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In intermittent drinking water distribution systems, large volumes of the water are wasted due to leaks in the distribution networks. Similarly, user service is not always satisfied in the time required to fill the storage, nor with sufficient pressure. Hence the importance of this study. Measuring the variability of pressure in the distribution network and determining the factors that influence the definition of a sufficient minimum hours of service, is a first step to change to a continuous service 24/7, in order to minimize the volumes of lost water and meet demand. In total, 347 pressure sensors were placed in a network to detect changes in pressure and obtain data for 3 years. This study presents a new approach to determine the operating policy of the operating agency that provides the service intermittently. Two objectives are pursued: pressure variability – to minimize leaks – and define the minimum hours of service. The analysis was performed using multivariate statistical techniques, including principal component analysis, correlation matrix and ANOVAs, to explore the association between objectives. The results obtained show that the pressure distribution has a Gaussian behavior and that the hours of service have a Poisson distribution. HIGHLIGHTS A pressure range between 7 and 30 mwc is essential for user satisfaction.; A minimum of 6 hours of service is recommended in IWS systems.; The behavior of service hours is not linear but exponential in its effect on the satisfaction of demand.; Multivariate analysis is an adequate technique to facilitate the decision making in a water supply system.; Pressure variation has normal behavior regardless of the number of hours supplied.;

In the plasma electrolytic oxidation (PEO) process, microdischarges are produced at the titanium surface immersed in an appropriate electrolyte by applying a voltage higher than dielectric breakdown of the oxide film. During this discharging stage, lasting between 30 and 300 μs, many species are transferred from electrolytic to surface producing the coatings. In the present work, pulses of electric current with duration of 50 μs and 100 μs were used in order to interrupt the microdischarges and, thus, control the PEO process. The effect of pulse duration, using different current densities and duty cycles, was investigated by the changes in energy consumption, in addition to the topographical, microstructural and chemical properties of the surface, in order to meet the requirements of a hypothetical surface for drug delivery from titanium implants. It was shown that surfaces treated with pulse duration of 50 μs had uniform pores and smaller mean diameters, better anatase/rutile and calcium/phosphorus ratios than those treated with pulses of 100 μs. Our results reveal that using a 50 μs current pulse, the process has lower energy consumption and more suitable properties for use in titanium implants with controlled drug delivery.

To achieve an accurate, efficient, and high dynamic control performance of electric motor drives, precise phase voltage information is required. However, measuring the phase voltages of electrical motor drives online is expensive and potentially contains measurement errors, so they are estimated by inverter models. In this paper, the idea is to investigate if various machine learning (ML) algorithms could be used to estimate the mean phase voltages and duty cycles of the black-box inverter model and black-box inverter compensation scheme with high accuracy using a publicly available dataset. Initially, nine ML algorithms were trained and tested using default parameters. Then, the randomized hyper-parameter search was developed and implemented alongside a 5-fold cross-validation procedure on each ML algorithm to find the hyper-parameters that will achieve high estimation accuracy on both the training and testing part of a dataset. Based on obtained estimation accuracies, the eight ML algorithms from all nine were chosen and used to build the stacking ensemble. The best mean estimation accuracy values achieved with stacking ensemble in the black-box inverter model are R ¯ 2 = 0.9998 ,   M A E ¯ = 1.03 , and R M S E ¯ = 1.54 , and in the case of the black-box inverter compensation scheme R ¯ 2 = 0.9991 ,   M A E ¯ = 0.0042 , and R M S E ¯ = 0.0063 , respectively. [ABSTRACT FROM AUTHOR]

A self-consisted mathematical model is presented, describing nonstationary processes of energy, momentum, mass and charge transfer in plasma column and anode boundary layer of an electric arc burning in atmospheric pressure inert gas at pulsed modulation of current. A numerical study of distributed and integrated characteristics of 2 mm long argon arc was performed in the case of current modulation by rectangular pulses at 10 kHz frequency and different values of the duty cycle (0.3; 0.5; 0.7) under the condition that the average current value remains unchanged and equal to 140 A. Calculated time dependencies of plasma temperature, velocity and current density in the arc column centre, as well as axial values of plasma temperature and pressure near the anode surface, anode current density and heat flux into the anode are given for the selected values of duty cycle. Radial distributions of averaged over the current modulation period heat flux, introduced by the arc into the anode, pressure and force of friction of arc plasma flow on its surface were calculated, which are the determinant ones for simulation of thermal and hydrodynamic processes in the metal being welded in TIG welding with high-frequency pulsed current (HFPC) modulation. Results of simulation of nonstationary arc characteristics are compared with the respective results for a direct current (DC) arc, at current equal to average value of modulated current. Analysis of the obtained results leads to the conclusion that in the case of HFPC TIG welding at 10 kHz frequency decrease of duty cycle (increase of pulse current) at constant value of average current leads to greater force impact of such an arc on weld pool metal and to increase of its penetrability, respectively. 20 Ref., 2 Tabl., 6 Fig. [ABSTRACT FROM AUTHOR]

