Effect Of Electric Field Research Articles

Quantum Hall effect in a CVD-grown oxide

Two-dimensional (2D) electron systems are promising for investigating correlated quantum phenomena. In particular, 2D oxides provide a platform that can host various quantum phases such as quantized Hall effect, superconductivity, or magnetism. The realization of such quantum phases in 2D oxides heavily relies on dedicated heterostructure growths. Here we show the integer quantum Hall effect achieved in chemical vapor deposition grown Bi2O2Se - a representative member of a more accessible oxide family. A single or few subband 2D electron system can be prepared in thin films of Bi2O2Se, where the film thickness acts as the key subband design parameter and the occupation is determined by the electric field effect. This oxide platform exhibits characteristic advantages in structural flexibility due to its layered nature, making it suitable for scalable growth. The unique small mass distinguishes Bi2O2Se from other high-mobility oxides, providing a new platform for exploring quantum Hall physics in 2D oxides.

Effect of External Electric Field on Fluidization of Rodlike Particles Using CFD–DEM

Effect of External Electric Field on Fluidization of Rodlike Particles Using CFD–DEM

Hydrogen Bonding and Noncovalent Electric Field Effects in the Photoconversion of a Phytochrome.

A profound understanding of protein structure and mechanism requires dedicated experimental and theoretical tools to elucidate electrostatic and hydrogen bonding interactions in proteins. In this work, we employed an approach to disentangle noncovalent and hydrogen-bonding electric field changes during the reaction cascade of a multidomain protein, i.e., the phytochrome Agp2. The approach exploits the spectroscopic properties of nitrile probes commonly used as reporter groups of the vibrational Stark effect. These probes were introduced into the protein through site-specific incorporation of noncanonical amino acids resulting in four variants with different positions and orientations of the nitrile groups. All substitutions left structures and the reaction mechanism unchanged. Structural models of the dark states (Pfr) were used to evaluate the total electric field at the nitrile label and its transition dipole moment. These quantities served as an internal standard to calculate the respective properties of the photoinduced products (Lumi-F, Meta-F, and Pr) based on the relative intensities of the nitrile stretching bands. In most cases, the spectral analysis revealed two substates with a nitrile in a hydrogen-bonded or hydrophobic environment. Using frequencies and intensities, we managed to extract the noncovalent contribution of the electric field from the individual substates. This analysis resulted in profiles of the noncovalent and hydrogen-bond-related electric fields during the photoinduced reaction cascade of Agp2. These profiles, which vary significantly among the four variants due to the different positions and orientations of the nitrile probes, were discussed in the context of the molecular events along the Pfr → Pr reaction cascade.

Comparative study of electronic, thermoelectric, and transport properties in germanene and carbon nanotubes

This study investigates the electronic, thermoelectric, and transport properties of Germanene nanotubes (GeNTs) using a tight-binding calculations and explores their potential advantages over carbon nanotubes (CNTs) in thermoelectric applications. The effect of external electric and magnetic fields, nanotube radius, and temperature on heat capacity, electrical conductivity, power factor, and Seebeck coefficient are systematically investigated. The heat capacity C(T) of GeNTs shows a more pronounced increase with the application of external fields, especially electric field and exceeds that of CNTs. GeNTs also exhibit a lower threshold temperature for non-zero electrical conductivity attributed to their smaller energy gap, which results from easier thermal excitation of charge carriers. This property becomes more pronounced as the electrical conductivity of GeNTs increases more rapidly with temperature than that of CNTs, particularly under stronger external fields. Additionally, the thermoelectric properties of GeNTs can be further enhanced under external fields. While CNTs possess higher Seebeck coefficients and Lorenz numbers, GeNTs demonstrate distinct advantages in tunable heat capacity and conductivity, making them promising candidates for efficient thermoelectric and nanoelectronic devices. These results underscore the potential of GeNTs as an effective alternative to CNTs for advanced energy conversion applications, demonstrating their promise as high-performance thermoelectric materials for energy conversion applications.

