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Since the ISO 5436 profile analysis presents the axial measurements of the step height/depth standards and does not present a direct method for the lateral measurements, a new method based on the Hamming area model for the lateral measurements of step height/depth standards is presented. The basic idea of the method is to mimic the experimental profile of the step height/depth by a combination of the Hamming window pass-band filter and the RMS model. The lateral position of the 50 % height/depth value of the mimicked Hamming height/depth is assigned. The areas up and down the assigned value are then computed and compared for the lateral measurements of the step height/depth standard. The method is applied for the lateral measurements of a groove structure of a transparent step depth standard. The results show that the total area included in the right line edge of the groove structure is greater than the total area included in the left line edge by 151.66 nm. The error in area measurement is computed to be 1.7 %. The proposed method can be applied to any step height/depth regardless of its height/depth, width, and sharpness of the line edges. • The article provides a new method for lateral measurements of step heights. • It is based on Hamming area model. • The method improves the axial measurements of the line/groove structures by around 2.3 %. • It is used to address the creep problem of a piezo electrical scanning system in AFM. [ABSTRACT FROM AUTHOR]

Summary: In this paper, for standalone and grid‐connected PV systems, a three‐phase simplified split‐source inverter (SSI) is proposed and controlled using a model‐predictive control (MPC). The maximum power point tracking (MPPT) approach used is an incremental conductance method based on a PI controller for both systems. The standalone system is composed of PV modules, a three‐phase SSI, and a bidirectional power DC–DC converter that connects a battery bank and a DC‐side capacitor. The output AC voltages of SSI are controlled using MPC. The bidirectional power DC–DC converter regulates the DC‐link voltage (DCLV). The grid‐connected system consists of PV modules, a three‐phase SSI, and an AC‐side L‐filter. The DC‐link PI controller generates reference currents for the MPC algorithm. The MPC uses these reference currents to adjust and deliver the PV power to the grid while regulating the DCLV. The PI controllers' parameters are selected for both systems using the Harris Hawks optimization method. Both PV systems simulation results show that under various operating conditions, they have succeeded in fixing a DCLV and producing a high‐quality AC output voltage and current at low THD. Experimental results for the three‐phase standalone PV system used to verify the system's performance. [ABSTRACT FROM AUTHOR]

Summary: Bridgeless ac‐dc converters are the optimal choice for many applications, as they offer many advantages such as low distorted supply current, high power factor, and improved efficiency. This paper presents a new topology for a single‐phase bridgeless ac‐dc converter. The proposed hybrid topology is based on integrating the inverting and non‐inverting buck‐boost dc‐dc converters that are connected to the ac supply through an LC filter. To insure sinusoidal supply current, the proposed hybrid bridgeless ac‐dc converter is operated in discontinuous current mode. The proposed converter has many merits, such as a reduced number of components, enhanced efficiency, and soft start‐up capability. The operation modes and design of the proposed converter are presented. In addition, a design method is proposed for the input LC filter to minimize the voltage stress across switches. Moreover, a small signal model for the proposed converter is developed. The proposed converter topology is simulated to evaluate the dynamic behavior and verify the accuracy of the presented small signal model. Furthermore, an 850 W prototype is developed to validate the features of the proposed converter experimentally. Tight voltage regulation, sinusoidal supply current, and near‐to‐unity power factor operation are observed from the results, regardless of supply or load disturbances. [ABSTRACT FROM AUTHOR]

Modular Multilevel Converters (MMCs) are promising candidates for high‐voltage high‐power applications. The main challenge of the MMCs is the zero‐frequency operation. To achieve a successful DC–DC conversion process with balanced capacitors' voltages with limited voltage ripple, this paper suggests the employment of the conventional two‐leg half‐bridge submodule‐based MMC structure in conjunction with a single bidirectional high‐voltage (HV) valve across the low‐voltage side. In the suggested structure, the HV valve is controlled on and off to ensure energy equalization for the MMC arms. In addition, soft‐switching for the HV valve is proposed to reduce the switching losses. Detailed illustration and design of the proposed concept are presented. Simulation and experimentation results are elucidated to show the effectiveness of the proposed DC–DC hybrid MMC. The results showed efficient performance of the suggested converter. [ABSTRACT FROM AUTHOR]

