Charging Mechanism Research Articles

Inherently Charged Particle (ICP) Sensor Design

Ambient particles from natural and anthropogenic sources are a major cause of premature deaths globally. While there are many instruments suitable for scientific measurements of aerosols, better methods for long-term monitoring purposes are still needed, especially low-maintenance, affordable solutions for ultrafine particles. In this article, we present a new sensor design and prototype, the inherently charged particle (ICP) sensor, which uses the preexisting electrical charge of particles to measure particle concentration, instead of employing a charging mechanism, as is typical for instruments based on electrical detection. When the ICP-sensor is employed in conjunction with another instrument, information on the particle charge state can also be derived. We present the results of a laboratory characterization as well as two measurements in suggested applications: 1) engine exhaust measurements and 2) ambient measurements in a traffic environment, where we compare the sensor response to three particle concentration metrics: 1) number; 2) surface area; and 3) mass. The sensor proved suitable for both applications, the signal correlated best with number concentration in the engine emission measurements and with particle surface area in the ambient measurements. The measured charge concentrations were well-correlated ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${R}^{\,2} &gt;0.8$ </tex-math></inline-formula> ) with theoretical values calculated from the number size distribution assuming an equilibrium charge distribution.

Analysis of Plasma Ion Distribution and Dust Collection Efficiency of Carbon-Brush Air Purifiers

In recent years, many studies on air purifiers have been conducted, as particulate matter and virus issues have emerged. In this study, the ion concentration distribution in an air purifier that applies a high voltage was investigated through simulation. For a single carbon brush that applied a high voltage of –8.5 kV, the simulation results of the ion concentration distribution in the ground direction were compared with the result of the experiment and an error of 4.3% was observed, thereby confirming the reliability of the simulation. On this basis, the ion concentration distribution was calculated according to the number and location of the brushes. In addition, the charging number was calculated by applying the charging mechanism to the distributed dust particles, and the dust collection efficiency was calculated by conducting particle multiphysics analysis. The dust collection efficiency increased from 0.5% to 1% as the number of brushes increased, and the dust collection efficiency was 82% when there were two brushes and 83% when there were four brushes. In the proposed modeling, the location of the brushes is more important than the number of brushes. These results are expected to provide more accurate design information for the number and location of brushes applicable to an air purifier.

A streaming-potential-based microfluidic measurement of surface charge at immiscible liquid-liquid interface

Surface charging at immiscible liquid-liquid interface is essential to the emulsion stability, surfactant adsorption, and various engineering applications such as drug delivery and mineral flotation. However, droplet electrophoresis, as a widely-used electrokinetic method to measure the surface charge density, has various limitations in physical modeling and sample preparation. In this work, an alternative experimental method based on streaming potential setup is proposed. A Y-Y shaped microchannel was used to make a flat and stable liquid-liquid interface. The inner wall was coated with polymer to suppress the interference of the solid-liquid interfacial electrokinetics in the liquid-liquid one. The experimental setup was first verified by revisiting the aqueous solution-silicon surface charging, after which the surfactant-free decane-KCl solution interface charging was investigated. The negative surface charge at the decane-KCl solution interface is confirmed and found to increase when increasing the pH. This result is compatible with the probable charging mechanism that the acquired negative surface charge results from hydroxyl ion adsorption onto the interface. The proposed method enables the simplicity and flexibility for further side-by-side studies on the liquid-liquid interface charging mechanism and will inspire the quantitative macroscopic interfacial modeling for numerous scenarios, such as the droplet electrophoresis and interfacial electro-hydrodynamics.

