High-performance Applications Research Articles

Implementation of FPGA-based Accelerator for Convolutional Neural Networks

This research paper presents a novel FPGA-based accelerator tailored for Convolutional Neural Networks (CNNs), specifically implemented on the Virtex-7 evaluation kit. By harnessing the inherent parallel processing capabilities of FPGAs, the architecture of the accelerator is meticulously crafted using Verilog. The FPGA implementation demonstrates a resource-efficient design, making use of 588 Look-Up Tables (LUTs) and 353 Flip Flops. Notably, the efficient utilization of these resources signifies a careful balance between computational efficiency and the available FPGA resources. This research significantly contributes to the field of hardware acceleration for CNNs by offering an optimized solution for high-performance deep learning applications. The presented architecture serves as a promising foundation for future advancements in FPGA-based accelerators, providing valuable insights for researchers and engineers working in the domain of hardware optimization for Convolutional Neural Networks.

Ferroelectric Based Low Power MOSFET for DC/RF Applications: Machine Learning Assisted Statistical Variation Analysis

The analog/radio-frequency (RF) performance of a ferroelectric-based substrate metal oxide semiconductor field effect transistor (FE-MOSFET) with dielectric spacer was designed and proposed. The utilization of gate side wall spacers aims to mitigate short-channel effects (SCEs), and improve overall device performance. Simulation results demonstrate enhanced performance metrics, including improved transconductance (80%), reduced gate leakage (95.4%), and enhanced cutoff frequency (25%), making this design a promising candidate for next-generation high-performance analog and RF applications. Additionally, a novel machine learning (ML)-assisted approach is proposed for investigating the spacer-based FE-MOSFET to reduce the computational cost of numerical TCAD device simulations with the help of conventional- artificial neural network (C-ANN). This method is reported for the first-time ML-based C-ANN for Fe-based low-power MOSFET, matches the similar accuracy of physics-based TCAD with the fastest learning rate and fastest computational speed (in 95–100 s). An ML-based prediction replacement for physics-based TCAD is developed to save around 8–10 h of runtime for each iteration. Because ML predictions can never be 100% accurate, it is essential to ensure approximately zero mean-square error in the final results.

Ultrahigh energy storage performance in AN-based superparaelectric ceramics

Ceramics capacitors, especially featuring antiferroelectric (AFE) structure, are widely used in pulsed power electronic systems due to distinctive high-power density and external field stability. Lead-free AFE material AgNbO3 has seized substantial research attention owing to its unique temperature driven multi-level phase transitions, and many works have greatly improved the energy storage properties by engineering these temperature-dependent phase boundaries. In this work, an ever-unadopted strategy was proposed to modulate the relaxor structure in AgNbO3 by designing room-temperature (RT) superparaelectric phase via Bi incorporation into AN lattice matrix. Structural analysis shows M phase (space group Pbcm) evolves into O phase (space group Cmcm) with 12 mol.% Bi-substitution, breaking the long-range AFE order into polar nanoregions. Hence, an ultra-high recoverable energy density (7.6 J/cm3) and a high efficiency (79 %) are simultaneously achieved in the Ag0.64Bi0.12NbO3 ceramics under 52.2 kV/mm. Moreover, the excellent energy storage properties are accompanied with good temperature and frequency stability, with the variation of Wrec less than ± 15% (over 25–120 °C) and ± 10% (over 1–200 Hz) under 25 kV/mm, respectively. The novel approach reported herein provides a new guidance for designing AgNbO3-based and other AFE materials for high-performance energy storage applications.

NXTamid-L as a substitute for Nylon 12 and 11

The NXTamid-L family of specialty engineered nylons are claimed to be unique in the performance they offer, and to be quite different from polyamide grades that might be more commonly seen in different applications, such as Nylon 6 or Nylon 66. These specialty high performance polyamides most commonly refer to Nylon 12, Nylon 11, and Nylon 1010. They reportedly are more flexible, have lower moisture absorption, more robust chemical resistance, and other special features that should make them unique for high performance applications. Nylon 11 and Nylon 12 are the most common of these nylons, and unfortunately can present some limitations on applications, including availability and price. To help address these needs, NYCOA announced a new family of specialty nylons to consider as substitutes to Nylon 12 and 11: NXTamid-L.