Horticultural crops are used for a variety of purposes, including nourishment and aesthetics. Human nutrition relies heavily on these plants for carbohydrates, proteins, organic acids, vitamins, and minerals. Drought, flood, nutrient inadequacy, heat, light, metal stress, and other abiotic stresses restrict crop plant development and output. A variety of tactics are used to improve abiotic stress tolerance, including the production of genetically modified cultivars by incorporating gene constructions to improve performance under stress. Nanotechnology is a multifaceted field that could be applied in every branch of research comprising medicine, industry and agriculture. Soil and water nanoremediation, plant nanoprotection and plant nanonutrition are some of the agricultural applications. To accomplish sustainable progress in horticultural plants challenged with various environmental challenges, numerous definitive directions have been developed to secure public acceptance and convenient utilization of nanoparticles. Even with the rapid increase in nanoparticle use in several applications, there is still a dearth of information on the actual outcomes of nanoparticle interaction with plants. This review assesses the role of nanomaterials in horticultural crops under abiotic stress, with a focus on recent research. In addition, this review focuses on explaining the broad roles of several nanoparticles in enhancing abiotic stress tolerance in horticulture plants. [ABSTRACT FROM AUTHOR]

White blood cells (WBCs) play a vital role in the diagnosis of many blood diseases. Such diagnosis is based on the morphological analysis of blood microscopic images which is performed manually by skilled hematologist. However, this method has many drawbacks, such as the dependence on the hematologist's skill, slow performance, and varying accuracy. Therefore, in the current study, a new optical method for discrimination between normal and cancer WBCs of peripheral blood film (PBF) images is presented. This method is based on holographic projection technique which is able to provide an accurate and fast optical reconstruction method of WBCs floating in the air. Besides, it can provide a 3D visualization map of one WBC with its characterization parameters from only a single 2D hologram. To achieve that, at first, WBCs are accurately segmented from the microscopic PBF images using a developed in-house MATLAB code. Then, their associated phase computer-generated holograms (CGHs) are calculated using the well-known iterative Fourier transform algorithm (IFTA). Within the utilized algorithm, a speckle noise reduction technique, based on temporal multiplexing of spatial frequencies, is applied to minimize the speckle noise across the reconstruction plane. Additionally, a special hologram modulation is added to the calculated holograms to provide a 3D visualization map of one WBC, and discriminate normal and cancer WBCs. Finally, the calculated phase-holograms are uploaded on a phase-only spatial light modulator (SLM) for optical reconstruction. The optical reconstruction of such phase-holograms yields precise representation of normal and cancer WBCs. Moreover, a 3D visualization map of one WBC with its characterization parameters is provided. Therefore, the proposed technique can be used as a valuable tool for interpretation and analysis of WBCs, this in turn could provide an improvement in diagnosis and prognosis of blood diseases. [ABSTRACT FROM AUTHOR]

In this work, a novel three‐phase unidirectional off‐board Electric Vehicles (EVs) fast charger is proposed. Each phase of the proposed converter consists of a two‐stage converter. The first stage is an AC–DC front‐end converter with power factor correction (PFC) control. The front‐end AC–DC converter is based on an isolated boost converter, which has a boosting capability and provides galvanic isolation. In this stage, parallel‐in parallel‐out isolated boost converter modules are employed in each phase. This enables sharing the current among modules to avoid implementing one module with a high current rating to meet the fast‐charging requirements. The multimodule option provides fault‐ride through capability for the proposed charger. The DC outputs of involved phases, that is, three isolated DC voltages, are fed to three cascaded DC–DC unidirectional buck converters. The charging terminals are used to charge the EV battery through a filter inductor with a charging current controller's aid. A detailed illustration of the suggested closed‐loop controllers is presented to ensure a successful operation for the proposed architecture. A simulation case study for a 25‐kW charger is presented. Finally, a 1‐kW prototype is implemented for experimental validation. [ABSTRACT FROM AUTHOR]

The modular multilevel converter (MMC) is a promising candidate for high-/medium-voltage high-power applications such as medium voltage ac drives due to its modularity, reliability, and scalability. The main challenge of a conventional MMC is low-frequency operation. Capacitor voltage ripple is inversely proportional to the operating frequency. Hence, operating at low frequency necessitates employing large submodule capacitances to limit voltage ripple or the utilization of energy equalization modules (EEMs). The first option negatively affects converter lifetime, and the second option requires a large number of semiconductor devices and isolating transformers. In this article, a modified MMC topology with self-energy equalization is proposed to ensure converter operation with balanced capacitor voltages with low ripple during zero-/low-frequency conditions. Operating with balanced capacitor voltages with low ripple is achieved by maintaining the same energy level in the involved upper and lower arms. A low device count alternative to the EEMs approach is proposed in this work. Detailed illustration of the operational concept and design of the associated passive components is presented. The performance of the proposed medium voltage ac drive is elucidated through simulation and experimental results. [ABSTRACT FROM AUTHOR]

