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UV-Enhanced Room-Temperature Ammonia Detection Using a Ga2O3/Ti3C2Tx MXene Gas Sensor

IEEE Sensors Journal 2025年第11期25卷 18731-18740页

作者： Cha, Goeun Shanmugasundaram, Arunkumar Paeng, Changung Kang, Yunsung Yoon, Youngsam Yim, Changyong Park, Jongsung Chonnam National University MEMS and Nanotechnology Laboratory School of Mechanical Engineering Gwangju61186 Korea Republic of Kyungpook National University Department of Precision Mechanical Engineering Sangju37224 Korea Republic of Korea Military Academy Department of Electrical Engineering Seoul01805 Korea Republic of Kyungpook National University School of Advanced Science and Technology Convergence Graduate School Sangju37224 Korea Republic of Kyungpook National University Department of Energy Materials & Chemical Engineering Sangju37224 Korea Republic of Kyungpook National University Convergence Research Center of Mechanical and Chemical Engineering Sangju37224 Korea Republic of

The present study proposes a Ga2O3/Ti3C2Tx heterojunction-based gas sensor capable of detecting NH3 at room temperature. In this heterojunction, Ga2O3 nanorods, a type of metal oxide, were synthesized on two-dimensional Ti3C2Tx MXene using a hydrothermal method. The sensor was fabricated by drop-casting the Ga2O3/Ti3C2Tx composite onto interdigitated electrodes and evaluated under varying NH3 concentrations with and without UV illumination. The fabricated Ga2O3/Ti3C2Tx heterojunction exhibits enhanced reactivity with ammonia gas due to the high surface area of Ga2O3 and the superior electrical conductivity of Ti3C2Tx, resulting in a synergistic effect that significantly improves NH3 detection performance. Additionally, when exposed to UV light at room temperature, the Ga2O3/Ti3C2Tx gas sensor demonstrates an increased response and stable baseline resistance recovery. The response to 25 ppm NH increased from 18.68% without UV to 23.47% with UV, highlighting the enhanced performance enabled by UV illumination. These findings indicate the sensor's potential for ammonia detection across a wide concentration range and highlight its promise for commercial applications in various environmental settings. © 2025 IEEE.

关键词： Nanorods

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Micromechanical modeling and evaluation of CNTs reinforced magnesium matrix composites based on stress softening modified constitutive model

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Journal of Magnesium and Alloys 2025年第1期13卷 243-259页

作者： Mingjie Shen Baojian Han Tao Ying Jingya Wang Liping Zhou Xiangzhen Xue Yang Gao Zongyang Yang College of Mechanical&Electrical Engineering Shaanxi University of Science&TechnologyXi’an 710021China National Engineering Research Center of Light Alloy Net Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Guizhou provincial key laboratory for aero-engine rotors structural integrity Guiyang550081China Aviation Military Representative Office of the Army Arament Department Aviation Military Representative Bureau in Shanghai Shanghai 200032China

Heterogeneous composites have strong anisotropy and are prone to dynamic recrystallization during hot compression,making the me-chanical response highly ***,it is a very challenging task to intellectually judge the thermal deformation characteristics of magnesium matrix composites(MgMCs).In view of this,this paper introduces a method to accurately solve the thermoplastic deformation of ***,a hot compression constitutive model of magnesium matrix composites based on stress softening correction was ***,the complex quasi-realistic micromechanics modeling of heterogeneous magnesium matrix composites was *** introducing the recrystallization softening factor and strain parameter into the constitutive equation,the accurate prediction of the global rheological response of the composites was realized,and the accuracy of the new constitutive model was ***,the thermal pro-cessing map of magnesium matrix composites was established,and the suitable processing range was *** paper has certain guiding values for the prediction of the thermodynamic response and thermal processing of magnesium matrix composites.

关键词： Newly constitutive model Prediction of the global rheological behavior Magnesium matrix composites

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Using plunging-Type testing to investigate process mechanics at micro scale machining 20

Using plunging-Type testing to investigate process mechanics...