Development of eco-friendly bio-composites using banana fibers for enhanced tensile and flexural properties

The synthetic fiber composite materials have witnessed widespread adoption in high-performance applications due to their lightweight and high-strength properties. However, the non-renewable and non-biodegradable nature of synthetic fibers has raised environmental concerns. This has spurred research into natural fiber composites, often referred to as “bio-composites,” as sustainable alternatives to synthetic counterparts. Among these, bio-composites reinforced with natural fibers include banana, coir, jute, silk, sisal, and bamboo have gained significant attention as industrial materials. This research endeavor focuses on the development of banana fiber-reinforced composites using hand lay-up and VARTM methods techniques and explores their mechanical properties. Three distinct types of composites were fabricated, employing natural banana fibers and banana fabric as reinforcement materials, with epoxy resin as the matrix. Mechanical characterization encompassing tensile and flexural properties was conducted to assess the performance of the bio-composites. SEM with EDS analysis revealed distinct microstructural features and elemental compositions. The bio-composites manufactured via the VARTM method employing banana fabrics exhibited significant enhancements in mechanical properties. The bio-composites made with VARTM showed an impressive 160 % improvement inflexural strength and a 217 % increase in tensile strength when compared to the hand-layup method. The findings of this experimental study underscore the superior load-carrying capacity of bio-composites fabricated through the VARTM method and banana fabric reinforcement when compared to other combinations. This research underscores the potential of banana fibers as a sustainable alternative to synthetic fibers in composite materials, contributing to eco-friendly and environmentally responsible solutions in various high-performance industries

V2O5:Cu thin films-based device fabrication for high-performance photosensing application

The Cu doped V2O5 thin film were prepared by varying the doping concentration from 0, 1, 2, 3, 4 and 5 wt % through cost effective nebulizer spray pyrolysis method. The structural, optical, surface morphology of the samples were carried out by XRD, UV–Visible spectroscopy, FESEM studies. The XRD studies confirmed the orthorhombic structure of the sample and the crystallite size changes from 31 to 44 nm for the undoped to 3 % Cu doped V2O5 thin film. FESEM studies were employed to understand the surface morphology of the thin films and uniform nanorods were observed from this study. The optical bandgap of the samples was determined and 3 % Cu doped V2O5 thin film exhibited lower value of 2.21 eV. The photoluminescent peaks occur at 480, 530 and 575 nm due to the defects present in the samples. The photosensing behaviour of the prepared samples were done and found that the essential photosensing properties such as responsivity (R), detectivity (D*) and external quantum efficiency (EQE) for the V2O5:Cu3 % sample were 4.92 × 10−1 AW−1, 1.06 × 1011 Jones and 159 % respectively which proved that the 3 % Cu doped V2O5 thin film would be a most preferential material for the low cost photodetector.

Indirect Field Oriented Control of Induction Motor

The various control strategies for the control of the inverter-fed induction motor have provided good steady-state but poor dynamic response. In the last decades, many control techniques have been developed providing good performance. Field-oriented control is one of the most significant control methods for high performance AC electric machines and drives. In particular, for induction machines, indirect field oriented control is a simple and highly reliable scheme which has essentially become an industry standard. With the advent of the vector control methods, an induction motor can be operated like a separately excited dc motor for high performance applications. The speed control is observed in closed-loop control applications. The speed regulation is achieved with a PI controller which converts the command speed into the command torque and therefore the speed of the drive. In this paper PI controller base indirect field orientation control of 3-phase 415V, 50Hz Induction motor using cascaded multilevel inverter is proposed in MATLAB/SIMMLINK 7.10.0 (R2010a).