Conventional modular multilevel converters (MMCs) are promising converters for high-voltage high-power applications. Unlike DC-AC conversion, DC-DC conversion of MMCs suffers from unbalanced capacitor voltages due to the energy drift problem. In this study, a new modular DC-DC converter is proposed, which consists of front-end half-bridge MMC with half-bridge submodules followed by full-bridge MMC with full-bridge submodules. The proposed modular multilevel DC-DC converter can be used effectively for connecting two different DC voltage levels in high-/medium-voltage DC grids. The proposed architecture provides successful DC-DC conversion with balanced capacitor voltages throughout the arm interchange concept. It also provides a high conversion ratio, bidirectional power flow, low losses, low current stresses, reduced number of submodules, and DC fault blocking capability. Detailed illustration, operational concept, and design of the proposed architecture with the arm interchange concept are presented. Simulation results for a high-voltage high-power DC-DC converter with the suggested approach are presented to demonstrate the system performance during different normal as well as abnormal operating conditions. Finally, a scaled-down prototype has been implemented for validation. The extracted simulation and experimental results elucidate the presented claims. [ABSTRACT FROM AUTHOR]

Conventional modular multilevel converters (MMCs) are promising converters for high‐voltage high‐power applications. Unlike DC–AC conversion, DC–DC conversion of MMCs suffers from unbalanced capacitor voltages due to the energy drift problem. In this study, a new modular DC–DC converter is proposed, which consists of front‐end half‐bridge MMC with half‐bridge submodules followed by full‐bridge MMC with full‐bridge submodules. The proposed modular multilevel DC–DC converter can be used effectively for connecting two different DC voltage levels in high‐/medium‐voltage DC grids. The proposed architecture provides successful DC–DC conversion with balanced capacitor voltages throughout the arm interchange concept. It also provides a high conversion ratio, bidirectional power flow, low losses, low current stresses, reduced number of submodules, and DC fault blocking capability. Detailed illustration, operational concept, and design of the proposed architecture with the arm interchange concept are presented. Simulation results for a high‐voltage high‐power DC–DC converter with the suggested approach are presented to demonstrate the system performance during different normal as well as abnormal operating conditions. Finally, a scaled‐down prototype has been implemented for validation. The extracted simulation and experimental results elucidate the presented claims. [ABSTRACT FROM AUTHOR]

• Fast phase shift technique for rapid inspection of samples is presented. • Results were compared with those extracted by three-step phase shift. • In term of accuracy, the obtained results are not bad. • This technique can be applied for fast inspection of optoelectronic samples. This paper presents a two-step phase-shifting interferometry technique for fast inspection of uniformity of optoelectronic samples. The in-line configuration was applied to make full use of the space-bandwidth product (SBP) of the camera and hence can resolve finer spatial details of the sample. Two-step phase-shifting (TSPS) algorithm was used to reconstruct the object with only two in-line interferograms generated when a quarter wave plate (QWP) is placed in the light path of one arm of the Mach-Zehnder interferometer. Experimental results show that the extracted phases calculated by the TSPS technique match with the phases extracted by the three-step phase-shifting (THSPS) technique. [ABSTRACT FROM AUTHOR]

Highlights • A new switching pattern is proposed for zero voltage switching of hybrid modular dc-dc converter. • The switching losses is greatly reduced by enabling operation with ZVS of the involved HV valve. • The dynamic voltage sharing of series-connected IGBTs based HV valve is simplified as the switching occurs at zero voltage. Abstract In this paper, a bidirectional non-isolated hybrid modular DC–DC converter for high-voltage (HV) applications is investigated. In this configuration, conventional Half-Bridge Sub-Modules (HB-SMs) are employed. The proposed DC–DC converter is based on connecting the SMs capacitors in series across the high DC voltage level while connecting them sequentially across the low DC voltage level. On another frontier, an HV valve, based on series-connected Insulated-Gate Bipolar Transistors (IGBTs), is required at the HV side. The main confronted challenge of the series-connected IGBTs is the voltage sharing during turn-on and turn-off periods, which necessitates the engagement of an intricate voltage sharing technique. In this work, a switching pattern is proposed to ensure zero-voltage switching (ZVS) of the involved HV valve. In order to reduce the switching losses and avoid complex active gate control recruited for dynamic voltage sharing, the zero-voltage state is extended beyond the switching time. A detailed illustration of the hybrid modular DC–DC converter is presented, elucidating the proposed switching pattern. Simulation results, using Matlab/Simulink platform, are presented to validate the contribution of the paper. Finally, a scaled-down prototype is employed for experimental verification. [ABSTRACT FROM AUTHOR]

