could improve diagnostics and be applied for precision medicine. In this review, we provide an overview of ciliary motion, imaging modalities, and ciliopathic diseases of the respiratory system including primary ciliary dyskinesia, cystic fibrosis, chronic obstructive pulmonary disease, and idiopathic pulmonary fibrosis.

The Effect of Viscosity Ratio on the Hydrodynamics of Separation From an Oil-Coated Particle

2014 ◽  
Author(s):  
Sasan Mehrabian ◽  
Nima Abbaspour ◽  
Markus Bussmann ◽  
Edgar Acosta
Keyword(s):  
Oil Sands ◽  
High Speed ◽  
Oil Spills ◽  
Viscosity Ratio ◽  
Solid Particles ◽  
Water Separation ◽  
Viscous Forces ◽  
Coated Particle ◽  
Oil Water ◽  
Maximum Separation

Separating oil from solid particles is of great importance in many industrial processes including the extraction of bitumen from oil sands, and the remediation of oil spills. The usual approach is to separate the oil from the solid by introducing another liquid (e.g. water). Separation is often assisted by fluid mixing, and chemical addition. Yet while oil-water-particle separation has been well studied from a chemical standpoint, little research has taken into account the effect of hydrodynamics on separation. In this work, the separation of oil from a single oil-coated spherical particle falling through an aqueous solution was evaluated as a function of viscosity ratio. Solvents were used to modify the viscosity of the oil. The experiments were recorded using a high-speed camera and post-processed using the MATLAB image-processing toolbox. A CFD model has also been developed to study this phenomenon. The results indicate that when viscous forces are strong enough, the oil film deforms, flows to the back of the sphere, and forms a tail that eventually breaks up into a series of droplets due to a capillary wave instability. When the viscosity ratio is small (i.e. the oil is less viscous than the solution), a thin tail forms quickly, the growth rate of the instability is high, and hence the tail breaks very quickly into smaller droplets. When the viscosity ratio is high (i.e. the oil is more viscous), more time is required for the deformation/separation to initiate, and the tail is thicker and breaks more slowly into larger droplets. It was observed that when the viscosity ratio is close to 1, the rate of separation is increased and maximum separation is achieved.

Emergency obstacle avoidance trajectory tracking control based on active disturbance rejection for autonomous vehicles

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142092110
Author(s):  
Runqiao Liu ◽  
Minxiang Wei ◽  
Nan Sang
Keyword(s):  
Obstacle Avoidance ◽  
Disturbance Rejection ◽  
Autonomous Vehicles ◽  
High Speed ◽  
Autonomous Vehicle ◽  
Angular Frequency ◽  
Vehicle Speed ◽  
Feed Forward ◽  
Yaw Rate ◽  
Active Disturbance Rejection

To solve the problem of understeer and oversteer for autonomous vehicle under high-speed emergency obstacle avoidance conditions, considering the effect of steering angular frequency and vehicle speed on yaw rate for four-wheel steering vehicles in the frequency domain, a feed-forward controller for four-wheel steering autonomous vehicles that tracks the desired yaw rate is proposed. Furthermore, the steering sensitivity coefficient of the vehicle is compensated linearly with the change in the steering angular frequency and vehicle speed. In addition, to minimize the tracking errors caused by vehicle nonlinearity and external disturbances, an active disturbance rejection control feedback controller that tracks the desired lateral displacement and desired yaw angle is designed. Finally, CarSim® obstacle avoidance simulation results show that an autonomous vehicle with the four-wheel steering path tracking controller consisting of feed-forward control and feedback control could not only improve the tire lateral forces but also reduce tail flicking (oversteer) and pushing ahead (understeer) under high-speed emergency obstacle avoidance conditions.

scholarly journals Evolution of Feeding Shapes Swimming Kinematics of Barnacle Naupliar Larvae: A Comparison between Trophic Modes

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
J Y Wong ◽  
B K K Chan ◽  
K Y K Chan
Keyword(s):  
Evolutionary Biology ◽  
High Speed ◽  
Morphological Changes ◽  
Marine Invertebrate ◽  
Ecological Functions ◽  
Micro Particle Image Velocimetry ◽  
Globular Body ◽  
Recovery Stroke ◽  
Induced Flow ◽  
Invertebrate Larvae

Synopsis A central goal in evolutionary biology is connecting morphological features with ecological functions. For marine invertebrate larvae, appendage movement determines locomotion, feeding, and predator avoidance ability. Barnacle larvae are morphologically diverse, and the morphology of non-feeding lecithotrophic nauplii are distinct from those that are planktotrophic. Lecithotrophic larvae have a more globular body shape and simplified appendages when compared with planktotrophs. However, little is known about whether and how such morphological changes affect kinematics, hydrodynamics, and ecological functions. Here, we compared the nauplii kinematics and hydrodynamics of a lecithotrophic Rhizocephalan species, Polyascus planus, against that of the planktotrophic nauplii of an intertidal barnacle, Tetraclita japonica. High-speed, micro-particle image velocimetry analysis showed that the Polyascus nauplii swam faster and had higher amplitude and more synchronous appendage beating than the Tetraclita nauplii. This fast swimming was accompanied by a faster attenuation of induced flow with distance, suggesting reduced predation risk. Tetraclita nauplii had more efficient per beat cycles with less backward displacement during the recovery stroke. This “anchoring effect” resulted from the anti-phase beating of appendages. This movement, together with a high-drag body form, likely helps direct the suction flow toward the ventral food capturing area. In sum, the tradeoff between swimming speed and predation risks may have been an important factor in the evolution of the observed larval forms.

High Speed Induced Flow Reciprocating Pumps

1972 ◽  
Vol 186 (1) ◽  
pp. 785-791
Author(s):  
R. L. Creedon ◽  
J. Lobo-Guerrero ◽  
P. R. Selwood ◽  
J. D. Burton
Keyword(s):  
Natural Frequency ◽  
High Speed ◽  
Performance Data ◽  
Analogue Computer ◽  
Pump Frequency ◽  
Discharge Line ◽  
New Type ◽  
Induced Flow ◽  
Hydraulic Accumulator ◽  
Work Done

Reciprocating pumps have been used for many years in conjunction with an air vessel or hydraulic accumulator placed between pump and discharge line, in order to control maximum cylinder pressures and to reduce the work done in overcoming friction. The air vessel and the discharge line are, in fact, capacitive and inductive components which together have some natural frequency generally different from the pump frequency. In this paper, it is shown that by matching the natural frequency of the discharge impedance to the pump frequency it is possible to obtain volumetric efficiencies of 200 per cent or more. This ‘induced flow principle’ was incorporated in a small high speed pump developed specifically to overcome the relative bulk and cost of conventional diaphragm pumps. Performance data for the new type of pump are compared with theoretical analogue computer solutions, and it appears that the induced flow principle may have a wider range of application than originally anticipated.

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