Charge Ratio Research Articles

On the estimation of near-field air blast peak overpressure from cylindrical charges

In the near field, the air blast peak overpressure from cylindrical charges may vary by several times with angles at the same scaled distance. We propose an estimation equation for the peak overpressure from cylindrical charges, which can predict the peak overpressure from cylindrical charges at any positions in the near field. The estimation equation is in the form of piecewise function which contains three variables of length-to-diameter ratio, angle and scaled distance, and the applicability of our estimation equation is verified by experiment and simulation. After preliminary verification, the application range of length-to-diameter ratio of cylindrical charge is [Formula: see text] and that of scaled distance is [Formula: see text]. The estimation equation can be rapidly applied to the assessment of near-field target damage and protection against air blast from cylindrical charges, which is a significant supplement to the traditional empirical equations for spherical charge.

EXPERIMENTAL INVESTIGATION OF INDIVIDUAL EVACUATED TUBE HEAT PIPE SOLAR WATER HEATING SYSTEMS

lar water heating systems with heat pipes of three diameter groups of 16, 22 and 28.5 mm. The first and third groups had evaporator lengths of 1150, 1300 and 1550 mm. The second group had an additional length of 1800 mm. all heat pipes were of fixed condenser length of 200 mm. Ethanol at 50% fill charge ratio of the evaporator volume was used as the heat pipes working fluid. Each heat pipe condenser section was inserted in a storage tank and the evaporator section inserted into an evacuated glass tube of the Owens- Illinois type. The combined heat pipe and evacuated glass tube form an active solar collector of a unique design.The resulting ten solar water heating systems were tested outdoors under the meteorological conditions of Baghdad, Iraq. Experiments were carried out with no load, intermittent and continuous load conditions. Some tests, at no load, were carried out with and without reflectors. The overall system efficiency was found to improve with load conditions by a maximum of 55%. The system employing an 1800 mm evaporator length and 22 mm heat pipe (HP7) showed the best performance by higher water temperatures, overall useful energy gain and efficiency at various load conditions. System performance was predicted theoretically using electrical analogy derived from an energy balance. An agreement of within 14% was obtained between theoretical and experimental values.

GCN2 kinase-mediated upregulation of ubiquitin C maintains intracellular glutamine level and tRNAGln (CUG) charging under amino acid starvation.

Each tRNA is aminoacylated (charged) with a genetic codon-specific amino acid. It remains unclear what factors are associated with tRNA charging and how tRNA charging is maintained. By using the individual tRNA acylation PCR (i-tRAP) method, we found that the charging ratio of tRNAGln (CUG) reflects cellular glutamine level. When uncharged tRNAGln (CUG) increased under amino acid starvation, the kinase GCN2, which is a key stimulator of the integrated stress response, was activated. Activation of GCN2 led to the upregulation of ubiquitin C (UBC) expression. Upregulated UBC, in turn, suppressed the further reduction of tRNAGln (CUG) charging levels. Thus, tRNA charging is sensitive to intracellular nutrient status and is an important initiator of intracellular signaling.

Parametric study to evaluate the influence of aspect ratio of cylindrical charges on blast pressures

The influence of the aspect ratio of a cylindrical charge on the spatial distribution of the effective pressure caused by an explosive blast on the front face of a concrete unit is investigated here. Distinct patterns of the spatial distribution of effective pressure can be discerned in the graphical comparison pertaining to the different aspect ratios. This can be attributed to the complex blast wave patterns generated by exploding cylindrical charges. The effective pressures decrease with an increase in the aspect ratio of the cylindrical charge. A 54% reduction in the effective pressure is observed when the aspect ratio is varied from 1 to 2. The study is expected to contribute to the ongoing research on the design and construction of blast-resistant structures, as cylindrical shaped charges are common in civil and military applications.

On the Fractionation and Physicochemical Characterisation of Self-Assembled Chitosan-DNA Polyelectrolyte Complexes.

