Portable Applications Research Articles

Onboard Miniature Jet Fuel Desulfurizer for Mobile Fuel Cell Power Systems

Owing to its high energy density and wide availability, jet fuel is a promising fuel for solid oxide fuel cell (SOFC) power systems. However, fuel‐reforming catalysts and SOFC anodes are easily poisoned by sulfur compounds present in the jet fuel. Therefore, effective removal of sulfur from the jet fuel is essential before its feeding to the SOFC system. Herein, a novel adsorptive desulfurization reactor for onboard desulfurization of jet fuel in mobile SOFC systems is developed. A laser‐based 3D printing method is used to fabricate the one‐piece stainless steel reactor that significantly simplifies the assembly and reduces the overall weight. The desulfurization performance of the reactor is evaluated using a regenerable nickel‐based sorbent under varying operating conditions. A strong influence of temperature and fuel flow rate on the desulfurization performance is observed. The results confirm that the developed desulfurization system is capable of reducing the sulfur content in jet fuel to a few ppm to sub‐ppm level. The proposed desulfurization system offers unique advantages in terms of geometric design flexibility, space optimization, scalability, and modularity for any onboard and/or on‐demand deep desulfurization needs in addition to fuel cell power systems for transport and portable applications.

Electricity and hydrogen production by integrating two kinds of fuel cells with copper chlorine thermo-chemical cycle

An innovative cogeneration system based on a solid oxide fuel cell (SOFC) and copper chlorine cycle is being investigated. Instead of directly making electricity by any thermodynamic cycle or thermoelectric generator, the waste heat from SOFC should be used to make hydrogen through the copper-chlorine cycle (Cu–Cl). A portable polymer exchange membrane fuel cell (PEMFC) has been suggested due to its compatibility with portable and non-portable applications. The obtained results reveal that increasing the current density of SOFC results in higher methane consumption, output power, overpotentials, and hydrogen production. Furthermore, temperature variation does not have as much influence on power generation and efficiency as current density, where the system efficiency, when operating at 0.7 A/cm2 and SOFC operating temperature of 900–1200 K, varies between 40.4 % and 46.3 %. Regarding the methane flow rate, as it increases, the output power increases as well, but the efficiency falls. The system's greatest power output is 677.5 kW and occurs at a methane flow rate of 2.13 mol/s, although the system efficiency is just 39.7 % at that point. Most importantly, SOFC generates nearly 65 % of the total power, while PEMFC generates around 35 %. Therefore, the percentage of additional power that PEMFC can produce is around 55 %.

A Security Framework for the Mobile Application Using Color Barcode

The thorough objective of this work is to establish a QR code framework for a secret key-secured concept. It is based on the asymmetric key verification context. SSH, server QR code is used for website login. The client-side stored RSA private key for encrypting information by implementing QR code verification, but presently QR codes are in the form of two-dimensional images for encryption purposes. The cell phones take the image of the QR code of the user and send a cryptographic reply to the server for broad verification. The upheld shading QR code inside the portable application for misusing the cyan (C), fuchsia (M), and yellow (Y) print the channels, and for the print shading by red (R), unpracticed (G), and blue channels, severally, apply the catch the shading picture. The hiding process embeds the quantized QR code so that it will not cause any visible distortion in the cover images and hides the QR code inside a color image. The results show the proposed method has high imperceptibility, integrity, and security.

A Mini-Review on Metal Oxide Semiconductor Gas Sensors for Carbon Monoxide Detection at Room Temperature

Carbon monoxide can cause severe harm to humans even at low concentrations. Metal Oxide Semiconductor (MOS) carbon monoxide gas sensors have excellent sensing performance regarding sensitivity, selectivity, response speed, and stability, making them very desirable candidates for carbon monoxide monitoring. However, MOS gas sensors generally work at temperatures higher than room temperature, and need a heating source that causes high power consumption. High power consumption is a great problem for long-term portable monitoring devices for point-of-care or wireless sensor nodes for IoT application. Room-temperature MOS carbon monoxide gas sensors can function well without a heater, making them rather suitable for IoT or portable applications. This review first introduces the primary working mechanism of MOS carbon monoxide sensors and then gives a detailed introduction to and analysis of room-temperature MOS carbon monoxide sensing materials, such as ZnO, SnO2, and TiO2. Lastly, several mechanisms for room-temperature carbon monoxide sensors based on MOSs are discussed. The review will be interesting to engineers and researchers working on MOS gas sensors.

