Flat Charge Research Articles

Anisotropic flat band and charge density wave in quasi-one-dimensional indium telluride

Anisotropic flat band and charge density wave in quasi-one-dimensional indium telluride

A framework for shared EV charging in residential renewable energy communities

Renewable energy communities with members which own electric vehicles (EVs) can benefit financially from the flexibility that EVs provide to distributed energy resources, such as photovoltaic generators. However, in residential environments, this benefit is often lost because during working hours, most EVs are not plugged in at the premises of the community. In this paper, we hypothesize that such communities can regain some of this lost benefit by offering membership to outside EV owners which are interested in charging their vehicles using the community's charging stations during these periods. This paper introduces an optimization model for energy communities consisting of prosumers, electric vehicles, and EV chargers. The model aims to evaluate the potential advantages of integrating external EV owners into an energy community. A hypothetical community representing a multi-apartment building is analyzed, considering scenarios both with and without external members. The analysis focuses on assessing the technical and economic benefits. The findings indicate that the economic benefits for the examined community are relatively small. However, a notable increase in these benefits is observed when the community is incentivized to share energy among members in the form of a flat network charge reduction for shared energy.

Nonlinear Transport due to Magnetic-Field-Induced Flat Bands in the Nodal-Line Semimetal ZrTe_{5}.

The Dirac material ZrTe_{5} at very low carrier density was recently found to be a nodal-line semimetal, where ultraflat bands are expected to emerge in magnetic fields parallel to the nodal-line plane. Here, we report that in very low carrier-density samples of ZrTe_{5}, when the current and the magnetic field are both along the crystallographic a axis, the current-voltage characteristics presents a pronounced nonlinearity which tends to saturate in the ultra quantum limit. The magnetic-field dependence of the nonlinear coefficient is well explained by the Boltzmann theory for flat-band transport, and we argue that this nonlinear transport is likely due to the combined effect of flat bands and charge puddles; the latter appear due to very low carrier densities.

Model of the Formation of a Fixed Charge in SiO<sub>2</sub>, Produced by Thermal Oxidation of Silicon

Solid-state recrystallization of the surface silicon layer after chemical and mechanical polishing with application of fast thermal treatment by pulses of one second duration is one of the feasible methods of improving the silicon surface properties. The purpose of this work is to explore the impact of fast thermal treatment resulting in solid state recrystallization of mechanically disrupted layer on generation of fixed charge in SiO2 at thermal oxidation of silicon. The results of studying P-doped electron silicon (KEF 4.5) and B-doped hole silicon (BDS 12) hole-type silicon of orientation <100> diameter 100 mm after chemical and mechanical polishing are provided. By the method of voltage-capacitance characteristic the flat zones voltage and charge density on the boundary of “silicon – silicon dioxide” were determined and by the method of scanning probe electrometry the surface distribution of these characteristic prior and after fast thermal treatment was determined. It has been ascertained that fast thermal treatment on silicon wafers KEF 4.5 and BDS 12 of orientation <100> due to solid state recrystallization of mechanically disrupted layer shall bring about 1.5 times decrease in surface potential along wafers area and residual fixed charge in silicon dioxide.

Effectiveness of Travel Demand Management Policies in Promoting Rail Transit Use and Reducing Private Vehicle Emissions: A Stated Preference Study of Bangkok, Thailand

In this study, we focused on policies to promote reduction in the use of private vehicles that could be implemented in Bangkok during periods of severe PM2.5 levels, including a flat charge for use of private cars, private vehicle bans, and public transport fare subsidization. The objective was to investigate how these policies can be used to help convince private car users to shift their travel modes to rail transit, and, thus, reduce vehicle emissions that contribute to air pollution. We conducted a stated preference survey of 731 private car users in Bangkok, Thailand, where stated-choice scenarios were specified with respect to all possible combinations of the proposed policies that could lead to a reduction of PM2.5 concentration. A binomial logit model was used for the analysis. Our results suggest that the effectiveness of the travel demand management policies would vary across geographical areas of the city. Public transport fare subsidization would be effective in reducing car use among residents in the inner suburbs. A car ban would be an effective measure in outer suburbs, while the flat charge would be effective among populations in central Bangkok and the inner suburbs.

Structural, electronic and optical properties of graphene/C2P4 van der Waals heterostructures with direct bandgap and high absorption coefficient

In this paper, we formed two graphene/C2P4 van der Waals (vdW) heterostructures (HSs) by stacking the graphene and the C2P4 monolayer which have been predicted by us. First, we investigated the stability of C2P4 monolayer, and calculated the binding energies and flat average differential charge density of two vdW-HSs. Second, we found that two graphene/C2P4 vdW-HSs are all direct semiconductors with bandgap as 0.051/0.064[Formula: see text]eV and 0.536/0.697[Formula: see text]eV under GGA-PBE/HSE06 functional, respectively, which provides a way to unfold the zero bandgap of graphene or let an indirect monolayer to be a relevant direct semiconductor. Additionally, two graphene/C2P4 vdW-HSs possess high absorption coefficients (16%∼18%) for the visible light and higher absorption coefficients (22%) for the near ultraviolet light, respectively. These admirable properties make two vdW-HSs as novel and potential two-dimensional materials applied on optoelectronic, electronic and photovoltaics devices.

