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Thermoelectric chalcopyrite-type ZnSnAs 2 compound with high power factor for low-grade waste-heat recovery

Journal of Alloys and Compounds 2025年 1033卷

作者： Koki Nakashima Shoma Miura Hiroki Ienaga Keita Nomoto Kenji Yoshino Kensuke Nishioka Akira Nagaoka Graduate School of Engineering University of Miyazaki Miyazaki 889-2192 Japan School of Aerospace Mechanical and Mechatronic Engineering and Australian Centre for Microscopy and Microanalysis The University of Sydney Sydney 2006 Australia Faculty of Engineering Electrical and Electronic System Program University of Miyazaki Miyazaki 889-2192 Japan GX Research Center University of Miyazaki Miyazaki 889-2192 Japan

Chalcopyrite compounds are promising thermoelectric (TE) materials owing to their excellent performance. Adopting a pseudocubic structure is a key strategy to improve the TE performance as it increases the degeneracy at the valence band edge. Herein, the TE properties of a II-IV-V 2 group, p-type ZnSnAs 2 chalcopyrite with a pseudocubic structure are systematically investigated. Polycrystalline, single phase, stoichiometric ZnSnAs 2 was obtained at growth temperatures above 700 ºC. The TE properties of ZnSnAs 2 depended on its intrinsic defect concentration, which was influenced by its Zn/Sn ratios. A high power factor value of 2890 μW/mK 2 was obtained in Zn-poor Zn 0.9 Sn 1.1 As 2 at 373 K. The TE figure of merit for the off-stoichiometric ZnSnAs 2 reached 0.1 at 573 K. Consequently, a maximum TE conversion efficiency of ∼1 % at a temperature gradient of 300 K was demonstrated for a ZnSnAs 2 -based single-leg device. These results can accelerate the development of TE technologies for low-energy harvesting.

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Machine learning applied to forecasting the manufacturing time of new products prototypes and ETO products: An exploratory study

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International Journal of Production Economics 2025年 287卷

作者： Roberto Canedo Rosa Marcelo Carneiro Gonçalves Sanderson César Macêdo Barbalho Federal Institute of Amazonas Campus Manaus Centro Manaus AM CEP: 69025-010 Brazil University of Brasilia Technology College. Department of Industrial Engineering Post-graduation Program of Mechatronic Systems Campus Darcy Ribeiro Brasilia DF CEP 70910-900 Brazil

Industry 4.0 is a transformative initiative that integrates various technologies and reshapes industrial processes, production methods, and business models. However, forecasting future events within this paradigm shift presents significant challenges. Predicting the cycle time for new product development (NPD) in a dynamic and competitive environment, especially in a highly globalized market driven by innovation, is crucial. Previous research has shown that prototype manufacturing lead times are key parameters for predicting NPD times-to-market. This study investigates the predictive capabilities of artificial intelligence algorithms in estimating manufacturing lead times under varying part geometries and materials at an aerospace and medical equipment company. By leveraging predictive analysis and machine learning techniques, specifically Artificial Neural Networks (ANN), Support Vector Machine (SVM), and Random Forest (RF) algorithms, the proposed methodology demonstrates its efficacy and variations. The results show that top-performing models achieve an accuracy rate exceeding 87 % and an average absolute error of less than one day, which have significant practical benefits for project production planners. They can utilize the most popular AI frameworks on easier-to-use programming platforms to estimate the time required to manufacture their prototypes, predict their new product development (NPD) cycle times, and negotiate lead times for in-house and third-party manufacturing more effectively, thereby improving project planning and delivery.

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Encapsulation of C. odorata extracts for antimicrobial activity

Encapsulation of C. odorata extracts for antimicrobial activ...

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2019 International Conference on Biomedical engineering, ICoBE 2019

作者： Azmi, Siti Nur Amylina Mohamad, Che Wan Sharifah Robiah Kasim, Khairul Farihan Biomedical Electronic Engineering Program School of Mechatronic Engineering Universiti Malaysia Perlis Perlis-Arau02600 Malaysia School of Bioprocess Engineering Universiti Malaysia Perlis Jejawi Perlis01000 Malaysia

The purpose of this study is to investigate the relationship between the methycellulose (MC) and ethylcellulose (EC) of encapsulated C. odorata extracts (methanol and ethanol) and their antimicrobial properties against E. coli and Staphylococcus aureus. The encapsulated of C. odorata extract was prepared by solvent displacement method through dialysis tube cellulose membrane and it was freeze-dried to obtain the suspension of encapsulated C. odorata extract. Then, antimicrobial properties of encapsulated C. odorata extracts was performed by broth dilution method on target bacteria. A few drops of hydrochloric acid (HCl) were added into growth media until pH 4 to mimic the acidic conditions in human stomach. The results showed the encapsulated methylcellulose of methanol extract (MC-M) inhibit both bacteria types. © 2019 IOP Publishing Ltd. All rights reserved.