Efficient water recovery and power generation system based on air-cooled fuel cell with semi-closed cathode circulation mode

Air-cooled proton exchange membrane hydrogen fuel cell with on-line hydrogen production by hydrolysis has potential for portable applications due to its high volumetric power density and self-humidification. However, plenty of reserve water significantly reduces the power density of fuel cell system. Moreover, water recovery from fuel cell tail gas is difficult, because the tail gas humidity is very low due to excess cathode air as coolant. In this work, the dead-ended anode and semi-closed cathode proton exchange membrane fuel cell is proposed to achieve efficient water recovery and energy conversion via semi-closed cathode circulation mode. In this mode, cathode O2-poor tail gas is recycled as coolant instead of fresh air, which helps to enlarge the tail gas humidity by reducing the stoichiometric ratio of cathode to anode gas. The system lumped model with detailed component description is developed for optimization. >96% water production can be recycled under atmosphere temperature. The demand of fresh air is greatly reduced from 56 to 2 times of the consumption. Besides, the multi-objective optimization between water recovery and electrochemical performance shows high-efficiency water recovery of 94.70% and high energy conversion efficiency of 54.82%.

СУЧАСНІ ТЕНДЕНЦІЇ РИНКУ ЛІТІЙ-ІОННИХ БАТАРЕЙ ДЛЯ ЕЛЕКТРОННИХ ПРИСТРОЇВ

A detailed review is presented in this work on the future perspectives of lithium-ion batteries with emphasis on potential of their application in portable electronic devices. As specific energy and power are key criteria in portable electronics applications, the Li-ion batteries have a clear advantage over other chemistries. The portable electronics sector requires miniaturization of batteries, while maintaining high capacity and power as well as complying with strict safety standards. Although LCO batteries still are dominant chemistry for portable electronics, it will gradually lose market share to NMC and NCA cells. These also have advantage of lower content of cobalt, which will become necessary within the overall strongly growing Li-ion battery market.

A Compact Self Isolated UWB-MIMO Antenna with WiMAX and WLAN Band Notched Characteristics for Portable Wireless Applications

A Compact Self Isolated UWB-MIMO Antenna with WiMAX and WLAN Band Notched Characteristics for Portable Wireless Applications

High Porous Activated Carbon Electrode Derived from Watermelon Peel Biomass Exposed with DC Glow Discharge Plasma Applied for Super Capacitors

The growing demand for sustainable and environmentally-friendly technologies has spurred the exploration of innovative methods for waste management and resource utilization. Among the various bio-wastes generated globally, watermelon peel emerges as a significant contributor. To characterize carbon materials in the presence of functional groups, for morphological analysis, and intensity, we subjected activated fruit peel carbon to X-ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman studies. Furthermore, we examined its electrochemical performance. Another method used to assess wettability is the contact angle. Watermelon-rind-activated carbon was exposed to a DC glow discharge oxygen and air plasma with a 450 V applied potential. The air-treated carbon demonstrated a noteworthy capacitance of 1669 F g−1 at 0.5 mA g−1 in a 2 M KOH electrolyte. Our study found that the properties of the activated carbon were enhanced through cold plasma treatment. This research provides valuable insights into the potential resources of fruit peels and proposes a novel adsorbent with cost-effective advantages in supercapacitors, which could provide effective energy storage for portable gadgets, electric cars, and renewable energy systems, thus presenting a solution for sustainable waste management.

Multiplier Design Based on Booth and Sequential Algorithm

Research on cellular networks and low-power electronic devices has ramped up in recent years, thanks to the proliferation of portable and mobile systems. There are many portable applications in the present day that require low power (smaller and more efficient batteries) and more milli ampere hours than before. As a result, designing low-power devices has grown in importance as a performance criterion. Multipliers arrangement (it is an organized set of adders) and delay make up the basic construction of a infinite impulse response filter. This paper deals with analytic procedure for performance evaluation to reduce time and RAM usage throughout the computation process. The Booth and Sequential multipliers have been used to simulate, and implement in this article. Using the Sequential and Booth Algorithms, respectively. Comparative study is carried out utilising Xilinx 14.7 with the virtex 5 family, devices for bit lengths 4, 8, 16, and 32.