Abstract In this paper, an off-axis digital holographic microscopy compensated with self-hologram rotation is presented. The process is implemented via subtracting the unwrapped phase maps of the off-axis parabolic hologram and its rotation 180° to eliminate the tilt induced by the angle between the spherical object wave O and the plane reference wave R. Merit of the proposed method is that it can be done without prior knowledge of physical parameters and hence can reconstruct a parabolic hologram of 1024 × 768 pixels within tens of milliseconds since it doesn't require a digital reference wave. The method is applied to characterize rough gold bumps and the obtained results were compared with those extracted from the conventional reconstruction method. The comparison showed that the proposed method can characterize rough surfaces with excellent contrast and in real-time. Merit of the proposed method is that it can be used for monitoring smaller biological cells and micro-fluidic devices. Highlights • Single shot digital holographic microscopy is presented for rough surface characterization. • Phase is obtained from subtraction of the raw hologram and its rotation 180°. • The proposed method is very fast since it doesn't require a reference digital wave. [ABSTRACT FROM AUTHOR]

High-voltage (HV) pulse generators (PGs) are the core of pulsed electric field applications. Applying HV pulses produces electrical pores in a biological cell membrane, in which if the size of the pores increases beyond a critical size, the cell will not survive. This paper proposes a new HV-PG based on the modular multilevel converter with full-bridge submodules (FB-SMs). In order to alleviate the need of complicated sensorless or sensor-based voltage balancing techniques for the FB-SM capacitors, a dedicated self-regulating charging circuit is connected across each FB-SM capacitor. The individual capacitor charging voltage level is obtained from three successive stages, namely, convert the low-voltage dc input voltage to a high-frequency square ac voltage, increase the ac voltage level via a nanocrystalline step-up transformer, and rectify the secondary transformer ac voltage via a diode FB rectifier. The HV bipolar pulses are formed across the load in a fourth stage through series connected FB-SMs. The flexibility of inserting and bypassing the FB-SM capacitors allows the proposed topology to generate different pulse-waveform shapes, including rectangular waveforms with specifically reduced dv/dt and ramp pulses. The practical results, from a scaled-down experimental rig with five FB-SMs and a 1-kV peak-to-peak pulse output, validate the proposed topology. [ABSTRACT FROM PUBLISHER]

In this paper a Four-Arm Three-Phase MMC (4A-TPMMC)-based DC–AC converter is proposed. The proposed converter generates a three-phase output voltage using a lower number of components, which reduces the converter complexity and cost. The concept of the proposed approach is presented in this paper. A comparison between the conventional Six-Arm Three-Phase MMC (6A-TPMMC) and the proposed 4A-TPMMC is conducted. Two simulation models are built, one for the 6A-TPMMC, and the other for the proposed 4A-TPMMC. The simulations are carried out for the same number of submodules per arm and the same AC output voltage magnitude. Moreover, a case study using the proposed 4A-TPMMC, as a three-phase medium voltage motor drive, is considered. Finally, an experimental validation for the proposed 4A-TPMMC is presented to prove the viability of the claimed contributions. [ABSTRACT FROM PUBLISHER]

In high-voltage applications, the magnitude of total semiconductor losses (on-state and switching) determines the viability of modular-type multilevel converters. Therefore, this paper presents a new cell arrangement that aims to lower total semiconductor loss of the modular multilevel converter (MMC) to less than that of the half-bridge modular multilevel converter (HB-MMC). Additional attributes of the proposed cell are: it eliminates the protective thyristors used in conventional half-bridge cells that deviate part of the dc-fault current away from the antiparallel diode of the main switch when the converter is blocked during a dc short-circuit fault, and it can facilitate continued operation of the MMC during cell failures without the need for a mechanical bypass switch. Thus, the MMC that uses the proposed cell retains all advantages of the HB-MMC such as full modularity of the power circuit and internal fault management. The claimed attributes of the proposed cell are verified using illustrative simulations and reduced scale experimentations. Additionally, this paper provides brief and critical discussions that highlight the attributes and limitations of popular MMC control methods and different MMC cells structures proposed in the literature, considering the power electronic system perspective. [ABSTRACT FROM AUTHOR]

Repetitive high pulsed electric field (PEF) is an effective method to kill microorganisms and bacteria in water treatment applications. The PEF can be generated by applying high-power electromagnetic pulse across the sample to be treated. There are two main types of high-voltage pulse generators, namely, unipolar and bipolar. In this paper, a full-bridge submodule-based modular high-voltage pulse generator, having the ability to generate unipolar and bipolar high-voltage pulses with different shapes from a relatively low-voltage input dc supply, is proposed. In the proposed configuration, relatively low-voltage insulated gate bipolar transistors (IGBTs) are required to generate the high-voltage bipolar pulses. A thyristor rated at the level of the pulsed output voltage is required in the proposed configuration to bypass the load during the charging process of capacitors. In the proposed approach, a thyristor is used instead of the self-commutated high-voltage switch (e.g., series-connected IGBTs), as thyristors are available with high-voltage ratings and possess inherent reverse voltage blocking capability. A detailed illustration of the proposed configuration and its operational concept are introduced in this paper. Simulation and experimental results are presented to validate the proposed approach. [ABSTRACT FROM AUTHOR]

