Powerful Output Research Articles

Estudio de teleconexión entre variables hidrológicas y climatológicas en una cuenca de cabecera del Rio Maipo para la aplicación de modelos de pronóstico

This study conducts a teleconnection analysis of the seasonal streamflow during the dry season (winter and summer) at the Olivares River basin, a headwater of the Maipo River basin, with traditional climate indices (Antarctic Oscillation, Niño1+2, and Niño3.4), new indices obtained from sea surface temperature (SST) anomaly spatial fields, and in situ hydrometeorological variables from the previous season to identify potential predictors for implementing seasonal streamflow forecast models in the study area. To illustrate the potential of the predictors identified, we fit multiple linear regression models (MLRM) for seasonal streamflow forecast for 0- and 3-month lead times. The forecasts are validated using the leave-1-year-out cross-validation (LOOCV) approach and performance metrics such as the Pearson correlation coefficient (R), BIAS, Nash-Sutcliffe efficiency (NSE), and continuous rank probability skill score (CRPSS). Results show a good performance of the forecast model for cross-validation with R and NSE values ranging from 0.55 to 0.95 and from 0.28 to 0.88 for 0- and 3-month lead times during the dry season. This early implementation provides good perspectives for implementing probabilistic seasonal streamflow forecasting models, which can provide a powerful output to develop robust water management strategies to tackle water scarcity in the study area.

Real-time Abnormal Detection of GWAC Light Curve based on Wavelet Transform Combined with GRU-Attention

Nowadays, astronomy has entered the era of Time-Domain Astronomy, and the study of the time-varying light curves of various types of objects is of great significance in revealing the physical properties and evolutionary history of celestial bodies. The Ground-based Wide Angle Cameras telescope, on which this paper is based, has observed more than 10 million light curves, and the detection of anomalies in the light curves can be used to rapidly detect transient rare phenomena such as microgravity lensing events from the massive data. However, the traditional statistically based anomaly detection methods cannot realize the fast processing of massive data. In this paper, we propose a Discrete Wavelet (DW)-Gate Recurrent Unit-Attention (GRU-Attention) light curve warning model. Wavelet transform has good effect on data noise reduction processing and feature extraction, which can provide richer and more stable input features for a neural network, and the neural network can provide more flexible and powerful output model for wavelet transform. Comparison experiments show an average improvement of 61% compared to the previous pure long-short-term memory unit (LSTM) model, and an average improvement of 53.5% compared to the previous GRU model. The efficiency and accuracy of anomaly detection in previous paper work are not good enough, the method proposed in this paper possesses higher efficiency and accuracy, which incorporates the Attention mechanism to find out the key parts of the light curve that determine the anomalies. These parts are assigned higher weights, and in the actual anomaly detection, the star is detected with 83.35% anomalies on average, and the DW-GRU-Attention model is compared with the DW-LSTM model, and the detection result f1 is improved by 5.75% on average, while having less training time, thus providing valuable information and guidance for astronomical observation and research.

Adaptive nanotube networks enabling omnidirectionally deformable electro-driven liquid crystal elastomers towards artificial muscles.

Artificial muscles that can convert electrical energy into mechanical energy promise broad scientific and technological applications. However, existing electro-driven artificial muscles have been plagued with problems that hinder their practical applications: large electro-mechanical attenuation during deformation, high-driving voltages, small actuation strain, and low power density. Here, we design and create novel electro-thermal-driven artificial muscles rationally composited by hierarchically structured carbon nanotube (HS-CNT) networks and liquid crystal elastomers (LCEs), which possess adaptive sandwiched nanotube networks with angulated-scissor-like microstructures, thus effectively addressing above problems. These HS-CNT/LCE artificial muscles demonstrate not only large strain (>40%), but also remarkable conductive robustness (R/R0 < 1.03 under actuation), excellent Joule heating efficiency (≈ 233 °C at 4 V), and high load-bearing capacity (R/R0 < 1.15 at 4000 times its weight loaded). In addition, our artificial muscles exhibit real-muscle-like morphing intelligence that enables preventing mechanical damage in response to excessively heavyweight loading. These high-performance artificial muscles uniquely combining omnidirectional stretchability, robust electrothermal actuation, low driving voltage, and powerful mechanical output would exert significant technological impacts on engineering applications such as soft robotics and wearable flexible electronics.

