Hasil untuk "Electric apparatus and materials. Electric circuits. Electric networks"

Paul Hänsch, Jacopo Pinna, Francesco Modena et al.

ABSTRACT Metal halide perovskites have emerged as a highly promising class of materials, garnering immense scientific and technological interest in recent years. Their exceptional properties make them particularly attractive for a wide range of optoelectronic applications, most notably in high‐efficiency solar cells and advanced photodetectors. Beyond these uses, hybrid perovskite materials have also demonstrated potential as sensitive platforms for detecting volatile organic compounds, further expanding their technological relevance. It has been demonstrated that the adsorption of these organic molecules can passivate surface defects, which improves the conductance of the perovskite layer. Here, we show that methylammonium lead bromide (MAPbBr3) and 2‐phenylethylammonium lead bromide ((PEA)2PbBr4) are highly effective in sensing 1‐propanol, which has been identified as biomarker for lung cancer. Both systems exhibit a response time of 1 s, and a recovery time of 1.7 and 14 s for MAPbBr3 and (PEA)2PbBr4, respectively. Going from a 3D to a 2D structure allows us to tailor electronic properties and trap density states, thereby greatly enhancing gas sensitivity. Both systems show a remarkable maximum response of 106 and 107 at 6000 and 7000 ppm, respectively, and a low detection limit of 90 ppm.

Zi-Qi Zhang, Liang Zhou

The inhomogeneous half-mode T-septum waveguide (IHMTSG) cavity is analyzed and applied to the design of miniaturized single- and dual-band band-pass filters (BPFs) in this paper. A defected microstrip structure (DMS) is utilized to achieve ultrawide stopband suppression while preserving transmission characteristics through its band-notched effect. The synthesized, simulated, and measured <italic>S</italic>-parameters of the single- and dual-band BPFs show good agreement. The fabricated single-band BPF operates at 5.8 GHz (<italic>f</italic>₁) with a 3-dB bandwidth of 9.5&#x0025; is designed for n46 frequency range, while the dual-band BPF operates at 4.69&#x002F;25.95 GHz (<italic>f</italic>₁&#x002F;<italic>f</italic>₂) with 3-dB bandwidths of 16.8&#x0025; and 14.73&#x0025; is designed for n79&#x002F;n258 in 5G application, respectively. Excellent upper stopband rejection is achieved, with suppression levels of 20 dB extending up to 9.3<italic>f</italic>₁ in the single-band BPF and 11.3<italic>f</italic>₁ in the dual-band BPF, without spurious modes in the mid-band region. The dual-band BPF achieves a large frequency ratio of 5.53. The proposed single- and dual-band BPFs exhibit competitive performance in terms of miniaturization, ultrawide stopband, and high frequency selectivity with clean mid-band characteristics using the in-house silicon-based MEMS photosensitive composite film fabrication process compared with state-of-the-art filters.

Bingjie Zhou, Yuankai Shao, Weikang Zhu et al.

The growing energy crisis has intensified the need for efficient energy storage solutions. Biomass has emerged as a promising resource for novel energy storage devices. Lignosulfonate, a byproduct of the forestry and pulp industries, contains quinone groups and has enormous potential for electrochemical energy storage. However, due to its poor electrical conductivity, this material must be combined with conductive materials to improve the energy storage efficiency. Carbon materials, particularly porous carbon, are ideal conductive substrates because of their high electrical conductivity, affordability, and ease of fabrication. This study demonstrates the synergistic effects of lignosulfonate/nanocarbon composites (LS/NC), in which heteroatom doping, high specific surface area, and quinone groups considerably enhance their electrochemical performance. Nanocarbon (NC) provides ion diffusion channels with low internal resistance and a large double-layer reaction area, promoting efficient electrolyte ion diffusion and transport. In addition, the introduction of oxygen and sulfur heteroatoms not only increases the material's hydrophilicity but also provides polar surfaces and accessible pseudocapacitive sites. Under acidic conditions, the LS/NC composite achieved a specific capacitance of 571 F g−1 at a discharge rate of 1 A g−1—approximately double that of NC alone (279 F g−1). These findings provide notable advancements in the development of efficient energy storage devices.