Unraveling energy storage behavior of independent ions in carbon electrode for supercapacitors by polymeric ionic liquids and electrochemical quartz crystal microbalance

A fundamental understanding of the charge storage mechanism of electrochemical double-layer capacitors (EDLCs) requires an in-depth storage behavior investigation of independent ions (individual cations or anions) on the electrode surface. The direct in-situ observation for energy storage behavior of individual ions under realistic conditions remains challenge. Herein, in-situ monitoring the energy storage behavior of independent ions is realized with assistance of polymeric ionic liquids skillfully. Triangle cyclic voltammogram (CV) curves indicate that polymeric imidazole cations PVBIm+ with huge size cannot enter the active carbon pores upon charging, whereas only free anions can. The CV and electrochemical quartz crystal microbalance (EQCM) simultaneously detect ion adsorption/desorption during charging. It’s proposed that ion adsorption/desorption is governed by electrostatic attraction and repulsion of charged particles. PVBIm+ are adsorbed on the electrode surface due to ion adsorption mechanism during the negative polarization and have a small capacity contribution. Free anions contribute capacitance, their number entering the pore is determined by the interaction between polycaions and anions. Moreover, PVBIm(0.1)+ with higher polymerization degree may promote desorption of polycations and prevent further adsorption of anions at higher potential in positive polarization. This work not only observes the charging behavior of independent ions, but also reveals the relevant charging mechanism through EQCM, paving the way for panorama of EDLC.

The electrostatic basis of diacylglycerol pyrophosphate-protein interaction.

Phosphatidic acid (PA) is an anionic lipid with a simple phosphate headgroup that recruits multiple proteins for its diverse functional roles in all eukaryotes. Its charge, shape and Electrostatic Hydrogen bond switch mechanism forms the basis of its interaction with membrane components. PA is phosphorylated to Diacylglycerol pyrophosphate (DGPP) in many signaling events in plants, yeast, and some parasites. DGPP has a pyrophosphate headgroup with similar ionization properties to PA, except that its charge at any given physiological pH is higher. The synthesis of DGPP in the signaling cascade potentially alters membrane dynamics and properties due to the differences in the physicochemical parameters between the two lipids. Thus, DGPP is expected to differ from PA in its interaction with membrane components. However, the overall effect on the biophysical properties of DGPP's interactions with proteins and ions are unexplored. In this study, we investigated the effect of the interactions of DGPP with model peptides KALP23 and WALP23 by 31P MAS NMR spectroscopy. In addition, we also analyzed the effect of DGPP with two positively charged lipids, dioleoyl trimethylammonium propane (DOTAP) and ethyl -phosphatidylcholine (EtPC) as well as with Magnesium and Calcium cations. Results from this study highlight a unique model for DGPP-protein interactions and has important implications in how DGPP interacts with membrane components in the signaling pathway.

A Reciprocal Charging Mechanism for Electric Vehicular Networks in Charging-Station-Absent Zones

The electric vehicles (EVs), as promising components of sustainable and eco-friendly transportation systems, are being widely adopted to reduce the consumption of fossil fuel and the pollution of environments. EVs are usually equipped with wireless communication modules to support the vehicle to vehicle (V2V) communications, and thus an electric vehicular network (EVN) is constituted. However, the electric energy of EVs is extremely limited, and some EVs are possible to exhaust their electric energy before reaching the destinations. More seriously, when the EVs travel into the zones without any charging stations, they cannot be timely charged. With the rapid developments of wireless charging technologies (such as magnetic resonance) and graphene supercapacitor technologies, the reciprocal charges between EVs become feasible, i.e., the EVs with insufficient energy (IEVs) can be charged by the EVs with surplus energy (SEVs). In this paper, the strategies of selecting the local-optimal SEVs for IEVs and rescheduling their travel routes are investigated, and a distributed Reciprocal Charging Mechanism (RCM) is proposed. Both mechanism analysis and simulation results demonstrate the performance superiority of RCM. Specifically, with the proposed reciprocal charging mechanism, IEVs can be charged by SEVs in a charging-station-absent zone, and the electric energy consumption can be approximatively minimized.

