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Green synthesis of iron oxide nanoparticles using Cymbopogon citratus extract and sodium carbonate salt: Nanotoxicological considerations for potential environmental applications

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Environmental Nanotechnology, Monitoring and Management 2020年 14卷

作者： Patiño-Ruiz, David Sánchez-Botero, Lina Tejeda-Benitez, Lesly Hinestroza, Juan Herrera, Adriana Engineering Doctorate Program Nanomaterials and Computer-Aided Process Engineering Research Group Universidad de Cartagena Cartagena 130010 Colombia Department of Fiber Science and Apparel Design Cornell University Ithaca United States Chemical Engineering Program Nanomaterials and Computer-Aided Process Engineering Research Group Universidad de Cartagena Cartagena 130010 Colombia

Synthesis of functional and biocompatible nanomaterials, based on the green chemistry paradigm, aims to innovate by using environmentally friendly techniques. Green synthesis using natural extracts instead of chemicals is proving to be an efficient route to prepare metal and metal oxide nanoparticles. In this study, the green synthesis of iron oxide nanoparticles (FeO-NPs) is reported, using a Cymbopogon citratus (C. citratus) extract and sodium carbonate as the reducing and pH stabilizer agents, respectively. FeO-NPs are extensively studied and applied due to the exceptional physicochemical properties, outstanding the superparamagnetism, and the large surface area. These properties are corroborated using different characterization techniques, in which a regular crystal structure and the magnetic response are similar compared with FeO-NPs synthesized via the traditional methods. The presence of magnetite and maghemite (Fe₃O₄ and γ-Fe₂O₃) phases are evidenced. A major composition of Fe₃O₄ allows predominant superparamagnetism. However, surface functionalization reduces the spin coordination avoiding a high saturation magnetization. The presence of phytochemical content in the C. citratus allows the reduction of iron(III) to iron(II) using H⁺ radicals produced from hydroxyl and carbonyl groups, and the in-situ functionalization using these groups. Additionally, the biocompatibility of the FeO-NPs is evaluated performing a nanotoxicological assessment, in which Caenorhabditis elegans nematodes are used as the biological model. The presence of organic molecules on FeO-NPs promotes no toxicity and low effects on the locomotion, growth, and reproduction, suggesting a low risk using these functional nanoparticles for environmental applications, and outstanding the synthesis route with a green approach. © 2020 Elsevier B.V.

关键词： Caenorhabditis elegans Cymbopogon citratus extract Ecotoxicological effects FeO nanoparticles Green synthesis Sodium carbonate

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Variations in the acoustic measurement of earbud earphones in an ane-choic chamber due to changes in the earphone placement in ear Concha

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Canadian Acoustics - Acoustique Canadienne 2020年第4期48卷 29-40页

作者： Pawar, S.J. Liu, Y.C. Huang, Jin H. Department of Applied Mechanics Motilal Nehru National Institute of Technology Allahabad Prayagraj India Bachelor's Program in Precision System Design Feng Chia University Taichung Taiwan Department of Mechanical and Computer-Aided Engineering Feng Chia University Taichung Taiwan

The growth of consumer electronic products is encouraged by innovations and has stimulated the persistent development of earphones for high-quality sound reproduction. Earbud earphone is located in the concha of the human ear facing an ear-canal. The placement of earphones in the concha plays a remarkable role in the sound pressure level response of an earphone. In this study, ten earphones were tested for frequency response and total harmonic distortion using head and torso simulator in an anechoic chamber. Three positions and two orientations of earphones in the concha were identified for measurement. Based on the responses of all earphones at all orientations and positions, it is concluded that there is a variation in the frequency response and total harmonic distortion. Even though the variation is small in magnitude, its effect on sound perception, sound exposure, and the hearing threshold is phenomenal. Based on the proposition presented in this work and the safe daily sound exposure, it has been determined that the variation in the frequency response affects the perceived loudness of sound and can cause signif-icant differences in the daily sound exposure limit for a human being. © 2020, Canadian Acoustical Association. All rights reserved.