Nitrogen-deficient C3N4 coupled with AgBr construction Z-scheme heterojunction form double electric field to promote photogenerated carrier separation enhancement hydrogen evolution

g-C3N4 is an excellent and affordable photocatalyst, but its weak built-in electric field slows down its photogenerated carrier separation rate. Meanwhile, modulating the interfacial electric field is also an effective way to increase the light-generated carrier separation efficiency. In this study, the built-in electric field of g-C3N4 is enhanced by using N vacancies (from 0.742 V to 0.868 V). Subsequently, the modified Nv-C3N4 (N0CN) is utilized to create a heterojunction with AgBr to generate a synergistic effect of built-in and interfacial electric fields (from 0.868 V to 1.032 V). The photogenerated carrier separation was significantly enhanced by the synergistic interaction of the dual electric fields, leading to a notable improvement in the photocatalytic efficiency of A-N0CN. The H2 production performance reached 1884.6 µmolg-1h−1, which was measured 1047 times higher than that of N0CN (1.8 µmolg-1h−1), A-CN (969.9 µmolg-1h−1) and CN (1.1 µmolg-1h−1), representing increases of 1.94 and 1713 times, respectively. This research offers a new perspective for catalyst design involving dual electric field synergy.

Quality assessment of yellow mealworm (Tenebrio molitor L.) powders processed by pulsed electric field and convective drying

Edible insects offer opportunities for food production, as they are an interesting source of many nutrients. In this study, the effect of pulsed electric field (PEF) and convective drying on the chemical composition with emphasizing the fat properties as well as physical, techno-functional, and thermal properties of yellow mealworm powders was investigated. The chemical composition of the yellow mealworm powders differed by PEF. When PEF was applied at 20 and 40 kJ/kg, the moisture, ash, and protein content were significantly lower, while the fat extraction yield significantly increased compared to the control sample. Furthermore, the fat extracted from these samples was characterized by a higher proportion of saturated and monounsaturated fatty acids as well as a higher thrombogenicity index, which is not beneficial from a nutritional point of view. After treatment with PEF at 5 kJ/kg, the powder was the lightest, redness and yellowness. Moreover, the highest hygroscopicity, water activity, and water and oil binding capacity for this powder were determined. The results revealed that yellow mealworm powders are a good source of macronutrients and exhibit beneficial techno-functional properties, nevertheless, the drawback is their high cohesiveness (1.27–1.44), which can be difficult to apply under industrial conditions.

Overall mass transfer approach for electrodialysis-based acid recovery

The reclamation of low-concentration waste acid (e.g., pH > 0.5) has garnered significant attention due to its prevalence, substantial output, and considerable potential value. Notably, a further concentration of the separated acid is typically required for practical applications, for which electrodialysis (ED) has been widely acknowledged as an effective method. However, various factors, including proton leakage, complicate the application of ED in acid systems compared to salt systems. This study presents a novel modeling approach for ED-based acid recovery utilizing the overall mass transfer (OMT) methodology for the first time. Importantly, regression models incorporating initial concentration and current density as independent variables have been developed to calculate the OMT coefficients and cell resistance following a quantitative analysis of the effects of acid media and electric field on mass transport phenomena, based on a series of carefully designed experiments. Subsequent predictions regarding a typical ED-based acid recovery process were conducted, yielding results that align closely with experimental data. For instance, the relative deviations for concentration and volume evolution were found to be less than ±8.4 % and ±7.9 %, respectively. Additionally, the relative deviations for energy consumption were recorded at 8.2 % and 3.2 % for the overall process and the ED stack, respectively. Furthermore, simulations were performed to evaluate the impacts of operational conditions on ED performance using the derived models. In conclusion, the efficacy of the OMT approach for modeling the ED process in acid systems has been substantiated. It is reasonable to assert that the developed models will be beneficial for production management and the optimization of operating conditions in ED-based acid recovery processes.

Electrically Controlled Excitons, Charge Transfer Induced Trions, and Narrowband Emitters in MoSe2-WSe2 Lateral Heterostructure.