THE POSSIBILITIES OF USING PARALLEL PROGRAMMING USING PYTHON

This article explores the development of parallel software applications using the Python programming language. Parallel programming is becoming increasingly important in the information technology world as multi-core processors and distributed computing become more common. Python provides developers with a variety of tools and libraries for creating parallel applications, including threads, processes, and asynchronous programming. This topic covers the basics of parallel programming in Python, including the principles of thread and process management, error handling, synchronization mechanisms, and resource management. He also considers asynchronous programming using the asyncio library, which allows you to efficiently handle asynchronous tasks. In addition, this topic raises issues of optimization and profiling of parallel applications, as well as explores distributed parallel programming using third-party libraries and frameworks. He also emphasizes the importance of testing and debugging in the context of parallel programming. Research and experiments in parallel programming using Python help developers create high-performance and efficient applications that can effectively use multi-core systems and distributed computing. This article offers an in-depth study that examines how Python is suitable for teaching parallel programming to inexperienced students. The results show that there are obstacles that prevent Python from maintaining its advantages in the transition from sequential programming to parallel.

Enhanced performance of microstrip antenna fabricated on a composite dielectric substrate coupled with multiple dielectric superstrates

In this study, we introduce a unique geometrical design of a rectangular patch antenna for sub-6 GHz 5G applications. The proposed antenna is designed at 5.2 GHz, and design criteria and performance characteristics have been investigated through numerical simulations and verified using measured data. A composite structure is suggested to overcome the restrictive parameters of conventional antennas. Two different materials, Rogers RT5880, and RT5870, are utilized, achieving a maximum gain of 6.210 dB, and a 90.2% radiation efficiency was attained. Four layers of superstrates are placed above the antenna to enhance the antenna's radiation performance further. The fabricated antenna is evaluated by measuring its radiation characteristics and return loss. The final antenna prototype offers a maximum bandwidth of about 896 MHz at a −10 dB reflection coefficient with a maximum gain of 9 dB. The proposed model achieved ultimate efficiency as high as 89% by employing four superstrates. The results showed good impedance matching (S11, VSWR), high efficiency, and appropriate radiation patterns. The outcomes from simulation and measurement are well aligned, making this antenna suitable for high-performance 5G applications.

Self-Assembled Interlayer Enables High-Performance Organic Photovoltaics with Power Conversion Efficiency Exceeding 20.

Interfacial layers (ILs) are prerequisites to form the selective charge transport for high-performance organic photovoltaics (OPVs) but mostly result in considerable parasitic absorption loss. Trimming the ILs down to a mono-molecular level via the self-assembled monolayer is an effective strategy to mitigate parasitic absorption loss. However, such a strategy suffers from inferior electrical contact with low surface coverage on rough surfaces and poor producibility. To address these issues, here, the self-assembled interlayer (SAI) strategy is developed, which involves a thin layer of 2-6nm to form a full coverage on the substrate via both covalent and van der Waals bonds by using a self-assembled molecule of 2-(9H-carbazol-9-yl) (2PACz). Via the facile spin coating without further rinsing and annealing process, it not only optimizes the electrical and optical properties of OPVs, which enables a world-record efficiency of 20.17% (19.79% certified) but also simplifies the tedious processing procedure. Moreover, the SAI strategy is especially useful in improving the absorbing selectivity for semi-transparent OPVs, which enables a record light utilization efficiency of 5.34%. This work provides an effective strategy of SAI to optimize the optical and electrical properties of OPVs for high-performance and solar window applications.

Flexible Indoor Perovskite Solar Cells by In Situ Bottom-Up Crystallization Modulation and Interfacial Passivation.

A robust perovskite-buried interface is pivotal for achieving high-performance flexible indoor photovoltaics as it significantly influences charge transport and extraction efficiency. Herein, a molecular bridge strategy is introduced utilizing sodium 2-cyanoacetate (SZC) additive at the perovskite-buried interface to simultaneously achieve in situ passivation of interfacial defects and bottom-up crystallization modulation, resulting in high-performance flexible indoor photovoltaic applications. Supported by both theoretical calculations and experimental evidences, it illustrates how SZCs serve as molecular bridges, establishing robust bonds between SnO2 transport layer and perovskite, mitigating oxygen vacancy defects and under-coordinated Pb defects at interface during flexible fabrication. This, in turn, enhances interfacial energy level alignment and facilitates efficient carrier transport. Moreover, this in situ investigation of perovskite crystallization dynamics reveals bottom-up crystallization modulation, extending perovskite growth at the buried interface and influencing subsequent surface recrystallization. This results in larger crystalline grains and improved lattice strain of the perovskite during flexible fabrication. Finally, the optimized flexible solar cells achieve an impressive efficiency exceeding 41% at 1000 lux, with a fill factor as high as 84.32%. The concept of the molecular bridge represents a significant advancement in enhancing the performance of perovskite-based flexible indoor photovoltaics for the upcoming era of Internet of Things (IoT).