关键词： Frequency response

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Adsorption kinetics, isotherms and desorption studies of mercury from aqueous solution at different temperatures on magnetic sodium alginate-thiourea microbeads

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Environmental Nanotechnology, Monitoring and Management 2019年 12卷

作者： Patiño-Ruiz, D. Bonfante, H. De Ávila, G. Herrera, Adriana Doctorate in Engineering Program Nanomaterials and Computer Aided Process Engineering Research Group Universidad de Cartagena Cartagena Colombia Chemical Engineering Program Process Design and Biomass Use Group Universidad de Cartagena Cartagena Colombia Chemical Engineering Program Nanomaterials and Computer Aided Process Engineering Research Group Universidad de Cartagena Cartagena Colombia

Magnetite (Fe3O4) nanoparticles and thiourea were employed to modify sodium alginate microbeads for adsorption of Hg ions from aqueous solution. The Fe3O4 nanoparticles were initially synthesized by co-precipitation m... 详细信息

Magnetite (Fe₃O₄) nanoparticles and thiourea were employed to modify sodium alginate microbeads for adsorption of Hg ions from aqueous solution. The Fe₃O₄ nanoparticles were initially synthesized by co-precipitation method. Fourier infrared spectroscopy (FTIR) determined the presence of hydroxyl, carboxyl, thiol and amine functional groups in the microbead molecular structure. According to BET and BJH methods, the MAT microbeads had surface area, pore diameter and volume of 7.3472 m²/g, 12.9058 nm and 0.0255 cm³/g, respectively. Scanning electron microscopy (SEM) equipped with an EDX system allowed to obtain morphological information of the MAT microbeads, in which was observed the main elements introduced by the presence of thiol groups and iron ions. The result of saturation magnetization (M_s) performed by a vibrating sample magnetometer (VSM), is common for superparamagnetic materials, which slightly decreased due to the low amount of magnetic nanoparticles in the microbead structure. Adsorption kinetics showed that highest rate was about 98% in the first 20 min, and then decreased to zero. Pseudo-first order was the model that better fitted to experimental data with a value about 2.6 mg/g. Meanwhile, adsorption isotherm was better described using Langmuir model, suggesting that the Hg ions adsorption was mainly given by electrostatic interaction and chemical bonding among the functional groups, as well as the formation of a saturated layer onto the microbead surface occupying all the available sites. © 2019

关键词： Adsorption Magnetic nanoparticles Mercury Sodium alginate microbeads Thiourea

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Optimization of production processes using predictive analytics apparatus in synthesis of systems of industrial Internet of Things

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AIP Conference Proceedings 2021年第1期2402卷

作者： A. L. Zolkin V. D. Munister V. A. Tikhonov I. V. Slabodenuk N. E. Amirov 1Computer and Information Sciences Department Povolzhskiy State University of Telecommunications and Informatics L.Tolstogo 23 Samara Russia 2Department of Mathematical Methods and Computer-Aided Design Private educational institution "Donetsk Academy of Transport" Dzerzhinsky Street 7 Donetsk Ukraine 3Department of chemical engineering and ecology Berezniki branch of the Perm National Research Polytechnic University TelmanaStreet 7 Perm region Berezniki Russia 4Chemical engineering of inorganic substances Master program Berezniki branch of the Perm National Research Polytechnic University TelmanaStreet 7 Perm region Berezniki Russia

The article presents an analysis of the optimal criterion. The role and significance of certain properties of fuzzy logic in predictive analytics of technical systems to support the functioning of the optimal level of production processes are considered. The role of calculation of the degree of inclusion of fuzzy sets is justified by the example of transfer characteristic functions in the generalized case. The author's research on the optimization value of the investigated mathematical apparatus is presented on the example of the synthesis of the industrial Internet of Things system within the framework of the model of automatic control of the air temperature in the greenhouse.

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Multiscale spectral subtraction method and support vector machine for clustering heavy background noise classification 24

Multiscale spectral subtraction method and support vector ma...

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24th International Congress on Sound and Vibration, ICSV 2017

作者： Tsai, Yu-Ting Huang, Jin H. Feng Chia University Bachelor's Program in Precision System Design Taichung Taiwan Feng Chia University Department of Mechanical and Computer-Aided Engineering Taichung Taiwan

For measuring the rotation engine vibration signals, the mechanical or acoustical sensors are dif-ficult to get the clean signals from the heavy background noise of the machinery environment. The noise reduction algorithm may anticipate to decrease the background noise without disturbing the unpolluted signal. The spectral subtraction methods for noise attenuation case are reached for many years due to its simple and effectively. In this paper, the proposed algorithm incorporates the multiscale spectral subtraction method (MSS) with voice activity detector (VAD) and sup-ports vector machine (SVM) for removing the background noise, since SVM can be required for distinguishing a multivariate signal into separated subcomponents. From the analysis case for the rotating machinery, MSS shows that the low frequency with their harmonics frequencies can be tracked through the clustering of the data from SVM. The present method is helpful in background noise and signal compartmentalization as its application can significantly lower the requirement for labelled training cases in both the inductive noise and wanted signals.