Over the past few years, the use of wireless sensor networks in a range of Internet of Things (IoT) scenarios has grown in popularity. Since IoT sensor devices have restricted battery power, a proper IoT data aggregation approach is crucial to prolong the network lifetime. To this end, current approaches typically form a virtual aggregation backbone based on a connected dominating set or maximal independent set to utilize independent transmissions of dominators. However, they usually have a fairly long aggregation delay because the dominators become bottlenecks for receiving data from all dominatees. The problem of time-efficient data aggregation in multichannel duty-cycled IoT sensor networks is analyzed in this paper. We propose a novel aggregation approach, named LInk-delay-aware REinforcement (LIRE), leveraging active slots of sensors to explore a routing structure with pipeline links, then scheduling all transmissions in a bottom-up manner. The reinforcement schedule accelerates the aggregation by exploiting unused channels and time slots left off at every scheduling round. LIRE is evaluated in a variety of simulation scenarios through theoretical analysis and performance comparisons with a state-of-the-art scheme. The simulation results show that LIRE reduces more than 80% aggregation delay compared to the existing scheme. [ABSTRACT FROM AUTHOR]

Currently, large number of devices have been connected to the Internet of Things (IoT). Ubiquitous IoT devices encounter emergencies and generate much data which may lead to congestion and urgency to be processed timely. To alleviate it, many approaches have been proposed and Adaptive Duty Cycle Control (ADCC) scheme is an effective one. The main contributions of this paper are as follows: (a) Unlike previous studies that mostly the efficiency of congestion control and real-time processing is experiment-oriented, specially, this paper theoretically gives a targeted optimization of duty cycle ratio, which can effectively guide the design of ADCC scheme for real time big data. (b) A general design principle is proposed to guide the scheme designing in order to improve the efficiency and performance of networks. (c) A comprehensive congestion avoidance and real-time processing scheme combining dynamic duty cycle adjustment and full utilization of residual energy is proposed. Thus, these ideas can meet the concept of Green IoT. Through our extensively theoretical and experimental analysis, the principle can effectively guide the design of ADCC scheme, and can reduce the delay, data drop ratio by 20.95% − 77.85% and 29.63% − 100% respectively, without affecting network lifetime, compared with previous scheme. [ABSTRACT FROM AUTHOR]

The additive manufacturing of mask-less localized electrodeposition technology is a new technology that combines the principle of electrochemical deposition with additive manufacturing. Micro-nickel columns were prepared by this technique under low voltage/small duty cycle, high voltage/large duty cycle, and high voltage/small duty cycle. The surface morphology, deposition rate, cross-section structure, and growth pattern of micro-nickel columns were studied to understand the formation process of micro-nickel columns and obtain high-quality micronickel columns. The research found that the diameter of the deposited micro-nickel column is uniform, the grain is fine and smooth under low voltage/small duty cycle (4.2V/0.3). The micro-nickel columns deposited under high voltage/large duty cycle conditions (4.8V/0.7) were thickerin diameter, but the particles were irregularly stacked. The volume deposition rate increases with the increase of voltage and duty cycle. The volume deposition rate is the highest when the duty cycle is 0.5. Three growth patterns are proposed: the layer-by-layer deposition in the initial deposition phase, accumulation deposition in the middle phase, and mixed deposition in the final phase. These three growth patterns are based on the surface morphology and cross-section microstructure of the micro-nickel column deposited under a high voltage/small duty cycle [ABSTRACT FROM AUTHOR]