Chitosan is extensively studied as a carrier for gene delivery and is an attractive non-viral gene vector owing to its polycationic, biodegradable, and biocompatible nature. Thus, it is essential to understand the chemistry of self-assembled chitosan-DNA complexation and their structural and functional properties, enabling the formation of an effective non-viral gene delivery system. In this study, two parent chitosans (samples NAS-032 and NAS-075; Mw range ~118-164 kDa) and their depolymerised derivatives (deploy nas-032 and deploy nas-075; Mw range 6-14 kDa) with degrees of acetylation 43.4 and 4.7%, respectively, were used to form polyelectrolyte complexes (PECs) with DNA at varying [-NH3+]/[-PO4-] (N/P) molar charge ratios. We investigated the formation of the PECs using ζ-potential, asymmetric flow field-flow fractionation (AF4) coupled with multiangle light scattering (MALS), refractive index (RI), ultraviolet (UV) and dynamic light scattering (DLS) detectors, and TEM imaging. PEC formation was confirmed by ζ-potential measurements that shifted from negative to positive values at N/P ratio ~2. The radius of gyration (Rg) was determined for the eluting fractions by AF4-MALS-RI-UV, while the corresponding hydrodynamic radius (Rh), by the DLS data. We studied the influence of different cross-flow rates on AF4 elution patterns for PECs obtained at N/P ratios 5, 10, and 20. The determined rho shape factor (ρ = Rg/Rh) values for the various PECs corresponded with a sphere morphology (ρ ~0.77-0.85), which was consistent with TEM images. The results of this study represent a further step towards the characterisation of chitosan-DNA PECs by the use of multi-detection AF4 as an important tool to fractionate and infer aspects of their morphology.

New Insights into Hybrid Low-Salinity Polymer Flooding through a Coupled Geochemical-Based Modeling Approach

Summary Low-salinity polymer (LSP) flooding is a synergic emergent enhanced oil recovery (EOR) technique. Previous laboratory experiments showed noticeable improvements in displacement efficiency, polymer rheology, injectivity, and viscoelasticity. Nevertheless, when it comes to modeling LSP flooding, it is still challenging to develop a mechanistic predictive model that captures polymer-brine-rock (PBR) interactions. Therefore, this study uses a coupled MATLAB reservoir simulation toolbox (MRST)-IPhreeqc simulator to investigate the effect of water chemistry on PBR interactions during LSP flooding through varying overall salinity and the concentrations of divalent and monovalent ions. For describing the related geochemistry, the presence of polymer in the aqueous phase was considered by introducing novel solution species (Poly) to the Phreeqc database. The developed model’s parameters were validated and history matched with experimental data reported in the literature. Moreover, different injection schemes were analyzed, including low-salinity (LS) water, LSP injection (1 × LSP), and 5-times spiked LSP injection (5 × LSP) with their related effects on polymer viscosity. Results showed that polymer viscosity during LSP flooding is affected directly by Ca2+ and Mg2+ and indirectly by SO42− owing to PBR interactions on a dolomite rock-forming mineral. Monovalent ions (viz. Na+ and K+) have minor effects on polymer viscosity. Ca2+ and Mg2+ ions discharged from dolomite dissolution create polymer complexes (acrylic acid, C3H4O2) to reduce polymer viscosity significantly. The increased SO42− concentration in the injected LSP solution affects the interactions between the polymer and positively charged aqueous species, leading to minimized polymer viscosity loss. For LSP flood derisking measures, the cation’s effect was related to the charge ratio (CR). Thus, it is key to obtain an optimal CR where viscosity loss is minimal. This paper is among the few to detail the mechanistic geochemical modeling of the LSP flooding technique. The validated MRST-IPhreeqc simulator evaluates the previously overlooked effects of water chemistry on polymer viscosity during the LSP process. Using this coupled simulator, several other geochemical reactions and parameters can be assessed, including rock and injected-water compositions, injection schemes, and other polymer characteristics.

A novel ultra large size organic light emitting diode display for premium televisions

AbstractIn this paper, we present novel ultra large size organic light emitting diode (OLED) display technologies with high image quality for premium televisions (TVs) using an advanced coplanar oxide thin film transistor (TFT) backplane, microlens array (MLA)‐based OLED, small size gate driver in panel for narrow bezel, and pixel charging enhancement method with external compensation. Using these technologies, we improved the luminance efficiency about 20% and reduced the integrated gate driver design area to 40%. We have achieved the life time of the gate driver in panel longer than 100,000 h in reliability test. The pixel charging ratio is more than 80% in all gray levels. Using the developed OLED display, we have successfully developed up to ultra large size 88‐in. 8K and 97‐in. 4K OLED TVs.