Controlling excitons and their transport in two-dimensional (2D) transition metal dichalcogenide heterostructures is central to advancing photonics and electronics on-chip integration. We investigate the controlled generation and manipulation of excitons and their complexes in monolayer MoSe2-WSe2 lateral heterostructures (LHSs). Incorporating graphene as a back gate and edge contact in a field-effect transistor geometry, we achieve the precise electrical tuning of exciton complexes and their transfer across interfaces. Photoluminescence and photocurrent maps at 4 K reveal the synergistic effect of the local electric field and interface phenomena in the modulation of excitons, trions, and free carriers. We observe spatial variations in the exciton and trion densities driven by exciton-trion conversion under electrical manipulation. Additionally, we demonstrate controlled narrow-band emissions within the LHS through carrier injection and electrical biasing. Density functional theory calculation reveals significant band modification at the lateral interfaces. This work advances exciton manipulation in LHS and shows promise for next-generation 2D quantum devices.

Enhanced Green Fluorescent Protein Streaming Dielectrophoresis in Insulator-Based Microfluidic Devices.

There is tantalizing evidence that proteins can be accurately and selectively manipulated by higher order electric field effects within microfluidic devices. The accurate and precise manipulation of proteins in these platforms promises to disrupt and revolutionize many fields, most notably analytical biochemistry. Several lines of experimental evidence suggest much higher forces are generated compared to those calculated from traditional theories and those higher forces arise from subtle structural features of the proteins providing selectivity. New theories reflect some of the experimental evidence in the magnitude of the force predicted and inclusion of subtle structural features absent in traditional continuum theory. Unfortunately, the experimental evidence is largely exploratory in nature and lacks one or more important elements that prevents a clear interpretation and comparison to not only the other existing data, but also quantitative comparison to the evolving theoretical descriptions. Here, a clear and interpretable experimental system is presented that quantitatively determines the dielectrophoretic susceptibility of unlabeled, unaggregated native-structure protein molecules that are exposed to modest electric fields (105-106V/m) for short periods of time (∼5ms) without significant increases in local concentration. The platform uses sub-nanogram quantities of protein, the probed volume upon determination is a few picoliters, and the total analysis time is 10 s.

Comparative Analysis of Thin and Thick MoTe2 Photodetectors: Implications for Next-Generation Optoelectronics.

Due to its outstanding optical and electronic properties, molybdenum ditelluride (MoTe2) has become a highly regarded material for next-generation optoelectronics. This study presents a comprehensive, comparative analysis of thin (8 nm) and thick (30 nm) MoTe2-based photodetectors to elucidate the impact of thickness on device performance. A few layers of MoTe2 were exfoliated on a silicon dioxide (SiO2) dielectric substrate, and electrical contacts were constructed via EBL and thermal evaporation. The thin MoTe2-based device presented a maximum photoresponsivity of 1.2 A/W and detectivity of 4.32 × 108 Jones, compared to 1.0 A/W and 3.6 × 108 Jones for the thick MoTe2 device at 520 nm. Moreover, at 1064 nm, the thick MoTe2 device outperformed the thin device with a responsivity of 8.8 A/W and specific detectivity of 3.19 × 109 Jones. Both devices demonstrated n-type behavior, with linear output curves representing decent ohmic contact amongst the MoTe2 and Au/Cr electrodes. The enhanced performance of the thin MoTe2 device at 520 nm is attributed to improved carrier dynamics resulting from effective electric field penetration. In comparison, the superior performance of the thick device at 1064 nm is due to sufficient absorption in the near-infrared range. These findings highlight the importance of thickness control in designing high-performance MoTe2-based photodetectors and position MoTe2 as a highly suitable material for next-generation optoelectronics.

Bipolar Membranes With Controlled, Microscale 3D Junctions Enhance the Rates of Water Dissociation and Formation

AbstractA soft lithographic method is developed for making bipolar membranes (BPMs) with catalytic junctions formed from arrays of vertically oriented microscale cylinders. The membranes are cast from reusable polydimethylsiloxane (PDMS) molds made from silicon masters, which are fabricated on 2″ to 4″ wafer scales by nanosphere lithography. High‐aspect‐ratio junctions are made on a length scale similar to the thickness of optimized catalyst layers for water dissociation, creating a platform for probing the dual effects of catalysis and local electric field at the microscale BPM junction. Optimized polymer materials and nanoscale metal oxide catalysts are used in this study. 3D BPMs are tested under reverse and forward bias conditions, exhibiting superior performance relative to their 2D counterparts. Under forward bias in H2‐O2 fuel cells, 3D BPMs achieve a current density of 1500 mA cm−2, ≈7 times higher than 2D membranes made from the same materials.