Squid-Inspired Powerful Untethered Soft Pumps via Magnetically Induced Phase Transitions.

Soft robots possess unique deformability and hence result in great adaptability to various unconstructive environments; meanwhile, untethered soft actuation techniques are critical in fully exploiting their potential for practical applications. However, restricted by the material's softness and structural compliance, most untethered actuation systems were incapable of achieving fully soft construction with a powerful output. While in Nature, with a fully soft body, a squid can burst high-pressure jet flow from a cavity that drives the squid to swim swiftly. Here, inspired by such a unique actuation strategy of squids, an entirely soft pump capable of high-pressure output, fast jetting, and untethered control is presented, and it helps a bionic soft robotic squid to achieve a high-efficient untethered motion in water. The soft pump is designed by a reversible liquid-gas phase transition of an inductive heating magnetic liquid metal composite that acts as an adjustable power source with high heat efficiency. In particular, being purely soft, the pump can yet lift ∼20 times its weight and achieve ∼3 times the specific pressure of the previous record. It may promote the application of soft robots with independent actuation, high output power, and embodied energy supply.

A multiband radio-frequency energy harvester for self-powered biosensor

This paper presents a novel nano-structure of radio frequency (RF) to direct current (DC) converter for the energy control unit in the biosensor. It is based on the Graëtz Bridge supplied with three-phase power (DP3). This circuit can be considered as the result of the proper combination of a common anode assembly and a common cathode assembly. In fact, the same three-phase converter structure was kept. The diodes have been replaced by six NMOS transistors connected in diodes. A number of capacitors have been added for each stage to boost voltage. The benefit of using this type of circuit is to obtain a powerful DC output signal with the smallest number of stages. The proposed architecture also enables MOS transistors to be driven by external 2.45 GHz voluntary signals originating from the implant's personal assistant. This would allow avoiding the use of transistor control circuits which are already power-consuming. For more power, the proposed converter receives two more involuntary global system for mobile signals (GSM) with 900 MHz and 1800 MHz frequencies bands in order to take advantage of the ambient energy. The proposed RF-DC converter efficiency reaches 62.8% for an input power equal to 10 dbm.

Dual Stage Speed Control of BLDC Motor Using Hybrid QPSO-CSO Technique

Systems for driving motors are frequently employed with renewable energy sources. By using cutting-edge methods and algorithms, the power converter controlling technology boosts performance. The switching state of the converter from the solar module’s generation unit is where the QPSO (Quantum Particle Swarm Optimization) technique is applied in the currently available work. The duty cycle depends on the swarm velocities, which indirectly depends on the QPSO parameters. Hence, the QPSO parameters inertia (W), and learning coefficients C1 and C2, were determined using the Cuckoo search algorithm (CSO). This approach helps to extract the most powerful solar panel output and continuously operate a BLDC motor performance increasing the power converter controlling technology by utilizing state-of-the-art techniques and algorithms. Every module of the suggested boost converter was examined by the experimental findings. Based on generation and load, a boost converter module is obtained. The Models for single-ended primary inductors (SEPIC) and zeta converters are contrasted with the suggested logic. The overall design model is done by using MATLAB/Simulink 2021a.

Highly Responsive Soft Electrothermal Actuator with High-Output Force Based on Polydimethylsiloxane (PDMS)-Coated Carbon Nanotube (CNT) Sponge.