Effective Deterministic Methodology for Enhanced Distribution Network Performance and Plug-in Electric Vehicles

The rapid depletion of fossil fuel motivates researchers and policymakers to switch from the internal combustion engine (ICE) to plug-in electric vehicles (PEVs). However, the electric power distribution networks are congested, which lowers the accommodation of PEVs and produces higher power losses. Therefore, the study proposes an effective deterministic methodology to maximize the accommodation of PEVs and percentage power loss reduction (%PLR) in radial distribution networks (RDNs). In the first stage, the PEVs are allocated to the best bus, which is chosen based on the loading capacity to power loss index (LCPLI), and the accommodation profile of PEVs is developed based on varying states of charge (SoC) and battery capacities (BCs). In the second stage, the power losses are minimized in PEV integrated networks with the allocation of DG units using a recently developed parallel-operated arithmetic optimization algorithm salp swarm algorithm (AOASSA). In the third stage, the charging and discharging ratios of PEVs are optimized analytically to minimize power losses after planning PEVs and DGs. The outcomes reveal that bus-2 is the most optimal bus for accommodation of PEVs, as it has the highest level of LCPLI, which is 9.81 in the 33-bus system and 28.24 in the 69-bus system. The optimal bus can safely accommodate the largest number of electric vehicles, with a capacity of 31,988 units in the 33-bus system and 92,519 units in the 69-bus system. Additionally, the parallel-operated AOASSA mechanism leads to a reduction in power losses of at least 0.09% and 0.25% compared with other algorithms that have been previously applied to the 33-bus and 69-bus systems, respectively. Moreover, with an optimal charging and discharging ratio of PEVs in the IEEE-33-bus radial distribution network (RDN), the %PLR further improved by 3.08%, 4.19%, and 2.29% in the presence of the optimal allocation of one, two and three DG units, respectively. In the IEEE-69-bus RDN, the %PLR further improved by 0.09%, 0.09%, and 0.08% with optimal charge and discharge ratios in the presence of one, two, and three DG units, respectively. The proposed study intends to help the local power distribution companies to maximize accommodation of PEV units and minimize power losses in RDNs.

Entanglement of stationary states in the presence of unstable quasiparticles

The effect of unstable quasiparticles in the out-of-equilibrium dynamics of certain integrable systems has been the subject of several recent studies. In this paper we focus on the stationary value of the entanglement entropy density, its growth rate, and related functions, after a quantum quench. We consider several quenches, each of which is characterised by a corresponding squeezed coherent state. In the quench action approach, the coherent state amplitudes K(θ) become input data that fully characterise the large-time stationary state, thus also the corresponding Yang-Yang entropy. We find that, as function of the mass of the unstable particle, the entropy growth rate has a global minimum signalling the depletion of entropy that accompanies a slowdown of stable quasiparticles at the threshold for the formation of an unstable excitation. We also observe a separation of scales governed by the interplay between the mass of the unstable particle and the quench parameter, separating a non-interacting regime described by free fermions from an interacting regime where the unstable particle is present. This separation of scales leads to a double-plateau structure of many functions, where the relative height of the plateaux is related to the ratio of central charges of the UV fixed points associated with the two regimes, in full agreement with conformal field theory predictions. The properties of several other functions of the entropy and its growth rate are also studied in detail, both for fixed quench parameter and varying unstable particle mass and viceversa.

Salt Solubilization Coupled with Membrane Filtration-Impact on the Structure/Function of Chickpea Compared to Pea Protein.

The demand for pulse proteins as alternatives to soy protein has been steeply increasing over the past decade. However, the relatively inferior functionality compared to soy protein is hindering the expanded use of pulse proteins, namely pea and chickpea protein, in various applications. Harsh extraction and processing conditions adversely impact the functional performance of pea and chickpea protein. Therefore, a mild protein extraction method involving salt extraction coupled with ultrafiltration (SE-UF) was evaluated for the production of chickpea protein isolate (ChPI). The produced ChPI was compared to pea protein isolate (PPI) produced following the same extraction method in terms of functionality and feasibility of scaling. Scaled-up (SU) ChPI and PPI were produced under industrially relevant settings and evaluated in comparison to commercial pea, soy, and chickpea protein ingredients. Controlled scaled-up production of the isolates resulted in mild changes in protein structural characteristics and comparable or improved functional properties. Partial denaturation, modest polymerization, and increased surface hydrophobicity were observed in SU ChPI and PPI compared to the benchtop counterparts. The unique structural characteristics of SU ChPI, including its ratio of surface hydrophobicity and charge, contributed to superior solubility at both a neutral and acidic pH compared to both commercial soy protein and pea protein isolates (cSPI and cPPI) and significantly outperformed cPPI in terms of gel strength. These findings demonstrated both the promising scalability of SE-UF and the potential of ChPI as a functional plant protein ingredient.