Electric Field Cycling of Physisorbed Antibodies Reduces Biolayer Polarization Dispersion.

The electric dipoles of proteins in a biolayer determine their dielectric properties through the polarization density P. Hence, its reproducibility is crucial for applications, particularly in bioelectronics. Biolayers encompassing capturing antibodies covalently bound at a biosensing interface are generally preferred for their assumed higher stability. However, surface physisorption is shown to offer advantages like easily scalable fabrication processes and high stability. The present study investigates the effects of electric-field (EF)-cycling of anti-Immunoglobulin M (anti-IgM) biolayers physisorbed on Au. The impact of EF-cycling on the dielectric, optical, and mechanical properties of anti-IgM biolayer is investigated. A reduction of the dispersion (standard deviation over a set of 31 samples) of the measured P values is observed, while the set median stays almost constant. Hence, physisorption combined with EF cycling, results in a biolayer with highly reproducible bioelectronic properties. Additionally, the study provides important insights into the mechanisms of dielectric rearrangement of dipole moments in capturing biolayers after EF-cycling. Notably, EF-cycling acts as an annealing process, driving the proteins in the biolayer into a statistically more probable and stable conformational state. Understanding these phenomena enhances the knowledge of the properties of physisorbed biolayers and can inform design strategies for bioelectronic devices.

Effect of Interfacial Electric Field on 2D Metal/Graphene Electrocatalysts for CO2 Reduction Reaction.

Understanding the influence of local electric fields on electrochemical reactions is crucial for designing highly selective electrocatalysts for CO2 reduction reactions (CO2RR). In this study, we provide a theoretical investigation of the effect of the local electric field induced by the negative-biased electrode and cations in the electrolyte on the energetics and reaction kinetics of CO2RR on 2D hybrid metal/graphene electrocatalysts. Our findings reveal that the electronic structures of the CO2 molecule undergo substantial modification, resulting in the increased adsorption energy of CO2 on metal/graphene structures, thus reducing the initial barrier of the CO2RR mechanism. This field-assisted CO2RR mechanism promotes CO production while suppressing HCOOH production. Our findings highlight the potential of manipulating electric fields to tailor the pathways of CO2RR, providing new avenues designing selective electrocatalysts.

Electric-field assisted silicon nanowire field effect transistor for the ultra-low concentration nucleic acid detection

Ultra-low concentration nucleic acid detection is crucial for disease diagnosis and prognosis. Silicon nanowire field-effect transistors (SiNW FETs) are promising due to their sensitivity, real-time capabilities, and compact design. A critical consideration for FETs is the reaction time required for nucleic acid diffusion to the detection surface, especially at low concentrations. This study utilizes polycrystalline silicon nanowire FETs (poly-SiNW FETs) as biosensors, employing a negative voltage on the liquid gate used for detection to create an electric field. This field accelerates nucleic acid diffusion towards the sensor surface to interact with immobilized probes. We adjusted the gate voltages and target solution injection flow rates to identify optimal parameters for nucleic acid detection and how the electrical field accelerates hybridization kinetics. We varied the probe immobilization times to show that higher ligand density accelerates the interaction with the immobilized probe. The study demonstrated stable diffusion of target DNA by combining FET with an electric field of −1 V and a slow injection flow rate, reducing the equilibrium time from 60 to 20 min. Additional improvement was achieved by enhancing probe immobilization density and applying an electric field, resulting in a faster probe-target hybridization reaction rate. These efforts significantly improved the signal to maintain superior performance and reduced the time required to reach equilibrium. This research pioneers using an external electric field to expedite detection time in field-effect transistors, demonstrating the potential for accelerated nucleic acid detection in nanowire FETs.

Effects of electric fields on the release and content of extracellular vesicles.

