Dynamic Response of an Electrospun PVDF-Fe3O4 Piezoelectric Composite Microfiber

2019 ◽  
Author(s):  
Krishna Chytanya Chinnam ◽  
Arnaldo Casalotti ◽  
Giulia Lanzara
Keyword(s):  
Electric Field ◽  
Dynamic Response ◽  
Resonance Frequency ◽  
Piezoelectric Composite ◽  
Test Results ◽  
Ac Electric Field ◽  
Wide Range ◽  
Pvdf Matrix ◽  
Fine Tune

Abstract In this paper the dynamic response of an electrospun nanocomposite piezoelectric microfiber is investigated. The microfiber is formed by magnetic nanoparticles dispersed in Polyvinylidene (PVDF) matrix. Focus is given on the influence of an AC electric field on the dynamic response of the microfiber. In particular, the resonance frequency of the fiber was assessed under an increasing AC electric field at a wide range of frequencies. The electromechanical test results show that the resonance frequency of the fiber is influenced by the applied voltage and, for this case study, it decreases with increasing voltage. The results reported in this paper suggest that, once the mechanism behind such response is fully understood, composite piezoelectric microfibers can be used to fine-tune the resonance frequency of hosting devices.

scholarly journals Evaluation of Official Healthcare Informatics Applications in Saudi Arabia and their Role in Addressing COVID-19 Pandemic

2021 ◽  
Vol 27 (3) ◽  
pp. 255-263
Author(s):  
Nouf Alassaf ◽  
Sulaiman Bah ◽  
Fatima Almulhim ◽  
Norah AlDossary ◽  
Munirah Alqahtani
Keyword(s):  
Saudi Arabia ◽  
Content Analysis ◽  
Data Collection ◽  
Qualitative Content Analysis ◽  
Test Results ◽  
Healthcare Informatics ◽  
Advantages And Disadvantages ◽  
Wide Range ◽  
Health Related

Objectives: The purpose of this study was to examine official healthcare informatics applications in Saudi Arabia in the context of their role in addressing the coronavirus disease 2019 (COVID-19) pandemic.Methods: This is a case study of official healthcare informatics programs and applications (apps) developed in Saudi Arabia before and during the COVID-19 pandemic. The qualitative content analysis (QCA) method was used. Data collection consisted of two components: a desktop review of documents and actual testing of the programs. According to the QCA method, we developed a matrix for abstracting information on different apps and programs in order to categorize the data. The compilation of information and discussion were based on information summarized in the matrix.Results: Six apps in total were developed before the COVID-19 pandemic. With the advent of the COVID-19 pandemic, three of the apps, SEHA, Mawid, and Sehaty were modified to address different aspects of the pandemic. Both SEHA and Mawid included information about COVID-19 awareness. During the COVID-19 pandemic, three official apps were developed: Tawakkalna, Tetamman, and Tabaud. The Tawakkalna app is mandatory for all citizens and residents to activate when visiting stores and institutions. It has a wide range of COVID-19 and other health-related functions. The Tetamman app provides COVID-19 test results and allows one to check his or her daily symptoms. It also has an educational content library and provides alerts. The Tabaud app notifies individuals if they have been exposed to COVID-19. The features, advantages, and disadvantages of all of the apps were examined.Conclusions: Overall, there were more strengths than shortcomings in the role played by healthcare informatics in the handling of the COVID-19 pandemic in Saudi Arabia.

Application of Dielectric Spectroscopy in ZnO Varistor Ceramics

2011 ◽  
Vol 393-395 ◽  
pp. 24-27 ◽  
Author(s):  
Peng Fei Cheng ◽  
Sheng Tao Li ◽  
Jian Ying Li
Keyword(s):  
Electric Field ◽  
Temperature Region ◽  
Dielectric Spectroscopy ◽  
Low Frequency ◽  
Dielectric Materials ◽  
The Other ◽  
Zno Varistor ◽  
Ac Electric Field ◽  
Wide Range ◽  
Dc Electric Field

There are two kinds of charges in dielectric materials, one is bound charge, and the other is free charge. Bound charge will introduce dielectric relaxation under applied AC electric field, which will be detected with dielectric spectroscopy. Free carrier will introduce DC conduction through the sample from one electrode to the other under DC electric field. But what can we do to obtain AC and DC properties of dielectric materials at the same time? In this paper, dielectric characteristics of ZnO varistor ceramics in a wide range of frequency and temperature are reported. DC conductivity is observed at low frequency and high temperature region and grainboundary Schottky barrier is obtained further. Dielectric loss peaks are observed at high frequency and low temperature region and single grainboundary electric breakdown voltage is calculated. At the end of the paper, the advancing trend of dielectric spectroscopy is discussed.

Fibrillar disruption by AC electric field induced oscillation: A case study with human serum albumin

2017 ◽  
Vol 226 ◽  
pp. 23-33 ◽  
Author(s):  
Shubhatam Sen ◽  
Monojit Chakraborty ◽  
Snigdha Goley ◽  
Swagata Dasgupta ◽  
Sunando DasGupta
Keyword(s):  
Human Serum Albumin ◽  
Electric Field ◽  
Serum Albumin ◽  
Human Serum ◽  
Ac Electric Field

Using Wireline Formation Tester Pressure Survey to Validate and Fine-tune Model Building: A Case Study for a Multi-layered Mature Reservoir

2014 ◽  
Author(s):  
S. I. Badusha ◽  
A. M. Qamber ◽  
S. Al-Rashdan ◽  
A. Safar ◽  
A. Mahato ◽  
...  
Keyword(s):  
Model Building ◽  
Fine Tune