On the crater of an ejection formed by an explosion of two flat surface cord charges

On the crater of an ejection formed by an explosion of two flat surface cord charges

Electric Vehicle Charging Pricing Design for Agent-Based Traffic Microsimulation

Over the past few years, electric vehicles (EVs) have become a popular mode of individual transportation due to their significant benefits over internal combustion engine vehicles, resulting in significant growth in their penetration rate. However, the current flat electricity charging pricing and rapid diffusion of EVs may impose challenges to both transportation systems and power grids. It is well-accepted that the implementation of charging pricing schemes is a promising solution for changing and controlling EV users’ charging behavior. Nevertheless, in most research studies that have examined pricing schemes, the charging logic is defined in a way that agents will charge their vehicles while performing their daily activities. This will make the application of pricing schemes unfeasible, as agents will not have the freedom to unplug their EVs whenever they want, to reduce their billing costs. Accordingly, this paper provides an agent and activity-based framework for charging pricing schemes by decoupling activity and charging start and end times. Following this, three different charging pricing schemes have been introduced, including time of use (TOU), non-linear and zonal pricing and tested on the Montreal scenario.

Cost-efficiency of ascites treatment in the G-DRG system

In Germany, around 1,000,000 people are affected by cirrhosis of the liver, with ascites being a common consequence. Hospitals are caught between the opposing aims of profitability and patient-centered treatment as a result of the increasing compression of services in hospitals and the increasing economization in the healthcare sector. Treatment costs are a crucial starting point for optimizing success and the optimal use of resources, given the restricted revenue flexibility due to established flat charges per case. The goal of this study is to examine the exact cost and income structures for ascites therapy at a university hospital that specializes in liver diseases. The treatment data of 778 patients admitted to the University Hospital Aachen's Department of Internal Medicine III between 2016 and 2019 were retrospectively and anonymously evaluated for this study. The revenue shares of the matrix of cost centers and cost types of the German Diagnosis-Related Groups (G-DRG) system were compared to the revenue shares of the specified services in the context of activity-based costing. Inadequate refinancing was discovered in every area of the therapy process that was investigated. As a result, the treatment of ascites in cirrhosis is currently underrepresented in the DRG system. This is owing to the fact that patients treated at the university hospital have a greater case severity.

Observation of competing, correlated ground states in the flat band of rhombohedral graphite.

In crystalline solids, the interactions of charge and spin can result in a variety of emergent quantum ground states, especially in partially filled, topological flat bands such as Landau levels or in "magic angle" graphene layers. Much less explored is rhombohedral graphite (RG), perhaps the simplest and structurally most perfect condensed matter system to host a flat band protected by symmetry. By scanning tunneling microscopy, we map the flat band charge density of 8, 10, 14, and 17 layers and identify a domain structure emerging from a competition between a sublattice antiferromagnetic insulator and a gapless correlated paramagnet. Our density matrix renormalization group calculations explain the observed features and demonstrate that the correlations are fundamentally different from graphene-based magnetism identified until now, forming the ground state of a quantum magnet. Our work establishes RG as a platform to study many-body interactions beyond the mean-field approach, where quantum fluctuations and entanglement dominate.

STUDY ON THE REASONABLE SPACING OF FLAT CHARGE IN THE FORM OF LONG AND PARALLEL CYLINDRICAL CHARGES FOR BREAKING ROCK

In practice, the flat charge is often used in the form of a group of long cylindrical charge set parallel and equidistant from each other and lying in the same plane. However, until now, the theory of the rock-destroying effect of flat charge has only mentioned flat charge as a flat plate explosive. Therefore, on the basis of the hydrodynamic theory of the destructive effect of a single charge, we have established a computational model, built a calculation program based on the Matlab programming language. Surveys of the explosive energy field of a group of long cylindrical charge set parallel and lying in the same plane were carried out when the relative distance parameter between the charges was changed. The results have shown that the reasonable range of the relative distance parameter between the corresponding charges receives the best destruction performance and also depends on the rock characteristics. The more stable the rock is, the smaller the reasonable distance between the long cylindrical charges is, and vice versa. The reasonable distance between long cylindrical charges is 10 to 15 times the blasting hole diameter when blasting in an endless rocky environment and 23 to 27 times the blasting hole diameter when smoldered blasting in claystone in water.

