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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 937 records · Page 52
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

The Global LAnd Surface Satellite (GLASS) evapotranspiration product Version 5.0: Algorithm development and preliminary validation

An accurate estimation of spatially and temporally continuous global terrestrial evapotranspiration (ET) is essential in the assessment of surface energy, water and carbon cycles. The Global LAnd Surface Satellite (GLASS) ET product Version 4.0 (v4.0) based on the Bayesian model averaging (BMA) method was generated to estimate global terrestrial ET. However, certain uncertainty for the GLASS ET product v4.0 limits its application. In this study, we introduced the deep neural networks (DNN) merging framework to improve terrestrial ET estimation for GLASS ET product Version 5.0 (v5.0) generation by integrating five satellite-derived ET products [Moderate Resolution Imaging Spectroradiometer (MODIS) ET product (MOD16), Shuttleworth–Wallace dual-source ET product (SW), Priestley–Taylor-based ET product (PT-JPL), modified satellite-based Priestley–Taylor ET product (MS-PT) and simple hybrid ET product (SIM)]. We compared the performance of DNN method against other merging methods, including GLASS ET algorithm v4.0 (BMA), the gradient boosting regression tree (GBRT) method and the random forest (RF) method, based on 195 global eddy covariance (EC) flux towers covering observations from 2000 through 2015. Validations indicated that the DNN had the highest accuracy among four merging methods across different land cover types, yielding the highest average determination coefficients (R 2 , 0.62), root-mean-squared-error (RMSE, 24.1 W/m 2 ) and Kling–Gupta efficiency (KGE, 0.77) with a of 99% confidence interval. Compared with GLASS ET algorithm v4.0, the DNN improved on the R 2 by approximately 7% (p < 0.01) and the KGE by 10%. Based on the DNN, we then generated 8-day GLASS ET product v5.0 globally with a 1 km spatial resolution from 2001 to 2015 driven by GLASS vegetation and surface net radiation (R n ) datasets and Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA2) datasets. Finally, this global terrestrial ET product provides a valuable dataset for monitoring regional and global water resources and environmental changes.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Evaluating electrolyte additives for lithium-ion cells: A new Figure of Merit approach

Electrolyte additives are known to improve the performance of lithium-ion cells. In this work we examine the performance of Li 1.03 Ni 0.5 Mn 0.3 Co 0.3 O 2 -graphite (NMC532/Gr) cells containing combinations of lithium bis(oxalate)borate (LiBOB), vinylene carbonate (VC), trivinylcyclotriboroxane (tVCBO), prop-1-ene-1,3-sultone (PES), phenyl boronic acid ethylene glycol ester (PBE), tris(trimethylsilyl) phosphite (TMSPi), triethylphosphite (TEPi), and lithium difluoro(oxalate)borate (LiDFOB) added to our baseline (1.2M LiPF 6 in EC:EMC, 3:7 w/w) electrolyte. In order to rank performance of the various electrolytes, we developed two separate figures of merit (FOM), which are based on the energy retention and power retention of the cells. Using these two metrics in conjunction, we show that only one of the fifteen electrolyte formulations tested significantly outperforms the baseline electrolyte: this electrolyte contains the 0.25 wt% tVCBO + 1 wt% TMSPi additive mix. Little correlation was observed between the FOMs for energy retention and power retention, which indicates that the mechanisms that govern these performance parameters are likely independent of each other. In conclusion, our FOM approach has general applicability and can be used to develop electrolyte and electrode formulations that prolong the life of lithium-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2017

The electrochemical behavior of poly 1-pyrenemethyl methacrylate binder and its effect on the interfacial chemistry of a silicon electrode

