scholarly journals Mass Sensors Based on Capacitive and Piezoelectric Micromachined Ultrasonic Transducers—CMUT and PMUT

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2010 ◽  
Author(s):  
Haleh Nazemi ◽  
Jenitha Antony Balasingam ◽  
Siddharth Swaminathan ◽  
Kenson Ambrose ◽  
Muhammad Umair Nathani ◽  
...  
Keyword(s):  
Concentration Level ◽  
Ultrasonic Transducers ◽  
Gas Detection ◽  
Design Parameters ◽  
New Approach ◽  
Mass Sensors ◽  
Readout Circuits ◽  
Highly Sensitive ◽  
Device Structures ◽  
Micromachined Sensors

Microelectromechanical system (MEMS)-based mass sensors are proposed as potential candidates for highly sensitive chemical and gas detection applications owing to their miniaturized structure, low power consumption, and ease of integration with readout circuits. This paper presents a new approach in developing micromachined mass sensors based on capacitive and piezoelectric transducer configurations for use in low concentration level gas detection in a complex environment. These micromachined sensors operate based on a shift in their center resonant frequencies. This shift is caused by a change in the sensor’s effective mass when exposed to the target gas molecules, which is then correlated to the gas concentration level. In this work, capacitive and piezoelectric-based micromachined sensors are investigated and their principle of operation, device structures and configurations, critical design parameters and their candidate fabrication techniques are discussed in detail.

scholarly journals Development of FRET-based indicators for visualizing homophilic trans interaction of a clustered protocadherin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Takashi Kanadome ◽  
Natsumi Hoshino ◽  
Takeharu Nagai ◽  
Tomoki Matsuda ◽  
Takeshi Yagi
Keyword(s):  
Fluorescent Proteins ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Direct Visualization ◽  
Binding Properties ◽  
New Approach ◽  
Self Recognition ◽  
Highly Sensitive ◽  
Donor And Acceptor ◽  
Clustered Protocadherins

AbstractClustered protocadherins (Pcdhs), which are cell adhesion molecules, play a fundamental role in self-recognition and non-self-discrimination by conferring diversity on the cell surface. Although systematic cell-based aggregation assays provide information regarding the binding properties of Pcdhs, direct visualization of Pcdh trans interactions across cells remains challenging. Here, we present Förster resonance energy transfer (FRET)-based indicators for directly visualizing Pcdh trans interactions. We developed the indicators by individually inserting FRET donor and acceptor fluorescent proteins (FPs) into the ectodomain of Pcdh molecules. They enabled successful visualization of specific trans interactions of Pcdh and revealed that the Pcdh trans interaction is highly sensitive to changes in extracellular Ca2+ levels. We expect that FRET-based indicators for visualizing Pcdh trans interactions will provide a new approach for investigating the roles of Pcdh in self-recognition and non-self-discrimination processes.

scholarly journals Approximation of the index for assessing ship sea-keeping performance on the basis of ship design parameters

2007 ◽  
Vol 14 (3) ◽  
pp. 21-26 ◽  
Author(s):  
Tomasz Cepowski
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Ship Design ◽  
Design Parameters ◽  
Preliminary Design ◽  
Operational Effectiveness ◽  
Design Problems ◽  
New Approach ◽  
Analytical Functions ◽  
Effectiveness Index

Approximation of the index for assessing ship sea-keeping performance on the basis of ship design parameters This paper presents a new approach which makes it possible to take into account seakeeping qualities of ship in the preliminary stage of its design. The presented concept is based on representing ship's behaviour in waves by means of the so called operational effectiveness index. Presented values of the index were calculated for a broad range of design parameters. On this basis were elaborated analytical functions which approximate the index depending on ship design parameters. Also, example approximations of the index calculated by using artificial neural networks, are attached. The presented approach may find application to ship preliminary design problems as well as in ship service stage to assess sea-keeping performance of a ship before its departure to sea.

