Prediction of the Mass Sensitivity of Phage-Coated Magnetoelastic Biosensors for the Detection of Single Pathogenic Bacteria

2011 ◽  
Vol 1301 ◽  
Author(s):  
Shin Horikawa ◽  
Suiqiong Li ◽  
Yating Chai ◽  
Valerly A. Petrenko ◽  
Bryan A. Chin
Keyword(s):  
Pathogenic Bacteria ◽  
Longitudinal Vibration ◽  
Three Dimensional ◽  
Case Scenario ◽  
Worst Case ◽  
Mass Sensitivity ◽  
Boltzmann Function ◽  
Frequency Changes ◽  
Three Dimensional Finite Element ◽  
Mass Position

ABSTRACTFreestanding, strip-shaped magnetoelastic (ME) biosensors are a class of wireless, mass-based biosensors that are being developed for the real-time detection of pathogenic bacteria for food safety and bio-security. The mass sensitivity of these biosensors operating in longitudinal-vibration modes is known to be largely dependent on the position of masses attached to the sensor surfaces. Hence, considering this dependence is crucial to the detection of low-concentration target pathogens, including single pathogenic bacteria, because their local attachment may cause varying sensor responses. In a worst case scenario, the resultant sensor responses (i.e., mass-induced resonance frequency changes of the sensor) may be too small to be detected despite the attachment of the target pathogenic masses. To address the issue, phage-coated ME biosensors (magnetostrictive strips (4 mm × 0.8 mm × 30 μm) coated with a phage probe specifically binding streptavidin protein) with localized masses (streptavidin-coated polystyrene beads) were fabricated, and mass-position-dependence of the sensor’s sensitivity under the fundamental-mode vibration was experimentally measured. In addition, three-dimensional finite element (FE) modal analysis was performed using the CalculiX software to simulate the phenomena. The experimental and theoretical results show close agreement: (1) the mass sensitivity was low when the mass was positioned in the middle of the sensor’s longest dimension and (2) a much higher mass sensitivity was, by contrast, obtained for the equivalent masses placed at both ends of the strip-shaped sensor. Furthermore, FE models were constructed for differently sized, phage-coated ME biosensors (100 – 500 μm in length with different widths and thicknesses) loaded with a single bacterial mass (2 μm × 0.4 μm × 0.4 μm, 1.05 g/cm3) at varying longitudinal positions. The mass sensitivity was found to be approximated by a mass-position-dependent Boltzmann function whose amplitude is inversely proportional to the length squared, width, and thickness of the sensor.

scholarly journals Spiral Sound Wave Transducer Based on the Longitudinal Vibration

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3674 ◽  
Author(s):  
Wei Lu ◽  
Yu Lan ◽  
Rongzhen Guo ◽  
Qicheng Zhang ◽  
Shichang Li ◽  
...  
Keyword(s):  
Sound Wave ◽  
Longitudinal Vibration ◽  
Three Dimensional ◽  
Low Frequency ◽  
Sound Field ◽  
Field Measurements ◽  
Sound Waves ◽  
Underwater Sound ◽  
Three Dimensional Finite Element ◽  
Wave Transducer

A spiral sound wave transducer comprised of longitudinal vibrating elements has been proposed. This transducer was made from eight uniform radial distributed longitudinal vibrating elements, which could effectively generate low frequency underwater acoustic spiral waves. We discuss the production theory of spiral sound waves, which could be synthesized by two orthogonal acoustic dipoles with a phase difference of 90 degrees. The excitation voltage distribution of the transducer for emitting a spiral sound wave and the measurement method for the transducer is given. Three-dimensional finite element modeling (FEM)of the transducer was established for simulating the vibration modes and the acoustic characteristics of the transducers. Further, we fabricated a spiral sound wave transducer based on our design and simulations. It was found that the resonance frequency of the transducer was 10.8 kHz and that the transmitting voltage resonance was 140.5 dB. The underwater sound field measurements demonstrate that our designed transducer based on the longitudinal elements could successfully generate spiral sound waves.

Conceptual Design of Lower-Mobility Parallel Manipulators Based on Wrench Graphs

2014 ◽  
Author(s):  
Gamal El-Ghazaly ◽  
Stéphane Caro
Keyword(s):  
Degrees Of Freedom ◽  
A Priori ◽  
Three Dimensional ◽  
Main Idea ◽  
Parallel Manipulators ◽  
Geometric Constraints ◽  
Design Stage ◽  
Case Scenario ◽  
Worst Case ◽  
Lower Mobility

This paper presents a design methodology for lower-mobility parallel manipulators based on classification of wrench systems into four main classes. Wrench systems are represented in a three-dimensional projective space ℙ3 using wrench graphs where it is easy to incorporate geometric constraints to have simple singularity conditions using Grassmann-Cayley algebra (GCA). The main idea of the approach is to design a PM with an overall (constraint and actuation) wrench system that complies with a given wrench graph for which singularity conditions have been predetermined. The main advantage of this methodology is that the singularity conditions are already known a priori and consequently, it gives an opportunity to avoid such conditions at the design stage and make them unreachable. In the worst case scenario, where none of singularity conditions cannot be avoided, one can have a PM with known singular configurations which are always difficult to determine for already designed manipulators. As illustrative examples, two different five degrees-of-freedom (dof) mechanisms have been designed based on some of the defined wrench graphs giving 3T2R motion pattern. The first mechanism has some avoided singularities and the second one is free of singularity.