The physico-chemical properties of poly (1-pyrenemethyl methacrylate) (PPy) are presented with respect to its use as a binder in a Si composite anode for Li-ion batteries. PPy thin-films on Si(100) wafer and Cu model electrodes are shown to exhibit superior adhesion as compared to conventional polyvinylidene difluoride (PVdF) binder. Electrochemical testing of the model bi-layer PPy/Si(100) electrodes in a standard organic carbonate electrolyte reveal higher electrolyte reduction current and an overall irreversible cathodic charge consumption during initial cycling versus the uncoated Si electrode. The PPy thin-film is also shown to impede lithiation of the underlying Si. XAS, AFM, TGA and ATR-FTIR analysis indicated that PPy binder is both chemically and electrochemically stable in the cycling potential range however significant swelling is observed due to a selective uptake of diethyl carbonate (DEC) from the electrolyte. The increased concentration of DEC and depletion of ethylene carbonate (EC) at the Si/PPy interface leads to continuous decomposition of the electrolyte and results in non-passivating behavior of the Si(100)/PPy electrode as compared to pristine silicon. Consequently, PPy binder improves the mechanical integrity of composite Si anodes but it influences mass transport at the Si(100)/PPy interface and alters electrochemical response of silicon during cycling in an adverse manner.

25 ENERGY STORAGE↗
DOE OSTI2019

Bis(trimethylsilyl) 2-fluoromalonate derivatives as electrolyte additives for high voltage lithium ion batteries

Three trimethylsilyl based malonate esters, bis(trimethylsilyl) 2-methyl-2-fluoromalonate (BTMSMFM), bis(trimethylsilyl) 2-ethyl-2-fluoromalonate (BTMSEFM) and bis(trimethylsilyl) 2-propyl-2-fluoromalonate (BTMSPFM), have been used as additives in 1.0 M LiPF 6 /ethylene carbonate (EC)-dimethyl carbonate (DMC)-diethyl carbonate (DEC) (1-1-1, by v) baseline electrolyte for LiNi 0.80 Co 0.15 Al 0.05 O 2 (NCA) based high voltage lithium ion batteries. The NCA half-cells with 5 wt% BTMSMFM exhibit higher capacity retention than that in the baseline electrolyte at different upper cut off voltages, that is, 4.2, 4.3, 4.4 and 4.5 V vs. Li/Li + . Scanning electron microscope (SEM) show that the additive successfully prevents the formation of thick solid electrolyte interphase (SEI) films on the surface of the NCA electrodes. X-ray diffraction (XRD) further reveals that the crystal structure of NCA is also maintained in the electrolyte with 5 wt% BTMSMFM at high cut off voltages. Finally, besides beneficial to NCA cathode, the BTMSMFM additive also ensures better cycling performance of the graphite based half-cells and NCA/graphite full-cells, and thus is a promising additive for application in rechargeable lithium ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

Enabling fast discharge of Li-ion batteries via electrolyte formulations for urban air mobility applications

High-power discharge requirements are critical for lithium-ion batteries (LIBs) used in electric Vertical Takeoff and Landing (eVTOL) vehicles that are increasingly considered in urban mobility. This investigation places a particular emphasis on understanding the impact of electrolytes on discharge processes and rate capability. We aim to compare the discharge behavior of LiBs using a conventional electrolyte (Gen 2: 1.2 M LiPF 6 in EC:EMC) and the dual salt LiTFSI-LiBOB-based electrolyte. Here we carefully examine the profiles of charging and discharging, the behavior during extended cycles, impedance spectroscopy results, and the characteristics of the electrode surface. Our research findings demonstrate the complex relationship between the composition of electrolytes and the specific high-power discharge requirements of electric vertical takeoff and landing (eVTOL) systems. This research highlights the importance of customizing electrolyte compositions to optimize energy storage density while simultaneously enabling higher power extraction to enhance performance in short-range electric aviation.

25 ENERGY STORAGE↗
DOE OSTI2017

One-step hydrothermal synthesis and electrochemical performance of sodium-manganese-iron phosphate as cathode material for Li-ion batteries