Extracellular vesicles (EVs) are small membrane-bound structures that originate from various cell types and carry molecular cargos to influence the behaviour of recipient cells. The use of EVs as biomarkers for diagnosis and as delivery vehicles for treatment in a wide range of human disease is a rapidly growing field in research and clinical practice. We hypothesized that electric fields (EFs) could influence the release and content of EVs. To examine this hypothesis, we developed a specialized bioreactor enabling cells to thrive in a three-dimensional setting, replicating in-vivo conditions amidst programmable EF environments. We established a three-step EV purification protocol to achieve high-density production of EVs. We also performed mass spectrometry-based proteomics analysis on EV-carrying proteins and used high-resolution nanoparticle flowcytometry for single-vesicle analysis. Findings from this report suggest that electrical stimulation, employing physiologically relevant amplitudes typical in therapeutic deep brain stimulation, influences the release of EVs and their cargo content in a frequency-dependent fashion. This conclusion could carry significant implications for both fundamental biological understanding and medical advancements. First, it raises an intriguing question about how the endogenous electrical activity of neuronal and other cellular assemblies influence the production and composition of EVs. Second, it reveals a novel underlying mechanism of how therapeutic electrical stimulations can modulate EVs and treat human brain disorders. Third, it provides a novel approach to utilize electrical stimulation for generating desired EV cargos in a programmable setting.

Performance of a novel annular electric field membrane bioreactor and its membrane fouling control in treating catering wastewater

This study aimed to investigate the effects of different voltage and aeration conditions on catering wastewater treatment and membrane fouling in a novel annular electric field membrane bioreactor (AEMBR). The results indicated that the synergistic effect of annular electric field and aeration promoted the degradation of wastewater and the alleviation of membrane fouling. The treatment effect was optimal under a micro electric field of 0.5 V, with removal rates for COD, NH4+-N, TP, and oil ranging from 96.85% to 99.36%, 80.43%–83.01%, 95.46%–97.79%, and 98.83%–99.15%, respectively. Additionally, the fluorescence intensity of macromolecular proteins and small molecular acids decreased. Simultaneously, the average growth rate of transmembrane pressure (TMP) reduced by approximately 0.4 kPa/d. The species abundance and diversity of activated sludge increased, promoting the growth of dominant bacteria, all while maintaining low energy consumption. The aeration intensity had relatively little impact on system operation, and the force of the annular electric field was greater than the force of aeration. This study verified the optimal benefits under micro electric field conditions and provided a basis for the optimization of future process design to achieve a more efficient and economical wastewater treatment system.

Limited Effectiveness in Early Human Clinical Experience with Pulsed Electrical Field Ablation

PurposeTo evaluate oncological outcomes, abscopal effect, and adverse events of pulsed electrical field (PEF) ablation of tumors in the chest, abdomen, and pelvis. Materials & MethodsPEF ablations performed at an academic medical center between May 2023 - January 2024 were retrospectively analyzed . 11 patients (male/female: 4/7, age:58 ± 19) underwent 11 PEF sessions targeting 13 tumors (lung metastasis from solitary fibrous tumor (n=3) and colorectal carcinoma(CA) (n=1), osteosarcoma pleural metastases (n=2), hepatocellular CA (n=2),liver metastasis from colorectal CA (n=1)and leiomyosarcoma (n=1), metastatic melanoma to pancreas (n=1), metastatic retroperitoneal lymph node from endometrial CA(n=1), recurrence of endometrial CA in vaginal cuff(n=1)) with the goal of complete coverage (n=11/13) or debulking (n=2/13). The mean tumor diameter was 1.9 ± 1.0 cm (range, 0.4 – 3.3 cm). Cross-sectional imaging follow-up was 5.3 ± 2.2 months (range, 1.9 - 7.9 months). Oncological outcomes, abscopal effect, and adverse events categorized according to SIR guidelines were reported. ResultsOf 11 tumors underwent ablation for complete coverage, complete coverage was achieved for 1 (9%) and residual detected in 9 (81%). 10 of 11 patients (91%) showed either residual, local or distant progression within a median of 3 months. No abscopal effect was observed. There were 2 mild and 2 severe adverse events. ConclusionsPEF ablation showed a low rate of complete coverage (9%) and a high rate (91%) of residual, local or distant progression. No abscopal effect was observed within a median of 5.1 months after the ablation.

