Discharge Duration Research Articles

Effects of Spark Energy on Spark Plug Fault Recognition in a Spark Ignition Engine

The increasing demands for fuel economy and emission reduction have led to the development of lean/diluted combustion strategies for modern Spark Ignition (SI) engines. The new generation of SI engines requires higher spark energy and a longer discharge duration to improve efficiency and reduce the backpressure. However, the increased spark energy gives negative impacts on the ignition system which results in deterioration of the spark plug. Therefore, a numerical model was used to estimate the spark energy of the ignition system based on the breakdown voltage. The trend of spark energy is then recognized by implementing the classification method. Significant features were identified from the Information Gain (IG) scoring of the statistical analysis. -Nearest Neighbor (KNN), Artificial Neural Network (ANN), and Support Vector Machine (SVM) models were studied to identify the best classifier for the classification stage. For all classifiers, the entire featured dataset was randomly divided into standardized parameter values of training and testing data sets with the ratio of 70–30 for each class. It was shown in the study that the KNN classifier acquired the highest Classification Accuracy (CA) of 94.1% compared to ANN and SVM that score 77.3% and 87.9% on the test data, respectively.

Prenatal alcohol exposure affects developmental differentiation of interictal discharges in septal and temporal hippocampus.

Prenatal alcohol exposure (PAE) provokes lifelong CNS dysfunction, including an increased susceptibility to seizure disorders. We investigated hippocampal excitability in vitro in the offspring of dams exposed to a mild ethanol concentration throughout pregnancy (ethanol 15%v/v in drinking water). Hippocampal slices were prepared from the offspring at a young (Y, 21-30 postnatal days, PND) or adult (A, 60 PND) age, with controls from same age normal rats (N). Synchronous spontaneous interictal-type epileptiform discharges (IEDs) were induced by bathing the slices in Mg2+-free ACSF or in 4-Aminopyridine (4-AP, 50µΜ) and were recorded from CA1 pyramidal layer of temporal (T) and septal slices (S). Hippocampal slices readily generated IEDs following NMDA receptor activation or K+ conductance block, with frequency and duration depending on location (septal or temporal), age, the activating mechanism, and prior conditioning (N or PAE). From the two media, 4-AP induced higher frequency (always), shorter duration (mostly) IEDs compared to Mg 2+-free ACSF. Temporal IED frequency increased with age, whereas septal was stable, indicating an earlier maturation of the latter part. The hippocampal "T to S" (high to low) excitability gradient appeared at/later than the end of the first postnatal month and mostly concerned discharge frequency. Discharge duration generally decreased with maturation but appeared to depend on many factors, including conditioning. Prenatal alcohol exposure differentiated the control of synchronous discharges by NMDA receptors and K+ conductances, and their developmental evolution, thus suggesting potential mechanisms for aberrant hippocampal neuronal network function.

White Layer Thickness Variation in Die Sinking EDM

Surfaces that were machined by Electrical Discharge Machining (EDM) inevitably exhibit a thin layer of resolidified material, commonly called “white layer”. It is usually regarded as disadvantage of ED machining as it induces tensile residual stresses to the parent material and therefore facilitates the formation of cracks. It therefore was subject to a number of scientific investigations that often dealt with its (non-)crystalline structure or the stress induction. Some research groups have also focused on the thickness of the white layer. However, the variation of its thickness has not yet been investigated comprehensively and therefore constitutes the focus of this work. Experiments were conducted on a conventional sinking EDM machine. A heat-treatable steel was used as a workpiece material and graphite was used for the tool electrode. The influence of the discharge duration te as well as the discharge current ie on the white layer formation were investigated. Results show that significant thickness variations occur on every ED machined surface and that increasing discharge energy leads to an increase of both, white layer thickness as well as its variation.