Comparison between two-dimensional and three-dimensional computational fluid dynamics techniques for two straight-bladed vertical-axis wind turbines in inline arrangement

2018 ◽  
Vol 42 (6) ◽  
pp. 647-664 ◽  
Author(s):  
Saeed Nazari ◽  
Mahdi Zamani ◽  
Sajad A Moshizi
Keyword(s):  
Transport Model ◽  
Three Dimensional ◽  
Vertical Axis ◽  
Two Dimensional ◽  
Dimensional Approach ◽  
Case Scenario ◽  
Worst Case ◽  
Simulation Techniques ◽  
Shear Stress Transport Model ◽  
Dimensional Simulation

This study is dedicated to drawing a comparison between two- and three-dimensional approach capabilities for the simulation of two similar rotors placed in three inline (or tandem) arrangements. This arrangement is generally recognized as the worst-case scenario for the downwind rotor considering the vortices and disorders produced by the upwind rotor. The rotor in question with the diameter of 2.5 m is made up of three NACA0015 blades with the chord length and span size equal to 0.4 and 3 m, respectively. Based on the authors’ previous works, the [Formula: see text] shear stress transport model was selected for this comparative study. According to the results, there is an appreciable deviation in the aerodynamic performance of the upwind rotor predicted by the two-dimensional and three-dimensional simulation techniques. There is no tangible difference between the two-dimensional and three-dimensional results in terms of the averaged power output for the downwind rotor. However, the study of flow field employing different means like vortex structures, axial velocity, and even torque variation indicates that the two-dimensional approach is unable to achieve realistic and reliable output data. The introduced “pillar effect” regarding the dimensional limitations of the two-dimensional approach, which affects the vorticity shape and its dissipation, is plausible evidence for this discrepancy.

Effect of Dowel Looseness on Response of Jointed Concrete Pavements Using Three-Dimensional Finite Element Analysis

2014 ◽  
Vol 900 ◽  
pp. 435-444 ◽  
Author(s):  
How Bing Sii ◽  
Gary W. Chai ◽  
Rudi van Staden ◽  
Hong Guan
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Three Dimensional ◽  
Element Analysis ◽  
Worst Case ◽  
Dimensional Finite Element ◽  
Loading Case ◽  
Wheel Loading ◽  
Base Course ◽  
Three Dimensional Finite Element

This paper evaluated an effect of dowel looseness on response of jointed concrete pavement using 3D finite-element analyses of rigid pavement systems that relies on an embedded formulation of a beam element. This embedded element allows the efficient modelling of dowel looseness using nodal contact approach and permits the dowels to be exactly located irrespective of the slab mesh lines. These studies indicate that significant reduction in load transfer efficiency and increase in both slab and base course stresses can be expected due to small gaps varies from 0.25 to 1.25mm between the dowels and the slabs. For the worst case the LTE were reduced to 11.3% and 11.6% respectively for single wheel loading and odd dual wheel loading case while there were voids present at the base course layer for 1.25 cases 4.

scholarly journals Numerical Investigation of Major Impact Factors Influencing Fracture-Driven Interactions in Tight Oil Reservoirs: A Case Study of Mahu Sug, Xinjiang, China

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4881
Author(s):  
Xiaolun Yan ◽  
Jianye Mou ◽  
Chuanyi Tang ◽  
Huazhi Xin ◽  
Shicheng Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
In Situ Stress ◽  
Impact Factors ◽  
Destructive Interference ◽  
Case Scenario ◽  
Worst Case ◽  
Well Production ◽  
Well Spacing ◽  
Infill Drilling ◽  
Unconventional Fracture Model

Fracture-driven interactions (FDIs) in unconventional reservoirs significantly affect well production and have thus garnered extensive attention from the scientific community. Furthermore, since the industry transitioned to using large completion designs with closer well spacing and infill drilling, FDIs have occurred more frequently and featured more prominently, which has primarily led to destructive interference. When infill wells (i.e., “child” wells) are fractured, older, adjacent producing wells (i.e., “parent” wells) are put directly at risk of premature changes in production behavior. Some wells may never fully recover following exposure to severe FDIs and, in the worst case scenario, will permanently stop producing. To date, previous investigations into FDIs have focused mainly on diagnosis and detection. As such, their formation mechanism is not well understood. To address this deficiency, a three-dimensional, multi-fracture propagation simulator was constructed based on the unconventional fracture model (UFM) and applied to a system that included both an older, adjacent passive well (“parent” well) and an active well (“child” well). Herein, the theoretical framework for overall complex fracture modeling is described. Furthermore, numerical simulation results are presented, demonstrating the critical roles of in-situ stress distribution and pre-existing natural fractures and aiding in the development of appropriate strategies for managing FDIs.

Reducing Probabilistic Weather Forecasts to the Worst Case Scenario: Anchoring Effects

2008 ◽  
Author(s):  
Sonia Savelli ◽  
Susan Joslyn ◽  
Limor Nadav-Greenberg ◽  
Queena Chen
Keyword(s):  
Case Scenario ◽  
Worst Case ◽  
Weather Forecasts ◽  
Worst Case Scenario ◽  
Anchoring Effects

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

Tire Modeling by Finite Elements

1992 ◽  
Vol 20 (1) ◽  
pp. 33-56 ◽  
Author(s):  
L. O. Faria ◽  
J. T. Oden ◽  
B. Yavari ◽  
W. W. Tworzydlo ◽  
J. M. Bass ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Rolling Contact ◽  
Test Problems ◽  
State Behavior ◽  
Normal Contact ◽  
New Developments ◽  
Applied Torque ◽  
Dimensional Finite Element ◽  
Tire Modeling ◽  
Three Dimensional Finite Element

Abstract Recent advances in the development of a general three-dimensional finite element methodology for modeling large deformation steady state behavior of tire structures is presented. The new developments outlined here include the extension of the material modeling capabilities to include viscoelastic materials and a generalization of the formulation of the rolling contact problem to include special nonlinear constraints. These constraints include normal contact load, applied torque, and constant pressure-volume. Several new test problems and examples of tire analysis are presented.

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