关键词： Methanol

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Event reconstruction algorithm proposal to study sensors elaboration based on nanostructures 23

Event reconstruction algorithm proposal to study sensors ela...

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23rd World Multi-Conference on Systemics, Cybernetics and Informatics, WMSCI 2019

作者： Calderón, Jesús A. Tafur, Julio C. Barriga, Eliseo B. Lozano, John H. Energy Laboratory Mechatronic Department Pontificia Universidad Católica del Perú Lima Peru Institute of Physics and IMN MacroNano TU Ilmenau University of Technology Germany Mechatronic Department Pontificia Universidad Católica del Perú Lima Peru Engineering Department Mechatronic Master Engineering Program Pontificia Universidad Católica del Perú Lima Peru

ISBN: (纸本)9781950492091

In this work is proposed a general algorithm to design event reconstruction of chemical/physical process to elaborate nanostructures through anodization in small pieces of aluminum, in order to get Aluminum Oxide (AAO) simples ready to be characterized, furthermore to be integrated as sensors of physical variables. By studying the evolution of border’s curves composed of figures from AAO sample, which is captured through Scanning Electron Microscope (SEM) is possible to make an integration in 3 dimensions (3D), furthermore the 3D figure obtained can be explained through mathematical model to estimate its geometrical evolution after physical/chemical reactions. In this work, there are analyzed images from every stage of the process to elaborate nanostructures based on AAO templates, such as for example the following sequence: image before cleaning process, images before electro polishing, images before anodization process;and finally, images after anodization which are expected to obtain a kind of nanostructures. Every image were processed studying [1], [8] in order to obtain a mathematical equation as reference to understand the geometry of the 3D structure based on its 2D image for every stage. By other side, with this information and processing every stage image, it was achieved a mathematical equation to describe the geometry of the structure between stages by "Optimal Prediction analysis" that is so important to get understanding of the structure geometry with internal process. © WMSCI 2019 - 23rd World Multi-Conference on Systemics, Cybernetics and Informatics, Proceedings. All rights reserved.

关键词： Nanostructures

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Low-Temperature Synthesis of Weakly Confined Carbyne inside Single-Walled Carbon Nanotubes

arXiv

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arXiv 2024年

作者： Zhang, Bo-Wen Qiu, Xi-Yang Ma, Yicheng Hu, Qingmei Fitó-Parera, Aina Kohata, Ikuma Feng, Ya Zheng, Yongjia Zhang, Chiyu Matsuo, Yutaka Wang, YuHuang Chiashi, Shohei Otsuka, Keigo Xiang, Rong Levshov, Dmitry I. Cambré, Sofie Wenseleers, Wim Rotkin, Slava V. Maruyama, Shigeo Department of Mechanical Engineering The University of Tokyo Tokyo113-8656 Japan State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical Engineering Zhejiang University Hangzhou310027 China Theory and Spectroscopy of Molecules and Materials Department of Physics University of Antwerp Antwerp2610 Belgium Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education School of Energy and Power Engineering Dalian University of Technology Liaoning 116024 China Department of Chemistry and Biochemistry Chemical Physics Program Maryland Nano Center University of Maryland College ParkMD20742 United States Department of Chemical Systems Engineering Graduate School of Engineering Nagoya University Nagoya464-8603 Japan Institute of Materials Innovation Institutes for Future Society Nagoya University Nagoya464-8603 Japan Theory and Spectroscopy of Molecules and Materials Department of Chemistry University of Antwerp Antwerp2610 Belgium Nanostructured and Organic Optical and Electronic Materials Department of Physics University of Antwerp Antwerp2610 Belgium Materials Research Institute Department of Engineering Science & Mechanics The Pennsylvania State University University ParkPA16802 United States