The sodium-manganese-iron phosphate Na{sub 2}Mn{sub 1.5}Fe{sub 1.5}(PO{sub 4}){sub 3} (NMFP) with alluaudite structure was obtained by a one-step hydrothermal synthesis route. The physical properties and structure of this material were obtained through XRD and Mössbauer analyses. X-ray diffraction Rietveld refinements confirm a cationic distribution of Na{sup +} and presence of vacancies in A(2)’, Na{sup +} and small amounts of Mn{sup 2+} in A(1), Mn{sup 2+} in M(1), 0.5 Mn{sup 2+} and Fe cations (Mn{sup 2+},Fe{sup 2+} and Fe{sup 3+}) in M(2), leading to the structural formula Na{sub 2}Mn(Mn{sub 0.5}Fe{sub 1.5})(PO{sub 4}){sub 3}. The particles morphology was investigated by SEM. Several reactions with different hydrothermal reaction times were attempted to design a suitable synthesis protocol of NMFP compound. The time of reaction was varied from 6 to 48 h at 220 °C. The pure phase of NMFP particles was firstly obtained when the hydrothermal reaction of NMFP precursors mixture was maintained at 220 °C for 6 h. When the reaction time was increased from 6 to 12, 24 and 48 h, the dandelion structure was destroyed in favor of NMFP micro-rods. The combination of NMFP (NMFP-6H, NMFP-12H, NMFP-24H and NMFP-48H) structure refinement and Mössbauer characterizations shows that the increase of the reaction time leads to the progressive increment of Fe(III) and the decrease of the crystal size. The electrochemical tests indicated that NMFP is a 3 V sodium intercalating cathode. The comparison of the discharge capacity evolution of studied NMFP electrode materials at C/5 current density shows different capacities of 48, 40, 34 and 34 mA h g{sup −1} for NMFP-6H, NMFP-12H, NMFP-24H and NMFP-48H respectively. Interestingly, all samples show excellent capacity retention of about 99% during 50 cycles. - Graphical abstract: SEM micrographs (left) and evolution of the discharge on cycling with increasing rates from C/15 to 4 C (right) of NMFP material prepared by hydrothermal synthesis at 220 °C at indicated time. Display Omitted - Highlights: • One-step hydrothermal method was used to prepare sodium manganese iron phosphate NMFP. • 3D-NMFP dandelion sphere-like particles were obtained at 220 °C after 6 h. • Increasing reaction time leads to the enhancement of the crystallinity and crystal stabilility of NMFP. • The growth of the particle size and change of morphology are correlated to the reaction time. • EC performance of NMFP powders were greatly affected by the synthesis conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Targeted inhibition of MASTL kinase activity induces apoptosis in breast cancer

Microtubule-associated serine/threonine kinase-like (MASTL) (or Greatwall kinase (GWL)) is an important cell cycle regulating kinase that regulates the G2-M transition. Uncontrolled MASTL activity is implicated in breast cancer progression. To date, very few inhibitors have been reported against this protein. Here, structure-based computational modeling indicates that the natural product flavopiridol (FLV) binds strongly to MASTL and these results are validated using molecular dynamics simulation studies. Further, an in vitro kinase assay reveals an EC 50 (effective concentration) value of FLV to be 82.1 nM and a better IC 50 compared to the positive reference compound, staurosporine. FLV is found to inhibit MASTL kinase activity, arresting the cell growth in the G1 phase and inducing apoptosis in breast cancer cells. Consistent with these results differential gene expression obtained using RNA sequencing studies, and validated by RT PCR and immunoblot analysis, indicate that MASTL inhibition induces cell cycle arrest and apoptotic-related genes. Furthermore, metastasis- and inflammation- related genes are downregulated. Thus, the deregulation of MASTL signaling pathways on targeted inhibition of its kinase activity is revealed. This study lays a strong foundation for investigating FLV as a lead compound in breast cancer therapeutics.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Preparation and characterization of Pb(Lu1/2Nb1/2)O3-Pb(Ni1/3Nb2/3)O3-PbTiO3 ternary ferroelectric ceramics with high piezoelectric constant

Highlights: • PLN-PNN-PT ternary ferroelectric systems were prepared by two-step method. • PLN-PNN-PT ceramics exhibit typical relaxor behavior. • 0.17PLN-0.47PNN-0.36PT ceramic has optimal properties (T{sub C} ∼ 142 °C, d{sub 33} ∼ 378 pC/N). - Abstract: Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}-Pb(Ni{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} ferroelectric ceramics were successfully prepared by a modified two-step columbite precursor method. The structural, dielectric, ferroelectric and piezoelectric properties were characterized by X-ray diffraction, ferroelectric and dielectric measurements. All the obtained samples have pure perovskite structure. The composition of 0.17PLN-0.47PNN-0.36PT within morphotropic phase boundary exhibits optimal properties with piezoelectric coefficient d{sub 33} = 378 pC/N, Curie temperature Tc = 142 °C, dielectric constant ε΄ = 4700, dielectric loss tangent tanδ = 0.05, remnant polarization Pr = 27.1 μC/cm{sup 2} and coercive field Ec = 8.89 KV/cm. According to Curie-Weiss Law and Lorentz-type quadratic relationship, the dielectric behavior was studied and the relaxor factor γ is between 1.55–1.87, indicating the character of diffuse phase transition of the Pb(Lu{sub 1/2}Nb{sub 1/2})O{sub 3}-Pb(Ni{sub 1/3}Nb{sub 2/3})O{sub 3}-PbTiO{sub 3} ceramics. The excellent piezoelectric properties and high Curie temperature make this system a promising material for high-power transducer applications in a broad temperature range.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Flexible and freestanding catalase-Fe3O4/reduced graphene oxide paper: Enzymatic hydrogen peroxide sensor applications

