Slow Propagation Research Articles

Effect of pH and Al Cations on Chromate Inhibition of Galvanic-Induced Corrosion of AA7050-T7451 Macro-Coupled to 316SS

The performance of chromate in protecting AA7050-T7451 coupled to 316SS in simulated fastener environments, including those representative of the boldly exposed surfaces and downhole conditions, was investigated utilizing a number of electrochemical and surface characterization techniques. The influence of pH and Al3+ on the galvanic coupling behavior and damage evolution on AA7050 as a function of chromate concentration were assessed. The degree of chromate inhibition was observed to decrease as pH decreased, owing to chromate speciation and reduced capacity to suppress the hydrogen evolution reaction (HER) compared to the oxygen reduction reaction (ORR). The addition of 0.1 M Al3+ significantly increased HER kinetics and produced a large buffer effect which overwhelmed the ability of chromate to slow damage propagation on AA7050. Assessment of cathodes indicated that Cu was more important than 316SS in driving damage initiation, but less active than 316SS in supporting high-rate damage propagation in simulated crevice environments. The implications of this study for actual bimetallic systems are discussed.

Simulation model for energy consumption and acoustic underwater communication of autonomous underwater vehicles

Recently, cooperative autonomous underwater vehicles (AUVs) have been deployed in application areas such as surveillance and protection of maritime infrastructures for inspection and monitoring purposes. These cooperative methodologies require wireless transmission of data between the different AUVs operating in the underwater environment. Communication over ranges exceeding 100 m exclusively relies on underwater acoustic communication. However, the propagating acoustic waves suffer from several challenges due to the presence of path loss, multi-path propagation, the slow and variant propagation speed, background noise, and Doppler distortion. Since the power supply of the AUVs is limited, communication must be very energy efficient and energy constraints have to be known to be able to plan the mission of AUVs. Due to the difficulties of real experiments, the modeling and simulation of the energy consumption and underwater acoustic communication play an essential role in studying and developing these systems. We provide a modular simulation model for the energy consumption and acoustic underwater communication of AUVs implemented in the network simulator OMNeT++ using the INET framework. More specifically, we extend several INET modules in such a way as to reflect the characteristics of AUVs and underwater communication. We study and analyze the AUVs’ energy consumption and dependence of the message quality on different properties such as those mentioned above.

Performance Degradation of Subsea Shield Tunnel Segment Accounting for Concrete Strength Loss and Steel Bar Corrosion

Subsea shield tunnels usually serve in a typical corrosive marine environment. Under the action of chloride penetration and carbonization, tunnel lining segments are often damaged because of concrete strength loss and steel bar corrosion induced concrete cracking during their service life, which seriously degrades the service performance of the tunnels. A systematical experimental and numerical investigation into the performance degradation of subsea shield tunnel segments accounting for concrete strength loss and steel bar corrosion is presented in this paper. The study demonstrates that chloride penetration decreases the peak strength and elastic modulus of the segment concrete by 42% and 46.1%, respectively. The average of the ratio of dissipated energy to the total energy of dry concrete is much smaller than that of water saturated concrete and chlorine solution saturated concrete, and chloride penetration reduces the energy storage capacity of concrete, and the ability to resist damage is weakened. When steel bars corrode for 120 days, the outer cracks continue to extend, and the concrete around the inner steel bars just begin to crack initiation; when corrode for 20 years, the length of the inner cracks gradually exceeds that of the outer cracks, and the inner cracks initiating from different steel bars coalesce with each other and form a continuous failure surface, causing great serious damage to the segment. Due to the difference in concrete strength, for the outer layer, the evolution processes of steel bar corrosion-induced cracks show the characteristics of early initiation, slow propagation, and late coalescence, and those for the inner layer have the characteristics of late initiation, rapid propagation, and early coalescence. During the whole process the propagation speed of the inner and outer cracks appears to be fast first and then slow. Moreover, the study also illustrates that the final state of segment performance degradation after crack coalescence presents the characteristics of whole lamellar exfoliation of the concrete cover.

Observation of Stark many-body localization without disorder.