An aggregator-based dynamic pricing mechanism and optimal scheduling scheme for the electric vehicle charging

High penetration of electric vehicles (EVs) in an uncontrolled manner could have disruptive impacts on the power grid, however, such impacts could be mitigated through an EV demand response program. The successful implementation of an efficient, effective, and aggregated demand response from EV charging depends on the incentive pricing mechanism and the load shifting protocols. In this study, a genetic algorithm-based multi-objective optimization model is developed to generate hourly dynamic Time-of-Use electricity tariffs and facilitate the decision making in load scheduling. As an illustrative example, a case study was carried out to examine the effect of applying demand response for EVs in Beijing, China. With the assumptions made, the maximum peak load can be reduced by 9.8% and the maximum customer savings for the EVs owners can reach 11.85%, compared to the business-as-usual case.

Fused ring pyrrolo[3,2-b]pyrrole-based tilde-shaped acceptor molecules for highly efficient organic solar cells

Tilde-shaped materials based on pyrrolo [3,2-b]pyrrole (PP) have attracted a lot of interest as potential acceptors for organic solar cells (OSCs) because of their wide range of energy levels, high absorption efficiency, and three-dimensional (3D) charge transport properties. Herein, we have effectively developed and characterized tilde-shaped PPIC-based acceptor materials (RK1-RK7) using PP as the central-core unit to probe their optical and optoelectronic characteristics. These engineered tilde-shaped (RK1-RK7) materials displayed deeper HOMO levels and more significant extinction coefficients, likely to provide improved phase separation morphology while blend formation. The complete theoretical characterization of these molecules (RK1-RK7) and reference (R) has been achieved using advanced quantum chemical approaches. In addition, density functional theory (DFT) and time-dependent (TD-DFT) simulations have explored the photophysical and optoelectronic properties. Optical properties, frontier molecular orbital (FMO), light harvesting efficiency (LHE), the density of states (DOS), open-circuit voltages, reorganization energy of holes and electrons, and transition density matrix (TDM) have all been studied in these substances. RK4 has an absorption maximum (λmax) at 783.47 nm and an optical band gap minimum of 0.87 eV. The mechanism of extraordinary charge shifting at the donor-acceptor interface was also revealed by a detailed investigation of RK4/PTB7-Th. Our proposed approach is the key backbone to construct efficient molecules for OSCs.

Ultrafast PEDOT:PSS/H2 SO4 Electrical Double Layer Capacitors: Comparison with Polyaniline Pseudocapacitors.

Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is one of the most widely studied conductive polymers, owing to its excellent electrical, optical, and mechanical properties, with various applications such as organic electrochemical transistors, electrochromics, and flexible/stretchable supercapacitors. The charging mechanism of PEDOT:PSS supercapacitors has been traditionally believed to be faradaic, which involves the transfer of charge across the electrode/electrolyte interface. In the present work, however, robust experimental evidence suggests that the PEDOT:PSS supercapacitors mainly store and deliver charge nonfaradaically. The various electrochemical properties of PEDOT:PSS electrical double layer capacitors (EDLCs) are clearly distinguishable from those of polyaniline (PANI) pseudocapacitors, which store charge faradaically. Owing to the nonfaradaic mechanism, the frequency response of PEDOT:PSS supercapacitors is comparable to that of state-of-the-art ultrafast EDLCs with carbon-based electrodes, making them suitable for high-frequency applications such as 60 Hz AC line filtering. This result is of great importance for the fundamental understanding of the charging mechanism of mixed ionic-electronic conducting polymers, such as PEDOT:PSS, and is expected to contribute to the development of various electrochemical devices based on this type of material.