Highlights: • The preparation of a new type of flexible Cat-Fe{sub 3}O{sub 4}/rGO paper was achieved by a simple method. • The characterization of the Fe{sub 3}O{sub 4} nanocrystals formed on rGO and Cat-Fe{sub 3}O{sub 4}/rGO paper were investigated by several techniques. • Cat-Fe{sub 3}O{sub 4}/rGO paper electrode was used as a flexible electrochemical sensor for H{sub 2}O{sub 2} determination. - Abstract: We proposed a new type of freestanding Catalase (EC 1.11.1.6) (Cat) modified paper electrode based on Fe{sub 3}O{sub 4} crystals decorated freestanding reduced graphene oxide (rGO) paper (Cat-Fe{sub 3}O{sub 4}/rGO) using a facile electrodeposition method. This enzyme modified paper electrode was used for the specific determination of hydrogen peroxide (H{sub 2}O{sub 2}). Structural, chemical, and morphological characterization of the Fe{sub 3}O{sub 4} crystals formed on rGO paper was investigated by (i) using scanning electron microscopy (SEM), (ii) energy-dispersive X-ray spectroscopy (EDS), (iii) X-ray photoelectron spectroscopy (XPS), (iv) X-ray diffraction spectroscopy (XRD), (v) Raman spectroscopy, (vi) electrochemical impedance spectroscopy (EIS) and (vii) cyclic voltammetry (CV) techniques. The Cat enzyme was successfully adsorbed on the Fe{sub 3}O{sub 4} nanocrystals surface which was demonstrated by fluorescence microscopy. The Cat-Fe{sub 3}O{sub 4}/rGO paper electrode showed excellent electrocatalytic activity toward H{sub 2}O{sub 2}. It is found that Cat-Fe{sub 3}O{sub 4}/rGO paper electrode shows a wide linear range, high sensitivity, and a low detection limit for H{sub 2}O{sub 2} detection.

36 MATERIALS SCIENCE↗
DOE OSTI2018

An inorganic coating and flexible regulating in situ of stent endothelialization by the controllable ion releasing

Highlights: • The Cu/Ti film with regulating the various responses of ECs and SMCs has been prepared. • The hemocompatibility could be adjusted via the ratio of Cu/Ti. • The volume and velocity of copper ion released from film was designed via the preparation processing. - Abstract: A facile approach to fabricate an inorganic coating with favorable blood compatibility and accelerating endothelialization is reported. The inorganic coating with various ratios of Cu and Ti atom are prepared on 316 L stainless steel by physical vapor deposition method. The phase composition and structure as well as the element concentration of the coating are investigated by X-ray diffraction and X-photoelectron energy spectrum. The hemolysis ratio, clotting time and platelet adhesion are utilized to characterize the materials’ hemocompatibility, the copper ion releasing was also investigated via immersing test. The result indicates that copper-titanium coating show good compatibility; however, as the ratio of Cu to Ti increases, the hemolysis ratio also increases. The endothelialization degree was accelerated owing to maintain less than 7.0 μg/ml of Cu{sup 2+} concentrate, and endothelial cells proliferate more readily than smooth muscle cells. The results demonstrate that this degradable copper-containing coating is suitable as a new surface modification for vascular stents.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Laccase-catalyzed synthesis of 2,3-ethylenedithio-1,4-quinones