Effects of various discharge strategies on ignition and combustion of lean natural gas mixture under the static and turbulent conditions

Diluted combustion can promote thermal efficiency and decrease NOx emissions for natural gas engines, but also presents high cycle-by-cycle variations. Enhancing the in-cylinder flow field is beneficial for the combustion stability, but brings challenges for the stable ignition. Therefore, advanced ignition strategies are critical for extending the diluted limit. In this work, by using the constant volume combustion vessel, rapid compression and expansion machine, and multi-cylinder natural gas engine, the lean methane/air or natural gas/air mixtures under the static and turbulent conditions are established to compare various discharge strategies. The comparisons include: (1) different discharge energies, (2) power and duration enhancements with similar discharge energies, (3) the continuous discharge and multi-strike. For the static condition, once the flame kernel can be successfully established, enhancing discharge power or duration has few effects on ignition. The continuous discharge and multi-strike show no clear differences. At the lean limit, the multi-strike shows better performance than the continuous discharge. For the turbulent condition, increasing discharge energy can promote the initial flame propagation. When the flow velocity around the spark plug increases to some extent, enhancing the discharge duration shows better performance than enhancing the discharge power. Moreover, the continuous discharge is better for the ignition processes than the multi-strike. For the multi-cylinder engine tests, compared to the single strike of one coil, the continuous discharge and multi-strike extend the lean limit from the excess air ratio of 1.51 to 1.61. The multi-strike is more beneficial for the combustion phase stability than the continuous discharge.

Platinum-Decorated TiO2: One Step Fast Monometallic Impregnation and Plasma Effect on Nanoparticles

In the present work, N-TiO2−x/Pt was synthesized using a homemade nitrogen plasma (AC) discharge system. The overall procedure use of low-power nitrogen plasma (100 watts) with 1 and 2 h of plasma discharge to successfully impregnate platinum nanoparticles on P25 titanium dioxide. The obtained samples were characterized using X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). The results reveal the incorporation of metallic Pt up to 2.9% on the surface of TiO2 by increasing the duration of plasma discharge by up to two hours with a constant power of 100 watts. Likewise, the incorporation of nitrogen atoms into a lattice crystal was also favored, confirming a direct relationship between the amount of Pt and nitrogen atoms introduced in TiO2 as a function of the duration of plasma treatment. By characterizing nanoparticles loaded on a N-TiO2−x/Pt surface, we show that joined platinum nanoparticles have two different patterns, and the boundary between these two regions coalesces. The results demonstrate that the use of nitrogen plasma to impregnate platinum nanoparticles on the surface of TiO2 to obtain N-TiO2−x/Pt allows wide and relevant physics and chemistry applications.

An 8-year study of admissions and discharges to a specialist intellectual disability inpatient unit.

In the United Kingdom, policy change has led to specialist intellectual disability inpatient bed reduction. Little evidence exists assessing the results for patients admitted to such units. This study evaluates the outcomes of a specialist intellectual disability inpatient unit. Gender/age/ethnicity/intellectual disability severity/co-morbid psychiatric/developmental disorders, treatment length and stay data were collected. The health of the nation outcome scales for people with learning disabilities (HoNOS-LD) scores at admission, treatment completion and discharge were recorded. Analysis of these multiple variables and correlations within different patient groups was investigated using various statistical tests. Of 169/176 patients (2010-2018), admission to discharge, HoNOS-LD global and all individual items score decreased significantly, for all patient categories. Treatment completion to discharge duration was significant for the whole cohort. This is the largest study of intellectual disability inpatient outcomes. Discharge from the hospital appears not associated with duration of treatment. Using HoNOS-LD to demonstrate treatment effectiveness is recommended.

Flexible nuclear plants with thermal energy storage and secondary power cycles: Virtual power plant integration in a UK energy system case study

