Increasing Delay Time Research Articles

Experimental study on mercury content in flue gas of coal-fired units based on laser-induced breakdown spectroscopy

Accurate measurement of trace heavy metal mercury (Hg) in flue gas of coal-fired units is great significance for ecological and environmental protection. Mixed gas was used to simulate the actual flue gas of a power plant in this study. A laser-induced breakdown spectroscopy (LIBS) system for Hg measurement in mixed gas was built to study the effect of mixed gas pressure, Hg concentration in mixed gas and delay time on Hg measurement. The experimental results show that the appropriate low mixed gas pressure can obtain high Hg signal intensity and signal to noise ratio. The Hg signal intensity and signal to noise ratio increased with the increase of Hg concentration in mixed gas. The Hg signal intensity and signal to noise ratio decreased with the increase in delay time. According to the above results, the optimized measurement conditions can be determined. Different Hg concentrations in mixed gas were quantitatively analyzed by the internal standard method and traditional calibration method respectively. The relative error of prediction of the test sample obtained by the internal standard method was within 11.11%. The relative error of prediction of the traditional calibration method was less than 14.54%. This proved that the internal standard method can improve the accuracy of quantitative analysis of Hg concentration in flue gas using LIBS.

Explosive Preparation of Rocks in Career with Well Retarders

The article deals with improving the quality of fragmentation of rocks by blast due to increase in intervals of delay. It shows the change in understanding of the mechanism of rock destruction under the influence of blast loads in recent decades. The mechanical effect of blast loads is manifested not only in crushing of rocks, but also in the weakening of their strength in remote distances from a charge. In the area of the blast wave compressive and tensile loads lead to the development of existing micro-defects and micro-cracks. The rock mass changes its strength properties, passes into a new state, called pre-destruction. The increase of delay time between blasts of charges increases the overall time of the blast, contributes to the merging of cracks and a gradual decrease in the sizes of the structural elements of the rocks. Impact on rocks alternating loads up to 20 or more times allows to increase the distance between the charges.

On the Propagation of Lightning-Radiated Electromagnetic Fields Across a Mountain

In this article, the effect of a mountain located on the propagation path of lightning-radiated electromagnetic fields was systematically studied by using the two-dimensional finite-difference time-domain method (2-D FDTD), considering the influence of the return stroke (RS) type, the ground conductivity, the mountain height and the width at the base, its position, and the observation distance. The field peak reduction and the wave arrival time delay, compared with those for the perfectly conducting flat ground, are analyzed in detail. The results show that, with an increase in the mountain height, the field peak reduces and the wave arrival time delay increases. The wave arrival time is insensitive to the change of mountain widths. The terrain envelope method can be used to estimate the additional time delay introduced by the mountain. For a mountain lower than 1 km or so, the additional attenuation effect of the mountain on the field peak can be ignored for most practical purposes. Furthermore, the propagation process of the lightning-radiated electromagnetic wave over the mountain was studied by analyzing the spatiotemporal evolution characteristics of the field. The analysis shows that the electromagnetic wave propagates to the back of the mountain through the diffraction process at the mountaintop.

Ventricular fibrillation waveform characteristics in out-of-hospital cardiac arrest and cardiovascular medication use

BackgroundVentricular fibrillation (VF) waveform analyses are considered a reliable proxy for OHCA characteristics in out-of-hospital cardiac arrest (OHCA), but patient characteristics such as cardiovascular medication use might also be associated with changes in VF waveform measures. ObjectivesTo assess associations between cardiovascular medication use and amplitude spectrum area (AMSA) of VF, while correcting for the presence of cardiovascular disease (CVD), CVD risk factors, and OHCA characteristics. MethodsWe included 990 VF patients from an OHCA registry in the Netherlands, with available information on medical history and cardiovascular medication use. Associations between cardiovascular medication use and AMSA were tested in a multivariate linear regression model, adjusting for CVD, CVD risk factors, and OHCA characteristics. Model performance was shown using R-square and R-change. We also calculated whether medication use was associated with faster dissolution of AMSA to lower values with increasing time delay. ResultsIn the multivariate analysis, when corrected for CVD, CVD risk factors and OHCA characteristics, only potassium-sparing agents were associated with a lower AMSA when compared to patients using other cardiovascular medications (OR 0.46 [95% CI 0.10–0.81]; P < 0.012). The decrease in AMSA with increasing EMS-call-to-ECG delay was the same for patients with and without cardiovascular medication use (all P > 0.05). Only a small part of the variance in AMSA could be explained by medication use (R-square 0.003– 0.026). Adding OHCA characteristics to the model resulted in the largest R square change (0.09–0.15). ConclusionsIt is unlikely that there is a strong and clinically relevant independent pharmacologic effect of cardiovascular medication use on AMSA. In OHCA, AMSA might be used as patient management tool without considering cardiovascular medication use.