Recently, soft actuators have been found to have great potential for various applications due to their ability to be mechanically reconfigured in response to external stimuli. However, the balance between output force and considerable strain constrains their potential for further application. In this work, a novel soft electrothermal actuator was fabricated by a polydimethylsiloxane (PDMS)-coated carbon nanotube sponge (CNTS). The results showed that CNTS was heated to 365 °C in ∼1 s when triggered by a voltage of 3.5 V. Consequently, due to the large amount of air inside, the actuator expanded in 2.9 s, lifting up to ∼50 times its weight, indicating an ultrafast response and powerful output force. In addition, even in water, the soft actuator showed quick response at a voltage of 6 V. This air-expand strategy and soft actuator design is believed to open a new horizon in the development of electronic textiles, smart soft robots, and so on.

Bio-inspired magnetic-driven folded diaphragm for biomimetic robot

Functional soft materials, exhibiting multiple types of deformation, have shown their potential/abilities to achieve complicated biomimetic behaviors (soft robots). Inspired by the locomotion of earthworm, which is conducted through the contraction and stretching between body segments, this study proposes a type of one-piece-mold folded diaphragm, consisting of the structure of body segments with radial magnetization property, to achieve large 3D and bi-directional deformation with inside-volume change capability subjected to the low homogeneous magnetically driving field (40 mT). Moreover, the appearance based on the proposed magnetic-driven folded diaphragm is able to be easily customized to desired ones and then implanted into different untethered soft robotic systems as soft drivers. To verify the above points, we design the diaphragm pump providing unique properties of lightweight, powerful output and rapid response, and the soft robot including the bio-earthworm crawling robot and swimming robot inspired by squid to exhibit the flexible and rapid locomotion excited by single homogeneous magnetic fields.

Development of a High-Speed Swimming Robot With the Capability of Fish-Like Leaping

Achieving fast and agile swimming still remains extremely challenging for a self-propelled robotic fish due to the constraint of actuator’s propulsion capability. In this article, we report an untethered bioinspired robotic fish, which combines a high-frequency oscillation and a compliant passive mechanism to realize fast swimming, high pitch maneuvers, and even the leaping motion. For pursuing the explosive propulsion of the robotic fish, we propose an actuation system with a powerful output and a compact structure. A dynamic model is established and indicates that the compliant joint is able to modulate the power transmitted to a caudal fin to affect its velocity in the return stroke for generating more peak thrust. The design is validated with extensive experimental results. Namely, the robotic fish can surprisingly reach up to a speed of 3.8 body lengths per second (BL/s). Compared to the case with a rigid joint, dramatic improvements, involving a speed of 1.2 BL/s and a swimming distance of 141.2 m (70.6%), have been obtained, which reveal that besides the high-frequency oscillation, the compliant passive mechanism is also of great significance to perform high-speed swimming. Additionally, the robotic fish demonstrates its high pitch maneuvers by performing an agile front flip motion with a radius of 0.4 BL and an average angular velocity of 439 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> /s. Most importantly, with a simple control strategy, our robotic fish can remarkably leap out of water completely. Results from this study provide significant insights into the innovative designs of next-generation robotic fishes, which require high speed and maneuverability.

Design and Testing of a Hollow Continuum Magnetic Millirobot with Multimodal Motion

Magnetic continuum millirobots have presented outstanding potential in ultrahigh-precision engineering including minimally invasive surgery, due to their flexible mechanical structures and dexterous manipulation. Traditional continuum millirobots exhibit limited cargo-loading capacity, which restricts their application. Herein, we propose a novel design scheme of a magnetically actuated untethered hollow continuum millirobot. The millirobot is composed of silicone as the mainframe structure and two tiny magnets for actuation. To improve the loading capacity, partial silicone is removed to create a flexible cavity, which enables cargo delivery and potential in vivo sampling functions under wireless magnetic actuation. Theoretical analysis and experimental testing are conducted to reveal the effectiveness of the proposed design. The soft structure brings a new strategy to achieve multimodal motion including rolling, tumbling, and swinging. Moreover, the magnet part can generate a powerful magnetic force output for dexterous manipulation. These functionalities lay a foundation for playing a greater role in next-generation biomedical applications.

