Compact System Research Articles

Review of Cockcroft-Walton High Voltage Low Current DC Power Supplies

High-voltage power supplies are key for developing particle accelerators, neutron generators, x-ray systems, ion implantation, etc. This paper reviews various developed voltage low current power supplies based on Cockcroft-Walton voltage multiplier circuits for accelerator-based neutron sources and other industrial and medical applications. The paper presents a detailed review of the topology of the power supply used for the high voltage generation, the key design parameters, key active and passive components used in the High Voltage (HV) system, key experimental results, protection and measurement circuit used in the power supply and about the system performance. The improvement that occurred in the size and performance of the power supplies due to the development in the technology of the magnetic components, semiconductors and energy storage devices in successive years is apparent in the discussion. Finally challenges and possible solutions for the compact design and system performance are concluded for the development of high voltage low current power supplies.

Detection of Novel spa Types in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus in Iraq

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a gram-positive bacterium that is an opportunistic pathogen, causing infections in hospital settings and communities. MRSA has become a significant and increasing problem in Iraq. The aim of this study was to evaluate the genetic mutations of MRSA strains, especially in the spa gene, isolated from patients in Wassit, Iraq.Methods and Results: Biochemical tests were conducted to identify S. aureus isolates and then on MRSA. The MRSA was identified by the Chrome Agar method and confirmed by PCR with genotyping of the mecA gene. The disk diffusion method was used to detect antibiotic resistance to three different common antibiotics used at Wassit hospitals. The Vitek-2 compact system was utilized for the detection of the minimum inhibitory concentration (MIC) of vancomycin. All MRSA strains in this study were tested to screen the mecA gene, with 21 strains subjected to the molecular typing method for the spa gene. Out of 166 samples, 132(79.5%) contained S. aureus and 34(20.4%) were identified as MRSA. Genotyping showed that out of 34 MRSA, 31(91.2%) isolates were mecA-positive. The spa gene was detected in 21(61.8%) isolates out of 34 MRSA samples. The spa typing of 21 MRSA samples revealed four different spa types, as follows: t386 (3/14.3%), t3576 (1/4.8%), t10002 (1/4.8%), and t10234 (1/4.8%). High polymorphism rates were shown in isolates of spa type t386. Conclusion: Our data represent the first report to detect novel mutations in the spa gene in the MRSA clinical isolates from Wassit hospitals, Iraq.

Binary Coalescences as Sources of Ultrahigh-Energy Cosmic Rays.

Binary coalescences are known sources of gravitational waves (GWs) and they encompass combinations of black holes (BHs) and neutron stars (NSs). Here we show that when BHs are embedded in magnetic fields (B's) larger than approximately 10^{10} G, charged particles colliding around their event horizons can easily have center-of-mass energies in the range of ultrahigh energies (≳10^{18} eV) and become more likely to escape. Such B-embedding and high-energy particles can take place in BH-NS binaries, or even in BH-BH binaries with one of the BHs being charged (with charge-to-mass ratios as small as 10^{-5}, which do not change GW waveforms) and having a residual accretion disk. Ultrahigh center-of-mass energies for particle collisions arise for basically any rotation parameter of the BH when B≳10^{10} G, meaning that it should be a common aspect in binaries, especially in BH-NS ones given the natural presence of a B onto the BH and charged particles due to the magnetosphere of the NS. We estimate that the number of ultrahigh center-of-mass collisions ranges from a few up to millions before the merger of binary compact systems. Thus, binary coalescences may also be efficient sources of ultrahigh energy cosmic rays (UHECRs) and constraints to NS/BH parameters would be possible if UHECRs are detected along with GWs.

Roadmap for Optical Metasurfaces.

Metasurfaces have recently risen to prominence in optical research, providing unique functionalities that can be used for imaging, beam forming, holography, polarimetry, and many more, while keeping device dimensions small. Despite the fact that a vast range of basic metasurface designs has already been thoroughly studied in the literature, the number of metasurface-related papers is still growing at a rapid pace, as metasurface research is now spreading to adjacent fields, including computational imaging, augmented and virtual reality, automotive, display, biosensing, nonlinear, quantum and topological optics, optical computing, and more. At the same time, the ability of metasurfaces to perform optical functions in much more compact optical systems has triggered strong and constantly growing interest from various industries that greatly benefit from the availability of miniaturized, highly functional, and efficient optical components that can be integrated in optoelectronic systems at low cost. This creates a truly unique opportunity for the field of metasurfaces to make both a scientific and an industrial impact. The goal of this Roadmap is to mark this "golden age" of metasurface research and define future directions to encourage scientists and engineers to drive research and development in the field of metasurfaces toward both scientific excellence and broad industrial adoption.