Advanced event‐base exhibition management mobile applications social networks using fuzzy reasoning‐based routing cum forwarding algorithm

Abstract5G is the fifth‐generation mobile innovation that not only just expands the downloading and transferring speeds over the mobile networks, however, it additionally decreases the latency, which is the time taken by a system to respond, builds energy proficiency, and offers increasingly stable system associations. It has been seen that the present Internet structure is not appropriate for current and developing traffic requests. Many content distributions advances such as content Delivery Networks and shared frameworks have developed to allow content access by name as instead of server area or address. In addition, to respond to the expanding volumes of traffic for such applications as video on demand and distributed cloud computing, numerous works have been attempted to empower reserving, content replication, and preparing inside the system. Such advancements are exceptionally dependent on the distribution channel and execute as an overlay on the current Internet structure, which results in various inefficient result aspects. In recent years, it is highly difficult to develop a routing cum forwarding algorithm in order to overcome the existing problems, the introduced fuzzy reasoning‐based routing cum forwarding algorithm. In this fuzzy method, the mobile devices evaluate the transmission priority and decide the transmission decision too. On comparing to the existing routing algorithms, the fuzzy concept should have reduced energy consumption, increased time delay, and high transmission efficiency and the above parametric results are verified by the fact of the fuzzy algorithm.

Impact of conflict resolution parameters on combined alternate-directions lane assignment and reservation-based intersection control

We recently proposed a concept, called Combined Alternate-Direction Lane Assignment and Reservation-based Intersection Control (CADLARIC), for organizing directionally unrestricted traffic flows in automated vehicle environment. The conflicts between through movements are handled by a reservation-based algorithm while the turning conflicts at the intersections are avoided altogether. This paper extends this research by analyzing the impacts that CADLARIC’s parameters, used to control the conflict-resolution processes, have on the efficiency and surrogate safety indicators. The investigated parameters include: (i) buffer time in cell’s reservation schedule; (ii) allowed speed to cross the reserved cell; (iii) distance from intersection from which a vehicle can make reservation, and (iv) duration of the lane-change process. For most of the investigated parameters, the numerical results show that less efficient operations lead not just to an increase in delay time and number of stops but also increase number of conflicting situations, because of vehicular queues formed within the intersection zone.

Conflict-free en-route operations with horizontal resolution manoeuvers using a heuristic algorithm

ABSTRACTAircraft conflict resolution is an important part of air traffic control operations. This study presents a mixed integer linear programming model (MILP) using a space discretisation technique to deal with aircraft conflict resolutions in en-route flight operations. The purpose of space discretisation is to concentrate on only the significant points of the airspace. The model integrates the multi entry point approach with an airspeed adjustment technique in the horizontal plane. The model aims to generate conflict-free trajectories while minimising the total changes in entry points and airspeed values. A new heuristic algorithm was developed due to the complexity of the problem. The computational results demonstrated that the proposed approach resolved aircraft conflicts for 450 different traffic scenarios in less than a minute. Considerable fuel savings were achieved with no significant increase in delay or flight time compared to conventional vectoring techniques in a fixed entry point airspace structure.

Numerical Study of the Effect of Pre-Pulse on THz Generation by Two-Color Laser-Induced Microplasma

In this article, a photocurrent model is used to investigate terahertz (THz) generation in two-color laser-induced preformed air microplasma. Comprehensive 2-D numerical particle-in-cell (PIC) simulations are done to understand the most important mechanism of THz generation in laser-induced microplasma. The model used in this simulation involves both ionization current (transverse current) and ponderomotive forces (longitudinal current). The laser pulse is divided into two types, a pre-pulse and a delayed main pulse, which propagate in a parallel direction (i.e., collinear configuration). Our simulation shows that the THz amplitude significantly reduces in the presence of a pre-pulse compared to the case with no pre-pulse. Also, in the study of how a time delay between the pre-pulse and the main pulse affects THz radiation, it has been demonstrated that THz radiation decreases as the time delay increases. Finally, through the investigation of the main pulse and pre-pulse intensity ratio, it emerged that the THz amplitude decreased with an increase in that ratio. The results point to the major role of tunneling ionization in THz generation via laser-induced microplasma.