Electricity markets are fast changing because of the increasing penetration of intermittent renewable generation, leading to a growing need for the flexible operation of power plants to provide regulation services to the grid. Previous studies have suggested that conventional power plants (e.g., nuclear) may benefit from the integration of thermal energy storage (TES), as this enables greater flexibility. In conventional Rankine-cycle power plants, steam can be extracted during off-peak periods to charge TES tanks filled with phase-change materials (PCMs); at a later time, when this is required and/or economically favourable, these tanks can feed secondary thermal power plants to generate power, for example, by acting as evaporators of organic Rankine cycle (ORC) plants. This solution offers greater flexibility than TES-only solutions that store thermal energy and then release this back to the base power plant, as it allows both derating and over-generation. The solution is applied here to a specific case study of a 670 MWel nuclear power plant in the UK, which is a typical baseload power plant not intended for flexible operation. It is found a maximum combined power of 822 MWel can be delivered during peak demand, which is 23% higher than the base plant's (nominal) rated power, and a maximum derating of 40%, i.e., down to 406 MWel during off-peak demand. An operational energy management strategy (EMS) is then proposed for optimising the charging of the TES tanks during off-peak demand periods and for controlling the discharging of the tanks for electricity generation during peak-demand periods. An economic analysis is performed to evaluate the potential benefits of this EMS. Profitability in the case study considered here can result when the average peak and off-peak electricity price variations are at least double those that occurred in the UK market in 2019 (with recent data now close to this), and when TES charge/discharge cycles are performed more than once per day with a discharge duration to the ORC plants longer than 2 h. When considering the most recent UK electricity prices in 2021 (to-date), the EMS investment cost for one 1-h charge and 1-h discharge cycle per day is 199 m£ with a total generation of 50 GWh per year and a levelised cost of electricity (LCOE) of 463 £/MWh. The investment cost drops significantly to 48 m£ when discharging for a longer duration of 8 h as the size of the ORC plants decrease. The projected LCOE also decreases to 159 £/MWh when doubling the total generated electricity (100 GWh/year) by employing two 8-h TES charge/discharge cycles per day. Importantly, it is found that the economics of the EMS are determined by a trade-off between longer discharge durations to the ORC plants that minimises their size and cost, and shorter charge/discharge durations that yield the highest spread between off-peak and peak electricity prices.

Short-, Medium-, and Long-Duration Energy Storage in a 100% Renewable Electricity Grid: A UK Case Study

Energy storage will be required over a wide range of discharge durations in future zero-emission grids, from milliseconds to months. No single technology is well suited for the complete range. Using 9 years of UK data, this paper explores how to combine different energy storage technologies to minimize the total cost of electricity (TCoE) in a 100% renewable-based grid. Hydrogen, compressed air energy storage (CAES) and Li-ion batteries are considered short-, medium-, and long-duration energy stores, respectively. This paper analyzes different system configurations to find the one leading to the lowest overall cost. Results suggest that the UK will need a storage capacity of ~66.6 TWh to decarbonize its grid. This figure considers a mix of 85% wind + 15% solar-photovoltaics, and 15% over-generation. The optimum distribution of the storage capacity is: 55.3 TWh in hydrogen, 11.1 TWh in CAES and 168 GWh in Li-ion batteries. More than 60% of all energy emerging from storage comes from medium-duration stores. Based on current costs, the storage capacity required represents an investment of ~£172.6 billion, or approximately 8% of the country’s GDP. With this optimum system configuration, a TCoE of ~75.6 £/MWh is attained.

Anticoagulation in COVID-19

Anticoagulation in COVID-19

Dynamic characteristics and energy analysis of Microwave-induced metal discharge

Small sparks or electric arcs referred to as microwave discharge are generally observed, when the metals are subjected to microwave irradiation. The dynamic characteristics of microwave-induced metal discharge in the work were evaluated by the evolution of discharge intensity, measured using photo-voltage conversion method. An energy analysis method of hydro-thermal exchange was used to measure the generated heat from microwave discharge. The performances of microwave-induced metal discharge were connected to microwave power, metal spices, size and quantity. It was revealed iron exhibited more favorable discharge performance than aluminum and copper. The discharge intensity of iron was 1.66 times and 1.22 times that of aluminum and copper, respectively. The increase of microwave power from 320 W to 480 W led to an enhancement of discharge duration, extending from 5.75 min to 7.25 min. The discharge intensity in the presence of three wires of iron increased by 44.6%, compared to that in the presence of one wire of iron. In spite of an appreciable decrease of discharge intensity with the increase of time, microwave discharge could improve the efficiency from electric energy conversion into heat energy to 48.41%, when utilizing one wire of iron with the length of 4 cm and the diameter of 1 mm at 480 W. The changes of the generated heat with discharge intensity conformed to a stepped attenuation relationship.