Thermalization is a ubiquitous process of statistical physics, in which a physical system reaches an equilibrium state that is defined by a few global properties such as temperature. Even in isolated quantum many-body systems, limited to reversible dynamics, thermalization typically prevails1. However, in these systems, there is another possibility: many-body localization (MBL) can result in preservation of a non-thermal state2,3. While disorder has long been considered an essential ingredient for this phenomenon, recent theoretical work has suggested that a quantum many-body system with a spatially increasing field-but no disorder-can also exhibit MBL4, resulting in 'Stark MBL'5. Here we realize Stark MBL in a trapped-ion quantum simulator and demonstrate its key properties: halting of thermalization and slow propagation of correlations. Tailoring the interactions between ionic spins in an effective field gradient, we directly observe their microscopic equilibration for a variety of initial states, and we apply single-site control to measure correlations between separate regions of the spin chain. Furthermore, by engineering a varying gradient, we create a disorder-free system with coexisting long-lived thermalized and non-thermal regions. The results demonstrate the unexpected generality of MBL, with implications about the fundamental requirements for thermalization and with potential uses in engineering long-lived non-equilibrium quantum matter.

Statistical Relationship Between the Decrease of Major Seismicity and Drought in Southern California Since 1900

The seismicity in Southern California significantly decreased over the last decades. The decrease went in parallel with the reduction of meteoric groundwater recharge, which is a well-known factor capable of affecting seismicity. In this work the existence of a systematic statistical relationship was investigated by comparing the time density of Mw ≥ 5.7 earthquakes since 1900 with the time series of the Palmer Drought Severity Index (PDSI), an indicator of soil moisture roughly correlated with groundwater recharge. Given the non-stationarity of the two signals, the formal comparison was performed using both binomial logistic regression and cointegration testing. The analysis showed a significant statistical relationship, with peaks of seismicity 8 years behind those of PDSI. This finding suggests the hypothesis that groundwater recharge might affect earthquakes at a multi-year time scale. Proving this theory requires accurate measures and hydrogeological modeling, which is behind the scope of this work. Nonetheless, according to previous studies, the observed time lag might be explained by the slow propagation of pore pressure from the surface to the seismogenic volume. The ongoing trend towards an arid climate, made more evident by the recent severe droughts, might have contributed to the earthquake reduction of the last decades. The connection is particularly evident in the Salton Trough, with possible implications for the interpretation of its paleoseismicity.

Dilatancy Toughening of Shear Cracks and Implications for Slow Rupture Propagation

AbstractDilatancy associated with fault slip produces a transient pore pressure drop which increases frictional strength. This effect is analyzed in a steadily propagating rupture model that includes frictional weakening, slip‐dependent fault dilation and fluid flow. Dilatancy is shown to increase the stress intensity factor required to propagate the rupture tip. With increasing rupture speed, an undrained (strengthened) region develops near the tip and extends beyond the frictionally weakened zone. Away from the undrained region, pore fluid diffusion gradually recharges the fault and strength returns to the drained, weakened value. For sufficiently large rupture dimensions, the dilation‐induced strength increase near the tip is equivalent to an increase in toughness that is proportional to the square root of the rupture speed. In general, dilation has the effect of increasing the stress required for rupture growth by decreasing the stress drop along the crack. Thermal pressurization has the potential to compensate for the dilatant strengthening effect, at the expense of an increased heating rate, which might lead to premature frictional melting. Using reasonable laboratory parameters, the dilatancy‐toughening effect leads to rupture dynamics that is quantitatively consistent with the dynamics of observed slow slip events in subduction zones.

Effect of longitudinal epsilon-near-zero regime in dynamics of ultrashort laser pulses in hyperbolic metamaterials

Optical properties of hyperbolic metamaterials (HMMs) are in stark contrast to properties of ordinary media that fuels interest to various applications of HMMs in photonics. Special attention is attributed to the epsilon-near zero regime (ENZ) of HMMs that is the spectral point in which real part of the permittivity of the HMM becomes zero. This is accompanied by the effects of field enhancement having far-reaching applications. Here we focus on the experimental and theoretical investigation of the propagation of an ultrashort laser pulse through the silver nanorod-based HMM slab in the spectral range over the ENZ. We revealed pronounced resonant change of the pulse delay in HMMs and the transition between the superluminal and slow pulse propagation at the ENZ spectral point. Observed dynamical phenomena are confirmed theoretically and attributed to unusual case when the spectral half of an ultrashort pulse has elliptical dispersion and another has the hyperbolic one. Special attention is payed to the propagation of chirped laser pulses in the HMMs.

Coherent Surface Plasmon Hole Burning via Spontaneously Generated Coherence.