Enhanced photocatalytic detoxication properties of OVs-rich Pd/N–TiO2 heterojunctions: excellent charge separation and mechanism insight

Improving the separation efficiency of photoinduced carriers and light absorption range is a crucial target to improve the photocatalytic properties of wide-band semiconductor photocatalysts. In this work, OVs-rich Pd/N–TiO2 was prepared by a sol-gel method. The results display that N doping and construction of OVs can meliorate the energy band structure of TiO2 based on the various characterizations. The surface plasmon resonance (SPR) effect of Pd0 particles, N doping and introduction of abundant OVs play a synergistic role, which elevates the separation efficiency of photoinduced charge pairs effectually and further enhances the photocatalytic properties of the catalysts. The Density Functional Theory (DFT) calculations solidly support that the construction of Schottky heterojunctions and the transfer of electrons from N–TiO2 to Pd0 particles, enabling efficient separation of photoinduced e−/h+ pairs. The strengthened photocatalytic performance of the optimized TiO2 can be contributed to the enhanced visible light absorption and the effective separation and migration of photogenerated carriers of catalysts. The results of photocatalytic degradation of two typical contaminants (phenol and RhB) reveal that OVs-rich Pd/N–TiO2 samples show superior activity than the reference N–TiO2. This work highlights a simple and effective method that can be used to prepare TiO2 composites with excellent photocatalytic properties.

A novel synthesis strategy for hybrid quaternary rGO/MnO2/NiO/CuO nanocomposite as electrode for enduring symmetric supercapacitor fabrication

Supercapacitors are one of the emerging energy devices due to the evolution in modern technologies which involve fast charging mechanisms with long-lasting stability and good retentivity. A hybrid quaternary composite of transition metal oxide consisting of MnO2, NiO, CuO nanospheres and reduced graphene oxide (rGO) was synthesized by a fusion method with enhanced supercapacitive behaviour. This nanocomposite was subjected to various structural, functional, morphological and electrochemical characterizations and further fabricated into a symmetric supercapacitor with benefiting and facile design. The electrochemical studies were carried out under electrolytes with different pH and mole concentrations both under 3-electrode and 2-electrode systems. The highest specific capacitance of 816.51 F/g was obtained with energy and power densities of 72.57 W h/kg and 0.5 kW/kg. The highest power density of 2.5 kW/kg was achieved corresponding to the current density of 5 A/g. Excellent cyclic retention of 86.46% was achieved after 5000 cycles proving long-term cyclic stability under 1 M KOH. Unfolding the nanocomposite to be a virtuous reference for supercapacitors’ future.

Roadway Embedded Smart Illumination Charging System for Electric Vehicles

Inspired by the fact that there is an immense amount of renewable energy sources available on the roadways, such as mechanical pressure, this study presents the development and implementation of an innovative charging technique for electric vehicles (EVs) by fully utilizing the existing roadways and state-of-the-art nanotechnology and power electronics. The developed Smart Illuminative Charging is a novel wireless charging system that uses LEDs powered by piezoelectric materials as the energy transmitter source and thin film solar panels placed at the bottom of the EVs as the receiver, which is then poised to deliver the harvested energy to the vehicle’s battery. The piezoelectric materials were tested for their mechanical-to-electrical energy conversion capabilities and the relatively large-area EH2N samples (2 cm × 2 cm) produced high output voltages of up to 52 mV upon mechanical pressure. Furthermore, a lab-scale prototype device was developed to testify the proposed mechanism of illuminative charging (i.e., “light” coupled pavement and vehicle as a wireless energy transfer medium).

Fabrication and characterization of octenyl succinate anhydride modified amylose with pH-responsive Pickering emulsion behavior

To make stable Pickering emulsion in stomach acid condition which are suitable for small intestine targeted delivery, the emulsifying ability and pH responsiveness mechanisms of octenyl succinate anhydride modified amylose (OSA-AM) with the formless state and nanoparticles (NP) form in the Pickering emulsion were compared. OSA-AMs and OSA-AM NPs were obtained by successively modification of OSA esterification reaction with amylose and nanoprecipitation process, respectively. OSA-AM NPs showed higher contact angle and lower interfacial tension than OSA-AMs, which suggested OSA-AM NPs have the stronger ability to form stable Pickering emulsion. In addition, to compare the stability of Pickering emulsion in different environment, the emulsion index (EI), photographs and microscopy images during storage time of 180 days in pH 2.0, pH 4.0 and pH 7.0 were monitored. Pickering emulsion formed by OSA-AM NPs exhibited stronger stability in acid environment (pH 2.0) than pH 4.0 and pH 7.0. However, Pickering emulsion stabilized by OSA-AMs presented the opposite pH-responsive behaviors with OSA-AM NPs. To further study the pH responsiveness mechanisms of Pickering emulsion, the morphology, contact angle, particle size and surface charge of OSA-AMs and OSA-AM NPs with pH changing were measured. These results suggested that the protonation/deprotonation process of carboxyl groups in difference pH condition revealed the pH-responsible behaviors of Pickering emulsion.