关键词： Support vector machines

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Application of programmable Logic Controller to Build-up an Intelligent Industry 4.0 Platform

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Procedia CIRP 2017年 63卷 150-155页

作者： Jian-Yu Chen Kuo-Cheng Tai Guo-Chin Chen Bachelor's Program of Precision System Design Feng Chia University No. 100 Wenhwa Rd. Seatwen Taichung 407 Taiwan Department of Mechanical and Computer-Aided Engineering Feng Chia University No. 100 Wenhwa Rd. Seatwen Taichung 407 Taiwan

Industry 4.0 is initiated by the German government as a high level technology strategy in order to keep Germany in a global leading position in manufacturing, also intends to solve energy and aging issues in parallel. Germany has proposed the “Reference Architecture Model Industries 4.0” which is based on the regulations published by the International Electrotechnical Commission. The manifestation of Industry 4.0 can be achieved by the realization of digital factory. And it's emphasized on total integration with Cyber Physical System as its core technology, via Internet of Things to realize the operational environment of human machine interaction, and the utilization of Big Data for decision making. The research motivation of this thesis is to utilize Totally Integrated Automation Portal as a digital factory software development platform, to achieve the fundamental educational requirements of digital factory, and to understand Industry 4.0 concept. Methodology of this research is based on a set of experimental and training mechanism, the sequence of machine movements is controlled by a programmable Logic Controller, and this PLC has to be complied with IEC61131 International Standard. Regarding communication technology also to be complied with IEC61158 and IEC62541 e.g. PROFINET and OPC UA protocol. And finally realizing the operational environment of human machine interaction via smart phone according to the outcome of this research, it has been shown that total integration concept can be realized by single production machine. By standardization of factory environment and increasing the level of operational environment of human machine interaction, productivity and quality of production could be significantly increased. PLC could be used to analyze intelligent platform and comply with the Industry 4.0 standard at the same time.

关键词： I4.0 Digitalization Factory PLC and IEC61131

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Preventing damage to miniature-loudspeaker by means of dynamic detection of excessive diaphragm displacement

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JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2017年第3期141卷 1615-1626页

作者： Tsai, Yu-Ting Pawar, S. J. Wang, Chi-Chang Huang, Jin H. Feng Chia Univ Bachelor Program Precis Syst Design 100 Wenhwa Rd Taichung 40724 Taiwan Motilal Nehru Natl Inst Technol Allahabad Dept Appl Mech Allahabad 211004 Uttar Pradesh India Feng Chia Univ Dept Mech & Computer Aided Engn 100 Wenhwa Rd Taichung 40724 Taiwan

The rapid development of consumer electronics and the extensive use of mobile devices require the ample use of miniature- loudspeakers for audio applications. The demand for better sound pushes manufacturers to design digital signal processing (DSP) chips (smart amplifiers), which in turn could cause unpleasant sound due to distortion and parameter nonlinearity or transducer damage caused by large diaphragm excursion or voice-coil (VC) burn. This article presents a methodology for nonlinear parameter estimation using an inverse method and displacement limiter for large VC displacement-dependent transducer damage prevention. A set of transduction equations is employed to inversely determine parameters using a polynomial expression. The appropriate selection of an objective function incorporating the unknown vector of nonlinear parameters leads to the adjoint problem that requires a gradient solution. A numerical solver is provided to obtain the VC displacement, current, and derivatives using a robust hybrid spline differential method. The dynamic limiter is proposed to control the peak values of the VC velocity so as to limit an excessive displacement which prevents impulsive damage to the receiver and further application of the DSP board. Numerical and experimental results indicate that the proposed method has high efficiency and can be widely used in transducer applications. (C) 2017 Acoustical Society of America.