High-performance asymmetric pseudocapacitor based on NiCo2O4@MnO2 cathode and N-doped graphene anode

The design and fabrication of scalable energy storage systems are crucial for portable applications, demanding advanced materials through large-scale and facile processing. In this report, an asymmetric solid-state pseudocapacitor (ASPC) is assembled using a core–shell NiCo2O4@MnO2 composite and solution-processed nitrogen-doped graphene (N-GP) as the positive and negative electrodes, respectively. With interconnected porous structures, the electrodes based on N-GP and NiCo2O4@MnO2 offer high specific capacitance and rate capability, broad operation voltage, and a binder-free design with no added conductive agent. With these benefits, the ASPC with a PVA-KOH electrolyte exhibits a specific capacitance of 103.3F g−1 at 1 A/g and exceptional energy density of 36.73 Wh kg−1 at a power density of 792 W kg−1. In addition, the specific capacitance retention reaches 90.9 % after 5000 cycles, indicating excellent cycling stability. In the broader context of solid-state supercapacitors based on solution-processed graphene, this ASPC exhibits highly competitive performance, establishing it as a promising candidate for advanced energy storage.

Inception‐YOLO: Computational cost and accuracy improvement of the YOLOv5 model based on employing modified CSP, SPPF, and inception modules

AbstractThe demand for less complex and more accurate architectures has always been a priority since the broad usage of computer vision in everyday life, like auto‐drive cars, portable applications, augmented reality systems, medical image analysis etc. There are a lot of methods that have been developed to improve the accuracy and complexity of object detection, like the generations of R‐CNNs and YOLOs. However, these methods are not the most efficient architectures, and there is always room to improve. In this study, the 5th version of YOLO is employed and the improved architecture, Inception‐YOLO, is presented. The model significantly outperforms the SOTA YOLO family. Specifically, the improvements can be summarised as follows: impressive improvement of floating point operations (FLOPs) and number of parameters, as well as improvement in accuracy compared to the models with fewer FLOPs. All our presented approaches, like the optimized inception module, proposed structures for CSP and SPPF, and the improved loss function used in this research, work together to incrementally improve detection results, accuracy, demanded memory, and FLOPs simultaneously. For a glimpse of performance, the Inception‐YOLO‐S model hits 38.7% AP with 5.9M parameters and 11.5 BFLOPs and outperforms YOLOv5‐S with 37.4% AP, 7.2M parameters, and 16.5 BFLOPs.

Visual Sensor with Host-Guest Specific Recognition and Light-Electrical Co-Controlled Switch.

Perception of UV radiation has important applications in medical health, industrial production, electronic communication, etc. In numerous application scenarios, there is an increasing demand for the intuitive and low-cost detection of UV radiation through colorimetric visual behavior, as well as the efficient and multi-functional utilization of UV radiation. However, photodetectors based on photoconductive modes or photosensitive colorimetric materials are not conducive to portable or multi-scene applications owing to their complex and expensive photosensitive components, potential photobleaching, and single-stimulus response behavior. Here, a multifunctional visual sensor based on the "host-guest photo-controlled permutation" strategy and the "lock and key" model is developed. The host-guest specific molecular recognition and electrochromic sensing platform is integrated at the micro-molecular scale, enabling multi-functional and multi-scene applications in the convenient and fast perception of UV radiation, military camouflage, and information erasure at the macro level of human-computer interaction through light-electrical co-controlled visual switching characteristics. This light-electrical co-controlled visual sensor based on an optoelectronic multi-mode sensing system is expected to provide new ideas and paradigms for healthcare, microelectronics manufacturing, and wearable electronic devices owing to its advantages of signal visualization, low energy consumption, low cost, and versatility.

Prototype development of a fully coreless multi-stage axial-flux permanent-magnet machine (AFPM) through the performance comparison between single-stator double-rotor (SSDR) and double-stator single-rotor (DSSR) configurations

Cascading rotor and stator in axial flux permanent magnet (AFPM) machine is a beneficial concept to increase the power density without increasing the diameter of the machine. Multi-stage AFPM can provide higher torque capability in applications requiring high power density. In this regard single-stator double- rotor (SSDR) and double-stator single-rotor (DSSR) are efficient machines compared to single -stage AFPM. Since SSDR and DSSR are also considered modular units to make multi-stage AFPM, like single-stage AFPM, this paper makes a comparison with analysis between SSDR and DSSR AFPM machines. Based on 3-D finite element analysis (FEA), the air-gap magnetic flux, voltage, current, torque, torque ripple, power and power density, efficiency are comparatively investigated to evaluate their performance. Results show that fully coreless topology only be achieved in SSDR AFPM machine with a higher power density. Finally, a prototype multi-stage coreless generator has been developed using a single stator double rotor (SSDR) configuration to justify the fully coreless concept. This prototype coreless generator eliminates eddy current losses and reduces weight, making it a suitable option for certain portable applications.