In this paper, the establishment of efficientWireless Sensor Network (WSN) networks has been projected to minimize the consumption of energy using a new Self-adaptive Multi-Objective Weighted Approach (SMOWA) algorithm for solving a multi-objective problem. The Different WSN nodes deployment policies have been proposed and applied in this paper to design an efficientWireless Sensor Network to minimize energy consumption. After that, the cluster head for each cluster has been selected with the help of the duty cycle. After configuring the WSN networks, the SMOWA algorithms have been developed to obtain the minimum energy consumption for the networks. Energy minimization, as well as the amount of day-saving, has been calculated for the differentWSNswhich has been configured through different deployment policies. The major finding of the research paper is to improve the durability of Wireless Sensor Network (i) applying different deployment strategies: (Random, S pattern and nautilus shell pattern), and (ii) using a new Meta-heuristic algorithm (SMOWA Algorithm). In this research, the lifetime of WSN has been increased to a significant level. To choose the best result set from all the obtained results set some constraints such as "equivalent distribution", "number of repetitions", "maximum amount energy storage by a node" has been set to an allowable range. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Switcher locomotives operate in railway yards where they shunt railcars and assemble trains. Shunting railcars requires frequent aggressive acceleration and deceleration events in order for the locomotive to push or pull railcars onto specific tracks. As a result, switcher locomotives rarely sustain tractive power for any significant period of time. Given that all switchers in North America rely on diesel-electric propulsion; the result is rapid and frequent transitions in engine power leading to a very low engine efficiency and high levels of emissions. Any attempt to quantify or remedy these issues will face a lack of a representative profile or test cycle. A locomotive duty cycle is a breakdown of time spent at each power level of the locomotive's engine. A major drawback of current duty cycles is that they only account for steady power. Such cycles are not representative of real switcher locomotive operation. This paper presents a real-world transient duty cycle for switcher locomotives that accounts for the rapid power transitions and is argued to be more statistically representative of actual operations. The methodology adopted relies on real-time data collection, microtrip based trip segmentation, and a finite mixture model-based clustering algorithm. Measurements were collected on a EMD 16-645 GP9 locomotive. The duty cycle developed herein is representative of switching operations in Southern Railway of British Columbia's New Westminster Yard as an example of the methodology which can be repeated in other cases as well. [ABSTRACT FROM AUTHOR]

This research proposes a seven-level inverter with quasi-Z-source boost converters. The proposed topology employs a packed U-cell asymmetrical type multilevel inverter along with front-end quasi-Z-source networks. The quasi networks provide high gain compared to a conventional boost converter. This topology is the most suitable for photovoltaic multi-string applications. The proposed topology has the potential to supply both the alternating current (AC) and direct current (DC) type load. The inverter structure has a lower number of active switches which helps in the reduction of losses and improvement in efficiency. In this paper, the operation principle of a quasi-network and inverter circuit are explained in detail. In addition, the simulation results for various modulation indices are presented. In the MATLAB/Simulink environment, the architecture is proposed by using gated sinusoidal "Pulse width modulation". [ABSTRACT FROM AUTHOR]

The fuel cell-based electric power generation system is playing a major role in the present electrical power distribution system. The fuel cell gives a nonlinear V-I curve. As a result, the extraction of fuel cell power is very difficult. To extract the peak power of the fuel cell, a Maximum Power Point Tracking (MPPT) technique is used. In this work, an Improved Beta-based Fuzzy Logic Controller (IBeta-FLC) is proposed to track the MPP with high speed. The proposed MPPT technique is compared with other hybrid MPPT techniques in terms of maximum power extraction, settling time, oscillations across MPP, tracking speed, and efficiency. The Proton Exchange Membrane Fuel Cell (PEMFC) stack gives high output current, and low output voltage. As a result, the overall system conduction losses are improved. So, in this work, a new Single Switch Universal Input-voltage Boost Converter (SSUIBC) is introduced to step-up the fuel cell output voltage. The features of the proposed boost converter are high voltage gain, less complexity in design, wide output operation, and less voltage stress across the switch. The proposed PEMFC fed boost converter system performance is evaluated successfully by using a MATLAB/Simulink window. In addition, the utilized boost converter is investigated experimentally by using an external DC-source. [ABSTRACT FROM AUTHOR]