Carbyne, a one-dimensional (1D) carbon allotrope with alternating triple and single bonds, has the highest known mechanical strength but is unstable to bending, limiting synthesis to short linear chains. Encapsulation within carbon nanotubes (CNTs) stabilizes carbyne, forming confined carbyne (CC), thus enabling further research concerning attractive 1D physics and materials properties of carbyne. While CC has been synthesized in multi-walled CNTs (MWCNTs) using the arc-discharge method and in double-walled CNTs (DWCNTs) via high-temperature high-vacuum (HTHV) method, synthesis in single-walled CNTs (SWCNTs) has been challenging due to their fragility under such conditions. In this work, we report a low-temperature method to synthesize CC inside SWCNTs (CC@SWCNT). By annealing SWCNTs containing ammonium deoxycholate (ADC) at 400°C, ADC is converted into CC without damaging the SWCNTs. Raman spectroscopy revealed a strong CC phonon (CC-mode) peak at 1860–1870 cm-1, much stronger than the SWCNT G-band peak, confirming a high fraction of CC in the resulting material. The Raman mapping result showed the uniformity of the CC-mode signal across the entire film sample, proving the high efficiency of this method in synthesizing CC in every SWCNT of appropriate size. Notably, the CC-mode peaks of CC@SWCNT (above 1860 cm-1) are higher than those reported in previous CC@CNT samples (mostly -1). This is attributed to larger SWCNT diameters (>0.95 nm) used in this study, compared to the typical 0.6–0.8 nm range. Larger diameters result in reduced confinement, allowing carbyne to closely resemble free-standing carbyne while remaining stabilized. This low-temperature synthesis of long-chain, nearly freestanding carbyne within large-diameter SWCNTs offers new opportunities for exploring 1D physics and the unique properties of carbyne for potential applications. © 2024, CC BY-NC-ND.

关键词： Single-walled carbon nanotubes (SWCN)

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Control algorithm proposal for a hybrid active magnetic bearing system with variable load 23

Control algorithm proposal for a hybrid active magnetic bear...

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23rd World Multi-Conference on Systemics, Cybernetics and Informatics, WMSCI 2019

作者： Lozano, John H. Tafur, Julio C. Calderón, Jesús A. Engineering Department Mechatronic Master Engineering Program Pontificia Universidad Católica del Perú Lima Peru Mechatronic Departament Pontificia Universidad Católica del Perú Lima Peru Energy Laboratory Mechatronic Department Pontificia Universidad Católica del Perú Lima Peru Institute of Physics and IMN MacroNano TU Ilmenau University of Technology Germany

ISBN: (纸本)9781950492091

The transmission of movement by the motor to a mechanical system is because of rotor joined with mechanical bearings such as in context of compressors, pumps, turbines;that by their design and structure generates deficiencies as heating due to friction, which needs a constant use of lubricants. For this reason, the mechanical bearings are replaced by magnetic bearings, in order to avoid friction because there is not mechanical contact between the magnetic bearings and the rotor. Otherwise, magnetic bearings enhance efficiency such as speed of rotation due to eliminating vibrations. The active magnetic bearing (AMB) looks for positioning a rotor when forces and torque break the mechanical movement equilibrium also its stability. Therefore, this work according to the algorithm proposed tries to achieve precision control position as dependence of requirements parameters like response time, overshoot and error in steady state. © WMSCI 2019 - 23rd World Multi-Conference on Systemics, Cybernetics and Informatics, Proceedings. All rights reserved.

关键词： Friction

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Active noise control proposal for rotating machines 23

Active noise control proposal for rotating machines

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23rd World Multi-Conference on Systemics, Cybernetics and Informatics, WMSCI 2019

ISBN: (纸本)9781950492091

Rotating machines are absolutely used in many engineering tasks, such as "Energy transmission" given by compressors, turbines, pumps. However, these machines produce high decibels of noise, for this reason is necessary to attenuate noise by many mechanisms as passive criterion, but that cannot get good response under low frequencies domain or under disturbances. Therefore, in this research is proposed an active mechanism supported that is controlled by "Least Mean Square" (LMS) strategies to get noise attenuation in 3 dimension space, furthermore a "Vibration Control Analysis" by sensors based in nanostructures was realized. © WMSCI 2019 - 23rd World Multi-Conference on Systemics, Cybernetics and Informatics, Proceedings. All rights reserved.

关键词： Active noise control

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Deep Learning Audio Spectrograms Processing to the Early COVID-19 Detection

Deep Learning Audio Spectrograms Processing to the Early COV...