关键词： LOUDSPEAKER design & construction TRANSDUCERS DIGITAL signal processing ELECTRONIC amplifiers LIMITER circuits

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Towards Implementing a Real-time Deformable Human Muscle Model in Digital Human Environments

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Procedia Manufacturing 2015年 3卷 3844-3851页

作者： Sharma, Abhinav Dani, Angela Mathai, Anith J. Marler, Timothy Abdel-Malek, Karim U.S. Army Virtual Soldier Research Program Center for Computer Aided Design The University of Iowa Iowa City IA 52242 United States

The current state of the art digital human models are a visual proxy for humans in part due to the advances in computer graphics. They perform with biomechanical accuracy that mimics real human motion. Models such as Santos® have a biomechanically accurate skeleton driving the motion, which in turn controls the deformation of a flexible skin for added realism, all in real time. However, these models lack realistic musculoskeletal systems that respond in real time to biomechanical motion. They require varying levels of pre-processing before motion can be applied to them, thus preventing the real time effect;muscle models need to be flexible and deformable, which in computer simulations generally translates to higher computation requirements. By combining advances in computer graphics, especially the fast rendering game graphics capability, with known literature on musculoskeletal modeling, a preliminary full body musculoskeletal system that deforms in real time is presented along with the skeleton and skin. Given the biomechanical studies focus of digital humans, the model implemented centers on the mathematical articulation, and not the graphical volumetric representation, of actual musculoskeletal systems. As such, each muscle is defined as a line that starts at an origin position, determined from anatomy, and ends at the corresponding insertion position, while wrapping as needed around cylindrical obstacles that emulate the minimum bulges required for that line to be at the centroid of the actual equivalent muscle. For each muscle, the origin position, insertion position and obstacle parameters (position, rotation, and scale) have to be obtained relative to key joints for accurate articulation. This was done manually on a per-muscle basis for 126 muscles, and can be extended to any anthropometric avatar. With this initial real-time model, there is potential for a quicker assessment of the effect of muscles on human task performance, leading to a complete model tha

关键词： Anatomy Digital humans Muscle model Musculoskeletal system Real time graphics

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A Methodology for Longitudinal Tooth Flank Crowning of the Helical Gear on a CNC Honing Machine

A Methodology for Longitudinal Tooth Flank Crowning of the H...

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2014 2nd International Conference on Future Materials Engineering and Industry Application(ICFMEIA 2014)

作者： Van-The Tran Ruei-Hung Hsu Chung-Biau Tsay Program of Mechanical and Aeronautical Engineering Feng Chia University Program in Precision System Design Feng Chia University Department of Mechanical and Computer-Aided Engineering Feng Chia University

The gear honing is the most economical way for hard finishing an involute helical gear after hobbing and heat treatment or after shaving and heat treatmentThe gear honing can also be applied to the modification of gear tooth surfaces to compensate for the distortions that occur during heat treatment processMost published papers on the technology of gear honing describes on the principle of generated gear surfaceHowever, the longitudinal tooth flank crowning of a helical gear with honing has not been investigated yetTherefore, in this paper, we proposed a novel method for longitudinal tooth flank crowning of work gear surfaces by setting a crossed angle between the honing cutter and work gear axes as a linear function of honing cutter's traverse feed in the honing processA mathematical model for the tooth profile of work gear honed by a standard honing cutter is also establishedThree numeral examples are presented to illustrate and verify the merits of the proposed gear honing method in longitudinal crowning.

关键词： Gear honing Longitudinal crowning Tooth flank Helical gear Mathematical model

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Artificial neural network-based prediction of human posture

Artificial neural network-based prediction of human posture

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4th Int. Conf. on Digital Human Modeling and Applications in Health, Safety, Ergonomics, and Risk Management: Human Body Modeling and Ergonomics, DHM 2013, Held as Part of 15th Int. Conf. on Human-computer Interaction, HCI 2013

作者： Bataineh, Mohammad Marler, Timothy Abdel-Malek, Karim Virtual Soldier Research Program Center for Computer-Aided Design University of Iowa Iowa City IA 52242 United States

ISBN: (纸本)9783642391811

The use of an artificial neural network (ANN) in many practical complicated problems encourages its implementation in the digital human modeling (DHM) world. DHM problems are complicated and need powerful tools like ANN to provide acceptable solutions. Human posture prediction is a DHM field that has been studied thoroughly in recent years. This work focuses on using a general regression neural network (GRNN) for human posture prediction. This type of ANN has advantages over others when incorporated in DHM problems like posture prediction. A new heuristic approach is also presented in this study to determine the GRNN parameters that lead to the best performance and prediction capability. The results are promising: a high success rate is obtained for predicting 41 outputs, which represent the upper-body degrees of freedom of a human model. This work initiates future focus on embedding GRNN to generalize human posture prediction in a task-based manner. © 2013 Springer-Verlag.

关键词： Neural networks

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