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Microstructural Effect on the Corrosion Behavior of N- and P-Type Bismuth Tellurides Fabricated by Induction Melting

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SSRN 2023年

作者： El-Makaty, Farah M. Nawaz, Muddasir Shakoor, R. Abdul Hammuda, Abdelmagid Youssef, Khaled M. Mechanical and Industrial Engineering Department Qatar University Doha2713 Qatar Qatar University Doha2713 Qatar Materials Science and Technology Graduate Program College of Arts and Sciences Qatar University Doha2713 Qatar

Numerous efforts have been made to understand and enhance the thermoelectric properties of bismuth telluride alloys. However, limited studies have been reported to investigate the corrosion behavior of these alloys and their suitability for industrial applications. This paper examines the corrosion behavior of three different bismuth telluride alloys prepared by induction melting: pristine Bi2Te3, n-type Bi2Te2.55Se0.45, and p-type Bi0.6Sb1.4Te3. The electrochemical response of the samples is tested in 3.5 wt.% NaCl solution at room temperature. Potentiodynamic polarization curves (Tafel plots) revealed that the n-type sample formed a passive layer compared to the pristine and the p-type samples, which showed pitting corrosion. The different trends observed in the samples were related to their evolved microstructures, where fingerprint-like features in the pristine and the p-type samples showed high susceptibility to pitting corrosion. In contrast, a unique needle-like microstructure of the n-type samples acted as nucleation sites for passive layer formation causing higher corrosion resistance in this sample. © 2023, The Authors. All rights reserved.

关键词： Microstructure

Graphene calorimetric single-photon detector

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arXiv 2024年

作者： Huang, Bevin Arnault, Ethan G. Jung, Woochan Fried, Caleb Russell, B. Jordan Watanabe, Kenji Taniguchi, Takashi Henriksen, Erik A. Englund, Dirk Lee, Gil-Ho Fong, Kin Chung Intelligence Community Postdoctoral Research Fellowship Program Massachusetts Institute of Technology CambridgeMA02139 United States Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA02139 United States Department of Physics Pohang University of Science and Technology Pohang790-784 Korea Republic of Department of Physics Washington University in St. Louis St. LouisMO United States Research Center for Electronic and Optical Materials National Institute for Materials Science 1-1 Namiki Tsukuba305-0044 Japan Research Center for Materials Nanoarchitectonics National Institute for Materials Science 1-1 Namiki Tsukuba305-0044 Japan RTX BBN Technologies Quantum Engineering and Computing Group CambridgeMA02138 United States

Single photon detectors (SPDs) [1, 2] are essential technology in quantum science, quantum network, biology, and advanced imaging [3-5]. To detect the small quantum of energy carried in a photon, conventional SPDs rely on energy excitation across either a semiconductor bandgap or superconducting gap. While the energy gap suppresses the false-positive error, it also sets an energy scale that can limit the detection efficiency of lower energy photons and spectral bandwidth of the SPD [6-8]. Here, we demonstrate an orthogonal approach to detect single near-infrared photons using graphene calorimeters [9-13]. By exploiting the extremely low heat capacity of the pseudo-relativistic electrons in graphene near its charge neutrality point [14], we observe an electron temperature rise up to ∼2 K using a hybrid Josephson junction. In this proof-of-principle experiment, we achieve an intrinsic quantum efficiency of 87% (75%) with dark count © 2024, CC BY.

关键词： Particle beams

Accurate and Data-Efficient Micro-XRD Phase Identification Using Multi-Task Learning: Application to Hydrothermal Fluids

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arXiv 2024年

作者： Li, Yanfei Liu, Juejing Zhao, Xiaodong Liu, Wenjun Geng, Tong Li, Ang Zhang, Xin Pacific Northwest National Laboratory RichlandWA99354 United States Materials Science and Engineering Program Washington State University PullmanWA99164 United States Advanced Photon Source Argonne National Laboratory LemontIL60439 United States Department of Electrical and Computer Engineering University of Rochester New York14627 United States

Traditional analysis of highly distorted micro-X-ray diffraction (μ-XRD) patterns from hydrothermal fluid environments is a time-consuming process, often requiring substantial data preprocessing and labeled experimental data. This study demonstrates the potential of deep learning with a multitask learning (MTL) architecture to overcome these limitations. We trained MTL models to identify phase information in μ-XRD patterns, minimizing the need for labeled experimental data and masking preprocessing steps. Notably, MTL models showed superior accuracy compared to binary classification CNNs. Additionally, introducing a tailored cross-entropy loss function improved MTL model performance. Most significantly, MTL models tuned to analyze raw and unmasked XRD patterns achieved close performance to models analyzing preprocessed data, with minimal accuracy differences. This work indicates that advanced deep learning architectures like MTL can automate arduous data handling tasks, streamline the analysis of distorted XRD patterns, and reduce the reliance on labor-intensive experimental datasets. Copyright © 2024, The Authors. All rights reserved.

