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Characterization of Ureolysis and Microbially Induced Calcium Carbonate Precipitation Under Different Incubation and Reaction Conditions

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SSRN 2025年

作者： Joo, Hyun-Woo Fyfe, Matthew H. Verdú, Irene Rahmaninezhad, Seyed Ali Sales, Christopher M. Srubar, Wil V. Hubler, Mija H. Department of Civil Environmental and Architectural Engineering University of Colorado Boulder BoulderCO United States 1111 Engineering Drive – UCB 428 ECOT 441 BoulderCO80309-0422 United States Department of Civil Architectural and Environmental Engineering Drexel University PhiladelphiaPA United States Environmental Department Terracon Consulting Inc. The ColonyTX United States Department of Civil Environmental and Architectural Engineering Materials Science and Engineering Program University of Colorado Boulder BoulderCO United States Department of Biology

This study investigates the ureolysis and microbially induced calcium carbonate precipitation (MICP) characteristics of Sporosarcina pasteurii and Lysinibacillus sphaericus under varying incubation and reaction conditions. A series of batch MICP experiments were conducted to assess the effects of incubation duration and pH, bacterial cell density, and reagent (i.e., urea and calcium ion) concentrations on ureolysis and CaCO3 precipitation characteristics. The findings indicate that both bacteria exhibit higher urease activity after 24 hours of incubation compared to 48 hours, regardless of incubation pH. S. pasteurii exhibits maximum specific urease activity at an alkaline pH (pH 9.0), whereas L. sphaericus reaches peak activity at a neutral pH (pH 7.2). Across six incubation conditions for each bacterium, S. pasteurii exhibits greater sensitivity in specific urease activity, while L. sphaericus maintains a more consistent ureolysis performance. In terms of cell density, a lower OD600 (~0.1) enhances specific urease activity and early-stage mineralization efficiency, whereas a higher OD600 (~1.0) accelerates overall CaCO3 precipitation, enhances terminal-stage mineralization efficiency, and promotes the prolonged presence of vaterite. High reagent concentrations (1.0 and 1.5 M) enhance specific urease activity and CaCO3 precipitation rates and lead to over 93% of vaterite formation, while low reagent concentration (0.3 M) favors calcite-dominant precipitation over time. These findings provide insights into evaluating and optimizing MICP performance under varying incubation and reaction conditions. © 2025, The Authors. All rights reserved.

关键词： Carbonation

Optimizing Lpbf-Parameters by Box-Behnken Design Allows to Print Crack-Free and Dense High-Boron Alloyed Stainless Steels

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SSRN 2024年

作者： Freitas, Brenda Juliet Martins Koga, Guilherme Yuuki Arneitz, Siegfried Bolfarini, Claudemiro de Traglia Amancio-Filho, Sergio Federal University of São Carlos Graduate Program in Materials Science and Engineering São Carlos13.565-905 Brazil Graz University of Technology Institute of Materials Science Joining and Forming Graz8010 Austria Federal University of São Carlos Department of Materials Engineering São Carlos13.565-905 Brazil Rod. Washington Luis São Carlos13565-905 Brazil

Boron has almost null solubility in iron, and its addition to stainless steels leads to the formation of hard borides, beneficial for increasing the wear resistance. However, these boron-containing steels have poor printability, with the occurrence of pronounced cracking, high porosity and risk of delamination. In this work Box-Behnken design coupled to analysis of variance (ANOVA) were used to optimize the LPBF (Laser Powder Bed Fusion) processing parameters of a highly boron-alloyed stainless steel reinforced with a boride network. The proposed models demonstrated to be accurate to determine the porosity percentage for the studied alloys, in which the laser power and scanning speed play the main role on the alloys’ densification, and absence of extensive defects. These results indicate that the use of design of experiments tools are essential to produce defect-free boron-modified stainless steel specimens with a relatively low number of experiments, identifying a narrow optimized processing window to build bulk composite materials. © 2024, The Authors. All rights reserved.

关键词： Design of experiments

Ultrafine-Grained Stainless Steel with Wear-Resistant Nanoborides Decorating Grain Boundaries Produced by Laser Powder Bed Fusion

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SSRN 2024年

作者： Martins Freitas, Brenda Juliet Koga, Guilherme Yuuki Miguel Rodrigues, Luana Cristina Botta Filho, Walter José Amancio-Filho, Sergio de Traglia Bolfarini, Claudemiro Federal University of São Carlos Graduate Program in Materials Science and Engineering São Carlos13.565-905 Brazil Graz University of Technology Institute of Materials Science Joining and Forming Graz8010 Austria Federal University of São Carlos Department of Materials Engineering São Carlos13.565-905 Brazil Rod. Washington Luis São Carlos13565-905 Brazil