Low-cost dual-comb spectrometer for CO2 monitoring based on gain-switched semiconductor lasers

Dual-comb spectroscopy (DCS) is an emerging technique that has attracted the attention of the research community due to its fast data acquisition and high-spectral resolution properties. Despite its versatility and mechanical stability, the complexity and cost of high performance DCS are still experimentally challenging. We propose a simple and compact DCS system that significantly reduces system costs by incorporating three low-cost key components: direct digital synthesizers and step recovery diodes in the signal generator to operate the lasers under gain-switching regime, and a software-defined radio as a digitizer. The viability of this configuration is demonstrated by performing DCS measurements of carbon dioxide (CO2), with a standard deviation of residual error of only ∼ 0.01. These results will pave the way to the commercial availability of compact, high-resolution DCS systems.

Determining the I/O point policy in a robotic live-cube compact storage system

The robotic live-cube compact storage system can provide a higher storage capacity and more flexible throughput than other automated warehousing systems. The extant studies usually fix the input/output point at the bottom-left of such storage systems and have not investigated other configurations of the input/output point. In this study, we propose six policies for the configuration of the input/output point and evaluate their performance by using an analytical model and simulations. A sensitivity analysis is carried out by considering different shape-related factors, system heights, and energy consumption to explore the optimal configuration of the input/output point. For most input/output point policies, a shape factor (length divided by depth) of 0.5 results in good system performance in terms of retrieval time. When using optimal system dimension, the input/output point located in the upper-middle part along the length and depth performs best compared with other policies. Specifically, this configuration reduces the retrieval time by 40.23% and energy consumption by 42.31% compared with the bottom-left corner input/output point. We find that there exists a trade-off among the cost of setup, number of empty grids, and retrieval time when varying the number of input/output points.

High-order sensory processing nanocircuit based on coupled VO2 oscillators

Conventional circuit elements are constrained by limitations in area and power efficiency at processing physical signals. Recently, researchers have delved into high-order dynamics and coupled oscillation dynamics utilizing Mott devices, revealing potent nonlinear computing capabilities. However, the intricate yet manageable population dynamics of multiple artificial sensory neurons with spatiotemporal coupling remain unexplored. Here, we present an experimental hardware demonstration featuring a capacitance-coupled VO2 phase-change oscillatory network. This network serves as a continuous-time dynamic system for sensory pre-processing and encodes information in phase differences. Besides, a decision-making module for special post-processing through software simulation is designed to complete a bio-inspired dynamic sensory system. Our experiments provide compelling evidence that this transistor-free coupling network excels in sensory processing tasks such as touch recognition and gesture recognition, achieving significant advantages of fewer devices and lower energy-delay-product compared to conventional methods. This work paves the way towards an efficient and compact neuromorphic sensory system based on nano-scale nonlinear dynamics.

Assessing Different PCR Master Mixes for Ultrarapid DNA Amplification: Important Analytical Parameters.

The basic principles of ultrafast plasmonic PCR have been promulgated in the scientific and technological literature for over a decade. Yet, its everyday diagnostic utility remains unvalidated in pre-clinical and clinical settings. Although the impressive speed of plasmonic PCR reaction is well-documented, implementing this process into a device form compatible with routine diagnostic tasks has been challenging. Here, we show that combining careful system engineering and process control with innovative and specific PCR biochemistry makes it possible to routinely achieve a sensitive and robust "10 min" PCR assay in a compact and lightweight system. The critical analytical parameters of PCR reactions are discussed in the current instrument setting.