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20th CIRP Conference on Modeling of Machining Operations in Mons, CIRP CMMO 2025

作者： Adeeb, Syed Ahsan Karpat, Yigit Bilkent University Department of Industrial Engineering Ankara06800 Turkey Bilkent University Department of Mechanical Engineering Ankara06800 Turkey UNAM-Institute of Materials Science and Nanotechnology Ankara06800 Turkey

In plunging-Type tests, a cutting tool is given a sinusoidal movement as the work material with a web on its surface is rotated at a constant speed. If the amplitude and feed rate of the cutting tool and rotational speed of the work material are correctly set, the plunging test can be completed within a full rotation. As a result, a detailed investigation of different episodes of micro-scale machining, such as rubbing, plowing, and shearing, can be conducted with a single test. Combined with force measurements and cut chip morphology, the process mechanics can be investigated in detail. This study conducted plunging tests on an ultra-precision CNC with a diamond cutting tool on commercially pure titanium alloy. The differences in tangential and normal forces observed during plunge-in and pull-out periods corresponding to the same amplitude were analyzed using an analytical model. Resultant forces during the pull-out phase are larger than those observed in the plunge-in phase, attributed to an increase in cut chip thickness. A computational model of the plunging-Type experiment has also been developed based on the findings of the analytical model. The proposed hybrid approach may be useful to improve identification of material constitutive model parameters based on micro scale machining experiments. © 2025 The Authors.

关键词： Titanium alloys

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One-Shot Real-to-Sim via End-to-End Differentiable Simulation and Rendering

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IEEE Robotics and Automation Letters 2025年第6期10卷 6320-6327页

作者： Zhu, Yifan Xiang, Tianyi Dollar, Aaron M. Pan, Zherong Yale University Department of Mechanical Engineering and Materials Science New HavenCT06520 United States LightSpeed Studios SeattleWA98039 United States

Identifying predictive world models for robots from sparse online observations is essential for robot task planning and execution in novel environments. However, existing methods that leverage differentiable programming to identify world models are incapable of jointly optimizing the geometry, appearance, and physical properties of the scene. In this work, we introduce a novel rigid object representation that allows the joint identification of these properties. Our method employs a novel differentiable point-based geometry representation coupled with a grid-based appearance field, which allows differentiable object collision detection and rendering. Combined with a differentiable physical simulator, we achieve end-to-end optimization of world models or rigid objects, given the sparse visual and tactile observations of a physical motion sequence. Through a series of world model identification tasks in simulated and real environments, we show that our method can learn both simulation- and rendering-ready rigid world models from only one robot action sequence. © 2025 IEEE.

关键词： Rendering (computer graphics)

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Finite Element Modeling of Thermo-Viscoelastoplastic Behavior of Dievar Alloy under Hot Rotary Swaging

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CMES - Computer Modeling in engineering and sciences 2025年第3期142卷 3115-3133页

作者： Izák, Josef Benč, Marek Opěla, Petr Department of Manufacturing Technology Faculty of Mechanical Engineering Brno University of Technology Brno61600 Czech Republic Department of Metallurgical Technologies Faculty of Materials Science and Technology VŠB Technical University of Ostrava Ostrava70800 Czech Republic

The paper deals with the FEM (Finite Element Method) simulation of rotary swaging of Dievar alloy produced by additive manufacturing technology Selective Laser Melting and conventional process. Swaging was performed at a temperature of 900◦C. True flow stress-strain curves were determined for 600◦C–900◦C and used to construct a Hensel-Spittel model for FEM simulation. The process parameters, i.e., stress, temperature, imposed strain, and force, were investigation during the rotary swaging process. Firstly, the stresses induced during rotary swaging and the resistance of the material to deformation were investigated. The amount and distribution of imposed strain in the cross-section can serve as a valuable indicator of the reduction in porosity and the texture evolution of the material. The simulation revealed the force required to swag the Dievar alloy. It also showed the evolution of temperature, which is important for phase transformation during solidification. Furthermore, microstructure evolution was observed before and then after rotary swaging. Dievar alloy is a critical material in the manufacture of dies for high-pressure die casting, forging tools, and other equipment subjected to high temperatures and mechanical loads. Understanding its viscoelastoplastic behavior under rotary swaging conditions is essential to optimize its performance in these demanding industrial applications. Copyright © 2025 The Authors.

关键词： Steel ingots

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Numerical Investigation on Transient Response of Transpiration Cooling with Phase Change

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International Journal of Gas Turbine, Propulsion and Power Systems 2025年第1期16卷 1-9页

作者： Liu, Taolue Liu, Yifei Ding, Rui He, Fei Wang, Jianhua CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Thermal Science and Energy Engineering University of Science and Technology of China Anhui Hefei230027 China Northwest Institute of Nuclear Technology Xi an710024 China