Hybrid multilevel converters are contemplated in an attempt to optimize the performance of voltage source converters in terms of magnitude of semiconductor losses and converter footprint, and to achieve additional features such as dc short circuit proof, which is essential for a high integrity multiterminal HVDC grid. Therefore, this paper considers an emerging hybrid cascaded converter that offers the dc side short circuit proof feature at reduced loss and footprint compared to the existing multilevel and other hybrid converters. Its operating principle, modulation, and capacitor voltage balancing strategies are described in detail. Furthermore, hybrid converter scalability to high voltage applications is investigated. The validity of the modulation and capacitor voltage strategy presented are confirmed using simulation and experimentation. The hybrid cascaded converter is extendable to a large number of cells, making it applicable to high voltage applications, and operation is independent of modulation index and power factor. On these ground, the converter is expected to be applicable for both real and reactive power applications. [ABSTRACT FROM AUTHOR]

The hydrogen evolution and nitrite reduction reactions are key to producing green hydrogen and ammonia. Antenna–reactor nanoparticles hold promise to improve the performances of these transformations under visible‐light excitation, by combining plasmonic and catalytic materials. However, current materials involve compromising either on the catalytic activity or the plasmonic enhancement and also lack control of reaction selectivity. Here, we demonstrate that ultralow loadings and non‐uniform surface segregation of the catalytic component optimize catalytic activity and selectivity under visible‐light irradiation. Taking Pt−Au as an example we find that fine‐tuning the Pt content produces a 6‐fold increase in the hydrogen evolution compared to commercial Pt/C as well as a 6.5‐fold increase in the nitrite reduction and a 2.5‐fold increase in the selectivity for producing ammonia under visible light excitation relative to dark conditions. Density functional theory suggests that the catalytic reactions are accelerated by the intimate contact between nanoscale Pt‐rich and Au‐rich regions at the surface, which facilitates the formation of electron‐rich hot‐carrier puddles associated with the Pt‐based active sites. The results provide exciting opportunities to design new materials with improved photocatalytic performance for sustainable energy applications. [ABSTRACT FROM AUTHOR]

In this paper, a comparative study assessing net metering and feed-in tariffs is proposed for grid-connected photovoltaic (PV) systems in the Kuwaiti market. This study measures the impact of the two mechanisms as well as a mechanism combining both approaches in deploying solar energy systems in residential areas. The advantages and disadvantages of each approach are inspected to determine the optimal approach for Kuwaiti market conditions. A feasibility study on installing a roof-mounted PV system in a typical Kuwaiti residential building is utilized to validate the optimum solar electricity mechanism. The proposed study intends to reduce the peak load demand in Kuwait's electric grid as a solution to the shortage of electric production capacity by encouraging investors and house owners to invest in solar energy. PV*Sol premium 2018 (R10) and RETScreen software packages are utilized to perform the assessment and study analysis. [ABSTRACT FROM AUTHOR]

• This paper proposes topologies A,B and C of acdc buck–boost converters for MV applications, with 'A' and 'C' have been identified as promising. • Topologies 'A' and 'C' facilitate scalability to higher and lower MV applications, with 'C' uses a novel parallel charging of inductors. • The theoretical principles that underpin the operation of the proposed topologies are established and verified using simulations and experiments. This paper proposes three topologies of single-stage three-phase ac–dc buck–boost converters suitable for medium-voltage and high-power wind energy conversion systems (WECS). The proposed converters draw sinusoidal input currents with nearly unity power factor from wind generators over wide range of ac voltages and frequencies. The proposed converters reduce the voltage and current stresses on the self-commutated switching device compared to existing solutions; thus, promising for new generation of relatively cheap WECSs. The proposed converters operate in Discontinuous Condition Mode (DCM), with their ac terminals connected to three-phase generator with open ended windings, or to ac supply using three single-phase transformers with isolated windings at converter side. The validity of the proposed converters and its detailed theoretical analysis and discussions are confirmed using PSCAD/EMTDC simulations, and further corroborated by experimentations, considering different operating conditions. [ABSTRACT FROM AUTHOR]

