scholarly journals Towards a Highly Sensitive Piezoelectric Nano-Mass Detection—A Model-Based Concept Study

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2533
Author(s):  
Jens Twiefel ◽  
Anatoly Glukhovkoy ◽  
Sascha de Wall ◽  
Marc Christopher Wurz ◽  
Merle Sehlmeyer ◽  
...  
Keyword(s):  
Piezoelectric Element ◽  
Element Model ◽  
Equivalent Model ◽  
Mass Detection ◽  
Bending Vibrations ◽  
Simultaneous Excitation ◽  
Model Based ◽  
Novel Approach ◽  
Highly Sensitive ◽  
First Time

The detection of exceedingly small masses still presents a large challenge, and even though very high sensitivities have been archived, the fabrication of those setups is still difficult. In this paper, a novel approach for a co-resonant mass detector is theoretically presented, where simple fabrication is addressed in this early concept phase. To simplify the setup, longitudinal and bending vibrations were combined for the first time. The direct integration of an aluminum nitride (AlN) piezoelectric element for simultaneous excitation and sensing further simplified the setup. The feasibility of this concept is shown by a model-based approach, and the underlying parameter dependencies are presented with an equivalent model. To include the geometrical and material aspects, a finite element model that supports the concept as a very promising approach for future nano-mass detectors is established.

scholarly journals Static behavior of weighing cells

2018 ◽  
Vol 7 (2) ◽  
pp. 587-600 ◽  
Author(s):  
Maximilian Darnieder ◽  
Markus Pabst ◽  
Ronny Wenig ◽  
Lena Zentner ◽  
René Theska ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Element Model ◽  
Novel Approach ◽  
Stiffness Characteristic ◽  
Highly Sensitive ◽  
Rigid Body Model ◽  
Mechanical Models ◽  
Parametric Studies

Abstract. Compliant mechanisms in precision weighing technology are highly sensitive mechanical systems with continuously rising demands for performance in terms of resolution and measurement uncertainty. The systematic combination of adjustment measures represents a promising option for the enhancement of weighing cells which is not yet fully exhausted. A novel adjustment concept for electromagnetic force compensated weighing cells designed for 1 kg mass standards is introduced. The effect on the mechanical behavior is analyzed in detail using a planar compliant mechanism with semi-circular flexure hinges. Design equations for a first layout of the mechanical system are derived from a linearized rigid body model. Existing adjustment concepts for the stiffness characteristic and the sensitivity to quasi-static ground tilt are included. They are extended by the novel approach to attach trim weights to the levers of the linear guide. Based on this concept, an optimal design for the weighing cell is determined. The comparison with a finite element model reveals further effects given by the more precise description of the mechanical behavior. By parametric studies of the adjustment parameters in the mechanical models, it is shown that the stiffness and tilt sensitivity can be reduced significantly compared to the non-adjusted weighing cell. The principal correlation of the trim weights and their effect on the mechanical properties is experimentally verified using a commercially available weighing cell.

Model Based Design of Piezoelectric Generators Utilizing Geometrical and Material Properties

Aerospace ◽  
2006 ◽  
Author(s):  
Bjo¨rn Richter ◽  
Jens Twiefel ◽  
Tobias Hemsel ◽  
Jo¨rg Wallaschek
Keyword(s):  
Output Power ◽  
Material Properties ◽  
General Model ◽  
Piezoelectric Element ◽  
Equivalent Model ◽  
Electric Load ◽  
Practical Applications ◽  
Model Based ◽  
Set Up

This paper presents a general model based on the electromechanical circuit theory. The model is set up as a mechanical equivalent model for base excited systems and describes the behaviour of a piezoelectric element around one resonance frequency which is sufficient for most practical applications. The model is extended to obtain the influence of geometrical and material properties. The derivated properties are used to describe the parameters of the general model which is easy to handle. Using this model either the calculation of the output power on a specific electric load or the determination of the design of the used piezoelectric element for a needed electric output power is possible. The paper focuses on the design of the ratio of length and width of a piezoelectric bimorph. The validity of the model is shown by the comparison of computed and experimental results.

scholarly journals Urban temporary housing environments—from a systematic comparison towards an integrated typology

2021 ◽  
Author(s):  
Mirjam Stocker ◽  
Gerda Schneider ◽  
Julia Zeilinger ◽  
Gloria Rose ◽  
Doris Damyanovic ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Housing Demand ◽  
Economic Aspects ◽  
Temporary Housing ◽  
Open Spaces ◽  
Systematic Comparison ◽  
Human Needs ◽  
Novel Approach ◽  
Environmental Events ◽  
First Time