Transpiration cooling with phase change is a novel active thermal protection method with higher cooling efficiency. The modified two-phase mixture model and the multi-domain coupling computation are adopted to study its transient response. Different fluctuation periods of coolant mass flux and different thermal conductivities of the porous matrix are discussed, respectively. The simulation results show that there are clear delay and accumulation effect in the transient response, and the coolant injection pressure is much more sensitive than the temperature to the coolant mass flux. Moreover, both temperature and injection pressure have their own extreme values during transient response. Then, the instability on the porous matrix surface is closely related to the location of the coolant phase transition. Using the porous matrix with greater thermal conductivity can not only help to reduce the surface temperature of the structure under steady condition, but also has stronger stability under transient condition. The research of this work is of great guidance and practical importance for the extension of the application of transpiration cooling with phase change in the real environment. Copyright ©2025 Taolue Liu, Yifei Liu, Rui Ding, Fei He and Jianhua Wang.

关键词： Thermal conductivity of liquids

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Dense carbon nanofiber self-supporting electrode fabricated by orientation/compaction strategy for high volumetric lithium storage capacity

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Progress in Natural science:materials International 2025年第1期35卷 229-237页

作者： Haihui Liu Chaoqun Chen Qiang Xu Yan Song Xiangwu Zhang Chang Ma Tianjin Municipal Key Lab of Advanced Fiber and Energy Storage Technology Tiangong University CAS Key Laboratory of Carbon Materials Institute of Coal Chemistry Chinese Academy of Sciences Fiber and Polymer Science Program Department of Textile Engineering Chemistry and Science Wilson College of Textiles North Carolina State University

Low bulk density greatly restricts the large-scale application of electrospun carbon-based fiber membrane as electrode in energy storage devices. To solve the above challenges, herein an orientation-compaction densification strategy is proposed to enhance the bulk density and volumetric capacity of PAN-based carbon nanofiber membranes as self-supporting electrode used in lithium-ion batteries（LIBs）. Specifically, highly-oriented fibers are achieved by high-speed roller collecting during electrospinning, and compaction densification is conducted by hot-pressing treatment. The effects of collecting speed and hot-pressing pressure on the morphology, conductivity,bulk density, tensile strength, and flexibility of the obtained carbon nanofiber membrane are *** to conventional fiber membranes, of which fibers are disorderly stacked, the oriented fiber membrane is much easier to achieve dense stacking by compaction. The obtained dense carbon nanofiber membrane demonstrates a bulk density of 0.566 g cm-3, and shows a significantly-enhanced volumetric capacity(318.3 mA h cm-3), high-rate performance(86.6 mA h cm-3at 5 A g-1), and satisfactory cycling stability when used as selfsupporting electrode of LIBs.

关键词： Bulk density Densification Electrospinning Orientation-compaction Volumetric capacity

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Feasibility Study of Precoated Binder-Type Electric Arc Furnace Oxidizing Slags as Aggregates for Cement Mortar 1st

Feasibility Study of Precoated Binder-Type Electric Arc Furn...

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1st International Conference on Net-Zero Built Environment: Innovations in materials, Structures, and Management Practices, NTZR 2024

作者： Lin, Wei-Ting Sprince, Andīna Hebda, Marek Mucsi, Gábor Cheng, An Pan, Huang-Hsing Department of Civil Engineering National Ilan University Yilan Taiwan Institute of Civil Engineering Faculty of Civil and Mechanical Engineering Riga Technical University Riga Latvia Department of Materials Engineering Faculty of Materials Engineering and Physics Cracow University of Technology Kraków Poland Institute of Raw Materials Preparation and Environmental Technologies University of Miskolc Miskolc Hungary Department of Civil Engineering National Kaohsiung University of Science and Technology Kaohsiung Taiwan

ISBN: (纸本)9783031696251

The study used electric arc furnace oxidizing slag (EAFOS) to substitute natural fine aggregates. However, EAFOS replacement may cause volumetric instability. Therefore, a cement, fly ash, or slag layer was coated with EAFOS as a precoated technique. Then, the effect of EAFOS on engineering properties was investigated, and the optimum amount of EAFOS was identified. The amount of coated binders was set at 20%, 25%, 30%, 35%, and 40% of the weight of EAFOS, and the water-to-binder ratio (w/b) of the coated binders was fixed at 0.50 to 0.20. The proportion of EAFOS replacing fine aggregates was 10%, 20%, 30%, 40%, and 50%, and the w/b of the mortar was fixed at 0.55. The results showed that the proportion of precoated binder was 30% of the EAFOS and the w/b was 0.30. Curing time was up to 28 days, and slag was the appropriate precoated binder. Maximum compressive strengths of mortars made with precoated EAFOS were 42.94 and 56.96 MPa at 7 and 28 days (40% replacement for fine aggregates). The maximum compressive strengths of specimens without coated EAFOS were 36.67 and 47.55 MPa at 7 and 28 days (the identical replacement). The drying shrinkage of 40% precoated slag specimens was 0.054% at 7 days and 0.074% at 28 days. The appearance of the specimens did not reveal any abnormality after 28 days of immersion in water at 70 °C. The precoated technique adopted in this study can be used as a stabilization procedure for replacing natural fine aggregates with EAFOS. © The Author(s) 2025.