Diffusion Coefficients of 56Fe in C–O and O–Ne White Dwarfs

The diffusion coefficients of neutron rich nuclei in crystallizing white dwarf (WD) stars are essential microphysics input for modeling the evolution of the composition profile. Recently, molecular dynamics simulations have been used to compute diffusion coefficients for realistic mixtures of C–O and O–Ne WDs with many trace nuclides that could be important sedimentary heat sources such as 22Ne, 23Na, 25Mg, and 27Mg. In this brief note, I repeat these simulations but now include 56Fe. I find that for the large charge ratios involved in these mixtures the empirical law developed in our earlier work tends to under-predict diffusion coefficients in the moderately coupled regime by 30%–40%. As this formalism is presently implemented in the stellar evolution code MESA, it is important for authors studying mixtures containing heavy nuclides like 56Fe to be aware of these systematics. However, the impact on astrophysics is expected to be small.

Development of a linear ion trap mass spectrometer capable of analyzing megadalton MALDI ions

Detecting megadalton matrix-assisted laser desorption/ionization (MALDI) ions in an ion trap mass spectrometer is a technical challenge. In this study, megadalton protein and polymer ions were successfully measured by MALDI linear ion trap mass spectrometer (LIT-MS) for the first time. The LIT-MS is comprised of a Thermo linear ion trap mass analyzer and a highly sensitive charge-sensing particle detector (CSPD). A newly designed radio frequency (rf) scan mode with dipolar resonance ejection techniques is proposed to extend the mass range of LIT-MS up to one million Thomson (Th). We analyze high mass ions with mass-to charge (m/z) ratios ranging from 100 kTh to 1 MTh, including thyroglobulin, alpha-2-macroglobulin, immunoglobulins (e.g., IgG and IgM), and polymer (∼ 940 kTh) ions. Besides, it is also very challenging for ion trap mass spectrometry to detect megadalton ions at low concentrations. By adopting high affinity carboxylated/oxidized detonation nanodiamonds (oxDNDs) to enrich IgM molecules and form antibody-nanodiamond conjugates, we have successfully reached ∼ 5 nM (5 μg/mL) concentration which is better than that by the other techniques.

Effects of soft sparking on micro/nano structure and bioactive components of microarc oxidation coatings on selective laser melted Ti6Al4V alloy

We used the soft sparking mode to fabricate microarc oxidation coatings containing micro/nano-scale pores and bioactive Ca/P components on Ti6Al4V alloy samples formed by selective laser melting. The effect of soft sparking on the microstructure and corrosion resistance of the coatings and the codeposition mechanism of the electrolyte anions in the soft sparking layer were investigated using different negative/positive charge ratios. The results showed that the negative charge significantly decreased the intensity of microarc discharge, resuling in the soft sparking phenomenon, which promotes the formation of a thin amorphous TiO2 layer at the barrier layer/substrate interface. In turn, this interface facilitated the electron tunneling and aggregation of the electrolyte anions, which leads to soft sparking at voltages significantly lower than the breakdown voltage of the anodic oxide film on the selective laser melted Ti alloys. Soft sparking promoted the codeposition of the electrolyte anions, including PO43− and Ca2+ ions, in the form of bulk amorphous phases in the coating formed by soft sparking. The soft sparking layer contained amorphous phases, which were corroded more readily than that the outer ceramic layer. However, the submicro/nano-scale pores in the soft sparking layer improved its corrosion resistance. With an increase in negative/positive charge ratio, the effect of soft sparking on the surface morphology of the MAO coating weakened, and the amounts of Ca and P codeposited in the soft sparking layer increased. Finally, the corrosion resistance of the coating was found to first increase and then decrease, reaching the maximum at the 1.1 ratio.

Smart Miniature Mass Spectrometer Enabled by Machine Learning.