PENGKAJIAN KEKUATAN BETON STRUKTUR JEMBATAN PASCA KEBAKARAN

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Sudarmadi Sudarmadi
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Strength Assessment ◽  
Concrete Testing

In this paper a case study about concrete strength assessment of bridge structure experiencing fire is discussed. Assessment methods include activities of visual inspection, concrete testing by Hammer Test, Ultrasonic Pulse Velocity Test, and Core Test. Then, test results are compared with the requirement of RSNI T-12-2004. Test results show that surface concrete at the location of fire deteriorates so that its quality is decreased into the category of Very Poor with ultrasonic pulse velocity ranges between 1,14 – 1,74 km/s. From test results also it can be known that concrete compressive strength of inner part of bridge pier ranges about 267 – 274 kg/cm2 and concrete compressive strength of beam and plate experiencing fire directly is about 173 kg/cm2 and 159 kg/cm2. It can be concluded that surface concrete strength at the location of fire does not meet the requirement of RSNI T-12-2004. So, repair on surface concrete of pier, beam, and plate at the location of fire is required.

Site specific agricultural soil management with the use of new technologies

2013 ◽  
Vol 16 (1) ◽  
pp. 59-67
Keyword(s):  
New Technologies ◽  
Digital Interface ◽  
Appropriate Treatment ◽  
Wide Range ◽  
Soil Variation ◽  
Soil Information ◽  
Remote Sensing Techniques ◽  
Agricultural Areas

<p>The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.</p>

Development of PEF extraction technology by Maguin

2015 ◽  
pp. 758-760
Author(s):  
Romain Delecourt ◽  
Loïc Marsal
Keyword(s):  
Sugar Beet ◽  
Electric Field ◽  
Pulsed Electric Field ◽  
Extraction Technology ◽  
Application System ◽  
Wide Range ◽  
Type Machine

Maguin (France) is still active in the application of pulsed electric field (PEF) technology. After having carried out successful tests on a 10 t/h pilot screw-type machine on sugar beet cossettes, a new application system based on a roller technology has been developed. This technology allows a wide range of application due to its flexibility with flowrates and materials. A variety of process schemes are proposed to ensure the best performance of the PEF technology.

Oxford Studies in Ancient Philosophy, Volume 55

2018 ◽  
Keyword(s):  
Middle Ages ◽  
Ancient Philosophy ◽  
Recent Book ◽  
Loss Of Control ◽  
Ancient Greek ◽  
Original Essays ◽  
Constant Change ◽  
Wide Range ◽  
Metaphysical Principle

Oxford Studies in Ancient Philosophy provides, twice each year, a collection of the best current work in the field of ancient philosophy. Each volume features original essays that contribute to an understanding of a wide range of themes and problems in all periods of ancient Greek and Roman philosophy, from the beginnings to the threshold of the Middle Ages. From its first volume in 1983, OSAP has been a highly influential venue for work in the field, and has often featured essays of substantial length as well as critical essays on books of distinctive importance. Volume LV contains: a methodological examination on how the evidence for Presocratic thought is shaped through its reception by later thinkers, using discussions of a world soul as a case study; an article on Plato’s conception of flux and the way in which sensible particulars maintain a kind of continuity while undergoing constant change; a discussion of J. L. Austin’s unpublished lecture notes on Aristotle’s Nicomachean Ethics and his treatment of loss of control (akrasia); an article on the Stoics’ theory of time and in particular Chrysippus’ conception of the present and of events; and two articles on Plotinus, one that identifies a distinct argument to show that there is a single, ultimate metaphysical principle; and a review essay discussing E. K. Emilsson’s recent book, Plotinus.

scholarly journals Assessing the Relation between Mud Components and Rheology for Loss Circulation Prevention Using Polymeric Gels: A Machine Learning Approach

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1377
Author(s):  
Musaab I. Magzoub ◽  
Raj Kiran ◽  
Saeed Salehi ◽  
Ibnelwaleed A. Hussein ◽  
Mustafa S. Nasser
Keyword(s):  
Machine Learning ◽  
Rheological Properties ◽  
Nearest Neighbor ◽  
Drilling Fluid ◽  
Gradient Boosting ◽  
K Nearest Neighbor ◽  
Wide Range ◽  
Machine Learning Approach ◽  
Drilling Operations

The traditional way to mitigate loss circulation in drilling operations is to use preventative and curative materials. However, it is difficult to quantify the amount of materials from every possible combination to produce customized rheological properties. In this study, machine learning (ML) is used to develop a framework to identify material composition for loss circulation applications based on the desired rheological characteristics. The relation between the rheological properties and the mud components for polyacrylamide/polyethyleneimine (PAM/PEI)-based mud is assessed experimentally. Four different ML algorithms were implemented to model the rheological data for various mud components at different concentrations and testing conditions. These four algorithms include (a) k-Nearest Neighbor, (b) Random Forest, (c) Gradient Boosting, and (d) AdaBoosting. The Gradient Boosting model showed the highest accuracy (91 and 74% for plastic and apparent viscosity, respectively), which can be further used for hydraulic calculations. Overall, the experimental study presented in this paper, together with the proposed ML-based framework, adds valuable information to the design of PAM/PEI-based mud. The ML models allowed a wide range of rheology assessments for various drilling fluid formulations with a mean accuracy of up to 91%. The case study has shown that with the appropriate combination of materials, reasonable rheological properties could be achieved to prevent loss circulation by managing the equivalent circulating density (ECD).

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