The convective heat transfer coefficient in a pulsating cylindrical fluidized bed using microcapsule particle‐phase change material (MPCM) was examined experimentally. A solenoid on and off valve was used to provide the pulsation and was varied from 1 to 10 Hz. The test section in the bed was loaded with granular microparticle‐phase change material (MPCM) with an average diameter of 200 µm. The pulsation effect on the thermal field, thermal storage, and heat transfer coefficient was investigated for 1.5, 2, and 2.5 of minimum fluidization velocity. Results indicated that the amplitude of the oscillation decreases with increasing in pulsation frequency. An increase in heat transfer rate was shown to be related to the superficial velocity. The maximum performance was obtained for the frequency of 7 Hz at the velocity ratio of 2.5. The convective heat transfer increased by 17% for frequency pulsation of 7 Hz. Furthermore, the Duty cycle (η) is defined as the ratio of turn‐on duration to the total turn‐on and off duration for entering airflow to the solenoid valve. It was shown that the η > 0.4 led to better mixing and higher heat transfer. However, the pulsation effect was shown to disappear for the duty cycle of higher than 0.8. Comparison with the available experimental data of others for continuous flow was in good agreement. [ABSTRACT FROM AUTHOR]

Based on the plasma modified model and photoionization optimization model, this article constructs a low temperature and subatmospheric pressure air streamer discharge model. Through the model, the characteristics of streamer discharge under high-frequency square wave voltage are studied. Streamer discharge exhibits a different discharge pattern from dc voltage in the voltage drop stage and low-level stage. In addition, duty cycle and rise (fall) time have different effects on parameters, such as electron density, positive ion density, electric field, space charge density, photoionization rate, and streamer propagation velocity. [ABSTRACT FROM AUTHOR]

Tannic acid or tannin, type of phenolic compound contains in kenaf bast fibre. Conventional extraction has certain limitations in terms of time, energy, and solvent consumption. Ultrasound assisted extraction (UAE) can extract bioactive components in shorter time, low temperature, with lesser energy and solvent requirement. UAE as alternative extraction technique is better equipped to retain the functionality of the bioactive compounds. In this study, the conditions for ultrasound assisted extraction (UAE) of tannic acid from kenaf bast fibre by assessing the effect of sonication time and different duty cycles were optimized. The use of ultrasound to extract tannic acid from kenaf bast fiber was evaluated. Ultrasound-assisted extraction (UAE) was carried out using ethanol as solvent to intensify the extraction efficacy. Phytochemical screening was conducted to identify the presence of tannic acid in extracts. The extracts then were analyzed using High-Performance Liquid Chromatography (HPLC) and Scanning Electron Microscopy (SEM). It was found that 0.2429 mg/mL of tannic acid was obtained under the extraction conditions of extraction temperature of 40°C, sonication time of 20 minutes and duty cycle of 50%. From SEM analysis, it was found that the raw sample demonstrated rough surface and no porous but kenaf bast fibre display smoother surface with less impurities and few pores appeared after the extraction process using UAE. These results indicate that ultrasound-assisted extraction is an efficient method for extracting tannic acid from kenaf bast fibre with the advantages of lower extraction time and higher extraction yield. [ABSTRACT FROM AUTHOR]

Energy efficiency with mobility support plays an important role in Wireless Sensor Networks. Duty cycling mechanism is used to reduce energy consumption of idle listening and coordinates sleep and wake-up period of nodes to prolong the network life time. The delay sensitive applications require the duty cycle adjustment with network traffic conditions to accomplish energy efficiency and low latency. The proposed Energy Efficient and Mobility Aware Hybrid MAC (EMH-MAC) protocol with adaptive duty cycle reduce the delay for prioritized services. In this approach, the duty cycle is dynamically adjusted with mobility and queue length of priority packets. The proposed protocol offers better data transmission rates in high traffic load conditions and also saves energy in low traffic. [ABSTRACT FROM AUTHOR]

Precise localization is considered one of the most salient features of Industry 4.0 manufacturing facilities. For this reason, multiple solutions have already been proposed. The method presented in this paper entails the use of double-band radio and optical technologies for near-real-time location tracking and remote reporting, with a final tracking accuracy of 0.5 meters. To preserve low-energy operations, the system infrastructure part is deployed on passive radio-frequency identification (RFID) tags, whereas the part installed on tracked assets implements energy-saving mechanisms. The system was deployed in an automotive production plant which allowed us to draw practical remarks on such aspects as the separation of onboard Ultra High Frequency (UHF) antennas; proper electromagnetic isolation of radio modules to prevent signal blocking; the placement and mechanical securing of RFID tags on the floor; as well as how to implement procedures to decrease the duty cycle, allowing for a trade-off between system sensitivity and energetic efficiency. [ABSTRACT FROM AUTHOR]