Experimental study on ignition and combustion of coal-rice husk blends pellets in air and oxy-fuel conditions

The ignition and combustion characteristics of anthracite-rice husk (AC-RH) and bituminous coal-rice husk (BC-RH) pellets were investigated in a vertical heating tube furnace under different experimental condition, for gas temperature (873 K–1073 K) and under air and different oxygen concentration (21–70%) in CO2/O2 atmosphere. The investigation of the ignition and combustion characteristics focused on ignition mechanism, ignition delay, ignition temperature and combustion process. AC-RH pellets had two ignition mechanism in CO2/O2 atmosphere: homogeneous ignition of volatile and heterogeneous ignition of char. Heterogeneous ignition region decreased while homogeneous ignition increased as rice husk blending ratio increased in oxygen concentration-gas temperature plane. Only homogeneous ignition was observed when rice husk blending ratio was 30%. As for BC-RH pellets, only homogeneous ignition occurred in all experimental conditions. The effect of the rice husk blending on the anthracite was more pronounced than the bituminous coal for ignition mechanism. As oxygen concentration increased, a significant reduction in ignition delay and ignition temperature was observed at low rice husk blending ratio and low gas temperature. but at 1073 K, high oxidizer temperature weakened the effect of biomass blending and oxygen concentration on ignition delay and ignition temperature. Meanwhile, at 20% and 30% rice husk blending ratio, it also weakened the effect of oxygen concentration and oxidizer temperature on ignition delay and ignition temperature. In contrast, blending ratio had a more significant effect on ignition behavior. The replacement of N2 by CO2 at the same oxygen concentration contributed to an increase in ignition delay time and internal ignition temperature, which suppressed the ignition behavior. Different ignition mechanisms corresponded to different combustion processes.

Fire‐Resistant Structural Material Enabled by an Anisotropic Thermally Conductive Hexagonal Boron Nitride Coating

AbstractFire retardant coatings have been proven effective at reducing the heat release rate (HRR) of structural materials during burning; yet effective methods for increasing the ignition temperature and delay time prior to burning are rarely reported. Herein, a strong, fire‐resistant wood structural material is developed by combining a densification treatment with an anisotropic thermally conductive flame‐retardant coating of hexagonal boron nitride (h‐BN) nanosheets to produce BN‐densified wood. The thermal management properties created by the BN coating provide fast, in‐plane thermal diffusion, slowing the conduction of heat through the densified wood, which improves the material's ignition properties. Compared with densified wood without the BN coating, a 41 °C enhancement in ignition temperature (Tig), a twofold increase in ignition delay time (tig), and a 25% decrease in the maximum HRR of BN‐densified wood can be achieved. As a proof of concept for scalability, the pieces of the BN‐densified wood are fabricated with a length larger than 25 cm, width greater than 15 cm, and thickness more than 7 mm. The improved thermal management, fire resistance, mechanical strength, and scalable production of BN‐densified wood position it as a promising structural material for safe and energy‐efficient buildings.

Lattice hydrodynamic modeling with continuous self-delayed traffic flux integral and vehicle overtaking effect

This paper presents a new lattice hydrodynamic model with vehicle overtaking and the continuous self-delayed traffic flux integral. The linear stability condition of the model is derived through the linear stability analysis, which shows that the stable region can be enlarged by increasing the step of delay time. The modified Korteweg–de Vries (mKdV) equation is formulated through nonlinear analysis to describe the propagating behavior of traffic density wave near the critical point. The kink–anti-kink solution under different passing constants is also obtained. Results show that when the passing constant is lower than a threshold (Case I) that is associated with the delay time step, uniform flow and kink jam phase exhibits, and jamming transition occurs between the uniform flow and kink jam. When the passing constant exceeds the threshold (Case II), jamming transitions occur from uniform traffic flow to kink-Bando traffic wave through chaotic phase with decreasing sensitivity. Simulation examples verify that when the delay time increases from 0 to 0.6, the fluctuation amplitude of the traffic density is reduced from 0.07 to 0 even with exogenous initial disturbance, whereas under Case II, chaotic traffic flow appears when the density ranges from 0.18 to 0.31 and the delay time is 0.6.

Stability and Hopf bifurcation in a virus model with self-proliferation and delayed activation of immune cells.