A comprehensive investigation on machining of composites by EDM for microfeatures and surface integrity

In electro-discharge machining (EDM), the material removal takes place by precisely controlled sparks that occur between tool and workpiece separated with a spark gap in the presence of a dielectric. Generally, the non-contacting type and less material removal rates are attributed to attain a good surface finish and close dimensional tolerances during an EDM of monolithic metals and alloys. But the dimensional accuracy and surface integrity parameters would considerably affect during EDM of composites due to the existence of more than one material phase constituents. Therefore, the present work aims to study and optimize the performance characteristics under various EDM conditions employed in making rectangular channels on AA6061-B4C composite material. Initially, AA6061-4wt.%B4C composites were fabricated by ultrasonically assisted stir-casting, and the improved properties were obtained from various mechanical characterizations. The EDM experiments were conducted according to the full factorial experimental design. The three levels of input conditions such as discharge Current (I), discharge duration (T On), and discharge idle time (T Off) were considered. The considered output responses are material removal rate (MRR),taper (θ) of the machined channel, tool wear rate (TWR), average surface roughness (R) of the machined surface, and average recast layer thickness (ARLT) of the machined zone. These responses are co-related with multi-objective types in the sense that the MRR has to be maximized with all other responses minimized. Hence, principal component analysis (PCA) coupled with grey relation analysis (GRA) was used for optimization in which the results were normalized, and all the responses were converted into a single response named weighted grey relation grade (WGRG) for each trial. The experimental trial, which had the highest WGRG, was considered as a local optimum. The global optimum parameters were obtained by performing the Taguchi method (TM) (higher-the-better) for the maximization of WGRG. The analysis of variance (ANOVA) was performed to know the contribution of each EDM parameter toward the WGRG. The optimum levels of Current, T On, and T Off were identified as 8 A, 25 µs, and 36 µs, respectively. Results showed that all three input parameters significantly affected the WGRG, and a higher contribution of Current (52.11%) followed by the T On (26.72%) was observed. The interaction between the Current and T Off was found to be greater than other interactions. Taper values were observed to be reduced at the combination of 8 A discharge Current and 25 µs T On. None of the input parameters significantly affected the Ra, except for Current, which showed a slight effect. ARLT values showed an increasing trend of T On from 25 µs to 45 µs but decreased slightly at 65 µs for all Current levels. The moderate Current level 6 A was observed to be favorable in reducing ARLT when compared to low (4 A) and high (8 A) for all Ton values.

Failure Probability Analysis of Levees Affected by Mammal Bioerosion

AbstractMammal bioerosion is an emergent threat to the functionality of levees. In the present paper, the problem of assessing the failure probability of levees affected by mammal bioerosion is addressed. A fully bivariate description of peak flow discharge and flood duration is combined with a deterministic unsteady seepage flow model to obtain a suitable model of variably disturbed levee response to the observed natural variability of floods. Monte Carlo analysis is also implemented to evaluate the epistemic uncertainty connected to the description of the river system. The obtained model is tested with respect to a real‐world levee located along the Secchia River in northern Italy, which underwent a disastrous failure caused by mammal bioerosion in 2014. The convex linear combination of two Archimedean copulas is found to fit the empirical dependence structure between peak flow discharge and flood duration. The reliability of the unsteady seepage flow model is tested against detailed numerical simulations of the seepage occurring through the levee body. A limit state function is obtained by comparing the maximum extent of the seepage front to the distance between the den end and the riverside levee slope, and the corresponding levee safety and failure regions are delimited. Results obtained from the developed model reveal a significant impact of mammal dens located near the levee crest in terms of failure probability and related return period. This impact is consistent with failures observed in the study area.

Calculations of Settings in the Protection and Blocking Circuits of the Power Supply System of Electromagnetic Windings and the Duration of Plasma Discharges in T-15MD Tokamak

Calculations of Settings in the Protection and Blocking Circuits of the Power Supply System of Electromagnetic Windings and the Duration of Plasma Discharges in T-15MD Tokamak

The Hybrid Pulsed Power Circuit Modeled as a Double-Discharge Circuit for Gas Laser Applications

Long pulse gas lasers utilizing double-discharge circuits are different from the single-short pulse gas lasers in that they do not require all of the desired energy to be deposited into the peaking capacitors prior to ignition of the main gap. Instead, the majority of the energy is held in another capacitor that is then discharged in the form of a longer duration discharge pulse output compared with that of single-short pulse lasers. Extended stability of the discharge is typically achieved by igniting the main gap discharge at higher ignition voltages. Several double-discharge circuit topologies exist in the literature. However, each topology has its own disadvantages primarily centered around the components needed and the resulting complexity. In this article we introduce the application of the new hybrid circuit pulsed power topology as a double-discharge circuit with high ignition voltages. The hybrid circuit pulsed power topology was originally published by the authors of this article in their previous publication titled “A New Hybrid Pulsed Power Circuit Topology for Gas Laser Applications.” The advantage of the hybrid circuit as a double-discharge circuit is that it does not require any special device [e.g., semiconductor opening switch (SOS) diode] and can use commonly available components.