The conventional model predictive power control suffers from heavy computational burden and large power ripple. To address the problem, this paper proposes a simplified three-vector-based model predictive direct power control, which can greatly optimize the control set. Firstly, a switching table is designed to exclude the redundant virtual voltage vectors (VVs). Only half of the candidate VVs are retained. Then, the effect of each VV on power is analyzed in detail. The deviation of reactive power is used as the evidence to further simplify the control set. In this way, the prediction behavior is reduced from 12 to 2, which effectively reduces the computational burden. In addition, the concept of power deadbeat is employed to determine the duty cycles of the two virtual VVs and one zero VV. Thus, the power ripples and current harmonics can be considerably suppressed. With this proposed method, the calculation complexity is reduced, and the steady-state performance is improved. The simulation and experimental results are given to verify the proposed method. [ABSTRACT FROM AUTHOR]

In general, a power transformer is equipped with differential protection relay with the second harmonic restraint criterion to improve reliability. However, this criterion may fail in some cases, resulting in incorrect operation of protection relay. Therefore, to further upgrade the performance of differential protection, this paper proposes a duty cycle-based scheme as complement. Firstly, the waveform of the differential current in one cycle and its two derived waveforms, constructed by translating and taking absolute, are transformed into corresponding square waves, respectively. Then, duty cycles of these square waves are calculated, and three criteria are presented to quantify the differences between the duty cycles of disturbances and faults. Finally, the criteria and the second harmonic restraint are combined through three logic gates to form the proposed scheme for protection. A large number of simulation experiments have verified the effectiveness of the proposed scheme, which outperforms the frequently used protection schemes. [ABSTRACT FROM AUTHOR]

Wireless Sensor Network (WSN) is considered as an integral part of the Internet of Things (IoT) for collecting real-time data from the site having many applications in industry 4.0 and smart cities. The task of nodes is to sense the environment and send the relevant information over the internet. Though this task seems very straightforward but it is vulnerable to certain issues like energy consumption, delay, throughput, etc. To efficiently address these issues, this work develops a cross-layer model for the optimization between MAC and the Network layer of the OSI model for WSN. A high value of duty cycle for nodes is selected to control the delay and further enhances data transmission reliability. A node measurement prediction system based on the Kalman filter has been introduced, which uses the constraint based on covariance value to decide the scheduling scheme of the nodes. The concept of duty cycle for node scheduling is employed with a greedy data forwarding scheme. The proposed Duty Cycle-based Greedy Routing (DCGR) scheme aims to minimize the hop count, thereby mitigating the energy consumption rate. The proposed algorithm is tested using a real-world wastewater treatment dataset. The proposed method marks an 87.5% increase in the energy efficiency and reduction in the network latency by 61% when validated with other similar pre-existing schemes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Signal Processing is the property of Journal of Signal Processing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pada era teknologi yang semakin berkembang pesat, penggunaan elektronika daya semakin banyak digunakan seperti untuk penggontrolan motor dan lain – lain. Untuk mendukung semua itu tentu juga di iringi dengan metode – metode interfacing yang memudahkan user dalam penggunaaan alat – alat elektronika daya seperti contohnya buck conveter. Interfacing yang di maksud disini adalah dengan melakukan pengaturan keluaran buck converter dengan menggunakan interfacing pada personal computer sekaligus memonitoringnya. Buck converter adalah jenis dc-dc converter yang berfungsi untuk mengubah keluaran tegangan output lebh kecil dibandingkan dengan tegangan keluaran input. Perancangan monitoring menggunakan visual basic dalam pembuatan interfacing, hal ini dilakukan karena kemudahan komunikasi antara visual basic dengan arduino. Metode pengontrolan menggunakan pengaturan duty cycle yang diberikan dari visual basic ke arduino. Dengan mengatur duty cycle, maka tegangan yang dkeluarkan pun akan berubah-ubah. Berdasarkan hasil pengujiaan, maka dengan memperbesar duty cycle maka keluaran tegangan dari buck converter akan semakin kecil, Dengan hasil pengukuran buck converter pada input tegangan 24 volt dan duty 15.97 menghasilkan tegangan keluaran sebesar 19,5 sedangkan pada duty cycle 34.57 menghasilkan tegangan sebesar 13.9.