Dusty weather is a most important disturbance for photovoltaic (PV) systems, that may result in PV panels exposure to partial shading conditions where the PV panel characteristics show several maximum power points. Moreover, dusty weather conditions may lead to rapid changes in solar radiations. Thus, conventional power system tracking algorithms are not being capable to track the global maximum power point (GMPP). This paper provides an advanced maximum power point tracker for partial shading and dusty weather conditions. In the presented technique, scanning and power lock conditions are added to the conventional perturbations and observation technique in photovoltaic system under partial shading or dusty weather conditions. This tracking method scans the PV characteristic in steps and stores all the maximum power points in order to get the GMPP. The proposed tracker is capable to identify the uniform weather conditions to save it from having unnecessary scanning. In addition, this tracker permits dynamic tracking of the GMPP under dusty weather conditions with less fluctuations and stable operation compared to the conventional methods. Accurate and fast conversion to the GMPP during various weather conditions is accomplished using the proposed technique. The proposed modified perturb and observe technique is validated using simulation and practical results. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This article presents an isolated high-frequency (HF) multiport dc–dc converter for photovoltaics (PV) interfacing systems. In the proposed multiport converter, an HF transformer with multiple input windings and single output winding is utilized. Each input port is based on a proposed two-quadrant inverter topology, which connects a PV module to the HF transformer. The output port is tied to a dc bus using a rectifier. The proposed two-quadrant inverter topology prevents current flow from the ac side to the dc side. This action prevents circulating currents between different ports. Each two-quadrant inverter is controlled to harvest maximum power from its associated PV module. The analysis and operation scenarios of the proposed multiport converter are discussed. PSCAD/EMTDC software package is used to simulate the proposed PV interfacing system to investigate the operation of the proposed multiport converter topology and to examine the dynamic system behavior. In addition, an experimental prototype is developed to validate the operation scenarios of the proposed multiport dc–dc converter and to examine the performance of the presented PV interfacing system. [ABSTRACT FROM AUTHOR]

This paper proposes a medium-/high-voltage high-power hybrid modular dc–dc converter to interconnect two different dc-voltage levels in medium-/high-voltage dc grids. The converter consists of half-bridge submodules (SMs) rated at a moderate voltage level, i.e., series connection of semiconductor devices is avoided while connecting two high dc-voltage levels. The proposed architecture provides self-balancing operation, i.e., unlike conventional modular converters, no need for capacitor voltage measurement, which enhances the system reliability and simplicity. Sequential charging/discharging of SMs capacitors is adopted in the proposed approach to ensure a self-balanced operation. The proposed architecture can provide a high conversion ratio as well as power transfer in both directions, i.e., bidirectional dc–dc converter. Detailed illustration of the proposed approach operational concept, design, and overall control system is presented. Simulation and experimental results are presented to show the viability of the proposed configuration and validate the claims. [ABSTRACT FROM AUTHOR]

This paper employs an amplitude modulation with sinusoidal plus third harmonic injection instead of trapezoidal modulation to operate a controlled transition bridge (CTB) converter as ac/dc and dc/ac converter terminals. With such an operation, the CTB converter may require small ac filters; thus attractive for high-voltage direct current (HVDC) transmission systems. To facilitate ac voltage control over a wide range and black-start capability, the injected 3rd harmonic allows the cell capacitor voltages of the CTB converter to be regulated independent of the modulation index and power factor. The insertion of 3rd harmonic into modulating signals achieves two objectives: extends the regions around voltage zeros so that the total voltage unbalanced can be distributed between the cell capacitors, thereby exploiting the bipolar capability of the full-bridge cells in each limb; and to ensure that each limb can be clamped to the positive and negative dc rails every half fundamental period independent of the modulation index to allow recharge of the cell capacitors from the active dc link. The suitability of the CTB converter for HVDC type applications is demonstrated using a two-terminal HVDC link that employs a 21-cell CTB converter, considering normal operation and ac faults. [ABSTRACT FROM AUTHOR]

Here, a new bi‐directional hybrid modular non‐isolated DC–DC converter is proposed where it consists of a boost converter (BC) fed from the high‐voltage (HV) side. At the BC output stage, a certain number of half bridge submodules (HB‐SMs) is connected across the BC switch. During the turn‐on period of BC switch, the HB‐SMs are connected sequentially to the low‐voltage (LV) side, which results in charging/discharging their capacitors from/into the LV side. While, during the turn‐off period, the LV side is bypassed and the HB‐SMs capacitors are connected in series across the BC output stage, which results in discharging/charging them into/from the HV side. The power flow is controlled in both directions by controlling the duty cycle. The proposed configuration provides self‐balancing operation thanks to the sequential connection of HB‐SMs capacitors, and it also provides the ability to operate with high conversion ratios. Illustration and analysis of the proposed converter and its closed‐loop controller are presented. A full design of the values and ratings of the involved components are presented. Simulation study for a 2.5 MW (25 kV/10 kV) DC–DC converter is presented. Finally, experimental results for a downscaled prototype are presented for validation. [ABSTRACT FROM AUTHOR]