Ratiba Fellag, Mahmoud Belhocine, Meziane Hamel

This study introduces a robust trajectory-tracking control strategy in a two-degrees-of-freedom (2-DOF) helicopter system, combining passivity theory and integral sliding mode control (ISMC) strengths. The proposed integral passivity-based sliding mode control (IPBSMC) integrates passivity-based energy shaping, which inherently accounts for the system's natural dynamics, with integral sliding mode control to enhance tracking performance and reduce control effort. The controller's effectiveness is validated through simulations and real-time experiments with band-limited white noise disturbances using the Quanser AERO 2 platform interfaced with MATLAB/Simulink. Results indicate good trajectory tracking, with steady-state errors below ±0.2 rad under non-vanishing Gaussian disturbances. The experimental implementation further validates the proposed method's practical applicability and highlights its potential for real-world deployment in coupled systems requiring high accuracy and robustness under varied operating conditions.

Somi Park, Akeem Raji, So‐Young Boo et al.

Abstract Tandem organic light‐emitting diodes (OLEDs) are two or more emitting units that are connected in series with charge generation layer(s) (CGLs). Although these devices can achieve higher efficiencies and longer operating lifetimes, the CGL is a key element that determines the lifetime and efficiency of these devices. This study investigates the charge generation and operation mechanisms in pristine and aged organic p–n heterojunction CGLs with and without an interlayer (IL) using impedance spectroscopy (IS) and equivalent circuit simulations. Current density and voltage (J–V) analyses show a nearly three times higher current density of the CGL devices with an IL, requiring lower operating voltage and an unchanged onset voltage after aging, demonstrating device stability. The IS and equivalent circuit simulation results reveal that the charge generation efficiency of CGL devices with an IL can be attributed to the lower energy barrier imposed by the IL at the p–n heterojunction and the stability of its molecules after electrical aging. Further investigations providing a clear understanding of the reason behind the stability and efficient operating mechanism in these devices intuitively demonstrate that IS and equivalent circuit simulations can be effectively employed for electrical stability research on multilayered organic devices.

Yangzi Shen, Hongcai Tang, Ge Yan et al.

Abstract Due to defect‐assisted non‐radiative recombination and ion migration, the high defect density in the perovskite light‐absorbing layer severely limits the device's efficiency and stability. Here, pyrene‐4,5,9,10‐tetraone is introduced as an additive to the perovskite precursor. Pyrene‐4,5,9,10‐tetraone retards the crystallization of perovskite through coordination and hydrogen bonding, reducing the defect density and improving the crystal quality. Meanwhile, pyrene‐4,5,9,10‐tetraone distributed at the grain boundaries forms an energy well for free‐moving iodide ions, which doubles the activation energy of ion migration. Due to the improved crystal quality and defect passivation, the pyrene‐4,5,9,10‐tetraone‐based device demonstrates an efficiency of 25.90%. After 1000 h of damp heat test, the efficiency of the encapsulated device decays by 4.9%. It still maintains 92.4% of its initial efficiency after 2016 h aging under maximum power point tracking.

Wojciech Wieczorek, Tomasz Mazur, Weronika Górka‐Kumik et al.

Abstract Here, the fabrication method of ultrathin Zener diodes is presented utilizing a novel hybrid system of zinc sulfide (ZnS) nanoparticles embedded within a poly(methacrylic acid) (PMAA) matrix, surface‐grafted via ARGET‐ATRP polymerization. The controlled polymerization method facilitates precise control over layer thickness, while the in situ synthesis of ZnS nanoparticles ensures uniform coverage throughout the polymer matrix. The obtained hybrid systems with nanometric thickness (<40 nm) are characterized by diode conductivity with a clear breakdown characteristic of the Zener system. The obtained ultra‐thin layers on p‐doped silicon, in addition to their electrical characteristics, are studied using an atomic force microscope (AFM) and secondary ion mass spectrometry (SIMS) to examine the structure and composition of a hybrid polymer‐nanoparticle system.