关键词： Mortar

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Two-Electrode Screen-Printed pH Sensors for Monitoring Soil and Other Growing Media

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IEEE Sensors Journal 2025年第11期25卷 18692-18701页

作者： Crichton, Catherine A. Lahann, Lucas Barba, Juan Pablo Cisneros Yuan, Titan Strand, Elliot J. Bruno, Nicholas Goodrich, Payton J. Baumbauer, Carol L. Atreya, Madhur Bihar, Eloise Silver, Whendee L. Pister, Kristofer Arias, Ana Claudia Whiting, Gregory L. University of California Berkeley Department of Electrical Engineering and Computer Science 253 Cory Hall BerkeleyCA94720 United States University of California Berkeley Department of Environmental Science Policy and Management 130 Mulford Hall BerkeleyCA94720 United States University of Colorado Boulder Paul M. Rady Department of Mechanical Engineering 1111 Engineering Drive BoulderCO80309 United States University of Colorado Boulder Materials Science and Engineering 4001 Discovery Drive BoulderCO80303 United States

Monitoring soil pH is important for optimizing plant biomass production, understanding nutrient cycling, predicting and mitigating greenhouse gas emissions, and improving soil health. Soil pH can vary significantly over time and space, and high spatiotemporal resolution data are needed to enable informed land management decisions. A potential method to address this need is to use large numbers of easily distributed pH sensor systems which can be placed at high density in soils. An approach for fabricating such sensors is described here using a voltammetric screen-printed pH sensor with a working electrode that incorporates Alizarin (a pH-sensitive dye) throughout its bulk. The use of a Nafion membrane on top of the working electrode and a salt membrane over the reference electrode provides near-Nernstian sensitivity and enhanced device stability in buffered media, soil, and hydroponic fluid. Critically, these devices can function effectively in a novel 2-electrode (working and reference) configuration with a sensitivity of 56.38 mV/pH and a resolution of 0.28 pH (n=3), enabling the use of simple, low-cost readout electronics for evaluating the sensor state. These results show that a printed pH sensor paired with affordable electronics can be used to monitor the pH of unbuffered media, providing a potential path to high-spatial density real-time measurement of pH in soils and hydroponics. © 2001-2012 IEEE.

关键词： Alizarin

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Lactic acid oligomer grafted gum acacia encapsulated controlled release nitrogen fertilizer for crops improvements and greener soil sustainability

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South African Journal of Chemical engineering 2025年 53卷 158-175页

作者： Wasie, Yihun Periyasamy, Selvakumar Tesfaye, Melakuu Department of Chemical Engineering Shambu Campus Wollega University Shambu Ethiopia Department of Chemical Engineering School of Mechanical Chemical and Materials Engineering Adama Science and Technology University Adama 1888 Ethiopia Department of Biomaterials SIMATS Saveetha Dental College and Hospitals Saveetha University Chennai 600077 India

Nitrogen (N) is an essential nutrient for plant growth and productivity. Urea contains 46 % N, the highest content of solid nitrogenous fertilizers, but it is limited in its delivery system. In this research work, urea was encapsulated in a hydrophobic bio-adhesive, which was synthesized through a poly-condensation reaction of lactic acid (LA) and gum acacia (GA) to control its dissolution rate in water. Box-Behnken method of design expert software was used to investigate the effect of process parameters on the grafting efficiency and urea release rate. The grafting efficiency and the urea release rate were inversely proportional. The grafting of lactic acid oligomer (LAO) chains at the O–H and N–H functional groups of the GA backbone was confirmed by FTIR and NMR analyses. The solubility and hydrophobicity tests of LAO-g-GA exhibit that both increase with grafting efficiency. The study found that the urea release rate increases with the temperature of the medium and urea concentration but decreases with the increase in pH of the medium. The results observed from the study could help commercialize slow-release urea fertilizer for the effective use of nitrogen and maintain a pollution-free environment. © 2025 The Author(s)

关键词： Biofertilizer Controlled nitrogen release Essential nutrient Green soil sustainability

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