Analysis of option-like fund performance fees in asset management via Monte Carlo actuarial distortion pricing

Abstract A detailed analysis of management and performance fees for asset managers and investment funds is undertaken. While fund fees are considered as a cost of capital for investors, the structuring of such fee mechanisms in a fund can also influence a fund manager’s decisions and investment strategy, thereby also influencing the investment performance of the investors funds. The study undertaken will allow for an assessment of the effect of fee structures and the potential for asymmetric incentives to arise that may promote adverse risk-taking behaviours by the fund manager, to the detriment of the investor or retiree who places a portion of their retirement savings into such a managed fund with such fee structures. As such, understanding the mechanism of fee charging as well as pricing the fees correctly is vital. An exploration of the application of actuarial distortion pricing methods for complete and incomplete market valuation is performed on a variety of path-dependent option-like performance fee structures for various funds in the European and American markets. Furthermore, several scenario analysis and sensitivity studies are undertaken. The class of Net Asset Value models adopted are Lévy processes, and the pricing is performed via Monte Carlo techniques.

Elucidation of the Charging Mechanisms and the Coupled Structural–Mechanical Behavior of Ti3C2Tx (MXenes) Electrodes by In Situ Techniques

AbstractThe discovery of the Ti3C2Tx compounds (MXenes) a decade ago opened new research directions and valuable opportunities for high‐rate energy storage applications. The unique ability of the MXenes to host various mono‐ and multivalent cations and their high stability in different electrolyte environments including aqueous, organic, and ionic liquid solutions, promoted the rapid development of advanced MXene‐based electrodes for a large variety of applications. Unlike the vast majority of typical intercalation compounds, the electrochemical performance of MXene electrodes is strongly influenced by the presence of co‐inserted solvent molecules, which cannot be detected by conventional current/potential electrochemical measurements. Furthermore, the electrochemical insertion of ions into MXene interspaces results in strong coupling with the intercalation‐induced structural, dimensional, and viscoelastic changes in the polarized MXene electrodes. To shed light on the charging mechanisms of MXene systems and their associated phenomena, the use of a large variety of real‐time monitoring techniques has been proposed in recent years. This review summarizes the most essential findings related to the charging mechanism of Ti3C2Tx electrodes and their potential induced structural and mechanical phenomena obtained by in situ investigations.

IMPROVEMENT OF THE BILLING SYSTEM FOR A TELECOMMUNICATION OPERATOR

The article considers one of the directions of charging, accounting, and billing mechanisms of a telecommunications operator, taking into account modern requirements and the development of network technologies. Electronic telecommunications operators (operators) is an organization that provides services for accessing, using, managing in the Internet in Ukraine. Internet access integrates the processes of authorization, authentication and billing of subscribers and must meet certain technical, user and legal requirements. Given that these requirements may change, the organization of access is an actual task. Purpose of research is to improve the Internet access for subscribers of a telecommunications operator, taking into account modern requirements and the development of network technologies. Based on the analysis of technologies for organizing user Internet access technologies that allow organizing Internet access in the context of modern requirements were identified. Based on the analysis of the subject area, relevant technologies and research of existing billing systems, requirements for a software system for monitoring, accounting and Internet access of telecommunications operator subscribers are formed. Empirically, testing and research of the operability of the billing system was performed. The practical significance of the developed system lies in the availability of the necessary functionality for organizing access and billing of subscribers of a telecommunications operator, taking into account modern requirements and the development of network technologies. Scientific novelty consists in the development of an improved algorithm for charging packages of telecommunications operator subscribers and additional features for controlling Internet access. The practical significance of the developed system lies in the availability of the necessary functionality for charging, accounting, and billing mechanisms of a telecommunications operator, taking into account modern requirements and the development of network technologies.