Surface plasmon (SP)—induced spectral hole burning (SHB) at the silver-dielectric interface is investigated theoretically. We notice a typical lamb dip at a selective frequency, which abruptly reduces the absorption spectrum of the surface plasmons polaritons (SPP). Introducing the spontaneous generated coherence (SGC) in the atomic medium, the slope of dispersion becomes normal. Additionally, slow SPP propagation is also noticed at the interface. The spectral hole burning dip is enhanced with the SGC effect and can be modified and controlled with the frequency and intensity of the driving fields. The SPP propagation length at the hole-burning region is greatly enhanced under the effect of SGC. A propagation length of the order of 600 µm is achieved for the modes, which is a remarkable result. The enhancement of plasmon hole burning under SGC will find significant applications in sensing technology, optical communication, optical tweezers and nano-photonics.

Development of a fracture-mechanics based fatigue testing method for epoxy/electrical steel laminates with thin adhesive layer

A fatigue fracture mechanics method was developed, implemented and used to characterize the crack kinetics of laminated electrical steel. Tests were carried out on double cantilever beam specimen based on electrical steel sheets and an epoxy adhesive layer with a thickness of just 10 µm. Two different crack length measurement methods based on optical measurement or compliance calculation were evaluated. As validation method specimens with different artificial initial crack length were used. The accuracy is limited to thin and stiff adhesives ensuring a small plastic zone size compared to the crack length. The accuracy of the crack length evaluation methods was higher for the compliance based approach meeting standard specifications at low to intermediate crack length values. The compliance based method was applied to investigate a specimen series varying the pre-curing temperature of the epoxy adhesive systematically. The fatigue tests were performed at ambient condition and 60 °C. At ambient temperature, laminates based on coated electrical steel pre-cured at low to intermediate temperatures revealed rather slow crack propagation rates in comparison to laminates made from coated steel pre-cured at 250 °C. The differences in the stable crack propagation rate of the investigated laminates at ambient conditions were up to two orders of magnitude higher. At 60 °C, the worst performance was also obtained for laminates based on coated steel sheets pre-cured at 250 °C. The failure mode was similar for laminates tested at 23 and 60 °C. While interfacial failure was ascertained for laminates based on coated steel sheets pre-cured at 190 and 250 °C, the better performing laminates made from sheets with epoxy coating pre-cured at 210 or 230 °C exhibited mainly cohesive failure. Hence, adequate pre-curing conditions are of utmost importance for the crack kinetics of adhesively bonded electrical steel.

Numerical investigation on combustion processes of an aircraft piston engine fueled with aviation kerosene and gasoline

Replacing gasoline with aviation kerosene for spark-ignition (SI) piston engines applied for aircrafts can get better security and easier logistics, however, this action cannot proceed smoothly by serious knocking combustion. In this study, the in-cylinder combustion for gasoline and aviation kerosene are investigated through computed-fluid-dynamics (CFD) to analyze combustion characteristics, and try to use pre-chamber technology to improve combustion issues.All CFD results demonstrate in-cylinder combustion differences effectively: All injected aviation kerosene cannot be completely evaporated, leading to non-uniformed unburned mixture and slow flame propagation. Some odd test phenomena are caused by unevaporated kerosene. The slower turbulence flame speed, worse equivalence ratio, higher local temperature and lower spontaneous combustion temperature lead to mixture auto-ignition and knocking combustion eventually. After adding a passive pre-chamber, the mixture distribution near spark plugs is more reasonable, higher turbulence kinetic energy (TKE) inside pre-chamber accelerates burning process, the ignition delay period is reduced by about 21.6%. The pre-chamber increases main-chamber's TKE, the whole combustion process is shortened by about 9%, the pre-flame reaction of unburned mixture near cylinder is shortened, contributing to suppress knocking combustion effectively. The passive pre-chamber technology is of great significance to the popularization and application for SI aircraft piston engine fueled with aviation kerosene.

Source Imaging With a Multi‐Array Local Back‐Projection and Its Application to the 2019Mw6.4 andMw7.1 Ridgecrest Earthquakes

AbstractThis study aims to improve the multi‐array local back‐projection (MLBP) approach and to apply it to the 2019Mw6.4 andMw7.1 Ridgecrest, California earthquakes to resolve more details about their kinematic process, with the dense seismic network in California. Compared with teleseismic BPs, seismic array processing with stations located at local to regional distances images earthquake rupture process more quickly with higher resolution. To increase the objectivity of stations selection criteria and to be prepared for future real‐time BP implementations, we improve MLBP with an automatic procedure to group stations based on waveform coherence. We also apply empirical aftershock calibrations to account for the 3D path effect. Our MLBP highlights the rupture complexity in a multi‐fault system. TheMw6.4 quake initiates on a 5‐km‐long NW‐trending segment, then ruptures the primary SW‐trending fault at the speed of ∼1.3 km/s. TheMw7.1 quake ruptures bilaterally for 10 and 22 km, on the NW and SE portion of the fault, respectively, at the speed of 1–1.6 km/s. The rupture paths agree with aftershock distributions and surface rupture estimated from satellite imagery. The slow rupture propagation may be driven by the low structural maturity of the fault. This case study demonstrates the effectiveness of MLBP for earthquake source imaging and rapid hazard assessment.