Design, development and characterization of Blumlein Pulse Forming Line based pulsed power system for High Power Microwave source research

This paper describes a complete cycle of designing, developing, and characterising a Pulsed Power System (PPS) and generating microwaves using the relativistic source. For low impedance relativistic High Power Microwave (HPM) sources, Blumlein Pulse Forming Line (BPFL) based high voltage pulsed power systems are the most suited. An HPM source such as a virtual cathode oscillator (VIRCATOR) operating in nanosecond durations consists of a primary voltage source that charges a Marx pulse generator’s capacitor bank over a long time. The requirements of a diode load are met by compressing the output pulse width of a Marx generator by a BPFL. This article describes the novel design, construction and characterization of a circulating De-Ionized (DI) water insulated BPFL pulsed power system. A novel approach of insulating gas filled Marx generator of this class/rating is attempted. A pulse power system consisting of high pressure gas insulated Marx generator and circulating DI water-based BPFL was developed and experimented with the resistive load as well as HPM source. The PSPICE simulation of the Blumlein circuit for various load conditions is described. Criticalities in the design of end bushings are elaborated along with the development and testing of a compact BPFL-based pulsed power system.

Simultaneous sensing profiles of beam attenuation coefficient and volume scattering function at 180° using a single-photon underwater elastic-Raman lidar.

Lidar has emerged as a promising technique for vertically profiling optical parameters in water. The application of single-photon technology has enabled the development of compact oceanic lidar systems, facilitating their deployment underwater. This is crucial for conducting ocean observations that are free from interference at the air-sea interface. However, simultaneous inversion of the volume scattering function at 180° at 532 nm (βm) and the lidar attenuation coefficient at 532 nm (K l i d a r m) from the elastic backscattered signals remains challenging, especially in the case of near-field signals affected by the geometric overlap factor (GOF). To address this challenge, this work proposes adding a Raman channel, obtaining Raman backscattered profiles using single-photon detection. By normalizing the elastic backscattered signals with the Raman signals, the sensitivity of the normalized signal to variations in the lidar attenuation coefficient is significantly reduced. This allows for the application of a perturbation method to invert βm and subsequently obtain the K l i d a r m. Moreover, the influence of GOF and fluctuations in laser power on the inversion can be reduced. To further improve the accuracy of the inversion algorithm for stratified water bodies, an iterative algorithm is proposed. Additionally, since the optical telescope of the lidar adopts a small aperture and narrow field of view design, K l i d a r m tends to the beam attenuation coefficient at 532 nm (cm). Using Monte Carlo simulation, a relationship between cm and K l i d a r m is established, allowing cm derivation from K l i d a r m. Finally, the feasibility of the algorithm is verified through inversion error analysis. The robustness of the lidar system and the effectiveness of the algorithm are validated through a preliminary experiment conducted in a water tank. These results demonstrate that the lidar can accurately profile optical parameters of water, contributing to the study of particulate organic carbon (POC) in the ocean.

Sub-50 fs pulses generation from an all-fiber monolithic gain-managed nonlinear amplifier with CFBG-based pre-compressor

We demonstrate an all-fiber monolithic laser source from a gain-managed nonlinear (GMN) fiber amplifier with a CFBG-based pre-compressor that generates high-contrast pulses with a repetition rate of 80 MHz, average power of 1.6 W, and pulse duration of sub-50 fs. The compressed pulse quality can be optimized by tuning the parameters of the seed pulses injected into the GMN amplifier by controlling the pump power of the fiber pre-amplifier. This compact and cost-effective laser system is a simplified design of the GMN amplification-based femtosecond fiber laser systems. With alignment-free characteristics in the amplifiers and clean compressed pulses, it is easy to assemble and use in applications such as multi-photon microscopy.

A Seamless, Large‐Area Silk‐based Interface for Immersive On‐Palm Tactile Feedback

AbstractWearable haptic devices are developed as key components to enhance the highly immersive metaverse experience. However, conventional haptic devices enabling the sensation and interaction with virtual objects are often constrained by their bulky design, tethered operation, and physical interference with the skin, especially when integrated with human hands. In this study, a cross‐interface modification process that achieves the conversion of multilayered silk fibroin films from rigid to soft is reported. This modification is favorable for applications involving large angles and multiple degrees of freedom motions. By applying electrical current through silk‐based electrodes and utilizing a self‐designed circuit, virtual tactile sensations can be generated on the entire palm. The high flexibility, stretchability, tailorable modulus, and water permeability of silk substrates enable the electrotactile devices to maintain their functionalities without impeding fine movements and natural tactile sensations in the hand. This compact electrotactile system serves as a user's new interactive terminal through wireless communications. The intimate contact interfaces reduce the unstable adhesion commonly encountered in electrotactile applications, ensuring consistent sensation during hand motions. These materials design methods and integrated systems represent a significant advancement in fabricating and integrating large‐area soft electronics.