Hierarchical eco-driving and energy management control for hydrogen powered hybrid trains

Climate change and emissions reductions are important issues on the rail industry’s agenda. The use of hydrogen as an alternative fuel for rail brings many potential benefits, most notably that it is a clean energy source and supports zero carbon strategies. Compared to fossil fuels, hydrogen fuel cell technology can also provide a more powerful and efficient energy output. In this work, we explore the possibility of reducing the overall operating cost of hydrogen and battery-powered trains, from train eco-driving control to energy distribution along the power chain, while satisfying safety, punctuality, and energy efficiency of travel. To address this multi-objective problem, we split it into a long-horizon model predictive controller (MPC) to optimize the driving profile online, a short-horizon MPC to ensure on-time train operation, and an energy management MPC to distribute fuel cell and battery power to achieve energy savings and battery charge sustaining. Finally, simulations are performed with realistic railway routes to verify fuel economy, charge sustaining, location accuracy and robustness to temporary speed restrictions (TSR). The results show the superiority of the proposed hierarchical control.

Klystron-like Cyclotron Amplification of a Transversely Propagating Wave by a Spatially Developed Electron Beam

A klystron-like gyro-amplifier based on the excitation of a wave propagating across a spatially developed (in the transverse direction) electron beam is described within the simplest 2-D model. Such a configuration is attractive as a way of implementation of a short-wavelength source with a relatively high level of output power and with the possibility of quasicontinuous frequency tuning. We study the peculiarities of the 2-D process (developing in both the axial and transverse directions) of electron bunching and “free” wave emission from the electron beam in the open drift space, as well as the excitation of the output cavity used to provide formation of a compact and powerful output wave signal. The main problem of this 2-D process is that different fractions of the electron beam (located at different points of its cross-section) move in different wave fields. In addition, excitation of the parasitic wave propagating in the opposite direction relative to the operating wave is possible. However, we show that it is possible to organize effective electron–wave energy exchange for almost all fractions of the electron beam.

A Novel Approach on the Advancement in Polymer Phase Change Material in Solar Energy

A wide interest has been shown in the application of solar energy in recent times. This motivated the researchers to make a development in the approach of solar energy, but there are different technologies like MPPT, CPG, and grid mode that have been used to maintain a constant temperature. Among these, phase change material has been used to regulate the temperature in the system. Solar energy is becoming an essential approach for increasing the efficiency of thermal energy conversion and utilizing polymeric step change composites, which have attracted extremely large interest in recent years due to their advantages of high energy density and powerful energy output stability. A plethora of reviews and reports have been published to compile the diverse range of PCMs made available for various applications. PCMs are created by improving thermophysical thermodynamic stability, latent heat, and heat capacity. Furthermore, the possible applications of polymer phase PCMs in a variety of fields, such as energy storage devices, thermal corrective action, and temperature-controlled drug carriers, are detailed. In this paper, a novel approach on the advancement of nanoconfined phase change material is defined along with the application of the solar energy system.

A new parallel processing architecture for accelerating image encryption based on chaos

This study introduces a novel parallel processing architecture for accelerating image encryption based on chaos. In the proposed architecture, whole image data is split into partitions of particular size to create separate encryption threads. As the proposed cryptosystem employs several identical chaotic ciphers running concurrently and independently to process the partitions, it greatly leverages the degree of parallelism to some extent. A powerful output mixing logic based on an additional chaotic function, and simple exclusive-OR and shift operations is innovatively incorporated to ensure inter-partition diffusion. Since there is no dependency on previous data bytes in the introduced logic, blending operations applied on the outputs of independent encryption threads can be concurrently executed by exploiting loop-level parallelism to the extent allowed by data processing units available. The number of blending operations that should be carried out for an image is kept proportional to the partition size which also directly determines the number of separate encryption threads created. In order to measure encryption/decryption runtimes, the proposed architecture has been tested on two different multi-core CPUs, namely 4-core and 8-core. The obtained results show that the proposed cryptosystem parallelising sequential operations by introducing a multi-threaded encryption architecture is much faster than the base cipher and most of the other state-of-the-art algorithms. Having successfully passed various security tests, the proposed cryptosystem manifests its robustness against cryptographic attacks, and hence become evident that it is efficient for secure transmission.