Antagonism of the ghrelin receptor type 1a in the rat brain induces status epilepticus in an electrical kindling model of epilepsy.

Studies have shown the anti-seizure properties of the ghrelin hormone in different models of epilepsy. Nevertheless, the role of the endogenous ghrelin is unknown in the electrical kindling model of epilepsy. In this study, we evaluated the effect of the antagonism of the ghrelin receptors in the brain of fully kindled rats. Adult male Wistar rats weighing 300g were used. Animals were stereotaxically implanted with two uni-polar electrodes in the skull surface and a tri-polar electrode in the basolateral amygdala, and a guide cannula in the left lateral ventricle. Animals underwent a rapid kindling protocol. After showing three consecutive stages of five seizures, the animals were considered fully kindled. D-Lys-3-GHRP-6 (1, 50, and 100μg/rat) was injected intracerebroventricularly (i.c.v.) in the kindled animals. Each rat was considered as its control and received a single dose of D-Lys-3-GHRP-6. Seizure parameters including after discharge duration (ADD), seizure stage (SS), stage four latency (S4L), and stage five duration (S5D) were recorded. The paired t test indicated a significant increase in seizure induction. D-Lys-3-GHRP-6 (1μg/rat; i.c.v.) prolonged ADD in the kindled rats, significantly. D-Lys-3-GHRP-6 (50 and 100μg/rat; i.c.v.) induced spontaneous seizures, which led to status epilepticus in the kindled rats. The results indicate that the antagonism of the ghrelin functional receptors prolongs seizures and induces status epilepticus in the kindling model of epilepsy, and propose that the endogenous ghrelin signaling has crucial antiepileptic properties.

The influence of smoking on the frequency and characteristics of complications following large loop excision of the transformation zone (LLETZ)

Purpose: Large loop excision of the transformation zone (LLETZ) is the procedure of choice for treating patients with suspected or confirmed cervical intraepithelial lesions. Since it has been established that smoking impairs wound healing, we wanted to determine if smoking increases the incidence of themost common complications that follow the LLETZ procedure and how it affects their intensity and duration.
 Methods: We included 434 patients that underwent the LLETZ procedure between 1993 and 2015 in the Department of Gynecology and Perinatology, University Medical Centre Maribor. Patients were asked to assess the intensity and duration of abdominal pain, vaginal bleeding and vaginal discharge after the procedure, and to complete a questionnaire on a daily basis. Data obtained from the questionnaires were then analysed.
 Results: The study group consisted of 237 (54.6%) smokers and 197 (45.4%) non-smokers. After the LLETZ procedure, 237 (54.6%) patients noted the occurrence of vaginal discharge, 193 (44.5%) lower abdominal pain, and 181 (41.7%) vaginal bleeding. No significant difference was observed in terms of the incidence of the observed events when comparing smokers and non-smokers. The duration and intensity of vaginal discharge and pain were not significantly different between the two groups. Non-smokers experienced bleeding that was more severe than smokers.
 Conclusions: According to the results of our study, smoking did not increase the incidence of vaginal bleeding, vaginal discharge, and lower abdominal pain following the LLETZ procedure, nor did it crucially influence their duration and intensity.

A fast method to predict the transient, subcritical gas discharge from a pressure vessel

Based on the Bernoulli’s equation a fast and accurate model is developed to predict the transient gas discharge from a pressure vessel. The system is considered adiabatic, isentropic, compressible, and subcritical and the gas is considered ideal. Based on an energy balance, a simplified method is presented to check whether the system can be assumed to be adiabatic. The opening of the vessel should be at least five outlet diameters D2 away from the other walls or corners in order to fulfil the assumption that the flow velocity inside the vessel is negligible. The model is compared with CFD simulations, which are performed with ANSYS CFX©. Furthermore, a new dimensionless number is introduced, which takes into account the gas and vessel properties. In combination with the developed discharge model and a conducted parameter study, a universal correlation for estimating the discharge duration is developed. The application does not require any further knowledge of fluid mechanics, making it a quick estimation tool for everyone. The model is able to calculate isentropic cooling and the resulting transient behaviour with a deviation from the simulation of <12%. The model and the correlation for the dimensionless number are able to capture the discharge behaviour of any gases and vessels that meet the requirements listed above. The correlation is a fast and accurate tool for estimating safety problems in process engineering.