Dielectric flow- and tab-based battery thermal management system for EV high performance application

From the perspectives of security, durability, and proper operation, effective temperature control via thermal management systems (TMSs) on lithium-ion batteries is crucial for electric vehicle use. In this regard, a novel TMS based on dielectric flow and tab cooling was presented in this paper. A functional prototype of the system was developed and experimentally tested for performance analysis. A thermal model was built on computational fluid dynamics software, and a comparative analysis of the initial and an optimised geometry of the prototype was carried on after validation. Results demonstrate the adequate response of the system. Thermally speaking, temperature decrease was noticed during operation, and the internal and among-cells thermal gradient was preserved into the recommended span. Besides, the used dielectric fluid assisted with a low auxiliary consumption due to its particular viscosity. With the new geometry, the dielectric flow duct volume was reduced by 79.8%, and the system particularities were enhanced due to heat dissipation improvement: operating temperatures were even lower in every scenario examined. The temperature difference among cells was reduced by 15%. Thermal dispersion within the cells was still below the limit, despite being increased. Moreover, the necessary pumping energy consumption was below 0.004% of the exchanged battery module’s energy, demonstrating the TMS efficiency. Thus, the application potential of the dielectric tab cooling-based system for electric vehicles was highlighted.

Broadband Photodetection of Centimeter-Scale T-Phase Gallium Telluride Grown by Molecular Beam Epitaxy.

Two-dimensional (2D) semiconductors have recently attracted considerable attention due to their promising applications in future integrated electronic and optoelectronic devices. Large-scale synthesis of high-quality 2D semiconductors is an increasingly essential requirement for practical applications, such as sensing, imaging, and communications. In this work, homogeneous 2D GaTe films on a centimeter scale are epitaxially grown on fluorphlogopite mica substrates by molecular beam epitaxy (MBE). The epitaxial GaTe thin films showed an atomically 2D layered lattice structure with a T phase, which has not been discovered in the GaTe geometric isomer. Furthermore, semiconducting behavior and high mobility above room temperature were found in T-GaTe epitaxial films, which are essential for application in semiconducting devices. The T-GaTe-based photodetectors demonstrated respectable photodetection performance with a responsivity of 13 mA/W and a fast response speed. By introducing monolayer graphene as the substrate, we successfully realized high-quality GaTe/graphene heterostructures. The performance has been significantly improved, such as the responsivity was enhanced more than 20 times. These results highlight a feasible scheme for exploring the crystal phase of 2D GaTe and realizing the controlled growth of GaTe films on large substrates, which could promote the development of broadband, high-performance, and large-scale photodetection applications.

Accelerating range minimum queries with ray tracing cores

Over the past decade, GPU technology has undergone a notable transformation, evolving from pure general-purpose computation to the integration of application-specific integrated circuits (ASICs), including Tensor Cores and Ray Tracing (RT) cores. While these specialized GPU cores were initially developed to enhance specific domains like AI and real-time rendering, recent research has successfully harnessed their capabilities to expedite other tasks traditionally reliant on conventional GPU computing. One GPU task that is still yet to find its way into RT cores is the processing of range minimum queries (RMQs) in parallel, which is fundamental in fields such as information retrieval or pattern matching, among others. In this context, accelerating RMQs with RT cores would impact many of the applications that heavily rely on this task. In this work we present RTXRMQ, a new approach that can compute RMQs with RT cores. The main contribution is the proposal of a geometric solution for RMQ, where elements become triangles that are placed and shaped according to the element’s value and position in the array, respectively, such that the closest hit of a ray launched from a point given by the query parameters corresponds to the result of that query. Experimental results show that RTXRMQ is currently best suited for small query ranges relative to the input size, achieving up to 5× and 2.3× of speedup over parallel state of the art CPU and GPU approaches, respectively. For medium and large query ranges RTXRMQ is still slower than the state of the art GPU approach, but still competitive by being 2.5× and 4× faster than a state of the art CPU method running in parallel as well. Furthermore, performance scaling experiments across the latest RTX GPU architectures show that if the current RT core scaling trend continues, then RTXRMQ’s performance would scale at a higher rate than the other compared approaches, making it an attractive tool for future high performance applications that employ many batches of RMQs.