Similar to smartphones, smart or automatic level is also a critical feature for a miniature mass spectrometer. Compared to large-scale instruments, miniature mass spectrometers often have a lower mass resolution and larger mass drift, making it challenging to identify molecules with close mass-charge ratios. In this work, a miniature mass spectrometer (the Brick-V model) was combined with intelligent algorithms to realize rapid and accurate identification. This Brick-V mass spectrometer developed in our lab was equipped with a vacuum ultraviolet photoionization (VUV-PI) source, which ionizes volatile organic compounds (VOCs) with minor fragments. Machine learning would be especially helpful when analyzing samples with multiple characteristic peaks. Four machine learning algorithms were tested and compared in terms of precision, recall, balanced F score (F1 score), and accuracy. After optimization, the multilayer perceptron (MLP) method was selected and first applied for the automatic identification and differentiation of ten different fruits. By recognizing the pattern of multiple VOCs diffused from fruits, an average accuracy of 97% was achieved. This system was further applied to determine the freshness of strawberries, and strawberry picking at different times (especially during the first 24 h at room temperature of winter) could be well discriminated. After building a database of 63 VOCs, a rapid method to identify compounds in the database was established. In this method, molecular ions, fragment ions, and dimer ions in the full mass spectrum were all utilized in the machine learning program. A satisfactory prediction accuracy for the 63 VOCs could be achieved (>99%).

COMPARISON ON STUDY OF LITHIUM ION PARALLEL AND LEAD ACID PARALLEL CHARGING AND DISCHARGING CHARACTERISTICS

Lead acid battery may be used in parallel with one or more batteries of equal voltage. When connecting batteries in parallel, the current from the charger will tend to divide almost equally between the batteries. No special matching of batteries required .If the batteries of unequal capacity are connected parallel, the current will tend to divide between the batteries in the ratio of capacities (actually, internal resistances).When charging batteries in parallel, where different ratios of charge are to be expected, it is best to make provisions to assure the currents will not vary too much between batteries. Lithium batteries can be connected to generate more energy to run larger motors or extra capacity. Connecting the lithium batteries in parallel is one way to increase the ampere-hours of a battery. As far as disadvantages, placing batteries in parallel can make them take longer to charge. Also, the lower voltage means higher current draw and more voltage drop. It may be difficult to power large applications, and one need thicker cables. Imbalanced lithium-ion cells die the first time one try to use them. This is why balancing is absolutely required. Battery cells, especially lithium cells are very sensitive to overcharging and over-discharging. Balancing is only necessary for packs that contain more than one cell in series. Parallel cells will naturally balance since they are directly connected to each other, but groups of parallel wired cells, wired in series (parallel-series wiring) must be balanced between cell groups.

Research and experiment of electrostatic spraying system for agricultural plant protection unmanned vehicle

IntroductionThe traditional spraying system is not suitable for agricultural plant protection in small plots due to its disadvantages of weak droplet refining ability, small spraying area, large pesticide consumption, and high manual spraying cost. At present, spraying pesticide is the main way to resist crop diseases and insect pests. The utilization rate of pesticide is only 38.8% in China, which leads to serious waste and serious environmental pollution. It is necessary to develop advanced plant protection equipment and pesticide application technology to solve the problem. The combination of agricultural plant protection vehicle and electrostatic spray technology may solve the problems of spraying efficiency, droplet adsorption rate and evenness. It is of great significance to improve the efficiency of plant protection and pesticide utilization.MethodsIn this paper, the principle of droplet charging is described, an electrostatic spraying system is designed and tested, and the effects of charging voltage and pump pressure on the droplet charge ratio and droplet size are analyzed.Results and discussionThis study has shown that electrostatic spraying systems are suitable for agricultural plant protection unmanned vehicles.

A transient numerical study for heat transfer and flow characteristics of dimpled piston cooling gallery of a diesel engine

Piston cooling gallery is an effective cooling method to achieve an acceptable piston temperature field. This paper aims to analyze the effects of teardrop dimples size and dimple head-and-tail orientation on flow and heat transfer inside the cooling gallery. To do so, the computational fluid dynamics model for galleries with different teardrop dimples were established. The results indicate that the local oil flow patterns in the axial and circumferential directions are affected by the dimples. Compared with smooth gallery, the presence of dimple enlarges the fluid charge ratio (FCR). Specifically, when radius of teardrop shaped dimples are R2 and R3 respectively, their corresponding gallery FCRs achieve 55% and 58%. Further, the variation in FCR makes a difference in the distribution of heat transfer, an in-depth analysis finds the dimples increase the heat transfer area between the gallery surface and the oil and simultaneously reduce the space of oil suspending in the gallery. Therefore, the heat transfer coefficient of a dimpled gallery is always greater than that of the smooth gallery, with the maximum improvement of 2.42%. Moreover, the change of heat transfer distribution reconstructs the heat transfer uniformity of the cooling gallery, with the maximum improvement of 24.25%.