关键词： Deep learning

Revisiting the Temperature Dependence of Protein Diffusion inside Bacteria: Validity of the Stokes-Einstein Equation

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Physical Review Letters 2022年第1期129卷 018101-018101页

作者： Asmaa A. Sadoon William F. Oliver Yong Wang Department of Physics University of Arkansas Fayetteville Arkansas 72701 USA Materials Science and Engineering Program University of Arkansas Fayetteville Arkansas 72701 USA Department of Physics University of Thi-Qar Nassiriya 64001 Iraq Cell and Molecular Biology Program University of Arkansas Fayetteville Arkansas 72701 USA

Although the transport and mixing of proteins and other molecules inside bacteria rely on the diffusion of molecules, many aspects of the molecular diffusion in bacterial cytoplasm remain unclear or controversial, including how the diffusion-temperature relation follows the Stokes-Einstein equation. In this study, we applied single-particle tracking photoactivated localization microscopy to investigate the diffusion of histonelike nucleoid structuring (HNS) proteins and free dyes in bacterial cytoplasm at different temperatures. Although the diffusion of HNS proteins in both live and dead bacteria increased at higher temperatures and appeared to follow the Arrhenius equation, the diffusion of free dyes decreased at higher temperatures, questioning the previously proposed theories based on superthermal fluctuations. To understand the measured diffusion-temperature relations, we developed an alternative model, in which the bacterial cytoplasm is considered as a polymeric network or mesh. In our model, the Stokes-Einstein equation remains valid, while the polymeric network contributes a significant term to the viscosity experienced by the molecules diffusing in bacterial cytoplasm. Our model was successful in predicting the diffusion-temperature relations for both HNS proteins and free dyes in bacteria. In addition, we systematically examined the predicted diffusion-temperature relations with different parameters in the model, and predicted the possible existence of phase transitions.

关键词： Anomalous diffusion Diffusion Intracellular transport Network diffusion Proteins

Structural, Optical, and Electrical Properties of Multi-Component P-Type Oxide-Semiconductor Cu-Mn-Sn-O Thin Films

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SSRN 2024年

作者： Nguyen Quoc Trinh, Bui Dinh, The Nam Vietnam National University Hanoi University of Science Faculty of Physics 334 Nguyen Trai Thanh Xuan Hanoi Viet Nam Tokyo Institute of Technology School of Materials and Chemical Technology Department of Materials Science and Engineering 2-12-1 Okayama Meguro Tokyo152-8550 Japan Vietnam National University Hanoi Vietnam Japan University Faculty of Advanced Technology and Engineering Nanotechnology Program Luu Huu Phuoc Nam Tu Liem Hanoi Viet Nam

P-type oxide semiconductors as a conducting channel layer have attracted huge attention owing to wide applications in electronic devices. In this study, multi-component oxide-semiconductor Cu1-2xMnxSnxO thin films with x = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, and 0.33 were successfully prepared on glass substrates, by using a solution process accompanied with a spin-coating technique. One obtained that, a phase transition between the CuO monoclinic structure and the rock salt structure was observed when leveling up the concentration of Mn and Sn, simultaneously to descending the concentration of Cu in the precursors. The crystallite size was found to decrease throughout the samples, with a minimum value of 9.8 nm towards the equimolar ratio. The scanning electron microscope confirmed further the downward tendency as mentioned above, and indicated an improvement in the film surfaces as well. According to the optical absorption measurement, the bandgap energy was determined to be in a range from 2.68 eV to 3.44 eV. Interestingly, the sheet resistance of Cu1-2xMnxSnxO films witnessed a sharp drop from 5.24 kΩ/sq of CuO to 0.034 kΩ/sq at the film with the molar ratio Cu:Mn:Sn being 34:33:33. © 2024, The Authors. All rights reserved.

关键词： Crystallite size

Characterization of Water-Soluble Inorganic Ions and Carbonaceous Aerosols in the Urban Atmosphere in Amman, Jordan

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SSRN 2024年

作者： Al-Hunaiti, Afnan Bakri, Zaid Li, Xinyang Duan, Lian Al-Abdallat, Asal Alastuey, Andres Viana, Mar Arar, Sharif Petäjä, Tuukka Hussein, Tareq Department of Chemistry School of Science University of Jordan Amman11942 Jordan Department of Chemistry and Materials Science School of Chemical Engineering Nanochemistry and Nanoengineering Aalto University Aalto00076 Finland Department of Physics and Atmospheric Sciences Program Michigan Technological University HoughtonMI49931 United States UHELFI- Helsinki00014 Finland Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention Department of Environmental Science & Engineering Fudan University Shanghai200438 China Department of Physics School of Science University of Jordan Amman11942 Jordan Barcelona08034 Spain

