256 research outputs found
Dynamic hysteresis based modeling Of piezoelectric actuators
No full textPiezoelectric actuators are popularly applied as actuators in high precision systems due to their small displacement resolution, fast response and simple construction. However, the hysteresis nonlinear behavior limits the dynamic modeling and tracking control of piezoelectric actuators. This paper studies a dynamic model of a moving stage driven by piezoelectric stack actuator. The Bouc-Wen model is introduced and analyzed to express the nonlinear hysteresis term. Two triangular actuating voltages with frequency of 1 Hz and amplitudes of 80 V and 90 V are applied to drive the piezoelectric stack actuator. The results demonstrate the existence of the hysteresis phenomenon between the input voltage and the output displacement of the piezoelectric stack actuator, and validate the correctness of the model
Methodology of Interpretation of Abu Marwan Bin Musa in the Book of Hidāyatul Insān Bi Tafsīr Al-Qur’ān
No full textInterpretive research cannot be separated from methodology. As time goes by, efforts to understand God's words in the Qur'an and human efforts are growing. Reading the Qur'an will occur and develop from time to time both in terms of mode of interpretation, epistemology, methodology, etc. As long as the interpretation process is carried out, it will not stop. When interpreting the Qur'an, each interpreter will be influenced by the social and cultural conditions in which he lives, and the political situation around him has a great influence on him, as was Abu Marwan bin Musa. Tafsīr Hidāyat al Insān bi Tafsīr al-Qur`ān written by Abu Marwan bin Musa is one of the products of contemporary interpretation, as is the case in 21. The book of Tafsīr Hidāyat al Insān bi Tafsīr al-Qur`ān uses the ittijāh al-salafī paradigm to interpret verses Quran verses. In this study, the author examines the method of interpretation of Abu Marwan bin Musa in the book "Tafsīr Hidāyat al Insān bi Tafsīr al-Qur'ān" and evaluates the book. Therefore, the author tries to look at the methodology of Abu Marwan bin Musa in this book
Author Correction: WOODIV, a database of occurrences, functional traits, and phylogenetic data for all Euro-Mediterranean trees (Scientific Data, (2021), 8, 1, (89), 10.1038/s41597-021-00873-3)
No full textThe original version of this Data Descriptor contained an error in the author affiliations. Marwan Cheikh Albassatneh was incorrectly associated with Institute of Ecology and Environmental Sciences, Sorbonne University, Paris, France and Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle (MNHN), CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France was inadvertently omitted. This has now been corrected in both the PDF and HTML versions of the Data Descriptor
Modeling and control of piezoelectric stack actuators with hysteresis
Get PDFPiezoelectric actuators are popularly applied as actuators in high precision systems due to their small displacement resolution, fast response and simple construction. However, the hysteresis nonlinear behavior limits the dynamic modeling and tracking control of piezoelectric actuators. This thesis studies a dynamic model of a moving stage driven by piezoelectric stack actuator. The Bouc-Wen model is introduced and analyzed to express the nonlinear hysteresis term of the piezoelectric stack actuator, where the values of the parameters of the model have been taken from a previous work. The simulated results using MATLAB/Simulink demonstrate the existence of the hysteresis phenomenon between the input voltage and the output displacement of the piezoelectric stack actuator, and validate the correctness of the model. Moreover, a Luenberger observer is designed to estimate the hysteresis nonlinearity of the system, and then combined with the voltage input signal to form a Luenberger-based feedforward controller to control the displacement of the system. Furthermore, a Proportional-Integral-Derivative (PID) feedback controller is integrated with the feedforward controller to achieve more accurate output displacement, where the gains of the PID controller are optimized using Particle Swarm Optimization. Several performance index formulas have been studied to get the best solution of the PID’s gains. An Integral Time Squared Error plus Absolute Error performance index formula has been proposed to achieve zero overshoot and steady-state error. The simulated results accomplished using MATLAB/Simulink show the ability of the designed controllers to vastly reduce the amount of error of the output displacement and the response time of the system
Frequency-controlled wireless passive microfluidic devices
Get PDFMicrofluidics is a promising technology that is increasingly attracting the attention of researchers due to its high efficiency and low-cost features. Micropumps, micromixers, and microvalves have been widely applied in various biomedical applications due to their compact size and precise dosage controllability. Nevertheless, despite the vast amount of research reported in this research area, the ability to implement these devices in portable and implantable applications is still limited. To date, such devices are constricted to the use of wires, or on-board power supplies, such as batteries. This thesis presents novel techniques that allow wireless control of passive microfluidic devices using an external radiofrequency magnetic field utilizing thermopneumatic principle. Three microfluidic devices are designed and developed to perform within the range of implantable drug-delivery devices. To demonstrate the wireless control of microfluidic devices, a wireless implantable thermopneumatic micropump is presented. Thermopneumatic pumping with a maximum flow rate of 2.86 μL/min is realized using a planar wirelessly-controlled passive inductor-capacitor heater. Then, this principle was extended in order to demonstrate the selective wireless control of multiple passive heaters. A passive wirelessly-controlled thermopneumatic zigzag micromixer is developed as a mean of a multiple drug delivery device. A maximum mixing efficiency of 96.1% is achieved by selectively activating two passive wireless planar inductor-capacitor heaters that have different resonant frequency values. To eliminate the heat associated with aforementioned wireless devices, a wireless piezoelectric normally-closed microvalve for drug delivery applications is developed. A piezoelectric diaphragm is operated wirelessly using the wireless power that is transferred from an external magnetic field. Valving is achieved with a percentage error as low as 3.11% in a 3 days long-term functionality test. The developed devices present a promising implementation of the reported wireless actuation principles in various portable and implantable biomedical applications, such as drug delivery, analytical assays, and cell lysis devices
Vocalization in Group Writing
Get PDFThe so-called group writing or syllabic orthography is a special orthography used in Egyptian hieroglyphic texts starting from the New Kingdom/Late Bronze Age. The nature and function of this orthography, especially the way it notates vowels, has been a topic of debate for more than a century, without any consensus being reached. In this book, Marwan Kilani presents a new interpretative model that provides a fresh explanation of how the syllabic orthography notates vowels. The author starts from a critical reanalysis of previous suggestions and from a thorough reassessment of the evidence. He then infers the functioning of the system by comparing the group writing spelling of Late Egyptian words surviving in Coptic with the reconstructions of their vocalizations. This approach leads to the recognition of a system that not only coherently explains all the spellings attested in the corpus, but which also produces interpretations of the spellings in group writing that agree with current reconstructions of the Egyptian vocalization. The book contains indexes and an Appendix listing the words analysed in the study
Vocalization in Group Writing
Get PDFThe so-called group writing or syllabic orthography is a special orthography used in Egyptian hieroglyphic texts starting from the New Kingdom/Late Bronze Age. The nature and function of this orthography, especially the way it notates vowels, has been a topic of debate for more than a century, without any consensus being reached. In this book, Marwan Kilani presents a new interpretative model that provides a fresh explanation of how the syllabic orthography notates vowels. The author starts from a critical reanalysis of previous suggestions and from a thorough reassessment of the evidence. He then infers the functioning of the system by comparing the group writing spelling of Late Egyptian words surviving in Coptic with the reconstructions of their vocalizations. This approach leads to the recognition of a system that not only coherently explains all the spellings attested in the corpus, but which also produces interpretations of the spellings in group writing that agree with current reconstructions of the Egyptian vocalization. The book contains indexes and an Appendix listing the words analysed in the study
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