Shuanglong Wang, Hong Lian, Yongge Yang et al.

Abstract The emergence of perovskite semiconductors for field‐effect transistor (FET) applications has received significant research attention due to their excellent electronic properties. The rapid development of perovskite FETs over the last few years has been driven by advances in understanding the thin‐film morphologies of perovskite layers and their intriguing correlations with charge carrier transport, device performance, and stability. Here we summarize the progress in morphological engineering aimed at improving the electrical parameters of perovskite FETs. We first discuss the mechanisms of crystal nucleation and growth in solution‐processed polycrystalline perovskite thin films, along with their morphological characteristics, including grain boundaries, defects, ionic and charge transport properties. We then elaborate on the impacts of these microstructures on the performance of perovskite FET devices. Representative optimization strategies are also presented, showcasing how fundamental understandings have been translated into state‐of‐the‐art perovskite FETs. Finally, we provide a perspective on the remaining challenges and future directions of optimizing perovskite morphologies, toward an in‐depth understanding of the relationships between film morphology, electrical property and device performance for the next advances in transistor.

Yan Sun

Gaurav Singhal, Sujan Dewanjee, Gwangmin Bae et al.

Abstract A nanostructured copper oxide (nCO) coating which can be electrochemically reduced to copper metal is demonstrated as an anti‐reflection coating, enabling interference lithography of three‐dimensionally structured templates on a surface compatible with subsequent electrodeposition steps. The nCO presents a black needle‐like structure which effectively absorbs the incident radiation during interference lithography. Specular and diffused reflectivity measurements confirm nCO has near‐zero reflectivity from at least UV (350 nm) to near IR (700 nm) wavelengths. A particularly important aspect of the nCO is its ability to be reduced to copper metal, enabling electrodeposition inside porous templates fabricated on the nCO. It is demonstrated electrodeposition of copper within 3D templates defined by interference lithography and proximity field nano‐patterning processes, forming mesostructured metals which enhance two‐phase cooling. The resultant 5 µm thick structures exhibited up to 3 times the critical heat flux and 2 times heat transfer coefficient of bare silicon. The structures are optimized via computational tools including Finite Difference Time Domain (FDTD) and COMSOL Multiphysics. The use of the approach demonstrated here can potentially find application in many areas given the broad importance of mesostructured metals for energy, biomedical, and mechanical applications.

Zhong Yihui

The wide application of sensor networks has brought great challenges to cloud data storage, such as transmission security, data privacy protection and financial risk control. In order to deal with these challenges, the system establishes a comprehensive management early warning system to ensure the data security and financial risk control of the sensor network. The system integrates sensor network technology and cloud data storage technology, and stores data in the cloud through the collection and transmission of environmental data by sensor nodes. In order to ensure the security of the stored process, the system adopts a series of security mechanisms, such as data encryption, access control and identity authentication, and also introduces the financial risk control module, which helps users to warn and manage financial risks through real-time monitoring and analysis of data in the sensor network. The system provides a user-friendly management interface, allowing users to easily configure and monitor the operating state of the sensor network, and supports flexible expansion and customization to adapt to the needs of different scenarios. Through the application of this system, users can effectively manage and control the security and financial risks of sensor networks in cloud data storage, and improve the efficiency and reliability of data storage management.

Hesham Okeil, Tobias Erlbacher, Gerhard Wachutka

Abstract In this study ion‐implanted lateral 4H‐SiC pin diodes are reported, which show an unexpectedly high room temperature in‐plane magnetic field sensitivity approaching 100 % at 0.5 Tesla. Using dedicated TCAD simulations the underlying transduction mechanism is studied, and the effect of implantation‐induced carrier traps on the observed high sensitivity is unraveled. The study shows how such traps can greatly control the injection conditions at the highly doped implant regions providing a plausible explanation for an observed portion in the IV‐characteristics of the pin diodes exhibiting the aforementioned high magnetic field sensitivity.