Modeling of High Module Power Sources Systems Safety Processes

The paper provides an assessment of the safety processes of high-modulus energy sources systems during the initiation of flat and cylindrical high-modulus energy sources. The expressions, which establish the relationship between the parameters of flat and hollow cylindrical charges of explosives under the only condition of equality of the developed pressure pulse on the surface of the charge of explosives, provided all other things being equal, were obtained. In contrast to the earlier studies, which assert the existence of a direct relationship between the parameters during the initiation of flat and cylindrical surfaces, the current study demonstrates energy consumption during the initiation of cylindrical surfaces is higher than the initiation of flat surfaces, all other things being equal.

Battery State Estimation with ANN and SVR Evaluating Electrochemical Impedance Spectra Generalizing DC Currents

The demand for energy storage is increasing massively due to the electrification of transport and the expansion of renewable energies. Current battery technologies cannot satisfy this growing demand as they are difficult to recycle, as the necessary raw materials are mined under precarious conditions, and as the energy density is insufficient. Metal–air batteries offer a high energy density as there is only one active mass inside the cell and the cathodic reaction uses the ambient air. Various metals can be used, but zinc is very promising due to its disposability and non-toxic behavior, and as operation as a secondary cell is possible. Typical characteristics of zinc–air batteries are flat charge and discharge curves. On the one hand, this is an advantage for the subsequent power electronics, which can be optimized for smaller and constant voltage ranges. On the other hand, the state determination of the system becomes more complex, as the voltage level is not sufficient to determine the state of the battery. In this context, electrochemical impedance spectroscopy is a promising candidate as the resulting impedance spectra depend on the state of charge, working point, state of aging, and temperature. Previous approaches require a fixed operating state of the cell while impedance measurements are being performed. In this publication, electrochemical impedance spectroscopy is therefore combined with various machine learning techniques to also determine successfully the state of charge during charging of the cell at non-fixed charging currents.

Preliminary experimental study on the mechanisms of explosion-electric coupling

Electric energy is one of the most widely used forms of energy. It is valuable to couple electric energy with an explosion to boost detonation performance. The phenomenon of electric energy enhancing an explosion is referred to herein as explosion-electric coupling (EEC) by the author. An experimental device was designed to explore this phenomenon, and the device was equipped with measuring devices to collect data related to the electric and detonation characteristics of explosives. Trinitrotoluene and aluminized explosives were selected as test explosives and pressed into flat and cylindrical charges. Thus, different kinds of explosives with different shapes were able to be studied. The change of the current-voltage curve of the EEC was analyzed, and the process of the EEC was divided into three stages: explosion initiation, detonation growth, and steady-state detonation propagation. The results showed that the enhanced pressure of the von Neumann spike varied with the explosive type, the same as for the increase of the detonation velocity. However, the increased pressure of the Chapman-Jouguet point mattered for the shape of the explosive charges. According to the features of the electrical characteristics and the increases of the detonation properties, a hypothesis was proposed to explain how the electric energy affected the explosion. The external electric field and the large pulse current were two forms of electric energy that influenced the explosion, and these forms of electric energy had different effects on different detonation properties.

On the crater of an ejection formed by an explosion of two flat surface cord charges

In article the problem of the interaction of two flat cord charges at explosion on the ground surface is considered. The impulse-hydrodynamic solid-liquid model is used. The action of charges on the medium by the pressure pulse is determined. The boundary of the ejection crater is a surface with some constant speed module value. It is believed that in general the charges have different widths and pressure pulses characterizing the effect of charges on the medium may be different. The exact solution to the problem is built by displaying the areas of change complex potential and complex speed per area of change auxiliary parametric variable. Detailed parametric analysis done for the case of equal charges The behavior of the solution when changing the main dimensionless parameters is learned. Limitations on values of determining parameters are specified. Limiting cases is investigated The results of calculations of the shape of the ejection crater for various sets of values of defining parameters are given.

Traversable wormholes in the bulge of Milky Way galaxy with Global Monopole Charge

The present work looks for the existence of completely new wormhole geometries in the bulge of the Milky Way galaxy (MWG) situated on the dark matter (DM) density profile followed from MacMillan (MNRAS 76:465, 2017) and Boshkayev and Malafarina (MNRAS 484:3325, 2019) concerned with Global Monopole Charge. The obtained shape function is positively increasing against the radial coordinate and it increases faster with the increasing values of Global Monopole Charge. Moreover, the reported shape function satisfies all the essential criterions and hence it constructs wormhole geometry in the bulge of the MWG. Further, the DM candidate around bulge is suitable to harbor wormhole by violating the null energy condition(NEC) corresponding to three different redshift functions. The striking point of our solution is that for zero Global Monopole Charge the wormholes are asymptotically flat corresponding to the first two choices of redshift functions while for positive values of Global Monopole Charge wormhole becomes non asymptotically flat and Global Monopole Charge also has the crucial effect on the violation of NEC. In our solutions, one can note that the total amount of averaged NEC violating matter in the wormhole spacetime depends on the Global Monopole Charge eta . Furthermore, the respective wormhole solutions are in equilibrium positions.