Performance Portable Graphics Processing Unit Acceleration of a High-Order Finite Element Multiphysics Application

Abstract The Lawrence Livermore National Laboratory (LLNL) will soon have in place the El Capitan exascale supercomputer, based on advanced micro devices (AMD) graphics processing units (GPUs). As part of a multiyear effort under the National Nuclear Security Administration (NNSA) Advanced Simulation and Computing (ASC) program, we have been developing marbl, a next generation, performance portable multiphysics application based on high-order finite elements. In previous years, we successfully ported the Arbitrary Lagrangian–Eulerian (ALE), multimaterial, compressible flow capabilities of marbl to nvidia GPUs as described in Vargas et al. (2022, “Matrix-Free Approaches for GPU Acceleration of a High-Order Finite Element Hydrodynamics Application Using MFEM, Umpire, and RAJA,” Int. J. High Perform. Comput. Appl., 36(4), pp. 492–509). In this paper, we describe our ongoing effort in extending marbl's GPU capabilities with additional physics, including multigroup radiation diffusion and thermonuclear burn for high energy density physics (HEDP) and fusion modeling. We also describe how our portability abstraction approach based on the raja Portability Suite and the mfem finite element discretization library has enabled us to achieve high performance on AMD based GPUs with minimal effort in hardware-specific porting. Throughout this work, we highlight numerical and algorithmic developments that were required to achieve GPU performance.

High‐Performance Fully Transparent Ultraviolet Photodetector Fabricated Using GaN‐Based Schottky Barrier Photodiode

Transparent electronics is a burgeoning field with exciting potential for next‐generation “see‐through” devices. The creation of high‐performance fully transparent ultraviolet photodetectors (PDs) is essential for enabling wearable and portable applications. In this study, metal–semiconductor–metal (MSM) type Al‐doped ZnO (AZO)/GaN/AZO and indium tin oxide (ITO)/GaN/ITO‐transparent ultraviolet PDs, are initially designed, utilizing AZO‐ and ITO‐transparent conductive electrodes. In these investigations, it is revealed that AZO and ITO form Ohmic and Schottky contacts, respectively, with GaN. Subsequently, building on these findings, a fully transparent Schottky barrier photodiode (SBPD) is developed for ultraviolet photodetection using AZO/GaN/ITO. The SBPD displays a high responsivity (R) of 1.41 × 103 A W−1, a detectivity (D*) of 6.85 × 1014 Jones, and a photo‐to‐dark current ratio exceeding 1 × 104 at a − 5 V bias. Furthermore, the SBPD demonstrates an ultrahigh responsivity of 1.18 A W−1 at 0 V bias, indicating its potential as a self‐powered device under extreme conditions. In these results, the tremendous potential of the high‐performance and fully transparent GaN‐based SBPD is demonstrated for environmental monitoring, optical communication, military radar, and other fields.

Phosphorus-Containing Polymer Electrolytes for Li Batteries

Lithium-ion polymer batteries, also known as lithium-polymer, abbreviated Li-po, are one of the main research topics nowadays in the field of energy storage. This review focuses on the use of the phosphorus containing compounds in Li-po batteries, such as polyphosphonates and polyphosphazenes. Li-po batteries are mini-devices, capable of providing power for any portable gadget. From a constructive point of view, Li-po batteries contain an anode (carbon), a cathode (metal oxide), and a polymer electrolyte, which could be liquid electrolytes or solid electrolytes. In general, a divider is used to keep the anode and cathode from touching each other directly. Since liquid electrolytes have a generally high ionic conductivity, they are frequently employed in Li-ion batteries. In the last decade, the research in this field has also focused on solving safety issues, such as the leakage of electrolytes and risk of ignition due to volatile and flammable organic solvents. The research topics in the field of Li-po remain focused on solving safety problems and improving performance.