Rashi Rastogi, Mamta Bansal

Diabetes is the leading cause of death in the world, and it also affects kidney disease, loss of vision, and heart disease. Data mining techniques contribute to health care decisions for accurate disease diagnosis and treatment, reducing the workload of experts. Diabetes prediction is a rapidly expanding field of research. Early diabetes prediction will result in improved treatment. Diabetes causes a variety of health issues. Therefore, it is critical to prevent, monitor, and raise awareness about it. Type 1 and Type 2 diabetes can cause heart disease, renal problems, and eye difficulties. In this paper, we propose a diabetes prediction model using data mining techniques. We apply four data mining techniques such as Random Forest, Support Vector Machine (SVM), Logistic Regression, and Naive Bayes. The proposed mechanism is trained using Python and analysed with a real dataset, which is collected from Kaggle. Furthermore, the performance of the proposed mechanism is analysed using the confusion matrix, sensitivity and accuracy performance metrices. In logistic regression, the accuracy is high, i.e., 82.46%, in comparison to other data mining techniques.

Rongrong Yuan, Wentao Qian, Ying Zhang et al.

Abstract Flexible and transparent conductive (FTC) thin films are indispensable elements in building high‐performance flexible or soft electronics and displays. Slim inorganic nanowires (NWs), with excellent conductivity and durability, are ideal one‐dimensional ingredients to weave a quasi‐continuous FTC network. However, a precise spatial arrangement of these ultrathin NWs, to form an optimal interconnected network, represents still a difficult challenge. In this work, a catalytic growth of orderly SiNW arrays, via an in‐plane solid‐liquid‐solid mechanism, and an orthogonal‐stacking integration of the SiNWs into a 2‐layer cross‐linked network, followed by a direct alloy formation and soldering of highly conductive SiNi alloy NWs upon a flexible polyimide polymer, is demonstrated. It is also shown that the flexibility of the SiNi FTC network can be significantly enhanced with an elastic spring design of the silicide NW channels, leading to an impressive transmittance of ≈90%, a moderately equivalent sheet resistance of 130 Ω sq−1 and a durable flexibility that can sustain repetitive bending to a 2 mm radius for >1000 cycles. These results highlight the unique capabilities of an optimal spatial arrangement, precise assembly/soldering and elastic geometry design of alloy NWs to enable a new generation of high‐performance FTC thin film material for future flexible electronics, displays, and bio‐interfaced sensors.

Iulia Salaoru, Swapnodoot Ganguly, Dave Morris et al.

The continuous development of the semiconductor industry to meet the increasing demand of modern electronic devices which can enhance computing capabilities is attributed to the exploration of efficient, simple, high-speed operation and multistate information storage capacity of electronic devices called memory devices. Nowadays, one of the main challenges the industry faces is limitations in manufacturing as the current fabrication pathway is complex and relies on the use of rigid substrates that do not match with the needs of industry for flexible, bendable electronics. 3D printing has a huge potential to address this challenge and to completely replace the current fabrication pathways and protocols. In this paper, the materials and the 3D printing technologies that have been explored to fabricate an emerging flexible, bendable memory device will be presented.

Jungmin Kim, Shin Geun Park, Minseok Kim et al.

Abstract The colloidal dispersion in a nonpolar medium is an essential material for electrophoretic displays (EPD) with low‐power consumption. A uniform‐sized superparamagnetic iron oxide nanoparticle (SPION) is a promising candidate for EPD, which exhibits tunable structural color by Bragg diffraction. In this study, the surface of SPION is charged in a nonpolar medium by inverse micelles of Solsperse‐17k, an oil‐soluble polymeric surfactant. A photonic ink of SPION dispersion exhibits simultaneous magnetochromism and electrochromism. The photonic ink is encapsulated via a complex coacervation process, in which double layers of gelatin/gum Arabic form a stable shell for µ‐capsule. The µ‐capsules show tunable structural colors, which depends upon the size of SPION in photonic ink. The increased surfactant content in photonic ink brings about a decrease in µ‐capsule size due to a reduced surface tension. A lowered gelatin concentration during coacervation results in a smaller µ‐capsule, which exhibits an electrical color tunability. Optical characterization using a confocal microscopy enables 3D visualization of the inner structure of µ‐capsules and the formation of particle chain structure of SPION in H‐field. The encapsulated photonic ink exhibits magnetochromism for 1 year, illuminating the long‐term stability of µ‐capsules developed in this study.