Laccases (benzenediol:oxygen oxidoreductase EC 1.10.3.2) are part of a family of multicopper oxidases. These environmentally friendly enzymes require O 2 as their only co-substrate and produce H 2 O as their sole by-product. As a result, they have acquired increasing use in biotechnological applications, particularly in the field of organic synthesis. In the current study, laccases have been employed to successfully couple 1,2-ethanedithiol to various substituted hydroquinones to produce novel 2,3-ethylenedithio-1,4-quinones in good yields via an oxidation–addition–oxidation–addition–oxidation mechanism. The reactions proceeded in one-pot under mild conditions (room temperature, pH 5.0). This study further supports the use of laccases as green tools in organic chemistry. Furthermore, it provides evidence that laccase-catalyzed cross-coupling reactions involving small thiols are possible, in spite of research that suggests small thiols are potent inhibitors of laccases.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Three-dimensional electronic resistivity mapping of solid electrolyte interphase on Si anode materials

Silicon is a promising candidate for the lithium ion battery (LIB) anode because of the order-of-magnitude improvement in capacity over current state-of-the-art graphite anodes. In systems featuring both C and Si anodes, electronic resistivity of the solid-electrolyte interphase (SEI) layer is a critical factor for preventing continuous electrolyte-decomposition reactions at the electrode/electrolyte interface. However, the in-situ measurement of SEI electronic resistance has been complicated by ion transport and electronic contributions from other parts of the battery circuit. Ex-situ measurements of SEI resistivity at microscopic scales are also lacking. We report on a nanometer-resolution three-dimensional technique that enables ex-situ mapping of electronic resistivity of SEI formed on a model single-crystalline wafer Si anode. Our novel experimental approach uses scanning spreading-resistance microscopy resistance imaging and mechanical depth profiling. In addition to resistance mapping, this method also provides an alternative technique for locating buried interfaces, where mechanical or electronic properties differ sufficiently between layers. Further validation of this method was obtained by resistance mapping of a reference sample with a designed a-Si:H layer stack of different doping concentrations. The results show relatively uniform lateral resistivity distribution of the SEIs but steep decreases in resistivity in the vertical direction. Resistivity vs. depth profiles are highly dependent on cycling conditions, but they generally show a resistivity decrease from the most superficial levels of SEI and a thickness increase with continued cycling prior to SEI stabilization. The most prominent resistivity increase was observed on SEI formed in Gen2 electrolyte (EC:EMC [3:7 by wt.] + 1.2 M LiPF6) with 10 wt% fluoroethylene carbonate additive; this result may partially explain the significant improvements of sustained electrochemical cycling and coulombic efficiency observed with this electrolyte additive. Our approach provides a novel and unparalleled three-dimensional approach in characterizing electronic resistivity, which contributes significantly to understanding SEI formation and the intrinsic properties critical to battery performance.

25 ENERGY STORAGE↗
DOE OSTI2017

Nuclear Data Sheets for A=244

Available information pertaining to the nuclear structure of ground and excited states for all known nuclei with mass numbers A=244 have been compiled and evaluated. The adopted level and decay schemes, as well as the detailed nuclear properties and configuration assignments based on experimental data are presented for these nuclides. When there are insufficient data, expected values from systematics of nuclear properties and/or theoretical calculations are quoted. Unexpected or discrepant experimental results are also noted. Information provided in 244 U is tentative as it from the the possible production in the study of 1960 Di03 of debris of the first large-scale thermonuclear test (Ivy Mike) of November 1, 1952 in the Pacific Ocean. No new data are available for 244 Np and the information for g.s Jp is tentative. More experiment work is needed for 244 Np as theoretical work suggest an isomer with Jp=7- and g.s with Jp=2+. In 244Pu, a new K isomer was identified and in addition rotational bands built on the isomer have been observed via the deep inelastic excitation. In 244 Am, specifically in the (d,p)transfer reaction and in the (n,g ) secondary g ’s, there are a large number of gammas that are unplaced. Since its last measurement in 1966, the electron capture dataset has been updated with a tentative partial level scheme for 244 Cm which also provided a new half life measurement for 244 Bk. In 244 Fm, a fusion evaporation experiment measured the half life and provided upper limit for the SF, a and EC branching. A summary and compilation of the discovery of various isotopes in this mass region is given in 2013 Fr02 ( 244 Np, 244 Pu, 244 Am, 244 Cm, 244 Bk, and 244 Cf), 2011Me01 ( 244 Es), and 2013 Th02 ( 244 Fm). This work supersedes the 2003 evaluation by Y.A. Akovali( 2003Ak04).