Chemical Adsorption of HF, HCl, and H2O onto YF3 and Isostructural HoF3 Surfaces by First Principles

The two elements, yttrium and holmium, form a geochemical twin pair as their cations possess equivalent ratios of charge to radius. However, despite their equal electrostatics, a subtle difference in their fluoride or chloride affinity is known within solutions. In this work, we investigated whether this affinity gap is also present within the solid phase and how it depends on the surface configuration. We modeled adsorptions onto β-YF3 (waimirite) and isostructural β-HoF3 by periodic density functional theory. To draw conclusions on the affinity toward fluoride and chloride vs. water, adsorbates of HF, HCl, or H2O onto any of the four highly abundant surfaces of (010), (100), (011), and (101) were studied. Among others, the conformational landscape was explored by 200 ps of ab initio molecular dynamics. For stoichiometric surfaces of both MF3, we indeed found stronger adsorptions for HF than HCl. All (hkl)·H2O showed slightly stronger adsorption energies for HoF3, while for HF and HCl, the metal preferences varied by the surface. While (100) showed the strongest preference for HoF3, (101) preferred YF3 by the same magnitude.

Lyophilization for Formulation Optimization of Drug-Loaded Thermoresponsive Polyelectrolyte Complex Nanogels from Functionalized Hyaluronic Acid

The lyophilization of nanogels is practical not only for their long-term conservation but also for adjusting their concentration and dispersant type during reconstitution for different applications. However, lyophilization strategies must be adapted to each kind of nanoformulation in order to minimize aggregation after reconstitution. In this work, the effects of formulation aspects (i.e., charge ratio, polymer concentration, thermoresponsive grafts, polycation type, cryoprotectant type, and concentration) on particle integrity after lyophilization and reconstitution for different types of polyelectrolyte complex nanogels (PEC-NGs) from hyaluronic acid (HA) were investigated. The main objective was to find the best approach for freeze-drying thermoresponsive PEC-NGs from Jeffamine-M-2005-functionalized HA, which has recently been developed as a potential platform for drug delivery. It was found that freeze-drying PEC-NG suspensions prepared at a relatively low polymer concentration of 0.2 g.L-1 with 0.2% (m/v) trehalose as a cryoprotectant allow the homogeneous redispersion of PEC-NGs when concentrated at 1 g.L-1 upon reconstitution in PBS without important aggregation (i.e., average particle size remaining under 350 nm), which could be applied to concentrate curcumin (CUR)-loaded PEC-NGs for optimizing CUR content. The thermoresponsive release of CUR from such concentrated PEC-NGs was also reverified, which showed a minor effect of freeze-drying on the drug release profile.

Event-Based EV Charging Scheduling in a Microgrid of Buildings

With the popularization of electric vehicles (EVs), EV charging demand is becoming an important load in the building. Considering the mobility of EVs from building to building and their uncertain charging demand, it is of great practical interest to control the EV charging process in a microgrid of buildings to optimize the total operation cost while ensuring transmission security between the microgrid and the main grid. We consider this important problem in this article and make the following contributions. First, we formulate this problem as a Markov decision process (MDP) to capture the uncertain supply and EV charging demand in the microgrid of buildings. Besides reducing the total operation cost of buildings, the model also considers the power exchange limitation to ensure transmission security. Second, this model is reformulated within an event-based optimization (EBO) framework to mitigate the impact of large state and action space. A randomized parametric event-based control policy is proposed for the microgrid controller to determine the charge ratio for each building. Then, a selecting-to-charging principle is implemented for each building controller to determine the charge control of each EV in the building. Third, a constrained gradient-based policy optimization method is developed to find the optimal event-based control policy. Furthermore, an adjustment mechanism is also introduced to ensure transmission security during optimization. Numerical experiments are conducted to analyze the structure and the performance of the event-based control policy for EV charging in a microgrid of three buildings.