Visualization study on lean combustion characteristics of the premixed methanol by the jet ignition of an ignition chamber

As an important low-carbon fuel, methanol has great potential in reducing CO2 emissions and low-temperature combustion. Meanwhile, the lean operation of methanol can reduce fuel consumption and NOx emission. However, with high latent heat of vaporization, the methanol was not easy to be ignited, especial for lean conditions. To improve the ignition energy and burning quality of the lean premixed methanol, the ignition chamber was used to produce jet flow to enhance the ignition and improve flame propagation speed under the condition of lean premixed methanol. Moreover, methanol is used in both ignition chamber and main chamber. Visualization experiment was applied by shadowgraph method to investigate the jet flow, ignition, flame propagation, and burning processes. To improve the lean burning quality of the premixed methanol, the channel diameter between the ignition chamber and main chamber, and equivalent ratio in the main chamber were selected to study the ignition and combustion characteristics. The ultra-lean premixed methanol combustion was also investigated. With a proper channel diameter, the jet flow speed was quicken with a decreased channel diameter or with lean premixed methanol. The peak pressure and pressure rise in the main chamber were also decreased with a lower equivalent ratio due to the slow jet ignition flame propagation speed under the lean mixture. For the exploratory research of the lean flammability limit of the premixed methanol (ϕ = 0.5–0.35), the ignition delay was changed so long that a misfire phenomenon was found under the equivalent ratio of 0.4, and the equivalent ratio of 0.45 was found to be proper for lean burning limit of the premixed methanol.

Ca2+ transients in ICC-MY define the basis for the dominance of the corpus in gastric pacemaking

Myenteric interstitial cells of Cajal (ICC-MY) generate and actively propagate electrical slow waves in the stomach. Slow wave generation and propagation are altered in gastric motor disorders, such as gastroparesis, and the mechanism for the gradient in slow wave frequency that facilitates proximal to distal propagation of slow waves and normal gastric peristalsis is poorly understood. Slow waves depend upon Ca2+-activated Cl− channels (encoded by Ano1). We characterized Ca2+ signaling in ICC-MY in situ using mice engineered to have cell-specific expression of GCaMP6f in ICC. Ca2+ signaling differed in ICC-MY in corpus and antrum. Localized Ca2+ transients were generated from multiple firing sites and were organized into Ca2+ transient clusters (CTCs). Ca2+ transient refractory periods occurred upon cessation of CTCs, but a relatively higher frequency of Ca2+ transients persisted during the inter-CTC interval in corpus than in antrum ICC-MY. The onset of Ca2+ transients after the refractory period was associated with initiation of the next CTC. Thus, CTCs were initiated at higher frequencies in corpus than in antrum ICC-MY. Initiation and propagation of CTCs (and electrical slow waves) depends upon T-type Ca2+ channels, and durations of CTCs relied upon L-type Ca2+ channels. The durations of CTCs mirrored the durations of slow waves. CTCs and Ca2+ transients between CTCs resulted from release of Ca2+ from intracellular stores and were maintained, in part, by store-operated Ca2+ entry. Our data suggest that Ca2+ release and activation of Ano1 channels both initiate and contribute to the plateau phase of slow waves.

Green's Function Solutions of One- and Two-Dimensional Dual-Phase-Lag Laser Heating Problems in Nano/Microstructures

Abstract Lasers and laser heating have a wide variety of applications such as spectroscopy, laser welding, laser cutting, and even biological applications like tumor irradiation and surgery. Theoretical modeling of laser heating has proven to be quite difficult, and classical heating equations have shown to be inaccurate due to the large temperature gradients created by the laser heating. Furthermore, the commonly used Fourier's Law assumed the speed for a thermal wave to propagate as infinite; this is unrealistic in any medium and especially in domains with slow propagation speeds such as biological media and in fast nano/microscale heating applications. This study helps fill some of the gaps in accurate model of laser heating by presenting unique 1D and 2D models of the analytically solved Dual-Phase-Lag heating equations which can much more accurately describe the temperature of such interactions in both the temporal and spatial domains.