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2016

Structural Basis of Diverse Homophilic Recognition by Clustered α- and β-Protocadherins

Clustered protocadherin proteins (α-, β-, and γ-Pcdhs) provide a high level of cell-surface diversity to individual vertebrate neurons, engaging in highly specific homophilic interactions to mediate important roles in mammalian neural circuit development. How Pcdhs bind homophilically through their extracellular cadherin (EC) domains among dozens of highly similar isoforms has not been determined. Here, we report crystal structures for extracellular regions from four mouse Pcdh isoforms (α4, α7, β6, and β8), revealing a canonical head-to-tail interaction mode for homophilic trans dimers comprising primary intermolecular EC1:EC4 and EC2:EC3 interactions. A subset of trans interface residues exhibit isoform-specific conservation, suggesting roles in recognition specificity. Mutation of these residues, along with trans-interacting partner residues, altered the specificities of Pcdh interactions. Altogether, these data show how sequence variation among Pcdh isoforms encodes their diverse strict homophilic recognition specificities, which are required for their key roles in neural circuit assembly.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Branching ratio and γ -ray emission probabilities in the decay of the J π = 13 / 2 + isomer in 197Hg

Gamma rays following the decay of the 197 g Hg and 197 m Hg radionuclides were measured using chemically-purified sources and a planar HPGe detector. In the case of 197 m Hg, precise values of 94.68 (9)% and 5.32 (9)% were confirmed for the IT and EC branches, respectively, the latter discovered to differ significantly from previously published data. The half-lives of 197 g Hg and 197 m Hg were also measured as 64.81 (24) h and 23.82 (4) h.

197𝑔Hg↗
DOE OSTI2023

Characterizing pulse reverse-pulse uranium recovery in molten LiCl-KCl with intermittent electrochemical impedance spectroscopy

In this work, EIS was applied to characterize the temporal recovery of uranium from UCl 4 onto a tungsten electrode in molten LiCl-KCl salt between sets of pulse reverse-pulse (PRP) deposition steps. Impedance measurements were fitted to an equivalent circuit (EC) model of the electrode interface using Simplex optimization to calculate the double layer capacitance, charge transfer resistance, Warburg impedance, and CPE-restricted diffusion. Diffusion of uranium towards the electrode surface dominated the surface interactions for the first 80 cycles, followed by a transition to kinetic control for the remaining 520 cycles. A decrease in the Warburg impedance showed depletion of uranium from the bulk melt, which was confirmed to be a 52.5% reduction through ICP-OES. Reduction in the phasance from CPE-restricted diffusion suggested the formation of pores in the uranium deposits, which was confirmed through SEM characterization.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2026

Designing resilient IoT and Edge Computing with federated tinyML

The rapid growth of the Internet of Things (IoT) and Edge Computing (EC) has brought significant conveniences to modern society but has also greatly expanded the cyber attack surfaces, particularly as these technologies are being increasingly integrated into critical systems such as power grids, healthcare, and smart homes. Here, to improve IoT/EC’s cybersecurity posture, we leveraged Artificial Intelligence (AI) and Machine Learning (ML) by employing tinyML to monitor voluminous IoT data for cyber threats while addressing devices’ resource constraints, and utilizing Federated Learning (FL) to share local detection knowledge across the system while preserving privacy. Building on our three-layer architecture combining tinyML and FL to enhance autonomous cyber attack detection, this paper demonstrated that the architecture improves detection accuracy, reduces resource consumption, and enables lightweight, secure IoT device monitoring. These results were validated using the public N-BaIoT dataset as well as real IoT network traffic data collected under multiple attack scenarios from our testbeds. Additionally, we introduced an enhanced FL methodology with a novel preprocessing stage, including federated feature selection and global preprocessor construction, to address IoT/EC data heterogeneity. We developed a physical IoT testbed for attack simulations and data collection, implemented a tinyML-powered detector for realistic model validation, and also built a virtual testbed for scalable evaluations of FL models across diverse network environments.

Cognitive cyber↗