In this research, sensing performance of mono and bimetallic nanophotonics SERS sensors of gold-silver nano-columns for the detection of chlorpyrifos was investigated. For optimum substrates for Gold-silver/nano-column surface-enhanced, Raman scattering (SERS) was achieved with the silicon substrate. By combining the Ag SERS activity with the Au chemical stability and nano-columns Si large field enhancement, the Au-Ag/nano-columns Si substrate revealed perfect reproducibility, homogeneity, sensitivity in addition to chemical stability. The sensors were tested by Atomic force microscope (AFM), field emission scanning electron microscope (FESEM), energy-dispersive X-ray analysis (EDS), and X-ray diffraction (XRD). Findings presented in this research indicated modified distributions and sizes of formed alloy nanoparticles, and the hot spots junctions within the nanophotonics layer after changing the nanoparticles types. The SERS sensors performance displayed an excellent recognition of ultra-low concentrations of chlorpyrifos solutions with an exponential relationship with the Raman signal. The highest enhancement factor (Ef=1.56×106) and minimum limit of detection 0.069 mg/Kg were obtained with Au-Ag sensors.

Wireless networks play an important role in science, including medicine, agriculture, the military, geography, and so on. The main issue with a network of wireless sensors is how to manage resource utilization to extend its lifetime. This paper investigates the various aspects of increased energy usage that may improve network life. Variables related to energy consumption and various performance metrics are investigated in terms of energy efficiency. To investigate how the network’s energy usage can be managed, a quick overview of clustering protocols, routing protocols, MAC protocols, and load balancing protocols is conducted. This paper can provide researchers with an idea of the various parameters that influence energy consumption and what methodologies could be adapted by each parameter to conserve energy, thereby extending the network’s lifetime.

Nowadays, developing a driving cycle has become argumentative with the local country traffic infrastructure considerations to make emission standard drafts, control vehicles emissions, and also develop related parts. Aside from that, constructing a duty cycle would be a better option for vehicle parts development. In this article, the output is a hydraulic pressure-time plot of the TIBA vehicle for the best similarity with all acquired data. The main ideas and also algorithms are the same as developing the driving cycle. However, the difference is new definitions of inputs such as the average hydraulic pressure, the average loaded hydraulic pressure, the average steering angle, the angular velocity, and the unloaded pressure ratio. The K-means clustering technique is conducted in this research with the principal component analysis (PCA) and the effects of the number of clustering are checked to make results more efficient. The outputs illustrate that the root mean square (RMS) and Chi-square errors for the methodology are 0.166 and 0.068, respectively, which has a significant drop of 86.4% and 95.4%, in comparison to the conventional method.

This paper develops a mathematical model for analyzing the steady state performance of the static rotor resistance chopper control induction motor (SRRCCIM) operates under unbalance supply voltage conditions. The IEC definition indices of voltage unbalance factor (VUF) and complex voltage unbalance factor (CVUF) which consists of magnitude and phase angle of the unbalance supply are used for the analysis. Also, this paper evaluates the impact of voltage unbalance and duty cycle of chopper circuit on the stator and rotor motor parameters, motor currents, efficiency, power factor, torque-speed characteristics, maximum torque starting and torque. The proposed mathematical model of SRRCCIM is validated using MATLAB-Simulink. The results have shown that the performance of the SRRCCIM and variation of positive sequence stator current, negative sequence stator current, current unbalance factor(CUF), efficiency, and developed torque are depending on the magnitude of the voltage unbalance and chopper circuit duty cycle.

• Three asymmetric grating structures not only significantly improve the output power of lasers, but also improve the utilization efficiency of output power to reduce energy consumption. • Silicon evanescent lasers with designed waveguide structure exhibit large waveguide-coupled power and low threshold current density. • Calculation method combines the advantages of eigenmode expansion method and coupled-wave theory. Great achievements in the bonded III–V lasers have pushed the productization process of silicon photonic chips. In this work, we report the design of silicon evanescent lasers with asymmetric gratings, which can provide high output power and stable single-longitudinal-mode operation. The high coupling efficiency and low threshold current density are achieved by linearly expanding the width of rib waveguide from 0.4 µm to 2 µm through 150 µm taper coupler. By optimizing the λ/4 phase-shift position ratio from conventional 0.50 to 0.64, the ratio of output power at both sides of the bonded lasers (P 2 / P 1) is improved from1.0 to 5.0, and the normalized grating coupling coefficient (κ L) remains at 2.78. By optimizing the duty cycle at one side of λ/4 phase-shift from 0.5 to 0.8 and another side remains at 0.5, P 2 / P 1 is 3.3, and κ L lowers from 2.78 to 2.21. Besides, keeping the phase-shift position ratio at 0.64 while changing the duty cycle to 0.7, P 2 / P 1 increases significantly to 7.5 with κ L of 2.59. This work provides a step forward towards the development of high-power silicon-based light sources. [ABSTRACT FROM AUTHOR]