Stainless steel composites combine corrosion resistance and toughness of the metallic matrix with wear resistance granted by hard reinforcing nanoparticles. Given their near-net-shape manufacturing characteristics, additive manufacturing techniques are attractive to produce these hard and wear-resistant classes of materials with low machinability. In this work, from a SAF 2205 duplex stainless steel with boron addition, laser powder bed fusion (LBPF) was employed to produce an ultrafine-grained (~1 µm), dense (porosity ~0.1%), and crack-free ferritic-induced matrix composite with Cr2B-nanoborides reinforcing the grain boundaries (GBs) without formation of Cr-depleted regions. The composite showed significant higher hardness (up to 456 HV0.5) and wear resistance (4.4 x 10-5 mm3 N-1m-1) in sliding condition compared to a hot-rolled (225 HV0.5 and 2.9 x 10-3 mm3 N-1m-1) and a LPBF-produced SAF 2205 (314 HV0.5 and 3.3 x 10-4 mm3 N-1m-1). © 2024, The Authors. All rights reserved.

关键词： Wear of materials

Oxygen Non-Stoichiometry and Point Defect Equilibria in (La1/6Pr1/6Nd1/6Gd1/6Ba1/6Sr1/6)MnO3-δ

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Oxygen Non-Stoichiometry and Point Defect Equilibria in (La1...

243rd ECS Meeting

作者： Bishop, Sean R. Zhang, Dawei Liu, Cijie Li, Wei Salinas, Perla A. Smith, Andrew I. Coker, Eric N. De Santiago, Héctor A. Liu, Xingbo McDaniel, Anthony H. Luo, Jian Sandia National Laboratories AlbuquerqueNM87123 United States Program of Materials Science and Engineering University of California La Jolla San DiegoCA92093 United States Department of Mechanical and Aerospace Engineering Benjamin M. Statler College of Engineering and Mineral Resources West Virginia University MorgantownWV26506 United States Sandia National Laboratories LivermoreCA94550 United States Department of NanoEngineering University of California La Jolla San DiegoCA92093 United States

ISBN: (纸本)9781607685395

In this work, the A-site of the common SOFC cathode La0.8Sr0.2MnO3-δ (LSM) is modified with additional lanthanide and alkali elements, resulting in the composition (La1/6Pr1/6Nd1/6Gd1/6Ba1/6Sr1/6)MnO3-δ. We show that the amount of oxygen released during reduction measured by thermo-gravimetric analysis is significantly greater for this "high entropy" perovskite oxide (HEPO) in comparison with La2/3Sr1/3MnO3-δ, the latter having the same amount of total acceptor dopant and with a similar average A-site radius. The origins of enhanced reduction will be discussed. © The Electrochemical Society.

关键词： Thermogravimetric analysis

Measurement of Cationic Diffusivity Through Er2O3/Y2O3 Interdiffusion Under AC-Flash Event

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SSRN 2024年

作者： Yang, Ying Masuda, Hiroshi Yoshida, Hidehiro Department of Materials Science and Engineering School of Engineering The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-8656 Japan Next Generation Zirconia Social Cooperation Program Institute of Engineering Innovation The University of Tokyo 2-11-16 Yayoi Bunkyo-ku Tokyo113-8656 Japan

The diffusivity of Er cations in Y2O3 was directly investigated using Er2O3/Y2O3 interdiffusion couples under alternating current (AC) flash events. Compared to the conventional heat treatment with no electric field, the AC-flash treatment resulted in a 3-times longer diffusion distance within a 33-times shorter duration at comparable specimen temperatures. This indicates that the cationic interdiffusion was athermally promoted by an AC electric field. At the specimen temperatures of 1520℃–1760℃, both the lattice and grain boundary diffusivities were 2–3 orders greater under AC-flash events than without the electric field. Grain growth and grain boundary migration associated with remarkable grain boundary bowing-out were also enhanced with increasing current density. The pronounced decrease in the activation energy of grain boundary diffusion under flash events was suggested as the origin of the athermal effect of AC electric field on the mass transport kinetics. © 2024, The Authors. All rights reserved.

关键词： Grain growth

Fucoxanthin induces human melanoma cytotoxicity by thwarting the JAK2/STAT3/BCL-xL signaling axis

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Environmental Toxicology 2024年第6期39卷 3356-3366页