Nanoelectromechanical Disk Resonators as Highly Sensitive Mass Sensors

2018 ◽  
Vol 39 (11) ◽  
pp. 1744-1747 ◽  
Author(s):  
Vahid Qaradaghi ◽  
A. Ramezany ◽  
S. Babu ◽  
J. B. Lee ◽  
S. Pourkamali
Keyword(s):  
Mass Sensors ◽  
Disk Resonators ◽  
Highly Sensitive

scholarly journals New Approach Methods to Evaluate Health Risks of Air Pollutants: Critical Design Considerations for In Vitro Exposure Testing

2020 ◽  
Vol 17 (6) ◽  
pp. 2124 ◽  
Author(s):  
Jose Zavala ◽  
Anastasia N. Freedman ◽  
John T. Szilagyi ◽  
Ilona Jaspers ◽  
John F. Wambaugh ◽  
...  
Keyword(s):  
Air Pollution ◽  
Lessons Learned ◽  
Air Pollutant ◽  
In Vivo Studies ◽  
Design Parameters ◽  
Vast Number ◽  
New Approach ◽  
In Vitro Exposure

Air pollution consists of highly variable and complex mixtures recognized as major contributors to morbidity and mortality worldwide. The vast number of chemicals, coupled with limitations surrounding epidemiological and animal studies, has necessitated the development of new approach methods (NAMs) to evaluate air pollution toxicity. These alternative approaches include in vitro (cell-based) models, wherein toxicity of test atmospheres can be evaluated with increased efficiency compared to in vivo studies. In vitro exposure systems have recently been developed with the goal of evaluating air pollutant-induced toxicity; though the specific design parameters implemented in these NAMs-based studies remain in flux. This review aims to outline important design parameters to consider when using in vitro methods to evaluate air pollutant toxicity, with the goal of providing increased accuracy, reproducibility, and effectiveness when incorporating in vitro data into human health evaluations. This review is unique in that experimental considerations and lessons learned are provided, as gathered from first-hand experience developing and testing in vitro models coupled to exposure systems. Reviewed design aspects include cell models, cell exposure conditions, exposure chambers, and toxicity endpoints. Strategies are also discussed to incorporate in vitro findings into the context of in vivo toxicity and overall risk assessment.

Evaluation of diagnostic accuracy in free-response detection-localization tasks using ROC tools

2018 ◽  
Vol 28 (6) ◽  
pp. 1808-1825 ◽  
Author(s):  
Andriy I Bandos ◽  
Nancy A Obuchowski
Keyword(s):  
Cancer Detection ◽  
Roc Analysis ◽  
Operating Characteristic ◽  
Roc Curves ◽  
Design Parameters ◽  
Diagnostic Systems ◽  
Free Response ◽  
New Approach ◽  
Alternative Approaches ◽  
Response Detection

Diagnostic systems designed to detect possibly multiple lesions per patient (e.g. multiple polyps during CT colonoscopy) are often evaluated in “free-response” studies that allow for diagnostic responses unconstrained in their number and locations. Analysis of free-response studies requires extensions of the traditional receiver operating characteristic (ROC) analysis, which are termed free-response ROC (FROC) methodology. Despite substantial developments in this area, FROC tools and approaches are much more cumbersome than traditional ROC methods. Alternative approaches that use well-known ROC tools (e.g. ROI-ROC) require defining and physically delineating regions of interest (ROI) and combine FROC data within ROIs. We propose an approach that allows analyzing FROC data using conventional ROC tools without delineating the actual ROIs or reducing data. The design parameters of FROC study are used to make FROC data analyzable using ROC tools and to calibrate the corresponding FROC and ROC curves on both conceptual and numerical levels. Differences in the performance indices of the nonparametric FROC and the new approach are shown to be asymptotically negligible and typically rather small in practice. Data from a large multi-reader study of colon cancer detection are used to illustrate the new approach.