High entropy (AlCrNbSiTi)N hard coatings have been deposited by pulsed arc ion plating with various duty cycles. The effects of duty cycles on the morphology, chemical composition, microstructure and mechanical properties of coatings are studied. Higher duty cycles result in the increase of deposited particles and holes on the surface of the coatings. The coatings exhibited a single-phase face centered cubic structure with preferred orientation of (200). Appropriate duty cycle can significantly improve the comprehensive mechanical properties of the coatings. The coating exhibits highest hardness and elastic modulus of 43.4 GPa and 573.4 GPa, respectively. Formation of surface oxides during friction process are observed, which play a self-lubricating role. • The cross sections of all coatings are featureless and dense. • The coatings have typical single-phase B1–NaCl FCC solid solution crystal structure with (200) preferred orientation. • Coating deposited at 60 % duty cycle exhibits highest hardness of 43.4 GPa. [ABSTRACT FROM AUTHOR]

Given the importance of promoting a greener and more sustainable future, it is crucial to promptly tackle and improve the issues surrounding carbon emissions and inefficiency linked to traditional energy sources. This study presents a new optimization method for PV systems. It combines an IGWO Algorithm with PID-type SMC to enhance the effectiveness of MPPT. Using IGWO, the optimal MPP voltage is determined even in the face of changing environmental conditions. Afterwards, the PID-type SMC adjusts the actual output voltage of the Boost based on the expected voltage to generate the required duty cycle. The integrated approach considers the natural fluctuations in PV systems, where changes in the environment can greatly affect the maximum power point. An in-depth evaluation was conducted using simulation software based on MATLAB, and a practical testing platform was built accordingly. The simulation and experimental results in real-world scenarios show that the new MPPT strategy has excellent overall performance and can quickly determine and track the voltage value for MPP compared to established algorithms. This study lays the groundwork for applying IGWO and new SMC control theories in the field of renewable energy generation. It also contributes to the development of MPPT technology, considering the challenges posed by the controlled environment. [ABSTRACT FROM AUTHOR]

Electro-dewatering of sewage sludge with pulsating voltage was conducted under the two different wave shapes (square wave (SQW) and half-sine wave (HSW)) to investigate the influence of wave shape and duty cycle on sludge dewatering performance. The results indicated that, under the same average voltage, the moisture content of dewatered sludge with HSW was 10.3%–35.4% lower than that with SQW, suggesting the better dewatering performance of HSW. The optimal dewatering performance was achieved at duty cycle of 80% for SQW and 60% for SHW. The chemical oxygen demand of filtrate from HSW could be 13% higher than that from SQW, indicating the higher capacity of HSW in breaking sludge cells/floc structure. The applied voltage during electrochemical treatment promoted the hydrolysis of protein in filtrate, and the main components in the electro-dewatered filtrate were fulvic acid- and humic acid-like substances. The specific energy consumption for sludge electro-dewatering were 0.015–0.269 kWh/(kg removed water), and it was almost in linear relationship with duty cycle. By overall considering the energy consumption and electro-dewatering performance, the condition of 60% duty cycle with HSW was obviously better than other conditions, which provides a meaningful guidance for future application of sludge electro-dewatering technology with pulsating voltage. [Display omitted] • Pulsating voltage of half-sine waveform (HSW) showed higher dewatering performance than square waveform (SQW). • Moisture content of dewatered sludge with HSW was 10.3–35.4% lower than SQW. • HSW showed higher ability in breaking sludge cells and floc structures than SQW. • The specific energy consumption was in the range of 0.015–0.269 kWh/(kg RW). [ABSTRACT FROM AUTHOR]

