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Modeling Common-Mode Current due to Asymmetric Aging of Machine Winding Insulation

作者： parke Ross d.

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Complex System Modeling and Simulation 2023年第2期3卷 118-128页

作者： Jin Zhao aaron d.Brovont department of Electrical and Computer Engineering The University of AlabamaTuscaloosaAL 35487USA the PC Krause and Associates West LafayetteIN 47906USA

Machine stator winding insulation degradation is one of the main results of machine *** is non-negligible once this degradation process becomes asymmetric between *** traditional way to determine the insulation state of health is a partial discharge ***,this method requires the system offline,which causes production loss and extra administrative *** paper presents an idea for better characterizing the insulation machine’s state of health using common-mode(CM)behavior in the machine-drive *** the help of circuit decomposition methods and modeling tools,the CM quantities due to asymmetric aging show a unique characteristic that distinguishes itself from other differential-mode(dM)quantities in the equivalent *** is shown effective to represent the asymmetric aging effect from the detection of system leakage *** paper provides an analytical method to quantify this characteristic from mathematical approaches,and a proper approximation has been made on the CM equivalent model(CEM)such that the CM behavior is accurately *** proposed method will serve the purpose of predicting machine abnormal behavior using the simple RLC *** can adapt this method to quantify and characterize the machine insulation state of health(SOH).

关键词： common-mode equivalent circuit machine decomposition machine stator winding insulation health model approximation

Application of rare earths in fluid catalytic cracking： A review

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Journal of Rare Earths 2017年第10期35卷 941-956页

作者： aaron Akah Research and development Center Saudi Aramco Dhahran 31311 Saudi Arabia

The need for more active and hydrothermally stable fluid catalytic cracking（FCC）catalysts to combat the effect of metal contaminants has led to an increase in demand for rare earth *** earth oxides enhance catalyst activity and prevent the loss of acid sites during the FCC unit operation,especially when heavy residue with high metal content is used as *** this paper,a review was carried out to show the effects of rare earth elements on the structure,activity,and stability of FCC ***,the use of rare earth elements as vanadium traps was analyzed in conjunction with the mechanism of catalyst deactivation by *** objective was to elucidate the interaction of vanadium species with the zeolite component of the FCC catalysts and the role of rare earth elements in countering the deleterious effects of vanadium on the FCC catalysts.

关键词： FCC catalyst rare earth vanadium trap zeolites

Chiral carbon dots:synthesis,optical properties,and emerging applications

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Light(Science & Applications) 2022年第4期11卷 542-564页

作者： aaron doring Elena Ushakova Andrey L.Rogach department of Materials Science and Engineering and Centre for Functional Photonics(CFP)City University of Hong Kong83 Tat Chee AvenueKowloonHong Kong SARChina. Center of Information Optical Technologies ITMO UniversitySaint Petersburg 197101Russia. Shenzhen Research Institute City University of Hong Kong518057 ShenzhenChina

Carbon dots are luminescent carbonaceous nanoparticles that can be endowed with chiral properties,making them particularly interesting for biomedical applications due to their low cytotoxicity and facile *** recent years,synthetic efforts leading to chiral carbon dots with other attractive optical properties such as two-photon absorption and circularly polarized light emission have *** start this review by introducing examples of molecular chirality and its origins and providing a summary of chiroptical spectroscopy used for its *** approaches used to induce chirality in nanomaterials are *** the main part of this review we focus on chiral carbon dots,introducing their fabrication techniques such as bottom-up and top-down chemical syntheses,their morphology,and optical/chiroptical *** then consider emerging applications of chiral carbon dots in sensing,bioimaging,and catalysis,and conclude this review with a summary and future challenges.

关键词： properties synthesis chiral

Calculation and interpretation of classical turning surfaces in solids

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npj Computational Materials 2021年第1期7卷 229-238页

作者： aaron d.Kaplan Stewart J.Clark Kieron Burke John P.Perdew department of Physics Temple UniversityPhiladelphiaPA 19122USA Centre for Materials Physics Durham UniversityDurham DH13LEUK departments of Chemistry and Physics University of CaliforniaIrvineCA 92697USA departments of Physics and Chemistry Temple UniversityPhiladelphiaPA 19122USA

Classical turning surfaces of Kohn–Sham potentials separate classically allowed regions(CARs)from classically forbidden regions(CFRs).They are useful for understanding many chemical properties of molecules but need not exist in solids,where the density never decays to *** equilibrium geometries,we find that CFRs are absent in perfect metals,rare in covalent semiconductors at equilibrium,but common in ionic and molecular *** all materials,CFRs appear or grow as the internuclear distances are uniformly *** can also appear at a monovacancy in a *** with several approximate density functionals and codes confirm these behaviors.A classical picture of conduction suggests that CARs should be connected in metals,and disconnected in wide-gap insulators,and is confirmed in the limits of extreme compression and ***,many semiconductors have no CFR at equilibrium,a key finding for density functional ***,a strong correlation with insulating behavior can still be ***,equilibrium bond lengths for all cases can be estimated from the bond type and the sum of the classical turning radii of the free atoms or ions.