Derivatives and Parameter Designs of Arbitrary Cross-Section Inhomogenous Beams’ Modes

2013 ◽  
Author(s):  
J. W. Xing ◽  
G. T. Zheng
Keyword(s):  
Cantilever Beam ◽  
Cross Section ◽  
Analytical Solutions ◽  
Structural Parameters ◽  
Arbitrary Cross Section ◽  
Mode Shapes ◽  
Design Parameters ◽  
Structural Parameter ◽  
Highly Sensitive ◽  
Sensitivity Analysis Method

As highly sensitive to structural parameter variations, it is necessary to study relations between derivatives of displacement modes and structural design parameters. This paper proposes an integral technique for obtaining the analytical solutions of slope and curvature modes of arbitrary cross-section inhomogeneous cantilever beam. The method is validated by comparing the computation results of modal frequencies and shapes with both numerical and analytical solutions. Furthermore, based on the presented method, we have established explicit expressions for the structural parameters sensitivity of the slope/curvature mode shapes. An example of parameter design is also presented for a cantilever beam with the proposed sensitivity analysis method.

Robust Fault Detection Based on Nonlinear Analytic Redundancy Techniques With Applications to Robotics

2005 ◽  
Author(s):  
Bibhrajit Halder ◽  
Nilanjan Sarkar
Keyword(s):  
Fault Detection ◽  
Design Method ◽  
Actuator Fault ◽  
Actuator Faults ◽  
Sensor Fault ◽  
New Approach ◽  
Model Plant ◽  
Robust Fault Detection ◽  
Highly Sensitive ◽  
Process Disturbances

A new approach to sensor and actuator fault detection in the presence of model uncertainty and disturbances, and its application to a wheeled mobile robot (WMR) are presented in this paper. Robust fault detection is important because of the universal existence of model uncertainties and process disturbances in most systems. This paper proposes a new approach, called robust nonlinear analytic redundancy (RNLAR) technique, to sensor and actuator fault detection for input-affine nonlinear multivariable dynamic systems in the presence of model-plant-mismatch and process disturbance. The proposed RNLAR can be used to design primary residual vectors (PRV) for nonlinear systems to detect sensor fault that are completely insensitive to both the model-plant-mismatch and process disturbance. It is shown that the PRV for actuator fault cannot be made completely insensitive to these factors. In order to overcome this problem, a nonlinear PRV design method to detect actuator faults is proposed where the PRVs are highly sensitive to the actuator faults and less sensitive to model-plant-mismatch and process disturbance. The proposed robust fault detection methodology is applied to a WMR and the simulation results are presented to demonstrate the effectiveness of this new approach.

Probabilistic Performance of Helical Compound Planetary System in Wind Turbine

2015 ◽  
Vol 10 (4) ◽  
Author(s):  
Fisseha M. Alemayehu ◽  
Stephen Ekwaro-Osire
Keyword(s):  
Wind Turbine ◽  
Multibody Systems ◽  
Planetary System ◽  
Design Parameters ◽  
Wind Turbine Gearbox ◽  
New Approach ◽  
Highly Nonlinear ◽  
Multibody Dynamic ◽  
Input Variables ◽  
Maintenance Process

The dynamics of contact, stress and failure analysis of multibody systems is highly nonlinear. Nowadays, several commercial and other analysis software dedicated for this purpose are available. However, these codes do not consider the uncertainty involved in loading, design, and assembly parameters. One of these systems with a combined high nonlinearity and uncertainty of parameters is the gearbox of wind turbines (WTs). Wind turbine gearboxes (WTG) are subjected to variable torsional and nontorsional loads. In addition, the manufacturing and assembly process of these devices results in uncertainty of the design parameters of the system. These gearboxes are reported to fail in their early life of operation, within three to seven years as opposed to the expected twenty years of operation. Their downtime and maintenance process is the most costly of any failure of subassembly of WTs. The objective of this work is to perform a probabilistic multibody dynamic analysis (PMBDA) of a helical compound planetary stage of a selected wind turbine gearbox that considers ten random variables: two loading (the rotor speed, generator side torque), and eight design parameters. The reliability or probabilities of failure of each gear and probabilistic sensitivities of the input variables toward two performance functions have been measured and conclusions have been drawn. The results revealed that PMBDA has demonstrated a new approach of gear system design beyond a traditional deterministic approach. The method demonstrated the components' reliability or probability of failure and sensitivity results that will be used as a tool for designers to make sound decisions.

Sign in / Sign up

Export Citation Format

Share Document