Effects of electric and magnetic fields in magnetic mixing in electroosmotic flows

In this paper, mixing efficiency in electroosmotic flow is numerically simulated at the electric double layer region in the presence of a magnetic field. An incompressible and laminar model is adopted to numerically solve the governing equations involving the magnetic field, electric potential fields, concentration distribution for positive and negative ions (Nernst–Planck), and species concentration. To validate the numerical study, an ideal electroosmotic flow with charged walls is simulated and the results are compared with the analytical solution. For the case with a Reynolds number of 0.02, microchannel length of 40 μm, the results show that by applying a magnetic field, the mixing efficiency along the microchannel length increases from 60.5% to 79.67%. It is found that the existence of a magnetic field in the electric double layer has a significant impact on pressure distribution along the microchannel wall, however, its effects on the electric fields (internal and external), the distribution of positive and negative ions, and the net electrical charge density are marginal. In addition, the presence of magnetic field creates two relatively large vortices inside the microchannel. The outcomes of the present study will help to improve mixing efficiency in micro-devices with applications in micro-analysis systems and lab-on-a-chip instruments.

Improved piezoelectric properties and thermal stability in ZnO-modified 0.39BiScO3-0.61PbTiO3 ceramics by structure regulation

In this work, ZnO was introduced into 0.39BiScO3-0.61PbTiO3 (xZn-BS-61PT), and the phase structure and local structure of ceramics were controlled by a combination of cation substitution and ceramic/semiconductor composite, so as to improve the piezoelectric properties and temperature stability of ceramics. Zn2+ substitute B-site Ti4+ of BS-61PT, resulting in a stable coexistence of rhombohedral (R)-tetragonal (T)-monoclinic (M) phases dominated by T phase. Excessive Zn ions displace the Sc ions, making Sc ions spontaneously crystallize at grain boundaries in the form of an oxide at x ≥ 0.015. The piezoelectric coefficient and Curie temperature (d33, Tc) are increased from (326 pC/N, 416 °C) for x = 0 to (431 pC/N, 433 °C) for x= 0.015. After annealing at 200 °C, the ZnO-modified samples still retrain high d33 value (d33 > 330 pC/N). For x=0.015 sample, after aged 12 months, the retrained d33 is 395 pC/N, only down 8%. The improved properties are attributed to the synergistic effects of phase structure, point defects and local electric fields. Our results provide a design strategy to simultaneously improve the piezoelectric properties and temperature stability. Meanwhile, it is beneficial to broaden the phase.boundary (MPB) composition range of BS-xPT ceramics, and reduce the dependence of performance on components.

Ionospheric Disturbances Observed Over the Peruvian Sector During the Mother's Day Storm (G5‐Level) on 10–12 May 2024

AbstractThis article presents the recent extreme and rare G5‐level geomagnetic storm (Mother's Day Storm) effects on the equatorial and low‐latitude ionosphere observed at the Peruvian sector by the Jicamarca (11.9°S, 76.8°W, magnetic dip 1°N) incoherent scatter radar and associated instruments. This storm was produced by multiple Earth‐directed coronal mass ejections, which generated significant modifications in the Earth's magnetic field, leading to the Sym‐H of ∼−518 nT. On the dayside, due to the strong eastward penetration electric field, vertical plasma drift and equatorial electrojet (EEJ) enhanced for 2–3 hr and remained consistent at values of ∼95 m/s and 260 nT between 1700 and 1900 UT (1200 and 1400 LT). At the same time, vertical E B plasma drift uplifted the equatorial ionosphere, producing the dusk‐side super plasma fountain and transferring electron density to higher latitudes. A huge increase (∼1,325%) in electron density (from 11 to 142 TECu) is observed at low and mid‐latitudes from ∼20°S to 50°S between 2000 and 0400 UT (1500–2300 LT). The strong westward penetration electric field suppressed pre‐reversal enhancement, leading to downward plasma drift (∼−96 m/s) at around 2400 UT (1900 LT). Overnight, vertical plasma drift fluctuated between ±90 m/s, and the combined effect of penetration and disturbance dynamo electric fields caused a significant increase (∼530 km) in ionospheric virtual height. In the main and early recovery phase, consistent short‐ and long‐duration electric field disturbances persisted for approximately 30 hr, with periods of ∼48 and 90 min.