关键词： turning solids expanded

Ectomycorrhizal and Saprotrophic Fungal Communities Vary Across mm-Scale Soil Microsites differing in Phosphatase Activity

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Pedosphere 2019年第3期29卷 344-359页

作者： aaron GOdIN denise BROOKS Sue J. GRAYSTON Melanie d. JONES Biology department University of British Columbia Okanagan campus Kelowna V1V 1V7 (Canada) department of Forest & Conservation Sciences Faculty of Forestry University of British Columbia Vancouver V6T 1Z4 (Canada)

To understand nutrient cycling in soils, soil processes and microorganisms need be better characterized. To determine whether specific trophic groups of fungi are associated with soil enzyme activity, we used soil imprinting to guide mm-scale sampling from microsites with high and low phosphatase activities in birch/douglas-fir stands. Study 1 involved sampling one root window per site at 12 sites of different ages(stands);study 2 was conducted at one of the stem-exclusion stands, at which 5 root windows had been installed. Total fungal and ectomycorrhizal(EM) fungal terminal-restriction fragment length polymorphism(TRFLP)fingerprints differed between high-and low-phosphatase activity microsites at 8 of 12 root windows across 12 sites. Where differences were detected, fewer EM fungi were detected in high-than low-phosphatase activity microsites. Using 5 root windows at one site,next-generation sequencing detected similar fungal communities across microsites, but the ratio of saprotrophic to EM fungal reads was higher in high-phosphatase activity microsites in the two windows that had low EM fungal richness. In windows with differences in fungal communities, both studies indicated that EM fungi were less successful than saprotrophic fungi in colonizing fine-scale,organic matter-rich microsites. Fine-scale sampling linked with in situ detection of enzyme activity revealed relationships between soil fungal communities and phosphatase activity that could not be observed at the scales employed by conventional approaches, thereby contributing to the understanding of fine-scale phosphorus cycling in forest soils.

关键词： ectomycorrhizae fine scale fungal communities phosphatase root windows saprotrophic fungi soil imprinting

H_(2)mediated mixed culture microbial electrosynthesis for high titer acetate production from CO_(2)

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Environmental Science and Ecotechnology 2024年第3期19卷 125-131页

作者： Yanhong Bian aaron Leininger Harold d.May Zhiyong Jason Ren department of Civil and Environmental Engineering Princeton University86 Olden StPrincetonNJ08544United States Andlinger Center for Energy and the Environment Princeton University86 Olden St.PrincetonNJ08544United States

Microbial electrosynthesis(MES)converts CO_(2)into value-added products such as volatile fatty acids(VFAs)with minimal energy use,but low production titer has limited scale-up and *** electron transfer via H_(2)on the MES cathode has shown a higher conversion rate than the direct biofilm-based approach,as it is tunable via cathode potential control and accelerates electrosynthesis from CO_(2).Here we report high acetate titers can be achieved via improved in situ H_(2)supply by nickel foam decorated carbon felt cathode in mixed community MES *** concentration of 12.5 g L^(-1)was observed in 14 days with nickel-carbon cathode at a poised potential of-0.89 V(*** hydrogen electrode,SHE),which was much higher than cathodes using stainless steel(5.2 g L^(-1))or carbon felt alone(1.7 g L^(-1))with the same projected surface area.A higher acetate concentration of 16.0 g L^(-1)in the cathode was achieved over long-term operation for 32 days,but crossover was observed in batch operation,as additional acetate(5.8 g L^(-1))was also found in the abiotic anode *** observed the low Faradaic efficiencies in acetate production,attributed to partial H_(2)utilization for *** selective acetate production with high titer demonstrated in this study shows the H_(2)-mediated electron transfer with common cathode materials carries good promise in MES development.

关键词： Microbial electrosynthesis Indirect electron transfer CO_(2)electrolysis VFAs production

Nano functional neural interfaces

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Nano Research 2018年第10期11卷 5065-5106页

作者： Yongchen Wang Hanlin Zhu Huiran Yang aaron d. Argall Lan Luan Chong Xie Liang Guo department of Biomedical Engineering The Ohio State University Columbus 43210 USA department of Biomedical Engineering The University of Texas at Austin Austin 78712 USA department of Electrical and Computer Engineering The Ohio State University Columbus 43210 USA Key Laboratory of Flexible Electronics and Institute of Advanced Materials Jiangsu National Synergetic Innovation Center for Advanced Materials Nanjing Tech University Nanjing 211816 China Biomedical Sciences Graduate Program The Ohio State University Columbus 43210 USA department of Neuroscience The Ohio State University Columbus 43210 USA