Push-Pull Bis-Norbornadienes for Solar Thermal Energy Storage.

The norbornadiene/quadricyclane (NBD/QC) photoswitch pair represents a promising system for application in molecular solar thermal energy storage (MOST). Often, the NBD derivatives have very limited overlap with the solar spectrum, and substitution to redshift the absorption leads to a decrease in the gravimetric energy density. Dimeric systems mitigate this factor because two switches can 'share' a substituent. Here, we present five new NBD dimers with red-shifted absorption spectra. One dimer features the most red-shifted absorption onset (539 nm) and a significantly red-shifted absorption maximum (404 nm) for NBD systems reported so far, without compromising thermal half-life. Promising properties for high-performance MOST applications are demonstrated, such as high absorption onsets reaching 539 nm, and energy densities of 379 kJ/kg, while still maintaining long half-lives of the metastable isomer, up to 23 hours at 25 °C.

Experimental and statistical study on the effect of process parameters on the quality of continuous fiber composites made via additive manufacturing

Ongoing research in additive manufacturing towards structural and industrial application has led to the use of commingled roving as a manufacturing feedstock for printing high fiber volume fraction composites. The prospects of using this technology for high performance applications necessitates the need for a comprehensive experimental investigation into the effects of processing parameters on the quality of an additively manufactured composite printed from commingled roving feedstock. In this work, transverse flexure and void fraction matrix pyrolysis testing are both performed to evaluate composite quality. The transverse flexure test is a testing approach that evaluates the quality of the interfacial fiber-matrix bond while the void fraction test estimates the void content in the printed composite. A full observational study consisting of 27 different test combinations is done to investigate the effects of three different process parameters namely, temperature, pressure, and print speed across three different levels. Composite samples were made from commingled roving of E-glass and amorphous PET using an in-house built continuous fiber composite digital manufacturing system. Least squares regression analysis is performed to study the main, interaction and quadratic effects of process parameters. A statistical regression model having an R2 adjusted value of 80.1% is generated from the transverse flexure study, which is used to explain main and interaction effects and also predict performance. Response surface plots are also generated and are used to optimize process parameters which can subsequently be of help in scaling up composite manufacturing. Results show that all three process parameters are highly statistically significant at the 0.01 level of significance. Pressure * Temperature and Pressure * Printspeed are significant interaction terms. Pressure plays a weightier role when print speed is increased or temperature is decreased as it closes more voids that would ordinarily have been introduced because of drop in polymer melt viscosity. Micrographic analysis is also performed.

Constructing ionic highway in capacitive deionization via integrated electrodes based on bifunctional ionomer

In this work, bifunctional ionomeric capacitive deionization (BICDI) electrode are constructed by using bifunctional ionomer as electrode binder and ion exchange material for the enhancement of desalination performance. Compared with traditional membrane capacitive deionization (MCDI) electrodes, the BICDI electrodes were fabricated by using the poly(arylene alkylene) based ionomer to substitute the PVDF binder and ion exchange membrane (IEM). The BICDI electrode based on bifunctional ionomer exhibits higher hydrophilicity, special ion exchange capability, as well as excellent electrochemical properties in comparsion with that of MCDI electrode counterpart. The built-in ionic groups in poly(arylene alkylene) based ionomers could create interconnected ionic highway between different electrode particles, which encourages effective ion transport. The desalination results validated that the salt adsorption capacity (SAC) of carbon-based BICDI electrodes reached 19.2 mg g−1, which is 2.2 times that of MCDI electrodes during adsorption-desorption cycles. Meanwhile, BICDI electrode possesses exceptional charge efficiency (96.6 %), which is much higher than that of MCDI (76.8 %). In the case of BICDI device, the ionomer utilization rate increased by a factor of 88 compared to that of ion exchange membrane in MCDI device. Especially, the economic cost of the integrated BICDI electrodes module is only $35 m−2, which is much cheaper than that in conventional MCDI system ($520 m−2). It is reasonable to believe that the integrated BICDI electrode incorporated with charged bifunctional ionomer proposed in this work provide novel insights and strategies for the high-performance and large-scale CDI applications.