A new mathematical model was proposed to study the effect of self-proliferation and delayed activation of immune cells in the process of virus infection. The global stability of the boundary equilibria was obtained by constructing appropriate Lyapunov functional. For positive equilibrium, the conditions of stability and Hopf bifurcation were obtained by taking the delay as the bifurcation parameter. Furthermore, the direction and stability of the Hopf bifurcation are derived by using the theory of normal form and center manifold. These results indicate that self-proliferation intensity can significantly affect the kinetics of viral infection, and the delayed activation of immune cells can induce periodic oscillation scenario. Along with the increase of delay time, numerical simulations give the corresponding bifurcation diagrams under different self-proliferation rates, and verify that there exists stability switch phenomenon under some conditions.

Determination of Optimum Segmentation Schemes for Pattern Recognition-Based Myoelectric Control: A Multi-Dataset Investigation

Pattern recognition (PR) algorithms have shown promising results for upper limb myoelectric control (MEC). Several studies have explored the efficacy of different pre and post processing techniques in implementing PR-based MECs. This paper explores the effect of segmentation type (disjoint and overlap) and segment size on the performance of PR-based MEC, for multiple datasets recorded with different recording devices. Two PR-based methods; linear discriminant analysis (LDA) and support vector machine (SVM) are used to classify hand gestures. Optimum values of segment size, step size and segmentation type were considered as performance measure for a robust MEC. Statistical analysis showed that optimum values of segment size for disjoint segmentation are between 250ms and 300ms for both LDA and SVM. For overlap segmentation, best results have been observed in the range of 250ms-300ms for LDA and 275ms-300ms for SVM. For both classifiers the step size of 20% achieved highest mean classification accuracy (MCA) on all datasets for overlap segmentation. Overall, there is no significant difference in MCA of disjoint and overlap segmentation for LDA (P-value = 0.15) but differ significantly in the case of SVM (P-value <; 0.05). For disjoint segmentation, MCA of LDA is 88.68% and for SVM, it is 77.83%. Statistical analysis showed that LDA outperformed SVM for disjoint segmentation (P-value<; 0.05). For overlap segmentation, MCA of LDA is 89.86% and for SVM, it is 89.16%, showing that statistically, there is no significant difference between MCA of both classifiers for overlap segmentation (P-value = 0.45). The indicated values of segment size and overlap size can be used to achieve better performance results, without increasing delay time, for a robust PR-based MEC system.

Numerical Study of Modified Mathieu Equation with Time-Delayed Fractional-Order PIλDμ Controller using a Recursive Filter

Abstract In this paper, we have studied numerically free vibration of modified Mathieu Equation with quadratic damping using time-delayed FOPID (fractional-order Proportional-Integral-Derivative) controller focussed on displacement feedback. A special filter known as Oustaloup filter is employed to carry out the fractional order differetiation and integration numerically with the help of Matlab Simulink. The effect of time delayed FOPID with displacement feedback on control performance of the parametrically excited system based on modified Mathieu equation are studied by time response. The results show that the system becomes unstable when time delay increases. It also shows that the use of FOPID becomes quite advantageous over traditional integer order PID (IOPID) control only when the natural frequency is kept low. Equivalent damping of the system could be enhanced to increase the differential gain in order to stabilize the system. On increasing the proportional and integral gain, the system gets destabilized which is in good agreement with the classical integer-order PID control

Analysis of the robustness of a single-tier pipeline inventory model

This paper examines the conditions necessary to specify a robust element of a supply chain using control theory and proposes a new robustness criterion clearly separating robustness from resilience...

Revisiting Lightweight Encryption for IoT Applications: Error Performance and Throughput in Wireless Fading Channels With and Without Coding

Employing heavy conventional encryption algorithms in communications suffers from added overhead and processing time delay; and in wireless communications, in particular, suffers from severe performance deterioration (avalanche effect) due to fading. Consequently, a tremendous reduction in data throughput and increase in complexity and time delay may occur especially when information traverse resource-limited devices as in Internet-of-Things (IoT) applications. To overcome these drawbacks, efficient lightweight encryption algorithms have been recently proposed in literature. One of those, that is of particular interest, requires using conventional encryption only for the first block of data in a given frame being transmitted. All the information in the remaining blocks is transmitted securely without the need for using heavy conventional encryption. Unlike the conventional encryption algorithms, this particular algorithm achieves lower overhead/complexity and higher data throughput. Assuming the additive white Gaussian noise (AWGN) channel, the performance of the lightweight encryption algorithm under study had been evaluated in literature in terms of throughput under the assumption that the first block, that undergoes conventional encryption, is free of error, which is practically unfeasible. In this paper, we consider the AWGN channel with Rayleigh fading and assume that the signal experiences a certain channel bit error probability and investigate the performance of the lightweight encryption algorithm under study in terms of bit error probability and throughput. We derive analytical expressions for these performance metrics considering modulated signals with and without coding. In addition, we propose an extension to the lightweight encryption algorithm under study by further enhancing its security level without significantly affecting the overhead size and processing time. Via numerical results we show the superiority of the lightweight encryption algorithm under study over the conventional encryption algorithms (like the AES) and the lightweight encryption algorithms proposed in literature in terms of error and throughput performance.