Compact fiber microsphere coupling system and its temperature response characteristics

The compact and free-stand fiber-microsphere system was established to produce the whispering gallery modes (WGMs). In this system, the BaTiO3 microsphere in the diameter of ∼73 μm was placed and fixed in an air cone, which was prepared by cascade-splicing and tapering a single mode fiber with a hollow core fiber. Either the wavelength or the intensity of the reflected spectra changes as function of the environmental temperature. The corresponding sensitivities were determined to be 9.75 pm/°C and −0.0133 dBm/°C, respectively, during 30 °C–70 °C. The proposed composite fiber WGMs system is compact, stable, moveable, easily-integrated and flexibly-adjustable, which will pave its promising potential way to developing the novel biochemical probes with high performance.

Monitoring and evaluation of a compact system for gray water treatment and agricultural use

Water reuse is necessary for industrial, commercial and domestic activities, being a reality in several countries, but not yet widespread in Brazil, an efficient instrument for managing water resources and minimizing water scarcity in the semi-arid region. The aim is to monitor a compact gray water treatment and agricultural use station, consisting of a septic tank, anaerobic filter and artificial ultraviolet reactor, which was installed in an experimental area of the Universidade Federal Rural do Semi-Árido, Mossoró/RN. From October to December 2017, the system's treatment performance was evaluated through physical-chemical analyses: Biochemical Oxygen Demand, Chemical Oxygen Demand, pH, electrical conductivity and turbidity, microbiological: Total coliforms and Escherichia coli of gray water with and without treatment, in order to meet the standards established for water reuse for agricultural and forestry purposes. The results indicated that the system showed efficiency in removing the studied variables and, consequently, meeting the maximum permissible standards, with the exception of turbidity and Escherichia coli.

Current progress in semi-batch reverse osmosis for brackish water desalination

Semi-batch reverse osmosis (SBRO) is an innovative membrane process renowned for its compact system and high recovery in desalination and water reuse. While academic research provides valuable insights, aligning it with real-world implementation is crucial. The study aims to understand the current progress in SBRO for brackish water desalination by identifying performance disparities between academic research and practical applications, evaluating practical performances under realistic parameters, and proposing future research directions. Through gathering and comparing data from SBRO research and practices, performance disparities between theoretical projections and real-world applications were identified. The analysis revealed that specific energy consumption (SEC) in academic research had been underestimated by applying impractical pump efficiencies, and permeate quality was often neglected. To assess the practical SEC and permeate quality of SBRO, engineering design calculations were performed with realistic parameters. Based on the evaluation, the importance of maintaining suitable recovery and incorporating a permeate tank was emphasized to avoid a significant increase in SEC and to stabilize water quality, respectively. Given the challenges of the SBRO system, the discussion further outlined research directions addressing issues in energy efficiency, permeate quality, membrane fouling/scaling, and practical design/operation. It recommended considering these practical aspects for the broader applications of SBRO.

Design, Fabrication, and Experimental Analysis of a PV Panel for a Smart Sunflower System

The Smartflower, an innovative compact energy-generation system inspired by sunflowers, stands out in energy innovation. Unlike traditional photovoltaic (PV) panels, it integrates foldable solar cells within a foundational structure for solar tracking aligned with the sun's path. The present paper focuses on designing, fabricating, and analyzing a proposed Smartflower-PV panel solar system. The study aims to comprehensively evaluate the performance of the proposed PV panel under different atmospheric conditions. The significant impact of insolation and temperature on the panel's efficiency was revealed by comparing empirical results from the PV sunflower panel with analytical calculations using MATLAB (m. file code). Enhanced solar radiation improved the system’s performance and efficiency, resulting in higher power output. Analytical insights showed a direct correlation between a 104% increase in solar radiation and parallel increases of 115% in peak power production and 100% in output current. Conversely, higher temperatures reduced power output, with a 400% temperature rise causing an 11.11% power reduction. Empirical observations align with analytical analyses under equivalent conditions, validating the model’s accuracy. This study serves as a catalyst and guide for completing and advancing the Smartflower system's manufacturing, including control, tracking, and the entire energy-generation framework.