Understanding the charging of supercapacitors by electrochemical quartz crystal microbalance

Supercapacitors are highly valued energy storage devices and it's crucial to understand their charging mechanism. We present a comprehensive discussion on the applications of EQCM in the supercapacitor community.

5G Charging Mechanism Based on Dynamic Step Size

In this work, a newly dynamic step size-based 5G charging mechanism was proposed with the introduction of random forest algorithm, user daily traffic forecast model, and RG distribution model for the pressure release on charging system caused by the growing consumption demands based on the behavior feature selection of subscribers. After the verification of the dynamic step size mechanism, optimization analysis was performed from three aspects, including authorization step statistical results, Charging Data Record, and timely reminders by utilizing the real monthly traffic usage data of 13,000 users from China Telecom. Result shows that the amount of charging messages between the network elements and the charging systems decreases by about 35%, and the timeliness rate of reminder service increases by approximately 30%. This research realizes an innovative updating of traditional charging systems to effectively improve the efficiency of the 5G charging system and achieves a reduction in system maintenance and resource occupation. Along with the improvement of service quality and user experience, this work provides an innovation method for operators and different associated businesses to tackle new challenges in 5G.

Role of aggregates and microstructure of mixed-ionic-electronic-conductors on charge transport in electrochemical transistors.

Synthetic efforts have delivered a library of organic mixed ionic-electronic conductors (OMIECs) with high performance in electrochemical transistors. The most promising materials are redox-active conjugated polymers with hydrophilic side chains that reach high transconductances in aqueous electrolytes due to volumetric electrochemical charging. Current approaches to improve transconductance and device stability focus mostly on materials chemistry including backbone and side chain design. However, other parameters such as the initial microstructure and microstructural rearrangements during electrochemical charging are equally important and are influenced by backbone and side chain chemistry. In this study, we employ a polymer system to investigate the fundamental electrochemical charging mechanisms of OMIECs. We couple in situ electronic charge transport measurements and spectroelectrochemistry with ex situ X-ray scattering electrochemical charging experiments and find that polymer chains planarize during electrochemical charging. Our work shows that the most effective conductivity modulation is related to electrochemical accessibility of well-ordered, interconnected aggregates that host high mobility electronic charge carriers. Electrochemical stress cycling induces microstructural changes, but we find that these aggregates can largely maintain order, providing insights on the structural stability and reversibility of electrochemical charging in these systems. This work shows the importance of material design for creating OMIECs that undergo structural rearrangements to accommodate ions and electronic charge carriers during which percolating networks are formed for efficient electronic charge transport.

Numerical Simulation of Contamination Accumulation Characteristics of Composite Insulators in Salt Fog Environment

To investigate the fouling characteristics of the composite insulator surface under the salt fog environment, the FXBW-110/120-2 composite insulator was taken as the research object. Based on the field-induced charge mechanism, the multi-physical field coupling software COMSOL was used to numerically simulate the fouling characteristics, explored the calculation method of ESDD, and demonstrated its rationality. Based on this method, the pollution characteristics of the composite insulator under the pollution fog environment were studied, and the influence of wind speed, droplet size, and voltage type on the pollution characteristics of the composite insulator was analyzed. The results showed that: with the increase in wind speed, the amount of accumulated pollution of insulator increases in the range of droplet size, and the relationship between wind speed and accumulated pollution is approximately linear; at the same wind speed, the amount of accumulated pollution increases with the increase of droplet size under the action of DC voltage; when there is no voltage, the amount of dirt on the upper surface of the insulator is more than that on the lower surface, while it is the opposite under DC voltage.