作者： Kuo, Min-Yung Dai, Wen-Chyi Chang, Jie-Li Chang, Jo-Shu Lee, Tse-Min Chang, Chia-Che Pediatric Surgery Division Department of Surgery Tungs' Taichung MetroHarbor Hospital Taichung Taiwan Doctoral Program in Biotechnology Industrial Innovation and Management National Chung Hsing University Taichung Taiwan Taichung Municipal Taichung First Senior High School Taichung Taiwan Department of Chemical and Materials Engineering Research Center for Smart Sustainable Circular Economy Tunghai University Taichung Taiwan Department of Life Sciences National Chung Hsing University Taichung Taiwan Department of Marine Biotechnology and Resources National Sun Yat-sen University Kaohsiung Taiwan Graduate Institute of Biomedical Sciences Master Program in Precision Health Doctoral Program in Translational Medicine Rong Hsing Research Center for Translational Medicine The iEGG and Animal Biotechnology Research Center National Chung Hsing University Taichung Taiwan Department of Medical Laboratory Science and Biotechnology Asia University Taichung Taiwan Department of Medical Research China Medical University Hospital Taichung Taiwan Traditional Herbal Medicine Research Center Taipei Medical University Hospital Taipei Taiwan

Melanoma is the most lethal skin malignancy. Fucoxanthin is a marine carotenoid with significant anticancer activities. Intriguingly, Fucoxanthin's impact on human melanoma remains elusive. Signal Transducer and Activator of Transcription 3 (STAT3) represents a promising target in cancer therapy due to its persistent activation in various cancers, including melanoma. Herein, we revealed that Fucoxanthin is cytotoxic to human melanoma cell lines A2758 and A375 while showing limited cytotoxicity to normal human melanocytes. Apoptosis is a primary reason for Fucoxanthin's melanoma cytotoxicity, as the pan-caspase inhibitor z-VAD-fmk drastically abrogated Fucoxanthin-elicited clonogenicity blockage. Besides, Fucoxanthin downregulated tyrosine 705-phosphorylated STAT3 (p-STAT3 (Y705)), either inherently present in melanoma cells or inducible by interleukin 6 (IL-6) stimulation. Notably, ectopic expression of STAT3-C, a dominant-active STAT3 mutant, abolished Fucoxanthin-elicited melanoma cell apoptosis and clonogenicity inhibition, supporting the pivotal role of STAT3 blockage in Fucoxanthin's melanoma cytotoxicity. Moreover, Fucoxanthin lowered BCL-xL levels by blocking STAT3 activation, while ectopic BCL-xL expression rescued melanoma cells from Fucoxanthin-induced killing. Lastly, Fucoxanthin was found to diminish the levels of JAK2 with dual phosphorylation at tyrosine residues 1007 and 1008 in melanoma cells, suggesting that Fucoxanthin impairs STAT3 signaling by blocking JAK2 activation. Collectively, we present the first evidence that Fucoxanthin is cytotoxic selectively against human melanoma cells while sparing normal melanocytes. Mechanistically, Fucoxanthin targets the JAK2/STAT3/BCL-xL antiapoptotic axis to provoke melanoma cell death. This discovery implicates the potential application of Fucoxanthin as a chemopreventive or therapeutic strategy for melanoma management. © 2024 Wiley Periodicals LLC.

关键词： Carotenoids

A novel strategy towards the fabrication of highly stable and sensitive non-enzymatic glucose sensor based on Ni3N thin films using high power impulse magnetron sputtering

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Applied Surface science 2024年 669卷

作者： Pardhi, Nishchal Cheng, Wei-Chun Chen, Sheng-Chi Akshay Joshi, Shikha Govindasamy, Mani Department of Mechanical Engineering National Taiwan University of Science and Technology Taipei106 Taiwan Department of Materials Engineering and Center for Plasma and Thin Film Technologies Ming Chi University of Technology New Taipei City243303 Taiwan College of Engineering and Center for Green Technology Chang Gung University Taoyuan333 Taiwan Department of Materials Engineering Indian Institute of Science Bangalore560012 India International Ph.D. Program in Innovative Technology of Biomedical Engineering and Medical Devices Ming Chi University of Technology New Taipei City243303 Taiwan Tamil Nadu Chennai602105 India Research Center for Intelligence Medical Devices Ming Chi University of Technology New Taipei City243303 Taiwan

Glucose level surveillance in mankind is considered the greatest need of recent times to achieve healthy lifestyle goals due to its health-related concern for humans. To fulfill the need, Nickel-based compounds emerge with excellent bio-mimic properties. However, due to the poor electrical properties of oxides and hydroxides of Ni, developing a supporting base that can enhance electron transportation is mandatory. The present work is dedicated to non-enzymatic glucose detection by electrochemical means on the Ni3N thin film on an Indium-doped Tin Oxide (ITO) substrate as a working electrode in an alkaline medium. The Ni3N films use HiPIMS as a deposition technique due to its high ionization rate of sputtered species and dense plasma which helps the Ni ions to react with nitrogen in the formation of a perfect Ni3N phase, and it is a green process that can contribute to sustainable manufacturing. Ni3N thin film deposited at a 60 % N2 flow ratio shows the largest crystallinity and catalytic properties, which helps this modified electrode to have significant potential for glucose detection. The Ni3N modified electrode acquires a lower linear range of 0.001–1.25 mM with sensitivity and Limit of Detection (LOD) of 337.46 µAmM–1cm−2, and 0.78 µM, respectively, and a higher linear range of 1.25–7.3161 mM with a sensitivity of 158.58 µAmM–1cm−2. The amperometric measurements reveal the fast response of the electrode towards glucose detection at 2.46 secs. The key measures of the electrode according to the corresponding measurements are satisfactory selectivity, reproducibility, repeatability, and operational stability. The modified electrode shows a significant response for real samples such as commercially available honey, apple juice, and biological fluids. © 2024 Elsevier B.V.