Experimental Study on the Characteristics of Adsorbed Gas and Gas Production in Shale Formations

Adsorbed gas and free gas both exist in shale reservoirs simultaneously due to the unique nanoscale pore structure, resulting in the complex flow mechanism of gas in the reservoir during the development process. The dynamic performance analysis of shale reservoirs has mostly been conducted by the numerical simulation and theoretical model, while the physical simulation method for relevant research is seen rarely in the literature. Thus, in this paper, an experiment system was designed to simulate the degraded development experiments of shale, coal, and tight sandstone to reveal the output law of gas in different occurrence states of shale reservoirs and clarify the pressure propagation rules of different reservoirs, and then, adsorption gas and free gas production laws were studied by theoretical models. Research indicated the following: (1) The gas occurrence state is the main factor that causes the difference of the pressure drop rate and gas production law of shale, coal, and tight sandstone. During the early stage of the development of shale gas, the free gas is mainly produced; the final contribution of free gas production can reach more than 90%. (2) The static desorption and dynamic experiments confirm that the critical desorption pressure of adsorbed gas is generally between 12 and 15 MPa. When the gas reservoir pressure is lower than the critical desorption pressure in shale and coal formation, desorption occurs. Due to the slow propagation of shale matrix pressure, desorption of adsorbed gas occurs mainly in the low-pressure region close to the fracture surface. (3) The material balance theory of closed gas reservoirs and the one-dimensional flow model of shale gas have subsequently validated the production performance law of adsorbed gas and free gas by the physical simulation. Therefore, in the practical development of shale gas reservoirs, it is recommended to shorten the matrix supply distance, reduce the pressure in the fracture, increase the effective pressure gradient, and enhance the potential utilization of adsorbed gas as soon as possible to increase the ultimate recovery. The findings of this study can help for a better understanding of the shale reservoir utilization law so as to provide a reference for production optimization and development plan formulation of the shale gas reservoirs.

Cardiac Toxicity of Cadmium Involves Complex Interactions Among Multiple Ion Currents in Rainbow Trout (Oncorhynchus mykiss) Ventricular Myocytes.

Cadmium (Cd2+ ) is cardiotoxic to fish, but its effect on the electrical excitability of cardiac myocytes is largely unknown. To this end, we used the whole-cell patch-clamp method to investigate the effects of Cd2+ on ventricular action potentials (APs) and major ion currents in rainbow trout (Oncorhynchus mykiss) ventricular myocytes. Trout were acclimated to +4 °C, and APs were measured at the acclimated temperature and elevated temperature (+18 °C). Cd2+ (10, 20, and 100 µM) altered the shape of the ventricular AP in a complex manner. The early plateau fell to less positive membrane voltages, and the total duration of AP prolonged. These effects were obvious at both +4 °C and +18 °C. The depression of the early plateau is due to the strong Cd2+ -induced inhibition of the L-type calcium (Ca2+ ) current (ICaL ), whereas the prolongation of the AP is an indirect consequence of the ICaL inhibition: at low voltages of the early plateau, the delayed rectifier potassium (K+ ) current (IKr ) remains small, delaying repolarization of AP. Cd2+ reduced the density and slowed the kinetics of the Na+ current (INa ) but left the inward rectifier K+ current (IK1 ) intact. These altered cellular and molecular functions can explain several Cd2+ -induced changes in impulse conduction of the fish heart, for example, slowed propagation of the AP in atrial and ventricular myocardia (inhibition of INa ), delayed relaxation of the ventricle (prolongation of ventricular AP duration), bradycardia, and atrioventricular block (inhibition of ICaL ). These findings indicate that the cardiotoxicity of Cd2+ in fish involves multiple ion currents that are directly and indirectly altered by Cd2+ . Through these mechanisms, Cd2+ may trigger cardiac arrhythmias and impair myocardial contraction. Elevated temperature (+18 °C) slightly increases Cd2+ toxicity in trout ventricular myocytes. Environ Toxicol Chem 2021;40:2874-2885. © 2021 SETAC.

Quench Detection and Protection for High-Temperature Superconductor Accelerator Magnets

High-temperature superconductors (HTS) are being increasingly used for magnet applications. One of the known challenges of practical conductors made with high-temperature superconductor materials is a slow normal zone propagation velocity resulting from a large superconducting temperature margin in combination with a higher heat capacity compared to conventional low-temperature superconductors (LTS). As a result, traditional voltage-based quench detection schemes may be ineffective for detecting normal zone formation in superconducting accelerator magnet windings. A developing hot spot may reach high temperatures and destroy the conductor before a practically measurable resistive voltage is detected. The present paper discusses various approaches to mitigating this problem, specifically focusing on recently developed non-voltage techniques for quench detection.