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International Conference on Computational Intelligence and Communication Networks (CICN)

作者： Ciro Rodriguez Rodriguez Daniel Angeles Renzo Chafloque Freddy Kaseng Bishwajeet Pandey Software Engineering School National University Mayor de San Marcos Lima Peru Mechatronic Engineering Program National University Federico Villarreal Lima Peru Gyancity Research Lab Birla Institute of Applied Science Bhintal India

ISBN: (数字)9781728193939

ISBN: (纸本)9781728193946

The objective of the paper is to provide a model capable of serving as a basis for retraining a convolutional neural network that can be used to detect COVID-19 cases through spectrograms of coughing, sneezing and other respiratory sounds from infected people. To address this challenge, the methodology was focused on Deep Learning technics worked with a dataset of sounds of sick and non-sick people, and using ImageNet's Xception architecture to train the model to be presented through Fine-Tuning. The results obtained were a precision of 0.75 to 0.80, this being drastically affected by the quality of the dataset at our availability, however, when getting relatively high results for the conditions of the data used, we can conclude that the model can present much better results if it is working with a dataset specifically of respiratory sounds of COVID-19 cases with high quality.

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Methodology for Optimization of the Electric Wire Arc - Spraying Process to the Mixture of Coatings 140MXC-530AS and 140MXC-560AS Using a Multi-objective Genetic Algorithm

Research Square

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Research Square 2020年

作者： Rojas, Héctor F. Guzmán, María A. Luna, Oscar E. Aragón, Diana F. Universidad Libre Bogotá Headquarters Faculty of Engineering Mechanical Engineering Program Bosque Popular Campus AvCra 70 No 53-40 Colombia National University of Colombia Bogotá Headquarters Faculty of Engineering Mechanical and Mechatronic Engineering Program AvCra 30 St 45 Colombia National Learning Service - SENA Regional Capital District Materials and Testing Center - CME Av Cra 30 No 17B 25 south Colombia

The Corporation of Science and Technology for the Development of the Maritime and Fluvial Shipbuilding Industry COTECMAR has been using for more than 4 years the process of electric arc thermal projection with commercial materials such as 530AS, 560AS and 140MXC to mitigate corrosion phenomena and wear of the different devices that make up the boats. The problem lies in mixing these materials (140MXC-530AS and 140MXC-560AS) to produce dissimilar coatings, making it more difficult to optimize the process, whose problem lies in the parameterization of the arc-beam thermal imaging equipment. In the first phase of the project, a Taguchi L9 (34-2) model (fractional factorial orthogonal arrangement) was used to produce the coatings, taking into account the projection parameters of the equipment such as current (A), voltage (V) Primary air pressure (Pp) and secondary air pressure (Ps), which were considered as input variables or experiments for the optimization process. Subsequently the coatings were characterized by techniques such as Scanning Electron Microscopy (SEM) and microhardness to take these data as attributes or output of results in order to obtain the minimization of the size of the projected particles (corrosion) and the microhardness maximization of the coatings (wear). Symbolic regression was used as a technique for obtaining the mathematical models (objective functions), which was done through the "Eureqa Formulize-Desktop" program, because it is considered very complex the modeling of all input variables by conventional mathematical methods. The adaptation of the NSGA-II Multi-Objective Genetic Algorithm was performed through a structured programming in "Matlab", being able to verify that the optimal Pareto fronts obtained in the runs with this Algorithm meet the requirements of the objective functions which are related with the attributes of the selected coatings. © 2020, CC BY.

关键词： Genetic algorithms

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Improving power scooter in systematic innovative thinking

International Journal of Systematic Innovation

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International Journal of Systematic Innovation 2018年第2期5卷 35-44页

作者： Pai, Po-Han Shaw, Heiu-Jou Engineering Management Graduate Program College of Engineering National Cheng Kung University Taiwan Department of System and Naval Mechatronic Engineering National Cheng Kung University Taiwan

With the improvement of medicine and health care, the elderly are facing the dilemma of independent mobility Because the life expectancy of people in Taiwan has greatly increased. And the population structure of this society has been ageing rapidly . At this time, the power scooter is the most important action aids in life, so the design of safety of power scooters is a vital factor, especially in the initial launch, out of c ontrol scooters likely to sudden unintended acceleration (SUA). In order to prevent all possible accidents, it is essential to ensure that the scooter is in a safe state when traveling along a route. In order to deal with these problems above, our study proposes a Triz-based theory by redesigning the speed controller system. Firstly, use the method of The Systematic Innovative Thinking defines the potential problems and key disadvantage. Then, take use of Contradiction matrix and 40 Inventive principles to target solution. Finally, by using Trimming tool to delete unnecessary elements. These methods can maintain functional integrity of power scooters and increase the safety of people who take the vehicle. The study improve speed controller system of power scooters and add PWM and Soft-starter to correct the problem of sudden unintended acceleration. Power scooters traffic accidents caused by improper handing have declined greatly. Provide the elderly a kind of safe assistive devices for independent mobility. © 2018 Society of Sytematic Innovation.

关键词： Elderly Power scooter Sudden unintended acceleration (SUA) TRIZ

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