Donor-acceptor codoping effects on tuned visible light response of TiO2

The monodopants in TiO2 can improve the visible light harvest of TiO2 through the modification of the electronic structures and defects generation. However, most dopants will introduce extra electrons or holes in the system for the unbalanced charge and the defects also act as recombination centers for photo excited electron-hole pairs. The charge compensated codoping technique with donor and accepter is expected to overcome the shortcomings of the monodoping technique. The review collected some typical reports on the codoping effects in TiO2 for high performance photocatalysts through the enhancement of visible light harvest. Theoretical calculation predicts some donor-acceptor codoped TiO2 as practical photocatalyst for water purification or water splitting. In addition to the doping induced light response variation, the experimental results also reveal that the dopants and micromorphology show comprehensive influence on the photocatalytic performance in terms of photon absorption, exciton separation, carrier diffusion, carrier transport, catalytic efficiency and mass transfer phenomena. The review includes three sections to summarize metal/metal codoping, non-metal/non-metal codoping, and metal/non-metal codoping effects on visible light response and one more section to discussion the collaborative effects of bandgap, flat band potential, charge transport, charge transfer, surface potential, and concentration of surface active sites on the photocatalytic reaction.

Na2Li2Ti6O14 nanowires as ultra-long cycling performance anode material for lithium ion storage

Na2Li2Ti6O14 nanowires prepared through electrospinning and subsequent calcination method are reported as an anode material for lithium ion storage. During the initial cycle, as-synthesized Na2Li2Ti6O14 nanowires deliver a quite flat charge platform at 1.32 V with the charge capacity of 94.0 mAh g-1 at 100 mA g-1. Specifically, after a long cycle of 2500 times, Na2Li2Ti6O14 nanowires still hold a reversible charge capacity of 88.8 mAh g-1 with a remarkable capacity retention of 94.47%, which also show a high Coulombic efficiency of 99.83%. The favorable electrochemical performance may stem from its unique nanostructures, which not only preserve structural integrity during repeated cycles but also reduce the distance of lithium ion transport.

Nanostructured Cu2O Synthesized via Bipolar Electrochemistry.

Cuprous oxide (Cu2O) was synthesized for the first time via an open bipolar electrochemistry (BPE) approach and characterized in parallel with the commercially available material. As compared to the reference, Cu2O formed through a BPE reaction demonstrated a decrease in particle size; an increase in photocurrent; more efficient light scavenging; and structure-correlated changes in the flat band potential and charge carrier concentration. More importantly, as-synthesized oxides were all phase-pure, defect-free, and had an average crystallite size of 20 nm. Ultimately, this study demonstrates the impact of reaction conditions (e.g., applied potential, reaction time) on structure, morphology, surface chemistry, and photo-electrochemical activity of semiconducting oxides, and at the same time, the ability to maintain a green synthetic protocol and potentially create a scalable product. In the proposed BPE synthesis, we introduced a common food supplement (potassium gluconate) as a reducing and complexing agent, and as an electrolyte, allowing us to replace the more harmful reactants that are conventionally used in Cu2O production. In addition, in the BPE process very corrosive reactants, such as hydroxides and metal precursors (required for synthesis of oxides), are generated in situ in stoichiometric quantity, providing an alternative methodology to generate various nanostructured materials in high yields under mild conditions.

Charged particle production rate from cosmic censorship in dilaton black hole spacetimes

Hiscock and Weems showed that under Hawking evaporation, an isolated asymptotically flat Reissner-Nordström (RN) black hole evolves in a surprising manner: if it starts with a relatively small value of charge-to-mass ratio Q/M, then said value will temporarily increase along its evolutionary path, before finally decreases towards zero. This contrasts with highly charged ones that simply radiate away its charge steadily. The combination of these two effects is the cosmic censor at work: there exists an attractor that flows towards the Schwazschild limit, which ensures that extremality — and hence naked singularity — can never be reached under Hawking evaporation. We apply the scheme of Hiscock and Weems to model the evaporation of an asymptotically flat dilatonic charge black hole known as the Garfinkle-Horowitz-Strominger (GHS) black hole. We found that upholding the cosmic censorship requires us to modify the charged particle production rate, which remarkably agrees with the expression obtained independently via direct computation of charged particle production rate on curved spacetime background. This not only strengthens the case for cosmic censorship, but also provides an example in which cosmic censorship can be a useful principle to deduce other physics. We also found that the attractor behavior is not necessarily related to the specific heat, contrary to the claim by Hiscock and Weems.