Impact of flash boiling multiple injections timing on the combustion and thermal efficiency of a gasoline direct injection engine under lean-burn

Lean burn mode of direct injection spark ignition engines (DISI) can improve the engine's thermal efficiency. However, it showed slow flame propagation and combustion instabilities which are strongly related to mixture distribution. Multiple injections can improve control over in-cylinder charge distribution and consequently on burn mode. Additionally, multiple injections can reduce spray impingement and enhance the turbulence in the compression stroke, particularly with late injection, but the time is not enough for spray evaporation. Fuel injection under flash boiling conditions boosts fuel vaporization and spray-airflow interaction of the late injections. This study investigates the effect of flash boiling multiple injections on the combustion of lean gasoline/air mixture in an optical DISI engine. This work uses Mie scattering, CFD, high-speed imaging, and flame images postprocessing model to investigate spray characteristics, spray-airflow interaction, flame propagation, and CH* digital intensity. The results reveal that flash boiling multiple injections has significantly mitigated the liquid spray intensity indicates the elevated rate of vaporization with reduced spray impingement and better interaction with the tumble flow compared to the subcooled single injection. The optimal engine performance and combustion were achieved when the second injection and highest tumble ratio point were timely synchronized, for example, 260°bTDC at 800 rpm and 280°bTDC at 1500 rpm. Thus, flash boiling multiple injections can effectively enhance the thermal efficiency by 54.65% and 11%, respectivly. The CH* digital intensity and heat release showed that flash boiling multiple injections could effectively improve the lean-burn operation of the DISI engine.

The hodograph equation for slow and fast anisotropic interface propagation.

Using the model of fast phase transitions and previously reported equation of the Gibbs–Thomson-type, we develop an equation for the anisotropic interface motion of the Herring–Gibbs–Thomson-type. The derived equation takes the form of a hodograph equation and in its particular case describes motion by mean interface curvature, the relationship ‘velocity—Gibbs free energy’, Klein–Gordon and Born–Infeld equations related to the anisotropic propagation of various interfaces. Comparison of the present model predictions with the molecular-dynamics simulation data on nickel crystal growth (obtained by Jeffrey J. Hoyt et al. and published in Acta Mater. 47 (1999) 3181) confirms the validity of the derived hodograph equation as applicable to the slow and fast modes of interface propagation.This article is part of the theme issue ‘Transport phenomena in complex systems (part 1)’.

Blockchain and artificial intelligence for 5G‐enabled Internet of Things: Challenges, opportunities, and solutions

AbstractInternet of Things (IoT) has revolutionized the digital world by connecting billions of electronic devices over the internet. IoT devices play an essential role in the modern era when conventional devices become more autonomous and smart. On the one hand, high‐speed data transfer is a major issue where the 5G‐enabled environment plays an important role. On the other hand, these IoT devices transfer the data by using protocols based on centralized architecture and may cause several security issues for the data. Merging artificial intelligence to 5G wireless systems solves several issues such as autonomous robots, self‐driving vehicles, virtual reality, and engender security problems. Building trust among the network users without trusting third party authorities is the system's primary concern. Blockchain emerged as a key technology based on a distributed ledger to maintain the network's event logs. Blockchain provides a secure, decentralized, and trustless environment for IoT devices. However, integrating IoT and blockchain also has several challenges; for example, major challenge is low throughput. Currently, the ethereum blockchain network can process approximately 12 to 15 transactions per second, while IoT devices require relatively higher throughput. Therefore, blockchains are incapable of providing functionality for a 5G‐enabled IoT based network. The limiting factor of throughput in the blockchain is their network. The slow propagation of transactions and blocks in the P2P network does not allow miners and verifiers to fastly mine and verify new blocks, respectively. Therefore, network scalability is the major issue of IoT based blockchains. In this work, we solved the network scalability issue using blockchain distributed network while to increase the throughput of blockchain, this article uses the Raft consensus algorithm. Another most important issue with IoT networks is privacy. Unfortunately, the blockchain distributed ledgers are public and sensitive information is available on the network for everyone are private, but in such cases, third party editing is not possible without revealing the original contents. To solve privacy issues, we used zkLedger as a solution that is based on zero knowledge‐based cryptography.