Due to the growing attention for the environmental impacts and power loss minimization, distributed generators (DGs) have been introduced widely into the electric power system. One of the challenges of integrating with the power system is to determine their optimal placement and sizing, which, when not respected, adversely affects the performance of the electrical network. In this paper, three multi‐objective algorithms of particle swarm optimization (PSO), variable constants (VCPSO) and genetic algorithm (GA) are adopted and implemented. The main objectives are to detect the optimum size and location of multiple DGs aiming to reduce the active power loss and improve bus voltage deviations in the distribution networks. The paper conducts a comprehensive review of the optimal size and location of the DG via systematic procedures, including definition, classifications, technologies of DGs. Then, the performances evaluation of the three optimization methods are presented and compared with other methods. The presented optimization methods are tested on the IEEE‐33 bus, 32‐line radial distribution network. Four different scenario‐based studies including base case and different number of DGs are performed to examine the accuracy of the presented algorithms. The obtained results prove that all the three algorithms are suitable for this multi‐objective optimization and VCPSO offers the best solution in terms of convergence and, and it has lowest average computation time. The performance and accuracy of the presented approaches and their improvements in the power loss and bus voltage profile are discussed and presented in detail. The obtained results show that more than 65% of active power loss reduction has been attained with the proper sizing and placement of DG systems. © 2023 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This article proposes a new active power flow controller for dc–dc multiactive bridge (MAB) converters with minimum current point tracking (MCPT) to minimize conductive losses. Unlike recent efforts in this area, the proposed controller does not require look-up table for implementation nor complex nonlinear converter modeling and is not circuit parameter dependent. The proposed control scheme is also generalized for MAB converters with any number of ports and is derived in per unit form to enable standard implementation for buck/boost/unity-gain operating modes. The proposed MCPT algorithm is based on an innovative adaptive perturb and observe tracking of the minimum current point (MCP) on the MAB converter current characteristic plane. This MCP is tracked while active power regulation is simultaneously achieved based on a new phase shift decoupler to enable direct regulation of individual port active power. Detailed design procedure of the proposed controller is presented and extensive simulation is carried out to validate the effectiveness of the proposed MCPT closed loop controller. Experimental implementation is also provided to substantiate the simulation results. [ABSTRACT FROM AUTHOR]

Abstract: Background: Malignant pleural mesothelioma (MPM) is an asbestos related aggressive tumor. Asbestos causes genetic modifications and cell signaling events that favor resistance to chemotherapy. A variety of receptor tyrosine kinases have been identified to play a central role in various aspects of tumorigenesis. Epidermal growth factor receptor (EGFR) is overexpressed in a variety of epithelial malignancies including lung cancer in which EGFR aberrations not only predict response to EGFR tyrosine kinase inhibitors but also indicate tumor progression. However in MPM, the role of EGFR is less clear. This study was designed to identify serum and tissue EGFR levels in patients with MPM and to evaluate the relationship between serum and tissue EGFR levels and clinicao-pathological prognostic factors and survival. Methods: We investigated 71 cases of MPM for EGFR expression in tissue. Serum EGFR was assessed in 40 out of those 71 cases and 20 healthy subjects as a control. Pre-treatment serum EGFR levels were measured using quantitative enzyme-linked immunosorbent assay. Tissue EGFR protein overexpression was assessed by immunohistochemistry and gene amplification was assessed by the chromogen in situ hybridization (CISH) technique. Results were correlated with the clinical–pathological factors of the patients and overall survival (OS). Results: Out of the 71 patients included in the study, 19 had undergone extrapleural pneumonectomy. As for the rest of the patients, 46 received chemotherapy while 6 had only best supportive care. EGFR immuno-reactivity was detected in 74.6% of the cases, 37 (52.1%) cases were positive for EGFR gene amplification by CISH, 31 of them revealed moderate to high (++, +++) EGFR immuno-reactivity. Elevated serum EGFR >2.5ng/ml (the median concentration of EGFR in MPM) was reported in 45% of the cases. The overall response rate (RR) for the 46 treated patients who received chemotherapy was 24.1%. After a median follow up of 29 months, the median overall survival (OS) was 10 months. Elevated serum and tissue EGFR is significantly associated with advanced disease stage. However neither EGFR overexpression in tissues nor high serum levels were associated with survival rates. Conclusions: EGFR expression is a common feature in MPM patients. High pre-treatment levels of serum EGFR are associated with advanced stage but not with reduced OS. Detailed mutational analysis of EGFR on a larger number of patients is still needed to clarify the exact role of EGFR in MPM patients. [Copyright &y& Elsevier]