Thomas E Gage, Daniel B Durham, Haihua Liu et al.

Electrical pulse stimulation drives many important physical phenomena in condensed matter as well as in electronic systems and devices. Often, nanoscopic and mesoscopic mechanisms are hypothesized, but methods to image electrically driven dynamics on both their native length and time scales have so far been largely undeveloped. Here, we present an ultrafast electron microscopy approach that uses electrical pulses to induce dynamics and records both the local time-resolved electric field and corresponding material behavior with nanometer-nanosecond spatiotemporal resolution. Quantitative measurement of the time-dependent field via the electron beam deflection is demonstrated by recording the field between two electrodes with single-ns temporal resolution. We then show that this can be applied in a material by correlating applied field with resulting dynamics in TaS$_{2}$. First, time-resolved electron diffraction is used to simultaneously record the electric field and crystal structure change in a selected region during a 20 ns voltage pulse, showing how a charge density wave transition evolves during and after the applied field. Then, time-resolved nanoimaging is demonstrated, revealing heterogeneous distortions that occur in the freestanding flake during a longer, lower amplitude pulse. Altogether, these results pave the way for future experiments that will uncover the nanoscale dynamics underlying electrically driven phenomena.

Dror Liran, Jiaqi Hu, Nathanial Lydick et al.

Electrically controlled photonic circuits hold promise for information technologies with greatly improved energy efficiency and quantum information processing capabilities. However, weak nonlinearity and electrical response of typical photonic materials have been two critical challenges. Therefore hybrid electronic-photonic systems, such as semiconductor exciton-polaritons, have been intensely investigated for their potential to allow higher nonlinearity and electrical control, with limited success so far. Here we demonstrate an electrically-gated waveguide architecture for dipolar-polaritons that allows enhanced and electrically-controllable polariton nonlinearities, enabling an electrically-tuned reflecting switch (mirror) and transistor of the dipolar-polaritons. The polariton transistor displays blockade and anti-blockade by compressing a dilute dipolar-polariton pulse exhibiting very strong dipolar interactions. The large nonlinearities are explained using a simple density-dependent polarization field that very effectively screens the external electric field, with an order of magnitude enhancement of the nonlinearities as compared to fixed dipoles. We project that a quantum blockade at the single polariton level is feasible in such a device.

KHAWLA DIB, YOUCEF ZENNIR, HICHEM BOUNEZOUR et al.

the main object of this paper is to evaluate safety barriers intervening against overpressure implemented on a crude oil heater using layers of protection analysis approach suggested in IEC 61508 (International Electrotechnical Commission) Standard for the determination of safety requirements are illustrated. Accident scenarios are pre-identified using Hazard an Operability approach, Fault tree approach is required for an effective risk assessment process. In order to better appreciate accident scenarios, PHAST (Process Hazard Analysis Software Tool) is utilized to simulate them.

Khalan J. Rostam, Suzan S. Haydar

Deciding on a fuzzy environment faces many difficulties due to the lack of accuracy in data or permanently changing data. Fuzzy linear programming is one of the best methods used in a fuzzy environment which has a big role in making the right decision to solve a problem. This paper aims to identify the method of Fuzzy Linear Programming (FLP) to take the optimal decision and reach the optimal production for crude oil products of the North Refineries Company, This paper constructs the FLP model and solves the model to reach a production decision that contributes to maximizing profit and solves the model by using the methods of FLP. The fuzziness was removed from the model by using five methods. Comparison between the methods of removing fuzzy in a linear programming model to get maximum profit. The paper results that the highest maximum profit is (993423791) million dinars when using the bounded and decomposition method for the linear programming problem, which is higher than the profits achieved by the research company by (50%). The results were implemented by the software package python 3.9.