Clustering of Spontaneous Recurrent Seizures in a Mouse Model of Extended Hippocampal Kindling.

Acute repetitive seizures or seizure clusters are common in epileptic patients. Seizure clusters are associated with a high risk of developing status epilepticus and increased morbidity and mortality. Seizure clusters are also recognizable in spontaneous recurrent seizures (SRS) that occur in animal models of epilepsy. The electrical kindling of a limbic structure is a commonly used model of temporal lobe epilepsy. Although classic kindling over the course of a few weeks does not generally induce SRS, extended kindling over the course of a few months can induce SRS in several animal species. SRS in kindled cats often occur in clusters, but the existence of seizure clusters in rodent models of extended kindling remains to be demonstrated. We explored the existence of seizure clusters in mice following extended hippocampal kindling. Adult male mice (C57BL/6) experienced twice daily hippocampal stimulations and underwent continuous 24-hour electroencephalogram (EEG)-video monitoring after ≥80 stimulations. SRS events were recognized by EEG discharges and associated motor seizures. Seizure clusters, defined as ≥4 seizures per cluster and intra-cluster inter-seizure intervals ≤ 120 min, were observed in 19 of the 20 kindled mice. Individual mice showed variable seizure clusters in terms of cluster incidence and circadian-like expression patterns. For clusters consisting of 4–7 seizures and intra-seizure intervals ≤ 20 min, no consistent changes in inter-seizure intervals, EEG discharge duration, or motor seizure severity scores were observed approaching cluster termination. These results suggested that seizure clustering represents a prominent feature of SRS in hippocampal kindled mice. We speculate that, despite experimental limitations and confounding factors, systemic homeostatic mechanisms that have yet to be explored may play an important role in governing the occurrence and termination of seizure clusters.

Parametric study of high-frequency characteristics of plasma synthetic jet actuator

A major issue of plasma synthetic jet actuator (PSJA) is the severe performance deterioration at high working frequency. In this study, experiments and numerical simulation are combined together to investigate the influence of thermal conductivity, throat length (L th) and discharge duration (T d) on the high-frequency characteristics of PSJA. Results show that the variation of the actuator thermal conductivity and discharge duration will not alter the saturation frequency of the actuator, whereas decreasing the throat length results in an increase of the saturation frequency. For a short-duration capacitive discharge of 1.7 μs, a clear shock wave is issued from the orifice, followed by a weak jet. As a comparison, when the discharge duration is increased up to 202.6 μs, a strong jet column is formed and no obvious shock wave can be visualized. Based on numerical simulation results, it becomes clear that the long-duration pulse-DC discharge is able to heat the cavity gas to a much higher temperature (3141 K) than capacitive discharge, greatly improving the conversion efficiency of the arc discharge energy to the internal energy of the cavity gas. In addition, high-speed Schlieren imaging is deployed to study the performance degradation mechanism of PSJA at high working frequency. Monitor of the exit jet grayscale indicates that as long as the saturation frequency is exceeded, the actuator becomes unstable due to insufficient refresh time. The higher the discharge frequency, the more frequently the phenomenon of ‘misfires’ will occur, which explains well the decaying jet total pressure at above saturation frequency.

Low-cost manganese dioxide semi-solid electrode for flow batteries

<h2>Summary</h2> Manganese dioxide is abundant, low-cost, and has the potential to be utilized as a semi-solid electrode for long-duration energy storage technologies such as flow batteries. However, the more stringent pumping requirements of semi-solid electrodes compared to the electrolytes of all-liquid flow battery might limit their techno-economic feasibility. Here, we developed a rechargeable MnO₂ semi-solid electrode, performed electrochemical and rheological characterizations, and bottom-up techno-economic analysis of the Zn-MnO₂ semi-solid flow battery (SSFB) system. The high power needed for pumping (ranging from 8% to 50% of the power output) leads to a system with high cost of power. Using our experimental results, we suggest strategies to minimize the pumping power requirement for Zn-MnO₂ SSFB. As a result of the low cost of its chemical constituents, we show that a Zn-MnO₂ SSFB can be cheaper than Li-ion and vanadium redox flow battery solutions for long discharge durations (e.g., >24 h per cycle).