Exploring the mechanical, rheological, and thermal performance of self‐reinforced composites based on polyamides and multi‐walled carbon nanotubes

AbstractSelf‐reinforced composites (SRCs) based on different blends of PA6, PA12, and multi‐walled carbon nanotubes (MWCNTs) as matrices and a PA6.6 plain woven fabric as reinforcement were prepared by the film stacking method. The morphology of the SRCs was analyzed using optical and scanning electron microscopy, both on cryo‐fractured and included polished cross‐sections samples. Rheological measurements were performed to assess the materials microstructure and thermal stability. In addition, uniaxial tensile tests were carried out to determine mechanical properties such as stiffness, strength, strain at break, and tensile toughness. The assessment of failure mechanisms was performed through acoustic emission in situ during tensile tests. Furthermore, fracture tests were carried out to evaluate the impact of incorporating MWCNTs on SRCs failure and fracture behavior. The obtained results suggest a notable improvement in the mechanical properties of the SRCs compared with the matrices, that is, tensile strength increased by 132% for SRC‐0, 83% for SRC‐0.5, 54% for SRC‐2.5, and only by 13% for SRC‐8. This study indicates that these SRCs appear as promising materials for high performance applications, which also require multifunctional characteristics.

Enhancing ferroelectric performance in hafnia-based MFIS capacitor through interface passivation and bulk doping

In recent times, there has been a notable surge of interests in hafnia (HfO2)-based ferroelectrics, primarily due to their remarkable ferroelectric properties employed in ultra-thin configurations, alongside their compatibility with the conventional CMOS manufacturing process. In order to harness the full potential of HfO2-based films for high-performance non-volatile memory applications, it is imperative to enhance their ferroelectric characteristics and durability. This study introduces a straightforward approach aimed at augmenting the ferroelectric performance of Hf x Zr1−x O2 (HZO) films deposited on silicon (Si) substrates through the engineering of oxygen vacancies (V O). The results of this endeavor demonstrate a significant enhancement in ferroelectric performance, characterized by a 2Pr value of 47 μC cm−2 and impressive endurance, enduring up to 108 cycles under an 8 MV cm−1 electric field without the need of a wake-up process. This marked improvement can be attributed to a dual-pronged approach, involving the incorporation of an Al2O3 interlayer and the introduction of Al atoms into the HZO film. The Al2O3 interlayer primarily serves to mitigate the presence of oxygen vacancies at the interface, while the introduction of Al dopants elevates the concentration of oxygen vacancies within the bulk material. This modulation of oxygen vacancy concentration proves instrumental in facilitating the formation of a ferroelectric o-III phase within the HZO-based films, thereby further augmenting their ferroelectric performance. This innovative and effective strategy offers an alternative avenue for enhancing the ferroelectric properties of materials characterized by a fluorite crystal structure.

Heteroatom doping carbon film derived from hyphae as a self-supporting cathode for advanced lithium sulfur batteries

Much attention has been paid to lithium sulfur battery due to its high energy density. However, low S loading and poor cycling stability have hindered their commercialization. In this work, a porous carbon film with rich heteroatom doping was prepared from the Penicillium chrysogenum hyphae film by freezing drying and high-temperature carbonization. Then the carbon film loaded polysulfide solution was utilized as a self-supporting cathode for Li-S batteries. The self-supporting cathode exhibited good rate performance (513.1 mAh/g at 1C) and improved cycling stability (more than 400 cycles) under a high current density (0.5C). This is mainly attributed to the abundant heteroatoms that provided active sites with superior adsorption ability for lithium polysulfide, which not only enhanced the cycling stability but also facilitated the conversion kinetics. Besides, the fibrous network morphology with affluent porous structures inherited from hyphae provided a large specific surface area and sufficient space for accommodating active substances. This work shows the great potential of hyphae derived porous carbon electrodes for high-performance energy storage applications.