关键词： Thin films

Electric polarization reversal and nonlinear magnetoelectric coupling in the honeycomb antiferromagnet Fe4Nb2O9 single crystal

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Physical Review B 2023年第2期107卷 024108-024108页

作者： J. H. Zhang Y. S. Tang L. Lin L. Y. Li G. Z. Zhou B. Yang L. Huang X. Y. Li G. Y. Li S. H. Zheng M. F. Liu M. Zeng D. Wu Z. B. Yan X. K. Huang C. Chen X. P. Jiang J.-M. Liu Laboratory of Solid State Microstructures Nanjing University Nanjing 210093 China Department of Applied Physics College of Science Nanjing Forestry University Nanjing 210037 China Institute for Advanced Materials Guangdong Provincial Key Laboratory of Optical Information Materials and Technology South China Academy of Advanced Optoelectronics South China Normal University Guangzhou 510006 China Institute for Advanced Materials Hubei Normal University Huangshi 435002 China School of Materials Science and Engineering Jingdezhen Ceramic Institute Jingdezhen 333001 China

As a new magnetoelectric material, honeycomb-based antiferromagnet Fe4Nb2O9 has attracted a great deal of attention due to its prominent magnetoelectric (ME) coupling and high Néel temperature, while the physics of magnetoelectricity is far from understood. In the present study, we present our systematic investigations of the anisotropic ME effect, electric polarization reversal, and nonlinear ME effect of Fe4Nb2O9 single crystals, thus highlighting the phase diagram extended down to 10 K. Our results provide clear evidence for electric polarization reversal driven by magnetic field (H) along the [110] and [1-10] directions, respectively, while no such polarization reversal occurs as H is applied along the [001] direction. The nonlinear ME effects and electric control of magnetism are unambiguously demonstrated. In addition, the angular-dependent probing reveals a 2θ rotation of the induced electric polarization around the c axis upon the rotation of magnetic field by an angle θ. The electric polarization responses and concomitant ME coupling are well explained by means of the metal-ligand hybridization p−d mechanism. This work represents an essential step forward in the understanding of ME coupling not only in this A4M2O9 honeycomb magnet.

关键词： Magnetoelectric effect Multiferroics Single crystal materials Magnetization measurements

Simultaneous Control of Mechanical Strength and Hierarchical Porosity in Freeze-Casted Porous Alumina by Two-Step Sintering

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SSRN 2023年

作者： Jeon, Sang-Chae Woo, Jong-Won Kim, Sung-Hyun Ha, Jang-Hoon Yang, Dong-Yeol Moon, Kyoung-Seok Wu, Haoyue Kim, Dong-Kyu School of Materials Science and Engineering Changwon National University 20 Changwondaehak-ro Gyeongsangnam-do Changwon51140 Korea Republic of Ceramic Materials Division Korea Institute of Materials Science 797 Changwondae-ro Gyeongsangnam-do Changwon51508 Korea Republic of Department of 3D Printing Materials Korea Institute of Materials Science 797 Changwondae-ro Gyeongsangnam-do Changwon51508 Korea Republic of School of Materials Science and Engineering Gyeongsang National University 501 Jinjudae-ro Gyeongnam-do Jinju52828 Korea Republic of Department of Mechanical & Aerospace Engineering Konkuk University 120 Neungdongro Gwangjin-gu Seoul05029 Korea Republic of

Higher porosity with hierarchical pore structure is required in porous ceramics but it often leads to poor mechanical strength. Here, an effective Two-Step Sintering (TSS) technique capable of producing highly porous alumina with enhanced mechanical strength is suggested. Based on the sintering theories, here, a significantly lower activation energy for densification at low temperature region allowed a beneficial temperature range for the TSS to be deduced. With a specific TSS regime (T1 = 1550 oC and T2 = 1400 oC), significantly higher compressive strength levels (8.00-15.24 MPa) were measured compared to conventional sintering (1.03-1.86 MPa). Specifically, another TSS regime (T1 = 1550 oC and T2 = 1380 oC) left submicron-sized open pores within the lamellar walls, providing a hierarchical porous structure with enhanced mechanical strength. An evaluation of the mechanical stability by a finite element analysis (FEA) indicated outstanding compressive strength even with small pores in the lamella walls. © 2023, The Authors. All rights reserved.

关键词： Mechanical stability