Bionic visual-audio photodetectors with in-sensor perception and preprocessing.

Serving as the "eyes" and "ears" of the Internet of Things, optical and acoustic sensors are the fundamental components in hardware systems. Nowadays, mainstream hardware systems, often comprising numerous discrete sensors, conversion modules, and processing units, tend to result in complex architectures that are less efficient compared to human sensory pathways. Here, a visual-audio photodetector inspired by the human perception system is proposed to enable all-in-one visual and acoustic signal detection with computing capability. This device not only captures light but also optically records sound waves, thus achieving "watching" and "listening" within a single unit. The gate-tunable positive, negative, and zero photoresponses lead to highly programmable responsivities. This programmability enables the execution of diverse functions, including visual feature extraction, object classification, and sound wave manipulation. These results showcase the potential of expanding perception approaches in neuromorphic devices, opening up new possibilities to craft intelligent and compact hardware systems.

Unveiling Fundamentals of Multi-Beam Pulsed Laser Ablation in Liquids toward Scaling up Nanoparticle Production.

Pulsed laser ablation in liquids (PLAL) is a versatile technique to produce high-purity colloidal nanoparticles. Despite considerable recent progress in increasing the productivity of the technique, there is still significant demand for a practical, cost-effective method for upscaling PLAL synthesis. Here we employ and unveil the fundamentals of multi-beam (MB) PLAL. The MB-PLAL upscaling approach can bypass the cavitation bubble, the main limiting factor of PLAL efficiency, by splitting the laser beam into several beams using static diffractive optical elements (DOEs). A multimetallic high-entropy alloy CrFeCoNiMn was used as a model material and the productivity of its nanoparticles in the MB-PLAL setup was investigated and compared with that in the standard single-beam PLAL. We demonstrate that the proposed multi-beam method helps to bypass the cavitation bubble both temporally (lower pulse repetition rates can be used while keeping the optimum processing fluence) and spatially (lower beam scanning speeds are needed) and thus dramatically increases the nanoparticle yield. Time-resolved imaging of the cavitation bubble was performed to correlate the observed production efficiencies with the bubble bypassing. The results suggest that nanoparticle PLAL productivity at the level of g/h can be achieved by the proposed multi-beam strategy using compact kW-class lasers and simple inexpensive scanning systems.

PresTo: A liquid-filled camera for low-cost imaging in the deep sea

Deep-sea imaging systems are traditionally expensive to manufacture and are physically scaled depending on the operating depth of their housing and the internal camera/lens components. Liquid and epoxy filled instrument designs are increasing in popularity as a way to reduce the cost and size of deep-sea housings. Recent advances in 3D printing have facilitated rapid prototyping of these pressure tolerant deep-sea designs. This study presents the design of PresTo, a liquid-filled pressure tolerant camera manufactured using SLA 3D printing methods. This is a compact and low-cost imaging system filled with deionized water and coated in epoxy to remove all implodable air volumes in the camera. The lens design for PresTo can be easily customized to any focal length and with zoom capabilities using a magnetically driven focus mechanism. Images taken with PresTo likely have minimal image distortions compared to other underwater cameras with flat viewports because, due to the elimination of a flat viewport solely for the reason of pressure isolation, there is an inherent reduction in the refractive indices of the surrounding environment and internal medium. The presented system has been field-tested to depths exceeding 1700 m and has been hydrostatically tested to function beyond 2600 m.

Development of Compact and Robust Physical System for Strontium Optical Lattice Clock

Compact and robust optical clocks are significant in scientific research and engineering. Here, we present a physical system for a strontium atomic optical clock with dimensions of 465 mm × 588 mm × 415 mm and a weight of 66.6 kg. To date, this is one of the most compact physical systems ever reported. The application of the magnetic shielding box in this physical system allowed the effect of external magnetic field fluctuation on cold atoms to be negligible. The physical system passed rigorous environmental tests and remained operational. A wavelength meter integrated in this physical system could monitor the wavelengths of the incident laser, and it could automatically calibrate the wavelengths of all lasers using a microcomputer. This compact and robust physical system could be a hardware basis for demonstrating a portable optical clock or even a space optical clock.