Engineered functional neural interfaces （fNIs） serve as essential abiotic-biotic transducers between an engineered system and the nervous system. They convert external physical stimuli to cellular signals in stimulation mode or read out biological processes in recording mode. Information can be exchanged using electricity, light, magnetic fields, mechanical forces, heat, or chemical signals. fNIs have found applications for studying processes in neural circuits from cell cultures to organs to whole organisms, fNI-facilitated signal transduction schemes, coupled with easily manipulable and observable external physical signals, have attracted considerable attention in recent years. This enticing field is rapidly evolving toward miniaturization and biomimicry to achieve long-term interface stability with great signal transduction efficiency. Not only has a new generation of neuroelectrodes been invented, but the use of advanced fNIs that explore other physical modalities of neuromodulation and recording has begun to increase. This review covers these exciting developments and applications of fNIs that rely on nanoelectrodes, nanotransducers, or bionanotransducers to establish an interface with the nervous system. These nano fNIs are promising in offering a high spatial resolution, high target specificity, and high communication bandwidth by allowing for a high density and count of signal channels with minimum material volume and area to dramatically improve the chronic integration of the fNI to the target neural tissue. Such demanding advances in nano fNIs will greatly facilitate new opportunities not only for studying basic neuroscience but also for diagnosing and treating various neurological diseases.

关键词： neural interface neurotechnology nanoelectrode nanomaterial neural recording neural stimulation

determining minimum sample size for the conditioned Latin hypercube sampling algorithm

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Pedosphere 2024年第3期34卷 530-539页

作者： daniel d.SAURETTE Asim BISWAS Richard J.HECK Adam W.GILLESPIE aaron A.BERG School of Environmental Sciences University of Guelph50 Stone Rd EastGuelph ON N1G 2W1(Canada) Ontario Ministry of Agriculture Food and Rural Affairs1 Stone Rd WestGuelph ON N1G 2Y4(Canada) Geography Environment&GeomaticsUniversity of Guelph50 Stone Rd EastGuelph ON N1G 2W1(Canada)

In digital soil mapping(dSM),a fundamental assumption is that the spatial variability of the target variable can be explained by the predictors or environmental *** to adequately sample the predictors have been well documented,with the conditioned Latin hypercube sampling(cLHS)algorithm receiving the most attention in the dSM *** advances in sampling design,a critical gap remains in determining the number of samples required for dSM *** propose a simple workflow and function coded in R language to determine the minimum sample size for the cLHS algorithm based on histograms of the predictor variables using the Freedman-diaconis rule for determining optimal bin *** preprocessing was included to correct for multimodal and non-normally distributed data,as these can affect sample size determination from the *** on a user-selected quantile range(QR)for the sample plan,the densities of the histogram bins at the upper and lower bounds of the QR were used as a scaling factor to determine minimum sample *** technique was applied to a field-scale set of environmental covariates for a well-sampled agricultural study site near Guelph,Ontario,Canada,and tested across a range of *** results showed increasing minimum sample size with an increase in the QR *** sample size increased from 44 to 83 when the QR increased from 50% to 95% and then increased exponentially to 194 for the 99%*** technique provides an estimate of minimum sample size that can be used as an input to the cLHS algorithm.

关键词： bin width digital soil mapping normal distribution quantile range sampling design

The convergence of lactic acid microbiomes and metabolites in long-term electrofermentation

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Environmental Science and Ecotechnology 2024年第6期22卷 256-265页

作者： aaron Leininger Sidan Lu Jinyue Jiang Yanhong Bian Harold d.May Zhiyong Jason Ren department of Civil and Environmental Engineering Princeton UniversityUSA Andlinger Center for Energy and the Environment Princeton UniversityUSA

Regulating electron transfer in predominantly fermentative microbiomes has broad implications in environmental,chemical,food,and medical *** we demonstrate electrochemical control in fermenting food waste,digestate,and wastewater to improve lactic acid *** hypothesize that applying anodic potential will expedite and direct fermentation towards lactic *** operation that introduced epi/endophytic communities(Lactococcus,Lactobacillus,Weissella)to pure culture Lactiplantibacillus plantarum reactors with static electrodes was associated with the loss of anode-induced process intensification despite 80%*** *** fluidized electrodes discouraged biofilm formation and extended electrode influence to planktonic gram-positive fermenters using mediated extracellular electron *** short-term experiments differentially enriched Lactococcus and Klebsiella spp.,longer-term operations indicated convergent microbiomes and product *** results highlight a functional resilience of environmental fermentative microbiomes to perturbations in redox potential,underscoring the need to better understand electrode induced polymicrobial interactions and physiological impacts to engineer tunable open-culture or synthetic consortia.

关键词： Fermentation Food wasteLactic acid Microbiome Electrofermentation Resource recovery