• The new BTMS has two heat transfer paths, including OHP and liquid cooling plate. • Pulsating flow improves OHP stability through periodic enhanced thermal loads. • Optimal OHP stability lies in 38% or 62% duty cycles, 0.03–0.05 Hz frequencies. • Stably operating OHP enhances the new system's heat transfer performance. After a comprehensive review of oscillating heat pipe (OHP) based on battery thermal management system (BTMS), a novel battery liquid-cooling system with a ⊥-shaped OHP is presented to increase the volume utilization efficiency of battery module and the total amount of heat dissipation. The new system retains the heat transfer path of the OHP while incorporating an additional heat dissipation route where the liquid cooling plate is in direct contact with the cells. In this paper, pulsating flow is used to tackle the problem of the OHP failing to operate stably due to the insufficient heat load achieved in the new system. The parametric effects of pulsating flow frequencies, cooling initiation temperatures, and duty cycles on the operational performance of the OHP and the average surface temperature of the battery module ( T b ) within the new system were investigated. The results indicate that pulsating flow periodically elevates the heat load on the battery surface, enhancing the OHP working properly. The smaller the pulsating flow frequency, the greater the impact on the temperature fluctuations of the new system. The T b is lowest when the pulsating flow frequencies range from 0.03 Hz to 0.05 Hz. Beyond a frequency of 0.06 Hz, the OHP cannot operate stably. Additionally, moderately increasing the cooling initiation temperature is beneficial for enhancing the average temperature oscillation amplitude of the OHP. The cooling initiation temperature between 45 °C and 47 °C results in a better T b . Both pulsating flow duty cycles of 38% and 62% contribute to OHP running effectively. The new system with OHP under optimum pulsating flow condition has the optimal T b , eventually rising by 17.5 °C, which is a 9.8% decrease in temperature rise compared to the system without OHP. And the battery module's surface temperature uniformity has been improved through a reduction of 1.3 °C in the maximum temperature difference ( ΔT max ), amounting to a 17.8% decrease. It has been proved that the improved thermal performance of the new system under pulsating flow is attributed to the stable operation of the OHP. [ABSTRACT FROM AUTHOR]

The use of low-cost sensors in conjunction with high-precision instrumentation for air pollution monitoring has shown promising results in recent years. One of the main challenges for these sensors has been the quality of their data, which is why the main efforts have focused on calibrating the sensors using machine learning techniques to improve the data quality. However, there is one aspect that has been overlooked, that is, these sensors are mounted on nodes that may have energy consumption restrictions if they are battery-powered. In this paper, we show the usual sensor data gathering process and we study the existing trade-offs between the sampling of such sensors, the quality of the sensor calibration, and the power consumption involved. To this end, we conduct experiments on prototype nodes measuring tropospheric ozone, nitrogen dioxide, and nitrogen monoxide at high frequency. The results show that the sensor sampling strategy directly affects the quality of the air pollution estimation and that each type of sensor may require different sampling strategies. In addition, duty cycles of 0.1 can be achieved when the sensors have response times in the order of two minutes, and duty cycles between 0.01 and 0.02 can be achieved when the sensor response times are negligible, calibrating with hourly reference values and maintaining a quality of calibrated data similar to when the node is connected to an uninterruptible power supply. [ABSTRACT FROM AUTHOR]

Wireless sensor networks (WSNs) develop IoT (Internet of Things) that carry out an important part and include low-cost intelligent devices to gather information. However, these modern accessories have limitations concerning calculation, time taken for processing, storage capacity, and vitality sources. In addition to such restrictions, the foremost primary challenge for sensor networks is achieving reliable data transfer with the secured transmission in a hostile ambience containing vulnerable nodes. The proposed work initially analyses the relation between deployment configuration, lifetime of the deployed network, and transmission delay with this motivation. Besides, it also introduces a new cellular automata-based scheme for improving the security of the network. Each device has a unique id based on its properties (or random number with timestamp). While initializing the communication, they will broadcast their id to all neighbour nodes; to pair with other nodes, they should exchange their unique id. The main advantage of this work is the infinitive states' existence, i.e., the encoded codes generated by cellular automata are infinite. Besides, a modern approach named Fast Particle Swarm Optimization is used to collect data for nodes ar away from the sink and slow data collection for nodes Close to the Sink (FPSO-FSC). Hence the proposed energy-efficient method reduces the end-to-end delay. Comparison studies report that the performance of FPSO-FSC outperforms the previously proposed methods. [ABSTRACT FROM AUTHOR]