The effects of electrically exploding gold bridgewires into inert and explosive powder beds

The particle velocity created in beds of both low-density inert sugar and explosive PETN as a function of distance from an exploding bridgewire was measured using optical velocimetry and a silvered PMMA window. As expected, more violent bridge-bursts (from a greater-stored-energy capacitive discharge unit) resulted in greater particle velocities and a better supported compaction wave in sugar. In all cases, ramp waves, not shocks, were observed in the inert sugar. Large window velocities were observed for very powerful bursts (up to 270 m/s), but bursts required for stochastic detonator operation conditions resulted in sugar/PMMA window velocities of only 8–10 m/s 0.85 mm from the bridge location. In contrast, after a distance of only 0.65 mm, a building shock wave was observed in PETN under both threshold and reliable firing conditions. Subsequently a hot-spot-driven shock-to-detonation (SDT) process was observed prior to full detonation. The measured buildup process accounts for approx 66% of the so-called excess transit time (ETT) between the observed and theoretical total function time for the particular exploding-bridge-wire (EBW) detonator studied. The remainder must occur in the powerful output pellet region. In contrast to a common understanding, the ETT is found to be a weak function of the discharge energy. Thus, the operation of the detonator after a bridge-burst energy-to-powder reaction transition process is found to be hot-spot-driven SDT in both the low- and high-density pellets.

BiG-SLiCE: A highly scalable tool maps the diversity of 1.2 million biosynthetic gene clusters.

BackgroundGenome mining for biosynthetic gene clusters (BGCs) has become an integral part of natural product discovery. The >200,000 microbial genomes now publicly available hold information on abundant novel chemistry. One way to navigate this vast genomic diversity is through comparative analysis of homologous BGCs, which allows identification of cross-species patterns that can be matched to the presence of metabolites or biological activities. However, current tools are hindered by a bottleneck caused by the expensive network-based approach used to group these BGCs into gene cluster families (GCFs).ResultsHere, we introduce BiG-SLiCE, a tool designed to cluster massive numbers of BGCs. By representing them in Euclidean space, BiG-SLiCE can group BGCs into GCFs in a non-pairwise, near-linear fashion. We used BiG-SLiCE to analyze 1,225,071 BGCs collected from 209,206 publicly available microbial genomes and metagenome-assembled genomes within 10 days on a typical 36-core CPU server. We demonstrate the utility of such analyses by reconstructing a global map of secondary metabolic diversity across taxonomy to identify uncharted biosynthetic potential. BiG-SLiCE also provides a “query mode” that can efficiently place newly sequenced BGCs into previously computed GCFs, plus a powerful output visualization engine that facilitates user-friendly data exploration.ConclusionsBiG-SLiCE opens up new possibilities to accelerate natural product discovery and offers a first step towards constructing a global and searchable interconnected network of BGCs. As more genomes are sequenced from understudied taxa, more information can be mined to highlight their potentially novel chemistry. BiG-SLiCE is available via https://github.com/medema-group/bigslice.