AbstractHousing plays a central role in everyday life and the fulfillment of human needs. Temporary housing demand can occur due to migration, extreme environmental events or personal decisions, and is expected to increase in the upcoming years. This study aims to create a general understanding of temporary housing. We conducted an integrated comparison of 66 international temporary housing examples via tabulation (table work), in an interdisciplinary manner considering details regarding built structure, open spaces, area, infrastructure, organizational and socio-economic aspects. It is the first time that a systematic comparison via tabulation (based on the approach of Braun-Blanquet) is used to classify temporary housing environments. The process is described in detail. The application of the systematic comparison creates a detailed typology that allows extensions and further differentiations. The types that emerge from the tabulation have specific concepts regarding the structural-spatial organization, technical infrastructure, and organizational matters, among others. The typology was further examined in the context of previous groupings in published literature. This novel approach of analyzing and structuring temporary housing offers a comprehensive perspective that can work as a universal understanding and language for precise communication among different disciplines regarding temporary housing.

scholarly journals Multi-Inputs and Multi-Outputs equivalent model based on data driven controller for a robotic system

2020 ◽  
Vol 53 (2) ◽  
pp. 9784-9789
Author(s):  
Josué Gómez ◽  
Chidentree Treesatayapun ◽  
América Morales
Keyword(s):  
Robotic System ◽  
Data Driven ◽  
Equivalent Model ◽  
Model Based

scholarly journals Imaging the Human Thyroid Using Three-Dimensional Diffuse Optical Tomography: A Preliminary Study

2021 ◽  
Vol 11 (4) ◽  
pp. 1670
Author(s):  
Tetsuya Mimura ◽  
Shinpei Okawa ◽  
Hiroshi Kawaguchi ◽  
Yukari Tanikawa ◽  
Yoko Hoshi
Keyword(s):  
Optical Tomography ◽  
Tumor Hypoxia ◽  
Three Dimensional ◽  
Diffuse Optical Tomography ◽  
Element Model ◽  
Needle Aspiration ◽  
Human Thyroid ◽  
Tissue Oxygen Saturation ◽  
Preliminary Study ◽  
First Time

Thyroid cancer is usually diagnosed by ultrasound imaging and fine-needle aspiration biopsy. However, diagnosis of follicular thyroid carcinomas (FTC) is difficult because FTC lacks nuclear atypia and a consensus on histological interpretation. Diffuse optical tomography (DOT) offers the potential to diagnose FTC because it can measure tumor hypoxia, while image reconstruction of the thyroid is still challenging mainly due to the complex anatomical features of the neck. In this study, we attempted to solve this issue by creating a finite element model of the human neck excluding the trachea (a void region). By reconstruction of the absorption coefficients at three wavelengths, 3D tissue oxygen saturation maps of the human thyroid are obtained for the first time by DOT.

Estimating local arterial stiffness using mixed-effects model-based residuals: a novel approach

2021 ◽  
Author(s):  
Avinash Chandran ◽  
Derek W. Brown ◽  
Gabriel H. Zieff ◽  
Zachary Y. Kerr ◽  
Daniel Credeur ◽  
...  
Keyword(s):  
Arterial Stiffness ◽  
Mixed Effects ◽  
Mixed Effects Model ◽  
Model Based ◽  
Novel Approach

scholarly journals A Novel Approach to Fabricate Foam Ceramics from Steel Slag

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yu Zheng ◽  
Xudong Luo ◽  
Jinlong Yang ◽  
Wenlong Huo ◽  
Chi Kang
Keyword(s):  
Compressive Strength ◽  
Ph Value ◽  
Steel Slag ◽  
Raw Material ◽  
Solid Loading ◽  
Insulation Material ◽  
Ceramic Foams ◽  
Novel Approach ◽  
The Stability ◽  
First Time

A novel approach is used for fabricating steel slag foam ceramics based on the particle-stabilized foaming method. In this work, steel slag was used as the raw material and propyl gallate (PG) was used as the surface modifier. For the first time, steel slag ceramic foams were successfully fabricated based on particle-stabilized foams. The results show that the stability of the ceramic foams was closely related to the pH value and PG concentration. The porosity and compressive strength could be controlled by changing the solid loading of steel slag and sintering temperature. The porosity of steel slag foam ceramics ranged from 85.6% to 62.53%, and the compressive strength was from 1.74 MPa to 10.42 MPa. The thermal conductivity of steel slag foam ceramics was only 0.067 W (m·K)−1, which shows that it could be used as a thermal insulation material.