A high-frequency multi-port (HFMP) direct current (DC) to DC converter is presented. The proposed HFMP is utilized to interface a photovoltaic (PV) system. The presented HFMP is compact and can perform maximum power point tracking. It consists of a high-frequency transformer with many identical input windings and one output winding. Each input winding is connected to a PV module through an H-bridge inverter, and the maximum PV power is tracked using the perturb and observe (P&O) technique. The output winding is connected to a DC bus through a rectifier. The detailed analysis and operation of the proposed HFMP DC-DC converter are presented. Extensive numerical simulations are conducted, using power system computer aided design (PSCAD)/electromagnetic transients including DC (EMTDC) software, to evaluate the operation and dynamic behavior of the proposed PV interfacing scheme. In addition, an experimental setup is built to verify the performance of the HFMP DC-DC converter. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive and generalized analysis of the bidirectional dual active bridge (DAB) dc–dc converter using triple phase shift (TPS) control to enable closed-loop power regulation while minimizing current stress. The key new achievements are a generic analysis in terms of possible conversion ratios/converter voltage gains (i.e., Buck/Boost/Unity), per unit based equations regardless of DAB ratings, and a new simple closed-loop controller implementable in real time to meet desired power transfer regulation at minimum current stress. Per unit based analytical expressions are derived for converter ac rms current as well as power transferred. An offline particle swarm optimization (PSO) method is used to obtain an extensive set of TPS ratios for minimizing the rms current in the entire bidirectional power range of –1 to 1 per unit. The extensive set of results achieved from PSO presents a generic data pool, which is carefully analyzed to derive simple useful relations. Such relations enable a generic closed-loop controller design that can be implemented in real time avoiding the extensive computational capacity that iterative optimization techniques require. A detailed Simulink DAB switching model is used to validate the precision of the proposed closed-loop controller under various operating conditions. An experimental prototype also substantiates the results achieved. [ABSTRACT FROM AUTHOR]

• Nanoemulsions of some natural oils i.e., clove, black seed, orange and lemon and their fungicidal activity against postharvest fruit rot of cucumber were prepared and studied. • Nanoformulations of clove and black seed essential oils (2:1) reduced mycelial linear growth, andcompletely inhibited (100%) conidia sporulation of fungal isolates. • Nanoformulation of clove and black seed essential oils (2:1) respectively is a promising safe alternative fungicide for application against postharvest rot of cucumber fruits management. There are growing concerns about the extensive use of synthetic fungicides worldwide due to their negative health effect on humans, ecosystem, and the development of fungal resistance. Therefore, developing new and safe eco-friendly antifungal agents such as plant-based oils is of major interest. This study was conducted for the first time to develop and evaluate the efficiency of eco-friendly nanoemulsions of some natural oils and evaluating of its efficiency against postharvest fruit rot of cucumber caused by the following fungal isolates: Galactomyces candidum (MF373433), Alternaria tenuissima (MF 373440) and Fusarium solani (MF373443). Nanoemulsions of clove, black seed, lemon, and orange oils were formulated by using ultrasound and subjected to physicochemical and stability studies. The efficiency of these nanoemulsions was evaluated against the postharvest fruit rot fungi of cucumber. The oils of promising nanoemulsions have been analyzed by gas chromatography-mass spectrometry analysis (GC/MS). The acute toxicity study was conducted on rats and on the luminescence emitted of Vibrio fischeri bacteriausing Microtox®. The smaller droplet size of nanoemulsions was found after 10 min of sonication with an oil to Tween 80 ratio of 1:1 and 1:2 for clove and black seed oils, respectively. Nanoemulsion of black seed and clove oils from Egypt at 5000 ppm showed a significantly high reduction in the linear mycelial growth of fungal isolates. The mixture formula (2:1 v/v) of nanoemulsions of clove and black seed oils showed a significantly high reduction in linear mycelial growth, completely inhibited (100%) conidia sporulation of fungal isolates, and highly reduced the percentage of the rot of germinated seeds as well mortality of cucumber developed seedlings. Nanoemulsion formulation of clove and black seed (2:1) at concentration 2.0 % as soaking treatment of cucumber fruits before artificial infestation by inocula of fungal pathogens caused completely (100%) suppress postharvest fruit rot of cucumber. Both clove and black seed oils nanoemulsions and their combination showed no signs of toxicity or mortality in rats and no toxic effects on the luminescence emitted of Vibrio fischeri bacteria using Microtox® assay. Therefore, it can be concluded that the nanoformulation of clove and black seed oils at the ratio of 2:1 is a promising green and safe alternative to synthetic fungicide for application against postharvest rot of cucumber fruits. [ABSTRACT FROM AUTHOR]