Enhancing service availability and resource deployment in IoT using a shared service replication method

In many real-world contexts, the Internet of Things (IoT) is valued for its capacity to facilitate the smooth operation of interoperable applications and services. It is critical to ensure the accessibility and replication of IoT resources to improve the agility of these applications. As a solution, the Network Function Virtualization (NFV) paradigm is embedded into the IoT design to leverage information from various endpoint applications better and maximize resource utilization. In this study, the Shared Replication Augmenting Method (SRAM) is proposed to increase resource usage in underutilized NFVs and maintain service availability simultaneously. The regressive decision-making learning used by SRAM enables the detection of NFV needs for data and application portability across various real-time use cases. This regression method can uncover data needs and their causes, allowing for prompt answers and more efficient use of available resources. The suggested SRAM technique dynamically modifies the procedure while considering computation-less function allocations, making it suitable for various interoperable applications. It distributes root-to-service virtualization and availability based on historical use and data replication. Therefore, SRAM improves resource usage by 7.09 % with no increase in latency or delays. It also increases service availability by 10.4 %, reduces latency by 11.89 %, eliminates backlogs by 11.1 %, and reduces data repetition by 8.97 %. This study enhances resource consumption and productivity in IoT settings by offering SRAM as a viable solution. The study's results prove its potential to reduce the occurrence of replication, delay, and queues while raising the availability of services.

Bias-independent subthreshold swing in ballistic cold-source field-effect transistors by drain density-of-states engineering

Low power consumption and stable performance insensitive to power supply are highly required for field-effect transistors integrated in portable technologies. Here, we report a mechanism of bias-independent sub-60 mV/dec subthreshold swing (SS) in ballistic cold-source field-effect transistors (CS-FETs) for portable electronics. Our first-principles and quantum-transport simulations demonstrate that, in the ballistic-transport regime, the energy alignment of the number of conduction modes (NOCM) between the drain and source electrodes is critical to achieving bias-independent SS of C31/MoS2-based CS-FETs. By revealing the connection between NOCM and density of states (DOS), we propose a device model to demonstrate how similar slopes of the NOCM and DOS in the drain falling into the gate window can stabilize the SS of the devices under different bias. This study underscores the significance of drain DOS engineering in the design of bias-insensitive CS-FETs for portable electronic applications.

Triboelectric Nanogenerator‐Enabled 3D Microporous Polydimethylsiloxane–Graphene Oxide Nanocomposite for Flexible Self‐Powered Humidity Sensing Applications

The imperative to meet the energy needs of contemporary electronic devices has spurred extensive exploration into self‐powered systems. Given the anticipated ubiquity of sensor networks in future cities, a novel battery‐free sensing paradigm, rooted in triboelectric nanogenerators (TENG), has gained prominence. Utilizing mechanical energy otherwise wasted daily for electricity generation presents a promising alternative to conventional sensors. Embedding the sensing electrode within the TENG structure enables the creation of gas sensors suitable for portable and wireless applications. This study focuses on fabricating a 3D microporous sponge of polydimethylsiloxane (PDMS) using sugar cubes and graphene oxide (GO) nanosheets. Leveraging the hydrophilic properties of the GO enhances moisture absorption, elevating the humidity sensor's responsivity. In addition, the porous structure not only improves sensitivity to high humidity but also mitigates surface saturation issues prevalent in nonporous sensors. The porous self‐powered sensor, composed of PDMS with 0.5 wt% of GO, exhibits a response of up to 2500%, quantified as ((ΔV/V) × 100%), to relative humidity changes from 20% to 99%. Furthermore, the response and recovery times stand at 1.2 and 2.3 s, respectively. These findings underscore the feasibility of integrating TENG electrodes, utilizing a porous PDMS–GO nanocomposite, to create various types of integrated gas sensors.

Radiation Detector Front-End Readout Chip with Nonbinary Successive Approximation Register Analog-to-Digital Converter for Wearable Healthcare Monitoring Applications.

A 16-channel front-end readout chip for a radiation detector is designed for portable or wearable healthcare monitoring applications. The proposed chip reads the signal of the radiation detector and converts it into digital serial-out data by using a nonbinary successive approximation register (SAR) analog-to-digital converter (ADC) that has a 1-MS/s sampling rate and 10-b resolution. The minimum-to-maximum differential and integral nonlinearity are measured as -0.32 to 0.33 and -0.43 to 0.37 least significant bits, respectively. The signal-to-noise-and-distortion ratio and effective number of bits are 57.41 dB and 9.24 bits, respectively, for an input frequency of 500 kHz and a sampling rate of 1 MS/s. The SAR ADC has a 38.9-fJ/conversion step figure of merit at the sampling rate of 1 MS/s. The proposed chip can read input signals with peak currents ranging from 20 to 750 μA and convert the analog signal into a 10-bit serial-output digital signal. The input dynamic range is 2-75 pC. The resolution of the peak current is 208.3 nA. The chip, which has an area of 1.444 mm × 10.568 mm, is implemented using CMOS 0.18-μm 1P6M technology, and the power consumption of each channel is 19 mW. This design is suitable for wearable devices, especially biomedical devices.