Optimum Strain Gauge Application to Bladed Assemblies

2002 ◽  
Author(s):  
J. Szwedowicz ◽  
S. M. Senn ◽  
R. S. Abhari
Keyword(s):  
Strain Gauge ◽  
Element Model ◽  
Strain Gauges ◽  
Structural Components ◽  
Algorithm Optimization ◽  
Rotating Blades ◽  
Novel Approach ◽  
Present Technique ◽  
Optimization Function ◽  
Rotating Impeller

Optimum placements of the strain gauges assure reliable vibration measurements of structural components such as rotating blades. Within the framework of cyclic vibration theory, a novel approach has been developed for computation of the optimum gauge positions on tuned bladed discs regarding the determined sensitivity, orthogonality, gradient and distance criteria. The utilized genetic algorithm optimization tool allows for an effective numerical search of suitable solutions of the defined optimization function. A rotating impeller disc represented by a cyclic finite element model demonstrates the application of this method. The present technique can be easily applied to other structural components requiring optimal strain gauge instrumentation.

scholarly journals Lecture attendance improves success in medical physiology

2017 ◽  
Vol 41 (4) ◽  
pp. 599-603 ◽  
Author(s):  
Enver Ahmet Demir ◽  
Okan Tutuk ◽  
Hatice Dogan ◽  
Duygu Egeli ◽  
Cemil Tumer
Keyword(s):  
Correct Answer ◽  
The Internet ◽  
Correlation Analyses ◽  
Novel Approach ◽  
Second Year ◽  
Educational Sources ◽  
First Time

The educators have underlined the importance of lecture attendance for decades. Nowadays, students have ample online educational sources, which began a debate on the necessity of in-class lectures. In the present study, we investigated the influence of lecture attendance on the exam success. To this aim, we adopted a novel approach and matched second-year medicine students’ answers in three interim exams with the lectures related to those questions. Thereby, we were able to evaluate if attending lectures increases the chance of giving a correct answer to the exam question generated from the attended lecture. Furthermore, we examined students who had never taken the course before (first-time takers) and students who had failed and repeated the course (repeat takers) separately, since repeat takers may have attended a lecture previously. We found that first-time takers attended more lectures and gained higher total scores than repeat takers. Lecture-matched correct answers were significantly higher for attended lectures than for skipped lectures in all interim exams. Moreover, the correlation analyses revealed that the number of correct answers increases by lecture attendance in both first-time and repeat takers. These results indicate that in-class lectures still should be considered as an essential part of the medical physiology education, even in the internet era.

scholarly journals Towards a better understanding of the origins, chemical composition and aging of oxygenated organic aerosols: case study of a Mediterranean industrialized environment, Marseille

2013 ◽  
Vol 13 (15) ◽  
pp. 7875-7894 ◽  
Author(s):  
I. El Haddad ◽  
B. D'Anna ◽  
B. Temime-Roussel ◽  
M. Nicolas ◽  
A. Boreave ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Aerosols ◽  
Industrial Emissions ◽  
Aerosol Mass Spectrometer ◽  
Statistical Confidence ◽  
Aerosol Mass ◽  
Novel Approach ◽  
Organic Markers ◽  
The Impact ◽  
First Time

Abstract. As part of the FORMES summer 2008 experiment, an Aerodyne compact time-of-flight aerosol mass spectrometer (cToF-AMS) was deployed at an urban background site in Marseille to investigate the sources and aging of organic aerosols (OA). France's second largest city and the largest port in the Mediterranean, Marseille, provides a locale that is influenced by significant urban industrialized emissions and an active photochemistry with very high ozone concentrations. Particle mass spectra were analyzed by positive matrix factorization (PMF2) and the results were in very good agreement with previous apportionments obtained using a chemical mass balance (CMB) approach coupled to organic markers and metals (El Haddad et al., 2011a). AMS/PMF2 was able to identify for the first time, to the best of our knowledge, the organic aerosol emitted by industrial processes. Even with significant industries in the region, industrial OA was estimated to contribute only ~ 5% of the total OA mass. Both source apportionment techniques suggest that oxygenated OA (OOA) constitutes the major fraction, contributing ~ 80% of OA mass. A novel approach combining AMS/PMF2 data with 14C measurements was applied to identify and quantify the fossil and non-fossil precursors of this fraction and to explicitly assess the related uncertainties. Results show with high statistical confidence that, despite extensive urban and industrial emissions, OOA is overwhelmingly non-fossil, formed via the oxidation of biogenic precursors, including monoterpenes. AMS/PMF2 results strongly suggest that the variability observed in the OOA chemical composition is mainly driven in our case by the aerosol photochemical age. This paper presents the impact of photochemistry on the increase of OOA oxygenation levels, formation of humic-like substances (HULIS) and the evolution of α-pinene SOA (secondary OA) components.

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