Numerical Analysis of 3.92 μm Dual-Wavelength Pumped Heavily-Holmium-Doped Fluoroindate Fiber Lasers

The 3.92 μm laser pumped by 888 and 962 nm sources in a high concentration holmium-doped InF3 fiber is predicted and verified by simulation for the first time. Most parameters involved in the numerical model are taken from published results about the fundamental properties of holmium in fluoroindate glasses. The remaining unknown parameters are estimated from published 888 nm single-wavelength pumping experimental data. Simulated results indicate that the dual-wavelength pumping system can give a more powerful output than the single-wavelength pumping system when the total launched power is at the same level. The laser output as a function of the power of each source, as well as several macro factors such as fiber length and output coupler reflectivity, are investigated to find the best condition for higher output. To evaluate the importance and influence of the known interionic energy transfer processes, we analyze the corresponding laser output and changes of population densities of laser upper and lower levels by isolating each process. This investigation gives a preliminary insight into the 3.92 μm laser performance and interionic dynamics of the dual-wavelength pumping system in holmium-doped InF3 fibers.

Numerical study of sum frequency ultrashort pulse compression in borate crystals

Second harmonic generation (SHG) of picosecond pulses in type II phase-matched nonlinear optical crystals is not widely employed because of the lower efficiencies compared to the type I phase-matching scheme. The limited efficiencies come from the difference between group velocities (GV difference) of the ordinary and extraordinary polarized input pulses. However, if the input pulses are delayed before the nonlinear crystal, a short second harmonic pulse can be generated with a slowly widening temporal overlap. Furthermore, this GV difference can be controlled by the tilting of the pulse fronts, and optimal GV difference can be obtained to achieve powerful output pulses with durations an order of magnitude lower than those of the input pulses. In this work, we present numerical results of SHG pulse compression in a beta barium borate (BBO) nonlinear crystal, which is ideal for SHG of high-power 1030 nm thin-disk lasers. The pulse compression is controlled by predelay and tilting of the pulse fronts. We find optimal parameters to achieve five-fold increase in output power and 20-fold pulse compression of 1.7 ps input pulses. Finally, we consider the experimental aspects of the group velocity control.

Triboelectric-nanogenerator-inspired light-emitting diode-in-capacitors for flexible operation in high-voltage and wireless drive modes

The triboelectric nanogenerator (TENG) coupling contact electrification and electric induction is a landmark development in the field of energy and self-powered systems. Usually, TENGs drive light-emitting diode (LED) arrays directly to demonstrate their powerful output capabilities. However, detailed investigations of the mechanisms underlying LEDs operating at voltages much higher than those normally used have not been conducted. Here, the optical and the electrical performances of LEDs driven by TENGs are studied. Inspired by the operation mode of a TENG-driven LED, we propose a structure composed of a capacitor-LED-capacitor series, namely, LED-in-capacitors, driven by alternating current voltage. We demonstrate that the LED-in-capacitors can be directly lit by using the main power supply without a transformer and that the number of LEDs connected in series may be easily changed. In addition, due to electrostatic induction, the LED-in-capacitors can be lit wirelessly without the need for carrier injection. As a novel type of electronic device, TENG-related technology is expected to provide impetus for the development of traditional LED lighting and display technology.

Synergy between the anthocyanin and RDR6/SGS3/DCL4 siRNA pathways expose hidden features of Arabidopsis carbon metabolism

Anthocyanin pigments furnish a powerful visual output of the stress and metabolic status of Arabidopsis thaliana plants. Essential for pigment accumulation is TRANSPARENT TESTA19 (TT19), a glutathione S-transferase proposed to bind and stabilize anthocyanins, participating in their vacuolar sequestration, a function conserved across the flowering plants. Here, we report the identification of genetic suppressors that result in anthocyanin accumulation in the absence of TT19. We show that mutations in RDR6, SGS3, or DCL4 suppress the anthocyanin defect of tt19 by pushing carbon towards flavonoid biosynthesis. This effect is not unique to tt19 and extends to at least one other anthocyanin pathway gene mutant. This synergy between mutations in components of the RDR6-SGS3-DCL4 siRNA system and the flavonoid pathway reveals genetic/epigenetic mechanisms regulating metabolic fluxes.