Impact of Diethyl Ether Dripping Delay Time on the Electronic Structure of Methylammonium Lead Triiodide Perovskite Film

Recently, organolead halide perovskites have demonstrated excellent performance in solar cell application. For efficient perovskite solar cells, a uniform and dense perovskite film should be fabricated. A popular method to obtain such film is anti-solvent dripping during the intermediate phase formation. This dripping should be performed at the certain delay time after the spin start. The change in delay time could impact defect formation, significantly varying the electronic structure. The electronic structure of a perovskite film plays a crucial role in the charge transport and recombination in the devices. Thus, the determination of the electronic structure is of major significance to analyze the device performance. In this study, we investigated the electronic structure of methylammonium lead triiodide films fabricated with the different delay time of diethyl ether (DE) dripping. The core level and the valence band were measured using X-ray and ultraviolet photoelectron spectroscopy. As the DE dripping delay time increases, the I/N ratio increases while the work function decreases. This would be attributed to the n-doping effect by the positively charged I-interstitial defect formation.

Effects of in utero exposure to lanthanum on neurological behavior in rat offspring

The increasing use of rare-earth elements in various fields has raised concern from public heath perspective regarding their accumulation in human body. Long-term exposure to lanthanum, one of the frequently used rare-earth elements in biomedicine and agriculture, has been previously shown to exert neurotoxicity during development in rats; however, the effects of short-term exposure to lanthanum during gestation on neurobehavioral development in rat offspring is still not clear. The purpose of this study is to investigate the effects of intrauterine exposure to lanthanum on neurobehavioral development in rat offspring. Dams were orally exposed to 0, 2, 20, & 60 mg/kg BW of lanthanum nitrate from gestation day 7 to day 16. Morris water maze test, hindlimb strength test, nociceptive perception test, and grip strength test were conducted during postnatal day 61 to 66 in rat offspring. Blood lanthanum concentration and plasma neurotransmitters were measured after sacrifice. The results showed that intrauterine exposure to lanthanum nitrate significantly impaired memory and spatial learning in Morris water maze test. Lanthanum treatment dose-dependently increased blood lanthanum concentration in dams and pups. Lanthanum treatment significantly decreased hindlimb and grip strength and increased delay time in nociceptive response. Plasma neurotransmitter results showed that lanthanum treatment significantly decreased the level of acetylcholine and serotonin while increased the level of glutamate in rat offspring. These results suggest that short-term in utero exposure to lanthanum has potential adverse effects on neurodevelopment in rat offspring.

The resonance behavior in the fractional harmonic oscillator with time delay and fluctuating mass

We study stochastic resonance (SR) in a fractional harmonic oscillator with time delay and mass fluctuation. Using a moment equation, we derive the exact analytical expression of the output amplitude and find that fluctuations in the output amplitude are nonmonotonic. Using numerical simulations we verify the accuracy of the analytical result. We find (i) that the evolution of output amplitude versus the frequency of the external periodic force exhibits One-Peak SR and Two-Peaks SR, resonance region and resonance form largely depend on the noise correlation rate and noise intensity, (ii) that the evolution of output amplitude versus the noise intensity exhibits One-Peak SR and the increasing time delay lower the critical driving frequency, and (iii) that the evolution of output amplitude versus feedback gain performs diverse resonance forms, the increasing time delay widens the region for occurrence of SR and diversifies the resonance form.

Simple and low-cost object detection method based on observation of effective permittivity change

The permittivity of a material is generally larger than that of air. When an object is present near an electric wire, the effective permittivity of the space around the wire becomes larger than that without the object. It follows that in the presence of an object, the velocity of the signal propagating along the wire decreases and the propagation delay time increases. This change can be easily detected by a simple electronic circuit composed of standard semiconductor devices. The principle of this object detection method can be used not only for proximity sensors but also for the detection or measurement of phenomena involving changes in permittivity.