The Eastern Mediterranean is a unique region for air pollution because it is the crossroads between three continents exchanging air pollution. Here, we investigated urban particulate matter (PM) carbonaceous and water-soluble ions in Amman, Jordan. The PM2.5 total carbon (TC) annual mean was 7.6±3.6 µg/m3 (organic carbon (OC) 5.9±2.8 µg/m3 and elemental carbon (EC) 1.7±1.1 µg/m3), which was about 16.3% of the PM2.5. The PM10 TC annual mean was 8.4±3.9 µg/m3 (OC 6.5 ± 3.1 µg/m3 and elemental carbon (EC) 11.9±1.1µg/m3), about 13.3% of the PM10. The PM2.5 total water-soluble ions annual mean was 7.9±1.9 µg/m3 (about 16.9%), and that of the PM10 was 10.1±2.8 µg/m3 (about 16.0%). The minor ions (F-, NO2-, Br-, and PO43-) constituted less than 1% in the PM fractions. The significant fraction was for SO42- (PM2.5 4.7±1.6 µg/m3 (10.0%) and PM10 5.3±1.9 µg/m3 (8.3%)). The NH4+ had higher amounts of PM2.5 (1.3±0.6 µg/m3;2.7%) than that PM10 (0.9±0.4 µg/m3;1.4%). During sand and dust storm (SDS) events, TC, Cl-, and NO3- were doubled in PM, SO42- did not increase significantly, and NH4+ slightly decreased. Regression analysis revealed: (1) carbonaceous aerosols come equally from primary and secondary sources, (2) about 50% of the OC came from non-combustion sources, (3) traffic emissions dominate the PM, (4) agricultural sources have a negligible effect, (5) SO42- is completely neutralized by NH4+ in the PM2.5 but there could be additional reactions involved in the PM10, and (6) (NH4)2SO4, was the major species formed by SO42-and NH4+ instead of NH4HSO4. © 2024, The Authors. All rights reserved.

关键词： Ions

Magneto-optical Kerr spectra of gold induced by spin accumulation

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arXiv 2021年

作者： Ortiz, Víctor H. Coh, Sinisa Wilson, Richard B. Department of Mechanical Engineering and Materials Science and Engineering Program University of California RiversideCA92521 United States

We report the magneto optic Kerr effect (MOKE) angle of Au magnetically excited by spin accumulation. We perform time resolved polar MOKE measurements on Au/Co heterostructures. In our experiment, the ultrafast optical excitation of the Co drives spin accumulation into an adjacent Au layer. The spin accumulation, together with spin-orbit coupling, leads to non-zero terms in the off-diagonal conductivity tensor of Au, which we measure by recording the polarization and ellipticity of light reflected from the Au surface for photon energies between 1.3 and 3.1 eV. At energies near the interband transition threshold of Au, the Kerr rotation per A/m exceeds 1 µrad. Typical values for Kerr rotation per moment in transition ferromagnetic metals like Ni are © 2021, CC BY.

关键词： Heavy metals

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

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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)

Neural Network for Classification of Mns Microinclusions in Steels

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SSRN 2023年

作者： de Oliveira Filho, Marcos Fernando Amelio Briquet Caradec, Pierre D. Calsaverini, Rafael Spinelli, José Eduardo Ishikawa, Tomaz Toshimi Graduate Program in Materials Science and Engineering UFSCar SP São Carlos13565-905 Brazil Villares Metals S/A Sumaré SP São Paulo13178-902 Brazil Nubank SP São Paulo05409-000 Brazil Department of Materials Engineering UFSCar SP São Carlos13565-905 Brazil

The influence of MnS inclusions on steel properties is highly noticeable. Manual inclusions classification methods are the most used in laboratories and metallurgical sector industries because of their low cost, while automatic methods have high operating costs, which makes their use more restrict. Neural network models, on the other hand, are extremely advantageous for several applications. The present study is motivated by the use of a neural network model for classifying inclusions in steels. The aim is to achieve the highest possible accuracy in classifying the MnS inclusions severities (0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, and 4.5) using optical images captured from steel specimens. The results have showed that the classification of MnS severities was very sensitive to the database number of images. A 98% training accuracy was obtained by increasing the number of images from 3,156 to 4,136, mostly adding images for some severity levels. However, validation and test results were not satisfactory. As such, a severity re-categorization of the database was able to enhance the true positive values, with an error of 8%. In general, the neural network represented speed in decision making, proving to be a potential tool for classifying steel inclusions. © 2023, The Authors. All rights reserved.

关键词： Operating costs